id stringlengths 9 14 | submitter stringlengths 1 56 ⌀ | authors stringlengths 5 7.68k | title stringlengths 3 299 | comments stringlengths 1 1.15k ⌀ | journal-ref stringlengths 9 298 ⌀ | doi stringlengths 12 97 ⌀ | report-no stringlengths 3 341 ⌀ | categories stringclasses 869 values | license stringclasses 9 values | orig_abstract stringlengths 16 2.44k | versions listlengths 1 39 | update_date stringlengths 10 10 | authors_parsed listlengths 1 565 | abstract stringlengths 13 2.44k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2108.07826 | Ioannis Tsinikos | Rikkert Frederix, Ioannis Tsinikos | On improving NLO merging for $t \bar t W$ production | 21 pages, 8 figures, 4 tables | null | 10.1007/JHEP11(2021)029 | LU-TP 21-34 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce an improvement to the FxFx matrix element merging procedure for
$pp\to t \bar t W$ production at NLO in QCD with one and/or two additional
jets. The main modification is an improved treatment of jets that are not
logarithmically enhanced in the low transverse-momentum regime. We provide
predictions for the inclusive cross section and the $t \bar t W$ differential
distributions including parton-shower effects. Taking also the NLO EW
corrections into account, this results in the most-accurate predictions for
this process to date. We further proceed to include the on-shell LO decays of
the $t \bar t W$ including the tree-level spin correlations within the
narrow-width approximation, focusing on the multi-lepton signatures studied at
the LHC. We find a $\sim\!\!30\%$ increase over the NLO QCD prediction and
large non-flat $K$-factors to differential distributions.
| [
{
"created": "Tue, 17 Aug 2021 18:03:14 GMT",
"version": "v1"
}
] | 2021-11-24 | [
[
"Frederix",
"Rikkert",
""
],
[
"Tsinikos",
"Ioannis",
""
]
] | We introduce an improvement to the FxFx matrix element merging procedure for $pp\to t \bar t W$ production at NLO in QCD with one and/or two additional jets. The main modification is an improved treatment of jets that are not logarithmically enhanced in the low transverse-momentum regime. We provide predictions for the inclusive cross section and the $t \bar t W$ differential distributions including parton-shower effects. Taking also the NLO EW corrections into account, this results in the most-accurate predictions for this process to date. We further proceed to include the on-shell LO decays of the $t \bar t W$ including the tree-level spin correlations within the narrow-width approximation, focusing on the multi-lepton signatures studied at the LHC. We find a $\sim\!\!30\%$ increase over the NLO QCD prediction and large non-flat $K$-factors to differential distributions. |
1906.05829 | Narayan Rana | J. Ablinger, J. Bl\"umlein, P. Marquard, N. Rana, C. Schneider | Three loop heavy quark form factors and their asymptotic behavior | 8 pages; To appear in the contributions of DAE-BRNS 2018, 10th - 14th
December 2018, Chennai, India; | null | null | DESY 19-096, DO-TH 19/09, SAGEX-2019-13 | hep-ph hep-th math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A summary of the calculation of the color-planar and complete light quark
contributions to the massive three-loop form factors is presented. Here a novel
calculation method for the Feynman integrals is used, solving general
uni-variate first order factorizable systems of differential equations. We also
present predictions for the asymptotic structure of these form factors.
| [
{
"created": "Thu, 13 Jun 2019 17:19:15 GMT",
"version": "v1"
}
] | 2019-06-14 | [
[
"Ablinger",
"J.",
""
],
[
"Blümlein",
"J.",
""
],
[
"Marquard",
"P.",
""
],
[
"Rana",
"N.",
""
],
[
"Schneider",
"C.",
""
]
] | A summary of the calculation of the color-planar and complete light quark contributions to the massive three-loop form factors is presented. Here a novel calculation method for the Feynman integrals is used, solving general uni-variate first order factorizable systems of differential equations. We also present predictions for the asymptotic structure of these form factors. |
hep-ph/9904318 | Haim Goldberg | Haim Goldberg | Gravitons and the Drell-Hearn-Gerasimov Sum Rule | 12 pages, LaTex, 1 figure. Replacement conforms with version to be
published in Physics Letters B | Phys.Lett. B472 (2000) 280-286 | 10.1016/S0370-2693(99)01381-7 | null | hep-ph | null | One-loop diagrams containing a graviton provide a finite contribution to the
anomalous magnetic moment $\al$ of a lepton, whether or not the graviton
propagates in $n$ large extra compact dimensions. In the present work, the tree
graph photoproduction of a graviton, integrated up to an arbitrary cutoff, is
shown to violate the Drell-Hearn-Gerasimov sum rule for $\al^2$. The
possibility of resurrecting the sum rule from high energy contributions
originating in string excitations is discussed in a qualitative manner, and
various problems associated with such a program are pointed out.
| [
{
"created": "Tue, 13 Apr 1999 16:53:08 GMT",
"version": "v1"
},
{
"created": "Fri, 14 May 1999 17:04:35 GMT",
"version": "v2"
},
{
"created": "Wed, 19 May 1999 16:10:25 GMT",
"version": "v3"
},
{
"created": "Wed, 19 Jan 2000 16:06:16 GMT",
"version": "v4"
}
] | 2009-10-31 | [
[
"Goldberg",
"Haim",
""
]
] | One-loop diagrams containing a graviton provide a finite contribution to the anomalous magnetic moment $\al$ of a lepton, whether or not the graviton propagates in $n$ large extra compact dimensions. In the present work, the tree graph photoproduction of a graviton, integrated up to an arbitrary cutoff, is shown to violate the Drell-Hearn-Gerasimov sum rule for $\al^2$. The possibility of resurrecting the sum rule from high energy contributions originating in string excitations is discussed in a qualitative manner, and various problems associated with such a program are pointed out. |
hep-ph/0301250 | Sheldon Lee Glashow | Sheldon Lee Glashow | Neutrinos with Seesaw Masses and Suppressed Interactions | 7 pages, harvmac | null | null | null | hep-ph | null | Mixing between light and heavy neutrino states has been proposed as an
explanation (or partial explanation) for the 3-sigma NuTeV anomaly and the
2-sigma departure of the $Z^0$ invisible width from its expected value. I
assume herein that neutrino masses and mixings result from the conventional
seesaw mechanism involving six chiral neutrino states, the first three being
members of weak doublets, the others weak singlets. A finely-tuned choice of
both the (bare) Majorana masses and the (Higgs-induced) Dirac masses can fit
solar and atmospheric neutrino data and also result in significant (but
necessarily flavor-dependent) mixing between singlet and doublet states such as
would yield detectable suppression of light neutrino interaction amplitudes.
The possibility for this kind of suppressive mixing is constrained by the
observed upper limit on radiative muon decay.
| [
{
"created": "Tue, 28 Jan 2003 19:57:33 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Glashow",
"Sheldon Lee",
""
]
] | Mixing between light and heavy neutrino states has been proposed as an explanation (or partial explanation) for the 3-sigma NuTeV anomaly and the 2-sigma departure of the $Z^0$ invisible width from its expected value. I assume herein that neutrino masses and mixings result from the conventional seesaw mechanism involving six chiral neutrino states, the first three being members of weak doublets, the others weak singlets. A finely-tuned choice of both the (bare) Majorana masses and the (Higgs-induced) Dirac masses can fit solar and atmospheric neutrino data and also result in significant (but necessarily flavor-dependent) mixing between singlet and doublet states such as would yield detectable suppression of light neutrino interaction amplitudes. The possibility for this kind of suppressive mixing is constrained by the observed upper limit on radiative muon decay. |
0804.3478 | Richard Williams | Reinhard Alkofer, Christian S. Fischer, Richard Williams | U_A(1) anomaly and eta' mass from an infrared singular quark-gluon
vertex | 8 pages, 4 figures. Version to appear in EPJA | Eur.Phys.J.A38:53-60,2008 | 10.1140/epja/i2008-10646-x | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The $U_A(1)$ problem of QCD is inevitably tied to the infrared behaviour of
quarks and gluons with its most visible effect being the $\eta^\prime$ mass. A
dimensional argument of Kogut and Susskind showed that the mixing of the
pseudoscalar flavour-singlet mesons with gluons can provide a screening of the
Goldstone pole in this channel if the full quark-quark interaction is strongly
infrared singular as $\sim 1/k^4$. We investigate this idea using previously
obtained results for the Landau gauge ghost and gluon propagator, together with
recent determinations for the singular behaviour of the quark-gluon vertex. We
find that, even with an infrared vanishing gluon propagator, the singular
structure of the quark-gluon vertex for certain kinematics is apposite for
yielding a non-zero screening mass.
| [
{
"created": "Tue, 22 Apr 2008 09:29:58 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Sep 2008 11:01:33 GMT",
"version": "v2"
}
] | 2008-12-18 | [
[
"Alkofer",
"Reinhard",
""
],
[
"Fischer",
"Christian S.",
""
],
[
"Williams",
"Richard",
""
]
] | The $U_A(1)$ problem of QCD is inevitably tied to the infrared behaviour of quarks and gluons with its most visible effect being the $\eta^\prime$ mass. A dimensional argument of Kogut and Susskind showed that the mixing of the pseudoscalar flavour-singlet mesons with gluons can provide a screening of the Goldstone pole in this channel if the full quark-quark interaction is strongly infrared singular as $\sim 1/k^4$. We investigate this idea using previously obtained results for the Landau gauge ghost and gluon propagator, together with recent determinations for the singular behaviour of the quark-gluon vertex. We find that, even with an infrared vanishing gluon propagator, the singular structure of the quark-gluon vertex for certain kinematics is apposite for yielding a non-zero screening mass. |
hep-ph/0203264 | Maxim V. Polyakov | N. Kivel, M.V. Polyakov | One Loop Chiral Corrections to Hard Exclusive Processes:I. Pion Case | 17 pages, 3 figures | null | 10.1016/S0375-9474(02)01219-8 | RUB-TPII-02/02 | hep-ph | null | We computed the leading non-analytic chiral corrections to the generalized
parton distributions (GPDs) of the pion and to the two-pion distribution
amplitudes. This allows us to obtain the corresponding corrections for the hard
exclusive processes, such as gamma^* gamma -> pi pi, gamma^* N -> 2pi N' and
deeply virtual Compton scattering on the pion target.
| [
{
"created": "Thu, 28 Mar 2002 10:16:19 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Kivel",
"N.",
""
],
[
"Polyakov",
"M. V.",
""
]
] | We computed the leading non-analytic chiral corrections to the generalized parton distributions (GPDs) of the pion and to the two-pion distribution amplitudes. This allows us to obtain the corresponding corrections for the hard exclusive processes, such as gamma^* gamma -> pi pi, gamma^* N -> 2pi N' and deeply virtual Compton scattering on the pion target. |
hep-ph/9606267 | Martin Maul | R. Kirschner, L. Mankiewicz, A. Sch\"afer, and L. Szymanowski | Small $x$ behaviour of the chirally-odd parton distribution $h_1(x,Q^2)$ | 16 pages latex | Z.Phys. C74 (1997) 501-508 | null | UFTP 416 preprint/1996, NTZ 26/96, TUM/T39-96-16 | hep-ph | null | The small $x$ behaviour of the structure function $h_1(x,Q^2)$ is studied
within the leading logarithmic approximation of perturbative QCD. There are two
contributions relevant at small $x$. The leading one behaves like
$(\frac{1}{x})^0$ i.e. it is just a constant in this limit. The second
contribution, suppressed by one power of $x$, includes the terms summed by the
GLAP equation. Thus for $h_1(x,Q^2)$ the GLAP asymptotics and Regge asymptotics
are completely different, making $h_1(x,Q^2)$ quite an interesting quantity for
the study of small $x$ physics.
| [
{
"created": "Fri, 7 Jun 1996 15:19:30 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kirschner",
"R.",
""
],
[
"Mankiewicz",
"L.",
""
],
[
"Schäfer",
"A.",
""
],
[
"Szymanowski",
"L.",
""
]
] | The small $x$ behaviour of the structure function $h_1(x,Q^2)$ is studied within the leading logarithmic approximation of perturbative QCD. There are two contributions relevant at small $x$. The leading one behaves like $(\frac{1}{x})^0$ i.e. it is just a constant in this limit. The second contribution, suppressed by one power of $x$, includes the terms summed by the GLAP equation. Thus for $h_1(x,Q^2)$ the GLAP asymptotics and Regge asymptotics are completely different, making $h_1(x,Q^2)$ quite an interesting quantity for the study of small $x$ physics. |
1801.09943 | Andreas Otto | Andreas Otto, Hans Oppitz, Burkhard K\"ampfer | Assisted Vacuum Decay by Time Dependent Electric Fields | 9 pages, 7 figures | null | 10.1140/epja/i2018-12473-x | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the vacuum decay by electron-positron pair production in
spatially homogeneous, time dependent electric fields by means of quantum
kinetic equations. Our focus is on the impact of various pulse shapes as
envelopes of oscillating fields and the assistance effects in multi-scale
fields, which are also seen in photons accompanying the creation and motion of
pairs.
| [
{
"created": "Tue, 30 Jan 2018 11:54:25 GMT",
"version": "v1"
}
] | 2018-04-04 | [
[
"Otto",
"Andreas",
""
],
[
"Oppitz",
"Hans",
""
],
[
"Kämpfer",
"Burkhard",
""
]
] | We consider the vacuum decay by electron-positron pair production in spatially homogeneous, time dependent electric fields by means of quantum kinetic equations. Our focus is on the impact of various pulse shapes as envelopes of oscillating fields and the assistance effects in multi-scale fields, which are also seen in photons accompanying the creation and motion of pairs. |
hep-ph/0410096 | Alejandro Szynkman | Ezequiel Alvarez, Luis N. Epele, Daniel Gomez Dumm, Alejandro Szynkman | Right handed currents and FSI phases in B^0 --> \phi K^{*0} | 16 pages, no figures. Comments and references added, conclusions
unchanged. Final version to appear in Phys. Rev. D | Phys.Rev. D70 (2004) 115014 | 10.1103/PhysRevD.70.115014 | null | hep-ph | null | We consider possible effects of New Physics (NP) on the angular distributions
of the decay B^0 --> \phi K^{*0}, showing how these effects depend on the
nature of nonstandard interactions. In a general framework based on
factorization, we show that triple products can be used to probe the chirality
of NP currents. In this analysis we take into account the presence of
non-vanishing strong phases, which is motivated by recent experimental
evidence. It is seen that the observability of right-handed NP is strongly
dependent on the relation between the relative magnitude of these phases and
the ratio of Standard Model and NP scales. As an application we estimate the
expected values of relevant observables in a particular Left Right Symmetric
Model.
| [
{
"created": "Wed, 6 Oct 2004 21:16:22 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Dec 2004 18:38:18 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Alvarez",
"Ezequiel",
""
],
[
"Epele",
"Luis N.",
""
],
[
"Dumm",
"Daniel Gomez",
""
],
[
"Szynkman",
"Alejandro",
""
]
] | We consider possible effects of New Physics (NP) on the angular distributions of the decay B^0 --> \phi K^{*0}, showing how these effects depend on the nature of nonstandard interactions. In a general framework based on factorization, we show that triple products can be used to probe the chirality of NP currents. In this analysis we take into account the presence of non-vanishing strong phases, which is motivated by recent experimental evidence. It is seen that the observability of right-handed NP is strongly dependent on the relation between the relative magnitude of these phases and the ratio of Standard Model and NP scales. As an application we estimate the expected values of relevant observables in a particular Left Right Symmetric Model. |
hep-ph/9812430 | Zhang Ai Lin | Tao Huang, Hongying Jin and Ailin Zhang | Decay of heavy-light hybrids in HQET sum rules | 14 pages, latex file, 4 ps figs, Published version, some numerical
results changed | Phys.Rev.D60:114004,1999 | 10.1103/PhysRevD.60.114004 | null | hep-ph | null | The decay widths of the 0^{++} and 1^{-+} heavy-light hybrids to B(D) and
pion are calculated by using the QCD sum rules. The interpolated current of the
hybrid is chosen as $g\bar q\gamma_{\alpha}G_{\alpha\mu}^aT^ah_{\it v}(x)$. In
order to simplify the calculation and avoid the ambiguity of three-point
correlation function, a two-point correlation function between the pion and
vacuum is used instead. The decay width of the $0^{++}\to B(D)$ is about 12(16)
MeV while the $1^{-+}\to B(D)$ is around 0.4(1.8) MeV. We keep the leading
order of 1/M_Q expansion in our calculation for convenience.
| [
{
"created": "Fri, 18 Dec 1998 14:57:05 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Mar 1999 04:23:21 GMT",
"version": "v2"
},
{
"created": "Sat, 6 Nov 1999 07:58:26 GMT",
"version": "v3"
}
] | 2011-01-25 | [
[
"Huang",
"Tao",
""
],
[
"Jin",
"Hongying",
""
],
[
"Zhang",
"Ailin",
""
]
] | The decay widths of the 0^{++} and 1^{-+} heavy-light hybrids to B(D) and pion are calculated by using the QCD sum rules. The interpolated current of the hybrid is chosen as $g\bar q\gamma_{\alpha}G_{\alpha\mu}^aT^ah_{\it v}(x)$. In order to simplify the calculation and avoid the ambiguity of three-point correlation function, a two-point correlation function between the pion and vacuum is used instead. The decay width of the $0^{++}\to B(D)$ is about 12(16) MeV while the $1^{-+}\to B(D)$ is around 0.4(1.8) MeV. We keep the leading order of 1/M_Q expansion in our calculation for convenience. |
2403.02401 | Nayan Das | Debasish Borah, Nayan Das, Suruj Jyoti Das, and Rome Samanta | Cogenesis of baryon and dark matter with PBH and QCD axion | 33 pages, 9 captioned figures | null | null | CTPU-PTC-24-06 | hep-ph astro-ph.CO | http://creativecommons.org/licenses/by/4.0/ | We study the role of an ultra-light primordial black hole (PBH) dominated
phase on the generation of baryon asymmetry of the Universe (BAU) and dark
matter (DM) in a type-I seesaw framework augmented by Peccei-Quinn (PQ)
symmetry which solves the strong CP problem. While the BAU is generated via
leptogenesis from the decay of heavy right-handed neutrino (RHN) at the seesaw
scale dictated by the PQ scale, DM can arise either from QCD axion or one of
the RHNs depending upon the PQ scale. The ultra-light PBH not only affects the
axion DM production via misalignment mechanism, but can also produce superheavy
RHN DM via evaporation. Depending upon the PBH parameters and relative
abundance of axion DM, axion mass can vary over a wide range from sub-$\mu$eV
to sub-eV keeping the detection prospects promising across a wide range of
experiments. While hot axions produced from PBH evaporation can lead to
observable $\Delta N_{\rm eff}$ to be probed at future cosmic microwave
background (CMB) experiments, stochastic gravitational waves (GW) produced from
PBH density fluctuations can be observed at future detectors like CE, DECIGO,
LISA and even future runs of LIGO-VIRGO.
| [
{
"created": "Mon, 4 Mar 2024 19:00:08 GMT",
"version": "v1"
}
] | 2024-03-06 | [
[
"Borah",
"Debasish",
""
],
[
"Das",
"Nayan",
""
],
[
"Das",
"Suruj Jyoti",
""
],
[
"Samanta",
"Rome",
""
]
] | We study the role of an ultra-light primordial black hole (PBH) dominated phase on the generation of baryon asymmetry of the Universe (BAU) and dark matter (DM) in a type-I seesaw framework augmented by Peccei-Quinn (PQ) symmetry which solves the strong CP problem. While the BAU is generated via leptogenesis from the decay of heavy right-handed neutrino (RHN) at the seesaw scale dictated by the PQ scale, DM can arise either from QCD axion or one of the RHNs depending upon the PQ scale. The ultra-light PBH not only affects the axion DM production via misalignment mechanism, but can also produce superheavy RHN DM via evaporation. Depending upon the PBH parameters and relative abundance of axion DM, axion mass can vary over a wide range from sub-$\mu$eV to sub-eV keeping the detection prospects promising across a wide range of experiments. While hot axions produced from PBH evaporation can lead to observable $\Delta N_{\rm eff}$ to be probed at future cosmic microwave background (CMB) experiments, stochastic gravitational waves (GW) produced from PBH density fluctuations can be observed at future detectors like CE, DECIGO, LISA and even future runs of LIGO-VIRGO. |
2311.10829 | Gordan Krnjaic | Cari Cesarotti, Yonatan Kahn, Gordan Krnjaic, Duncan Rocha, Joshua
Spitz | New $\mu$ Forces From $\nu_\mu$ Sources | 6 pages, 6 figures | null | null | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | Accelerator-based experiments reliant on charged pion and kaon decays to
produce muon-neutrino beams also deliver an associated powerful flux of muons.
Therefore, these experiments can additionally be sensitive to light new
particles that preferentially couple to muons and decay to visible final states
on macroscopic length scales. Such particles are produced through rare 3-body
meson decays in the decay pipe or via muon scattering in the beam dump, and
decay in a downstream detector. To demonstrate the potential of this search
strategy, we recast existing MiniBooNE and MicroBooNE studies of neutral pion
production in neutrino-induced neutral-current scattering ($\nu_\mu N \to
\nu_\mu N \pi^0,~\pi^0\rightarrow \gamma\gamma$) to place new leading limits on
light ($< 2m_\mu$) muon-philic scalar particles that decay to diphotons through
loops of virtual muons. Our results exclude scalars of mass between 10 and 60
MeV in which this scenario resolves the muon $g-2$ anomaly. We also make
projections for the sensitivity of SBND to these models and provide a road map
for future neutrino experiments to perform dedicated searches for muon-philic
forces.
| [
{
"created": "Fri, 17 Nov 2023 19:20:24 GMT",
"version": "v1"
}
] | 2023-11-21 | [
[
"Cesarotti",
"Cari",
""
],
[
"Kahn",
"Yonatan",
""
],
[
"Krnjaic",
"Gordan",
""
],
[
"Rocha",
"Duncan",
""
],
[
"Spitz",
"Joshua",
""
]
] | Accelerator-based experiments reliant on charged pion and kaon decays to produce muon-neutrino beams also deliver an associated powerful flux of muons. Therefore, these experiments can additionally be sensitive to light new particles that preferentially couple to muons and decay to visible final states on macroscopic length scales. Such particles are produced through rare 3-body meson decays in the decay pipe or via muon scattering in the beam dump, and decay in a downstream detector. To demonstrate the potential of this search strategy, we recast existing MiniBooNE and MicroBooNE studies of neutral pion production in neutrino-induced neutral-current scattering ($\nu_\mu N \to \nu_\mu N \pi^0,~\pi^0\rightarrow \gamma\gamma$) to place new leading limits on light ($< 2m_\mu$) muon-philic scalar particles that decay to diphotons through loops of virtual muons. Our results exclude scalars of mass between 10 and 60 MeV in which this scenario resolves the muon $g-2$ anomaly. We also make projections for the sensitivity of SBND to these models and provide a road map for future neutrino experiments to perform dedicated searches for muon-philic forces. |
hep-ph/9909350 | Dejan Stojkovic | Glenn D. Starkman and Dejan Stojkovic | Neutrino Masses and Mixing with General Mass Matrices | LaTeX, 12 pages | Phys.Lett. B480 (2000) 381-391 | 10.1016/S0370-2693(00)00397-X | null | hep-ph | null | We consider the most general neutrino masses and mixings including Dirac mass
terms, M_D, as well as Majorana masses, M_R and M_L. Neither the Majorana nor
the Dirac mass matrices are expected to be diagonal in the eigenbasis of weak
interactions, and so the resulting eigenstates of the Hamiltonian are
admixtures of $\SU(2)_L$ singlet and doublet fields of different
``generations.'' We show that for three generations each of doublet and singlet
neutrinos, diagonalization of the Hamiltonian to obtain the propagating
eigenstates in the general case requires diagonalization of a $12\times12$
Hermitian matrix, rather than the traditional $6\times6$ symmetric mass matrix.
The symmetries of the $12\times12$ matrix {\em are} such that it has 6 pairs of
real eigenvalues. Although the standard "see-saw" mechanism remains valid, and
indeed the eigenvalues obtained are identical to the standard ones, the correct
description of diagonalization and mixing is more complicated. The analogs of
the CKM matrix for the light and the heavy neutrinos are nonunitary, enriching
the opportunities for CP violation in the full neutrino sector.
| [
{
"created": "Mon, 13 Sep 1999 19:39:41 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Starkman",
"Glenn D.",
""
],
[
"Stojkovic",
"Dejan",
""
]
] | We consider the most general neutrino masses and mixings including Dirac mass terms, M_D, as well as Majorana masses, M_R and M_L. Neither the Majorana nor the Dirac mass matrices are expected to be diagonal in the eigenbasis of weak interactions, and so the resulting eigenstates of the Hamiltonian are admixtures of $\SU(2)_L$ singlet and doublet fields of different ``generations.'' We show that for three generations each of doublet and singlet neutrinos, diagonalization of the Hamiltonian to obtain the propagating eigenstates in the general case requires diagonalization of a $12\times12$ Hermitian matrix, rather than the traditional $6\times6$ symmetric mass matrix. The symmetries of the $12\times12$ matrix {\em are} such that it has 6 pairs of real eigenvalues. Although the standard "see-saw" mechanism remains valid, and indeed the eigenvalues obtained are identical to the standard ones, the correct description of diagonalization and mixing is more complicated. The analogs of the CKM matrix for the light and the heavy neutrinos are nonunitary, enriching the opportunities for CP violation in the full neutrino sector. |
0802.4085 | Pran Nath | Daniel Feldman, Zuowei Liu, and Pran Nath | Sparticles at the LHC | 38 pages, 15 figures; Published in JHEP | JHEP 0804:054,2008 | 10.1088/1126-6708/2008/04/054 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Sparticle mass hierarchies will play an important role in the type of
signatures that will be visible at the Large Hadron Collider. We analyze these
hierarchies for the four lightest sparticles for a general class of
supergravity unified models including nonuniversalities in the soft breaking
sector. It is shown that out of nearly $10^4$ possibilities of sparticle mass
hierarchies, only a small number survives the rigorous constraints of radiative
electroweak symmetry breaking, relic density and other experimental
constraints. The signature space of these mass patterns at the Large Hadron
Collider is investigated using a large set of final states including
multi-leptonic states, hadronically decaying $\tau$s, tagged $b$ jets and other
hadronic jets. In all, we analyze more than 40 such lepton plus jet and missing
energy signatures along with several kinematical signatures such as missing
transverse momentum, effective mass, and invariant mass distributions of final
state observables. It is shown that a composite analysis can produce
significant discrimination among sparticle mass patterns allowing for a
possible identification of the source of soft breaking. While the analysis
given is for supergravity models, the techniques based on mass pattern analysis
are applicable to wide class of models including string and brane models.
| [
{
"created": "Thu, 28 Feb 2008 20:50:44 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Apr 2008 19:16:30 GMT",
"version": "v2"
}
] | 2011-06-10 | [
[
"Feldman",
"Daniel",
""
],
[
"Liu",
"Zuowei",
""
],
[
"Nath",
"Pran",
""
]
] | Sparticle mass hierarchies will play an important role in the type of signatures that will be visible at the Large Hadron Collider. We analyze these hierarchies for the four lightest sparticles for a general class of supergravity unified models including nonuniversalities in the soft breaking sector. It is shown that out of nearly $10^4$ possibilities of sparticle mass hierarchies, only a small number survives the rigorous constraints of radiative electroweak symmetry breaking, relic density and other experimental constraints. The signature space of these mass patterns at the Large Hadron Collider is investigated using a large set of final states including multi-leptonic states, hadronically decaying $\tau$s, tagged $b$ jets and other hadronic jets. In all, we analyze more than 40 such lepton plus jet and missing energy signatures along with several kinematical signatures such as missing transverse momentum, effective mass, and invariant mass distributions of final state observables. It is shown that a composite analysis can produce significant discrimination among sparticle mass patterns allowing for a possible identification of the source of soft breaking. While the analysis given is for supergravity models, the techniques based on mass pattern analysis are applicable to wide class of models including string and brane models. |
0801.2018 | S Dev Sharma | S. Dev and Sanjeev Kumar | Two-Zero Symmetric Neutrino Mass Matrices in Minimal Supersymmetric
SO(10) | 12 pages, two tables | null | null | null | hep-ph | null | The phenomenological neutrino mass matrix for two-zero symmetric texture has
been obtained and used to rule out all possible two-zero symmetric neutrino
mass matrices obtained from Yukawa couplings to $\mathbf{10}$ and
$\mathbf{126}$ Higgs representations within the framework of minimal
supersymmetric SO(10).
| [
{
"created": "Mon, 14 Jan 2008 07:26:12 GMT",
"version": "v1"
}
] | 2008-01-15 | [
[
"Dev",
"S.",
""
],
[
"Kumar",
"Sanjeev",
""
]
] | The phenomenological neutrino mass matrix for two-zero symmetric texture has been obtained and used to rule out all possible two-zero symmetric neutrino mass matrices obtained from Yukawa couplings to $\mathbf{10}$ and $\mathbf{126}$ Higgs representations within the framework of minimal supersymmetric SO(10). |
1703.03832 | Heather E. Logan | Mary-Jean Harris and Heather E. Logan (Carleton U.) | Constraining the scalar septet model through vector boson scattering | 9 pages, 1 figure. v2: reference added, minor improvements to text,
version accepted by PRD | Phys. Rev. D 95, 095003 (2017) | 10.1103/PhysRevD.95.095003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The scalar septet model extends the Standard Model Higgs sector by an isospin
septet with hypercharge chosen to preserve $\rho \equiv M_W^2/M_Z^2
\cos^2\theta_W = 1$. In this paper we constrain the model at high septet masses
using perturbative unitarity of longitudinal vector boson scattering
amplitudes. We also apply the constraints from LHC searches for doubly-charged
Higgs bosons produced in vector boson fusion, which constrain the model at
lower septet masses. We point out some important differences between the septet
model and extended Higgs models that preserve custodial symmetry in the scalar
spectrum.
| [
{
"created": "Fri, 10 Mar 2017 20:11:06 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Apr 2017 17:55:13 GMT",
"version": "v2"
}
] | 2017-05-10 | [
[
"Harris",
"Mary-Jean",
"",
"Carleton U."
],
[
"Logan",
"Heather E.",
"",
"Carleton U."
]
] | The scalar septet model extends the Standard Model Higgs sector by an isospin septet with hypercharge chosen to preserve $\rho \equiv M_W^2/M_Z^2 \cos^2\theta_W = 1$. In this paper we constrain the model at high septet masses using perturbative unitarity of longitudinal vector boson scattering amplitudes. We also apply the constraints from LHC searches for doubly-charged Higgs bosons produced in vector boson fusion, which constrain the model at lower septet masses. We point out some important differences between the septet model and extended Higgs models that preserve custodial symmetry in the scalar spectrum. |
hep-ph/0001007 | Pierre Ramond | P. Ramond (Physics Department, University of Florida) | Introduction to Neutrinos | Invited Talk at the XI Rencontre de Blois, June 27-July 3, 1999.
Latex, 11 pages | null | null | null | hep-ph | null | We discuss current theoretical and experimental issues associated with the
recent SuperKamiokande discovery. We survey theoretical models for predictings
the new Standard Model parameters needed to explain this discovery, and point
out how quark-lepton symmetries, either in the framework of Grand Unification,
or of string theories, can be used to determine them.
| [
{
"created": "Sun, 2 Jan 2000 18:35:58 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ramond",
"P.",
"",
"Physics Department, University of Florida"
]
] | We discuss current theoretical and experimental issues associated with the recent SuperKamiokande discovery. We survey theoretical models for predictings the new Standard Model parameters needed to explain this discovery, and point out how quark-lepton symmetries, either in the framework of Grand Unification, or of string theories, can be used to determine them. |
2302.01143 | Zhijie Zhao | Sichun Sun, Qi-Shu Yan, Xiaoran Zhao, Zhijie Zhao | Constraining rare B decays by $\mu^+\mu^-\to tc$ at future lepton
colliders | 29 pages, 8 figures, 3 tables, added references, publication version | Phys.Rev.D 108 (2023) 7, 075016 | 10.1103/PhysRevD.108.075016 | null | hep-ph | http://creativecommons.org/publicdomain/zero/1.0/ | Motivated by the recent rare B decays measurements, we study the matching
procedure of operators $O_9, O_{10}$ in the low energy effective Hamiltonian
and operators in the Standard Model effective theory (SMEFT). It is noticed
that there are more related operators in the SMEFT whose coefficients can not
be determined only from the low-energy data from B physics. We demonstrate how
to determine these coefficients with some new physics models, like $Z^\prime$
model and leptoquark models, and then consider how to probe these operators of
SMEFT at high energy by using the process $\mu^+\mu^-\to tc$ at future muon
colliders, which can provide complementary information except for $\mu^+ \mu^-
\to b s$ on the underlying models which lead to rare B decay processes. We
perform a Monte Carlo study (a hadron level analysis) to show how to separate
the signal events from the SM background events and estimate the sensitivity to
the Wilson coefficients for different models.
| [
{
"created": "Thu, 2 Feb 2023 14:57:18 GMT",
"version": "v1"
},
{
"created": "Fri, 24 Feb 2023 17:54:07 GMT",
"version": "v2"
},
{
"created": "Wed, 18 Oct 2023 13:47:24 GMT",
"version": "v3"
}
] | 2023-10-19 | [
[
"Sun",
"Sichun",
""
],
[
"Yan",
"Qi-Shu",
""
],
[
"Zhao",
"Xiaoran",
""
],
[
"Zhao",
"Zhijie",
""
]
] | Motivated by the recent rare B decays measurements, we study the matching procedure of operators $O_9, O_{10}$ in the low energy effective Hamiltonian and operators in the Standard Model effective theory (SMEFT). It is noticed that there are more related operators in the SMEFT whose coefficients can not be determined only from the low-energy data from B physics. We demonstrate how to determine these coefficients with some new physics models, like $Z^\prime$ model and leptoquark models, and then consider how to probe these operators of SMEFT at high energy by using the process $\mu^+\mu^-\to tc$ at future muon colliders, which can provide complementary information except for $\mu^+ \mu^- \to b s$ on the underlying models which lead to rare B decay processes. We perform a Monte Carlo study (a hadron level analysis) to show how to separate the signal events from the SM background events and estimate the sensitivity to the Wilson coefficients for different models. |
1210.2633 | David R. Entem | P. G. Ortega, D. R. Entem, F. Fern\'andez | Quark model description of the \Lambda_c(2940)^+ as a molecular D^*N
state and the possible existence of the \Lambda_b(6248) | 5 pages, no figures, 4 tables | null | 10.1016/j.physletb.2012.12.025 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The \Lambda_c(2940)^+ baryon is studied in a constituent quark model as a
molecular state composed by nucleons and D^* mesons. A bound state with the
right binding energy is found for the J^\pi=3/2^- channel. The partial widths
\Lambda_c(2940)^+\to ND and \Lambda_c(2940)^+\to \Sigma_c \pi are calculated
and the results are consistent with the experimental data. Additionally a
bottom partner \bar B^*N is predicted with a mass of 6248 MeV/c^2.
| [
{
"created": "Tue, 9 Oct 2012 15:06:34 GMT",
"version": "v1"
}
] | 2015-06-11 | [
[
"Ortega",
"P. G.",
""
],
[
"Entem",
"D. R.",
""
],
[
"Fernández",
"F.",
""
]
] | The \Lambda_c(2940)^+ baryon is studied in a constituent quark model as a molecular state composed by nucleons and D^* mesons. A bound state with the right binding energy is found for the J^\pi=3/2^- channel. The partial widths \Lambda_c(2940)^+\to ND and \Lambda_c(2940)^+\to \Sigma_c \pi are calculated and the results are consistent with the experimental data. Additionally a bottom partner \bar B^*N is predicted with a mass of 6248 MeV/c^2. |
hep-ph/9712352 | Levai Peter | J. Zimanyi, T.S. Biro and P. Levai | The dependence of strange hadron multiplicities on the speed of
hadronization | 8 pages, LaTeX in IOP style, appeared in the Proceedings of
Strangeness'97 Conference, Santorini, April 14-18 1997, J. of Physics G23
(1997) 1941 | J.Phys.G23:1941,1997 | 10.1088/0954-3899/23/12/018 | null | hep-ph | null | Hadron multiplicities are calculated in the ALCOR model for the Pb+Pb
collisions at CERN SPS energy. Considering the newest experimental results, we
display our prediction obtained from the ALCOR model for stable hadrons
including strange baryons and anti-baryons.
| [
{
"created": "Thu, 11 Dec 1997 18:29:41 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Zimanyi",
"J.",
""
],
[
"Biro",
"T. S.",
""
],
[
"Levai",
"P.",
""
]
] | Hadron multiplicities are calculated in the ALCOR model for the Pb+Pb collisions at CERN SPS energy. Considering the newest experimental results, we display our prediction obtained from the ALCOR model for stable hadrons including strange baryons and anti-baryons. |
hep-ph/9911522 | Gino Isidori | G. D'Ambrosio, G. Isidori and G. Martinelli | Direct CP violation in K->3pi decays induced by SUSY chromomagnetic
penguins | Latex, 11 pages, 1 figure | Phys.Lett.B480:164-170,2000 | 10.1016/S0370-2693(00)00361-0 | INFNNA-99/39, LPT ORSAY 99/99 | hep-ph | null | An analysis of the CP violating asymmetry in $K^\pm \to (3\pi)^\pm$ decays in
the Standard Model and, by means of the mass insertion approximation, in a wide
class of possible supersymmetric extensions, is presented. We find that the
natural order of magnitude for this asymmetry is $\cO(10^{-5})$ in both cases.
Within supersymmetric models effects as large as $\cO(10^{-4})$ are possible,
but only in a restricted range of the relevant parameters.
| [
{
"created": "Mon, 29 Nov 1999 17:44:37 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"D'Ambrosio",
"G.",
""
],
[
"Isidori",
"G.",
""
],
[
"Martinelli",
"G.",
""
]
] | An analysis of the CP violating asymmetry in $K^\pm \to (3\pi)^\pm$ decays in the Standard Model and, by means of the mass insertion approximation, in a wide class of possible supersymmetric extensions, is presented. We find that the natural order of magnitude for this asymmetry is $\cO(10^{-5})$ in both cases. Within supersymmetric models effects as large as $\cO(10^{-4})$ are possible, but only in a restricted range of the relevant parameters. |
1910.08002 | George W.-S. Hou | George W.-S. Hou | Top-Higgs Associated Production involving {\boldmath ${A^0},\, {H^0}$}
with Mass at 300 GeV | 8 pages, 7 figures, to appear in proceedings of EPS-HEP2019 held in
Ghent, Belgium | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We advocate two Higgs doublet model without $Z_2$ symmetry, and focus on the
extra top Yukawa couplings $\rho_{tt}$ and $\rho_{tc}$. We show that $A^0$ and
$H^0$ bosons are still allowed at 300 GeV mass, where $cg \to tA^0$, $tH^0$ can
lead to $tt\bar c$ same-sign top, or top-assisted di-Higgs $th^0h^0$
signatures, resp. As bonus material, we explore the constraint provided by
current 4-top search, but advocate direct search for triple-top generated by
$cg \to tH^0/A^0 \to tt\bar t$ for $H^0,\, A^0$ above $t\bar t$ threshold, and
offer some insight on the mild but intriguing "excess" found by CMS in $gg \to
A^0 \to t\bar t$ at 400 GeV.
| [
{
"created": "Thu, 17 Oct 2019 16:20:59 GMT",
"version": "v1"
}
] | 2019-10-18 | [
[
"Hou",
"George W. -S.",
""
]
] | We advocate two Higgs doublet model without $Z_2$ symmetry, and focus on the extra top Yukawa couplings $\rho_{tt}$ and $\rho_{tc}$. We show that $A^0$ and $H^0$ bosons are still allowed at 300 GeV mass, where $cg \to tA^0$, $tH^0$ can lead to $tt\bar c$ same-sign top, or top-assisted di-Higgs $th^0h^0$ signatures, resp. As bonus material, we explore the constraint provided by current 4-top search, but advocate direct search for triple-top generated by $cg \to tH^0/A^0 \to tt\bar t$ for $H^0,\, A^0$ above $t\bar t$ threshold, and offer some insight on the mild but intriguing "excess" found by CMS in $gg \to A^0 \to t\bar t$ at 400 GeV. |
1411.0668 | Doojin Kim | Doojin Kim, Hye-Sung Lee and Myeonghun Park | Invisible dark gauge boson search in top decays using a kinematic method | Journal-published version, minor modification in table numbers, 19
pages, 6 figures, 2 tables, references added | JHEP 1503 (2015) 134 | 10.1007/JHEP03(2015)134 | CERN-PH-TH-2014-209, APCTP Pre2014-013, IPMU14-0330 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the discovery potential of a dark force carrier ($Z'$) of very
light mass, $m_{Z'} \lesssim {\cal O}(1-10)$ GeV, at hadron colliders via rare
top quark decays, especially when it decays invisibly in typical search
schemes. We emphasize that the top sector is promising for the discovery of new
particles because top quark pairs are copiously produced at the Large Hadron
Collider. The signal process is initiated by a rare top decay into a bottom
quark and a charged Higgs boson ($H^\pm$) decaying subsequently into a $W$ and
one or multiple $Z'$s. The light $Z'$ can be invisible in collider searches in
various scenarios, and it would be hard to distinguish the relevant collider
signature from the regular $t\bar{t}$ process in the Standard Model. We suggest
a search strategy using the recently proposed on-shell constrained $M_2$
variables. Our signal process is featured by an $\textit{asymmetric}$ event
topology, while the $t\bar{t}$ is $\textit{symmetric}$. The essence behind the
strategy is to evoke some contradiction in the relevant observables by applying
the kinematic variables designed under the assumption of the $t\bar{t}$ event
topology. To see the viability of the proposed technique, we perform Monte
Carlo simulations including realistic effects such as cuts, backgrounds,
detector resolution, and so on at the LHC of $\sqrt{s}=14$ TeV.
| [
{
"created": "Mon, 3 Nov 2014 21:00:04 GMT",
"version": "v1"
},
{
"created": "Tue, 31 Mar 2015 04:22:24 GMT",
"version": "v2"
},
{
"created": "Thu, 17 Sep 2015 02:20:30 GMT",
"version": "v3"
}
] | 2015-09-18 | [
[
"Kim",
"Doojin",
""
],
[
"Lee",
"Hye-Sung",
""
],
[
"Park",
"Myeonghun",
""
]
] | We discuss the discovery potential of a dark force carrier ($Z'$) of very light mass, $m_{Z'} \lesssim {\cal O}(1-10)$ GeV, at hadron colliders via rare top quark decays, especially when it decays invisibly in typical search schemes. We emphasize that the top sector is promising for the discovery of new particles because top quark pairs are copiously produced at the Large Hadron Collider. The signal process is initiated by a rare top decay into a bottom quark and a charged Higgs boson ($H^\pm$) decaying subsequently into a $W$ and one or multiple $Z'$s. The light $Z'$ can be invisible in collider searches in various scenarios, and it would be hard to distinguish the relevant collider signature from the regular $t\bar{t}$ process in the Standard Model. We suggest a search strategy using the recently proposed on-shell constrained $M_2$ variables. Our signal process is featured by an $\textit{asymmetric}$ event topology, while the $t\bar{t}$ is $\textit{symmetric}$. The essence behind the strategy is to evoke some contradiction in the relevant observables by applying the kinematic variables designed under the assumption of the $t\bar{t}$ event topology. To see the viability of the proposed technique, we perform Monte Carlo simulations including realistic effects such as cuts, backgrounds, detector resolution, and so on at the LHC of $\sqrt{s}=14$ TeV. |
1706.10162 | Claude Duhr | {\O}yvind Almelid, Claude Duhr, Einan Gardi, Andrew McLeod, Chris D.
White | Bootstrapping the QCD soft anomalous dimension | 37 pages, 1 figure | null | 10.1007/JHEP09(2017)073 | Edinburgh 2017/13, CERN-TH-2017-138, CP3-17-20, SLAC-PUB-17089,
QMUL-PH-17-10 | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The soft anomalous dimension governs the infrared singularities of scattering
amplitudes to all orders in perturbative quantum field theory, and is a crucial
ingredient in both formal and phenomenological applications of non-abelian
gauge theories. It has recently been computed at three-loop order for massless
partons by explicit evaluation of all relevant Feynman diagrams. In this paper,
we show how the same result can be obtained, up to an overall numerical factor,
using a bootstrap procedure. We first give a geometrical argument for the fact
that the result can be expressed in terms of single-valued harmonic
polylogarithms. We then use symmetry considerations as well as known properties
of scattering amplitudes in collinear and high-energy (Regge) limits to
constrain an ansatz of basis functions. This is a highly non-trivial
cross-check of the result, and our methods pave the way for greatly simplified
higher-order calculations.
| [
{
"created": "Fri, 30 Jun 2017 11:58:16 GMT",
"version": "v1"
}
] | 2017-10-25 | [
[
"Almelid",
"Øyvind",
""
],
[
"Duhr",
"Claude",
""
],
[
"Gardi",
"Einan",
""
],
[
"McLeod",
"Andrew",
""
],
[
"White",
"Chris D.",
""
]
] | The soft anomalous dimension governs the infrared singularities of scattering amplitudes to all orders in perturbative quantum field theory, and is a crucial ingredient in both formal and phenomenological applications of non-abelian gauge theories. It has recently been computed at three-loop order for massless partons by explicit evaluation of all relevant Feynman diagrams. In this paper, we show how the same result can be obtained, up to an overall numerical factor, using a bootstrap procedure. We first give a geometrical argument for the fact that the result can be expressed in terms of single-valued harmonic polylogarithms. We then use symmetry considerations as well as known properties of scattering amplitudes in collinear and high-energy (Regge) limits to constrain an ansatz of basis functions. This is a highly non-trivial cross-check of the result, and our methods pave the way for greatly simplified higher-order calculations. |
hep-ph/0112092 | Ismd31 | Gang Chen, Yuan Hu, Lianshou Liu, W. Kittel, W.J. Metzger | Measurement of the Scaling Property of Factorial Moments in Hadronic Z
Decay | 4 pages, 4 figures in eps, talk given at XXXI International Symposium
on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. see
http://ismd31.ccnu.edu.cn/ | null | 10.1142/9789812778048_0062 | null | hep-ph | null | Both three- and one-dimensional studies of local multiplicity fluctuations in
hadronic Z decay are performed using data of the L3 experiment at LEP. The
normalized factorial moments in three dimensions exhibit power-law scaling,
indicating that the fluctuations are isotropic, which correspends to a
self-similar fractal. A detailed study of the corresponding one-dimensional
moments confirms this conclusion. However, two-jet subsamples have anisotropic
fluctuations, correspending to a self-affine fractal. These features are, at
least qualitatively, reproduced by the Monte Carlo models \JETSET and \HERWIG.
| [
{
"created": "Thu, 6 Dec 2001 03:29:06 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Dec 2001 09:33:12 GMT",
"version": "v2"
},
{
"created": "Wed, 19 Dec 2001 01:35:07 GMT",
"version": "v3"
}
] | 2017-08-23 | [
[
"Chen",
"Gang",
""
],
[
"Hu",
"Yuan",
""
],
[
"Liu",
"Lianshou",
""
],
[
"Kittel",
"W.",
""
],
[
"Metzger",
"W. J.",
""
]
] | Both three- and one-dimensional studies of local multiplicity fluctuations in hadronic Z decay are performed using data of the L3 experiment at LEP. The normalized factorial moments in three dimensions exhibit power-law scaling, indicating that the fluctuations are isotropic, which correspends to a self-similar fractal. A detailed study of the corresponding one-dimensional moments confirms this conclusion. However, two-jet subsamples have anisotropic fluctuations, correspending to a self-affine fractal. These features are, at least qualitatively, reproduced by the Monte Carlo models \JETSET and \HERWIG. |
hep-ph/9403392 | Jutta Kunz | Yves Brihaye and Jutta Kunz | On Axially Symmetric Solutions in the Electroweak Theory | 17 pages, latex, THU-94/07 | Phys.Rev.D50:4175-4182,1994 | 10.1103/PhysRevD.50.4175 | null | hep-ph | null | We present the general ansatz, the energy density and the Chern-Simons charge
for static axially symmetric configurations in the bosonic sector of the
electroweak theory. Containing the sphaleron, the multisphalerons and the
sphaleron-antisphaleron pair at finite mixing angle, the ansatz further allows
the construction of the sphaleron and multisphaleron barriers and of the
bisphalerons at finite mixing angle. We conjecture that further solutions
exist.
| [
{
"created": "Wed, 30 Mar 1994 11:22:42 GMT",
"version": "v1"
}
] | 2010-11-19 | [
[
"Brihaye",
"Yves",
""
],
[
"Kunz",
"Jutta",
""
]
] | We present the general ansatz, the energy density and the Chern-Simons charge for static axially symmetric configurations in the bosonic sector of the electroweak theory. Containing the sphaleron, the multisphalerons and the sphaleron-antisphaleron pair at finite mixing angle, the ansatz further allows the construction of the sphaleron and multisphaleron barriers and of the bisphalerons at finite mixing angle. We conjecture that further solutions exist. |
1904.01154 | Kun Xu | Kun Xu, Mei Huang | Quantized first-order phase transition and two sets of critical end
point in droplet quark matter | 15 pages, 8 figures, proceeding of CPOD2018 | null | null | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The finite-size effect on the chiral phase transition is investigated in the
Nambu--Jona-Lasinio model. To take into account finite-size effects, momentum
integrals are replaced by momentum summations. The ground state of quark matter
at finite size is favored when applying the periodic spatial boundary condition
for quarks. The zero-momentum contribution is taken into account in the
periodic boundary condition, and its contribution becomes important when the
system size is comparable with the pion wavelength. When the zero-mode
contribution becomes dominant, the conventional first-order chiral phase
transition at high baryon chemical potential splits into two first-order phase
transitions in small system of quark matter, and two sets of critical end point
show up in the temperature and chemical potential plane.
| [
{
"created": "Tue, 2 Apr 2019 00:26:47 GMT",
"version": "v1"
}
] | 2019-04-03 | [
[
"Xu",
"Kun",
""
],
[
"Huang",
"Mei",
""
]
] | The finite-size effect on the chiral phase transition is investigated in the Nambu--Jona-Lasinio model. To take into account finite-size effects, momentum integrals are replaced by momentum summations. The ground state of quark matter at finite size is favored when applying the periodic spatial boundary condition for quarks. The zero-momentum contribution is taken into account in the periodic boundary condition, and its contribution becomes important when the system size is comparable with the pion wavelength. When the zero-mode contribution becomes dominant, the conventional first-order chiral phase transition at high baryon chemical potential splits into two first-order phase transitions in small system of quark matter, and two sets of critical end point show up in the temperature and chemical potential plane. |
1503.04970 | P. S. Bhupal Dev | P. S. Bhupal Dev, Chang-Hun Lee, R. N. Mohapatra | TeV Scale Lepton Number Violation and Baryogenesis | 16 pages, 5 figures, 2 tables; Contribution to the Proceedings of
DISCRETE 2014, London; references added in v2. The results presented in
Section 4 of this paper are an updated version of those given in Section III
of 1408.2820 | J. Phys.: Conf. Ser. 631 012007 (2015) | 10.1088/1742-6596/631/1/012007 | MAN/HEP/2014/17 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Contrary to the common lore based on naive dimensional analysis, the seesaw
scale for neutrino masses can be naturally in the TeV range, with small
parameters coming from radiative corrections. We present one such class of
type-I seesaw models, based on the left-right gauge group $SU(2)_L\times
SU(2)_R\times U(1)_{B-L}$ realized at the TeV scale, which fits the observed
neutrino oscillation parameters as well as other low energy constraints. We
discuss how the small parameters of this scenario can arise naturally from one
loop effects. The neutrino fits in this model use quasi-degenerate heavy
Majorana neutrinos, as also required to explain the matter-antimatter asymmetry
in our Universe via resonant leptogenesis mechanism. We discuss the constraints
implied by the dynamics of this mechanism on the mass of the right-handed gauge
boson in this class of models with enhanced neutrino Yukawa couplings compared
to the canonical seesaw model and find a lower bound of $m_{W_R}\geq 9.9$ TeV
for successful leptogenesis assuming maximal CP asymmetry for each flavor. We
also present a model with explicit neutrino mass fit, where the lower bound
goes up to 13.1 TeV due to less than maximal primordial CP asymmetry predicted
by the model.
| [
{
"created": "Tue, 17 Mar 2015 09:57:13 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Mar 2015 18:04:43 GMT",
"version": "v2"
}
] | 2015-08-03 | [
[
"Dev",
"P. S. Bhupal",
""
],
[
"Lee",
"Chang-Hun",
""
],
[
"Mohapatra",
"R. N.",
""
]
] | Contrary to the common lore based on naive dimensional analysis, the seesaw scale for neutrino masses can be naturally in the TeV range, with small parameters coming from radiative corrections. We present one such class of type-I seesaw models, based on the left-right gauge group $SU(2)_L\times SU(2)_R\times U(1)_{B-L}$ realized at the TeV scale, which fits the observed neutrino oscillation parameters as well as other low energy constraints. We discuss how the small parameters of this scenario can arise naturally from one loop effects. The neutrino fits in this model use quasi-degenerate heavy Majorana neutrinos, as also required to explain the matter-antimatter asymmetry in our Universe via resonant leptogenesis mechanism. We discuss the constraints implied by the dynamics of this mechanism on the mass of the right-handed gauge boson in this class of models with enhanced neutrino Yukawa couplings compared to the canonical seesaw model and find a lower bound of $m_{W_R}\geq 9.9$ TeV for successful leptogenesis assuming maximal CP asymmetry for each flavor. We also present a model with explicit neutrino mass fit, where the lower bound goes up to 13.1 TeV due to less than maximal primordial CP asymmetry predicted by the model. |
hep-ph/0012145 | Shaaban Khalil | S. Abel, D. Bailin, S. Khalil, and O. Lebedev | Flavour-Dependent CP Violation and Natural Suppression of the Electric
Dipole Moments | revtex, 4 pages | Phys.Lett. B504 (2001) 241-246 | 10.1016/S0370-2693(01)00303-3 | SUSX-TH-00-022 | hep-ph | null | We revisit the supersymmetric CP problem and find that it can be naturally
resolved if the origin of CP violation is closely related to the origin of
flavour structures. In this case, the supersymmetry breaking dynamics do not
bring in any new CP-violating phases. This mechanism requires hermitian Yukawa
matrices which naturally arise in models with a U(3) flavour symmetry. The
neutron electric dipole moment (NEDM) is predicted to be within one-two orders
of magnitude below the current experimental limit. The model also predicts a
strong correlation between A_{CP}(b --> s gamma)and the NEDM. The strong CP
problem is mitigated although not completely solved.
| [
{
"created": "Wed, 13 Dec 2000 12:02:54 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Feb 2001 18:20:40 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Abel",
"S.",
""
],
[
"Bailin",
"D.",
""
],
[
"Khalil",
"S.",
""
],
[
"Lebedev",
"O.",
""
]
] | We revisit the supersymmetric CP problem and find that it can be naturally resolved if the origin of CP violation is closely related to the origin of flavour structures. In this case, the supersymmetry breaking dynamics do not bring in any new CP-violating phases. This mechanism requires hermitian Yukawa matrices which naturally arise in models with a U(3) flavour symmetry. The neutron electric dipole moment (NEDM) is predicted to be within one-two orders of magnitude below the current experimental limit. The model also predicts a strong correlation between A_{CP}(b --> s gamma)and the NEDM. The strong CP problem is mitigated although not completely solved. |
2402.02577 | Fran\c{c}ois Rondeau | Pascal Anastasopoulos, Ignatios Antoniadis, Karim Benakli,
Fran\c{c}ois Rondeau | Anomalous $U(1)$ extension of the Standard Model | 33 pages, 2 figures. Published version | JHEP07(2024)232 | 10.1007/JHEP07(2024)232 | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | We present a set of example models in which the Standard Model (SM) symmetry
group is extended by a new abelian symmetry. This additional symmetry appears
anomalous in the effective low-energy theory; however, the anomalies cancel out
when massive chiral fermions not present in the effective low-energy theory are
taken into account. These chiral fermions under the new abelian gauge group,
are chosen to be vector-like under the SM symmetries, and reside in the same
representations as quarks and leptons. This allows us to quantitatively
determine the magnitude of tree-level interactions between three vector bosons
induced in low-energy effective field theory by the integration of chiral heavy
fermions. We also examine the perturbativity constraints of the theory and the
ultraviolet cut-off. We conclude by highlighting possible extensions of our
work.
| [
{
"created": "Sun, 4 Feb 2024 18:05:40 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Jul 2024 10:28:54 GMT",
"version": "v2"
}
] | 2024-07-30 | [
[
"Anastasopoulos",
"Pascal",
""
],
[
"Antoniadis",
"Ignatios",
""
],
[
"Benakli",
"Karim",
""
],
[
"Rondeau",
"François",
""
]
] | We present a set of example models in which the Standard Model (SM) symmetry group is extended by a new abelian symmetry. This additional symmetry appears anomalous in the effective low-energy theory; however, the anomalies cancel out when massive chiral fermions not present in the effective low-energy theory are taken into account. These chiral fermions under the new abelian gauge group, are chosen to be vector-like under the SM symmetries, and reside in the same representations as quarks and leptons. This allows us to quantitatively determine the magnitude of tree-level interactions between three vector bosons induced in low-energy effective field theory by the integration of chiral heavy fermions. We also examine the perturbativity constraints of the theory and the ultraviolet cut-off. We conclude by highlighting possible extensions of our work. |
2212.00036 | Asimina Arvanitaki | Asimina Arvanitaki and Savas Dimopoulos | The Cosmic Neutrino Background on the Surface of the Earth | 14 pages, 6 figures, references updated | null | null | null | hep-ph astro-ph.CO hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We argue that the reflection of relic neutrinos from the surface of the Earth
results in a significant local $\nu-\bar{\nu}$ asymmetry, far exceeding the
expected primordial lepton asymmetry. The net fractional electron neutrino
number $\frac{n_{\nu_e}-n_{\bar{\nu}_e}}{n_{\nu_e}}$ is up to
$\mathcal{O}(10^5) \sqrt{\frac{m_\nu}{0.1~\text{eV}}}$ larger than that implied
by the baryon asymmetry. This enhancement is due to the weak 4-Fermi repulsion
of the $\nu_e$ from ordinary matter which slows down the $\nu_e$ near the
Earth's surface, and to the resulting evanescent neutrino wave that penetrates
below the surface. This repulsion thus creates a net $\nu_e$ overdensity in a
shell $\sim 7~\text{meters} \sqrt{\frac{0.1~\text{eV}}{m_\nu}}$ thick around
the Earth's surface. Similarly the repulsion between $\bar{\nu}_\mu$ or
$\bar{\nu}_\tau$ and ordinary matter creates an overdensity of $\bar{\nu}_{\mu,
\tau}$ of similar size. These local enhancements increase the size of
$\mathcal{O}(G_F)$ torques of the $C\nu B$ on spin-polarized matter by a factor
of order $10^5$. In addition, they create a gradient of the net neutrino
density which naturally provides a way out of the forty-year-old ``no-go''
theorems on the vanishing of $\mathcal{O}(G_F)$ forces. The torque resulting
from such a gradient force can be $10^8$ times larger than that of earlier
proposals. Although the size of these effects is still far from current reach,
they may point to new directions for $C\nu B$ detection.
| [
{
"created": "Wed, 30 Nov 2022 19:00:01 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Mar 2023 01:06:23 GMT",
"version": "v2"
}
] | 2023-03-15 | [
[
"Arvanitaki",
"Asimina",
""
],
[
"Dimopoulos",
"Savas",
""
]
] | We argue that the reflection of relic neutrinos from the surface of the Earth results in a significant local $\nu-\bar{\nu}$ asymmetry, far exceeding the expected primordial lepton asymmetry. The net fractional electron neutrino number $\frac{n_{\nu_e}-n_{\bar{\nu}_e}}{n_{\nu_e}}$ is up to $\mathcal{O}(10^5) \sqrt{\frac{m_\nu}{0.1~\text{eV}}}$ larger than that implied by the baryon asymmetry. This enhancement is due to the weak 4-Fermi repulsion of the $\nu_e$ from ordinary matter which slows down the $\nu_e$ near the Earth's surface, and to the resulting evanescent neutrino wave that penetrates below the surface. This repulsion thus creates a net $\nu_e$ overdensity in a shell $\sim 7~\text{meters} \sqrt{\frac{0.1~\text{eV}}{m_\nu}}$ thick around the Earth's surface. Similarly the repulsion between $\bar{\nu}_\mu$ or $\bar{\nu}_\tau$ and ordinary matter creates an overdensity of $\bar{\nu}_{\mu, \tau}$ of similar size. These local enhancements increase the size of $\mathcal{O}(G_F)$ torques of the $C\nu B$ on spin-polarized matter by a factor of order $10^5$. In addition, they create a gradient of the net neutrino density which naturally provides a way out of the forty-year-old ``no-go'' theorems on the vanishing of $\mathcal{O}(G_F)$ forces. The torque resulting from such a gradient force can be $10^8$ times larger than that of earlier proposals. Although the size of these effects is still far from current reach, they may point to new directions for $C\nu B$ detection. |
hep-ph/0503116 | Jing Jiang | N.G. Deshpande, J. Jiang | Signals for CP Violation in Split Supersymmetry | 14 pages, 4 figures; typos corrected, version submitted to PLB | Phys.Lett.B615:111-119,2005 | 10.1016/j.physletb.2005.04.015 | null | hep-ph | null | Split supersymmetry is characterized by relatively light chargino and
neutralino sector and very heavy sfermion sector. We study the consequence of
CP violation in this scenario by evaluating two-loop contributions to electric
dipole moments of fermions from Higgs-photon as well as $W$-$W$ diagrams. These
contributions add coherently and produce electron and neutron electric dipole
moments close to present bounds. We then explore Higgs production at a
photon-photon collider, and consider the feasibility of measuring CP violating
$h\gamma\gamma$ coupling induced by chargino loops. Methods of enhancing the
sensitivity are discussed. For lower chargino masses and lower Higgs boson
masses, the effect of the CP violation can be observed with 90% confidence
level significance.
| [
{
"created": "Mon, 14 Mar 2005 20:38:17 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Mar 2005 02:39:47 GMT",
"version": "v2"
}
] | 2014-11-18 | [
[
"Deshpande",
"N. G.",
""
],
[
"Jiang",
"J.",
""
]
] | Split supersymmetry is characterized by relatively light chargino and neutralino sector and very heavy sfermion sector. We study the consequence of CP violation in this scenario by evaluating two-loop contributions to electric dipole moments of fermions from Higgs-photon as well as $W$-$W$ diagrams. These contributions add coherently and produce electron and neutron electric dipole moments close to present bounds. We then explore Higgs production at a photon-photon collider, and consider the feasibility of measuring CP violating $h\gamma\gamma$ coupling induced by chargino loops. Methods of enhancing the sensitivity are discussed. For lower chargino masses and lower Higgs boson masses, the effect of the CP violation can be observed with 90% confidence level significance. |
2407.11117 | Timothy Martonhelyi | Michael J. Baker, Timothy Martonhelyi, Andrea Thamm, Riccardo Torre | A Simplified Model of Heavy Vector Singlets for the LHC and Future
Colliders | 59 pages, 18 figures, 7 tables | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a simplified model of two colourless heavy vector resonances in the
singlet representation of $SU(2)_{L}$, with zero and unit hypercharge. We
discuss mixing with the Standard Model gauge bosons due to electroweak symmetry
breaking, semi-analytic formulae for production at proton colliders,
requirements to obey the narrow width approximation and selected low energy
constraints. We show current LHC constraints and sensitivity projections for
the HL-LHC, HE-LHC, SPPC and FCC-hh on the charged and neutral heavy vectors.
The utility of the simplified model Lagrangian is demonstrated by matching
these results onto three explicit models: a weakly coupled abelian extension of
the Standard Model gauge group, a weakly coupled non-abelian extension and a
strongly coupled minimal composite Higgs model. All our results are presented
in terms of physical resonance masses, which are accurate even at vector masses
near the electroweak scale due to a parameter inversion we derive. We discuss
the importance of this inversion and point out that its effect, and the effects
of electroweak symmetry breaking, can remain important up to resonance masses
of several TeV. Finally, we clarify the relation between this simplified model
and the Heavy Vector Triplet (HVT) model, a simplified model for heavy
$SU(2)_{L}$ triplets with zero hypercharge, and provide exact and approximate
matching relations.
| [
{
"created": "Mon, 15 Jul 2024 18:00:01 GMT",
"version": "v1"
}
] | 2024-07-17 | [
[
"Baker",
"Michael J.",
""
],
[
"Martonhelyi",
"Timothy",
""
],
[
"Thamm",
"Andrea",
""
],
[
"Torre",
"Riccardo",
""
]
] | We study a simplified model of two colourless heavy vector resonances in the singlet representation of $SU(2)_{L}$, with zero and unit hypercharge. We discuss mixing with the Standard Model gauge bosons due to electroweak symmetry breaking, semi-analytic formulae for production at proton colliders, requirements to obey the narrow width approximation and selected low energy constraints. We show current LHC constraints and sensitivity projections for the HL-LHC, HE-LHC, SPPC and FCC-hh on the charged and neutral heavy vectors. The utility of the simplified model Lagrangian is demonstrated by matching these results onto three explicit models: a weakly coupled abelian extension of the Standard Model gauge group, a weakly coupled non-abelian extension and a strongly coupled minimal composite Higgs model. All our results are presented in terms of physical resonance masses, which are accurate even at vector masses near the electroweak scale due to a parameter inversion we derive. We discuss the importance of this inversion and point out that its effect, and the effects of electroweak symmetry breaking, can remain important up to resonance masses of several TeV. Finally, we clarify the relation between this simplified model and the Heavy Vector Triplet (HVT) model, a simplified model for heavy $SU(2)_{L}$ triplets with zero hypercharge, and provide exact and approximate matching relations. |
2110.02944 | Miguel Albaladejo | M. Albaladejo | $T_{cc}^{+}$ coupled channel analysis and predictions | Comments are more than welcome | null | 10.1016/j.physletb.2022.137052 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | A coupled channel analysis of the $D^{\ast+}D^0$ and $D^{\ast0}D^+$ system is
performed to study the doubly charmed $T_{cc}^+$ state recently discovered by
the LHCb collaboration. We use a simple model for the scattering amplitude that
allows us to describe well the experimental spectrum, and obtain the $T_{cc}^+$
pole in the coupled channel $T$-matrix. We find that this bound state has a
large molecular component. The isospin ($I=0$ or $I=1$) of the state cannot be
inferred from the $D^0 D^0 \pi^+$ spectrum alone. Therefore, we use the same
formalism to predict other $DD\pi$ spectra. In the case the $T_{cc}^+$ has
$I=1$, we also predict the location of the other two members ($T_{cc}^{++}$ and
$T_{cc}^0$) of the triplet. Finally, using Heavy-Quark Spin Symmetry, we
predict the location of possible heavier $D^\ast D^\ast$ ($I=0$ or $I=1$)
partners.
| [
{
"created": "Wed, 6 Oct 2021 17:49:24 GMT",
"version": "v1"
}
] | 2022-04-20 | [
[
"Albaladejo",
"M.",
""
]
] | A coupled channel analysis of the $D^{\ast+}D^0$ and $D^{\ast0}D^+$ system is performed to study the doubly charmed $T_{cc}^+$ state recently discovered by the LHCb collaboration. We use a simple model for the scattering amplitude that allows us to describe well the experimental spectrum, and obtain the $T_{cc}^+$ pole in the coupled channel $T$-matrix. We find that this bound state has a large molecular component. The isospin ($I=0$ or $I=1$) of the state cannot be inferred from the $D^0 D^0 \pi^+$ spectrum alone. Therefore, we use the same formalism to predict other $DD\pi$ spectra. In the case the $T_{cc}^+$ has $I=1$, we also predict the location of the other two members ($T_{cc}^{++}$ and $T_{cc}^0$) of the triplet. Finally, using Heavy-Quark Spin Symmetry, we predict the location of possible heavier $D^\ast D^\ast$ ($I=0$ or $I=1$) partners. |
0906.5521 | P\'ia Zurita | R. Sassot, M. Stratmann, P. Zurita | Medium-modified fragmentation functions | To appear in the proceedings of DIS 2009 Conference, 26-30 April
2009, Madrid | null | null | dep fis 001 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss preliminary results on medium-modified fragmentation functions
obtained in a combined NLO fit to data on semi-inclusive deep inelastic
scattering off nuclei and hadroproduction in deuteron-gold collisions.
| [
{
"created": "Tue, 30 Jun 2009 13:50:38 GMT",
"version": "v1"
}
] | 2009-07-01 | [
[
"Sassot",
"R.",
""
],
[
"Stratmann",
"M.",
""
],
[
"Zurita",
"P.",
""
]
] | We discuss preliminary results on medium-modified fragmentation functions obtained in a combined NLO fit to data on semi-inclusive deep inelastic scattering off nuclei and hadroproduction in deuteron-gold collisions. |
hep-ph/9601274 | null | Daniele Dominici | Degenerate BESS at future $e^+e^-$ colliders | Tex, uses epsf, 3 pages + 2 figures tar/compress/uuencoded Talk
presented at the IInd Rencontres du Vietnam, At the Frontiers of the Standard
Model, Hochiminh Ville, October 21-28 1995 | null | null | DFF-242 | hep-ph | null | The sensitivity of future $e^+e^-$ colliders to the new physics deriving from
a model of strong electroweak symmetry breaking is discussed. The model
considered is an effective lagrangian description of Goldstone bosons and of
new vector resonances degenerate in mass.
| [
{
"created": "Tue, 16 Jan 1996 10:13:58 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Dominici",
"Daniele",
""
]
] | The sensitivity of future $e^+e^-$ colliders to the new physics deriving from a model of strong electroweak symmetry breaking is discussed. The model considered is an effective lagrangian description of Goldstone bosons and of new vector resonances degenerate in mass. |
1702.01931 | Martin Spousta | Martin Spousta | Flavor aspects of parton energy loss | 12 Dec 2016; Submitted to: Proceedings of Hard Probes 2016 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Understanding flavor dependence of the parton energy loss is one of key tasks
of the jet quenching physics. In these proceedings we provide a summary of
recent works on a quantification of the flavor dependence of parton energy loss
along with a summary and discussion of a subset of contributions presented at
the Hard Probes 2016 conference which are related to the flavor aspects of
parton energy loss.
| [
{
"created": "Tue, 7 Feb 2017 09:12:43 GMT",
"version": "v1"
}
] | 2017-02-08 | [
[
"Spousta",
"Martin",
""
]
] | Understanding flavor dependence of the parton energy loss is one of key tasks of the jet quenching physics. In these proceedings we provide a summary of recent works on a quantification of the flavor dependence of parton energy loss along with a summary and discussion of a subset of contributions presented at the Hard Probes 2016 conference which are related to the flavor aspects of parton energy loss. |
hep-ph/9709347 | Igor G. Alekseev | I.I. Levintov (Institute for Theoretical and Experimental Physics,
Moscow) | Soft Binary Processes, NJL Model and Absolute Values of the Amplitudes
of Reactions pi- p --> pi0 n and pi- p --> eta n | LaTeX, 17 pages, 5 figures | Phys.Atom.Nucl.61:1380-1392,1998; Yad.Fiz.61:1486-1498,1998 | null | ITEP-24-97 | hep-ph | null | In the model the entire high-energy part of the amplitude (Regge power
dependence from the total energy) comes as consequence of Gribov's diffusion of
the constituent quarks in the space of rapidities and impact parameters. Charge
exchange of the quarks, which goes at small quark anti-quark invariant masses,
is described by low-energy Nambu - Jona-Lasinio model. It is shown that spin
structure of the amplitudes and dominating spin-orbit (spin-flip) amplitudes
are well described by this model without free parameters.
| [
{
"created": "Mon, 15 Sep 1997 15:14:09 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Levintov",
"I. I.",
"",
"Institute for Theoretical and Experimental Physics,\n Moscow"
]
] | In the model the entire high-energy part of the amplitude (Regge power dependence from the total energy) comes as consequence of Gribov's diffusion of the constituent quarks in the space of rapidities and impact parameters. Charge exchange of the quarks, which goes at small quark anti-quark invariant masses, is described by low-energy Nambu - Jona-Lasinio model. It is shown that spin structure of the amplitudes and dominating spin-orbit (spin-flip) amplitudes are well described by this model without free parameters. |
2107.08040 | M.C. David Marsh | M.C. David Marsh, James H. Matthews, Christopher Reynolds, and
Pierluca Carenza | The Fourier formalism for relativistic axion-photon conversion, with
astrophysical applications | 39 pages, 14 figures. v3: matches published version | null | 10.1103/PhysRevD.105.016013 | null | hep-ph astro-ph.HE | http://creativecommons.org/licenses/by/4.0/ | We study the weak mixing of photons and relativistic axion-like particles
(axions) in plasmas with background magnetic fields, ${\bf B}$. We show that,
to leading order in the axion-photon coupling, the conversion probability,
$P_{\gamma \to a}$, is given by the one-dimensional power spectrum of the
magnetic field components perpendicular to the particle trajectory.
Equivalently, we express $P_{\gamma \to a}$ as the Fourier transform of the
magnetic field autocorrelation function, and establish a dictionary between
properties of the real-space magnetic field and the energy-dependent conversion
probability. For axions more massive than the plasma frequency,
($m_a>\omega_{\rm pl}$), we use this formalism to analytically solve the
problem of perturbative axion-photon mixing in a general magnetic field. In the
general case where $\omega_{\rm pl}/m_a$ varies arbitrarily along the
trajectory, we show that a naive application of the standard formalism for
'resonant' conversion can give highly inaccurate results, and that a careful
calculation generically gives non-resonant contributions at least as large as
the resonant contribution. Furthermore, we demonstrate how techniques based on
the Fast Fourier Transform provide a new, highly efficient numerical method for
calculating axion-photon mixing. We briefly discuss magnetic field modelling in
galaxy clusters in the light of our results and argue, in particular, that a
recently proposed 'regular' model used for studying axion-photon mixing
(specifically applied to the Perseus cluster) is inconsistent with
observations. Our formalism suggest new methods to search for imprints of
axions, and will be important for spectrographs with percent level sensitivity,
which includes existing X-ray observations by Chandra as well as the upcoming
Athena mission.
| [
{
"created": "Fri, 16 Jul 2021 17:58:35 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Aug 2021 12:59:17 GMT",
"version": "v2"
},
{
"created": "Thu, 3 Feb 2022 10:29:01 GMT",
"version": "v3"
}
] | 2022-02-04 | [
[
"Marsh",
"M. C. David",
""
],
[
"Matthews",
"James H.",
""
],
[
"Reynolds",
"Christopher",
""
],
[
"Carenza",
"Pierluca",
""
]
] | We study the weak mixing of photons and relativistic axion-like particles (axions) in plasmas with background magnetic fields, ${\bf B}$. We show that, to leading order in the axion-photon coupling, the conversion probability, $P_{\gamma \to a}$, is given by the one-dimensional power spectrum of the magnetic field components perpendicular to the particle trajectory. Equivalently, we express $P_{\gamma \to a}$ as the Fourier transform of the magnetic field autocorrelation function, and establish a dictionary between properties of the real-space magnetic field and the energy-dependent conversion probability. For axions more massive than the plasma frequency, ($m_a>\omega_{\rm pl}$), we use this formalism to analytically solve the problem of perturbative axion-photon mixing in a general magnetic field. In the general case where $\omega_{\rm pl}/m_a$ varies arbitrarily along the trajectory, we show that a naive application of the standard formalism for 'resonant' conversion can give highly inaccurate results, and that a careful calculation generically gives non-resonant contributions at least as large as the resonant contribution. Furthermore, we demonstrate how techniques based on the Fast Fourier Transform provide a new, highly efficient numerical method for calculating axion-photon mixing. We briefly discuss magnetic field modelling in galaxy clusters in the light of our results and argue, in particular, that a recently proposed 'regular' model used for studying axion-photon mixing (specifically applied to the Perseus cluster) is inconsistent with observations. Our formalism suggest new methods to search for imprints of axions, and will be important for spectrographs with percent level sensitivity, which includes existing X-ray observations by Chandra as well as the upcoming Athena mission. |
hep-ph/9712280 | Randy Kobes | M. Carrington and R. Kobes | The general cancellation of ladder graphs at finite temperature | 28 pages, 20 figures included, uses RevTeX and epsf, also available
at http://theory.uwinnipeg.ca/users/randy/webfiles/diag.uu | Phys.Rev. D57 (1998) 6372-6385 | 10.1103/PhysRevD.57.6372 | WIN 97-22 | hep-ph | null | In some cases, an important example being at finite temperature, extreme
infrared, collinear, or light-cone behaviour may cause the usual loop expansion
to break down. For some of these cases higher order ladder graphs can become
important. In an earlier paper it was shown that, given a particular relation
between a vertex and a self-energy function, the resummation of the ladder
graphs simplifies significantly when other types of graphs are included in a
consistent effective expansion. In this paper we show that this assumed
relation is valid for a large class of vertex and self-energy functions at
finite temperature.
| [
{
"created": "Fri, 5 Dec 1997 23:29:27 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Carrington",
"M.",
""
],
[
"Kobes",
"R.",
""
]
] | In some cases, an important example being at finite temperature, extreme infrared, collinear, or light-cone behaviour may cause the usual loop expansion to break down. For some of these cases higher order ladder graphs can become important. In an earlier paper it was shown that, given a particular relation between a vertex and a self-energy function, the resummation of the ladder graphs simplifies significantly when other types of graphs are included in a consistent effective expansion. In this paper we show that this assumed relation is valid for a large class of vertex and self-energy functions at finite temperature. |
1710.00351 | Rupak Dutta | Rupak Dutta | Exploring $R_D$, $R_{D^{\ast}}$ and $R_{J/\Psi}$ anomalies | 9 pages, 2 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Deviations from the standard model predictions have been reported in various
observables concerned with the lepton flavor universality. At present, the
deviation of the measured values of $R_D$ and $R_{D^{\ast}}$ from the standard
model expectation is exceeded by $2.3\sigma$ and $3.4\sigma$, respectively.
Very recently LHCb has measured the ratio of branching ratio $R_{J/\Psi} =
\mathcal B(B_c \to J/\Psi\tau\nu)/\mathcal B(B_c \to J/\Psi\,l\,\nu)$, where $l
\in (e,\,\mu)$, to be $0.71\pm0.17\pm 0.18$ which is at more than $2\sigma$
away from the standard model prediction. We investigate the anomalies in $R_D$,
$R_{D^{\ast}}$, and $R_{J/\Psi}$ using a model independent framework with
minimal number of new physics couplings. We find various new physics models
that can explain these anomalies within $1\sigma$.
| [
{
"created": "Sun, 1 Oct 2017 13:58:34 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Oct 2017 16:38:23 GMT",
"version": "v2"
}
] | 2017-10-19 | [
[
"Dutta",
"Rupak",
""
]
] | Deviations from the standard model predictions have been reported in various observables concerned with the lepton flavor universality. At present, the deviation of the measured values of $R_D$ and $R_{D^{\ast}}$ from the standard model expectation is exceeded by $2.3\sigma$ and $3.4\sigma$, respectively. Very recently LHCb has measured the ratio of branching ratio $R_{J/\Psi} = \mathcal B(B_c \to J/\Psi\tau\nu)/\mathcal B(B_c \to J/\Psi\,l\,\nu)$, where $l \in (e,\,\mu)$, to be $0.71\pm0.17\pm 0.18$ which is at more than $2\sigma$ away from the standard model prediction. We investigate the anomalies in $R_D$, $R_{D^{\ast}}$, and $R_{J/\Psi}$ using a model independent framework with minimal number of new physics couplings. We find various new physics models that can explain these anomalies within $1\sigma$. |
1208.2404 | Tai-Fu Feng | Ke-Sheng Sun, Tai-Fu Feng, Tie-Jun Gao, Shu-Min Zhao | Search for lepton flavor violation in supersymmetric models via meson
decays | 30 pages, 13 figures | null | 10.1016/j.nuclphysb.2012.08.005 | null | hep-ph | http://creativecommons.org/licenses/by-nc-sa/3.0/ | Considering the constraints from the experimental data on $\mu\rightarrow
e\gamma$, $\mu\rightarrow3e$, $\mu-e$ conversion etc., we analyze the Lepton
Flavor Violating decays $\phi(J/\Psi,\Upsilon(1S)) \rightarrow
e^+\mu^-(\mu^+\tau^-)$ in the scenarios of the minimal supersymmetric
extensions of Standard Model with seesaw Mechanism. Numerically, there is
parameter space that the LFV processes of
$J/\Psi(\Upsilon)\rightarrow\mu^+\tau^-$ can reach the upper experimental
bounds, meanwhile the theoretical predictions on $\mu\rightarrow e\gamma$,
$\mu\rightarrow3e$, $\mu-e$ conversion satisfy the present experimental bounds.
For searching of new physics, Lepton Flavor Violating processes
$J/\Psi(\Upsilon)\rightarrow\mu^+\tau^-$ may be more promising and effective
channels.
| [
{
"created": "Sun, 12 Aug 2012 07:08:32 GMT",
"version": "v1"
}
] | 2015-06-11 | [
[
"Sun",
"Ke-Sheng",
""
],
[
"Feng",
"Tai-Fu",
""
],
[
"Gao",
"Tie-Jun",
""
],
[
"Zhao",
"Shu-Min",
""
]
] | Considering the constraints from the experimental data on $\mu\rightarrow e\gamma$, $\mu\rightarrow3e$, $\mu-e$ conversion etc., we analyze the Lepton Flavor Violating decays $\phi(J/\Psi,\Upsilon(1S)) \rightarrow e^+\mu^-(\mu^+\tau^-)$ in the scenarios of the minimal supersymmetric extensions of Standard Model with seesaw Mechanism. Numerically, there is parameter space that the LFV processes of $J/\Psi(\Upsilon)\rightarrow\mu^+\tau^-$ can reach the upper experimental bounds, meanwhile the theoretical predictions on $\mu\rightarrow e\gamma$, $\mu\rightarrow3e$, $\mu-e$ conversion satisfy the present experimental bounds. For searching of new physics, Lepton Flavor Violating processes $J/\Psi(\Upsilon)\rightarrow\mu^+\tau^-$ may be more promising and effective channels. |
1210.2100 | Ted Rogers | John C. Collins and Ted C. Rogers | Equality of Two Definitions for Transverse Momentum Dependent Parton
Distribution Functions | Fixed arrows on figures, added comments to the summary; 12 pages, 3
figures | null | 10.1103/PhysRevD.87.034018 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compare recent, seemingly different, approaches to TMD-factorization (due
to Echevarria, Idilbi, and Scimemi and to Collins), and show that they are the
same, apart from an apparent difference in their definition of the \MSbar{}
renormalization scheme.
| [
{
"created": "Sun, 7 Oct 2012 20:18:43 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Nov 2012 19:13:16 GMT",
"version": "v2"
}
] | 2013-03-14 | [
[
"Collins",
"John C.",
""
],
[
"Rogers",
"Ted C.",
""
]
] | We compare recent, seemingly different, approaches to TMD-factorization (due to Echevarria, Idilbi, and Scimemi and to Collins), and show that they are the same, apart from an apparent difference in their definition of the \MSbar{} renormalization scheme. |
1105.0039 | Thomas G. Rizzo | R.C. Cotta, J.L. Hewett, A. Ismail, M.-P.Le and T.G. Rizzo | Higgs Properties in the Fourth Generation MSSM: Boosted Signals Over the
3G Plan | 20 pages, 7 figures; typos fixed, refs added | null | 10.1103/PhysRevD.84.075019 | SLAC-PUB-14454 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The generalization of the MSSM to the case of four chiral fermion generations
(4GMSSM) can lead to significant changes in the phenomenology of the otherwise
familiar Higgs sector. In most of the 3GMSSM parameter space, the lighter
CP-even $h$ is $\sim 115-125$ GeV and mostly Standard Model-like while
$H,A,H^\pm$ are all relatively heavy. Furthermore, the ratio of Higgs vevs,
$\tan \beta$, is relatively unconstrained. In contrast to this, in the 4GMSSM,
heavy fourth generation fermion loops drive the masses of $h,H,H^\pm$ to large
values while the CP-odd boson, $A$, can remain relatively light and $\tan
\beta$ is restricted to the range $1/2 \lsim \tan \beta \lsim 2$ due to
perturbativity requirements on Yukawa couplings. We explore this scenario in
some detail, concentrating on the collider signatures of the light CP-odd Higgs
at both the Tevatron and LHC. We find that while $gg \to A$ may lead to a
potential signal in the $\tau^+\tau^-$ channel at the LHC, $A$ may first be
observed in the $\gamma \gamma$ channel due to a highly loop-enhanced cross
section that can be more than an order of magnitude greater than that of a SM
Higgs for $A$ masses of $\sim 115-120$ and $\tan\beta<1$. We find that the
CP-even states $h,H$ are highly mixed and can have atypical branching
fractions. Precision electroweak constraints, particularly for the light $A$
parameter space region, are examined in detail.
| [
{
"created": "Sat, 30 Apr 2011 01:18:07 GMT",
"version": "v1"
},
{
"created": "Fri, 6 May 2011 21:13:14 GMT",
"version": "v2"
}
] | 2013-05-29 | [
[
"Cotta",
"R. C.",
""
],
[
"Hewett",
"J. L.",
""
],
[
"Ismail",
"A.",
""
],
[
"Le",
"M. -P.",
""
],
[
"Rizzo",
"T. G.",
""
]
] | The generalization of the MSSM to the case of four chiral fermion generations (4GMSSM) can lead to significant changes in the phenomenology of the otherwise familiar Higgs sector. In most of the 3GMSSM parameter space, the lighter CP-even $h$ is $\sim 115-125$ GeV and mostly Standard Model-like while $H,A,H^\pm$ are all relatively heavy. Furthermore, the ratio of Higgs vevs, $\tan \beta$, is relatively unconstrained. In contrast to this, in the 4GMSSM, heavy fourth generation fermion loops drive the masses of $h,H,H^\pm$ to large values while the CP-odd boson, $A$, can remain relatively light and $\tan \beta$ is restricted to the range $1/2 \lsim \tan \beta \lsim 2$ due to perturbativity requirements on Yukawa couplings. We explore this scenario in some detail, concentrating on the collider signatures of the light CP-odd Higgs at both the Tevatron and LHC. We find that while $gg \to A$ may lead to a potential signal in the $\tau^+\tau^-$ channel at the LHC, $A$ may first be observed in the $\gamma \gamma$ channel due to a highly loop-enhanced cross section that can be more than an order of magnitude greater than that of a SM Higgs for $A$ masses of $\sim 115-120$ and $\tan\beta<1$. We find that the CP-even states $h,H$ are highly mixed and can have atypical branching fractions. Precision electroweak constraints, particularly for the light $A$ parameter space region, are examined in detail. |
1506.04057 | Clare Burrage | Philippe Brax, Clare Burrage and Christoph Englert | Disformal dark energy at colliders | 10 pages, 7 figures | Phys. Rev. D 92, 044036 (2015) | 10.1103/PhysRevD.92.044036 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Disformally coupled, light scalar fields arise in many of the theories of
dark energy and modified gravity that attempt to explain the accelerated
expansion of the universe. They have proved difficult to constrain with
precision tests of gravity because they do not give rise to fifth forces around
static non-relativistic sources. However, because the scalar field couples
derivatively to standard model matter, measurements at high energy particle
colliders offer an effective way to constrain and potentially detect a
disformally coupled scalar field. Here we derive new constraints on the
strength of the disformal coupling from LHC run 1 data and provide a forecast
for the improvement of these constraints from run 2. We additionally comment on
the running of disformal and standard model couplings in this scenario under
the renormalisation group flow.
| [
{
"created": "Thu, 11 Jun 2015 17:12:18 GMT",
"version": "v1"
}
] | 2015-08-26 | [
[
"Brax",
"Philippe",
""
],
[
"Burrage",
"Clare",
""
],
[
"Englert",
"Christoph",
""
]
] | Disformally coupled, light scalar fields arise in many of the theories of dark energy and modified gravity that attempt to explain the accelerated expansion of the universe. They have proved difficult to constrain with precision tests of gravity because they do not give rise to fifth forces around static non-relativistic sources. However, because the scalar field couples derivatively to standard model matter, measurements at high energy particle colliders offer an effective way to constrain and potentially detect a disformally coupled scalar field. Here we derive new constraints on the strength of the disformal coupling from LHC run 1 data and provide a forecast for the improvement of these constraints from run 2. We additionally comment on the running of disformal and standard model couplings in this scenario under the renormalisation group flow. |
1808.07727 | Cesar Bonilla | Alfredo Aranda, Cesar Bonilla, Eduardo Peinado | Dynamical generation of neutrino mass scales | 4 pages; References added. Matches published version | null | 10.1016/j.physletb.2019.01.068 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this letter we present a simple scenario where the mass scales associated
to atmospheric and solar neutrino oscillations are obtained through the
dynamical generation of neutrino masses. The main idea is that the two
different scales are the result of two independent mechanisms, namely a type-I
seesaw generating the atmospheric scale and a radiative 1-loop process
providing the solar one. A relation of the two scales, reminiscent of the
so-called sequential dominance, is thus obtained.
| [
{
"created": "Thu, 23 Aug 2018 12:50:47 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Mar 2019 14:51:57 GMT",
"version": "v2"
}
] | 2019-03-15 | [
[
"Aranda",
"Alfredo",
""
],
[
"Bonilla",
"Cesar",
""
],
[
"Peinado",
"Eduardo",
""
]
] | In this letter we present a simple scenario where the mass scales associated to atmospheric and solar neutrino oscillations are obtained through the dynamical generation of neutrino masses. The main idea is that the two different scales are the result of two independent mechanisms, namely a type-I seesaw generating the atmospheric scale and a radiative 1-loop process providing the solar one. A relation of the two scales, reminiscent of the so-called sequential dominance, is thus obtained. |
1612.04527 | Yi Liao | Yi Liao (Nankai U., ITP-CAS, CHEP, Peking U.), Xiao-Dong Ma (Nankai
U.) | Operators up to Dimension Seven in Standard Model Effective Field Theory
Extended with Sterile Neutrinos | 14 pages, 0 figures, 4 tables | Phys. Rev. D 96, 015012 (2017) | 10.1103/PhysRevD.96.015012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit the effective field theory of the standard model that is extended
with sterile neutrinos, $N$. We examine the basis of complete and independent
effective operators involving $N$ up to mass dimension seven (dim-7). By
employing equations of motion, integration by parts, and Fierz and group
identities, we construct relations among operators that were considered
independent in the previous literature, and find seven redundant operators at
dim-6, sixteen redundant operators and two new operators at dim-7. The correct
numbers of operators involving $N$ are, without counting Hermitian conjugates,
$16~(L\cap B)+1~(\slashed{L}\cap B)+2~(\slashed{L}\cap\slashed{B})$ at dim-6,
and $47~(\slashed{L}\cap B)+5~(\slashed{L}\cap\slashed{B})$ at dim-7. Here
$L/B~(\slashed L/\slashed B)$ stands for lepton/baryon number conservation
(violation). We verify our counting by the Hilbert series approach for $n_f$
generations of the standard model fermions and sterile neutrinos. When
operators involving different flavors of fermions are counted separately and
their Hermitian conjugates are included, we find there are $29~(1614)$ and
$80~(4206)$ operators involving sterile neutrinos at dim-6 and dim-7
respectively for $n_f=1~(3)$.
| [
{
"created": "Wed, 14 Dec 2016 08:26:56 GMT",
"version": "v1"
}
] | 2017-07-19 | [
[
"Liao",
"Yi",
"",
"Nankai U., ITP-CAS, CHEP, Peking U."
],
[
"Ma",
"Xiao-Dong",
"",
"Nankai\n U."
]
] | We revisit the effective field theory of the standard model that is extended with sterile neutrinos, $N$. We examine the basis of complete and independent effective operators involving $N$ up to mass dimension seven (dim-7). By employing equations of motion, integration by parts, and Fierz and group identities, we construct relations among operators that were considered independent in the previous literature, and find seven redundant operators at dim-6, sixteen redundant operators and two new operators at dim-7. The correct numbers of operators involving $N$ are, without counting Hermitian conjugates, $16~(L\cap B)+1~(\slashed{L}\cap B)+2~(\slashed{L}\cap\slashed{B})$ at dim-6, and $47~(\slashed{L}\cap B)+5~(\slashed{L}\cap\slashed{B})$ at dim-7. Here $L/B~(\slashed L/\slashed B)$ stands for lepton/baryon number conservation (violation). We verify our counting by the Hilbert series approach for $n_f$ generations of the standard model fermions and sterile neutrinos. When operators involving different flavors of fermions are counted separately and their Hermitian conjugates are included, we find there are $29~(1614)$ and $80~(4206)$ operators involving sterile neutrinos at dim-6 and dim-7 respectively for $n_f=1~(3)$. |
hep-ph/0305064 | Tommy Ohlsson | Magnus Jacobson, Tommy Ohlsson | Extrinsic CPT Violation in Neutrino Oscillations in Matter | 47 pages, 7 figures, RevTeX4. Final version to be published in Phys.
Rev. D | Phys.Rev.D69:013003,2004 | 10.1103/PhysRevD.69.013003 | null | hep-ph | null | We investigate matter-induced (or extrinsic) CPT violation effects in
neutrino oscillations in matter. Especially, we present approximate analytical
formulas for the CPT-violating probability differences for three flavor
neutrino oscillations in matter with an arbitrary matter density profile. Note
that we assume that the CPT invariance theorem holds, which means that the CPT
violation effects arise entirely because of the presence of matter. As special
cases of matter density profiles, we consider constant and step-function matter
density profiles, which are relevant for neutrino oscillation physics in
accelerator and reactor long baseline experiments as well as neutrino
factories. Finally, the implications of extrinsic CPT violation on neutrino
oscillations in matter for several past, present, and future long baseline
experiments are estimated.
| [
{
"created": "Wed, 7 May 2003 14:36:23 GMT",
"version": "v1"
},
{
"created": "Tue, 13 May 2003 15:57:49 GMT",
"version": "v2"
},
{
"created": "Wed, 22 Oct 2003 21:09:10 GMT",
"version": "v3"
}
] | 2009-05-20 | [
[
"Jacobson",
"Magnus",
""
],
[
"Ohlsson",
"Tommy",
""
]
] | We investigate matter-induced (or extrinsic) CPT violation effects in neutrino oscillations in matter. Especially, we present approximate analytical formulas for the CPT-violating probability differences for three flavor neutrino oscillations in matter with an arbitrary matter density profile. Note that we assume that the CPT invariance theorem holds, which means that the CPT violation effects arise entirely because of the presence of matter. As special cases of matter density profiles, we consider constant and step-function matter density profiles, which are relevant for neutrino oscillation physics in accelerator and reactor long baseline experiments as well as neutrino factories. Finally, the implications of extrinsic CPT violation on neutrino oscillations in matter for several past, present, and future long baseline experiments are estimated. |
1610.04975 | Vladimir Saleev | Anton Karpishkov, Vladimir Saleev, Alexandera Shipilova | Large-p_T production of D mesons at the LHCb in the parton Reggeization
approach | 16 pages, 12 figures. arXiv admin note: text overlap with
arXiv:1410.7139, arXiv:1411.7672 | Phys. Rev. D 94, 114012 (2016) | 10.1103/PhysRevD.94.114012 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The production of D mesons in proton-proton collisions at the LHCb detector
is studied. We consider the single production of D^0, D^+, D^star, and D_s^+
mesons and correlation spectra in the production of DbarD and DD pairs at the
sqrt{S}=7 TeV and sqrt{S}=13 TeV. In case of the single D-meson production we
calculate differential cross sections over transverse momentum p_T while in the
pair DbarD,DD-meson production the cross sections are calculated over the
azimuthal angle difference, rapidity difference, invariant mass of the pair M
and over the p_T of the one meson from a pair. The cross sections are obtained
at the leading order of the parton Reggeization approach using
Kimber-Martin-Ryskin unintegrated parton distribution functions in a proton. To
describe the D-meson production we use universal scale-dependent c-quark and
gluon fragmentation functions fitted to e^+e^- annihilation data from CERN
LEP1. Our predictions find a good agreement with the LHCb Collaboration data
within uncertainties and without free parameters.
| [
{
"created": "Mon, 17 Oct 2016 05:24:29 GMT",
"version": "v1"
}
] | 2017-11-27 | [
[
"Karpishkov",
"Anton",
""
],
[
"Saleev",
"Vladimir",
""
],
[
"Shipilova",
"Alexandera",
""
]
] | The production of D mesons in proton-proton collisions at the LHCb detector is studied. We consider the single production of D^0, D^+, D^star, and D_s^+ mesons and correlation spectra in the production of DbarD and DD pairs at the sqrt{S}=7 TeV and sqrt{S}=13 TeV. In case of the single D-meson production we calculate differential cross sections over transverse momentum p_T while in the pair DbarD,DD-meson production the cross sections are calculated over the azimuthal angle difference, rapidity difference, invariant mass of the pair M and over the p_T of the one meson from a pair. The cross sections are obtained at the leading order of the parton Reggeization approach using Kimber-Martin-Ryskin unintegrated parton distribution functions in a proton. To describe the D-meson production we use universal scale-dependent c-quark and gluon fragmentation functions fitted to e^+e^- annihilation data from CERN LEP1. Our predictions find a good agreement with the LHCb Collaboration data within uncertainties and without free parameters. |
2203.13485 | Abhishek Kumar Jha | Abhishek Kumar Jha, Akshay Chatla and Bindu A. Bambah | Neutrinos as qubits and qutrits | This version of the paper was submitted to the journal. 33 pages and
3 figures | Eur. Phys. J. Plus 139, 68 (2024) | 10.1140/epjp/s13360-024-04861-5 | null | hep-ph quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We map neutrinos to qubit and qutrit states of quantum information theory by
constructing the Poincar\'e sphere using SU(2) Pauli matrices and SU(3)
Gell-Mann matrices, respectively. The construction of the Poincar\'e sphere in
the two-qubit system enables us to construct the Bloch matrix, which yields
valuable symmetries in the Bloch vector space of two neutrino systems. By
identifying neutrinos with qutrits, we calculate the measures of qutrit
entanglement for neutrinos. We use SU(3) Gell-Mann matrices tensor products to
construct the Poincar\'e sphere of two qutrits neutrino systems. The comparison
between the entanglement measures of bipartite qubits and bipartite qutrits in
the two neutrino system are shown. The result warrants a study of two qutrits
entanglement in the three neutrino system.
| [
{
"created": "Fri, 25 Mar 2022 07:30:43 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Jan 2024 09:53:54 GMT",
"version": "v2"
}
] | 2024-01-31 | [
[
"Jha",
"Abhishek Kumar",
""
],
[
"Chatla",
"Akshay",
""
],
[
"Bambah",
"Bindu A.",
""
]
] | We map neutrinos to qubit and qutrit states of quantum information theory by constructing the Poincar\'e sphere using SU(2) Pauli matrices and SU(3) Gell-Mann matrices, respectively. The construction of the Poincar\'e sphere in the two-qubit system enables us to construct the Bloch matrix, which yields valuable symmetries in the Bloch vector space of two neutrino systems. By identifying neutrinos with qutrits, we calculate the measures of qutrit entanglement for neutrinos. We use SU(3) Gell-Mann matrices tensor products to construct the Poincar\'e sphere of two qutrits neutrino systems. The comparison between the entanglement measures of bipartite qubits and bipartite qutrits in the two neutrino system are shown. The result warrants a study of two qutrits entanglement in the three neutrino system. |
1904.06036 | Subhasish Chakrabarty | Subhasish Chakrabarty, Amitabha Lahiri | Geometrical contribution to neutrino mass matrix | 15 pp; v3: last paragraph has been replaced by a new section titled
'Discussion' | Eur. Phys. J. C (2019) 79: 697 | 10.1140/epjc/s10052-019-7209-2 | null | hep-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The dynamics of fermions on curved spacetime requires a spin connection,
which contains a part called contorsion, an auxiliary field without dynamics
but fully expressible in terms of the axial current density of fermions. Its
effect is the appearance of a quartic interaction of all fermions in the
action, leading to a nonlinear Dirac equation involving all fermions present.
Noting that left and right-chiral fermions may couple to contorsion by
different strengths, we show that all fermions gain an effective mass when
propagating through fermionic matter. This may have an observable effect on
neutrino oscillations. In particular we find that different neutrino flavors
can mix even if they have zero rest mass in vacuum, without requiring fields
beyond the Standard Model.
| [
{
"created": "Fri, 12 Apr 2019 05:06:23 GMT",
"version": "v1"
},
{
"created": "Sun, 9 Jun 2019 17:20:24 GMT",
"version": "v2"
},
{
"created": "Tue, 13 Aug 2019 10:24:54 GMT",
"version": "v3"
}
] | 2019-08-23 | [
[
"Chakrabarty",
"Subhasish",
""
],
[
"Lahiri",
"Amitabha",
""
]
] | The dynamics of fermions on curved spacetime requires a spin connection, which contains a part called contorsion, an auxiliary field without dynamics but fully expressible in terms of the axial current density of fermions. Its effect is the appearance of a quartic interaction of all fermions in the action, leading to a nonlinear Dirac equation involving all fermions present. Noting that left and right-chiral fermions may couple to contorsion by different strengths, we show that all fermions gain an effective mass when propagating through fermionic matter. This may have an observable effect on neutrino oscillations. In particular we find that different neutrino flavors can mix even if they have zero rest mass in vacuum, without requiring fields beyond the Standard Model. |
hep-ph/9610235 | Jorge L. Lopez | J. Lopez, D. Nanopoulos, and A. Zichichi | No-scale supergravity confronts LEP diphoton events | 9 pages, LaTeX, 4 figures (included). Updated to include full LEP161
data | null | null | DOE/ER/40717-34, CTP-TAMU-50/96 | hep-ph | null | We examine the possibility that some anomalous acoplanar diphoton events
observed at LEP may be consistent with the predictions of our previously
proposed one-parameter no-scale supergravity model with a light gravitino, via
the process e^+e^- -> chi chi -> gamma gamma+E_miss. We find that one such
event may indeed be consistent with the model predictions for m_chi \approx
(60-70) GeV. This region of parameter space is also consistent with the
selectron and chargino interpretations of the CDF ee gamma gamma + E_T,miss
event.
| [
{
"created": "Thu, 3 Oct 1996 18:09:43 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Oct 1996 13:26:29 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Lopez",
"J.",
""
],
[
"Nanopoulos",
"D.",
""
],
[
"Zichichi",
"A.",
""
]
] | We examine the possibility that some anomalous acoplanar diphoton events observed at LEP may be consistent with the predictions of our previously proposed one-parameter no-scale supergravity model with a light gravitino, via the process e^+e^- -> chi chi -> gamma gamma+E_miss. We find that one such event may indeed be consistent with the model predictions for m_chi \approx (60-70) GeV. This region of parameter space is also consistent with the selectron and chargino interpretations of the CDF ee gamma gamma + E_T,miss event. |
1204.4416 | Piotr Czerski | Piotr Czerski | Meson Correlation Function and Screening Mass in Thermal QCD | 11 pages | Cent. Eur. J. Phys. 10 (2012) 342 | 10.2478/s11534-011-0117-1 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Analytical results for the spatial dependence of the correlation functions
for all meson excitations in perturbative Quantum Chromodynamics, the lowest
order, are calculated. The meson screening mass is obtained as a large distance
limit of the correlation function. Our analysis leads to a better understanding
of the excitations of Quark Gluon Plasma at sufficiently large temperatures and
may be of relevance for future numerical calculations with fully interacting
Quantum Chromodynamics.
| [
{
"created": "Thu, 19 Apr 2012 17:23:12 GMT",
"version": "v1"
}
] | 2014-03-05 | [
[
"Czerski",
"Piotr",
""
]
] | Analytical results for the spatial dependence of the correlation functions for all meson excitations in perturbative Quantum Chromodynamics, the lowest order, are calculated. The meson screening mass is obtained as a large distance limit of the correlation function. Our analysis leads to a better understanding of the excitations of Quark Gluon Plasma at sufficiently large temperatures and may be of relevance for future numerical calculations with fully interacting Quantum Chromodynamics. |
1310.8459 | Gaetano Lambiase | G. Lambiase, S. Mohanty, and A.R. Prasanna | Neutrino coupling to cosmological background: A review on gravitational
Baryo/Leptogenesis | 62 pages, no figures. Invited review to appear in IJMPD | null | 10.1142/S0218271813300309 | null | hep-ph astro-ph.CO gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we review the theories of origin of matter-antimatter asymmetry
in the Universe. The general conditions for achieving baryogenesis and
leptogenesis in a CPT conserving field theory have been laid down by Sakharov.
In this review we discuss scenarios where a background scalar or gravitational
field spontaneously breaks the CPT symmetry and splits the energy levels
between particles and anti-particles. Baryon or Lepton number violating
processes in proceeding at thermal equilibrium in such backgrounds gives rise
to Baryon or Lepton number asymmetry.
| [
{
"created": "Thu, 31 Oct 2013 11:07:37 GMT",
"version": "v1"
}
] | 2015-06-17 | [
[
"Lambiase",
"G.",
""
],
[
"Mohanty",
"S.",
""
],
[
"Prasanna",
"A. R.",
""
]
] | In this work we review the theories of origin of matter-antimatter asymmetry in the Universe. The general conditions for achieving baryogenesis and leptogenesis in a CPT conserving field theory have been laid down by Sakharov. In this review we discuss scenarios where a background scalar or gravitational field spontaneously breaks the CPT symmetry and splits the energy levels between particles and anti-particles. Baryon or Lepton number violating processes in proceeding at thermal equilibrium in such backgrounds gives rise to Baryon or Lepton number asymmetry. |
hep-ph/9809579 | Juraev Obid Muminovich | O. Juraev (The Abdus Salam International Centre for Theoretical
Physics, Trieste, Italy) | The quark inside hadron | 9 pages, 3 figures, used psfig, revtex. Submited to Phys. Rev. D | null | null | null | hep-ph | null | We study and solved Schwinger-Dayson equation for massive quarks in the quark
model. Interaction potential is choose as sum oscillator and Coulomb terms. The
calculation show us that negative energy of quark exist under $m_{o} \ll \Vo$
i.e. when mass quark is less that parameters of scale. Us are offered to use
asymptotical behaviour at the solutions Schwinger-Dayson equation selection
physical and non-physical conditions. The quark condensate under different
values mass quarks are calculated. The scale parameters $\Vo$= 520 MeV.
| [
{
"created": "Tue, 29 Sep 1998 11:18:28 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Juraev",
"O.",
"",
"The Abdus Salam International Centre for Theoretical\n Physics, Trieste, Italy"
]
] | We study and solved Schwinger-Dayson equation for massive quarks in the quark model. Interaction potential is choose as sum oscillator and Coulomb terms. The calculation show us that negative energy of quark exist under $m_{o} \ll \Vo$ i.e. when mass quark is less that parameters of scale. Us are offered to use asymptotical behaviour at the solutions Schwinger-Dayson equation selection physical and non-physical conditions. The quark condensate under different values mass quarks are calculated. The scale parameters $\Vo$= 520 MeV. |
1005.0956 | Lorenzo Luis Salcedo | C. Garcia-Recio, L.S. Geng, J. Nieves, L.L. Salcedo | Low-lying even parity meson resonances and spin-flavor symmetry | 43 pages, 2 figures, 61 tables. Improved discussion of Section II. To
appear in Physical Review D | Phys.Rev.D83:016007,2011 | 10.1103/PhysRevD.83.016007 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A study is presented of the $s-$wave meson-meson interactions involving
members of the $\rho-$nonet and of the $\pi-$octet. The starting point is an
SU(6) spin-flavor extension of the SU(3) flavor Weinberg-Tomozawa Lagrangian.
SU(6) symmetry breaking terms are then included to account for the physical
meson masses and decay constants, while preserving partial conservation of the
axial current in the light pseudoscalar sector. Next, the $T-$matrix amplitudes
are obtained by solving the Bethe Salpeter equation in coupled-channel with the
kernel built from the above interactions. The poles found on the first and
second Riemann sheets of the amplitudes are identified with their possible
Particle Data Group (PDG) counterparts. It is shown that most of the low-lying
even parity PDG meson resonances, specially in the $J^P=0^+$ and $1^+$ sectors,
can be classified according to multiplets of the spin-flavor symmetry group
SU(6). The $f_0(1500)$, $f_1(1420)$ and some $0^+(2^{++})$ resonances cannot be
accommodated within this SU(6) scheme and thus they would be clear candidates
to be glueballs or hybrids. Finally, we predict the existence of five exotic
resonances ($I \ge 3/2$ and/or $|Y|=2$) with masses in the range 1.4--1.6 GeV,
which would complete the $27_1$, $10_3$, and $10_3^*$ multiplets of
SU(3)$\otimes$SU(2).
| [
{
"created": "Thu, 6 May 2010 09:53:26 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Nov 2010 09:10:16 GMT",
"version": "v2"
}
] | 2011-02-01 | [
[
"Garcia-Recio",
"C.",
""
],
[
"Geng",
"L. S.",
""
],
[
"Nieves",
"J.",
""
],
[
"Salcedo",
"L. L.",
""
]
] | A study is presented of the $s-$wave meson-meson interactions involving members of the $\rho-$nonet and of the $\pi-$octet. The starting point is an SU(6) spin-flavor extension of the SU(3) flavor Weinberg-Tomozawa Lagrangian. SU(6) symmetry breaking terms are then included to account for the physical meson masses and decay constants, while preserving partial conservation of the axial current in the light pseudoscalar sector. Next, the $T-$matrix amplitudes are obtained by solving the Bethe Salpeter equation in coupled-channel with the kernel built from the above interactions. The poles found on the first and second Riemann sheets of the amplitudes are identified with their possible Particle Data Group (PDG) counterparts. It is shown that most of the low-lying even parity PDG meson resonances, specially in the $J^P=0^+$ and $1^+$ sectors, can be classified according to multiplets of the spin-flavor symmetry group SU(6). The $f_0(1500)$, $f_1(1420)$ and some $0^+(2^{++})$ resonances cannot be accommodated within this SU(6) scheme and thus they would be clear candidates to be glueballs or hybrids. Finally, we predict the existence of five exotic resonances ($I \ge 3/2$ and/or $|Y|=2$) with masses in the range 1.4--1.6 GeV, which would complete the $27_1$, $10_3$, and $10_3^*$ multiplets of SU(3)$\otimes$SU(2). |
hep-ph/0402061 | Bruce Hoeneisen | Carlos A. Marin and B. Hoeneisen | Mass constraints, production cross sections, and decay rates in the Two
Higgs Doublet Model of type II | 37 pages, 33 figures | null | null | USFQ-40-2004 | hep-ph | null | We calculate masses, production cross sections, and decay rates in the Two
Higgs Doublet Model of type II. We also discuss running coupling constants and
Grand Unification.
| [
{
"created": "Thu, 5 Feb 2004 22:27:53 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Marin",
"Carlos A.",
""
],
[
"Hoeneisen",
"B.",
""
]
] | We calculate masses, production cross sections, and decay rates in the Two Higgs Doublet Model of type II. We also discuss running coupling constants and Grand Unification. |
hep-ph/0609025 | Steen Hannestad | Anders Basboll (Univ. Aarhus), Steen Hannestad (Univ. Aarhus, MPI
Physics, Munich) | Decay of heavy Majorana neutrinos using the full Boltzmann equation
including its implications for leptogenesis | 11 pages, 6 figures, minor changes | JCAP 0701:003,2007 | 10.1088/1475-7516/2007/01/003 | null | hep-ph | null | We have studied the two-body production and decay of a heavy, right-handed
neutrino to two light states using the full Boltzmann equation instead of the
usual integrated Boltzmann equation which assumes kinetic equilibrium of all
species. Decays and inverse decays are inefficient for thermalising the
distribution function of the heavy neutrino and in some parameter ranges there
can be very large deviations from kinetic equilibrium. This leads to
substantial numerical differences between the two approaches. Furthermore we
study the impact of this difference on the lepton asymmetry production during
leptogenesis and find that in the strong washout regime the final asymmetry is
changed by 15-30% when the full Boltzmann equation is used.
| [
{
"created": "Mon, 4 Sep 2006 12:50:23 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Sep 2006 18:46:49 GMT",
"version": "v2"
}
] | 2010-10-27 | [
[
"Basboll",
"Anders",
"",
"Univ. Aarhus"
],
[
"Hannestad",
"Steen",
"",
"Univ. Aarhus, MPI\n Physics, Munich"
]
] | We have studied the two-body production and decay of a heavy, right-handed neutrino to two light states using the full Boltzmann equation instead of the usual integrated Boltzmann equation which assumes kinetic equilibrium of all species. Decays and inverse decays are inefficient for thermalising the distribution function of the heavy neutrino and in some parameter ranges there can be very large deviations from kinetic equilibrium. This leads to substantial numerical differences between the two approaches. Furthermore we study the impact of this difference on the lepton asymmetry production during leptogenesis and find that in the strong washout regime the final asymmetry is changed by 15-30% when the full Boltzmann equation is used. |
1512.00647 | Massimiliano Grazzini | M. Grazzini | Standard Model Theory for Collider Physics | Plenary talk given at EPS-HEP 2015 conference, Vienna, july 2015 | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I briefly review the current theoretical description of Standard Model
processes relevant for the LHC, and the tools that are used in the
corresponding phenomenological applications. I discuss in particular the recent
theoretical progress in NLO and NNLO QCD calculations, electroweak corrections,
resummations, Monte Carlo tools and parton distribution functions.
| [
{
"created": "Wed, 2 Dec 2015 11:00:16 GMT",
"version": "v1"
}
] | 2015-12-03 | [
[
"Grazzini",
"M.",
""
]
] | I briefly review the current theoretical description of Standard Model processes relevant for the LHC, and the tools that are used in the corresponding phenomenological applications. I discuss in particular the recent theoretical progress in NLO and NNLO QCD calculations, electroweak corrections, resummations, Monte Carlo tools and parton distribution functions. |
1209.4102 | Derek Harnett Derek Harnett | D. Harnett, R. Berg, R. T. Kleiv, T. G. Steele | A Laplace Sum-Rules Analysis of Heavy Pseudoscalar ($J^{PC}=0^{-+}$)
Hybrids | 4 pages, 3 figures. Presentation given at QCD12 in Montpellier,
France, July 2--6, 2012 | Nucl. Phys. B Proc. Suppl. 234 (2013) 154-157 | 10.1016/j.nuclphysbps.2012.12.004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We use QCD sum-rules to predict ground state masses for pseudoscalar
($J^{PC}=0^{-+}$) charmonium and bottomonium hybrids. We find that the
inclusion of a six-dimensional gluon condensate contribution is needed to
stabilize the analyses. For the charmonium hybrid, we find a mass of
$(3.82\pm0.13)$ GeV; for the bottomonium hybrid, we find a mass of
$(10.64\pm0.19)$ GeV. We comment on possible phenomenological implications
concerning the Y(3940).
| [
{
"created": "Tue, 18 Sep 2012 21:00:40 GMT",
"version": "v1"
}
] | 2013-04-04 | [
[
"Harnett",
"D.",
""
],
[
"Berg",
"R.",
""
],
[
"Kleiv",
"R. T.",
""
],
[
"Steele",
"T. G.",
""
]
] | We use QCD sum-rules to predict ground state masses for pseudoscalar ($J^{PC}=0^{-+}$) charmonium and bottomonium hybrids. We find that the inclusion of a six-dimensional gluon condensate contribution is needed to stabilize the analyses. For the charmonium hybrid, we find a mass of $(3.82\pm0.13)$ GeV; for the bottomonium hybrid, we find a mass of $(10.64\pm0.19)$ GeV. We comment on possible phenomenological implications concerning the Y(3940). |
2401.07632 | Xuhang Jiang | Xuhang Jiang, Jiahao Liu, Xiaofeng Xu, Li Lin Yang | Symbol letters of Feynman integrals from Gram determinants | 7 pages, 2 figures | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Symbol letters are crucial for analytically calculating Feynman integrals in
terms of iterated integrals. We present a novel method to construct the symbol
letters for a given integral family without prior knowledge of the canonical
differential equations. We provide a program package implementing our
algorithm, and demonstrate its effectiveness in solving non-trivial problems
with multiple loops and legs. Using our method, we successfully bootstrap the
canonical differential equations for a two-loop five-point family with two
external masses and for a three-loop four-point family with two external
masses, which were previously unknown in the literature. We anticipate that our
method can be applied to a wide range of cutting-edge calculations in the
future.
| [
{
"created": "Mon, 15 Jan 2024 12:18:08 GMT",
"version": "v1"
}
] | 2024-01-17 | [
[
"Jiang",
"Xuhang",
""
],
[
"Liu",
"Jiahao",
""
],
[
"Xu",
"Xiaofeng",
""
],
[
"Yang",
"Li Lin",
""
]
] | Symbol letters are crucial for analytically calculating Feynman integrals in terms of iterated integrals. We present a novel method to construct the symbol letters for a given integral family without prior knowledge of the canonical differential equations. We provide a program package implementing our algorithm, and demonstrate its effectiveness in solving non-trivial problems with multiple loops and legs. Using our method, we successfully bootstrap the canonical differential equations for a two-loop five-point family with two external masses and for a three-loop four-point family with two external masses, which were previously unknown in the literature. We anticipate that our method can be applied to a wide range of cutting-edge calculations in the future. |
hep-ph/0602227 | Luis Bento | Zurab Berezhiani and Luis Bento | Fast Neutron - Mirror Neutron Oscillation and Ultra High Energy Cosmic
Rays | 14 pages; to appear in PLB (submitted 28 November 2005) | Phys.Lett. B635 (2006) 253-259 | 10.1016/j.physletb.2006.03.008 | null | hep-ph | null | If there exists the mirror world, a parallel hidden sector of particles with
exactly the same microphysics as that of the observable particles, then the
primordial nucleosynthesis constraints require that the temperature of the
cosmic background of mirror relic photons should be smaller than that of the
ordinary relic photons, T'/T < 0.5 or so. On the other hand, the present
experimental and astrophysical limits allow a rather fast neutron - mirror
neutron oscillation in vacuum, with an oscillation time $\tau \sim 1$ s, much
smaller than the neutron lifetime. We show that this could provide a very
efficient mechanism for transporting ultra high energy protons at large
cosmological distances. The mechanism operates as follows: a super-GZK energy
proton scatters a relic photon producing a neutron that oscillates into a
mirror neutron which then decays into a mirror proton. The latter undergoes a
symmetric process, scattering a mirror relic photon and producing back an
ordinary nucleon, but only after traveling a distance $(T/T')^{3}$ times larger
than ordinary protons. This may relax or completely remove the GZK-cutoff in
the cosmic ray spectrum and also explain the correlation between the observed
ultra high energy protons and far distant sources as are the BL Lacs.
| [
{
"created": "Fri, 24 Feb 2006 17:17:58 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Berezhiani",
"Zurab",
""
],
[
"Bento",
"Luis",
""
]
] | If there exists the mirror world, a parallel hidden sector of particles with exactly the same microphysics as that of the observable particles, then the primordial nucleosynthesis constraints require that the temperature of the cosmic background of mirror relic photons should be smaller than that of the ordinary relic photons, T'/T < 0.5 or so. On the other hand, the present experimental and astrophysical limits allow a rather fast neutron - mirror neutron oscillation in vacuum, with an oscillation time $\tau \sim 1$ s, much smaller than the neutron lifetime. We show that this could provide a very efficient mechanism for transporting ultra high energy protons at large cosmological distances. The mechanism operates as follows: a super-GZK energy proton scatters a relic photon producing a neutron that oscillates into a mirror neutron which then decays into a mirror proton. The latter undergoes a symmetric process, scattering a mirror relic photon and producing back an ordinary nucleon, but only after traveling a distance $(T/T')^{3}$ times larger than ordinary protons. This may relax or completely remove the GZK-cutoff in the cosmic ray spectrum and also explain the correlation between the observed ultra high energy protons and far distant sources as are the BL Lacs. |
1302.0012 | Wan-Zhe Feng | Wan-Zhe Feng, Anupam Mazumdar, Pran Nath | Baryogenesis from dark matter | 6 pages, 1 figure | Phys.Rev.D88:036014,2013 | 10.1103/PhysRevD.88.036014 | null | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the possibility that some primordial fields decay purely into the
dark sector creating asymmetric dark matter. This asymmetry is subsequently
transmuted into leptons and baryons. Within this paradigm we compute the amount
of asymmetric dark matter created from the out of equilibrium decays of the
primordial fields with CP violating Yukawa couplings. The dark matter asymmetry
is then transferred to the visible sector by the asymmetry transfer equation
and generates an excess of $B-L$. Baryogenesis occurs via sphaleron processes
which conserve $B-L$ but violate $B+L$. A mechanism for the annihilation of the
symmetric component of dark matter is also discussed. The model leads to
multi-component dark matter consisting of both bosonic and fermionic
components.
| [
{
"created": "Thu, 31 Jan 2013 21:00:05 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Oct 2013 05:09:06 GMT",
"version": "v2"
}
] | 2013-10-07 | [
[
"Feng",
"Wan-Zhe",
""
],
[
"Mazumdar",
"Anupam",
""
],
[
"Nath",
"Pran",
""
]
] | We consider the possibility that some primordial fields decay purely into the dark sector creating asymmetric dark matter. This asymmetry is subsequently transmuted into leptons and baryons. Within this paradigm we compute the amount of asymmetric dark matter created from the out of equilibrium decays of the primordial fields with CP violating Yukawa couplings. The dark matter asymmetry is then transferred to the visible sector by the asymmetry transfer equation and generates an excess of $B-L$. Baryogenesis occurs via sphaleron processes which conserve $B-L$ but violate $B+L$. A mechanism for the annihilation of the symmetric component of dark matter is also discussed. The model leads to multi-component dark matter consisting of both bosonic and fermionic components. |
0807.2470 | Philippe Crochet | R.Rapp, D.Blaschke and P.Crochet | Charmonium and bottomonium production in heavy-ion collisions | 75 pages, 51 figures, revised version, references added | Prog.Part.Nucl.Phys.65:209-266,2010 | 10.1016/j.ppnp.2010.07.002 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review the present status in the theoretical and phenomenological
understanding of charmonium and bottomonium production in heavy-ion collisions.
We start by recapitulating the basic notion of "anomalous quarkonium
suppression" in heavy-ion collisions and its recent amendments involving
regeneration reactions. We then survey in some detail concepts and ingredients
needed for a comprehensive approach to utilize heavy quarkonia as a probe of
hot and dense matter. The theoretical discussion encompasses recent lattice QCD
computations of quarkonium properties in the Quark-Gluon Plasma, their
interpretations using effective potential models, inelastic rate calculations
and insights from analyses of electromagnetic plasmas. We illustrate the
powerful techniques of thermodynamic Green functions (T-matrices) to provide a
general framework for implementing microscopic properties of heavy quarkonia
into a kinetic theory of suppression and regeneration reactions. The
theoretical concepts are tested in applications to heavy-ion reactions at SPS,
RHIC and LHC. We outline perspectives for future experiments on charmonium and
bottomonium production in heavy-ion collisions over a large range in energy
(FAIR, RHIC-II and LHC). These are expected to provide key insights into
hadronic matter under extreme conditions using quarkonium observables.
| [
{
"created": "Wed, 16 Jul 2008 13:18:43 GMT",
"version": "v1"
},
{
"created": "Fri, 2 Jan 2009 16:36:40 GMT",
"version": "v2"
},
{
"created": "Mon, 19 Jul 2010 15:41:48 GMT",
"version": "v3"
}
] | 2015-03-13 | [
[
"Rapp",
"R.",
""
],
[
"Blaschke",
"D.",
""
],
[
"Crochet",
"P.",
""
]
] | We review the present status in the theoretical and phenomenological understanding of charmonium and bottomonium production in heavy-ion collisions. We start by recapitulating the basic notion of "anomalous quarkonium suppression" in heavy-ion collisions and its recent amendments involving regeneration reactions. We then survey in some detail concepts and ingredients needed for a comprehensive approach to utilize heavy quarkonia as a probe of hot and dense matter. The theoretical discussion encompasses recent lattice QCD computations of quarkonium properties in the Quark-Gluon Plasma, their interpretations using effective potential models, inelastic rate calculations and insights from analyses of electromagnetic plasmas. We illustrate the powerful techniques of thermodynamic Green functions (T-matrices) to provide a general framework for implementing microscopic properties of heavy quarkonia into a kinetic theory of suppression and regeneration reactions. The theoretical concepts are tested in applications to heavy-ion reactions at SPS, RHIC and LHC. We outline perspectives for future experiments on charmonium and bottomonium production in heavy-ion collisions over a large range in energy (FAIR, RHIC-II and LHC). These are expected to provide key insights into hadronic matter under extreme conditions using quarkonium observables. |
2106.08815 | Mark Goodsell | Mark D. Goodsell and Lakshmi Priya | Long Dead Winos | 25 pages, 5 figures, 10 tables. Code available at the LLPrecasting
repository https://github.com/llprecasting/recastingCodes/ and at
https://goodsell.pages.in2p3.fr/hackanalysis/ | null | 10.1140/epjc/s10052-022-10188-1 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We describe a new code and approach using particle-level information to
recast the recent CMS disappearing track searches including all run 2 data.
Notably, the simulation relies on knowledge of the detector geometry, and we
also include the simulation of pileup events directly rather than as an
efficiency function. We validate it against provided acceptances and cutflows,
and use it in combination with heavy stable charged particle searches to place
limits on winos with any proper decay length above a centimetre. We also
provide limits for a simple model of a charged scalar that is only produced in
pairs, that decays to electrons plus an invisible fermion.
| [
{
"created": "Wed, 16 Jun 2021 14:27:16 GMT",
"version": "v1"
}
] | 2022-04-13 | [
[
"Goodsell",
"Mark D.",
""
],
[
"Priya",
"Lakshmi",
""
]
] | We describe a new code and approach using particle-level information to recast the recent CMS disappearing track searches including all run 2 data. Notably, the simulation relies on knowledge of the detector geometry, and we also include the simulation of pileup events directly rather than as an efficiency function. We validate it against provided acceptances and cutflows, and use it in combination with heavy stable charged particle searches to place limits on winos with any proper decay length above a centimetre. We also provide limits for a simple model of a charged scalar that is only produced in pairs, that decays to electrons plus an invisible fermion. |
0808.2362 | Ulrich Haisch | Ulrich Haisch | Something about Z-penguins I want to tell | Parallel talk at ICHEP08, Philadelphia, USA, July 2008. 5 pages,
PDFLaTeX, 2 pdf figures and 1 table; v2: LaTeX template and references
updated | null | null | MZ-TH/08-24 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We stress that in models with constrained minimal flavor violation large
negative corrections to the flavor-changing Z-penguin amplitudes are excluded
by the precision measurements of the Z -> b anti-b pseudo observables performed
at LEP and SLC. The derived stringent range for the non-standard contribution
to the universal Inami-Lim function C leads to tight two-sided limits for the
branching ratios of all Z-penguin dominated flavor-changing K- and B-decays.
| [
{
"created": "Mon, 18 Aug 2008 09:41:15 GMT",
"version": "v1"
},
{
"created": "Sun, 19 Oct 2008 17:18:15 GMT",
"version": "v2"
}
] | 2008-10-19 | [
[
"Haisch",
"Ulrich",
""
]
] | We stress that in models with constrained minimal flavor violation large negative corrections to the flavor-changing Z-penguin amplitudes are excluded by the precision measurements of the Z -> b anti-b pseudo observables performed at LEP and SLC. The derived stringent range for the non-standard contribution to the universal Inami-Lim function C leads to tight two-sided limits for the branching ratios of all Z-penguin dominated flavor-changing K- and B-decays. |
1512.02535 | Darren Scott | Andrea Ferroglia, Benjamin D. Pecjak, Darren J. Scott, and Li Lin Yang | QCD resummations for boosted top production | 7 pages, 1 figure, Talk given at TOP 2015, 8th International Workshop
on Top Quark Physics, 14-18 September 2015, Ischia, Italy | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present new results for QCD corrections to the top-pair invariant mass and
top-quark $p_T$ distributions in boosted top-quark pair production at hadron
colliders. They are derived from a formalism which allows the joint resummation
of soft and small-mass logarithms at NNLL$'$ order, thus taking into account
all potentially large corrections in the boosted regime, where the partonic
center-of-mass energy is parameterically much larger than the mass of the top
quark. We match these results with those from standard soft-gluon resummation
away from the small-mass limit to NNLL order and also with NLO fixed-order
calculations, so that our results are valid in the maximum possible range of
phase space. The resummation effects on the $p_T$ and top-pair invariant mass
distributions are significant, bringing theory predictions into better
agreement with experimental data compared to pure NLO calculations.
| [
{
"created": "Tue, 8 Dec 2015 16:48:20 GMT",
"version": "v1"
}
] | 2015-12-09 | [
[
"Ferroglia",
"Andrea",
""
],
[
"Pecjak",
"Benjamin D.",
""
],
[
"Scott",
"Darren J.",
""
],
[
"Yang",
"Li Lin",
""
]
] | We present new results for QCD corrections to the top-pair invariant mass and top-quark $p_T$ distributions in boosted top-quark pair production at hadron colliders. They are derived from a formalism which allows the joint resummation of soft and small-mass logarithms at NNLL$'$ order, thus taking into account all potentially large corrections in the boosted regime, where the partonic center-of-mass energy is parameterically much larger than the mass of the top quark. We match these results with those from standard soft-gluon resummation away from the small-mass limit to NNLL order and also with NLO fixed-order calculations, so that our results are valid in the maximum possible range of phase space. The resummation effects on the $p_T$ and top-pair invariant mass distributions are significant, bringing theory predictions into better agreement with experimental data compared to pure NLO calculations. |
0807.4507 | Vincenzo Cirigliano | Vincenzo Cirigliano (Los Alamos), Maurizio Giannotti (Los Alamos),
Helmut Neufeld (University of Vienna) | Electromagnetic effects in Kl3 decays | 14 pages. 2 figures, 2 tables | JHEP 0811:006,2008 | 10.1088/1126-6708/2008/11/006 | LA-UR-07-7940, UWThPh-2008-12 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the radiative corrections to all Kl3 decay modes to leading
non-trivial order in the chiral effective field theory, working with a fully
inclusive prescription on real photon emission. We present new results for Kmu3
modes and update previous results on Ke3 modes. Our analysis provides important
theoretical input for the extraction of the CKM element Vus from Kl3 decays.
| [
{
"created": "Mon, 28 Jul 2008 19:19:14 GMT",
"version": "v1"
}
] | 2009-01-06 | [
[
"Cirigliano",
"Vincenzo",
"",
"Los Alamos"
],
[
"Giannotti",
"Maurizio",
"",
"Los Alamos"
],
[
"Neufeld",
"Helmut",
"",
"University of Vienna"
]
] | We study the radiative corrections to all Kl3 decay modes to leading non-trivial order in the chiral effective field theory, working with a fully inclusive prescription on real photon emission. We present new results for Kmu3 modes and update previous results on Ke3 modes. Our analysis provides important theoretical input for the extraction of the CKM element Vus from Kl3 decays. |
hep-ph/0610371 | Daniel Cabrera | D. Cabrera, L. Tolos, A. Ramos, A. Polls | The kaon optical potential modified by \Theta^+ Pentaquark excitation | 3 pages, 6 figures, to appear in the proceedings of the IV
International Conference on Quarks and Nuclear Physics (QNP06), Madrid,
Spain, June 5-10, 2006 | null | null | null | hep-ph nucl-th | null | We study the kaon nuclear optical potential including the effect of the
\Theta^+ pentaquark in a self-consistent approach, starting from an extension
of the Juelich meson-exchange potential as bare kaon-nucleon interaction.
Significant differences between a fully self-consistent calculation and the
low-density T\rho approximation are observed. Whereas te influence of the KN ->
\Theta^+ absorption process is found to be negligible, due to the small
\Theta^+ KN coupling, the two-nucleon mechanism (KNN -> \Theta^+ N), estimated
from the two-meson coupling of the pentaquark, provides the necessary
additional kaon absorption to reconcile with data the systematically low
theoretical K^+ nucleus reaction cross sections.
| [
{
"created": "Fri, 27 Oct 2006 16:17:49 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Cabrera",
"D.",
""
],
[
"Tolos",
"L.",
""
],
[
"Ramos",
"A.",
""
],
[
"Polls",
"A.",
""
]
] | We study the kaon nuclear optical potential including the effect of the \Theta^+ pentaquark in a self-consistent approach, starting from an extension of the Juelich meson-exchange potential as bare kaon-nucleon interaction. Significant differences between a fully self-consistent calculation and the low-density T\rho approximation are observed. Whereas te influence of the KN -> \Theta^+ absorption process is found to be negligible, due to the small \Theta^+ KN coupling, the two-nucleon mechanism (KNN -> \Theta^+ N), estimated from the two-meson coupling of the pentaquark, provides the necessary additional kaon absorption to reconcile with data the systematically low theoretical K^+ nucleus reaction cross sections. |
1909.12284 | Katarzyna Krajewska | K. Krajewska and J. Z. Kami\'nski | Unitary vs pseudo-unitary time evolution and statistical effects in the
dynamical Sauter-Schwinger process | 30 pages, 8 figures | Phys. Rev. A 100, 062116 (2019) | 10.1103/PhysRevA.100.062116 | null | hep-ph physics.atom-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Dynamical Sauter-Schwinger mechanism of pair creation by a time-dependent
electric field comprising of $N_{\rm rep}$ identical pulses is analyzed within
the framework of the spinor and scalar quantum electrodynamics. For linearly
polarized pulses, both theories predict that a single eigenmode of the matter
wave follows the dynamics of a two-level system. This dynamics, however, is
either governed by a Hermitian (for spin 1/2 particles) or pseudo-Hermitian
(for spin 0 particles) Hamiltonian. Essentially, both theories lead to a
Fraunhofer-type enhancement of the momentum distributions of created pairs.
While in the fermionic case the enhancement is never perfect and it
deteriorates with increasing the number of pulses in a train $N_{\rm rep}$, in
the bosonic case we observe the opposite. More specifically, it is at
exceptional points where the spectra of bosonic pairs scale exactly as $N_{\rm
rep}^2$, and this scaling is even enhanced with increasing the number of pulses
in a train.
| [
{
"created": "Thu, 26 Sep 2019 17:47:55 GMT",
"version": "v1"
}
] | 2019-12-18 | [
[
"Krajewska",
"K.",
""
],
[
"Kamiński",
"J. Z.",
""
]
] | Dynamical Sauter-Schwinger mechanism of pair creation by a time-dependent electric field comprising of $N_{\rm rep}$ identical pulses is analyzed within the framework of the spinor and scalar quantum electrodynamics. For linearly polarized pulses, both theories predict that a single eigenmode of the matter wave follows the dynamics of a two-level system. This dynamics, however, is either governed by a Hermitian (for spin 1/2 particles) or pseudo-Hermitian (for spin 0 particles) Hamiltonian. Essentially, both theories lead to a Fraunhofer-type enhancement of the momentum distributions of created pairs. While in the fermionic case the enhancement is never perfect and it deteriorates with increasing the number of pulses in a train $N_{\rm rep}$, in the bosonic case we observe the opposite. More specifically, it is at exceptional points where the spectra of bosonic pairs scale exactly as $N_{\rm rep}^2$, and this scaling is even enhanced with increasing the number of pulses in a train. |
1211.1980 | Ayres Freitas | Ayres Freitas, Pedro Schwaller | Higgs CP Properties From Early LHC Data | 18 pages, 5 figures; v2: references added and minor typos fixed | Phys. Rev. D 87, 055014 (2013) | 10.1103/PhysRevD.87.055014 | ANL-HEP-PR-12-84 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we constrain CP violation in the Higgs sector using the
measured signal strengths in the various Higgs search channels. To this end, we
introduce a general parameterization for a resonance which is an admixture of a
CP-even Higgs-like state and a CP-odd scalar. By performing a fit to the
available data from the Tevatron and LHC experiments one obtains constraints on
the mixing angle and the couplings of the resonance to Standard Model fields.
Depending on the couplings, sizable mixing angles are still compatible with the
data, but small mixing is in general preferred by the fit. In particular we
find that a pure CP-odd state is disfavored by the current data at the 3 sigma
level. Additionally we consider a mixed fermiophobic resonance and a model with
two degenerate mixed resonances and find that both scenarios can successfully
fit the data within current errors. Finally, we estimate that the mixing angle
can be constrained to \alpha < 1.1 (0.7) in the full 8 TeV (14 TeV) run of the
LHC.
| [
{
"created": "Thu, 8 Nov 2012 21:00:55 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Mar 2013 21:15:10 GMT",
"version": "v2"
}
] | 2013-03-28 | [
[
"Freitas",
"Ayres",
""
],
[
"Schwaller",
"Pedro",
""
]
] | In this paper, we constrain CP violation in the Higgs sector using the measured signal strengths in the various Higgs search channels. To this end, we introduce a general parameterization for a resonance which is an admixture of a CP-even Higgs-like state and a CP-odd scalar. By performing a fit to the available data from the Tevatron and LHC experiments one obtains constraints on the mixing angle and the couplings of the resonance to Standard Model fields. Depending on the couplings, sizable mixing angles are still compatible with the data, but small mixing is in general preferred by the fit. In particular we find that a pure CP-odd state is disfavored by the current data at the 3 sigma level. Additionally we consider a mixed fermiophobic resonance and a model with two degenerate mixed resonances and find that both scenarios can successfully fit the data within current errors. Finally, we estimate that the mixing angle can be constrained to \alpha < 1.1 (0.7) in the full 8 TeV (14 TeV) run of the LHC. |
1203.1484 | Ninetta Saviano | Ninetta Saviano (Hamburg U., II Inst. Theor. Phys.), Sovan Chakraborty
(Hamburg U., II Inst. Theor. Phys.), Tobias Fischer (GSI and Technische Univ.
Darmstadt), Alessandro Mirizzi (Hamburg U., II Inst. Theor. Phys.) | Stability analysis of collective neutrino oscillations in the supernova
accretion phase with realistic energy and angle distributions | v2: 8 pages, 3 eps figures. Revised version. Minor changes.
References updated. Matches the version published on PRD | Physical Review D 85, 113002 (2012) | 10.1103/PhysRevD.85.113002 | null | hep-ph astro-ph.HE | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We revisit our previous results on the matter suppression of self-induced
neutrino flavor conversions during a supernova (SN) accretion phase, performing
a linearized stability analysis of the neutrino equations of motion, in the
presence of realistic SN density profiles. In our previous numerical study, we
used a simplified model based on an isotropic neutrino emission with a single
typical energy. Here, we take into account realistic neutrino energy and angle
distributions. We find that multi-energy effects have a sub-leading impact in
the flavor stability of the SN neutrino fluxes with respect to our previous
single-energy results. Conversely, realistic forward-peaked neutrino angular
distributions would enhance the matter suppression of the self-induced
oscillations with respect to an isotropic neutrino emission. As a result, in
our models for iron-core SNe, collective flavor conversions have a negligible
impact on the characterization of the observable neutrino signal during the
accretion phase. Instead, for a low-mass O-Ne-Mg core SN model, with lower
matter density profile and less forward-peaked angular distributions,
collective conversions are possible also at early times.
| [
{
"created": "Wed, 7 Mar 2012 14:34:32 GMT",
"version": "v1"
},
{
"created": "Wed, 6 Jun 2012 14:13:03 GMT",
"version": "v2"
}
] | 2015-06-04 | [
[
"Saviano",
"Ninetta",
"",
"Hamburg U., II Inst. Theor. Phys."
],
[
"Chakraborty",
"Sovan",
"",
"Hamburg U., II Inst. Theor. Phys."
],
[
"Fischer",
"Tobias",
"",
"GSI and Technische Univ.\n Darmstadt"
],
[
"Mirizzi",
"Alessandro",
"",
"Ha... | We revisit our previous results on the matter suppression of self-induced neutrino flavor conversions during a supernova (SN) accretion phase, performing a linearized stability analysis of the neutrino equations of motion, in the presence of realistic SN density profiles. In our previous numerical study, we used a simplified model based on an isotropic neutrino emission with a single typical energy. Here, we take into account realistic neutrino energy and angle distributions. We find that multi-energy effects have a sub-leading impact in the flavor stability of the SN neutrino fluxes with respect to our previous single-energy results. Conversely, realistic forward-peaked neutrino angular distributions would enhance the matter suppression of the self-induced oscillations with respect to an isotropic neutrino emission. As a result, in our models for iron-core SNe, collective flavor conversions have a negligible impact on the characterization of the observable neutrino signal during the accretion phase. Instead, for a low-mass O-Ne-Mg core SN model, with lower matter density profile and less forward-peaked angular distributions, collective conversions are possible also at early times. |
hep-ph/9501375 | Agustin Nieto | Eric Braaten and Agustin Nieto | Effective Field Theory Approach to High-Temperature Thermodynamics | 40 pages, LaTeX, 5 uuecoded figures | Phys.Rev. D51 (1995) 6990-7006 | 10.1103/PhysRevD.51.6990 | NUHEP-TH-95-2 | hep-ph | null | An effective field theory approach is developed for calculating the
thermodynamic properties of a field theory at high temperature $T$ and weak
coupling $g$. The effective theory is the 3-dimensional field theory obtained
by dimensional reduction to the bosonic zero-frequency modes. The parameters of
the effective theory can be calculated as perturbation series in the running
coupling constant $g^2(T)$. The free energy is separated into the contributions
from the momentum scales $T$ and $gT$, respectively. The first term can be
written as a perturbation series in $g^2(T)$. If all forces are screened at the
scale $gT$, the second term can be calculated as a perturbation series in
$g(T)$ beginning at order $g^3$. The parameters of the effective theory satisfy
renormalization group equations that can be used to sum up leading logarithms
of $T/(gT)$. We apply this method to a massless scalar field with a $\Phi^4$
interaction, calculating the free energy to order $g^6 \log g$ and the
screening mass to order $g^5 \log g$.
| [
{
"created": "Wed, 25 Jan 1995 20:47:46 GMT",
"version": "v1"
}
] | 2016-09-01 | [
[
"Braaten",
"Eric",
""
],
[
"Nieto",
"Agustin",
""
]
] | An effective field theory approach is developed for calculating the thermodynamic properties of a field theory at high temperature $T$ and weak coupling $g$. The effective theory is the 3-dimensional field theory obtained by dimensional reduction to the bosonic zero-frequency modes. The parameters of the effective theory can be calculated as perturbation series in the running coupling constant $g^2(T)$. The free energy is separated into the contributions from the momentum scales $T$ and $gT$, respectively. The first term can be written as a perturbation series in $g^2(T)$. If all forces are screened at the scale $gT$, the second term can be calculated as a perturbation series in $g(T)$ beginning at order $g^3$. The parameters of the effective theory satisfy renormalization group equations that can be used to sum up leading logarithms of $T/(gT)$. We apply this method to a massless scalar field with a $\Phi^4$ interaction, calculating the free energy to order $g^6 \log g$ and the screening mass to order $g^5 \log g$. |
1107.3100 | Paolo Gambino | Paolo Gambino | B semileptonic moments at NNLO | 28 pages, 9 figures | null | 10.1007/JHEP09(2011)055 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The calculation of the moments in inclusive B meson semileptonic decays is
upgraded to O(alphas^2). The first three moments of the lepton energy and
invariant hadronic mass distributions are computed for arbitrary cuts on the
lepton energy and in various renormalization schemes, finding in general small
deviations from the O(alphas^2 beta0) calculation. I also review the relation
between MSbar and kinetic heavy quark masses.
| [
{
"created": "Fri, 15 Jul 2011 16:21:48 GMT",
"version": "v1"
}
] | 2015-05-28 | [
[
"Gambino",
"Paolo",
""
]
] | The calculation of the moments in inclusive B meson semileptonic decays is upgraded to O(alphas^2). The first three moments of the lepton energy and invariant hadronic mass distributions are computed for arbitrary cuts on the lepton energy and in various renormalization schemes, finding in general small deviations from the O(alphas^2 beta0) calculation. I also review the relation between MSbar and kinetic heavy quark masses. |
1509.04582 | Marco Guzzi | Marco Guzzi, Achim Geiser, Flera Rizatdinova | DIS2015 Heavy Flavours Working Group Summary | 16 pages, 16 figures, Conference proceeding summary, DIS2015 "The
XXIII International Workshop on Deep Inelastic Scattering and Related
Subjects", April 27 - May 1, 2015, Southern Methodist University, Dallas,
Texas, USA | null | null | MAN/HEP/2015/16 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Studies presented in the heavy flavours working group are summarized. Very
recent results of measurements at the HERA, LHC, Tevatron, STAR, PHENIX, and
BaBar experiments are reviewed and new developments in theory and phenomenology
are discussed. In particular, aspects of the impact of heavy flavours on global
QCD analyses to determine the structure of the proton, and analyses in physics
beyond the Standard Model are considered.
| [
{
"created": "Tue, 15 Sep 2015 14:35:19 GMT",
"version": "v1"
}
] | 2015-09-16 | [
[
"Guzzi",
"Marco",
""
],
[
"Geiser",
"Achim",
""
],
[
"Rizatdinova",
"Flera",
""
]
] | Studies presented in the heavy flavours working group are summarized. Very recent results of measurements at the HERA, LHC, Tevatron, STAR, PHENIX, and BaBar experiments are reviewed and new developments in theory and phenomenology are discussed. In particular, aspects of the impact of heavy flavours on global QCD analyses to determine the structure of the proton, and analyses in physics beyond the Standard Model are considered. |
hep-ph/0604253 | Howard Baer | Howard Baer, Eun-Kyung Park, Xerxes Tata and Ting T. Wang | Collider and Dark Matter Searches in Models with Mixed Modulus-Anomaly
Mediated SUSY Breaking | 38 pages including 22 EPS figures; latest version posted to conform
with published version | JHEP 0608 (2006) 041 | 10.1088/1126-6708/2006/08/041 | FSU-HEP-060426, UH-511-1087-06 | hep-ph hep-th | null | We investigate the phenomenology of supersymmetric models where moduli fields
and the Weyl anomaly make comparable contributions to SUSY breaking effects in
the observable sector of fields. This mixed modulus-anomaly mediated
supersymmetry breaking (MM-AMSB) scenario is inspired by models of string
compactification with fluxes, which have been shown to yield a de Sitter vacuum
(as in the recent construction by Kachru {\it et al}). The phenomenology
depends on the so-called modular weights which, in turn, depend on the location
of various fields in the extra dimensions. We find that the model with zero
modular weights gives mass spectra characterized by very light top squarks
and/or tau sleptons, or where M_1\sim -M_2 so that the bino and wino are
approximately degenerate. The top squark mass can be in the range required by
successful electroweak baryogenesis. The measured relic density of cold dark
matter can be obtained via top squark co-annihilation at low \tan\beta, tau
slepton co-annihilation at large \tan\beta or via bino-wino coannihilation.
Then, we typically find low rates for direct and indirect detection of
neutralino dark matter. However, essentially all the WMAP-allowed parameter
space can be probed by experiments at the CERN LHC, while significant portions
may also be explored at an e^+e^- collider with \sqrt{s}=0.5--1 TeV. We also
investigate a case with non-zero modular weights. In this case,
co-annihilation, A-funnel annihilation and bulk annihilation of neutralinos are
all allowed. Results for future colliders are qualitatively similar, but
prospects for indirect dark matter searches via gamma rays and anti-particles
are somewhat better.
| [
{
"created": "Thu, 27 Apr 2006 20:23:14 GMT",
"version": "v1"
},
{
"created": "Fri, 28 Apr 2006 20:51:40 GMT",
"version": "v2"
},
{
"created": "Tue, 1 Aug 2006 13:33:45 GMT",
"version": "v3"
}
] | 2009-11-11 | [
[
"Baer",
"Howard",
""
],
[
"Park",
"Eun-Kyung",
""
],
[
"Tata",
"Xerxes",
""
],
[
"Wang",
"Ting T.",
""
]
] | We investigate the phenomenology of supersymmetric models where moduli fields and the Weyl anomaly make comparable contributions to SUSY breaking effects in the observable sector of fields. This mixed modulus-anomaly mediated supersymmetry breaking (MM-AMSB) scenario is inspired by models of string compactification with fluxes, which have been shown to yield a de Sitter vacuum (as in the recent construction by Kachru {\it et al}). The phenomenology depends on the so-called modular weights which, in turn, depend on the location of various fields in the extra dimensions. We find that the model with zero modular weights gives mass spectra characterized by very light top squarks and/or tau sleptons, or where M_1\sim -M_2 so that the bino and wino are approximately degenerate. The top squark mass can be in the range required by successful electroweak baryogenesis. The measured relic density of cold dark matter can be obtained via top squark co-annihilation at low \tan\beta, tau slepton co-annihilation at large \tan\beta or via bino-wino coannihilation. Then, we typically find low rates for direct and indirect detection of neutralino dark matter. However, essentially all the WMAP-allowed parameter space can be probed by experiments at the CERN LHC, while significant portions may also be explored at an e^+e^- collider with \sqrt{s}=0.5--1 TeV. We also investigate a case with non-zero modular weights. In this case, co-annihilation, A-funnel annihilation and bulk annihilation of neutralinos are all allowed. Results for future colliders are qualitatively similar, but prospects for indirect dark matter searches via gamma rays and anti-particles are somewhat better. |
1605.03199 | Tooraj Ghaffary | Tooraj Ghaffary | Charged Particles Multiplicity and Scaling Violation of Fragmentation
Functions in Electron-Positron Annihilation | 13 pages | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In electron positron annihilation, changing quarks into the final hadron
states is being described by fragmentation function. Based on the scaling
hypothesis, this function will be independent from the center of mass energy.
Gluon radiation violates the scaling feature. Transverse momentum distribution
plays an important role in scaling violation of fragmentation functions. In
this article, by the use of data resulted from the annihilation process of
electron positron in AMY detector at 60 GeV center of mass energy, first,
charged particles multiplicity distribution will be obtained and it will be
fitted with the KNO scaling. Furthermore, momentum spectra of charged particles
and momentum distribution respect to the jet axis will be obtained. Then, the
results will be compared regarding the different models of QCD; as well, the
distribution of fragmentation functions and scaling violations will be studied.
It is being expected that the scaling violations of the fragmentation functions
of gluon jet are stronger to the quark one. One of the reasons for such case is
that splitting function of jet is larger than splitting function of gluon.
| [
{
"created": "Tue, 10 May 2016 20:18:43 GMT",
"version": "v1"
}
] | 2016-05-12 | [
[
"Ghaffary",
"Tooraj",
""
]
] | In electron positron annihilation, changing quarks into the final hadron states is being described by fragmentation function. Based on the scaling hypothesis, this function will be independent from the center of mass energy. Gluon radiation violates the scaling feature. Transverse momentum distribution plays an important role in scaling violation of fragmentation functions. In this article, by the use of data resulted from the annihilation process of electron positron in AMY detector at 60 GeV center of mass energy, first, charged particles multiplicity distribution will be obtained and it will be fitted with the KNO scaling. Furthermore, momentum spectra of charged particles and momentum distribution respect to the jet axis will be obtained. Then, the results will be compared regarding the different models of QCD; as well, the distribution of fragmentation functions and scaling violations will be studied. It is being expected that the scaling violations of the fragmentation functions of gluon jet are stronger to the quark one. One of the reasons for such case is that splitting function of jet is larger than splitting function of gluon. |
1801.06476 | L. Evan Finch | L. Evan Finch, Stephen J. Murray | Investigating Local Parity Violation in Heavy-Ion Collisions Using
Lambda Helicity | 10 pages, 1 figure | Physical Review C, 96 (2017), 044911 | 10.1103/PhysRevC.96.044911 | null | hep-ph nucl-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose the measurement of net $\Lambda$ and $\bar{\Lambda}$ helicity,
correlated event-by-event with the magnitude and sign of charge separation
along the event's magnetic field direction, as a probe to investigate the
Chiral Magnetic Effect in Heavy-Ion Collisions. With a simple simulation model
of heavy-ion events that includes effects of Local Parity Violation, we
estimate the experimental correlation signal that could be expected at RHIC
given the results of previous measurements that are sensitive to the CME.
| [
{
"created": "Fri, 19 Jan 2018 16:04:52 GMT",
"version": "v1"
}
] | 2018-01-31 | [
[
"Finch",
"L. Evan",
""
],
[
"Murray",
"Stephen J.",
""
]
] | We propose the measurement of net $\Lambda$ and $\bar{\Lambda}$ helicity, correlated event-by-event with the magnitude and sign of charge separation along the event's magnetic field direction, as a probe to investigate the Chiral Magnetic Effect in Heavy-Ion Collisions. With a simple simulation model of heavy-ion events that includes effects of Local Parity Violation, we estimate the experimental correlation signal that could be expected at RHIC given the results of previous measurements that are sensitive to the CME. |
hep-ph/9905568 | Roberto Casalbuoni, Firenze | R. Casalbuoni, S. De Curtis, D. Dominici and R. Gatto | Bounds on New Physics from the New Data on Parity Violation in Atomic
Cesium | 11 pages, Latex, 1 PS figure, final version for Physics Letters | Phys.Lett.B460:135-140,1999 | 10.1016/S0370-2693(99)00762-5 | null | hep-ph | null | We assume the latest experimental determination of the weak charge of atomic
cesium and analyze its implications for possible new physics. We notice that
the data would imply positive upper and lower bounds on the new physics
contribution to the weak charge, $\delta_NQ_W$. The required new physics should
be of a type not severely constrained by the high energy precision data. A
simplest possibility would be new neutral vector bosons almost un-mixed to the
$Z$ and with sizeable couplings to fermions. The lower positive bound would
however forbid zero or negative $\delta_NQ_W$ and exclude not only the standard
model but also models with sequential $Z^\prime$, in particular simple-minded
towers of $Z$-like excitations from extra-dimensions. The bound would also
imply an upper limit on the $Z^\prime$ mass within the models allowed.
Conclusions are also derived for models of four-fermion contact interactions.
| [
{
"created": "Mon, 31 May 1999 14:58:42 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Jun 1999 17:03:36 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Casalbuoni",
"R.",
""
],
[
"De Curtis",
"S.",
""
],
[
"Dominici",
"D.",
""
],
[
"Gatto",
"R.",
""
]
] | We assume the latest experimental determination of the weak charge of atomic cesium and analyze its implications for possible new physics. We notice that the data would imply positive upper and lower bounds on the new physics contribution to the weak charge, $\delta_NQ_W$. The required new physics should be of a type not severely constrained by the high energy precision data. A simplest possibility would be new neutral vector bosons almost un-mixed to the $Z$ and with sizeable couplings to fermions. The lower positive bound would however forbid zero or negative $\delta_NQ_W$ and exclude not only the standard model but also models with sequential $Z^\prime$, in particular simple-minded towers of $Z$-like excitations from extra-dimensions. The bound would also imply an upper limit on the $Z^\prime$ mass within the models allowed. Conclusions are also derived for models of four-fermion contact interactions. |
1812.11964 | Tomasz Dutka Mr | Matthew J. Dolan, Tomasz P. Dutka and Raymond R. Volkas | Low-scale Leptogenesis with Minimal Lepton Flavour Violation | 60 pages, 20 figures; v2: Added discussion and figures on the
contribution of coherent sterile neutrino oscillations to asymmetry
generation; other, minor changes and added references. Conclusions unchanged.
Matches version to be published by PRD | Phys. Rev. D 99, 123508 (2019) | 10.1103/PhysRevD.99.123508 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyse the feasibility of low-scale leptogenesis where the inverse seesaw
(ISS) and linear seesaw (LSS) terms are not simultaneously present. In order to
generate the necessary mass splittings, we adopt a Minimal Lepton Flavour
Violation (MLFV) hypothesis where a sterile neutrino mass degeneracy is broken
by flavour effects. We find that resonant leptogenesis is feasible in both
scenarios. However, because of a flavour alignment issue, MLFV-ISS leptogenesis
succeeds only with a highly tuned choice of Majorana masses. For MLFV-LSS, on
the other hand, a large portion of parameter space is able to generate
sufficient asymmetry. In both scenarios we find that the lightest neutrino mass
must be of order $10^{-2}\text{ eV}$ or below for successful leptogenesis. We
briefly explore implications for low-energy flavour violation experiments, in
particular $\mu \rightarrow e\,\gamma$. We find that the future MEG-II
experiment, while sensitive to MLFV in our setup, will not be sensitive to the
specific regions required for resonant leptogenesis.
| [
{
"created": "Mon, 31 Dec 2018 18:58:03 GMT",
"version": "v1"
},
{
"created": "Wed, 30 Jan 2019 04:51:36 GMT",
"version": "v2"
},
{
"created": "Tue, 21 May 2019 03:57:49 GMT",
"version": "v3"
}
] | 2019-06-19 | [
[
"Dolan",
"Matthew J.",
""
],
[
"Dutka",
"Tomasz P.",
""
],
[
"Volkas",
"Raymond R.",
""
]
] | We analyse the feasibility of low-scale leptogenesis where the inverse seesaw (ISS) and linear seesaw (LSS) terms are not simultaneously present. In order to generate the necessary mass splittings, we adopt a Minimal Lepton Flavour Violation (MLFV) hypothesis where a sterile neutrino mass degeneracy is broken by flavour effects. We find that resonant leptogenesis is feasible in both scenarios. However, because of a flavour alignment issue, MLFV-ISS leptogenesis succeeds only with a highly tuned choice of Majorana masses. For MLFV-LSS, on the other hand, a large portion of parameter space is able to generate sufficient asymmetry. In both scenarios we find that the lightest neutrino mass must be of order $10^{-2}\text{ eV}$ or below for successful leptogenesis. We briefly explore implications for low-energy flavour violation experiments, in particular $\mu \rightarrow e\,\gamma$. We find that the future MEG-II experiment, while sensitive to MLFV in our setup, will not be sensitive to the specific regions required for resonant leptogenesis. |
1804.05874 | Dorival Goncalves | Dorival Goncalves, Kyoungchul Kong, Jeong Han Kim | Probing the Top-Higgs Yukawa CP Structure in dileptonic $t \bar t h$
with $M_2$-Assisted Reconstruction | 25 pages, 11 figures, 3 tables | null | 10.1007/JHEP06(2018)079 | PITT-PACC-1807 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Constraining the Higgs boson properties is a cornerstone of the LHC program.
We study the potential to directly probe the Higgs-top CP-structure via the
$t\bar{t}h$ channel at the LHC with the Higgs boson decaying to a bottom pair
and top-quarks in the dileptonic mode. We show that a combination of laboratory
and $t\bar{t}$ rest frame observables display large CP-sensitivity, exploring
the spin correlations in the top decays. To efficiently reconstruct our final
state, we present a method based on simple mass minimization and prove its
robustness to shower, hadronization and detector effects. In addition, the mass
reconstruction works as an extra relevant handle for background suppression.
Based on our results, we demonstrate that the Higgs-top CP-phase $(\alpha)$ can
be probed up to $\cos\alpha< 0.7$ at the high luminosity LHC.
| [
{
"created": "Mon, 16 Apr 2018 18:15:55 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Oct 2022 14:58:15 GMT",
"version": "v2"
}
] | 2022-10-05 | [
[
"Goncalves",
"Dorival",
""
],
[
"Kong",
"Kyoungchul",
""
],
[
"Kim",
"Jeong Han",
""
]
] | Constraining the Higgs boson properties is a cornerstone of the LHC program. We study the potential to directly probe the Higgs-top CP-structure via the $t\bar{t}h$ channel at the LHC with the Higgs boson decaying to a bottom pair and top-quarks in the dileptonic mode. We show that a combination of laboratory and $t\bar{t}$ rest frame observables display large CP-sensitivity, exploring the spin correlations in the top decays. To efficiently reconstruct our final state, we present a method based on simple mass minimization and prove its robustness to shower, hadronization and detector effects. In addition, the mass reconstruction works as an extra relevant handle for background suppression. Based on our results, we demonstrate that the Higgs-top CP-phase $(\alpha)$ can be probed up to $\cos\alpha< 0.7$ at the high luminosity LHC. |
0704.2628 | Jamal Jalilian-Marian | Jamal Jalilian-Marian | Average $p_t$ as a probe of high energy QCD dynamics | 8 pages, 3 figures | Nucl.Phys.A812:140-148,2008 | 10.1016/j.nuclphysa.2008.08.009 | BCCUNY-HEP-07-04 | hep-ph nucl-ex nucl-th | null | Average transverse momentum of hadrons produced in high energy collisions is
proposed as a diagnostic probe of high density (saturation) physics. We show
that by introducing and varying a transverse momentum cutoff in the definition
of the average transverse momentum, one can eliminate the uncertainty in the
overall magnitude of the leading order hadron production cross section in high
energy collisions, and semi-quantitatively map the different dynamical regions
predicted by the saturation physics. We discuss the applications of this method
to pion production at RHIC and LHC and make quantitative predictions for the
average transverse momentum of produced pions in the kinematics appropriate for
the RHIC and LHC experiments.
| [
{
"created": "Thu, 19 Apr 2007 22:35:16 GMT",
"version": "v1"
}
] | 2010-03-25 | [
[
"Jalilian-Marian",
"Jamal",
""
]
] | Average transverse momentum of hadrons produced in high energy collisions is proposed as a diagnostic probe of high density (saturation) physics. We show that by introducing and varying a transverse momentum cutoff in the definition of the average transverse momentum, one can eliminate the uncertainty in the overall magnitude of the leading order hadron production cross section in high energy collisions, and semi-quantitatively map the different dynamical regions predicted by the saturation physics. We discuss the applications of this method to pion production at RHIC and LHC and make quantitative predictions for the average transverse momentum of produced pions in the kinematics appropriate for the RHIC and LHC experiments. |
hep-ph/9909375 | Dietrich Bodeker | Dietrich Bodeker | Effective Theories for Hot Non-Abelian Dynamics | 11 pages, 3 figures; plenary talk given at Conference on Strong and
Electroweak Matter (SEWM 98), Copenhagen, Denmark, 2-5 Dec 1998 | null | null | NBI-HE-99-12 | hep-ph | null | The dynamics of soft ($|\vec{p}|\sim g^2 T$) non-Abelian gauge fields at
finite temperature is non-perturbative. The effective theory for the soft
fields can be obtained by first integrating out the momentum scale T, which
yields the well known hard thermal loop effective theory. Then the latter is
used to integrate out the scale gT. One obtains a Boltzmann equation, which can
be solved in a leading logarithmic approximation. The resulting effective
theory for the soft fields is described by a Langevin equation, and it is well
suited for non-perturbative lattice simulations.
| [
{
"created": "Tue, 14 Sep 1999 21:31:07 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bodeker",
"Dietrich",
""
]
] | The dynamics of soft ($|\vec{p}|\sim g^2 T$) non-Abelian gauge fields at finite temperature is non-perturbative. The effective theory for the soft fields can be obtained by first integrating out the momentum scale T, which yields the well known hard thermal loop effective theory. Then the latter is used to integrate out the scale gT. One obtains a Boltzmann equation, which can be solved in a leading logarithmic approximation. The resulting effective theory for the soft fields is described by a Langevin equation, and it is well suited for non-perturbative lattice simulations. |
1310.7833 | Claudia Hagedorn | C. Hagedorn | Charged lepton flavour violation in supersymmetric and holographic
composite Higgs models with flavour symmetries | 3 pages, 4 figures, contribution to proceedings of "1st Conference on
Charged Lepton Flavor Violation", based on poster, extends original
publications about holographic composite Higgs models: figures updated and
results of new flavor group discussed | null | 10.1016/j.nuclphysbps.2014.02.018 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss charged lepton flavour violating processes such as mu -> e gamma
in supersymmetric extensions of the Standard Model and in models with
gauge-Higgs unification and a warped extra dimension. In both classes of models
the processes turn out to be compatible with present experimental bounds, but
can be detected by future experiments, thanks to the presence of a flavour
symmetry G_f which constrains the form of the relevant couplings. The symmetry
G_f is chosen to be finite, discrete and non-abelian and also helps to predict
the peculiar lepton mixing pattern.
| [
{
"created": "Tue, 29 Oct 2013 15:21:21 GMT",
"version": "v1"
}
] | 2015-06-17 | [
[
"Hagedorn",
"C.",
""
]
] | We discuss charged lepton flavour violating processes such as mu -> e gamma in supersymmetric extensions of the Standard Model and in models with gauge-Higgs unification and a warped extra dimension. In both classes of models the processes turn out to be compatible with present experimental bounds, but can be detected by future experiments, thanks to the presence of a flavour symmetry G_f which constrains the form of the relevant couplings. The symmetry G_f is chosen to be finite, discrete and non-abelian and also helps to predict the peculiar lepton mixing pattern. |
hep-ph/0305152 | Sergio Palomares-Ruiz | J. Bernabeu, Sergio Palomares-Ruiz (Valencia U.) and S. T. Petcov
(SISSA, Trieste & INFN, Trieste) | Atmospheric Neutrino Oscillations, theta(13) and Neutrino Mass Hierarchy | 22 pp | Nucl.Phys.B669:255-276,2003 | 10.1016/j.nuclphysb.2003.07.025 | SISSA 28/03/EP, FTUV-03-0513, IFIC/03-21 | hep-ph | null | We derive predictions for the Nadir angle (theta(n)) dependence of the ratio
N(mu)/N(e) of the rates of the mu-like and e-like multi-GeV events measured in
water-Cerenkov detectors in the case of 3-neutrino oscillations of the
atmospheric nu(e) (antinu(e)) and nu(mu) (antinu(mu)), driven by one neutrino
mass squared difference, |Delta m2(31)| ~ (2.5 - 3.0) x 10^(-3) eV^2 >> Delta
m2(21). This ratio is particularly sensitive to the Earth matter effects in the
atmospheric neutrino oscillations, and thus to the values of sin^2(theta(13))
and sin^2(theta(23)), theta(13) and theta(23) being the neutrino mixing angle
limited by the CHOOZ and Palo Verde experiments and that responsible for the
dominant atmospheric nu(mu) -> nu(tau) (antinu(mu) -> antinu(tau))
oscillations. It is also sensitive to the type of neutrino mass spectrum which
can be with normal (Delta m2(31) > 0) or with inverted (Delta m2(31) < 0)
hierarchy. We show that for sin^2(theta(13)) > 0.01, sin^2(theta(23)) > 0.5 and
at cos(theta(n)) > 0.4, the Earth matter effects modify substantially the
theta(n)-dependence of the ratio N(mu)/N(e) and in a way which cannot be
reproduced with sin^2(theta(13)) = 0 and a different value of sin^2(theta(23)).
For normal hierarchy the effects can be as large as ~ 25% for cos(theta(n)) ~
(0.5 - 0.8), can reach ~ 35% in the Earth core bin cos(theta(n)) ~ (0.84 -
1.0), and might be observable. They are typically by ~ 10% smaller in the
inverted hierarchy case. An observation of the Earth matter effects in the
Nadir angle distribution of the ratio N(mu)/N(e) would clearly indicate that
sin^2(theta(13)) > 0.01 and sin^2(theta(23)) > 0.50.
| [
{
"created": "Wed, 14 May 2003 12:15:27 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Bernabeu",
"J.",
"",
"Valencia U."
],
[
"Palomares-Ruiz",
"Sergio",
"",
"Valencia U."
],
[
"Petcov",
"S. T.",
"",
"SISSA, Trieste & INFN, Trieste"
]
] | We derive predictions for the Nadir angle (theta(n)) dependence of the ratio N(mu)/N(e) of the rates of the mu-like and e-like multi-GeV events measured in water-Cerenkov detectors in the case of 3-neutrino oscillations of the atmospheric nu(e) (antinu(e)) and nu(mu) (antinu(mu)), driven by one neutrino mass squared difference, |Delta m2(31)| ~ (2.5 - 3.0) x 10^(-3) eV^2 >> Delta m2(21). This ratio is particularly sensitive to the Earth matter effects in the atmospheric neutrino oscillations, and thus to the values of sin^2(theta(13)) and sin^2(theta(23)), theta(13) and theta(23) being the neutrino mixing angle limited by the CHOOZ and Palo Verde experiments and that responsible for the dominant atmospheric nu(mu) -> nu(tau) (antinu(mu) -> antinu(tau)) oscillations. It is also sensitive to the type of neutrino mass spectrum which can be with normal (Delta m2(31) > 0) or with inverted (Delta m2(31) < 0) hierarchy. We show that for sin^2(theta(13)) > 0.01, sin^2(theta(23)) > 0.5 and at cos(theta(n)) > 0.4, the Earth matter effects modify substantially the theta(n)-dependence of the ratio N(mu)/N(e) and in a way which cannot be reproduced with sin^2(theta(13)) = 0 and a different value of sin^2(theta(23)). For normal hierarchy the effects can be as large as ~ 25% for cos(theta(n)) ~ (0.5 - 0.8), can reach ~ 35% in the Earth core bin cos(theta(n)) ~ (0.84 - 1.0), and might be observable. They are typically by ~ 10% smaller in the inverted hierarchy case. An observation of the Earth matter effects in the Nadir angle distribution of the ratio N(mu)/N(e) would clearly indicate that sin^2(theta(13)) > 0.01 and sin^2(theta(23)) > 0.50. |
hep-ph/0210065 | Mariusz Sadzikowski | M. Sadzikowski | Coexistence of pion condensation and color superconductivity in two
flavor quark matter | Change of the title. Journal-ref addad | Phys.Lett.B553:45-50,2003 | 10.1016/S0370-2693(02)03188-X | null | hep-ph | null | We show that the superconducting 2SC phase at high density and normal chiraly
broken quark phase at low density is separated by the mixed non-uniform phase
along the baryon density line.
| [
{
"created": "Fri, 4 Oct 2002 08:41:17 GMT",
"version": "v1"
},
{
"created": "Fri, 13 Jun 2003 07:39:30 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Sadzikowski",
"M.",
""
]
] | We show that the superconducting 2SC phase at high density and normal chiraly broken quark phase at low density is separated by the mixed non-uniform phase along the baryon density line. |
hep-ph/9708418 | Gabor Papp | Romuald A. Janik, Maciej A. Nowak, Gabor Papp and Ismail Zahed | New Developments In Non-Hermitian Random Matrix Models | 18 pages, 8 EPS figures included; Talk presented by M.A. Nowak at the
NATO Workshop ``New Developments in Quantum Field Theory'', June 14-20, 1997,
Zakopane, Poland | null | null | null | hep-ph chao-dyn cond-mat nlin.CD | null | In this talk we go over several new developments regarding the techniques for
a large class of non-hermitian matrix models with unitary randomness (complex
random numbers). In particular, we discuss:
(a) - A diagrammatic approach based on a $1/N$ expansion
(b) - A generalization of the addition theorem (R-transformation)
(c) - A conformal transformation on the position of pertinent singularities
(d) - A `phase' analysis using appropriate partition functions
(e) - A number of two-point functions and the issue of universality.
| [
{
"created": "Wed, 20 Aug 1997 11:25:32 GMT",
"version": "v1"
}
] | 2008-02-03 | [
[
"Janik",
"Romuald A.",
""
],
[
"Nowak",
"Maciej A.",
""
],
[
"Papp",
"Gabor",
""
],
[
"Zahed",
"Ismail",
""
]
] | In this talk we go over several new developments regarding the techniques for a large class of non-hermitian matrix models with unitary randomness (complex random numbers). In particular, we discuss: (a) - A diagrammatic approach based on a $1/N$ expansion (b) - A generalization of the addition theorem (R-transformation) (c) - A conformal transformation on the position of pertinent singularities (d) - A `phase' analysis using appropriate partition functions (e) - A number of two-point functions and the issue of universality. |
1802.05545 | Leong Khim Wong | Philippe Brax, Anne-Christine Davis, Benjamin Elder, Leong Khim Wong | Constraining screened fifth forces with the electron magnetic moment | 18 pages + appendices, 12 figures. Abstract abridged for arXiv
submission. v2: Minor typos corrected to match PRD version | Phys. Rev. D 97, 084050 (2018) | 10.1103/PhysRevD.97.084050 | null | hep-ph astro-ph.CO physics.atom-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Chameleon and symmetron theories serve as archetypal models for how light
scalar fields can couple to matter with gravitational strength or greater, yet
evade the stringent constraints from classical tests of gravity on Earth and in
the Solar System. In this work, we investigate how a precision measurement of
the electron magnetic moment places meaningful constraints on both chameleons
and symmetrons. Two effects are identified: First, virtual chameleons and
symmetrons run in loops to generate quantum corrections to the intrinsic value
of the magnetic moment; a common process widely considered in the literature
for many scenarios beyond the Standard Model. A second effect, however, is
unique to scalar fields that exhibit screening. A scalar bubblelike profile
forms inside the experimental vacuum chamber and exerts a fifth force on the
electron, leading to a systematic shift in the experimental measurement. In
quantifying this latter effect, we present a novel approach that combines
analytic arguments and a small number of numerical simulations to solve for the
bubblelike profile quickly for a large range of model parameters. Taken
together, both effects yield interesting constraints in complementary regions
of parameter space. While the constraints we obtain for the chameleon are
largely uncompetitive with those in the existing literature, this still
represents the tightest constraint achievable yet from an experiment not
originally designed to search for fifth forces. We break more ground with the
symmetron, for which our results exclude a large and previously unexplored
region of parameter space. Central to this achievement are the quantum
correction terms, which are able to constrain symmetrons with masses in the
range $\mu \in [10^{-3.88},10^8]\,\text{eV}$, whereas other experiments have
hitherto only been sensitive to 1 or 2 orders of magnitude at a time.
| [
{
"created": "Thu, 15 Feb 2018 14:19:41 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Apr 2018 23:09:01 GMT",
"version": "v2"
}
] | 2018-05-01 | [
[
"Brax",
"Philippe",
""
],
[
"Davis",
"Anne-Christine",
""
],
[
"Elder",
"Benjamin",
""
],
[
"Wong",
"Leong Khim",
""
]
] | Chameleon and symmetron theories serve as archetypal models for how light scalar fields can couple to matter with gravitational strength or greater, yet evade the stringent constraints from classical tests of gravity on Earth and in the Solar System. In this work, we investigate how a precision measurement of the electron magnetic moment places meaningful constraints on both chameleons and symmetrons. Two effects are identified: First, virtual chameleons and symmetrons run in loops to generate quantum corrections to the intrinsic value of the magnetic moment; a common process widely considered in the literature for many scenarios beyond the Standard Model. A second effect, however, is unique to scalar fields that exhibit screening. A scalar bubblelike profile forms inside the experimental vacuum chamber and exerts a fifth force on the electron, leading to a systematic shift in the experimental measurement. In quantifying this latter effect, we present a novel approach that combines analytic arguments and a small number of numerical simulations to solve for the bubblelike profile quickly for a large range of model parameters. Taken together, both effects yield interesting constraints in complementary regions of parameter space. While the constraints we obtain for the chameleon are largely uncompetitive with those in the existing literature, this still represents the tightest constraint achievable yet from an experiment not originally designed to search for fifth forces. We break more ground with the symmetron, for which our results exclude a large and previously unexplored region of parameter space. Central to this achievement are the quantum correction terms, which are able to constrain symmetrons with masses in the range $\mu \in [10^{-3.88},10^8]\,\text{eV}$, whereas other experiments have hitherto only been sensitive to 1 or 2 orders of magnitude at a time. |
1110.4846 | Stanislaw Mrowczynski | Margaret E. Carrington, Katarzyna Deja and Stanislaw Mrowczynski | Parton Energy Loss in an Unstable Quark-Gluon Plasma | 8 pages; presented at the HIC-for-FAIR Workshop and XXVIII Max-Born
Symposium `Three Days on Quarkyonic Island', Wroclaw, Poland, May 18-21,
2011; comments added and numerical results modified | Acta Physica Polonica B - Proceedings Supplement 5, 947 (2012) | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The energy loss of a fast parton scattering elastically in a weakly coupled
quark-gluon plasma is formulated as an initial value problem. The approach is
designed to study an unstable plasma, but it reproduces the well known result
in the case of an equilibrium plasma. Contributions to the energy loss due to
unstable modes are shown to exponentially grow in time. An unstable two-stream
system is considered as an example.
| [
{
"created": "Fri, 21 Oct 2011 17:21:35 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Nov 2011 22:14:36 GMT",
"version": "v2"
}
] | 2012-07-23 | [
[
"Carrington",
"Margaret E.",
""
],
[
"Deja",
"Katarzyna",
""
],
[
"Mrowczynski",
"Stanislaw",
""
]
] | The energy loss of a fast parton scattering elastically in a weakly coupled quark-gluon plasma is formulated as an initial value problem. The approach is designed to study an unstable plasma, but it reproduces the well known result in the case of an equilibrium plasma. Contributions to the energy loss due to unstable modes are shown to exponentially grow in time. An unstable two-stream system is considered as an example. |
hep-ph/9904487 | Susanne Tillich | W. Weise | QCD Aspects of Hadron Physics | 12 pages, 6 figures. Dedicated to Koichi Yazaki on the occasion of
his 60th birthday; invited talk presented at the KEK-Tanashi Symposium on
Physics of Hadrons and Nuclei, Tokyo, December 14-17, 1998 | Nucl.Phys. A670 (2000) 3-13 | 10.1016/S0375-9474(00)00062-2 | TUM/T39-99-05 | hep-ph | null | Several topics in hadron physics at different scales of resolution are
discussed. First, deep-inelastic scattering from nucleons and nuclei is viewed
in a light-cone coordinate space picture. Then the smooth transition from
parton to hadron degrees of freedom is demonstrated by using a generalized
Q^2-dependent polarizabilities of the nucleon. Turning to low energy QCD we
summarize recent developments related to the role of strange quarks in Chiral
SU(3) Dynamics, a non-perturbative coupled channel approach to hadronic
processes. Finally we elaborate on a unification of QCD Sum Rules with aspects
of spontaneous chiral symmetry breaking in the analysis of quark-antiquark
excitations of the condensed QCD vacuum and in nuclear matter.
| [
{
"created": "Thu, 29 Apr 1999 15:14:42 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Weise",
"W.",
""
]
] | Several topics in hadron physics at different scales of resolution are discussed. First, deep-inelastic scattering from nucleons and nuclei is viewed in a light-cone coordinate space picture. Then the smooth transition from parton to hadron degrees of freedom is demonstrated by using a generalized Q^2-dependent polarizabilities of the nucleon. Turning to low energy QCD we summarize recent developments related to the role of strange quarks in Chiral SU(3) Dynamics, a non-perturbative coupled channel approach to hadronic processes. Finally we elaborate on a unification of QCD Sum Rules with aspects of spontaneous chiral symmetry breaking in the analysis of quark-antiquark excitations of the condensed QCD vacuum and in nuclear matter. |
hep-ph/0606042 | Chitta Ranjan Das | C.R. Das and Larisa Laperashvili | Composite model of quark-leptons and duality | Prepared for the 17th DAE-BRNS High Energy Physics Symposium, IIT,
Kharagpur, India, 11-15 December, 2006; 17 pages, 2 figures; P.S: This
abstract is shorten due to arXiv restriction | null | null | IMSc/2006/6/14 | hep-ph hep-lat hep-th | null | In the present investigation the model of preons and their composites is
constructed in the framework of the superstring-inspired flipped E_6\times
\tilde E_6 gauge group of symmetry which reveals a generalized dual symmetry.
We assume that preons are dyons, which in our model are confined by
hyper-magnetic strings - composite N = 1 supersymmetric non-Abelian flux tubes
created by the condensation of spreons near the Planck scale. We show that the
six types of strings having fluxes \Phi_n = n\Phi_0 (n = \pm 1,\pm 2,\pm 3)
produce three generations of composite quark-leptons and bosons. We give an
explanation of hierarchies of masses in the Standard Model. The following
values of masses obtained in our preonic model: m_t\approx 173 GeV, m_c\approx
1 GeV and m_u\approx 4 MeV, m_b \approx 4 GeV, m_s\approx 140 MeV and
m_d\approx 4 MeV, m_\tau\approx 2 GeV \quad and m_\mu \approx 100 MeV, are in
agreement with the experimentally known results. The following left-handed
neutrino masses are predicted: m_1\approx 1.3\times 10^{-3} eV, m_2\approx
9.2\times 10^{-3} eV, m_3\approx 5.0\times 10^{-2} eV - for direct hierarchy,
m_1\approx 0.73\times 10^{-2} eV, m_2\approx 7.4\times 10^{-2} eV, m_3\approx
5.5\times 10^{-2} eV - for inverted hierarchy.
| [
{
"created": "Sun, 4 Jun 2006 12:14:43 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Jun 2006 20:46:45 GMT",
"version": "v2"
},
{
"created": "Sun, 27 Aug 2006 16:34:26 GMT",
"version": "v3"
},
{
"created": "Wed, 29 Nov 2006 06:42:14 GMT",
"version": "v4"
}
] | 2007-05-23 | [
[
"Das",
"C. R.",
""
],
[
"Laperashvili",
"Larisa",
""
]
] | In the present investigation the model of preons and their composites is constructed in the framework of the superstring-inspired flipped E_6\times \tilde E_6 gauge group of symmetry which reveals a generalized dual symmetry. We assume that preons are dyons, which in our model are confined by hyper-magnetic strings - composite N = 1 supersymmetric non-Abelian flux tubes created by the condensation of spreons near the Planck scale. We show that the six types of strings having fluxes \Phi_n = n\Phi_0 (n = \pm 1,\pm 2,\pm 3) produce three generations of composite quark-leptons and bosons. We give an explanation of hierarchies of masses in the Standard Model. The following values of masses obtained in our preonic model: m_t\approx 173 GeV, m_c\approx 1 GeV and m_u\approx 4 MeV, m_b \approx 4 GeV, m_s\approx 140 MeV and m_d\approx 4 MeV, m_\tau\approx 2 GeV \quad and m_\mu \approx 100 MeV, are in agreement with the experimentally known results. The following left-handed neutrino masses are predicted: m_1\approx 1.3\times 10^{-3} eV, m_2\approx 9.2\times 10^{-3} eV, m_3\approx 5.0\times 10^{-2} eV - for direct hierarchy, m_1\approx 0.73\times 10^{-2} eV, m_2\approx 7.4\times 10^{-2} eV, m_3\approx 5.5\times 10^{-2} eV - for inverted hierarchy. |
2212.14036 | Juven C. Wang | Juven Wang | Strong CP Problem and Symmetric Mass Solution | 30 pages. A companion to arXiv:2207.14813. An overview on Symmetric
Mass Generation arXiv:2204.14271 | null | null | null | hep-ph cond-mat.str-el hep-lat hep-th quant-ph | http://creativecommons.org/licenses/by/4.0/ | We propose a novel solution to the Strong CP problem -- to explain why SU(3)
strong force has a nearly zero theta angle $\bar\theta_3 \simeq 0$ for the 4d
Standard Model (SM). The new ingredient is Symmetric Mass Generation (SMG):
symmetry-preserving mass or energy gap can be generated without breaking any
symmetry $G$ and without any quadratic mean-field mass deformation as long as
$G$ is all perturbative local and nonperturbative global anomaly-free. In our
first model, we propose a disordered non-mean-field SMG gap (instead of the
ordered Anderson-Higgs induced mass gap) for the $u$ quark (or generally a set
of quarks and leptons totally anomaly-free in $G$) generated by multi-fermion
interactions or by dynamical disordered mass fields, absorbing $\bar\theta_3$.
Another variant of this first model is the SMG gapping a hypothetical hidden
full fourth family of SM fermions. In our second model, we have a chiral SM and
mirror SM together to respect the Nielsen-Ninomiya fermion-doubling and a
parity-reflection $\mathbb{Z}_2^{\rm PR}$ symmetry at high energy, so the
$\bar\theta_3 = 0$. Then the SMG lifts only the mirror SM with a large energy
gap but leaves the chiral SM at lower energy, which not only "spontaneously"
breaks the parity-reflection symmetry maximally but also relates our solution
to solve another nonperturbative chiral fermion regularization problem by
removing the fermion doubling. The predictive signature of both SMG-based
models is that some SM fermions or mirror fermions are highly interacting
(beyond the conventional SM Higgs or SM gauge interactions) mediated through
hypothetical direct multi-fermion or disordered mass-field interactions.
| [
{
"created": "Wed, 28 Dec 2022 18:59:51 GMT",
"version": "v1"
}
] | 2023-01-20 | [
[
"Wang",
"Juven",
""
]
] | We propose a novel solution to the Strong CP problem -- to explain why SU(3) strong force has a nearly zero theta angle $\bar\theta_3 \simeq 0$ for the 4d Standard Model (SM). The new ingredient is Symmetric Mass Generation (SMG): symmetry-preserving mass or energy gap can be generated without breaking any symmetry $G$ and without any quadratic mean-field mass deformation as long as $G$ is all perturbative local and nonperturbative global anomaly-free. In our first model, we propose a disordered non-mean-field SMG gap (instead of the ordered Anderson-Higgs induced mass gap) for the $u$ quark (or generally a set of quarks and leptons totally anomaly-free in $G$) generated by multi-fermion interactions or by dynamical disordered mass fields, absorbing $\bar\theta_3$. Another variant of this first model is the SMG gapping a hypothetical hidden full fourth family of SM fermions. In our second model, we have a chiral SM and mirror SM together to respect the Nielsen-Ninomiya fermion-doubling and a parity-reflection $\mathbb{Z}_2^{\rm PR}$ symmetry at high energy, so the $\bar\theta_3 = 0$. Then the SMG lifts only the mirror SM with a large energy gap but leaves the chiral SM at lower energy, which not only "spontaneously" breaks the parity-reflection symmetry maximally but also relates our solution to solve another nonperturbative chiral fermion regularization problem by removing the fermion doubling. The predictive signature of both SMG-based models is that some SM fermions or mirror fermions are highly interacting (beyond the conventional SM Higgs or SM gauge interactions) mediated through hypothetical direct multi-fermion or disordered mass-field interactions. |
hep-ph/9505444 | null | S.I. Blinnikov, A.D. Dolgov, L.B. Okun and M.B. Voloshin | How strong can the coupling of leptonic photons be? | 13 pages in standard LaTeX | Nucl.Phys. B458 (1996) 52-64 | 10.1016/0550-3213(95)00579-X | ITEP-31-95, FTUV/95-18, IFIC/95-18, TPI-MINN-95/12-T, UMN-TH-1342-95 | hep-ph | null | Consequences of possible existence of leptonic photon are considered for a
range of values of leptonic charge. In the case of a strong Coulomb-like
leptonic repulsion between electrons the existence of ordinary condensed matter
is impossible: antineutrinos cannot neutralize this destructive repulsion. The
upper limit of leptonic charge is inferred from the E\"{o}tv\"os type
experiments. If however there exist light stable scalar bosons with leptonic
charge (e.g. singlet antisneutrinos) they may neutralize the electron
repulsion. Possible experimental manifestations of such leptonic bosons in
gases and condensed matter are briefly discussed.
| [
{
"created": "Wed, 31 May 1995 19:34:47 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Blinnikov",
"S. I.",
""
],
[
"Dolgov",
"A. D.",
""
],
[
"Okun",
"L. B.",
""
],
[
"Voloshin",
"M. B.",
""
]
] | Consequences of possible existence of leptonic photon are considered for a range of values of leptonic charge. In the case of a strong Coulomb-like leptonic repulsion between electrons the existence of ordinary condensed matter is impossible: antineutrinos cannot neutralize this destructive repulsion. The upper limit of leptonic charge is inferred from the E\"{o}tv\"os type experiments. If however there exist light stable scalar bosons with leptonic charge (e.g. singlet antisneutrinos) they may neutralize the electron repulsion. Possible experimental manifestations of such leptonic bosons in gases and condensed matter are briefly discussed. |
hep-ph/9908355 | Danny Ashery | D. Ashery, H.J. Lipkin | Expected Polarization of $\Lambda$ particles produced in deep inelastic
polarized lepton scattering | 12 pages, 1 figure | Phys.Lett. B469 (1999) 263-269 | 10.1016/S0370-2693(99)01229-0 | null | hep-ph | null | We calculate the polarization of Lambda and Anti-Lambda particles produced in
deep inelastic polarized lepton scattering. We use two models: the naive quark
model and a model in which SU(3)$_F$ symmetry is used to deduce the spin
structure of SU(3) octet hyperons from that of the proton. We perform the
calculations for Lambda and Anti-Lambda produced directly or as decay products
of $\Sigma^0$ and $\Sigma^*$.
| [
{
"created": "Fri, 13 Aug 1999 17:57:08 GMT",
"version": "v1"
},
{
"created": "Wed, 27 Oct 1999 13:30:34 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Ashery",
"D.",
""
],
[
"Lipkin",
"H. J.",
""
]
] | We calculate the polarization of Lambda and Anti-Lambda particles produced in deep inelastic polarized lepton scattering. We use two models: the naive quark model and a model in which SU(3)$_F$ symmetry is used to deduce the spin structure of SU(3) octet hyperons from that of the proton. We perform the calculations for Lambda and Anti-Lambda produced directly or as decay products of $\Sigma^0$ and $\Sigma^*$. |
hep-ph/9903492 | Alberto Casas | J.A. Casas, G.B. Gelmini and A. Riotto | F-term inflation in Superstring Theories | 9 pages, LaTeX | Phys.Lett. B459 (1999) 91-96 | 10.1016/S0370-2693(99)00683-8 | null | hep-ph astro-ph gr-qc | null | A supersymmetric inflationary stage dominated by an $F$-term has the problem
that the flatness of the potential is spoiled by supergravity corrections, that
is the slow-roll parameter $\eta$ gets contributions of order unity. We show
that in $F$-term inflationary models based on strings there is natural way of
obtaining small values of $\eta$. This happens in models of hybrid inflation
based on orbifold constructions, in which a modulus $T$ field is responsible
for the large value of the potential during inflation, and a second field
$\phi$ with appropriate modular weight is responsible for the roll-over. We
illustrate the mechanism with a model in which the inflaton potential is
provided by gaugino condensation, leading to succesful inflation.
| [
{
"created": "Thu, 25 Mar 1999 14:47:06 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Casas",
"J. A.",
""
],
[
"Gelmini",
"G. B.",
""
],
[
"Riotto",
"A.",
""
]
] | A supersymmetric inflationary stage dominated by an $F$-term has the problem that the flatness of the potential is spoiled by supergravity corrections, that is the slow-roll parameter $\eta$ gets contributions of order unity. We show that in $F$-term inflationary models based on strings there is natural way of obtaining small values of $\eta$. This happens in models of hybrid inflation based on orbifold constructions, in which a modulus $T$ field is responsible for the large value of the potential during inflation, and a second field $\phi$ with appropriate modular weight is responsible for the roll-over. We illustrate the mechanism with a model in which the inflaton potential is provided by gaugino condensation, leading to succesful inflation. |
hep-ph/9806242 | Hwang Dae Sung | Dae Sung Hwang and Do-Won Kim | Model Independent Calculation of ${\cal{B}}({\bar{B}}^0\to D^{(*)+}
\tau^- {\bar{\nu}})/ {\cal{B}}({\bar{B}}^0\to D^{(*)+} e^- {\bar{\nu}})$ | 8 pages, 3 postscript figures. We corrected a mistake in computer
program for the numerical calculation, and modified the title and contents | null | null | null | hep-ph | null | Using the formulas for the $d\Gamma / dq^2$ distribution with non-zero lepton
mass and experimentally determined form factors, we calculate the $d\Gamma
(D^{(*)+} l^- {\bar{\nu}})/ dq^2$ spectra and branching fractions for $l=e$,
$\mu$ and $\tau$. We obtain the results ${\cal{B}}({\bar{B}}^0\rightarrow D^{+}
\tau^- {\bar{\nu}})/ {\cal{B}}({\bar{B}}^0\rightarrow D^{+} e^- {\bar{\nu}})=
0.278^{+0.049}_{-0.035}$ and ${\cal{B}}({\bar{B}}^0\rightarrow D^{*+} \tau^-
{\bar{\nu}})/ {\cal{B}}({\bar{B}}^0\rightarrow D^{*+} e^- {\bar{\nu}})=
0.256^{+0.014}_{-0.013}$ . Since we used the experimentally measured form
factors, these results are independent of theoretical models of form factors.
| [
{
"created": "Wed, 3 Jun 1998 11:56:58 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Jun 1998 12:01:17 GMT",
"version": "v2"
},
{
"created": "Tue, 5 Jan 1999 12:53:26 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Hwang",
"Dae Sung",
""
],
[
"Kim",
"Do-Won",
""
]
] | Using the formulas for the $d\Gamma / dq^2$ distribution with non-zero lepton mass and experimentally determined form factors, we calculate the $d\Gamma (D^{(*)+} l^- {\bar{\nu}})/ dq^2$ spectra and branching fractions for $l=e$, $\mu$ and $\tau$. We obtain the results ${\cal{B}}({\bar{B}}^0\rightarrow D^{+} \tau^- {\bar{\nu}})/ {\cal{B}}({\bar{B}}^0\rightarrow D^{+} e^- {\bar{\nu}})= 0.278^{+0.049}_{-0.035}$ and ${\cal{B}}({\bar{B}}^0\rightarrow D^{*+} \tau^- {\bar{\nu}})/ {\cal{B}}({\bar{B}}^0\rightarrow D^{*+} e^- {\bar{\nu}})= 0.256^{+0.014}_{-0.013}$ . Since we used the experimentally measured form factors, these results are independent of theoretical models of form factors. |
hep-ph/9608414 | Matteo Cacciari | M. Cacciari | Heavy Quarks Photoproduction | 4 pages, LaTeX, uses procl.sty (included). Talk given at the DIS'96
Workshop, Rome, April 1996 | null | null | DESY 96-145 | hep-ph | null | The state of the art of the theoretical calculations for heavy quarks
photoproduction is reviewed. The full next-to-leading order calculation and two
possible resummations, the high energy one for total cross sections and the
large $p_T$ one for differential cross sections, are described.
| [
{
"created": "Thu, 22 Aug 1996 17:17:41 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Cacciari",
"M.",
""
]
] | The state of the art of the theoretical calculations for heavy quarks photoproduction is reviewed. The full next-to-leading order calculation and two possible resummations, the high energy one for total cross sections and the large $p_T$ one for differential cross sections, are described. |
1709.02671 | Samuel Wallon | R. Boussarie, B. Duclou\'e, L. Szymanowski, S. Wallon | QCD resummation effects in forward $J/\psi$ and very backward jet
inclusive production at the LHC | 8 pages, 3 figures, to appear in the proceedings of XXV International
Workshop on Deep-Inelastic Scattering and Related Subject - DIS 2017, 3-7
April 2017, University of Birmingham, UK | null | null | LPT-Orsay-17-38 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose and study the inclusive production of a forward $J/\psi$ and a
very backward jet at the LHC as an observable to reveal high-energy resummation
effects \`a la BFKL. Our different predictions are based on the various
existing mechanisms to describe the production of the $J/\psi$, namely, NRQCD
singlet and octet contributions, and the color evaporation model.
| [
{
"created": "Fri, 8 Sep 2017 12:16:44 GMT",
"version": "v1"
}
] | 2017-09-11 | [
[
"Boussarie",
"R.",
""
],
[
"Ducloué",
"B.",
""
],
[
"Szymanowski",
"L.",
""
],
[
"Wallon",
"S.",
""
]
] | We propose and study the inclusive production of a forward $J/\psi$ and a very backward jet at the LHC as an observable to reveal high-energy resummation effects \`a la BFKL. Our different predictions are based on the various existing mechanisms to describe the production of the $J/\psi$, namely, NRQCD singlet and octet contributions, and the color evaporation model. |
hep-ph/0011264 | R. Sekhar Chivukula | R. Sekhar Chivukula | Lectures on Technicolor and Compositeness | Lectures presented at TASI 2000, Flavor Physics for the Millennium,
June 4-30, 2000, University of Colorado, Boulder, CO. 42 pages, LaTeX with
included style file | null | null | BUHEP-00-24 | hep-ph hep-ex hep-th | null | Lecture 1 provides an introduction to dynamical electroweak symmetry
breaking. Lectures 2 and 3 give an introduction to compositeness, with emphasis
on effective lagrangians, power-counting, and the 't Hooft anomaly-matching
conditions.
| [
{
"created": "Tue, 21 Nov 2000 16:35:33 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Chivukula",
"R. Sekhar",
""
]
] | Lecture 1 provides an introduction to dynamical electroweak symmetry breaking. Lectures 2 and 3 give an introduction to compositeness, with emphasis on effective lagrangians, power-counting, and the 't Hooft anomaly-matching conditions. |
hep-ph/0210280 | Barbot Cyrille | Barbot Cyrille | Ultra-high energy cosmic rays from super-heavy X particle decay | 7 pages, 3 figures, proceeding for a talk given at Susy 2002, DESY,
Hamburg | null | null | null | hep-ph astro-ph | null | In this talk, I present the last and more precise results obtained in the
computation of the final spectra of stable particles issued from the decay of
super-heavy X particles (M_X ~ 10^21 to 10^25 eV). Such very energetic decay
products, carrying a fraction of the mass of the X particle, are believed to be
a plausible explanation for the observed ultra-high energy cosmic rays (UHECR).
Combining these results with X-particle models and with a code describing the
propagation effects for UHECRs through the interstellar medium, it becomes
possible to make some predictions on the fluxes expected on Earth, hopefully
detectable in the next generation of experiments.
| [
{
"created": "Mon, 21 Oct 2002 15:26:35 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Cyrille",
"Barbot",
""
]
] | In this talk, I present the last and more precise results obtained in the computation of the final spectra of stable particles issued from the decay of super-heavy X particles (M_X ~ 10^21 to 10^25 eV). Such very energetic decay products, carrying a fraction of the mass of the X particle, are believed to be a plausible explanation for the observed ultra-high energy cosmic rays (UHECR). Combining these results with X-particle models and with a code describing the propagation effects for UHECRs through the interstellar medium, it becomes possible to make some predictions on the fluxes expected on Earth, hopefully detectable in the next generation of experiments. |
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