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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0603231 | C\'edric Lorc\'e | C\'edric Lorc\'e | Improvement of the Theta+ width estimation method on the Light Cone | 28 pages, 15 figures; typo corrected and few comments added | Phys.Rev. D74 (2006) 054019 | 10.1103/PhysRevD.74.054019 | null | hep-ph | null | Recently, Diakonov and Petrov have suggested a formalism in the Relativistic
Mean Field Approximation allowing one to derive the 3-, 5-, 7-,... quark
wavefunctions for the octet, decuplet and antidecuplet. They have used this
formalism and many strong approximations in order to estimate the exotic Theta+
width. The latter has been estimated to ~4 MeV. Besides they obtained that the
5-quark component of the nucleon is about 50% of its 3-quark component meaning
that relativistic effects are not small. We have improved the technique by
taking into account some relativistic corrections and considering the
previously neglected 5-quark exchange diagrams. We also have computed all
nucleon axial charges. It turns out that exchange diagrams affect very little
Diakonov's and Petrov's results while relativistic corrections reduce the
Theta+ width to ~2 MeV and the 5- to 3-quark component of the nucleon ratio to
30%.
| [
{
"created": "Tue, 28 Mar 2006 18:24:11 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Apr 2006 18:14:51 GMT",
"version": "v2"
},
{
"created": "Fri, 14 Apr 2006 09:59:42 GMT",
"version": "v3"
},
{
"created": "Thu, 29 Jun 2006 12:33:02 GMT",
"version": "v4"
}
] | 2009-11-11 | [
[
"Lorcé",
"Cédric",
""
]
] | Recently, Diakonov and Petrov have suggested a formalism in the Relativistic Mean Field Approximation allowing one to derive the 3-, 5-, 7-,... quark wavefunctions for the octet, decuplet and antidecuplet. They have used this formalism and many strong approximations in order to estimate the exotic Theta+ width. The latter has been estimated to ~4 MeV. Besides they obtained that the 5-quark component of the nucleon is about 50% of its 3-quark component meaning that relativistic effects are not small. We have improved the technique by taking into account some relativistic corrections and considering the previously neglected 5-quark exchange diagrams. We also have computed all nucleon axial charges. It turns out that exchange diagrams affect very little Diakonov's and Petrov's results while relativistic corrections reduce the Theta+ width to ~2 MeV and the 5- to 3-quark component of the nucleon ratio to 30%. |
0805.1474 | Andrey Grozin | A. G. Grozin | Three-loop results in HQET | Talk at Loops and Legs 2008 | Nucl.Phys.Proc.Suppl.183:302-307,2008 | 10.1016/j.nuclphysbps.2008.09.121 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent results and methods of three-loop calculations in HQET are reviewed.
| [
{
"created": "Sat, 10 May 2008 13:54:47 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Grozin",
"A. G.",
""
]
] | Recent results and methods of three-loop calculations in HQET are reviewed. |
hep-ph/0101240 | Roman Nikolaevich Lee | R.N.Lee, A.I.Milstein, M.Schumacher | Relativistic corrections to the electromagnetic polarizabilities of
compound systems | 19 pages, LaTeX | Phys.Rev.Lett.87:051601,2001 | 10.1103/PhysRevLett.87.051601 | Budker INP 2001-4 | hep-ph nucl-th | null | The low-energy amplitude of Compton scattering on the bound state of two
charged particles of arbitrary masses, charges and spins is calculated. A case
in which the bound state exists due to electromagnetic interaction (QED) is
considered. The term, proportional to $\omega^2$, is obtained taking into
account the first relativistic correction. It is shown that the complete result
for this correction differs essentially from the commonly used term
$\Delta\alpha$, proportional to the r.m.s. charge radius of the system. We
propose that the same situation can take place in the more complicated case of
hadrons.
| [
{
"created": "Mon, 22 Jan 2001 11:10:01 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Lee",
"R. N.",
""
],
[
"Milstein",
"A. I.",
""
],
[
"Schumacher",
"M.",
""
]
] | The low-energy amplitude of Compton scattering on the bound state of two charged particles of arbitrary masses, charges and spins is calculated. A case in which the bound state exists due to electromagnetic interaction (QED) is considered. The term, proportional to $\omega^2$, is obtained taking into account the first relativistic correction. It is shown that the complete result for this correction differs essentially from the commonly used term $\Delta\alpha$, proportional to the r.m.s. charge radius of the system. We propose that the same situation can take place in the more complicated case of hadrons. |
0903.2729 | Vladimir Zoller | N.N. Nikolaev and V.R.Zoller | Beauty, charm and $F_L$ at HERA: new data vs. early predictions | 16 pages, 4 figures. The contribution to the volume in honor of Lev
Okun's 80 birthday | Phys.Atom.Nucl.73:672-679,2010 | 10.1134/S1063778810040137 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | One of the well known effects of the asymptotic freedom is splitting of the
leading-$\log$ BFKL pomeron into a series of isolated poles in complex angular
momentum plane. Following our earlier works we explore the phenomenological
consequences of the emerging BFKL-Regge factorized expansion for the small-$x$
charm ($F_2^c$) and beauty ($F_{2}^{b}$) structure functions of the proton. As
we found earlier,the color dipole approach to the BFKL dynamics predicts
uniquely decoupling of subleading hard BFKL exchanges from $F_2^c$ at
moderately large $Q^{2}$. We predicted precocious BFKL asymptotics of
$F_2^c(x,Q^2)$ with intercept of the rightmost BFKL pole
$\alpha_{\Pom}(0)-1=\Delta_{\Pom}\approx 0.4$. High-energy open beauty photo-
and electro-production probes the vacuum exchange at much smaller distances and
detects significant corrections to the BFKL asymptotics coming from the
subleading vacuum poles. In view of the accumulation of the experimental data
on small-$x$ $F_{2}^{c}$ and $F_{2}^{b}$ we extended our early predictions to
the kinematical domain covered by new HERA measurements.Our structure functions
obtained in 1999 agree well with the determination of both $F_2^c$ and $F_2^b$
by the H1 published in 2006 but contradict to very recent (2008, preliminary)
H1 results on $F_2^b$. We present also comparison of our early predictions for
the longitudinal structure function $F_L$ with recent H1 data (2008) taken at
very low Bjorken $x$. We comment on the electromagnetic corrections to the
Okun-Pomeranchuk theorem.
| [
{
"created": "Mon, 16 Mar 2009 12:08:08 GMT",
"version": "v1"
}
] | 2010-04-30 | [
[
"Nikolaev",
"N. N.",
""
],
[
"Zoller",
"V. R.",
""
]
] | One of the well known effects of the asymptotic freedom is splitting of the leading-$\log$ BFKL pomeron into a series of isolated poles in complex angular momentum plane. Following our earlier works we explore the phenomenological consequences of the emerging BFKL-Regge factorized expansion for the small-$x$ charm ($F_2^c$) and beauty ($F_{2}^{b}$) structure functions of the proton. As we found earlier,the color dipole approach to the BFKL dynamics predicts uniquely decoupling of subleading hard BFKL exchanges from $F_2^c$ at moderately large $Q^{2}$. We predicted precocious BFKL asymptotics of $F_2^c(x,Q^2)$ with intercept of the rightmost BFKL pole $\alpha_{\Pom}(0)-1=\Delta_{\Pom}\approx 0.4$. High-energy open beauty photo- and electro-production probes the vacuum exchange at much smaller distances and detects significant corrections to the BFKL asymptotics coming from the subleading vacuum poles. In view of the accumulation of the experimental data on small-$x$ $F_{2}^{c}$ and $F_{2}^{b}$ we extended our early predictions to the kinematical domain covered by new HERA measurements.Our structure functions obtained in 1999 agree well with the determination of both $F_2^c$ and $F_2^b$ by the H1 published in 2006 but contradict to very recent (2008, preliminary) H1 results on $F_2^b$. We present also comparison of our early predictions for the longitudinal structure function $F_L$ with recent H1 data (2008) taken at very low Bjorken $x$. We comment on the electromagnetic corrections to the Okun-Pomeranchuk theorem. |
1709.03326 | Romain Contant | Romain Contant, Markus Q. Huber | The quark propagators of QCD and QCD-like theories | 6 pages, 3 figures, submitted to proceedings of Excited QCD 2017,
7-13 May 2017, Sintra, Portugal | null | null | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the phase structures of theories which differ from QCD only in
the gauge group and can be simulated on the lattice at non-vanishing chemical
potential $\mu$. These theories can thus serve as testing ground for functional
methods at non-vanishing density. We determine the chiral and
confinement/deconfinement transitions at $\mu=0$ for the three gauge groups
$SU(3)$, $SU(2)$ and $G_2$ for two quark flavors and extend the study of the
chiral transition to non-zero $\mu$. We locate the critical point where the
chiral crossover becomes a real phase transition. Within the employed
truncation, we find that all three theories behave qualitatively very
similarly.
| [
{
"created": "Mon, 11 Sep 2017 10:55:16 GMT",
"version": "v1"
}
] | 2017-09-12 | [
[
"Contant",
"Romain",
""
],
[
"Huber",
"Markus Q.",
""
]
] | We investigate the phase structures of theories which differ from QCD only in the gauge group and can be simulated on the lattice at non-vanishing chemical potential $\mu$. These theories can thus serve as testing ground for functional methods at non-vanishing density. We determine the chiral and confinement/deconfinement transitions at $\mu=0$ for the three gauge groups $SU(3)$, $SU(2)$ and $G_2$ for two quark flavors and extend the study of the chiral transition to non-zero $\mu$. We locate the critical point where the chiral crossover becomes a real phase transition. Within the employed truncation, we find that all three theories behave qualitatively very similarly. |
hep-ph/0610088 | Asimina Arvanitaki | Asimina Arvanitaki | Discovering Chiral Higgsinos at the LHC | 10 pages, 5 figures v2: minor corrections, 11 pages, 5 figures | Phys.Rev.D81:075008,2010 | 10.1103/PhysRevD.81.075008 | null | hep-ph | null | The concept of chirality is extended to the Minimal Supersymmetric Standard
Model (MSSM) and the mu term is forbidden by a gauged U(1)' symmetry. R-parity
automatically emerges after symmetry breaking, suppressing proton decay and
protecting the LSP. Exotics charged under the SM pose a challenge to
traditional SU(5) unification, but unification is still implemented in
deconstructed GUTs. Because of the multitude of additional states to the MSSM,
the Z' has a large width, and the SM background, neglected in previous
theoretical studies, becomes important for Z' discovery. As a result, the LHC
reach is reduced from 3.2 TeV, for a Z' with SM decays, to 1.5 TeV, when
additional decay channels are included. This model also predicts possibly
long-lived colored and electroweak exotics.
| [
{
"created": "Sun, 8 Oct 2006 19:16:39 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Oct 2006 16:15:50 GMT",
"version": "v2"
}
] | 2010-04-21 | [
[
"Arvanitaki",
"Asimina",
""
]
] | The concept of chirality is extended to the Minimal Supersymmetric Standard Model (MSSM) and the mu term is forbidden by a gauged U(1)' symmetry. R-parity automatically emerges after symmetry breaking, suppressing proton decay and protecting the LSP. Exotics charged under the SM pose a challenge to traditional SU(5) unification, but unification is still implemented in deconstructed GUTs. Because of the multitude of additional states to the MSSM, the Z' has a large width, and the SM background, neglected in previous theoretical studies, becomes important for Z' discovery. As a result, the LHC reach is reduced from 3.2 TeV, for a Z' with SM decays, to 1.5 TeV, when additional decay channels are included. This model also predicts possibly long-lived colored and electroweak exotics. |
hep-ph/9604380 | Uma Mahanta | Uma Mahanta | Dipole moments of tau as a sensitive probe for beyond standard model
physics | Tex file | Phys.Rev. D54 (1996) 3377-3381 | 10.1103/PhysRevD.54.3377 | MRI-PHY/16-96 | hep-ph | null | CP violating dipole moments of leptons vanish at least to three loop order
and are estimated to be $({m_l\over Mev})\times 1.6\times 10^{- 40}$ e-cm in
the standard model (SM), where $m_l$ is the mass of the lepton. However they
can receive potentially large contributions in some beyond SM scenarios and
this makes them very sensitive probes of new physics. In this article we show
that a non universal interaction, involving leptoquarks to the quark-lepton
pair of the third generation through helicity unsuppressed couplings of the
order of ordinary gauge couplings, can generate electric and weak dipole
moments of the order of $10^{-19}$ e-cm for the tau lepton. This is greater
than pure supersymmetric (SUSY) and left-right (L-R) contributions by almost
three orders of magnitude. It is also greater than mirror fermionic
contribution by an order of magnitude.
The measurements of $\dzt$ and $\dgt$ at LEP, SLC and TCF are expected to
reach sensitivities of $10^{-18}$ e-cm and $10^{-19}$ e-cm respectively in near
future. The observation of a non vanishing dipole moment of tau at these
facilities would therefore strongly favour superstring inspired light
leptoquark mediated interactions, over pure SUSY or L-R interactions and
perhaps also mirror generated mixings without some sort of quark-lepton
unification as its origin.
| [
{
"created": "Mon, 22 Apr 1996 10:21:27 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Mahanta",
"Uma",
""
]
] | CP violating dipole moments of leptons vanish at least to three loop order and are estimated to be $({m_l\over Mev})\times 1.6\times 10^{- 40}$ e-cm in the standard model (SM), where $m_l$ is the mass of the lepton. However they can receive potentially large contributions in some beyond SM scenarios and this makes them very sensitive probes of new physics. In this article we show that a non universal interaction, involving leptoquarks to the quark-lepton pair of the third generation through helicity unsuppressed couplings of the order of ordinary gauge couplings, can generate electric and weak dipole moments of the order of $10^{-19}$ e-cm for the tau lepton. This is greater than pure supersymmetric (SUSY) and left-right (L-R) contributions by almost three orders of magnitude. It is also greater than mirror fermionic contribution by an order of magnitude. The measurements of $\dzt$ and $\dgt$ at LEP, SLC and TCF are expected to reach sensitivities of $10^{-18}$ e-cm and $10^{-19}$ e-cm respectively in near future. The observation of a non vanishing dipole moment of tau at these facilities would therefore strongly favour superstring inspired light leptoquark mediated interactions, over pure SUSY or L-R interactions and perhaps also mirror generated mixings without some sort of quark-lepton unification as its origin. |
hep-ph/0304248 | Yili Wang | Yili Wang and David Atwood | Rate difference between b $\to$ s mu^+ mu^- and b $\to$ s e^+e^- in SUSY
with large tan$\beta$ | 9 pages and 4 figures | Phys.Rev.D68:094016,2003 | 10.1103/PhysRevD.68.094016 | null | hep-ph | null | We study the inclusive semileptonic rare decay $b \to s l^+ l^-$ in minimal
supergravity model (mSUGRA). If tan$\beta$ is large, down-type quark mass
matrices and their Yukawa couplings cannot be diagonalized at the same basis.
This induces the flavor violating neutral Higgs boson couplings. These
couplings contribute significantly to decay $b \to s mu^+ mu^-$ and $b \to s
tau^+ tau^-$, but negligible to $b \to s e^+ e^-$ decay because of its
negligible $m_e$ mass. The ratio $R \equiv B(b \to s mu^+ mu^-)/ B(b \to s e^+
e^-)$ can be very different from its corresponding value in the Standard Model.
We find that part of parameter space can accommodate a large R value, and that
maximum R value can be larger than 2. We also present our results in $b \to s
tau^+ tau^-$ decay channel. Although it can be not detected now, it is
potentially a new channel for the future observation of new physics.
| [
{
"created": "Fri, 25 Apr 2003 21:15:12 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Jun 2003 15:20:59 GMT",
"version": "v2"
},
{
"created": "Fri, 28 Nov 2003 20:57:56 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Wang",
"Yili",
""
],
[
"Atwood",
"David",
""
]
] | We study the inclusive semileptonic rare decay $b \to s l^+ l^-$ in minimal supergravity model (mSUGRA). If tan$\beta$ is large, down-type quark mass matrices and their Yukawa couplings cannot be diagonalized at the same basis. This induces the flavor violating neutral Higgs boson couplings. These couplings contribute significantly to decay $b \to s mu^+ mu^-$ and $b \to s tau^+ tau^-$, but negligible to $b \to s e^+ e^-$ decay because of its negligible $m_e$ mass. The ratio $R \equiv B(b \to s mu^+ mu^-)/ B(b \to s e^+ e^-)$ can be very different from its corresponding value in the Standard Model. We find that part of parameter space can accommodate a large R value, and that maximum R value can be larger than 2. We also present our results in $b \to s tau^+ tau^-$ decay channel. Although it can be not detected now, it is potentially a new channel for the future observation of new physics. |
hep-ph/9709457 | Changhao Jin | Changhao Jin | Calculation of the semileptonic decay width of the $\Lambda_b$ baryon | 11 pages, REVTeX | Phys.Rev. D56 (1997) 7267-7272 | 10.1103/PhysRevD.56.7267 | TTP97-31 | hep-ph | null | We extend the approach based on the light-cone expansion and the heavy quark
effective theory to the inclusive semileptonic decay of an unpolarized
$b$-flavored hadron. It is applied to calculate the semileptonic decay width of
the $\Lambda_b$ baryon and its ratio to that of the B meson. We obtain
$\Gamma_{SL}(\Lambda_b)= 51\pm 9 |V_{cb}|^2{ps}^{-1}$ and
$\Gamma_{SL}(\Lambda_b)/\Gamma_{SL}(B)= 1.052\pm 0.006$. From the latter, the
semileptonic branching fraction for $\Lambda_b$ is predicted to be $(8.7\pm
0.7)%$.
| [
{
"created": "Thu, 25 Sep 1997 13:43:21 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Jin",
"Changhao",
""
]
] | We extend the approach based on the light-cone expansion and the heavy quark effective theory to the inclusive semileptonic decay of an unpolarized $b$-flavored hadron. It is applied to calculate the semileptonic decay width of the $\Lambda_b$ baryon and its ratio to that of the B meson. We obtain $\Gamma_{SL}(\Lambda_b)= 51\pm 9 |V_{cb}|^2{ps}^{-1}$ and $\Gamma_{SL}(\Lambda_b)/\Gamma_{SL}(B)= 1.052\pm 0.006$. From the latter, the semileptonic branching fraction for $\Lambda_b$ is predicted to be $(8.7\pm 0.7)%$. |
1402.5501 | Zhenjun Xiao | Shan Cheng, Ying-Ying Fan, Xin Yu, Cai-Dian L\"u and Zhen-Jun Xiao | The NLO twist-3 contributions to $B \to \pi$ form factors in $k_{T}$
factorization | 25 pages, 12 figures, 5 Tables. More discussions, several new
references are added. The version to be published in Phys.Rev.D | Phys. Rev. D 89, 094004 (2014) | 10.1103/PhysRevD.89.094004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we calculate the next-to-leading-order (NLO) twist-3
contribution to the form factors of $B \to \pi$ transitions by employing the
$k_{T}$ factorization theorem. All the infrared divergences regulated by the
logarithms $\ln(k_{iT}^{2})$ cancel between those from the quark diagrams and
from the effective diagrams for the initial $B$ meson wave function and the
final pion meson wave function. An infrared finite NLO hard kernel is therefore
obtained, which confirms the application of the $k_{T}$ factorization theorem
to $B$ meson semileptonic decays at twist-3 level. From our analytical and
numerical evaluations, we find that the NLO twist-3 contributions to the form
factors $f^{+,0}(q^2)$ of $B \to \pi$ transition are similar in size, but have
an opposite sign with the NLO twist-2 contribution, which leads to a large
cancelation between these two NLO parts. For the case of $f^+(0)$, for example,
the $24\%$ NLO twist-2 enhancement to the full LO prediction is largely
canceled by the negative ( about $-17\%$ ) NLO twist-3 contribution, leaving a
small and stable $7\%$ enhancement to the full LO prediction in the whole range
of $0\leq q^2\leq 12$ GeV$^2$. At the full NLO level, the perturbative QCD
prediction is $F^{B \to \pi}(0)=0.269^{+0.054}_{-0.050}$. We also studied the
possible effects on the pQCD predictions when different sets of the B meson and
pion distribution amplitudes are used in the numerical evaluation.
| [
{
"created": "Sat, 22 Feb 2014 11:41:46 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Feb 2014 07:13:28 GMT",
"version": "v2"
},
{
"created": "Wed, 16 Apr 2014 23:29:19 GMT",
"version": "v3"
}
] | 2014-05-14 | [
[
"Cheng",
"Shan",
""
],
[
"Fan",
"Ying-Ying",
""
],
[
"Yu",
"Xin",
""
],
[
"Lü",
"Cai-Dian",
""
],
[
"Xiao",
"Zhen-Jun",
""
]
] | In this paper, we calculate the next-to-leading-order (NLO) twist-3 contribution to the form factors of $B \to \pi$ transitions by employing the $k_{T}$ factorization theorem. All the infrared divergences regulated by the logarithms $\ln(k_{iT}^{2})$ cancel between those from the quark diagrams and from the effective diagrams for the initial $B$ meson wave function and the final pion meson wave function. An infrared finite NLO hard kernel is therefore obtained, which confirms the application of the $k_{T}$ factorization theorem to $B$ meson semileptonic decays at twist-3 level. From our analytical and numerical evaluations, we find that the NLO twist-3 contributions to the form factors $f^{+,0}(q^2)$ of $B \to \pi$ transition are similar in size, but have an opposite sign with the NLO twist-2 contribution, which leads to a large cancelation between these two NLO parts. For the case of $f^+(0)$, for example, the $24\%$ NLO twist-2 enhancement to the full LO prediction is largely canceled by the negative ( about $-17\%$ ) NLO twist-3 contribution, leaving a small and stable $7\%$ enhancement to the full LO prediction in the whole range of $0\leq q^2\leq 12$ GeV$^2$. At the full NLO level, the perturbative QCD prediction is $F^{B \to \pi}(0)=0.269^{+0.054}_{-0.050}$. We also studied the possible effects on the pQCD predictions when different sets of the B meson and pion distribution amplitudes are used in the numerical evaluation. |
hep-ph/0407371 | Jean-Michel Levy | Jean-Michel Levy | Cross-section and polarization of neutrino-produced $\tau$'s made simple | 10 pages, no figures | J.Phys.G36:055002,2009 | 10.1088/0954-3899/36/5/055002 | LPNHE 2004-09 | hep-ph | null | Practical formulae are derived for the cross-section and polarization of the
$\tau$ lepton produced in deep-inelastic neutrino-nucleon scattering in the
frame of the simple quark-parton model.
| [
{
"created": "Fri, 30 Jul 2004 19:59:24 GMT",
"version": "v1"
},
{
"created": "Sun, 1 Aug 2004 11:33:26 GMT",
"version": "v2"
}
] | 2009-04-03 | [
[
"Levy",
"Jean-Michel",
""
]
] | Practical formulae are derived for the cross-section and polarization of the $\tau$ lepton produced in deep-inelastic neutrino-nucleon scattering in the frame of the simple quark-parton model. |
hep-ph/0204230 | Timo Arvid Lahde | T.A. Lahde, D.O. Riska (Helsinki Institute of Physics and Department
of Physics, University of Helsinki, Finland) | The Coupling of eta Mesons to Quarks and Baryons from D_s^* -> D_s pi^0
Decay | 17 pages, uses Feynmf. Submitted to Nuclear Physics A, accepted
version | Nucl.Phys. A710 (2002) 99-116 | 10.1016/S0375-9474(02)01125-9 | null | hep-ph | null | The known ratio of the branching fractions for D_s^* --> D_s pi^0 and D_s^*
--> D_s gamma may be used to extract the coupling of eta mesons to strange
quarks once the value of the pi^0-eta mixing angle is known. This requires that
realistic models for the spectra as well as the magnetic dipole (M1) decays of
the heavy-light (Q qbar) mesons are available. The coupling of eta mesons to
light quarks may then be estimated using SU(3) flavor symmetry. Applied to the
quark model for the baryons, an eta NN pseudovector coupling constant of f_{eta
NN} = 0.35^{+0.15}_{-0.25} is obtained. If the charm quark couples
significantly to the eta meson, as is suggested by the decay mode psi' -->
J/(psi eta), then somewhat larger values of f_{eta NN} can be obtained. These
values are sufficiently small to be consistent with phenomenological analysis
of photoproduction of the eta on the nucleon and the reaction pp --> pp eta.
| [
{
"created": "Fri, 19 Apr 2002 10:59:12 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Aug 2002 13:28:20 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Lahde",
"T. A.",
"",
"Helsinki Institute of Physics and Department\n of Physics, University of Helsinki, Finland"
],
[
"Riska",
"D. O.",
"",
"Helsinki Institute of Physics and Department\n of Physics, University of Helsinki, Finland"
]
] | The known ratio of the branching fractions for D_s^* --> D_s pi^0 and D_s^* --> D_s gamma may be used to extract the coupling of eta mesons to strange quarks once the value of the pi^0-eta mixing angle is known. This requires that realistic models for the spectra as well as the magnetic dipole (M1) decays of the heavy-light (Q qbar) mesons are available. The coupling of eta mesons to light quarks may then be estimated using SU(3) flavor symmetry. Applied to the quark model for the baryons, an eta NN pseudovector coupling constant of f_{eta NN} = 0.35^{+0.15}_{-0.25} is obtained. If the charm quark couples significantly to the eta meson, as is suggested by the decay mode psi' --> J/(psi eta), then somewhat larger values of f_{eta NN} can be obtained. These values are sufficiently small to be consistent with phenomenological analysis of photoproduction of the eta on the nucleon and the reaction pp --> pp eta. |
1503.07996 | Philipp Gubler | Philipp Gubler, Kie Sang Jeong, Su Houng Lee | New determination of $\mathcal{S} \mathcal{T} \langle N| \overline{q}
D_{\mu} D_{\nu} q |N \rangle$ based on recent experimental constraints | 22 pages, 4 figures, 4 tables; published version | Phys. Rev. D 92, 014010 (2015) | 10.1103/PhysRevD.92.014010 | null | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The symmetric and traceless part of the matrix element $\mathcal{S}
\mathcal{T} \langle N| \overline{q} D_{\mu} D_{\nu} q |N \rangle$ can be
determined from the second moment of the twist-3 parton distribution function
$e(x)$. Recently, novel experimental data on $e(x)$ have become available,
which enables us to evaluate the magnitude of the above matrix element with
considerably reduced systematic uncertainties. Based on the new experimental
data, we show that $\mathcal{S} \mathcal{T} \langle N| \overline{q} D_{\mu}
D_{\nu} q |N \rangle$ is likely to be at least an order of magnitude smaller
than what previous model-based estimates have so far suggested. We discuss the
consequences of this observation for the analysis of deep inelastic scattering
and QCD sum rules studies at finite density for the vector meson and the
nucleon, in which this matrix element is being used as an input parameter.
| [
{
"created": "Fri, 27 Mar 2015 09:17:07 GMT",
"version": "v1"
},
{
"created": "Thu, 9 Jul 2015 14:45:41 GMT",
"version": "v2"
}
] | 2015-07-10 | [
[
"Gubler",
"Philipp",
""
],
[
"Jeong",
"Kie Sang",
""
],
[
"Lee",
"Su Houng",
""
]
] | The symmetric and traceless part of the matrix element $\mathcal{S} \mathcal{T} \langle N| \overline{q} D_{\mu} D_{\nu} q |N \rangle$ can be determined from the second moment of the twist-3 parton distribution function $e(x)$. Recently, novel experimental data on $e(x)$ have become available, which enables us to evaluate the magnitude of the above matrix element with considerably reduced systematic uncertainties. Based on the new experimental data, we show that $\mathcal{S} \mathcal{T} \langle N| \overline{q} D_{\mu} D_{\nu} q |N \rangle$ is likely to be at least an order of magnitude smaller than what previous model-based estimates have so far suggested. We discuss the consequences of this observation for the analysis of deep inelastic scattering and QCD sum rules studies at finite density for the vector meson and the nucleon, in which this matrix element is being used as an input parameter. |
hep-ph/9904302 | Uma Sankar | Mohan Narayan and S. Uma Sankar (I.I.T., Bombay, India) | Probing the matter term at long baseline experiments | 9 pages including three figures | Phys.Rev. D61 (2000) 013003 | 10.1103/PhysRevD.61.013003 | null | hep-ph | null | We consider (\nu_\mu --> \nu_e) oscillations in long baseline experiments
within a three flavor framework. A non-zero measurement of this oscillation
probability implies that the (13) mixing angle `phi' is non-zero. We consider
the effect of neutrino propagation through the matter of earth's crust and show
that, given the constraints from solar neutrino and CHOOZ data, matter effects
enhance the mixing for neutrinos rather than for anti-neutrinos. We need data
from two different experiments with different baseline lengths (such as K2K and
MINOS) to distinguish matter effects unambiguously.
| [
{
"created": "Mon, 12 Apr 1999 14:37:26 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Narayan",
"Mohan",
"",
"I.I.T., Bombay, India"
],
[
"Sankar",
"S. Uma",
"",
"I.I.T., Bombay, India"
]
] | We consider (\nu_\mu --> \nu_e) oscillations in long baseline experiments within a three flavor framework. A non-zero measurement of this oscillation probability implies that the (13) mixing angle `phi' is non-zero. We consider the effect of neutrino propagation through the matter of earth's crust and show that, given the constraints from solar neutrino and CHOOZ data, matter effects enhance the mixing for neutrinos rather than for anti-neutrinos. We need data from two different experiments with different baseline lengths (such as K2K and MINOS) to distinguish matter effects unambiguously. |
2107.01552 | Sk Noor Alam | Sk Noor Alam, Victor Roy, Shakeel Ahmad and Subhasis Chattopadhyay | Electro-magnetic field fluctuation and its correlation with the
participant plane in Au+Au and isobaric collisions at $\sqrt{s_{NN}}=200$ GeV | null | null | 10.1103/PhysRevD.104.114031 | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | Intense transient electric ({\bf E}) and magnetic ({\bf B}) fields are
produced in the high energy heavy-ion collisions. The electromagnetic fields
produced in such high-energy heavy-ion collisions are proposed to give rise to
a multitude of exciting phenomenon including the Chiral Magnetic Effect. We use
a Monte Carlo (MC) Glauber model to calculate the electric and magnetic fields,
more specifically their scalar product $\bf{E}\cdot\bf{B}$, as a function of
space-time on an event-by-event basis for the Au+Au collisions at
$\sqrt{s_{NN}}=200$ GeV for different centrality classes. We also calculate the
same for the isobars Ruthenium and Zirconium at $\sqrt{s_{NN}}=200$ GeV. In the
QED sector $\bf{E}\cdot\bf{B}$ acts as a source of Chiral Separation Effect,
Chiral Magnetic Wave, etc., which are associated phenomena to the Chiral
Magnetic Effect. We also study the relationships between the electromagnetic
symmetry plane angle defined by $\bf{E}\cdot\bf{B}$ ($\psi_{E.B}$) and the
participant plane angle $\psi_{P}$ defined from the participating nucleons for
the second-fifth order harmonics.
| [
{
"created": "Sun, 4 Jul 2021 06:00:14 GMT",
"version": "v1"
}
] | 2021-12-28 | [
[
"Alam",
"Sk Noor",
""
],
[
"Roy",
"Victor",
""
],
[
"Ahmad",
"Shakeel",
""
],
[
"Chattopadhyay",
"Subhasis",
""
]
] | Intense transient electric ({\bf E}) and magnetic ({\bf B}) fields are produced in the high energy heavy-ion collisions. The electromagnetic fields produced in such high-energy heavy-ion collisions are proposed to give rise to a multitude of exciting phenomenon including the Chiral Magnetic Effect. We use a Monte Carlo (MC) Glauber model to calculate the electric and magnetic fields, more specifically their scalar product $\bf{E}\cdot\bf{B}$, as a function of space-time on an event-by-event basis for the Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV for different centrality classes. We also calculate the same for the isobars Ruthenium and Zirconium at $\sqrt{s_{NN}}=200$ GeV. In the QED sector $\bf{E}\cdot\bf{B}$ acts as a source of Chiral Separation Effect, Chiral Magnetic Wave, etc., which are associated phenomena to the Chiral Magnetic Effect. We also study the relationships between the electromagnetic symmetry plane angle defined by $\bf{E}\cdot\bf{B}$ ($\psi_{E.B}$) and the participant plane angle $\psi_{P}$ defined from the participating nucleons for the second-fifth order harmonics. |
0807.4442 | C. J. A. P. Martins | P.P. Avelino, C.J.A.P. Martins, J. Menezes, R. Menezes, J.C.R.E.
Oliveira | Dynamics of domain wall networks with junctions | Submitted to Phys. Rev. D | Phys.Rev.D78:103508,2008 | 10.1103/PhysRevD.78.103508 | null | hep-ph astro-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use a combination of analytic tools and an extensive set of the largest
and most accurate three-dimensional field theory numerical simulations to study
the dynamics of domain wall networks with junctions. We build upon our previous
work and consider a class of models which, in the limit of large number $N$ of
coupled scalar fields, approaches the so-called `ideal' model (in terms of its
potential to lead to network frustration). We consider values of $N$ between
N=2 and N=20, and a range of cosmological epochs, and we also compare this
class of models with other toy models used in the past. In all cases we find
compelling evidence for a gradual approach to scaling, strongly supporting our
no-frustration conjecture. We also discuss the various possible types of
junctions (including cases where there is a hierarchy of them) and their roles
in the dynamics of the network. Finally, we revise the Zel'dovich bound and
provide an updated cosmological bound on the energy scale of this type of
defect network: it must be lower than $10 {\rm keV}$.
| [
{
"created": "Mon, 28 Jul 2008 13:13:11 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Avelino",
"P. P.",
""
],
[
"Martins",
"C. J. A. P.",
""
],
[
"Menezes",
"J.",
""
],
[
"Menezes",
"R.",
""
],
[
"Oliveira",
"J. C. R. E.",
""
]
] | We use a combination of analytic tools and an extensive set of the largest and most accurate three-dimensional field theory numerical simulations to study the dynamics of domain wall networks with junctions. We build upon our previous work and consider a class of models which, in the limit of large number $N$ of coupled scalar fields, approaches the so-called `ideal' model (in terms of its potential to lead to network frustration). We consider values of $N$ between N=2 and N=20, and a range of cosmological epochs, and we also compare this class of models with other toy models used in the past. In all cases we find compelling evidence for a gradual approach to scaling, strongly supporting our no-frustration conjecture. We also discuss the various possible types of junctions (including cases where there is a hierarchy of them) and their roles in the dynamics of the network. Finally, we revise the Zel'dovich bound and provide an updated cosmological bound on the energy scale of this type of defect network: it must be lower than $10 {\rm keV}$. |
hep-ph/9609380 | Adam Falk | Adam F. Falk | The Many Uses of Excited Heavy Hadrons | 30 pages, LaTeX with sprocl.sty, to appear in the Proceedings of the
Twentieth Johns Hopkins Workshop on Current Problems in Particle Theory,
Heidelberg, Germany, June 27-29, 1996 | null | null | JHU-TIPAC-96014 | hep-ph | null | I discuss a variety of issues in the physics of excited bottom and charmed
hadrons. Recent developments in spectroscopy, strong decays, and production in
fragmentation and weak decays are reviewed.
| [
{
"created": "Tue, 17 Sep 1996 13:05:55 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Falk",
"Adam F.",
""
]
] | I discuss a variety of issues in the physics of excited bottom and charmed hadrons. Recent developments in spectroscopy, strong decays, and production in fragmentation and weak decays are reviewed. |
1706.08524 | Michael Andreas Schmidt | Yi Cai, Juan Herrero-Garc\'ia, Michael A. Schmidt, Avelino Vicente and
Raymond R. Volkas | From the trees to the forest: a review of radiative neutrino mass models | 90 pages, 23 figures and 11 tables. Minor changes, references and one
figure added, matches published version in Frontiers in Physics | Front. in Phys. 5 (2017) 63 | 10.3389/fphy.2017.00063 | ADP-17-29-T1035 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A plausible explanation for the lightness of neutrino masses is that
neutrinos are massless at tree level, with their mass (typically Majorana)
being generated radiatively at one or more loops. The new couplings, together
with the suppression coming from the loop factors, imply that the new degrees
of freedom cannot be too heavy (they are typically at the TeV scale).
Therefore, in these models there are no large mass hierarchies and they can be
tested using different searches, making their detailed phenomenological study
very appealing. In particular, the new particles can be searched for at
colliders and generically induce signals in lepton-flavor and lepton-number
violating processes (in the case of Majorana neutrinos), which are not
independent from reproducing correctly the neutrino masses and mixings. The
main focus of the review is on Majorana neutrinos. We order the allowed theory
space from three different perspectives: (i) using an effective operator
approach to lepton number violation, (ii) by the number of loops at which the
Weinberg operator is generated, (iii) within a given loop order, by the
possible irreducible topologies. We also discuss in more detail some popular
radiative models which involve qualitatively different features, revisiting
their most important phenomenological implications. Finally, we list some
promising avenues to pursue.
| [
{
"created": "Mon, 26 Jun 2017 18:00:01 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Jul 2017 16:41:03 GMT",
"version": "v2"
},
{
"created": "Sat, 25 Nov 2017 05:56:16 GMT",
"version": "v3"
}
] | 2017-12-18 | [
[
"Cai",
"Yi",
""
],
[
"Herrero-García",
"Juan",
""
],
[
"Schmidt",
"Michael A.",
""
],
[
"Vicente",
"Avelino",
""
],
[
"Volkas",
"Raymond R.",
""
]
] | A plausible explanation for the lightness of neutrino masses is that neutrinos are massless at tree level, with their mass (typically Majorana) being generated radiatively at one or more loops. The new couplings, together with the suppression coming from the loop factors, imply that the new degrees of freedom cannot be too heavy (they are typically at the TeV scale). Therefore, in these models there are no large mass hierarchies and they can be tested using different searches, making their detailed phenomenological study very appealing. In particular, the new particles can be searched for at colliders and generically induce signals in lepton-flavor and lepton-number violating processes (in the case of Majorana neutrinos), which are not independent from reproducing correctly the neutrino masses and mixings. The main focus of the review is on Majorana neutrinos. We order the allowed theory space from three different perspectives: (i) using an effective operator approach to lepton number violation, (ii) by the number of loops at which the Weinberg operator is generated, (iii) within a given loop order, by the possible irreducible topologies. We also discuss in more detail some popular radiative models which involve qualitatively different features, revisiting their most important phenomenological implications. Finally, we list some promising avenues to pursue. |
hep-ph/0102036 | Steven D. Bass | Steven D. Bass | Spin structure in non-forward partons | 15 pages | Phys.Rev. D65 (2002) 074025 | 10.1103/PhysRevD.65.074025 | TUM/T39-01-01 | hep-ph | null | Renormalisation induces anomalous contributions in light-cone correlation
functions. We discuss the role of the axial anomaly and gluon topology in
non-forward parton distributions noting that non-forward matrix elements of the
gluonic Chern-Simons current K_{\mu} are not gauge-invariant even in
perturbation theory. The axial anomaly means that one has to be careful how to
interpret information from hard exclusive reactions about the orbital
angular-momentum carried by the proton's internal constituents.
| [
{
"created": "Sun, 4 Feb 2001 16:50:26 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Bass",
"Steven D.",
""
]
] | Renormalisation induces anomalous contributions in light-cone correlation functions. We discuss the role of the axial anomaly and gluon topology in non-forward parton distributions noting that non-forward matrix elements of the gluonic Chern-Simons current K_{\mu} are not gauge-invariant even in perturbation theory. The axial anomaly means that one has to be careful how to interpret information from hard exclusive reactions about the orbital angular-momentum carried by the proton's internal constituents. |
1705.01837 | Kevork Abazajian | Kevork N. Abazajian (UC Irvine) | Sterile neutrinos in cosmology | Accepted version of an invited review for Physics Reports. 33 pages,
7 figures, approximately 16,000 words; v3: expanded discussion of low
reheating temperature universe models with a new figure, large scale
structure effects, scalar decay models | Physics Reports, Volumes 711-712, 10 November 2017, Pages 1-28 | 10.1016/j.physrep.2017.10.003 | UCI-TR-2017-03 | hep-ph astro-ph.CO astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Sterile neutrinos are natural extensions to the standard model of particle
physics in neutrino mass generation mechanisms. If they are relatively light,
less than approximately 10 keV, they can alter cosmology significantly, from
the early Universe to the matter and radiation energy density today. Here, we
review the cosmological role such light sterile neutrinos can play from the
early Universe, including production of keV-scale sterile neutrinos as dark
matter candidates, and dynamics of light eV-scale sterile neutrinos during the
weakly-coupled active neutrino era. We review proposed signatures of light
sterile neutrinos in cosmic microwave background and large scale structure
data. We also discuss keV-scale sterile neutrino dark matter decay signatures
in X-ray observations, including recent candidate $\sim$3.5 keV X-ray line
detections consistent with the decay of a $\sim$7 keV sterile neutrino dark
matter particle.
| [
{
"created": "Thu, 4 May 2017 13:48:23 GMT",
"version": "v1"
},
{
"created": "Wed, 10 May 2017 16:50:36 GMT",
"version": "v2"
},
{
"created": "Wed, 25 Oct 2017 17:38:59 GMT",
"version": "v3"
}
] | 2018-12-19 | [
[
"Abazajian",
"Kevork N.",
"",
"UC Irvine"
]
] | Sterile neutrinos are natural extensions to the standard model of particle physics in neutrino mass generation mechanisms. If they are relatively light, less than approximately 10 keV, they can alter cosmology significantly, from the early Universe to the matter and radiation energy density today. Here, we review the cosmological role such light sterile neutrinos can play from the early Universe, including production of keV-scale sterile neutrinos as dark matter candidates, and dynamics of light eV-scale sterile neutrinos during the weakly-coupled active neutrino era. We review proposed signatures of light sterile neutrinos in cosmic microwave background and large scale structure data. We also discuss keV-scale sterile neutrino dark matter decay signatures in X-ray observations, including recent candidate $\sim$3.5 keV X-ray line detections consistent with the decay of a $\sim$7 keV sterile neutrino dark matter particle. |
2210.02456 | Ameen Ismail | Csaba Csaki, Ameen Ismail, Maximilian Ruhdorfer, Joseph Tooby-Smith | Higgs Squared | 27 + 9 pages, 4 figures | null | 10.1007/JHEP04(2023)082 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a novel construction for a Higgs-VEV sensitive operator, which can
be used as a trigger operator in cosmic selection models for the electroweak
hierarchy problem. Our operator does not contain any degrees of freedom charged
under the SM gauge symmetries, leading to reduced tuning in the resulting
models. Our construction is based on the extension of a two Higgs doublet model
(2HDM) with a softly broken approximate global $D_8$ symmetry (the symmetry
group of a square). A cosmic crunching model based on our extended Higgs sector
has only a percent level tuning corresponding to the usual little hierarchy
problem. In large regions of parameter space the 2HDM is naturally pushed
towards the alignment limit. A complete model requires the introduction of
fermionic top partners to ensure the approximate $D_8$ symmetry in the fermion
sector. We also show that the same extended Higgs sector can be used for a
novel implementation of the seesaw mechanism of neutrino masses.
| [
{
"created": "Wed, 5 Oct 2022 18:00:00 GMT",
"version": "v1"
}
] | 2023-05-10 | [
[
"Csaki",
"Csaba",
""
],
[
"Ismail",
"Ameen",
""
],
[
"Ruhdorfer",
"Maximilian",
""
],
[
"Tooby-Smith",
"Joseph",
""
]
] | We present a novel construction for a Higgs-VEV sensitive operator, which can be used as a trigger operator in cosmic selection models for the electroweak hierarchy problem. Our operator does not contain any degrees of freedom charged under the SM gauge symmetries, leading to reduced tuning in the resulting models. Our construction is based on the extension of a two Higgs doublet model (2HDM) with a softly broken approximate global $D_8$ symmetry (the symmetry group of a square). A cosmic crunching model based on our extended Higgs sector has only a percent level tuning corresponding to the usual little hierarchy problem. In large regions of parameter space the 2HDM is naturally pushed towards the alignment limit. A complete model requires the introduction of fermionic top partners to ensure the approximate $D_8$ symmetry in the fermion sector. We also show that the same extended Higgs sector can be used for a novel implementation of the seesaw mechanism of neutrino masses. |
hep-ph/0309327 | A. A. Arkhipov | A.A. Arkhipov | Hadronic Spectra and Kaluza-Klein Picture of the World | 28 pages, 14 tables, Extended version of the talk presented at Xth
International Conference on Hadron Spectroscopy HADRON '03, August 31 --
September 6, 2003, Aschaffenburg, Germany; few clarifying comments added;
discussion of experiment and conclusion extended, available at
http://dbserv.ihep.su/~pubs/prep2003/ps/2003-37.pdf | null | 10.1063/1.1799779 | IHEP 2003-37 | hep-ph hep-ex nucl-ex | null | A manifestation of Kaluza-Klein picture in hadron spectra is discussed. It is
argued that the experimentally observed structures in hadron spectra confirm
the Kaluza-Klein picture of the world.
| [
{
"created": "Mon, 29 Sep 2003 18:18:57 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Sep 2003 16:04:17 GMT",
"version": "v2"
},
{
"created": "Tue, 21 Oct 2003 16:48:03 GMT",
"version": "v3"
},
{
"created": "Wed, 22 Oct 2003 15:58:01 GMT",
"version": "v4"
},
{
"created": "Thu, 12 Feb 2004 19:47:06 GMT",
"version": "v5"
}
] | 2009-11-10 | [
[
"Arkhipov",
"A. A.",
""
]
] | A manifestation of Kaluza-Klein picture in hadron spectra is discussed. It is argued that the experimentally observed structures in hadron spectra confirm the Kaluza-Klein picture of the world. |
hep-ph/0403251 | Kai-Peer Oliver Diener | Kai-Peer O. Diener | Electron to Muon Conversion in Low-Energy Electron-Nucleus Scattering | 9 pages, 1 figure | Nucl.Phys. B697 (2004) 387-396 | 10.1016/j.nuclphysb.2004.07.034 | PSI-PR-04-05 | hep-ph | null | We present an estimate of the electron to muon conversion cross section in
fixed-target elastic electron scattering. The matrix element $<\mu |
j_\mathrm{em}^\mu(0) | e>$ is calculated analytically in two scenarios
introducing suitable approximations. We consider on the one hand side the case
of three light Dirac neutrinos with CKM-type leptonic mixing and on the other
hand a typical see-saw scenario. We evaluate the coulombic contribution to the
scattering cross section in the limit of vanishing energy transfer to the
nucleus and, thus, obtain a realistic estimate for the total conversion cross
section. Although we find that in the see-saw scenario the cross section can be
enhanced by as much as twenty orders of magnitude in comparison to the Dirac
case, it is still not experimentally accessible.
| [
{
"created": "Wed, 24 Mar 2004 09:15:54 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Diener",
"Kai-Peer O.",
""
]
] | We present an estimate of the electron to muon conversion cross section in fixed-target elastic electron scattering. The matrix element $<\mu | j_\mathrm{em}^\mu(0) | e>$ is calculated analytically in two scenarios introducing suitable approximations. We consider on the one hand side the case of three light Dirac neutrinos with CKM-type leptonic mixing and on the other hand a typical see-saw scenario. We evaluate the coulombic contribution to the scattering cross section in the limit of vanishing energy transfer to the nucleus and, thus, obtain a realistic estimate for the total conversion cross section. Although we find that in the see-saw scenario the cross section can be enhanced by as much as twenty orders of magnitude in comparison to the Dirac case, it is still not experimentally accessible. |
2307.15117 | Marco Fedele | Marco Fedele, Felix Wuest and Ulrich Nierste | Renormalisation group analysis of scalar Leptoquark couplings addressing
flavour anomalies: emergence of lepton-flavour universality | 30 pages, 4 figures. References added, matching journal version | null | null | TTP23-027, P3H-23-048 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Leptoquarks with masses between 2 TeV and 50 TeV are commonly invoked to
explain deviations between data and Standard-Model (SM) predictions of several
observables in the decays $b\to c\tau \bar\nu$ and $b\to s \ell^+\ell^-$ with
$\ell=e,\mu$. While Leptoquarks appear in theories unifying quarks and leptons,
the corresponding unification scale $M_{QLU}$ is typically many orders of
magnitude above this mass range. We study the case that the mass gap between
the electroweak scale and $M_{QLU}$ is only populated by scalar Leptoquarks and
SM particles, restricting ourselves to scenarios addressing the mentioned
flavour anomalies, and determine the renormalisation-group evolution of
Leptoquark couplings to fermions below $M_{QLU}$. In the most general case, we
consider three SU(2) triplet Leptoquarks $S_3^\ell$, $\ell=e,\mu,\tau$, which
couple quark doublets to the lepton doublet $(\nu_\ell,\ell^-)$ to address the
$b\to s \ell^+\ell^-$ anomalies. In this case, we find a scenario in which the
Leptoquark couplings to electrons and muons are driven to the same infrared
fixed point, so that lepton flavour universality emerges dynamically. However,
the corresponding fixed point for the couplings to taus is necessarily opposite
in sign, leading to a unique signature in $b \to s\tau^+\tau^-$. For $b\to
c\tau \bar\nu$ we complement these with either an SU(2) singlet $S_1^\tau$ or
doublet $R_2^\tau$ and study further the cases that also these Leptoquarks come
in three replicas. The fixed point solutions for the $S_3^\ell$ couplings
explain the $b\to s \ell^+\ell^-$ data for $S_3^{e,\mu}$ masses around 10 TeV.
$b\to c\tau \bar\nu$ data can only be fully explained by couplings exceeding
their fixed-point values and evolving into Landau poles at high energies, so
that one can place an upper bound on $M_{QLU}$ between $10^{8}$ and $10^{11}$
GeV.
| [
{
"created": "Thu, 27 Jul 2023 18:00:02 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Nov 2023 17:55:14 GMT",
"version": "v2"
}
] | 2023-11-27 | [
[
"Fedele",
"Marco",
""
],
[
"Wuest",
"Felix",
""
],
[
"Nierste",
"Ulrich",
""
]
] | Leptoquarks with masses between 2 TeV and 50 TeV are commonly invoked to explain deviations between data and Standard-Model (SM) predictions of several observables in the decays $b\to c\tau \bar\nu$ and $b\to s \ell^+\ell^-$ with $\ell=e,\mu$. While Leptoquarks appear in theories unifying quarks and leptons, the corresponding unification scale $M_{QLU}$ is typically many orders of magnitude above this mass range. We study the case that the mass gap between the electroweak scale and $M_{QLU}$ is only populated by scalar Leptoquarks and SM particles, restricting ourselves to scenarios addressing the mentioned flavour anomalies, and determine the renormalisation-group evolution of Leptoquark couplings to fermions below $M_{QLU}$. In the most general case, we consider three SU(2) triplet Leptoquarks $S_3^\ell$, $\ell=e,\mu,\tau$, which couple quark doublets to the lepton doublet $(\nu_\ell,\ell^-)$ to address the $b\to s \ell^+\ell^-$ anomalies. In this case, we find a scenario in which the Leptoquark couplings to electrons and muons are driven to the same infrared fixed point, so that lepton flavour universality emerges dynamically. However, the corresponding fixed point for the couplings to taus is necessarily opposite in sign, leading to a unique signature in $b \to s\tau^+\tau^-$. For $b\to c\tau \bar\nu$ we complement these with either an SU(2) singlet $S_1^\tau$ or doublet $R_2^\tau$ and study further the cases that also these Leptoquarks come in three replicas. The fixed point solutions for the $S_3^\ell$ couplings explain the $b\to s \ell^+\ell^-$ data for $S_3^{e,\mu}$ masses around 10 TeV. $b\to c\tau \bar\nu$ data can only be fully explained by couplings exceeding their fixed-point values and evolving into Landau poles at high energies, so that one can place an upper bound on $M_{QLU}$ between $10^{8}$ and $10^{11}$ GeV. |
0906.0538 | Maxim V. Polyakov | M.V. Polyakov | On the Pion Distribution Amplitude Shape | Refernces and more discussion are added. Version published in JETP
Letters, v 90 p. 250 (2009) | JETP Lett.90:228-231,2009 | 10.1134/S0021364009160024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We argue that the recent BaBar data on $\gamma \to \pi$ e.m. transition form
factor at large photon virtuality supports the idea that pion distribution
amplitude (DA) is close to unity with $\phi_\pi^\prime(0)/6\gg 1$ at a
normalization point of $\mu=0.6\div 0.8$ GeV. Such pion DA can be obtained in
the effective chiral quark model. The possible flat shape of the pion DA
implies that the standard expansion of the DA in Gegenbauer polynomials can be
divergent.
On basis of chiral models we predict that the two-pion DA should exhibit
anomalous endpoint behaviour for pions in the S-wave and that such feature is
absent for higher partial waves. The latter implies that the $\rho, f_2$, etc.
meson DAs have no anomalous endpoint behaviour. Possible implications of such
pion DA for other hard exclusive processes are shortly discussed.
| [
{
"created": "Tue, 2 Jun 2009 17:15:52 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Oct 2009 09:00:53 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Polyakov",
"M. V.",
""
]
] | We argue that the recent BaBar data on $\gamma \to \pi$ e.m. transition form factor at large photon virtuality supports the idea that pion distribution amplitude (DA) is close to unity with $\phi_\pi^\prime(0)/6\gg 1$ at a normalization point of $\mu=0.6\div 0.8$ GeV. Such pion DA can be obtained in the effective chiral quark model. The possible flat shape of the pion DA implies that the standard expansion of the DA in Gegenbauer polynomials can be divergent. On basis of chiral models we predict that the two-pion DA should exhibit anomalous endpoint behaviour for pions in the S-wave and that such feature is absent for higher partial waves. The latter implies that the $\rho, f_2$, etc. meson DAs have no anomalous endpoint behaviour. Possible implications of such pion DA for other hard exclusive processes are shortly discussed. |
hep-ph/0602061 | Fuminobu Takahashi | Motoi Endo, Koichi Hamaguchi, Fuminobu Takahashi | Moduli-Induced Gravitino Problem | 5 pages, 1 figure. v2: minor changes, note added | Phys.Rev.Lett.96:211301,2006 | 10.1103/PhysRevLett.96.211301 | DESY06-014 | hep-ph astro-ph hep-th | null | We investigate the cosmological moduli problem by studying a modulus decay in
detail and find that the branching ratio of the gravitino production is
generically of O(0.01-1), which causes another cosmological disaster.
Consequently, the cosmological moduli problem cannot be solved simply by making
the modulus mass heavier than 100 TeV. We also illustrate our results by
explicitly calculating the branching ratio into the gravitinos in the mixed
modulus--anomaly/KKLT- and racetrack-type models.
| [
{
"created": "Tue, 7 Feb 2006 15:13:09 GMT",
"version": "v1"
},
{
"created": "Wed, 10 May 2006 08:50:14 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Endo",
"Motoi",
""
],
[
"Hamaguchi",
"Koichi",
""
],
[
"Takahashi",
"Fuminobu",
""
]
] | We investigate the cosmological moduli problem by studying a modulus decay in detail and find that the branching ratio of the gravitino production is generically of O(0.01-1), which causes another cosmological disaster. Consequently, the cosmological moduli problem cannot be solved simply by making the modulus mass heavier than 100 TeV. We also illustrate our results by explicitly calculating the branching ratio into the gravitinos in the mixed modulus--anomaly/KKLT- and racetrack-type models. |
hep-ph/9607295 | Joao Soares | Joao M. Soares (University of Massachusetts, Amherst) | Combining exclusive semi-leptonic and hadronic B decays to measure
|V_ub| | Latex, 7 pages, no figures | Phys.Rev. D55 (1997) 1418-1420 | 10.1103/PhysRevD.55.1418 | UMHEP-431 | hep-ph | null | The Cabibbo-Kobayashi-Maskawa matrix element |V_ub| can be extracted from the
rate for the semi-leptonic decay B -> pi + l + antineutrino_l, with little
theoretical uncertainty, provided the hadronic form factor for the B -> pi
transition can be measured from some other B decay. In here, we suggest using
the decay B -> pi J\psi. This is a color suppressed decay, and it cannot be
properly described within the usual factorization approximation; we use instead
a simple and very general phenomenological model for the b d J\psi vertex. In
order to relate the hadronic form factors in the B -> pi J\psi and B -> pi + l
+ antineutrino_l decays, we use form factor relations that hold for
heavy-to-light transitions at large recoil.
| [
{
"created": "Thu, 11 Jul 1996 19:37:37 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Dec 1996 16:30:33 GMT",
"version": "v2"
},
{
"created": "Wed, 23 Apr 1997 14:59:21 GMT",
"version": "v3"
}
] | 2016-09-06 | [
[
"Soares",
"Joao M.",
"",
"University of Massachusetts, Amherst"
]
] | The Cabibbo-Kobayashi-Maskawa matrix element |V_ub| can be extracted from the rate for the semi-leptonic decay B -> pi + l + antineutrino_l, with little theoretical uncertainty, provided the hadronic form factor for the B -> pi transition can be measured from some other B decay. In here, we suggest using the decay B -> pi J\psi. This is a color suppressed decay, and it cannot be properly described within the usual factorization approximation; we use instead a simple and very general phenomenological model for the b d J\psi vertex. In order to relate the hadronic form factors in the B -> pi J\psi and B -> pi + l + antineutrino_l decays, we use form factor relations that hold for heavy-to-light transitions at large recoil. |
1510.03626 | Luciano Maiani prof | H.-X. Chen, L. Maiani, A.D. Polosa, V. Riquer | Y(4260) --> gamma + X(3872) in the diquarkonium picture | references added and minor corrections, 11 pages, 1 figure | null | 10.1140/epjc/s10052-015-3781-2 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The observed Y(4260)\to \gamma + X(3872) decay is a natural consequence of
the diquark-antidiquark description of Y and X resonances. In this note we
attempt an estimate of the transition rate, \Gamma_{\rm rad}, by a
non-relativistic calculation of the electric dipole term of a diquarkonium
bound state. We compute \Gamma_{\rm rad} for generic composition values of the
isospin of X and Y. Specializing to I=0 for X(3872), we find \Gamma_{\rm rad}=
496~keV for Y(4260) with I=0 and \Gamma_{\rm rad}= 179~keV for I=1. Combining
with BESIII data, we derive upper bounds to B(Y\to J/\Psi+\pi+\pi) and to
\Gamma(Y\to \mu^+ \mu^-). We expect to confront these results with forthcoming
data from electron-positron and hadron colliders.
| [
{
"created": "Tue, 13 Oct 2015 11:21:14 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Nov 2015 09:18:30 GMT",
"version": "v2"
}
] | 2016-01-20 | [
[
"Chen",
"H. -X.",
""
],
[
"Maiani",
"L.",
""
],
[
"Polosa",
"A. D.",
""
],
[
"Riquer",
"V.",
""
]
] | The observed Y(4260)\to \gamma + X(3872) decay is a natural consequence of the diquark-antidiquark description of Y and X resonances. In this note we attempt an estimate of the transition rate, \Gamma_{\rm rad}, by a non-relativistic calculation of the electric dipole term of a diquarkonium bound state. We compute \Gamma_{\rm rad} for generic composition values of the isospin of X and Y. Specializing to I=0 for X(3872), we find \Gamma_{\rm rad}= 496~keV for Y(4260) with I=0 and \Gamma_{\rm rad}= 179~keV for I=1. Combining with BESIII data, we derive upper bounds to B(Y\to J/\Psi+\pi+\pi) and to \Gamma(Y\to \mu^+ \mu^-). We expect to confront these results with forthcoming data from electron-positron and hadron colliders. |
1410.4817 | Roberto Vega-Morales | Yi Chen, Emanuele DiMarco, Joe Lykken, Maria Spiropulu, Roberto
Vega-Morales, Si Xie | Technical Note for 8D Likelihood Effective Higgs Couplings Extraction
Framework in the Golden Channel | Technical note to accompany arXiv:1401.2077 | null | null | FERMILAB-PUB-14-396-T, LPT-Orsay-14-76, nuhep-th/14-06 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this technical note we present technical details on various aspects of the
framework introduced in arXiv:1401.2077 aimed at extracting effective Higgs
couplings in the $h\to 4\ell$ `golden channel'. Since it is the primary feature
of the framework, we focus in particular on the convolution integral which
takes us from `truth' level to `detector' level and the numerical and analytic
techniques used to obtain it. We also briefly discuss other aspects of the
framework.
| [
{
"created": "Fri, 17 Oct 2014 18:28:33 GMT",
"version": "v1"
}
] | 2014-10-20 | [
[
"Chen",
"Yi",
""
],
[
"DiMarco",
"Emanuele",
""
],
[
"Lykken",
"Joe",
""
],
[
"Spiropulu",
"Maria",
""
],
[
"Vega-Morales",
"Roberto",
""
],
[
"Xie",
"Si",
""
]
] | In this technical note we present technical details on various aspects of the framework introduced in arXiv:1401.2077 aimed at extracting effective Higgs couplings in the $h\to 4\ell$ `golden channel'. Since it is the primary feature of the framework, we focus in particular on the convolution integral which takes us from `truth' level to `detector' level and the numerical and analytic techniques used to obtain it. We also briefly discuss other aspects of the framework. |
1906.11862 | Heribertus B. Hartanto | Heribertus Bayu Hartanto, Simon Badger, Christian Br{\o}nnum-Hansen,
Tiziano Peraro | A numerical evaluation of planar two-loop helicity amplitudes for a
W-boson plus four partons | 24 pages, 3 figures | null | null | IPPP/19/56, ZU-TH 33/19 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the first numerical results for the two-loop helicity amplitudes
for the scattering of four partons and a W-boson in QCD. We use a finite field
sampling method to reduce directly from Feynman diagrams to the coefficients of
a set of master integrals after applying integration-by-parts identities. Since
the basis of master integrals is not yet fully known analytically, we identify
a set of master integrals with a simple divergence structure using local
numerator insertions. This allows for accurate numerical evaluation of the
amplitude using sector decomposition methods.
| [
{
"created": "Thu, 27 Jun 2019 18:24:17 GMT",
"version": "v1"
}
] | 2019-07-01 | [
[
"Hartanto",
"Heribertus Bayu",
""
],
[
"Badger",
"Simon",
""
],
[
"Brønnum-Hansen",
"Christian",
""
],
[
"Peraro",
"Tiziano",
""
]
] | We present the first numerical results for the two-loop helicity amplitudes for the scattering of four partons and a W-boson in QCD. We use a finite field sampling method to reduce directly from Feynman diagrams to the coefficients of a set of master integrals after applying integration-by-parts identities. Since the basis of master integrals is not yet fully known analytically, we identify a set of master integrals with a simple divergence structure using local numerator insertions. This allows for accurate numerical evaluation of the amplitude using sector decomposition methods. |
hep-ph/0306243 | Jose Ramon Espinosa | J.A. Casas, J.R. Espinosa and I. Navarro | Large mixing angles for neutrinos from infrared fixed points | 36 pages, 7 ps figures | JHEP 0309 (2003) 048 | 10.1088/1126-6708/2003/09/048 | IFT-UAM/CSIC-03-20 | hep-ph | null | Radiative amplification of neutrino mixing angles may explain the large
values required by solar and atmospheric neutrino oscillations. Implementation
of such mechanism in the Standard Model and many of its extensions (including
the Minimal Supersymmetric Standard Model) to amplify the solar angle, the
atmospheric or both requires (at least two) quasi-degenerate neutrino masses,
but is not always possible. When it is, it involves a fine-tuning between
initial conditions and radiative corrections. In supersymmetric models with
neutrino masses generated through the Kahler potential, neutrino mixing angles
can easily be driven to large values at low energy as they approach infrared
pseudo-fixed points at large mixing (in stark contrast with conventional
scenarios, that have infrared pseudo-fixed points at zero mixing). In addition,
quasi-degeneracy of neutrino masses is not always required.
| [
{
"created": "Tue, 24 Jun 2003 18:04:11 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Casas",
"J. A.",
""
],
[
"Espinosa",
"J. R.",
""
],
[
"Navarro",
"I.",
""
]
] | Radiative amplification of neutrino mixing angles may explain the large values required by solar and atmospheric neutrino oscillations. Implementation of such mechanism in the Standard Model and many of its extensions (including the Minimal Supersymmetric Standard Model) to amplify the solar angle, the atmospheric or both requires (at least two) quasi-degenerate neutrino masses, but is not always possible. When it is, it involves a fine-tuning between initial conditions and radiative corrections. In supersymmetric models with neutrino masses generated through the Kahler potential, neutrino mixing angles can easily be driven to large values at low energy as they approach infrared pseudo-fixed points at large mixing (in stark contrast with conventional scenarios, that have infrared pseudo-fixed points at zero mixing). In addition, quasi-degeneracy of neutrino masses is not always required. |
0810.4685 | Owe Philipsen | Owe Philipsen (ITP, U. Munster) | Static potentials for quarkonia at finite temperatures | 8 p. 3 figures; Invited talk at 'Strong and Electroweak Matter 2008',
26-29 August, Amsterdam, The Netherlands | null | 10.1016/j.nuclphysa.2009.01.016 | MS-TP-08-27 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review non-perturbative static potentials commonly used in potential
models for quarkonia at finite T. Potentials derived from Polyakov loop
correlators are shown to be inappropriate for this purpose. The q\bar{q} free
energy is physical but has the wrong spatial decay and perturbative limit. The
so-called singlet free energy is gauge dependent and unphysical. An appropriate
static real time potential can be defined through a generalisation of pNRQCD to
finite T. In perturbation theory, its real part reproduces the Debye-screened
potential, its imaginary part accounts for Landau damping. Possibilities for
its non-perturbative evaluation are discussed.
| [
{
"created": "Sun, 26 Oct 2008 11:53:20 GMT",
"version": "v1"
}
] | 2009-11-13 | [
[
"Philipsen",
"Owe",
"",
"ITP, U. Munster"
]
] | We review non-perturbative static potentials commonly used in potential models for quarkonia at finite T. Potentials derived from Polyakov loop correlators are shown to be inappropriate for this purpose. The q\bar{q} free energy is physical but has the wrong spatial decay and perturbative limit. The so-called singlet free energy is gauge dependent and unphysical. An appropriate static real time potential can be defined through a generalisation of pNRQCD to finite T. In perturbation theory, its real part reproduces the Debye-screened potential, its imaginary part accounts for Landau damping. Possibilities for its non-perturbative evaluation are discussed. |
2004.12662 | CaiChang Li | Gui-Jun Ding, Stephen F. King, Cai-Chang Li, Ye-Ling Zhou | Modular Invariant Models of Leptons at Level 7 | 45 pages, 3 figures | null | null | USTC-ICTS/PCFT-20-11 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider for the first time level 7 modular invariant flavour models where
the lepton mixing originates from the breaking of modular symmetry and
couplings responsible for lepton masses are modular forms. The latter are
decomposed into irreducible multiplets of the finite modular group $\Gamma_7$,
which is isomorphic to $PSL(2,Z_{7})$, the projective special linear group of
two dimensional matrices over the finite Galois field of seven elements,
containing 168 elements, sometimes written as $PSL_2(7)$ or $\Sigma(168)$. At
weight 2, there are 26 linearly independent modular forms, organised into a
triplet, a septet and two octets of $\Gamma_7$. A full list of modular forms up
to weight 8 are provided. Assuming the absence of flavons, the simplest
modular-invariant models based on $\Gamma_7$ are constructed, in which
neutrinos gain masses via either the Weinberg operator or the type-I seesaw
mechanism, and their predictions compared to experiment.
| [
{
"created": "Mon, 27 Apr 2020 09:22:01 GMT",
"version": "v1"
}
] | 2020-04-28 | [
[
"Ding",
"Gui-Jun",
""
],
[
"King",
"Stephen F.",
""
],
[
"Li",
"Cai-Chang",
""
],
[
"Zhou",
"Ye-Ling",
""
]
] | We consider for the first time level 7 modular invariant flavour models where the lepton mixing originates from the breaking of modular symmetry and couplings responsible for lepton masses are modular forms. The latter are decomposed into irreducible multiplets of the finite modular group $\Gamma_7$, which is isomorphic to $PSL(2,Z_{7})$, the projective special linear group of two dimensional matrices over the finite Galois field of seven elements, containing 168 elements, sometimes written as $PSL_2(7)$ or $\Sigma(168)$. At weight 2, there are 26 linearly independent modular forms, organised into a triplet, a septet and two octets of $\Gamma_7$. A full list of modular forms up to weight 8 are provided. Assuming the absence of flavons, the simplest modular-invariant models based on $\Gamma_7$ are constructed, in which neutrinos gain masses via either the Weinberg operator or the type-I seesaw mechanism, and their predictions compared to experiment. |
1008.4479 | Wan-lei Guo | Wan-Lei Guo, Yue-Liang Wu, Yu-Feng Zhou | Searching for Dark Matter Signals in the Left-Right Symmetric Gauge
Model with CP Symmetry | 24 pages, 8 figures. minor changes and a reference added, published
in Phys. Rev. D | Phys.Rev.D82:095004,2010 | 10.1103/PhysRevD.82.095004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate singlet scalar dark matter (DM) candidate in a left-right
symmetric gauge model with two Higgs bidoublets (2HBDM) in which the
stabilization of the DM particle is induced by the discrete symmetries P and
CP. According to the observed DM abundance, we predict the DM direct and
indirect detection cross sections for the DM mass range from 10 GeV to 500 GeV.
We show that the DM indirect detection cross section is not sensitive to the
light Higgs mixing and Yukawa couplings except the resonance regions. The
predicted spin-independent DM-nucleon elastic scattering cross section is found
to be significantly dependent on the above two factors. Our results show that
the future DM direct search experiments can cover the most parts of the allowed
parameter space. The PAMELA antiproton data can only exclude two very narrow
regions in the 2HBDM. It is very difficult to detect the DM direct or indirect
signals in the resonance regions due to the Breit-Wigner resonance effect.
| [
{
"created": "Thu, 26 Aug 2010 11:38:41 GMT",
"version": "v1"
},
{
"created": "Tue, 16 Nov 2010 09:11:22 GMT",
"version": "v2"
}
] | 2010-12-13 | [
[
"Guo",
"Wan-Lei",
""
],
[
"Wu",
"Yue-Liang",
""
],
[
"Zhou",
"Yu-Feng",
""
]
] | We investigate singlet scalar dark matter (DM) candidate in a left-right symmetric gauge model with two Higgs bidoublets (2HBDM) in which the stabilization of the DM particle is induced by the discrete symmetries P and CP. According to the observed DM abundance, we predict the DM direct and indirect detection cross sections for the DM mass range from 10 GeV to 500 GeV. We show that the DM indirect detection cross section is not sensitive to the light Higgs mixing and Yukawa couplings except the resonance regions. The predicted spin-independent DM-nucleon elastic scattering cross section is found to be significantly dependent on the above two factors. Our results show that the future DM direct search experiments can cover the most parts of the allowed parameter space. The PAMELA antiproton data can only exclude two very narrow regions in the 2HBDM. It is very difficult to detect the DM direct or indirect signals in the resonance regions due to the Breit-Wigner resonance effect. |
1507.08471 | Yang Zhang | Junjie Cao, Liangliang Shang, Jin Min Yang, Yang Zhang | Explanation of the ATLAS Z-peaked excess by squark pair production in
the NMSSM | 19 pages, 4 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The ATLAS collaboration recently reported a $3\sigma$ excess in the
leptonic-$Z+jets+E_{T}^{miss}$ channel. We intend to interpret this excess by
squark pair production in the Next-to-Minimal Supersymmetric Standard Model
(NMSSM). The decay chain we employ is $\tilde{q} \to q \tilde{\chi}_2^0 \to q
\tilde{\chi}_1^0 Z$, where $\tilde{\chi}_1^0$ and $\tilde{\chi}_2^0$ denote the
lightest and the next-to-lightest neutralinos with singlino and bino as their
dominant components respectively. Our simulations indicate that after
considering the constraints from the ATLAS searches for $jets + E_{T}^{miss}$
signal the central value of the excess can be obtained for $m_{\tilde{q}}
\lesssim 1.2 {\rm TeV}$, and if the constraint from the CMS on-$Z$ search is
further considered, more than 10 signal events are still attainable for
$m_{\tilde{q}} \lesssim 750 {\rm GeV}$. Compared with the interpretation by
gluino pair production, the squark explanation allows for a significantly wider
range of $m_{\tilde{q}}$ as well as a less compressed SUSY mass spectrum. We
also show that the squark explanation will be readily tested at the initial
stage of the 14 TeV LHC.
| [
{
"created": "Thu, 30 Jul 2015 12:06:29 GMT",
"version": "v1"
},
{
"created": "Mon, 3 Aug 2015 01:47:18 GMT",
"version": "v2"
},
{
"created": "Wed, 23 Sep 2015 14:34:59 GMT",
"version": "v3"
}
] | 2015-09-24 | [
[
"Cao",
"Junjie",
""
],
[
"Shang",
"Liangliang",
""
],
[
"Yang",
"Jin Min",
""
],
[
"Zhang",
"Yang",
""
]
] | The ATLAS collaboration recently reported a $3\sigma$ excess in the leptonic-$Z+jets+E_{T}^{miss}$ channel. We intend to interpret this excess by squark pair production in the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The decay chain we employ is $\tilde{q} \to q \tilde{\chi}_2^0 \to q \tilde{\chi}_1^0 Z$, where $\tilde{\chi}_1^0$ and $\tilde{\chi}_2^0$ denote the lightest and the next-to-lightest neutralinos with singlino and bino as their dominant components respectively. Our simulations indicate that after considering the constraints from the ATLAS searches for $jets + E_{T}^{miss}$ signal the central value of the excess can be obtained for $m_{\tilde{q}} \lesssim 1.2 {\rm TeV}$, and if the constraint from the CMS on-$Z$ search is further considered, more than 10 signal events are still attainable for $m_{\tilde{q}} \lesssim 750 {\rm GeV}$. Compared with the interpretation by gluino pair production, the squark explanation allows for a significantly wider range of $m_{\tilde{q}}$ as well as a less compressed SUSY mass spectrum. We also show that the squark explanation will be readily tested at the initial stage of the 14 TeV LHC. |
hep-ph/9504352 | null | D.J. Broadhurst, D. Kreimer | Knots and Numbers in $\phi^4$ Theory to 7 Loops and Beyond | 6 pages plain LaTex | Int.J.Mod.Phys. C6 (1995) 519-524 | 10.1142/S012918319500037X | OUT-4102-57 | hep-ph hep-th math.QA q-alg | null | We evaluate all the primitive divergences contributing to the 7--loop
$\beta$\/--function of $\phi^4$ theory, i.e.\ all 59 diagrams that are free of
subdivergences and hence give scheme--independent contributions. Guided by the
association of diagrams with knots, we obtain analytical results for 56
diagrams. The remaining three diagrams, associated with the knots $10_{124}$,
$10_{139}$, and $10_{152}$, are evaluated numerically, to 10 sf. Only one
satellite knot with 11 crossings is encountered and the transcendental number
associated with it is found. Thus we achieve an analytical result for the
6--loop contributions, and a numerical result at 7 loops that is accurate to
one part in $10^{11}$. The series of `zig--zag' counterterms,
$\{6\zeta_3,\,20\zeta_5,\, \frac{441}{8}\zeta_7,\,168\zeta_9,\,\ldots\}$,
previously known for $n=3,4,5,6$ loops, is evaluated to 10 loops, corresponding
to 17 crossings, revealing that the $n$\/--loop zig--zag term is $4C_{n-1}
\sum_{p>0}\frac{(-1)^{p n - n}}{p^{2n-3}}$, where $C_n=\frac{1}{n+1}{2n \choose
n}$ are the Catalan numbers, familiar in knot theory. The investigations
reported here entailed intensive use of REDUCE, to generate ${\rm O}(10^4)$
lines of code for multiple precision FORTRAN computations, enabled by Bailey's
MPFUN routines, running for ${\rm O}(10^3)$ CPUhours on DecAlpha machines.
| [
{
"created": "Fri, 21 Apr 1995 14:27:00 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Broadhurst",
"D. J.",
""
],
[
"Kreimer",
"D.",
""
]
] | We evaluate all the primitive divergences contributing to the 7--loop $\beta$\/--function of $\phi^4$ theory, i.e.\ all 59 diagrams that are free of subdivergences and hence give scheme--independent contributions. Guided by the association of diagrams with knots, we obtain analytical results for 56 diagrams. The remaining three diagrams, associated with the knots $10_{124}$, $10_{139}$, and $10_{152}$, are evaluated numerically, to 10 sf. Only one satellite knot with 11 crossings is encountered and the transcendental number associated with it is found. Thus we achieve an analytical result for the 6--loop contributions, and a numerical result at 7 loops that is accurate to one part in $10^{11}$. The series of `zig--zag' counterterms, $\{6\zeta_3,\,20\zeta_5,\, \frac{441}{8}\zeta_7,\,168\zeta_9,\,\ldots\}$, previously known for $n=3,4,5,6$ loops, is evaluated to 10 loops, corresponding to 17 crossings, revealing that the $n$\/--loop zig--zag term is $4C_{n-1} \sum_{p>0}\frac{(-1)^{p n - n}}{p^{2n-3}}$, where $C_n=\frac{1}{n+1}{2n \choose n}$ are the Catalan numbers, familiar in knot theory. The investigations reported here entailed intensive use of REDUCE, to generate ${\rm O}(10^4)$ lines of code for multiple precision FORTRAN computations, enabled by Bailey's MPFUN routines, running for ${\rm O}(10^3)$ CPUhours on DecAlpha machines. |
0902.1211 | Mauro Napsuciale | C. A. Vaquera-Araujo, M. Napsuciale | Is there an isovector companion of the X(2175)? | revised version accepted in PLB | Phys.Lett.B681:434-438,2009 | 10.1016/j.physletb.2009.10.049 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this letter we study the reaction e^{+}e^{-}\to\phi \pi^0 \eta with the
\pi^{0}\eta system in an isoscalar s-wave configuration. We use a formalism
recently developed for the study of e^{+}e^{-}\to\phi \pi\pi and
e^{+}e^{-}\to\phi K^{+}K^{-}. The obtained cross section is within the reach of
present e^{+}e^{-} machines. Measuring this channel would test the absence of
an isovector companion of the X(2175) as predicted by the three body approach
to this resonance.
| [
{
"created": "Sat, 7 Feb 2009 01:43:15 GMT",
"version": "v1"
},
{
"created": "Sun, 25 Oct 2009 16:45:53 GMT",
"version": "v2"
}
] | 2014-11-18 | [
[
"Vaquera-Araujo",
"C. A.",
""
],
[
"Napsuciale",
"M.",
""
]
] | In this letter we study the reaction e^{+}e^{-}\to\phi \pi^0 \eta with the \pi^{0}\eta system in an isoscalar s-wave configuration. We use a formalism recently developed for the study of e^{+}e^{-}\to\phi \pi\pi and e^{+}e^{-}\to\phi K^{+}K^{-}. The obtained cross section is within the reach of present e^{+}e^{-} machines. Measuring this channel would test the absence of an isovector companion of the X(2175) as predicted by the three body approach to this resonance. |
2104.07994 | Sven-Olaf Moch | S. Moch and V. Magerya | Calculating Four-Loop Corrections in QCD | 13 pages LaTeX, 2 figures; based on the talk given by S.Moch at the
DESY workshop "Antidifferentiation and the Calculation of Feynman
Amplitudes", Zeuthen, Oct 04-09, 2020 | null | null | DESY 21-047, KA-TP-05-2021 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We review the current status of perturbative corrections in QCD at four loops
for scattering processes with space- and time-like kinematics at colliders,
with specific focus on deep-inelastic scattering and electron-positron
annihilation. The calculations build on the parametric reduction of loop and
phase space integrals up to four-loop order using computer algebra programs
such as FORM, designed for large scale computations.
| [
{
"created": "Fri, 16 Apr 2021 09:44:03 GMT",
"version": "v1"
}
] | 2021-04-19 | [
[
"Moch",
"S.",
""
],
[
"Magerya",
"V.",
""
]
] | We review the current status of perturbative corrections in QCD at four loops for scattering processes with space- and time-like kinematics at colliders, with specific focus on deep-inelastic scattering and electron-positron annihilation. The calculations build on the parametric reduction of loop and phase space integrals up to four-loop order using computer algebra programs such as FORM, designed for large scale computations. |
2010.08535 | Linda Ghegal | Linda Ghegal | Probing Space-Time Noncommutativity in the Bhabha Scattering | null | null | 10.5506/APhysPolB.51.2031 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate Bhabha scattering with the Seiberg-Witten expended
noncommutative standard model scenario to first order of the noncommutativity
parameter $\Theta_{\mu \nu }$. This study is based on the definition of the
noncommutativity parameter that we have assumed. We explore the noncommutative
scale $\Lambda_{_{NC}}\geq0.8$ TeV considering different machine energy ranging
from $0.5$ TeV to $1.5$ TeV.
| [
{
"created": "Thu, 15 Oct 2020 16:01:52 GMT",
"version": "v1"
}
] | 2020-12-30 | [
[
"Ghegal",
"Linda",
""
]
] | We investigate Bhabha scattering with the Seiberg-Witten expended noncommutative standard model scenario to first order of the noncommutativity parameter $\Theta_{\mu \nu }$. This study is based on the definition of the noncommutativity parameter that we have assumed. We explore the noncommutative scale $\Lambda_{_{NC}}\geq0.8$ TeV considering different machine energy ranging from $0.5$ TeV to $1.5$ TeV. |
hep-ph/0609214 | Luis Anchordoqui | Luis A. Anchordoqui, Carlos A. Garcia Canal, Haim Goldberg, Daniel
Gomez Dumm, and Francis Halzen | Probing leptoquark production at IceCube | Matching version to be published in Phys. Rev. D | Phys.Rev.D74:125021,2006 | 10.1103/PhysRevD.74.125021 | null | hep-ph astro-ph hep-th | null | We emphasize the inelasticity distribution of events detected at the IceCube
neutrino telescope as an important tool for revealing new physics. This is
possible because the unique energy resolution at this facility allows to
separately assign the energy fractions for emergent muons and taus in neutrino
interactions. As a particular example, we explore the possibility of probing
second and third generation leptoquark parameter space (coupling and mass). We
show that production of leptoquarks with masses \agt 250 GeV and diagonal
generation couplings of O(1) can be directly tested if the cosmic neutrino flux
is at the Waxman-Bahcall level.
| [
{
"created": "Thu, 21 Sep 2006 17:48:32 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Dec 2006 14:55:50 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Anchordoqui",
"Luis A.",
""
],
[
"Canal",
"Carlos A. Garcia",
""
],
[
"Goldberg",
"Haim",
""
],
[
"Dumm",
"Daniel Gomez",
""
],
[
"Halzen",
"Francis",
""
]
] | We emphasize the inelasticity distribution of events detected at the IceCube neutrino telescope as an important tool for revealing new physics. This is possible because the unique energy resolution at this facility allows to separately assign the energy fractions for emergent muons and taus in neutrino interactions. As a particular example, we explore the possibility of probing second and third generation leptoquark parameter space (coupling and mass). We show that production of leptoquarks with masses \agt 250 GeV and diagonal generation couplings of O(1) can be directly tested if the cosmic neutrino flux is at the Waxman-Bahcall level. |
hep-ph/9704267 | null | V.S. Fadin, M.I. Kotsky, L.N. Lipatov | Gluon Pair Production in the Quasi-Multi-Regge Kinematics | 15 pages, LaTeX, 1 eps-figure is included | null | null | BudkerINP 96-92 | hep-ph | null | To find the region of applicability of the leading log(1/x) approximation for
parton distributions in the small x region and to fix the argument of the QCD
running coupling it is necessary to know radiative corrections to the kernel of
the BFKL equation. The next-to-leading corrections to the BFKL kernel are
expressed in terms of the two-loop correction to the gluon Regge trajectory,
one-loop correction to the Reggeon-Reggeon-gluon vertex, and contributions from
two-gluon and quark-antiquark production in the quasi-multi-Regge kinematics.
We calculate differential and total cross sections of the two gluon production.
Differential cross section can be applied for description of two jet production
in the quasi-multi-Regge kinematics; the total cross section defines
corresponding correction to the BFKL kernel. To escape the infrared
divergencies we use dimensional regularization of the Feynman integrals.
| [
{
"created": "Wed, 9 Apr 1997 08:05:40 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Apr 1997 10:48:51 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Fadin",
"V. S.",
""
],
[
"Kotsky",
"M. I.",
""
],
[
"Lipatov",
"L. N.",
""
]
] | To find the region of applicability of the leading log(1/x) approximation for parton distributions in the small x region and to fix the argument of the QCD running coupling it is necessary to know radiative corrections to the kernel of the BFKL equation. The next-to-leading corrections to the BFKL kernel are expressed in terms of the two-loop correction to the gluon Regge trajectory, one-loop correction to the Reggeon-Reggeon-gluon vertex, and contributions from two-gluon and quark-antiquark production in the quasi-multi-Regge kinematics. We calculate differential and total cross sections of the two gluon production. Differential cross section can be applied for description of two jet production in the quasi-multi-Regge kinematics; the total cross section defines corresponding correction to the BFKL kernel. To escape the infrared divergencies we use dimensional regularization of the Feynman integrals. |
hep-ph/0012245 | Covi Laura | Laura Covi (DESY) | Models of inflation, supersymmetry breaking and observational
constraints | 16 pages, 2 figures, LaTeX. To appear in the Proceedings of the
Conference ``DARK2000 - Third international conference on dark matter in
astro and particle physics'' at Heidelberg, Germanyon 10-15 July 2000 | null | null | DESY-00-184 | hep-ph | null | We review the connection between inflationary models and observations and
concentrate to describe models based on softly broken supersymmetry, in
particular running mass models, and their predictions. We then present a fit of
the spectral index of the curvature perturbation, assuming a flat $\Lambda$CDM
cosmology.
| [
{
"created": "Tue, 19 Dec 2000 14:41:52 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Covi",
"Laura",
"",
"DESY"
]
] | We review the connection between inflationary models and observations and concentrate to describe models based on softly broken supersymmetry, in particular running mass models, and their predictions. We then present a fit of the spectral index of the curvature perturbation, assuming a flat $\Lambda$CDM cosmology. |
1912.04888 | Keith Olive | John Ellis, Jason L. Evans, Natsumi Nagata, Keith A. Olive, and
Liliana Velasco-Sevilla | Supersymmetric Proton Decay Revisited | 53 pages, 17 figures | null | 10.1140/epjc/s10052-020-7872-3 | KCL-PH-TH/2019-91, CERN-TH-2019-216, UT-19-30, UMN-TH-3907/19,
FTPI-MINN-19/28 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Encouraged by the advent of a new generation of underground detectors---JUNO,
DUNE and Hyper-Kamiokande---that are projected to improve significantly on the
present sensitivities to various baryon decay modes, we revisit baryon decay in
the minimal supersymmetric SU(5) GUT. We discuss the phenomenological
uncertainties associated with hadronic matrix elements and the value of the
strong coupling $\alpha_s$---which are the most important---the weak mixing
angle $\theta_W$, quark masses including one-loop renormalization effects,
quark mixing and novel GUT phases that are not visible in electroweak
interaction processes. We apply our analysis to a variety of CMSSM, super- and
sub-GUT scenarios in which soft supersymmetry-breaking parameters are assumed
to be universal at, above and below the GUT scale, respectively. In many cases,
we find that the next generation of underground detectors should be able to
probe models with sparticle masses that are ${\cal O}(10)$~TeV, beyond the
reach of the LHC.
| [
{
"created": "Tue, 10 Dec 2019 18:55:57 GMT",
"version": "v1"
}
] | 2020-05-20 | [
[
"Ellis",
"John",
""
],
[
"Evans",
"Jason L.",
""
],
[
"Nagata",
"Natsumi",
""
],
[
"Olive",
"Keith A.",
""
],
[
"Velasco-Sevilla",
"Liliana",
""
]
] | Encouraged by the advent of a new generation of underground detectors---JUNO, DUNE and Hyper-Kamiokande---that are projected to improve significantly on the present sensitivities to various baryon decay modes, we revisit baryon decay in the minimal supersymmetric SU(5) GUT. We discuss the phenomenological uncertainties associated with hadronic matrix elements and the value of the strong coupling $\alpha_s$---which are the most important---the weak mixing angle $\theta_W$, quark masses including one-loop renormalization effects, quark mixing and novel GUT phases that are not visible in electroweak interaction processes. We apply our analysis to a variety of CMSSM, super- and sub-GUT scenarios in which soft supersymmetry-breaking parameters are assumed to be universal at, above and below the GUT scale, respectively. In many cases, we find that the next generation of underground detectors should be able to probe models with sparticle masses that are ${\cal O}(10)$~TeV, beyond the reach of the LHC. |
1905.13335 | Ermal Rrapaj | Ermal Rrapaj | Exact solution of multi-angle quantum many-body collective neutrino
flavor oscillations | null | Phys. Rev. C 101, 065805 (2020) | 10.1103/PhysRevC.101.065805 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I study the flavor evolution of a dense neutrino gas by considering vacuum
contributions, matter effects and neutrino self-interactions. Assuming a system
of two flavors in a uniform matter background, the time evolution of the
many-body system in discretized momentum space is computed. The multi-angle
neutrino-neutrino interactions are treated exactly and compared to both the
single-angle approximation and mean field calculations. %The time unit chosen
is $\mu_0^{-1}=(\frac{G_F}{2\sqrt{2}V})^{-1}$. The mono-energetic two neutrino
beam scenario is solved analytically. I proceed to solve flavor oscillations
for mono-energetic cubic lattices and quadratic lattices of two energy levels.
In addition I study various configurations of twelve, sixteen, and twenty
neutrinos. I find that when all neutrinos are initially of the same flavor, all
methods agree. When both flavors are present, I find collective oscillations
and flavor equilibration develop in the many body treatment but not in the mean
field method. This difference persists in dense matter with tiny mixing angle
and it can be ascribed to non-negligible flavor polarization correlations being
present. Entanglement entropy is significant in all such cases. The relevance
for supernovae or neutron stars mergers is contingent upon the value of the
normalization volume $V$ and the large $N$ dependence of the timescale
associated with oscillations. In future work, I intend to study this dependence
using larger lattices and also include anti-neutrinos.
| [
{
"created": "Thu, 30 May 2019 22:11:14 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Jul 2019 17:40:37 GMT",
"version": "v2"
},
{
"created": "Mon, 19 Aug 2019 21:08:54 GMT",
"version": "v3"
},
{
"created": "Thu, 25 Jun 2020 16:21:10 GMT",
"version": "v4"
}
] | 2020-07-01 | [
[
"Rrapaj",
"Ermal",
""
]
] | I study the flavor evolution of a dense neutrino gas by considering vacuum contributions, matter effects and neutrino self-interactions. Assuming a system of two flavors in a uniform matter background, the time evolution of the many-body system in discretized momentum space is computed. The multi-angle neutrino-neutrino interactions are treated exactly and compared to both the single-angle approximation and mean field calculations. %The time unit chosen is $\mu_0^{-1}=(\frac{G_F}{2\sqrt{2}V})^{-1}$. The mono-energetic two neutrino beam scenario is solved analytically. I proceed to solve flavor oscillations for mono-energetic cubic lattices and quadratic lattices of two energy levels. In addition I study various configurations of twelve, sixteen, and twenty neutrinos. I find that when all neutrinos are initially of the same flavor, all methods agree. When both flavors are present, I find collective oscillations and flavor equilibration develop in the many body treatment but not in the mean field method. This difference persists in dense matter with tiny mixing angle and it can be ascribed to non-negligible flavor polarization correlations being present. Entanglement entropy is significant in all such cases. The relevance for supernovae or neutron stars mergers is contingent upon the value of the normalization volume $V$ and the large $N$ dependence of the timescale associated with oscillations. In future work, I intend to study this dependence using larger lattices and also include anti-neutrinos. |
hep-ph/0305011 | Ralf Rapp | R. Rapp | Pi+ Pi- Emission in High-Energy Nuclear Collisions | 9 pages RevTeX including 5 eps-figures, summary slightly expanded and
5 references added | Nucl.Phys. A725 (2003) 254-268 | 10.1016/S0375-9474(03)01581-1 | null | hep-ph nucl-th | null | Realistic vacuum $\pi\pi$ interactions are employed to investigate thermal
$\pi^+\pi^-$ emission spectra from the late stages of heavy-ion reactions at
ultrarelativistic energies. Hadronic in-medium effects, including many-body
$\rho$-meson spectral functions used earlier to describe the dilepton excess
observed at CERN-SPS energies, are implemented to assess resulting
modifications in relation to recent measurements of $\pi^+\pi^-$ invariant-mass
spectra by the STAR collaboration in $p$-$p$ and $Au$-$Au$ collisions at
$\sqrt{s_{NN}}$=200 GeV. Statistical model estimates for the $\rho^0/\pi^-$ and
$K^*/K$ ratios close to the expected thermal freezeout are also given.
| [
{
"created": "Thu, 1 May 2003 19:36:46 GMT",
"version": "v1"
},
{
"created": "Sat, 10 May 2003 20:37:28 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Rapp",
"R.",
""
]
] | Realistic vacuum $\pi\pi$ interactions are employed to investigate thermal $\pi^+\pi^-$ emission spectra from the late stages of heavy-ion reactions at ultrarelativistic energies. Hadronic in-medium effects, including many-body $\rho$-meson spectral functions used earlier to describe the dilepton excess observed at CERN-SPS energies, are implemented to assess resulting modifications in relation to recent measurements of $\pi^+\pi^-$ invariant-mass spectra by the STAR collaboration in $p$-$p$ and $Au$-$Au$ collisions at $\sqrt{s_{NN}}$=200 GeV. Statistical model estimates for the $\rho^0/\pi^-$ and $K^*/K$ ratios close to the expected thermal freezeout are also given. |
hep-ph/9910473 | Dario Grasso | Dario Grasso and Anna Rossi (Padua U.,Italy) | Macroscopic Forces driven by Resonant Neutrino Conversion | 9 LaTeX pages, 1 ps figure file. Format changed. One formula
corrected. Some comments added to the text. Accepted for publication on Phys.
Lett. B | Phys.Lett. B483 (2000) 157-162 | 10.1016/S0370-2693(00)00594-3 | DFPD/99/TH/45 | hep-ph astro-ph | null | We show that neutrino oscillations in matter are always accompanied by
collective forces on the medium. This effect may produce interesting
consequences for the background and the neutrino oscillations themselves. The
force is maximal in the case of resonant neutrino conversion in the adiabatic
regime. We study here the forces driven by $\nu_e-\nu_{\mu,\tau}$ and
$\nu_e-\nu_s$ MSW conversion and shortly discuss their possible relevance for
the dynamics of a type II supernova.
| [
{
"created": "Mon, 25 Oct 1999 14:39:43 GMT",
"version": "v1"
},
{
"created": "Wed, 10 May 2000 13:19:58 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Grasso",
"Dario",
"",
"Padua U.,Italy"
],
[
"Rossi",
"Anna",
"",
"Padua U.,Italy"
]
] | We show that neutrino oscillations in matter are always accompanied by collective forces on the medium. This effect may produce interesting consequences for the background and the neutrino oscillations themselves. The force is maximal in the case of resonant neutrino conversion in the adiabatic regime. We study here the forces driven by $\nu_e-\nu_{\mu,\tau}$ and $\nu_e-\nu_s$ MSW conversion and shortly discuss their possible relevance for the dynamics of a type II supernova. |
hep-ph/0506308 | Arata Hayashigaki | Adrian Dumitru, Arata Hayashigaki and Jamal Jalilian-Marian | The Color Glass Condensate and hadron production in the forward region | Final version to appear in NPA; 22 pages, 10 figures, v3; three new
figures in appendix show that BRAHMS/STAR kinematics probe momentum fractions
in the nucleus of 0.001 - 0.0001 | Nucl.Phys.A765:464-482,2006 | 10.1016/j.nuclphysa.2005.11.014 | INT-PUB 05-14 | hep-ph nucl-ex nucl-th | null | We consider one loop corrections to single inclusive particle production in
parton-nucleus scattering at high energies, treating the target nucleus as a
Color Glass Condensate. We prove by explicit computation that in the leading
log Q^2 approximation, these corrections lead to collinear factorization and
DGLAP evolution of the projectile parton distribution and hadron fragmentation
functions. At leading logarithmic level, and in single-inclusive cross
sections, only two-point functions of Wilson lines in the adjoint and
fundamental representations (Mueller's dipoles) arise, which can be obtained
from the solution of the JIMWLK equations. The application of our results to
forward-rapidity production at RHIC energy shows that, in general, recoil
effects are large and that the forward rapidity region at RHIC is rather
different from the central region at LHC, despite comparable gluon densities in
the target. We show that both the quantum x-evolution of the high-density
target as well as the DGLAP Q^2-evolution of the parton distribution and
fragmentation functions are clearly seen in the BRAHMS data. This provides
additional strong evidence for the Color Glass Condensate at RHIC.
| [
{
"created": "Wed, 29 Jun 2005 15:08:21 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Jul 2005 10:15:26 GMT",
"version": "v2"
},
{
"created": "Tue, 6 Sep 2005 15:49:18 GMT",
"version": "v3"
}
] | 2014-11-18 | [
[
"Dumitru",
"Adrian",
""
],
[
"Hayashigaki",
"Arata",
""
],
[
"Jalilian-Marian",
"Jamal",
""
]
] | We consider one loop corrections to single inclusive particle production in parton-nucleus scattering at high energies, treating the target nucleus as a Color Glass Condensate. We prove by explicit computation that in the leading log Q^2 approximation, these corrections lead to collinear factorization and DGLAP evolution of the projectile parton distribution and hadron fragmentation functions. At leading logarithmic level, and in single-inclusive cross sections, only two-point functions of Wilson lines in the adjoint and fundamental representations (Mueller's dipoles) arise, which can be obtained from the solution of the JIMWLK equations. The application of our results to forward-rapidity production at RHIC energy shows that, in general, recoil effects are large and that the forward rapidity region at RHIC is rather different from the central region at LHC, despite comparable gluon densities in the target. We show that both the quantum x-evolution of the high-density target as well as the DGLAP Q^2-evolution of the parton distribution and fragmentation functions are clearly seen in the BRAHMS data. This provides additional strong evidence for the Color Glass Condensate at RHIC. |
1705.10458 | Sukadev Sahoo | D. Banerjee and S. Sahoo | Analysis of ${\Lambda}_b\rightarrow{\Lambda}l^+ l^-$ rare decays in a
non-universal $Z'$ model | 20 pages, 7 figures, 3 tables, It is accepted and to be published in
Chinese Physics C | Chinese Physics C, Vol. 41, Issue. 8, pp. 083101 (10 pages August
2017) | 10.1088/1674-1137/41/8/083101 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the rare baryonic ${\Lambda}_b\rightarrow{\Lambda}l^+ l^-$
decays in a non-universal $Z'$ model, which is one of the well-motivated
extensions of the standard model (SM). Considering the effects of $Z'$-mediated
flavour-changing neutral currents (FCNCs) we analyse the differential decay
rate, forward-backward asymmetries and lepton polarisation asymmetries for the
${\Lambda}_b\rightarrow{\Lambda}l^+ l^-$ decays. We find significant deviations
from their SM predictions, which could indicate new physics arising from the
$Z'$ gauge boson.
| [
{
"created": "Tue, 30 May 2017 05:31:10 GMT",
"version": "v1"
}
] | 2017-12-18 | [
[
"Banerjee",
"D.",
""
],
[
"Sahoo",
"S.",
""
]
] | We investigate the rare baryonic ${\Lambda}_b\rightarrow{\Lambda}l^+ l^-$ decays in a non-universal $Z'$ model, which is one of the well-motivated extensions of the standard model (SM). Considering the effects of $Z'$-mediated flavour-changing neutral currents (FCNCs) we analyse the differential decay rate, forward-backward asymmetries and lepton polarisation asymmetries for the ${\Lambda}_b\rightarrow{\Lambda}l^+ l^-$ decays. We find significant deviations from their SM predictions, which could indicate new physics arising from the $Z'$ gauge boson. |
2405.18054 | Andrei Prokhorov | S.P. Baranov, A.V. Lipatov, M.A. Malyshev, A.A. Prokhorov, P.M. Zhang | Forward $J/\psi + J/\psi$ and $J/\psi + \psi^\prime$ production with
High Energy Factorization | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We calculate the cross sections of associated $J/\psi + \psi^\prime$ and
$J/\psi + J/\psi$ production in $pp$ collisions at $\sqrt s = 13$ TeV in the
forward kinematic region. The High Energy Factorization ($k_T$-factorization)
framework supplemented with the Catani-Ciafaloni-Fiorani-Marchesini evolution
of gluon densities in a proton is applied. We demonstrate that latest data on
$J/\psi + J/\psi$ production and first experimental data on $J/\psi +
\psi^\prime$ events taken very recently by the LHCb Collaboration can be
described well by the color singlet terms and contributions from the double
parton scattering (DPS) with the standard choice for $\sigma_{\rm eff}$
parameter. The relative production rate $\sigma(J/\psi +
\psi^\prime)/\sigma(J/\psi + J/\psi)$ is found to be sensitive to the DPS terms
as well as to feeddown contributions.
| [
{
"created": "Tue, 28 May 2024 11:09:37 GMT",
"version": "v1"
}
] | 2024-05-29 | [
[
"Baranov",
"S. P.",
""
],
[
"Lipatov",
"A. V.",
""
],
[
"Malyshev",
"M. A.",
""
],
[
"Prokhorov",
"A. A.",
""
],
[
"Zhang",
"P. M.",
""
]
] | We calculate the cross sections of associated $J/\psi + \psi^\prime$ and $J/\psi + J/\psi$ production in $pp$ collisions at $\sqrt s = 13$ TeV in the forward kinematic region. The High Energy Factorization ($k_T$-factorization) framework supplemented with the Catani-Ciafaloni-Fiorani-Marchesini evolution of gluon densities in a proton is applied. We demonstrate that latest data on $J/\psi + J/\psi$ production and first experimental data on $J/\psi + \psi^\prime$ events taken very recently by the LHCb Collaboration can be described well by the color singlet terms and contributions from the double parton scattering (DPS) with the standard choice for $\sigma_{\rm eff}$ parameter. The relative production rate $\sigma(J/\psi + \psi^\prime)/\sigma(J/\psi + J/\psi)$ is found to be sensitive to the DPS terms as well as to feeddown contributions. |
2407.13385 | Weitao Ye | Zhaofeng Kang, Tianjun Li and Weitao Ye | The Stochastic Gravitational Wave Background from Primordial
Gravitational Atoms | null | null | null | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose a scenario of primordial gravitational atoms (PGAs), which may
exist in the current and past universe due to spinning primordial black holes
(PBHs) and very light bosonic fields. In a monochromatic mass scenario with a
sizable dimensionless spin, which may arise in a short matter dominated (MD)
era, we analyze the resulting stochastic gravitational wave background (SGWB)
signal. Its spectrum is approximately characterized by a rising $\propto f^3$
followed by a falling $\propto f^{-1}$ where $f$ is the frequency. Then, we
investigate the constraints and prospects of such a SGWB, and find that PGAs
with a core mass $M_{\rm BH}\sim {\cal O}(10)~M_{\odot}$ and a cloud of light
scalar with mass $\mu \sim {\cal O} (10^{-13})$ eV could yield constraints even
stronger than those from bare PBHs. Future detectors such as LISA, Taiji and
TianQin are able to explore PGAs over a narrow and elongated strap in the
$(\mu,M_{\rm BH})$ plane, spanning over 10 orders of magnitude for the maximum
spin, $10^{-8}~M_{\odot}\lesssim M_{\rm BH}\lesssim 10^4~M_{\odot}$,
$10^{-16}~{\rm eV}\lesssim \mu\lesssim 10^{-3}~\rm eV$. If the PGA is dressed
with a vector cloud, the SGWB signal has a much better opportunity to be
probed.
| [
{
"created": "Thu, 18 Jul 2024 10:43:32 GMT",
"version": "v1"
}
] | 2024-07-22 | [
[
"Kang",
"Zhaofeng",
""
],
[
"Li",
"Tianjun",
""
],
[
"Ye",
"Weitao",
""
]
] | We propose a scenario of primordial gravitational atoms (PGAs), which may exist in the current and past universe due to spinning primordial black holes (PBHs) and very light bosonic fields. In a monochromatic mass scenario with a sizable dimensionless spin, which may arise in a short matter dominated (MD) era, we analyze the resulting stochastic gravitational wave background (SGWB) signal. Its spectrum is approximately characterized by a rising $\propto f^3$ followed by a falling $\propto f^{-1}$ where $f$ is the frequency. Then, we investigate the constraints and prospects of such a SGWB, and find that PGAs with a core mass $M_{\rm BH}\sim {\cal O}(10)~M_{\odot}$ and a cloud of light scalar with mass $\mu \sim {\cal O} (10^{-13})$ eV could yield constraints even stronger than those from bare PBHs. Future detectors such as LISA, Taiji and TianQin are able to explore PGAs over a narrow and elongated strap in the $(\mu,M_{\rm BH})$ plane, spanning over 10 orders of magnitude for the maximum spin, $10^{-8}~M_{\odot}\lesssim M_{\rm BH}\lesssim 10^4~M_{\odot}$, $10^{-16}~{\rm eV}\lesssim \mu\lesssim 10^{-3}~\rm eV$. If the PGA is dressed with a vector cloud, the SGWB signal has a much better opportunity to be probed. |
2301.08152 | Oleg Boyarkin | O. M. Boyarkin and I. O. Boyarkina | Neutrino oscillations in vortex and twisting magnetic fields | 25 pages | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The behavior of the neutrino flux in vortex and twisting magnetic fields is
considered within the left-right symmetric model. By way of illustration of the
magnetic fields we discuss the magnetic fields of the coupled sunspots (CS's)
which are the sources of the future solar flares. It is expected that the
neutrinos have such multipole moments as the charge radius, the magnetic and
anapole moments. The evolution equation in the Schrodinger-like form is found
and all magnetic-induced resonance conversions are analyzed. It is demonstrated
that in the case of the high-energy flares the sizeable depletion of the
$\nu_{eL}$ neutrinos caused by their resonance absorptions takes place.
Possibilities of observations of this phenomena are investigated at neutrino
telescopes whose work is based on the reaction of the coherent elastic
neutrino-nucleus scattering.
| [
{
"created": "Thu, 19 Jan 2023 16:14:27 GMT",
"version": "v1"
},
{
"created": "Mon, 23 Jan 2023 13:19:12 GMT",
"version": "v2"
},
{
"created": "Sat, 15 Jul 2023 17:59:41 GMT",
"version": "v3"
}
] | 2023-07-18 | [
[
"Boyarkin",
"O. M.",
""
],
[
"Boyarkina",
"I. O.",
""
]
] | The behavior of the neutrino flux in vortex and twisting magnetic fields is considered within the left-right symmetric model. By way of illustration of the magnetic fields we discuss the magnetic fields of the coupled sunspots (CS's) which are the sources of the future solar flares. It is expected that the neutrinos have such multipole moments as the charge radius, the magnetic and anapole moments. The evolution equation in the Schrodinger-like form is found and all magnetic-induced resonance conversions are analyzed. It is demonstrated that in the case of the high-energy flares the sizeable depletion of the $\nu_{eL}$ neutrinos caused by their resonance absorptions takes place. Possibilities of observations of this phenomena are investigated at neutrino telescopes whose work is based on the reaction of the coherent elastic neutrino-nucleus scattering. |
2001.00175 | Xiang Liu | Jun-Zhang Wang, Ri-Qing Qian, Xiang Liu and Takayuki Matsuki | Are the $Y$ states around 4.6 GeV from $e^+e^-$ annihilation higher
charmonia? | 11 pages, 4 tables and 8 figures. More discussions and references
added. Accepted by Phys. Rev. D | Phys. Rev. D 101, 034001 (2020) | 10.1103/PhysRevD.101.034001 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work, we present the mass spectrum of higher charomona around and
above 4.6 GeV by adopting the unquenched potential model. We perform a combined
fit to the updated experimental data of $e^+e^- \to \psi(2S)\pi^+\pi^-$ and
$e^+e^-\to \Lambda_c\bar{\Lambda}_c$. To understand the "platform" structure
observed in the range of $4.57 \sim 4.60$ GeV existing in the
$\Lambda_c\bar{\Lambda}_c$ invariant mass spectrum of $e^+e^-\to
\Lambda_c\bar{\Lambda}_c$ of BESIII, we introduce two resonances in this
combined fit to the $e^+e^- \to \psi(2S)\pi^+\pi^-$ and $e^+e^-\to
\Lambda_c\bar{\Lambda}_c$, which have resonance parameters, $m_{Y_1}=4585\pm2$
MeV, $\Gamma_{Y_1}=29.8\pm8.0$ MeV, $m_{Y_2}=4676\pm7$ MeV, and
$\Gamma_{Y_2}=85.7\pm15.0$ MeV. Furthermore, combining with our theoretical
results, we indicate that the two charmonium-like $Y$ states can be due to two
higher charmonia, which are mixtures of $6S$ and $5D$ $c\bar{c}$ states. Their
two-body open-charm decay behaviors are given. Under the same framework, our
analysis of the data of $e^+e^-\to D_{s}^+D_{s1}(2536)^-$ recently released by
Belle supports to introduce these two higher charmonia around 4.6 GeV.
Additionally, we predict the masses and two-body open-charm decays of six
higher charmonia $\psi(nS)$ and $\psi(mD)$ with $n=7,8,9$ and $m=6,7,8$ above
4.6 GeV. Search for these higher charmonia will be an interesting issue for the
running BESIII and BelleII, and even the possible Super Tau-Charm Factory
discussed in China.
| [
{
"created": "Wed, 1 Jan 2020 09:33:20 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Jan 2020 02:25:44 GMT",
"version": "v2"
}
] | 2020-02-06 | [
[
"Wang",
"Jun-Zhang",
""
],
[
"Qian",
"Ri-Qing",
""
],
[
"Liu",
"Xiang",
""
],
[
"Matsuki",
"Takayuki",
""
]
] | In this work, we present the mass spectrum of higher charomona around and above 4.6 GeV by adopting the unquenched potential model. We perform a combined fit to the updated experimental data of $e^+e^- \to \psi(2S)\pi^+\pi^-$ and $e^+e^-\to \Lambda_c\bar{\Lambda}_c$. To understand the "platform" structure observed in the range of $4.57 \sim 4.60$ GeV existing in the $\Lambda_c\bar{\Lambda}_c$ invariant mass spectrum of $e^+e^-\to \Lambda_c\bar{\Lambda}_c$ of BESIII, we introduce two resonances in this combined fit to the $e^+e^- \to \psi(2S)\pi^+\pi^-$ and $e^+e^-\to \Lambda_c\bar{\Lambda}_c$, which have resonance parameters, $m_{Y_1}=4585\pm2$ MeV, $\Gamma_{Y_1}=29.8\pm8.0$ MeV, $m_{Y_2}=4676\pm7$ MeV, and $\Gamma_{Y_2}=85.7\pm15.0$ MeV. Furthermore, combining with our theoretical results, we indicate that the two charmonium-like $Y$ states can be due to two higher charmonia, which are mixtures of $6S$ and $5D$ $c\bar{c}$ states. Their two-body open-charm decay behaviors are given. Under the same framework, our analysis of the data of $e^+e^-\to D_{s}^+D_{s1}(2536)^-$ recently released by Belle supports to introduce these two higher charmonia around 4.6 GeV. Additionally, we predict the masses and two-body open-charm decays of six higher charmonia $\psi(nS)$ and $\psi(mD)$ with $n=7,8,9$ and $m=6,7,8$ above 4.6 GeV. Search for these higher charmonia will be an interesting issue for the running BESIII and BelleII, and even the possible Super Tau-Charm Factory discussed in China. |
hep-ph/0303098 | C. Pallis | C. Pallis and M.E. Gomez | Yukawa Quasi-Unification and Neutralino Relic Density | null | null | null | SISSA-19/2003/EP | hep-ph | null | The construction of a Supersymmetric Grand Unified Model based on the
Pati-Salam gauge group is briefly reviewed and the low energy consequences of
the derived asymptotic Yukawa quasi-unification conditions are examined. In the
framework of the resulting Constrained Minimal Supersymmetric Standard Model,
the cosmological relic density of the bino-like LSP is calculated and the
results are explicitly compared with {\tt micrOMEGAs}. In addition to the Cold
Dark Matter constraint, restrictions on the parameter space, arising from the
Higgs boson masses, the SUSY corrections to $b$-quark mass, the muon anomalous
magnetic moment and the inclusive decay $b\to s\gamma$ are, also, investigated.
For $\mu>0$, a wide and natural range of parameters is allowed. On the
contrary, the $\mu<0$ case not only is disfavored from the present experimental
data on the muon anomalous magnetic moment, but also, it can be excluded from
the combination of the Cold Dark Matter and BR($b\to s \gamma$) requirements.
| [
{
"created": "Wed, 12 Mar 2003 18:15:27 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Pallis",
"C.",
""
],
[
"Gomez",
"M. E.",
""
]
] | The construction of a Supersymmetric Grand Unified Model based on the Pati-Salam gauge group is briefly reviewed and the low energy consequences of the derived asymptotic Yukawa quasi-unification conditions are examined. In the framework of the resulting Constrained Minimal Supersymmetric Standard Model, the cosmological relic density of the bino-like LSP is calculated and the results are explicitly compared with {\tt micrOMEGAs}. In addition to the Cold Dark Matter constraint, restrictions on the parameter space, arising from the Higgs boson masses, the SUSY corrections to $b$-quark mass, the muon anomalous magnetic moment and the inclusive decay $b\to s\gamma$ are, also, investigated. For $\mu>0$, a wide and natural range of parameters is allowed. On the contrary, the $\mu<0$ case not only is disfavored from the present experimental data on the muon anomalous magnetic moment, but also, it can be excluded from the combination of the Cold Dark Matter and BR($b\to s \gamma$) requirements. |
1909.02018 | Vedran Brdar | Vedran Brdar, Lukas Graf, Alexander J. Helmboldt, Xun-Jie Xu | Gravitational Waves as a Probe of Left-Right Symmetry Breaking | 21 pages, 3 figures | JCAP12(2019)027 | 10.1088/1475-7516/2019/12/027 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Left-right symmetry at high energy scales is a well-motivated extension of
the Standard Model. In this paper we consider a typical minimal scenario in
which it gets spontaneously broken by scalar triplets. Such a realization has
been scrutinized over the past few decades chiefly in the context of collider
studies. In this work we take a complementary approach and investigate whether
the model can be probed via the search for a stochastic gravitational wave
background induced by the phase transition in which $SU(3)_C \times SU(2)_L
\times SU(2)_R \times U(1)_{B-L}$ is broken down to the Standard Model gauge
symmetry group. A prerequisite for gravitational wave production in this
context is a first-order phase transition, the occurrence of which we find in a
significant portion of the parameter space. Although the produced gravitational
waves are typically too weak for a discovery at any current or future detector,
upon investigating correlations between all relevant terms in the scalar
potential, we have identified values of parameters leading to observable
signals. This indicates that, given a certain moderate fine-tuning, the minimal
left-right symmetric model with scalar triplets features another powerful probe
which can lead to either novel constraints or remarkable discoveries in the
near future. Let us note that some of our results, such as the full set of
thermal masses, have to the best of our knowledge not been presented before and
might be useful for future studies, in particular in the context of electroweak
baryogenesis.
| [
{
"created": "Wed, 4 Sep 2019 18:00:06 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Dec 2019 16:50:29 GMT",
"version": "v2"
}
] | 2019-12-10 | [
[
"Brdar",
"Vedran",
""
],
[
"Graf",
"Lukas",
""
],
[
"Helmboldt",
"Alexander J.",
""
],
[
"Xu",
"Xun-Jie",
""
]
] | Left-right symmetry at high energy scales is a well-motivated extension of the Standard Model. In this paper we consider a typical minimal scenario in which it gets spontaneously broken by scalar triplets. Such a realization has been scrutinized over the past few decades chiefly in the context of collider studies. In this work we take a complementary approach and investigate whether the model can be probed via the search for a stochastic gravitational wave background induced by the phase transition in which $SU(3)_C \times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ is broken down to the Standard Model gauge symmetry group. A prerequisite for gravitational wave production in this context is a first-order phase transition, the occurrence of which we find in a significant portion of the parameter space. Although the produced gravitational waves are typically too weak for a discovery at any current or future detector, upon investigating correlations between all relevant terms in the scalar potential, we have identified values of parameters leading to observable signals. This indicates that, given a certain moderate fine-tuning, the minimal left-right symmetric model with scalar triplets features another powerful probe which can lead to either novel constraints or remarkable discoveries in the near future. Let us note that some of our results, such as the full set of thermal masses, have to the best of our knowledge not been presented before and might be useful for future studies, in particular in the context of electroweak baryogenesis. |
hep-ph/9910400 | Alexander Belyaev | A.Belyaev, M.Drees, O.J.P Eboli, J.K. Mizukoshi, S.F. Novaes | Supersymmetric Higgs pair discovery prospects at hadron colliders | 5 pages, hep99, 6 figures; Presented at the International Europhysics
Conference on High Energy Physics, Tampere, Finland, 15-21 July 1999 | null | null | CERN-TH/99-325 | hep-ph | null | We study the potential of hadron colliders in the search for the pair
production of neutral Higgs bosons in the framework of the Minimal
Supersymmetric Standard Model. Using analytical expressions for the relevant
amplitudes, we perform a detailed signal and background analysis, working out
efficient kinematical cuts for the extraction of the signal. The important role
of squark loop contributions to the signal is emphasised. If the signal is
sufficiently enhanced by these contributions, it could even be observable at
the next run of the upgraded Tevatron collider in the near future. At the LHC
the pair production of light and heavy Higgs bosons might be detectable
simultaneously.
| [
{
"created": "Tue, 19 Oct 1999 10:51:08 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Nov 1999 13:30:52 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Belyaev",
"A.",
""
],
[
"Drees",
"M.",
""
],
[
"Eboli",
"O. J. P",
""
],
[
"Mizukoshi",
"J. K.",
""
],
[
"Novaes",
"S. F.",
""
]
] | We study the potential of hadron colliders in the search for the pair production of neutral Higgs bosons in the framework of the Minimal Supersymmetric Standard Model. Using analytical expressions for the relevant amplitudes, we perform a detailed signal and background analysis, working out efficient kinematical cuts for the extraction of the signal. The important role of squark loop contributions to the signal is emphasised. If the signal is sufficiently enhanced by these contributions, it could even be observable at the next run of the upgraded Tevatron collider in the near future. At the LHC the pair production of light and heavy Higgs bosons might be detectable simultaneously. |
0711.3069 | Artem Lipatov | A.V. Lipatov, N.P. Zotov | Beauty production in two-photon interactions at LEP2: kt-factorization
versus data | 10 pages, 4 figures | JETP Lett.87:7-11,2008 | 10.1007/s11448-008-1003-y | null | hep-ph | null | Inclusive beauty quark production in photon-photon collisions at CERN LEP2 is
considered in the framework of the kt-factorization approach. Both direct and
resolved photon contributions are taken into account. The unintegrated gluon
distributions in a photon are either obtained from the full CCFM evolution
equation or from the Kimber-Martin-Ryskin prescription. The predicted beauty
cross section reasonably agrees with the recent experimental data taken by the
ALEPH collaboration. We argue that theoretical and experimental studies of the
azimuthal correlations in heavy quark production at high energies can serve as
a crucial probe of the unintegrated gluon densities.
| [
{
"created": "Tue, 20 Nov 2007 06:44:30 GMT",
"version": "v1"
}
] | 2011-03-23 | [
[
"Lipatov",
"A. V.",
""
],
[
"Zotov",
"N. P.",
""
]
] | Inclusive beauty quark production in photon-photon collisions at CERN LEP2 is considered in the framework of the kt-factorization approach. Both direct and resolved photon contributions are taken into account. The unintegrated gluon distributions in a photon are either obtained from the full CCFM evolution equation or from the Kimber-Martin-Ryskin prescription. The predicted beauty cross section reasonably agrees with the recent experimental data taken by the ALEPH collaboration. We argue that theoretical and experimental studies of the azimuthal correlations in heavy quark production at high energies can serve as a crucial probe of the unintegrated gluon densities. |
0810.0020 | Pavel Nadolsky | Edmond L. Berger, Pavel M. Nadolsky | Longitudinal parity-violating asymmetry in hadronic decays of weak
bosons in polarized proton collisions | 16 pages, 6 figures; accepted by Phys. Rev. D; extended discussion of
the sensitivity of A_L to the down-type antiquark PDF and other minor
modifications | Phys.Rev.D78:114010,2008 | 10.1103/PhysRevD.78.114010 | ANL-HEP-PR-08-59, NSF-KITP-08-46, SMU-HEP-08-16 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the possible measurement of parity-violating spin asymmetries
in jet pair production in proton-proton collisions at the Brookhaven
Relativistic Heavy Ion Collider (RHIC), with the goal to constrain
longitudinally polarized quark and antiquark distribution functions. A
measurable asymmetry could be observed in the vicinity of the massive weak W
boson resonance, where the parity-violating signal appears above the
parity-conserving background and is enhanced by interference of the strong and
electroweak production amplitudes. We discuss the potential for such
measurements, perhaps the first opportunity to measure a parity-violating
asymmetry in proton-proton collisions at RHIC. Sensitivity of this measurement
to the polarization of down-type antiquarks is demonstrated.
| [
{
"created": "Wed, 1 Oct 2008 17:48:32 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Nov 2008 17:49:41 GMT",
"version": "v2"
}
] | 2008-12-30 | [
[
"Berger",
"Edmond L.",
""
],
[
"Nadolsky",
"Pavel M.",
""
]
] | We investigate the possible measurement of parity-violating spin asymmetries in jet pair production in proton-proton collisions at the Brookhaven Relativistic Heavy Ion Collider (RHIC), with the goal to constrain longitudinally polarized quark and antiquark distribution functions. A measurable asymmetry could be observed in the vicinity of the massive weak W boson resonance, where the parity-violating signal appears above the parity-conserving background and is enhanced by interference of the strong and electroweak production amplitudes. We discuss the potential for such measurements, perhaps the first opportunity to measure a parity-violating asymmetry in proton-proton collisions at RHIC. Sensitivity of this measurement to the polarization of down-type antiquarks is demonstrated. |
hep-ph/9902478 | Asakawa Eri | Eri Asakawa, Miho Marui, Noriyuki Oshimo, Tomomi Saito, and Akio
Sugamoto | CP-odd WWZ couplings induced by vector-like quarks | 13 pages, 3 Postscript figures, figure sizes changed | Eur.Phys.J.C10:327-330,1999 | 10.1007/s100529900117 | ICRR-Report-448-99-6, OCHA-PP-132, KURE-PP/99-01 | hep-ph | null | A minimal extension of the standard model includes extra quarks with charges
2/3 and/or -1/3, whose left-handed and right-handed components are both SU(2)
singlets. This model predicts new interactions of flavor-changing neutral
current at the tree level, which also violate CP invariance. We study CP-odd
anomalous couplings for the gauge bosons W, W, and Z induced by the new
interactions at the one-loop level. These couplings become nonnegligible only
if both an up-type and a down-type extra quarks are incorporated. Their form
factors are estimated to be maximally of order $10^{-5}$. Such magnitudes are
larger than those predicted in the standard model, though smaller than those in
certain other models.
| [
{
"created": "Fri, 26 Feb 1999 12:01:10 GMT",
"version": "v1"
},
{
"created": "Sat, 13 Mar 1999 09:44:01 GMT",
"version": "v2"
}
] | 2011-09-13 | [
[
"Asakawa",
"Eri",
""
],
[
"Marui",
"Miho",
""
],
[
"Oshimo",
"Noriyuki",
""
],
[
"Saito",
"Tomomi",
""
],
[
"Sugamoto",
"Akio",
""
]
] | A minimal extension of the standard model includes extra quarks with charges 2/3 and/or -1/3, whose left-handed and right-handed components are both SU(2) singlets. This model predicts new interactions of flavor-changing neutral current at the tree level, which also violate CP invariance. We study CP-odd anomalous couplings for the gauge bosons W, W, and Z induced by the new interactions at the one-loop level. These couplings become nonnegligible only if both an up-type and a down-type extra quarks are incorporated. Their form factors are estimated to be maximally of order $10^{-5}$. Such magnitudes are larger than those predicted in the standard model, though smaller than those in certain other models. |
1609.08847 | Oleg Selyugin | O.V. Selyugin | The energy dependence of the diffraction minimum in the elastic
scattering and new LHC data | 10 pages, 3 Tables, 8 figures (add the journal reference) | Nucl.Phys. A 959 (2017) 116-128 | 10.1016/j.nuclphysa.2017.01.002 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The soft diffraction phenomena in the elastic proton-proton scattering are
reviewed from the viewpoint of experiments at the LHC (TOTEM and ATLAS
collaboration). In the framework of the High Energy Generalized Structure
(HEGS) model the form of the diffraction minimum in the nucleon-nucleon elastic
scattering in a wide energy region is analyzed. The energy dependences of the
main characteristics of the diffraction dip are obtained. The numerical
predictions at LHC energies are presented. The comparison of the model
predictions with the new LHC data at $\sqrt{s}=13$ TeV is made.
| [
{
"created": "Wed, 28 Sep 2016 10:12:28 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Oct 2016 11:00:32 GMT",
"version": "v2"
},
{
"created": "Mon, 14 Nov 2016 10:16:32 GMT",
"version": "v3"
},
{
"created": "Thu, 12 Jan 2017 11:08:14 GMT",
"version": "v4"
},
{
"created": "Fri, 14 Apr 2017 09:28:50 GMT",
"version": "v5"
}
] | 2017-04-17 | [
[
"Selyugin",
"O. V.",
""
]
] | The soft diffraction phenomena in the elastic proton-proton scattering are reviewed from the viewpoint of experiments at the LHC (TOTEM and ATLAS collaboration). In the framework of the High Energy Generalized Structure (HEGS) model the form of the diffraction minimum in the nucleon-nucleon elastic scattering in a wide energy region is analyzed. The energy dependences of the main characteristics of the diffraction dip are obtained. The numerical predictions at LHC energies are presented. The comparison of the model predictions with the new LHC data at $\sqrt{s}=13$ TeV is made. |
1108.4903 | Alessandro Strumia | Martti Raidal and Alessandro Strumia | Hints for a non-standard Higgs boson from the LHC | 6 pages, 2 figures. Final version to appear on PRD | null | 10.1103/PhysRevD.84.077701 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We reconsider Higgs boson invisible decays into Dark Matter in the light of
recent Higgs searches at the LHC. Present hints in the CMS and ATLAS data favor
a non-standard Higgs boson with approximately 50% invisible branching ratio,
and mass around 143 GeV. This situation can be realized within the simplest
thermal scalar singlet Dark Matter model, predicting a Dark Matter mass around
50 GeV and direct detection cross section just below present bound. The present
runs of the Xenon100 and LHC experiments can test this possibility.
| [
{
"created": "Wed, 24 Aug 2011 18:20:03 GMT",
"version": "v1"
},
{
"created": "Sat, 24 Sep 2011 19:10:18 GMT",
"version": "v2"
}
] | 2015-05-30 | [
[
"Raidal",
"Martti",
""
],
[
"Strumia",
"Alessandro",
""
]
] | We reconsider Higgs boson invisible decays into Dark Matter in the light of recent Higgs searches at the LHC. Present hints in the CMS and ATLAS data favor a non-standard Higgs boson with approximately 50% invisible branching ratio, and mass around 143 GeV. This situation can be realized within the simplest thermal scalar singlet Dark Matter model, predicting a Dark Matter mass around 50 GeV and direct detection cross section just below present bound. The present runs of the Xenon100 and LHC experiments can test this possibility. |
0907.5159 | Mingzhe Li | Mingzhe Li, Yi-Fu Cai, Xiulian Wang, Xinmin Zhang | $CPT$ Violating Electrodynamics and Chern-Simons Modified Gravity | 11 pages, 1 figure, the version to appear in Physics Letters B | Phys.Lett.B680:118-124,2009 | 10.1016/j.physletb.2009.08.053 | null | hep-ph astro-ph.CO gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The electrodynamics with a Chern-Simons term
$p_{\mu}A_{\nu}\widetilde{F}^{\mu\nu}$ violates Lorentz and $CPT$ symmetries
with a non-vanishing $p_{\mu}$. For a fixed vector $p_{\mu}$, in this paper we
point out that the energy-momentum tensor of this theory coupled to the gravity
minimally is symmetric but not divergence free, which consequently makes the
gravitational field equation inconsistent. To preserve the consistency, we
introduce a Chern-Simons term in the gravity sector with the coefficient
determined by the Lorentz and $CPT$ violating term in the electromagnetic
field. Further we study the phenomenologies of the model on the cosmic
microwave background radiation and the relic gravitational waves.
| [
{
"created": "Wed, 29 Jul 2009 15:32:36 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Aug 2009 03:49:53 GMT",
"version": "v2"
}
] | 2009-10-16 | [
[
"Li",
"Mingzhe",
""
],
[
"Cai",
"Yi-Fu",
""
],
[
"Wang",
"Xiulian",
""
],
[
"Zhang",
"Xinmin",
""
]
] | The electrodynamics with a Chern-Simons term $p_{\mu}A_{\nu}\widetilde{F}^{\mu\nu}$ violates Lorentz and $CPT$ symmetries with a non-vanishing $p_{\mu}$. For a fixed vector $p_{\mu}$, in this paper we point out that the energy-momentum tensor of this theory coupled to the gravity minimally is symmetric but not divergence free, which consequently makes the gravitational field equation inconsistent. To preserve the consistency, we introduce a Chern-Simons term in the gravity sector with the coefficient determined by the Lorentz and $CPT$ violating term in the electromagnetic field. Further we study the phenomenologies of the model on the cosmic microwave background radiation and the relic gravitational waves. |
hep-ph/0011159 | Gary Felder | Gary Felder and Igor Tkachev | LATTICEEASY: A Program for Lattice Simulations of Scalar Fields in an
Expanding Universe | 4 pages, 2 figures | Comput.Phys.Commun.178:929-932.2008 | 10.1016/j.cpc.2008.02.009 | null | hep-ph gr-qc hep-lat hep-th | null | We describe a C++ program that we have written and made available for
calculating the evolution of interacting scalar fields in an expanding
universe. The program is particularly useful for the study of reheating and
thermalization after inflation. The program and its full documentation are
available on the Web at http://physics.stanford.edu/gfelder/latticeeasy/ . In
this paper we provide a brief overview of what the program does and what it is
useful for.
| [
{
"created": "Mon, 13 Nov 2000 16:59:24 GMT",
"version": "v1"
}
] | 2010-11-11 | [
[
"Felder",
"Gary",
""
],
[
"Tkachev",
"Igor",
""
]
] | We describe a C++ program that we have written and made available for calculating the evolution of interacting scalar fields in an expanding universe. The program is particularly useful for the study of reheating and thermalization after inflation. The program and its full documentation are available on the Web at http://physics.stanford.edu/gfelder/latticeeasy/ . In this paper we provide a brief overview of what the program does and what it is useful for. |
1303.2917 | Leo Stodolsky | Leo Stodolsky | Observability of`Cascade Mixing' in B0 --> J/psi K0 | 21 pages, 3 tables, no figures, many small corrections and
improvements, notation for m_k made consistent. One substantive change: sign
of Eq 51, corresponding element in Table 3 changed | null | 10.1103/PhysRevD.87.096007 | null | hep-ph quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In high statistics observations of B^o --> J/\psi K0, originating from the
process Upsilon(4S)--> B0 B0, it should be possible to observe `cascade
mixing', where one mixing particle, the B0, turns into another, the K0. This is
possible despite the difficulty that the length of the beam crossing region
makes a precise definition of the primary vertex impossible. This difficulty is
circumvented by using an `away side' tag to specify the initial time. We review
the formalism for describing such processes, and first apply it to simple B0
mixing, noting it gives a transparent description for CP and T asymmetries. In
particular we show that three different asymmetries of the CP and T type, with
neglect of direct CP violation, are given by the same expression.
For "cascade mixing" we present predictions for processes of the type B_i -->
K_j via J/psi, where in the limit of no direct CP violation each state i or j
is determined by a simple tag. There are 16 such simple measureable processes,
involving 10 functions of the two time intervals involved. The coefficients of
the functions are different for each of the processes and are given in terms of
the mass splitting and the CP, T violating parameter of the B0 mass matrix m_2.
The results presented here are just consquences of the quantum mechanics of
particle mixing and do not involve any particular model of CP violation.
| [
{
"created": "Tue, 12 Mar 2013 15:35:11 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Apr 2013 10:03:26 GMT",
"version": "v2"
}
] | 2013-05-22 | [
[
"Stodolsky",
"Leo",
""
]
] | In high statistics observations of B^o --> J/\psi K0, originating from the process Upsilon(4S)--> B0 B0, it should be possible to observe `cascade mixing', where one mixing particle, the B0, turns into another, the K0. This is possible despite the difficulty that the length of the beam crossing region makes a precise definition of the primary vertex impossible. This difficulty is circumvented by using an `away side' tag to specify the initial time. We review the formalism for describing such processes, and first apply it to simple B0 mixing, noting it gives a transparent description for CP and T asymmetries. In particular we show that three different asymmetries of the CP and T type, with neglect of direct CP violation, are given by the same expression. For "cascade mixing" we present predictions for processes of the type B_i --> K_j via J/psi, where in the limit of no direct CP violation each state i or j is determined by a simple tag. There are 16 such simple measureable processes, involving 10 functions of the two time intervals involved. The coefficients of the functions are different for each of the processes and are given in terms of the mass splitting and the CP, T violating parameter of the B0 mass matrix m_2. The results presented here are just consquences of the quantum mechanics of particle mixing and do not involve any particular model of CP violation. |
hep-ph/9706280 | J. L. Chkareuli | Jon Chkareuli | Natural Flavour-Unifying GUTs: SU(8) | 9 pages, LaTeX, Talk given at the Trieste Conference on Quarks and
Leptons: Masses and Mixings (Trieste, October 7-11, 1996) | null | null | IOP-TH-97/12 | hep-ph | null | Some implications of flavour unification in supersymmetric Grand Unified
Theories are briefly reviewed. We argue that the gauge hierarchy phenomenon
properly interpreted in terms of the natural missing VEV solution for the
adjoint scalar in general SU(N) SUSY GUT could give insight into both of the
basic features of low-energy physics accommodated in MSSM just as some strict
colour-flavour (or colour-family) interrelation, so the SU(2) symmetry
structure of weak interactions. There, apart from the ordinary triple matter of
MSSM, just three families of the pseudo-Goldstone states appear in the minimal
SU(8) theory to be of necessity detected at a TeV scale.
| [
{
"created": "Sat, 7 Jun 1997 16:55:30 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Chkareuli",
"Jon",
""
]
] | Some implications of flavour unification in supersymmetric Grand Unified Theories are briefly reviewed. We argue that the gauge hierarchy phenomenon properly interpreted in terms of the natural missing VEV solution for the adjoint scalar in general SU(N) SUSY GUT could give insight into both of the basic features of low-energy physics accommodated in MSSM just as some strict colour-flavour (or colour-family) interrelation, so the SU(2) symmetry structure of weak interactions. There, apart from the ordinary triple matter of MSSM, just three families of the pseudo-Goldstone states appear in the minimal SU(8) theory to be of necessity detected at a TeV scale. |
hep-ph/9910351 | Amir Fariborz | Deirdre Black, Amir H. Fariborz, Joseph Schechter | Chiral Lagrangian treatment of pi eta scattering | 29 pages, 15 figures | Phys.Rev.D61:074030,2000 | 10.1103/PhysRevD.61.074030 | SU-4240-711 | hep-ph | null | We study pi eta scattering in a model which starts from the tree diagrams of
a non-linear chiral Lagrangian including appropriate resonances. Previously,
models of this type were applied to pi pi and pi K scattering and were seen to
require the existence of light scalar sigma(560) and kappa(900) mesons and to
be consistent with the f0(980). The present calculation extends this to include
the a0(980), thereby completing a possible nonet of light scalars, all ``seen''
in the same manner. We note that, at the initial level, the pi eta channel is
considerably cleaner than the pi pi and pi K channels for the study of light
scalars. This is because the large competing effects of vector meson exchange
and ``current-algebra'' contact terms are absent. The simplicity of this
channel enables us to demonstrate the closeness of our exactly crossing
symmetric amplitude to a related exactly unitary amplitude. The calculation is
also extended to higher energies in order to let us discuss the role played by
the a0(1450) resonance.
| [
{
"created": "Fri, 15 Oct 1999 00:41:52 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Black",
"Deirdre",
""
],
[
"Fariborz",
"Amir H.",
""
],
[
"Schechter",
"Joseph",
""
]
] | We study pi eta scattering in a model which starts from the tree diagrams of a non-linear chiral Lagrangian including appropriate resonances. Previously, models of this type were applied to pi pi and pi K scattering and were seen to require the existence of light scalar sigma(560) and kappa(900) mesons and to be consistent with the f0(980). The present calculation extends this to include the a0(980), thereby completing a possible nonet of light scalars, all ``seen'' in the same manner. We note that, at the initial level, the pi eta channel is considerably cleaner than the pi pi and pi K channels for the study of light scalars. This is because the large competing effects of vector meson exchange and ``current-algebra'' contact terms are absent. The simplicity of this channel enables us to demonstrate the closeness of our exactly crossing symmetric amplitude to a related exactly unitary amplitude. The calculation is also extended to higher energies in order to let us discuss the role played by the a0(1450) resonance. |
hep-ph/9907565 | Don Colladay | Don Colladay | Possible Spontaneous Breaking of Lorentz and CPT Symmetry | Talk presented at Non-Accelerator New Physics, Dubna, Russia, July
1999 | Phys.Atom.Nucl.63:1097-1102,2000; Yad.Fiz.63N6:1172-1177,2000 | 10.1134/1.855753 | null | hep-ph | null | One possible ramification of unified theories of nature such as string theory
that may underlie the conventional standard model is the possible spontaneous
breakdown of Lorentz and CPT symmetry. In this talk, the formalism for
inclusion of such effects into a low-energy effective field theory is
presented. An extension of the standard model that includes Lorentz- and
CPT-breaking terms is developed. The restriction of the standard model
extension to the QED sector is then discussed.
| [
{
"created": "Fri, 30 Jul 1999 15:25:44 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Colladay",
"Don",
""
]
] | One possible ramification of unified theories of nature such as string theory that may underlie the conventional standard model is the possible spontaneous breakdown of Lorentz and CPT symmetry. In this talk, the formalism for inclusion of such effects into a low-energy effective field theory is presented. An extension of the standard model that includes Lorentz- and CPT-breaking terms is developed. The restriction of the standard model extension to the QED sector is then discussed. |
0705.4117 | Juan Antonio Aguilar-Saavedra | F. del Aguila, J. A. Aguilar-Saavedra | Like-sign dilepton signals from a leptophobic Z' boson | 19 pages, 11 PS figures. Paper significantly enlarged to include
analysis for LHC | JHEP 0711:072,2007 | 10.1088/1126-6708/2007/11/072 | null | hep-ph | null | A new leptophobic neutral gauge boson Z' with small mixing to the Z can have
a mass as light as M_Z' ~ 350 GeV, and still have escaped detection at LEP and
Tevatron. Such a Z' boson can be derived from E6 and, if the new heavy neutrino
singlets in the 27 representation are lighter than M_Z'/2, the process p
p(pbar) -> Z' -> NN -> l+- l+- X is observable. Indeed, this new signal could
explain the small excess of like-sign dileptons found at Tevatron. Implications
for LHC are also discussed. In particular, the Tevatron excess could be
confirmed with less than 1 fb-1, and leptophobic Z' masses up to 2.5 TeV can be
probed with 30 fb-1.
| [
{
"created": "Tue, 29 May 2007 18:22:06 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Oct 2007 10:05:38 GMT",
"version": "v2"
}
] | 2009-01-06 | [
[
"del Aguila",
"F.",
""
],
[
"Aguilar-Saavedra",
"J. A.",
""
]
] | A new leptophobic neutral gauge boson Z' with small mixing to the Z can have a mass as light as M_Z' ~ 350 GeV, and still have escaped detection at LEP and Tevatron. Such a Z' boson can be derived from E6 and, if the new heavy neutrino singlets in the 27 representation are lighter than M_Z'/2, the process p p(pbar) -> Z' -> NN -> l+- l+- X is observable. Indeed, this new signal could explain the small excess of like-sign dileptons found at Tevatron. Implications for LHC are also discussed. In particular, the Tevatron excess could be confirmed with less than 1 fb-1, and leptophobic Z' masses up to 2.5 TeV can be probed with 30 fb-1. |
0803.1592 | Guidal | M. Guidal | Discussion on the recent proton-DVCS results of Jefferson Lab | proceeding of the Photon2007 conference (International Conference on
the Structure and Interactions of the Photon, Paris 9-13 July 2007) | Nucl.Phys.Proc.Suppl.184:234-238,2008 | 10.1016/j.nuclphysbps.2008.09.171 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the recent data issued from the Halls A and B of Jefferson
Laboratory for the Deep Virtual Compton Scattering Process on the proton. An
important set of data for beam spin asymmetries, unpolarized cross sections and
differences of polarized cross sections have been obtained. We modestly attempt
a first "global" analysis of these three observables at a single $<x_B>$,
$<Q^2>$ and $<-t>$ kinematic point. We find that it is extremely challenging to
describe simultaneously these data in the framework of a few Generalized Parton
Distributions models.
| [
{
"created": "Tue, 11 Mar 2008 14:05:24 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Mar 2008 22:26:13 GMT",
"version": "v2"
}
] | 2008-12-18 | [
[
"Guidal",
"M.",
""
]
] | We present the recent data issued from the Halls A and B of Jefferson Laboratory for the Deep Virtual Compton Scattering Process on the proton. An important set of data for beam spin asymmetries, unpolarized cross sections and differences of polarized cross sections have been obtained. We modestly attempt a first "global" analysis of these three observables at a single $<x_B>$, $<Q^2>$ and $<-t>$ kinematic point. We find that it is extremely challenging to describe simultaneously these data in the framework of a few Generalized Parton Distributions models. |
hep-ph/9504419 | Valery Nazaruk | V.I.Nazaruk | Neutron-antineutron transitions | 8 pages, Text on pg.4 was slightly changed | null | null | INR-995 | hep-ph nucl-th | null | We confirm our previous limit on the free-space neutron-antineutron
oscillation time t>4.7*10**31 y. The approach is verified by the example of
exactly solvable model. We also discuss the all existing remarks. The approach
with finite time interval includes potential model as an extremely simplified
special case. It is shown that potential model is inapplicable to the problem
in hand because for antineutron-nucleus decay probability it gives W=2. In
particular, as we transparently show, this "decay law" (normalized by factor 2)
is used by Dover, Gal and Richard for refutation of our results.
| [
{
"created": "Thu, 27 Apr 1995 19:48:00 GMT",
"version": "v1"
},
{
"created": "Wed, 3 May 1995 19:13:00 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Nazaruk",
"V. I.",
""
]
] | We confirm our previous limit on the free-space neutron-antineutron oscillation time t>4.7*10**31 y. The approach is verified by the example of exactly solvable model. We also discuss the all existing remarks. The approach with finite time interval includes potential model as an extremely simplified special case. It is shown that potential model is inapplicable to the problem in hand because for antineutron-nucleus decay probability it gives W=2. In particular, as we transparently show, this "decay law" (normalized by factor 2) is used by Dover, Gal and Richard for refutation of our results. |
hep-ph/0510386 | J\"org Ruppert | Jorg Ruppert | Jet-medium interactions: wakes in the QCD medium | 4 pages, poster proceedings for Quark Matter 2005 | ActaPhys.Hung.A27:267-270,2006 | 10.1556/APH.27.2006.2-3.20 | null | hep-ph | null | We calculate the wake induced in a hot, dense QCD medium by a fast parton in
the framework of linear response theory. We discuss two different scenarios:
(i) a weakly coupled quark gluon plasma (pQGP) described by hard-thermal loop
(HTL) perturbation theory and (ii) a scenario where the plasma has the
properties of a quantum liquid. We show that Mach cones can appear in the
second scenario, but not in the first one.
| [
{
"created": "Fri, 28 Oct 2005 17:55:50 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Ruppert",
"Jorg",
""
]
] | We calculate the wake induced in a hot, dense QCD medium by a fast parton in the framework of linear response theory. We discuss two different scenarios: (i) a weakly coupled quark gluon plasma (pQGP) described by hard-thermal loop (HTL) perturbation theory and (ii) a scenario where the plasma has the properties of a quantum liquid. We show that Mach cones can appear in the second scenario, but not in the first one. |
hep-ph/0412011 | Nobuchika Okada | Darwin Chang, Takeshi Fukuyama, Yong-Yeon Keum, Tatsuru Kikuchi, and
Nobuchika Okada | Perturbative SO(10) Grand Unification | 14 pages, no figure, section5 was slightly modified | Phys.Rev. D71 (2005) 095002 | 10.1103/PhysRevD.71.095002 | KEK-TH-995 | hep-ph | null | We consider a phenomenologically viable SO(10) grand unification model of the
unification scale $M_G$ around $10^{16} $ GeV which reproduces the MSSM at low
energy and allows perturbative calculations up to the Planck scale $M_P$ or the
string scale $M_{st}$. Both requirements strongly restrict a choice of Higgs
representations in a model. We propose a simple SO(10) model with a set of
Higgs representations $\{2 \times {\bf 10} + {\bf \bar{16}} + {\bf 16} + {\bf
45} \}$ and show its phenomenological viability. This model can indeed
reproduce the low-energy experimental data relating the charged fermion masses
and mixings. Neutrino oscillation data can be consistently incorporated in the
model, leading to the right-handed neutrino mass scale $M_R \simeq M_G^2/M_P$.
Furthermore, there exists a parameter region which results the proton life time
consistent with the experimental results.
| [
{
"created": "Wed, 1 Dec 2004 15:26:39 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Mar 2005 06:06:45 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Chang",
"Darwin",
""
],
[
"Fukuyama",
"Takeshi",
""
],
[
"Keum",
"Yong-Yeon",
""
],
[
"Kikuchi",
"Tatsuru",
""
],
[
"Okada",
"Nobuchika",
""
]
] | We consider a phenomenologically viable SO(10) grand unification model of the unification scale $M_G$ around $10^{16} $ GeV which reproduces the MSSM at low energy and allows perturbative calculations up to the Planck scale $M_P$ or the string scale $M_{st}$. Both requirements strongly restrict a choice of Higgs representations in a model. We propose a simple SO(10) model with a set of Higgs representations $\{2 \times {\bf 10} + {\bf \bar{16}} + {\bf 16} + {\bf 45} \}$ and show its phenomenological viability. This model can indeed reproduce the low-energy experimental data relating the charged fermion masses and mixings. Neutrino oscillation data can be consistently incorporated in the model, leading to the right-handed neutrino mass scale $M_R \simeq M_G^2/M_P$. Furthermore, there exists a parameter region which results the proton life time consistent with the experimental results. |
hep-ph/0102272 | Tomoi Koide | T.Koide, M.Maruyama and F.Takagi | Projection Operator Approach to Langevin Equations in $\phi^4$ Theory | 35pages,2figures, Prog. Theor. Phys. Vol. 107 No. 5 in press | Prog.Theor.Phys. 107 (2002) 1001-1035 | 10.1143/PTP.107.1001 | null | hep-ph hep-th nucl-th quant-ph | null | We apply the projection operator method (POM) to $\phi^4$ theory and derive
both quantum and semiclassical equations of motion for the soft modes. These
equations have no time-convolution integral term, in sharp contrast with other
well-known results obtained using the influence functional method (IFM) and the
closed time path method (CTP). However, except for the fluctuation force field
terms, these equations are similar to the corresponding equations obtained
using IFM with the linear harmonic approximation, which was introduced to
remove the time-convolution integral. The quantum equation of motion in POM can
be regarded as a kind of quantum Langevin equation in which the fluctuation
force field is given in terms of the operators of the hard modes. These
operators are then replaced with c-numbers using a certain procedure to obtain
a semiclassical Langevin equation. It is pointed out that there are significant
differences between the fluctuation force fields introduced in this paper and
those introduced in IFM. The arbitrariness of the definition of the fluctuation
force field in IFM is also discussed.
| [
{
"created": "Thu, 22 Feb 2001 06:14:17 GMT",
"version": "v1"
},
{
"created": "Sat, 27 Apr 2002 12:10:40 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Koide",
"T.",
""
],
[
"Maruyama",
"M.",
""
],
[
"Takagi",
"F.",
""
]
] | We apply the projection operator method (POM) to $\phi^4$ theory and derive both quantum and semiclassical equations of motion for the soft modes. These equations have no time-convolution integral term, in sharp contrast with other well-known results obtained using the influence functional method (IFM) and the closed time path method (CTP). However, except for the fluctuation force field terms, these equations are similar to the corresponding equations obtained using IFM with the linear harmonic approximation, which was introduced to remove the time-convolution integral. The quantum equation of motion in POM can be regarded as a kind of quantum Langevin equation in which the fluctuation force field is given in terms of the operators of the hard modes. These operators are then replaced with c-numbers using a certain procedure to obtain a semiclassical Langevin equation. It is pointed out that there are significant differences between the fluctuation force fields introduced in this paper and those introduced in IFM. The arbitrariness of the definition of the fluctuation force field in IFM is also discussed. |
1401.7243 | Monojit Ghosh | Monojit Ghosh, Pomita Ghoshal, Srubabati Goswami, Sushant K. Raut | Evidence for leptonic CP phase from NO$\nu$A, T2K and ICAL: A
chronological progression | 38 pages, 21 figures, version accepted in Nuclear Physics B | null | 10.1016/j.nuclphysb.2014.04.013 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the synergy between the long-baseline (LBL) experiments NO$\nu$A and
T2K and the atmospheric neutrino experiment ICAL@INO for obtaining the first
hint of CP violation in the lepton sector. We also discuss how precisely the
leptonic CP phase ($\delta_{CP}$) can be measured by these experiments. The CP
sensitivity is first described at the level of oscillation probabilities,
discussing its dependence on the parameters -- $\theta_{13}$, mass hierarchy
and $\theta_{23}$. In particular, we discuss how the precise knowledge or lack
thereof of these parameters can affect the CP sensitivity of LBL experiments.
We follow a staged approach and analyze the $\delta_{CP}$ sensitivity that can
be achieved at different points of time over the next 15 years from these LBL
experiments alone and/or in conjunction with ICAL@INO. We find that the CP
sensitivity of NO$\nu$A/T2K is enhanced due to the synergies between the
different channels and between the two experiments. On the other hand the lack
of knowledge of hierarchy and octant makes the CP sensitivity poorer for some
parameter ranges. Addition of ICAL data to T2K and NO$\nu$A can exclude these
spurious wrong-hierarchy and/or wrong-octant solutions and cause a significant
increase in the range of $\delta_{CP}$ values for which a hint of CP violation
can be achieved. In fact in parameter regions unfavourable for NO$\nu$A/T2K, we
may get the first evidence of CP violation by adding the ICAL data to these.
Similarly the precision with which $\delta_{CP}$ can be measured also improves
with inclusion of ICAL data.
| [
{
"created": "Tue, 28 Jan 2014 16:11:09 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Apr 2014 13:39:25 GMT",
"version": "v2"
}
] | 2014-06-02 | [
[
"Ghosh",
"Monojit",
""
],
[
"Ghoshal",
"Pomita",
""
],
[
"Goswami",
"Srubabati",
""
],
[
"Raut",
"Sushant K.",
""
]
] | We study the synergy between the long-baseline (LBL) experiments NO$\nu$A and T2K and the atmospheric neutrino experiment ICAL@INO for obtaining the first hint of CP violation in the lepton sector. We also discuss how precisely the leptonic CP phase ($\delta_{CP}$) can be measured by these experiments. The CP sensitivity is first described at the level of oscillation probabilities, discussing its dependence on the parameters -- $\theta_{13}$, mass hierarchy and $\theta_{23}$. In particular, we discuss how the precise knowledge or lack thereof of these parameters can affect the CP sensitivity of LBL experiments. We follow a staged approach and analyze the $\delta_{CP}$ sensitivity that can be achieved at different points of time over the next 15 years from these LBL experiments alone and/or in conjunction with ICAL@INO. We find that the CP sensitivity of NO$\nu$A/T2K is enhanced due to the synergies between the different channels and between the two experiments. On the other hand the lack of knowledge of hierarchy and octant makes the CP sensitivity poorer for some parameter ranges. Addition of ICAL data to T2K and NO$\nu$A can exclude these spurious wrong-hierarchy and/or wrong-octant solutions and cause a significant increase in the range of $\delta_{CP}$ values for which a hint of CP violation can be achieved. In fact in parameter regions unfavourable for NO$\nu$A/T2K, we may get the first evidence of CP violation by adding the ICAL data to these. Similarly the precision with which $\delta_{CP}$ can be measured also improves with inclusion of ICAL data. |
1002.0473 | Xavier Calmet | X. Calmet | Renormalization of Newton's constant and Particle Physics | 3 pages, to appear in the proceedings of the 12th Marcel Grossman
Meeting | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report on particle physics applications of the renormalization group
equation of Newton's constant.
| [
{
"created": "Tue, 2 Feb 2010 13:06:51 GMT",
"version": "v1"
}
] | 2010-02-03 | [
[
"Calmet",
"X.",
""
]
] | We report on particle physics applications of the renormalization group equation of Newton's constant. |
hep-ph/0210290 | Per Osland | Per Osland (Bergen) | Three-Neutrino MSW Effect and the Lehmann Mass Matrix | 6 pages, LaTeX, 1 figure. Invited talk given at the conference
"Beyond the Desert 2002", 2-7 June 2002, Oulu, Finland, to be published in
the proceedings | null | null | null | hep-ph | null | Recent work on analytical solutions to the MSW equations for three neutrino
flavours is reviewed, with emphasis on the exponential density. Application to
a particular mass matrix, proposed by Lehmann, Newton and Wu, is also
discussed. Within this model, the experimental data allow a determination of
the three neutrino masses. They are found to be 0.002-0.004, 0.01 and 0.05 eV.
| [
{
"created": "Tue, 22 Oct 2002 09:07:51 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Osland",
"Per",
"",
"Bergen"
]
] | Recent work on analytical solutions to the MSW equations for three neutrino flavours is reviewed, with emphasis on the exponential density. Application to a particular mass matrix, proposed by Lehmann, Newton and Wu, is also discussed. Within this model, the experimental data allow a determination of the three neutrino masses. They are found to be 0.002-0.004, 0.01 and 0.05 eV. |
2010.02590 | Miguel Vanvlasselaer | Aleksandr Azatov, Miguel Vanvlasselaer | Bubble wall velocity: heavy physics effects | Non-vanishing width of the bubble wall effects are taken into account | null | 10.1088/1475-7516/2021/01/058 | SISSA 247/2020/FISI | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyse the dynamics of the relativistic bubble expansion during the first
order phase transition focusing on the ultra relativistic velocities $\gamma\gg
1$. We show that fields much heavier than the scale of the phase transition can
significantly contribute to the friction and modify the motion of the bubble
wall leading to interesting phenomenological consequences. NLO effects on the
friction due to the soft vector field emission are reviewed as well.
| [
{
"created": "Tue, 6 Oct 2020 10:00:44 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Oct 2020 08:58:17 GMT",
"version": "v2"
},
{
"created": "Thu, 26 Nov 2020 12:17:38 GMT",
"version": "v3"
}
] | 2021-02-03 | [
[
"Azatov",
"Aleksandr",
""
],
[
"Vanvlasselaer",
"Miguel",
""
]
] | We analyse the dynamics of the relativistic bubble expansion during the first order phase transition focusing on the ultra relativistic velocities $\gamma\gg 1$. We show that fields much heavier than the scale of the phase transition can significantly contribute to the friction and modify the motion of the bubble wall leading to interesting phenomenological consequences. NLO effects on the friction due to the soft vector field emission are reviewed as well. |
0805.4088 | Alexandr Korchin | S. Ivashyn, A. Korchin | Radiative decays with a0(980) and f0(980) from ChPT at order p^4 | 5 pages, 2 figures; talk presented at Workshop on Scalar Mesons and
Related Topics (SCADRON 70), Lisbon, Portugal, 11-16 Feb 2008; to appear in
AIP Conf. Proc | AIPConf.Proc.1030:123-127,2008 | 10.1063/1.2973485 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A consistent description of the pi0 pi0 invariant mass distribution in the
phi(1020) -> f0(980) gamma -> pi0 pi0 gamma decay and the pi0 eta in phi(1020)
-> a0(980) gamma -> pi0 eta gamma is suggested. A search for the consequences
of the flavor SU(3) symmetry for the scalar mesons can be based on such an
analysis. In order to accurately treat the pseudoscalar meson dynamics, which
is very important for the scalar meson decays, we employ Resonance Chiral
Theory.
| [
{
"created": "Tue, 27 May 2008 10:08:39 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Ivashyn",
"S.",
""
],
[
"Korchin",
"A.",
""
]
] | A consistent description of the pi0 pi0 invariant mass distribution in the phi(1020) -> f0(980) gamma -> pi0 pi0 gamma decay and the pi0 eta in phi(1020) -> a0(980) gamma -> pi0 eta gamma is suggested. A search for the consequences of the flavor SU(3) symmetry for the scalar mesons can be based on such an analysis. In order to accurately treat the pseudoscalar meson dynamics, which is very important for the scalar meson decays, we employ Resonance Chiral Theory. |
hep-ph/0408206 | Tim Stockamp | T. Stockamp (Universitaet Bielefeld) | Classical approximation of the Boltzmann equation in high energy QCD | 10 pages, 12 figures | J.Phys. G32 (2006) 39-46 | 10.1088/0954-3899/32/1/004 | null | hep-ph | null | Recently, Mueller and Son discussed the time evolution of a dense system
towards equilibrium in a scalar field theory. They show the equivalence of the
classical field approximation and the Boltzmann equation in all but linear
terms in the occupation number. Here we present the generalization to high
energy QCD.
| [
{
"created": "Wed, 18 Aug 2004 11:07:16 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Stockamp",
"T.",
"",
"Universitaet Bielefeld"
]
] | Recently, Mueller and Son discussed the time evolution of a dense system towards equilibrium in a scalar field theory. They show the equivalence of the classical field approximation and the Boltzmann equation in all but linear terms in the occupation number. Here we present the generalization to high energy QCD. |
0710.1563 | Zsolt Szep | P. Kovacs, Zs. Szep | Influence of the isospin and hypercharge chemical potentials on the
location of the CEP in the mu_B-T phase diagram of the SU(3)_L x SU(3)_R
chiral quark model | RevTeX4, 13 pages, 6 figures, version accepted for publication in
Phys. Rev. D | Phys.Rev.D77:065016,2008 | 10.1103/PhysRevD.77.065016 | null | hep-ph | null | We investigate the influence of the asymmetric quark matter (rho_u\ne
rho_d\ne rho_s) on the mass of the quasiparticles and the phase diagram of the
chiral quark model parametrized at one-loop level of the renormalized theory,
using the optimized perturbation theory for the resummation of the perturbative
series. The effect of various chemical potentials introduced in the grand
canonical ensemble is investigated with the method of relativistic many-body
theory. The temperature dependence of the topological susceptibility is
estimated with the help of the Witten-Veneziano mass formula.
| [
{
"created": "Mon, 8 Oct 2007 14:42:08 GMT",
"version": "v1"
},
{
"created": "Sun, 3 Feb 2008 22:08:31 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Kovacs",
"P.",
""
],
[
"Szep",
"Zs.",
""
]
] | We investigate the influence of the asymmetric quark matter (rho_u\ne rho_d\ne rho_s) on the mass of the quasiparticles and the phase diagram of the chiral quark model parametrized at one-loop level of the renormalized theory, using the optimized perturbation theory for the resummation of the perturbative series. The effect of various chemical potentials introduced in the grand canonical ensemble is investigated with the method of relativistic many-body theory. The temperature dependence of the topological susceptibility is estimated with the help of the Witten-Veneziano mass formula. |
0711.3424 | Claudio Coriano | R. Armillis, C. Coriano and M. Guzzi | Trilinear Anomalous Gauge Interactions from Intersecting Branes and the
Neutral Currents Sector | 68 pages, 21 figures Revised Version, to appear in JHEP | JHEP0805:015,2008 | 10.1088/1126-6708/2008/05/015 | null | hep-ph | null | We present a study of the trilinear gauge interactions in extensions of the
Standard Model (SM) with several anomalous extra U(1)'s, identified in various
constructions, from special vacua of string theory to large extra dimensions.
In these models an axion and generalized Chern-Simons interactions for
anomalies cancelation are present. We derive generalized Ward identities for
these vertices and discuss their structure in the Stuckelberg and
Higgs-Stuckelberg phases. We give their explicit expressions in all the
relevant cases, which can be used for phenomenological studies of these models
at the LHC.
| [
{
"created": "Wed, 21 Nov 2007 18:18:51 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Nov 2007 08:42:01 GMT",
"version": "v2"
},
{
"created": "Wed, 19 Mar 2008 15:33:20 GMT",
"version": "v3"
},
{
"created": "Wed, 19 Mar 2008 20:11:44 GMT",
"version": "v4"
},
{
"created": "Wed, 23 Apr 2008 12:43:33 GMT",
"version": "v5"
}
] | 2008-11-26 | [
[
"Armillis",
"R.",
""
],
[
"Coriano",
"C.",
""
],
[
"Guzzi",
"M.",
""
]
] | We present a study of the trilinear gauge interactions in extensions of the Standard Model (SM) with several anomalous extra U(1)'s, identified in various constructions, from special vacua of string theory to large extra dimensions. In these models an axion and generalized Chern-Simons interactions for anomalies cancelation are present. We derive generalized Ward identities for these vertices and discuss their structure in the Stuckelberg and Higgs-Stuckelberg phases. We give their explicit expressions in all the relevant cases, which can be used for phenomenological studies of these models at the LHC. |
0710.1267 | Jean-Philippe Lansberg | J.P. Lansberg, B. Pire and L. Szymanowski | Production of a pion in association with a high-Q2 dilepton pair in
antiproton-proton annihilation at GSI-FAIR | Latex, 5 pages, 3 figures | Phys.Rev.D76:111502,2007 | 10.1103/PhysRevD.76.111502 | null | hep-ph hep-ex nucl-th | null | We evaluate the cross section for anti-p p -> l+ l- pi0 in the forward
direction and for large lepton pair invariant mass. In this kinematical region,
the leading-twist amplitude factorises into a short-distance matrix element,
long-distance dominated antiproton Distribution Amplitudes and proton to pion
Transition Distribution Amplitudes (TDA). Using a modelling inspired from the
chiral limit for these TDAs, we obtain a first estimate of this cross section,
thus demonstrating that this process can be measured at GSI-FAIR.
| [
{
"created": "Fri, 5 Oct 2007 16:59:11 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Lansberg",
"J. P.",
""
],
[
"Pire",
"B.",
""
],
[
"Szymanowski",
"L.",
""
]
] | We evaluate the cross section for anti-p p -> l+ l- pi0 in the forward direction and for large lepton pair invariant mass. In this kinematical region, the leading-twist amplitude factorises into a short-distance matrix element, long-distance dominated antiproton Distribution Amplitudes and proton to pion Transition Distribution Amplitudes (TDA). Using a modelling inspired from the chiral limit for these TDAs, we obtain a first estimate of this cross section, thus demonstrating that this process can be measured at GSI-FAIR. |
hep-ph/0402062 | John F. Gunion | M. Battaglia (U.C. Berkeley and LBNL), D. Dominici (CERN and INFN,
Florence), J.F. Gunion (U.C. Davis) and J.D. Wells (Michigan) | The Invisible Higgs Decay Width in the Add Model at the LHC | 6 pages, 2 figures, To appear in the Proceedings of the Les Houches
Workshop 2003: ``Physics at TeV Colliders'', ed. F. Boudjema | null | null | UCD-2004-18 | hep-ph | null | Assuming flat universal extra dimensions, we demonstrate that for a light
Higgs boson the process $pp\to W^*W^* +X \to Higgs,graviscalars +X \to
invisible+X$ will be observable at the $5 \sigma$ level at the LHC for the
portion of the Higgs-graviscalar mixing ($\xi$) and effective Planck mass
($M_D$) parameter space where channels relying on visible Higgs decays fail to
achieve a $5 \sigma$ signal. Further, we show that even for very modest values
of $\xi$ the invisible decay signal probes to higher $M_D$ than does the
($\xi$-independent) jets/$\gam$ + missing energy signal from graviton
radiation. We also discuss various effects, such as Higgs decay to two
graviscalars, that could become important when $m_h/M_D$ is of order 1.
| [
{
"created": "Thu, 5 Feb 2004 23:54:18 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Battaglia",
"M.",
"",
"U.C. Berkeley and LBNL"
],
[
"Dominici",
"D.",
"",
"CERN and INFN,\n Florence"
],
[
"Gunion",
"J. F.",
"",
"U.C. Davis"
],
[
"Wells",
"J. D.",
"",
"Michigan"
]
] | Assuming flat universal extra dimensions, we demonstrate that for a light Higgs boson the process $pp\to W^*W^* +X \to Higgs,graviscalars +X \to invisible+X$ will be observable at the $5 \sigma$ level at the LHC for the portion of the Higgs-graviscalar mixing ($\xi$) and effective Planck mass ($M_D$) parameter space where channels relying on visible Higgs decays fail to achieve a $5 \sigma$ signal. Further, we show that even for very modest values of $\xi$ the invisible decay signal probes to higher $M_D$ than does the ($\xi$-independent) jets/$\gam$ + missing energy signal from graviton radiation. We also discuss various effects, such as Higgs decay to two graviscalars, that could become important when $m_h/M_D$ is of order 1. |
2301.10461 | Zhi-zhong Xing | Zhi-zhong Xing | The formal seesaw mechanism of Majorana neutrinos with unbroken gauge
symmetry | 18 pages. The title changed, more discussions and references added,
accepted for publication in NPB | null | 10.1016/j.nuclphysb.2023.116106 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We reformulate the canonical seesaw mechanism in the case that the
electroweak gauge symmetry is unbroken, and show that it can "formally" work
and allow us to derive an exact seesaw formula for the light and heavy Majorana
neutrinos. We elucidate the reason why there is a mismatch between the mass
eigenstates of heavy Majorana neutrinos associated with thermal leptogenesis
and those associated with the seesaw framework, and establish the exact and
explicit relations between the "original" and "derivational" seesaw parameters
by using an Euler-like parametrization of the $6\times 6$ active-sterile flavor
mixing matrix.
| [
{
"created": "Wed, 25 Jan 2023 08:42:16 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Feb 2023 09:20:46 GMT",
"version": "v2"
}
] | 2023-02-22 | [
[
"Xing",
"Zhi-zhong",
""
]
] | We reformulate the canonical seesaw mechanism in the case that the electroweak gauge symmetry is unbroken, and show that it can "formally" work and allow us to derive an exact seesaw formula for the light and heavy Majorana neutrinos. We elucidate the reason why there is a mismatch between the mass eigenstates of heavy Majorana neutrinos associated with thermal leptogenesis and those associated with the seesaw framework, and establish the exact and explicit relations between the "original" and "derivational" seesaw parameters by using an Euler-like parametrization of the $6\times 6$ active-sterile flavor mixing matrix. |
hep-ph/0209266 | Paolo Gondolo | Gintaras Duda (UCLA), Graciela Gelmini (UCLA), Paolo Gondolo (CWRU),
Joakim Edsjo (Stockholm), Joseph Silk (Oxford) | Indirect detection of a subdominant density component of cold dark
matter | 15 pages plus 17 figures | Phys.Rev. D67 (2003) 023505 | 10.1103/PhysRevD.67.023505 | UCLA/02/TEP/22, CWRU-P11-02, NSF-ITP-02-96 | hep-ph | null | We examine the detectability through indirect means of weakly interacting
dark matter candidates that may constitute not all but only a subdominant
component of galactic cold dark matter. We show that the possibility of
indirect detection of neutralinos from their annihilations in the Earth and Sun
is not severely hampered by decreasing neutralino relic density. Upward-going
muon fluxes in underground detectors from neutralino annihilations in the Sun
can remain above the threshold of detectability of 10 muons/km^2/yr for
neutralinos composing 1% or more of the halo dark matter. Similarly, signals
from neutralino annihilations in the Earth can also remain high for neutralino
densities of 1% of the halo and actually would only be observable close to this
low density for neutralinos lighter than 150 GeV. We also show that there are
many models which simultaneously have high direct and indirect detection rates
making some model discrimination possible if a signal is seen in any of the
current dark matter searches.
| [
{
"created": "Mon, 23 Sep 2002 19:38:30 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Duda",
"Gintaras",
"",
"UCLA"
],
[
"Gelmini",
"Graciela",
"",
"UCLA"
],
[
"Gondolo",
"Paolo",
"",
"CWRU"
],
[
"Edsjo",
"Joakim",
"",
"Stockholm"
],
[
"Silk",
"Joseph",
"",
"Oxford"
]
] | We examine the detectability through indirect means of weakly interacting dark matter candidates that may constitute not all but only a subdominant component of galactic cold dark matter. We show that the possibility of indirect detection of neutralinos from their annihilations in the Earth and Sun is not severely hampered by decreasing neutralino relic density. Upward-going muon fluxes in underground detectors from neutralino annihilations in the Sun can remain above the threshold of detectability of 10 muons/km^2/yr for neutralinos composing 1% or more of the halo dark matter. Similarly, signals from neutralino annihilations in the Earth can also remain high for neutralino densities of 1% of the halo and actually would only be observable close to this low density for neutralinos lighter than 150 GeV. We also show that there are many models which simultaneously have high direct and indirect detection rates making some model discrimination possible if a signal is seen in any of the current dark matter searches. |
hep-ph/9509417 | Harald Griesshammer | H. W. Grie\{ss}hammer (Uni Erlangen-N"urnberg, Germany) | Large Gauge Transformations and Magnetic Vortices in Axial Gauge
QCD_{3+1} | LaTeX, 14 pages, to be published in the proceedings of the "Workshop
on Nonperturbative Approaches to QCD" at the ECT, Trento; no special macros | null | null | FAU-TP3-95/9 | hep-ph | null | It is shown that in the modified axial gauge version of canonically quantized
QCD$_{3+1}$ on a torus only nongeneric gauge field configurations allow for
large gauge transformations. For the other configurations, the gauge is fixed
completely. Such configurations carry nonzero total magnetic abelian fluxes,
correspond to magnetic vortices parallel to the coordinate axes and are
incorporated using both singular gauge fields and a change of boundary
conditions.
| [
{
"created": "Fri, 29 Sep 1995 11:51:51 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Grie\\{ss}hammer",
"H. W.",
"",
"Uni Erlangen-N\"urnberg, Germany"
]
] | It is shown that in the modified axial gauge version of canonically quantized QCD$_{3+1}$ on a torus only nongeneric gauge field configurations allow for large gauge transformations. For the other configurations, the gauge is fixed completely. Such configurations carry nonzero total magnetic abelian fluxes, correspond to magnetic vortices parallel to the coordinate axes and are incorporated using both singular gauge fields and a change of boundary conditions. |
1403.6695 | Ivanka Bozovic-Jelisavcic | I. Bozovic-Jelisavcic, S. Lukic, G. Milutinovic-Dumbelovic and M.
Pandurovic | SM-like Higgs decay into two muons at 1.4 TeV CLIC | Talk presented at the International Workshop on Future Linear
Colliders (LCWS13), Tokyo, Japan, 11-15 November 2013 on behalf of the CLIC
Detector and Physics Collaboration | null | null | CLICdp-Draft-2014-005 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The branching fraction measurement of the SM-like Higgs boson decay into two
muons at 1.4 TeV CLIC will be described in this paper contributed to the
LCWS13. The study is performed in the fully simulated ILD detector concept for
CLIC, taking into consideration all the relevant physics and the beam-induced
backgrounds, as well as the instrumentation of the very forward region to tag
the high-energy electrons. Higgs couplings are known to be sensitive to BSM
physics and we prove that BR times the Higgs production cross section can be
measured with approximately 35.5% statistical accuracy in four years of the
CLIC operation at 1.4 TeV centre-of-mass energy with unpolarised beams. The
result is preliminary as the equivalent photon approximation is not considered
in the cross-section calculations. This study complements the Higgs physics
program foreseen at CLIC.
| [
{
"created": "Wed, 26 Mar 2014 14:41:45 GMT",
"version": "v1"
}
] | 2014-03-27 | [
[
"Bozovic-Jelisavcic",
"I.",
""
],
[
"Lukic",
"S.",
""
],
[
"Milutinovic-Dumbelovic",
"G.",
""
],
[
"Pandurovic",
"M.",
""
]
] | The branching fraction measurement of the SM-like Higgs boson decay into two muons at 1.4 TeV CLIC will be described in this paper contributed to the LCWS13. The study is performed in the fully simulated ILD detector concept for CLIC, taking into consideration all the relevant physics and the beam-induced backgrounds, as well as the instrumentation of the very forward region to tag the high-energy electrons. Higgs couplings are known to be sensitive to BSM physics and we prove that BR times the Higgs production cross section can be measured with approximately 35.5% statistical accuracy in four years of the CLIC operation at 1.4 TeV centre-of-mass energy with unpolarised beams. The result is preliminary as the equivalent photon approximation is not considered in the cross-section calculations. This study complements the Higgs physics program foreseen at CLIC. |
hep-ph/0212115 | Haibin Wang | R. Akhoury, H. Wang and O. Yakovlev | On the Resummation of Large QCD Corrections to photon photon to b anti-b | 31 pages, 14 figures | Phys.Rev.D68:073006,2003 | 10.1103/PhysRevD.68.073006 | MCTP-02-66 | hep-ph | null | We study the resummation of large QCD radiative corrections up to the next to
leading logarithmic accuracy to the process photon photon to b anti-b; i.e., we
resum logarithms of the type alpha_s^p log^{2p}{m^2/s} and alpha_s^p
log^{2p-1}{m^2/s} (m is the quark mass). The only source of all the logarithms
to this accuracy is the off-shell Sudakov form factor included into the
triangle topologies of the one-loop box diagram. We prove that any other
configurations of diagrams to this accuracy, either cancel in subgroups or
develop a universal on-shell Sudakov exponent due to the final quark anti-quark
lines. We study the mechanism of cancellations between the different diagrams,
which leads to the simple resummed results. We show the cancellation explicitly
at three loops for the leading and at two loops for the next-to-leading
logarithms. We also point out the general mechanism responsible for it, and
discuss how it can be extended to higher orders.
| [
{
"created": "Sun, 8 Dec 2002 15:59:16 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Akhoury",
"R.",
""
],
[
"Wang",
"H.",
""
],
[
"Yakovlev",
"O.",
""
]
] | We study the resummation of large QCD radiative corrections up to the next to leading logarithmic accuracy to the process photon photon to b anti-b; i.e., we resum logarithms of the type alpha_s^p log^{2p}{m^2/s} and alpha_s^p log^{2p-1}{m^2/s} (m is the quark mass). The only source of all the logarithms to this accuracy is the off-shell Sudakov form factor included into the triangle topologies of the one-loop box diagram. We prove that any other configurations of diagrams to this accuracy, either cancel in subgroups or develop a universal on-shell Sudakov exponent due to the final quark anti-quark lines. We study the mechanism of cancellations between the different diagrams, which leads to the simple resummed results. We show the cancellation explicitly at three loops for the leading and at two loops for the next-to-leading logarithms. We also point out the general mechanism responsible for it, and discuss how it can be extended to higher orders. |
hep-ph/9604300 | Zheng Huang | Zheng Huang (U. of Arizona) and Xin-Nian Wang (LBL) | Dilepton and Photon Productions from a Coherent Pion Oscillation | 11 pages in RevTeX with 2 figures (epsfig style) embedded | Phys.Lett. B383 (1996) 457-462 | 10.1016/0370-2693(96)00814-3 | AZPH-TH/96-11, LBL-38582 | hep-ph nucl-th | null | Since the electromagnetic current for a pion system coincides with the third
component of the isovector current, the isospin angular oscillation of a
coherent field can be a significant source for the electromagnetic emissions.
We study the characteristic dilepton and photon emissions from the classical
pion field oscillation in the QCD vacuum. The general analytical solution
obtained in the nonlinear sigma model is used to calculate the electromagnetic
current density, which exhibits a light-front singularity and decreases rapidly
as inverse square of the proper time due to a longitudinal expansion. The
momentum and invariant mass spectra of the direct photon and dilepton are found
to be a sensitive probe of the space-time evolution of the chiral condensate
field.
| [
{
"created": "Thu, 11 Apr 1996 21:50:48 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Huang",
"Zheng",
"",
"U. of Arizona"
],
[
"Wang",
"Xin-Nian",
"",
"LBL"
]
] | Since the electromagnetic current for a pion system coincides with the third component of the isovector current, the isospin angular oscillation of a coherent field can be a significant source for the electromagnetic emissions. We study the characteristic dilepton and photon emissions from the classical pion field oscillation in the QCD vacuum. The general analytical solution obtained in the nonlinear sigma model is used to calculate the electromagnetic current density, which exhibits a light-front singularity and decreases rapidly as inverse square of the proper time due to a longitudinal expansion. The momentum and invariant mass spectra of the direct photon and dilepton are found to be a sensitive probe of the space-time evolution of the chiral condensate field. |
hep-ph/0110376 | Chao-Qiang Geng | C.Q. Geng, C.W. Hwang, and C.C. Liu | Study of Rare $B_c^+\to D_{d,s}^{(*) +}l\bar{l}$ Decays | 22 pages, 9 Figures, version to appear in PRD | Phys.Rev.D65:094037,2002 | 10.1103/PhysRevD.65.094037 | null | hep-ph | null | We study the rare decays of $B_c^+\to D_{q}^{(*)+}l\bar{l}$ ($q=d,s$ and
$l=\nu_l,e,\mu,\tau)$ in the standard model. The form factors are evaluated in
the light front and constituent quark models, respectively. We find that the
decay branching ratios calculated in the two models for $B_c^+\to D^+_q
l\bar{l}$ agree well with each other, whereas those for $B_c^+\to
D_q^{*+}l\bar{l}$ are different.
| [
{
"created": "Mon, 29 Oct 2001 19:18:38 GMT",
"version": "v1"
},
{
"created": "Sun, 31 Mar 2002 10:28:04 GMT",
"version": "v2"
}
] | 2011-03-23 | [
[
"Geng",
"C. Q.",
""
],
[
"Hwang",
"C. W.",
""
],
[
"Liu",
"C. C.",
""
]
] | We study the rare decays of $B_c^+\to D_{q}^{(*)+}l\bar{l}$ ($q=d,s$ and $l=\nu_l,e,\mu,\tau)$ in the standard model. The form factors are evaluated in the light front and constituent quark models, respectively. We find that the decay branching ratios calculated in the two models for $B_c^+\to D^+_q l\bar{l}$ agree well with each other, whereas those for $B_c^+\to D_q^{*+}l\bar{l}$ are different. |
hep-ph/0208090 | Stanislaw Tatur | J. Bartelski, S. Tatur | A determination of gluon spin distribution from the deep inelastic
scattering data | latex, 8 pages, 2 eps figures. To apear in Acta Physica Polonica.
Dedicated to prof. Stefan Pokorski on the occasion of his 60th birthday | Acta Phys.Polon. B33 (2002) 2673-2680 | null | null | hep-ph | null | In order to determine polarized parton densities in nucleon we have made fits
using all experimental data on spin asymmetries measured in the deep inelastic
scattering on different nucleon targets. We have used in our analysis next to
leading order QCD corrections in bar{MS} renormalization scheme. The functional
forms of polarized densities are based on the fit to unpolarized deep inelastic
data made by the MRST group (MRST 99). We have concentrated on different models
for gluon spin distributions. In the best fit we get for gluon polarization (at
Gev^{2}) Delta G=-1.0 +/- 0.6. The obtained result does not depend very much on
various model assumptions
| [
{
"created": "Fri, 9 Aug 2002 12:41:31 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bartelski",
"J.",
""
],
[
"Tatur",
"S.",
""
]
] | In order to determine polarized parton densities in nucleon we have made fits using all experimental data on spin asymmetries measured in the deep inelastic scattering on different nucleon targets. We have used in our analysis next to leading order QCD corrections in bar{MS} renormalization scheme. The functional forms of polarized densities are based on the fit to unpolarized deep inelastic data made by the MRST group (MRST 99). We have concentrated on different models for gluon spin distributions. In the best fit we get for gluon polarization (at Gev^{2}) Delta G=-1.0 +/- 0.6. The obtained result does not depend very much on various model assumptions |
2308.16436 | Bo-Yan Cui | Bo-Yan Cui, Yue-Long Shen, Chao Wang and Yan-Bing Wei | QCD factorization for the $B\to \gamma\ell\nu_{\ell}$ decay beyond
leading power | 29 pages, 6 figures | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | The radiative leptonic $B\to \gamma\ell\nu_{\ell}$ decay serves as an ideal
platform to determine the $B$-meson inverse moment which is a fundamental
nonperturbative parameter for the $B$ meson. In this paper, we explore precise
QCD contributions to this decay with an energetic photon. We reproduce the
next-to-next-to-leading-logarithmic resummation formula for the decay amplitude
at leading power in $\Lambda_{\rm QCD}/m_b$. Employing operator identities, we
calculate subleading-power contributions from the expansion of the
hard-collinear propagator of the internal up quark and the heavy-quark
expansion of the bottom quark. We update the contributions from the hadronic
structure of the photon to the $\decay$ process with the dispersion technique.
Together with other yet known power corrections, phenomenological applications
including the partial branching fraction and ratio of the branching fractions
of the radiative $B$ decay are investigated.
| [
{
"created": "Thu, 31 Aug 2023 03:52:47 GMT",
"version": "v1"
}
] | 2023-09-01 | [
[
"Cui",
"Bo-Yan",
""
],
[
"Shen",
"Yue-Long",
""
],
[
"Wang",
"Chao",
""
],
[
"Wei",
"Yan-Bing",
""
]
] | The radiative leptonic $B\to \gamma\ell\nu_{\ell}$ decay serves as an ideal platform to determine the $B$-meson inverse moment which is a fundamental nonperturbative parameter for the $B$ meson. In this paper, we explore precise QCD contributions to this decay with an energetic photon. We reproduce the next-to-next-to-leading-logarithmic resummation formula for the decay amplitude at leading power in $\Lambda_{\rm QCD}/m_b$. Employing operator identities, we calculate subleading-power contributions from the expansion of the hard-collinear propagator of the internal up quark and the heavy-quark expansion of the bottom quark. We update the contributions from the hadronic structure of the photon to the $\decay$ process with the dispersion technique. Together with other yet known power corrections, phenomenological applications including the partial branching fraction and ratio of the branching fractions of the radiative $B$ decay are investigated. |
1711.05741 | Fredrik Bj\"orkeroth | Fredrik Bj\"orkeroth, Eung Jin Chun, Stephen F. King | Accidental Peccei-Quinn Symmetry from Discrete Flavour Symmetry and
Pati-Salam | 14 pages, 2 figures | null | 10.1016/j.physletb.2017.12.058 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We show how an accidental $U(1)$ Peccei-Quinn (PQ) symmetry can arise from a
discrete $A_4$ family symmetry combined with a discrete flavour symmetry $
\mathbb{Z}_3 \times \mathbb{Z}_5^2 $, in a realistic Pati-Salam unified theory
of flavour. Imposing only these discrete flavour symmetries, the axion solution
to the strong $ CP $ problem is protected from PQ-breaking operators to the
required degree. A QCD axion arises from a linear combination of $ A_4 $
triplet flavons, which are also responsible for fermion flavour structures due
to their vacuum alignments. We find that the requirement of an accidental PQ
symmetry arising from a discrete flavour symmetry constrains the form of the
Yukawa matrices, providing a link between flavour and the strong $ CP $
problem. Our model predicts specific flavour-violating couplings of the
flavourful axion and thus puts a strong limit on the axion scale from kaon
decays.
| [
{
"created": "Wed, 15 Nov 2017 19:00:01 GMT",
"version": "v1"
}
] | 2018-02-01 | [
[
"Björkeroth",
"Fredrik",
""
],
[
"Chun",
"Eung Jin",
""
],
[
"King",
"Stephen F.",
""
]
] | We show how an accidental $U(1)$ Peccei-Quinn (PQ) symmetry can arise from a discrete $A_4$ family symmetry combined with a discrete flavour symmetry $ \mathbb{Z}_3 \times \mathbb{Z}_5^2 $, in a realistic Pati-Salam unified theory of flavour. Imposing only these discrete flavour symmetries, the axion solution to the strong $ CP $ problem is protected from PQ-breaking operators to the required degree. A QCD axion arises from a linear combination of $ A_4 $ triplet flavons, which are also responsible for fermion flavour structures due to their vacuum alignments. We find that the requirement of an accidental PQ symmetry arising from a discrete flavour symmetry constrains the form of the Yukawa matrices, providing a link between flavour and the strong $ CP $ problem. Our model predicts specific flavour-violating couplings of the flavourful axion and thus puts a strong limit on the axion scale from kaon decays. |
1306.2897 | Nils Strodthoff | Nils Strodthoff and Lorenz von Smekal | Polyakov-Quark-Meson-Diquark Model for two-color QCD | 8 pages, 9 figures; published version | Physics Letters B 731C (2014), pp. 350-357 | 10.1016/j.physletb.2014.03.008 | null | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an update on the phase diagram of two-color QCD from a chiral
effective model approach based on a quark-meson-diquark model using the
Functional Renormalization Group (FRG). We discuss the impact of perturbative
UV contributions, the inclusion of gauge field dynamics via a phenomenological
Polyakov loop potential, and the impact of matter backcoupling on the gauge
sector. The corresponding phase diagram including these effects is found to be
in qualitative agreement with recent lattice investigations.
| [
{
"created": "Wed, 12 Jun 2013 17:01:24 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Mar 2014 12:36:57 GMT",
"version": "v2"
}
] | 2014-03-27 | [
[
"Strodthoff",
"Nils",
""
],
[
"von Smekal",
"Lorenz",
""
]
] | We present an update on the phase diagram of two-color QCD from a chiral effective model approach based on a quark-meson-diquark model using the Functional Renormalization Group (FRG). We discuss the impact of perturbative UV contributions, the inclusion of gauge field dynamics via a phenomenological Polyakov loop potential, and the impact of matter backcoupling on the gauge sector. The corresponding phase diagram including these effects is found to be in qualitative agreement with recent lattice investigations. |
1601.00138 | Ernest Ma | Ernest Ma (UC Riverside and HKUST/JCIAS) | Soft $A_4 \to Z_3$ Symmetry Breaking and Cobimaximal Neutrino Mixing | 8 pages, 4 figures | null | 10.1016/j.physletb.2016.02.032 | UCRHEP-T562 (Jan 2016) | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I propose a model of radiative charged-lepton and neutrino masses with $A_4$
symmetry. The soft breaking of $A_4$ to $Z_3$ lepton triality is accomplished
by dimension-three terms. The breaking of $Z_3$ by dimension-two terms allow
cobimaximal neutrino mixing $(\theta_{13} \neq 0, \theta_{23} = \pi/4,
\delta_{CP} = \pm \pi/2)$ to be realized with only very small finite calculable
deviations from the residual lepton triality. This construction solves a
long-standing technical problem inherent in renormalizable $A_4$ models since
their inception.
| [
{
"created": "Sat, 2 Jan 2016 04:46:58 GMT",
"version": "v1"
}
] | 2016-03-23 | [
[
"Ma",
"Ernest",
"",
"UC Riverside and HKUST/JCIAS"
]
] | I propose a model of radiative charged-lepton and neutrino masses with $A_4$ symmetry. The soft breaking of $A_4$ to $Z_3$ lepton triality is accomplished by dimension-three terms. The breaking of $Z_3$ by dimension-two terms allow cobimaximal neutrino mixing $(\theta_{13} \neq 0, \theta_{23} = \pi/4, \delta_{CP} = \pm \pi/2)$ to be realized with only very small finite calculable deviations from the residual lepton triality. This construction solves a long-standing technical problem inherent in renormalizable $A_4$ models since their inception. |
1207.5177 | Ivan Vitev | Wei Dai, Ivan Vitev, Ben-Wei Zhang | Momentum imbalance of isolated photon-tagged jet production at RHIC and
LHC | 4 pages, 3 eps figures, 1 table. Version to appear in PRL | Phys. Rev. Lett. 110, 142001 (2013) | 10.1103/PhysRevLett.110.142001 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In collisions of ultra-relativistic nuclei, photon-tagged jets provide a
unique opportunity to compare jet production and modification due to parton
shower formation and propagation in strongly-interacting matter at vastly
different center-of-mass energies. We present first results for the cross
sections of jets tagged by an isolated photon to ${\cal O}(\alpha_{\rm em}
\alpha_s^2)$ in central Au+Au reactions with $\sqrt{s_{NN}}=200$ GeV at RHIC
and central Pb+Pb reactions with $\sqrt{s_{NN}}=2.76$ TeV at LHC. We evaluate
the increase in the transverse momentum imbalance of the observed $\gamma$+jet
state, induced by the dissipation of the parton shower energy due to strong
final-state interactions. Theoretical predictions to help interpret recent and
upcoming experimental data are presented.
| [
{
"created": "Sat, 21 Jul 2012 20:44:42 GMT",
"version": "v1"
},
{
"created": "Thu, 7 Mar 2013 19:53:24 GMT",
"version": "v2"
}
] | 2015-03-20 | [
[
"Dai",
"Wei",
""
],
[
"Vitev",
"Ivan",
""
],
[
"Zhang",
"Ben-Wei",
""
]
] | In collisions of ultra-relativistic nuclei, photon-tagged jets provide a unique opportunity to compare jet production and modification due to parton shower formation and propagation in strongly-interacting matter at vastly different center-of-mass energies. We present first results for the cross sections of jets tagged by an isolated photon to ${\cal O}(\alpha_{\rm em} \alpha_s^2)$ in central Au+Au reactions with $\sqrt{s_{NN}}=200$ GeV at RHIC and central Pb+Pb reactions with $\sqrt{s_{NN}}=2.76$ TeV at LHC. We evaluate the increase in the transverse momentum imbalance of the observed $\gamma$+jet state, induced by the dissipation of the parton shower energy due to strong final-state interactions. Theoretical predictions to help interpret recent and upcoming experimental data are presented. |
2407.07944 | Lucian Harland-Lang | L. A. Harland-Lang, T. Cridge, R.S. Thorne | A Stress Test of Global PDF Fits: Closure Testing the MSHT PDFs and a
First Direct Comparison to the Neural Net Approach | 95 pages, 44 figures, 7 tables. Version submitted to journal: Section
3.3 rewritten and expanded, Section 8 describing PDF availability added,
Appendix A added | null | null | DESY-24-101 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a first global closure test of the fixed parameterisation (MSHT)
approach to PDF fitting. We find that the default MSHT20 parameterisation can
reproduce the features of the input set in such a closure test to well within
the textbook uncertainties. This provides strong evidence that parameterisation
inflexibility in the MSHT20 fit is not a significant issue in the data region.
We also present the first completely like-for-like comparison between two
global PDF fits, namely MSHT and NNPDF, where the only difference is guaranteed
to be due to the fitting methodology. To achieve this, we present a fit to the
NNPDF4.0 data and theory inputs, but with the MSHT fixed parameterisation. We
find that this gives a moderately, but noticeably, better fit quality than the
central NNPDF4.0 fits, both with perturbative and fitted charm, and that this
difference persists at the level of the PDFs and benchmark cross sections. The
NNPDF4.0 uncertainties are found to be broadly in line with the MSHT results if
a textbook $T^2=1$ tolerance is applied, but to be significantly smaller if a
tolerance typical of the MSHT20 fit is applied. This points to an inherent
inconsistency between these approaches. We discuss the need for an enlarged
tolerance criterion in global PDF fits in detail, and demonstrate the impact of
data/theory inconsistencies in the closure test setting; namely, these do not
lead to any increase in the $T^2=1$ PDF uncertainty. We also investigate the
impact of restricting the PDF parameterisation to have fewer free parameters
than the default MSHT20 case, and find this can be significant at the level of
both closure tests and the full fit.
| [
{
"created": "Wed, 10 Jul 2024 18:00:02 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Aug 2024 12:31:47 GMT",
"version": "v2"
}
] | 2024-08-12 | [
[
"Harland-Lang",
"L. A.",
""
],
[
"Cridge",
"T.",
""
],
[
"Thorne",
"R. S.",
""
]
] | We present a first global closure test of the fixed parameterisation (MSHT) approach to PDF fitting. We find that the default MSHT20 parameterisation can reproduce the features of the input set in such a closure test to well within the textbook uncertainties. This provides strong evidence that parameterisation inflexibility in the MSHT20 fit is not a significant issue in the data region. We also present the first completely like-for-like comparison between two global PDF fits, namely MSHT and NNPDF, where the only difference is guaranteed to be due to the fitting methodology. To achieve this, we present a fit to the NNPDF4.0 data and theory inputs, but with the MSHT fixed parameterisation. We find that this gives a moderately, but noticeably, better fit quality than the central NNPDF4.0 fits, both with perturbative and fitted charm, and that this difference persists at the level of the PDFs and benchmark cross sections. The NNPDF4.0 uncertainties are found to be broadly in line with the MSHT results if a textbook $T^2=1$ tolerance is applied, but to be significantly smaller if a tolerance typical of the MSHT20 fit is applied. This points to an inherent inconsistency between these approaches. We discuss the need for an enlarged tolerance criterion in global PDF fits in detail, and demonstrate the impact of data/theory inconsistencies in the closure test setting; namely, these do not lead to any increase in the $T^2=1$ PDF uncertainty. We also investigate the impact of restricting the PDF parameterisation to have fewer free parameters than the default MSHT20 case, and find this can be significant at the level of both closure tests and the full fit. |
0805.0354 | Ashutosh Alok | Ashutosh Kumar Alok, Amol Dighe, S. Uma Sankar | Probing extended Higgs sector through rare b --> s mu+ mu- transitions | 21 pages, 4 figures | Phys.Rev.D78:034020,2008 | 10.1103/PhysRevD.78.034020 | TIFR/TH/08-15 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the constraints on the contribution of new physics in the form of
scalar/pseudoscalar operators to the average forward backward asymmetry
<A_{FB}> of muons in B --> K mu+ mu- and the longitudinal polarization
asymmetry A_{LP} of muons in B_s --> mu+ mu-. We find that the maximum possible
value of <A_{FB}> allowed by the present upper bound on B(B_s --> mu+ mu-) is
about 1% at 95% C.L. and hence will be very difficult to measure. On the other
hand, the present bound on B(B_s --> mu+ mu-) fails to put any constraints on
A_{LP}, which can be as high as 100% even if B(B_s --> mu+ mu-) is close to its
standard model prediction. The measurement of A_{LP} will be a direct evidence
for an extended Higgs sector, and combined with the branching ratio B(B_s -->
mu+ mu-) it can even separate the new physics scalar and pseudoscalar
contributions.
| [
{
"created": "Sat, 3 May 2008 10:49:30 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Alok",
"Ashutosh Kumar",
""
],
[
"Dighe",
"Amol",
""
],
[
"Sankar",
"S. Uma",
""
]
] | We study the constraints on the contribution of new physics in the form of scalar/pseudoscalar operators to the average forward backward asymmetry <A_{FB}> of muons in B --> K mu+ mu- and the longitudinal polarization asymmetry A_{LP} of muons in B_s --> mu+ mu-. We find that the maximum possible value of <A_{FB}> allowed by the present upper bound on B(B_s --> mu+ mu-) is about 1% at 95% C.L. and hence will be very difficult to measure. On the other hand, the present bound on B(B_s --> mu+ mu-) fails to put any constraints on A_{LP}, which can be as high as 100% even if B(B_s --> mu+ mu-) is close to its standard model prediction. The measurement of A_{LP} will be a direct evidence for an extended Higgs sector, and combined with the branching ratio B(B_s --> mu+ mu-) it can even separate the new physics scalar and pseudoscalar contributions. |
hep-ph/0012266 | C. S. Lim | Makoto Kobayashi (KEK) and C.S. Lim (Kobe U.) | Pseudo-Dirac Scenario for Neutrino Oscillations | 17 pages, LaTeX file | Phys.Rev. D64 (2001) 013003 | 10.1103/PhysRevD.64.013003 | KEK-TH-733, KOBE-TH-00-10 | hep-ph | null | We argue how pseudo-Dirac scenario for neutrinos leads to rich neutrino
oscillation phenomena, including oscillation inside each generation. The
pseudo-Dirac scenario is generalized by incorporating generation mixings and
formulae for the various neutrino oscillations are derived. As the application
we compare the formulae with the corresponding data. We find that observed
pattern of mixings, such as almost maximal mixing in the atmospheric neutrino
oscillation, is naturally explained in the generalized Pseudo-Dirac scenario
with small generation mixings. We, however, also point out that there remain
some problems to be settled for this scenario to be viable. The possible
theoretical framework to realize the pseudo-Dirac scenario is also briefly
commented on.
| [
{
"created": "Wed, 20 Dec 2000 10:03:53 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Kobayashi",
"Makoto",
"",
"KEK"
],
[
"Lim",
"C. S.",
"",
"Kobe U."
]
] | We argue how pseudo-Dirac scenario for neutrinos leads to rich neutrino oscillation phenomena, including oscillation inside each generation. The pseudo-Dirac scenario is generalized by incorporating generation mixings and formulae for the various neutrino oscillations are derived. As the application we compare the formulae with the corresponding data. We find that observed pattern of mixings, such as almost maximal mixing in the atmospheric neutrino oscillation, is naturally explained in the generalized Pseudo-Dirac scenario with small generation mixings. We, however, also point out that there remain some problems to be settled for this scenario to be viable. The possible theoretical framework to realize the pseudo-Dirac scenario is also briefly commented on. |
1709.09781 | Guanwen Yan | Guanwen Yan | Effect of sterile Neutrinos and Nonstandard Interactions on the
Geo-neutrino Flux | 5 pages, 4 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the effect of sterile neutrinos and nonstandard neutrino
interactions on the flux of active neutrinos from the Earth's crust and mantle
taking matter effect into account in both cases. For simple Earth model and
using previous emission flux estimates at the source, we find that for
reasonable choice of parameters for both the sterile neutrino and nonstandard
interaction, the effect on the neutrino flux is a few percent or less.
| [
{
"created": "Thu, 28 Sep 2017 02:05:13 GMT",
"version": "v1"
},
{
"created": "Thu, 18 Jan 2018 04:00:11 GMT",
"version": "v2"
}
] | 2018-01-19 | [
[
"Yan",
"Guanwen",
""
]
] | We calculate the effect of sterile neutrinos and nonstandard neutrino interactions on the flux of active neutrinos from the Earth's crust and mantle taking matter effect into account in both cases. For simple Earth model and using previous emission flux estimates at the source, we find that for reasonable choice of parameters for both the sterile neutrino and nonstandard interaction, the effect on the neutrino flux is a few percent or less. |
hep-ph/9701360 | Richard Holman | D. Boyanovsky, H.J. de Vega, R. Holman, and S. Prem Kumar | Photoproduction Enhancement from Non Equilibrium Disoriented Chiral
Condensates | 33 pages, 11 figures, uses revtex and epsfig | Phys.Rev.D56:5233-5250,1997 | 10.1103/PhysRevD.56.5233 | PITT-97-1; CMU-HEP-97-03; DOR-ER/40682-128 | hep-ph nucl-th | null | We study photoproduction during the non-equilibrium stages of the formation
of chiral condensates within the ``quench'' scenario of the chiral phase
transition. The dynamics is modeled with a gauged linear sigma model. A novel
quantum kinetic approach to the description of photoproduction far off
equilibrium is developed. We find that non-equilibrium spinodal instabilities
of long wavelength pion fluctuations are responsible for an enhanced
photoproduction rate for energies $\leq 80$ MeV at order $\alpha$. These
non-equilibrium effects lead to a larger contribution than the typical
processes in the medium, including that of the anomalous neutral pion decay
$\pi^0 \rightarrow 2 \gamma$ (which is of order $\alpha^2$). We follow the
evolution of the dynamics throughout the phase transition, which in this
scenario occurs on a time scale of about $2.5-3$ fm/c and integrate the photon
yield through its evolution. The spectrum of photons produced throughout the
phase transition is a non- equilibrium one. For thermal initial conditions at
the time of the quench it interpolates between a thermal distribution about 6%
above the initial temperature (at the time of the quench) for low energy $\leq
80$ MeV photons, and a high energy tail in thermal equilibrium at the initial
temperature, with a smooth crossover at 100 MeV. The rate displays a peak at
$\sim 35$ MeV which receives a larger enhancement the closer the initial
temperature at the time of the quench is to the critical temperature. It is
found that the enhancement of photoproduction at low energies is not an
artifact caused by the initial distribution of the photons, but is due to the
pionic instabilities. We suggest that these strong out of equilibrium effects
may provide experimental signatures for the formation and relaxation of DCC's
in heavy ion collisions.
| [
{
"created": "Thu, 23 Jan 1997 22:07:57 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Boyanovsky",
"D.",
""
],
[
"de Vega",
"H. J.",
""
],
[
"Holman",
"R.",
""
],
[
"Kumar",
"S. Prem",
""
]
] | We study photoproduction during the non-equilibrium stages of the formation of chiral condensates within the ``quench'' scenario of the chiral phase transition. The dynamics is modeled with a gauged linear sigma model. A novel quantum kinetic approach to the description of photoproduction far off equilibrium is developed. We find that non-equilibrium spinodal instabilities of long wavelength pion fluctuations are responsible for an enhanced photoproduction rate for energies $\leq 80$ MeV at order $\alpha$. These non-equilibrium effects lead to a larger contribution than the typical processes in the medium, including that of the anomalous neutral pion decay $\pi^0 \rightarrow 2 \gamma$ (which is of order $\alpha^2$). We follow the evolution of the dynamics throughout the phase transition, which in this scenario occurs on a time scale of about $2.5-3$ fm/c and integrate the photon yield through its evolution. The spectrum of photons produced throughout the phase transition is a non- equilibrium one. For thermal initial conditions at the time of the quench it interpolates between a thermal distribution about 6% above the initial temperature (at the time of the quench) for low energy $\leq 80$ MeV photons, and a high energy tail in thermal equilibrium at the initial temperature, with a smooth crossover at 100 MeV. The rate displays a peak at $\sim 35$ MeV which receives a larger enhancement the closer the initial temperature at the time of the quench is to the critical temperature. It is found that the enhancement of photoproduction at low energies is not an artifact caused by the initial distribution of the photons, but is due to the pionic instabilities. We suggest that these strong out of equilibrium effects may provide experimental signatures for the formation and relaxation of DCC's in heavy ion collisions. |
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