id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0210106 | Mark G. Alford | Mark G. Alford, Jeffrey A. Bowers, Jack M. Cheyne, Greig A. Cowan | Single color and single flavor color superconductivity | 30 pages, LaTeX | Phys.Rev. D67 (2003) 054018 | 10.1103/PhysRevD.67.054018 | GUTPA/02/09/03, MIT-CTP-3315 | hep-ph nucl-th | null | We survey the non-locked color-flavor-spin channels for quark-quark (color
superconducting) condensates in QCD, using an NJL model. We also study
isotropic quark-antiquark (mesonic) condensates. We make mean-field estimates
of the strength and sign of the self-interaction of each condensate, using
four-fermion interaction vertices based on known QCD interactions. For the
attractive quark pairing channels, we solve the mean-field gap equations to
obtain the size of the gap as a function of quark density. We also calculate
the dispersion relations for the quasiquarks, in order to see how fully gapped
the spectrum of fermionic excitations will be. We use our results to specify
the likely pairing patterns in neutral quark matter, and comment on possible
phenomenological consequences.
| [
{
"created": "Mon, 7 Oct 2002 15:42:31 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Alford",
"Mark G.",
""
],
[
"Bowers",
"Jeffrey A.",
""
],
[
"Cheyne",
"Jack M.",
""
],
[
"Cowan",
"Greig A.",
""
]
] | We survey the non-locked color-flavor-spin channels for quark-quark (color superconducting) condensates in QCD, using an NJL model. We also study isotropic quark-antiquark (mesonic) condensates. We make mean-field estimates of the strength and sign of the self-interaction of each condensate, using four-fermion interaction vertices based on known QCD interactions. For the attractive quark pairing channels, we solve the mean-field gap equations to obtain the size of the gap as a function of quark density. We also calculate the dispersion relations for the quasiquarks, in order to see how fully gapped the spectrum of fermionic excitations will be. We use our results to specify the likely pairing patterns in neutral quark matter, and comment on possible phenomenological consequences. |
hep-ph/0503092 | Bipin singh Koranga | Bipin Singh Koranga, Mohan Narayan and S. Uma Sankar (I.I.T. Bombay) | Do two flavour oscillations explain both KamLAND data and the Solar
Neutrino Spectrum? | 10 pages, 2 figures | Int.J.Theor.Phys.50:1515-1521,2011 | 10.1007/s10773-010-0660-3 | null | hep-ph | null | The recent measurement of Delta_{sol} by the KamLAND experiment with very
small errors, makes definitive predictions for the energy dependence of the
solar neutrino survival probability P_{ee}. We fix Delta_{sol} to be the
KamLAND best fit value of 8*10^{-5} eV^2 and study the energy dependence of
P_{ee} for solar neutrinos in the framework of two flavour oscillations and
also of three flavour oscillations. For the case of two flavour oscillations,
P_{ee} has a measurable slope in the 5-8 MeV range but the solar spectrum
measurements in this range find P_{ee} to be flat. The predicted values of
P_{ee}, even for the best fit value of theta_{sol}, differ by 2 to 3 sigma from
the Super-K measured values in each of the three energy bins of the 5-8 MeV
range. If future measurements of solar neutrinos by Super-K and SNO find a flat
spectrum with reduced error bars (by a factor of 2), it will imply that two
flavour oscillations can no longer explain both KamLAND data and the solar
spectrum. However a flat solar neutrino spectrum and the Delta_{sol} measured
by KamLAND can be reconciled in a three flavour oscillation framework with a
moderate value of theta_{13} approx 13 degrees.
| [
{
"created": "Thu, 10 Mar 2005 11:02:07 GMT",
"version": "v1"
}
] | 2011-03-31 | [
[
"Koranga",
"Bipin Singh",
"",
"I.I.T. Bombay"
],
[
"Narayan",
"Mohan",
"",
"I.I.T. Bombay"
],
[
"Sankar",
"S. Uma",
"",
"I.I.T. Bombay"
]
] | The recent measurement of Delta_{sol} by the KamLAND experiment with very small errors, makes definitive predictions for the energy dependence of the solar neutrino survival probability P_{ee}. We fix Delta_{sol} to be the KamLAND best fit value of 8*10^{-5} eV^2 and study the energy dependence of P_{ee} for solar neutrinos in the framework of two flavour oscillations and also of three flavour oscillations. For the case of two flavour oscillations, P_{ee} has a measurable slope in the 5-8 MeV range but the solar spectrum measurements in this range find P_{ee} to be flat. The predicted values of P_{ee}, even for the best fit value of theta_{sol}, differ by 2 to 3 sigma from the Super-K measured values in each of the three energy bins of the 5-8 MeV range. If future measurements of solar neutrinos by Super-K and SNO find a flat spectrum with reduced error bars (by a factor of 2), it will imply that two flavour oscillations can no longer explain both KamLAND data and the solar spectrum. However a flat solar neutrino spectrum and the Delta_{sol} measured by KamLAND can be reconciled in a three flavour oscillation framework with a moderate value of theta_{13} approx 13 degrees. |
hep-ph/0611075 | Luis Roca | L.Roca, A.Hosaka and E.Oset | Quantum loops in radiative decays of the $a_1$ and $b_1$ axial-vector
mesons | 16 pages, 4 figurs Added extra discussion | Phys.Lett.B658:17-26,2007 | 10.1016/j.physletb.2007.10.035 | null | hep-ph | null | A previous model where the low-lying axial-vector mesons are dynamically
generated, implementing unitarity in coupled channels in the
vector-pseudoscalar ($VP$) meson interaction, is applied to evaluate the decay
widths of the a_1(1260)$ and $b_1(1235)$ axial-vector mesons into $\pi\gamma$.
Unlike the case of the $a_1$, the $b_1$ radiative decay is systematically
underestimated at tree level. In this work we evaluate for the first time the
loop contribution coming from an initial $VP$ vertex. Despite the large
superficial divergence of the loops, the convergence of the relevant loops can
be established by using arguments of gauge invariance. The partial decay widths
obtained agree very well with the experimental values within uncertainties, and
show that the loop contribution is crucial in the $b_1$ case and also important
for the $a_1$ case.
| [
{
"created": "Tue, 7 Nov 2006 10:50:11 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Sep 2007 18:12:30 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Roca",
"L.",
""
],
[
"Hosaka",
"A.",
""
],
[
"Oset",
"E.",
""
]
] | A previous model where the low-lying axial-vector mesons are dynamically generated, implementing unitarity in coupled channels in the vector-pseudoscalar ($VP$) meson interaction, is applied to evaluate the decay widths of the a_1(1260)$ and $b_1(1235)$ axial-vector mesons into $\pi\gamma$. Unlike the case of the $a_1$, the $b_1$ radiative decay is systematically underestimated at tree level. In this work we evaluate for the first time the loop contribution coming from an initial $VP$ vertex. Despite the large superficial divergence of the loops, the convergence of the relevant loops can be established by using arguments of gauge invariance. The partial decay widths obtained agree very well with the experimental values within uncertainties, and show that the loop contribution is crucial in the $b_1$ case and also important for the $a_1$ case. |
hep-ph/0608300 | Michael Trott | Michael Trott | Jets in Effective Theory: Summing Phase Space Logs | 25 pages, 4 figures, V2: Typos fixed, writing clarified, detail on
PSRG added. Matching onto jet definition changed to taking place at collinear
scale | Phys.Rev.D75:054011,2007 | 10.1103/PhysRevD.75.054011 | null | hep-ph | null | We demonstrate how to resum phase space logarithms in the Sterman-Weinberg
(SW) dijet decay rate within the context of Soft Collinear Effective theory
(SCET). An operator basis corresponding to two and three jet events is defined
in SCET and renormalized. We obtain the RGE of the two and three jet operators
and run the operators from the scale $\mu^2 = Q^2$ to the phase space scale $
\mu^2_\delta = \delta^2 Q^2$. This phase space scale, where $\delta$ is the
cone half angle of the jet, defines the angular region of the jet. At $
\mu^2_{\delta}$ we determine the mixing of the three and two jet operators. We
combine these results with the running of the two jet shape function, which we
run down to an energy cut scale $\mu^2_{\beta}$. This defines the resumed SW
dijet decay rate in the context of SCET. The approach outlined here
demonstrates how to establish a jet definition in the context of SCET. This
allows a program of systematically improving the theoretical precision of jet
phenomenology to be carried out.
| [
{
"created": "Mon, 28 Aug 2006 21:17:48 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Nov 2006 21:23:43 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Trott",
"Michael",
""
]
] | We demonstrate how to resum phase space logarithms in the Sterman-Weinberg (SW) dijet decay rate within the context of Soft Collinear Effective theory (SCET). An operator basis corresponding to two and three jet events is defined in SCET and renormalized. We obtain the RGE of the two and three jet operators and run the operators from the scale $\mu^2 = Q^2$ to the phase space scale $ \mu^2_\delta = \delta^2 Q^2$. This phase space scale, where $\delta$ is the cone half angle of the jet, defines the angular region of the jet. At $ \mu^2_{\delta}$ we determine the mixing of the three and two jet operators. We combine these results with the running of the two jet shape function, which we run down to an energy cut scale $\mu^2_{\beta}$. This defines the resumed SW dijet decay rate in the context of SCET. The approach outlined here demonstrates how to establish a jet definition in the context of SCET. This allows a program of systematically improving the theoretical precision of jet phenomenology to be carried out. |
2204.04563 | Moha Ouali | M. Ouali, M. Ouhammou, R. Benbrik, S. Taj, B. Manaut | Production of Higgs boson in association with a pair of fermions in the
presence of a circularly polarized laser field | 7 pages, 4 figures | null | 10.1007/s12648-023-02836-3 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In the centre of mass frame, we have investigated the process of Higgs
production in association with a pair of fermions, $e^{+}e^{-}\rightarrow
f\bar{f} H$, at the leading order inside an intense electromagnetic field with
circular polarization. Our analytical calculations are based on the Narrow
Width Approximation (NWA), which is valid in the leading order. We have
considered only the initial particles inside the laser field as a first step.
In the second part, we have embedded both initial and final particles in the
laser field. We have analyzed the angular distribution of the produced Higgs
boson as a function of the laser parameters in both cases. We have found that
in the case where both initial and final particles are embedded in the laser
field, the order of magnitude of the differential cross-section of the process
$e^{+}e^{-}\rightarrow\mu^{+}\mu^{-}H$ is reduced more significantly, while
that of the process $e^{+}e^{-}\rightarrow\nu\bar{\nu}H$ is enhanced.
| [
{
"created": "Sat, 9 Apr 2022 22:49:21 GMT",
"version": "v1"
}
] | 2023-08-02 | [
[
"Ouali",
"M.",
""
],
[
"Ouhammou",
"M.",
""
],
[
"Benbrik",
"R.",
""
],
[
"Taj",
"S.",
""
],
[
"Manaut",
"B.",
""
]
] | In the centre of mass frame, we have investigated the process of Higgs production in association with a pair of fermions, $e^{+}e^{-}\rightarrow f\bar{f} H$, at the leading order inside an intense electromagnetic field with circular polarization. Our analytical calculations are based on the Narrow Width Approximation (NWA), which is valid in the leading order. We have considered only the initial particles inside the laser field as a first step. In the second part, we have embedded both initial and final particles in the laser field. We have analyzed the angular distribution of the produced Higgs boson as a function of the laser parameters in both cases. We have found that in the case where both initial and final particles are embedded in the laser field, the order of magnitude of the differential cross-section of the process $e^{+}e^{-}\rightarrow\mu^{+}\mu^{-}H$ is reduced more significantly, while that of the process $e^{+}e^{-}\rightarrow\nu\bar{\nu}H$ is enhanced. |
0811.0355 | Bernd Kniehl | A.A. Almasy, B.A. Kniehl, A. Sirlin | Quark mixing renormalization effects in the determination of the CKM
parameters |V_{ij}| | 10 pages; title changed, discussion substantially modified and
extended, table and references added; accepted for publication in Phys. Rev.
D | Phys.Rev.D79:076007,2009; Erratum-ibid.D82:059901,2010 | 10.1103/PhysRevD.79.076007 10.1103/PhysRevD.82.059901 | DESY 08-155, NYU-TH/08/10/31 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We briefly review existing proposals for the renormalization of the
Cabibbo-Kobayashi-Maskawa (CKM) matrix and study the numerical effects of
several of them on the W-boson hadronic partial decay widths. We then use these
results to evaluate the relative shifts on the CKM parameters |V_{ij}|^2
induced by the quark mixing renormalization effects, as well as their scheme
dependence. We also discuss the implications of this analysis for the most
precise unitarity test of the CKM matrix.
| [
{
"created": "Mon, 3 Nov 2008 18:11:43 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Apr 2009 17:29:18 GMT",
"version": "v2"
}
] | 2014-11-18 | [
[
"Almasy",
"A. A.",
""
],
[
"Kniehl",
"B. A.",
""
],
[
"Sirlin",
"A.",
""
]
] | We briefly review existing proposals for the renormalization of the Cabibbo-Kobayashi-Maskawa (CKM) matrix and study the numerical effects of several of them on the W-boson hadronic partial decay widths. We then use these results to evaluate the relative shifts on the CKM parameters |V_{ij}|^2 induced by the quark mixing renormalization effects, as well as their scheme dependence. We also discuss the implications of this analysis for the most precise unitarity test of the CKM matrix. |
hep-ph/0406235 | Yue Chongxing | Chongxing Yue, Wei Wang, Feng Zhang | The neutral top-pion and the lepton flavor violating $Z$ decays $Z\to
l_{i}l_{j}$ | 12 pages and 3 figures. To be published in J. Phys. G | J.Phys. G30 (2004) 1065-1072 | 10.1088/0954-3899/30/9/007 | null | hep-ph | null | Taking into account the constraints of the present experimental limit of the
process $\mu\to e\gamma$ on the free parameters of topcolor-assisted
technicolor(TC2) models, we calculate the contributions of the neutral top-pion
to the lepton flavor violating(LFV) $Z$ decays $Z\to l_{i}l_{j}$. Our results
show that the value of the branching ratio $Br(Z\to \tau l)$ is larger than
that of $Br(Z\to \mu e)$ in all of the parameter space and there is $Br(Z\to
\tau\mu)\approx Br(Z\to \tau e)\simeq 2\times 10^{-14} $, which is far from the
reach of present or future experiments.
| [
{
"created": "Mon, 21 Jun 2004 23:49:18 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Yue",
"Chongxing",
""
],
[
"Wang",
"Wei",
""
],
[
"Zhang",
"Feng",
""
]
] | Taking into account the constraints of the present experimental limit of the process $\mu\to e\gamma$ on the free parameters of topcolor-assisted technicolor(TC2) models, we calculate the contributions of the neutral top-pion to the lepton flavor violating(LFV) $Z$ decays $Z\to l_{i}l_{j}$. Our results show that the value of the branching ratio $Br(Z\to \tau l)$ is larger than that of $Br(Z\to \mu e)$ in all of the parameter space and there is $Br(Z\to \tau\mu)\approx Br(Z\to \tau e)\simeq 2\times 10^{-14} $, which is far from the reach of present or future experiments. |
hep-ph/0010193 | Jose Illana | J.I. Illana and T. Riemann | Charged Lepton Flavour Violation from Massive Neutrinos in Z Decays | 24 pages, 4 figures, LaTeX, uses axodraw.sty | Phys.Rev.D63:053004,2001 | 10.1103/PhysRevD.63.053004 | DESY 00-127, UG-FT-122/00 | hep-ph | null | Present evidences for neutrino masses and lepton flavour mixings allow to
predict, in the Standard Model with light neutrinos, branching rates for the
decays Z --> e mu, mu tau, e tau of less than 10^{-54}, while present
experimental exclusion limits from LEP 1 are of order 10^{-5}. The GigaZ option
of the TESLA Linear Collider project will extend the sensitivity down to about
10^{-8}. We study in a systematic way some minimal extensions of the Standard
Model and show that GigaZ might well be sensitive to the rates predicted from
these scenarios.
| [
{
"created": "Tue, 17 Oct 2000 18:04:46 GMT",
"version": "v1"
}
] | 2010-11-09 | [
[
"Illana",
"J. I.",
""
],
[
"Riemann",
"T.",
""
]
] | Present evidences for neutrino masses and lepton flavour mixings allow to predict, in the Standard Model with light neutrinos, branching rates for the decays Z --> e mu, mu tau, e tau of less than 10^{-54}, while present experimental exclusion limits from LEP 1 are of order 10^{-5}. The GigaZ option of the TESLA Linear Collider project will extend the sensitivity down to about 10^{-8}. We study in a systematic way some minimal extensions of the Standard Model and show that GigaZ might well be sensitive to the rates predicted from these scenarios. |
hep-ph/0502129 | Stephen Barr | S.M. Barr | How a Non-hierarchical Neutrino Mass Matrix Can Arise | 12 pages, 5 figures, LaTex | Phys.Lett.B622:131-135,2005 | 10.1016/j.physletb.2005.06.087 | null | hep-ph | null | One puzzle of neutrino masses and mixings is that they do not exhibit the
kind of strong "hierarchy" that is found for the quarks and charged leptons.
Neutrino mass ratios and mixing angles are not small. A possible reason for
this is proposed here. It is based on the fact that typical realistic grand
unified models contain particles with unification-scale masses which, when
integrated out, can yield a neutrino mass matrix that is not of the standard
seesaw form.
| [
{
"created": "Mon, 14 Feb 2005 15:59:41 GMT",
"version": "v1"
}
] | 2011-05-12 | [
[
"Barr",
"S. M.",
""
]
] | One puzzle of neutrino masses and mixings is that they do not exhibit the kind of strong "hierarchy" that is found for the quarks and charged leptons. Neutrino mass ratios and mixing angles are not small. A possible reason for this is proposed here. It is based on the fact that typical realistic grand unified models contain particles with unification-scale masses which, when integrated out, can yield a neutrino mass matrix that is not of the standard seesaw form. |
hep-ph/9809301 | Vysotsky | Z.Berezhiani, Z.Tavartkiladze, M.Vysotsky | $d=5$ operators in SUSY GUT: fermion masses versus proton decay | Added reference | null | null | null | hep-ph | null | In the minimal SU(5) SUSY GUT $d =5$ operators lead to $p\to K^+ \nu$ decay
with the proton life time of the order of $10^{28}$ years for the natural
choice of the parameters of the theory. This value is in strong contradiction
with experimental bound $\tau_{p\to K\nu} > 10^{32}$ years. $d=5$ operators are
induced by colored Higgsino exchanges and are closely (through SU(5) and super
symmetry) related to another wrong prediction of SU(5) SUSY GUT: $m_d /m_s =
m_e /m_{\mu}$. We demonstrate how in the model where reasonable pattern of
quark and lepton masses and CKM mixing angles are obtained proton decay can be
suppressed and proton life time can be close to the present experimental bound.
| [
{
"created": "Tue, 8 Sep 1998 14:19:35 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Sep 1998 13:51:27 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Berezhiani",
"Z.",
""
],
[
"Tavartkiladze",
"Z.",
""
],
[
"Vysotsky",
"M.",
""
]
] | In the minimal SU(5) SUSY GUT $d =5$ operators lead to $p\to K^+ \nu$ decay with the proton life time of the order of $10^{28}$ years for the natural choice of the parameters of the theory. This value is in strong contradiction with experimental bound $\tau_{p\to K\nu} > 10^{32}$ years. $d=5$ operators are induced by colored Higgsino exchanges and are closely (through SU(5) and super symmetry) related to another wrong prediction of SU(5) SUSY GUT: $m_d /m_s = m_e /m_{\mu}$. We demonstrate how in the model where reasonable pattern of quark and lepton masses and CKM mixing angles are obtained proton decay can be suppressed and proton life time can be close to the present experimental bound. |
hep-ph/9706254 | David Benjamin Kaplan | David B. Kaplan | Strongly Coupled Supersymmetry as the Possible Origin of Flavor | Latex file; 2 figures, uses epsf.tex | null | null | DOE/ER/40561-329-INT97-00-173 | hep-ph | null | Talk presented at Rencontres de Moriond "Electroweak Interactions and Unified
Theories", March 15-22, 1997, based on work with F. Lepeintre and M. Schmaltz,
hep-ph/9705411.
| [
{
"created": "Thu, 5 Jun 1997 06:20:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kaplan",
"David B.",
""
]
] | Talk presented at Rencontres de Moriond "Electroweak Interactions and Unified Theories", March 15-22, 1997, based on work with F. Lepeintre and M. Schmaltz, hep-ph/9705411. |
hep-ph/9605336 | Christopher Sachrajda | G.Martinelli and C.T.Sachrajda | On The Difficulty of Computing Higher-Twist Corrections | 27 pages, uuencoded file containing latex source and axodraw.sty file | Nucl.Phys.B478:660-686,1996 | 10.1016/0550-3213(96)00415-4 | CERN-TH/96-117, ROME prep. 1149/96, SHEP 96-11 | hep-ph | null | We discuss the evaluation of power corrections to hard scattering and decay
processes for which an operator product expansion is applicable. The Wilson
coefficient of the leading-twist operator is the difference of two perturbative
series, each of which has a renormalon ambiguity of the same order as the power
corrections themselves, but which cancel in the difference. We stress the
necessity of calculating this coefficient function to sufficiently high orders
in perturbation theory so as to make the uncertainty of the same order or
smaller than the relevant power corrections. We investigate in some simple
examples whether this can be achieved. Our conclusion is that in most of the
theoretical calculations which include power corrections, the uncertainties are
at least comparable to the power corrections themselves, and that it will be a
very difficult task to improve the situation.
| [
{
"created": "Fri, 17 May 1996 09:36:05 GMT",
"version": "v1"
}
] | 2009-10-09 | [
[
"Martinelli",
"G.",
""
],
[
"Sachrajda",
"C. T.",
""
]
] | We discuss the evaluation of power corrections to hard scattering and decay processes for which an operator product expansion is applicable. The Wilson coefficient of the leading-twist operator is the difference of two perturbative series, each of which has a renormalon ambiguity of the same order as the power corrections themselves, but which cancel in the difference. We stress the necessity of calculating this coefficient function to sufficiently high orders in perturbation theory so as to make the uncertainty of the same order or smaller than the relevant power corrections. We investigate in some simple examples whether this can be achieved. Our conclusion is that in most of the theoretical calculations which include power corrections, the uncertainties are at least comparable to the power corrections themselves, and that it will be a very difficult task to improve the situation. |
1412.0109 | Shymaa Mohamed Seif | S. M. Seif and T.A. Azim | Complete One-Loop Corrections to $e^+ e^-\rightarrow{\tilde{\chi}}_1^0
{\tilde{\chi}}_1^0 h^0$ for Different Scenarios | 9 pages, 8 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this work, the radiative corrections to the production of a light Higgs
boson ($h^0$) with a pair of lightest neutralinos (${\tilde{\chi}}_1^0$) in
$e^+ e^-$ collisions within MSSM are presented, including the on-shell
renormalization scheme in the loop calculations. We have studied the QED
corrections as well as the weak corrections, where the contribution from both
corrections is significant and needs to be taken into account in the future
linear colliders experiments. The result includes the numerical calculations
for two different SUSY scenarios---Higgsino and Gaugino scenarios--- for $e^+
e^-\rightarrow{\tilde{\chi}}_1^0 {\tilde{\chi}}_1^0 h^0$.
| [
{
"created": "Sat, 29 Nov 2014 13:42:16 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Sep 2015 13:19:35 GMT",
"version": "v2"
},
{
"created": "Wed, 21 Dec 2016 17:22:42 GMT",
"version": "v3"
}
] | 2016-12-22 | [
[
"Seif",
"S. M.",
""
],
[
"Azim",
"T. A.",
""
]
] | In this work, the radiative corrections to the production of a light Higgs boson ($h^0$) with a pair of lightest neutralinos (${\tilde{\chi}}_1^0$) in $e^+ e^-$ collisions within MSSM are presented, including the on-shell renormalization scheme in the loop calculations. We have studied the QED corrections as well as the weak corrections, where the contribution from both corrections is significant and needs to be taken into account in the future linear colliders experiments. The result includes the numerical calculations for two different SUSY scenarios---Higgsino and Gaugino scenarios--- for $e^+ e^-\rightarrow{\tilde{\chi}}_1^0 {\tilde{\chi}}_1^0 h^0$. |
2404.11692 | Gayatri Ghosh Dr. | Gayatri Ghosh | Annihilation of NMSSM neutralinos and Branching Ratios, Particle Decay
Channel of lightest CP odd, even Higgs in NMSSM | 23 pages, 12 Figures and 5 tables | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The next$-$to$-$minimal supersymmetric standard model (NMSSM) featuring
constrained mSUGRA model, has the capability to inherently anticipate a light
dark matter component within the existing limitations encompassing Higgs data,
sparticle$-$mass constraints, dark matter exploration, muon g-2. We examine
neutralino dark matter within the NMSSM framework by conducting a comprehensive
analysis of its parameter space. This involves evaluating neutralino capture
and annihilation rates within the Sun. The exploration of potential detection
strategies for neutralino dark matter in neutrino experiments hinges on the
composition of neutralinos and their primary annihilation pathways. Our study
also involves reassessing the maximum thresholds for branching ratios of lepton
flavour violation decays $BR(\mu\rightarrow e+\gamma)$, $BR(\tau\rightarrow
e+\gamma)$ by directly referencing the constrained limits on $ \Delta a_{\mu} $
from $ g_{\mu}-2 $ experiment. This work also presents constraints of muon
flux, photon, positron and antiproton flux, specifically its independence from
experimental intricacies and the universal applicability of recalculation
coefficients across NMSSM model. Within the scope of this research, we have
chosen to utilize this NMSSM scenario as a case study to investigate the
funnel$-$ annihilation mechanisms pertaining to light dark matter and the
concealed Higgs decay. In this particular scenario, our findings reveal that
there exist decay channel$-$annihilation mechanisms for the lightest
supersymmetric particle $ \tilde{\chi_{1}^{0}} $, which include the $h_{2},
h_{1}, Z, W^{+}, W^{-}, G, s, S, b, B, c, C, a, A, d, D, l, L $ decay funnels.
| [
{
"created": "Wed, 17 Apr 2024 18:46:20 GMT",
"version": "v1"
},
{
"created": "Fri, 31 May 2024 14:17:55 GMT",
"version": "v2"
}
] | 2024-06-03 | [
[
"Ghosh",
"Gayatri",
""
]
] | The next$-$to$-$minimal supersymmetric standard model (NMSSM) featuring constrained mSUGRA model, has the capability to inherently anticipate a light dark matter component within the existing limitations encompassing Higgs data, sparticle$-$mass constraints, dark matter exploration, muon g-2. We examine neutralino dark matter within the NMSSM framework by conducting a comprehensive analysis of its parameter space. This involves evaluating neutralino capture and annihilation rates within the Sun. The exploration of potential detection strategies for neutralino dark matter in neutrino experiments hinges on the composition of neutralinos and their primary annihilation pathways. Our study also involves reassessing the maximum thresholds for branching ratios of lepton flavour violation decays $BR(\mu\rightarrow e+\gamma)$, $BR(\tau\rightarrow e+\gamma)$ by directly referencing the constrained limits on $ \Delta a_{\mu} $ from $ g_{\mu}-2 $ experiment. This work also presents constraints of muon flux, photon, positron and antiproton flux, specifically its independence from experimental intricacies and the universal applicability of recalculation coefficients across NMSSM model. Within the scope of this research, we have chosen to utilize this NMSSM scenario as a case study to investigate the funnel$-$ annihilation mechanisms pertaining to light dark matter and the concealed Higgs decay. In this particular scenario, our findings reveal that there exist decay channel$-$annihilation mechanisms for the lightest supersymmetric particle $ \tilde{\chi_{1}^{0}} $, which include the $h_{2}, h_{1}, Z, W^{+}, W^{-}, G, s, S, b, B, c, C, a, A, d, D, l, L $ decay funnels. |
1708.03007 | Carlos Andr\'es Florez | Florez Andr\'es, Gurrola Alfredo, Gui Kaiwen, Pati\~no Carlos,
Restrepo Diego | Expanding the Reach of Heavy Neutrino Searches at the LHC | 9 pages, 13 figures.arXiv admin note: text overlap with
arXiv:1609.09765 | null | 10.1016/j.physletb.2018.01.009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The observation of neutrino oscillations establishes that neutrinos
($\nu_{\ell}$) have non-zero mass and provides one of the more compelling
arguments for physics beyond the standard model (SM) of particle physics. We
present a feasibility study to search for hypothetical Majorana neutrinos
($N_{\ell}$) with TeV scale masses, predicted by extensions of the SM to
explain the small but non-zero $\nu_{\ell}$ mass, using vector boson fusion
(VBF) processes at the 13 TeV LHC. In the context of the minimal Type-I seesaw
mechanism (mTISM), the VBF $\ell N_{\ell}$ production cross-section surpasses
that of the Drell-Yan process at approximately $m_{N_{\ell}} = 1.4$ TeV. We
consider $\mu N_{\mu}$ and $\tau N_{\tau}$ production through VBF processes
(e.g. $qq'\to \tau N_{\tau}qq'$), with subsequent $N_{\mu}$ and $N_{\tau}$
decays to $\mu jj$ and $\tau jj$, as benchmark cases to show the effectiveness
of the VBF topology for $N_{\ell}$ seaches at the 13 TeV LHC. The requirement
of a dilepton pair combined with four jets, two of which are identified as VBF
jets with large separation in pseudorapidity and a TeV scale dijet mass, is
effective at reducing the SM background. This criteria may provide expected
exclusion bounds, at 95\% confidence level, of $m_{N_{\ell}} < 1.7$ ($2.4$)
TeV, assuming $100$ (1000) fb$^{-1}$ of 13 TeV data from the LHC and mixing
$|V_{\ell N_{\ell}}|^{2} = 1$. The use of the VBF topology to search for
$m_{N_{\ell}}$ increases the discovery reach at the LHC, with expected
significances greater than 5$\sigma$ (3$\sigma$) for $N_{\ell}$ masses up to
1.7 (2.05) TeV using 1000 fb$^{-1}$ of 13 TeV data from the LHC.
| [
{
"created": "Mon, 7 Aug 2017 22:18:49 GMT",
"version": "v1"
}
] | 2018-02-01 | [
[
"Andrés",
"Florez",
""
],
[
"Alfredo",
"Gurrola",
""
],
[
"Kaiwen",
"Gui",
""
],
[
"Carlos",
"Patiño",
""
],
[
"Diego",
"Restrepo",
""
]
] | The observation of neutrino oscillations establishes that neutrinos ($\nu_{\ell}$) have non-zero mass and provides one of the more compelling arguments for physics beyond the standard model (SM) of particle physics. We present a feasibility study to search for hypothetical Majorana neutrinos ($N_{\ell}$) with TeV scale masses, predicted by extensions of the SM to explain the small but non-zero $\nu_{\ell}$ mass, using vector boson fusion (VBF) processes at the 13 TeV LHC. In the context of the minimal Type-I seesaw mechanism (mTISM), the VBF $\ell N_{\ell}$ production cross-section surpasses that of the Drell-Yan process at approximately $m_{N_{\ell}} = 1.4$ TeV. We consider $\mu N_{\mu}$ and $\tau N_{\tau}$ production through VBF processes (e.g. $qq'\to \tau N_{\tau}qq'$), with subsequent $N_{\mu}$ and $N_{\tau}$ decays to $\mu jj$ and $\tau jj$, as benchmark cases to show the effectiveness of the VBF topology for $N_{\ell}$ seaches at the 13 TeV LHC. The requirement of a dilepton pair combined with four jets, two of which are identified as VBF jets with large separation in pseudorapidity and a TeV scale dijet mass, is effective at reducing the SM background. This criteria may provide expected exclusion bounds, at 95\% confidence level, of $m_{N_{\ell}} < 1.7$ ($2.4$) TeV, assuming $100$ (1000) fb$^{-1}$ of 13 TeV data from the LHC and mixing $|V_{\ell N_{\ell}}|^{2} = 1$. The use of the VBF topology to search for $m_{N_{\ell}}$ increases the discovery reach at the LHC, with expected significances greater than 5$\sigma$ (3$\sigma$) for $N_{\ell}$ masses up to 1.7 (2.05) TeV using 1000 fb$^{-1}$ of 13 TeV data from the LHC. |
1409.6837 | Hai-Bin Zhang | Hai-Bin Zhang, Guo-Hui Luo, Tai-Fu Feng, Shu-Min Zhao, Tie-Jun Gao,
Ke-Sheng Sun | $\bar{B}\rightarrow X_s\gamma$ in the $\mu\nu$SSM | 18 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:1407.7365 | Mod.Phys.Lett. A29 (2014) 1450196 | 10.1142/S021773231450196X | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The $\mu\nu$SSM, one of supersymmetric extensions beyond the Standard Model,
introduces three singlet right-handed neutrino superfields to solve the $\mu$
problem and can generate three tiny Majorana neutrino masses through the seesaw
mechanism. In this work, we investigate the rare decay process
$\bar{B}\rightarrow X_s\gamma$ in the $\mu\nu$SSM, under a minimal flavor
violating assumption for the soft breaking terms. Constrained by the SM-like
Higgs with mass around 125 GeV, the numerical results show that the new physics
can fit the experimental data for $\bar{B}\rightarrow X_s\gamma$ and further
constrain the parameter space.
| [
{
"created": "Wed, 24 Sep 2014 06:03:59 GMT",
"version": "v1"
},
{
"created": "Sat, 20 Dec 2014 08:28:59 GMT",
"version": "v2"
}
] | 2014-12-23 | [
[
"Zhang",
"Hai-Bin",
""
],
[
"Luo",
"Guo-Hui",
""
],
[
"Feng",
"Tai-Fu",
""
],
[
"Zhao",
"Shu-Min",
""
],
[
"Gao",
"Tie-Jun",
""
],
[
"Sun",
"Ke-Sheng",
""
]
] | The $\mu\nu$SSM, one of supersymmetric extensions beyond the Standard Model, introduces three singlet right-handed neutrino superfields to solve the $\mu$ problem and can generate three tiny Majorana neutrino masses through the seesaw mechanism. In this work, we investigate the rare decay process $\bar{B}\rightarrow X_s\gamma$ in the $\mu\nu$SSM, under a minimal flavor violating assumption for the soft breaking terms. Constrained by the SM-like Higgs with mass around 125 GeV, the numerical results show that the new physics can fit the experimental data for $\bar{B}\rightarrow X_s\gamma$ and further constrain the parameter space. |
2104.11874 | Lei Ming | Lei Ming | The Thermal Feedback Effects on the Temperature Evolution during
Reheating | 27 pages, 6 figures | Int. J. Mod. Phys. A (2021) 2150170 | 10.1142/S0217751X21501700 | null | hep-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The time dependence of the temperature during the reheating process is
studied. We consider the thermal feedback effects of the produced particles on
the effective dissipation rate of the inflaton field, which can lead to
enhanced production of particles. We parameterize the temperature dependence of
the dissipation rate in terms of a Taylor expansion containing the vacuum decay
rate and the thermal terms. By solving the Boltzmann equations for the energy
densities of the inflaton and radiation, we provide analytic estimates for a
general power law dependence on the temperature. In this way we describe the
entire reheating process. The maximum temperature of the reheating process and
its dependence on model parameters are studied in different cases. The impact
of the thermal feedback effects on the expansion history of the universe and
the cosmic microwave background (CMB) is discussed. We also discuss the range
of validity of our approach.
| [
{
"created": "Sat, 24 Apr 2021 03:26:58 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Jun 2021 04:43:38 GMT",
"version": "v2"
}
] | 2021-09-28 | [
[
"Ming",
"Lei",
""
]
] | The time dependence of the temperature during the reheating process is studied. We consider the thermal feedback effects of the produced particles on the effective dissipation rate of the inflaton field, which can lead to enhanced production of particles. We parameterize the temperature dependence of the dissipation rate in terms of a Taylor expansion containing the vacuum decay rate and the thermal terms. By solving the Boltzmann equations for the energy densities of the inflaton and radiation, we provide analytic estimates for a general power law dependence on the temperature. In this way we describe the entire reheating process. The maximum temperature of the reheating process and its dependence on model parameters are studied in different cases. The impact of the thermal feedback effects on the expansion history of the universe and the cosmic microwave background (CMB) is discussed. We also discuss the range of validity of our approach. |
1408.2841 | Jonathan Eckel | Jonathan Eckel, Michael J. Ramsey-Musolf, William Shepherd, Shufang Su | Impact of LSP Character on Slepton Reach at the LHC | 24 pages, 10 figures | null | 10.1007/JHEP11(2014)117 | ACFI-T14-08 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Searches for supersymmetry at the Large Hadron Collider (LHC) have
significantly constrained the parameter space associated with colored
superpartners, whereas the constraints on color-singlet superpartners are
considerably less severe. In this study, we investigate the dependence of
slepton decay branching fractions on the nature of the lightest supersymmetric
particle (LSP). In particular, in the Higgsino-like LSP scenarios, both decay
branching fractions of $\tilde\ell_L$ and $\tilde\nu_\ell$ depend strongly on
the sign and value of $M_1/M_2$, which has strong implications for the reach of
dilepton plus MET searches for slepton pair production. We extend the
experimental results for same flavor, opposite sign dilepton plus MET searches
at the 8 TeV LHC to various LSP scenarios. We find that the LHC bounds on
sleptons are strongly enhanced for a non-Bino-like LSP: the 95% C.L. limit for
$m_{\tilde\ell_L}$ extends from 300 GeV for a Bino-like LSP to about 370 GeV
for a Wino-like LSP. The bound for $\tilde\ell_L$ with a Higgsino-like LSP is
the strongest (~ 490 GeV) for $M_1/M_2$ ~ $-\tan^2\theta_W$ and is the weakest
(~ 220 GeV) for $M_1/M_2$ ~ $\tan^2\theta_W$. We also calculate prospective
slepton search reaches at the 14 TeV LHC. With 100 fb$^{-1}$ integrated
luminosity, the projected 95% C.L. mass reach for the left-handed slepton
varies from 550 (670) GeV for a Bino-like (Wino-like) LSP to 900 (390) GeV for
a Higgsino-like LSP under the most optimistic (pessimistic) scenario. The reach
for the right-handed slepton is about 440 GeV. The corresponding 5$\sigma$
discovery sensitivity is about 100 GeV smaller. For 300 fb$^{-1}$ integrated
luminosity, the reach is about 50 - 100 GeV higher.
| [
{
"created": "Tue, 12 Aug 2014 20:28:50 GMT",
"version": "v1"
}
] | 2015-06-22 | [
[
"Eckel",
"Jonathan",
""
],
[
"Ramsey-Musolf",
"Michael J.",
""
],
[
"Shepherd",
"William",
""
],
[
"Su",
"Shufang",
""
]
] | Searches for supersymmetry at the Large Hadron Collider (LHC) have significantly constrained the parameter space associated with colored superpartners, whereas the constraints on color-singlet superpartners are considerably less severe. In this study, we investigate the dependence of slepton decay branching fractions on the nature of the lightest supersymmetric particle (LSP). In particular, in the Higgsino-like LSP scenarios, both decay branching fractions of $\tilde\ell_L$ and $\tilde\nu_\ell$ depend strongly on the sign and value of $M_1/M_2$, which has strong implications for the reach of dilepton plus MET searches for slepton pair production. We extend the experimental results for same flavor, opposite sign dilepton plus MET searches at the 8 TeV LHC to various LSP scenarios. We find that the LHC bounds on sleptons are strongly enhanced for a non-Bino-like LSP: the 95% C.L. limit for $m_{\tilde\ell_L}$ extends from 300 GeV for a Bino-like LSP to about 370 GeV for a Wino-like LSP. The bound for $\tilde\ell_L$ with a Higgsino-like LSP is the strongest (~ 490 GeV) for $M_1/M_2$ ~ $-\tan^2\theta_W$ and is the weakest (~ 220 GeV) for $M_1/M_2$ ~ $\tan^2\theta_W$. We also calculate prospective slepton search reaches at the 14 TeV LHC. With 100 fb$^{-1}$ integrated luminosity, the projected 95% C.L. mass reach for the left-handed slepton varies from 550 (670) GeV for a Bino-like (Wino-like) LSP to 900 (390) GeV for a Higgsino-like LSP under the most optimistic (pessimistic) scenario. The reach for the right-handed slepton is about 440 GeV. The corresponding 5$\sigma$ discovery sensitivity is about 100 GeV smaller. For 300 fb$^{-1}$ integrated luminosity, the reach is about 50 - 100 GeV higher. |
hep-ph/0010217 | Stefan Wolf | Stefan Wolf (TTP, U. of Karlsruhe) | Kinematic Effects in Radiative Quarkonia Decays | LaTeX, 17 pages, 5 figures. The complete paper is also available via
the www at http://www-ttp.physik.uni-karlsruhe.de/Preprints/ | Phys.Rev. D63 (2001) 074020 | 10.1103/PhysRevD.63.074020 | TTP00-22 | hep-ph | null | Non-relativistic QCD (NRQCD) predicts colour octet contributions to be
significant not only in many production processes of heavy quarkonia but also
in their radiative decays. We investigate the photon energy distributions in
these processes in the endpoint region. There the velocity expansion of NRQCD
breaks down which requires a resummation of an infinite class of colour octet
operators to so-called shape functions. We model these non-perturbative
functions by the emission of a soft gluon cluster in the initial state. We
found that the spectrum in the endpoint region is poorly understood if the
values for the colour octet matrix elements are taken as large as indicated
from NRQCD scaling rules. Therefore the endpoint region should not be taken
into account for a fit of the strong coupling constant at the scale of the
heavy quark mass.
| [
{
"created": "Thu, 19 Oct 2000 10:27:12 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Wolf",
"Stefan",
"",
"TTP, U. of Karlsruhe"
]
] | Non-relativistic QCD (NRQCD) predicts colour octet contributions to be significant not only in many production processes of heavy quarkonia but also in their radiative decays. We investigate the photon energy distributions in these processes in the endpoint region. There the velocity expansion of NRQCD breaks down which requires a resummation of an infinite class of colour octet operators to so-called shape functions. We model these non-perturbative functions by the emission of a soft gluon cluster in the initial state. We found that the spectrum in the endpoint region is poorly understood if the values for the colour octet matrix elements are taken as large as indicated from NRQCD scaling rules. Therefore the endpoint region should not be taken into account for a fit of the strong coupling constant at the scale of the heavy quark mass. |
0811.0172 | Thomas Hambye | Thomas Hambye | Hidden vector dark matter | 13 pages, 7 figures, JHEP published version (2009) + update of
section 7 (reference to arXiv:0912.4496) | JHEP 0901:028,2009 | 10.1088/1126-6708/2009/01/028 | ULB-TH/08-35 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that dark matter could be made of massive gauge bosons whose
stability doesn't require to impose by hand any discrete or global symmetry.
Stability of gauge bosons can be guaranteed by the custodial symmetry
associated to the gauge symmetry and particle content of the model. The
particle content we consider to this end is based on a hidden sector made of a
vector multiplet associated to a non-abelian gauge group and of a scalar
multiplet charged under this gauge group. The hidden sector interacts with the
Standard Model particles through the Higgs portal quartic scalar interaction in
such a way that the gauge bosons behave as thermal WIMPS. This can lead easily
to the observed dark matter relic density in agreement with the other various
constraints, and can be tested experimentally in a large fraction of the
parameter space. In this model the dark matter direct detection rate and the
annihilation cross section can decouple if the Higgs portal interaction is
weak.
| [
{
"created": "Mon, 3 Nov 2008 14:00:13 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Mar 2010 12:26:49 GMT",
"version": "v2"
}
] | 2010-03-26 | [
[
"Hambye",
"Thomas",
""
]
] | We show that dark matter could be made of massive gauge bosons whose stability doesn't require to impose by hand any discrete or global symmetry. Stability of gauge bosons can be guaranteed by the custodial symmetry associated to the gauge symmetry and particle content of the model. The particle content we consider to this end is based on a hidden sector made of a vector multiplet associated to a non-abelian gauge group and of a scalar multiplet charged under this gauge group. The hidden sector interacts with the Standard Model particles through the Higgs portal quartic scalar interaction in such a way that the gauge bosons behave as thermal WIMPS. This can lead easily to the observed dark matter relic density in agreement with the other various constraints, and can be tested experimentally in a large fraction of the parameter space. In this model the dark matter direct detection rate and the annihilation cross section can decouple if the Higgs portal interaction is weak. |
0805.1049 | Francesco Hautmann | F.Hautmann and H.Jung | Angular correlations in multi-jet final states from kt-dependent parton
showers | 25 pages. Discussion and references expanded; results unchanged.
Additional calculations included | JHEP0810:113,2008 | 10.1088/1126-6708/2008/10/113 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate parton-branching methods based on transverse-momentum
dependent (TMD) parton distributions and matrix elements for the Monte Carlo
simulation of multi-particle final states at high-energy colliders. We observe
that recently measured angular correlations in ep final states with multiple
hadronic jets probe QCD coherence effects in the space-like branching,
associated with finite-angle gluon radiation from partons carrying small
longitudinal momenta, and not included in standard shower generators. We
present Monte Carlo calculations for azimuthal two-jet and three-jet
distributions, for jet multiplicities and for correlations in the
transverse-momentum imbalance between the leading jets. We discuss comparisons
with current experimental multi-jet data, and implications of corrections to
collinear-ordered showers for LHC final states.
| [
{
"created": "Wed, 7 May 2008 19:20:59 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Jun 2008 16:40:50 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Sep 2008 19:29:38 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Hautmann",
"F.",
""
],
[
"Jung",
"H.",
""
]
] | We investigate parton-branching methods based on transverse-momentum dependent (TMD) parton distributions and matrix elements for the Monte Carlo simulation of multi-particle final states at high-energy colliders. We observe that recently measured angular correlations in ep final states with multiple hadronic jets probe QCD coherence effects in the space-like branching, associated with finite-angle gluon radiation from partons carrying small longitudinal momenta, and not included in standard shower generators. We present Monte Carlo calculations for azimuthal two-jet and three-jet distributions, for jet multiplicities and for correlations in the transverse-momentum imbalance between the leading jets. We discuss comparisons with current experimental multi-jet data, and implications of corrections to collinear-ordered showers for LHC final states. |
2212.07620 | Jae Sik Lee | Dong-Won Jung, Yongtae Heo, Jae Sik Lee | On the mass spectrum of heavy Higgs bosons in two-Higgs-doublet model in
the light of the CDF $W$-mass anomaly | 20pages, 7 figures, 1 table: version to appear in PRD | null | 10.1103/PhysRevD.108.015027 | IUEP-HEP-22-02 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the mass spectrum of the charged and neutral Higgs bosons in the
framework of two Higgs doublet model (2HDM) in the light of the precision
measurement of the $W$ boson mass by the CDF collaboration. We have considered
the most general 2HDM potential with explicit CP violation in the Higgs basis
which contains the three CP-mixed neutral mass eigenstates $H_1$, $H_2$, and
$H_3$ with $M_{H_1}\leq M_{H_2}\leq M_{H_3}$. The high-precision CDF
measurement of the $W$ boson mass is characterized by the large positive value
of the $T$ parameter. By identifying the lightest neutral Higgs boson $H_1$ as
the SM-like one discovered at the LHC, we find that it is necessary to have the
mass splitting between the charged Higgs boson $H^\pm$ and the second heaviest
neutral one $H_2$ to accommodate the sizable positive deviation of the $T$
parameter from its SM value of $0$. By combining the mass splitting between
$H^\pm$ and $H_2$ with the theoretical constraints from the perturbative
unitarity and for the Higgs potential to be bounded from below, we implement
comprehensive analysis of the mass spectrum of the heavy Higgs bosons taking
account of the effects of deviation from the alignment limit and also the mass
splitting between $H_3$ and $H_2$. We further analyze the behavior of the
heavy-Higgs mass spectrum according to the variation of the $T$ parameter.
Finally, concentrating on the heavy mass region $M\equiv
(M_{H_2}+M_{H^\pm})/2\gsim 500$ GeV in which we find a mass hierarchy of $M\gg
M_{H_1}\sim |\Delta| \gsim \delta$ with $\Delta \equiv M_{H_2}-M_{H^\pm}$ and
$\delta \equiv M_{H_3}-M_{H_2}$, we discuss some benchmarking scenarios for the
searches of heavy Higgs bosons at future colliders such as the high luminosity
option of the LHC and a 100 TeV hadron collider.
| [
{
"created": "Thu, 15 Dec 2022 05:37:28 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Jul 2023 05:15:29 GMT",
"version": "v2"
}
] | 2023-08-02 | [
[
"Jung",
"Dong-Won",
""
],
[
"Heo",
"Yongtae",
""
],
[
"Lee",
"Jae Sik",
""
]
] | We analyze the mass spectrum of the charged and neutral Higgs bosons in the framework of two Higgs doublet model (2HDM) in the light of the precision measurement of the $W$ boson mass by the CDF collaboration. We have considered the most general 2HDM potential with explicit CP violation in the Higgs basis which contains the three CP-mixed neutral mass eigenstates $H_1$, $H_2$, and $H_3$ with $M_{H_1}\leq M_{H_2}\leq M_{H_3}$. The high-precision CDF measurement of the $W$ boson mass is characterized by the large positive value of the $T$ parameter. By identifying the lightest neutral Higgs boson $H_1$ as the SM-like one discovered at the LHC, we find that it is necessary to have the mass splitting between the charged Higgs boson $H^\pm$ and the second heaviest neutral one $H_2$ to accommodate the sizable positive deviation of the $T$ parameter from its SM value of $0$. By combining the mass splitting between $H^\pm$ and $H_2$ with the theoretical constraints from the perturbative unitarity and for the Higgs potential to be bounded from below, we implement comprehensive analysis of the mass spectrum of the heavy Higgs bosons taking account of the effects of deviation from the alignment limit and also the mass splitting between $H_3$ and $H_2$. We further analyze the behavior of the heavy-Higgs mass spectrum according to the variation of the $T$ parameter. Finally, concentrating on the heavy mass region $M\equiv (M_{H_2}+M_{H^\pm})/2\gsim 500$ GeV in which we find a mass hierarchy of $M\gg M_{H_1}\sim |\Delta| \gsim \delta$ with $\Delta \equiv M_{H_2}-M_{H^\pm}$ and $\delta \equiv M_{H_3}-M_{H_2}$, we discuss some benchmarking scenarios for the searches of heavy Higgs bosons at future colliders such as the high luminosity option of the LHC and a 100 TeV hadron collider. |
0711.0187 | Mohamad Ali Gomshi Nobary | M.A. Gomshi Nobary and R. Sepahvand | Ground state heavy baryon production in a relativistic quark-diquark
model | 8 pages, 4 figures. To appear in Phys. Rev. D | Phys.Rev.D76:114006,2007 | 10.1103/PhysRevD.76.114006 | Razi-Hep 133 | hep-ph | null | We use current-current interaction to calculate the fragmentation functions
to describe the production of spin-1/2, spin-1/2$'$ and spin-3/2 baryons with
massive constituents in a relativistic quark-diquark model. Our results are in
their analytic forms and are applicable for singly, doubly and triply heavy
baryons. We discuss the production of $\Omega_{bbc}$, $\Omega_{bcc}$ and
$\Omega_{ccc}$ baryons in some detail. The results are satisfactorily compared
with those obtained for triply heavy baryons calculated in a perturbative
regime within reasonable values of the parameters involved.
| [
{
"created": "Thu, 1 Nov 2007 18:59:12 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Nobary",
"M. A. Gomshi",
""
],
[
"Sepahvand",
"R.",
""
]
] | We use current-current interaction to calculate the fragmentation functions to describe the production of spin-1/2, spin-1/2$'$ and spin-3/2 baryons with massive constituents in a relativistic quark-diquark model. Our results are in their analytic forms and are applicable for singly, doubly and triply heavy baryons. We discuss the production of $\Omega_{bbc}$, $\Omega_{bcc}$ and $\Omega_{ccc}$ baryons in some detail. The results are satisfactorily compared with those obtained for triply heavy baryons calculated in a perturbative regime within reasonable values of the parameters involved. |
2307.06935 | Fanyi Zhao | Zhong-Bo Kang, Kyle Lee, Ding Yu Shao, Fanyi Zhao | Collins-type Energy-Energy Correlators and Nucleon Structure | Presented at DIS2023: XXX International Workshop on Deep-Inelastic
Scattering and Related Subjects, Michigan State University, USA, 27-31 March
2023 | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We generalize the conventional Energy-Energy Correlator (EEC) to include the
azimuthal angle dependence, so to define azimuthal angle dependent EEC
observables. We study this new EEC observable in $e^+e^-$ and semi-inclusive
deep inelastic scattering (SIDIS). In the back-to-back region, we find that the
azimuthal angle dependent EEC is sensitive to both the unpolarized EEC jet
function and a Collins-type EEC jet function. While the unpolarized EEC jet
function is related to the unpolarized transverse momentum dependent (TMD)
fragmentation function, the Collins-type EEC jet function is connected with the
Collins fragmentation function. We further demonstrate how the new observables
allow us to access to the 3D structure of nucleons, especially the
spin-dependent ones.
| [
{
"created": "Thu, 13 Jul 2023 17:55:31 GMT",
"version": "v1"
}
] | 2023-07-14 | [
[
"Kang",
"Zhong-Bo",
""
],
[
"Lee",
"Kyle",
""
],
[
"Shao",
"Ding Yu",
""
],
[
"Zhao",
"Fanyi",
""
]
] | We generalize the conventional Energy-Energy Correlator (EEC) to include the azimuthal angle dependence, so to define azimuthal angle dependent EEC observables. We study this new EEC observable in $e^+e^-$ and semi-inclusive deep inelastic scattering (SIDIS). In the back-to-back region, we find that the azimuthal angle dependent EEC is sensitive to both the unpolarized EEC jet function and a Collins-type EEC jet function. While the unpolarized EEC jet function is related to the unpolarized transverse momentum dependent (TMD) fragmentation function, the Collins-type EEC jet function is connected with the Collins fragmentation function. We further demonstrate how the new observables allow us to access to the 3D structure of nucleons, especially the spin-dependent ones. |
hep-ph/0205340 | Jean-Philippe Uzan | Jean-Philippe Uzan (IAP, GReCO, Paris and LPT, Orsay) | The fundamental constants and their variation: observational status and
theoretical motivations | 56 pages, l7 figures, submitted to Rev. Mod. Phys | Rev.Mod.Phys.75:403,2003 | 10.1103/RevModPhys.75.403 | null | hep-ph astro-ph gr-qc hep-th | null | This article describes the various experimental bounds on the variation of
the fundamental constants of nature. After a discussion on the role of
fundamental constants, of their definition and link with metrology, the various
constraints on the variation of the fine structure constant, the gravitational,
weak and strong interactions couplings and the electron to proton mass ratio
are reviewed. This review aims (1) to provide the basics of each measurement,
(2) to show as clearly as possible why it constrains a given constant and (3)
to point out the underlying hypotheses. Such an investigation is of importance
to compare the different results, particularly in view of understanding the
recent claims of the detections of a variation of the fine structure constant
and of the electron to proton mass ratio in quasar absorption spectra. The
theoretical models leading to the prediction of such variation are also
reviewed, including Kaluza-Klein theories, string theories and other
alternative theories and cosmological implications of these results are
discussed. The links with the tests of general relativity are emphasized.
| [
{
"created": "Thu, 30 May 2002 14:26:19 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Uzan",
"Jean-Philippe",
"",
"IAP, GReCO, Paris and LPT, Orsay"
]
] | This article describes the various experimental bounds on the variation of the fundamental constants of nature. After a discussion on the role of fundamental constants, of their definition and link with metrology, the various constraints on the variation of the fine structure constant, the gravitational, weak and strong interactions couplings and the electron to proton mass ratio are reviewed. This review aims (1) to provide the basics of each measurement, (2) to show as clearly as possible why it constrains a given constant and (3) to point out the underlying hypotheses. Such an investigation is of importance to compare the different results, particularly in view of understanding the recent claims of the detections of a variation of the fine structure constant and of the electron to proton mass ratio in quasar absorption spectra. The theoretical models leading to the prediction of such variation are also reviewed, including Kaluza-Klein theories, string theories and other alternative theories and cosmological implications of these results are discussed. The links with the tests of general relativity are emphasized. |
2003.03589 | Sangho Kim | Sang-Ho Kim and Seung-il Nam | Investigation of electroproduction of $\phi$ mesons off protons | 16 pages, 10 figures | Phys. Rev. C 101, 065201 (2020) | 10.1103/PhysRevC.101.065201 | PKNU-NuHaTh-2020-01 | hep-ph hep-ex nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate $\phi$-meson electroproduction off the proton target, i.e.,
$\gamma^* p \to \phi p$, by employing a tree-level effective Lagrangian
approach in the kinematical ranges of $Q^2$ = (0$-$4) $\mathrm{GeV}^2$, $W$ =
(2$-$5) GeV, and $|t| \leq 2\,\mathrm{GeV}^2$. In addition to the universally
accepted Pomeron exchange, we consider various meson exchanges in the $t$
channel with the Regge method. Direct $\phi$-meson radiations in the $s$- and
$u$-channels are also taken into account. We find that the $Q^2$ dependence of
the transverse ($\sigma_{\mathrm{T}}$) and longitudinal ($\sigma_{\mathrm{L}}$)
cross sections are governed by Pomeron and $(a_0,f_0)$ scalar meson exchanges,
respectively. Meanwhile, the contributions of $(\pi,\eta)$ pseudoscalar- and
$f_1(1285)$ axial-vector-meson exchanges are much more suppressed. The results
of the interference cross sections ($\sigma_{\mathrm{LT}},
\sigma_{\mathrm{LT}}$) and the spin-density matrix elements indicate that
$s$-channel helicity conservation holds at $Q^2$ = (1$-$4) $\mathrm{GeV}^2$.
The result of the parity asymmetry yield $P \simeq 0.95$ at $W$ = 2.5 GeV,
meaning that natural-parity exchange dominates the reaction process. Our
numerical results are in fair agreement with the experimental data and thus the
use of our effective Reggeized model is justified over the considered
kinematical ranges of $Q^2$, $W$, and $t$.
| [
{
"created": "Sat, 7 Mar 2020 15:02:59 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Jun 2020 08:56:28 GMT",
"version": "v2"
}
] | 2020-06-25 | [
[
"Kim",
"Sang-Ho",
""
],
[
"Nam",
"Seung-il",
""
]
] | We investigate $\phi$-meson electroproduction off the proton target, i.e., $\gamma^* p \to \phi p$, by employing a tree-level effective Lagrangian approach in the kinematical ranges of $Q^2$ = (0$-$4) $\mathrm{GeV}^2$, $W$ = (2$-$5) GeV, and $|t| \leq 2\,\mathrm{GeV}^2$. In addition to the universally accepted Pomeron exchange, we consider various meson exchanges in the $t$ channel with the Regge method. Direct $\phi$-meson radiations in the $s$- and $u$-channels are also taken into account. We find that the $Q^2$ dependence of the transverse ($\sigma_{\mathrm{T}}$) and longitudinal ($\sigma_{\mathrm{L}}$) cross sections are governed by Pomeron and $(a_0,f_0)$ scalar meson exchanges, respectively. Meanwhile, the contributions of $(\pi,\eta)$ pseudoscalar- and $f_1(1285)$ axial-vector-meson exchanges are much more suppressed. The results of the interference cross sections ($\sigma_{\mathrm{LT}}, \sigma_{\mathrm{LT}}$) and the spin-density matrix elements indicate that $s$-channel helicity conservation holds at $Q^2$ = (1$-$4) $\mathrm{GeV}^2$. The result of the parity asymmetry yield $P \simeq 0.95$ at $W$ = 2.5 GeV, meaning that natural-parity exchange dominates the reaction process. Our numerical results are in fair agreement with the experimental data and thus the use of our effective Reggeized model is justified over the considered kinematical ranges of $Q^2$, $W$, and $t$. |
hep-ph/0301202 | Wojciech Broniowski | Enrique Ruiz Arriola, Wojciech Broniowski | Spectral quark model and low-energy hadron phenomenology | revtex, 24 pages, 3 figures | Phys.Rev. D67 (2003) 074021 | 10.1103/PhysRevD.67.074021 | null | hep-ph | null | We propose a spectral quark model which can be applied to low energy hadronic
physics. The approach is based on a generalization of the Lehmann
representation of the quark propagator. We work at the one-quark-loop level.
Electromagnetic and chiral invariance are ensured with help of the gauge
technique which provides particular solutions to the Ward-Takahashi identities.
General conditions on the quark spectral function follow from natural physical
requirements. In particular, the function is normalized, its all positive
moments must vanish, while the physical observables depend on negative moments
and the so-called log-moments. As a consequence, the model is made finite,
dispersion relations hold, chiral anomalies are preserved, and the twist
expansion is free from logarithmic scaling violations, as requested of a
low-energy model. We study a variety of processes and show that the framework
is very simple and practical. Finally, incorporating the idea of vector-meson
dominance, we present an explicit construction of the quark spectral function
which satisfies all the requirements. The corresponding momentum representation
of the resulting quark propagator exhibits only cuts on the physical axis, with
no poles present anywhere in the complex momentum space. The momentum-dependent
quark mass compares very well to recent lattice calculations. A large number of
predictions and relations can be deduced from our approach for such quantities
as the pion light-cone wave function, non-local quark condensate, pion
transition form factor, pion valence parton distribution function, etc.
| [
{
"created": "Thu, 23 Jan 2003 12:24:40 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Arriola",
"Enrique Ruiz",
""
],
[
"Broniowski",
"Wojciech",
""
]
] | We propose a spectral quark model which can be applied to low energy hadronic physics. The approach is based on a generalization of the Lehmann representation of the quark propagator. We work at the one-quark-loop level. Electromagnetic and chiral invariance are ensured with help of the gauge technique which provides particular solutions to the Ward-Takahashi identities. General conditions on the quark spectral function follow from natural physical requirements. In particular, the function is normalized, its all positive moments must vanish, while the physical observables depend on negative moments and the so-called log-moments. As a consequence, the model is made finite, dispersion relations hold, chiral anomalies are preserved, and the twist expansion is free from logarithmic scaling violations, as requested of a low-energy model. We study a variety of processes and show that the framework is very simple and practical. Finally, incorporating the idea of vector-meson dominance, we present an explicit construction of the quark spectral function which satisfies all the requirements. The corresponding momentum representation of the resulting quark propagator exhibits only cuts on the physical axis, with no poles present anywhere in the complex momentum space. The momentum-dependent quark mass compares very well to recent lattice calculations. A large number of predictions and relations can be deduced from our approach for such quantities as the pion light-cone wave function, non-local quark condensate, pion transition form factor, pion valence parton distribution function, etc. |
hep-ph/9605236 | Shmaryu Shvartsman | V. Davidovsky and Sh. Shvartsman | High energy proton acceleration in dissolving plasma clots | 7 pages, latex, no figures | null | null | CWRU hep-th 96-8 | hep-ph acc-phys astro-ph plasm-ph | null | We consider the acceleration of particles (protons) in a plasma clot by an
induced field which appears due to the dissolving of the clot. The mechanism of
this acceleration is based on a model where the clot consists of double flat
moving current layers. It is assumed that the currents flow in opposite
directions, while the clot moves in a perpendicular one. It is shown that
protons can reach the highest observed energy (of the order of $10^{11}-
10^{12}$GeV), providing that the size of the clot is large enough.
| [
{
"created": "Mon, 6 May 1996 20:34:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Davidovsky",
"V.",
""
],
[
"Shvartsman",
"Sh.",
""
]
] | We consider the acceleration of particles (protons) in a plasma clot by an induced field which appears due to the dissolving of the clot. The mechanism of this acceleration is based on a model where the clot consists of double flat moving current layers. It is assumed that the currents flow in opposite directions, while the clot moves in a perpendicular one. It is shown that protons can reach the highest observed energy (of the order of $10^{11}- 10^{12}$GeV), providing that the size of the clot is large enough. |
hep-ph/0406041 | Tatsuo Kobayashi | Pyungwon Ko, Tatsuo Kobayashi and Jae-hyeon Park | Quark masses and mixing angles in heterotic orbifold models | 16 pages, latex | Phys.Lett. B598 (2004) 263-272 | 10.1016/j.physletb.2004.08.007 | null | hep-ph hep-th | null | We study systematically the possibility for realizing realistic values of
quark mass ratios $m_c/m_t$ and $m_s/m_b$ and the mixing angle $V_{cb}$ by
using only renormalizable Yukawa couplings derived from heterotic orbifold
models. We assume one pair of up and down sector Higgs fields. We show
realistic examples including hierarchical and democratic forms of Yukawa
matrices.
| [
{
"created": "Thu, 3 Jun 2004 22:44:46 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Jun 2004 00:56:33 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Ko",
"Pyungwon",
""
],
[
"Kobayashi",
"Tatsuo",
""
],
[
"Park",
"Jae-hyeon",
""
]
] | We study systematically the possibility for realizing realistic values of quark mass ratios $m_c/m_t$ and $m_s/m_b$ and the mixing angle $V_{cb}$ by using only renormalizable Yukawa couplings derived from heterotic orbifold models. We assume one pair of up and down sector Higgs fields. We show realistic examples including hierarchical and democratic forms of Yukawa matrices. |
1210.3490 | Vladimir Smolyar | I. V. Sharf, K. K. Merkotan, N. A. Podolyan, D. A. Ptashynskyy, A. V.
Tykhonov, M. A. Deliyergiyev, G. O. Sokhrannyi, V. D. Rusov | Gluon Loops in the Inelastic Processes in QCD | 16 pages, 16 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is shown that inelastic process of the exchange with two massless gluons
is formally equivalent to the process of the exchange with one massive
particle. Thus, using the Laplace's method, a new mechanism of mass generation
in inelastic processes is discovered, which is described by the non-Abelian
gauge theory. Furthermore, it is shown that in the QCD perturbation theory, the
same mechanisms of cross-sections growth take place, similar to the ones
discovered before in the effective scalar theories.
| [
{
"created": "Fri, 12 Oct 2012 12:21:47 GMT",
"version": "v1"
}
] | 2012-10-15 | [
[
"Sharf",
"I. V.",
""
],
[
"Merkotan",
"K. K.",
""
],
[
"Podolyan",
"N. A.",
""
],
[
"Ptashynskyy",
"D. A.",
""
],
[
"Tykhonov",
"A. V.",
""
],
[
"Deliyergiyev",
"M. A.",
""
],
[
"Sokhrannyi",
"G. O.",
""
... | It is shown that inelastic process of the exchange with two massless gluons is formally equivalent to the process of the exchange with one massive particle. Thus, using the Laplace's method, a new mechanism of mass generation in inelastic processes is discovered, which is described by the non-Abelian gauge theory. Furthermore, it is shown that in the QCD perturbation theory, the same mechanisms of cross-sections growth take place, similar to the ones discovered before in the effective scalar theories. |
0903.4633 | Lorenzo Mercolli | Lorenzo Mercolli | Revisiting CP-violation in Minimal Flavour Violation | Talk given at the International Workshop on Effective Field Theories:
from the pion to the upsilon, February 2-6 2009, Valencia, Spain | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | After a brief review of the minimal flavour violation hypothesis and its
implementation in the MSSM, the most general parametrisation of the soft
supersymmetry-breaking terms by means of the charged lepton and neutrino
spurions is constructed. Thereby a type I seesaw mechanism is assumed to
generate neutrino masses. This expansion introduces several new CP-violating
phases, whose effects on the leptonic electric dipole moments are investigated.
| [
{
"created": "Thu, 26 Mar 2009 17:05:02 GMT",
"version": "v1"
}
] | 2009-03-27 | [
[
"Mercolli",
"Lorenzo",
""
]
] | After a brief review of the minimal flavour violation hypothesis and its implementation in the MSSM, the most general parametrisation of the soft supersymmetry-breaking terms by means of the charged lepton and neutrino spurions is constructed. Thereby a type I seesaw mechanism is assumed to generate neutrino masses. This expansion introduces several new CP-violating phases, whose effects on the leptonic electric dipole moments are investigated. |
1508.07469 | Stephen Barr | S.M. Barr and Robert J. Scherrer | Cogenerating and Pre-annihilating Dark Matter by a New Gauge Interaction
in a Unified Model | 14 pages, a fully unified model presented in much greater detail | null | 10.1088/1475-7516/2016/05/065 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Grand unified theories based on large groups (with rank greater or equal to 6
are a natural context for dark matter models. They contain
Standard-Model-singlet fermions that could be dark matter candidates, and can
contain new non-abelian interactions whose sphalerons convert baryons, leptons,
and dark matter into each other, "cogenerating" a dark matter asymmetry
comparable to the baryon asymmetry. In this paper it is shown that the same
non-abelian interactions can "pre-annihilate" the symmetric component of heavy
dark matter particles, which then decay late into light stable dark matter
particles that inherit their asymmetry. It is shown that such decays can come
from d=5 operators that are Planck or GUT suppressed. We derive constraints on
such models and present a simple realization based on the group SU(7).
| [
{
"created": "Sat, 29 Aug 2015 15:58:20 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Sep 2015 18:06:11 GMT",
"version": "v2"
},
{
"created": "Sat, 12 Dec 2015 17:20:34 GMT",
"version": "v3"
},
{
"created": "Tue, 31 May 2016 17:29:48 GMT",
"version": "v4"
}
] | 2016-06-08 | [
[
"Barr",
"S. M.",
""
],
[
"Scherrer",
"Robert J.",
""
]
] | Grand unified theories based on large groups (with rank greater or equal to 6 are a natural context for dark matter models. They contain Standard-Model-singlet fermions that could be dark matter candidates, and can contain new non-abelian interactions whose sphalerons convert baryons, leptons, and dark matter into each other, "cogenerating" a dark matter asymmetry comparable to the baryon asymmetry. In this paper it is shown that the same non-abelian interactions can "pre-annihilate" the symmetric component of heavy dark matter particles, which then decay late into light stable dark matter particles that inherit their asymmetry. It is shown that such decays can come from d=5 operators that are Planck or GUT suppressed. We derive constraints on such models and present a simple realization based on the group SU(7). |
hep-ph/0603267 | Christian Hacker Mr. | C. Hacker, N. Wies, J. Gegelia, S. Scherer | Magnetic dipole moment of the $\Delta(1232)$ in chiral perturbation
theory | 9 pages, 2 figures, REVTeX 4 | Eur.Phys.J.A28:5-9,2006 | 10.1140/epja/i2006-10043-7 | MKPH-T-06-06 | hep-ph | null | The magnetic dipole moment of the $\Delta (1232)$ is calculated in the
framework of manifestly Lorentz-invariant baryon chiral perturbation theory in
combination with the extended on-mass-shell renormalization scheme. As in the
case of the nucleon, at leading order both isoscalar and isovector anomalous
magnetic moments are given in terms of two low-energy constants. In contrast to
the nucleon case, at next-to-leading order the isoscalar anomalous magnetic
moment receives a (real) loop contribution. Moreover, due to the unstable
nature of the $\Delta (1232)$, at next-to-leading order the isovector anomalous
magnetic moment not only receives a real but also an imaginary loop
contribution.
| [
{
"created": "Fri, 31 Mar 2006 15:58:11 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Hacker",
"C.",
""
],
[
"Wies",
"N.",
""
],
[
"Gegelia",
"J.",
""
],
[
"Scherer",
"S.",
""
]
] | The magnetic dipole moment of the $\Delta (1232)$ is calculated in the framework of manifestly Lorentz-invariant baryon chiral perturbation theory in combination with the extended on-mass-shell renormalization scheme. As in the case of the nucleon, at leading order both isoscalar and isovector anomalous magnetic moments are given in terms of two low-energy constants. In contrast to the nucleon case, at next-to-leading order the isoscalar anomalous magnetic moment receives a (real) loop contribution. Moreover, due to the unstable nature of the $\Delta (1232)$, at next-to-leading order the isovector anomalous magnetic moment not only receives a real but also an imaginary loop contribution. |
1601.07730 | Timo K\"arkk\"ainen | Katri Huitu, Timo J. K\"arkk\"ainen, Jukka Maalampi and Sampsa Vihonen | Constraining the non-standard interaction parameters in long baseline
neutrino experiments | 15 pages, 2 figures | Phys. Rev. D 93, 053016 (2016) | 10.1103/PhysRevD.93.053016 | HIP-2016-03/TH | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this article we investigate the prospects for probing the strength of the
possible non-standard neutrino interactions (NSI) in long baseline neutrino
oscillation experiments. We find that these experiments are sensitive to NSI
couplings down to the level of 0.01-0.1 depending on the oscillation channel
and the baseline length, as well as on the detector's fiducial mass. We also
investigate the interference of the leptonic CP angle $\delta_{CP}$ with the
constraining of the NSI couplings. It is found that the interference is strong
in the case of the $\nu_{e}\leftrightarrow\nu_{\mu}$ and
$\nu_{e}\leftrightarrow\nu_{\tau}$ transitions but not significant in other
transitions. In our numerical analysis we apply the GLoBES software and use the
LBNO setup as our benchmark.
| [
{
"created": "Thu, 28 Jan 2016 11:44:06 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Feb 2016 09:43:00 GMT",
"version": "v2"
}
] | 2016-04-06 | [
[
"Huitu",
"Katri",
""
],
[
"Kärkkäinen",
"Timo J.",
""
],
[
"Maalampi",
"Jukka",
""
],
[
"Vihonen",
"Sampsa",
""
]
] | In this article we investigate the prospects for probing the strength of the possible non-standard neutrino interactions (NSI) in long baseline neutrino oscillation experiments. We find that these experiments are sensitive to NSI couplings down to the level of 0.01-0.1 depending on the oscillation channel and the baseline length, as well as on the detector's fiducial mass. We also investigate the interference of the leptonic CP angle $\delta_{CP}$ with the constraining of the NSI couplings. It is found that the interference is strong in the case of the $\nu_{e}\leftrightarrow\nu_{\mu}$ and $\nu_{e}\leftrightarrow\nu_{\tau}$ transitions but not significant in other transitions. In our numerical analysis we apply the GLoBES software and use the LBNO setup as our benchmark. |
hep-ph/9410354 | Pankaj Agrawal | Pankaj Agrawal, David Bowser-Chao, and Kingman Cheung | Signature of the Intermediate Mass Higgs Boson at the LHC With Flavor
Tagging | 27 pages, 7 uuencoded postscript figures included, LaTeX;
MSU-HEP/40901, CPP-94-32 | Phys.Rev.D51:6114-6124,1995 | 10.1103/PhysRevD.51.6114 | null | hep-ph | null | We revisit the exclusive signature $e^\pm (\mu^\pm) + b\bar b$ in the
associated production of the intermediate mass Higgs boson with a $W$ boson. We
show that it is feasible to use this signature to identify the Higgs boson in
the lower intermediate mass region ($90$ to $130$ GeV) at the LHC with
reasonable acceptance cuts by assuming effective bottom-jet identification. We
further demonstrate that the background can be reduced with judicious cuts down
to the level of the signal.
| [
{
"created": "Sun, 23 Oct 1994 22:26:42 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Agrawal",
"Pankaj",
""
],
[
"Bowser-Chao",
"David",
""
],
[
"Cheung",
"Kingman",
""
]
] | We revisit the exclusive signature $e^\pm (\mu^\pm) + b\bar b$ in the associated production of the intermediate mass Higgs boson with a $W$ boson. We show that it is feasible to use this signature to identify the Higgs boson in the lower intermediate mass region ($90$ to $130$ GeV) at the LHC with reasonable acceptance cuts by assuming effective bottom-jet identification. We further demonstrate that the background can be reduced with judicious cuts down to the level of the signal. |
2101.07803 | Adrian Carmona | Adrian Carmona, Christiane Scherb and Pedro Schwaller | Charming ALPs | v2: inclusion of constraints from CHARM and SN1987a. 20 pages, 7
figures, 1 table | null | 10.1007/JHEP08(2021)121 | MITP-21-003 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | Axion-like particles (ALPs) are ubiquitous in models of new physics
explaining some of the most pressing puzzles of the Standard Model. However,
until relatively recently, little attention has been paid to its interplay with
flavour. In this work, we study in detail the phenomenology of ALPs that
exclusively interact with up-type quarks at the tree-level, which arise in some
well-motivated ultra-violet completions such as QCD-like dark sectors or
Froggatt-Nielsen type models of flavour. Our study is performed in the
low-energy effective theory to highlight the key features of these scenarios in
a model independent way. We derive all the existing constraints on these models
and demonstrate how upcoming experiments at fixed-target facilities and the LHC
can probe a vast region of the parameter space, which is currently not excluded
by cosmological and astrophysical bounds. We also emphasize how a future
measurement of the currently unavailable meson decay $D \to \pi +
\rm{invisible}$ could complement these upcoming searches and help to probe a
large unexplored region of their parameter space.
| [
{
"created": "Tue, 19 Jan 2021 19:00:01 GMT",
"version": "v1"
},
{
"created": "Thu, 29 Apr 2021 16:38:36 GMT",
"version": "v2"
}
] | 2021-09-15 | [
[
"Carmona",
"Adrian",
""
],
[
"Scherb",
"Christiane",
""
],
[
"Schwaller",
"Pedro",
""
]
] | Axion-like particles (ALPs) are ubiquitous in models of new physics explaining some of the most pressing puzzles of the Standard Model. However, until relatively recently, little attention has been paid to its interplay with flavour. In this work, we study in detail the phenomenology of ALPs that exclusively interact with up-type quarks at the tree-level, which arise in some well-motivated ultra-violet completions such as QCD-like dark sectors or Froggatt-Nielsen type models of flavour. Our study is performed in the low-energy effective theory to highlight the key features of these scenarios in a model independent way. We derive all the existing constraints on these models and demonstrate how upcoming experiments at fixed-target facilities and the LHC can probe a vast region of the parameter space, which is currently not excluded by cosmological and astrophysical bounds. We also emphasize how a future measurement of the currently unavailable meson decay $D \to \pi + \rm{invisible}$ could complement these upcoming searches and help to probe a large unexplored region of their parameter space. |
hep-ph/0701015 | Mikkel Johnson | M.B. Johnson, B.Z. Kopeliovich, and Ivan Schmidt | Cronin effect in the Drell-Yan reaction | LATEX, 30 pages, 12 figures; figures updated and discussion added in
Sect. 2 | Phys.Rev.C75:064905,2007 | 10.1103/PhysRevC.75.064905 | Report-no: USM-TH-200, LA-UR-06-8858 | hep-ph | null | We explore the mechanism of transverse momentum broadening of fast quarks
propagating in nuclei, using Drell-Yan (DY) transverse momentum distributions
measured in the experiment E866 at FermiLab with beams of 800 GeV protons. Our
theoretical analysis is based on the color dipole approach in the target rest
frame, which has provided a successful phenomenological description of a
variety of hadronic reactions. The present application is relevant to the
regime of short coherence length (SCL), where the spatial extent of the
fluctuations of the projectile responsible for the Drell-Yan reaction is short
compared to the internucleon spacing. In this limit, momentum broadening comes
from initial state interactions and is described as color filtering, i.e.
absorption of large-size dipoles leading to diminished transverse separation
and hence enhanced transverse momentum. The predictions we present are in good
agreement with the E866 data. The interactions leading to the acquisition of
transverse momentum arise from the color-dipole cross section determined
previously from deep-inelastic scattering on proton targets. Aside from the
determination of the color-dipole cross section, no other phenomenological
input is needed to explain the experimental results. The mean-square momentum
broadening of dileptons determined in a recent separate analysis of the data is
likewise well described by our theory. These results confirm that the origin of
momentum broadening in DY is the color dipole cross section mediating soft
initial state interactions between the parton of the projectile that initiates
the reaction and the nucleons of the nucleus, as provided by the color dipole
description. Predictions for broadening observables at RHIC are presented.
| [
{
"created": "Tue, 2 Jan 2007 21:01:47 GMT",
"version": "v1"
},
{
"created": "Thu, 5 Apr 2007 20:11:57 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Johnson",
"M. B.",
""
],
[
"Kopeliovich",
"B. Z.",
""
],
[
"Schmidt",
"Ivan",
""
]
] | We explore the mechanism of transverse momentum broadening of fast quarks propagating in nuclei, using Drell-Yan (DY) transverse momentum distributions measured in the experiment E866 at FermiLab with beams of 800 GeV protons. Our theoretical analysis is based on the color dipole approach in the target rest frame, which has provided a successful phenomenological description of a variety of hadronic reactions. The present application is relevant to the regime of short coherence length (SCL), where the spatial extent of the fluctuations of the projectile responsible for the Drell-Yan reaction is short compared to the internucleon spacing. In this limit, momentum broadening comes from initial state interactions and is described as color filtering, i.e. absorption of large-size dipoles leading to diminished transverse separation and hence enhanced transverse momentum. The predictions we present are in good agreement with the E866 data. The interactions leading to the acquisition of transverse momentum arise from the color-dipole cross section determined previously from deep-inelastic scattering on proton targets. Aside from the determination of the color-dipole cross section, no other phenomenological input is needed to explain the experimental results. The mean-square momentum broadening of dileptons determined in a recent separate analysis of the data is likewise well described by our theory. These results confirm that the origin of momentum broadening in DY is the color dipole cross section mediating soft initial state interactions between the parton of the projectile that initiates the reaction and the nucleons of the nucleus, as provided by the color dipole description. Predictions for broadening observables at RHIC are presented. |
hep-ph/9811454 | Jorge Crispim Romao | Jorge C. Romao (Lisbon, IST) | Supersymmetric Theories with R-Parity Violation | 40 pages, 15 Figures in Postscript. One reference added and one
Figure moved from Section 3.2.2 to 3.2.1. Lectures given at the V Gleb
Wataghin School, Campinas, Brazil, July 1998 | null | null | FISIST/15-98/CFIF | hep-ph | null | In these Lectures we review the Minimal Supersymmetric Standard Model as well
as some of its extensions that include R-Parity violation. The cases of
spontaneous breaking of R-Parity as well as that of explicit violation through
bilinear terms in the superpotential are studied in detail. The signals at LEP
and the prospects for LHC are discussed.
| [
{
"created": "Tue, 24 Nov 1998 11:59:36 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Dec 1998 12:05:24 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Romao",
"Jorge C.",
"",
"Lisbon, IST"
]
] | In these Lectures we review the Minimal Supersymmetric Standard Model as well as some of its extensions that include R-Parity violation. The cases of spontaneous breaking of R-Parity as well as that of explicit violation through bilinear terms in the superpotential are studied in detail. The signals at LEP and the prospects for LHC are discussed. |
1504.07792 | Keisho Hidaka | K. Hidaka (1), A. Bartl (2), H. Eberl (3), E. Ginina (3) and W.
Majerotto (3) ((1) Tokyo Gakugei U., (2) Vienna U., (3) IHEP, Vienna) | Impact of quark flavor violation on the decay $h^0(125GeV) \to c\bar{c}$
in the MSSM | 4 pages, 2 figures, Proceedings of International Workshop on Higgs as
a Probe of New Physics 2015 (HPNP2015), Toyama, Japan, 11-15, February, 2015
(to be published in eConf) | null | null | HEPHY-PUB 950/15, UWThPh-2015-08 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the decay width of $h^0 \to c \bar{c}$ in the MSSM with quark
flavor violation (QFV) at full one-loop level in the $\overline{\rm DR}$
renormalization scheme. We study the effects of $\tilde{c}-\tilde{t}$ mixing,
taking into account the constraints on QFV from the B meson data. We find that
the full one-loop corrected decay width $\Gamma(h^0 \to c \bar{c})$ is very
sensitive to the MSSM QFV parameters. In a scenario with large
$\tilde{c}_{L,R}-\tilde{t}_{L,R}$ mixing, $\Gamma (h^0 \to c \bar{c})$ can
differ up to $\sim \pm 35\%$ from its SM value. After estimating the
uncertainties of the width, we conclude that an observation of these QFV SUSY
effects is possible at a future $e^+ e^-$ collider such as ILC.
| [
{
"created": "Wed, 29 Apr 2015 10:09:35 GMT",
"version": "v1"
}
] | 2015-04-30 | [
[
"Hidaka",
"K.",
"",
"Tokyo Gakugei U"
],
[
"Bartl",
"A.",
"",
"Vienna U"
],
[
"Eberl",
"H.",
"",
"IHEP, Vienna"
],
[
"Ginina",
"E.",
"",
"IHEP, Vienna"
],
[
"Majerotto",
"W.",
"",
"IHEP, Vienna"
]
] | We compute the decay width of $h^0 \to c \bar{c}$ in the MSSM with quark flavor violation (QFV) at full one-loop level in the $\overline{\rm DR}$ renormalization scheme. We study the effects of $\tilde{c}-\tilde{t}$ mixing, taking into account the constraints on QFV from the B meson data. We find that the full one-loop corrected decay width $\Gamma(h^0 \to c \bar{c})$ is very sensitive to the MSSM QFV parameters. In a scenario with large $\tilde{c}_{L,R}-\tilde{t}_{L,R}$ mixing, $\Gamma (h^0 \to c \bar{c})$ can differ up to $\sim \pm 35\%$ from its SM value. After estimating the uncertainties of the width, we conclude that an observation of these QFV SUSY effects is possible at a future $e^+ e^-$ collider such as ILC. |
0909.0724 | Ana Rodriguez Sanchez | M.Herrero, J.Portoles, A.Rodriguez-Sanchez | Sensitivity to the Higgs sector of SUSY-seesaw models via LFV tau decays | 4 pages, 3 figures, conference SUSY09 Boston (M.Herrero) | AIP Conf.Proc.1200:908-911,2010 | 10.1063/1.3327759 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Here we study and compare the sensitivity to the Higgs sector of the
SUSY-seesaw models via the LFV tau decays: tau-> 3 mu, tau->K^{+}K^{-}, tau->mu
eta and tau-> mu f_{0}. We emphasize that, at present, the two later channels
are the most efficient ones to test indirectly the Higgs particles.
| [
{
"created": "Thu, 3 Sep 2009 17:57:04 GMT",
"version": "v1"
}
] | 2015-05-14 | [
[
"Herrero",
"M.",
""
],
[
"Portoles",
"J.",
""
],
[
"Rodriguez-Sanchez",
"A.",
""
]
] | Here we study and compare the sensitivity to the Higgs sector of the SUSY-seesaw models via the LFV tau decays: tau-> 3 mu, tau->K^{+}K^{-}, tau->mu eta and tau-> mu f_{0}. We emphasize that, at present, the two later channels are the most efficient ones to test indirectly the Higgs particles. |
1506.02656 | Yevgeny Kats | Shikma Bressler, Thomas Flacke, Yevgeny Kats, Seung J. Lee, Gilad
Perez | Hadronic Calorimeter Shower Size: Challenges and Opportunities for Jet
Substructure in the Superboosted Regime | 6 pages, 4 figures; v2: minor improvements of presentation; published
version | Phys. Lett. B 756 (2016) 137 | 10.1016/j.physletb.2016.02.068 | null | hep-ph physics.ins-det | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Hadrons have finite interaction size with dense material, a basic feature
common to known forms of hadronic calorimeters (HCAL). We argue that
substructure variables cannot use HCAL information to access the microscopic
nature of jets much narrower than the hadronic shower size, which we call
superboosted massive jets. It implies that roughly 15% of their transverse
energy profile remains inaccessible due to the presence of long-lived neutral
hadrons. This part of the jet substructure is also subject to order-one
fluctuations. We demonstrate that the effects of the fluctuations are not
reduced when a global correction to jet variables is applied. The above leads
to fundamental limitations in the ability to extract intrinsic information from
jets in the superboosted regime. The neutral fraction of a jet is correlated
with its flavor. This leads to an interesting and possibly useful difference
between superboosted W/Z/h/t jets and their corresponding backgrounds. The QCD
jets that form the background to the signal superboosted jets might also be
qualitatively different in their substructure as their mass might lie at or
below the Sudakov mass peak. Finally, we introduce a set of zero-cone
longitudinal jet substructure variables and show that while they carry
information that might be useful in certain situations, they are not in general
sensitive to the jet substructure.
| [
{
"created": "Mon, 8 Jun 2015 20:00:27 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Mar 2016 13:25:34 GMT",
"version": "v2"
}
] | 2016-03-17 | [
[
"Bressler",
"Shikma",
""
],
[
"Flacke",
"Thomas",
""
],
[
"Kats",
"Yevgeny",
""
],
[
"Lee",
"Seung J.",
""
],
[
"Perez",
"Gilad",
""
]
] | Hadrons have finite interaction size with dense material, a basic feature common to known forms of hadronic calorimeters (HCAL). We argue that substructure variables cannot use HCAL information to access the microscopic nature of jets much narrower than the hadronic shower size, which we call superboosted massive jets. It implies that roughly 15% of their transverse energy profile remains inaccessible due to the presence of long-lived neutral hadrons. This part of the jet substructure is also subject to order-one fluctuations. We demonstrate that the effects of the fluctuations are not reduced when a global correction to jet variables is applied. The above leads to fundamental limitations in the ability to extract intrinsic information from jets in the superboosted regime. The neutral fraction of a jet is correlated with its flavor. This leads to an interesting and possibly useful difference between superboosted W/Z/h/t jets and their corresponding backgrounds. The QCD jets that form the background to the signal superboosted jets might also be qualitatively different in their substructure as their mass might lie at or below the Sudakov mass peak. Finally, we introduce a set of zero-cone longitudinal jet substructure variables and show that while they carry information that might be useful in certain situations, they are not in general sensitive to the jet substructure. |
1112.1039 | Juergen Reuter | W. Kilian, J. Reuter, S. Schmidt, D. Wiesler | An Analytic Initial-State Parton Shower | 42 pages, 22 figures, minor changes matching the published version | JHEP 1204 (2012) 013 | 10.1007/JHEP04(2012)013 | DESY 11-214; SI-HEP-2011-16 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a new algorithm for an analytic parton shower. While the algorithm
for the final-state shower has been known in the literature, the construction
of an initial-state shower along these lines is new. The aim is to have a
parton shower algorithm for which the full analytic form of the probability
distribution for all branchings is known. For these parton shower algorithms it
is therefore possible to calculate the probability for a given event to be
generated, providing the potential to reweight the event after the simulation.
We develop the algorithm for this shower including scale choices and angular
ordering. Merging to matrix elements is used to describe high-energy tails of
distributions correctly. Finally, we compare our results with those of other
parton showers and with experimental data from LEP, Tevatron and LHC.
| [
{
"created": "Mon, 5 Dec 2011 19:51:36 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Apr 2012 15:44:29 GMT",
"version": "v2"
}
] | 2012-04-17 | [
[
"Kilian",
"W.",
""
],
[
"Reuter",
"J.",
""
],
[
"Schmidt",
"S.",
""
],
[
"Wiesler",
"D.",
""
]
] | We present a new algorithm for an analytic parton shower. While the algorithm for the final-state shower has been known in the literature, the construction of an initial-state shower along these lines is new. The aim is to have a parton shower algorithm for which the full analytic form of the probability distribution for all branchings is known. For these parton shower algorithms it is therefore possible to calculate the probability for a given event to be generated, providing the potential to reweight the event after the simulation. We develop the algorithm for this shower including scale choices and angular ordering. Merging to matrix elements is used to describe high-energy tails of distributions correctly. Finally, we compare our results with those of other parton showers and with experimental data from LEP, Tevatron and LHC. |
1710.11210 | Giulia Pancheri Dr. | G. Pancheri, A. Grau, Y.N. Srivastava, D.A. Fagundes and O.
Shekhovtsova | The non-diffractive pp cross-section and Survival Probabilities at LHC | 6 pages, 2 figures, Presented at EDS Blois 2017, Prague, Czech
Republic, June 26-30, 2017 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an estimate of survival probability from an eikonal mini- jet
model implemented with a proposal for soft gluon resummation to all orders. We
compare it with experimental data for diffractive di-jet production from LHC
experiments, CMS and ATLAS, both at LO and NLO order.
| [
{
"created": "Mon, 30 Oct 2017 19:36:52 GMT",
"version": "v1"
}
] | 2017-11-01 | [
[
"Pancheri",
"G.",
""
],
[
"Grau",
"A.",
""
],
[
"Srivastava",
"Y. N.",
""
],
[
"Fagundes",
"D. A.",
""
],
[
"Shekhovtsova",
"O.",
""
]
] | We present an estimate of survival probability from an eikonal mini- jet model implemented with a proposal for soft gluon resummation to all orders. We compare it with experimental data for diffractive di-jet production from LHC experiments, CMS and ATLAS, both at LO and NLO order. |
2105.13035 | Artem Lipatov | S.P. Baranov, A.V. Lipatov, A.A. Prokhorov | Charm fragmentation and associated $J/\psi + Z/W^\pm$ production at the
LHC | 11 pages, 4 figures | Phys. Rev. D 104, 034018 (2021) | 10.1103/PhysRevD.104.034018 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the production of electroweak $Z$ or $W^\pm$ bosons associated
with $J/\psi$ mesons at the LHC conditions. Our attention is focused on new
partonic subprocesses which yet have never been considered in the literature,
namely, the charmed or strange quark excitation subprocesses followed by the
charmed quark fragmentation $c\to J/\psi+c$. Additionally we take into account
the effects of multiple quark and gluon radiation in the initial and final
states. We find that the contributions from the new mechanisms are important
and significantly reduce the gap between the theoretical and experimental
results on the $J/\psi + Z$ and $J/\psi + W^\pm$ production cross sections.
| [
{
"created": "Thu, 27 May 2021 10:04:53 GMT",
"version": "v1"
}
] | 2021-08-25 | [
[
"Baranov",
"S. P.",
""
],
[
"Lipatov",
"A. V.",
""
],
[
"Prokhorov",
"A. A.",
""
]
] | We consider the production of electroweak $Z$ or $W^\pm$ bosons associated with $J/\psi$ mesons at the LHC conditions. Our attention is focused on new partonic subprocesses which yet have never been considered in the literature, namely, the charmed or strange quark excitation subprocesses followed by the charmed quark fragmentation $c\to J/\psi+c$. Additionally we take into account the effects of multiple quark and gluon radiation in the initial and final states. We find that the contributions from the new mechanisms are important and significantly reduce the gap between the theoretical and experimental results on the $J/\psi + Z$ and $J/\psi + W^\pm$ production cross sections. |
1912.06507 | Wolfgang Sch\"afer | A.D. Bolognino, A. Szczurek, W. Sch\"afer | Exclusive production of $\phi$ meson in the $\gamma^*\,p \to \phi\,p$
reaction at large photon virtualities within $k_T$-factorization approach | 16 pages, 12 figures | Phys. Rev. D 101, 054041 (2020) | 10.1103/PhysRevD.101.054041 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We apply the $k_T$-factorization approach to the production of $\phi$ meson
in deep-inelastic scattering. The helicity-conserving $\gamma^*(T,L) \to \phi$
impact factor is calculated for longitudinal and transverse photon polarization
using $\phi$ meson distribution amplitudes. Different unintegrated gluon
distributions are used in the calculations. The formalism for massless
quarks/antiquarks gives too large transverse and longitudinal cross sections
for photon virtualities below $Q^2\sim 8 \, \rm{GeV}^2$. We suggest how to
improve the description of the HERA data by introducing effective strange quark
masses into the formalism. We derive the corresponding massive impact factor by
comparing to the light-cone wave function representation used in previous
$k_T$-factorization calculations and the color-dipole approaches. As a
byproduct we present expressions for higher twist-amplitudes as weighted
integrals over the light-cone wave function. The quark mass $m_q \approx 0.5$
GeV allows to improve the description of both longitudinal and transverse cross
section down to $Q^2 \sim$ 4 GeV$^2$. We present also the polarized cross
section ratio $\sigma_L/\sigma_T$ and the behavior of the total cross section
$\sigma_{tot} = \sigma_{L} + \sigma_{T}$ as a function of photon virtuality.
| [
{
"created": "Fri, 13 Dec 2019 14:12:33 GMT",
"version": "v1"
}
] | 2020-04-08 | [
[
"Bolognino",
"A. D.",
""
],
[
"Szczurek",
"A.",
""
],
[
"Schäfer",
"W.",
""
]
] | We apply the $k_T$-factorization approach to the production of $\phi$ meson in deep-inelastic scattering. The helicity-conserving $\gamma^*(T,L) \to \phi$ impact factor is calculated for longitudinal and transverse photon polarization using $\phi$ meson distribution amplitudes. Different unintegrated gluon distributions are used in the calculations. The formalism for massless quarks/antiquarks gives too large transverse and longitudinal cross sections for photon virtualities below $Q^2\sim 8 \, \rm{GeV}^2$. We suggest how to improve the description of the HERA data by introducing effective strange quark masses into the formalism. We derive the corresponding massive impact factor by comparing to the light-cone wave function representation used in previous $k_T$-factorization calculations and the color-dipole approaches. As a byproduct we present expressions for higher twist-amplitudes as weighted integrals over the light-cone wave function. The quark mass $m_q \approx 0.5$ GeV allows to improve the description of both longitudinal and transverse cross section down to $Q^2 \sim$ 4 GeV$^2$. We present also the polarized cross section ratio $\sigma_L/\sigma_T$ and the behavior of the total cross section $\sigma_{tot} = \sigma_{L} + \sigma_{T}$ as a function of photon virtuality. |
2109.13960 | Evgeny Akhmedov | Evgeny Akhmedov (MPIK Heidelberg) | Nuclear fusion catalyzed by doubly charged scalars: Implications for
energy production | RevTeX, 17 pages,3 tables. v3: Note on recent ATLAS results on events
with anomalously large ionization energy loss and their interpretation in
terms of charge-2 long lived particles by Giudice et al. added; references
added; supplemented material turned into appendices. v4: minor typos
corrected | null | 10.1103/PhysRevD.106.035013 | null | hep-ph astro-ph.SR hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A number of popular extensions of the Standard Model of particle physics
predict the existence of doubly charged scalar particles $X^{\pm\pm}$. Such
particles may be long-lived or even stable. If exist, $X^{--}$ could form
atomic bound states with light nuclei and catalyze their fusion by essentially
eliminating the Coulomb barrier between them. Such an $X$-catalyzed fusion
($X$CF) process does not require high temperatures or pressure and may have
important applications for energy production. A similar process of
muon-catalyzed fusion ($\mu$CF) has been shown not to be a viable source of
energy because of the sticking of negative muons to helium nuclei produced in
the fusion of hydrogen isotopes, which stops the catalytic process. We analyze
$X$CF in deuterium environments and show that the $X$-particles can only stick
to $^6$Li nuclei, which are produced in the third-stage reactions downstream in
the catalytic cycle. The corresponding sticking probability is very low, and,
before getting bound to $^6$Li, each $X$-particle can catalyze $\sim 3.5\cdot
10^{9}$ fusion cycles, producing $\sim 7\cdot 10^{4}$ TeV of energy. We also
discuss the ways of reactivating the $X$-particles from the Coulomb-bound
(${\rm ^6Li}X$) states, which would allow re-using them in $X$CF reactions.
| [
{
"created": "Tue, 28 Sep 2021 18:01:30 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Oct 2021 14:00:04 GMT",
"version": "v2"
},
{
"created": "Mon, 18 Jul 2022 18:01:42 GMT",
"version": "v3"
},
{
"created": "Tue, 13 Sep 2022 18:00:04 GMT",
"version": "v4"
}
] | 2022-09-15 | [
[
"Akhmedov",
"Evgeny",
"",
"MPIK Heidelberg"
]
] | A number of popular extensions of the Standard Model of particle physics predict the existence of doubly charged scalar particles $X^{\pm\pm}$. Such particles may be long-lived or even stable. If exist, $X^{--}$ could form atomic bound states with light nuclei and catalyze their fusion by essentially eliminating the Coulomb barrier between them. Such an $X$-catalyzed fusion ($X$CF) process does not require high temperatures or pressure and may have important applications for energy production. A similar process of muon-catalyzed fusion ($\mu$CF) has been shown not to be a viable source of energy because of the sticking of negative muons to helium nuclei produced in the fusion of hydrogen isotopes, which stops the catalytic process. We analyze $X$CF in deuterium environments and show that the $X$-particles can only stick to $^6$Li nuclei, which are produced in the third-stage reactions downstream in the catalytic cycle. The corresponding sticking probability is very low, and, before getting bound to $^6$Li, each $X$-particle can catalyze $\sim 3.5\cdot 10^{9}$ fusion cycles, producing $\sim 7\cdot 10^{4}$ TeV of energy. We also discuss the ways of reactivating the $X$-particles from the Coulomb-bound (${\rm ^6Li}X$) states, which would allow re-using them in $X$CF reactions. |
1611.08457 | Daniel Gomez Dumm | D. Gomez Dumm, S. Noguera, N.N. Scoccola | $\eta$-$\gamma$ and $\eta'$-$\gamma$ transition form factors in a
nonlocal NJL model | 31 pages, 3 figures | Phys. Rev. D 95, 054006 (2017) | 10.1103/PhysRevD.95.054006 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the $\eta$ and $\eta'$ distribution amplitudes (DAs) in the context
of a nonlocal SU(3)_L x SU(3)_R chiral quark model. The corresponding
Lagrangian allows to reproduce the phenomenological values of pseudoscalar
meson masses and decay constants, as well as the momentum dependence of the
quark propagator arising from lattice calculations. It is found that the
obtained DAs have two symmetric maxima, which arise from new contributions
generated by the nonlocal character of the interactions. These DAs are then
applied to the calculation of the $\eta$-$\gamma$ and $\eta'$-$\gamma$
transition form factors. Implications of our results regarding higher twist
corrections and/or contributions to the transition form factors originated by
gluon-gluon components in the $\eta$ and $\eta'$ mesons are discussed.
| [
{
"created": "Fri, 25 Nov 2016 14:02:13 GMT",
"version": "v1"
}
] | 2017-03-15 | [
[
"Dumm",
"D. Gomez",
""
],
[
"Noguera",
"S.",
""
],
[
"Scoccola",
"N. N.",
""
]
] | We study the $\eta$ and $\eta'$ distribution amplitudes (DAs) in the context of a nonlocal SU(3)_L x SU(3)_R chiral quark model. The corresponding Lagrangian allows to reproduce the phenomenological values of pseudoscalar meson masses and decay constants, as well as the momentum dependence of the quark propagator arising from lattice calculations. It is found that the obtained DAs have two symmetric maxima, which arise from new contributions generated by the nonlocal character of the interactions. These DAs are then applied to the calculation of the $\eta$-$\gamma$ and $\eta'$-$\gamma$ transition form factors. Implications of our results regarding higher twist corrections and/or contributions to the transition form factors originated by gluon-gluon components in the $\eta$ and $\eta'$ mesons are discussed. |
2309.10841 | Yohei Ema | Yohei Ema, Sarunas Verner | Cosmological Collider Signatures of Higgs-$R^2$ Inflation | 43 pages, 4 figures; v2: version accepted in JCAP | null | null | UMN-TH-4224/23, FTPI-MINN-23-16 | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | We study the cosmological collider signatures in the Higgs-$R^2$ inflation
model. We consider two distinct types of signals: one originating from the
inflaton coupling to Standard Model fermions and gauge bosons, and another
arising from the isocurvature mode interaction with the inflaton. In the former
case, we determine that the signal magnitude is likely too small for detection
by upcoming probes, primarily due to suppression by both the Planck scale and
slow-roll parameters. However, we provide a detailed computation of the signal
which could be potentially applicable to various Higgs inflation variants. For
the isocurvature mode signals, we observe that the associated couplings remain
unsuppressed when the isocurvature mode is relatively light or comparable to
the inflationary scale. In this case, we study the Higgs-$R^2$ inflation
parameter space that corresponds to the quasi-single-field inflation regime and
find that the signal strength could be as large as $|f_{\rm NL}| > 1$, making
Higgs-$R^2$ inflation a viable candidate for observation by future 21-cm
surveys.
| [
{
"created": "Tue, 19 Sep 2023 18:00:01 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Feb 2024 16:12:21 GMT",
"version": "v2"
}
] | 2024-02-27 | [
[
"Ema",
"Yohei",
""
],
[
"Verner",
"Sarunas",
""
]
] | We study the cosmological collider signatures in the Higgs-$R^2$ inflation model. We consider two distinct types of signals: one originating from the inflaton coupling to Standard Model fermions and gauge bosons, and another arising from the isocurvature mode interaction with the inflaton. In the former case, we determine that the signal magnitude is likely too small for detection by upcoming probes, primarily due to suppression by both the Planck scale and slow-roll parameters. However, we provide a detailed computation of the signal which could be potentially applicable to various Higgs inflation variants. For the isocurvature mode signals, we observe that the associated couplings remain unsuppressed when the isocurvature mode is relatively light or comparable to the inflationary scale. In this case, we study the Higgs-$R^2$ inflation parameter space that corresponds to the quasi-single-field inflation regime and find that the signal strength could be as large as $|f_{\rm NL}| > 1$, making Higgs-$R^2$ inflation a viable candidate for observation by future 21-cm surveys. |
2010.03573 | Michele Cicoli | Rouzbeh Allahverdi, Igor Broeckel, Michele Cicoli, Jacek K. Osi\'nski | Superheavy Dark Matter from String Theory | 16 pages, 9 figures | null | 10.1007/JHEP02(2021)026 | null | hep-ph astro-ph.CO gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Explicit string models which can realize inflation and low-energy
supersymmetry are notoriously difficult to achieve. Given that sequestering
requires very specific configurations, supersymmetric particles are in general
expected to be very heavy implying that the neutralino dark matter should be
overproduced in a standard thermal history. However, in this paper we point out
that this is generically not the case since early matter domination driven by
string moduli can dilute the dark matter abundance down to the observed value.
We argue that generic features of string compactifications, namely a high
supersymmetry breaking scale and late time epochs of modulus domination, might
imply superheavy neutralino dark matter with mass around $10^{10}-10^{11}$ GeV.
Interestingly, this is the right range to explain the recent detection of
ultra-high-energy neutrinos by IceCube and ANITA via dark matter decay.
| [
{
"created": "Wed, 7 Oct 2020 18:00:03 GMT",
"version": "v1"
}
] | 2021-02-24 | [
[
"Allahverdi",
"Rouzbeh",
""
],
[
"Broeckel",
"Igor",
""
],
[
"Cicoli",
"Michele",
""
],
[
"Osiński",
"Jacek K.",
""
]
] | Explicit string models which can realize inflation and low-energy supersymmetry are notoriously difficult to achieve. Given that sequestering requires very specific configurations, supersymmetric particles are in general expected to be very heavy implying that the neutralino dark matter should be overproduced in a standard thermal history. However, in this paper we point out that this is generically not the case since early matter domination driven by string moduli can dilute the dark matter abundance down to the observed value. We argue that generic features of string compactifications, namely a high supersymmetry breaking scale and late time epochs of modulus domination, might imply superheavy neutralino dark matter with mass around $10^{10}-10^{11}$ GeV. Interestingly, this is the right range to explain the recent detection of ultra-high-energy neutrinos by IceCube and ANITA via dark matter decay. |
1709.09964 | Daniele Binosi | Daniele Binosi and Joannis Papavassiliou | Coupled dynamics in gluon mass generation and the impact of the
three-gluon vertex | 19 pages, 6 figures | Phys. Rev. D 97, 054029 (2018) | 10.1103/PhysRevD.97.054029 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a detailed study of the subtle interplay transpiring at the level
of two integral equations that are instrumental for the dynamical generation of
a gluon mass in pure Yang-Mills theories. The main novelty is the joint
treatment of the Schwinger-Dyson equation governing the infrared behaviour of
the gluon propagator and of the integral equation that controls the formation
of massless bound-state excitations, whose inclusion is instrumental for
obtaining massive solutions from the former equation. The self-consistency of
the entire approach imposes the requirement of using a single value for the
gauge coupling entering in the two key equations; its fulfillment depends
crucially on the details of the three-gluon vertex, which contributes to both
of them, but with different weight. In particular, the characteristic
suppression of this vertex at intermediate and low energies enables the
convergence of the iteration procedure to a single gauge coupling, whose value
is reasonably close to that extracted from related lattice simulations.
| [
{
"created": "Thu, 28 Sep 2017 13:49:46 GMT",
"version": "v1"
}
] | 2018-04-04 | [
[
"Binosi",
"Daniele",
""
],
[
"Papavassiliou",
"Joannis",
""
]
] | We present a detailed study of the subtle interplay transpiring at the level of two integral equations that are instrumental for the dynamical generation of a gluon mass in pure Yang-Mills theories. The main novelty is the joint treatment of the Schwinger-Dyson equation governing the infrared behaviour of the gluon propagator and of the integral equation that controls the formation of massless bound-state excitations, whose inclusion is instrumental for obtaining massive solutions from the former equation. The self-consistency of the entire approach imposes the requirement of using a single value for the gauge coupling entering in the two key equations; its fulfillment depends crucially on the details of the three-gluon vertex, which contributes to both of them, but with different weight. In particular, the characteristic suppression of this vertex at intermediate and low energies enables the convergence of the iteration procedure to a single gauge coupling, whose value is reasonably close to that extracted from related lattice simulations. |
1612.09329 | Rachid Benbrik | A. Arhrib, R. Benbrik, J. El Falaki, W. Hollik | Triple Higgs coupling effect on $h^0 \to b \bar b$ and $h^0 \to \tau^+
\tau^-$ in the 2HDM | 18 pages, 6 figures, typos corrected, references added | null | 10.1016/j.physletb.2017.09.065 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the one loop electroweak radiative corrections to
$h^0\to b\bar{b}$ and $h^0\to \tau^+\tau^-$ in the framework of two Higgs
doublet Model (2HDM). We evaluate the deviation of these couplings from their
Standard Model (SM) values. $h^0\to b\bar{b}$ and $h^0\to \tau^+\tau^-$ may
receives large contribution from triple couplings $h^0H^0H^0$, $H^0h^0h^0$,
$h^0A^0A^0$ and $h^0H^+H^-$ which are absent in the Standard Model. It is found
that in 2HDM, these corrections could be significant and may reach more than
20\% for not tow heavy $H^0$ or $A^0$ or $H^\pm$. We also study the ratio of
branching ratios $R=BR(h^0\to b\bar{b})/BR(h^0\to \tau^+\tau^-)$ of Higgs boson
decays which could be used to disentangle SM from other models such as 2HDM.
| [
{
"created": "Thu, 29 Dec 2016 22:04:41 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Jun 2017 18:53:20 GMT",
"version": "v2"
}
] | 2017-11-22 | [
[
"Arhrib",
"A.",
""
],
[
"Benbrik",
"R.",
""
],
[
"Falaki",
"J. El",
""
],
[
"Hollik",
"W.",
""
]
] | We study the one loop electroweak radiative corrections to $h^0\to b\bar{b}$ and $h^0\to \tau^+\tau^-$ in the framework of two Higgs doublet Model (2HDM). We evaluate the deviation of these couplings from their Standard Model (SM) values. $h^0\to b\bar{b}$ and $h^0\to \tau^+\tau^-$ may receives large contribution from triple couplings $h^0H^0H^0$, $H^0h^0h^0$, $h^0A^0A^0$ and $h^0H^+H^-$ which are absent in the Standard Model. It is found that in 2HDM, these corrections could be significant and may reach more than 20\% for not tow heavy $H^0$ or $A^0$ or $H^\pm$. We also study the ratio of branching ratios $R=BR(h^0\to b\bar{b})/BR(h^0\to \tau^+\tau^-)$ of Higgs boson decays which could be used to disentangle SM from other models such as 2HDM. |
0910.5506 | Peter Rembiesa | P. Rembiesa | An effective Lagrangian for scalar bound states in a dense medium | 21 pages, 6 figures | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent analyses suggest that in TeV scales that will be made accessible at
the LHC copious amounts of color scalar parton bound states may be produced.
Would this be the case, the scalars would leave long enough to interact and
this could lead to new physics. These interaction could be direct, but also
take place with a mediation of the dense parton medium through which they
propagate. Since multiple processes would have to be included, the latter case
is too convoluted to be treated with perturbative methods applied to the
Standard Model. We explore a possibility of describing such interaction by a
nonlocal Lagrangian which is an infinite polynomial in the field variables,
momentum and mass. We treat all scalars as identical, use a O(N)-symmetric
Lagrangian, where N is the number of scalars and discuss the problem in 1/N
expansion. Nonrenormalizable by all traditional criteria, such model still
requires only a limited set of multiplicative renormalizations, provided that
the parameters in the Lagrangian are not treated as an infinite set of
independent coupling constants, but as finite expansion coefficients of the
Lagrangian in powers of field variables, mass and momenta. The necessary
constraints on the relative magnitudes of these coefficients can be determined
order by order in a double series in the single coupling constant and 1/N.
| [
{
"created": "Wed, 28 Oct 2009 22:05:20 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Rembiesa",
"P.",
""
]
] | Recent analyses suggest that in TeV scales that will be made accessible at the LHC copious amounts of color scalar parton bound states may be produced. Would this be the case, the scalars would leave long enough to interact and this could lead to new physics. These interaction could be direct, but also take place with a mediation of the dense parton medium through which they propagate. Since multiple processes would have to be included, the latter case is too convoluted to be treated with perturbative methods applied to the Standard Model. We explore a possibility of describing such interaction by a nonlocal Lagrangian which is an infinite polynomial in the field variables, momentum and mass. We treat all scalars as identical, use a O(N)-symmetric Lagrangian, where N is the number of scalars and discuss the problem in 1/N expansion. Nonrenormalizable by all traditional criteria, such model still requires only a limited set of multiplicative renormalizations, provided that the parameters in the Lagrangian are not treated as an infinite set of independent coupling constants, but as finite expansion coefficients of the Lagrangian in powers of field variables, mass and momenta. The necessary constraints on the relative magnitudes of these coefficients can be determined order by order in a double series in the single coupling constant and 1/N. |
hep-ph/0202233 | Georg Weiglein | B.C. Allanach, M. Battaglia, G.A. Blair, M. Carena, A. De Roeck, A.
Dedes, A. Djouadi, D. Gerdes, N. Ghodbane, J. Gunion, H.E. Haber, T. Han, S.
Heinemeyer, J.L. Hewett, I. Hinchliffe, J. Kalinowski, H.E. Logan, S.P.
Martin, H.-U. Martyn, K.T. Matchev, S. Moretti, F. Moortgat, G.
Moortgat-Pick, S. Mrenna, U. Nauenberg, Y. Okada, K.A. Olive, W. Porod, M.
Schmitt, S. Su, C.E.M. Wagner, G. Weiglein, J. Wells, G.W. Wilson, P. Zerwas | The Snowmass Points and Slopes: Benchmarks for SUSY Searches | 12 pages, 3 figures | Eur.Phys.J.C25:113-123,2002 | 10.1007/s10052-002-0949-3 | BNL-HET-02/6, CERN-TH/2002-020, DCPT/02/16, DESY 02-022,
FERMILAB-Conf-02/011-T, HEPHY-PUB 751, IPPP/02/08, PM/01-69, SLAC-PUB-9134,
UCD-2002-01, UFIFT-HEP-02-2, UMN-TH-2043/02, ZU-TH 3/02 | hep-ph | null | The ``Snowmass Points and Slopes'' (SPS) are a set of benchmark points and
parameter lines in the MSSM parameter space corresponding to different
scenarios in the search for Supersymmetry at present and future experiments.
This set of benchmarks was agreed upon at the 2001 ``Snowmass Workshop on the
Future of Particle Physics'' as a consensus based on different existing
proposals.
| [
{
"created": "Mon, 25 Feb 2002 18:08:58 GMT",
"version": "v1"
}
] | 2009-01-14 | [
[
"Allanach",
"B. C.",
""
],
[
"Battaglia",
"M.",
""
],
[
"Blair",
"G. A.",
""
],
[
"Carena",
"M.",
""
],
[
"De Roeck",
"A.",
""
],
[
"Dedes",
"A.",
""
],
[
"Djouadi",
"A.",
""
],
[
"Gerdes",
"D."... | The ``Snowmass Points and Slopes'' (SPS) are a set of benchmark points and parameter lines in the MSSM parameter space corresponding to different scenarios in the search for Supersymmetry at present and future experiments. This set of benchmarks was agreed upon at the 2001 ``Snowmass Workshop on the Future of Particle Physics'' as a consensus based on different existing proposals. |
2407.02550 | Pralay Chakraborty | Pralay Chakraborty, Subhankar Roy | Exploring Exponential Parametrization of Neutrino Mass Matrix | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We explore the exponential parameterization of the Majorana neutrino mass
matrix texture. In this regard, the elements of the mass matrix are expressed
in terms of their absolute values and arguments. We propose a neutrino mass
matrix texture that highlights four correlations among its elements. The mixing
scheme obtained from the proposed texture is consistent with experimental
observations. In addition, we derive the proposed texture from the $SU(2)_L
\times U(1)_Y \times A_4 \times Z_{10}$ group in the light of the seesaw
mechanism.
| [
{
"created": "Tue, 2 Jul 2024 16:02:49 GMT",
"version": "v1"
}
] | 2024-07-04 | [
[
"Chakraborty",
"Pralay",
""
],
[
"Roy",
"Subhankar",
""
]
] | We explore the exponential parameterization of the Majorana neutrino mass matrix texture. In this regard, the elements of the mass matrix are expressed in terms of their absolute values and arguments. We propose a neutrino mass matrix texture that highlights four correlations among its elements. The mixing scheme obtained from the proposed texture is consistent with experimental observations. In addition, we derive the proposed texture from the $SU(2)_L \times U(1)_Y \times A_4 \times Z_{10}$ group in the light of the seesaw mechanism. |
2010.00555 | Shahin Atashbar Tehrani | Hamzeh Khanpour, Maryam Soleymaninia, S. Atashbar Tehrani, Hubert
Spiesberger and Vadim Guzey | Nuclear parton distribution functions with uncertainties in a general
mass variable flavor number scheme | 34 Pages 9 Tables 19 Figs | Phys. Rev. D 104, 034010 (2021) | 10.1103/PhysRevD.104.034010 | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this article we obtain a new set of nuclear parton distribution functions
(nuclear PDFs) at next-to-leading order and next-to-next-to-leading order
accuracy in perturbative QCD. The common nuclear deep-inelastic scattering
(DIS) data analyzed in our study are complemented by the available
charged-current neutrino DIS data with nuclear targets and data from Drell-Yan
cross-section measurements for several nuclear targets. In addition, the most
recent DIS data from the Jefferson Lab CLAS and Hall C experiments are also
added to our data sample. For these specific datasets, we consider the impact
of target mass corrections and higher twist effects which are expected to be
important in the region of large $x$ and intermediate-to-low $Q^2$. Our
analysis is based on a publicly available open-source tool {\tt APFEL}, which
has been modified to be applicable for our analysis of nuclear PDFs. Heavy
quark contributions to nuclear DIS are considered within the framework of the
{\tt FONLL} general-mass variable-flavor-number scheme. The most recent {\tt
CT18} PDFs are used as baseline proton PDFs. The uncertainties of nuclear PDFs
are determined using the standard Hessian approach. The results of our global
QCD analysis are compared with existing nuclear PDF sets and with the fitted
cross-sections, for which our set of nuclear PDFs provides a very good
description.
| [
{
"created": "Thu, 1 Oct 2020 17:13:37 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Aug 2021 16:06:44 GMT",
"version": "v2"
}
] | 2021-08-17 | [
[
"Khanpour",
"Hamzeh",
""
],
[
"Soleymaninia",
"Maryam",
""
],
[
"Tehrani",
"S. Atashbar",
""
],
[
"Spiesberger",
"Hubert",
""
],
[
"Guzey",
"Vadim",
""
]
] | In this article we obtain a new set of nuclear parton distribution functions (nuclear PDFs) at next-to-leading order and next-to-next-to-leading order accuracy in perturbative QCD. The common nuclear deep-inelastic scattering (DIS) data analyzed in our study are complemented by the available charged-current neutrino DIS data with nuclear targets and data from Drell-Yan cross-section measurements for several nuclear targets. In addition, the most recent DIS data from the Jefferson Lab CLAS and Hall C experiments are also added to our data sample. For these specific datasets, we consider the impact of target mass corrections and higher twist effects which are expected to be important in the region of large $x$ and intermediate-to-low $Q^2$. Our analysis is based on a publicly available open-source tool {\tt APFEL}, which has been modified to be applicable for our analysis of nuclear PDFs. Heavy quark contributions to nuclear DIS are considered within the framework of the {\tt FONLL} general-mass variable-flavor-number scheme. The most recent {\tt CT18} PDFs are used as baseline proton PDFs. The uncertainties of nuclear PDFs are determined using the standard Hessian approach. The results of our global QCD analysis are compared with existing nuclear PDF sets and with the fitted cross-sections, for which our set of nuclear PDFs provides a very good description. |
0806.0179 | Vimal Simha | Vimal Simha, Gary Steigman | Constraining The Universal Lepton Asymmetry | null | JCAP0808:011,2008 | 10.1088/1475-7516/2008/08/011 | null | hep-ph astro-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The relic cosmic background neutrinos accompanying the cosmic microwave
background (CMB) photons may hide a universal lepton asymmetry orders of
magnitude larger than the universal baryon asymmetry. At present, the only
direct way to probe such an asymmetry is through its effect on the abundances
of the light elements produced during primordial nucleosynthesis. The relic
light element abundances also depend on the baryon asymmetry, parameterized by
the baryon density parameter (eta_B = n_B/n_gamma = 10^(-10)*eta_10), and on
the early-universe expansion rate, parameterized by the expansion rate factor
(S = H'/H) or, equivalently by the effective number of neutrinos (N_nu = 3 +
43(S^2 - 1)/7). We use data from the CMB (and Large Scale Structure: LSS) along
with the observationally-inferred relic abundances of deuterium and helium-4 to
provide new bounds on the universal lepton asymmetry, finding for eta_L, the
analog of eta_B, 0.072 +/- 0.053 if it is assumed that N_nu = 3 and, 0.115 +/-
0.095 along with N_nu = 3.3^{+0.7}_{-0.6}, if N_nu is free to vary.
| [
{
"created": "Sun, 1 Jun 2008 22:15:41 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Simha",
"Vimal",
""
],
[
"Steigman",
"Gary",
""
]
] | The relic cosmic background neutrinos accompanying the cosmic microwave background (CMB) photons may hide a universal lepton asymmetry orders of magnitude larger than the universal baryon asymmetry. At present, the only direct way to probe such an asymmetry is through its effect on the abundances of the light elements produced during primordial nucleosynthesis. The relic light element abundances also depend on the baryon asymmetry, parameterized by the baryon density parameter (eta_B = n_B/n_gamma = 10^(-10)*eta_10), and on the early-universe expansion rate, parameterized by the expansion rate factor (S = H'/H) or, equivalently by the effective number of neutrinos (N_nu = 3 + 43(S^2 - 1)/7). We use data from the CMB (and Large Scale Structure: LSS) along with the observationally-inferred relic abundances of deuterium and helium-4 to provide new bounds on the universal lepton asymmetry, finding for eta_L, the analog of eta_B, 0.072 +/- 0.053 if it is assumed that N_nu = 3 and, 0.115 +/- 0.095 along with N_nu = 3.3^{+0.7}_{-0.6}, if N_nu is free to vary. |
2408.04084 | Ivan Aleksandrov | A. G. Tkachev, I. A. Aleksandrov, V. M. Shabaev | Schwinger pair production in counterpropagating laser pulses:
Identifying volume factors | 11 pages, 5 figures | null | null | null | hep-ph quant-ph | http://creativecommons.org/licenses/by/4.0/ | We investigate the nonperturbative process of vacuum pair production in a
combination of two counterpropagating linearly polarized laser pulses of a
finite spatial extent. By means of the locally-constant field approximation
(LCFA), we calculate the total particle yield for the corresponding
four-dimensional setup and compare it with the estimates obtained for
simplified low-dimensional scenarios. Within the domain where the LCFA is well
justified, we examine a combination of two plane-wave pulses, a standing
electromagnetic wave, and a spatially uniform oscillating field and demonstrate
that at each of these three levels of approximation, one can accurately predict
the actual particle number by multiplying the results by properly chosen volume
factors depending on the field parameters. We present closed-form expressions
for these factors providing universal prescriptions for evaluating the particle
yield. Our final formula connecting the spatially uniform setup with the
four-dimensional scenario has a relative uncertainty of the level of $5\%$. The
explicit correspondences deduced in this study not only prove the relevance of
the approximate predictions, but also allow one to quickly estimate the number
of pairs for various realistic scenarios without performing complicated
numerical calculations.
| [
{
"created": "Wed, 7 Aug 2024 20:55:39 GMT",
"version": "v1"
}
] | 2024-08-09 | [
[
"Tkachev",
"A. G.",
""
],
[
"Aleksandrov",
"I. A.",
""
],
[
"Shabaev",
"V. M.",
""
]
] | We investigate the nonperturbative process of vacuum pair production in a combination of two counterpropagating linearly polarized laser pulses of a finite spatial extent. By means of the locally-constant field approximation (LCFA), we calculate the total particle yield for the corresponding four-dimensional setup and compare it with the estimates obtained for simplified low-dimensional scenarios. Within the domain where the LCFA is well justified, we examine a combination of two plane-wave pulses, a standing electromagnetic wave, and a spatially uniform oscillating field and demonstrate that at each of these three levels of approximation, one can accurately predict the actual particle number by multiplying the results by properly chosen volume factors depending on the field parameters. We present closed-form expressions for these factors providing universal prescriptions for evaluating the particle yield. Our final formula connecting the spatially uniform setup with the four-dimensional scenario has a relative uncertainty of the level of $5\%$. The explicit correspondences deduced in this study not only prove the relevance of the approximate predictions, but also allow one to quickly estimate the number of pairs for various realistic scenarios without performing complicated numerical calculations. |
1102.2777 | Juan Nieves Dr. | J. Nieves, I. Ruiz Simo and M. J. Vicente Vacas | Inclusive Charged--Current Neutrino--Nucleus Reactions | 25 pages, 19 figures | null | 10.1103/PhysRevC.83.045501 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a model for weak CC induced nuclear reactions at energies of
interest for current and future neutrino oscillation experiments. This model is
a natural extension of the work of Refs.[1,2], where the QE contribution to the
inclusive electron and neutrino scattering on nuclei was analyzed. The model is
based on a systematic many body expansion of the gauge boson absorption modes
that includes one, two and even three body mechanisms, as well as the
excitation of Delta isobars. The whole scheme has no free parameters, besides
those previously adjusted to the weak pion production off the nucleon cross
sections in the deuteron, since all nuclear effects were set up in previous
studies of photon, electron and pion interactions with nuclei. We have
discussed at length the recent charged current quasi-elastic MiniBooNE cross
section data, and showed that two nucleon knockout mechanisms are essential to
describe these measurements.
| [
{
"created": "Mon, 14 Feb 2011 14:22:20 GMT",
"version": "v1"
}
] | 2013-05-29 | [
[
"Nieves",
"J.",
""
],
[
"Simo",
"I. Ruiz",
""
],
[
"Vacas",
"M. J. Vicente",
""
]
] | We present a model for weak CC induced nuclear reactions at energies of interest for current and future neutrino oscillation experiments. This model is a natural extension of the work of Refs.[1,2], where the QE contribution to the inclusive electron and neutrino scattering on nuclei was analyzed. The model is based on a systematic many body expansion of the gauge boson absorption modes that includes one, two and even three body mechanisms, as well as the excitation of Delta isobars. The whole scheme has no free parameters, besides those previously adjusted to the weak pion production off the nucleon cross sections in the deuteron, since all nuclear effects were set up in previous studies of photon, electron and pion interactions with nuclei. We have discussed at length the recent charged current quasi-elastic MiniBooNE cross section data, and showed that two nucleon knockout mechanisms are essential to describe these measurements. |
hep-ph/9306310 | null | Adam F. Falk and Benjamin Grinstein | $\bar B\to\bar K\e^+\e^-$ in Chiral Perturbation Theory | 16 pages, 4 postscript figures appended, uses harvmac.tex,
SLAC-PUB-6237, SSCL-Preprint-422 | Nucl.Phys. B416 (1994) 771-785 | 10.1016/0550-3213(94)90554-1 | null | hep-ph | null | The combined use of chiral $SU(3)$ and heavy quark symmetries allows one to
relate the hadronic form factors for the decay $\bar B\to \bar K\e^+\e^-$ to
those for $\bar B\to\pi\e^-\bar\nu$. We investigate departures from the
symmetry limit which arise from chiral symmetry breaking. The analysis uses
chiral perturbation theory and the heavy quark limit to compute the relevant
hadronic matrix elements. We estimate the size of $SU(3)$ corrections by
computing, at one loop order, the leading nonanalytic dependence on the light
quark masses. The calculation is trustworthy only in the portion of the Dalitz
plot in which the momentum of the kaon or pion is small. We find the
corrections to be~$\sim40\%$.
| [
{
"created": "Thu, 24 Jun 1993 20:04:00 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Falk",
"Adam F.",
""
],
[
"Grinstein",
"Benjamin",
""
]
] | The combined use of chiral $SU(3)$ and heavy quark symmetries allows one to relate the hadronic form factors for the decay $\bar B\to \bar K\e^+\e^-$ to those for $\bar B\to\pi\e^-\bar\nu$. We investigate departures from the symmetry limit which arise from chiral symmetry breaking. The analysis uses chiral perturbation theory and the heavy quark limit to compute the relevant hadronic matrix elements. We estimate the size of $SU(3)$ corrections by computing, at one loop order, the leading nonanalytic dependence on the light quark masses. The calculation is trustworthy only in the portion of the Dalitz plot in which the momentum of the kaon or pion is small. We find the corrections to be~$\sim40\%$. |
hep-ph/9508203 | Gennaro Miele | G. Miele | Quantum Statistics and Parton Distributions | 20 pages, LaTeX, 8 epsfigures as uuencoded file. Contributed paper to
LP95 | null | null | DSF-34/95 | hep-ph | null | A novel approach to parton distributions parameterization in terms of quantum
statistical functions is here outlined. The description, already proposed in
previous publications, is here improved by adding to the statistical
distributions an unpolarized {\it liquid} component. This new contribution to
fermion partons is able to reproduce the expected low $x$ behaviour of
structure functions. The analysis provides a satisfactory description of
polarized and unpolarized deep inelastic data and shows a possible connection
between the Gottfried and Bjorken sum rules.
| [
{
"created": "Tue, 1 Aug 1995 12:08:55 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Miele",
"G.",
""
]
] | A novel approach to parton distributions parameterization in terms of quantum statistical functions is here outlined. The description, already proposed in previous publications, is here improved by adding to the statistical distributions an unpolarized {\it liquid} component. This new contribution to fermion partons is able to reproduce the expected low $x$ behaviour of structure functions. The analysis provides a satisfactory description of polarized and unpolarized deep inelastic data and shows a possible connection between the Gottfried and Bjorken sum rules. |
1205.3898 | Chun-Khiang Chua | Chun-Khiang Chua | Implications of Br(\mu -> e \gamma) and \Delta a_mu on Muonic Lepton
Flavor Violating Processes | 24 pages, 11 figures, version to appear in Phys. Rev. D | null | 10.1103/PhysRevD.86.093009 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the implications of the experimental results on the \mu -> e\gamma
decay rate and the muon anomalous magnetic moment, on muonic lepton flavor
violating processes, such as \mu -> 3 e and \mu N -> e N. We use a model
independent approach in this analysis, where these processes are considered to
be loop induced by exchanging spin 1/2 and spin 0 particles. We explore two
complementary cases, which has no or has an internal (built-in) cancellation
mechanism in amplitudes. Our main results are as following. (a) Bounds from
rates are used to constrain parameters, such as coupling constants and masses.
These constraints can be easily updated by simple scalings, if the experimental
situations change. (b) The muon g-2 data favors non-chiral interactions. (c) In
\mu -> 3 e and \mu N -> e N processes, Z-penguin diagrams may play some role,
while box diagrams contributions are usually highly constrained. (d) In the
first case (without any built-in cancellation mechanism), using the recent \mu
-> e\gamma bound, we find that \mu -> 3e and \mu N -> e N rates are bounded
below the present experimental limits by two to three orders of magnitudes in
general. Furthermore, by comparing \Delta a_\mu and Br(\mu->e\gamma) data, the
couplings of \mu and e are found to be highly hierarchical. Additional
suppression mechanism should be called for. (e) In the second case (with a
built-in cancellation mechanism), mixing angles can provide additional
suppression factors to satisfy the \Delta a_\mu and Br(\mu -> e\gamma) bounds.
While the \mu-> 3 e rate remains suppressed, the bounds on \mu N -> e N rates,
implicated from the latest \mu -> e\gamma bound, can be relaxed significantly
and can be just below the present experimental limits.
| [
{
"created": "Thu, 17 May 2012 10:28:54 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Oct 2012 14:25:30 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Chua",
"Chun-Khiang",
""
]
] | We study the implications of the experimental results on the \mu -> e\gamma decay rate and the muon anomalous magnetic moment, on muonic lepton flavor violating processes, such as \mu -> 3 e and \mu N -> e N. We use a model independent approach in this analysis, where these processes are considered to be loop induced by exchanging spin 1/2 and spin 0 particles. We explore two complementary cases, which has no or has an internal (built-in) cancellation mechanism in amplitudes. Our main results are as following. (a) Bounds from rates are used to constrain parameters, such as coupling constants and masses. These constraints can be easily updated by simple scalings, if the experimental situations change. (b) The muon g-2 data favors non-chiral interactions. (c) In \mu -> 3 e and \mu N -> e N processes, Z-penguin diagrams may play some role, while box diagrams contributions are usually highly constrained. (d) In the first case (without any built-in cancellation mechanism), using the recent \mu -> e\gamma bound, we find that \mu -> 3e and \mu N -> e N rates are bounded below the present experimental limits by two to three orders of magnitudes in general. Furthermore, by comparing \Delta a_\mu and Br(\mu->e\gamma) data, the couplings of \mu and e are found to be highly hierarchical. Additional suppression mechanism should be called for. (e) In the second case (with a built-in cancellation mechanism), mixing angles can provide additional suppression factors to satisfy the \Delta a_\mu and Br(\mu -> e\gamma) bounds. While the \mu-> 3 e rate remains suppressed, the bounds on \mu N -> e N rates, implicated from the latest \mu -> e\gamma bound, can be relaxed significantly and can be just below the present experimental limits. |
hep-ph/0601252 | Alfredo Valcarce | T. Fernandez-Carames, A. Valcarce, H. Garcilazo, P. Gonzalez | Strange tribaryons | 16 pages, 10 figures, 4 tables. Accepted for publication in Phys.
Rev. C | Phys.Rev.C73:034004,2006 | 10.1103/PhysRevC.73.034004 | null | hep-ph hep-ex nucl-th | null | We use two-body potentials derived from a constituent quark cluster model to
analyze the bound-state problem of the $\Sigma NN$ system. The observables of
the two-body subsystems, $NN$ and $\Sigma N$, are well reproduced. We do not
find $\Sigma NN$ bound states, but there are two attractive channels with a
resonance close above the three-body threshold. These channels are the
$(I,J)=(1,1/2)$ and $(0,1/2)$, their quantum numbers, widths and energy
ordering consistent with the recently measured strange tribaryons from the
$^{4}{\rm He}(K_{{\rm stopped}}^{-},N)$ reactions in the KEK PS E471
experiment.
| [
{
"created": "Mon, 30 Jan 2006 19:11:10 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Fernandez-Carames",
"T.",
""
],
[
"Valcarce",
"A.",
""
],
[
"Garcilazo",
"H.",
""
],
[
"Gonzalez",
"P.",
""
]
] | We use two-body potentials derived from a constituent quark cluster model to analyze the bound-state problem of the $\Sigma NN$ system. The observables of the two-body subsystems, $NN$ and $\Sigma N$, are well reproduced. We do not find $\Sigma NN$ bound states, but there are two attractive channels with a resonance close above the three-body threshold. These channels are the $(I,J)=(1,1/2)$ and $(0,1/2)$, their quantum numbers, widths and energy ordering consistent with the recently measured strange tribaryons from the $^{4}{\rm He}(K_{{\rm stopped}}^{-},N)$ reactions in the KEK PS E471 experiment. |
0809.3648 | Riazuddin Riazuddin | Riazuddin | Tribimaximal mixing and leptogenesis in a seesaw model | 8 pages, no figure | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is pointed out that if a neutrino mass matrix for right-handed neutrinos
in seesaw mechanism has mu -tau symmetry and total lepton number L_{e}+L_{\mu
}+L_{\tau} remains constant (not zero), exact tribimaximal neutrino mixing in
this sector is produced. The same follows for the effective Majorana light
neutrino mass matrix provided that Yukawa couplings (multiplied by the
corresponding Higgs vacuum expectation values) in Dirac mass matrix satisfy
some constraints which in general implies zero leptongenesis asymmetry. However
this can be avoided when two of the heavy right-hand neutrinos [the third one
is irrelevant when mu -tau symmetry is assumed] are (nearly) degenerate.
| [
{
"created": "Mon, 22 Sep 2008 08:17:53 GMT",
"version": "v1"
}
] | 2008-09-23 | [
[
"Riazuddin",
"",
""
]
] | It is pointed out that if a neutrino mass matrix for right-handed neutrinos in seesaw mechanism has mu -tau symmetry and total lepton number L_{e}+L_{\mu }+L_{\tau} remains constant (not zero), exact tribimaximal neutrino mixing in this sector is produced. The same follows for the effective Majorana light neutrino mass matrix provided that Yukawa couplings (multiplied by the corresponding Higgs vacuum expectation values) in Dirac mass matrix satisfy some constraints which in general implies zero leptongenesis asymmetry. However this can be avoided when two of the heavy right-hand neutrinos [the third one is irrelevant when mu -tau symmetry is assumed] are (nearly) degenerate. |
1805.05167 | Tobias Wistisen | Tobias N. Wistisen and Antonino Di Piazza | The impact of the quantized transverse motion on radiation emission in a
Dirac harmonic oscillator | null | Phys. Rev. A 98, 022131 (2018) | 10.1103/PhysRevA.98.022131 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the radiation emitted by an ultrarelativistic electron
traveling in a 1-dimensional parabolic potential. Having in mind a simplified
model for beamstrahlung, we consider the realistic case of the electron motion
being highly directional, with the transverse momentum being much smaller than
the longitudinal one. In this case we can find solutions of the Dirac equation
and we calculate exactly the radiation emission using first-order perturbation
theory. We compare the results obtained to that obtained via the semi-classical
method of Baier and Katkov which includes quantum effects due to photon recoil
in the radiation emission but ignores the quantum nature of the electron
motion. On the one hand, we confirm a prediction of the semi-classical method
that the emission spectrum should coincide with that in the case of a linearly
polarized monochromatic wave. On the other hand, however, we find that the
semi-classical method does not yield the exact result when the quantum number
describing the transverse motion becomes small. In this way, we address
quantitatively the problem of the limits of validity of the semi-classical
method, which is known, generally speaking, to be applicable for large quantum
numbers. Finally, we also discuss which beam conditions would be necessary to
enter the studied regime where also the motion of the particles must be
considered quantum mechanically to yield the correct spectrum.
| [
{
"created": "Mon, 14 May 2018 13:34:31 GMT",
"version": "v1"
}
] | 2018-08-29 | [
[
"Wistisen",
"Tobias N.",
""
],
[
"Di Piazza",
"Antonino",
""
]
] | We investigate the radiation emitted by an ultrarelativistic electron traveling in a 1-dimensional parabolic potential. Having in mind a simplified model for beamstrahlung, we consider the realistic case of the electron motion being highly directional, with the transverse momentum being much smaller than the longitudinal one. In this case we can find solutions of the Dirac equation and we calculate exactly the radiation emission using first-order perturbation theory. We compare the results obtained to that obtained via the semi-classical method of Baier and Katkov which includes quantum effects due to photon recoil in the radiation emission but ignores the quantum nature of the electron motion. On the one hand, we confirm a prediction of the semi-classical method that the emission spectrum should coincide with that in the case of a linearly polarized monochromatic wave. On the other hand, however, we find that the semi-classical method does not yield the exact result when the quantum number describing the transverse motion becomes small. In this way, we address quantitatively the problem of the limits of validity of the semi-classical method, which is known, generally speaking, to be applicable for large quantum numbers. Finally, we also discuss which beam conditions would be necessary to enter the studied regime where also the motion of the particles must be considered quantum mechanically to yield the correct spectrum. |
hep-ph/9602246 | null | M.Genovese, N.N.Nikolaev, B.G.Zakharov | Factorization properties of the diffraction dissociation of longitudinal
photons | 11 pages | Phys.Lett. B380 (1996) 213-219 | 10.1016/0370-2693(96)00478-9 | DFTT 5/96, KFA-IKP(Th)-1996-1 | hep-ph | null | We develop the pQCD description of the diffraction dissociation (DD) of
longitudinal photons. We demonstrate that the longitudinal diffractive
structure function does not factor into the flux of pomerons and the partonic
structure function of the pomeron, thus defying the usually assumed Regge
factorization. In contrast to DD of the transverse photons, DD of the
longitudinal photons is strongly peaked at $\beta =1$. We comment on duality
properties of DD in deep inelastic scattering.
| [
{
"created": "Wed, 7 Feb 1996 15:14:29 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Genovese",
"M.",
""
],
[
"Nikolaev",
"N. N.",
""
],
[
"Zakharov",
"B. G.",
""
]
] | We develop the pQCD description of the diffraction dissociation (DD) of longitudinal photons. We demonstrate that the longitudinal diffractive structure function does not factor into the flux of pomerons and the partonic structure function of the pomeron, thus defying the usually assumed Regge factorization. In contrast to DD of the transverse photons, DD of the longitudinal photons is strongly peaked at $\beta =1$. We comment on duality properties of DD in deep inelastic scattering. |
1712.00085 | Alexander Titov I. | Sang-Ho Kim, Yongseok Oh, and Alexander I. Titov | Decay angular distributions of $K^*$ and $D^*$ mesons as a tool for the
dynamics of open strange and charm production | Talk at 11th APCTP-BLTP(JINR)-PNPI(SPbU) Joint Workshop, Petergof,
St.Petersburg, Jul 2017, 5pp | null | 10.1134/S1547477118040131 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze decay spin-density matrix elements of $K^*$ and $D^*$ vector
mesons and find that the corresponding vector meson decay distributions are
sensitive to the production mechanisms. This suggests that the measurement of
these quantities can be used to unravel the production mechanisms.
| [
{
"created": "Thu, 30 Nov 2017 21:16:59 GMT",
"version": "v1"
}
] | 2018-08-01 | [
[
"Kim",
"Sang-Ho",
""
],
[
"Oh",
"Yongseok",
""
],
[
"Titov",
"Alexander I.",
""
]
] | We analyze decay spin-density matrix elements of $K^*$ and $D^*$ vector mesons and find that the corresponding vector meson decay distributions are sensitive to the production mechanisms. This suggests that the measurement of these quantities can be used to unravel the production mechanisms. |
0908.3287 | Schoeffel Laurent | Laurent Schoeffel (CEA Saclay/Irfu-SPP, France) | Advances in diffraction of subnuclear waves | 64 pages, 62 figures, review To be published in Progress in Particle
and Nuclear Physics | Prog.Part.Nucl.Phys.65:9-49,2010 | 10.1016/j.ppnp.2010.02.002 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this review, we present and discuss the most recent results on inclusive
and exclusive diffractive processes at HERA and Tevatron colliders.
Measurements from fixed target experiments at HERMES and Jefferson laboratory
are also reviewed. The complementarity of all these results is analysed in the
context of perturbative QCD and new challenging issues in nucleon tomography
are studied. A first understanding of how partons are localised in the nucleon
to build orbital momenta can be addressed with these experimental results. Some
prospects are outlined for new measurements in fixed target kinematic, at
Jefferson laboratory and CERN, at COMPASS, or at the LHC. Of special interest
is the exclusive (coherent) production of Higgs boson and heavy objects at the
LHC. Based on the present knowledge, some perspectives are presented in this
direction.
| [
{
"created": "Sun, 23 Aug 2009 08:08:27 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Aug 2009 07:44:22 GMT",
"version": "v2"
},
{
"created": "Tue, 22 Sep 2009 15:59:51 GMT",
"version": "v3"
}
] | 2012-07-04 | [
[
"Schoeffel",
"Laurent",
"",
"CEA Saclay/Irfu-SPP, France"
]
] | In this review, we present and discuss the most recent results on inclusive and exclusive diffractive processes at HERA and Tevatron colliders. Measurements from fixed target experiments at HERMES and Jefferson laboratory are also reviewed. The complementarity of all these results is analysed in the context of perturbative QCD and new challenging issues in nucleon tomography are studied. A first understanding of how partons are localised in the nucleon to build orbital momenta can be addressed with these experimental results. Some prospects are outlined for new measurements in fixed target kinematic, at Jefferson laboratory and CERN, at COMPASS, or at the LHC. Of special interest is the exclusive (coherent) production of Higgs boson and heavy objects at the LHC. Based on the present knowledge, some perspectives are presented in this direction. |
1503.08836 | Jun Gao | Edmond L. Berger, Jun Gao, Zhong-Bo Kang, Jian-Wei Qiu, Hao Zhang | Hadronic production of $W$ and $Z$ bosons at large transverse momentum | 14 pages, 12 figures; matches journal version | Phys. Rev. D 91, 113001 (2015) | 10.1103/PhysRevD.91.113001 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce a modified factorization formalism in quantum chromodynamics for
hadronic production of $W$ and $Z$ bosons at large transverse momentum $p_T$.
When $p_T$ is much larger than the invariant mass $Q$ of the vector boson, this
new factorization formalism systematically resums the large fragmentation
logarithms, $\alpha_s^m\ln^m(p_T^2/Q^2)$, to all orders in the strong coupling
$\alpha_s$. Using our modified factorization formalism, we calculate the
next-to-leading order (NLO) predictions for $W$ and $Z$ boson production at
high $p_T$ at the CERN Large Hadron Collider and at a future 100 TeV
proton-proton collider. Our NLO results are about $5\%$ larger in
normalization, and they show improved convergence and moderate reduction of the
scale variation compared to the NLO predictions derived in a conventional
fixed-order perturbative expansion.
| [
{
"created": "Mon, 30 Mar 2015 20:00:36 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Jun 2015 22:16:40 GMT",
"version": "v2"
}
] | 2015-06-10 | [
[
"Berger",
"Edmond L.",
""
],
[
"Gao",
"Jun",
""
],
[
"Kang",
"Zhong-Bo",
""
],
[
"Qiu",
"Jian-Wei",
""
],
[
"Zhang",
"Hao",
""
]
] | We introduce a modified factorization formalism in quantum chromodynamics for hadronic production of $W$ and $Z$ bosons at large transverse momentum $p_T$. When $p_T$ is much larger than the invariant mass $Q$ of the vector boson, this new factorization formalism systematically resums the large fragmentation logarithms, $\alpha_s^m\ln^m(p_T^2/Q^2)$, to all orders in the strong coupling $\alpha_s$. Using our modified factorization formalism, we calculate the next-to-leading order (NLO) predictions for $W$ and $Z$ boson production at high $p_T$ at the CERN Large Hadron Collider and at a future 100 TeV proton-proton collider. Our NLO results are about $5\%$ larger in normalization, and they show improved convergence and moderate reduction of the scale variation compared to the NLO predictions derived in a conventional fixed-order perturbative expansion. |
2003.14289 | Johannes Bl\"umlein | J. Bl\"umlein, A. De Freitas, C. Raab, and K. Sch\"onwald | The $O(\alpha^2)$ Initial State QED Corrections to $e^+e^- \rightarrow
\gamma^*/Z_0^*$ | 32 pages Latex, several figures | null | 10.1016/j.nuclphysb.2020.115055 | DESY 18--196, DO--TH 19/31, TTP 19--045, SAGEX 19--34 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the complete $O(\alpha^2)$ initial state radiation corrections
to $e^+ e^-$ annihilation into a neutral vector boson in a direct analytic
computation without any approximation. The corrections are represented in terms
of iterated incomplete (elliptic) integrals over alphabets of square--root
valued letters. Performing the limit $s \gg m_e^2$, we find discrepancies with
the earlier results of Ref.~\cite{Berends:1987ab} and confirm results obtained
in Ref.~\cite{Blumlein:2011mi} where the effective method of massive operator
matrix elements has been used, which works for all but the power corrections in
$m^2_e/s$. In this way, we also confirm the validity of the factorization of
massive partons in the Drell--Yan process. We add non--logarithmic terms at
$O(\alpha^2)$ which have not been considered in previous calculations. The
final results in the limit $s \gg m_e^2$ can be given in terms of Nielsen
integrals.
| [
{
"created": "Tue, 31 Mar 2020 15:22:52 GMT",
"version": "v1"
}
] | 2020-06-24 | [
[
"Blümlein",
"J.",
""
],
[
"De Freitas",
"A.",
""
],
[
"Raab",
"C.",
""
],
[
"Schönwald",
"K.",
""
]
] | We calculate the complete $O(\alpha^2)$ initial state radiation corrections to $e^+ e^-$ annihilation into a neutral vector boson in a direct analytic computation without any approximation. The corrections are represented in terms of iterated incomplete (elliptic) integrals over alphabets of square--root valued letters. Performing the limit $s \gg m_e^2$, we find discrepancies with the earlier results of Ref.~\cite{Berends:1987ab} and confirm results obtained in Ref.~\cite{Blumlein:2011mi} where the effective method of massive operator matrix elements has been used, which works for all but the power corrections in $m^2_e/s$. In this way, we also confirm the validity of the factorization of massive partons in the Drell--Yan process. We add non--logarithmic terms at $O(\alpha^2)$ which have not been considered in previous calculations. The final results in the limit $s \gg m_e^2$ can be given in terms of Nielsen integrals. |
hep-ph/9708235 | null | W. Roberts (Old Dominion University, JLAB), B. Silvestre-Brac
(Institut des Sciences Nucleaires) | Meson Decays In A Quark Model | 13 pages, RevTeX. 2 postscript figures, uses epsf | Phys.Rev. D57 (1998) 1694-1702 | 10.1103/PhysRevD.57.1694 | JLAB-TH-97-30 | hep-ph | null | A recent model of hadron states is extended to include meson decays. We find
that the overall success of the model is quite good. Possible improvements to
the model are suggested.
| [
{
"created": "Mon, 4 Aug 1997 19:36:14 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Roberts",
"W.",
"",
"Old Dominion University, JLAB"
],
[
"Silvestre-Brac",
"B.",
"",
"Institut des Sciences Nucleaires"
]
] | A recent model of hadron states is extended to include meson decays. We find that the overall success of the model is quite good. Possible improvements to the model are suggested. |
1003.4361 | Yao-Yuan Mao | Wei-Shu Hou, Yao-Yuan Mao, Chia-Hsien Shen | Leading Effect of CP Violation with Four Generations | 12 pages, no figure | Phys.Rev.D82:036005,2010 | 10.1103/PhysRevD.82.036005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the Standard Model with a fourth generation of quarks, we study the
relation between the Jarlskog invariants and the triangle areas in the 4-by-4
CKM matrix. To identify the leading effects that may probe the CP violation in
processes involving quarks, we invoke small mass and small angle expansions,
and show that these leading effects are enhanced considerably compared to the
three generation case by the large masses of fourth generation quarks. We
discuss the leading effect in several cases, in particular the possibility of
large CP violation in $ b \to s $ processes, which echoes the heightened recent
interest because of experimental hints.
| [
{
"created": "Tue, 23 Mar 2010 09:56:30 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Jun 2010 07:09:23 GMT",
"version": "v2"
},
{
"created": "Mon, 27 Sep 2010 00:19:59 GMT",
"version": "v3"
}
] | 2010-09-28 | [
[
"Hou",
"Wei-Shu",
""
],
[
"Mao",
"Yao-Yuan",
""
],
[
"Shen",
"Chia-Hsien",
""
]
] | In the Standard Model with a fourth generation of quarks, we study the relation between the Jarlskog invariants and the triangle areas in the 4-by-4 CKM matrix. To identify the leading effects that may probe the CP violation in processes involving quarks, we invoke small mass and small angle expansions, and show that these leading effects are enhanced considerably compared to the three generation case by the large masses of fourth generation quarks. We discuss the leading effect in several cases, in particular the possibility of large CP violation in $ b \to s $ processes, which echoes the heightened recent interest because of experimental hints. |
1401.8216 | Francesca Aceti | F. Aceti, M. Bayar, E. Oset, A. Martinez Torres, K. P. Khemchandani,
J. M. Dias, F. S. Navarra and M. Nielsen | Prediction of an $I=1$ $D \bar D^*$ state and relationship to the
claimed $Z_c(3900)$, $Z_c(3885)$ | arXiv admin note: text overlap with arXiv:1401.2076 | Phys. Rev. D 90, 016003 (2014) | 10.1103/PhysRevD.90.016003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study here the interaction of $D \bar D^*$ in the isospin $I=1$ channel in
the light of recent theoretical advances that allow to combine elements of the
local hidden gauge approach with heavy quark spin symmetry. We find that the
exchange of light $q \bar q$ is OZI suppressed and, thus, we concentrate on the
exchange of heavy vectors and of two pion exchange. The latter is found to be
small compared to the exchange of heavy vectors, which then determines the
strength of the interaction. A barely $D\bar{D}^*$ bound state decaying into
$\eta_c\rho$ and $\pi J/\psi$ is found. At the same time we reanalyze the data
of the BESIII experiment on $e^+ e^- \to \pi^{\pm} (D \bar D^*)^\mp$, from
where a $Z_c(3885)$ state was claimed, associated to a peak in the $(D \bar
D^*)^\mp$ invariant mass distribution close to threshold, and we find the data
compatible with a resonance with mass around $3875$ MeV and width around $30$
MeV. We discuss the possibility that this and the $Z_c(3900)$ state found at
BESIII, reconfirmed at 3896 MeV at Belle, or 3885 MeV at CLEO, could all be the
same state and correspond to the one that we find theoretically.
| [
{
"created": "Fri, 31 Jan 2014 16:21:39 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Sep 2014 15:16:49 GMT",
"version": "v2"
}
] | 2014-09-17 | [
[
"Aceti",
"F.",
""
],
[
"Bayar",
"M.",
""
],
[
"Oset",
"E.",
""
],
[
"Torres",
"A. Martinez",
""
],
[
"Khemchandani",
"K. P.",
""
],
[
"Dias",
"J. M.",
""
],
[
"Navarra",
"F. S.",
""
],
[
"Nielsen",
... | We study here the interaction of $D \bar D^*$ in the isospin $I=1$ channel in the light of recent theoretical advances that allow to combine elements of the local hidden gauge approach with heavy quark spin symmetry. We find that the exchange of light $q \bar q$ is OZI suppressed and, thus, we concentrate on the exchange of heavy vectors and of two pion exchange. The latter is found to be small compared to the exchange of heavy vectors, which then determines the strength of the interaction. A barely $D\bar{D}^*$ bound state decaying into $\eta_c\rho$ and $\pi J/\psi$ is found. At the same time we reanalyze the data of the BESIII experiment on $e^+ e^- \to \pi^{\pm} (D \bar D^*)^\mp$, from where a $Z_c(3885)$ state was claimed, associated to a peak in the $(D \bar D^*)^\mp$ invariant mass distribution close to threshold, and we find the data compatible with a resonance with mass around $3875$ MeV and width around $30$ MeV. We discuss the possibility that this and the $Z_c(3900)$ state found at BESIII, reconfirmed at 3896 MeV at Belle, or 3885 MeV at CLEO, could all be the same state and correspond to the one that we find theoretically. |
2312.11427 | Le Tho Hue | T. T. Hong, Q.Duyet Tran, T. Phong Nguyen, L.T. Hue and N.H.T. Nha | $(g-2)_{e,\mu}$ anomalies and decays $h\to e_a e_b$, $Z\to e_ae_b$, and
$e_b\to e_a \gamma$ in a two Higgs doublet model with inverse seesaw
neutrinos | Version accepted for publication in EPJC | null | null | null | hep-ph | http://creativecommons.org/publicdomain/zero/1.0/ | The lepton flavor violating decays $h\to e_b^\pm e_a^\mp $, $Z\to e_b^\pm
e_a^\mp$, and $e_b\to e_a \gamma$ will be discussed in the framework of the Two
Higgs doublet model with presence of new inverse seesaw neutrinos and a singly
charged Higgs boson that accommodate both $1\sigma$ experimental data of
$(g-2)$ anomalies of the muon and electron. Numerical results indicate that
there exist regions of the parameter space supporting all experimental data of
$(g-2)_{e,\mu}$ as well as the promising LFV signals corresponding to the
future experimental sensitivities.
| [
{
"created": "Mon, 18 Dec 2023 18:31:27 GMT",
"version": "v1"
},
{
"created": "Thu, 28 Mar 2024 12:05:44 GMT",
"version": "v2"
}
] | 2024-03-29 | [
[
"Hong",
"T. T.",
""
],
[
"Tran",
"Q. Duyet",
""
],
[
"Nguyen",
"T. Phong",
""
],
[
"Hue",
"L. T.",
""
],
[
"Nha",
"N. H. T.",
""
]
] | The lepton flavor violating decays $h\to e_b^\pm e_a^\mp $, $Z\to e_b^\pm e_a^\mp$, and $e_b\to e_a \gamma$ will be discussed in the framework of the Two Higgs doublet model with presence of new inverse seesaw neutrinos and a singly charged Higgs boson that accommodate both $1\sigma$ experimental data of $(g-2)$ anomalies of the muon and electron. Numerical results indicate that there exist regions of the parameter space supporting all experimental data of $(g-2)_{e,\mu}$ as well as the promising LFV signals corresponding to the future experimental sensitivities. |
hep-ph/9709359 | Guest Account | S.V.Goloskokov | Spin Effects In Diffractive High-Energy Reactions | 6 pages, Latex, 4 PS Figures included. Talk at the 7 International
Seminar Spin97, July 7-12, Dubna, 1997 | null | null | null | hep-ph | null | Spin effects in diffractive $pp$ and $lp$ reactions are analyzed. It is shown
that the structure of the pomeron coupling can be studied in future polarized
experiments.
| [
{
"created": "Tue, 16 Sep 1997 11:26:44 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Goloskokov",
"S. V.",
""
]
] | Spin effects in diffractive $pp$ and $lp$ reactions are analyzed. It is shown that the structure of the pomeron coupling can be studied in future polarized experiments. |
1510.04872 | Dmitry Zhuridov Dr. | Tomasz Jeli\'nski and Dmitry Zhuridov | Leptogluons in dilepton production at LHC | 7 pages, 4 figures. Proceedings to the conference "Matter to the
Deepest", Ustro\'n, Poland, September 13-18, 2015 | Acta Phys.Polon. B46 (2015) 11, 2185 | 10.5506/APhysPolB.46.2185 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the composite models with colored substructure of the fermions the color
singlet leptons are accompanied by a composite color octet partners, which are
known as leptogluons. We consider the effect of leptogluons in the dilepton
production at the LHC and show that in the reachable parameter range this
effect is typically dominated by t-channel leptogluon exchange (indirect
channel). We show that this channel alone can give a sizable contribution to
the dimuon production at the LHC for TeV scale values of the invariant mass of
the muon-antimuon pairs.
| [
{
"created": "Fri, 16 Oct 2015 13:14:02 GMT",
"version": "v1"
}
] | 2016-02-15 | [
[
"Jeliński",
"Tomasz",
""
],
[
"Zhuridov",
"Dmitry",
""
]
] | In the composite models with colored substructure of the fermions the color singlet leptons are accompanied by a composite color octet partners, which are known as leptogluons. We consider the effect of leptogluons in the dilepton production at the LHC and show that in the reachable parameter range this effect is typically dominated by t-channel leptogluon exchange (indirect channel). We show that this channel alone can give a sizable contribution to the dimuon production at the LHC for TeV scale values of the invariant mass of the muon-antimuon pairs. |
1007.2619 | Astrid Eichhorn | Jens Braun, Astrid Eichhorn, Holger Gies and Jan M. Pawlowski | On the Nature of the Phase Transition in SU(N), Sp(2) and E(7)
Yang-Mills theory | 15 pages | Eur.Phys.J.C70:689-702,2010 | 10.1140/epjc/s10052-010-1485-1 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the nature of the confinement phase transition in d=3+1 dimensions
in various non-abelian gauge theories with the approach put forward in [1]. We
compute an order-parameter potential associated with the Polyakov loop from the
knowledge of full 2-point correlation functions. For SU(N) with N=3,...,12 and
Sp(2) we find a first-order phase transition in agreement with general
expectations. Moreover our study suggests that the phase transition in E(7)
Yang-Mills theory also is of first order. We find that it is weaker than for
SU(N). We show that this can be understood in terms of the eigenvalue
distribution of the order parameter potential close to the phase transition.
| [
{
"created": "Thu, 15 Jul 2010 17:20:24 GMT",
"version": "v1"
}
] | 2010-12-15 | [
[
"Braun",
"Jens",
""
],
[
"Eichhorn",
"Astrid",
""
],
[
"Gies",
"Holger",
""
],
[
"Pawlowski",
"Jan M.",
""
]
] | We study the nature of the confinement phase transition in d=3+1 dimensions in various non-abelian gauge theories with the approach put forward in [1]. We compute an order-parameter potential associated with the Polyakov loop from the knowledge of full 2-point correlation functions. For SU(N) with N=3,...,12 and Sp(2) we find a first-order phase transition in agreement with general expectations. Moreover our study suggests that the phase transition in E(7) Yang-Mills theory also is of first order. We find that it is weaker than for SU(N). We show that this can be understood in terms of the eigenvalue distribution of the order parameter potential close to the phase transition. |
hep-ph/0505246 | Alexander Sidorov Viktorovich | A. V. Sidorov (JINR, BLTP, Dubna) | On the Relation Between x-dependence of the Higher Twist Contribution to
F_3 and g_1^p - g_1^n | 6 pages, 3 figures | Phys.Part.Nucl.Lett. 3N2 (2006) 69-71; Pisma
Fiz.Elem.Chast.Atom.Yadra 3N2 (2006) 7-11 | 10.1134/S1547477106020014 | null | hep-ph | null | We compare the higher twist (HT) contribution to the unpolarized structure
function $F_3$ with that one to the nonsinglet combination g_1^p - g_1^n of the
polarized proton and neutron structure functions using the assumption that the
HT contributions to the Gross-Llewellyn Smith and the Bjorken sum rules are
similar. We have found, that the relation 1/3x h^{xF_3}(x) ~ 6/g_A h^{g_1^p -
g_1^n}(x) is valid for x > 0.1 and for x > 0.2 in the case of LO and NLO QCD
approximations, respectively.
| [
{
"created": "Mon, 30 May 2005 08:40:53 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Sidorov",
"A. V.",
"",
"JINR, BLTP, Dubna"
]
] | We compare the higher twist (HT) contribution to the unpolarized structure function $F_3$ with that one to the nonsinglet combination g_1^p - g_1^n of the polarized proton and neutron structure functions using the assumption that the HT contributions to the Gross-Llewellyn Smith and the Bjorken sum rules are similar. We have found, that the relation 1/3x h^{xF_3}(x) ~ 6/g_A h^{g_1^p - g_1^n}(x) is valid for x > 0.1 and for x > 0.2 in the case of LO and NLO QCD approximations, respectively. |
1305.5420 | German Valencia | Xiao-Gang He, Yong Tang and German Valencia | Interplay between new physics in one-loop Higgs couplings and the
top-quark Yukawa coupling | 14 pages, 5 figures | null | 10.1103/PhysRevD.88.033005 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | After the discovery of a 126 GeV state at the LHC it is imperative to
establish whether this particle really is the Higgs boson of the standard
model. The early measurements have not yet pinpointed any of the Higgs
couplings to fermions, the Yukawa couplings of the standard model. In this
paper we study the values of the top-quark-Higgs coupling, $g_{ht\bar{t}}$,
that are still allowed by the one-loop couplings of the Higgs to two gluons or
two photons. We first assume that both the gluon fusion production of the Higgs
and its decay into two photons proceed through loops with standard model
particles only, albeit with an arbitrary top-Higgs coupling. We find that the
current Higgs data still allows for 20% deviations in $g_{ht\bar{t}}$ from its
standard model value. We then investigate the effect of new particles
contributing to the effective one-loop couplings. Specifically we consider a
color octet electroweak doublet extension of the scalar sector and find that in
this case $g_{ht\bar{t}}$ is allowed to deviate by 40% from its standard model
value by the current data.
| [
{
"created": "Thu, 23 May 2013 13:53:52 GMT",
"version": "v1"
}
] | 2013-08-21 | [
[
"He",
"Xiao-Gang",
""
],
[
"Tang",
"Yong",
""
],
[
"Valencia",
"German",
""
]
] | After the discovery of a 126 GeV state at the LHC it is imperative to establish whether this particle really is the Higgs boson of the standard model. The early measurements have not yet pinpointed any of the Higgs couplings to fermions, the Yukawa couplings of the standard model. In this paper we study the values of the top-quark-Higgs coupling, $g_{ht\bar{t}}$, that are still allowed by the one-loop couplings of the Higgs to two gluons or two photons. We first assume that both the gluon fusion production of the Higgs and its decay into two photons proceed through loops with standard model particles only, albeit with an arbitrary top-Higgs coupling. We find that the current Higgs data still allows for 20% deviations in $g_{ht\bar{t}}$ from its standard model value. We then investigate the effect of new particles contributing to the effective one-loop couplings. Specifically we consider a color octet electroweak doublet extension of the scalar sector and find that in this case $g_{ht\bar{t}}$ is allowed to deviate by 40% from its standard model value by the current data. |
hep-ph/9710331 | Robert Fleischer | Robert Fleischer (CERN) | Towards Extractions of the CKM Angle $\gamma$ from $B_{u,d}\to\pi K$ and
Untagged $B_s\to K\bar{K}$ Decays | 34 pages, LaTeX, 12 figures, extended version including a detailed
discussion of rescattering and electroweak penguin effects | Phys.Rev.D58:093001,1998 | 10.1103/PhysRevD.58.093001 | CERN-TH/97-281 | hep-ph | null | The decays $B_d\to\pi^\mp K^\pm$ and $B^\pm\to\pi^\pm K$ provide interesting
constraints on the angle $\gamma$ of the unitarity triangle of the CKM matrix.
It is shown that bounds on $\gamma$ can also be obtained from the time
evolution of untagged $B_s\to K^+K^-$ and $B_s\to K^0\bar{K^0}$ decays,
provided the $B_s$ system exhibits a sizeable width difference
$\Delta\Gamma_s$. A detailed discussion of rescattering processes and
electroweak penguin effects, which limit the theoretical accuracy of these
constraints, and of methods to control them through experimental data is given.
Moreover, strategies are pointed out to go beyond these bounds by relating the
$B_{u,d}\to\pi K$ and untagged $B_s\to K\bar{K}$ decays through the SU(3)
flavour symmetry of strong interactions. If a tagged, time-dependent
measurement of the $B_s\to K^+K^-$ and $B_s\to K^0\bar{K^0}$ modes should
become possible, $\gamma$ could be determined from the corresponding
observables in a way that makes use of only the SU(2) isospin symmetry and
takes into account rescattering effects ``automatically''. The impact of
new-physics contributions to $B^0_s - \bar{B^0_s}$ mixing is also analysed, and
interesting features arising in such a scenario of physics beyond the Standard
Model are pointed out.
| [
{
"created": "Mon, 13 Oct 1997 14:17:36 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Apr 1998 13:39:07 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Fleischer",
"Robert",
"",
"CERN"
]
] | The decays $B_d\to\pi^\mp K^\pm$ and $B^\pm\to\pi^\pm K$ provide interesting constraints on the angle $\gamma$ of the unitarity triangle of the CKM matrix. It is shown that bounds on $\gamma$ can also be obtained from the time evolution of untagged $B_s\to K^+K^-$ and $B_s\to K^0\bar{K^0}$ decays, provided the $B_s$ system exhibits a sizeable width difference $\Delta\Gamma_s$. A detailed discussion of rescattering processes and electroweak penguin effects, which limit the theoretical accuracy of these constraints, and of methods to control them through experimental data is given. Moreover, strategies are pointed out to go beyond these bounds by relating the $B_{u,d}\to\pi K$ and untagged $B_s\to K\bar{K}$ decays through the SU(3) flavour symmetry of strong interactions. If a tagged, time-dependent measurement of the $B_s\to K^+K^-$ and $B_s\to K^0\bar{K^0}$ modes should become possible, $\gamma$ could be determined from the corresponding observables in a way that makes use of only the SU(2) isospin symmetry and takes into account rescattering effects ``automatically''. The impact of new-physics contributions to $B^0_s - \bar{B^0_s}$ mixing is also analysed, and interesting features arising in such a scenario of physics beyond the Standard Model are pointed out. |
hep-ph/0409287 | Elena G. Ferreiro | Elena G. Ferreiro | Large transverse momentum suppression at RHIC: Shadowing and absorption | 6 pages, 2 figures. Contribution to the 8th Workshop on
Non-Perturbative Quantum Chromodynamics, June 7-11, 2004, l'Institut
Astrophysique de Paris, France | Int.J.Mod.Phys. A20 (2005) 4456-4461 | 10.1142/S0217751X05028065 | null | hep-ph | null | We propose a model of suppression of $\pi^0$'s based on two different
effects: at low $p_T$ we take into account the shadowing corrections, which are
non-linear and essential for the description of the inclusive spectra, while at
large $p_T$ the suppression is produced through the interaction of the large
$p_T$ pion with the dense medium created in the collision. The main features of
the data on $AuAu$ and $dAu$ collisions at RHIC energies are reproduced both at
mid and at forward rapidities.
| [
{
"created": "Fri, 24 Sep 2004 15:47:27 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Ferreiro",
"Elena G.",
""
]
] | We propose a model of suppression of $\pi^0$'s based on two different effects: at low $p_T$ we take into account the shadowing corrections, which are non-linear and essential for the description of the inclusive spectra, while at large $p_T$ the suppression is produced through the interaction of the large $p_T$ pion with the dense medium created in the collision. The main features of the data on $AuAu$ and $dAu$ collisions at RHIC energies are reproduced both at mid and at forward rapidities. |
2107.07399 | Alexander Millar | Alexander J. Millar, Sebastian Baum, Matthew Lawson, M.C. David Marsh | Axion-photon conversion in strongly magnetised plasmas | v3: Matches published version. 27 pages, 4 figures | JCAP 11, 013 (2021) | 10.1088/1475-7516/2021/11/013 | NORDITA 2021-064 | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | Axion dark matter can resonantly convert to photons in the magnetosphere of
neutron stars, possibly giving rise to radio signals observable on Earth. This
method for the indirect detection of axion dark matter has recently received
significant attention in the literature. The calculation of the radio signal is
complicated by a number of effects; most importantly, the gravitational infall
of the axions onto the neutron star accelerates them to semi-relativistic
speed, and the neutron star magnetosphere is highly anisotropic. Both of these
factors complicate the calculation of the conversion of axions to photons. In
this work, we present the first fully three-dimensional calculation of the
axion-photon conversion in highly magnetised anisotropic media. Depending on
the axion trajectory, this calculation leads to orders-of-magnitude differences
in the conversion compared to the simplified one-dimensional calculation used
so far in the literature, altering the directionality of the produced photons.
Our results will have important implications for the radio signal one would
observe in a telescope.
| [
{
"created": "Thu, 15 Jul 2021 15:30:08 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Jul 2021 08:15:06 GMT",
"version": "v2"
},
{
"created": "Tue, 9 Nov 2021 20:24:25 GMT",
"version": "v3"
}
] | 2021-11-11 | [
[
"Millar",
"Alexander J.",
""
],
[
"Baum",
"Sebastian",
""
],
[
"Lawson",
"Matthew",
""
],
[
"Marsh",
"M. C. David",
""
]
] | Axion dark matter can resonantly convert to photons in the magnetosphere of neutron stars, possibly giving rise to radio signals observable on Earth. This method for the indirect detection of axion dark matter has recently received significant attention in the literature. The calculation of the radio signal is complicated by a number of effects; most importantly, the gravitational infall of the axions onto the neutron star accelerates them to semi-relativistic speed, and the neutron star magnetosphere is highly anisotropic. Both of these factors complicate the calculation of the conversion of axions to photons. In this work, we present the first fully three-dimensional calculation of the axion-photon conversion in highly magnetised anisotropic media. Depending on the axion trajectory, this calculation leads to orders-of-magnitude differences in the conversion compared to the simplified one-dimensional calculation used so far in the literature, altering the directionality of the produced photons. Our results will have important implications for the radio signal one would observe in a telescope. |
1608.02540 | Jihn E. Kim | Jihn E. Kim | Gravity wave and model-independent axion | 4 pages of TeX file | J. Korean Phys. Soc. 71, 127 (2017) | 10.3938/jkps.71.127 | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this short comment, we notice that the model-independent axion
contribution to the graviton mass at just outside the Schwarzschild radius is
completely negligible in GW150914. The model-independent axion contribution to
the graviton mass at the order $10^{-22}\,$eV might be possible for merger of
black holes of mass of order $2\times 10^{14}\,$kg.
| [
{
"created": "Mon, 8 Aug 2016 18:22:07 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Apr 2017 21:27:33 GMT",
"version": "v2"
}
] | 2017-08-11 | [
[
"Kim",
"Jihn E.",
""
]
] | In this short comment, we notice that the model-independent axion contribution to the graviton mass at just outside the Schwarzschild radius is completely negligible in GW150914. The model-independent axion contribution to the graviton mass at the order $10^{-22}\,$eV might be possible for merger of black holes of mass of order $2\times 10^{14}\,$kg. |
hep-ph/0311173 | Marco Radici | Alessandro Bacchetta and Marco Radici | Two-hadron semi-inclusive production including subleading twist | 16 pages, RevTeX4, 5 figures, revised notation of several formulae,
added text in Secs. III-V, added references | Phys.Rev. D69 (2004) 074026 | 10.1103/PhysRevD.69.074026 | null | hep-ph | null | We extend the analysis of two-hadron fragmentation functions to the
subleading twist, discussing also the issue of color gauge invariance. Our
results can be used anywhere two unpolarized hadrons are semi-inclusively
produced in the same fragmentation region, also at moderate values of the hard
scale Q. Here, we consider the example of polarized deep-inelastic production
of two hadrons and we give a complete list of cross sections and spin
asymmetries up to subleading twist. Among the results, we highlight the
possibility of extracting the transversity distribution with longitudinally
polarized targets and also the twist-3 distribution e(x), which is related to
the pion-nucleon sigma term and to the strangeness content of the nucleon.
| [
{
"created": "Thu, 13 Nov 2003 17:49:31 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Dec 2003 10:01:09 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Bacchetta",
"Alessandro",
""
],
[
"Radici",
"Marco",
""
]
] | We extend the analysis of two-hadron fragmentation functions to the subleading twist, discussing also the issue of color gauge invariance. Our results can be used anywhere two unpolarized hadrons are semi-inclusively produced in the same fragmentation region, also at moderate values of the hard scale Q. Here, we consider the example of polarized deep-inelastic production of two hadrons and we give a complete list of cross sections and spin asymmetries up to subleading twist. Among the results, we highlight the possibility of extracting the transversity distribution with longitudinally polarized targets and also the twist-3 distribution e(x), which is related to the pion-nucleon sigma term and to the strangeness content of the nucleon. |
1304.6119 | Bartosz Fornal | Jonathan M. Arnold, Bartosz Fornal, Mark B. Wise | Phenomenology of scalar leptoquarks | 7 pages, 9 figures | Phys.Rev.D88:035009,2013 | 10.1103/PhysRevD.88.035009 | CALT 68-2931 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the simplest renormalizable scalar leptoquark models where the
standard model is augmented only by one additional scalar representation of
SU(3) x SU(2) x U(1). The requirement that there be no proton decay from
renormalizable interactions singles out two such models, one of which exhibits
an unusual top mass enhancement of the mu -> e gamma decay rate. We analyze the
phenomenology of the model with the unusual top mass enhancement of loop level
chirality changing charged lepton processes in the light of existing and
upcoming experiments. Both of the models that do not allow proton decay from
renormalizable interactions have dimension five operators that, even if
suppressed by the Planck scale, can give rise to an unacceptably high level of
baryon number violation. We discuss symmetries that can forbid these dimension
five operators.
| [
{
"created": "Mon, 22 Apr 2013 22:15:00 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Jun 2013 19:00:00 GMT",
"version": "v2"
}
] | 2013-08-26 | [
[
"Arnold",
"Jonathan M.",
""
],
[
"Fornal",
"Bartosz",
""
],
[
"Wise",
"Mark B.",
""
]
] | We study the simplest renormalizable scalar leptoquark models where the standard model is augmented only by one additional scalar representation of SU(3) x SU(2) x U(1). The requirement that there be no proton decay from renormalizable interactions singles out two such models, one of which exhibits an unusual top mass enhancement of the mu -> e gamma decay rate. We analyze the phenomenology of the model with the unusual top mass enhancement of loop level chirality changing charged lepton processes in the light of existing and upcoming experiments. Both of the models that do not allow proton decay from renormalizable interactions have dimension five operators that, even if suppressed by the Planck scale, can give rise to an unacceptably high level of baryon number violation. We discuss symmetries that can forbid these dimension five operators. |
hep-ph/9705329 | Heinz Sorge | Heinz Sorge, Edward Shuryak, Ismail Zahed | $\Psi'/\Psi $ ratio in Nucleus-Nucleus Collisions : a Measure for the
Chiral Symmetry Restoration Temperature ? | 4 pages revtex including 3 postscript figures | Phys.Rev.Lett. 79 (1997) 2775-2778 | 10.1103/PhysRevLett.79.2775 | SUNY-NTG 97-19 | hep-ph nucl-th | null | We argue that a decrease of the chiral scalar meson mass is responsible for
re-creation of $\Psi'$ from $J/\Psi$ in ultrarelativistic nucleus-nucleus
collisions. This causes the charmonium yields to freeze out at temperatures
close to the chiral symmetry restoration temperature $T_c$. As a result
$\Psi'/\Psi$ may serve as a thermometer for $T_c$ itself. Results in a detailed
reaction model support the conjecture. They show good agreement with recent
data of NA38 and NA50 for $J/\Psi$ and $\Psi'$ production in S on U and Pb on
Pb collisions.
| [
{
"created": "Thu, 15 May 1997 17:55:51 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Sorge",
"Heinz",
""
],
[
"Shuryak",
"Edward",
""
],
[
"Zahed",
"Ismail",
""
]
] | We argue that a decrease of the chiral scalar meson mass is responsible for re-creation of $\Psi'$ from $J/\Psi$ in ultrarelativistic nucleus-nucleus collisions. This causes the charmonium yields to freeze out at temperatures close to the chiral symmetry restoration temperature $T_c$. As a result $\Psi'/\Psi$ may serve as a thermometer for $T_c$ itself. Results in a detailed reaction model support the conjecture. They show good agreement with recent data of NA38 and NA50 for $J/\Psi$ and $\Psi'$ production in S on U and Pb on Pb collisions. |
1111.3839 | David Scheffler | David Scheffler, Michael Buballa, Jochen Wambach | PNJL model analysis of the Roberge-Weiss transition endpoint at
imaginary chemical potential | Presented at the HIC for FAIR Workshop and XXVIII Max Born Symposium
"Three Days on Quarkyonic Island", Wroc{\l}aw, Poland, May 19-21, 2011 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivated by lattice QCD studies we investigate the RW transition endpoint at
imaginary chemical potential in a two-flavor PNJL model. We focus on the
quark-mass dependence of the endpoint using different forms of the
Polyakov-loop potential.
| [
{
"created": "Wed, 16 Nov 2011 15:43:05 GMT",
"version": "v1"
}
] | 2011-11-17 | [
[
"Scheffler",
"David",
""
],
[
"Buballa",
"Michael",
""
],
[
"Wambach",
"Jochen",
""
]
] | Motivated by lattice QCD studies we investigate the RW transition endpoint at imaginary chemical potential in a two-flavor PNJL model. We focus on the quark-mass dependence of the endpoint using different forms of the Polyakov-loop potential. |
2012.15554 | Zheng Zhao | Zheng Zhao, Kai Xu, Attaphon Kaewsnod, Xuyang Liu, Ayut Limphirat and
Yupeng Yan | Study of charmonium-like and fully-charm tetraquark spectroscopy | null | Phys. Rev. D 103, 116027 (2021) | 10.1103/PhysRevD.103.116027 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The masses of tetraquark states of all $qc\bar q \bar c$ and $cc\bar c \bar
c$ quark configurations are evaluated in a constituent quark model, where the
Cornell-like potential and one-gluon exchange spin-spin coupling are employed.
All model parameters are predetermined by comparing the theoretical and
experimental masses of light, charmed and bottom mesons. The theoretical
predictions of the charmoniumlike tetraquarks are compared with the observed
$XYZ$ states, and one tentative assignment is suggested. The work suggests that
the $X(6900)$ observed by LHCb is likely to be the first radial excited
fully-charm tetraquark state with $J^{PC} = 1^{+-}$ in the $\bar 3_c \otimes
3_c$ configuration, and the ground and second radial excited states of
fully-charm tetraquark are around $6494$ and $7253$ MeV respectively.
| [
{
"created": "Thu, 31 Dec 2020 11:26:27 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Aug 2021 13:12:26 GMT",
"version": "v2"
}
] | 2021-08-16 | [
[
"Zhao",
"Zheng",
""
],
[
"Xu",
"Kai",
""
],
[
"Kaewsnod",
"Attaphon",
""
],
[
"Liu",
"Xuyang",
""
],
[
"Limphirat",
"Ayut",
""
],
[
"Yan",
"Yupeng",
""
]
] | The masses of tetraquark states of all $qc\bar q \bar c$ and $cc\bar c \bar c$ quark configurations are evaluated in a constituent quark model, where the Cornell-like potential and one-gluon exchange spin-spin coupling are employed. All model parameters are predetermined by comparing the theoretical and experimental masses of light, charmed and bottom mesons. The theoretical predictions of the charmoniumlike tetraquarks are compared with the observed $XYZ$ states, and one tentative assignment is suggested. The work suggests that the $X(6900)$ observed by LHCb is likely to be the first radial excited fully-charm tetraquark state with $J^{PC} = 1^{+-}$ in the $\bar 3_c \otimes 3_c$ configuration, and the ground and second radial excited states of fully-charm tetraquark are around $6494$ and $7253$ MeV respectively. |
1312.6678 | Giovanni Ossola | Hans van Deurzen, Gionata Luisoni, Pierpaolo Mastrolia, Edoardo
Mirabella, Giovanni Ossola, Tiziano Peraro | Multi-leg One-loop Massive Amplitudes from Integrand Reduction via
Laurent Expansion | v3: 39 pages, minor typos and one benchmark point corrected | JHEP03(2014)115 | 10.1007/JHEP03(2014)115 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the application of a novel reduction technique for one-loop
scattering amplitudes based on the combination of the integrand reduction and
Laurent expansion. We describe the general features of its implementation in
the computer code NINJA, and its interface to GoSam. We apply the new reduction
to a series of selected processes involving massive particles, from six to
eight legs.
| [
{
"created": "Mon, 23 Dec 2013 20:58:34 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Mar 2014 13:07:20 GMT",
"version": "v2"
},
{
"created": "Tue, 18 Nov 2014 20:43:14 GMT",
"version": "v3"
}
] | 2015-06-18 | [
[
"van Deurzen",
"Hans",
""
],
[
"Luisoni",
"Gionata",
""
],
[
"Mastrolia",
"Pierpaolo",
""
],
[
"Mirabella",
"Edoardo",
""
],
[
"Ossola",
"Giovanni",
""
],
[
"Peraro",
"Tiziano",
""
]
] | We present the application of a novel reduction technique for one-loop scattering amplitudes based on the combination of the integrand reduction and Laurent expansion. We describe the general features of its implementation in the computer code NINJA, and its interface to GoSam. We apply the new reduction to a series of selected processes involving massive particles, from six to eight legs. |
2104.14443 | Juan Carlos Criado | Juan Carlos Criado, Abdelhak Djouadi, Manuel Perez-Victoria, Jose
Santiago | A complete Effective Field Theory for Dark Matter | 39 pages, 4 figures | null | 10.1007/JHEP07(2021)081 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an effective field theory describing the relevant interactions of
the Standard Model with an electrically neutral particle that can account for
the dark matter in the Universe. The possible mediators of these interactions
are assumed to be heavy. The dark matter candidates that we consider have spin
0, 1/2 or 1, belong to an electroweak multiplet with arbitrary isospin and
hypercharge and their stability at cosmological scales is guaranteed by
imposing a $\mathbb{Z}_2$ symmetry. We present the most general framework for
describing the interaction of the dark matter with standard particles, and
construct a general non-redundant basis of the gauge-invariant operators up to
dimension six. The basis includes multiplets with non-vanishing hypercharge,
which can also be viable DM candidates. We give two examples illustrating the
phenomenological use of such a general effective framework. First, we consider
the case of a scalar singlet, provide convenient semi-analytical expressions
for the relevant dark matter observables, use present experimental data to set
constraints on the Wilson coefficients of the operators, and show how the
interplay of different operators can open new allowed windows in the parameter
space of the model. Then we study the case of a lepton isodoublet, which
involves co-annihilation processes, and we discuss the impact of the operators
on the particle mass splitting and direct detection cross sections. These
examples highlight the importance of the contribution of the various
non-renormalizable operators, which can even dominate over the gauge
interactions in certain cases.
| [
{
"created": "Thu, 29 Apr 2021 16:02:59 GMT",
"version": "v1"
}
] | 2021-07-28 | [
[
"Criado",
"Juan Carlos",
""
],
[
"Djouadi",
"Abdelhak",
""
],
[
"Perez-Victoria",
"Manuel",
""
],
[
"Santiago",
"Jose",
""
]
] | We present an effective field theory describing the relevant interactions of the Standard Model with an electrically neutral particle that can account for the dark matter in the Universe. The possible mediators of these interactions are assumed to be heavy. The dark matter candidates that we consider have spin 0, 1/2 or 1, belong to an electroweak multiplet with arbitrary isospin and hypercharge and their stability at cosmological scales is guaranteed by imposing a $\mathbb{Z}_2$ symmetry. We present the most general framework for describing the interaction of the dark matter with standard particles, and construct a general non-redundant basis of the gauge-invariant operators up to dimension six. The basis includes multiplets with non-vanishing hypercharge, which can also be viable DM candidates. We give two examples illustrating the phenomenological use of such a general effective framework. First, we consider the case of a scalar singlet, provide convenient semi-analytical expressions for the relevant dark matter observables, use present experimental data to set constraints on the Wilson coefficients of the operators, and show how the interplay of different operators can open new allowed windows in the parameter space of the model. Then we study the case of a lepton isodoublet, which involves co-annihilation processes, and we discuss the impact of the operators on the particle mass splitting and direct detection cross sections. These examples highlight the importance of the contribution of the various non-renormalizable operators, which can even dominate over the gauge interactions in certain cases. |
hep-ph/0011321 | Saurabh Rindani | Saurabh D. Rindani | Decay-lepton angular distributions in e+e- -> t tbar to O(alpha_s) in
the soft-gluon approximation | 15 pages, Latex, 3 figures, condensed version of version 2, with
discussion of numerical results limited to only two values of c.m. energies,
and with figures for triple angular distributions omitted. Some equations are
omitted | Phys.Lett.B503:292-300,2001 | 10.1016/S0370-2693(01)00252-0 | PRL-TH-00/2 (revised) | hep-ph | null | Order-alpha_s QCD corrections in the soft-gluon approximation to angular
distributions of decay charged leptons in the process e+e- -> t tbar, followed
by semileptonic decay of t or tbar, are obtained in the e+e- centre-of-mass
frame. As compared to distributions in the top rest frame, these have the
advantage that they would allow direct comparison with experiment without the
need to reconstruct the top rest frame or a spin quantization axis. Analytic
expressions for the distribution in the charged-lepton polar angle and triple
distribution in the polar angle of t and polar and azimuthal angles of the
lepton are obtained. Numerical values are discussed for total c.m. energies of
400 GeV and 800 GeV.
| [
{
"created": "Mon, 27 Nov 2000 11:39:40 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Dec 2000 10:02:03 GMT",
"version": "v2"
},
{
"created": "Thu, 25 Jan 2001 04:08:31 GMT",
"version": "v3"
}
] | 2011-03-23 | [
[
"Rindani",
"Saurabh D.",
""
]
] | Order-alpha_s QCD corrections in the soft-gluon approximation to angular distributions of decay charged leptons in the process e+e- -> t tbar, followed by semileptonic decay of t or tbar, are obtained in the e+e- centre-of-mass frame. As compared to distributions in the top rest frame, these have the advantage that they would allow direct comparison with experiment without the need to reconstruct the top rest frame or a spin quantization axis. Analytic expressions for the distribution in the charged-lepton polar angle and triple distribution in the polar angle of t and polar and azimuthal angles of the lepton are obtained. Numerical values are discussed for total c.m. energies of 400 GeV and 800 GeV. |
hep-ph/0503022 | Harry Lipkin J. | Harry J. Lipkin | Is observed direct CP violation in $B_d \to K^+ \pi^-$ due to new
physics? Check standard model prediction of equal violation in $B_s \to K^-
\pi^+$ | 9 pages | Phys.Lett. B621 (2005) 126-132 | 10.1016/j.physletb.2005.06.023 | WIS/06/05-FEB-DPP, TAUP 2798-05, ANL-HEP-PR-05-11 | hep-ph | null | The recently observed direct CP violation in $B_d \to K^+ \pi^-$ has raised
suggestions of possible new physics. A robust test of the standard model vs.
new physics is its prediction of equal direct CP violation in $B_s \to K^-
\pi^+$ decay. CPT invariance requires the observed CP violation to arise from
the interference between the dominant penguin amplitude and another amplitude
with a different weak phase and a different strong phase. The penguin
contribution to $B_d \to K^+ \pi^-$ is known to be reduced by a CKM factor in
$B_s \to K^- \pi^+$. Thus the two branching ratios are very different and a
different CP violation is expected. But in the standard model a miracle occurs
and the interfering tree diagram is enhanced by the same CKM factor that
reduces the penguin to give the predicted equality. This miracle is not
expected in new physics; thus a search for and measurement of the predicted CP
violation in $B_s \to K^- \pi^+$ decay is a sensitive test for a new physics
contribution. A detailed analysis shows this prediction to be robust and
insensitive to symmetry breaking effects and possible additional contributions.
| [
{
"created": "Wed, 2 Mar 2005 12:20:13 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Apr 2005 06:46:13 GMT",
"version": "v2"
}
] | 2010-04-05 | [
[
"Lipkin",
"Harry J.",
""
]
] | The recently observed direct CP violation in $B_d \to K^+ \pi^-$ has raised suggestions of possible new physics. A robust test of the standard model vs. new physics is its prediction of equal direct CP violation in $B_s \to K^- \pi^+$ decay. CPT invariance requires the observed CP violation to arise from the interference between the dominant penguin amplitude and another amplitude with a different weak phase and a different strong phase. The penguin contribution to $B_d \to K^+ \pi^-$ is known to be reduced by a CKM factor in $B_s \to K^- \pi^+$. Thus the two branching ratios are very different and a different CP violation is expected. But in the standard model a miracle occurs and the interfering tree diagram is enhanced by the same CKM factor that reduces the penguin to give the predicted equality. This miracle is not expected in new physics; thus a search for and measurement of the predicted CP violation in $B_s \to K^- \pi^+$ decay is a sensitive test for a new physics contribution. A detailed analysis shows this prediction to be robust and insensitive to symmetry breaking effects and possible additional contributions. |
1708.07328 | T. Lappi | B. Duclou\'e, H. H\"anninen, T. Lappi, Y. Zhu | Deep inelastic scattering in the dipole picture at next-to-leading order | 8 pages, RevTeX, 5 figures | Phys. Rev. D 96, 094017 (2017) | 10.1103/PhysRevD.96.094017 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study quantitatively the importance of the recently derived NLO
corrections to the DIS structure functions at small x in the dipole formalism.
We show that these corrections can be significant and depend on the
factorization scheme used to resum large logarithms of energy into
renormalization group evolution with the BK equation. This feature is similar
to what has recently been observed for single inclusive forward hadron
production. Using a factorization scheme consistent with the one recently
proposed for the single inclusive cross section, we show that it is possible to
obtain meaningful results for the DIS cross sections.
| [
{
"created": "Thu, 24 Aug 2017 09:16:12 GMT",
"version": "v1"
}
] | 2017-11-29 | [
[
"Ducloué",
"B.",
""
],
[
"Hänninen",
"H.",
""
],
[
"Lappi",
"T.",
""
],
[
"Zhu",
"Y.",
""
]
] | We study quantitatively the importance of the recently derived NLO corrections to the DIS structure functions at small x in the dipole formalism. We show that these corrections can be significant and depend on the factorization scheme used to resum large logarithms of energy into renormalization group evolution with the BK equation. This feature is similar to what has recently been observed for single inclusive forward hadron production. Using a factorization scheme consistent with the one recently proposed for the single inclusive cross section, we show that it is possible to obtain meaningful results for the DIS cross sections. |
1908.04678 | Fu-Hu Liu | Hai-Ling Lao, Ya-Qin Gao, Fu-Hu Liu | Light particle and quark chemical potentials from negatively to
positively charged particle yield ratios corrected by removing strong and
weak decays | 11 pages, 3 figures. Advances in High Energy Physics, accepted. arXiv
admin note: text overlap with arXiv:1806.04309 | Advances in High Energy Physics 2020, 5064737 (2020) (11 pages) | 10.1155/2020/5064737 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The yield ratios of negatively to positively charged pions ($\pi^-/\pi^+$),
negatively to positively charged kaons ($K^-/K^+$), and anti-protons to protons
($\bar p/p$) produced in mid-rapidity interval in central gold-gold (Au-Au)
collisions, central lead-lead (Pb-Pb) collisions, and inelastic (INEL) or
non-single-diffractive (NSD) proton-proton ($pp$) collisions, as well as in
forward rapidity region in INEL $pp$ collisions are analyzed in the present
work. Over an energy range from a few GeV to above 10 TeV, the chemical
potentials of light flavor particles (pion, kaon, and proton) and quarks (up,
down, and strange quarks) are extracted from the mentioned yield ratios in
which the contributions of strong decay from high-mass resonance and weak decay
from heavy flavor hadrons are removed. Most energy dependent chemical
potentials show the maximum at about 4 GeV, while the energy dependent yield
ratios do not show such an extremum.
| [
{
"created": "Sun, 11 Aug 2019 09:02:47 GMT",
"version": "v1"
}
] | 2020-05-12 | [
[
"Lao",
"Hai-Ling",
""
],
[
"Gao",
"Ya-Qin",
""
],
[
"Liu",
"Fu-Hu",
""
]
] | The yield ratios of negatively to positively charged pions ($\pi^-/\pi^+$), negatively to positively charged kaons ($K^-/K^+$), and anti-protons to protons ($\bar p/p$) produced in mid-rapidity interval in central gold-gold (Au-Au) collisions, central lead-lead (Pb-Pb) collisions, and inelastic (INEL) or non-single-diffractive (NSD) proton-proton ($pp$) collisions, as well as in forward rapidity region in INEL $pp$ collisions are analyzed in the present work. Over an energy range from a few GeV to above 10 TeV, the chemical potentials of light flavor particles (pion, kaon, and proton) and quarks (up, down, and strange quarks) are extracted from the mentioned yield ratios in which the contributions of strong decay from high-mass resonance and weak decay from heavy flavor hadrons are removed. Most energy dependent chemical potentials show the maximum at about 4 GeV, while the energy dependent yield ratios do not show such an extremum. |
hep-ph/0410234 | Tetsuya Shinozaki | Tetsuya Shinozaki, Makoto Oka and Sachiko Takeuchi | Contribution of Instanton Induced Interaction for Penta-quarks in MIT
Bag Model | 4 pages, 2 figures, Talk given at International Workshop PENTAQUARK04
at SPring-8, Japan, July 20-23, 2004 | null | 10.1142/9789812701855_0039 | null | hep-ph | null | Roles of instanton induced interactions (III) in the masses of pentaquark
baryons, Theta^+ (J=1/2 and 3/2) and Xi^{--}, and a dibaryon, H, are discussed
using the MIT bag model. It is shown that the two-body terms in III give a
strong attraction mainly due to the increase of the number of pairs in
multi-quark systems. In contrast, the three-body $u$-$d$-$s$ interaction is
repulsive. It is found that III lowers the mass of negative-parity Theta^+ as
much as 100 MeV from the mass predicted by the bag model without III.
| [
{
"created": "Fri, 15 Oct 2004 16:46:23 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Shinozaki",
"Tetsuya",
""
],
[
"Oka",
"Makoto",
""
],
[
"Takeuchi",
"Sachiko",
""
]
] | Roles of instanton induced interactions (III) in the masses of pentaquark baryons, Theta^+ (J=1/2 and 3/2) and Xi^{--}, and a dibaryon, H, are discussed using the MIT bag model. It is shown that the two-body terms in III give a strong attraction mainly due to the increase of the number of pairs in multi-quark systems. In contrast, the three-body $u$-$d$-$s$ interaction is repulsive. It is found that III lowers the mass of negative-parity Theta^+ as much as 100 MeV from the mass predicted by the bag model without III. |
2106.03159 | Neda Darvishi | Neda Darvishi, M.R. Masouminia and Apostolos Pilaftsis | Maximally Symmetric Three Higgs Doublet Model | 45 pages and 6 figures | Phys. Rev. D 104, 115017 (2021) | 10.1103/PhysRevD.104.115017 | IPPP/20/110 | hep-ph | http://creativecommons.org/publicdomain/zero/1.0/ | We consider the general Three-Higgs Doublet Model (3HDM) and identify all
limits that lead to exact SM alignment. After discussing the underlying
symmetries that can naturally enforce such an alignment, we focus on the most
economic setting, called here the Maximally Symmetric Three-Higgs Doublet Model
(MS-3HDM). The potential of the MS-3HDM obeys an $\mathrm{Sp(6)}$ symmetry,
softly broken by bilinear masses and explicitly by hypercharge and Yukawa
couplings through renormalisation-group effects, whilst the theory allows for
quartic coupling unification up to the Planck scale. Besides the two ratios of
vacuum expectation values, $\tan\beta_{1,2}$, the MS-3HDM is predominantly
governed by only three input parameters: the masses of the two charged Higgs
bosons, $M_{h_{1,2}^{\pm}}$, and their mixing angle $\sigma$. Most remarkably,
with these input parameters, we obtain definite predictions for the entire
scalar mass spectrum of the theory, as well as for the SM-like Higgs-boson
couplings to the gauge bosons and fermions. The predicted deviations of these
couplings from their SM values might be probed at future precision high-energy
colliders. The new phenomenological aspects of the MS-3HDM with respect to the
earlier studied MS-2HDM are discussed.
| [
{
"created": "Sun, 6 Jun 2021 15:48:45 GMT",
"version": "v1"
}
] | 2021-12-16 | [
[
"Darvishi",
"Neda",
""
],
[
"Masouminia",
"M. R.",
""
],
[
"Pilaftsis",
"Apostolos",
""
]
] | We consider the general Three-Higgs Doublet Model (3HDM) and identify all limits that lead to exact SM alignment. After discussing the underlying symmetries that can naturally enforce such an alignment, we focus on the most economic setting, called here the Maximally Symmetric Three-Higgs Doublet Model (MS-3HDM). The potential of the MS-3HDM obeys an $\mathrm{Sp(6)}$ symmetry, softly broken by bilinear masses and explicitly by hypercharge and Yukawa couplings through renormalisation-group effects, whilst the theory allows for quartic coupling unification up to the Planck scale. Besides the two ratios of vacuum expectation values, $\tan\beta_{1,2}$, the MS-3HDM is predominantly governed by only three input parameters: the masses of the two charged Higgs bosons, $M_{h_{1,2}^{\pm}}$, and their mixing angle $\sigma$. Most remarkably, with these input parameters, we obtain definite predictions for the entire scalar mass spectrum of the theory, as well as for the SM-like Higgs-boson couplings to the gauge bosons and fermions. The predicted deviations of these couplings from their SM values might be probed at future precision high-energy colliders. The new phenomenological aspects of the MS-3HDM with respect to the earlier studied MS-2HDM are discussed. |
1904.10808 | Ying-nan Mao | Kingman Cheung, Wai-Yee Keung, Ying-nan Mao, and Chen Zhang | Constraining CP-violating electron-gluonic operators | 22 pages (21 pages + cover), 4 figures, 7 tables; JHEP accepted
version; Introduction, footnotes, table captions, acknowledgement, and
references updated; typos corrected | JHEP 07 (2019), 074 | 10.1007/JHEP07(2019)074 | NCTS-PH/1903 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an analysis of constraints on two types of CP-odd electron-gluonic
operators $(\bar{e}i\gamma^5 e)G_{\mu\nu}^a G^{a\mu\nu}$ and
$(\bar{e}e)G_{\mu\nu}^a \tilde{G}^{a\mu\nu}$ from current and future electric
dipole moment (EDM) experiments. The recent result from the ACME experiment
using ThO molecules is used to derive an impressive lower bound on the
effective scale for $(\bar{e}i\gamma^5 e)G_{\mu\nu}^a G^{a\mu\nu}$ at 8 TeV,
assuming a QCD one-loop factor and no helicity suppression from new physics.
One interesting aspect is that $(\bar{e}i\gamma^5 e)G_{\mu\nu}^a G^{a\mu\nu}$
contributes to the observable EDM in ThO experiment mainly through CP-odd
electron-nucleon interaction rather than direct electron EDM which arises from
three-loop running and matching. For $(\bar{e}e)G_{\mu\nu}^a
\tilde{G}^{a\mu\nu}$ the current bound is much weaker and suffers from large
uncertainties. We also discuss the QCD running and matching for the CP-odd
electron-gluonic operators and give an estimate of the relevant nucleon matrix
elements and uncertainties that are needed in the calculation.
| [
{
"created": "Wed, 24 Apr 2019 13:31:49 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Jul 2019 01:35:54 GMT",
"version": "v2"
}
] | 2019-07-17 | [
[
"Cheung",
"Kingman",
""
],
[
"Keung",
"Wai-Yee",
""
],
[
"Mao",
"Ying-nan",
""
],
[
"Zhang",
"Chen",
""
]
] | We present an analysis of constraints on two types of CP-odd electron-gluonic operators $(\bar{e}i\gamma^5 e)G_{\mu\nu}^a G^{a\mu\nu}$ and $(\bar{e}e)G_{\mu\nu}^a \tilde{G}^{a\mu\nu}$ from current and future electric dipole moment (EDM) experiments. The recent result from the ACME experiment using ThO molecules is used to derive an impressive lower bound on the effective scale for $(\bar{e}i\gamma^5 e)G_{\mu\nu}^a G^{a\mu\nu}$ at 8 TeV, assuming a QCD one-loop factor and no helicity suppression from new physics. One interesting aspect is that $(\bar{e}i\gamma^5 e)G_{\mu\nu}^a G^{a\mu\nu}$ contributes to the observable EDM in ThO experiment mainly through CP-odd electron-nucleon interaction rather than direct electron EDM which arises from three-loop running and matching. For $(\bar{e}e)G_{\mu\nu}^a \tilde{G}^{a\mu\nu}$ the current bound is much weaker and suffers from large uncertainties. We also discuss the QCD running and matching for the CP-odd electron-gluonic operators and give an estimate of the relevant nucleon matrix elements and uncertainties that are needed in the calculation. |
2312.11165 | Wei Liu | Wei Liu, Frank F. Deppisch, Zixiang Chen | Testing Leptogenesis and Seesaw using Long-lived Particle Searches in
the $B-L$ Model | 16 pages, 10 figures, plus appendix and references, to be published
in PRD | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We discuss the potential of using long-lived particle (LLP) searches for
right-handed neutrinos (RHNs) to test resonant leptogenesis and the seesaw
mechanism. This is challenging if only RHNs are added to the Standard Model
(SM), as naturally the active-sterile mixing strengths $|V_{\ell N}|^2$ are
small, for 1 GeV $\lesssim M_N \lesssim 1000$ GeV. Instead, we consider the
minimal $B-L$ gauge model, where a $Z^\prime$ gauge boson couples to fermions
including the RHNs. During leptogenesis, this gauge coupling introduces
scattering processes that washout the $B-L$ asymmetry. At colliders, it can
lead to abundant production of RHNs which allows probing the associated seesaw
mechanism using LLP searches. We find that LLP searches at the FCC-hh can test
leptogenesis and the seesaw mechanism simultaneously, and probe the
active-sterile mixing at or below the seesaw floor.
| [
{
"created": "Mon, 18 Dec 2023 13:09:09 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Aug 2024 03:22:19 GMT",
"version": "v2"
}
] | 2024-08-09 | [
[
"Liu",
"Wei",
""
],
[
"Deppisch",
"Frank F.",
""
],
[
"Chen",
"Zixiang",
""
]
] | We discuss the potential of using long-lived particle (LLP) searches for right-handed neutrinos (RHNs) to test resonant leptogenesis and the seesaw mechanism. This is challenging if only RHNs are added to the Standard Model (SM), as naturally the active-sterile mixing strengths $|V_{\ell N}|^2$ are small, for 1 GeV $\lesssim M_N \lesssim 1000$ GeV. Instead, we consider the minimal $B-L$ gauge model, where a $Z^\prime$ gauge boson couples to fermions including the RHNs. During leptogenesis, this gauge coupling introduces scattering processes that washout the $B-L$ asymmetry. At colliders, it can lead to abundant production of RHNs which allows probing the associated seesaw mechanism using LLP searches. We find that LLP searches at the FCC-hh can test leptogenesis and the seesaw mechanism simultaneously, and probe the active-sterile mixing at or below the seesaw floor. |
hep-ph/9801222 | Vladimir Braun | V.M. Braun | Light-Cone Sum Rules | Plenary talk given at the IVth International Workshop on Progress in
Heavy Quark Physics Rostock, Germany, 20--22 September 1997; 15 pages, 4
Postscript figures, uses procsla.sty (included) | null | null | NORDITA-98-1-P | hep-ph | null | A short introduction is given to the method of light-cone sum rules, their
theoretical background and main modifications. The discussion is concentrated
but not restricted to the applications to heavy quark decays.
| [
{
"created": "Tue, 6 Jan 1998 13:12:19 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Braun",
"V. M.",
""
]
] | A short introduction is given to the method of light-cone sum rules, their theoretical background and main modifications. The discussion is concentrated but not restricted to the applications to heavy quark decays. |
1405.7529 | Vadim Guzey | V. Guzey and M. Zhalov (PNPI, Gatchina) | Photoproduction of $J/\psi$ and $\psi(2S)$ in proton-proton
ultraperipheral collisions at the LHC | 10 pages, 4 figures, 1 table | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the framework of leading order perturbative QCD along with the CTEQ6L1
gluon distribution of the proton and high-energy HERA data on the $\gamma p \to
J/\psi p$ and $\gamma p \to \psi(2S) p$ cross sections along with the
corresponding H1 fit, we obtain a good description of the rapidity dependence
of the cross sections of photoproduction of $J/\psi$ or $\psi(2S)$ mesons in
proton--proton ultraperipheral collisions (UPCs) measured by the LHCb
collaboration at the LHC. Within the same framework we also make predictions
for the $pp \to pp J/\psi$ and $pp \to pp \psi(2S)$ UPC cross sections at
$\sqrt{s_{NN}}=8$ and 14 TeV. We show that the possible contribution of the $p
\to \Delta \gamma$ transition to the photon flux discernibly increases the $pp
\to ppV$ UPC cross section and thus can affect the theoretical interpretation
of results.
| [
{
"created": "Thu, 29 May 2014 11:42:20 GMT",
"version": "v1"
}
] | 2014-05-30 | [
[
"Guzey",
"V.",
"",
"PNPI, Gatchina"
],
[
"Zhalov",
"M.",
"",
"PNPI, Gatchina"
]
] | Using the framework of leading order perturbative QCD along with the CTEQ6L1 gluon distribution of the proton and high-energy HERA data on the $\gamma p \to J/\psi p$ and $\gamma p \to \psi(2S) p$ cross sections along with the corresponding H1 fit, we obtain a good description of the rapidity dependence of the cross sections of photoproduction of $J/\psi$ or $\psi(2S)$ mesons in proton--proton ultraperipheral collisions (UPCs) measured by the LHCb collaboration at the LHC. Within the same framework we also make predictions for the $pp \to pp J/\psi$ and $pp \to pp \psi(2S)$ UPC cross sections at $\sqrt{s_{NN}}=8$ and 14 TeV. We show that the possible contribution of the $p \to \Delta \gamma$ transition to the photon flux discernibly increases the $pp \to ppV$ UPC cross section and thus can affect the theoretical interpretation of results. |
hep-ph/9605460 | Sreerup Raychaudhuri | Dilip Kumar Ghosh, Rohini M. Godbole, Sreerup Raychaudhuri | Can the Aleph Four-Jet Excess be Explained in a Supersymmetric Model
with R-Parity Violation? | 31 pages, Latex, uses epsf, extensively revised and updated | Z.Phys. C75 (1997) 357-365 | null | BU-TH/96-2; IISc-CTS-7/96; TIFR/TH/96-21 | hep-ph | null | We investigate the possibility that the excess of four-jet events in $e^+e^-$
collisions at LEP-1.5 which has been reported by the ALEPH Collaboration could
be due to the production of charginos or neutralinos, followed by their decay
into quark jets through baryon number-violating ($\lambda^{\prime\prime}$)
couplings. An estimate at the parton level shows, however, that these events
cannot be due to neutralinos because of the low cross-section, and is unlikely
to be due to the production of chargino pairs because of the largely different
event shapes.
| [
{
"created": "Sat, 1 Jun 1996 08:57:00 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Sep 1996 01:53:29 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Ghosh",
"Dilip Kumar",
""
],
[
"Godbole",
"Rohini M.",
""
],
[
"Raychaudhuri",
"Sreerup",
""
]
] | We investigate the possibility that the excess of four-jet events in $e^+e^-$ collisions at LEP-1.5 which has been reported by the ALEPH Collaboration could be due to the production of charginos or neutralinos, followed by their decay into quark jets through baryon number-violating ($\lambda^{\prime\prime}$) couplings. An estimate at the parton level shows, however, that these events cannot be due to neutralinos because of the low cross-section, and is unlikely to be due to the production of chargino pairs because of the largely different event shapes. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.