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/9509427 | M. Prisznyak | V. Gogohia, Gy. Kluge and M. Priszny\'ak (RMKI, Department of
Theoretical Physics, Central Research Institute for Physics, Budapest,
Hungary) | A Nonperturbative Calculation of Basic Chiral QCD Parameters within
Dynamical Equations Approach to QCD at Low Energies | null | null | null | null | hep-ph | null | Basic chiral QCD parameters (the pion decay constant, the quark and gluon
condensates, the dynamically generated quark mass, etc) as well as the vacuum
energy density have been calculated from first principles within a recently
proposed dynamical equations approach to QCD at low energies. The zero modes
enhancement (ZME) model of quark confinement and dynamical chiral symmetry
breaking (DCSB) based on the solution to the Schwinger-Dyson (SD) equation for
the quark propagator in the infrared (IR) domain was used for this purpose.
There are only two independent quantities by means of which calculations should
be done within our approach. Our unique input data was chosen to be the pion
decay constant in the chiral limit given by the chiral perturbation theory at
the hadronic level (CHPTh). Phenomenological estimates of these quantities, as
well as the vacuum energy density, are in good agreement with our numerical
results. The nonperturbative vacuum structure which emerges from the ZME model,
appears to be well suited to describe quark confinement, DCSB,
current-effective (dynamical)-constituent, as well as constituent-valence quark
transformations, the Okubo-Zweig-Iizuka (OZI) rule, dimensional transmutation,
etc. The importance of the instanton-type fluctuations in the true QCD vacuum
for the ZME model is also emphasized. This allows to predict new, more
realistic values for the vacuum energy density (apart from the sign, by
definition, the bag constant) and the gluon condensate.
| [
{
"created": "Fri, 29 Sep 1995 20:16:41 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Oct 1995 17:40:40 GMT",
"version": "v2"
},
{
"created": "Mon, 30 Oct 1995 21:23:41 GMT",
"version": "v3"
},
{
"created": "Fri, 3 Nov 1995 20:44:57 GMT",
"version": "v4"
},
{
"cre... | 2008-02-03 | [
[
"Gogohia",
"V.",
"",
"RMKI, Department of\n Theoretical Physics, Central Research Institute for Physics, Budapest,\n Hungary"
],
[
"Kluge",
"Gy.",
"",
"RMKI, Department of\n Theoretical Physics, Central Research Institute for Physics, Budapest,\n Hungary"
],
[
"Pris... | Basic chiral QCD parameters (the pion decay constant, the quark and gluon condensates, the dynamically generated quark mass, etc) as well as the vacuum energy density have been calculated from first principles within a recently proposed dynamical equations approach to QCD at low energies. The zero modes enhancement (ZME) model of quark confinement and dynamical chiral symmetry breaking (DCSB) based on the solution to the Schwinger-Dyson (SD) equation for the quark propagator in the infrared (IR) domain was used for this purpose. There are only two independent quantities by means of which calculations should be done within our approach. Our unique input data was chosen to be the pion decay constant in the chiral limit given by the chiral perturbation theory at the hadronic level (CHPTh). Phenomenological estimates of these quantities, as well as the vacuum energy density, are in good agreement with our numerical results. The nonperturbative vacuum structure which emerges from the ZME model, appears to be well suited to describe quark confinement, DCSB, current-effective (dynamical)-constituent, as well as constituent-valence quark transformations, the Okubo-Zweig-Iizuka (OZI) rule, dimensional transmutation, etc. The importance of the instanton-type fluctuations in the true QCD vacuum for the ZME model is also emphasized. This allows to predict new, more realistic values for the vacuum energy density (apart from the sign, by definition, the bag constant) and the gluon condensate. |
2202.08287 | Olcyr Sumensari | Ilja Dor\v{s}ner, Svjetlana Fajfer, Olcyr Sumensari | Triple-leptoquark interactions for tree- and loop-level proton decays | 14 pages, 3 figures; Minor corrections and references added | null | 10.1007/JHEP05(2022)183 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We study the impact of triple-leptoquark interactions on matter stability for
two specific proton decay topologies that arise at the tree- and one-loop level
if and when they coexist. We demonstrate that the one-loop level topology is
much more relevant than the tree-level one when it comes to the proton decay
signatures despite the usual loop-suppression factor. We subsequently present
detailed analysis of the triple-leptoquark interaction effects on the proton
stability within one representative scenario to support our claim, where the
scenario in question simultaneously features a tree-level topology that yields
three-body proton decay $p\to e^+ e^+ e^-$ and a one-loop level topology that
induces two-body proton decays $p\to \pi^0 e^+$ and $p\to \pi^+ \bar{\nu}$. We
also provide a comprehensive list of the leading-order proton decay channels
for all non-trivial cubic and quartic contractions involving three scalar
leptoquark multiplets that generate triple-leptoquark interactions of our
interest, where in the latter case one of the scalar multiplets is the Standard
Model Higgs doublet.
| [
{
"created": "Wed, 16 Feb 2022 19:00:06 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Feb 2022 15:23:42 GMT",
"version": "v2"
}
] | 2022-06-15 | [
[
"Doršner",
"Ilja",
""
],
[
"Fajfer",
"Svjetlana",
""
],
[
"Sumensari",
"Olcyr",
""
]
] | We study the impact of triple-leptoquark interactions on matter stability for two specific proton decay topologies that arise at the tree- and one-loop level if and when they coexist. We demonstrate that the one-loop level topology is much more relevant than the tree-level one when it comes to the proton decay signatures despite the usual loop-suppression factor. We subsequently present detailed analysis of the triple-leptoquark interaction effects on the proton stability within one representative scenario to support our claim, where the scenario in question simultaneously features a tree-level topology that yields three-body proton decay $p\to e^+ e^+ e^-$ and a one-loop level topology that induces two-body proton decays $p\to \pi^0 e^+$ and $p\to \pi^+ \bar{\nu}$. We also provide a comprehensive list of the leading-order proton decay channels for all non-trivial cubic and quartic contractions involving three scalar leptoquark multiplets that generate triple-leptoquark interactions of our interest, where in the latter case one of the scalar multiplets is the Standard Model Higgs doublet. |
1901.08290 | Carlo Marzo | Carlo Marzo, Luca Marzola, Martti Raidal | Common explanation to the $R_{K^{(*)}}$, $R_{D^{(*)}}$ and
$\epsilon^\prime/\epsilon$ anomalies in a 3HDM+$\nu_R$ and connections to
neutrino physics | 18 pages, 11 figures | Phys. Rev. D 100, 055031 (2019) | 10.1103/PhysRevD.100.055031 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Scalar theories can account for the current $R_{D^{(*)}}$ measurements
through a vector operator $\bar{c}_L \gamma_{\mu} b_L\,\bar{\tau}_L
\gamma^{\mu}\nu_L$ induced at the loop level. Once the vector contribution is
considered on top of a subdominant tree-level scalar component, the predicted
value of $R_{D^{(*)}}$ falls within the $1\sigma$ region indicated by the
experiments. We explicitly demonstrate this claim in the framework of a three
Higgs doublet model extended with GeV scale right-handed neutrinos, by matching
the anomalous signal for perturbative values of the involved couplings and
respecting the bounds from complementary flavour physics measurements.
Remarkably, we furthermore show that the proposed framework can be employed to
simultaneously explain also the present $R_{K^{(*)}}$ measurement, as well as
the deviation in $\epsilon'/\epsilon$ currently being debated in the
literature. These results are obtained by considering the contribution of
relatively light right-handed neutrinos which are fundamental in mediating the
processes behind the anomalous signals. In this way our findings reveal a new
possible connection that links the flavour anomalies to the phenomenology of
extended Higgs sector and neutrino physics.
| [
{
"created": "Thu, 24 Jan 2019 08:58:05 GMT",
"version": "v1"
}
] | 2019-09-25 | [
[
"Marzo",
"Carlo",
""
],
[
"Marzola",
"Luca",
""
],
[
"Raidal",
"Martti",
""
]
] | Scalar theories can account for the current $R_{D^{(*)}}$ measurements through a vector operator $\bar{c}_L \gamma_{\mu} b_L\,\bar{\tau}_L \gamma^{\mu}\nu_L$ induced at the loop level. Once the vector contribution is considered on top of a subdominant tree-level scalar component, the predicted value of $R_{D^{(*)}}$ falls within the $1\sigma$ region indicated by the experiments. We explicitly demonstrate this claim in the framework of a three Higgs doublet model extended with GeV scale right-handed neutrinos, by matching the anomalous signal for perturbative values of the involved couplings and respecting the bounds from complementary flavour physics measurements. Remarkably, we furthermore show that the proposed framework can be employed to simultaneously explain also the present $R_{K^{(*)}}$ measurement, as well as the deviation in $\epsilon'/\epsilon$ currently being debated in the literature. These results are obtained by considering the contribution of relatively light right-handed neutrinos which are fundamental in mediating the processes behind the anomalous signals. In this way our findings reveal a new possible connection that links the flavour anomalies to the phenomenology of extended Higgs sector and neutrino physics. |
hep-ph/0602022 | Sreerup Raychaudhuri | Sreerup Raychaudhuri, Saswati Sarkar | Using Invisible Graviton Radiation to Detect Heavy Electroweak
Resonances at a 500 GeV e+e- Collider | 13 pages, 5 figures | null | null | null | hep-ph | null | The process e+e- --> mu+ mu- + missing E_T, where the missing energy is due
to the production of a tower of invisible graviton states in a model with large
extra dimensions, is considered. We focus on the scenario when this process is
used to detect a heavy dileptonic resonance in the electroweak sector of the
model, taking as example some models with an extra Z' boson. It turns out that
at a 500 GeV machine with 1000 inverse fb of luminosity, it may be possible to
use this process to such detect resonances if there are two large extra
dimensions and the string scale is not too far above a TeV.
| [
{
"created": "Thu, 2 Feb 2006 15:34:22 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Raychaudhuri",
"Sreerup",
""
],
[
"Sarkar",
"Saswati",
""
]
] | The process e+e- --> mu+ mu- + missing E_T, where the missing energy is due to the production of a tower of invisible graviton states in a model with large extra dimensions, is considered. We focus on the scenario when this process is used to detect a heavy dileptonic resonance in the electroweak sector of the model, taking as example some models with an extra Z' boson. It turns out that at a 500 GeV machine with 1000 inverse fb of luminosity, it may be possible to use this process to such detect resonances if there are two large extra dimensions and the string scale is not too far above a TeV. |
1805.11764 | Patricia Magalh\~aes | R.T. Aoude, P.C. Magalh\~aes, A.C. dos Reis, M.R. Robilotta | Multi-Meson Model for the $D^+\to K^+K^-K^+$ decay amplitude | null | Phys. Rev. D 98, 056021 (2018) | 10.1103/PhysRevD.98.056021 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a novel approach to describe the $D^+\to K^+K^-K^+$ decay
amplitude, based on chiral effective Lagrangians, which can be used to extract
information about $K\bar{K}$ scattering. Our trial function is an alternative
to the widely used isobar model and includes both nonresonant three-body
interactions and two-body rescattering amplitudes, based on coupled channels
and resonances, for S- and P-waves with isospin $0$ and $1$. The latter are
unitarized in the $K$-matrix approximation and represent the only source of
complex phases in the problem. Free parameters are just resonance masses and
coupling constants, with transparent physical meanings. The nonresonant
component, given by chiral symmetry as a real polynomium, is an important
prediction of the model, which goes beyond the (2+1) approximation. Our
approach allows one to disentangle the two-body scalar contributions with
different isospins, associated with the $f_0(980)$ and $a_0(980)$ channels. We
show how the $K\bar{K}$ amplitude can be obtained from the decay $D^+\to
K^+K^-K^+$ and discuss extensions to other three-body final states.
| [
{
"created": "Wed, 30 May 2018 01:05:49 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Jun 2018 20:52:49 GMT",
"version": "v2"
}
] | 2018-10-03 | [
[
"Aoude",
"R. T.",
""
],
[
"Magalhães",
"P. C.",
""
],
[
"Reis",
"A. C. dos",
""
],
[
"Robilotta",
"M. R.",
""
]
] | We propose a novel approach to describe the $D^+\to K^+K^-K^+$ decay amplitude, based on chiral effective Lagrangians, which can be used to extract information about $K\bar{K}$ scattering. Our trial function is an alternative to the widely used isobar model and includes both nonresonant three-body interactions and two-body rescattering amplitudes, based on coupled channels and resonances, for S- and P-waves with isospin $0$ and $1$. The latter are unitarized in the $K$-matrix approximation and represent the only source of complex phases in the problem. Free parameters are just resonance masses and coupling constants, with transparent physical meanings. The nonresonant component, given by chiral symmetry as a real polynomium, is an important prediction of the model, which goes beyond the (2+1) approximation. Our approach allows one to disentangle the two-body scalar contributions with different isospins, associated with the $f_0(980)$ and $a_0(980)$ channels. We show how the $K\bar{K}$ amplitude can be obtained from the decay $D^+\to K^+K^-K^+$ and discuss extensions to other three-body final states. |
1708.07510 | Marco Bonvini | Marco Bonvini, Simone Marzani and Claudio Muselli | Towards parton distribution functions with small-$x$ resummation: HELL
2.0 | 65 pages, 7 figures. Improved structure of the presentation of our
results, added some extra content, new plots in the results section. JHEP
version | JHEP 12 (2017) 117 | 10.1007/JHEP12(2017)117 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In global fits of parton distribution functions (PDFs) a large fraction of
data points, mostly from the HERA collider, lies in a region of $x$ and $Q^2$
that is sensitive to small-$x$ logarithmic enhancements. Thus, the proper
theoretical description of these data requires the inclusion of small-$x$
resummation. In this work we provide all the necessary ingredients to perform a
PDF fit to deep-inelastic scattering (DIS) data which includes small-$x$
resummation in the evolution of PDFs and in the computation of DIS structure
functions. To this purpose, not only we include the resummation of DIS massless
structure functions, but we also consider the production of a massive final
state (e.g. a charm quark), and the consistent resummation of mass collinear
logarithms through the implementation of a variable flavour number scheme at
small $x$. As a result, we perform the small-$x$ resummation of the matching
conditions in PDF evolution at heavy flavour thresholds. The resummed results
are accurate at next-to-leading logarithmic (NLL) accuracy and matched, for the
first time, to next-to-next-to-leading order (NNLO). Furthermore, we improve on
our previous work by considering a novel all-order treatment of running
coupling contributions. These results, which are implemented in a new release
of HELL, version 2.0, will allow to fit PDFs from DIS data at the highest
possible theoretical accuracy, NNLO+NLL, thus providing an important step
forward towards precision determination of PDFs and consequently precision
phenomenology at the LHC and beyond.
| [
{
"created": "Thu, 24 Aug 2017 18:00:00 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Dec 2017 17:19:40 GMT",
"version": "v2"
}
] | 2017-12-22 | [
[
"Bonvini",
"Marco",
""
],
[
"Marzani",
"Simone",
""
],
[
"Muselli",
"Claudio",
""
]
] | In global fits of parton distribution functions (PDFs) a large fraction of data points, mostly from the HERA collider, lies in a region of $x$ and $Q^2$ that is sensitive to small-$x$ logarithmic enhancements. Thus, the proper theoretical description of these data requires the inclusion of small-$x$ resummation. In this work we provide all the necessary ingredients to perform a PDF fit to deep-inelastic scattering (DIS) data which includes small-$x$ resummation in the evolution of PDFs and in the computation of DIS structure functions. To this purpose, not only we include the resummation of DIS massless structure functions, but we also consider the production of a massive final state (e.g. a charm quark), and the consistent resummation of mass collinear logarithms through the implementation of a variable flavour number scheme at small $x$. As a result, we perform the small-$x$ resummation of the matching conditions in PDF evolution at heavy flavour thresholds. The resummed results are accurate at next-to-leading logarithmic (NLL) accuracy and matched, for the first time, to next-to-next-to-leading order (NNLO). Furthermore, we improve on our previous work by considering a novel all-order treatment of running coupling contributions. These results, which are implemented in a new release of HELL, version 2.0, will allow to fit PDFs from DIS data at the highest possible theoretical accuracy, NNLO+NLL, thus providing an important step forward towards precision determination of PDFs and consequently precision phenomenology at the LHC and beyond. |
0905.0585 | Karol Kampf | Karol Kampf | Chiral expansion for pi^0 decays | 7 pages; to appear in the proceedings of EFT'09 | PoS EFT09:030,2009 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | New ongoing experimental activities that have direct reference to pi^0 decay
modes call for a new theoretical study in this area. We will summarize some
details and interesting facts that concern main decay modes of this lightest
meson.
| [
{
"created": "Tue, 5 May 2009 12:03:51 GMT",
"version": "v1"
}
] | 2014-11-18 | [
[
"Kampf",
"Karol",
""
]
] | New ongoing experimental activities that have direct reference to pi^0 decay modes call for a new theoretical study in this area. We will summarize some details and interesting facts that concern main decay modes of this lightest meson. |
1807.07846 | Ricky Nathvani Mr | Ricky Nathvani, Lucian Harland-Lang, Robert Thorne, Alan Martin | Ad Lucem: The Photon in the MMHT PDFs | 5 pages, 4 figures, conference proceeding | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We describe the inclusion of the photon as an additional component of the
proton's Parton Distribution Functions (PDFs) in the MMHT framework. The input
for the photon is adopted from the recent LUXqed determination. We describe the
similarities and differences above the input scale with other photon PDF
determinations and the contributions to the MMHT photon from both leading twist
and higher twist contributions, and their uncertainties. We study the impact of
QED effects on the quark and gluon PDFs and the fit quality, and outline our
development of an equivalent set of neutron PDFs.
| [
{
"created": "Fri, 20 Jul 2018 14:01:37 GMT",
"version": "v1"
}
] | 2018-07-23 | [
[
"Nathvani",
"Ricky",
""
],
[
"Harland-Lang",
"Lucian",
""
],
[
"Thorne",
"Robert",
""
],
[
"Martin",
"Alan",
""
]
] | We describe the inclusion of the photon as an additional component of the proton's Parton Distribution Functions (PDFs) in the MMHT framework. The input for the photon is adopted from the recent LUXqed determination. We describe the similarities and differences above the input scale with other photon PDF determinations and the contributions to the MMHT photon from both leading twist and higher twist contributions, and their uncertainties. We study the impact of QED effects on the quark and gluon PDFs and the fit quality, and outline our development of an equivalent set of neutron PDFs. |
2002.12342 | Luis Flores | L. J. Flores, Newton Nath, E. Peinado | Non-standard neutrino interactions in $U(1)'$ model after COHERENT data | 29 pages, 4 figures, 8 tables. Included analysis with latest CENNS-10
detector data. Discussion added. Version to appear in JHEP | null | 10.1007/JHEP06(2020)045 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the potential to prove light extra gauge $Z^\prime$ boson inducing
non-standard neutrino interactions (NSIs) in the coherent-elastic
neutrino-nucleus scattering (CE$ \nu $NS) experiments. We intend to examine how
the latest COHERENT-CsI and CENNS-10 data can constrain this model. A detailed
investigation for the upcoming Ge, LAr-1t, and NaI detectors of COHERENT
collaboration has also been made. Depending on numerous other constraints
coming from oscillation experiments, muon $ (g-2) $, beam-dump experiments,
LHCb, and reactor experiment CONUS, we explore the parameter space in
$Z^\prime$ boson mass vs coupling constant plane. Moreover, we study the
predictions of two-zero textures that are allowed in the concerned model in
light of the latest global-fit data.
| [
{
"created": "Thu, 27 Feb 2020 18:57:36 GMT",
"version": "v1"
},
{
"created": "Mon, 11 May 2020 22:44:47 GMT",
"version": "v2"
}
] | 2020-07-15 | [
[
"Flores",
"L. J.",
""
],
[
"Nath",
"Newton",
""
],
[
"Peinado",
"E.",
""
]
] | We explore the potential to prove light extra gauge $Z^\prime$ boson inducing non-standard neutrino interactions (NSIs) in the coherent-elastic neutrino-nucleus scattering (CE$ \nu $NS) experiments. We intend to examine how the latest COHERENT-CsI and CENNS-10 data can constrain this model. A detailed investigation for the upcoming Ge, LAr-1t, and NaI detectors of COHERENT collaboration has also been made. Depending on numerous other constraints coming from oscillation experiments, muon $ (g-2) $, beam-dump experiments, LHCb, and reactor experiment CONUS, we explore the parameter space in $Z^\prime$ boson mass vs coupling constant plane. Moreover, we study the predictions of two-zero textures that are allowed in the concerned model in light of the latest global-fit data. |
hep-ph/9609204 | Zhi-zhong Xing | Zhi-zhong Xing | Implications of the Quark Mass Hierarchy on Flavor Mixings | Latex 19 pages including 5 PS figures | J.Phys.G23:1563-1578,1997 | 10.1088/0954-3899/23/11/006 | DPNU-96-39 | hep-ph | null | We stress that the observed pattern of flavor mixings can be partly
interpreted by the quark mass hierarchy without the assumption of specific
quark mass matrices. The quantitatively proper relations between the
Kobayashi-Maskawa matrix elements and quark mass ratios, such as $$|V_{cb}|
\approx |V_{ts}| \approx \sqrt{2} (\frac{m_s}{m_b} -\frac{m_c}{m_t}) [1 + 3
(\frac{m_s}{m_b} + \frac{m_c}{m_t} ) ],$$ are obtainable from a simple {\it
Ansatz} of flavor permutation symmetry breaking at the weak scale. We prescribe
the same {\it Ansatz} at the supersymmetric grand unified theory scale, and
find that its all low-energy consequences on flavor mixings and $CP$ violation
are in good agreement with current experimental data.
| [
{
"created": "Fri, 30 Aug 1996 12:32:20 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Xing",
"Zhi-zhong",
""
]
] | We stress that the observed pattern of flavor mixings can be partly interpreted by the quark mass hierarchy without the assumption of specific quark mass matrices. The quantitatively proper relations between the Kobayashi-Maskawa matrix elements and quark mass ratios, such as $$|V_{cb}| \approx |V_{ts}| \approx \sqrt{2} (\frac{m_s}{m_b} -\frac{m_c}{m_t}) [1 + 3 (\frac{m_s}{m_b} + \frac{m_c}{m_t} ) ],$$ are obtainable from a simple {\it Ansatz} of flavor permutation symmetry breaking at the weak scale. We prescribe the same {\it Ansatz} at the supersymmetric grand unified theory scale, and find that its all low-energy consequences on flavor mixings and $CP$ violation are in good agreement with current experimental data. |
hep-ph/9906551 | Deog Ki Hong | Deog Ki Hong, Mannque Rho, and Ismail Zahed | Qualitons At High Density | 13 pages, no figure, LaTeX. slight modifications in the manuscript | Phys.Lett. B468 (1999) 261-269 | 10.1016/S0370-2693(99)01227-7 | KIAS-P99046, HUTP-99/A036 | hep-ph hep-th nucl-th | null | In the color-flavor-locked (CFL) phase of the QCD superconductor we show that
baryons behave as qualitons (called "superqualitons") with quantum numbers
$B=(1 {\rm mod} 2)/3$, S=1/2 and Y=B. An intriguing possibility implied by this
identification is that light baryonic modes in the form of superqualitons could
be excited below the (color) superconducting gap in the CFL phase, a novel
phenomenon foreign to normal superconductors.
| [
{
"created": "Wed, 30 Jun 1999 20:39:15 GMT",
"version": "v1"
},
{
"created": "Sat, 7 Aug 1999 02:26:22 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Hong",
"Deog Ki",
""
],
[
"Rho",
"Mannque",
""
],
[
"Zahed",
"Ismail",
""
]
] | In the color-flavor-locked (CFL) phase of the QCD superconductor we show that baryons behave as qualitons (called "superqualitons") with quantum numbers $B=(1 {\rm mod} 2)/3$, S=1/2 and Y=B. An intriguing possibility implied by this identification is that light baryonic modes in the form of superqualitons could be excited below the (color) superconducting gap in the CFL phase, a novel phenomenon foreign to normal superconductors. |
1401.8183 | Branimir Radovcic | Branimir Radovcic and Sanjin Benic | Electroweak breaking and Dark Matter from the common scale | 9 pages, 2 figures, references added, published in PLB | Phys.Lett. B732 (2014) 91-94 | 10.1016/j.physletb.2014.03.018 | ZTF-EP-14-03 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a classically scale invariant extension of the Standard Model
where the electroweak symmetry breaking and the mass of the Dark Matter
particle come from the common scale. We introduce $U(1)_X$ gauge symmetry and
$X$-charged scalar $\Phi$ and Majorana fermion $N$. Scale invariance is broken
via Coleman-Weinberg mechanism providing the vacuum expectation value of the
scalar $\Phi$. Stability of the dark matter candidate $N$ is guaranteed by a
remnant $Z_2$ symmetry. The Higgs boson mass and the mass of the Dark Matter
particle have a common origin, the vacuum expectation value of $\Phi$. Dark
matter relic abundance is determined by annihilation $NN \to \Phi\Phi$. We scan
the parameter space of the model and find the mass of the dark matter particle
in the range from 500 GeV to a few TeV.
| [
{
"created": "Fri, 31 Jan 2014 14:54:58 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Mar 2014 10:42:32 GMT",
"version": "v2"
}
] | 2014-03-28 | [
[
"Radovcic",
"Branimir",
""
],
[
"Benic",
"Sanjin",
""
]
] | We propose a classically scale invariant extension of the Standard Model where the electroweak symmetry breaking and the mass of the Dark Matter particle come from the common scale. We introduce $U(1)_X$ gauge symmetry and $X$-charged scalar $\Phi$ and Majorana fermion $N$. Scale invariance is broken via Coleman-Weinberg mechanism providing the vacuum expectation value of the scalar $\Phi$. Stability of the dark matter candidate $N$ is guaranteed by a remnant $Z_2$ symmetry. The Higgs boson mass and the mass of the Dark Matter particle have a common origin, the vacuum expectation value of $\Phi$. Dark matter relic abundance is determined by annihilation $NN \to \Phi\Phi$. We scan the parameter space of the model and find the mass of the dark matter particle in the range from 500 GeV to a few TeV. |
1601.07777 | Eligio Lisi | F.Capozzi, E. Lisi, A. Marrone, D. Montanino, A. Palazzo | Neutrino masses and mixings: Status of known and unknown $3\nu$
parameters | 15 pages, 9 figures, 2 tables. Invited contribution prepared for the
Nuclear Physics B Special Issue on "Neutrino Oscillations" celebrating the
Nobel Prize in Physics 2015 | null | 10.1016/j.nuclphysb.2016.02.016 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Within the standard 3nu mass-mixing framework, we present an up-to-date
global analysis of neutrino oscillation data (as of January 2016), including
the latest available results from experiments with atmospheric neutrinos
(Super-Kamiokande and IceCube DeepCore), at accelerators (first T2K anti-nu and
NOvA nu runs in both appearance and disappearance mode), and at short-baseline
reactors (Daya Bay and RENO far/near spectral ratios), as well as a reanalysis
of older KamLAND data in the light of the "bump" feature recently observed in
reactor spectra. We discuss improved constraints on the five known oscillation
parameters (delta m^2, |Delta m^2|, sin^2theta_12, sin^2theta_13,
sin^2theta_23), and the status of the three remaining unknown parameters: the
mass hierarchy, the theta_23 octant, and the possible CP-violating phase delta.
With respect to previous global fits, we find that the reanalysis of KamLAND
data induces a slight decrease of both delta m^2 and sin^2theta_12, while the
latest accelerator and atmospheric data induce a slight increase of |Delta
m^2|. Concerning the unknown parameters, we confirm the previous intriguing
preference for negative values of sin(delta) [with best-fit values around
sin(delta) ~ -0.9], but we find no statistically significant indication about
the theta_23 octant or the mass hierarchy (normal or inverted). Assuming an
alternative (so-called LEM) analysis of NOvA data, some delta ranges can be
excluded at >3 sigma, and the normal mass hierarchy appears to be slightly
favored at 90% C.L. We also describe in detail the covariances of selected
pairs of oscillation parameters. Finally, we briefly discuss the implications
of the above results on the three non-oscillation observables sensitive to the
(unknown) absolute nu mass scale: the sum of nu masses, the effective nu_e
mass, and the effective Majorana mass.
| [
{
"created": "Thu, 28 Jan 2016 14:48:44 GMT",
"version": "v1"
}
] | 2016-06-22 | [
[
"Capozzi",
"F.",
""
],
[
"Lisi",
"E.",
""
],
[
"Marrone",
"A.",
""
],
[
"Montanino",
"D.",
""
],
[
"Palazzo",
"A.",
""
]
] | Within the standard 3nu mass-mixing framework, we present an up-to-date global analysis of neutrino oscillation data (as of January 2016), including the latest available results from experiments with atmospheric neutrinos (Super-Kamiokande and IceCube DeepCore), at accelerators (first T2K anti-nu and NOvA nu runs in both appearance and disappearance mode), and at short-baseline reactors (Daya Bay and RENO far/near spectral ratios), as well as a reanalysis of older KamLAND data in the light of the "bump" feature recently observed in reactor spectra. We discuss improved constraints on the five known oscillation parameters (delta m^2, |Delta m^2|, sin^2theta_12, sin^2theta_13, sin^2theta_23), and the status of the three remaining unknown parameters: the mass hierarchy, the theta_23 octant, and the possible CP-violating phase delta. With respect to previous global fits, we find that the reanalysis of KamLAND data induces a slight decrease of both delta m^2 and sin^2theta_12, while the latest accelerator and atmospheric data induce a slight increase of |Delta m^2|. Concerning the unknown parameters, we confirm the previous intriguing preference for negative values of sin(delta) [with best-fit values around sin(delta) ~ -0.9], but we find no statistically significant indication about the theta_23 octant or the mass hierarchy (normal or inverted). Assuming an alternative (so-called LEM) analysis of NOvA data, some delta ranges can be excluded at >3 sigma, and the normal mass hierarchy appears to be slightly favored at 90% C.L. We also describe in detail the covariances of selected pairs of oscillation parameters. Finally, we briefly discuss the implications of the above results on the three non-oscillation observables sensitive to the (unknown) absolute nu mass scale: the sum of nu masses, the effective nu_e mass, and the effective Majorana mass. |
1810.06388 | Gastaldi Ugo | Ugo Gastaldi | Decays of the f0(1370) scalar glueball candidate in pp Central Exclusive
Production (CEP) and in antiproton annihilations at rest | 8 pages, 5 figures, presented at QCD@Work-International Workshop on
QCD Theory and Experiment, 25-28 June 2018, Matera, Italy (to be published in
Proceedings). arXiv admin note: text overlap with arXiv:1809.04496 | null | 10.1051/epjconf/201819200036 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Decays into two charged pions of the f0(1370) are the main source of an
isolated structure localized between 1.2 and 1.5 GeV in the two charged pions
mass spectrum measured in pp Central Exclusive Production (CEP) at 200 GeV at
very low four momentum transfer ltl by the STAR experiment. These data confirm
in the two charged pions decay channel the existence of the f0(1370) as an
isolated well identified structure previously observed in K+K-, KsKs, 4 charged
pions, two charged and two neutral pions and 4 neutral pions decays measured in
antiproton annihilations at rest. The ensemble of these data point at a high
gluon content of the f0(1370). CEP interactions at higher energies favour
production of 0++ and 2++ mesons. Selection of events with lower ltl at both
proton vertices suppresses 2++ structures. LHC runs dedicated to pp CEP
measurements at low ltl could then provide a unique source of all the low
energy scalars. This would make it clear if and where scalar gluonium is
resident and the nature (composition in terms of quarks, antiquarks and gluons)
of f0(500), f0(980), f0(1370), f0(1500) and f0(1710).
| [
{
"created": "Thu, 11 Oct 2018 18:03:16 GMT",
"version": "v1"
}
] | 2018-12-05 | [
[
"Gastaldi",
"Ugo",
""
]
] | Decays into two charged pions of the f0(1370) are the main source of an isolated structure localized between 1.2 and 1.5 GeV in the two charged pions mass spectrum measured in pp Central Exclusive Production (CEP) at 200 GeV at very low four momentum transfer ltl by the STAR experiment. These data confirm in the two charged pions decay channel the existence of the f0(1370) as an isolated well identified structure previously observed in K+K-, KsKs, 4 charged pions, two charged and two neutral pions and 4 neutral pions decays measured in antiproton annihilations at rest. The ensemble of these data point at a high gluon content of the f0(1370). CEP interactions at higher energies favour production of 0++ and 2++ mesons. Selection of events with lower ltl at both proton vertices suppresses 2++ structures. LHC runs dedicated to pp CEP measurements at low ltl could then provide a unique source of all the low energy scalars. This would make it clear if and where scalar gluonium is resident and the nature (composition in terms of quarks, antiquarks and gluons) of f0(500), f0(980), f0(1370), f0(1500) and f0(1710). |
1202.4448 | Ran Lu | Gordon Kane, Ran Lu, Bob Zheng | Discovering Gluino Events at LHC-8 via Disappearing Chargino Tracks | 6 pages, 1 figure | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this note, we advocate a new method for identifying gluino pair production
events at the LHC. The method is motivated by and works for theories with heavy
squarks and Wino-like LSPs (with nearly degenerate LSP and chargino). Such
theories are well motivated and their gluinos typically have a O(50%) branching
ratio to charged Winos. Observing the track of a long lived charged Wino
produced from gluino decay could give a clear identification of a gluino event.
Charged Wino NLSPs produced in colliders can be long-lived enough to leave a
reconstructable high pT charged track before decaying into a soft pion (or a
soft lepton) and the LSP, a signature with low SM background. By supplementing
the canonical gluino search strategy with a search for these stiff chargino
tracks, our results suggest it will be possible to find gluinos with
significantly less luminosity. In addition, we describe a procedure for
obtaining a kinematic measurement of the gluino mass using the three momenta of
the reconstructed chargino tracks. With measurements of the gluino mass and
cross section, it will be possible to determine the gluino spin, and confirm
that the excess events are indeed due to a spin 1/2 superpartner. It may also
be possible to use these stiff Wino tracks to obtain an approximate measurement
of the chargino mass, and therefore the LSP (dark matter) mass.
| [
{
"created": "Mon, 20 Feb 2012 20:56:53 GMT",
"version": "v1"
}
] | 2012-02-23 | [
[
"Kane",
"Gordon",
""
],
[
"Lu",
"Ran",
""
],
[
"Zheng",
"Bob",
""
]
] | In this note, we advocate a new method for identifying gluino pair production events at the LHC. The method is motivated by and works for theories with heavy squarks and Wino-like LSPs (with nearly degenerate LSP and chargino). Such theories are well motivated and their gluinos typically have a O(50%) branching ratio to charged Winos. Observing the track of a long lived charged Wino produced from gluino decay could give a clear identification of a gluino event. Charged Wino NLSPs produced in colliders can be long-lived enough to leave a reconstructable high pT charged track before decaying into a soft pion (or a soft lepton) and the LSP, a signature with low SM background. By supplementing the canonical gluino search strategy with a search for these stiff chargino tracks, our results suggest it will be possible to find gluinos with significantly less luminosity. In addition, we describe a procedure for obtaining a kinematic measurement of the gluino mass using the three momenta of the reconstructed chargino tracks. With measurements of the gluino mass and cross section, it will be possible to determine the gluino spin, and confirm that the excess events are indeed due to a spin 1/2 superpartner. It may also be possible to use these stiff Wino tracks to obtain an approximate measurement of the chargino mass, and therefore the LSP (dark matter) mass. |
0910.0333 | Howard Baer | Howard Baer and Andrew D. Box | Fine-tuning favors mixed axion/axino cold dark matter over neutralinos
in the minimal supergravity model | 23 pages with 17 .eps figures | Eur.Phys.J.C68:523-537,2010 | 10.1140/epjc/s10052-010-1356-9 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Over almost all of minimal supergravity (mSUGRA or CMSSM) model parameter
space, there is a large overabundance of neutralino cold dark matter (CDM). We
find that the allowed regions of mSUGRA parameter space which match the
measured abundance of CDM in the universe are highly fine-tuned. If instead we
invoke the Peccei-Quinn-Weinberg-Wilczek solution to the strong CP problem,
then the SUSY CDM may consist of an axion/axino admixture with an axino mass of
order the MeV scale, and where mixed axion/axino or mainly axion CDM seems
preferred. In this case, fine-tuning of the relic density is typically much
lower, showing that axion/axino CDM (a\tilde{a}CDM) is to be preferred in the
paradigm model for SUSY phenomenology. For mSUGRA with a\tilde{a}CDM, quite
different regions of parameter space are now DM-favored as compared to the case
of neutralino DM. Thus, rather different SUSY signatures are expected at the
LHC in the case of mSUGRA with a\tilde{a}CDM, as compared to mSUGRA with
neutralino CDM.
| [
{
"created": "Fri, 2 Oct 2009 07:02:21 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Dec 2009 15:56:17 GMT",
"version": "v2"
},
{
"created": "Fri, 21 May 2010 14:52:26 GMT",
"version": "v3"
}
] | 2014-11-20 | [
[
"Baer",
"Howard",
""
],
[
"Box",
"Andrew D.",
""
]
] | Over almost all of minimal supergravity (mSUGRA or CMSSM) model parameter space, there is a large overabundance of neutralino cold dark matter (CDM). We find that the allowed regions of mSUGRA parameter space which match the measured abundance of CDM in the universe are highly fine-tuned. If instead we invoke the Peccei-Quinn-Weinberg-Wilczek solution to the strong CP problem, then the SUSY CDM may consist of an axion/axino admixture with an axino mass of order the MeV scale, and where mixed axion/axino or mainly axion CDM seems preferred. In this case, fine-tuning of the relic density is typically much lower, showing that axion/axino CDM (a\tilde{a}CDM) is to be preferred in the paradigm model for SUSY phenomenology. For mSUGRA with a\tilde{a}CDM, quite different regions of parameter space are now DM-favored as compared to the case of neutralino DM. Thus, rather different SUSY signatures are expected at the LHC in the case of mSUGRA with a\tilde{a}CDM, as compared to mSUGRA with neutralino CDM. |
0811.3470 | Yoshio Koide | Yoshio Koide | Charged Lepton Mass Relations in a Supersymmetric Yukawaon Model | 9 pages, no figure, final version to appear in Phys.Rev.D | Phys.Rev.D79:033009,2009 | 10.1103/PhysRevD.79.033009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | According to an idea that effective Yukawa coupling constants Y_f^{eff} are
given vacuum expectation values < Y_f> of fields ("Yukawaons") Y_f as
Y_f^{eff}=y_f < Y_f>/\Lambda, a possible superpotential form in the charged
lepton sector under a U(3) [or O(3)] flavor symmetry is investigated. It is
found that a specific form of the superpotential can lead to an empirical
charged lepton mass relation without any adjustable parameters.
| [
{
"created": "Fri, 21 Nov 2008 05:22:12 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Feb 2009 07:30:13 GMT",
"version": "v2"
}
] | 2010-01-15 | [
[
"Koide",
"Yoshio",
""
]
] | According to an idea that effective Yukawa coupling constants Y_f^{eff} are given vacuum expectation values < Y_f> of fields ("Yukawaons") Y_f as Y_f^{eff}=y_f < Y_f>/\Lambda, a possible superpotential form in the charged lepton sector under a U(3) [or O(3)] flavor symmetry is investigated. It is found that a specific form of the superpotential can lead to an empirical charged lepton mass relation without any adjustable parameters. |
0804.0336 | Osamu Seto | Shaaban Khalil and Osamu Seto | Sterile neutrino dark matter in $B-L$ extension of the standard model
and galactic 511 keV line | 10 pages, 1 figure, references added, final version appeared in JCAP | JCAP 0810:024,2008 | 10.1088/1475-7516/2008/10/024 | IFT-UAM/CSIC08-19 | hep-ph astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Sterile right-handed neutrinos can be naturally embedded in a low scale
gauged $U(1)_{B-L}$ extension of the standard model. We show that, within a low
reheating scenario, such a neutrino is an interesting candidate for dark
matter. We emphasize that if the neutrino mass is of order of MeV, then it
accounts for the measured dark matter relic density and also accommodates the
observed flux of 511 keV photons from the galactic bulge.
| [
{
"created": "Wed, 2 Apr 2008 11:46:25 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Dec 2008 17:59:58 GMT",
"version": "v2"
}
] | 2009-02-09 | [
[
"Khalil",
"Shaaban",
""
],
[
"Seto",
"Osamu",
""
]
] | Sterile right-handed neutrinos can be naturally embedded in a low scale gauged $U(1)_{B-L}$ extension of the standard model. We show that, within a low reheating scenario, such a neutrino is an interesting candidate for dark matter. We emphasize that if the neutrino mass is of order of MeV, then it accounts for the measured dark matter relic density and also accommodates the observed flux of 511 keV photons from the galactic bulge. |
1605.01398 | Liliana Velasco-Sevilla | John Ellis (1 and 2), Keith Olive (3) and Liliana Velasco-Sevilla (4)
((1) King's Coll. London, (2) CERN, (3) Minnesota U., Theor. Phys. Inst., (4)
University of Bergen, DPT) | Maximal Sfermion Flavor Violation in Super-GUTs | 38 pp, 16 figures. Change of title to describe better the scope of
the work, minor comments added, one reference added, matches published
version | null | 10.1140/epjc/s10052-016-4398-9 | KCL-PH-TH/2016-20, LCTS/2016-13, CERN-PH-TH/2016-095,
UMN-TH-3526/16, FTPI-MINN-16/16 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider supersymmetric grand unified theories with soft
supersymmetry-breaking scalar masses $m_0$ specified above the GUT scale
(super-GUTs) and patterns of Yukawa couplings motivated by upper limits on
flavour-changing interactions beyond the Standard Model. If the scalar masses
are smaller than the gaugino masses $m_{1/2}$, as is expected in no-scale
models, the dominant effects of renormalization between the input scale and the
GUT scale are generally expected to be those due to the gauge couplings, which
are proportional to $m_{1/2}$ and generation-independent. In this case, the
input scalar masses $m_0$ may violate flavour maximally, a scenario we call
MaxSFV, and there is no supersymmetric flavour problem. We illustrate this
possibility within various specific super-GUT scenarios that are deformations
of no-scale gravity.
| [
{
"created": "Wed, 4 May 2016 19:49:37 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Oct 2016 18:50:10 GMT",
"version": "v2"
}
] | 2016-11-23 | [
[
"Ellis",
"John",
"",
"1 and 2"
],
[
"Olive",
"Keith",
""
],
[
"Velasco-Sevilla",
"Liliana",
""
]
] | We consider supersymmetric grand unified theories with soft supersymmetry-breaking scalar masses $m_0$ specified above the GUT scale (super-GUTs) and patterns of Yukawa couplings motivated by upper limits on flavour-changing interactions beyond the Standard Model. If the scalar masses are smaller than the gaugino masses $m_{1/2}$, as is expected in no-scale models, the dominant effects of renormalization between the input scale and the GUT scale are generally expected to be those due to the gauge couplings, which are proportional to $m_{1/2}$ and generation-independent. In this case, the input scalar masses $m_0$ may violate flavour maximally, a scenario we call MaxSFV, and there is no supersymmetric flavour problem. We illustrate this possibility within various specific super-GUT scenarios that are deformations of no-scale gravity. |
2206.14259 | Geraldine Servant | Cem Er\"oncel, Ryosuke Sato, Geraldine Servant, Philip S{\o}rensen | ALP Dark Matter from Kinetic Fragmentation: Opening up the Parameter
Window | 38 pages (main text) + 16 pages (appendices) + 9 pages (references),
16 figures | null | 10.1088/1475-7516/2022/10/053 | DESY 22-106, OU-HET-1148 | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | The main mechanism responsible for Axion-Like-Particle (ALP) production in
the early universe is the so-called misalignment mechanism. Three regimes have
been investigated in this context: standard misalignment, large misalignment
and kinetic misalignment. The latter applies if the axion inherits a large
initial velocity in the early universe, such that the field rolls through many
wiggles during its evolution, before it gets trapped in one minimum. This
largely opens the region of parameter space for ALP dark matter towards higher
values for the axion-photon coupling, which can be probed by the whole set of
next decade's upcoming experiments. In fact, almost the entire parameter space
in the [mass, decay constant] plane can now accommodate dark matter. In this
paper, we show that in kinetic misalignment, the axion field is almost always
entirely fragmented, meaning that the energy density of the homogeneous field
is redistributed over higher-mode axions. We present a general
model-independent analytical description of kinetic fragmentation, including
discussion of the modified initial conditions for the mode functions due to the
axion's initial velocity, and how they impact the growth of the adiabatic
fluctuations. We calculate precisely the parameter regions corresponding
respectively to standard misalignment, kinetic misalignment with weak
fragmentation, fragmentation after trapping and fragmentation before trapping.
While axion fragmentation can impact the precise determination of the relic
abundance, another main observational implication is the formation of much
denser compact axion halos, that is described in a companion paper. We also
point out a new gravitational-wave signature that arises in the large
misalignment regime with complete fragmentation and could be seen in
measurements of $\mu$ distortions in the Cosmic Microwave Background.
| [
{
"created": "Tue, 28 Jun 2022 19:23:07 GMT",
"version": "v1"
}
] | 2022-10-26 | [
[
"Eröncel",
"Cem",
""
],
[
"Sato",
"Ryosuke",
""
],
[
"Servant",
"Geraldine",
""
],
[
"Sørensen",
"Philip",
""
]
] | The main mechanism responsible for Axion-Like-Particle (ALP) production in the early universe is the so-called misalignment mechanism. Three regimes have been investigated in this context: standard misalignment, large misalignment and kinetic misalignment. The latter applies if the axion inherits a large initial velocity in the early universe, such that the field rolls through many wiggles during its evolution, before it gets trapped in one minimum. This largely opens the region of parameter space for ALP dark matter towards higher values for the axion-photon coupling, which can be probed by the whole set of next decade's upcoming experiments. In fact, almost the entire parameter space in the [mass, decay constant] plane can now accommodate dark matter. In this paper, we show that in kinetic misalignment, the axion field is almost always entirely fragmented, meaning that the energy density of the homogeneous field is redistributed over higher-mode axions. We present a general model-independent analytical description of kinetic fragmentation, including discussion of the modified initial conditions for the mode functions due to the axion's initial velocity, and how they impact the growth of the adiabatic fluctuations. We calculate precisely the parameter regions corresponding respectively to standard misalignment, kinetic misalignment with weak fragmentation, fragmentation after trapping and fragmentation before trapping. While axion fragmentation can impact the precise determination of the relic abundance, another main observational implication is the formation of much denser compact axion halos, that is described in a companion paper. We also point out a new gravitational-wave signature that arises in the large misalignment regime with complete fragmentation and could be seen in measurements of $\mu$ distortions in the Cosmic Microwave Background. |
hep-ph/9705407 | Sergei Bashinsky | S. V. Bashinsky and R. L. Jaffe (CTP, MIT) | Quark States near a Threshold and the Unstable H-dibaryon | 28 pages, 7 figures, RevTeX, uses aps.sty, fps.sty | Nucl.Phys.A625:167-191,1997 | 10.1016/S0375-9474(97)81459-5 | MIT-CTP-2643 | hep-ph | null | We consider the interplay of a quark state and a hadronic threshold in the
framework of the P-matrix formalism, which is reviewed and extended for use
together with conventional methods of computing quark-gluon dynamics. We
provide a quantitative dynamical interpretation of the reduced R or K matrices
and their poles that suggests a natural classification of threshold phenomena.
At a threshold with a quark state close to it up to three S-matrix poles can be
found. The scattering amplitudes for the corresponding cases are discussed. Our
analysis is applied to make an outlook for experimental observation of the
doubly strange H-dibaryon if it is not stable to strong decays.
| [
{
"created": "Fri, 23 May 1997 16:55:57 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Bashinsky",
"S. V.",
"",
"CTP, MIT"
],
[
"Jaffe",
"R. L.",
"",
"CTP, MIT"
]
] | We consider the interplay of a quark state and a hadronic threshold in the framework of the P-matrix formalism, which is reviewed and extended for use together with conventional methods of computing quark-gluon dynamics. We provide a quantitative dynamical interpretation of the reduced R or K matrices and their poles that suggests a natural classification of threshold phenomena. At a threshold with a quark state close to it up to three S-matrix poles can be found. The scattering amplitudes for the corresponding cases are discussed. Our analysis is applied to make an outlook for experimental observation of the doubly strange H-dibaryon if it is not stable to strong decays. |
hep-ph/0012298 | Lev Kofman | Lev Kofman (U. of Toronto) | Preheating, Thermalization and Supergravity | 15 pages, latex, 8 figures, talk at Dark2000, Heidelberg | null | null | CITA-00-62 | hep-ph astro-ph hep-th | null | This contribution to the proceedings collects new recent results on
preheating after inflation. We discuss tachyonic preheating in the SUSY
motivated hybrid inflation; development of equilibrium after preheating; theory
of fermionic preheating and the problem of gravitino overproduction from
preheating.
| [
{
"created": "Thu, 21 Dec 2000 18:56:03 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kofman",
"Lev",
"",
"U. of Toronto"
]
] | This contribution to the proceedings collects new recent results on preheating after inflation. We discuss tachyonic preheating in the SUSY motivated hybrid inflation; development of equilibrium after preheating; theory of fermionic preheating and the problem of gravitino overproduction from preheating. |
1912.07529 | Craig Roberts | Minghui Ding, Kh\'epani Raya, Daniele Binosi, Lei Chang, Craig D.
Roberts and Sebastian M. Schmidt | Drawing insights from pion parton distributions | 6 pages, 1 figure. To be published as a Letter in Chinese Physics C.
arXiv admin note: substantial text overlap with arXiv:1905.05208 | null | 10.1088/1674-1137/44/3/031002 | NJU-INP 012/19 | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A symmetry-preserving continuum approach to the two valence-body bound-state
problem is used to calculate the valence, glue and sea distributions within the
pion; unifying them with, inter alia, electromagnetic pion elastic and
transition form factors. The analysis reveals the following momentum fractions
at the scale $\zeta_2:=2\,$GeV: $\langle x_{\rm valence} \rangle = 0.48(3)$,
$\langle x_{\rm glue} \rangle = 0.41(2)$, $\langle x_{\rm sea} \rangle =
0.11(2)$; and despite hardening induced by the emergent phenomenon of dynamical
chiral symmetry breaking, the valence-quark distribution function,
${q}^\pi(x)$, exhibits the $x\simeq 1$ behaviour predicted by quantum
chromodynamics (QCD). After evolution to $\zeta=5.2\,$GeV, the prediction for
${q}^\pi(x)$ matches that obtained using lattice-regularised QCD. This
confluence should both stimulate improved analyses of existing data and aid in
planning efforts to obtain new data on the pion distribution functions.
| [
{
"created": "Fri, 13 Dec 2019 03:45:57 GMT",
"version": "v1"
}
] | 2020-04-22 | [
[
"Ding",
"Minghui",
""
],
[
"Raya",
"Khépani",
""
],
[
"Binosi",
"Daniele",
""
],
[
"Chang",
"Lei",
""
],
[
"Roberts",
"Craig D.",
""
],
[
"Schmidt",
"Sebastian M.",
""
]
] | A symmetry-preserving continuum approach to the two valence-body bound-state problem is used to calculate the valence, glue and sea distributions within the pion; unifying them with, inter alia, electromagnetic pion elastic and transition form factors. The analysis reveals the following momentum fractions at the scale $\zeta_2:=2\,$GeV: $\langle x_{\rm valence} \rangle = 0.48(3)$, $\langle x_{\rm glue} \rangle = 0.41(2)$, $\langle x_{\rm sea} \rangle = 0.11(2)$; and despite hardening induced by the emergent phenomenon of dynamical chiral symmetry breaking, the valence-quark distribution function, ${q}^\pi(x)$, exhibits the $x\simeq 1$ behaviour predicted by quantum chromodynamics (QCD). After evolution to $\zeta=5.2\,$GeV, the prediction for ${q}^\pi(x)$ matches that obtained using lattice-regularised QCD. This confluence should both stimulate improved analyses of existing data and aid in planning efforts to obtain new data on the pion distribution functions. |
1410.0601 | Grigory Ovanesyan | Grigory Ovanesyan, Luca Vecchi | Direct detection of dark matter polarizability | 18 pages in JHEP style, 3 figures, and an appendix; published version | null | null | null | hep-ph astro-ph.CO astro-ph.HE nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We point out that the direct detection of dark matter via its
electro-magnetic polarizability is described by two new nuclear form factors,
which are controlled by the 2-nucleon nuclear density. The signature manifests
a peculiar dependence on the atomic and mass numbers of the target nuclei, as
well as on the momentum transfer, and can differ significantly from experiment
to experiment. We also discuss UV completions of our scenario.
| [
{
"created": "Thu, 2 Oct 2014 16:17:05 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Aug 2015 21:45:23 GMT",
"version": "v2"
}
] | 2015-08-07 | [
[
"Ovanesyan",
"Grigory",
""
],
[
"Vecchi",
"Luca",
""
]
] | We point out that the direct detection of dark matter via its electro-magnetic polarizability is described by two new nuclear form factors, which are controlled by the 2-nucleon nuclear density. The signature manifests a peculiar dependence on the atomic and mass numbers of the target nuclei, as well as on the momentum transfer, and can differ significantly from experiment to experiment. We also discuss UV completions of our scenario. |
1011.2206 | Michael Rauch | G. Bozzi, F. Campanario, M. Rauch, H. Rzehak, D. Zeppenfeld | NLO QCD corrections to $W^\pm Z\gamma$ production with leptonic decays | 13 pages, 2 tables, 7 figures | Phys.Lett.B696:380-385,2011 | 10.1016/j.physletb.2010.12.051 | FTUV--10--1109, KA--TP--33--2010, SFB/CPP-10-96, IFUM-967-FT | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a computation of the O(alpha_s) QCD corrections to W^\pm Z \gamma
production at the Large Hadron Collider. The photon is considered as real, and
we include full leptonic decays for the W and Z bosons. Based on the structure
of the VBFNLO program package, we obtain numerical results through a fully
flexible Monte Carlo program, which allows to implement general cuts and
distributions of the final-state particles. The NLO QCD corrections are sizable
and strongly exceed the theory error obtained by a scale variation of the
leading-order result. Also, the shapes of relevant observables are
significantly altered.
| [
{
"created": "Tue, 9 Nov 2010 21:00:09 GMT",
"version": "v1"
}
] | 2011-02-03 | [
[
"Bozzi",
"G.",
""
],
[
"Campanario",
"F.",
""
],
[
"Rauch",
"M.",
""
],
[
"Rzehak",
"H.",
""
],
[
"Zeppenfeld",
"D.",
""
]
] | We present a computation of the O(alpha_s) QCD corrections to W^\pm Z \gamma production at the Large Hadron Collider. The photon is considered as real, and we include full leptonic decays for the W and Z bosons. Based on the structure of the VBFNLO program package, we obtain numerical results through a fully flexible Monte Carlo program, which allows to implement general cuts and distributions of the final-state particles. The NLO QCD corrections are sizable and strongly exceed the theory error obtained by a scale variation of the leading-order result. Also, the shapes of relevant observables are significantly altered. |
1912.00008 | Wei-Liang Qian | Hong-Hao Ma, Kai Lin, Wei-Liang Qian, Bin Wang | Centrality dependence of multiplicity fluctuations from a hydrodynamical
approach | 10 pages, 2 figures. arXiv admin note: text overlap with
arXiv:1910.00705 | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | As one of the possible signals for the whereabouts of the critical point on
the QCD phase diagram, recently, the multiplicity fluctuations in heavy-ion
collisions have aroused much attention. It is a crucial observable of the Beam
Energy Scan program of the Relativistic Heavy Ion Collider. In this work, we
investigate the centrality dependence of the multiplicity fluctuations
regarding the recent measurements from STAR Collaboration. By employing a
hydrodynamical approach, the present study is dedicated to the noncritical
aspects of the phenomenon. To be specific, in addition to the thermal
fluctuations, finite volume corrections, and resonance decay at the freeze-out
surface, the model is focused on the properties of the hydrodynamic expansion
of the system and the event-by-event initial fluctuations. It is understood
that the real signal of the critical point can only be obtained after
appropriately subtracting the background, the latter is investigated in the
present work. Besides the experimental data, our results are also compared to
those of the hadronic resonance gas, as well as transport models.
| [
{
"created": "Fri, 29 Nov 2019 04:19:53 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Jan 2020 11:54:30 GMT",
"version": "v2"
}
] | 2020-01-24 | [
[
"Ma",
"Hong-Hao",
""
],
[
"Lin",
"Kai",
""
],
[
"Qian",
"Wei-Liang",
""
],
[
"Wang",
"Bin",
""
]
] | As one of the possible signals for the whereabouts of the critical point on the QCD phase diagram, recently, the multiplicity fluctuations in heavy-ion collisions have aroused much attention. It is a crucial observable of the Beam Energy Scan program of the Relativistic Heavy Ion Collider. In this work, we investigate the centrality dependence of the multiplicity fluctuations regarding the recent measurements from STAR Collaboration. By employing a hydrodynamical approach, the present study is dedicated to the noncritical aspects of the phenomenon. To be specific, in addition to the thermal fluctuations, finite volume corrections, and resonance decay at the freeze-out surface, the model is focused on the properties of the hydrodynamic expansion of the system and the event-by-event initial fluctuations. It is understood that the real signal of the critical point can only be obtained after appropriately subtracting the background, the latter is investigated in the present work. Besides the experimental data, our results are also compared to those of the hadronic resonance gas, as well as transport models. |
2009.13740 | Jos\'e Luis Hern\'andez Hern\'andez | Alejandro Ayala, Jos\'e Luis Hern\'andez, L. A. Hern\'andez, Ricardo
L. S. Farias and R. Zamora | Magnetic corrections to the boson self-coupling and boson-fermion
coupling in the linear sigma model with quarks | 14 pages, 6 figures, expanded discussion, conclusions unchanged,
version to appear in Phys. Rev. D | Phys. Rev. D 102, 114038 (2020) | 10.1103/PhysRevD.102.114038 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute the magnetic field-induced modifications to the boson
self-coupling and the boson-fermion coupling, in the static limit, using an
effective model of QCD, the linear sigma model with quarks. The former is
computed for arbitrary field strengths as well as using the strong field
approximation. The latter is obtained in the strong field limit. The arbitrary
field result for the boson self-coupling depends on the ultraviolet
renormalization scale and this dependence cannot be removed by a simple vacuum
subtraction. Using the strong field result as a guide, we find the appropriate
choice for this scale and discuss the physical implications. The boson-fermion
coupling depends on the Schwinger's phase and we show how this phase can be
treated consistently in such a way that the magnetic field induced vertex
modification is both gauge invariant and can be written with an explicit factor
corresponding to energy-momentum conservation for the external particles. Both
couplings show a modest decrease with the field strength.
| [
{
"created": "Tue, 29 Sep 2020 03:01:56 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Dec 2020 20:12:23 GMT",
"version": "v2"
}
] | 2021-01-04 | [
[
"Ayala",
"Alejandro",
""
],
[
"Hernández",
"José Luis",
""
],
[
"Hernández",
"L. A.",
""
],
[
"Farias",
"Ricardo L. S.",
""
],
[
"Zamora",
"R.",
""
]
] | We compute the magnetic field-induced modifications to the boson self-coupling and the boson-fermion coupling, in the static limit, using an effective model of QCD, the linear sigma model with quarks. The former is computed for arbitrary field strengths as well as using the strong field approximation. The latter is obtained in the strong field limit. The arbitrary field result for the boson self-coupling depends on the ultraviolet renormalization scale and this dependence cannot be removed by a simple vacuum subtraction. Using the strong field result as a guide, we find the appropriate choice for this scale and discuss the physical implications. The boson-fermion coupling depends on the Schwinger's phase and we show how this phase can be treated consistently in such a way that the magnetic field induced vertex modification is both gauge invariant and can be written with an explicit factor corresponding to energy-momentum conservation for the external particles. Both couplings show a modest decrease with the field strength. |
1110.1211 | Yuryi A. Tarasov | Yu.A. Tarasov | Collisional energy losses of heavy quarks in relativistic nuclear
collisions at energies available at the BNL Relativistic Heavy Ion Collider | 8 pages, 3 figures | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the energy losses of $b$ and $c$ quarks at hard collisions
with gluons and light quarks in quark-gluon plasma produced in central $Au +
Au$ collisions at RHIC energy($\sqrt{s_{NN}} = 200$ GeV). As the coupling
constant at hard collision in the perturbative QCD is limited by Landau pole at
momenta $Q^{2} = \Lambda^{2}$, we use the analytic models of QCD, where the
Landau pole is absent. We calculate the energy losses of $b$ and $c$ quarks in
analytic model of QCD at $Q^{2} \ge \Lambda^{2}$. At calculations we use the
effective quasiparticle model. We use at calculations of total nuclear
modification factor $R_{AA}^{b+c}$ the fragmentation of $b$ and $c$ quarks into
heavy hadrons with accounting theirs energy losses. We show that this factor
gives the considerably suppression of heavy $B$ and $D$ mesons in the region of
middle meanings of $p_{\perp}$. The experimental data \cite{2} show, that
nonphotonic electrons have the analogous suppression in the same region of
$p_{\perp}$.
| [
{
"created": "Thu, 6 Oct 2011 10:27:17 GMT",
"version": "v1"
}
] | 2011-10-07 | [
[
"Tarasov",
"Yu. A.",
""
]
] | We investigate the energy losses of $b$ and $c$ quarks at hard collisions with gluons and light quarks in quark-gluon plasma produced in central $Au + Au$ collisions at RHIC energy($\sqrt{s_{NN}} = 200$ GeV). As the coupling constant at hard collision in the perturbative QCD is limited by Landau pole at momenta $Q^{2} = \Lambda^{2}$, we use the analytic models of QCD, where the Landau pole is absent. We calculate the energy losses of $b$ and $c$ quarks in analytic model of QCD at $Q^{2} \ge \Lambda^{2}$. At calculations we use the effective quasiparticle model. We use at calculations of total nuclear modification factor $R_{AA}^{b+c}$ the fragmentation of $b$ and $c$ quarks into heavy hadrons with accounting theirs energy losses. We show that this factor gives the considerably suppression of heavy $B$ and $D$ mesons in the region of middle meanings of $p_{\perp}$. The experimental data \cite{2} show, that nonphotonic electrons have the analogous suppression in the same region of $p_{\perp}$. |
hep-ph/9804249 | Changhao Jin | Changhao Jin | Determinations of |V_ub| and |V_cb| from measurements of B ->
X_u,c\ell\nu differential decay rates | 11 pages, 2 figures, version as published in Mod. Phys. Lett. A, more
discussion, references added, title change | Mod. Phys. Lett. A 14 (1999) 1163-1173 | 10.1142/S0217732399001255 | null | hep-ph hep-ex | null | Methods are described in the framework of light-cone expansion which allow
one to determine the Cabibbo-Kobayashi-Maskawa matrix elements |V_ub| and
|V_cb| from measurements of the differential decay rates as a function of the
scaling variables in the inclusive semileptonic decays of B mesons. By these
model-independent methods the dominant hadronic uncertainties can be avoided
and the B -> X_u\ell\nu decay can be very efficiently differentiated from the B
-> X_c\ell\nu decay, which may lead to precise determinations of |V_ub| and
|V_cb|.
| [
{
"created": "Tue, 7 Apr 1998 14:56:39 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Jul 1999 07:45:12 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Jin",
"Changhao",
""
]
] | Methods are described in the framework of light-cone expansion which allow one to determine the Cabibbo-Kobayashi-Maskawa matrix elements |V_ub| and |V_cb| from measurements of the differential decay rates as a function of the scaling variables in the inclusive semileptonic decays of B mesons. By these model-independent methods the dominant hadronic uncertainties can be avoided and the B -> X_u\ell\nu decay can be very efficiently differentiated from the B -> X_c\ell\nu decay, which may lead to precise determinations of |V_ub| and |V_cb|. |
1108.1220 | Juan Barranco | J. Barranco, A. Bolanos, E. A. Garces, O. G. Miranda and T. I. Rashba | Tensorial NSI and Unparticle physics in neutrino scattering | 15 pages, 6 figures, 2 tables. Accepted for publication in
International Journal of Modern Physics A | null | 10.1142/S0217751X12501473 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have analyzed the electron anti-neutrino scattering off electrons and the
electron anti-neutrino-nuclei coherent scattering in order to obtain
constraints on tensorial couplings. We have studied the formalism of
non-standard interactions (NSI), as well as the case of Unparticle physics. For
our analysis we have focused on the recent TEXONO collaboration results and we
have obtained current constraints to possible electron anti-neutrino-electron
tensorial couplings in both new physics formalisms. The possibility of
measuring for the first time electron anti-neutrino-nucleus coherent scattering
and its potential to further constrain electron anti-neutrino-quark tensorial
couplings is also discussed.
| [
{
"created": "Thu, 4 Aug 2011 21:05:21 GMT",
"version": "v1"
},
{
"created": "Fri, 31 Aug 2012 22:37:31 GMT",
"version": "v2"
}
] | 2012-10-04 | [
[
"Barranco",
"J.",
""
],
[
"Bolanos",
"A.",
""
],
[
"Garces",
"E. A.",
""
],
[
"Miranda",
"O. G.",
""
],
[
"Rashba",
"T. I.",
""
]
] | We have analyzed the electron anti-neutrino scattering off electrons and the electron anti-neutrino-nuclei coherent scattering in order to obtain constraints on tensorial couplings. We have studied the formalism of non-standard interactions (NSI), as well as the case of Unparticle physics. For our analysis we have focused on the recent TEXONO collaboration results and we have obtained current constraints to possible electron anti-neutrino-electron tensorial couplings in both new physics formalisms. The possibility of measuring for the first time electron anti-neutrino-nucleus coherent scattering and its potential to further constrain electron anti-neutrino-quark tensorial couplings is also discussed. |
0802.1481 | Basudeb Dasgupta | Basudeb Dasgupta, Amol Dighe (Tata Inst., Mumbai), Alessandro Mirizzi
(Max Planck Inst., Munich) | Identifying neutrino mass hierarchy at extremely small theta(13) through
Earth matter effects in a supernova signal | Final version: Text clarified, references updated. Matches the
version published in Physical Review Letters | Phys.Rev.Lett.101:171801,2008 | 10.1103/PhysRevLett.101.171801 | MPP-2008-14; TIFR/TH/08-04 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Collective neutrino flavor transformations deep inside a supernova are
sensitive to the neutrino mass hierarchy even at extremely small values of
theta(13). Exploiting this effect, we show that comparison of the antineutrino
signals from a galactic supernova in two megaton class water Cherenkov
detectors, one of which is shadowed by the Earth, will enable us to distinguish
between the hierarchies if sin^2 theta(13) < 10^{-5}. On the other hand, the
observation of Earth effects in the inverted hierarchy for sin^2 theta(13) >
10^{-3} will provide a robust observable signature of collective oscillations
occurring deep inside the supernova.
| [
{
"created": "Mon, 11 Feb 2008 17:34:13 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Feb 2008 20:20:40 GMT",
"version": "v2"
},
{
"created": "Mon, 20 Oct 2008 18:14:42 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Dasgupta",
"Basudeb",
"",
"Tata Inst., Mumbai"
],
[
"Dighe",
"Amol",
"",
"Tata Inst., Mumbai"
],
[
"Mirizzi",
"Alessandro",
"",
"Max Planck Inst., Munich"
]
] | Collective neutrino flavor transformations deep inside a supernova are sensitive to the neutrino mass hierarchy even at extremely small values of theta(13). Exploiting this effect, we show that comparison of the antineutrino signals from a galactic supernova in two megaton class water Cherenkov detectors, one of which is shadowed by the Earth, will enable us to distinguish between the hierarchies if sin^2 theta(13) < 10^{-5}. On the other hand, the observation of Earth effects in the inverted hierarchy for sin^2 theta(13) > 10^{-3} will provide a robust observable signature of collective oscillations occurring deep inside the supernova. |
1006.5331 | Jonathan Parry | J.K. Parry | The like-sign dimuon charge asymmetry in SUSY models | 4 pages, 4 eps figures, version accepted for publication | Phys.Lett.B694:363-366,2011 | 10.1016/j.physletb.2010.10.011 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the new physics (NP) implications of the recently reported 3.2 sigma
Standard Model (SM) deviation in the like-sign dimuon asymmetry at the
Tevatron. Assuming that new physics only enters the B(s) mixing amplitude we
explore the implications for generic new physics, general supersymmetric (SUSY)
models and also SUSY SU(5). In the case of SUSY SU(5) we exploit the GUT scale
relationship between slepton and squark soft masses to predict rates for lepton
flavour violation (LFV). The predicted rates for tau --> mu + gamma are found
to be detectable at future Super-B factories.
| [
{
"created": "Mon, 28 Jun 2010 12:33:43 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Feb 2011 04:05:25 GMT",
"version": "v2"
}
] | 2011-02-09 | [
[
"Parry",
"J. K.",
""
]
] | We study the new physics (NP) implications of the recently reported 3.2 sigma Standard Model (SM) deviation in the like-sign dimuon asymmetry at the Tevatron. Assuming that new physics only enters the B(s) mixing amplitude we explore the implications for generic new physics, general supersymmetric (SUSY) models and also SUSY SU(5). In the case of SUSY SU(5) we exploit the GUT scale relationship between slepton and squark soft masses to predict rates for lepton flavour violation (LFV). The predicted rates for tau --> mu + gamma are found to be detectable at future Super-B factories. |
0909.5643 | Rouzbeh Allahverdi | Rouzbeh Allahverdi | Sneutrino dark matter in light of PAMELA | 4 pages, 2 figures. Submitted conference proceedings, based on a talk
presented at SUSY 2009 conference | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the U(1)_{B-L} extension of the minimal supersymmetric standard model the
right-handed sneutrino is a natural candidate for thermal dark matter.
Sneutrino annihilation at the present time can be considerably enhanced due to
the exchange of the lightest field in the Higgs sector that breaks U(1)_{B-L}.
The annihilation mainly produces taus (or muons) by the virtue of B-L charge
assignments. A sneutrino mass of 1-2 TeV provides a good fit to the PAMELA and
is compatible with the latest results from the FERMI experiment. In addition,
the sneutrino-nucleon elastic scattering cross section is within the reach of
the upcoming and future direct detection experiments.
| [
{
"created": "Wed, 30 Sep 2009 15:43:04 GMT",
"version": "v1"
}
] | 2009-10-01 | [
[
"Allahverdi",
"Rouzbeh",
""
]
] | In the U(1)_{B-L} extension of the minimal supersymmetric standard model the right-handed sneutrino is a natural candidate for thermal dark matter. Sneutrino annihilation at the present time can be considerably enhanced due to the exchange of the lightest field in the Higgs sector that breaks U(1)_{B-L}. The annihilation mainly produces taus (or muons) by the virtue of B-L charge assignments. A sneutrino mass of 1-2 TeV provides a good fit to the PAMELA and is compatible with the latest results from the FERMI experiment. In addition, the sneutrino-nucleon elastic scattering cross section is within the reach of the upcoming and future direct detection experiments. |
hep-ph/0105326 | Kang-young Lee | Kang Young Lee, JeongHyeon Song (KIAS), Seong Chan Park, H. S. Song,
Chaehyun Yu (SNU) | Probing large extra dimensions with spin configuration of top quark pair
production at the JLC | 14 pages, 4 figures. To be published in the proceedings of the theory
meeting on physics at Linear Colliders, 15 - 17 March 2001, KEK, Japan | null | null | KIAS P01030 | hep-ph | null | We explore signatures of large extra dimensions with a polarized
electron/positrn beam at the Joint Linear Collider (JLC). We point out that
spin informations can be useful to study indirect signals for large extra
dimensions due to spin-2 nature of Kaluza-Klein gravitons. The spin
configurations of the top quark pair production at $e^+ e^-$ and $\gamma
\gamma$ collisions provide an unique testing ground to search for effects of
the large extra dimensions. Especially we show the forward-backward asymmetry
is a good probe at $e^+ e^- \to t \bar{t}$ process and we can define a new
asymmetry observable effective for $\gamma \gamma \to t \bar{t}$ process.
| [
{
"created": "Wed, 30 May 2001 17:57:42 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Jun 2001 02:58:57 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Lee",
"Kang Young",
"",
"KIAS"
],
[
"Song",
"JeongHyeon",
"",
"KIAS"
],
[
"Park",
"Seong Chan",
"",
"SNU"
],
[
"Song",
"H. S.",
"",
"SNU"
],
[
"Yu",
"Chaehyun",
"",
"SNU"
]
] | We explore signatures of large extra dimensions with a polarized electron/positrn beam at the Joint Linear Collider (JLC). We point out that spin informations can be useful to study indirect signals for large extra dimensions due to spin-2 nature of Kaluza-Klein gravitons. The spin configurations of the top quark pair production at $e^+ e^-$ and $\gamma \gamma$ collisions provide an unique testing ground to search for effects of the large extra dimensions. Especially we show the forward-backward asymmetry is a good probe at $e^+ e^- \to t \bar{t}$ process and we can define a new asymmetry observable effective for $\gamma \gamma \to t \bar{t}$ process. |
hep-ph/0105251 | Jim Cline | James M. Cline | Quintessence, Cosmological Horizons, and Self-Tuning | 13 pp., 5 figures; references added | JHEP 0108:035,2001 | 10.1088/1126-6708/2001/08/035 | MCGILL-01-12 | hep-ph astro-ph hep-th | null | We point out that quintessence with an exponential potential V_0 exp(- beta
phi / 3^{1/2} M_p) can account for the present observed acceleration of the
universe, without necessarily leading to eternal acceleration. This occurs for
2.4 < beta < 2.8. Thus a cosmological horizon, which is supposed to be
problematic within the context of string theory, can be avoided. We argue that
this class of models is not particularly fine-tuned. We further examine this
question in the context of a modified Friedmann equation, H^2 ~ rho + p, which
is suggested by higher dimensional self-tuning approaches to the cosmological
constant problem. It is shown that the self-tuning case can also be consistent
with observations, if 1.8 < beta < 2.4. Future observations of high-z
supernovae will be able to test whether beta lies in the desired range.
| [
{
"created": "Wed, 23 May 2001 21:48:33 GMT",
"version": "v1"
},
{
"created": "Fri, 25 May 2001 20:54:52 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Cline",
"James M.",
""
]
] | We point out that quintessence with an exponential potential V_0 exp(- beta phi / 3^{1/2} M_p) can account for the present observed acceleration of the universe, without necessarily leading to eternal acceleration. This occurs for 2.4 < beta < 2.8. Thus a cosmological horizon, which is supposed to be problematic within the context of string theory, can be avoided. We argue that this class of models is not particularly fine-tuned. We further examine this question in the context of a modified Friedmann equation, H^2 ~ rho + p, which is suggested by higher dimensional self-tuning approaches to the cosmological constant problem. It is shown that the self-tuning case can also be consistent with observations, if 1.8 < beta < 2.4. Future observations of high-z supernovae will be able to test whether beta lies in the desired range. |
hep-ph/0703113 | Fabio Maltoni | J. Campbell, F. Maltoni, F. Tramontano | QCD corrections to J/psi and Upsilon production at hadron colliders | 5 pages, 5 figures | null | 10.1103/PhysRevLett.98.252002 | null | hep-ph | null | We calculate the cross section for hadroproduction of a pair of heavy quarks
in a 3S1 color-singlet state at next-to-leading order in QCD. This corresponds
to the leading contribution in the NRQCD expansion for J/psi and Upsilon
production. The higher-order corrections have a large impact on the p_T
distributions, enhancing the production at high p_T both at the Tevatron and at
the LHC. The total decay rate of a 3S1 into hadrons at NLO is also computed,
confirming for the first time the result obtained by Mackenzie and Lepage in
1981.
| [
{
"created": "Mon, 12 Mar 2007 18:32:03 GMT",
"version": "v1"
}
] | 2009-11-13 | [
[
"Campbell",
"J.",
""
],
[
"Maltoni",
"F.",
""
],
[
"Tramontano",
"F.",
""
]
] | We calculate the cross section for hadroproduction of a pair of heavy quarks in a 3S1 color-singlet state at next-to-leading order in QCD. This corresponds to the leading contribution in the NRQCD expansion for J/psi and Upsilon production. The higher-order corrections have a large impact on the p_T distributions, enhancing the production at high p_T both at the Tevatron and at the LHC. The total decay rate of a 3S1 into hadrons at NLO is also computed, confirming for the first time the result obtained by Mackenzie and Lepage in 1981. |
1410.8386 | Anton Godizov | A.A. Godizov | QCD and nuclear physics. How to explain the coincidence between the
action radius of nuclear forces and the characteristic scale of the
neutron-neutron electrostatic interaction? | 7 pages; two footnotes are added on page 6 | Int. J. Theor. Phys. 55 (2016) 1937-1943 | 10.1007/s10773-015-2833-6 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | An attempt is made to interpret, in the framework of QCD, the likeness
between the shapes of the neutron-neutron strong and electrostatic interactions
at the distances $\sim 1\div 3$ fm.
| [
{
"created": "Thu, 30 Oct 2014 14:56:02 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Dec 2014 13:37:58 GMT",
"version": "v2"
},
{
"created": "Mon, 12 Jan 2015 15:02:13 GMT",
"version": "v3"
},
{
"created": "Sun, 12 Apr 2015 18:41:44 GMT",
"version": "v4"
},
{
"c... | 2016-03-11 | [
[
"Godizov",
"A. A.",
""
]
] | An attempt is made to interpret, in the framework of QCD, the likeness between the shapes of the neutron-neutron strong and electrostatic interactions at the distances $\sim 1\div 3$ fm. |
hep-ph/0607016 | Chuan-Jie Zhu | Xun Su, Zhi-Guang Xiao, Gang Yang, Chuan-Jie Zhu | The rational parts of one-loop QCD amplitudes II: The five-gluon case | 25 pages, 16 figures and LaTeX file; minor corrections, references
added, to be published in Nucl. Phys. B | Nucl.Phys.B758:35-52,2006 | 10.1016/j.nuclphysb.2006.09.007 | null | hep-ph hep-th | null | The rational parts of 5-gluon one-loop amplitudes are computed by using the
newly developed method for computing the rational parts directly from Feynman
integrals. We found complete agreement with the previously well-known results
of Bern, Dixon and Kosower obtained by using the string theory method.
Intermediate results for some combinations of Feynman diagrams are presented in
order to show the efficiency of the method and the local cancellation between
different contributions.
| [
{
"created": "Mon, 3 Jul 2006 15:35:07 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Sep 2006 15:39:41 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Su",
"Xun",
""
],
[
"Xiao",
"Zhi-Guang",
""
],
[
"Yang",
"Gang",
""
],
[
"Zhu",
"Chuan-Jie",
""
]
] | The rational parts of 5-gluon one-loop amplitudes are computed by using the newly developed method for computing the rational parts directly from Feynman integrals. We found complete agreement with the previously well-known results of Bern, Dixon and Kosower obtained by using the string theory method. Intermediate results for some combinations of Feynman diagrams are presented in order to show the efficiency of the method and the local cancellation between different contributions. |
0906.1187 | Fumihiro Takayama | Wilfried Buchm\"uller, Alejandro Ibarra, Tetsuo Shindou, Fumihiro
Takayama, and David Tran | Probing Gravitino Dark Matter with PAMELA and Fermi | 21 pages, 6 figures. v3: published version | JCAP 0909:021, 2009 | 10.1088/1475-7516/2009/09/021 | DESY 09-055, TUM-HEP 720/09 | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the cosmic-ray signatures of decaying gravitino dark matter in a
model independent way based on an operator analysis. Thermal leptogenesis and
universal boundary conditions at the GUT scale restrict the gravitino mass to
be below 600 GeV. Electron and positron fluxes from gravitino decays, together
with the standard GALPROP background, cannot explain both, the PAMELA positron
fraction and the electron + positron flux recently measured by Fermi LAT. For
gravitino dark matter, the observed fluxes require astrophysical sources. The
measured antiproton flux allows for a sizable contribution of decaying
gravitinos to the gamma-ray spectrum, in particular a line at an energy below
300 GeV. Future measurements of the gamma-ray flux will provide important
constraints on possible signatures of decaying gravitino dark matter at the
LHC.
| [
{
"created": "Fri, 5 Jun 2009 19:36:15 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Jun 2009 14:09:49 GMT",
"version": "v2"
},
{
"created": "Mon, 31 Aug 2009 09:28:40 GMT",
"version": "v3"
}
] | 2009-09-16 | [
[
"Buchmüller",
"Wilfried",
""
],
[
"Ibarra",
"Alejandro",
""
],
[
"Shindou",
"Tetsuo",
""
],
[
"Takayama",
"Fumihiro",
""
],
[
"Tran",
"David",
""
]
] | We analyze the cosmic-ray signatures of decaying gravitino dark matter in a model independent way based on an operator analysis. Thermal leptogenesis and universal boundary conditions at the GUT scale restrict the gravitino mass to be below 600 GeV. Electron and positron fluxes from gravitino decays, together with the standard GALPROP background, cannot explain both, the PAMELA positron fraction and the electron + positron flux recently measured by Fermi LAT. For gravitino dark matter, the observed fluxes require astrophysical sources. The measured antiproton flux allows for a sizable contribution of decaying gravitinos to the gamma-ray spectrum, in particular a line at an energy below 300 GeV. Future measurements of the gamma-ray flux will provide important constraints on possible signatures of decaying gravitino dark matter at the LHC. |
2012.12790 | Caner Unal | Caner Unal, Fabio Pacucci, Abraham Loeb | Properties of Ultralight Bosons from Spins of Heavy Quasars via
Superradiance | 15 pages, 7 figures, version accepted for publication to JCAP | JCAP 05, 007 (2021) | 10.1088/1475-7516/2021/05/007 | null | hep-ph astro-ph.CO astro-ph.HE gr-qc hep-th | http://creativecommons.org/licenses/by/4.0/ | The mass and the spin of accreting and jetted black holes, at the center of
Active Galactic Nuclei (AGNs), can be probed by analyzing their electromagnetic
spectra. For this purpose, we use the Spin-Modified Fundamental Plane of black
hole activity, which non-linearly connects the following four variables (in the
source frame): radio luminosity, X-ray or optical luminosity (via the [OIII]
emission line), black hole mass and spin. Taking into account the uncertainties
in luminosity measurements, conversion factors, relativistic beaming and
physical properties of the AGN system, we derive lower bounds on the spins of a
group of heavy, jetted AGNs. Using these results, we study the direct
implications on the mass spectrum of the ultra-light particles of scalar
(axion-like), vector (dark photon) and tensor types (additional spin-2
particles). We close unexplored gap in the parameter space
$10^{-20}-10^{-19}$eV. We obtain upper bounds on the axion decay constant
(equivalently lower bounds on the self-interaction strength) considering
self-interactions could prevent the axion particles entering the instability,
and be the reason for non-observation of superradiance. Assuming axion is
described by mass and decay constant, we obtain upper limits on what fraction
of dark matter can be formed by ultra-light particles and find that single
spieces axion-like light particle can constitute at most $10\%$ of the dark
matter in the mass range: $ 10^{-21} < \mu \, (\mathrm{eV}) < 10^{-17}$.
| [
{
"created": "Wed, 23 Dec 2020 16:47:37 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Feb 2021 19:32:26 GMT",
"version": "v2"
},
{
"created": "Mon, 19 Apr 2021 11:31:25 GMT",
"version": "v3"
}
] | 2024-07-12 | [
[
"Unal",
"Caner",
""
],
[
"Pacucci",
"Fabio",
""
],
[
"Loeb",
"Abraham",
""
]
] | The mass and the spin of accreting and jetted black holes, at the center of Active Galactic Nuclei (AGNs), can be probed by analyzing their electromagnetic spectra. For this purpose, we use the Spin-Modified Fundamental Plane of black hole activity, which non-linearly connects the following four variables (in the source frame): radio luminosity, X-ray or optical luminosity (via the [OIII] emission line), black hole mass and spin. Taking into account the uncertainties in luminosity measurements, conversion factors, relativistic beaming and physical properties of the AGN system, we derive lower bounds on the spins of a group of heavy, jetted AGNs. Using these results, we study the direct implications on the mass spectrum of the ultra-light particles of scalar (axion-like), vector (dark photon) and tensor types (additional spin-2 particles). We close unexplored gap in the parameter space $10^{-20}-10^{-19}$eV. We obtain upper bounds on the axion decay constant (equivalently lower bounds on the self-interaction strength) considering self-interactions could prevent the axion particles entering the instability, and be the reason for non-observation of superradiance. Assuming axion is described by mass and decay constant, we obtain upper limits on what fraction of dark matter can be formed by ultra-light particles and find that single spieces axion-like light particle can constitute at most $10\%$ of the dark matter in the mass range: $ 10^{-21} < \mu \, (\mathrm{eV}) < 10^{-17}$. |
2103.01857 | Eliecer Hern\'andez Gajate | N. Penalva, E. Hern\'andez and J. Nieves | New physics and the tau polarization vector in $b\to c \tau
\bar\nu_\tau$ decays | 34 latex pages, 10 figures, 1 table. Enlarged and modified
discussion. New references and one new figure added | null | 10.1007/JHEP06(2021)118 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For a general $H_b\to H_c\tau\bar\nu_\tau$ decay we analyze the role of the
$\tau$ polarization vector ${\cal P}^\mu$ in the context of lepton flavor
universality violation studies. We use a general phenomenological approach that
includes, in addition to the Standard Model (SM) contribution, vector, axial,
scalar, pseudoscalar and tensor new physics (NP) terms which strength is
governed by, complex in general, Wilson coefficients. We show that both in the
laboratory frame, where the initial hadron is at rest, and in the center of
mass of the two final leptons, a $\vec {\cal P}$ component perpendicular to the
plane defined by the three-momenta of the final hadron and the $\tau$ lepton is
only possible for complex Wilson coefficients, being a clear signal for physics
beyond the SM as well as time reversal (or CP-symmetry) violation. We make
specific evaluations of the different polarization vector components for the
$\Lambda_b\to\Lambda_c$, $\bar B_c\to\eta_c,J/\psi$ and $\bar B\to D^{(*)}$
semileptonic decays, and describe NP effects in the complete two-dimensional
space associated with the independent kinematic variables on which the
polarization vector depends. We find that the detailed study of ${\cal P}^\mu$
has great potential to discriminate between different NP scenarios for $0^-\to
0^-$ decays, but also for $\Lambda_b \to \Lambda_c$ transitions. For this
latter reaction, we pay special attention to corrections to the SM predictions
derived from complex Wilson coefficients contributions.
| [
{
"created": "Tue, 2 Mar 2021 16:48:32 GMT",
"version": "v1"
},
{
"created": "Tue, 18 May 2021 11:30:02 GMT",
"version": "v2"
}
] | 2021-07-07 | [
[
"Penalva",
"N.",
""
],
[
"Hernández",
"E.",
""
],
[
"Nieves",
"J.",
""
]
] | For a general $H_b\to H_c\tau\bar\nu_\tau$ decay we analyze the role of the $\tau$ polarization vector ${\cal P}^\mu$ in the context of lepton flavor universality violation studies. We use a general phenomenological approach that includes, in addition to the Standard Model (SM) contribution, vector, axial, scalar, pseudoscalar and tensor new physics (NP) terms which strength is governed by, complex in general, Wilson coefficients. We show that both in the laboratory frame, where the initial hadron is at rest, and in the center of mass of the two final leptons, a $\vec {\cal P}$ component perpendicular to the plane defined by the three-momenta of the final hadron and the $\tau$ lepton is only possible for complex Wilson coefficients, being a clear signal for physics beyond the SM as well as time reversal (or CP-symmetry) violation. We make specific evaluations of the different polarization vector components for the $\Lambda_b\to\Lambda_c$, $\bar B_c\to\eta_c,J/\psi$ and $\bar B\to D^{(*)}$ semileptonic decays, and describe NP effects in the complete two-dimensional space associated with the independent kinematic variables on which the polarization vector depends. We find that the detailed study of ${\cal P}^\mu$ has great potential to discriminate between different NP scenarios for $0^-\to 0^-$ decays, but also for $\Lambda_b \to \Lambda_c$ transitions. For this latter reaction, we pay special attention to corrections to the SM predictions derived from complex Wilson coefficients contributions. |
1905.13670 | Rasmus Sloth Lundkvist Hansen | Rasmus S. L. Hansen and Alexei Yu. Smirnov | Effect of extended neutrino production region on collective oscillations
in supernovae | 31 pages, 5 figures, a few details and clarifications added. Accepted
for publication in JCAP | null | 10.1088/1475-7516/2019/10/027 | null | hep-ph astro-ph.HE astro-ph.SR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In supernovae neutrinos are emitted from a region with a width $r_{\rm eff}$
of a few kilometers (rather than from a surface of infinitesimal width). We
study the effect of integration (averaging) over such an extended emission
region on collective oscillations. The averaging leads to additional
suppression of the correlation (off-diagonal element of the density matrix) by
a factor $ \sim 1/r_{\rm eff} V_e \sim 10^{-10}$, where $V_e$ is the matter
potential. This factor enters the initial condition for further collective
oscillations and, consequently, leads to a delay of the strong flavour
transitions. We justify and quantify this picture using a simple example of
collective effects in two intersecting fluxes. We have derived the evolution
equation for the density matrix elements integrated over the emission region
and solved it both numerically and analytically. For the analytic solution we
have used linearized equations. We show that the delay of the development of
the instability and the collective oscillations depends on the suppression
factor due to the averaging (integration) logarithmically. If the instability
develops inside the production region, the integration leads not only to a
delay but also to a modification of the exponential grow.
| [
{
"created": "Fri, 31 May 2019 15:14:56 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Sep 2019 08:30:24 GMT",
"version": "v2"
}
] | 2019-10-16 | [
[
"Hansen",
"Rasmus S. L.",
""
],
[
"Smirnov",
"Alexei Yu.",
""
]
] | In supernovae neutrinos are emitted from a region with a width $r_{\rm eff}$ of a few kilometers (rather than from a surface of infinitesimal width). We study the effect of integration (averaging) over such an extended emission region on collective oscillations. The averaging leads to additional suppression of the correlation (off-diagonal element of the density matrix) by a factor $ \sim 1/r_{\rm eff} V_e \sim 10^{-10}$, where $V_e$ is the matter potential. This factor enters the initial condition for further collective oscillations and, consequently, leads to a delay of the strong flavour transitions. We justify and quantify this picture using a simple example of collective effects in two intersecting fluxes. We have derived the evolution equation for the density matrix elements integrated over the emission region and solved it both numerically and analytically. For the analytic solution we have used linearized equations. We show that the delay of the development of the instability and the collective oscillations depends on the suppression factor due to the averaging (integration) logarithmically. If the instability develops inside the production region, the integration leads not only to a delay but also to a modification of the exponential grow. |
1707.03802 | Manuel Pavon Valderrama | Mario Sanchez Sanchez, Li-Sheng Geng, Jun-Xu Lu, Tetsuo Hyodo, Manuel
Pavon Valderrama | Exotic Doubly Charmed Ds0*(2317)D and Ds1*(2460)D* Molecules | 6 Pages, 1 Figure | Phys. Rev. D 98, 054001 (2018) | 10.1103/PhysRevD.98.054001 | YITP-17-70 | hep-ph hep-ex hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The $D_{s0}^*(2317) D$ and $D_{s1}^*(2460) D^*$ heavy meson systems can
exchange a kaon that is emitted in S-wave owing to the opposite intrinsic
parity of the $D_{s0}^*$($D_{s1}^*$) and $D$($D^*$) mesons. As a consequence of
the mass difference of the $D_{s0}^*$($D_{s1}^*$) and $D$($D^*$) mesons, the
range of the kaon exchange potential will be significantly longer than
expected, corresponding to an effective mass of about $200\,{\rm MeV}$. The
potential will be very strong: the strength of the interaction is proportional
to $(m_{D_{s0}} - m_D)^2 / f_{\pi}^2$ and $(m_{D_{s1}} - m_{D^*})^2 /
f_{\pi}^2$. This combination of range and strength almost guarantees the
existence of $D_{s0}^*(2317) D$ and $D_{s1}^*(2460) D^*$ bound states with $J^P
= 0^{-}$ and $J^P = 0^{-}, 2^{-}$ respectively. Concrete calculations indicate
a binding energy of $5-15\,{\rm MeV}$ independently of $J^P$. The
$D_{s0}^*(2317) D$ and $D_{s1}^*(2460) D^*$ molecules have manifestly exotic
flavour quantum numbers: $C=2$, $S=1$ and $I=1/2$. We expect the existence of
bottom counterparts composed of the $B B_{s0}$ and $B^* B_{s1}^*$ mesons, which
will be more bound and have a richer spectrum that might include a shallow
P-wave state and an excited S-wave state.
| [
{
"created": "Wed, 12 Jul 2017 17:11:40 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Sep 2018 16:40:15 GMT",
"version": "v2"
}
] | 2018-09-06 | [
[
"Sanchez",
"Mario Sanchez",
""
],
[
"Geng",
"Li-Sheng",
""
],
[
"Lu",
"Jun-Xu",
""
],
[
"Hyodo",
"Tetsuo",
""
],
[
"Valderrama",
"Manuel Pavon",
""
]
] | The $D_{s0}^*(2317) D$ and $D_{s1}^*(2460) D^*$ heavy meson systems can exchange a kaon that is emitted in S-wave owing to the opposite intrinsic parity of the $D_{s0}^*$($D_{s1}^*$) and $D$($D^*$) mesons. As a consequence of the mass difference of the $D_{s0}^*$($D_{s1}^*$) and $D$($D^*$) mesons, the range of the kaon exchange potential will be significantly longer than expected, corresponding to an effective mass of about $200\,{\rm MeV}$. The potential will be very strong: the strength of the interaction is proportional to $(m_{D_{s0}} - m_D)^2 / f_{\pi}^2$ and $(m_{D_{s1}} - m_{D^*})^2 / f_{\pi}^2$. This combination of range and strength almost guarantees the existence of $D_{s0}^*(2317) D$ and $D_{s1}^*(2460) D^*$ bound states with $J^P = 0^{-}$ and $J^P = 0^{-}, 2^{-}$ respectively. Concrete calculations indicate a binding energy of $5-15\,{\rm MeV}$ independently of $J^P$. The $D_{s0}^*(2317) D$ and $D_{s1}^*(2460) D^*$ molecules have manifestly exotic flavour quantum numbers: $C=2$, $S=1$ and $I=1/2$. We expect the existence of bottom counterparts composed of the $B B_{s0}$ and $B^* B_{s1}^*$ mesons, which will be more bound and have a richer spectrum that might include a shallow P-wave state and an excited S-wave state. |
2204.07078 | Maxim Laletin | Andrzej Hryczuk and Maxim Laletin | Impact of dark matter self-scattering on its relic abundance | 13 pages, 8 figures; matches published version | Phys.Rev.D 106 (2022) 2, 023007 | 10.1103/PhysRevD.106.023007 | null | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | Elastic self-scatterings do not change the number of dark matter particles
and as such have been neglected in the calculation of its relic abundance. In
this work we highlight the scenarios where the presence of self-scatterings has
a significant impact on the effectiveness of annihilation processes through the
modification of dark matter momentum distribution. We study a few example
freeze-out scenarios involving resonant and sub-threshold annihilations, as
well as a model with an additional source of dark matter particles from the
decays of a heavier mediator state. Interestingly, when the calculation is
performed at the level of dark matter momentum distribution function, we find
that the injection of additional energetic dark matter particles onto the
thermal population can lead to a $\textit{decrease}$ of its final relic
abundance.
| [
{
"created": "Thu, 14 Apr 2022 16:17:22 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Oct 2022 15:13:54 GMT",
"version": "v2"
}
] | 2022-10-11 | [
[
"Hryczuk",
"Andrzej",
""
],
[
"Laletin",
"Maxim",
""
]
] | Elastic self-scatterings do not change the number of dark matter particles and as such have been neglected in the calculation of its relic abundance. In this work we highlight the scenarios where the presence of self-scatterings has a significant impact on the effectiveness of annihilation processes through the modification of dark matter momentum distribution. We study a few example freeze-out scenarios involving resonant and sub-threshold annihilations, as well as a model with an additional source of dark matter particles from the decays of a heavier mediator state. Interestingly, when the calculation is performed at the level of dark matter momentum distribution function, we find that the injection of additional energetic dark matter particles onto the thermal population can lead to a $\textit{decrease}$ of its final relic abundance. |
1506.00840 | Ran Huo | Ran Huo | Standard Model Effective Field Theory: Integrating out Vector-Like
Fermions | Corrections made and references added, version to appear in JHEP | JHEP 1509 (2015) 037 | 10.1007/JHEP09(2015)037 | IPMU15-0079 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We apply the covariant derivative expansion of the Coleman-Weinberg potential
to vector-like fermion models, matching the UV theory to the relevant
dimension-6 operators in the standard model effective field theory. The
$\gamma$ matrix induced complication in the fermionic covariant derivative
expansion is studied in detail, and all the contributing combinations are
enumerated. From this analytical result we also provide numerical constraints
for a generation of vector-like quarks and vector-like leptons.
| [
{
"created": "Tue, 2 Jun 2015 11:12:44 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Sep 2015 08:15:31 GMT",
"version": "v2"
}
] | 2019-07-05 | [
[
"Huo",
"Ran",
""
]
] | We apply the covariant derivative expansion of the Coleman-Weinberg potential to vector-like fermion models, matching the UV theory to the relevant dimension-6 operators in the standard model effective field theory. The $\gamma$ matrix induced complication in the fermionic covariant derivative expansion is studied in detail, and all the contributing combinations are enumerated. From this analytical result we also provide numerical constraints for a generation of vector-like quarks and vector-like leptons. |
1512.06587 | Xiao-Fang Han | Xiao-Fang Han, Lei Wang | Implication of the 750 GeV diphoton resonance on two-Higgs-doublet model
and its extensions with Higgs field | 17 pages, 4 figures; some discussions and refs added | Phys. Rev. D 93, 055027 (2016) | 10.1103/PhysRevD.93.055027 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine the implication of the 750 GeV diphoton resonance on the
two-Higgs-doublet model imposing various theoretical and experimental
constraints. The production rate of two-Higgs-doublet model is smaller than the
cross section observed at the LHC by two order magnitude. In order to
accommodate the 750 GeV diphoton resonance, we extend the two-Higgs-doublet
model by introducing additional Higgs fields, and focus on two different
extensions, an inert complex Higgs triplet and a real scalar septuplet. With
the 125 GeV Higgs being agreement with the observed data, the production rate
for the 750 GeV diphoton resonance can be enhanced to 0.6 fb for the former and
4.5 fb for the latter. The results of the latter are well consistent with the
750 GeV diphoton excess at the LHC.
| [
{
"created": "Mon, 21 Dec 2015 11:39:57 GMT",
"version": "v1"
},
{
"created": "Sun, 27 Dec 2015 15:13:58 GMT",
"version": "v2"
},
{
"created": "Fri, 18 Mar 2016 16:04:24 GMT",
"version": "v3"
}
] | 2016-03-21 | [
[
"Han",
"Xiao-Fang",
""
],
[
"Wang",
"Lei",
""
]
] | We examine the implication of the 750 GeV diphoton resonance on the two-Higgs-doublet model imposing various theoretical and experimental constraints. The production rate of two-Higgs-doublet model is smaller than the cross section observed at the LHC by two order magnitude. In order to accommodate the 750 GeV diphoton resonance, we extend the two-Higgs-doublet model by introducing additional Higgs fields, and focus on two different extensions, an inert complex Higgs triplet and a real scalar septuplet. With the 125 GeV Higgs being agreement with the observed data, the production rate for the 750 GeV diphoton resonance can be enhanced to 0.6 fb for the former and 4.5 fb for the latter. The results of the latter are well consistent with the 750 GeV diphoton excess at the LHC. |
hep-ph/0703308 | Jin Min Yang | Junjie Cao, Guoli Liu, Jin Min Yang, Huanjun Zhang | Top-quark FCNC Productions at LHC in Topcolor-assisted Technicolor Model | 5 pages, 4 figs | Phys.Rev.D76:014004,2007 | 10.1103/PhysRevD.76.014004 | null | hep-ph hep-ex | null | We evaluate the top-quark FCNC productions induced by the topcolor assisted
technicolor (TC2) model at the LHC. These productions proceed respectively
through the parton-level processes g g -> t c_bar, c g->t, c g -> t g, c g -> t
Z and c g -> t \gamma. We show the dependence of the production rates on the
relevant TC2 parameters and compare the results with the predictions in the
minimal supersymmetric model. We find that for each channel the TC2 model
predicts a much larger production rate than the supersymmetric model. All these
rare productions in the TC2 model can be enhanced above the 3-sigma sensitivity
of the LHC. Since in the minimal supersymmetric model only c g -> t is slightly
larger than the corresponding LHC sensitivity, the observation of these
processes will favor the TC2 model over the supersymmetric model. In case of
unobservation, the LHC can set meaningful constraints on the TC2 parameters.
| [
{
"created": "Thu, 29 Mar 2007 12:52:08 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Cao",
"Junjie",
""
],
[
"Liu",
"Guoli",
""
],
[
"Yang",
"Jin Min",
""
],
[
"Zhang",
"Huanjun",
""
]
] | We evaluate the top-quark FCNC productions induced by the topcolor assisted technicolor (TC2) model at the LHC. These productions proceed respectively through the parton-level processes g g -> t c_bar, c g->t, c g -> t g, c g -> t Z and c g -> t \gamma. We show the dependence of the production rates on the relevant TC2 parameters and compare the results with the predictions in the minimal supersymmetric model. We find that for each channel the TC2 model predicts a much larger production rate than the supersymmetric model. All these rare productions in the TC2 model can be enhanced above the 3-sigma sensitivity of the LHC. Since in the minimal supersymmetric model only c g -> t is slightly larger than the corresponding LHC sensitivity, the observation of these processes will favor the TC2 model over the supersymmetric model. In case of unobservation, the LHC can set meaningful constraints on the TC2 parameters. |
hep-ph/0504266 | Alejandro Gutierrez | A. Gutierrez-Rodriguez, M. A. Hernandez-Ruiz and O. A. Sampayo | Pairs-Production of Higgs in Association with Bottom Quarks Pairs at
$e^+e^-$ Colliders | 12 pages, 6 figures | Mod.Phys.Lett. A20 (2005) 2629-2638 | 10.1142/S0217732305017548 | null | hep-ph | null | In a previous paper, we studied the Higgs pair production in the standard
model with the reaction $e^{+}e^{-}\to t \bar t HH$. Based on this, we study
the Higgs pair production via $e^{+}e^{-}\to b \bar b HH$. We evaluate the
total cross section of $b\bar bHH$ and calculate the number total of events
considering the complete set of Feynman diagrams at tree-level, and compare
this process with the process $e^{+}e^{-}\to t \bar t HH$. The numerical
computation is done for the energy which is expected to be available at a
possible Next Linear $e^{+}e^{-}$ Collider with a center-of-mass energy $800,
1000, 1600$ $GeV$ and luminosity 1000 $fb^{-1}$.
| [
{
"created": "Wed, 27 Apr 2005 22:37:34 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Gutierrez-Rodriguez",
"A.",
""
],
[
"Hernandez-Ruiz",
"M. A.",
""
],
[
"Sampayo",
"O. A.",
""
]
] | In a previous paper, we studied the Higgs pair production in the standard model with the reaction $e^{+}e^{-}\to t \bar t HH$. Based on this, we study the Higgs pair production via $e^{+}e^{-}\to b \bar b HH$. We evaluate the total cross section of $b\bar bHH$ and calculate the number total of events considering the complete set of Feynman diagrams at tree-level, and compare this process with the process $e^{+}e^{-}\to t \bar t HH$. The numerical computation is done for the energy which is expected to be available at a possible Next Linear $e^{+}e^{-}$ Collider with a center-of-mass energy $800, 1000, 1600$ $GeV$ and luminosity 1000 $fb^{-1}$. |
hep-ph/0407109 | Lokhtin | I.P.Lokhtin, L.I.Sarycheva, A.M.Snigirev, K.Yu.Teplov | Medium-modified fragmentation of b-jets tagged by a leading muon in
ultrarelativistic heavy ion collisions | 12 pages in LaTeX (including 3 figures in EPS-format) | Eur.Phys.J.C37:465-469,2004 | 10.1140/epjc/s2004-02003-4 | null | hep-ph | null | The possibility to observe the medium-modified fragmentation of hard b-quarks
tagged by a leading muon in ultrarelativistic heavy ion collisions is analyzed.
We have found that reasonable statistics, ~20000 events per 1 month of LHC run
with lead beams, can be expected for the realistic geometrical acceptance and
kinematic cuts. The numerical estimates on the effect of the medium-induced
softening b-jet fragmentation function are given.
| [
{
"created": "Fri, 9 Jul 2004 10:17:14 GMT",
"version": "v1"
}
] | 2011-01-27 | [
[
"Lokhtin",
"I. P.",
""
],
[
"Sarycheva",
"L. I.",
""
],
[
"Snigirev",
"A. M.",
""
],
[
"Teplov",
"K. Yu.",
""
]
] | The possibility to observe the medium-modified fragmentation of hard b-quarks tagged by a leading muon in ultrarelativistic heavy ion collisions is analyzed. We have found that reasonable statistics, ~20000 events per 1 month of LHC run with lead beams, can be expected for the realistic geometrical acceptance and kinematic cuts. The numerical estimates on the effect of the medium-induced softening b-jet fragmentation function are given. |
hep-ph/9704443 | null | M. Caffo, H. Czyz, E. Remiddi | BHAGEN95: a Monte Carlo program for Bhabha scattering at LEP1/SLC and
LEP2 energies | 24 pages, Latex, 4 composite Postscript figures, uses epsfig.sty | Nuovo Cim. A110 (1997) 515-536 | 10.1007/BF03035898 | DFUB 96-21, TP-USL/96/12 | hep-ph | null | We present the Monte Carlo program BHAGEN95, for calculating the
cross-section of the Bhabha scattering process at LEP1/SLC and LEP2 energies,
usable with continuity from small to large-angle configurations. We discuss
some improvements in the event generator BHAGEN94, which is now part of the new
code. In particular the weak and QCD corrections are implemented up to two
loops for the relevant contributions, and the emission of one hard photon is
treated exactly. We have included all the radiative corrections which are
necessary to obtain, for a typical experimental event selection, a precision of
0.1-0.2% at small-angle. At large-angle we estimate a precision of 0.5%, with
the exception of the region where the beam energy is a few GeV above the Z
boson resonance, where it is up to 1%. A detailed comparison with other codes
for both small-angle and large-angle Bhabha scattering is performed.
| [
{
"created": "Wed, 30 Apr 1997 07:55:08 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Caffo",
"M.",
""
],
[
"Czyz",
"H.",
""
],
[
"Remiddi",
"E.",
""
]
] | We present the Monte Carlo program BHAGEN95, for calculating the cross-section of the Bhabha scattering process at LEP1/SLC and LEP2 energies, usable with continuity from small to large-angle configurations. We discuss some improvements in the event generator BHAGEN94, which is now part of the new code. In particular the weak and QCD corrections are implemented up to two loops for the relevant contributions, and the emission of one hard photon is treated exactly. We have included all the radiative corrections which are necessary to obtain, for a typical experimental event selection, a precision of 0.1-0.2% at small-angle. At large-angle we estimate a precision of 0.5%, with the exception of the region where the beam energy is a few GeV above the Z boson resonance, where it is up to 1%. A detailed comparison with other codes for both small-angle and large-angle Bhabha scattering is performed. |
hep-ph/0511020 | Eulogio Oset | E. Oset, J. R. Pelaez, L. Roca | Discussion of the eta to pi^0 gamma gamma decay within a chiral unitary
approach | Talk at the eta05 Workshop on production and decay of eta and eta'
mesons, Krakow, September05. Includes discussion on a proper comparison of
data with old chiral perturbation results | ActaPhys.Slov.56:327-334,2006 | null | FTUV-05-1103, IFIC-05-1103 | hep-ph | null | We improve the calculations of the $\eta \to \pi^0 \gamma \gamma$ decay
within the context of meson chiral lagrangians. We use a chiral unitary
approach for the meson-meson interaction, thus generating the $a_0(980)$
resonance and fixing the longstanding sign ambiguity on its contribution. This
also allows us to calculate the loops with one vector meson exchange, thus
removing a former source of uncertainty. In addition we ensure the consistency
of the approach with other processes. First, by using vector meson dominance
couplings normalized to agree with radiative vector meson decays. And, second,
by checking the consistency of the calculations with the related $\gamma \gamma
\to \pi^0 \eta$ reaction. We find an $\eta \to \pi^0 \gamma \gamma$ decay width
of $0.47\pm 0.10$ eV, in clear disagreement with published data but in
remarkable agreement with the most recent measurement.
| [
{
"created": "Wed, 2 Nov 2005 18:44:03 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Oset",
"E.",
""
],
[
"Pelaez",
"J. R.",
""
],
[
"Roca",
"L.",
""
]
] | We improve the calculations of the $\eta \to \pi^0 \gamma \gamma$ decay within the context of meson chiral lagrangians. We use a chiral unitary approach for the meson-meson interaction, thus generating the $a_0(980)$ resonance and fixing the longstanding sign ambiguity on its contribution. This also allows us to calculate the loops with one vector meson exchange, thus removing a former source of uncertainty. In addition we ensure the consistency of the approach with other processes. First, by using vector meson dominance couplings normalized to agree with radiative vector meson decays. And, second, by checking the consistency of the calculations with the related $\gamma \gamma \to \pi^0 \eta$ reaction. We find an $\eta \to \pi^0 \gamma \gamma$ decay width of $0.47\pm 0.10$ eV, in clear disagreement with published data but in remarkable agreement with the most recent measurement. |
hep-ph/9609498 | null | Mary Alberg, Ernest M. Henley, Xiangdong Ji and A.W. Thomas | Determination of flavor asymmetry for $\Sigma^{\pm}$ by the Drell-Yan
process | 15 pages, latex. Figures available from alberg@phys.washington.edu.
To be published in Phys. Lett. B | Phys.Lett.B389:367-373,1996 | 10.1016/S0370-2693(96)01272-5 | DOE/ER/40427-6-N96; ADP-96-24/T223 | hep-ph | null | Flavor asymmetries for the valence and sea quarks of the $\Sigma^{\pm}$ can
be obtained from Drell-Yan experiments using charged hyperon beams on proton
and deuteron targets. A large, measurable difference in sea quark asymmetries
is predicted between SU(3) and pseudoscalar meson models. The latter predict
that in $\Sigma^{+}$, $\bar{u}/\bar{d} \leq 1/2$, whereas the former predict
$\bar{u}/\bar{d} \approx 4/3$. Estimates of valence quark asymmetries based on
quark models also show large deviations from SU(3) predictions, which should be
measurable.
| [
{
"created": "Thu, 26 Sep 1996 23:04:32 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Alberg",
"Mary",
""
],
[
"Henley",
"Ernest M.",
""
],
[
"Ji",
"Xiangdong",
""
],
[
"Thomas",
"A. W.",
""
]
] | Flavor asymmetries for the valence and sea quarks of the $\Sigma^{\pm}$ can be obtained from Drell-Yan experiments using charged hyperon beams on proton and deuteron targets. A large, measurable difference in sea quark asymmetries is predicted between SU(3) and pseudoscalar meson models. The latter predict that in $\Sigma^{+}$, $\bar{u}/\bar{d} \leq 1/2$, whereas the former predict $\bar{u}/\bar{d} \approx 4/3$. Estimates of valence quark asymmetries based on quark models also show large deviations from SU(3) predictions, which should be measurable. |
1306.2613 | Jorge Noronha | Stefano I. Finazzo (Sao Paulo U.) and Jorge Noronha (Sao Paulo U.) | Estimates for the Thermal Width of Heavy Quarkonia in Strongly Coupled
Plasmas from Holography | 45 pages, 20 figures; new references and appendix added | null | 10.1007/JHEP11(2013)042 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The gauge/gravity duality is used to investigate the imaginary part of the
heavy quark potential (defined via the rectangular Wilson loop) in strongly
coupled plasmas. This quantity can be used to estimate the width of heavy
quarkonia in a plasma at strong coupling. In this paper the thermal worldsheet
fluctuation method, proposed in [J.Noronha and A.Dumitru, Phys.\ Rev.\ Lett.\
{\bf 103}, 152304 (2009)], is revisited and general conditions for the
existence of an imaginary part for the heavy quark potential computed within
classical gravity models are obtained. We prove a general result that
establishes the connection between this imaginary part of the potential
determined holographically and the area law displayed by the Wilson loop in the
vacuum of confining gauge theories. We also determine the imaginary part of the
heavy quark potential in a strongly coupled plasma dual to Gauss-Bonnet
gravity. This provides an estimate of how the thermal width of heavy quarkonia
changes with the shear viscosity to entropy density ratio, $\eta/s$, at strong
coupling.
| [
{
"created": "Tue, 11 Jun 2013 19:10:02 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Jun 2013 22:17:54 GMT",
"version": "v2"
}
] | 2015-06-16 | [
[
"Finazzo",
"Stefano I.",
"",
"Sao Paulo U."
],
[
"Noronha",
"Jorge",
"",
"Sao Paulo U."
]
] | The gauge/gravity duality is used to investigate the imaginary part of the heavy quark potential (defined via the rectangular Wilson loop) in strongly coupled plasmas. This quantity can be used to estimate the width of heavy quarkonia in a plasma at strong coupling. In this paper the thermal worldsheet fluctuation method, proposed in [J.Noronha and A.Dumitru, Phys.\ Rev.\ Lett.\ {\bf 103}, 152304 (2009)], is revisited and general conditions for the existence of an imaginary part for the heavy quark potential computed within classical gravity models are obtained. We prove a general result that establishes the connection between this imaginary part of the potential determined holographically and the area law displayed by the Wilson loop in the vacuum of confining gauge theories. We also determine the imaginary part of the heavy quark potential in a strongly coupled plasma dual to Gauss-Bonnet gravity. This provides an estimate of how the thermal width of heavy quarkonia changes with the shear viscosity to entropy density ratio, $\eta/s$, at strong coupling. |
hep-ph/0105293 | Tommy Ohlsson | Tommy Ohlsson and Walter Winter | Reconstruction of the Earth's matter density profile using a single
neutrino baseline | 8 pages, 3 figures, LaTeX | Phys.Lett. B512 (2001) 357-364 | 10.1016/S0370-2693(01)00731-6 | TUM-HEP-418/01 | hep-ph physics.geo-ph | null | In this paper, we show numerically that a symmetric Earth matter density
profile can, in principle, be reconstructed from a single baseline energy
spectrum up to a certain precision. For the numerical evaluations in the high
dimensional parameter space we use a genetic algorithm.
| [
{
"created": "Mon, 28 May 2001 14:32:30 GMT",
"version": "v1"
},
{
"created": "Wed, 30 May 2001 14:16:11 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Ohlsson",
"Tommy",
""
],
[
"Winter",
"Walter",
""
]
] | In this paper, we show numerically that a symmetric Earth matter density profile can, in principle, be reconstructed from a single baseline energy spectrum up to a certain precision. For the numerical evaluations in the high dimensional parameter space we use a genetic algorithm. |
1811.02863 | Jean-Marc Richard | Jean-Marc Richard, Alfredo Valcarce, Javier Vijande | Doubly-heavy baryons, tetraquarks, and related topics | To appear in the Proc. of the Workshop "Double-Charm Baryons and
Dimesons", Bled (Slovenia), June 17-23, 2018, ed. M.~Rosina et al | BLED Workshops in Physics Vol. 19, No. 1 P. 24 (2018) | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review the physics of doubly-heavy baryons $QQq$ and tetraquarks $QQ\bar
q\bar q$. For the latter, the stability is reached for large enough mass ratio
$M/m$, even when spin forces and color mixing are neglected. It is thus
customarily claimed that $bb\bar q\bar q$ in its ground state cannot decay into
$b\bar q+b\bar q$. In some model, $cc\bar u\bar d$ is shown to be stable if
color mixing and spin effects are properly taken into account. It is
conjectured that some $bc\bar q\bar q'$ benefits from favorable adjustments of
the gluon tubes in the confinement regime. Some recent studies of pentaquarks
and hexaquarks are also summarized.
| [
{
"created": "Wed, 7 Nov 2018 12:50:04 GMT",
"version": "v1"
}
] | 2018-12-11 | [
[
"Richard",
"Jean-Marc",
""
],
[
"Valcarce",
"Alfredo",
""
],
[
"Vijande",
"Javier",
""
]
] | We review the physics of doubly-heavy baryons $QQq$ and tetraquarks $QQ\bar q\bar q$. For the latter, the stability is reached for large enough mass ratio $M/m$, even when spin forces and color mixing are neglected. It is thus customarily claimed that $bb\bar q\bar q$ in its ground state cannot decay into $b\bar q+b\bar q$. In some model, $cc\bar u\bar d$ is shown to be stable if color mixing and spin effects are properly taken into account. It is conjectured that some $bc\bar q\bar q'$ benefits from favorable adjustments of the gluon tubes in the confinement regime. Some recent studies of pentaquarks and hexaquarks are also summarized. |
hep-ph/0112204 | Liu Chun | Chao-Shang Huang, Chun Liu, and Shi-Lin Zhu | \Lambda_b Lifetime from the HQET Sum Rule | 5 pages, latex, no figures, uses sprocl.sty (included). Talk by C.
Liu at Int. Conf. on Flavor Phys., Zhang-Jia-Jie, 31/5-6/6 2001 | null | 10.1142/9789812777379_0040 | AS-ITP-2001-020, KRL-MAP-280, MZ-TH-01-37 | hep-ph | null | The HQET sum rule analysis for the \Lambda_b matrix element of the four-quark
operator relevant to its lifetime is reported. Our main conclusion is that the
lifetime ratio \tau(\Lambda_b)/\tau(B^0) can be as low as 0.91.
| [
{
"created": "Fri, 14 Dec 2001 17:43:55 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Huang",
"Chao-Shang",
""
],
[
"Liu",
"Chun",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] | The HQET sum rule analysis for the \Lambda_b matrix element of the four-quark operator relevant to its lifetime is reported. Our main conclusion is that the lifetime ratio \tau(\Lambda_b)/\tau(B^0) can be as low as 0.91. |
2001.05310 | David Shih | Gregor Kasieczka and David Shih | DisCo Fever: Robust Networks Through Distance Correlation | 9 pages, v2: essentially the journal version (refs added, typos
fixed, minor improvements) | Phys. Rev. Lett. 125, 122001 (2020) | 10.1103/PhysRevLett.125.122001 | null | hep-ph hep-ex physics.data-an | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | While deep learning has proven to be extremely successful at supervised
classification tasks at the LHC and beyond, for practical applications, raw
classification accuracy is often not the only consideration. One crucial issue
is the stability of network predictions, either versus changes of individual
features of the input data, or against systematic perturbations. We present a
new method based on a novel application of "distance correlation" (DisCo), a
measure quantifying non-linear correlations, that achieves equal performance to
state-of-the-art adversarial decorrelation networks but is much simpler and
more stable to train. To demonstrate the effectiveness of our method, we
carefully recast a recent ATLAS study of decorrelation methods as applied to
boosted, hadronic W-tagging. We also show the feasibility of DisCo
regularization for more powerful convolutional neural networks, as well as for
the problem of hadronic top tagging.
| [
{
"created": "Mon, 13 Jan 2020 19:00:05 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Sep 2020 18:33:00 GMT",
"version": "v2"
}
] | 2020-10-02 | [
[
"Kasieczka",
"Gregor",
""
],
[
"Shih",
"David",
""
]
] | While deep learning has proven to be extremely successful at supervised classification tasks at the LHC and beyond, for practical applications, raw classification accuracy is often not the only consideration. One crucial issue is the stability of network predictions, either versus changes of individual features of the input data, or against systematic perturbations. We present a new method based on a novel application of "distance correlation" (DisCo), a measure quantifying non-linear correlations, that achieves equal performance to state-of-the-art adversarial decorrelation networks but is much simpler and more stable to train. To demonstrate the effectiveness of our method, we carefully recast a recent ATLAS study of decorrelation methods as applied to boosted, hadronic W-tagging. We also show the feasibility of DisCo regularization for more powerful convolutional neural networks, as well as for the problem of hadronic top tagging. |
2209.04671 | Mike Williams | Stefania Gori, Mike Williams, Phil Ilten, Nhan Tran, Gordan Krnjaic,
Natalia Toro, Brian Batell, Nikita Blinov, Christopher Hearty, Robert
McGehee, Philip Harris, Philip Schuster, and Jure Zupan | Dark Sector Physics at High-Intensity Experiments | Report of the RF6 Topical Group for Snowmass 2021 | null | null | null | hep-ph astro-ph.CO hep-ex hep-th | http://creativecommons.org/licenses/by/4.0/ | Is Dark Matter part of a Dark Sector? The possibility of a dark sector
neutral under Standard Model (SM) forces furnishes an attractive explanation
for the existence of Dark Matter (DM), and is a compelling new-physics
direction to explore in its own right, with potential relevance to fundamental
questions as varied as neutrino masses, the hierarchy problem, and the
Universe's matter-antimatter asymmetry. Because dark sectors are generically
weakly coupled to ordinary matter, and because they can naturally have
MeV-to-GeV masses and respect the symmetries of the SM, they are only mildly
constrained by high-energy collider data and precision atomic measurements. Yet
upcoming and proposed intensity-frontier experiments will offer an
unprecedented window into the physics of dark sectors, highlighted as a
Priority Research Direction in the 2018 Dark Matter New Initiatives (DMNI) BRN
report. Support for this program -- in the form of dark-sector analyses at
multi-purpose experiments, realization of the intensity-frontier experiments
receiving DMNI funds, an expansion of DMNI support to explore the full breadth
of DM and visible final-state signatures (especially long-lived particles)
called for in the BRN report, and support for a robust dark-sector theory
effort -- will enable comprehensive exploration of low-mass thermal DM
milestones, and greatly enhance the potential of intensity-frontier experiments
to discover dark-sector particles decaying back to SM particles.
| [
{
"created": "Sat, 10 Sep 2022 14:08:23 GMT",
"version": "v1"
}
] | 2022-09-13 | [
[
"Gori",
"Stefania",
""
],
[
"Williams",
"Mike",
""
],
[
"Ilten",
"Phil",
""
],
[
"Tran",
"Nhan",
""
],
[
"Krnjaic",
"Gordan",
""
],
[
"Toro",
"Natalia",
""
],
[
"Batell",
"Brian",
""
],
[
"Blinov",
... | Is Dark Matter part of a Dark Sector? The possibility of a dark sector neutral under Standard Model (SM) forces furnishes an attractive explanation for the existence of Dark Matter (DM), and is a compelling new-physics direction to explore in its own right, with potential relevance to fundamental questions as varied as neutrino masses, the hierarchy problem, and the Universe's matter-antimatter asymmetry. Because dark sectors are generically weakly coupled to ordinary matter, and because they can naturally have MeV-to-GeV masses and respect the symmetries of the SM, they are only mildly constrained by high-energy collider data and precision atomic measurements. Yet upcoming and proposed intensity-frontier experiments will offer an unprecedented window into the physics of dark sectors, highlighted as a Priority Research Direction in the 2018 Dark Matter New Initiatives (DMNI) BRN report. Support for this program -- in the form of dark-sector analyses at multi-purpose experiments, realization of the intensity-frontier experiments receiving DMNI funds, an expansion of DMNI support to explore the full breadth of DM and visible final-state signatures (especially long-lived particles) called for in the BRN report, and support for a robust dark-sector theory effort -- will enable comprehensive exploration of low-mass thermal DM milestones, and greatly enhance the potential of intensity-frontier experiments to discover dark-sector particles decaying back to SM particles. |
1810.06856 | Dmitry Kirpichnikov | S.N. Gninenko, D.V. Kirpichnikov and N.V. Krasnikov | Probing millicharged particles with NA64 experiment at CERN | 9 pages, 3 figures, version accepted for publication in PRD | Phys. Rev. D 100, 035003 (2019) | 10.1103/PhysRevD.100.035003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this note we estimate the sensitivity of the NA64 experiment to
millicharged particles ($\chi$). That experimental facility is dedicated to the
searching for dark sector particles in missing energy events at the CERN SPS.
We consider missing momentum signatures in the $\simeq$ 100 GeV electron and
muon beams and show that the later one allows to obtain more stringent bounds
on the millicharge $Q_{\chi}$, which for the $\chi$ masses $100$~MeV $\leq
m_{\chi} \leq 500$~MeV at the level $ Q_{\chi}/e\lesssim O(10^{-3}) -
O(10^{-2})$.
| [
{
"created": "Tue, 16 Oct 2018 07:50:54 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Feb 2021 15:07:43 GMT",
"version": "v2"
}
] | 2021-03-01 | [
[
"Gninenko",
"S. N.",
""
],
[
"Kirpichnikov",
"D. V.",
""
],
[
"Krasnikov",
"N. V.",
""
]
] | In this note we estimate the sensitivity of the NA64 experiment to millicharged particles ($\chi$). That experimental facility is dedicated to the searching for dark sector particles in missing energy events at the CERN SPS. We consider missing momentum signatures in the $\simeq$ 100 GeV electron and muon beams and show that the later one allows to obtain more stringent bounds on the millicharge $Q_{\chi}$, which for the $\chi$ masses $100$~MeV $\leq m_{\chi} \leq 500$~MeV at the level $ Q_{\chi}/e\lesssim O(10^{-3}) - O(10^{-2})$. |
2311.17157 | Nicoline Hemme | Elias Bernreuther, Nicoline Hemme, Felix Kahlhoefer, Suchita Kulkarni | Dark matter relic density in strongly interacting dark sectors with
light vector mesons | 10 pages revtex4, 3 figures; v2: additional diagrams included,
results updated, conclusions unchanged | null | null | FERMILAB-PUB-23-744-T, TTP23-057, P3H-23-096 | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | Stable dark matter particles may arise as pseudo-Goldstone bosons from the
confinement of dark quarks interacting via a non-Abelian gauge force. Their
relic abundance is determined not by annihilations into visible particles but
by dark pion number-changing processes within the dark sector, such as $3 \pi_D
\to 2 \pi_D$. However, if the dark vector mesons $\rho_D$ are light enough for
$3 \pi_D \to \pi_D \rho_D$ annihilations to be kinematically allowed, this
process dominates and significantly delays freeze-out. As a result, the
preferred dark matter mass scale increases and bounds from the Bullet Cluster
can be evaded.
| [
{
"created": "Tue, 28 Nov 2023 19:00:04 GMT",
"version": "v1"
},
{
"created": "Wed, 22 May 2024 08:50:35 GMT",
"version": "v2"
}
] | 2024-05-24 | [
[
"Bernreuther",
"Elias",
""
],
[
"Hemme",
"Nicoline",
""
],
[
"Kahlhoefer",
"Felix",
""
],
[
"Kulkarni",
"Suchita",
""
]
] | Stable dark matter particles may arise as pseudo-Goldstone bosons from the confinement of dark quarks interacting via a non-Abelian gauge force. Their relic abundance is determined not by annihilations into visible particles but by dark pion number-changing processes within the dark sector, such as $3 \pi_D \to 2 \pi_D$. However, if the dark vector mesons $\rho_D$ are light enough for $3 \pi_D \to \pi_D \rho_D$ annihilations to be kinematically allowed, this process dominates and significantly delays freeze-out. As a result, the preferred dark matter mass scale increases and bounds from the Bullet Cluster can be evaded. |
1001.3408 | Timothy Cohen | Timothy Cohen, Daniel J. Phalen and Aaron Pierce | On the Correlation Between the Spin-Independent and Spin-Dependent
Direct Detection of Dark Matter | 31 pages, 6 figures, 3 appendices; v2: refs added, minor typos
corrected, journal version | Phys.Rev.D81:116001,2010 | 10.1103/PhysRevD.81.116001 | MCTP-10-01 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the correlation between spin-independent and spin-dependent
scattering in the context of MSSM neutralino dark matter for both thermal and
non-thermal histories. We explore the generality of this relationship with
reference to other models. We discuss why either fine-tuning or numerical
coincidences are necessary for the correlation to break down. We derive upper
bounds on spin-dependent scattering mediated by a Z boson.
| [
{
"created": "Wed, 20 Jan 2010 20:38:55 GMT",
"version": "v1"
},
{
"created": "Mon, 31 May 2010 19:11:07 GMT",
"version": "v2"
}
] | 2014-11-20 | [
[
"Cohen",
"Timothy",
""
],
[
"Phalen",
"Daniel J.",
""
],
[
"Pierce",
"Aaron",
""
]
] | We study the correlation between spin-independent and spin-dependent scattering in the context of MSSM neutralino dark matter for both thermal and non-thermal histories. We explore the generality of this relationship with reference to other models. We discuss why either fine-tuning or numerical coincidences are necessary for the correlation to break down. We derive upper bounds on spin-dependent scattering mediated by a Z boson. |
hep-ph/0204049 | Xing ZhiZhong | Zhi-zhong Xing | Nearly Tri-Bimaximal Neutrino Mixing and CP Violation | LaTex 10 pages. Phys. Lett. B (in press) | Phys.Lett.B533:85-93,2002 | 10.1016/S0370-2693(02)01649-0 | BIHEP-TH-2002-13 | hep-ph | null | We point out two simple but instructive possibilities to modify the
tri-bimaximal neutrino mixing ansatz, such that leptonic CP violation can
naturally be incorporated into the resultant scenarios of nearly tri-bimaximal
flavor mixing. The consequences of two new ansaetze on solar, atmospheric and
reactor neutrino oscillations are analyzed. We also discuss an interesting
approach to construct lepton mass matrices under permutation symmetry, from
which one may derive another nearly tri-bimaximal neutrino mixing scenario with
no intrinsic CP violation in neutrino oscillations.
| [
{
"created": "Thu, 4 Apr 2002 09:47:05 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Xing",
"Zhi-zhong",
""
]
] | We point out two simple but instructive possibilities to modify the tri-bimaximal neutrino mixing ansatz, such that leptonic CP violation can naturally be incorporated into the resultant scenarios of nearly tri-bimaximal flavor mixing. The consequences of two new ansaetze on solar, atmospheric and reactor neutrino oscillations are analyzed. We also discuss an interesting approach to construct lepton mass matrices under permutation symmetry, from which one may derive another nearly tri-bimaximal neutrino mixing scenario with no intrinsic CP violation in neutrino oscillations. |
1904.06660 | Stephen King | Stephen F King | Theory Review of Neutrino Models and CP Violation | Talk presented at NuPhys2018 (London, 19-21 December 2018). 13 pages,
LaTeX, 12 pdf figures | null | null | NuPhys2018-King | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Although the measurement of the reactor angle has killed tribimaximal lepton
mixing, its descendants survive with charged lepton corrections, or in less
constrained forms such as trimaximal mixing and/or mu-tau symmetry, each with
characteristic predictions. Such patterns may be enforced by a remnant of some
non-Abelian discrete family symmetry, possibly together with a generalised CP
symmetry, which could originate from continuous gauge symmetry and/or
superstring theory in compactified extra dimensions, as a finite subgroup of
the modular symmetry.
| [
{
"created": "Sun, 14 Apr 2019 09:09:34 GMT",
"version": "v1"
},
{
"created": "Sat, 20 Apr 2019 07:41:37 GMT",
"version": "v2"
},
{
"created": "Fri, 3 May 2019 15:35:26 GMT",
"version": "v3"
}
] | 2019-05-06 | [
[
"King",
"Stephen F",
""
]
] | Although the measurement of the reactor angle has killed tribimaximal lepton mixing, its descendants survive with charged lepton corrections, or in less constrained forms such as trimaximal mixing and/or mu-tau symmetry, each with characteristic predictions. Such patterns may be enforced by a remnant of some non-Abelian discrete family symmetry, possibly together with a generalised CP symmetry, which could originate from continuous gauge symmetry and/or superstring theory in compactified extra dimensions, as a finite subgroup of the modular symmetry. |
hep-ph/9707245 | null | Abdellatif Abada, Michael C. Birse (University of Manchester) | Disoriented chiral condensate formation from tubes of hot quark plasma | 18 pages (RevTeX), 8 figures (psfig) | Phys.Rev. D57 (1998) 292-298 | 10.1103/PhysRevD.57.292 | MC/TH 97/09 | hep-ph nucl-th | null | We investigate the time evolution of a system of quarks interacting with
sigma and pion fields starting from an initial configuration consisting of a
tube of hot quark plasma undergoing a boost-invariant longitudinal expansion.
We work within the framework of the linear sigma model using classical
transport equations for the quarks coupled to the mean-field equations for the
meson fields. In certain cases we find strong amplifications of any initial
pion fields. For large-radius tubes, starting from quark densities that are
very close to critical, we find that a disoriented chiral condensate can form
in the centre of the tube. Eventually the collapse of the tube drives this
state back to the true vacuum. This process converts the disoriented
condensate, dominated by long-wavelength pion modes, into a coherent excitation
of the pion field that includes significant components with transverse momenta
of around 400 MeV. In contrast, for narrow tubes or larger initial
temperatures, amplification occurs only via the pion-laser-like mechanism found
previously for spherical systems. In addition, we find that explicit chiral
symmetry breaking significantly suppresses the formation of disoriented
condensates.
| [
{
"created": "Fri, 4 Jul 1997 09:21:23 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Abada",
"Abdellatif",
"",
"University of Manchester"
],
[
"Birse",
"Michael C.",
"",
"University of Manchester"
]
] | We investigate the time evolution of a system of quarks interacting with sigma and pion fields starting from an initial configuration consisting of a tube of hot quark plasma undergoing a boost-invariant longitudinal expansion. We work within the framework of the linear sigma model using classical transport equations for the quarks coupled to the mean-field equations for the meson fields. In certain cases we find strong amplifications of any initial pion fields. For large-radius tubes, starting from quark densities that are very close to critical, we find that a disoriented chiral condensate can form in the centre of the tube. Eventually the collapse of the tube drives this state back to the true vacuum. This process converts the disoriented condensate, dominated by long-wavelength pion modes, into a coherent excitation of the pion field that includes significant components with transverse momenta of around 400 MeV. In contrast, for narrow tubes or larger initial temperatures, amplification occurs only via the pion-laser-like mechanism found previously for spherical systems. In addition, we find that explicit chiral symmetry breaking significantly suppresses the formation of disoriented condensates. |
hep-ph/0611149 | Walter Grimus | W. Grimus, L. Lavoura | A three-parameter model for the neutrino mass matrix | 16 pages, one eps figure; some clarifications added, contains new
section 5, version accepted for publication in J. Phys. G | J.Phys.G34:1757-1770,2007 | 10.1088/0954-3899/34/7/014 | UWThPh-2006-28 | hep-ph | null | Using the type-II seesaw mechanism with three Higgs doublets phi_alpha (alpha
= e, mu, tau) and four Higgs triplets, we build a model for lepton mixing based
on a 384-element horizontal symmetry group, generated by the permutation group
S_3 and by six Z_2 transformations. The charged-lepton mass matrix is diagonal;
the symmetries of the model would require all the three masses m_alpha to be
equal, but different vacuum expectation values of the phi_alpha allow the
m_alpha to split. The number of parameters in the Majorana neutrino mass matrix
m_nu depends on two options: full breaking of the permutation group S_3, or
leaving a mu--tau interchange symmetry intact; and hard or spontaneous
violation of CP. We discuss in detail the case with the minimal number of three
parameters, wherein m_nu is real, symmetric under mu--tau interchange, and has
equal diagonal elements. In that case, CP is conserved in lepton mixing,
atmospheric neutrino mixing is maximal, and theta_{13} = 0; moreover, the type
of neutrino mass spectrum and the absolute neutrino mass scale are sensitive
functions of the solar mixing angle.
| [
{
"created": "Fri, 10 Nov 2006 19:13:37 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Jan 2007 07:20:39 GMT",
"version": "v2"
},
{
"created": "Thu, 24 May 2007 08:20:53 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Grimus",
"W.",
""
],
[
"Lavoura",
"L.",
""
]
] | Using the type-II seesaw mechanism with three Higgs doublets phi_alpha (alpha = e, mu, tau) and four Higgs triplets, we build a model for lepton mixing based on a 384-element horizontal symmetry group, generated by the permutation group S_3 and by six Z_2 transformations. The charged-lepton mass matrix is diagonal; the symmetries of the model would require all the three masses m_alpha to be equal, but different vacuum expectation values of the phi_alpha allow the m_alpha to split. The number of parameters in the Majorana neutrino mass matrix m_nu depends on two options: full breaking of the permutation group S_3, or leaving a mu--tau interchange symmetry intact; and hard or spontaneous violation of CP. We discuss in detail the case with the minimal number of three parameters, wherein m_nu is real, symmetric under mu--tau interchange, and has equal diagonal elements. In that case, CP is conserved in lepton mixing, atmospheric neutrino mixing is maximal, and theta_{13} = 0; moreover, the type of neutrino mass spectrum and the absolute neutrino mass scale are sensitive functions of the solar mixing angle. |
hep-ph/9608288 | Leonid Burakovsky | L. Burakovsky | First Order Quark-Gluon/Hadron Transition May Affect Cosmological
Nucleosynthesis | 10 pages, LaTeX, to appear in Phys. Lett. B, 1996 | Phys.Lett. B382 (1996) 13-18 | 10.1016/0370-2693(96)00517-5 | LA-UR-95-4527 | hep-ph | null | In the model of a first order quark-gluon/hadron phase transition in which
the hadronic phase is considered as vacuum bubbles growing in the quark-gluon
background with chiral symmetry broken inside the bubble, we find the estimate
for the length scale associated with inhomogeneities originated during the
transition, $10$ m $\;\stackrel{<}{\sim }\ell \stackrel{<}{\sim }40$ m, being
sufficient to produce significant effects on cosmological nucleosynthesis.
| [
{
"created": "Fri, 9 Aug 1996 17:37:26 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Burakovsky",
"L.",
""
]
] | In the model of a first order quark-gluon/hadron phase transition in which the hadronic phase is considered as vacuum bubbles growing in the quark-gluon background with chiral symmetry broken inside the bubble, we find the estimate for the length scale associated with inhomogeneities originated during the transition, $10$ m $\;\stackrel{<}{\sim }\ell \stackrel{<}{\sim }40$ m, being sufficient to produce significant effects on cosmological nucleosynthesis. |
2309.00672 | Chandan Hati | Fei Gao, Julia Harz, Chandan Hati, Yi Lu, Isabel M. Oldengott, Graham
White | Sphaleron freeze-in baryogenesis with gravitational waves from the QCD
transition | 7 pages, 3 figures | null | null | MITP-23-049, ULB-TH/23-08, IFIC/23-41 | hep-ph astro-ph.CO astro-ph.HE hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A large primordial lepton asymmetry is capable of explaining the baryon
asymmetry of the Universe (BAU) through suppression of the electroweak
sphaleron rates (``sphaleron freeze-in") which can lead to a first-order cosmic
QCD transition with an observable gravitational wave (GW) signal. With
next-to-leading order dimensional reduction and the exact 1-loop fluctuation
determinant, we accurately compute the lepton asymmetry needed to realize this
paradigm, finding it to be an order of magnitude smaller than previous
estimates. Further, we apply an improved QCD equation of state capable of
describing the phase transition line together with the critical endpoint
leading to better agreement with lattice and functional QCD results. Based on
this, we identify the range of lepton flavor asymmetries inducing a first-order
cosmic QCD transition. We then extract the parameters relevant to the
prediction of GW signal from a first-order cosmic QCD transition. Our result
showcases the possibility of probing the sphaleron freeze-in paradigm as an
explanation of BAU by future gravitational wave experiments like $\mu$Ares.
| [
{
"created": "Fri, 1 Sep 2023 18:00:00 GMT",
"version": "v1"
}
] | 2023-09-06 | [
[
"Gao",
"Fei",
""
],
[
"Harz",
"Julia",
""
],
[
"Hati",
"Chandan",
""
],
[
"Lu",
"Yi",
""
],
[
"Oldengott",
"Isabel M.",
""
],
[
"White",
"Graham",
""
]
] | A large primordial lepton asymmetry is capable of explaining the baryon asymmetry of the Universe (BAU) through suppression of the electroweak sphaleron rates (``sphaleron freeze-in") which can lead to a first-order cosmic QCD transition with an observable gravitational wave (GW) signal. With next-to-leading order dimensional reduction and the exact 1-loop fluctuation determinant, we accurately compute the lepton asymmetry needed to realize this paradigm, finding it to be an order of magnitude smaller than previous estimates. Further, we apply an improved QCD equation of state capable of describing the phase transition line together with the critical endpoint leading to better agreement with lattice and functional QCD results. Based on this, we identify the range of lepton flavor asymmetries inducing a first-order cosmic QCD transition. We then extract the parameters relevant to the prediction of GW signal from a first-order cosmic QCD transition. Our result showcases the possibility of probing the sphaleron freeze-in paradigm as an explanation of BAU by future gravitational wave experiments like $\mu$Ares. |
1702.05081 | Vladimir Saleev | Anton Karpishkov, Maxim Nefedov, Vladimir Saleev, Alexandra Shipilova | Heavy quark production at the LHC in the Parton Reggeization Approach | 10 pages, 5 figures, Talk at the Helmholtz - DIAS International
Summer School, Quantum Field Theory at the Limits: from Strong Fields to
Heavy Quarks, JINR, Dubna, 18-30 July, 2016 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the general introduction to the Parton Reggeization Approach and
discuss some new results on large-p_T production for heavy quarks at the LHC.
We concentrate here on study of different correlation spectra for b\barb-jet
pairs, D\barD-meson pairs and DD-meson pairs.
| [
{
"created": "Thu, 16 Feb 2017 18:37:00 GMT",
"version": "v1"
}
] | 2017-02-17 | [
[
"Karpishkov",
"Anton",
""
],
[
"Nefedov",
"Maxim",
""
],
[
"Saleev",
"Vladimir",
""
],
[
"Shipilova",
"Alexandra",
""
]
] | We present the general introduction to the Parton Reggeization Approach and discuss some new results on large-p_T production for heavy quarks at the LHC. We concentrate here on study of different correlation spectra for b\barb-jet pairs, D\barD-meson pairs and DD-meson pairs. |
1402.4481 | Jared Evans | Jared A. Evans | A Swarm of Bs | 14 pages, 4 figures, 2 tables, journal version | JHEP 1408 (2014) 073 | 10.1007/JHEP08(2014)073 | RUNHETC-2014-01 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | New physics signals containing five or more b-tagged jets, but without MET or
leptons, could realistically be sitting within the current 8 TeV LHC data set
without receiving meaningful constraints from any of the existing LHC searches
at either ATLAS or CMS. This work provides several examples of simple,
motivated models that yield final states containing many b-jets. To study the
potential for uncovering new physics in these high b-jet multiplicity channels,
this paper focuses on a natural supersymmetry scenario where each of the
pair-produced stops decays to an on-shell chargino, which subsequently decays
via an MFV-motivated, R-parity violating coupling. This gives rise to an
eight-jet final state containing six b-quarks. Although no public measurements
exist, estimates indicate that the standard model backgrounds in high b-jet
multiplicity channels should be very small. To circumvent the background
uncertainty, an asymmetric method is presented that utilizes two different
techniques to conservatively exclude or to discover new physics in high b-jet
multiplicity final states.
| [
{
"created": "Tue, 18 Feb 2014 21:00:20 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Aug 2014 20:59:40 GMT",
"version": "v2"
}
] | 2015-06-18 | [
[
"Evans",
"Jared A.",
""
]
] | New physics signals containing five or more b-tagged jets, but without MET or leptons, could realistically be sitting within the current 8 TeV LHC data set without receiving meaningful constraints from any of the existing LHC searches at either ATLAS or CMS. This work provides several examples of simple, motivated models that yield final states containing many b-jets. To study the potential for uncovering new physics in these high b-jet multiplicity channels, this paper focuses on a natural supersymmetry scenario where each of the pair-produced stops decays to an on-shell chargino, which subsequently decays via an MFV-motivated, R-parity violating coupling. This gives rise to an eight-jet final state containing six b-quarks. Although no public measurements exist, estimates indicate that the standard model backgrounds in high b-jet multiplicity channels should be very small. To circumvent the background uncertainty, an asymmetric method is presented that utilizes two different techniques to conservatively exclude or to discover new physics in high b-jet multiplicity final states. |
1712.08052 | Gauhar Abbas | Gauhar Abbas | Solving the fermionic mass hierarchy of the standard model | 17 pages, published version | Int.J.Mod.Phys. A 34 (2019) 1950104 | 10.1142/S0217751X19501045 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show that a simultaneous explanation for fermionic mass hierarchy among
and within the fermionic families, quark-mixing, can be obtained in an
extension of the standard model, with real singlet scalar fields, which is UV
completed by vector-like fermions and a strongly interacting sector.
| [
{
"created": "Thu, 21 Dec 2017 16:19:02 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Jul 2018 08:21:50 GMT",
"version": "v2"
},
{
"created": "Sat, 15 Jun 2019 13:42:09 GMT",
"version": "v3"
},
{
"created": "Tue, 16 Jul 2019 04:38:03 GMT",
"version": "v4"
}
] | 2019-07-17 | [
[
"Abbas",
"Gauhar",
""
]
] | We show that a simultaneous explanation for fermionic mass hierarchy among and within the fermionic families, quark-mixing, can be obtained in an extension of the standard model, with real singlet scalar fields, which is UV completed by vector-like fermions and a strongly interacting sector. |
2009.14356 | Shan-Liang Zhang | Shan-Liang Zhang, Xin-Nian Wang and Ben-Wei Zhang | Production of W+jets in Relativistic heavy-ion collisions | 4 pages, 4 figures, talks at HardProbes2020 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We carry out a detailed calculations of W+jets production in Pb+Pb collisions
at the Large Hadron Collider (LHC). In our calculations, the production of
W+jet in p+p reference is obtained from Sherpa, which matches
next-to-leading-order matrix elements to the resummation of parton shower
calculations. Jet propagation and medium response in the quark-gluon plasma is
simulated with the Linear Boltzmann Transport (LBT) model. We calculate five
observables of W+jets productions with jet quenching effect in Pb+Pb
collisions: event distribution as a function of the vector sum of the lepton
and jets $|\vec{p}_T^{Miss}|$, nuclear effects for tagged jet cross sections
$I_{AA}$, azimuthal angle correlations $\Delta \phi_{jW}$, mean value of
momentum imbalance $\langle x_{jW}\rangle$, average number of jets per W boson
$R_{jW}$. The nuclear modifications of these 5 observables due to jet quenching
in Pb+Pb relative to that in p+p collisions are discussed.
| [
{
"created": "Wed, 30 Sep 2020 00:25:15 GMT",
"version": "v1"
}
] | 2020-10-01 | [
[
"Zhang",
"Shan-Liang",
""
],
[
"Wang",
"Xin-Nian",
""
],
[
"Zhang",
"Ben-Wei",
""
]
] | We carry out a detailed calculations of W+jets production in Pb+Pb collisions at the Large Hadron Collider (LHC). In our calculations, the production of W+jet in p+p reference is obtained from Sherpa, which matches next-to-leading-order matrix elements to the resummation of parton shower calculations. Jet propagation and medium response in the quark-gluon plasma is simulated with the Linear Boltzmann Transport (LBT) model. We calculate five observables of W+jets productions with jet quenching effect in Pb+Pb collisions: event distribution as a function of the vector sum of the lepton and jets $|\vec{p}_T^{Miss}|$, nuclear effects for tagged jet cross sections $I_{AA}$, azimuthal angle correlations $\Delta \phi_{jW}$, mean value of momentum imbalance $\langle x_{jW}\rangle$, average number of jets per W boson $R_{jW}$. The nuclear modifications of these 5 observables due to jet quenching in Pb+Pb relative to that in p+p collisions are discussed. |
1303.0660 | Wenyu Wang | Wenyu Wang, Zhao-Hua Xiong and Si-Hong Zhou | Complete Analysis on the Short Distance Contribution of $B_s\to
\ell^+\ell^-\gamma$ in Standard Model | arXiv admin note: substantial text overlap with arXiv:1207.1978 | null | 10.1088/0256-307X/30/11/111202 | null | hep-ph | http://creativecommons.org/licenses/by/3.0/ | Using the $B_s$ meson wave function extracted from non-leptonic $B_s$ decays,
we evaluate the short distance contribution of rare decays $B_s\to
\ell^+\ell^-\gamma(\ell=e,\mu)$ in the standard model, including all the
possible diagrams. We focus on the contribution from four-quark operators which
are not taken into account properly in previous researches. We found that the
contribution is large, leading to the branching ratio of $B_s\to
\ell^+\ell^-\gamma$ being nearly enhanced by a factor 3 and up to $1.7\times
10^{-8}$. The predictions for such processes can be tested in the LHC-b and B
factories in near future.
| [
{
"created": "Mon, 4 Mar 2013 09:59:02 GMT",
"version": "v1"
}
] | 2015-06-15 | [
[
"Wang",
"Wenyu",
""
],
[
"Xiong",
"Zhao-Hua",
""
],
[
"Zhou",
"Si-Hong",
""
]
] | Using the $B_s$ meson wave function extracted from non-leptonic $B_s$ decays, we evaluate the short distance contribution of rare decays $B_s\to \ell^+\ell^-\gamma(\ell=e,\mu)$ in the standard model, including all the possible diagrams. We focus on the contribution from four-quark operators which are not taken into account properly in previous researches. We found that the contribution is large, leading to the branching ratio of $B_s\to \ell^+\ell^-\gamma$ being nearly enhanced by a factor 3 and up to $1.7\times 10^{-8}$. The predictions for such processes can be tested in the LHC-b and B factories in near future. |
hep-ph/0604272 | Rachel Jeannerot | R. Jeannerot (Leiden U.) | Cosmology of B-L cosmic strings | 7 pages, 1 figure. Proceedings of the Rencontres de Moriond Energy
Densities in the Universe, Les Arcs, France (January 22-29, 2000) | null | null | null | hep-ph | null | ${\rm B - L}$ cosmic strings form in a wide class of theories beyond the
Standard Model which contain a ${\rm U}(1)_{{\rm B - L}}$ gauge symmetry. They
can form at the end of hybrid inflation and explain, together with inflation,
the Cosmic Microwave Background anisotropies and the formation of large scale
structure. They can produce Cold Dark Matter in the form of the Lightest
SuperParticle and they can be at the origin of the baryon asymmetry of our
universe. One major advantage of these mechanisms is that they are non-thermal.
| [
{
"created": "Fri, 28 Apr 2006 16:43:55 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Jeannerot",
"R.",
"",
"Leiden U."
]
] | ${\rm B - L}$ cosmic strings form in a wide class of theories beyond the Standard Model which contain a ${\rm U}(1)_{{\rm B - L}}$ gauge symmetry. They can form at the end of hybrid inflation and explain, together with inflation, the Cosmic Microwave Background anisotropies and the formation of large scale structure. They can produce Cold Dark Matter in the form of the Lightest SuperParticle and they can be at the origin of the baryon asymmetry of our universe. One major advantage of these mechanisms is that they are non-thermal. |
1402.5716 | Ping Wang | W. Xie and P. Wang | Unified Hamiltonian model for mesons and baryons | 1 figure, 4 tables | null | 10.1088/1674-1137/39/5/053102 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A new Hamiltonian model is introduced to study the spectrum of light hadrons.
It combines relativistic field theory with elements of the constituent quark
model. In addition to the standard linear confining and pseudoscalar meson
exchange interactions with predetermined parameters, an additional interaction
with different covariant spin structures is examined. Using a large scale Monte
Carlo variational procedure, the resulting model Hamiltonian provides a very
good, unified description of the light quark baryon (both octet and decuplet)
and meson spectra.
| [
{
"created": "Mon, 24 Feb 2014 03:58:43 GMT",
"version": "v1"
}
] | 2015-06-11 | [
[
"Xie",
"W.",
""
],
[
"Wang",
"P.",
""
]
] | A new Hamiltonian model is introduced to study the spectrum of light hadrons. It combines relativistic field theory with elements of the constituent quark model. In addition to the standard linear confining and pseudoscalar meson exchange interactions with predetermined parameters, an additional interaction with different covariant spin structures is examined. Using a large scale Monte Carlo variational procedure, the resulting model Hamiltonian provides a very good, unified description of the light quark baryon (both octet and decuplet) and meson spectra. |
2002.01789 | Leonardo Di Giustino | Leonardo Di Giustino, Stanley J. Brodsky, Sheng-Quan Wang and
Xing-Gang Wu | PMC$_\infty$: Infinite-Order Scale-Setting using the Principle of
Maximum Conformality, A Remarkably Efficient Method for Eliminating
Renormalization Scale Ambiguities for Perturbative QCD | 10 pages, 6 figures | Phys. Rev. D 102, 014015 (2020) | 10.1103/PhysRevD.102.014015 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We identify a property of renormalizable SU(N)/U(1) gauge theories, the
intrinsic Conformality ($iCF$), which underlies the scale invariance of
physical observables and leads to a remarkably efficient method to solve the
conventional renormalization scale ambiguity at every order in pQCD: the
PMC$_\infty$. This new method reflects the underlying conformal properties
displayed by pQCD at NNLO, eliminates the scheme dependence of pQCD predictions
and is consistent with the general properties of the PMC (Principle of Maximum
Conformality). We introduce a new method to identify conformal and
$\beta$-terms which can be applied either to numerical or to theoretical
calculations. We illustrate the PMC$_\infty$ for the thrust and C-parameter
distributions in $e^+ e^-$ annihilation and then we show how to apply this new
method to general observables in QCD. We point out how the implementation of
the PMC$_\infty$ can significantly improve the precision of pQCD predictions;
its implementation in multi-loop analysis also simplifies the calculation of
higher orders corrections in a general renormalizable gauge theory.
| [
{
"created": "Wed, 5 Feb 2020 13:54:28 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Feb 2020 09:29:17 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Jun 2020 11:40:26 GMT",
"version": "v3"
}
] | 2020-07-15 | [
[
"Di Giustino",
"Leonardo",
""
],
[
"Brodsky",
"Stanley J.",
""
],
[
"Wang",
"Sheng-Quan",
""
],
[
"Wu",
"Xing-Gang",
""
]
] | We identify a property of renormalizable SU(N)/U(1) gauge theories, the intrinsic Conformality ($iCF$), which underlies the scale invariance of physical observables and leads to a remarkably efficient method to solve the conventional renormalization scale ambiguity at every order in pQCD: the PMC$_\infty$. This new method reflects the underlying conformal properties displayed by pQCD at NNLO, eliminates the scheme dependence of pQCD predictions and is consistent with the general properties of the PMC (Principle of Maximum Conformality). We introduce a new method to identify conformal and $\beta$-terms which can be applied either to numerical or to theoretical calculations. We illustrate the PMC$_\infty$ for the thrust and C-parameter distributions in $e^+ e^-$ annihilation and then we show how to apply this new method to general observables in QCD. We point out how the implementation of the PMC$_\infty$ can significantly improve the precision of pQCD predictions; its implementation in multi-loop analysis also simplifies the calculation of higher orders corrections in a general renormalizable gauge theory. |
hep-ph/9403367 | null | K. Sailer | Phase structure of $SU(2)$ Yang-Mills theory with global center symmetry | 37 pages, KLTE-DTP/1994/1 | null | null | null | hep-ph | null | Retaining only the `timelike' component $A_0$ of the vector potential a
skelet model with explicit global center symmetry is constructed for $SU(2)$
Yang-Mills theory. It is shown that the $A_0$ gluon vacuum is equivalent with
the 4-dimensional Coulomb-gas. In 1--loop approximation, the effective theory
of the skelet model exhibits non-local self-interaction. A coupling constant
$\lambda$ is found that governs the loop expansion. For $\lambda < 1$ the
effective theory does not confine (the string tension vanishes), whereas for
$\lambda = 1$ confinement (with non-vanishing string tension) takes place. In
the deconfined phase the $A_0$ gluons exhibit non-zero rest mass and global
center symmetry is broken by the vacuum state.
Confinement sets on for $\lambda =1$ when the rest mass of $A_0$ gluons
vanishes and the global center symmetry of the vacuum is restored.
| [
{
"created": "Fri, 25 Mar 1994 13:09:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Sailer",
"K.",
""
]
] | Retaining only the `timelike' component $A_0$ of the vector potential a skelet model with explicit global center symmetry is constructed for $SU(2)$ Yang-Mills theory. It is shown that the $A_0$ gluon vacuum is equivalent with the 4-dimensional Coulomb-gas. In 1--loop approximation, the effective theory of the skelet model exhibits non-local self-interaction. A coupling constant $\lambda$ is found that governs the loop expansion. For $\lambda < 1$ the effective theory does not confine (the string tension vanishes), whereas for $\lambda = 1$ confinement (with non-vanishing string tension) takes place. In the deconfined phase the $A_0$ gluons exhibit non-zero rest mass and global center symmetry is broken by the vacuum state. Confinement sets on for $\lambda =1$ when the rest mass of $A_0$ gluons vanishes and the global center symmetry of the vacuum is restored. |
1609.04367 | Dr. Rukmani Mohanta | Suchismita Sahoo, Rukmani Mohanta, Anjan K. Giri | Explaining the $R_{K}$ and $R_{D^{(*)}}$ anomalies with vector
leptoquarks | 33 pages, 14 figures, typos corrected | Phys. Rev. D 95, 035027 (2017) | 10.1103/PhysRevD.95.035027 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently the $B$ factories BaBar and Belle as well as the LHCb experiment
have reported several anomalies in the semileptonic $B$ meson decays such as
$R_{K}$ and $R_{D^{(*)}}$ etc. We investigate these deviations by considering
the vector leptoquarks relevant for both $b \to s l^+ l^-$ and $b \to c l \bar
\nu_l$ transitions. The leptoquark parameter space is constrained by using the
experimentally measured branching ratios of $B_s \to l^+ l^-$, $\bar B \to X_s
l^+ l^- (\nu \bar \nu)$ and $B_u^+ \to l^+ \nu_l$ processes. Using the
constrained leptoquark couplings, we compute the branching ratios,
forward-backward asymmetries, $\tau$ and $D^*$ polarization parameters in the
$\bar B \to D^{(*)} l \bar \nu_l$ processes. We find that the vector
leptoquarks can explain both $R_{D^{(*)}}$ and $R_K$ anomalies simultaneously.
Furthermore, we study the rare leptonic $B_{u, c}^* \to l \bar\nu$ decay
processes in this model.
| [
{
"created": "Wed, 14 Sep 2016 17:59:03 GMT",
"version": "v1"
},
{
"created": "Sat, 4 Feb 2017 14:54:18 GMT",
"version": "v2"
},
{
"created": "Thu, 23 Feb 2017 12:10:07 GMT",
"version": "v3"
}
] | 2017-03-01 | [
[
"Sahoo",
"Suchismita",
""
],
[
"Mohanta",
"Rukmani",
""
],
[
"Giri",
"Anjan K.",
""
]
] | Recently the $B$ factories BaBar and Belle as well as the LHCb experiment have reported several anomalies in the semileptonic $B$ meson decays such as $R_{K}$ and $R_{D^{(*)}}$ etc. We investigate these deviations by considering the vector leptoquarks relevant for both $b \to s l^+ l^-$ and $b \to c l \bar \nu_l$ transitions. The leptoquark parameter space is constrained by using the experimentally measured branching ratios of $B_s \to l^+ l^-$, $\bar B \to X_s l^+ l^- (\nu \bar \nu)$ and $B_u^+ \to l^+ \nu_l$ processes. Using the constrained leptoquark couplings, we compute the branching ratios, forward-backward asymmetries, $\tau$ and $D^*$ polarization parameters in the $\bar B \to D^{(*)} l \bar \nu_l$ processes. We find that the vector leptoquarks can explain both $R_{D^{(*)}}$ and $R_K$ anomalies simultaneously. Furthermore, we study the rare leptonic $B_{u, c}^* \to l \bar\nu$ decay processes in this model. |
2207.08563 | Teng Ji | Teng Ji, Xiang-Kun Dong, Miguel Albaladejo, Meng-Lin Du, Feng-Kun Guo
and Juan Nieves | Establishing the heavy quark spin and light flavor molecular multiplets
of the $X(3872)$, $Z_c(3900)$ and $X(3960)$ | 19 pages, 4 figures and 5 tables. Version to appear in PRD | Phys.Rev.D 106 (2022) 9, 094002 | 10.1103/PhysRevD.106.094002 | null | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recently, the LHCb Collaboration reported a near-threshold enhancement,
$X(3960)$, in the $D_s^+D_s^-$ invariant mass distribution. We show that the
data can be well described by either a bound or a virtual state below the
$D_s^+D_s^-$ threshold. The mass given by the pole position is $(3928\pm3)$
MeV. Using this mass and the existing information on the $X(3872)$ and
$Z_c(3900)$ resonances, a complete spectrum of the $S$-wave hadronic molecules
formed by a pair of ground state charmed and anticharmed mesons is established.
Thus, pole positions of the partners of the $X(3872)$, $Z_c(3900)$ and the
newly observed $D_s^+D_s^-$ state are predicted. Calculations have been carried
out at the leading order of nonrelativistic effective field theory and
considering both heavy quark spin and light flavor SU(3) symmetries, though
conservative errors from the breaking of these symmetries are provided.
| [
{
"created": "Mon, 18 Jul 2022 12:45:06 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Oct 2022 12:35:10 GMT",
"version": "v2"
}
] | 2023-09-14 | [
[
"Ji",
"Teng",
""
],
[
"Dong",
"Xiang-Kun",
""
],
[
"Albaladejo",
"Miguel",
""
],
[
"Du",
"Meng-Lin",
""
],
[
"Guo",
"Feng-Kun",
""
],
[
"Nieves",
"Juan",
""
]
] | Recently, the LHCb Collaboration reported a near-threshold enhancement, $X(3960)$, in the $D_s^+D_s^-$ invariant mass distribution. We show that the data can be well described by either a bound or a virtual state below the $D_s^+D_s^-$ threshold. The mass given by the pole position is $(3928\pm3)$ MeV. Using this mass and the existing information on the $X(3872)$ and $Z_c(3900)$ resonances, a complete spectrum of the $S$-wave hadronic molecules formed by a pair of ground state charmed and anticharmed mesons is established. Thus, pole positions of the partners of the $X(3872)$, $Z_c(3900)$ and the newly observed $D_s^+D_s^-$ state are predicted. Calculations have been carried out at the leading order of nonrelativistic effective field theory and considering both heavy quark spin and light flavor SU(3) symmetries, though conservative errors from the breaking of these symmetries are provided. |
2405.05212 | Qiyu Yan | Qiyu Yan, Kajetan Niewczas, Alexis Nikolakopoulos, Ra\'ul
Gonz\'alez-Jim\'enez, Natalie Jachowicz, Xianguo Lu, Jan Sobczyk, and
Yangheng Zheng | The Ghent Hybrid Model in NuWro: a new neutrino single-pion production
model in the GeV regime | 23 pages, 12 figures | null | null | null | hep-ph hep-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | Neutrino-induced single-pion production constitutes an essential interaction
channel in modern neutrino oscillation experiments, with its products building
up a significant fraction of the observable hadronic final states. Frameworks
of oscillation analyses strongly rely on Monte Carlo neutrino event generators,
which provide theoretical predictions of neutrino interactions on nuclear
targets. Thus, it is crucial to integrate state-of-the-art single-pion
production models with Monte Carlo simulations to prepare for the upcoming
systematics-dominated landscape of neutrino measurements. In this work, we
present the implementation of the Ghent Hybrid model for neutrino-induced
single-pion production in the NuWro Monte Carlo event generator. The
interaction dynamics includes coherently-added contributions from nucleon
resonances and a non-resonant background, merged into the pythia branching
predictions in the deep-inelastic regime, as instrumented by NuWro. This
neutrino-nucleon interaction model is fully incorporated into the nuclear
framework of the generator, allowing it to account for the influence of both
initial- and final-state nuclear medium effects. We compare the predictions of
this integrated implementation with recent pion production data from
accelerator-based neutrino experiments. The results of the novel model show
improved agreement of the generator predictions with the data and point to the
significance of the refined treatment of the description of pion-production
processes beyond the $\Delta$ region.
| [
{
"created": "Wed, 8 May 2024 17:00:06 GMT",
"version": "v1"
}
] | 2024-05-09 | [
[
"Yan",
"Qiyu",
""
],
[
"Niewczas",
"Kajetan",
""
],
[
"Nikolakopoulos",
"Alexis",
""
],
[
"González-Jiménez",
"Raúl",
""
],
[
"Jachowicz",
"Natalie",
""
],
[
"Lu",
"Xianguo",
""
],
[
"Sobczyk",
"Jan",
""
... | Neutrino-induced single-pion production constitutes an essential interaction channel in modern neutrino oscillation experiments, with its products building up a significant fraction of the observable hadronic final states. Frameworks of oscillation analyses strongly rely on Monte Carlo neutrino event generators, which provide theoretical predictions of neutrino interactions on nuclear targets. Thus, it is crucial to integrate state-of-the-art single-pion production models with Monte Carlo simulations to prepare for the upcoming systematics-dominated landscape of neutrino measurements. In this work, we present the implementation of the Ghent Hybrid model for neutrino-induced single-pion production in the NuWro Monte Carlo event generator. The interaction dynamics includes coherently-added contributions from nucleon resonances and a non-resonant background, merged into the pythia branching predictions in the deep-inelastic regime, as instrumented by NuWro. This neutrino-nucleon interaction model is fully incorporated into the nuclear framework of the generator, allowing it to account for the influence of both initial- and final-state nuclear medium effects. We compare the predictions of this integrated implementation with recent pion production data from accelerator-based neutrino experiments. The results of the novel model show improved agreement of the generator predictions with the data and point to the significance of the refined treatment of the description of pion-production processes beyond the $\Delta$ region. |
1409.0005 | David Curtin | David Curtin, Patrick Meade, Chiu-Tien Yu | Testing Electroweak Baryogenesis with Future Colliders | 26 pages + references, 10 figures. Fixed minor typos, updated TLEP
and 100 TeV projections. Conclusions unchanged | null | 10.1007/JHEP11(2014)127 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Electroweak Baryogenesis (EWBG) is a compelling scenario for explaining the
matter-antimatter asymmetry in the universe. Its connection to the electroweak
phase transition makes it inherently testable. However, completely excluding
this scenario can seem difficult in practice, due to the sheer number of
proposed models. We investigate the possibility of postulating a "no-lose"
theorem for testing EWBG in future e+e- or hadron colliders. As a first step we
focus on a factorized picture of EWBG which separates the sources of a stronger
phase transition from those that provide new sources of CP violation. We then
construct a "nightmare scenario" that generates a strong first-order phase
transition as required by EWBG, but is very difficult to test experimentally.
We show that a 100 TeV hadron collider is both necessary and possibly
sufficient for testing the parameter space of the nightmare scenario that is
consistent with EWBG.
| [
{
"created": "Fri, 29 Aug 2014 20:00:05 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Sep 2014 19:34:54 GMT",
"version": "v2"
},
{
"created": "Tue, 21 Oct 2014 16:26:43 GMT",
"version": "v3"
},
{
"created": "Mon, 4 May 2015 21:37:03 GMT",
"version": "v4"
}
] | 2015-06-22 | [
[
"Curtin",
"David",
""
],
[
"Meade",
"Patrick",
""
],
[
"Yu",
"Chiu-Tien",
""
]
] | Electroweak Baryogenesis (EWBG) is a compelling scenario for explaining the matter-antimatter asymmetry in the universe. Its connection to the electroweak phase transition makes it inherently testable. However, completely excluding this scenario can seem difficult in practice, due to the sheer number of proposed models. We investigate the possibility of postulating a "no-lose" theorem for testing EWBG in future e+e- or hadron colliders. As a first step we focus on a factorized picture of EWBG which separates the sources of a stronger phase transition from those that provide new sources of CP violation. We then construct a "nightmare scenario" that generates a strong first-order phase transition as required by EWBG, but is very difficult to test experimentally. We show that a 100 TeV hadron collider is both necessary and possibly sufficient for testing the parameter space of the nightmare scenario that is consistent with EWBG. |
hep-ph/0210228 | Amon Ilakovac | Amon Ilakovac | Production and Polarization Effects in Some Tau-Lepton Decays | Invited Talk at the Seventh International Workshop on Tau Lepton
Physics (TAU02), Santa Cruz, CA, USA, Sept. 2002, 6 pages LaTeX; One typo
corrected, a note added, one reference added | eConf C0209101 (2002) WE02 | 10.1016/S0920-5632(03)80317-1 | null | hep-ph | null | The conditions for the independence of decays of the spin-1/2 resonances on
the production mechanism of the resonances and on polarizations of the incoming
and outgoing particles are derived and applied in the case of several
tau-lepton decays. The necessity for inclusion of the influence of the
production mechanism in the evaluation of the lepton flavour violating decays
is stressed.
| [
{
"created": "Wed, 16 Oct 2002 15:21:30 GMT",
"version": "v1"
},
{
"created": "Sun, 3 Nov 2002 10:25:25 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Ilakovac",
"Amon",
""
]
] | The conditions for the independence of decays of the spin-1/2 resonances on the production mechanism of the resonances and on polarizations of the incoming and outgoing particles are derived and applied in the case of several tau-lepton decays. The necessity for inclusion of the influence of the production mechanism in the evaluation of the lepton flavour violating decays is stressed. |
1708.05463 | Timothy Hobbs | T. J. Hobbs | Quantifying finite-momentum effects in meson quasi-PDFs | 10 pages, 4 two-panel figures | Phys. Rev. D 97, 054028 (2018) | 10.1103/PhysRevD.97.054028 | NT@UW-17-15 | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The recently proposed large momentum effective theory (LaMET) of Ji has led
to a burst of activity among lattice practitioners to perform and control the
first pioneering calculations of the quasi-PDFs of the nucleon. These
calculations represent approximations to the standard PDFs defined as
correlation functions of fields with lightlike separation, being instead
correlations along a longitudinal direction of the operator $\gamma^z$; as
such, they differ from standard PDFs by power-suppressed $1 \big/ p^2_z$
corrections, becoming exact in the limit $p_z \to \infty$. Investigating the
systematics of this behavior thus becomes crucial to understanding the validity
of LaMET calculations. While this has been done using models for the nucleon,
an analogous dedicated study has not been carried out for the $\pi$ and $\rho$
quark distribution functions. Using a constituent quark model, a systematic
calculation is performed to estimate the size and $x$ dependence of the
finite-$p_z$ effects in these quasi-PDFs, finding them to be potentially tamer
for lighter mesons than for the collinear quasi-PDFs of the nucleon.
| [
{
"created": "Thu, 17 Aug 2017 23:29:30 GMT",
"version": "v1"
}
] | 2018-03-28 | [
[
"Hobbs",
"T. J.",
""
]
] | The recently proposed large momentum effective theory (LaMET) of Ji has led to a burst of activity among lattice practitioners to perform and control the first pioneering calculations of the quasi-PDFs of the nucleon. These calculations represent approximations to the standard PDFs defined as correlation functions of fields with lightlike separation, being instead correlations along a longitudinal direction of the operator $\gamma^z$; as such, they differ from standard PDFs by power-suppressed $1 \big/ p^2_z$ corrections, becoming exact in the limit $p_z \to \infty$. Investigating the systematics of this behavior thus becomes crucial to understanding the validity of LaMET calculations. While this has been done using models for the nucleon, an analogous dedicated study has not been carried out for the $\pi$ and $\rho$ quark distribution functions. Using a constituent quark model, a systematic calculation is performed to estimate the size and $x$ dependence of the finite-$p_z$ effects in these quasi-PDFs, finding them to be potentially tamer for lighter mesons than for the collinear quasi-PDFs of the nucleon. |
1510.04596 | Peter Stangl | Peter Stangl | Lepton flavour universality violation from composite muons | 8 pages, 3 figures. To be published in the proceedings of the
European Physical Society Conference on High Energy Physics (EPS-HEP), 22-29
July 2015, Vienna, Austria | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe a possibility to explain the $2.6\sigma$ deviation from lepton
flavour universality observed by the LHCb collaboration in $B^+\to
K^+\ell^+\ell^-$ decays in the context of minimal composite Higgs models. We
find that a sizable degree of compositeness of partially composite muons can
lead to a good agreement with the experimental data. Our construction predicts
a new physics contribution to $B_s$-$\bar{B}_s$ mixing. Additionally, it
accounts for the deficit in the invisible $Z$ width measured at LEP.
| [
{
"created": "Thu, 15 Oct 2015 15:49:28 GMT",
"version": "v1"
}
] | 2015-10-16 | [
[
"Stangl",
"Peter",
""
]
] | We describe a possibility to explain the $2.6\sigma$ deviation from lepton flavour universality observed by the LHCb collaboration in $B^+\to K^+\ell^+\ell^-$ decays in the context of minimal composite Higgs models. We find that a sizable degree of compositeness of partially composite muons can lead to a good agreement with the experimental data. Our construction predicts a new physics contribution to $B_s$-$\bar{B}_s$ mixing. Additionally, it accounts for the deficit in the invisible $Z$ width measured at LEP. |
hep-ph/0610235 | Jean-S\'ebastien Gagnon | J.-S. Gagnon, S. Jeon | Leading Order Calculation of Electric Conductivity in Hot Quantum
Electrodynamics from Diagrammatic Methods | 45 pages, 16 figures. Typos corrected, some explanations added to
power counting, some clarifications added in various places | Phys.Rev.D75:025014,2007; Erratum-ibid.D76:089902,2007 | 10.1103/PhysRevD.75.025014 10.1103/PhysRevD.76.089902 | null | hep-ph | null | Using diagrammatic methods, we show how the Ward identity can be used to
constrain the ladder kernel in transport coefficient calculations. More
specifically, we use the Ward identity to determine the necessary diagrams that
must be resummed using an integral equation. One of our main results is an
equation relating the kernel of the integral equation with functional
derivatives of the full self-energy; it is similar to what is obtained with 2PI
effective action methods. However, since we use the Ward identity as our
starting point, gauge invariance is preserved. Using power counting arguments,
we also show which self-energies must be included in the resummation at leading
order, including 2 to 2 scatterings and 1 to 2 collinear scatterings with the
LPM effect. We show that our quantum field theory result is equivalent to the
one of Arnold, Moore and Yaffe obtained using effective kinetic theory. In this
paper we restrict our discussion to electrical conductivity in hot QED, but our
method can in principle be generalized to other transport coefficients and
other theories.
| [
{
"created": "Wed, 18 Oct 2006 14:48:05 GMT",
"version": "v1"
},
{
"created": "Tue, 28 Nov 2006 20:38:42 GMT",
"version": "v2"
},
{
"created": "Fri, 12 Jan 2007 19:50:30 GMT",
"version": "v3"
}
] | 2014-11-18 | [
[
"Gagnon",
"J. -S.",
""
],
[
"Jeon",
"S.",
""
]
] | Using diagrammatic methods, we show how the Ward identity can be used to constrain the ladder kernel in transport coefficient calculations. More specifically, we use the Ward identity to determine the necessary diagrams that must be resummed using an integral equation. One of our main results is an equation relating the kernel of the integral equation with functional derivatives of the full self-energy; it is similar to what is obtained with 2PI effective action methods. However, since we use the Ward identity as our starting point, gauge invariance is preserved. Using power counting arguments, we also show which self-energies must be included in the resummation at leading order, including 2 to 2 scatterings and 1 to 2 collinear scatterings with the LPM effect. We show that our quantum field theory result is equivalent to the one of Arnold, Moore and Yaffe obtained using effective kinetic theory. In this paper we restrict our discussion to electrical conductivity in hot QED, but our method can in principle be generalized to other transport coefficients and other theories. |
1801.10488 | Ara Ioannisian Dr. | Ara Ioannisian and Stefan Pokorski | Three Neutrino Oscillations in Matter | added discussion of results, one appendix is removed | null | 10.1016/j.physletb.2018.06.001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Following similar approaches in the past, the Schrodinger equation for three
neutrino propagation in matter of constant density is solved analytically by
two successive diagonalizations of 2x2 matrices. The final result for the
oscillation probabilities is obtained directly in the conventional parametric
form as in the vacuum but with explicit simple modification of two mixing
angles ($\theta_{12}$ and $\theta_{13}$) and mass eigenvalues.
| [
{
"created": "Wed, 31 Jan 2018 15:22:43 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Feb 2018 17:08:03 GMT",
"version": "v2"
},
{
"created": "Tue, 13 Feb 2018 14:13:55 GMT",
"version": "v3"
},
{
"created": "Thu, 12 Jul 2018 13:54:12 GMT",
"version": "v4"
}
] | 2018-07-13 | [
[
"Ioannisian",
"Ara",
""
],
[
"Pokorski",
"Stefan",
""
]
] | Following similar approaches in the past, the Schrodinger equation for three neutrino propagation in matter of constant density is solved analytically by two successive diagonalizations of 2x2 matrices. The final result for the oscillation probabilities is obtained directly in the conventional parametric form as in the vacuum but with explicit simple modification of two mixing angles ($\theta_{12}$ and $\theta_{13}$) and mass eigenvalues. |
hep-ph/9803224 | Robert Delbourgo | R Delbourgo, Dongsheng Liu (University of Tasmania) | Nonleptonic decays: Amplitude analysis and supermultiplet schemes | 12 pages, Latex2.09, sprocl.sty style file needed | null | null | UTAS-PHYS-98-01 | hep-ph | null | We give best covariant amplitude decompositions for two-body decay processes
involving ground state hadrons ($0^-, 1^-, {1/2}^+, {3/2}^+$) and show how
these are simply related to helicity amplitudes. After discussing how
electromagnetic interactions are incorporated via meson dominance in a
relativistic supermultiplet scheme, we extend the analysis to weak flavour
changing nonleptonic processes. Such weak interactions are described by three
generic amplitudes, which we estimate according to the rules of calculation
within covariant SU(2N$_f$).
| [
{
"created": "Tue, 3 Mar 1998 06:00:09 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Delbourgo",
"R",
"",
"University of Tasmania"
],
[
"Liu",
"Dongsheng",
"",
"University of Tasmania"
]
] | We give best covariant amplitude decompositions for two-body decay processes involving ground state hadrons ($0^-, 1^-, {1/2}^+, {3/2}^+$) and show how these are simply related to helicity amplitudes. After discussing how electromagnetic interactions are incorporated via meson dominance in a relativistic supermultiplet scheme, we extend the analysis to weak flavour changing nonleptonic processes. Such weak interactions are described by three generic amplitudes, which we estimate according to the rules of calculation within covariant SU(2N$_f$). |
hep-ph/0409126 | Csaba Csaki | Giacomo Cacciapaglia, Csaba Csaki, Christophe Grojean and John Terning | Curing the Ills of Higgsless Models: the S Parameter and Unitarity | 21 pages, LaTeX, 5 figures. References and acknowledgements added | Phys.Rev.D71:035015,2005 | 10.1103/PhysRevD.71.035015 | null | hep-ph | null | We consider various constraints on Higgsless models of electroweak symmetry
breaking based on a bulk SU(2)_L x SU(2)_R x U(1)_{B-L} gauge group in warped
space. First we show that the S parameter which is positive if fermions are
localized on the Planck brane can be lowered (or made vanishing) by changing
the localization of the light fermions. If the wave function of the light
fermions is almost flat their coupling to the gauge boson KK modes will be
close to vanishing, and therefore contributions to the S parameter will be
suppressed. At the same time the experimental bounds on such Z' and W' gauge
bosons become very weak, and their masses can be lowered to make sure that
perturbative unitarity is not violated in this theory before reaching energies
of several TeV. The biggest difficulty of these models is to incorporate a
heavy top quark mass without violating any of the experimental bounds on bottom
quark gauge couplings. In the simplest models of fermion masses a sufficiently
heavy top quark also implies an unacceptably large correction to the Zb\bar{b}
vertex and a large splitting between the KK modes of the top and bottom quarks,
yielding large loop corrections to the T-parameter. We present possible
directions for model building where perhaps these constraints could be obeyed
as well.
| [
{
"created": "Mon, 13 Sep 2004 17:11:36 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Sep 2004 20:42:59 GMT",
"version": "v2"
}
] | 2009-09-17 | [
[
"Cacciapaglia",
"Giacomo",
""
],
[
"Csaki",
"Csaba",
""
],
[
"Grojean",
"Christophe",
""
],
[
"Terning",
"John",
""
]
] | We consider various constraints on Higgsless models of electroweak symmetry breaking based on a bulk SU(2)_L x SU(2)_R x U(1)_{B-L} gauge group in warped space. First we show that the S parameter which is positive if fermions are localized on the Planck brane can be lowered (or made vanishing) by changing the localization of the light fermions. If the wave function of the light fermions is almost flat their coupling to the gauge boson KK modes will be close to vanishing, and therefore contributions to the S parameter will be suppressed. At the same time the experimental bounds on such Z' and W' gauge bosons become very weak, and their masses can be lowered to make sure that perturbative unitarity is not violated in this theory before reaching energies of several TeV. The biggest difficulty of these models is to incorporate a heavy top quark mass without violating any of the experimental bounds on bottom quark gauge couplings. In the simplest models of fermion masses a sufficiently heavy top quark also implies an unacceptably large correction to the Zb\bar{b} vertex and a large splitting between the KK modes of the top and bottom quarks, yielding large loop corrections to the T-parameter. We present possible directions for model building where perhaps these constraints could be obeyed as well. |
1308.1090 | Gero von Gersdorff | Emilian Dudas, Gero von Gersdorff, Stefan Pokorski, Robert Ziegler | Linking Natural Supersymmetry to Flavour Physics | 29 pages, v2: Discussion on mu->e gamma modified, added some
clarifications and references; published version | null | 10.1007/JHEP01(2014)117 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | With the aim of linking natural supersymmetry to flavour physics, a model is
proposed based on a family symmetry G \times U(1), where G is a discrete
nonabelian subgroup of SU(2), with both F-term and (abelian) D-term
supersymmetry breaking. A good fit to the fermion masses and mixing is obtained
with the same U(1) charges for the left- and right- handed quarks of the first
two families and the right-handed bottom quark, and with zero charge for the
left-handed top-bottom doublet and the the right handed top. The model shows an
interesting indirect correlation between the correct prediction for the
V_{ub}/V_{cb} ratio and large right-handed rotations in the (s,b) sector,
required to diagonalise the Yukawa matrix. For the squarks, one obtains almost
degenerate first two generations. The main source of the FCNC and CP violation
effects is the splitting between the first two families and the right-handed
sbottom determined by the relative size of F-term and D-term supersymmetry
breaking. The presence of the large right-handed rotation implies that the
bounds on the masses of the first two families of squarks and the right handed
sbottom are in a few to a few tens TeV range. The picture that emerges is light
stops and left handed sbottom and much heavier other squarks.
| [
{
"created": "Mon, 5 Aug 2013 20:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 7 Feb 2014 17:28:53 GMT",
"version": "v2"
}
] | 2015-06-16 | [
[
"Dudas",
"Emilian",
""
],
[
"von Gersdorff",
"Gero",
""
],
[
"Pokorski",
"Stefan",
""
],
[
"Ziegler",
"Robert",
""
]
] | With the aim of linking natural supersymmetry to flavour physics, a model is proposed based on a family symmetry G \times U(1), where G is a discrete nonabelian subgroup of SU(2), with both F-term and (abelian) D-term supersymmetry breaking. A good fit to the fermion masses and mixing is obtained with the same U(1) charges for the left- and right- handed quarks of the first two families and the right-handed bottom quark, and with zero charge for the left-handed top-bottom doublet and the the right handed top. The model shows an interesting indirect correlation between the correct prediction for the V_{ub}/V_{cb} ratio and large right-handed rotations in the (s,b) sector, required to diagonalise the Yukawa matrix. For the squarks, one obtains almost degenerate first two generations. The main source of the FCNC and CP violation effects is the splitting between the first two families and the right-handed sbottom determined by the relative size of F-term and D-term supersymmetry breaking. The presence of the large right-handed rotation implies that the bounds on the masses of the first two families of squarks and the right handed sbottom are in a few to a few tens TeV range. The picture that emerges is light stops and left handed sbottom and much heavier other squarks. |
0706.0897 | Maria Amparo T\'ortola | S. S. Masood, S. Nasri, J. Schechter, M. A. T\'ortola, J. W. F. Valle
and C. Weinheimer | Exact relativistic beta decay endpoint spectrum | 12 pages, 3 figures | Phys.Rev.C76:045501,2007 | 10.1103/PhysRevC.76.045501 | null | hep-ph nucl-ex | null | The exact relativistic form for the beta decay endpoint spectrum is derived
and presented in a simple factorized form. We show that our exact formula can
be well approximated to yield the endpoint form used in the fit method of the
KATRIN collaboration. We also discuss the three neutrino case and how
information from neutrino oscillation experiments may be useful in analyzing
future beta decay endpoint experiments.
| [
{
"created": "Wed, 6 Jun 2007 20:04:52 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Masood",
"S. S.",
""
],
[
"Nasri",
"S.",
""
],
[
"Schechter",
"J.",
""
],
[
"Tórtola",
"M. A.",
""
],
[
"Valle",
"J. W. F.",
""
],
[
"Weinheimer",
"C.",
""
]
] | The exact relativistic form for the beta decay endpoint spectrum is derived and presented in a simple factorized form. We show that our exact formula can be well approximated to yield the endpoint form used in the fit method of the KATRIN collaboration. We also discuss the three neutrino case and how information from neutrino oscillation experiments may be useful in analyzing future beta decay endpoint experiments. |
hep-ph/9302288 | null | Giuseppe Degrassi | Current Algebra Approach to Heavy Top Effects in $Z \rightarrow b+
\bar{b}$ | 21 pages, 6 figures (not included) available upon request, LaTex,
DFPD 93/TH/03 | Nucl.Phys. B407 (1993) 271-289 | 10.1016/0550-3213(93)90058-W | null | hep-ph | null | The $O(\alpha m_t^2/m_w^2)$ and $O(\alpha \alpha_s m_t^2/m_w^2)$ corrections
to the partial decay width $\Gamma(Z \rightarrow b + \bar{b})$ are computed
using the current algebra formulation of radiative corrections. This framework
allows one to easily enforce the relevant Ward identity that greatly simplifies
the calculations. As a result, the one-loop $O(\alpha m_t^2/m_w^2)$
contribution is computed through the investigation of only two convergent
diagrams. The computation of the QCD corrections to the one-loop $O(\alpha
m_t^2/m_w^2)$ term involves fewer diagrams than in the standard approach. In
particular, the number of infrared divergent contribution is reduced. The
calculation is performed in the dimensional regularization scheme and no term
more divergent than $\frac{1}{n-4}$ is found. Our result confirms the screening
of the one-loop top mass effect recently found by Fleischer {\em et al.}.
| [
{
"created": "Mon, 22 Feb 1993 16:57:55 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Degrassi",
"Giuseppe",
""
]
] | The $O(\alpha m_t^2/m_w^2)$ and $O(\alpha \alpha_s m_t^2/m_w^2)$ corrections to the partial decay width $\Gamma(Z \rightarrow b + \bar{b})$ are computed using the current algebra formulation of radiative corrections. This framework allows one to easily enforce the relevant Ward identity that greatly simplifies the calculations. As a result, the one-loop $O(\alpha m_t^2/m_w^2)$ contribution is computed through the investigation of only two convergent diagrams. The computation of the QCD corrections to the one-loop $O(\alpha m_t^2/m_w^2)$ term involves fewer diagrams than in the standard approach. In particular, the number of infrared divergent contribution is reduced. The calculation is performed in the dimensional regularization scheme and no term more divergent than $\frac{1}{n-4}$ is found. Our result confirms the screening of the one-loop top mass effect recently found by Fleischer {\em et al.}. |
hep-ph/9809266 | Emanuel Norrbin | Emanuel Norrbin and Torbj\"orn Sj\"ostrand | Production mechanisms of charm hadrons in the string model | 13 pages, 7 figures, submitted to Phys. Lett. B | Phys.Lett.B442:407-416,1998 | 10.1016/S0370-2693(98)01244-1 | LU TP 98-18 | hep-ph | null | In the hadroproduction of charm in the context of string fragmentation, the
pull of a beam remnant at the other end of a string may give a charm hadron
more energy than the perturbatively produced charm quark. The collapse of a
low-mass string to a single hadron is the extreme case in this direction, and
gives rise to asymmetries between charm and anticharm hadron spectra. We study
these phenomena, and develop models that describe the characteristics not only
of the charm hadrons but also of the associated event.
| [
{
"created": "Fri, 4 Sep 1998 12:00:41 GMT",
"version": "v1"
}
] | 2011-01-13 | [
[
"Norrbin",
"Emanuel",
""
],
[
"Sjöstrand",
"Torbjörn",
""
]
] | In the hadroproduction of charm in the context of string fragmentation, the pull of a beam remnant at the other end of a string may give a charm hadron more energy than the perturbatively produced charm quark. The collapse of a low-mass string to a single hadron is the extreme case in this direction, and gives rise to asymmetries between charm and anticharm hadron spectra. We study these phenomena, and develop models that describe the characteristics not only of the charm hadrons but also of the associated event. |
hep-ph/0011116 | Frank N. Ndili | F. N. Ndili | Spiral Multi-component Structure in Pade - Approximant QCD | 78 pages, 4 tables, 44 graphs | Phys.Rev. D64 (2001) 014018 | 10.1103/PhysRevD.64.014018 | null | hep-ph | null | We present a graphical method of analyzing the infra-red fixed point
structure of Pade approximant QCD. The analysis shows a spiral multi-component
couplant structure as well as an infra-red attractor behavior of PQCD couplant
for all flavors $0 \le N_{f} \le 16$.
| [
{
"created": "Wed, 8 Nov 2000 19:21:28 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Ndili",
"F. N.",
""
]
] | We present a graphical method of analyzing the infra-red fixed point structure of Pade approximant QCD. The analysis shows a spiral multi-component couplant structure as well as an infra-red attractor behavior of PQCD couplant for all flavors $0 \le N_{f} \le 16$. |
hep-ph/9805510 | Howard Georgi | Howard Georgi, Jihn E. Kim, and Hans-Peter Nilles | Hidden Sector Gaugino Condensation and the Model-independent Axion | 7 pages, no figures | Phys.Lett.B437:325-330,1998 | 10.1016/S0370-2693(98)00916-2 | SNUTP 98/036, HUTP-98/A024 | hep-ph | null | In the effective field theory framework, we consider the effect of
supersymmetry breaking via gaugino condensation and supergravity in the hidden
sector gauge group on the hidden sector vacuum angle $\theta_h$. The $\theta_h$
parameter dependence of the potential yields phenomenologically acceptable
invisible axion solutions if the $U(1)_R$ symmetry is broken down to a discrete
subgroup $Z_N$ with $N\ge 3$ (N=4 is marginal). Anomalous U(1) superstring
models are good candidates for this invisible axion resolution of the strong CP
puzzle.
| [
{
"created": "Fri, 29 May 1998 20:53:01 GMT",
"version": "v1"
}
] | 2009-09-11 | [
[
"Georgi",
"Howard",
""
],
[
"Kim",
"Jihn E.",
""
],
[
"Nilles",
"Hans-Peter",
""
]
] | In the effective field theory framework, we consider the effect of supersymmetry breaking via gaugino condensation and supergravity in the hidden sector gauge group on the hidden sector vacuum angle $\theta_h$. The $\theta_h$ parameter dependence of the potential yields phenomenologically acceptable invisible axion solutions if the $U(1)_R$ symmetry is broken down to a discrete subgroup $Z_N$ with $N\ge 3$ (N=4 is marginal). Anomalous U(1) superstring models are good candidates for this invisible axion resolution of the strong CP puzzle. |
hep-ph/9509380 | Manuel Reenders | V.P. Gusynin, A.H. Hams and M. Reenders (University of Groningen) | (2+1)-Dimensional QED with Dynamically Massive Fermions in the Vacuum
Polarization | 17 pages, ReVTeX file and 3 uuencoded figures in one file | Phys.Rev. D53 (1996) 2227-2235 | 10.1103/PhysRevD.53.2227 | UG-10/95 | hep-ph | null | We study chiral symmetry breaking in $\rm QED_3$ with $N_f$ flavors of
four-component fermions. A closed system of Schwinger-Dyson equations for
fermion and photon propagators and the full fermion-photon vertex is proposed,
which is consistent with the Ward-Takahashi identity. A simplified version of
that set of equations is reduced (in nonlocal gauge) to the equation for a
dynamical fermion mass function, where the one-loop vacuum polarization with
dynamically massive fermions has been taken into account. The linearized
equation for the fermion mass function is analyzed in real space. The
analytical solution is compared with the results of numerical calculations of
the nonlinear integral equation in momentum space.
| [
{
"created": "Mon, 25 Sep 1995 14:41:04 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Gusynin",
"V. P.",
"",
"University of Groningen"
],
[
"Hams",
"A. H.",
"",
"University of Groningen"
],
[
"Reenders",
"M.",
"",
"University of Groningen"
]
] | We study chiral symmetry breaking in $\rm QED_3$ with $N_f$ flavors of four-component fermions. A closed system of Schwinger-Dyson equations for fermion and photon propagators and the full fermion-photon vertex is proposed, which is consistent with the Ward-Takahashi identity. A simplified version of that set of equations is reduced (in nonlocal gauge) to the equation for a dynamical fermion mass function, where the one-loop vacuum polarization with dynamically massive fermions has been taken into account. The linearized equation for the fermion mass function is analyzed in real space. The analytical solution is compared with the results of numerical calculations of the nonlinear integral equation in momentum space. |
1901.01725 | Avik Banerjee | Avik Banerjee, Gautam Bhattacharyya, Nilanjana Kumar | Impact of Yukawa-like dimension-5 operators on the Georgi-Machacek model | 11 pages, 2 captioned figures, minor changes in text, to appear in
Phys. Rev. D | Phys. Rev. D 99, 035028 (2019) | 10.1103/PhysRevD.99.035028 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the effects of including Yukawa-like dimension-5 operators in the
Georgi-Machacek model where the Standard Model is augmented with triplet
scalars. We focus only on the charged Higgs sector and investigate the
constraints arising from radiative B-meson decays, neutral B-meson mixing and
precision measurement of Zbb vertex. We observe that the inclusion of the
dimension-5 operators causes substantial alteration of the limits on the
charged Higgs masses and the vacuum expectation value of the triplets, derived
otherwise using only the dimension-4 operators.
| [
{
"created": "Mon, 7 Jan 2019 09:46:50 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Jan 2019 11:25:02 GMT",
"version": "v2"
}
] | 2019-02-21 | [
[
"Banerjee",
"Avik",
""
],
[
"Bhattacharyya",
"Gautam",
""
],
[
"Kumar",
"Nilanjana",
""
]
] | We study the effects of including Yukawa-like dimension-5 operators in the Georgi-Machacek model where the Standard Model is augmented with triplet scalars. We focus only on the charged Higgs sector and investigate the constraints arising from radiative B-meson decays, neutral B-meson mixing and precision measurement of Zbb vertex. We observe that the inclusion of the dimension-5 operators causes substantial alteration of the limits on the charged Higgs masses and the vacuum expectation value of the triplets, derived otherwise using only the dimension-4 operators. |
hep-ph/0606088 | Matthew Buckley | M. R. Buckley and H. Murayama | How can we test seesaw experimentally? | 5 pages, 4 figures | Phys.Rev.Lett.97:231801,2006 | 10.1103/PhysRevLett.97.231801 | null | hep-ph | null | The seesaw mechanism for the small neutrino mass has been a popular paradigm,
yet it has been believed that there is no way to test it experimentally. We
present a conceivable outcome from future experiments that would convince us of
the seesaw mechanism. It would involve a variety of data from LHC, ILC,
cosmology, underground, and low-energy flavor violation experiments to
establish the case.
| [
{
"created": "Wed, 7 Jun 2006 23:06:23 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Buckley",
"M. R.",
""
],
[
"Murayama",
"H.",
""
]
] | The seesaw mechanism for the small neutrino mass has been a popular paradigm, yet it has been believed that there is no way to test it experimentally. We present a conceivable outcome from future experiments that would convince us of the seesaw mechanism. It would involve a variety of data from LHC, ILC, cosmology, underground, and low-energy flavor violation experiments to establish the case. |
1702.04796 | Mikhail Salykin | M.A. Braun and M.Yu. Salykin (Saint-Petersburg State University,
Russia) | Off-shell gluon production in interaction of a projectile with 2 or 3
targets | 13 pages, 6 figures; submitted to Eur.Phys.Jour.C | null | 10.1140/epjc/s10052-017-5053-9 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Within the effective QCD action for the Regge kinematics amplitudes for
virtual gluon emission are studied in collision of a projectile with two and
three targets. It is demonstrated that all un- Feynman singularities cancel
between induced vertices and rescattering contributions. Formulas simplify
considerably in a special gauge which is a straightforward generalization of
the light-cone gauge for emission of real gluons.
| [
{
"created": "Wed, 15 Feb 2017 21:58:41 GMT",
"version": "v1"
},
{
"created": "Sat, 4 Mar 2017 20:42:08 GMT",
"version": "v2"
},
{
"created": "Tue, 13 Jun 2017 12:44:38 GMT",
"version": "v3"
}
] | 2017-09-13 | [
[
"Braun",
"M. A.",
"",
"Saint-Petersburg State University,\n Russia"
],
[
"Salykin",
"M. Yu.",
"",
"Saint-Petersburg State University,\n Russia"
]
] | Within the effective QCD action for the Regge kinematics amplitudes for virtual gluon emission are studied in collision of a projectile with two and three targets. It is demonstrated that all un- Feynman singularities cancel between induced vertices and rescattering contributions. Formulas simplify considerably in a special gauge which is a straightforward generalization of the light-cone gauge for emission of real gluons. |
1206.2279 | Xiaoyong Chu | Xiaoyong Chu, Thomas Hambye, Tiziana Scarna, Michel H. G. Tytgat | What if Dark Matter Gamma-Ray Lines come with Gluon Lines? | 6 figures, 10 pages | null | 10.1103/PhysRevD.86.083521 | ULB-TH/12-11 | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In dark matter (DM) models, the production of a gamma line (or of a
"box-shaped" gamma-ray spectrum) from DM annihilation proceeds in general from
a loop diagram involving a heavy charged particle. If the charged particle in
the loop carries also a color charge, this leads inevitably to DM annihilation
to gluons, with a naturally larger rate. We consider a scenario in which DM
candidates annihilate dominantly into gluon pairs, and determine (as far as
possible, model-independent) constraints from a variety of observables: a) the
dark matter relic density, b) the production of anti-protons, c) DM direct
detection and d) gluon-gluon fusion processes at LHC. Among other things, we
show that this scenario together with the recent claim for a possible gamma
line from the Galactic center in the Fermi-LAT data, leads to a relic abundance
of DM that may be naturally close to the cosmological observations.
| [
{
"created": "Mon, 11 Jun 2012 16:37:14 GMT",
"version": "v1"
}
] | 2015-06-05 | [
[
"Chu",
"Xiaoyong",
""
],
[
"Hambye",
"Thomas",
""
],
[
"Scarna",
"Tiziana",
""
],
[
"Tytgat",
"Michel H. G.",
""
]
] | In dark matter (DM) models, the production of a gamma line (or of a "box-shaped" gamma-ray spectrum) from DM annihilation proceeds in general from a loop diagram involving a heavy charged particle. If the charged particle in the loop carries also a color charge, this leads inevitably to DM annihilation to gluons, with a naturally larger rate. We consider a scenario in which DM candidates annihilate dominantly into gluon pairs, and determine (as far as possible, model-independent) constraints from a variety of observables: a) the dark matter relic density, b) the production of anti-protons, c) DM direct detection and d) gluon-gluon fusion processes at LHC. Among other things, we show that this scenario together with the recent claim for a possible gamma line from the Galactic center in the Fermi-LAT data, leads to a relic abundance of DM that may be naturally close to the cosmological observations. |
2402.13843 | Muhammad Usman Ashraf | A.M. Khan, M.U. Ashraf, H.M. Alfanda and M. Uzair. Aslam | Dynamics of identified particles production in oxygen-oxygen collisions
at \sqrt{s_{\mathrm{NN}} = 7 TeV using EPOS4 | 10 pages, 8 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The Large Hadron Collider (LHC) aims to inject oxygen (${}^{16}O$) ions in
the next run into its experiments. This include the anticipated one-day physics
run focusing on $OO$ collisions at center-of-mass energy \sqrt{s_{\mathrm{NN}}
= 7 Tev. In this study, we have used recently developed version of the EPOS
(EPOS4) to study the production of identified particles ($\pi^\pm$, $K^\pm$ and
$p(\overline{p})$) in $OO$ collisions at 7 Tev. Predictions of transverse
momentum ($p_T$) spectra, $\langle p_T \rangle$, integrated yield (dN/dy) for
different centrality classes are studied. To provide insight into the
collective nature of the produced particles, we look into the
$p_T$-differential particle ratios ($K/\pi$ and $p/\pi$) and $p_T$-integrated
particle ratios to ($\pi^++\pi^-$) as a function of charge particle
multiplicity. The shape of the charge particle multiplicity ($dN/d\eta$) and
$\langle p_T \rangle$ is well described by the EPOS4. The EPOS4 predictions for
the ratios of $K/\pi$ and $p/\pi$ exhibit a systematic overestimation compared
to the observed trends as a function of charged-particle multiplicity.
Interestingly, the $OO$ results of $p_T$-integrated particle ratios shows a
clear final state multiplicity overlap with $pp$, $p-Pb$ and $Pb-Pb$
collisions. EPOS4 mimics signs of collectivity and is one of the suitable
candidates to study ultra-relativistic heavy-ion collisions. Furthermore, the
foreseen data from $OO$ collisions at the LHC, when available, will help to
better understand the heavy-ion-like behavior in small systems as well as help
to put possible constraints on the model parameters.
| [
{
"created": "Wed, 21 Feb 2024 14:42:23 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Apr 2024 10:37:22 GMT",
"version": "v2"
},
{
"created": "Mon, 8 Jul 2024 22:11:10 GMT",
"version": "v3"
},
{
"created": "Mon, 12 Aug 2024 10:14:13 GMT",
"version": "v4"
}
] | 2024-08-13 | [
[
"Khan",
"A. M.",
""
],
[
"Ashraf",
"M. U.",
""
],
[
"Alfanda",
"H. M.",
""
],
[
"Aslam",
"M. Uzair.",
""
]
] | The Large Hadron Collider (LHC) aims to inject oxygen (${}^{16}O$) ions in the next run into its experiments. This include the anticipated one-day physics run focusing on $OO$ collisions at center-of-mass energy \sqrt{s_{\mathrm{NN}} = 7 Tev. In this study, we have used recently developed version of the EPOS (EPOS4) to study the production of identified particles ($\pi^\pm$, $K^\pm$ and $p(\overline{p})$) in $OO$ collisions at 7 Tev. Predictions of transverse momentum ($p_T$) spectra, $\langle p_T \rangle$, integrated yield (dN/dy) for different centrality classes are studied. To provide insight into the collective nature of the produced particles, we look into the $p_T$-differential particle ratios ($K/\pi$ and $p/\pi$) and $p_T$-integrated particle ratios to ($\pi^++\pi^-$) as a function of charge particle multiplicity. The shape of the charge particle multiplicity ($dN/d\eta$) and $\langle p_T \rangle$ is well described by the EPOS4. The EPOS4 predictions for the ratios of $K/\pi$ and $p/\pi$ exhibit a systematic overestimation compared to the observed trends as a function of charged-particle multiplicity. Interestingly, the $OO$ results of $p_T$-integrated particle ratios shows a clear final state multiplicity overlap with $pp$, $p-Pb$ and $Pb-Pb$ collisions. EPOS4 mimics signs of collectivity and is one of the suitable candidates to study ultra-relativistic heavy-ion collisions. Furthermore, the foreseen data from $OO$ collisions at the LHC, when available, will help to better understand the heavy-ion-like behavior in small systems as well as help to put possible constraints on the model parameters. |
2309.05342 | Stephan Narison | Stephan Narison (LUPM-CNRS/IN2P3, Univ. Montpellier-FR and iHEPMAD,
Univ. Antananarivo-MG) | QCD parameters and SM-high precisions from $e^+e^-\to$ Hadrons : Summary | 11 pages, 17 figures, 3 Tables, Talk given at the 26th international
conference in HEP (QCD23), 10-14th july 2023, Montpellier-FR. The comparison
of the muon anomaly with the new experiment is updated. Some misprints have
been corrected. Version to appear in Nuclear and Particle Physics Proceedings | null | null | null | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk, I summarize the results obtained recently in Ref.\,\cite{SNe}
using the PDG 22 compilation of the $e^+e^-\to$ Hadrons $\oplus$ the recent
CMD3 data for the pion form factor. Using the gluon condensate $\langle
\alpha_s G^2\rangle=(6.49\pm 0.35)\times 10^{-2}$ GeV$^4$ from heavy quark sum
rules, the extracted QCD four-quark and dimension eight condensate condensates
values are: $\rho\alpha_s\langle\bar\psi\psi\rangle^2= (5.98\pm 0.64)\times
10^{-4}$ GeV$^6$ and $d_8= (4.3\pm 3.0)\times 10^{-2}$ GeV$^8$ from the ratio
${\cal R}_{10}$ of Laplace sum rules to order $\alpha_s^4$. Inversely using
these estimated values of the condensates, we obtain from ${\cal R}_{10}$:
$\langle \alpha_s G^2\rangle=(6.12\pm 0.61)\times 10^{-2}$ GeV$^4$ which leads
to the average $(6.40\pm 0.30)\times 10^{-2}$ GeV$^4$. %from light and heavy
quark systems. Using the lowest $\tau$-like decay moment, the mean result of
Fixed Order (FO) and Contour Improved (CI) PT series within the standard OPE is
: $\alpha_s(M_\tau)=0.3385(50)(136)_{syst}$ [resp. $0.3262(37)(78)_{syst}$] to
order $\alpha_s^4$ [resp. $\alpha_s^5$] leading to
$\alpha_s(M_Z)$=0.1207(17)(3) [resp. 0.1193(11)(3)], while the sum of the
non-perturbative contribution at $M_\tau$ is\,: $\delta^V_{NP}(M_\tau)=(2.3\pm
0.2)\times 10^{-2}$. Using the same data, one also obtains the LO hadronic
vacuum polarization to the muon and $\tau$ anomalous magnetic moments:
$a_\mu\vert^{hvp}_{l.o}= (7036.5\pm 38.9)\times10^{-11}, \,
a_\tau\vert^{hvp}_{l.o}= (3494.8\pm 24.7)\times10^{-9} $ which leads to :
$\Delta a_\mu\equiv a_\mu^{exp}-a_\mu^{th} = (143\pm 42_{th}\pm 22_{exp})\times
10^{-11}$ indicating about 3$\sigma$ discrepancy between the SM predictions and
experiment. One also finds: $\alpha^{(5)}(M_Z)\vert_{had}=(2766.3\pm 4.5)\times
10^{-5}$.
| [
{
"created": "Mon, 11 Sep 2023 09:41:14 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Feb 2024 07:18:48 GMT",
"version": "v2"
}
] | 2024-02-26 | [
[
"Narison",
"Stephan",
"",
"LUPM-CNRS/IN2P3, Univ. Montpellier-FR and iHEPMAD,\n Univ. Antananarivo-MG"
]
] | In this talk, I summarize the results obtained recently in Ref.\,\cite{SNe} using the PDG 22 compilation of the $e^+e^-\to$ Hadrons $\oplus$ the recent CMD3 data for the pion form factor. Using the gluon condensate $\langle \alpha_s G^2\rangle=(6.49\pm 0.35)\times 10^{-2}$ GeV$^4$ from heavy quark sum rules, the extracted QCD four-quark and dimension eight condensate condensates values are: $\rho\alpha_s\langle\bar\psi\psi\rangle^2= (5.98\pm 0.64)\times 10^{-4}$ GeV$^6$ and $d_8= (4.3\pm 3.0)\times 10^{-2}$ GeV$^8$ from the ratio ${\cal R}_{10}$ of Laplace sum rules to order $\alpha_s^4$. Inversely using these estimated values of the condensates, we obtain from ${\cal R}_{10}$: $\langle \alpha_s G^2\rangle=(6.12\pm 0.61)\times 10^{-2}$ GeV$^4$ which leads to the average $(6.40\pm 0.30)\times 10^{-2}$ GeV$^4$. %from light and heavy quark systems. Using the lowest $\tau$-like decay moment, the mean result of Fixed Order (FO) and Contour Improved (CI) PT series within the standard OPE is : $\alpha_s(M_\tau)=0.3385(50)(136)_{syst}$ [resp. $0.3262(37)(78)_{syst}$] to order $\alpha_s^4$ [resp. $\alpha_s^5$] leading to $\alpha_s(M_Z)$=0.1207(17)(3) [resp. 0.1193(11)(3)], while the sum of the non-perturbative contribution at $M_\tau$ is\,: $\delta^V_{NP}(M_\tau)=(2.3\pm 0.2)\times 10^{-2}$. Using the same data, one also obtains the LO hadronic vacuum polarization to the muon and $\tau$ anomalous magnetic moments: $a_\mu\vert^{hvp}_{l.o}= (7036.5\pm 38.9)\times10^{-11}, \, a_\tau\vert^{hvp}_{l.o}= (3494.8\pm 24.7)\times10^{-9} $ which leads to : $\Delta a_\mu\equiv a_\mu^{exp}-a_\mu^{th} = (143\pm 42_{th}\pm 22_{exp})\times 10^{-11}$ indicating about 3$\sigma$ discrepancy between the SM predictions and experiment. One also finds: $\alpha^{(5)}(M_Z)\vert_{had}=(2766.3\pm 4.5)\times 10^{-5}$. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.