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2105.07007
Harikrishnan Ramani
James B. Dent, Bhaskar Dutta, Andrew Jastram, Doojin Kim, Andrew Kubik, Rupak Mahapatra, Surjeet Rajendran, Harikrishnan Ramani, Adrian Thompson and Shubham Verma
Pathfinder for a High Statistics Search for Missing Energy In Gamma Cascades
22 pages, 9 Figures
null
10.1103/PhysRevD.105.015030
null
hep-ph astro-ph.CO hep-ex
http://creativecommons.org/licenses/by/4.0/
We investigate the feasibility of a high statistics experiment to search for invisible decay modes in nuclear gamma cascades using 200 kg of %36 Cs(Tl) scintillators that are presently available at Texas A\&M. The experiment aims to search for missing energy by robustly establishing the absence of a photon in a well identified gamma cascade. We report on the experimental demonstration of the energy resolution necessary for this search. Prior explorations of this detector concept focused on baryonically coupled physics that could be emitted in $E_2$ transitions. We point out that this protocol can also search for particles that are coupled to photons by searching for the conversion of a photon produced in a gamma cascade into a hidden particle. Examples of these processes include the oscillation of a photon into a hidden photon and the conversion of a photon into an axion-like-particle either in the presence of a magnetic field or via the Primakoff process. This proof-of-concept apparatus appears to have the ability to search for hitherto unconstrained baryonically coupled scalars and pseudoscalars produced in $E_0$ and $M_0$ transitions. If successfully implemented, this experiment serves as a pathfinder for a larger detector with greater containment that can thoroughly probe the existence of new particles with mass below 4 MeV that lie in the poorly constrained supernova ``trapping window'' that exists between 100 keV and 30 MeV.
[ { "created": "Fri, 14 May 2021 18:00:03 GMT", "version": "v1" } ]
2022-02-09
[ [ "Dent", "James B.", "" ], [ "Dutta", "Bhaskar", "" ], [ "Jastram", "Andrew", "" ], [ "Kim", "Doojin", "" ], [ "Kubik", "Andrew", "" ], [ "Mahapatra", "Rupak", "" ], [ "Rajendran", "Surjeet", "" ], [ "Ramani", "Harikrishnan", "" ], [ "Thompson", "Adrian", "" ], [ "Verma", "Shubham", "" ] ]
We investigate the feasibility of a high statistics experiment to search for invisible decay modes in nuclear gamma cascades using 200 kg of %36 Cs(Tl) scintillators that are presently available at Texas A\&M. The experiment aims to search for missing energy by robustly establishing the absence of a photon in a well identified gamma cascade. We report on the experimental demonstration of the energy resolution necessary for this search. Prior explorations of this detector concept focused on baryonically coupled physics that could be emitted in $E_2$ transitions. We point out that this protocol can also search for particles that are coupled to photons by searching for the conversion of a photon produced in a gamma cascade into a hidden particle. Examples of these processes include the oscillation of a photon into a hidden photon and the conversion of a photon into an axion-like-particle either in the presence of a magnetic field or via the Primakoff process. This proof-of-concept apparatus appears to have the ability to search for hitherto unconstrained baryonically coupled scalars and pseudoscalars produced in $E_0$ and $M_0$ transitions. If successfully implemented, this experiment serves as a pathfinder for a larger detector with greater containment that can thoroughly probe the existence of new particles with mass below 4 MeV that lie in the poorly constrained supernova ``trapping window'' that exists between 100 keV and 30 MeV.
hep-ph/0408114
Chris J. Maxwell
M.J. Dinsdale and C.J. Maxwell
Lambda-based QCD perturbation theory-: sidestepping the scheme-dependence problem
38 pages, 6 figures
null
null
IPPP/04/47, DCPT/04/94
hep-ph
null
We advocate the replacement of standard alphas(mu)-based QCD perturbation theory, in which the coupling and truncated perturbative predictions are dependent on the chosen renormalisation scheme, by a Lambda-based approach in which QCD observables are directly related to the dimensional transmutation parameter, Lambda, of the theory. The shortcomings of the standard approach are emphasised by formulating it in the Lambda-based language. We show how the Lambda-based approach can be extended to include massive quarks. We also consider the use of Lambda-based perturbation theory in the case when a resummation of large infrared logarithms is required, performing a phenomenological analysis for the e+e- event shape observables thrust and heavy jet mass. We show by fitting to data that smaller power corrections are required than in the standard approach.
[ { "created": "Mon, 9 Aug 2004 15:40:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dinsdale", "M. J.", "" ], [ "Maxwell", "C. J.", "" ] ]
We advocate the replacement of standard alphas(mu)-based QCD perturbation theory, in which the coupling and truncated perturbative predictions are dependent on the chosen renormalisation scheme, by a Lambda-based approach in which QCD observables are directly related to the dimensional transmutation parameter, Lambda, of the theory. The shortcomings of the standard approach are emphasised by formulating it in the Lambda-based language. We show how the Lambda-based approach can be extended to include massive quarks. We also consider the use of Lambda-based perturbation theory in the case when a resummation of large infrared logarithms is required, performing a phenomenological analysis for the e+e- event shape observables thrust and heavy jet mass. We show by fitting to data that smaller power corrections are required than in the standard approach.
1010.6226
Kenji Fukushima
Kenji Fukushima, Kazuhiko Kamikado, Bertram Klein
Second-order and Fluctuation-induced First-order Phase Transitions with Functional Renormalization Group Equations
15 pages, 10 figures, collapsed expressions in the abstract fixed
Phys.Rev.D83:116005,2011
10.1103/PhysRevD.83.116005
YITP-10-66
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate phase transitions in scalar field theories using the functional renormalization group (RG) equation. We analyze a system with $U(2)\times U(2)$ symmetry, in which there is a parameter $\lambda_2$ that controls the strength of the first-order phase transition driven by fluctuations. In the limit of $\lambda_2\to0$, the $U(2)\times U(2)$ theory is reduced to an $O(8)$ scalar theory that exhibits a second-order phase transition in three dimensions. We develop a new insight for the understanding of the fluctuation-induced first-order phase transition as a smooth continuation from the standard RG flow in the $O(8)$ system. In our view from the RG flow diagram on coupling parameter space, the region that favors the first-order transition emerges from the unphysical region to the physical one as $\lambda_2$ increases from zero. We give this interpretation based on the Taylor expansion of the functional RG equations up to the fourth order in terms of the field, which encompasses the $\epsilon$-expansion results. We compare results from the expansion and from the full numerical calculation and find that the fourth-order expansion is only of qualitative use and that the sixth-order expansion improves the quantitative agreement.
[ { "created": "Fri, 29 Oct 2010 14:36:56 GMT", "version": "v1" }, { "created": "Mon, 16 May 2011 18:28:38 GMT", "version": "v2" }, { "created": "Fri, 24 Mar 2023 11:03:04 GMT", "version": "v3" } ]
2023-03-27
[ [ "Fukushima", "Kenji", "" ], [ "Kamikado", "Kazuhiko", "" ], [ "Klein", "Bertram", "" ] ]
We investigate phase transitions in scalar field theories using the functional renormalization group (RG) equation. We analyze a system with $U(2)\times U(2)$ symmetry, in which there is a parameter $\lambda_2$ that controls the strength of the first-order phase transition driven by fluctuations. In the limit of $\lambda_2\to0$, the $U(2)\times U(2)$ theory is reduced to an $O(8)$ scalar theory that exhibits a second-order phase transition in three dimensions. We develop a new insight for the understanding of the fluctuation-induced first-order phase transition as a smooth continuation from the standard RG flow in the $O(8)$ system. In our view from the RG flow diagram on coupling parameter space, the region that favors the first-order transition emerges from the unphysical region to the physical one as $\lambda_2$ increases from zero. We give this interpretation based on the Taylor expansion of the functional RG equations up to the fourth order in terms of the field, which encompasses the $\epsilon$-expansion results. We compare results from the expansion and from the full numerical calculation and find that the fourth-order expansion is only of qualitative use and that the sixth-order expansion improves the quantitative agreement.
1204.0755
Roberto Maluf
B. Charneski, M. Gomes, R. V. Maluf, A. J. da Silva
Lorentz violation bounds on Bhabha scattering
6 pages, 6 figures
Phys. Rev. D 86, 045003 (2012)
10.1103/PhysRevD.86.045003
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the effect of Lorentz-violating terms on Bhabha scattering in two distinct cases correspondent to vectorial and axial nonminimal couplings in QED. In both cases, we find significant modifications with respect to the usual relativistic result. Our results reveal an anisotropy of the differential cross section which imply new constraints on the possible Lorentz violating terms.
[ { "created": "Tue, 3 Apr 2012 18:15:37 GMT", "version": "v1" }, { "created": "Tue, 2 Oct 2012 23:54:17 GMT", "version": "v2" } ]
2012-10-04
[ [ "Charneski", "B.", "" ], [ "Gomes", "M.", "" ], [ "Maluf", "R. V.", "" ], [ "da Silva", "A. J.", "" ] ]
We investigate the effect of Lorentz-violating terms on Bhabha scattering in two distinct cases correspondent to vectorial and axial nonminimal couplings in QED. In both cases, we find significant modifications with respect to the usual relativistic result. Our results reveal an anisotropy of the differential cross section which imply new constraints on the possible Lorentz violating terms.
hep-ph/9311308
Martin John Savage
Michael Luke, Martin J. Savage and Mark B. Wise
Hadronic Event Shapes in $B$ Decay
11 pages, 3 uuencoded figures included, uses harvmac and epsf, UTPT 93-28, CMU-HEP 93-24, CALT-68-1905
Phys.Lett. B322 (1994) 154-158
10.1016/0370-2693(94)90504-5
null
hep-ph
null
We compute the differential momentum correlation function for hadrons produced in the decay of $B$-mesons. This measure of hadronic event shapes tests the free $b$-quark decay picture for nonleptonic and semileptonic decays of $B$-mesons. Our results can also be applied to $B_s$ and $\Lambda_b$ decay.
[ { "created": "Thu, 18 Nov 1993 04:19:39 GMT", "version": "v1" } ]
2009-10-22
[ [ "Luke", "Michael", "" ], [ "Savage", "Martin J.", "" ], [ "Wise", "Mark B.", "" ] ]
We compute the differential momentum correlation function for hadrons produced in the decay of $B$-mesons. This measure of hadronic event shapes tests the free $b$-quark decay picture for nonleptonic and semileptonic decays of $B$-mesons. Our results can also be applied to $B_s$ and $\Lambda_b$ decay.
hep-ph/0209228
David London
Wafia Bensalam, David London, Nita Sinha and Rahul Sinha
Lepton Polarization and Forward-Backward Asymmetries in b -> s tau+ tau-
21 pages, LaTeX, 4 figures (included). Paper somewhat reorganized, references greatly expanded, conclusions unchanged
Phys.Rev. D67 (2003) 034007
10.1103/PhysRevD.67.034007
UdeM-GPP-TH-02-107, IMSc-2002/09/33
hep-ph
null
We study the spin polarizations of both tau leptons in the decay b -> s tau+ tau-. In addition to the polarization asymmetries involving a single tau, we construct asymmetries for the case where both polarizations are simultaneously measured. We also study forward-backward asymmetries with polarized tau's. We find that a large number of asymmetries are predicted to be large, >~ 10%. This permits the measurement of all Wilson coefficients and the b-quark mass, thus allowing the standard model (SM) to be exhaustively tested. Furthermore, there are many unique signals for the presence of new physics. For example, asymmetries involving triple-product correlations are predicted to be tiny within the SM, O(10^{-2}). Their observation would be a clear signal of new physics.
[ { "created": "Thu, 19 Sep 2002 14:30:06 GMT", "version": "v1" }, { "created": "Mon, 9 Dec 2002 19:22:33 GMT", "version": "v2" } ]
2009-11-07
[ [ "Bensalam", "Wafia", "" ], [ "London", "David", "" ], [ "Sinha", "Nita", "" ], [ "Sinha", "Rahul", "" ] ]
We study the spin polarizations of both tau leptons in the decay b -> s tau+ tau-. In addition to the polarization asymmetries involving a single tau, we construct asymmetries for the case where both polarizations are simultaneously measured. We also study forward-backward asymmetries with polarized tau's. We find that a large number of asymmetries are predicted to be large, >~ 10%. This permits the measurement of all Wilson coefficients and the b-quark mass, thus allowing the standard model (SM) to be exhaustively tested. Furthermore, there are many unique signals for the presence of new physics. For example, asymmetries involving triple-product correlations are predicted to be tiny within the SM, O(10^{-2}). Their observation would be a clear signal of new physics.
hep-ph/9706265
Pene
V. Mor\'enas, A. Le Yaouanc, L. Oliver, O. P\`ene and J.-C. Raynal
Quantitative Predictions for $B$ semileptonic decays into $D,D^*$ and the orbitally excited $D^{**}$ in quark models \`a la Bakamjian-Thomas
18 pages, 6 figures, Latex2e, AMS-LaTeX, corrections in the figures
Phys.Rev.D56:5668-5680,1997
10.1103/PhysRevD.56.5668
LPTHE-Orsay 97/19, PCCF RI 9707
hep-ph
null
Once chosen the dynamics in one frame, the rest frame in this paper, the Bakamjian and Thomas method allows to define relativistic quark models in any frame. These models have been shown to provide, in the infinite quark mass limit, fully covariant current form factors as matrix elements of the quark current operator. In this paper we use the rest frame dynamics fitted from the meson spectrum by various authors, already shown to provide a reasonable value for $\rho^2$. From the general formulae for the scaling invariant form factors $\xi^{(n)}(w)$, $\tau_{1/2}^{(n)}(w)$ and $\tau_{3/2}^{(n)}(w)$, we predict quantitavely the $B$ semileptonic branching ratios to the ground state and orbitally excited charmed mesons $D, D^\ast$ and $D^{\ast\ast}$. We check Bjorken's sum rule and discuss the respective contributions to it. We find $\xi(w)\simeq (2/(1+w)) ^2$, resulting from the fact that the ground state wave function is Coulomb-like. We also find $\tau_{3/2}\simeq 0.5 (2/(1+w))^3$ and $\tau_{1/2}(w)\ll \tau_{3/2}(w)$. Very small branching ratios into $j=1/2$ orbitally excited $D$'s results. The overall agreement with experiment is rather good within the present accuracy which is poor for the orbitally excited charmed mesons. We predict a ratio $Br(B\to D^\ast_2 l \nu)/Br(B\to D_1 l \nu)=1.55\pm 0.15$ as a mere consequence of the heavy quark symmetry. If some faint experimental indications that $Br(B\to D_1 l \nu)\simeq Br(B\to D^\ast_2 l \nu)$ were confirmed, it would indicate a sizeable $O(1/m_c)$ correction.
[ { "created": "Thu, 5 Jun 1997 17:01:57 GMT", "version": "v1" }, { "created": "Fri, 6 Jun 1997 11:14:53 GMT", "version": "v2" } ]
2014-11-17
[ [ "Morénas", "V.", "" ], [ "Yaouanc", "A. Le", "" ], [ "Oliver", "L.", "" ], [ "Pène", "O.", "" ], [ "Raynal", "J. -C.", "" ] ]
Once chosen the dynamics in one frame, the rest frame in this paper, the Bakamjian and Thomas method allows to define relativistic quark models in any frame. These models have been shown to provide, in the infinite quark mass limit, fully covariant current form factors as matrix elements of the quark current operator. In this paper we use the rest frame dynamics fitted from the meson spectrum by various authors, already shown to provide a reasonable value for $\rho^2$. From the general formulae for the scaling invariant form factors $\xi^{(n)}(w)$, $\tau_{1/2}^{(n)}(w)$ and $\tau_{3/2}^{(n)}(w)$, we predict quantitavely the $B$ semileptonic branching ratios to the ground state and orbitally excited charmed mesons $D, D^\ast$ and $D^{\ast\ast}$. We check Bjorken's sum rule and discuss the respective contributions to it. We find $\xi(w)\simeq (2/(1+w)) ^2$, resulting from the fact that the ground state wave function is Coulomb-like. We also find $\tau_{3/2}\simeq 0.5 (2/(1+w))^3$ and $\tau_{1/2}(w)\ll \tau_{3/2}(w)$. Very small branching ratios into $j=1/2$ orbitally excited $D$'s results. The overall agreement with experiment is rather good within the present accuracy which is poor for the orbitally excited charmed mesons. We predict a ratio $Br(B\to D^\ast_2 l \nu)/Br(B\to D_1 l \nu)=1.55\pm 0.15$ as a mere consequence of the heavy quark symmetry. If some faint experimental indications that $Br(B\to D_1 l \nu)\simeq Br(B\to D^\ast_2 l \nu)$ were confirmed, it would indicate a sizeable $O(1/m_c)$ correction.
hep-ph/9907470
Marco Stratmann
M. Stratmann (Durham Univ.), W. Vogelsang (SUNY, Stony Brook)
Towards the Parton Densities of Polarized Photons at HERA
5 pages, LaTeX, 3 eps figures, uses amssymb and epsfig styles; Contribution to the Proceedings of the workshop on `Polarized Protons at High Energies - Accelerator Challenges and Physics Opportunities', DESY, Germany, May 1999
null
null
DTP/99/86, ITP-SB-99-38
hep-ph
null
Di-jet photoproduction in polarized ep collisions at HERA is studied as a possible tool to determine the parton content of circularly polarized photons. The concept of the `effective parton density' approximation is extended to the spin-dependent case.
[ { "created": "Fri, 23 Jul 1999 12:24:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Stratmann", "M.", "", "Durham Univ." ], [ "Vogelsang", "W.", "", "SUNY, Stony Brook" ] ]
Di-jet photoproduction in polarized ep collisions at HERA is studied as a possible tool to determine the parton content of circularly polarized photons. The concept of the `effective parton density' approximation is extended to the spin-dependent case.
2112.04776
Zhi-Gang Wang
Zhi-Gang Wang, Qi Xin
Analysis of the pseudoscalar hidden-charm tetraquark states with the QCD sum rules
12 pages, 3 figures
Nucl. Phys. B978 (2022) 115761
10.1016/j.nuclphysb.2022.115761
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, we take all the color-antitriplet diquarks, such as the scalar, pseudoscalar, vector, axialvector and tensor diquarks, as the basic constituents to construct the local pseudoscalar four-quark currents without importing the explicit P-waves to implement the negative-parity, and investigate the mass spectroscopy of the pseudoscalar hidden-charm tetraquark states without strange, with strange and with hidden-strange in the framework of the QCD sum rules in a consistent and comprehensive way. We obtain the lowest mass $4.56\pm0.08\,\rm{GeV}$ for the pseudoscalar tetraquark state with the symbolic quark constituents $c\bar{c}u\bar{d}$, which is much larger than the experimental value $4239\pm18{}^{+45}_{-10}\,\rm{MeV}$ extracted by the LHCb collaboration.
[ { "created": "Thu, 9 Dec 2021 09:05:19 GMT", "version": "v1" }, { "created": "Fri, 18 Feb 2022 03:57:29 GMT", "version": "v2" }, { "created": "Fri, 25 Feb 2022 13:24:21 GMT", "version": "v3" } ]
2022-04-11
[ [ "Wang", "Zhi-Gang", "" ], [ "Xin", "Qi", "" ] ]
In this work, we take all the color-antitriplet diquarks, such as the scalar, pseudoscalar, vector, axialvector and tensor diquarks, as the basic constituents to construct the local pseudoscalar four-quark currents without importing the explicit P-waves to implement the negative-parity, and investigate the mass spectroscopy of the pseudoscalar hidden-charm tetraquark states without strange, with strange and with hidden-strange in the framework of the QCD sum rules in a consistent and comprehensive way. We obtain the lowest mass $4.56\pm0.08\,\rm{GeV}$ for the pseudoscalar tetraquark state with the symbolic quark constituents $c\bar{c}u\bar{d}$, which is much larger than the experimental value $4239\pm18{}^{+45}_{-10}\,\rm{MeV}$ extracted by the LHCb collaboration.
1406.5518
Andrew J Powell
Joseph P. Conlon, Andrew J. Powell
A 3.55 keV line from $\text{DM}\rightarrow a \rightarrow \gamma$: predictions for cool-core and non-cool-core clusters
14 pages, 6 figures
null
10.1088/1475-7516/2015/01/019
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We further study a scenario in which a 3.55 keV X-ray line arises from decay of dark matter to an axion-like particle (ALP), that subsequently converts to a photon in astrophysical magnetic fields. We perform numerical simulations of Gaussian random magnetic fields with radial scaling of the magnetic field magnitude with the electron density, for both cool-core `Perseus' and non-cool-core `Coma' electron density profiles. Using these, we quantitatively study the resulting signal strength and morphology for cool-core and non-cool-core clusters. Our study includes the effects of fields of view that cover only the central part of the cluster, the effects of offset pointings on the radial decline of signal strength and the effects of dividing clusters into annuli. We find good agreement with current data and make predictions for future analyses and observations.
[ { "created": "Fri, 20 Jun 2014 20:08:28 GMT", "version": "v1" } ]
2015-06-22
[ [ "Conlon", "Joseph P.", "" ], [ "Powell", "Andrew J.", "" ] ]
We further study a scenario in which a 3.55 keV X-ray line arises from decay of dark matter to an axion-like particle (ALP), that subsequently converts to a photon in astrophysical magnetic fields. We perform numerical simulations of Gaussian random magnetic fields with radial scaling of the magnetic field magnitude with the electron density, for both cool-core `Perseus' and non-cool-core `Coma' electron density profiles. Using these, we quantitatively study the resulting signal strength and morphology for cool-core and non-cool-core clusters. Our study includes the effects of fields of view that cover only the central part of the cluster, the effects of offset pointings on the radial decline of signal strength and the effects of dividing clusters into annuli. We find good agreement with current data and make predictions for future analyses and observations.
hep-ph/9906257
null
Urs Achim Wiedemann and Miklos Gyulassy
Transverse Momentum Dependence of the Landau-Pomeranchuk-Migdal Effect
20 pages, Latex, 4 eps-figures, replaced by published version, minor typos corrected
Nucl.Phys.B560:345-382,1999
10.1016/S0550-3213(99)00458-7
null
hep-ph nucl-th
null
We study the transverse momentum dependence of the Landau-Pomeranchuk-Migdal effect in QED, starting from the high energy expansion of the solution of the Dirac equation in the presence of an external field. The angular integrated energy loss formula differs from an earlier expression of Zakharov by taking finite kinematical boundaries into account. In an expansion in powers of the opacity of the medium, we derive explicit expressions for the radiation cross section associated with N=1, 2 and 3 scatterings. We verify the Bethe-Heitler and the factorization limit, and we calculate corrections to the factorization limit proportional to the square of the target size. A closed form expression valid to arbitrary orders in the opacity is derived in the dipole approximation. The resulting radiation spectrum is non-analytic in the coupling constant which is traced back to the transverse momentum broadening of a hard parton undergoing multiple small angle Moliere scattering. In extending the results to QCD, we test a previously used dipole prescription by comparing to direct pQCD results for N=1 and 2. For N=1, the QCD dipole prescription reproduces exactly the Bertsch-Gunion radiation spectrum. For N=2, we find a sizeable correction which reduces to a multiplicative factor 17/8 at large separation.
[ { "created": "Fri, 4 Jun 1999 14:20:02 GMT", "version": "v1" }, { "created": "Fri, 8 Oct 1999 13:10:59 GMT", "version": "v2" } ]
2009-10-09
[ [ "Wiedemann", "Urs Achim", "" ], [ "Gyulassy", "Miklos", "" ] ]
We study the transverse momentum dependence of the Landau-Pomeranchuk-Migdal effect in QED, starting from the high energy expansion of the solution of the Dirac equation in the presence of an external field. The angular integrated energy loss formula differs from an earlier expression of Zakharov by taking finite kinematical boundaries into account. In an expansion in powers of the opacity of the medium, we derive explicit expressions for the radiation cross section associated with N=1, 2 and 3 scatterings. We verify the Bethe-Heitler and the factorization limit, and we calculate corrections to the factorization limit proportional to the square of the target size. A closed form expression valid to arbitrary orders in the opacity is derived in the dipole approximation. The resulting radiation spectrum is non-analytic in the coupling constant which is traced back to the transverse momentum broadening of a hard parton undergoing multiple small angle Moliere scattering. In extending the results to QCD, we test a previously used dipole prescription by comparing to direct pQCD results for N=1 and 2. For N=1, the QCD dipole prescription reproduces exactly the Bertsch-Gunion radiation spectrum. For N=2, we find a sizeable correction which reduces to a multiplicative factor 17/8 at large separation.
0805.0717
Wolfgang Sch\"afer
A. Rybarska, W. Sch\"afer, A. Szczurek
Exclusive photoproduction of Upsilon: from HERA to Tevatron
14 pages, 8 figures; predictions for LHC included
Phys.Lett.B668:126-132,2008
10.1016/j.physletb.2008.08.022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The forward photoproduction amplitude for gamma p to Upsilon p is calculated in a pQCD k_t-factorization approach with an unintegrated gluon distribution constrained by inclusive deep-inelastic structure functions. The total cross section for diffractive Upsilons is compared with a recent HERA data. We also discuss the 2S/1S ratio in diffractive Upsilon-production. The amplitude is used to predict the cross section for exclusive Upsilon production in hadronic reactions. Differential distributions for the exclusive p pbar to p Upsilon pbar process are calculated for Tevatron energies. We also show predictions for LHC. Absorption effects are included.
[ { "created": "Tue, 6 May 2008 13:08:16 GMT", "version": "v1" }, { "created": "Tue, 22 Jul 2008 08:35:05 GMT", "version": "v2" } ]
2008-11-26
[ [ "Rybarska", "A.", "" ], [ "Schäfer", "W.", "" ], [ "Szczurek", "A.", "" ] ]
The forward photoproduction amplitude for gamma p to Upsilon p is calculated in a pQCD k_t-factorization approach with an unintegrated gluon distribution constrained by inclusive deep-inelastic structure functions. The total cross section for diffractive Upsilons is compared with a recent HERA data. We also discuss the 2S/1S ratio in diffractive Upsilon-production. The amplitude is used to predict the cross section for exclusive Upsilon production in hadronic reactions. Differential distributions for the exclusive p pbar to p Upsilon pbar process are calculated for Tevatron energies. We also show predictions for LHC. Absorption effects are included.
hep-ph/0210047
Mikaelyan Lev
L.A. Mikaelyan (RRC Kurchatov Institute, Moscow, Russia)
Investigation of Neutrino Properties in Experiments at Nuclear Reactors: Present Status and Prospects
Latex2e, 18 pages, 13 figures, 3 tables
Phys.Atom.Nucl. 65 (2002) 1173-1187; Yad.Fiz. 65 (2002) 1206-1219
10.1134/1.1495017
null
hep-ph
null
This paper was submitted in Russian edition of Journal Physics of Atomic Nuclei in 2001. The present status of experiments that are being performed at nuclear reactors in order to seek the neutrino masses, mixing, and magnetic moments, whose discovery would be a signal of the existence of physics beyond the Standard Model, is considered, along with their future prospects.
[ { "created": "Thu, 3 Oct 2002 07:34:30 GMT", "version": "v1" }, { "created": "Fri, 4 Oct 2002 08:21:52 GMT", "version": "v2" }, { "created": "Mon, 7 Oct 2002 16:07:52 GMT", "version": "v3" } ]
2009-11-07
[ [ "Mikaelyan", "L. A.", "", "RRC Kurchatov Institute, Moscow, Russia" ] ]
This paper was submitted in Russian edition of Journal Physics of Atomic Nuclei in 2001. The present status of experiments that are being performed at nuclear reactors in order to seek the neutrino masses, mixing, and magnetic moments, whose discovery would be a signal of the existence of physics beyond the Standard Model, is considered, along with their future prospects.
hep-ph/0207152
Uleshchenko V. V. ofti off 337 fon
A. Szczurek
Charm and bottom quark production in photon-nucleon and photon-photon collisions
A talk presented at DIS2002, 30 April - 4 May 2002, Cracow
Acta Phys.Polon.B33:3251-3256,2002
null
null
hep-ph
null
I discuss mechanisms of heavy quark production in (real) photon-nucleon and (real) photon - (real) photon collisions. In particular, I focuse on application of the Saturation Model. In addition to the main dipole-nucleon or dipole-dipole contribution included in recent analyses, I propose how to calculate within the same formalism the hadronic single-resolved contribution to heavy quark production. At high photon-photon energies this yields a sizeable correction of about 30-40 % for inclusive charm production and 15-20 % for bottom production.
[ { "created": "Fri, 12 Jul 2002 11:15:13 GMT", "version": "v1" } ]
2011-01-25
[ [ "Szczurek", "A.", "" ] ]
I discuss mechanisms of heavy quark production in (real) photon-nucleon and (real) photon - (real) photon collisions. In particular, I focuse on application of the Saturation Model. In addition to the main dipole-nucleon or dipole-dipole contribution included in recent analyses, I propose how to calculate within the same formalism the hadronic single-resolved contribution to heavy quark production. At high photon-photon energies this yields a sizeable correction of about 30-40 % for inclusive charm production and 15-20 % for bottom production.
1007.0243
Oram Gedalia
C\'edric Delaunay, Oram Gedalia, Seung J. Lee, Gilad Perez and Eduardo Pont\'on
Ultra Visible Warped Model From Flavor Triviality & Improved Naturalness
44 pages, 6 figures; v2: major revision: author added; title changed; extended statistical analysis; added discussion about fine-tuning and flavor appendix; results slightly changed. v3: minor corrections and clarifications; reference added; matches published version
Phys.Rev.D83:115003,2011
10.1103/PhysRevD.83.115003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A warped extra-dimensional model, where the Standard Model Yukawa hierarchy is set by UV physics, is shown to have a sweet spot of parameters with improved experimental visibility and possibly naturalness. Upon marginalizing over all the model parameters, a Kaluza-Klein scale of 2.1 TeV can be obtained at 2 sigma (95.4 CL) without conflicting with electroweak precision measurements. Fitting all relevant parameters simultaneously can relax this bound to 1.7 TeV. In this bulk version of the Rattazzi-Zaffaroni shining model, flavor violation is also highly suppressed, yielding a bound of 2.4 TeV. Non-trivial flavor physics at the LHC in the form of flavor gauge bosons is predicted. The model is also characterized by a depletion of the third generation couplings -- as predicted by the general minimal flavor violation framework -- which can be tested via flavor precision measurements. In particular, sizable CP violation in Delta B=2 transitions can be obtained, and there is a natural region where Bs mixing is predicted to be larger than Bd mixing, as favored by recent Tevatron data. Unlike other proposals, the new contributions are not linked to Higgs or any scalar exchange processes.
[ { "created": "Thu, 1 Jul 2010 19:46:11 GMT", "version": "v1" }, { "created": "Fri, 17 Sep 2010 12:08:31 GMT", "version": "v2" }, { "created": "Sun, 5 Jun 2011 12:47:01 GMT", "version": "v3" } ]
2011-06-13
[ [ "Delaunay", "Cédric", "" ], [ "Gedalia", "Oram", "" ], [ "Lee", "Seung J.", "" ], [ "Perez", "Gilad", "" ], [ "Pontón", "Eduardo", "" ] ]
A warped extra-dimensional model, where the Standard Model Yukawa hierarchy is set by UV physics, is shown to have a sweet spot of parameters with improved experimental visibility and possibly naturalness. Upon marginalizing over all the model parameters, a Kaluza-Klein scale of 2.1 TeV can be obtained at 2 sigma (95.4 CL) without conflicting with electroweak precision measurements. Fitting all relevant parameters simultaneously can relax this bound to 1.7 TeV. In this bulk version of the Rattazzi-Zaffaroni shining model, flavor violation is also highly suppressed, yielding a bound of 2.4 TeV. Non-trivial flavor physics at the LHC in the form of flavor gauge bosons is predicted. The model is also characterized by a depletion of the third generation couplings -- as predicted by the general minimal flavor violation framework -- which can be tested via flavor precision measurements. In particular, sizable CP violation in Delta B=2 transitions can be obtained, and there is a natural region where Bs mixing is predicted to be larger than Bd mixing, as favored by recent Tevatron data. Unlike other proposals, the new contributions are not linked to Higgs or any scalar exchange processes.
1304.2675
Sven Faller
Sven Faller, Stefan Gadatsch and Thomas Mannel
Minimal Flavour Violation and Anomalous Top Decays
12 pages, 6 figures
null
10.1103/PhysRevD.88.035006
SI-HEP-2012-09, Nikhef-2012-008
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Top quark physics at the LHC may open a window to physics beyond the standard model and even lead us to an understanding of the phenomenon "flavour". However, current flavour data is a strong hint that no "new physics" with a generic flavour structure can be expected in the TeV scale. In turn, if there is "new physics" at the TeV scale, it must be "minimally flavour violating". This has become a widely accepted assumption for "new physics" models. In this paper we propose a model-independent scheme to test minimal flavour violation for the anomalous charged $Wtq$, $q\in{d,s,b}$, and flavour-changing $Vtq$, $q\in{u,c}$ and $V\in{Z,\gamma,g}$ couplings within an effective field theory framework, i.e., in a model-independent way. We perform a spurion analysis of our effective field theory approach and calculate the decay rates for the anomalous top-quark decays in terms of the effective couplings for different helicities by using a two-Higgs doublet model of type II, under the assumption that the top-quark is produced at a high-energy collision and decays as a quasi-free particle.
[ { "created": "Tue, 9 Apr 2013 17:38:56 GMT", "version": "v1" }, { "created": "Wed, 21 Aug 2013 11:05:33 GMT", "version": "v2" } ]
2013-08-22
[ [ "Faller", "Sven", "" ], [ "Gadatsch", "Stefan", "" ], [ "Mannel", "Thomas", "" ] ]
Top quark physics at the LHC may open a window to physics beyond the standard model and even lead us to an understanding of the phenomenon "flavour". However, current flavour data is a strong hint that no "new physics" with a generic flavour structure can be expected in the TeV scale. In turn, if there is "new physics" at the TeV scale, it must be "minimally flavour violating". This has become a widely accepted assumption for "new physics" models. In this paper we propose a model-independent scheme to test minimal flavour violation for the anomalous charged $Wtq$, $q\in{d,s,b}$, and flavour-changing $Vtq$, $q\in{u,c}$ and $V\in{Z,\gamma,g}$ couplings within an effective field theory framework, i.e., in a model-independent way. We perform a spurion analysis of our effective field theory approach and calculate the decay rates for the anomalous top-quark decays in terms of the effective couplings for different helicities by using a two-Higgs doublet model of type II, under the assumption that the top-quark is produced at a high-energy collision and decays as a quasi-free particle.
0910.4474
Zhi-Zhong Xing
Zhi-zhong Xing
A Test of CPT Symmetry in K^0 vs \bar{K}^0 to \pi^+\pi^-\pi^0 Decays
4 pages, 1 figure. To appear in the Proceedings of the International PHIPSI09 Workshop, October 2009, Beijing, China
Chin.Phys.C34:753-756,2010
10.1088/1674-1137/34/6/024
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I show that the CP-violating asymmetry in K^0 vs \bar{K}^0 \to \pi^+\pi^-\pi^0 decays differs from that in K_L \to \pi^+\pi^-, K_L \to \pi^0\pi^0 or the semileptonic K_L transitions, if there exists CPT violation in K^0-\bar{K}^0 mixing. A delicate measurement of this difference at a super flavor factory (e.g., the \phi factory) will provide us with a robust test of CPT symmetry in the neutral kaon system.
[ { "created": "Fri, 23 Oct 2009 10:28:24 GMT", "version": "v1" } ]
2011-04-07
[ [ "Xing", "Zhi-zhong", "" ] ]
I show that the CP-violating asymmetry in K^0 vs \bar{K}^0 \to \pi^+\pi^-\pi^0 decays differs from that in K_L \to \pi^+\pi^-, K_L \to \pi^0\pi^0 or the semileptonic K_L transitions, if there exists CPT violation in K^0-\bar{K}^0 mixing. A delicate measurement of this difference at a super flavor factory (e.g., the \phi factory) will provide us with a robust test of CPT symmetry in the neutral kaon system.
hep-ph/0309093
Michael Strickland
Paul Romatschke and Michael Strickland
Energy Loss of a Heavy Fermion in an Anisotropic QED Plasma
19 pages, 18 figures. v2 - Correction to normalization of numerical results; some figures modified as a result; discussion of role of unstable modes added along with two new figures
Phys.Rev.D69:065005,2004
10.1103/PhysRevD.69.065005
TUW-03-25
hep-ph nucl-th
null
We compute the leading-order collisional energy loss of a heavy fermion propagating in a QED plasma with an electron distribution function which is anisotropic in momentum space. We show that in the presence of such anisotropies there can be a significant directional dependence of the heavy fermion energy loss with the effect being quite large for highly-relativistic velocities. We also repeat the analysis of the isotropic case more carefully and show that the final result depends on the intermediate scale used to separate hard and soft contributions to the energy loss. We then show that the canonical isotropic result is obtained in the weak-coupling limit. For intermediate-coupling we use the residual scale dependence as a measure of our theoretical uncertainty. We also discuss complications which could arise due to the presence of unstable soft photonic modes and demonstrate that the calculation of the energy loss is safe.
[ { "created": "Tue, 9 Sep 2003 12:42:34 GMT", "version": "v1" }, { "created": "Mon, 6 Oct 2003 12:21:40 GMT", "version": "v2" } ]
2008-11-26
[ [ "Romatschke", "Paul", "" ], [ "Strickland", "Michael", "" ] ]
We compute the leading-order collisional energy loss of a heavy fermion propagating in a QED plasma with an electron distribution function which is anisotropic in momentum space. We show that in the presence of such anisotropies there can be a significant directional dependence of the heavy fermion energy loss with the effect being quite large for highly-relativistic velocities. We also repeat the analysis of the isotropic case more carefully and show that the final result depends on the intermediate scale used to separate hard and soft contributions to the energy loss. We then show that the canonical isotropic result is obtained in the weak-coupling limit. For intermediate-coupling we use the residual scale dependence as a measure of our theoretical uncertainty. We also discuss complications which could arise due to the presence of unstable soft photonic modes and demonstrate that the calculation of the energy loss is safe.
1408.2991
Sarah Judith M\"uller
Sarah J. M\"uller, Christoph H. Keitel, and Carsten M\"uller
Particle Production Reactions in Laser-Boosted Lepton Collisions
16 pages, 17 figures
Phys. Rev. D 90, 094008 (2014)
10.1103/PhysRevD.90.094008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The need for ever higher energies in lepton colliders gives rise to the investigation of new accelerator schemes for elementary particle physics experiments. One perceivable way to increase the collision energy would be to combine conventional lepton acceleration with strong laser fields, making use of the momentum boost a charged particle experiences inside a plane electromagnetic wave. As an example for a process taking place in such a laser-boosted collision, Higgs boson creation is studied in detail. We further discuss other possible particle production processes that could be implemented in such a collider scheme and specify the required technical demands.
[ { "created": "Wed, 13 Aug 2014 12:14:08 GMT", "version": "v1" }, { "created": "Sun, 28 Dec 2014 18:13:53 GMT", "version": "v2" } ]
2014-12-30
[ [ "Müller", "Sarah J.", "" ], [ "Keitel", "Christoph H.", "" ], [ "Müller", "Carsten", "" ] ]
The need for ever higher energies in lepton colliders gives rise to the investigation of new accelerator schemes for elementary particle physics experiments. One perceivable way to increase the collision energy would be to combine conventional lepton acceleration with strong laser fields, making use of the momentum boost a charged particle experiences inside a plane electromagnetic wave. As an example for a process taking place in such a laser-boosted collision, Higgs boson creation is studied in detail. We further discuss other possible particle production processes that could be implemented in such a collider scheme and specify the required technical demands.
hep-ph/0012227
Maurizio Piai
M. Fabbrichesi, M. Piai and G. Tasinato
Gravitational Interaction of Neutrinos in Models with Large Extra Dimensions
Final version, published in The European Physical Journal C. Includes also preprint hep-ph/0103249. Comments added and typos corrected
Eur.Phys.J.C27:283-290,2003
10.1140/epjc/s2002-01101-7
null
hep-ph
null
Whenever fields are allowed to propagate in different portions of space-time, the four dimensional theory exhibits an effective violation of the principle of equivalence. We discuss the conditions under which such an effect is relevant for neutrino physics. In the simplest case of compactification on a flat manifold, the effect of gravity is many orders of magnitude too weak and plays no role for solar neutrino oscillation. Instead, it could be important in the study of ultra high-energy neutrinos in cosmic rays. Gravity could also be relevant for lower energy neutrino processes involving bulk sterile states, if the mechanism of compactification is more subtle than that on torii.
[ { "created": "Mon, 18 Dec 2000 15:36:28 GMT", "version": "v1" }, { "created": "Tue, 23 Jan 2001 09:52:25 GMT", "version": "v2" }, { "created": "Mon, 30 Jul 2001 15:53:31 GMT", "version": "v3" }, { "created": "Tue, 4 Feb 2003 16:18:47 GMT", "version": "v4" } ]
2009-01-07
[ [ "Fabbrichesi", "M.", "" ], [ "Piai", "M.", "" ], [ "Tasinato", "G.", "" ] ]
Whenever fields are allowed to propagate in different portions of space-time, the four dimensional theory exhibits an effective violation of the principle of equivalence. We discuss the conditions under which such an effect is relevant for neutrino physics. In the simplest case of compactification on a flat manifold, the effect of gravity is many orders of magnitude too weak and plays no role for solar neutrino oscillation. Instead, it could be important in the study of ultra high-energy neutrinos in cosmic rays. Gravity could also be relevant for lower energy neutrino processes involving bulk sterile states, if the mechanism of compactification is more subtle than that on torii.
0902.0688
Roberto Iengo
R.Iengo (SISSA, Trieste)
Sommerfeld enhancement: general results from field theory diagrams
published version, it contains also the material of 0903.0317
JHEP 0905:024,2009
10.1088/1126-6708/2009/05/024
null
hep-ph astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Assuming that two incoming annihilating particles interact by a generally massive attractive vector potential,we find, by taking the non-relativistic limit of the field theory ladder diagrams, that the complete annihilation amplitude A is equal to: the convolution of a solution of the Schroedinger equation (including the vector potential) with the Fourier transform of the bare (i.e. ignoring the attraction) annihilation amplitude A0. The main novelty is that A0 is completely arbitrary. In particular for a massless vector potential we find for the l-partial-wave cross-section the Sommerfeld enhancement 2pi/(l!)^2 (alpha/ v)^{2l+1} (v relative velocity), e.g. for the P wave the enhancement 2pi(alpha/ v)^3.
[ { "created": "Wed, 4 Feb 2009 18:36:50 GMT", "version": "v1" }, { "created": "Wed, 11 Feb 2009 10:53:56 GMT", "version": "v2" }, { "created": "Wed, 13 May 2009 09:21:19 GMT", "version": "v3" } ]
2010-04-23
[ [ "Iengo", "R.", "", "SISSA, Trieste" ] ]
Assuming that two incoming annihilating particles interact by a generally massive attractive vector potential,we find, by taking the non-relativistic limit of the field theory ladder diagrams, that the complete annihilation amplitude A is equal to: the convolution of a solution of the Schroedinger equation (including the vector potential) with the Fourier transform of the bare (i.e. ignoring the attraction) annihilation amplitude A0. The main novelty is that A0 is completely arbitrary. In particular for a massless vector potential we find for the l-partial-wave cross-section the Sommerfeld enhancement 2pi/(l!)^2 (alpha/ v)^{2l+1} (v relative velocity), e.g. for the P wave the enhancement 2pi(alpha/ v)^3.
0704.1956
Oldrich Kepka
O. Kepka and C. Royon ((1) DAPNIA/Service de physique des particules, CEA/Saclay, Gif-sur-Yvette cedex, France, (2) IPNP, Faculty of Mathematics and Physics, Charles University, Prague, (3) Center for Particle Physics, Institute of Physics, Academy of Science, Prague)
Search for exclusive events using the dijet mass fraction at the Tevatron
21 pages, 21 figures, submitted to Physical Review D
Phys.Rev.D76:034012,2007
10.1103/PhysRevD.76.034012
null
hep-ph
null
In this paper, we discuss the observation of exclusive events using the dijet mass fraction as measured by the CDF collaboration at the Tevatron. We compare the data to pomeron exchange inspired models as well as Soft color interaction ones. We also provide the prediction on dijet mass fraction at the LHC using both exclusive and inclusive diffractive events.
[ { "created": "Mon, 16 Apr 2007 09:19:37 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kepka", "O.", "" ], [ "Royon", "C.", "" ] ]
In this paper, we discuss the observation of exclusive events using the dijet mass fraction as measured by the CDF collaboration at the Tevatron. We compare the data to pomeron exchange inspired models as well as Soft color interaction ones. We also provide the prediction on dijet mass fraction at the LHC using both exclusive and inclusive diffractive events.
1309.5273
Aleksandr Azatov
Aleksandr Azatov and Ayan Paul
Probing Higgs couplings with high p_T Higgs production
15 pages 10 figures; typos in Eq. 1.1 and 1.3 fixed
null
10.1007/JHEP01(2014)014
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Possible extensions of the Standard Model predict modifications of the Higgs couplings to gluons and to the SM top quark. The values of these two couplings can, in general, be independent. We discuss a way to measure these interactions by studying the Higgs production at high p_T within an effective field theory formalism. We also propose an observable r_\pm with reduced theoretical errors and suggest its experimental interpretation.
[ { "created": "Fri, 20 Sep 2013 14:08:28 GMT", "version": "v1" }, { "created": "Tue, 24 Dec 2013 07:28:02 GMT", "version": "v2" }, { "created": "Fri, 28 Mar 2014 14:30:25 GMT", "version": "v3" } ]
2014-03-31
[ [ "Azatov", "Aleksandr", "" ], [ "Paul", "Ayan", "" ] ]
Possible extensions of the Standard Model predict modifications of the Higgs couplings to gluons and to the SM top quark. The values of these two couplings can, in general, be independent. We discuss a way to measure these interactions by studying the Higgs production at high p_T within an effective field theory formalism. We also propose an observable r_\pm with reduced theoretical errors and suggest its experimental interpretation.
1006.4729
Claude Semay
Fabien Buisseret, Claude Semay
Light baryon masses in different large-$N_c$ limits
Final version to appear in Phys. Rev. D
Phys.Rev.D82:056008,2010
10.1103/PhysRevD.82.056008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the behavior of light baryon masses in three inequivalent large-$N_c$ limits: 't~Hooft, QCD$_{{\rm AS}}$ and Corrigan-Ramond. Our framework is a constituent quark model with relativistic-type kinetic energy, stringlike confinement and one-gluon-exchange term, thus leading to well-defined results even for massless quarks. We analytically prove that the light baryon masses scale as $N_c$, $N_c^2$ and $1$ in the 't~Hooft, QCD$_{{\rm AS}}$ and Corrigan-Ramond limits respectively. Those results confirm previous ones obtained by using either diagrammatic methods or constituent approaches, mostly valid for heavy quarks.
[ { "created": "Thu, 24 Jun 2010 09:42:00 GMT", "version": "v1" }, { "created": "Fri, 20 Aug 2010 07:32:21 GMT", "version": "v2" } ]
2014-11-21
[ [ "Buisseret", "Fabien", "" ], [ "Semay", "Claude", "" ] ]
We investigate the behavior of light baryon masses in three inequivalent large-$N_c$ limits: 't~Hooft, QCD$_{{\rm AS}}$ and Corrigan-Ramond. Our framework is a constituent quark model with relativistic-type kinetic energy, stringlike confinement and one-gluon-exchange term, thus leading to well-defined results even for massless quarks. We analytically prove that the light baryon masses scale as $N_c$, $N_c^2$ and $1$ in the 't~Hooft, QCD$_{{\rm AS}}$ and Corrigan-Ramond limits respectively. Those results confirm previous ones obtained by using either diagrammatic methods or constituent approaches, mostly valid for heavy quarks.
2306.09512
Vladimir Tello
Goran Senjanovi\'c and Vladimir Tello
Spontaneous Parity Violation
14 pages, 6 figures. Talk given at Discrete 2022, 8th Symposium on Prospects in the Physics of Discrete Symmetries, 7-11 November, 2022, Baden-Baden, Germany
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review here the central features of the idea of spontaneous breakdown of parity, in the context of its minimal realization, the Left-Right symmetric gauge theory.
[ { "created": "Thu, 15 Jun 2023 21:15:02 GMT", "version": "v1" } ]
2023-06-19
[ [ "Senjanović", "Goran", "" ], [ "Tello", "Vladimir", "" ] ]
We review here the central features of the idea of spontaneous breakdown of parity, in the context of its minimal realization, the Left-Right symmetric gauge theory.
1005.1106
Cheng-Wei Chiang
Hai-Yang Cheng and Cheng-Wei Chiang
Long-Distance Contributions to D^0-D^0bar Mixing Parameters
18 pages and 1 figure; footnotes and references added; to appear in Phys. Rev. D
Phys.Rev.D81:114020,2010
10.1103/PhysRevD.81.114020
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Long-distance contributions to the $D^0$-$\bar D^0$ mixing parameters $x$ and $y$ are evaluated using latest data on hadronic $D^0$ decays. In particular, we take on two-body $D \to PP$ and $VP$ decays to evaluate the contributions of two-body intermediate states because they account for $\sim 50%$ of hadronic $D^0$ decays. Use of the diagrammatic approach has been made to estimate yet-observed decay modes. We find that $y$ is of order a few $\times 10^{-3}$ and $x$ of order $10^{-3}$ from hadronic $PP$ and $VP$ modes. These are in good agreement with the latest direct measurement of $D^0$-$\bar D^0$ mixing parameters using the $D^0 \to K_S \pi^+\pi^-$ and $K_S K^+ K^-$ decays by BaBar. We estimate the contribution to $y$ from the $VV$ modes using the factorization model and comment on the single-particle resonance effects and contributions from other two-body modes involving even-parity states.
[ { "created": "Thu, 6 May 2010 23:26:22 GMT", "version": "v1" }, { "created": "Sun, 23 May 2010 04:25:58 GMT", "version": "v2" }, { "created": "Tue, 25 May 2010 02:55:59 GMT", "version": "v3" } ]
2014-11-21
[ [ "Cheng", "Hai-Yang", "" ], [ "Chiang", "Cheng-Wei", "" ] ]
Long-distance contributions to the $D^0$-$\bar D^0$ mixing parameters $x$ and $y$ are evaluated using latest data on hadronic $D^0$ decays. In particular, we take on two-body $D \to PP$ and $VP$ decays to evaluate the contributions of two-body intermediate states because they account for $\sim 50%$ of hadronic $D^0$ decays. Use of the diagrammatic approach has been made to estimate yet-observed decay modes. We find that $y$ is of order a few $\times 10^{-3}$ and $x$ of order $10^{-3}$ from hadronic $PP$ and $VP$ modes. These are in good agreement with the latest direct measurement of $D^0$-$\bar D^0$ mixing parameters using the $D^0 \to K_S \pi^+\pi^-$ and $K_S K^+ K^-$ decays by BaBar. We estimate the contribution to $y$ from the $VV$ modes using the factorization model and comment on the single-particle resonance effects and contributions from other two-body modes involving even-parity states.
2104.03887
Jia-Yue Zhang
Yingsheng Huang, Feng Feng, Yu Jia, Wen-Long Sang, De-Shan Yang, Jia-Yue Zhang
Inclusive production of fully-charmed ${\bm 1}^{\bm{+}\bm{-}}$ tetraquark at $\bm B$ factory
11 pages, 3 figures
null
10.1088/1674-1137/ac0b38
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the recent discovery of the $X(6900)$ meson at {\tt LHCb} experiment, we investigate the inclusive production rate of the $C$-odd fully-charmed tetraquarks associated with light hadrons at the $B$ factory within the nonrelativistic QCD (NRQCD) factorization framework. The short-distance coefficient is computed at lowest order in velocity and $\alpha_s$. Employing the diquark-antidiquark model to roughly estimate the long-distance NRQCD matrix elements, we predict the rate for inclusive production of the $1^{+-}$ $T_{4c}$ state and discuss the observation prospects at {\tt Belle 2} experiment.
[ { "created": "Thu, 8 Apr 2021 16:57:24 GMT", "version": "v1" } ]
2021-09-22
[ [ "Huang", "Yingsheng", "" ], [ "Feng", "Feng", "" ], [ "Jia", "Yu", "" ], [ "Sang", "Wen-Long", "" ], [ "Yang", "De-Shan", "" ], [ "Zhang", "Jia-Yue", "" ] ]
Inspired by the recent discovery of the $X(6900)$ meson at {\tt LHCb} experiment, we investigate the inclusive production rate of the $C$-odd fully-charmed tetraquarks associated with light hadrons at the $B$ factory within the nonrelativistic QCD (NRQCD) factorization framework. The short-distance coefficient is computed at lowest order in velocity and $\alpha_s$. Employing the diquark-antidiquark model to roughly estimate the long-distance NRQCD matrix elements, we predict the rate for inclusive production of the $1^{+-}$ $T_{4c}$ state and discuss the observation prospects at {\tt Belle 2} experiment.
1707.00926
Emiliano Molinaro
Emiliano Molinaro and Natascia Vignaroli
Diphoton Resonances at the LHC
13 pages, 3 figures; invited review for MPLA; journal version
Mod. Phys. Lett. A, Vol. 32, No. 27 (2017) 1730024
10.1142/S0217732317300245
CP3-Origins-2017-026 DNRF90
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the current status of searches for new physics beyond the Standard Model in the diphoton channel at the LHC and estimate the reach with future collected data. We perform a model independent analysis based on an effective field theory approach and different production mechanisms. As an illustrative example, we apply our results to a scenario of minimal composite dynamics.
[ { "created": "Tue, 4 Jul 2017 11:42:27 GMT", "version": "v1" }, { "created": "Thu, 24 Aug 2017 06:41:32 GMT", "version": "v2" }, { "created": "Fri, 1 Sep 2017 13:50:10 GMT", "version": "v3" } ]
2017-09-04
[ [ "Molinaro", "Emiliano", "" ], [ "Vignaroli", "Natascia", "" ] ]
We review the current status of searches for new physics beyond the Standard Model in the diphoton channel at the LHC and estimate the reach with future collected data. We perform a model independent analysis based on an effective field theory approach and different production mechanisms. As an illustrative example, we apply our results to a scenario of minimal composite dynamics.
1210.0559
Nathaniel Craig
Nathaniel Craig, Jared A. Evans, Richard Gray, Can Kilic, Michael Park, Sunil Somalwar, Scott Thomas
Multi-Lepton Signals of Multiple Higgs Bosons
39 pages, 11 tables, 11 figures
null
10.1007/JHEP02(2013)033
RU-NHETC-2012-20, UTTG-12-12, TCC-012-12
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We identify and investigate novel multi-lepton signatures of extended Higgs sectors at the LHC in the guise of CP- and flavor-conserving two-Higgs-doublet models (2HDMs). Rather than designing individual searches tailored to specific 2HDM signals, we employ the combination of many exclusive multi-lepton search channels to probe the collective signal from the totality of production and decay processes. Multi-lepton signals of 2HDMs can arise from a variety of sources, including Standard Model-like production of the CP-even scalars, $h$ and $H$, through gluon-fusion with $h,H \to ZZ^{(*)}$, or associated production with vector bosons or top quarks, with $h,H \to WW^{(*)}, ZZ^{(*)},\tau\tau$. Additional sources include gluon-fusion production of the heavy CP-even scalar with decays through the light CP-even scalar, the CP-odd scalar, $A$, or the charged scalar, $H^\pm$, such as $H \to hh$, $H \to AA$, $H \to H^+ H^-$, $H \to ZA$, with $A \to Zh, \tau\tau$, $H^\pm \to Wh$, and $h \to WW^*, ZZ^*,\tau\tau$. Altogether, the combined multi-lepton signal may greatly exceed that of the Standard Model Higgs boson and provides a sensitive probe of extended Higgs sectors. As a proof of principle, we use a factorized mapping procedure between model parameters and signatures to determine multi-lepton sensitivities in four different flavor conserving 2HDM parameter spaces by simulating the acceptance times efficiency in 20 exclusive multi-lepton channels for 222 independent production and decay topologies that arise for four benchmark 2HDM spectra within each parameter space. A comparison of these sensitivities with the results of a multi-lepton search conducted by the CMS collaboration using 5 fb$^{-1}$ of data collected from 7 TeV $pp$ collisions yields new limits in regions of 2HDM parameter space that have not previously been covered by other types of direct experimental searches.
[ { "created": "Mon, 1 Oct 2012 20:10:48 GMT", "version": "v1" } ]
2015-06-11
[ [ "Craig", "Nathaniel", "" ], [ "Evans", "Jared A.", "" ], [ "Gray", "Richard", "" ], [ "Kilic", "Can", "" ], [ "Park", "Michael", "" ], [ "Somalwar", "Sunil", "" ], [ "Thomas", "Scott", "" ] ]
We identify and investigate novel multi-lepton signatures of extended Higgs sectors at the LHC in the guise of CP- and flavor-conserving two-Higgs-doublet models (2HDMs). Rather than designing individual searches tailored to specific 2HDM signals, we employ the combination of many exclusive multi-lepton search channels to probe the collective signal from the totality of production and decay processes. Multi-lepton signals of 2HDMs can arise from a variety of sources, including Standard Model-like production of the CP-even scalars, $h$ and $H$, through gluon-fusion with $h,H \to ZZ^{(*)}$, or associated production with vector bosons or top quarks, with $h,H \to WW^{(*)}, ZZ^{(*)},\tau\tau$. Additional sources include gluon-fusion production of the heavy CP-even scalar with decays through the light CP-even scalar, the CP-odd scalar, $A$, or the charged scalar, $H^\pm$, such as $H \to hh$, $H \to AA$, $H \to H^+ H^-$, $H \to ZA$, with $A \to Zh, \tau\tau$, $H^\pm \to Wh$, and $h \to WW^*, ZZ^*,\tau\tau$. Altogether, the combined multi-lepton signal may greatly exceed that of the Standard Model Higgs boson and provides a sensitive probe of extended Higgs sectors. As a proof of principle, we use a factorized mapping procedure between model parameters and signatures to determine multi-lepton sensitivities in four different flavor conserving 2HDM parameter spaces by simulating the acceptance times efficiency in 20 exclusive multi-lepton channels for 222 independent production and decay topologies that arise for four benchmark 2HDM spectra within each parameter space. A comparison of these sensitivities with the results of a multi-lepton search conducted by the CMS collaboration using 5 fb$^{-1}$ of data collected from 7 TeV $pp$ collisions yields new limits in regions of 2HDM parameter space that have not previously been covered by other types of direct experimental searches.
hep-ph/0501209
Harry Lipkin J.
Harry J. Lipkin
Why pentaquarks are seen in some experiments and not in others
4 pages
null
10.1142/9789812702227_0205
TAUP 2785-04; ANL-HEP-CP-04-102
hep-ph
null
The $\Theta^+$ Pentaquark is a Very narrow $\Gamma \approx 1$ MeV KN Resonance. Why do some experiments see it and others do not? The lowest quark configuration that can describe it is exotic $uudd \bar s$. Why have no exotics been seen before? Is this the beginning of a new spectroscopy? Can it help toteach us about How QCD makes hadrons from quarks and gluons?
[ { "created": "Sun, 23 Jan 2005 20:17:51 GMT", "version": "v1" } ]
2017-08-23
[ [ "Lipkin", "Harry J.", "" ] ]
The $\Theta^+$ Pentaquark is a Very narrow $\Gamma \approx 1$ MeV KN Resonance. Why do some experiments see it and others do not? The lowest quark configuration that can describe it is exotic $uudd \bar s$. Why have no exotics been seen before? Is this the beginning of a new spectroscopy? Can it help toteach us about How QCD makes hadrons from quarks and gluons?
hep-ph/0411170
Stephen King
O. J. Eyton-Williams and S. F. King
Inflationary Solution to the Strong CP and $\mu$ Problems
Version to appear in Physics Letters B. 14 pages
Phys.Lett. B610 (2005) 87-93
10.1016/j.physletb.2005.01.075
null
hep-ph
null
We show that the vacuum expectation value of the inflaton at the Peccei-Quinn axion scale can generate the supersymmetric Higgs mass $\mu$ term. This provides an inflationary simultaneous solution to the strong CP problem and the $\mu$ problem of the Minimal Supersymmetric Standard Model, and gives a testable prediction for the $\mu$ parameter: $\mu^2 \approx (0.25-0.5)m_0^2$, where $m_0$ is the soft Higgs scalar mass. Our model involves a very small Yukawa coupling of order $10^{-10}$, which could originate from an extra-dimensional scenario or type I string theory.
[ { "created": "Fri, 12 Nov 2004 15:11:36 GMT", "version": "v1" }, { "created": "Fri, 26 Nov 2004 16:07:08 GMT", "version": "v2" }, { "created": "Wed, 9 Feb 2005 11:51:25 GMT", "version": "v3" } ]
2009-11-10
[ [ "Eyton-Williams", "O. J.", "" ], [ "King", "S. F.", "" ] ]
We show that the vacuum expectation value of the inflaton at the Peccei-Quinn axion scale can generate the supersymmetric Higgs mass $\mu$ term. This provides an inflationary simultaneous solution to the strong CP problem and the $\mu$ problem of the Minimal Supersymmetric Standard Model, and gives a testable prediction for the $\mu$ parameter: $\mu^2 \approx (0.25-0.5)m_0^2$, where $m_0$ is the soft Higgs scalar mass. Our model involves a very small Yukawa coupling of order $10^{-10}$, which could originate from an extra-dimensional scenario or type I string theory.
1601.07666
Bernard Pire
B. Pire, L. Szymanowski and J. Wagner
Probing the transversity spin structure of a nucleon in neutrino-production of a charmed meson
6 pages, 2 figures, 6th international conference on Physics Opportunities at an Electron-Ion Collider, POETIC-6, September 7-11 2015, Ecole polytechnique, Palaiseau, France; v2 : eq.10 and Fig. 2 corrected
null
10.1051/epjconf/201611201018
CPHT-PC004.012016
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Including O(m_c) terms in the coefficient functions and/or O(m_D) twist 3 contributions in the heavy meson distribution amplitudes leads to a non-zero transverse amplitude for exclusive neutrino production of a D pseudoscalar charmed meson on an unpolarized target. We work in the framework of the collinear QCD approach where chiral-odd transversity generalized parton distributions (GPDs) factorize from perturbatively calculable coefficient functions.
[ { "created": "Thu, 28 Jan 2016 06:52:07 GMT", "version": "v1" }, { "created": "Tue, 2 Feb 2016 08:23:47 GMT", "version": "v2" } ]
2016-04-20
[ [ "Pire", "B.", "" ], [ "Szymanowski", "L.", "" ], [ "Wagner", "J.", "" ] ]
Including O(m_c) terms in the coefficient functions and/or O(m_D) twist 3 contributions in the heavy meson distribution amplitudes leads to a non-zero transverse amplitude for exclusive neutrino production of a D pseudoscalar charmed meson on an unpolarized target. We work in the framework of the collinear QCD approach where chiral-odd transversity generalized parton distributions (GPDs) factorize from perturbatively calculable coefficient functions.
hep-ph/9912401
Boris Polishchuk
V.V. Ezhela, B.V. Polishchuk
Reanalysis of ep Elastic Scattering Data in Terms of Proton Electromagnetic Formfactors
added reference and acknowledgement, links refreshed
null
10.1142/9789812817624_0038
IHEP 99-48
hep-ph
null
We have made the comparison of three parametrizations of the proton electromagnetic form factors in the space-like region using the largest data set on $e^{\pm} p$ elastic scattering ever used. All models have a correct analytical structure with a minimal set of well known singularities. For the first time an effective two-pion intermediate coulombic bound state (pionium) was included into GVMD for nucleon formfactors. For the proton charge radius an estimate derived from our best fits is as follows: r_E^p [\rm fm] = 0.897 \pm 0.002(exp) \pm 0.001(norm) \pm 0.003(models). The traditional ``model independent'' fit by quadratic polynomial gives, in our estimation technology, a much cruder estimate r^p_{E,polinomial} [\rm fm] = 0.887 \pm 0.006(exp) \pm 0.096(norm). Both estimates are closer to the value estimated from the recent hydrogen Lamb shift measurements.
[ { "created": "Fri, 17 Dec 1999 14:23:40 GMT", "version": "v1" }, { "created": "Wed, 22 Mar 2000 13:44:58 GMT", "version": "v2" } ]
2016-11-23
[ [ "Ezhela", "V. V.", "" ], [ "Polishchuk", "B. V.", "" ] ]
We have made the comparison of three parametrizations of the proton electromagnetic form factors in the space-like region using the largest data set on $e^{\pm} p$ elastic scattering ever used. All models have a correct analytical structure with a minimal set of well known singularities. For the first time an effective two-pion intermediate coulombic bound state (pionium) was included into GVMD for nucleon formfactors. For the proton charge radius an estimate derived from our best fits is as follows: r_E^p [\rm fm] = 0.897 \pm 0.002(exp) \pm 0.001(norm) \pm 0.003(models). The traditional ``model independent'' fit by quadratic polynomial gives, in our estimation technology, a much cruder estimate r^p_{E,polinomial} [\rm fm] = 0.887 \pm 0.006(exp) \pm 0.096(norm). Both estimates are closer to the value estimated from the recent hydrogen Lamb shift measurements.
2104.13937
Taylor Gray
Catarina Cosme, Ma\'ira Dutra, Stephen Godfrey, Taylor R. Gray
Testing freeze-in with axial and vector $Z'$ bosons
v2: Minor corrections, discussion expanded, updated figures, references added. Matches journal version
Cosme, C., Dutra, M., Godfrey, S. et al. Testing freeze-in with axial and vector Z' bosons. J. High Energ. Phys. 2021, 56 (2021). https://doi.org/10.1007/JHEP09(2021)056
10.1007/JHEP09(2021)056
null
hep-ph astro-ph.CO astro-ph.HE hep-th
http://creativecommons.org/licenses/by/4.0/
The freeze-in production of Feebly Interacting Massive Particle (FIMP) dark matter in the early universe is an appealing alternative to the well-known - and constrained - Weakly Interacting Massive Particle (WIMP) paradigm. Although challenging, the phenomenology of FIMP dark matter has been receiving growing attention and is possible in a few scenarios. In this work, we contribute to this endeavor by considering a $Z^\prime$ portal to fermionic dark matter, with the $Z^\prime$ having both vector and axial couplings and a mass ranging from MeV up to PeV. We evaluate the bounds on both freeze-in and freeze-out from direct detection, atomic parity violation, leptonic anomalous magnetic moments, neutrino-electron scattering, collider, and beam dump experiments. We show that FIMPs can already be tested by most of these experiments in a complementary way, whereas WIMPs are especially viable in the $Z^\prime$ low mass regime, in addition to the $Z^\prime$ resonance region. We also discuss the role of the axial couplings of $Z^\prime$ in our results. We therefore hope to motivate specific realizations of this model in the context of FIMPs, as well as searches for these elusive dark matter candidates.
[ { "created": "Wed, 28 Apr 2021 18:00:05 GMT", "version": "v1" }, { "created": "Mon, 11 Oct 2021 16:31:17 GMT", "version": "v2" } ]
2021-10-12
[ [ "Cosme", "Catarina", "" ], [ "Dutra", "Maíra", "" ], [ "Godfrey", "Stephen", "" ], [ "Gray", "Taylor R.", "" ] ]
The freeze-in production of Feebly Interacting Massive Particle (FIMP) dark matter in the early universe is an appealing alternative to the well-known - and constrained - Weakly Interacting Massive Particle (WIMP) paradigm. Although challenging, the phenomenology of FIMP dark matter has been receiving growing attention and is possible in a few scenarios. In this work, we contribute to this endeavor by considering a $Z^\prime$ portal to fermionic dark matter, with the $Z^\prime$ having both vector and axial couplings and a mass ranging from MeV up to PeV. We evaluate the bounds on both freeze-in and freeze-out from direct detection, atomic parity violation, leptonic anomalous magnetic moments, neutrino-electron scattering, collider, and beam dump experiments. We show that FIMPs can already be tested by most of these experiments in a complementary way, whereas WIMPs are especially viable in the $Z^\prime$ low mass regime, in addition to the $Z^\prime$ resonance region. We also discuss the role of the axial couplings of $Z^\prime$ in our results. We therefore hope to motivate specific realizations of this model in the context of FIMPs, as well as searches for these elusive dark matter candidates.
1511.04860
Yutaro Shoji
Motoi Endo, Takeo Moroi, Mihoko M. Nojiri, and Yutaro Shoji
Renormalization-Scale Uncertainty in the Decay Rate of False Vacuum
15 pages, 2 figures; added references
null
10.1007/JHEP01(2016)031
UT-15-40, KEK-TH-1875
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study radiative corrections to the decay rate of false vacua, paying particular attention to the renormalization-scale dependence of the decay rate. The decay rate exponentially depends on the bounce action. The bounce action itself is renormalization scale dependent. To make the decay rate scale-independent, radiative corrections, which are due to the field fluctuations around the bounce, have to be included. We show quantitatively that the inclusion of the fluctuations suppresses the scale dependence, and hence is important for the precise calculation of the decay rate. We also apply our analysis to a supersymmetric model and show that the radiative corrections are important for the Higgs-stau system with charge breaking minima.
[ { "created": "Mon, 16 Nov 2015 08:19:54 GMT", "version": "v1" }, { "created": "Tue, 24 Nov 2015 14:35:45 GMT", "version": "v2" }, { "created": "Thu, 24 Dec 2015 11:54:23 GMT", "version": "v3" } ]
2016-02-17
[ [ "Endo", "Motoi", "" ], [ "Moroi", "Takeo", "" ], [ "Nojiri", "Mihoko M.", "" ], [ "Shoji", "Yutaro", "" ] ]
We study radiative corrections to the decay rate of false vacua, paying particular attention to the renormalization-scale dependence of the decay rate. The decay rate exponentially depends on the bounce action. The bounce action itself is renormalization scale dependent. To make the decay rate scale-independent, radiative corrections, which are due to the field fluctuations around the bounce, have to be included. We show quantitatively that the inclusion of the fluctuations suppresses the scale dependence, and hence is important for the precise calculation of the decay rate. We also apply our analysis to a supersymmetric model and show that the radiative corrections are important for the Higgs-stau system with charge breaking minima.
1508.03676
Pilar Hernandez
P. Hern\'andez, M.Kekic, J. L\'opez-Pav\'on, J. Racker and N. Rius
Leptogenesis in GeV scale seesaw models
34 pages, 13 figures. Several typos corrected
null
null
IFIC/15-44, SISSA 35/2015/FISI
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the production of leptonic asymmetries in minimal extensions of the Standard Model that can explain neutrino masses, involving extra singlets with Majorana masses in the GeV scale. We study the quantum kinetic equations both analytically, via a perturbative expansion up to third order in the mixing angles, and numerically. The analytical solution allows us to identify the relevant CP invariants, and simplifies the exploration of the parameter space. We find that sizeable lepton asymmetries are compatible with non-degenerate neutrino masses and measurable active-sterile mixings.
[ { "created": "Fri, 14 Aug 2015 23:28:49 GMT", "version": "v1" }, { "created": "Mon, 11 Apr 2016 14:30:04 GMT", "version": "v2" } ]
2016-04-12
[ [ "Hernández", "P.", "" ], [ "Kekic", "M.", "" ], [ "López-Pavón", "J.", "" ], [ "Racker", "J.", "" ], [ "Rius", "N.", "" ] ]
We revisit the production of leptonic asymmetries in minimal extensions of the Standard Model that can explain neutrino masses, involving extra singlets with Majorana masses in the GeV scale. We study the quantum kinetic equations both analytically, via a perturbative expansion up to third order in the mixing angles, and numerically. The analytical solution allows us to identify the relevant CP invariants, and simplifies the exploration of the parameter space. We find that sizeable lepton asymmetries are compatible with non-degenerate neutrino masses and measurable active-sterile mixings.
1701.06801
Clara Murgui
Pavel Fileviez Perez, Clara Murgui
Lepton Flavour Violation in Left-Right Theory
Minor corrections, version published in Physical Review D
Phys. Rev. D 95, 075010 (2017)
10.1103/PhysRevD.95.075010
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the predictions for lepton flavour number violating processes in the context of a simple left-right symmetric theory. In this context neutrinos are Majorana fermions and their masses are generated at the quantum level through the Zee mechanism using the simplest Higgs sector. We show that the right handed neutrinos are generically light and can give rise to large lepton number violating contributions to rare processes. We discuss the correlation between the collider constrains and the predictions for lepton number violating processes. We find that using the predictions for mu to e gamma and mu to e conversion together with the collider signatures one could test this theory in the near future.
[ { "created": "Tue, 24 Jan 2017 10:44:49 GMT", "version": "v1" }, { "created": "Thu, 16 Mar 2017 12:46:04 GMT", "version": "v2" }, { "created": "Tue, 11 Apr 2017 16:07:04 GMT", "version": "v3" } ]
2017-04-12
[ [ "Perez", "Pavel Fileviez", "" ], [ "Murgui", "Clara", "" ] ]
We investigate the predictions for lepton flavour number violating processes in the context of a simple left-right symmetric theory. In this context neutrinos are Majorana fermions and their masses are generated at the quantum level through the Zee mechanism using the simplest Higgs sector. We show that the right handed neutrinos are generically light and can give rise to large lepton number violating contributions to rare processes. We discuss the correlation between the collider constrains and the predictions for lepton number violating processes. We find that using the predictions for mu to e gamma and mu to e conversion together with the collider signatures one could test this theory in the near future.
1703.04855
Yongcheng Wu
Xin Chen and Yongcheng Wu
Search for CP violation effects in the $h\to \tau\tau$ decay with $e^+e^-$ colliders
12 pages, 8 figures, refs added, match to published version
Eur. Phys. J. C (2017) 77: 697
10.1140/epjc/s10052-017-5258-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new method is proposed to reconstruct the neutrinos in the $e^+e^-\to Zh$ process followed by the $h\to\tau\tau$ decay. With the help of a refined Higgs momentum reconstruction from the recoiling system and the impact parameters, high precision in the determination of the momentum of neutrinos can be achieved. The prospect of measuring the Higgs CP mixing angle with the $h\to\tau\tau$ decay at future $e^+e^-$ colliders is studied with the new method. The analysis is based on a detailed detector simulation of the signal and backgrounds. The fully reconstructed neutrinos and also other visible products from the tau decay are used to build matrix element (ME) based CP observables. With 5 $ab^{-1}$ of data at $E_{\text{CM}}=250$ GeV, a precision of $2.9^\circ$ can be achieved for the CP mixing angle with three main one-prong decay modes of the taus. The precision is found to be about 35\% better than the other methods.
[ { "created": "Wed, 15 Mar 2017 00:52:26 GMT", "version": "v1" }, { "created": "Wed, 15 Nov 2017 15:28:31 GMT", "version": "v2" } ]
2017-11-16
[ [ "Chen", "Xin", "" ], [ "Wu", "Yongcheng", "" ] ]
A new method is proposed to reconstruct the neutrinos in the $e^+e^-\to Zh$ process followed by the $h\to\tau\tau$ decay. With the help of a refined Higgs momentum reconstruction from the recoiling system and the impact parameters, high precision in the determination of the momentum of neutrinos can be achieved. The prospect of measuring the Higgs CP mixing angle with the $h\to\tau\tau$ decay at future $e^+e^-$ colliders is studied with the new method. The analysis is based on a detailed detector simulation of the signal and backgrounds. The fully reconstructed neutrinos and also other visible products from the tau decay are used to build matrix element (ME) based CP observables. With 5 $ab^{-1}$ of data at $E_{\text{CM}}=250$ GeV, a precision of $2.9^\circ$ can be achieved for the CP mixing angle with three main one-prong decay modes of the taus. The precision is found to be about 35\% better than the other methods.
2405.11552
Sachiko Takeuchi
Sachiko Takeuchi, Makoto Takizawa, Yasuhiro Yamaguchi, and Atsushi Hosaka
The impact of quark many-body effects on exotic hadrons
11 pages, 2 figures; 25th European Few-Body Conference (Mainz, Germany, from July 30th to August 4th, 2023). This preprint has not undergone peer review (when applicable) or any post-submission improvements or corrections. The Version of Record of this article is published in Few Body Systems, and is available online at https://doi.org/10.1007/s00601-024-01932-2
Few-Body Systems 65(62) 1-8 2024; https://rdcu.be/dI4Dx
10.1007/s00601-024-01932-2
null
hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
We investigate the exotic hadrons consisting of two light quarks and two heavy antiquarks, $(q\bar Q)$-$(q\bar Q)$. The spin-dependent term between quarks is known to give an attraction to the $ud$ spin-0 component in the isospin-0 $u\bar c d\bar c$ system, $T_{cc}$. However, the said component also gets a repulsion from the partial Pauli-blocking. By the dynamical calculation with a simplified quark model, we discuss that the competition of the two effects leads to a shallow bound state for $T_{cc}$, which is preferred from the experiment, and a deep bound state for $T_{bb}$.
[ { "created": "Sun, 19 May 2024 14:04:10 GMT", "version": "v1" } ]
2024-05-28
[ [ "Takeuchi", "Sachiko", "" ], [ "Takizawa", "Makoto", "" ], [ "Yamaguchi", "Yasuhiro", "" ], [ "Hosaka", "Atsushi", "" ] ]
We investigate the exotic hadrons consisting of two light quarks and two heavy antiquarks, $(q\bar Q)$-$(q\bar Q)$. The spin-dependent term between quarks is known to give an attraction to the $ud$ spin-0 component in the isospin-0 $u\bar c d\bar c$ system, $T_{cc}$. However, the said component also gets a repulsion from the partial Pauli-blocking. By the dynamical calculation with a simplified quark model, we discuss that the competition of the two effects leads to a shallow bound state for $T_{cc}$, which is preferred from the experiment, and a deep bound state for $T_{bb}$.
2203.12684
Francisco Arco
F. Arco, S. Heinemeyer, and M.J. Herrero
Triple Higgs Couplings in the 2HDM: The Complete Picture
40 pages, 15 figures, version published in Eur. Phys. J. C
null
10.1140/epjc/s10052-022-10485-9
IFT--UAM/CSIC-22-032
hep-ph
http://creativecommons.org/licenses/by/4.0/
The measurement of the triple Higgs coupling is one of the main tasks of the (HL-)LHC and future lepton colliders. Similarly, triple Higgs couplings involving BSM Higgs bosons are of high interest. Within the framework of Two Higgs Doublet Models (2HDM) we investigate the allowed ranges for all triple Higgs couplings involving at least one light, SM-like Higgs boson. We present newly the allowed ranges for 2HDM type III and IV and update the results within the type I and II. We take into account theoretical constraints from unitarity and stability, experimental constraints from direct BSM Higgs-boson searches, measurements of the rates of the SM-like Higgs-boson at the LHC, as well as flavor observables and electroweak precision data. For the SM-type triple Higgs coupling w.r.t. its SM value, $\lambda_{hhh}/\lambda_{hhh}^\mathrm{SM}$, we find allowed intervals of $\sim [-0.5,1.3]$ in type~I and $\sim [0.5,1.0]$ in the other Yukawa types. These allowed ranges have important implications for the experimental determination of this coupling at future collider experiments. We find the coupling $\lambda_{hhH}$ between $\sim -1.5$ and $\sim +1.5$ in the four Yukawa types. For the triple Higgs couplings involving two heavy neutral Higgs bosons, $\lambda_{hHH}$ and $\lambda_{hAA}$ we find values between $\sim -0.5$ and $\sim 16$, and between $\sim -1$ and $\sim 32$ for $\lambda_{hH^+H^-}$. These potentially large values could lead to strongly enhanced production of two Higgs-bosons at the HL-LHC or high-energy lepton colliders.
[ { "created": "Wed, 23 Mar 2022 19:15:54 GMT", "version": "v1" }, { "created": "Thu, 7 Jul 2022 10:36:29 GMT", "version": "v2" } ]
2022-07-08
[ [ "Arco", "F.", "" ], [ "Heinemeyer", "S.", "" ], [ "Herrero", "M. J.", "" ] ]
The measurement of the triple Higgs coupling is one of the main tasks of the (HL-)LHC and future lepton colliders. Similarly, triple Higgs couplings involving BSM Higgs bosons are of high interest. Within the framework of Two Higgs Doublet Models (2HDM) we investigate the allowed ranges for all triple Higgs couplings involving at least one light, SM-like Higgs boson. We present newly the allowed ranges for 2HDM type III and IV and update the results within the type I and II. We take into account theoretical constraints from unitarity and stability, experimental constraints from direct BSM Higgs-boson searches, measurements of the rates of the SM-like Higgs-boson at the LHC, as well as flavor observables and electroweak precision data. For the SM-type triple Higgs coupling w.r.t. its SM value, $\lambda_{hhh}/\lambda_{hhh}^\mathrm{SM}$, we find allowed intervals of $\sim [-0.5,1.3]$ in type~I and $\sim [0.5,1.0]$ in the other Yukawa types. These allowed ranges have important implications for the experimental determination of this coupling at future collider experiments. We find the coupling $\lambda_{hhH}$ between $\sim -1.5$ and $\sim +1.5$ in the four Yukawa types. For the triple Higgs couplings involving two heavy neutral Higgs bosons, $\lambda_{hHH}$ and $\lambda_{hAA}$ we find values between $\sim -0.5$ and $\sim 16$, and between $\sim -1$ and $\sim 32$ for $\lambda_{hH^+H^-}$. These potentially large values could lead to strongly enhanced production of two Higgs-bosons at the HL-LHC or high-energy lepton colliders.
1302.2064
Adrian Dumitru
Adrian Dumitru, Yasushi Nara and Elena Petreska
Magnetic flux loop in high-energy heavy-ion collisions
4 pages, 5 figures; v2: added plot of Z(N) part of loop in fig.1; v3: added magnetic loop for asymmetric projectile/target saturation momenta, estimate of vortex density, and an appendix; v4: corrected outline of perturbative calculation of Wilson loop; to appear in PRD
null
10.1103/PhysRevD.88.054016
RBRC 1008
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the expectation value of a magnetic flux loop in the immediate forward light cone of collisions of heavy nuclei at high energies. Such collisions are characterized by a non-linear scale Q_s where color fields become strong. We find that loops of area greater than ~2/Q_s^2 exhibit area law behavior, which determines the scale of elementary flux excitations ("vortices"). We also estimate the magnetic string tension, sigma_M = 0.12 Q_s^2. By the time t ~ 1/Q_s even small loops satisfy an area law. We describe corrections to the propagator of semi-hard gluons at very early times in the background of fluctuating magnetic fields.
[ { "created": "Fri, 8 Feb 2013 15:18:27 GMT", "version": "v1" }, { "created": "Thu, 14 Feb 2013 13:05:47 GMT", "version": "v2" }, { "created": "Sat, 22 Jun 2013 07:53:17 GMT", "version": "v3" }, { "created": "Mon, 16 Sep 2013 18:57:36 GMT", "version": "v4" } ]
2013-09-25
[ [ "Dumitru", "Adrian", "" ], [ "Nara", "Yasushi", "" ], [ "Petreska", "Elena", "" ] ]
We consider the expectation value of a magnetic flux loop in the immediate forward light cone of collisions of heavy nuclei at high energies. Such collisions are characterized by a non-linear scale Q_s where color fields become strong. We find that loops of area greater than ~2/Q_s^2 exhibit area law behavior, which determines the scale of elementary flux excitations ("vortices"). We also estimate the magnetic string tension, sigma_M = 0.12 Q_s^2. By the time t ~ 1/Q_s even small loops satisfy an area law. We describe corrections to the propagator of semi-hard gluons at very early times in the background of fluctuating magnetic fields.
1405.0389
Wei-Min Yang
Wei-Min Yang
Baryogenesis and Asymmetric Dark Matter from The Left-Right Mirror Symmetric Model
24 pages, 4 figures. arXiv admin note: text overlap with arXiv:1309.1955
null
10.1016/j.nuclphysb.2014.06.002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The paper suggests a left-right mirror symmetric model to account for the baryogenesis and asymmetric dark matter. The model can simultaneously accommodate the standard model, neutrino physics, matter-antimatter asymmetry and dark matter. In particular, it naturally and elegantly explains the origin of the baryon and dark matter asymmetries, and clearly gives the close interrelations of them. In addition, the model predicts a number of interesting results, e.g. the cold dark matter neutrino mass is $3.1$ times the proton mass. It is also feasible and promising to test the model in future experiments.
[ { "created": "Fri, 2 May 2014 12:09:21 GMT", "version": "v1" } ]
2015-06-19
[ [ "Yang", "Wei-Min", "" ] ]
The paper suggests a left-right mirror symmetric model to account for the baryogenesis and asymmetric dark matter. The model can simultaneously accommodate the standard model, neutrino physics, matter-antimatter asymmetry and dark matter. In particular, it naturally and elegantly explains the origin of the baryon and dark matter asymmetries, and clearly gives the close interrelations of them. In addition, the model predicts a number of interesting results, e.g. the cold dark matter neutrino mass is $3.1$ times the proton mass. It is also feasible and promising to test the model in future experiments.
2406.12970
Rayne Liu
Rayne Liu, Wayne Hu, Huangyu Xiao
Warm and Fuzzy Dark Matter: Free Streaming of Wave Dark Matter
16 pages, 11 figures
null
null
FERMILAB-PUB-24-0296-T
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Wave or fuzzy dark matter that is produced with relativistic wavenumbers exhibits free streaming effects analogous to warm or hot particle dark matter with relativistic momenta. Axions produced after inflation provide such a warm or mildly relativistic candidate, where the enhanced suppression and observational bounds are only moderately stronger than that from wave propagation of initially cold axions. More generally, the free streaming damping also impacts isocurvature fluctuations from generation in causally disconnected patches. As coherent spatial fluctuations free stream away they leave incoherent and transient superpositions in their wakes. These multiple wave momentum streams are the wave analogue of particle phase space fluctuations or directional collisionless damping of massive neutrinos or hot dark matter. The observable impact on both adiabatic and isocurvature fluctuations of fuzzy dark matter can differ from their cold dark matter counterparts due to free streaming depending on how warm or hot is their momentum distribution.
[ { "created": "Tue, 18 Jun 2024 18:00:01 GMT", "version": "v1" } ]
2024-06-21
[ [ "Liu", "Rayne", "" ], [ "Hu", "Wayne", "" ], [ "Xiao", "Huangyu", "" ] ]
Wave or fuzzy dark matter that is produced with relativistic wavenumbers exhibits free streaming effects analogous to warm or hot particle dark matter with relativistic momenta. Axions produced after inflation provide such a warm or mildly relativistic candidate, where the enhanced suppression and observational bounds are only moderately stronger than that from wave propagation of initially cold axions. More generally, the free streaming damping also impacts isocurvature fluctuations from generation in causally disconnected patches. As coherent spatial fluctuations free stream away they leave incoherent and transient superpositions in their wakes. These multiple wave momentum streams are the wave analogue of particle phase space fluctuations or directional collisionless damping of massive neutrinos or hot dark matter. The observable impact on both adiabatic and isocurvature fluctuations of fuzzy dark matter can differ from their cold dark matter counterparts due to free streaming depending on how warm or hot is their momentum distribution.
1705.09124
Charilaos Tsagkarakis Dr.
N.G.Antoniou, F.K.Diakonos, X.N.Maintas and C.E.Tsagkarakis
Locating the QCD critical endpoint through finite-size scaling
4 pages, 3 figures
Phys. Rev. D 97, 034015 (2018)
10.1103/PhysRevD.97.034015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Considering the 3d Ising universality class of the QCD critical endpoint we use a universal effective action for the description of the baryon-number density fluctuations around the critical region. Calculating the baryon-number multiplicity moments and determining their scaling with system's size we show that the critical region is very narrow in the direction of the baryon chemical potential $\mu$ and wide in the temperature direction $T$ for $T > T_c$. In this context, published experimental results on local proton density-fluctuation measurements obtained by intermittency analysis in transverse momentum space in NA49 central A+A collisions at $\sqrt{s_{NN}}=17.2$ GeV (A=C,Si,Pb), restrict significantly the location $(\mu_c,T_c)$ of the QCD critical endpoint. The main constraint is provided by the freeze-out chemical potential of the Si+Si system, which shows non-conventional baryon density fluctuations, restricting $(\mu_c,T_c)$ within a narrow domain, $119~\textrm{MeV} \leq T_c \leq 162~\textrm{MeV}$, $252~\textrm{MeV} \leq \mu_c \leq 258~\textrm{MeV}$, of the phase diagram.
[ { "created": "Thu, 25 May 2017 10:57:31 GMT", "version": "v1" } ]
2018-02-21
[ [ "Antoniou", "N. G.", "" ], [ "Diakonos", "F. K.", "" ], [ "Maintas", "X. N.", "" ], [ "Tsagkarakis", "C. E.", "" ] ]
Considering the 3d Ising universality class of the QCD critical endpoint we use a universal effective action for the description of the baryon-number density fluctuations around the critical region. Calculating the baryon-number multiplicity moments and determining their scaling with system's size we show that the critical region is very narrow in the direction of the baryon chemical potential $\mu$ and wide in the temperature direction $T$ for $T > T_c$. In this context, published experimental results on local proton density-fluctuation measurements obtained by intermittency analysis in transverse momentum space in NA49 central A+A collisions at $\sqrt{s_{NN}}=17.2$ GeV (A=C,Si,Pb), restrict significantly the location $(\mu_c,T_c)$ of the QCD critical endpoint. The main constraint is provided by the freeze-out chemical potential of the Si+Si system, which shows non-conventional baryon density fluctuations, restricting $(\mu_c,T_c)$ within a narrow domain, $119~\textrm{MeV} \leq T_c \leq 162~\textrm{MeV}$, $252~\textrm{MeV} \leq \mu_c \leq 258~\textrm{MeV}$, of the phase diagram.
1404.3204
Marco Bonvini
Marco Bonvini, Richard D. Ball, Stefano Forte, Simone Marzani, Giovanni Ridolfi
Updated Higgs cross section at approximate N$^3$LO
5 pages, 1 figure. Updated plot and numerical results after bug fixing in ggHiggs v1.9. Conclusions unaffected. Final version, to be published in Journal of Physics G
J. Phys. G: Nucl. Part. Phys. 41 (2014) 095002
10.1088/0954-3899/41/9/095002
DESY 14-052, IFUM-1026-FT, DCPT/14/62, IPPP/14/31
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We update our estimate of the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order (N$^3$LO) in $\alpha_s$ in view of the recent full computation of the result in the soft limit for infinite top mass, which determines a previously unknown constant. We briefly discuss the phenomenological implications. Results are available through the updated version of the ggHiggs code.
[ { "created": "Fri, 11 Apr 2014 19:59:53 GMT", "version": "v1" }, { "created": "Thu, 17 Apr 2014 19:33:27 GMT", "version": "v2" }, { "created": "Thu, 3 Jul 2014 14:41:49 GMT", "version": "v3" } ]
2014-07-28
[ [ "Bonvini", "Marco", "" ], [ "Ball", "Richard D.", "" ], [ "Forte", "Stefano", "" ], [ "Marzani", "Simone", "" ], [ "Ridolfi", "Giovanni", "" ] ]
We update our estimate of the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order (N$^3$LO) in $\alpha_s$ in view of the recent full computation of the result in the soft limit for infinite top mass, which determines a previously unknown constant. We briefly discuss the phenomenological implications. Results are available through the updated version of the ggHiggs code.
2111.05971
Howard Baer
Howard Baer, Vernon Barger and Robert Wiley Deal
An anthropic solution to the cosmological moduli problem
12 pages plus 5 .png figures; version 2 contains new Fig. 4 with added text
null
null
OU-HEP-211110
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Light moduli fields, gravitationally coupled scalar fields with no classical potential and which are expected to emerge as remnants from string theory compactification, are dangerous to cosmology in that 1. their late-time decays may disrupt successful Big Bang Nucleosynthesis (BBN), 2. they may decay into gravitino pairs which result in violation of BBN constraints or overproduction of lightest SUSY particles (LSPs, assumed to constitute at least a portion of the dark matter in the universe) and 3. they may decay directly into LSPs, resulting in gross DM overproduction. Together, these constitute the cosmological moduli problem (CMP). The combined effects require lightest modulus mass m_\phi >~10^4 TeV, and if the lightest modulus mass m_\phi is correlated with the SUSY breaking scale m_{3/2}, then the underlying SUSY model would be highly unnatural. We present a solution to the CMP wherein the lightest modulus initial field strength \phi_0 is anthropically selected to be \phi_0\sim 10^{-7}m_P by the requirement that the dark matter-to-baryonic matter ratio be not-too-far removed from its present value so that sufficient baryons are present in the universe to create observers. In this case, instead of dark matter overproduction via neutralino reannihilation at the modulus decay temperature, the neutralinos inherit the reduced moduli number density, thereby gaining accord with the measured dark matter relic density.
[ { "created": "Wed, 10 Nov 2021 22:29:43 GMT", "version": "v1" }, { "created": "Mon, 22 Nov 2021 20:03:42 GMT", "version": "v2" }, { "created": "Wed, 22 Dec 2021 21:56:53 GMT", "version": "v3" } ]
2021-12-24
[ [ "Baer", "Howard", "" ], [ "Barger", "Vernon", "" ], [ "Deal", "Robert Wiley", "" ] ]
Light moduli fields, gravitationally coupled scalar fields with no classical potential and which are expected to emerge as remnants from string theory compactification, are dangerous to cosmology in that 1. their late-time decays may disrupt successful Big Bang Nucleosynthesis (BBN), 2. they may decay into gravitino pairs which result in violation of BBN constraints or overproduction of lightest SUSY particles (LSPs, assumed to constitute at least a portion of the dark matter in the universe) and 3. they may decay directly into LSPs, resulting in gross DM overproduction. Together, these constitute the cosmological moduli problem (CMP). The combined effects require lightest modulus mass m_\phi >~10^4 TeV, and if the lightest modulus mass m_\phi is correlated with the SUSY breaking scale m_{3/2}, then the underlying SUSY model would be highly unnatural. We present a solution to the CMP wherein the lightest modulus initial field strength \phi_0 is anthropically selected to be \phi_0\sim 10^{-7}m_P by the requirement that the dark matter-to-baryonic matter ratio be not-too-far removed from its present value so that sufficient baryons are present in the universe to create observers. In this case, instead of dark matter overproduction via neutralino reannihilation at the modulus decay temperature, the neutralinos inherit the reduced moduli number density, thereby gaining accord with the measured dark matter relic density.
2004.01657
S. Weinzierl
Robin Baumeister and Stefan Weinzierl
Cutoff dependence of the thrust peak position in the dipole shower
13 pages, v2: version to be published
null
10.1140/epjc/s10052-020-8425-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse the dependence of the peak position of the thrust distribution on the cutoff value in the Nagy-Soper dipole shower. We compare the outcome of the parton shower simulations to a relation of the dependence from an analytic computation, derived within soft-collinear effective theory. We show that the result of the parton shower simulations and the analytic computation are in good agreement.
[ { "created": "Fri, 3 Apr 2020 16:26:25 GMT", "version": "v1" }, { "created": "Mon, 7 Sep 2020 08:17:31 GMT", "version": "v2" } ]
2020-10-28
[ [ "Baumeister", "Robin", "" ], [ "Weinzierl", "Stefan", "" ] ]
We analyse the dependence of the peak position of the thrust distribution on the cutoff value in the Nagy-Soper dipole shower. We compare the outcome of the parton shower simulations to a relation of the dependence from an analytic computation, derived within soft-collinear effective theory. We show that the result of the parton shower simulations and the analytic computation are in good agreement.
1512.04913
Yann Mambrini
Yann Mambrini, Giorgio Arcadi and Abdelhak Djouadi
The LHC diphoton resonance and dark matter
9 pages, 5 figures, typos corrected, text improved, reference added and analysis extended by one more scenario; conclusions unchanged
null
10.1016/j.physletb.2016.02.049
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A Higgs-like resonance with a mass of approximately 750 GeV has recently been observed at the LHC in its diphoton decay. If this state is not simply a statistical fluctuation which will disappear with more data, it will have important implications not only for particle physics but also for cosmology. In this note, we analyze the implications of such a resonance for the dark matter (DM). Assuming a spin 1/2 DM particle, we first verify that indeed the correct relic density can be obtain for a wide range of the particle mass and weak scale coupling that are compatible with present data. We then show that the combination of near future direct and indirect detection experiments will allow to probe the CP-nature of the mediator resonance, i.e. check whether it is a scalar or a pseudoscalar like particle.
[ { "created": "Tue, 15 Dec 2015 20:05:04 GMT", "version": "v1" }, { "created": "Mon, 21 Dec 2015 18:40:06 GMT", "version": "v2" } ]
2016-03-23
[ [ "Mambrini", "Yann", "" ], [ "Arcadi", "Giorgio", "" ], [ "Djouadi", "Abdelhak", "" ] ]
A Higgs-like resonance with a mass of approximately 750 GeV has recently been observed at the LHC in its diphoton decay. If this state is not simply a statistical fluctuation which will disappear with more data, it will have important implications not only for particle physics but also for cosmology. In this note, we analyze the implications of such a resonance for the dark matter (DM). Assuming a spin 1/2 DM particle, we first verify that indeed the correct relic density can be obtain for a wide range of the particle mass and weak scale coupling that are compatible with present data. We then show that the combination of near future direct and indirect detection experiments will allow to probe the CP-nature of the mediator resonance, i.e. check whether it is a scalar or a pseudoscalar like particle.
1403.6299
Araki Ken-Ji
Ken-Ji Araki, Keisuke Ohtani, Philipp Gubler, Makoto Oka
QCD sum rules on the complex Borel plane
22 pages, 10 figures
null
10.1093/ptep/ptu092
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Borel transformed QCD sum rules conventionally use a real valued parameter (the Borel mass) for specifying the exponential weight over which hadronic spectral functions are averaged. In this paper, it is shown that the Borel mass can be generalized to have complex values and that new classes of sum rules can be derived from the resulting averages over the spectral functions. The real and imaginary parts of these novel sum rules turn out to have damped oscillating kernels and potentially contain a larger amount of information on the hadronic spectrum than the real valued QCD sum rules. As a first practical test, we have formulated the complex Borel sum rules for the phi meson channel and have analyzed them using the maximum entropy method, by which we can extract the most probable spectral function from the sum rules without strong assumptions on its functional form. As a result, it is demonstrated that, compared to earlier studies, the complex valued sum rules allow us to extract the spectral function with a significantly improved resolution and thus to study more detailed structures of the hadronic spectrum than previously possible.
[ { "created": "Tue, 25 Mar 2014 11:08:44 GMT", "version": "v1" } ]
2014-07-09
[ [ "Araki", "Ken-Ji", "" ], [ "Ohtani", "Keisuke", "" ], [ "Gubler", "Philipp", "" ], [ "Oka", "Makoto", "" ] ]
Borel transformed QCD sum rules conventionally use a real valued parameter (the Borel mass) for specifying the exponential weight over which hadronic spectral functions are averaged. In this paper, it is shown that the Borel mass can be generalized to have complex values and that new classes of sum rules can be derived from the resulting averages over the spectral functions. The real and imaginary parts of these novel sum rules turn out to have damped oscillating kernels and potentially contain a larger amount of information on the hadronic spectrum than the real valued QCD sum rules. As a first practical test, we have formulated the complex Borel sum rules for the phi meson channel and have analyzed them using the maximum entropy method, by which we can extract the most probable spectral function from the sum rules without strong assumptions on its functional form. As a result, it is demonstrated that, compared to earlier studies, the complex valued sum rules allow us to extract the spectral function with a significantly improved resolution and thus to study more detailed structures of the hadronic spectrum than previously possible.
1810.10796
Jihn E. Kim
Jihn E. Kim
R-parity from string compactification
21 pages with 3 figures
Phys. Rev. D 99, 093004 (2019)
10.1103/PhysRevD.99.093004
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we embed the $\Z_{4R}$ parity as a discrete subgroup of a global symmetry \UoR\,obtained from $\Z_{12-I}$ compactification of heterotic string $\EE8$. A part of \UoR\,transformation is the shift of the anticommuting variable $\vartheta$ to $e^{i\alpha}\vartheta$ which necessarily incoorporate the transformation of internal space coordinate. Out of six internal spaces, we identify three U(1)'s whose charges are denoted as $Q_{18},Q_{20}$, and $Q_{22}$. The \UoR~is defined as \UEE$\times$\UKK~where \UEE~is the part from $\EE8$ and \UKK~is the part generated by $Q_{18},Q_{20}$, and $Q_{22}$. We propose a method to define a \UoR~direction. The needed vacuum expectation values for breaking gauge U(1)'s except U(1)$_Y$ of the standard model carry \UoR~charge 4 modulo 4 such that \UoR~is broken down to $\Z_{4R}$ at the grand unification scale. $\Z_{4R}$ is broken to $\Z_{2R}$ between the intermediate ($\sim 10^{11\,}\gev$) and the electroweak scales ($100\,\gev\sim 1\,\tev$). The conditions we impose are proton longevity, a large top quark mass, and acceptable magnitudes for the $\mu$ term and neutrino masses.
[ { "created": "Thu, 25 Oct 2018 09:14:12 GMT", "version": "v1" }, { "created": "Mon, 11 Feb 2019 23:33:03 GMT", "version": "v2" } ]
2019-05-22
[ [ "Kim", "Jihn E.", "" ] ]
In this paper, we embed the $\Z_{4R}$ parity as a discrete subgroup of a global symmetry \UoR\,obtained from $\Z_{12-I}$ compactification of heterotic string $\EE8$. A part of \UoR\,transformation is the shift of the anticommuting variable $\vartheta$ to $e^{i\alpha}\vartheta$ which necessarily incoorporate the transformation of internal space coordinate. Out of six internal spaces, we identify three U(1)'s whose charges are denoted as $Q_{18},Q_{20}$, and $Q_{22}$. The \UoR~is defined as \UEE$\times$\UKK~where \UEE~is the part from $\EE8$ and \UKK~is the part generated by $Q_{18},Q_{20}$, and $Q_{22}$. We propose a method to define a \UoR~direction. The needed vacuum expectation values for breaking gauge U(1)'s except U(1)$_Y$ of the standard model carry \UoR~charge 4 modulo 4 such that \UoR~is broken down to $\Z_{4R}$ at the grand unification scale. $\Z_{4R}$ is broken to $\Z_{2R}$ between the intermediate ($\sim 10^{11\,}\gev$) and the electroweak scales ($100\,\gev\sim 1\,\tev$). The conditions we impose are proton longevity, a large top quark mass, and acceptable magnitudes for the $\mu$ term and neutrino masses.
1804.10698
Ernesto Arganda
Ernesto Arganda, Victor Martin-Lozano, Anibal D. Medina, Nicol\'as Mileo
Potential discovery of staus through heavy Higgs boson decays at the LHC
11 pages, 3 figures, 3 tables. This version v2 matches the manuscript published in JHEP
JHEP 1809 (2018) 056
10.1007/JHEP09(2018)056
BONN-TH-2018-06, IFT-UAM/CSIC-18-037
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we present a new search strategy for the discovery of staus at the LHC in the context of the minimal supersymmetric standard model. The search profits from the large s-channel $b$-quark annihilation production of the heavy CP-even and CP-odd Higgs bosons (H/A) which can be attained in regions of $\tan\beta\gg 1$ that avoid the stringent $H/A \to \tau^+ \tau^-$ searches via decays into stau pairs. We also focus on regions where the staus branching ratios are dominated by the decays into a tau lepton and the lightest neutralino. Thus the experimental signature consists of final states made up of a tau-lepton pair plus large missing transverse energy. We take advantage of the large stau-pair production cross sections via heavy Higgs boson decays, which are between one or two orders of magnitude larger than the usual electroweak production cross sections for staus. A set of basic cuts allow us to obtain significances of the signal over the SM backgrounds at the discovery level (5 standard deviations) in the next LHC run with a center-of-mass energy of 14 TeV and a total integrated luminosity of only 100 fb$^{-1}$.
[ { "created": "Fri, 27 Apr 2018 21:52:40 GMT", "version": "v1" }, { "created": "Tue, 18 Sep 2018 12:56:49 GMT", "version": "v2" } ]
2018-09-19
[ [ "Arganda", "Ernesto", "" ], [ "Martin-Lozano", "Victor", "" ], [ "Medina", "Anibal D.", "" ], [ "Mileo", "Nicolás", "" ] ]
In this work we present a new search strategy for the discovery of staus at the LHC in the context of the minimal supersymmetric standard model. The search profits from the large s-channel $b$-quark annihilation production of the heavy CP-even and CP-odd Higgs bosons (H/A) which can be attained in regions of $\tan\beta\gg 1$ that avoid the stringent $H/A \to \tau^+ \tau^-$ searches via decays into stau pairs. We also focus on regions where the staus branching ratios are dominated by the decays into a tau lepton and the lightest neutralino. Thus the experimental signature consists of final states made up of a tau-lepton pair plus large missing transverse energy. We take advantage of the large stau-pair production cross sections via heavy Higgs boson decays, which are between one or two orders of magnitude larger than the usual electroweak production cross sections for staus. A set of basic cuts allow us to obtain significances of the signal over the SM backgrounds at the discovery level (5 standard deviations) in the next LHC run with a center-of-mass energy of 14 TeV and a total integrated luminosity of only 100 fb$^{-1}$.
hep-ph/9405239
null
Hisakazu Minakata and Hiroshi Nunokawa
Testing the Principle of Equivalence by Solar Neutrinos
Latex, 17 pages + 6 uuencoded postscript figures, KEK-TH-396, TMUP-HEL-9402 (unnecessary one reference was removed)
Phys.Rev. D51 (1995) 6625-6634
10.1103/PhysRevD.51.6625
null
hep-ph
null
We discuss the possibility of testing the principle of equivalence with solar neutrinos. If there exists a violation of the equivalence principle quarks and leptons with different flavors may not universally couple with gravity. The method we discuss employs a quantum mechanical phenomenon of neutrino oscillation to probe into the non-universality of the gravitational couplings of neutrinos. We develop an appropriate formalism to deal with neutrino propagation under the weak gravitational fields of the sun in the presence of the flavor mixing. We point out that solar neutrino observation by the next generation water Cherenkov detectors can improve the existing bound on violation of the equivalence principle by 3-4 orders of magnitude if the nonadiabatic Mikheyev-Smirnov-Wolfenstein mechanism is the solution to the solar neutrino problem.
[ { "created": "Fri, 6 May 1994 00:43:36 GMT", "version": "v1" }, { "created": "Fri, 6 May 1994 18:07:19 GMT", "version": "v2" } ]
2009-10-28
[ [ "Minakata", "Hisakazu", "" ], [ "Nunokawa", "Hiroshi", "" ] ]
We discuss the possibility of testing the principle of equivalence with solar neutrinos. If there exists a violation of the equivalence principle quarks and leptons with different flavors may not universally couple with gravity. The method we discuss employs a quantum mechanical phenomenon of neutrino oscillation to probe into the non-universality of the gravitational couplings of neutrinos. We develop an appropriate formalism to deal with neutrino propagation under the weak gravitational fields of the sun in the presence of the flavor mixing. We point out that solar neutrino observation by the next generation water Cherenkov detectors can improve the existing bound on violation of the equivalence principle by 3-4 orders of magnitude if the nonadiabatic Mikheyev-Smirnov-Wolfenstein mechanism is the solution to the solar neutrino problem.
2104.00685
Jared Reiten
Michael Lublinsky, Jared Reiten, and Andrey V. Sadofyev
Magnetic monopole in a chiral plasma: chiral dyon
9 pages, 2 figures. v2: Journal version
Phys. Rev. D 103, 125017 (2021)
10.1103/PhysRevD.103.125017
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The placement of a magnetic monopole into an electrically-neutral chiral plasma with a non-zero axial density results in an electric polarization of the matter. The electric current produced by the chiral magnetic effect is balanced by charge diffusion and Ohmic dissipation, which generates a non-trivial charge distribution. In turn, the latter induces a separation of chiralities along the magnetic field of the monopole due to the chiral separation effect. We find the stationary states of such a system, with vanishing total electric current and stationary axial current balanced by the chiral anomaly. In this solution, the monopole becomes "dressed" with an electric charge that is proportional to the averaged chiral density of the matter -- forming a chiral dyon. The interplay between the chiral effects on the one hand, and presence of magnetic field of the monopole on the other, may affect the evolution of the monopole density in the early Universe, contribute to the process of baryogenesis, and can also be instrumental for detection of relic monopoles using chiral materials.
[ { "created": "Thu, 1 Apr 2021 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 22 Jun 2021 15:55:13 GMT", "version": "v2" } ]
2021-06-23
[ [ "Lublinsky", "Michael", "" ], [ "Reiten", "Jared", "" ], [ "Sadofyev", "Andrey V.", "" ] ]
The placement of a magnetic monopole into an electrically-neutral chiral plasma with a non-zero axial density results in an electric polarization of the matter. The electric current produced by the chiral magnetic effect is balanced by charge diffusion and Ohmic dissipation, which generates a non-trivial charge distribution. In turn, the latter induces a separation of chiralities along the magnetic field of the monopole due to the chiral separation effect. We find the stationary states of such a system, with vanishing total electric current and stationary axial current balanced by the chiral anomaly. In this solution, the monopole becomes "dressed" with an electric charge that is proportional to the averaged chiral density of the matter -- forming a chiral dyon. The interplay between the chiral effects on the one hand, and presence of magnetic field of the monopole on the other, may affect the evolution of the monopole density in the early Universe, contribute to the process of baryogenesis, and can also be instrumental for detection of relic monopoles using chiral materials.
hep-ph/9705259
Carlos Alberto Salgado Lopez
E. G. Ferreiro and C. Pajares
Strangeness enhancement in the String Fusion Model Code
LaTeX, 19 pages, 4 Postscript figures
J.Phys.G23:1961-1968,1997
10.1088/0954-3899/23/12/021
US-FT/14-97
hep-ph
null
String Fusion Model Code results for Pb--Pb central collisions at SPS energies including the string fusion interaction mechanism are compared to the last experimental data. Predictions for RHIC energies are also presented. On the other hand, the evolution of the strangeness enhancement ratio $E_s=\frac{<\Lambda>+4<K_s^0>}{3<\pi^->}$ with the energy and with the atomic number of participant nuclei is discussed.
[ { "created": "Wed, 7 May 1997 17:12:23 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ferreiro", "E. G.", "" ], [ "Pajares", "C.", "" ] ]
String Fusion Model Code results for Pb--Pb central collisions at SPS energies including the string fusion interaction mechanism are compared to the last experimental data. Predictions for RHIC energies are also presented. On the other hand, the evolution of the strangeness enhancement ratio $E_s=\frac{<\Lambda>+4<K_s^0>}{3<\pi^->}$ with the energy and with the atomic number of participant nuclei is discussed.
hep-ph/9810222
null
Hsiang-nan Li
Perturbative QCD analysis of exclusive $B$ meson decays
numerical outcomes are revised
null
null
NCKU-HEP-98-13
hep-ph
null
We review the perturbative QCD formalism for exclusive heavy meson decays, concentrating on the three-scale factorization theorem for nonleptonic processes. The formalism is then extended to the radiative decay $B\to K^*\gamma$, which occurs through penguin diagrams. It is observed that the contributions from the operators other than the penguin one $b\to s\gamma$ are not negligible. From the best fit to the experimental data of the branching ratio ${\cal B}(B\to K^*\gamma)$, we extract the $B$ meson wave function, which possesses a sharp peak in the region with a small momentum fraction.
[ { "created": "Fri, 2 Oct 1998 09:29:19 GMT", "version": "v1" }, { "created": "Tue, 27 Oct 1998 09:33:50 GMT", "version": "v2" } ]
2007-05-23
[ [ "Li", "Hsiang-nan", "" ] ]
We review the perturbative QCD formalism for exclusive heavy meson decays, concentrating on the three-scale factorization theorem for nonleptonic processes. The formalism is then extended to the radiative decay $B\to K^*\gamma$, which occurs through penguin diagrams. It is observed that the contributions from the operators other than the penguin one $b\to s\gamma$ are not negligible. From the best fit to the experimental data of the branching ratio ${\cal B}(B\to K^*\gamma)$, we extract the $B$ meson wave function, which possesses a sharp peak in the region with a small momentum fraction.
1510.06934
Andrey Tarasov
Andrey Tarasov
Evolution of gluon TMDs from small to moderate x
12 pages, conference contribution, QCD evolution 2015, Jefferson Lab, Newport News, 26 - 30 May, 2015
null
null
JLAB-THY-15-2155
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently we obtained an evolution equation of gluon TMDs, which addresses a problem of unification of different kinematic regimes. It describes evolution in the whole range of Bjorken $x_B$ and the whole range of transverse momentum $k_\perp$. In this notes I study different limits of this evolution equation and show how it yields several well-known and some previously unknown results.
[ { "created": "Fri, 23 Oct 2015 14:02:50 GMT", "version": "v1" } ]
2015-10-26
[ [ "Tarasov", "Andrey", "" ] ]
Recently we obtained an evolution equation of gluon TMDs, which addresses a problem of unification of different kinematic regimes. It describes evolution in the whole range of Bjorken $x_B$ and the whole range of transverse momentum $k_\perp$. In this notes I study different limits of this evolution equation and show how it yields several well-known and some previously unknown results.
hep-ph/0406094
Santi Peris
O. Cata and S. Peris (IFAE and UAB)
Kaon mixing and the charm mass
20 pages, 5 figures. Typos fixed
JHEP0407:079,2004
10.1088/1126-6708/2004/07/079
null
hep-ph hep-lat
null
We study contributions to the Delta S=2 weak Chiral Lagrangian producing K0-K0bar mixing which are not enhanced by the charm mass. For the real part, these contributions turn out to be related to the box diagram with up quarks but, unlike in perturbation theory, they do not vanish in the limit m_u->0. They increase the leading contribution to the K_L-K_S mass difference by ~10%. This means that short distances amount to (90+-15)% of this mass difference. For the imaginary part, we find a correction to the lambda_c^2 m_c^2 term of -5% from the integration of charm, which is a small contribution to epsilon_K. The calculation is done in the large-Nc limit and we show explicitly how to match short and long distances.
[ { "created": "Tue, 8 Jun 2004 13:06:55 GMT", "version": "v1" }, { "created": "Wed, 15 Sep 2004 12:23:47 GMT", "version": "v2" } ]
2009-11-10
[ [ "Cata", "O.", "", "IFAE and UAB" ], [ "Peris", "S.", "", "IFAE and UAB" ] ]
We study contributions to the Delta S=2 weak Chiral Lagrangian producing K0-K0bar mixing which are not enhanced by the charm mass. For the real part, these contributions turn out to be related to the box diagram with up quarks but, unlike in perturbation theory, they do not vanish in the limit m_u->0. They increase the leading contribution to the K_L-K_S mass difference by ~10%. This means that short distances amount to (90+-15)% of this mass difference. For the imaginary part, we find a correction to the lambda_c^2 m_c^2 term of -5% from the integration of charm, which is a small contribution to epsilon_K. The calculation is done in the large-Nc limit and we show explicitly how to match short and long distances.
1812.09052
Alexander Belyaev
Alexander Belyaev, Azaria Coupe, Nick Evans, Marc Scott
Any Room Left for Technicolor? Dilepton Searches at the LHC and Beyond
9 pages, 3 figures
Phys. Rev. D 99, 095006 (2019)
10.1103/PhysRevD.99.095006
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Precision electroweak data, a light higgs and LHC searches for new spin one particles are all very constraining on technicolor models. We use a holographic model of walking techicolor (WTC) gauge dynamics, tuned to produce a light higgs and low $S$ parameter, to estimate the range of possible vector($\rho$) and pseudo-vector($A$) resonance masses and couplings as a function of the number of colours and the number of flavours of techni-singlet and techni-doublet quarks. The resulting models predict techni-hadron masses and couplings above the current limits from dilepton resonance searches at the LHC because their masses are enhanced by the strong coupling extending into the multi-TeV range, while couplings to Standard Model fermions are partly suppressed. The models emphasize the contortions needed to continue to realize technicolor, {the need to explore new signatures beyond dilepton for LHC and also motivate a 100 TeV proton collider.
[ { "created": "Fri, 21 Dec 2018 11:14:22 GMT", "version": "v1" } ]
2019-05-15
[ [ "Belyaev", "Alexander", "" ], [ "Coupe", "Azaria", "" ], [ "Evans", "Nick", "" ], [ "Scott", "Marc", "" ] ]
Precision electroweak data, a light higgs and LHC searches for new spin one particles are all very constraining on technicolor models. We use a holographic model of walking techicolor (WTC) gauge dynamics, tuned to produce a light higgs and low $S$ parameter, to estimate the range of possible vector($\rho$) and pseudo-vector($A$) resonance masses and couplings as a function of the number of colours and the number of flavours of techni-singlet and techni-doublet quarks. The resulting models predict techni-hadron masses and couplings above the current limits from dilepton resonance searches at the LHC because their masses are enhanced by the strong coupling extending into the multi-TeV range, while couplings to Standard Model fermions are partly suppressed. The models emphasize the contortions needed to continue to realize technicolor, {the need to explore new signatures beyond dilepton for LHC and also motivate a 100 TeV proton collider.
1407.4134
Jonathan Kozaczuk
Jonathan Kozaczuk, Stefano Profumo, Laurel Stephenson Haskins, Carroll L. Wainwright
Cosmological Phase Transitions and their Properties in the NMSSM
49 pages + 2 appendices, 6 figures. v2: Minor corrections; matches version published in JHEP
JHEP 1501 (2015) 144
10.1007/JHEP01(2015)144
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study cosmological phase transitions in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) in light of the Higgs discovery. We use an effective field theory approach to calculate the finite temperature effective potential, focusing on regions with significant tree-level contributions to the Higgs mass, a viable neutralino dark matter candidate, 1-2 TeV stops, and with the remaining particle spectrum compatible with current LHC searches and results. The phase transition structure in viable regions of parameter space exhibits a rich phenomenology, potentially giving rise to one- or two-step first-order phase transitions in the singlet and/or $SU(2)$ directions. We compute several parameters pertaining to the bubble wall profile, including the bubble wall width and $\Delta\beta$ (the variation of the ratio in Higgs vacuum expectation values across the wall). These quantities can vary significantly across small regions of parameter space and can be promising for successful electroweak baryogenesis. We estimate the wall velocity microphysically, taking into account the various sources of friction acting on the expanding bubble wall. Ultra-relativistic solutions to the bubble wall equations of motion typically exist when the electroweak phase transition features substantial supercooling. For somewhat weaker transitions, the bubble wall instead tends to be sub-luminal and, in fact, likely sub-sonic, suggesting that successful electroweak baryogenesis may indeed occur in regions of the NMSSM compatible with the Higgs discovery.
[ { "created": "Tue, 15 Jul 2014 20:05:40 GMT", "version": "v1" }, { "created": "Wed, 11 Mar 2015 17:42:23 GMT", "version": "v2" } ]
2015-03-12
[ [ "Kozaczuk", "Jonathan", "" ], [ "Profumo", "Stefano", "" ], [ "Haskins", "Laurel Stephenson", "" ], [ "Wainwright", "Carroll L.", "" ] ]
We study cosmological phase transitions in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) in light of the Higgs discovery. We use an effective field theory approach to calculate the finite temperature effective potential, focusing on regions with significant tree-level contributions to the Higgs mass, a viable neutralino dark matter candidate, 1-2 TeV stops, and with the remaining particle spectrum compatible with current LHC searches and results. The phase transition structure in viable regions of parameter space exhibits a rich phenomenology, potentially giving rise to one- or two-step first-order phase transitions in the singlet and/or $SU(2)$ directions. We compute several parameters pertaining to the bubble wall profile, including the bubble wall width and $\Delta\beta$ (the variation of the ratio in Higgs vacuum expectation values across the wall). These quantities can vary significantly across small regions of parameter space and can be promising for successful electroweak baryogenesis. We estimate the wall velocity microphysically, taking into account the various sources of friction acting on the expanding bubble wall. Ultra-relativistic solutions to the bubble wall equations of motion typically exist when the electroweak phase transition features substantial supercooling. For somewhat weaker transitions, the bubble wall instead tends to be sub-luminal and, in fact, likely sub-sonic, suggesting that successful electroweak baryogenesis may indeed occur in regions of the NMSSM compatible with the Higgs discovery.
hep-ph/0104212
Euro Spallucci
S. Ansoldi, A. Aurilia, E. Spallucci
Vacuum Bubbles Nucleation and Dark Matter Production through Gauge Symmetry Rearrangement
22pages, RevTeX, no figures; accepted for publication in Phys.Rev.D
Phys.Rev. D64 (2001) 025008
10.1103/PhysRevD.64.025008
null
hep-ph hep-th
null
Modern particle physics and cosmology support the idea that a background of invisible material pervades the whole universe, and identify in the cosmic vacuum the ultimate source of matter-energy, both seen and unseen. Within the framework of the theory of fundamental relativistic membranes, we suggest a self-consistent, vacuum energy-driven mechanism for dark matter creation through gauge symmetry rearrangement.
[ { "created": "Sat, 21 Apr 2001 06:52:00 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ansoldi", "S.", "" ], [ "Aurilia", "A.", "" ], [ "Spallucci", "E.", "" ] ]
Modern particle physics and cosmology support the idea that a background of invisible material pervades the whole universe, and identify in the cosmic vacuum the ultimate source of matter-energy, both seen and unseen. Within the framework of the theory of fundamental relativistic membranes, we suggest a self-consistent, vacuum energy-driven mechanism for dark matter creation through gauge symmetry rearrangement.
hep-ph/9908273
Graham Shore
G.M. Shore
$\eta'\to\gamma\gamma$ and the topological susceptibility
4 pages, LaTeX, uses espcrc2.sty. To appear in Proceedings, QCD99 Montpellier
Nucl.Phys.Proc.Suppl. 86 (2000) 368-371
10.1016/S0920-5632(00)00588-0
CERN-TH/99-238, SWAT/99-235
hep-ph
null
The radiative decays $\eta'(\eta)\rta\gamma\gamma$ are discussed. The modifications of the conventional PCAC formulae due to the gluonic contribution to the flavour singlet axial anomaly are given. The decay constants satisfy a modified Dashen formula which generalises the Witten--Veneziano formula for the mass of the $\eta'$. It is shown how the topological susceptibility in QCD with massive, dynamical quarks may be extracted from measurements of $\eta'(\eta)\rta\gamma\gamma$.
[ { "created": "Thu, 5 Aug 1999 15:29:12 GMT", "version": "v1" } ]
2009-10-31
[ [ "Shore", "G. M.", "" ] ]
The radiative decays $\eta'(\eta)\rta\gamma\gamma$ are discussed. The modifications of the conventional PCAC formulae due to the gluonic contribution to the flavour singlet axial anomaly are given. The decay constants satisfy a modified Dashen formula which generalises the Witten--Veneziano formula for the mass of the $\eta'$. It is shown how the topological susceptibility in QCD with massive, dynamical quarks may be extracted from measurements of $\eta'(\eta)\rta\gamma\gamma$.
1604.00537
Ricardo Farias
D\'erick S. Rosa, R. L. S. Farias and Rudnei O. Ramos
Reliability of the optimized perturbation theory in the 0-dimensional $O(N)$ scalar field model
38 pages, 13 figures, v2 Physica A version
Physica A 464 (2016) 11
10.1016/j.physa.2016.07.067
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the reliability of the Optimized Perturbation Theory (OPT) in the context of the 0-dimensional $O(N)$ scalar field model. The effective potential, the self-energy and the 1PI four-point Green's function for the model are computed using different optimization schemes and the results contrasted to the exact results for the model. Our results are also compared to those obtained with the $1/N$-expansion and with those from ordinary perturbation theory. The OPT results are shown to be stable even at large couplings and to have better convergence properties than the ones produced in the $1/N$-expansion. It is also shown that the principle of minimal sensitive optimization procedure used in conjunction with the OPT method tends to always produce better results, in particular when applied directly to the self-energy.
[ { "created": "Sat, 2 Apr 2016 17:53:35 GMT", "version": "v1" }, { "created": "Fri, 22 Jul 2016 13:09:28 GMT", "version": "v2" } ]
2016-10-10
[ [ "Rosa", "Dérick S.", "" ], [ "Farias", "R. L. S.", "" ], [ "Ramos", "Rudnei O.", "" ] ]
We address the reliability of the Optimized Perturbation Theory (OPT) in the context of the 0-dimensional $O(N)$ scalar field model. The effective potential, the self-energy and the 1PI four-point Green's function for the model are computed using different optimization schemes and the results contrasted to the exact results for the model. Our results are also compared to those obtained with the $1/N$-expansion and with those from ordinary perturbation theory. The OPT results are shown to be stable even at large couplings and to have better convergence properties than the ones produced in the $1/N$-expansion. It is also shown that the principle of minimal sensitive optimization procedure used in conjunction with the OPT method tends to always produce better results, in particular when applied directly to the self-energy.
2104.03351
Nivedita Ghosh
Indrani Chakraborty, Dilip Kumar Ghosh, Nivedita Ghosh and Santosh Kumar Rai
Dark Matter and Collider Searches in $S_3$-Symmetric 2HDM with Vector Like Leptons
51 Pages, 10 Captioned figures and 20 Tables, minor changes made in the manuscript, version accepted for publication in The European Physical Journal C journal
null
10.1140/epjc/s10052-021-09446-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the $S_3$-symmetric two Higgs doublet model by adding two generations of vector like leptons (VLL) which are odd under a discrete $Z_2$ symmetry. The lightest neutral component of the VLL acts as a dark matter (DM) whereas the full VLL set belongs to a dark sector with no mixings allowed with the standard model fermions. We analyse the model in light of dark matter and collider searches. We show that the DM is compatible with the current relic density data as well as satisfying all direct and indirect dark matter search constraints. We choose some representative points in the model parameter space allowed by all aforementioned dark matter constraints and present a detailed collider analysis of multi-lepton signal viz. the mono-lepton, di-lepton, tri-lepton and four-lepton along with missing transverse energy in the final state using both the cut-based analysis and multivariate analysis respectively at the high luminosity 14 TeV LHC run.
[ { "created": "Wed, 7 Apr 2021 19:05:35 GMT", "version": "v1" }, { "created": "Sat, 17 Jul 2021 15:35:43 GMT", "version": "v2" } ]
2021-07-20
[ [ "Chakraborty", "Indrani", "" ], [ "Ghosh", "Dilip Kumar", "" ], [ "Ghosh", "Nivedita", "" ], [ "Rai", "Santosh Kumar", "" ] ]
We study the $S_3$-symmetric two Higgs doublet model by adding two generations of vector like leptons (VLL) which are odd under a discrete $Z_2$ symmetry. The lightest neutral component of the VLL acts as a dark matter (DM) whereas the full VLL set belongs to a dark sector with no mixings allowed with the standard model fermions. We analyse the model in light of dark matter and collider searches. We show that the DM is compatible with the current relic density data as well as satisfying all direct and indirect dark matter search constraints. We choose some representative points in the model parameter space allowed by all aforementioned dark matter constraints and present a detailed collider analysis of multi-lepton signal viz. the mono-lepton, di-lepton, tri-lepton and four-lepton along with missing transverse energy in the final state using both the cut-based analysis and multivariate analysis respectively at the high luminosity 14 TeV LHC run.
1103.3661
Ergash Tursunov M.
E.M. Tursunov
A periodic table for the excited Nucleon and Delta spectrum in a relativistic chiral quark model
7 pages; text corrected and extended
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A possibility of the construction of a periodic table for the excited baryon spectrum is shown in the frame of a relativistic chiral quark model based on selection rules derived from the one-pion exchange mechanism. It is shown that all the $N^*$ and $\Delta^*$ resonances appearing in the $\pi N$ scattering data and strongly coupling to the $\pi N$ channel are identified with the orbital configurations $(1S_{1/2})^2(nlj)$. Baryon resonances corresponding to the orbital configuration with two valence quarks in excited states couple strongly to the $\pi \pi N$-channel, but not to the $\pi N$ channel. At low energy scale up to 2000 MeV, the obtained numerical estimations for the SU(2) baryon states (up to and including F-wave $N^*$ and $\Delta^*$ resonances) within the schematic periodic table are mostly consistent with the experimental data. It is argued that due-to the overestimation of the ground state N(939) and Roper resonance N(1440) almost by the same amount and that the Roper resonance is a radial excitation of the N(939), the "lowering mechanism" for the both baryon states must be the same. The same mechanism is expected in the $\Delta$ sector. At higher energies, where the experimental data are poor, we can extend our model schematically and predict seven new $N^*$ and four $\Delta^*$ resonances with larger spin values.
[ { "created": "Fri, 18 Mar 2011 16:42:05 GMT", "version": "v1" }, { "created": "Wed, 30 Mar 2011 09:22:38 GMT", "version": "v2" }, { "created": "Fri, 22 Jul 2011 14:26:11 GMT", "version": "v3" }, { "created": "Fri, 28 Oct 2011 14:37:03 GMT", "version": "v4" } ]
2011-10-31
[ [ "Tursunov", "E. M.", "" ] ]
A possibility of the construction of a periodic table for the excited baryon spectrum is shown in the frame of a relativistic chiral quark model based on selection rules derived from the one-pion exchange mechanism. It is shown that all the $N^*$ and $\Delta^*$ resonances appearing in the $\pi N$ scattering data and strongly coupling to the $\pi N$ channel are identified with the orbital configurations $(1S_{1/2})^2(nlj)$. Baryon resonances corresponding to the orbital configuration with two valence quarks in excited states couple strongly to the $\pi \pi N$-channel, but not to the $\pi N$ channel. At low energy scale up to 2000 MeV, the obtained numerical estimations for the SU(2) baryon states (up to and including F-wave $N^*$ and $\Delta^*$ resonances) within the schematic periodic table are mostly consistent with the experimental data. It is argued that due-to the overestimation of the ground state N(939) and Roper resonance N(1440) almost by the same amount and that the Roper resonance is a radial excitation of the N(939), the "lowering mechanism" for the both baryon states must be the same. The same mechanism is expected in the $\Delta$ sector. At higher energies, where the experimental data are poor, we can extend our model schematically and predict seven new $N^*$ and four $\Delta^*$ resonances with larger spin values.
1609.06502
Ushoshi Maitra
Abhishek M. Iyer, Ushoshi Maitra
Dissecting new physics models through kinematic edges
2 figures added, title modified, a benchmark point added, references added Matches with the published version
Phys. Rev. D 95, 035039 (2017)
10.1103/PhysRevD.95.035039
TIFR/TH/16-31
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Kinematic edges in the invariant mass distributions of different final state particles are typically a signal of new physics. In this work we propose a scenario wherein these edges could be utilised in discriminating between different classes of models. To this effect, we consider the resonant production of a heavy Higgs like resonance (H 1 ) as a case study. Such states are a characteristic feature of many new physics scenarios beyond the Standard Model (SM). In the event of a discovery, it is essential to identify the true nature of the underlying theory. In this work we propose a channel, $H_1 \rightarrow t_2 t$, where t_2 is a vector-like gauge singlet top-partner that decays into W b, Zt, ht. Invariant mass distributions constructed out of these final states are characterized by the presence of kinematic edges, which are unique to the topology under consideration. Further, since all the final state particles are SM states, the position in the edges of these invariant mass distributions can be used to exclusively determine the masses of the resonances. Observation of these features are meant to serve as a trigger, thereby mandating a more detailed analysis in a particular direction of parameter space. The absence of these edge like features, in the specific invariant mass distributions considered here, in minimal versions of supersymmetric models (MSSM) also serves as a harbinger of such non MSSM-like scenarios.
[ { "created": "Wed, 21 Sep 2016 11:26:11 GMT", "version": "v1" }, { "created": "Sun, 5 Mar 2017 05:59:07 GMT", "version": "v2" } ]
2017-03-08
[ [ "Iyer", "Abhishek M.", "" ], [ "Maitra", "Ushoshi", "" ] ]
Kinematic edges in the invariant mass distributions of different final state particles are typically a signal of new physics. In this work we propose a scenario wherein these edges could be utilised in discriminating between different classes of models. To this effect, we consider the resonant production of a heavy Higgs like resonance (H 1 ) as a case study. Such states are a characteristic feature of many new physics scenarios beyond the Standard Model (SM). In the event of a discovery, it is essential to identify the true nature of the underlying theory. In this work we propose a channel, $H_1 \rightarrow t_2 t$, where t_2 is a vector-like gauge singlet top-partner that decays into W b, Zt, ht. Invariant mass distributions constructed out of these final states are characterized by the presence of kinematic edges, which are unique to the topology under consideration. Further, since all the final state particles are SM states, the position in the edges of these invariant mass distributions can be used to exclusively determine the masses of the resonances. Observation of these features are meant to serve as a trigger, thereby mandating a more detailed analysis in a particular direction of parameter space. The absence of these edge like features, in the specific invariant mass distributions considered here, in minimal versions of supersymmetric models (MSSM) also serves as a harbinger of such non MSSM-like scenarios.
hep-ph/9911227
Theodore N. Tomaras
L. Perivolaropoulos and T.N. Tomaras
Superconducting String Texture
RevTex, 14 pages, 8 figures
Phys.Rev. D62 (2000) 025012
10.1103/PhysRevD.62.025012
null
hep-ph astro-ph
null
We present a detailed analytical and numerical study of a novel type of static, superconducting, classically stable string texture in a renormalizable topologically trivial massive U(1) gauge model with one charged and one neutral scalar. An upper bound on the mass of the charged scalar as well as on the current that the string can carry are established. A preliminary unsuccesful search for stable solutions corresponding to large superconducting loops is also reported.
[ { "created": "Wed, 3 Nov 1999 20:59:38 GMT", "version": "v1" } ]
2009-10-31
[ [ "Perivolaropoulos", "L.", "" ], [ "Tomaras", "T. N.", "" ] ]
We present a detailed analytical and numerical study of a novel type of static, superconducting, classically stable string texture in a renormalizable topologically trivial massive U(1) gauge model with one charged and one neutral scalar. An upper bound on the mass of the charged scalar as well as on the current that the string can carry are established. A preliminary unsuccesful search for stable solutions corresponding to large superconducting loops is also reported.
hep-ph/9305271
null
A.A.Anselm and A.A.Johansen
Can Electro-Weak $\h$-Term be Observable ?
21 pages, Preprint TPI-MINN-93/24-T
Nucl.Phys.B412:553-573,1994
10.1016/0550-3213(94)90392-1
null
hep-ph
null
We rederive and discuss the result of the previous paper that in the standard model $\theta$-term related to $W$-boson field can not be induced by weak instantons. This follows from the existence of the fermion zero mode in the instanton field even when Yukawa couplings are switched on and there are no massless particles. We consider the new index theorem connecting the topological charge of the weak gauge field with the number of fermion zero modes of a certain differential operator which depends not only on gauge but also on Higgs fields. The possible generalizations of the standard model are discussed which lead to nonvanishing weak $\theta$-term. In $SU(2)_L \times SU(2)_R$ model the $\theta$ dependence of the vacuum energy is computed.
[ { "created": "Fri, 14 May 1993 19:57:24 GMT", "version": "v1" } ]
2010-11-01
[ [ "Anselm", "A. A.", "" ], [ "Johansen", "A. A.", "" ] ]
We rederive and discuss the result of the previous paper that in the standard model $\theta$-term related to $W$-boson field can not be induced by weak instantons. This follows from the existence of the fermion zero mode in the instanton field even when Yukawa couplings are switched on and there are no massless particles. We consider the new index theorem connecting the topological charge of the weak gauge field with the number of fermion zero modes of a certain differential operator which depends not only on gauge but also on Higgs fields. The possible generalizations of the standard model are discussed which lead to nonvanishing weak $\theta$-term. In $SU(2)_L \times SU(2)_R$ model the $\theta$ dependence of the vacuum energy is computed.
1410.5480
Ilkay Turk Cakir
I. T. Cakir (Istanbul Aydin Univ.), S. Kuday (Istanbul Aydin Univ.), O. Cakir (Istanbul Aydin Univ. and Ankara Univ.)
Production and decay of up-type and down-type new heavy quarks through anomalous interactions at the LHC
21 pages, 11 figures and 14 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the process pp->QVX (where Q=t,b and V=g,gamma,Z) through the anomalous interactions of the new heavy quarks at the LHC. Considering the present limits on the masses and mixings, the signatures of the heavy quark anomalous interactions are discussed and analysed at the LHC for the center of mass energy of 13 TeV. An important sensitivity to anomalous couplings kappa_{g}^{t'}/Lambda=0.10 TeV^{-1}, kappa_{\gamma}^{t'}/Lambda=0.14 TeV^{-1}, kappa_{Z}^{t'}/Lambda=0.19 TeV^{-1} and kappa_{g}^{b'}/Lambda=0.15 TeV^{-1}, kappa_{Z}^{b'}/Lambda=0.19 TeV$^{-1}, kappa_{\gamma}^{b'}/Lambda=0.30 TeV$^{-1} for the mass of 750 GeV of the new heavy quarks t' and b' can be reached for an integrated luminosity of L_{int}=100 fb^{-1}.
[ { "created": "Mon, 20 Oct 2014 21:45:57 GMT", "version": "v1" } ]
2014-10-22
[ [ "Cakir", "I. T.", "", "Istanbul Aydin Univ." ], [ "Kuday", "S.", "", "Istanbul Aydin Univ." ], [ "Cakir", "O.", "", "Istanbul Aydin Univ. and Ankara Univ." ] ]
We study the process pp->QVX (where Q=t,b and V=g,gamma,Z) through the anomalous interactions of the new heavy quarks at the LHC. Considering the present limits on the masses and mixings, the signatures of the heavy quark anomalous interactions are discussed and analysed at the LHC for the center of mass energy of 13 TeV. An important sensitivity to anomalous couplings kappa_{g}^{t'}/Lambda=0.10 TeV^{-1}, kappa_{\gamma}^{t'}/Lambda=0.14 TeV^{-1}, kappa_{Z}^{t'}/Lambda=0.19 TeV^{-1} and kappa_{g}^{b'}/Lambda=0.15 TeV^{-1}, kappa_{Z}^{b'}/Lambda=0.19 TeV$^{-1}, kappa_{\gamma}^{b'}/Lambda=0.30 TeV$^{-1} for the mass of 750 GeV of the new heavy quarks t' and b' can be reached for an integrated luminosity of L_{int}=100 fb^{-1}.
2212.05292
Renat Sadykov
A. Arbuzov, S. Bondarenko, Ya. Dydyshka, L. Kalinovskaya, R. Sadykov, V. Yermolchyk, Yu. Yermolchyk
Electroweak Effects in Neutral Current Drell-Yan Processes within SANC System
null
null
10.1134/S1063779623030048
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
The complete one-loop electroweak radiative corrections to the neutral current Drell-Yan process $pp \to \ell^+\ell^- X$ are presented for the case of longitudinal polarization of initial particles. The calculations are based on the SANC computer system. The paper contains a brief description of the SANC approach and a discussion of the sources of theoretical uncertainties in electroweak effects.
[ { "created": "Sat, 10 Dec 2022 12:47:36 GMT", "version": "v1" } ]
2023-06-28
[ [ "Arbuzov", "A.", "" ], [ "Bondarenko", "S.", "" ], [ "Dydyshka", "Ya.", "" ], [ "Kalinovskaya", "L.", "" ], [ "Sadykov", "R.", "" ], [ "Yermolchyk", "V.", "" ], [ "Yermolchyk", "Yu.", "" ] ]
The complete one-loop electroweak radiative corrections to the neutral current Drell-Yan process $pp \to \ell^+\ell^- X$ are presented for the case of longitudinal polarization of initial particles. The calculations are based on the SANC computer system. The paper contains a brief description of the SANC approach and a discussion of the sources of theoretical uncertainties in electroweak effects.
hep-ph/0310100
Takehiko Asaka
Takehiko Asaka, Dmitri Grigoriev, Vadim Kuzmin, Mikhail Shaposhnikov
Late Reheating, Hadronic Jets and Baryogenesis
4 pages, 2 figures, revtex4
Phys.Rev.Lett. 92 (2004) 101303
10.1103/PhysRevLett.92.101303
null
hep-ph
null
If inflaton couples very weakly to ordinary matter the reheating temperature of the universe can be lower than the electroweak scale. In this letter we show that the late reheating occurs in a highly non-uniform way, within narrow areas along the jets produced by ordinary particles originated from inflaton decays. Depending on inflaton mass and decay constant, the initial temperature inside the lumps of the overheated plasma may be large enough to trigger the unsuppressed sphaleron processes with baryon number non-conservation, allowing for efficient local electroweak baryogenesis.
[ { "created": "Wed, 8 Oct 2003 14:22:31 GMT", "version": "v1" } ]
2009-11-10
[ [ "Asaka", "Takehiko", "" ], [ "Grigoriev", "Dmitri", "" ], [ "Kuzmin", "Vadim", "" ], [ "Shaposhnikov", "Mikhail", "" ] ]
If inflaton couples very weakly to ordinary matter the reheating temperature of the universe can be lower than the electroweak scale. In this letter we show that the late reheating occurs in a highly non-uniform way, within narrow areas along the jets produced by ordinary particles originated from inflaton decays. Depending on inflaton mass and decay constant, the initial temperature inside the lumps of the overheated plasma may be large enough to trigger the unsuppressed sphaleron processes with baryon number non-conservation, allowing for efficient local electroweak baryogenesis.
hep-ph/0403156
Rainer Kuehne
Rainer W. K\"uhne
Support for the Jaffe-Wilczek Diquark Model of Pentaquarks
4 pages, latex
null
null
null
hep-ph nucl-th
null
I examine the diquark model of pentaquarks that was suggested by Jaffe and Wilczek. Based upon this model, I predict the states Theta(1530), N(1710), Sigma(1880) and Xi(1770) to be members of the same anti-decuplet. Moreover I predict the states N(1440), Lambda(1600), Sigma(1660) and Xi(1950) to be members of the corresponding octet.
[ { "created": "Mon, 15 Mar 2004 10:17:09 GMT", "version": "v1" } ]
2014-10-14
[ [ "Kühne", "Rainer W.", "" ] ]
I examine the diquark model of pentaquarks that was suggested by Jaffe and Wilczek. Based upon this model, I predict the states Theta(1530), N(1710), Sigma(1880) and Xi(1770) to be members of the same anti-decuplet. Moreover I predict the states N(1440), Lambda(1600), Sigma(1660) and Xi(1950) to be members of the corresponding octet.
hep-ph/9710379
Marco Stratmann
M. Stratmann
Radiative Parton Model Analysis of Recent Polarized DIS Data
11 pages, LaTeX, 5 figures, uses amssymb, epsfig and a41 (included) styles; Invited talk presented at the workshop 'Deep Inelastic Scattering off Polarized Targets: Theory Meets Experiment', Zeuthen, Germany, Sept. 1-5, 1997
null
null
DO-TH 97/22, DTP/97/90
hep-ph
null
An updated next-to-leading order (NLO) QCD analysis of the spin asymmetries A_1^N(x,Q^2) and parton distributions delta f(x,Q^2) in longitudinally polarized deep-inelastic lepton-nucleon scattering is presented within the framework of the radiative parton model taking into account recent experimental results. The theoretical framework and the main features of the radiative parton model analysis are briefly reviewed. The small-x behaviour of the polarized structure function g_1^N(x,Q^2) as well as the shape of the polarized gluon distribution delta g(x,Q^2) are shown to be still hardly constrained by present fixed target data.
[ { "created": "Thu, 16 Oct 1997 11:38:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Stratmann", "M.", "" ] ]
An updated next-to-leading order (NLO) QCD analysis of the spin asymmetries A_1^N(x,Q^2) and parton distributions delta f(x,Q^2) in longitudinally polarized deep-inelastic lepton-nucleon scattering is presented within the framework of the radiative parton model taking into account recent experimental results. The theoretical framework and the main features of the radiative parton model analysis are briefly reviewed. The small-x behaviour of the polarized structure function g_1^N(x,Q^2) as well as the shape of the polarized gluon distribution delta g(x,Q^2) are shown to be still hardly constrained by present fixed target data.
hep-ph/9709401
Bert-Jan Nauta
B. J. Nauta, Ch. G. van Weert
Real-time contour propagator for high temperature dimensional reduction
6 pages, Revtex
Phys.Lett. B444 (1998) 463-468
10.1016/S0370-2693(98)01352-5
null
hep-ph
null
We discuss the extension of dimensional reduction in thermal field theory at high temperature to real-time correlation functions. It is shown that the perturbative corrections to the leading classical behavior of a scalar bosonic field theory are determined by an effective contour propagator. On the real-time-branch of the time-path contour the effective propagator is obtained by subtracting the classical propagator from the contour propagator of thermal field theory, whereas on the Euclidean branch it reduces to the non-static Matsubara propagator of standard dimensional reduction.
[ { "created": "Fri, 19 Sep 1997 09:54:00 GMT", "version": "v1" } ]
2009-10-30
[ [ "Nauta", "B. J.", "" ], [ "van Weert", "Ch. G.", "" ] ]
We discuss the extension of dimensional reduction in thermal field theory at high temperature to real-time correlation functions. It is shown that the perturbative corrections to the leading classical behavior of a scalar bosonic field theory are determined by an effective contour propagator. On the real-time-branch of the time-path contour the effective propagator is obtained by subtracting the classical propagator from the contour propagator of thermal field theory, whereas on the Euclidean branch it reduces to the non-static Matsubara propagator of standard dimensional reduction.
1608.08686
Christian Weiss
E. Chudakov, D. Higinbotham, Ch. Hyde, S. Furletov, Yu. Furletova, D. Nguyen, M. Stratmann, M. Strikman, C. Weiss, R. Yoshida
Probing nuclear gluons with heavy quarks at EIC
5 pages, 4 figures. Proceedings of XXIV International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2016), DESY Hamburg, Germany, 11-15 April, 2016
null
null
JLAB-THY-16-2329
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the feasibility of direct measurements of nuclear gluon densities using heavy-quark production (open charm, beauty) at a future Electron-Ion Collider (EIC). We focus on the regions x > 0.3 (EMC effect) and x ~ 0.05-0.1 (antishadowing), where the nuclear modifications of the gluon density offer insight into non-nucleonic degrees of freedom and the QCD structure of nucleon-nucleon interactions. We describe the charm production rates and momentum distributions in nuclear deep-inelastic scattering (DIS) at large x_B, and comment on the possible methods for charm reconstruction using next-generation detectors at the EIC (pi/K identification, tracking, vertex detection).
[ { "created": "Tue, 30 Aug 2016 23:06:48 GMT", "version": "v1" } ]
2016-09-01
[ [ "Chudakov", "E.", "" ], [ "Higinbotham", "D.", "" ], [ "Hyde", "Ch.", "" ], [ "Furletov", "S.", "" ], [ "Furletova", "Yu.", "" ], [ "Nguyen", "D.", "" ], [ "Stratmann", "M.", "" ], [ "Strikman", "M.", "" ], [ "Weiss", "C.", "" ], [ "Yoshida", "R.", "" ] ]
We explore the feasibility of direct measurements of nuclear gluon densities using heavy-quark production (open charm, beauty) at a future Electron-Ion Collider (EIC). We focus on the regions x > 0.3 (EMC effect) and x ~ 0.05-0.1 (antishadowing), where the nuclear modifications of the gluon density offer insight into non-nucleonic degrees of freedom and the QCD structure of nucleon-nucleon interactions. We describe the charm production rates and momentum distributions in nuclear deep-inelastic scattering (DIS) at large x_B, and comment on the possible methods for charm reconstruction using next-generation detectors at the EIC (pi/K identification, tracking, vertex detection).
1607.00369
Howard Georgi
Howard Georgi
Complementarity and Stability Conditions
12 pages
null
10.1016/j.physletb.2017.06.008
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the issue of complementarity between the confining phase and the Higgs phase for gauge theories in which there are no light particles below the scale of confinement or spontaneous symmetry breaking. We show with a number of examples that even though the low energy effective theories are the same (and trivial), discontinuous changes in the structure of heavy stable particles can signal a phase transition and thus we can sometimes argue that two phases which have different structures of heavy particles cannot be continuously connected and thus the phases cannot be complementary. We discuss what this means and suggest that such "stability conditions" can be a useful physical check for complementarity.
[ { "created": "Fri, 1 Jul 2016 19:50:27 GMT", "version": "v1" }, { "created": "Fri, 31 Mar 2017 17:39:41 GMT", "version": "v2" }, { "created": "Wed, 31 May 2017 16:01:41 GMT", "version": "v3" } ]
2017-06-14
[ [ "Georgi", "Howard", "" ] ]
We discuss the issue of complementarity between the confining phase and the Higgs phase for gauge theories in which there are no light particles below the scale of confinement or spontaneous symmetry breaking. We show with a number of examples that even though the low energy effective theories are the same (and trivial), discontinuous changes in the structure of heavy stable particles can signal a phase transition and thus we can sometimes argue that two phases which have different structures of heavy particles cannot be continuously connected and thus the phases cannot be complementary. We discuss what this means and suggest that such "stability conditions" can be a useful physical check for complementarity.
hep-ph/9602346
null
M. Takizawa (Institute for Nuclear Study, University of Tokyo), Y. Nemoto and M. Oka (Department of Physics, Tokyo Institute of Technology)
$\eta$-Meson Decays and Strong $U_A(1)$ Breaking in the Three-Flavor Nambu-Jona-Lasinio Model
12 pages, LaTeX, 2 eps figures, Talk given at the Joint Japan-Australia Workshop on Quarks, Hadrons and Nuclei, Adelaide, Australia, Nov. 15-24, 1995
Austral.J.Phys.50:187-197,1997
10.1071/P96047
INS-Rep.-1134 and TIT/HEP-319/NP
hep-ph
null
We study the $\eta \to \gamma \gamma$ and $\eta \to \pi^0 \gamma \gamma$ decays using an extended three-flavor Nambu-Jona-Lasinio model that includes the 't~Hooft instanton induced interaction. We find that the $\eta$-meson mass, the $\eta \to \gamma \gamma$ decay width and the $\eta \to \pi^0 \gamma \gamma$ decay width are in good agreement with the experimental values when the $U_{A}(1)$ breaking is strong and the flavor $SU(3)$ singlet-octet mixing angle $\theta$ is about zero. The effects of the $U_A(1)$ breaking on the baryon number one and two systems are also studied.
[ { "created": "Tue, 20 Feb 1996 07:10:26 GMT", "version": "v1" } ]
2015-06-25
[ [ "Takizawa", "M.", "", "Institute for Nuclear Study, University of Tokyo" ], [ "Nemoto", "Y.", "", "Department of Physics, Tokyo Institute of Technology" ], [ "Oka", "M.", "", "Department of Physics, Tokyo Institute of Technology" ] ]
We study the $\eta \to \gamma \gamma$ and $\eta \to \pi^0 \gamma \gamma$ decays using an extended three-flavor Nambu-Jona-Lasinio model that includes the 't~Hooft instanton induced interaction. We find that the $\eta$-meson mass, the $\eta \to \gamma \gamma$ decay width and the $\eta \to \pi^0 \gamma \gamma$ decay width are in good agreement with the experimental values when the $U_{A}(1)$ breaking is strong and the flavor $SU(3)$ singlet-octet mixing angle $\theta$ is about zero. The effects of the $U_A(1)$ breaking on the baryon number one and two systems are also studied.
2210.17172
Yannick Ulrich
Sophie Kollatzsch and Yannick Ulrich
Lepton pair production at NNLO in QED with EW effects
17 pages, 4 figures, published version
SciPost Phys. 15, 104 (2023)
10.21468/SciPostPhys.15.3.104
IPPP/22/74, PSI-PR-22-31
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a fully differential calculation of lepton pair production, taking into account the dominant next-to-next-to-leading order QED corrections as well as next-to-leading order electroweak and polarisation effects. We include all lepton masses, hard photon emission, as well as non-perturbative hadronic corrections. The corresponding matrix elements are implemented in the Monte Carlo framework McMule. In order to obtain a numerically stable implementation, we extend next-to-soft stabilisation, a universal technique based on a next-to-leading-power expansion, to calculations with polarised leptons. As an example, we show results tailored to the Belle II detector with the current setup as well as a potential future configuration that includes polarised beams.
[ { "created": "Mon, 31 Oct 2022 09:36:32 GMT", "version": "v1" }, { "created": "Wed, 18 Oct 2023 15:49:53 GMT", "version": "v2" } ]
2023-10-19
[ [ "Kollatzsch", "Sophie", "" ], [ "Ulrich", "Yannick", "" ] ]
We present a fully differential calculation of lepton pair production, taking into account the dominant next-to-next-to-leading order QED corrections as well as next-to-leading order electroweak and polarisation effects. We include all lepton masses, hard photon emission, as well as non-perturbative hadronic corrections. The corresponding matrix elements are implemented in the Monte Carlo framework McMule. In order to obtain a numerically stable implementation, we extend next-to-soft stabilisation, a universal technique based on a next-to-leading-power expansion, to calculations with polarised leptons. As an example, we show results tailored to the Belle II detector with the current setup as well as a potential future configuration that includes polarised beams.
hep-ph/9706239
Plamen Krastev
J.N. Bahcall and P.I. Krastev
Does the Sun Appear Brighter at Night in Neutrinos?
49 pages, 16 figures, uses REVTEX, Seven exportable viewgraphs based upon paper are available at this http URL, where the table of solar zenith-angle distributions can also be found
Phys.Rev.C56:2839-2857,1997
10.1103/PhysRevC.56.2839
IASSNS-AST 97/31
hep-ph astro-ph nucl-th
null
We calculate accurately the number of solar neutrino events expected as a function of solar zenith angle, with and without neutrino oscillations, for detectors at the locations of Super-Kamiokande, SNO, and the Gran Sasso National Laboratory. Using different earth models to estimate geophysical uncertainties, and different solar models to estimate solar uncertainties, we evaluate distortions predicted by the MSW effect in the zenith angle distributions of solar neutrino events. The distortions are caused by oscillations and by $\nu-e$ interactions in the earth that regenerate $\nu_e$ from $\nu_\mu$ or $\nu_\tau$. We show that the first two moments of the zenith-angle distribution are more sensitive to the small mixing angle MSW solution than the conventionally studied day-night asymmetry. We present iso-sigma contours that illustrate the potential of Super-Kamiokande, SNO, BOREXINO, ICARUS and HERON/HELLAZ for detecting the earth regeneration effect at their actual locations (and at the equator). MSW solutions favored by the four pioneering solar neutrino experiments predict characteristic distortions for Super-Kamiokande, SNO, BOREXINO, and ICARUS that range from being unmeasurably small to $> 5\sigma$ (stat) after only a few years of observations.
[ { "created": "Wed, 4 Jun 1997 00:19:02 GMT", "version": "v1" }, { "created": "Tue, 16 Sep 1997 00:30:25 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bahcall", "J. N.", "" ], [ "Krastev", "P. I.", "" ] ]
We calculate accurately the number of solar neutrino events expected as a function of solar zenith angle, with and without neutrino oscillations, for detectors at the locations of Super-Kamiokande, SNO, and the Gran Sasso National Laboratory. Using different earth models to estimate geophysical uncertainties, and different solar models to estimate solar uncertainties, we evaluate distortions predicted by the MSW effect in the zenith angle distributions of solar neutrino events. The distortions are caused by oscillations and by $\nu-e$ interactions in the earth that regenerate $\nu_e$ from $\nu_\mu$ or $\nu_\tau$. We show that the first two moments of the zenith-angle distribution are more sensitive to the small mixing angle MSW solution than the conventionally studied day-night asymmetry. We present iso-sigma contours that illustrate the potential of Super-Kamiokande, SNO, BOREXINO, ICARUS and HERON/HELLAZ for detecting the earth regeneration effect at their actual locations (and at the equator). MSW solutions favored by the four pioneering solar neutrino experiments predict characteristic distortions for Super-Kamiokande, SNO, BOREXINO, and ICARUS that range from being unmeasurably small to $> 5\sigma$ (stat) after only a few years of observations.
2007.02104
Gennady Kozlov
Gennady Kozlov
Dark matter, dark photons through the observables
12 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse dark matter (DM) produced somehow in space-time is charged under the hidden $U^{\prime} (1)$ gauge symmetry and interacting with Standard Model (SM) through the scale invariance breaking sector containing dilatons and dark photons (DP). We find the solutions for DM and DP in terms of observables. The DM observable is under DP field shape influence. DP is the natural mediator between DM and the SM sectors. The phenomenology of DP physics and the registration of dark photons are discussed.
[ { "created": "Sat, 4 Jul 2020 14:10:30 GMT", "version": "v1" }, { "created": "Thu, 10 Dec 2020 12:48:55 GMT", "version": "v2" } ]
2020-12-11
[ [ "Kozlov", "Gennady", "" ] ]
We analyse dark matter (DM) produced somehow in space-time is charged under the hidden $U^{\prime} (1)$ gauge symmetry and interacting with Standard Model (SM) through the scale invariance breaking sector containing dilatons and dark photons (DP). We find the solutions for DM and DP in terms of observables. The DM observable is under DP field shape influence. DP is the natural mediator between DM and the SM sectors. The phenomenology of DP physics and the registration of dark photons are discussed.
1606.06861
Andreas Crivellin
Andreas Crivellin
B-anomalies related to leptons and lepton flavour universality violation
9 pages, 3 figures, no equations. Proceedings of BEAUTY 2016: 16th International Conference on B-Physics at Frontier Machines, Marseille, France. Extended version of arXiv:1605.02934
null
null
PSI-PR-16-08
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several experiments observed deviations from the Standard Model (SM) in the flavour sector: LHCb found a $4-5\,\sigma$ discrepancy compared to the SM in $b\to s\mu^+\mu^-$ transitions (recently supported by an Belle analysis) and CMS reported a non-zero measurement of $h\to\mu\tau$ with a significance of $2.4\,\sigma$. Furthermore, BELLE, BABAR and LHCb founds hints for the violation of flavour universality in $B\to D^{(*)}\tau\nu$. In addition, there is the long-standing discrepancy in the anomalous magnetic moment of the muon. Interestingly, all these anomalies are related to muons and taus, while the corresponding electron channels seem to be SM like. This suggests that these deviations from the SM might be correlated and we briefly review some selected models providing simultaneous explanations.
[ { "created": "Wed, 22 Jun 2016 09:13:32 GMT", "version": "v1" } ]
2016-06-23
[ [ "Crivellin", "Andreas", "" ] ]
Several experiments observed deviations from the Standard Model (SM) in the flavour sector: LHCb found a $4-5\,\sigma$ discrepancy compared to the SM in $b\to s\mu^+\mu^-$ transitions (recently supported by an Belle analysis) and CMS reported a non-zero measurement of $h\to\mu\tau$ with a significance of $2.4\,\sigma$. Furthermore, BELLE, BABAR and LHCb founds hints for the violation of flavour universality in $B\to D^{(*)}\tau\nu$. In addition, there is the long-standing discrepancy in the anomalous magnetic moment of the muon. Interestingly, all these anomalies are related to muons and taus, while the corresponding electron channels seem to be SM like. This suggests that these deviations from the SM might be correlated and we briefly review some selected models providing simultaneous explanations.
1904.08341
Francesca Day
Francesca V. Day and Jamie I. McDonald
Axion superradiance in rotating neutron stars
Version accepted for publication
JCAP10(2019)051
10.1088/1475-7516/2019/10/051
null
hep-ph astro-ph.HE gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is a well-known fact that compact gravitating objects admit bound state configurations for massive bosonic fields. In this work we describe a new class of superradiant instabilities of axion bound states in neutron star magnetospheres. The instability arises from the mixing of axion and photon modes in the magnetic field of the neutron star which extract energy from the rotating magnetosphere. Unlike for black holes, where the dissipation required for superradiance is provided by an absorbative horizon, the non-hermitian dynamics in this paper come from the resistivity in the stellar magnetosphere arising from a finite bulk conductivity. The axion field mixes with photon modes which superradiantly scatter off the magnetosphere, extracting rotational energy which is then deposited back into the axion sector leading to an instability. We derive the superradiant eigenfrequencies for the axion-photon system using quantum mechanical perturbation theory on the axion boundstate, drawing an analogy with atomic selection rules. We then compare the characteristic time scale of the instability to the spin-down measurements of pulsars which limit the allowed rate of angular momentum extraction from neutron stars.
[ { "created": "Wed, 17 Apr 2019 16:09:48 GMT", "version": "v1" }, { "created": "Mon, 28 Oct 2019 12:29:20 GMT", "version": "v2" } ]
2019-10-29
[ [ "Day", "Francesca V.", "" ], [ "McDonald", "Jamie I.", "" ] ]
It is a well-known fact that compact gravitating objects admit bound state configurations for massive bosonic fields. In this work we describe a new class of superradiant instabilities of axion bound states in neutron star magnetospheres. The instability arises from the mixing of axion and photon modes in the magnetic field of the neutron star which extract energy from the rotating magnetosphere. Unlike for black holes, where the dissipation required for superradiance is provided by an absorbative horizon, the non-hermitian dynamics in this paper come from the resistivity in the stellar magnetosphere arising from a finite bulk conductivity. The axion field mixes with photon modes which superradiantly scatter off the magnetosphere, extracting rotational energy which is then deposited back into the axion sector leading to an instability. We derive the superradiant eigenfrequencies for the axion-photon system using quantum mechanical perturbation theory on the axion boundstate, drawing an analogy with atomic selection rules. We then compare the characteristic time scale of the instability to the spin-down measurements of pulsars which limit the allowed rate of angular momentum extraction from neutron stars.
hep-ph/0212313
Oleg Selugin
O.V. Selyugin, M. Lokaj\'i\v{c}ek, V. Kundr\'at
High-energy spin effects and structure of elastic scattering amplitude
8 pages, LaTeX, 4 figures.ps
Czech.J.Phys.53:B101-B108,2003
null
null
hep-ph
null
A behavior of imaginary and real parts of the high-energy elastic hadron scattering amplitude is examined in the diffraction region. It is shown that the interference between Coulomb and hadronic scattering at small momentum transfers and especially in the region of diffractive minimum can bring some information about the structure of the hadron spin-non-flip amplitude.
[ { "created": "Fri, 20 Dec 2002 15:15:25 GMT", "version": "v1" } ]
2016-08-16
[ [ "Selyugin", "O. V.", "" ], [ "Lokajíček", "M.", "" ], [ "Kundrát", "V.", "" ] ]
A behavior of imaginary and real parts of the high-energy elastic hadron scattering amplitude is examined in the diffraction region. It is shown that the interference between Coulomb and hadronic scattering at small momentum transfers and especially in the region of diffractive minimum can bring some information about the structure of the hadron spin-non-flip amplitude.
2404.05999
Alexander Ritter
Alexander C. Ritter and Raymond R. Volkas
Explaining the cosmological dark matter coincidence in asymmetric dark QCD
28 pages, 9 figures, 8 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
To properly solve the coincidence problem ($\Omega_\mathrm{DM} \simeq 5\Omega_\mathrm{VM}$) in a model of asymmetric dark matter, one cannot simply relate the number densities of visible and dark matter without also relating their particle masses. Following previous work, we consider a framework where the dark matter is a confined state of a dark QCD gauge group whose confinement scale is dynamically related to the QCD confinement scale by a mechanism utilising infrared fixed points of the two gauge couplings. In this work we present a new, `zero-coupling infrared fixed point' approach, which allows a larger proportion of models in this framework to generically relate the masses of the visible and dark matter particles. Due to the heavy mass scale required for the new field content, we introduce supersymmetry to the theory. We consider how these models may be incorporated in a full theory of asymmetric dark matter, presenting some example leptogenesis-like models. We also discuss the phenomenology of these models; in particular, there are gravitational wave signals which, while weak, may be measurable at future mHz and $\mu$Hz detectors.
[ { "created": "Tue, 9 Apr 2024 04:08:16 GMT", "version": "v1" } ]
2024-04-10
[ [ "Ritter", "Alexander C.", "" ], [ "Volkas", "Raymond R.", "" ] ]
To properly solve the coincidence problem ($\Omega_\mathrm{DM} \simeq 5\Omega_\mathrm{VM}$) in a model of asymmetric dark matter, one cannot simply relate the number densities of visible and dark matter without also relating their particle masses. Following previous work, we consider a framework where the dark matter is a confined state of a dark QCD gauge group whose confinement scale is dynamically related to the QCD confinement scale by a mechanism utilising infrared fixed points of the two gauge couplings. In this work we present a new, `zero-coupling infrared fixed point' approach, which allows a larger proportion of models in this framework to generically relate the masses of the visible and dark matter particles. Due to the heavy mass scale required for the new field content, we introduce supersymmetry to the theory. We consider how these models may be incorporated in a full theory of asymmetric dark matter, presenting some example leptogenesis-like models. We also discuss the phenomenology of these models; in particular, there are gravitational wave signals which, while weak, may be measurable at future mHz and $\mu$Hz detectors.
1305.2920
Javier Redondo
Javier Redondo, Georg Raffelt
Solar constraints on hidden photons re-visited
17 pages, 4 figures
JCAP 1308 (2013) 034
10.1088/1475-7516/2013/08/034
MPP-2013-110
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We re-examine solar emission of hidden photons gamma' (mass m) caused by kinetic mixing. We calculate the emission rate with thermal field theory methods and with a kinetic equation that includes "flavor oscillations" and photon absorption and emission by the thermal medium. In the resonant case both methods yield identical emission rates which, in the longitudinal channel, are enhanced by a factor w_P^2/m^2 (plasma frequency w_P) in agreement with An, Pospelov and Pradler (2013). The Sun must not emit more energy in a "dark channel" than allowed by solar neutrino measurements, i.e., not more than 10% of its photon luminosity. Together with the revised emission rate, this conservative requirement implies a bound \chi<4\times 10^-12 eV/m for the kinetic mixing parameter. This is the most restrictive stellar limit below m ~ 3 eV, whereas for larger masses the transverse channel dominates together with limits from other stars. A recent analysis of XENON10 data marginally improves the solar limit, leaving open the opportunity to detect solar hidden photons with future large-scale dark matter experiments. Detecting low-mass hidden photons with the ALPS-II photon-regeneration experiment also remains possible.
[ { "created": "Mon, 13 May 2013 20:00:03 GMT", "version": "v1" } ]
2015-02-02
[ [ "Redondo", "Javier", "" ], [ "Raffelt", "Georg", "" ] ]
We re-examine solar emission of hidden photons gamma' (mass m) caused by kinetic mixing. We calculate the emission rate with thermal field theory methods and with a kinetic equation that includes "flavor oscillations" and photon absorption and emission by the thermal medium. In the resonant case both methods yield identical emission rates which, in the longitudinal channel, are enhanced by a factor w_P^2/m^2 (plasma frequency w_P) in agreement with An, Pospelov and Pradler (2013). The Sun must not emit more energy in a "dark channel" than allowed by solar neutrino measurements, i.e., not more than 10% of its photon luminosity. Together with the revised emission rate, this conservative requirement implies a bound \chi<4\times 10^-12 eV/m for the kinetic mixing parameter. This is the most restrictive stellar limit below m ~ 3 eV, whereas for larger masses the transverse channel dominates together with limits from other stars. A recent analysis of XENON10 data marginally improves the solar limit, leaving open the opportunity to detect solar hidden photons with future large-scale dark matter experiments. Detecting low-mass hidden photons with the ALPS-II photon-regeneration experiment also remains possible.
hep-ph/0502005
Panagiota Kanti
Christopher M. Harris
Physics Beyond the Standard Model: Exotic Leptons and Black Holes at Future Colliders
190 pages, 41 figures, PhD thesis submitted to the University of Cambridge in December 2003
null
null
null
hep-ph
null
The Standard Model of particle physics has been remarkably successful in describing present experimental results. However, it is assumed to be only a low-energy effective theory which will break down at higher energy scales, theoretically motivated to be around 1 TeV. There are a variety of proposed models of new physics beyond the Standard Model, most notably supersymmetric and extra dimension models. New charged and neutral heavy leptons are a feature of a number of theories of new physics, including the `intermediate scale' class of supersymmetric models. Using a time-of-flight technique to detect the charged leptons at the Large Hadron Collider, the discovery range (in the particular scenario studied in the first part of this thesis) is found to extend up to masses of 950 GeV. Extra dimension models, particularly those with large extra dimensions, allow the possible experimental production of black holes. The remainder of the thesis describes some theoretical results and computational tools necessary to model the production and decay of these miniature black holes at future particle colliders. The grey-body factors which describe the Hawking radiation emitted by higher-dimensional black holes are calculated numerically for the first time and then incorporated in a Monte Carlo black hole event generator; this can be used to model black hole production and decay at next-generation colliders. It is hoped that this generator will allow more detailed examination of black hole signatures and help to devise a method for extracting the number of extra dimensions present in nature.
[ { "created": "Tue, 1 Feb 2005 11:35:16 GMT", "version": "v1" } ]
2007-05-23
[ [ "Harris", "Christopher M.", "" ] ]
The Standard Model of particle physics has been remarkably successful in describing present experimental results. However, it is assumed to be only a low-energy effective theory which will break down at higher energy scales, theoretically motivated to be around 1 TeV. There are a variety of proposed models of new physics beyond the Standard Model, most notably supersymmetric and extra dimension models. New charged and neutral heavy leptons are a feature of a number of theories of new physics, including the `intermediate scale' class of supersymmetric models. Using a time-of-flight technique to detect the charged leptons at the Large Hadron Collider, the discovery range (in the particular scenario studied in the first part of this thesis) is found to extend up to masses of 950 GeV. Extra dimension models, particularly those with large extra dimensions, allow the possible experimental production of black holes. The remainder of the thesis describes some theoretical results and computational tools necessary to model the production and decay of these miniature black holes at future particle colliders. The grey-body factors which describe the Hawking radiation emitted by higher-dimensional black holes are calculated numerically for the first time and then incorporated in a Monte Carlo black hole event generator; this can be used to model black hole production and decay at next-generation colliders. It is hoped that this generator will allow more detailed examination of black hole signatures and help to devise a method for extracting the number of extra dimensions present in nature.
0911.4194
Ilkay Turk Cakir
I.T.Cakir, O.Cakir, S.Sultansoy
Anomalous Single Top Production at the LHeC Based gamma p Collider
11 pages, 8 figures, 3 tables
Phys.Lett.B685:170-173,2010
10.1016/j.physletb.2010.01.047
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The top quark could provide very important information for the Standard Model extentions due to its large mass close to the electroweak symmetry breaking scale. In this work, anomalous single top production is studied by using gamma p-->W^{+}b process at the LHeC based gamma p collider. The sensitivity to anomalous coupling kappa/Lambda could be reached down to 0.01 TeV^{-1}.
[ { "created": "Sat, 21 Nov 2009 17:32:57 GMT", "version": "v1" }, { "created": "Sun, 13 Dec 2009 11:15:00 GMT", "version": "v2" } ]
2010-03-04
[ [ "Cakir", "I. T.", "" ], [ "Cakir", "O.", "" ], [ "Sultansoy", "S.", "" ] ]
The top quark could provide very important information for the Standard Model extentions due to its large mass close to the electroweak symmetry breaking scale. In this work, anomalous single top production is studied by using gamma p-->W^{+}b process at the LHeC based gamma p collider. The sensitivity to anomalous coupling kappa/Lambda could be reached down to 0.01 TeV^{-1}.
hep-ph/0601196
George Rupp
Michael D. Scadron, Frieder Kleefeld, and George Rupp
Pion Chiral Symmetry Breaking in the Quark-Level Linear Sigma Model and Chiral Perturbation Theory
16 pages, 1 EPS figure
null
null
null
hep-ph
null
Chiral symmetry breaking (ChSB) is reviewed to some extent within the quark-level-linear-sigma-model (QLL$\sigma$M) theory and standard chiral perturbation theory (ChPT). It is shown, on the basis of several examples related to the pion, as a well-known Goldstone boson of chiral symmetry breaking, that even the non-unitarized QLL$\sigma$M approach accounts, to a good approximation, for a rather simple, self-consistent, linear, and very predictive description of Nature. On the other hand, ChPT -- even when unitarized -- provides a highly distorted, nonlinear, hardly predictive picture of Nature, which fits experiment only at the price of a lot of parameters, and requires a great deal of unnecessary theoretical effort. As the origin of this distortion, we identify the fact that ChPT, reflecting only direct ChSB by nonvanishing, current-quark-mass values, does not -- contrary to Quantum Chromodynamics (QCD) and the QLL$\sigma$M -- contain any mechanism for the spontaneous generation of the dynamical component of the constituent quark mass. This leads to a very peculiar picture of Nature, since the strange current quark mass has to compensate for the absence of nonstrange dynamical quark masses. We thus conclude that standard ChPT -- contrary to common wisdom -- is unlikely to be the low-energy limit of QCD. On the contrary, a chiral perturbation theory derived from the QLL$\sigma$M, presumably being the true low-energy limit of QCD, is expected instead to provide a distortion-free description of Nature, which is based on the heavy standard-model Higgs boson as well as light scalar mesons, as the source of spontaneous generation of current and dynamical quark masses, respectively.
[ { "created": "Tue, 24 Jan 2006 11:42:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Scadron", "Michael D.", "" ], [ "Kleefeld", "Frieder", "" ], [ "Rupp", "George", "" ] ]
Chiral symmetry breaking (ChSB) is reviewed to some extent within the quark-level-linear-sigma-model (QLL$\sigma$M) theory and standard chiral perturbation theory (ChPT). It is shown, on the basis of several examples related to the pion, as a well-known Goldstone boson of chiral symmetry breaking, that even the non-unitarized QLL$\sigma$M approach accounts, to a good approximation, for a rather simple, self-consistent, linear, and very predictive description of Nature. On the other hand, ChPT -- even when unitarized -- provides a highly distorted, nonlinear, hardly predictive picture of Nature, which fits experiment only at the price of a lot of parameters, and requires a great deal of unnecessary theoretical effort. As the origin of this distortion, we identify the fact that ChPT, reflecting only direct ChSB by nonvanishing, current-quark-mass values, does not -- contrary to Quantum Chromodynamics (QCD) and the QLL$\sigma$M -- contain any mechanism for the spontaneous generation of the dynamical component of the constituent quark mass. This leads to a very peculiar picture of Nature, since the strange current quark mass has to compensate for the absence of nonstrange dynamical quark masses. We thus conclude that standard ChPT -- contrary to common wisdom -- is unlikely to be the low-energy limit of QCD. On the contrary, a chiral perturbation theory derived from the QLL$\sigma$M, presumably being the true low-energy limit of QCD, is expected instead to provide a distortion-free description of Nature, which is based on the heavy standard-model Higgs boson as well as light scalar mesons, as the source of spontaneous generation of current and dynamical quark masses, respectively.
0803.1527
Somorendro Singh shougaijam
S. Somorendro Singh, Yogesh Kumar and D. S. Gosain
Dilepton from Quark-Gluon Plasma and Quark-Hadron Phase Transition
5 pages, 8 figeures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A model of statistical quark-gluon plasma formation is considered.We look the dilepton production at critical temperature $T_{c}\sim170 Mev $ and completely free out temperature $T=150 MeV$ with the initial temperature as $T_{0}=570,400 (250) MeV$. Now we consider that quark mass is depending on the coupling value through parameterisation factor of the fireball formation and temperature. The rate of production is shown for invariant mass $M$ at the particular value of $ E=2.0,3.0 GeV$.It shows the significant production of leptons in this process for small value of invariant mass. However, the quark-hadron phase transition is a very weakly changed in the entropy of the system during this process of hadronisation.
[ { "created": "Tue, 11 Mar 2008 06:57:05 GMT", "version": "v1" } ]
2008-03-12
[ [ "Singh", "S. Somorendro", "" ], [ "Kumar", "Yogesh", "" ], [ "Gosain", "D. S.", "" ] ]
A model of statistical quark-gluon plasma formation is considered.We look the dilepton production at critical temperature $T_{c}\sim170 Mev $ and completely free out temperature $T=150 MeV$ with the initial temperature as $T_{0}=570,400 (250) MeV$. Now we consider that quark mass is depending on the coupling value through parameterisation factor of the fireball formation and temperature. The rate of production is shown for invariant mass $M$ at the particular value of $ E=2.0,3.0 GeV$.It shows the significant production of leptons in this process for small value of invariant mass. However, the quark-hadron phase transition is a very weakly changed in the entropy of the system during this process of hadronisation.
1606.07624
Aleksander Kusina
A. Kusina
nCTEQ15 nuclear parton distributions with uncertainties
Presented at the 50th Rencontres de Moriond QCD and High Energy Interactions, La Thuile, Italy, 19-26 March, 2016
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the first official release of the nCTEQ nuclear parton distribution functions (nPDFs) with errors. The main addition to the previous nCTEQ PDFs is the introduction of PDF uncertainties based on the Hessian method. Another important improvement is the inclusion of pion production data from RHIC giving us a handle to constrain gluon PDF. In this presentation we briefly discuss the framework of our analysis and concentrate on the comparison of our results with those of other groups.
[ { "created": "Fri, 24 Jun 2016 09:55:34 GMT", "version": "v1" } ]
2016-06-27
[ [ "Kusina", "A.", "" ] ]
We present the first official release of the nCTEQ nuclear parton distribution functions (nPDFs) with errors. The main addition to the previous nCTEQ PDFs is the introduction of PDF uncertainties based on the Hessian method. Another important improvement is the inclusion of pion production data from RHIC giving us a handle to constrain gluon PDF. In this presentation we briefly discuss the framework of our analysis and concentrate on the comparison of our results with those of other groups.
hep-ph/0603007
Zhi-Gang Wang
Z. G. Wang, S. L. Wan
Structure of the $D_{s0}(2317)$ and the strong coupling constant $g_{D_{s0} D K}$ with the light-cone QCD sum rules
17 pages, 7 figure, revised version, add detailed error analysis
Phys.Rev.D73:094020,2006
10.1103/PhysRevD.73.094020
null
hep-ph
null
In this article, we take the point of view that the charmed scalar meson $D_{s0}(2317)$ is the conventional $c\bar{s}$ meson and calculate the strong coupling constant $g_{D_{s0} D K}$ within the framework of the light-cone QCD sum rules approach. The numerical values for the large scalar-$DK$ coupling constant $g_{D_{s0} D K}$ support the hadronic dressing mechanism. Just like the scalar mesons $f_0(980)$ and $a_0(980)$, the $D_{s0}(2317)$ may have small scalar $c\bar{s}$ kernel of the typical $c\bar{s}$ meson size. The strong coupling to the hadronic channels (or the virtual mesons loops) may result in smaller mass than the conventional scalar $c\bar{s}$ meson in the constituent quark models, and enrich the pure $c\bar{s}$ state with other components. The $D_{s0}(2317)$ may spend part (or most part) of its lifetime as virtual $ D K $ state.
[ { "created": "Wed, 1 Mar 2006 12:48:58 GMT", "version": "v1" }, { "created": "Wed, 3 May 2006 10:08:29 GMT", "version": "v2" } ]
2008-11-26
[ [ "Wang", "Z. G.", "" ], [ "Wan", "S. L.", "" ] ]
In this article, we take the point of view that the charmed scalar meson $D_{s0}(2317)$ is the conventional $c\bar{s}$ meson and calculate the strong coupling constant $g_{D_{s0} D K}$ within the framework of the light-cone QCD sum rules approach. The numerical values for the large scalar-$DK$ coupling constant $g_{D_{s0} D K}$ support the hadronic dressing mechanism. Just like the scalar mesons $f_0(980)$ and $a_0(980)$, the $D_{s0}(2317)$ may have small scalar $c\bar{s}$ kernel of the typical $c\bar{s}$ meson size. The strong coupling to the hadronic channels (or the virtual mesons loops) may result in smaller mass than the conventional scalar $c\bar{s}$ meson in the constituent quark models, and enrich the pure $c\bar{s}$ state with other components. The $D_{s0}(2317)$ may spend part (or most part) of its lifetime as virtual $ D K $ state.
1612.00024
Prasanna Kumar Dhani
Taushif Ahmed, Pulak Banerjee, Prasanna K. Dhani, Prakash Mathews, Narayan Rana and V. Ravindran
Three loop form factors of a massive spin-2 particle with nonuniversal coupling
24 pages, Journal version
Phys. Rev. D 95, 034035 (2017)
10.1103/PhysRevD.95.034035
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the interaction of spin-2 fields with those of Standard Model in a model independent framework. We have considered interactions where the spin-2 fields couple to two sets of gauge invariant tensorial operators that are not conserved unlike the energy momentum tensor with different coupling strengths. Such interactions not only change the ultraviolet behaviour of the couplings but also expand the scope of the searches of spin-2 particles at the colliders. We present all the relevant renormalisation constants up to three loop level in QCD and also the form factors that contribute to potential observables. This sets the ground to investigate the phenomenological consequences of these interactions with spin-2 fields through more than one tensorial operator.
[ { "created": "Wed, 30 Nov 2016 21:00:13 GMT", "version": "v1" }, { "created": "Wed, 8 Mar 2017 10:56:26 GMT", "version": "v2" } ]
2017-03-15
[ [ "Ahmed", "Taushif", "" ], [ "Banerjee", "Pulak", "" ], [ "Dhani", "Prasanna K.", "" ], [ "Mathews", "Prakash", "" ], [ "Rana", "Narayan", "" ], [ "Ravindran", "V.", "" ] ]
We investigate the interaction of spin-2 fields with those of Standard Model in a model independent framework. We have considered interactions where the spin-2 fields couple to two sets of gauge invariant tensorial operators that are not conserved unlike the energy momentum tensor with different coupling strengths. Such interactions not only change the ultraviolet behaviour of the couplings but also expand the scope of the searches of spin-2 particles at the colliders. We present all the relevant renormalisation constants up to three loop level in QCD and also the form factors that contribute to potential observables. This sets the ground to investigate the phenomenological consequences of these interactions with spin-2 fields through more than one tensorial operator.
1206.4998
Pier Francesco Monni
Andrea Banfi, Pier Francesco Monni, Gavin P. Salam, Giulia Zanderighi
Higgs and Z-boson production with a jet veto
6 pages and 2 figures, plus 8 pages and 2 figures of supplemental material. v2 contains additional references and small textual changes
null
10.1103/PhysRevLett.109.202001
CERN-PH-TH/2012-173; LPN12-061; OUTP-12-14P; ZU-ZH 10/12
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive first next-to-next-to-leading logarithmic resummations for jet-veto efficiencies in Higgs and Z-boson production at hadron colliders. Matching with next-to-next-to-leading order results allows us to provide a range of phenomenological predictions for the LHC, including cross-section results, detailed uncertainty estimates and comparisons to current widely-used tools.
[ { "created": "Thu, 21 Jun 2012 19:54:41 GMT", "version": "v1" }, { "created": "Wed, 25 Jul 2012 12:43:31 GMT", "version": "v2" } ]
2015-06-05
[ [ "Banfi", "Andrea", "" ], [ "Monni", "Pier Francesco", "" ], [ "Salam", "Gavin P.", "" ], [ "Zanderighi", "Giulia", "" ] ]
We derive first next-to-next-to-leading logarithmic resummations for jet-veto efficiencies in Higgs and Z-boson production at hadron colliders. Matching with next-to-next-to-leading order results allows us to provide a range of phenomenological predictions for the LHC, including cross-section results, detailed uncertainty estimates and comparisons to current widely-used tools.
2111.10944
Takaaki Nomura
Takaaki Nomura, Hiroshi Okada, Yong-hui Qi
Zee model in a modular $A_4$ symmetry
21 pages, 4 figures, references added. arXiv admin note: text overlap with arXiv:2111.05674, arXiv:2109.13779
null
null
APCTP Pre2021-028, CTP-SCU/2021034
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study a Zee model applying a modular $A_4$ symmetry, where we construct our lepton model as minimum modular weight as possible. We show our predictions on phases and neutrino masses through our $\Delta \chi^2$ analysis. We find that normal hierarchy is favored, and $\tau$ is localized to 2.3$i$ that is close to a fixed point of $i\times \infty$. In this limit, our neutrino mass matrix comes to a two zero texture, which is called $B_1$ of the neutrino mass matrix. We show that our phase predictions are in good agreement with the ones of $B_1$.
[ { "created": "Mon, 22 Nov 2021 01:58:50 GMT", "version": "v1" }, { "created": "Mon, 6 Dec 2021 10:53:24 GMT", "version": "v2" } ]
2021-12-07
[ [ "Nomura", "Takaaki", "" ], [ "Okada", "Hiroshi", "" ], [ "Qi", "Yong-hui", "" ] ]
We study a Zee model applying a modular $A_4$ symmetry, where we construct our lepton model as minimum modular weight as possible. We show our predictions on phases and neutrino masses through our $\Delta \chi^2$ analysis. We find that normal hierarchy is favored, and $\tau$ is localized to 2.3$i$ that is close to a fixed point of $i\times \infty$. In this limit, our neutrino mass matrix comes to a two zero texture, which is called $B_1$ of the neutrino mass matrix. We show that our phase predictions are in good agreement with the ones of $B_1$.
2005.06144
Amy Geddes
Julian C. Berengut, C\'edric Delaunay, Amy Geddes, Yotam Soreq
Generalized King linearity and new physics searches with isotope shifts
null
Phys. Rev. Research 2, 043444 (2020)
10.1103/PhysRevResearch.2.043444
null
hep-ph hep-ex physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Atomic spectral lines for different isotopes are shifted, revealing a change in the properties of the nucleus. For spinless nuclei such isotope shifts for two distinct transitions are expected to be linearly related, at least at leading order in a change of the nuclear mass and charge distribution. Looking for a breaking of linearity in so-called King plots was proposed as a novel method to search for physics beyond the standard model. In the light of the recent experimental progress in isotope shift spectroscopy, the sensitivity of these searches will become limited by the determination of the isotope masses and/or by nuclear effects which may induce nonlinearities at an observable level. In this work, we propose two possible generalizations of the traditional King plot that overcome these limitations by including additional isotope shift measurements, thus significantly extending the new physics reach of King plots in a purely spectroscopy-driven approach.
[ { "created": "Wed, 13 May 2020 04:14:02 GMT", "version": "v1" } ]
2021-01-04
[ [ "Berengut", "Julian C.", "" ], [ "Delaunay", "Cédric", "" ], [ "Geddes", "Amy", "" ], [ "Soreq", "Yotam", "" ] ]
Atomic spectral lines for different isotopes are shifted, revealing a change in the properties of the nucleus. For spinless nuclei such isotope shifts for two distinct transitions are expected to be linearly related, at least at leading order in a change of the nuclear mass and charge distribution. Looking for a breaking of linearity in so-called King plots was proposed as a novel method to search for physics beyond the standard model. In the light of the recent experimental progress in isotope shift spectroscopy, the sensitivity of these searches will become limited by the determination of the isotope masses and/or by nuclear effects which may induce nonlinearities at an observable level. In this work, we propose two possible generalizations of the traditional King plot that overcome these limitations by including additional isotope shift measurements, thus significantly extending the new physics reach of King plots in a purely spectroscopy-driven approach.
hep-ph/0212187
Altug Ozpineci
T. M. Aliev, I. Kanik, A. Ozpineci
Radiative rho --> eta gamma decay in light cone QCD
7 pages, 1 figure
null
null
null
hep-ph
null
The coupling constant of rho --> eta gamma decay is calculated in the framework of light cone QCD sum rules. A comparison of our prediction on the coupling constant with the result obtained from analysis of the experimental data is performed.
[ { "created": "Fri, 13 Dec 2002 09:54:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Aliev", "T. M.", "" ], [ "Kanik", "I.", "" ], [ "Ozpineci", "A.", "" ] ]
The coupling constant of rho --> eta gamma decay is calculated in the framework of light cone QCD sum rules. A comparison of our prediction on the coupling constant with the result obtained from analysis of the experimental data is performed.
hep-ph/0205034
Alex Pomarol
Daniel Marti and Alex Pomarol
Fayet-Iliopoulos terms in 5d theories and their phenomenological implications
15 pages, Latex, axodraw
Phys.Rev. D66 (2002) 125005
10.1103/PhysRevD.66.125005
null
hep-ph hep-th
null
Supersymmetric theories in 5d orbifold can have Fayet-Iliopoulos (FI) terms on the boundaries. These terms induce a 5d mass for the bulk matter fields. We analyze this effect using N=1 superfields and show how it can be understood as a mixing between the U(1) gauge boson and the graviphoton. We also study the implications of the FI-terms in the mass spectrum of theories with Scherk-Schwarz supersymmetry breaking. We present a new 5d supersymmetric model that has the massless spectrum of the Standard Model and predicts a Higgs boson with a mass around the present experimental limit.
[ { "created": "Fri, 3 May 2002 19:40:35 GMT", "version": "v1" }, { "created": "Wed, 15 May 2002 13:54:02 GMT", "version": "v2" } ]
2009-11-07
[ [ "Marti", "Daniel", "" ], [ "Pomarol", "Alex", "" ] ]
Supersymmetric theories in 5d orbifold can have Fayet-Iliopoulos (FI) terms on the boundaries. These terms induce a 5d mass for the bulk matter fields. We analyze this effect using N=1 superfields and show how it can be understood as a mixing between the U(1) gauge boson and the graviphoton. We also study the implications of the FI-terms in the mass spectrum of theories with Scherk-Schwarz supersymmetry breaking. We present a new 5d supersymmetric model that has the massless spectrum of the Standard Model and predicts a Higgs boson with a mass around the present experimental limit.
1701.04927
Archil Kobakhidze
Archil Kobakhidze and Shelley Liang
Standard Model with hidden scale invariance and light dilaton
9 pages, 1 figure
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the minimal Standard Model as an effective low-energy description of an unspecified fundamental theory with spontaneously broken conformal symmetry. The effective theory exhibits classical scale invariance which manifest itself through the dilaton field. The mass of the dilaton is generated via the quantum scale anomaly at two-loop level and is proportional to the techically stable hierarchy between the electroweak scale and a high energy scale given by a dilaton vacuum expectation value. We find that a generic prediction of this class of models is the existence of a very light dilaton with mass between $\sim 0.01$ $\mu$eV to $\sim 100$ MeV, depending on the hierarchy of scales. Searches for such a light scalar particle may reveal a fundamental role of conformal invariance in nature.
[ { "created": "Wed, 18 Jan 2017 02:33:02 GMT", "version": "v1" } ]
2017-01-19
[ [ "Kobakhidze", "Archil", "" ], [ "Liang", "Shelley", "" ] ]
We consider the minimal Standard Model as an effective low-energy description of an unspecified fundamental theory with spontaneously broken conformal symmetry. The effective theory exhibits classical scale invariance which manifest itself through the dilaton field. The mass of the dilaton is generated via the quantum scale anomaly at two-loop level and is proportional to the techically stable hierarchy between the electroweak scale and a high energy scale given by a dilaton vacuum expectation value. We find that a generic prediction of this class of models is the existence of a very light dilaton with mass between $\sim 0.01$ $\mu$eV to $\sim 100$ MeV, depending on the hierarchy of scales. Searches for such a light scalar particle may reveal a fundamental role of conformal invariance in nature.
0902.0357
John Ellis
John Ellis
Physics Beyond the Standard Model
12 pages, 5 figures, summary talk at the 2008 PANIC conference
Nucl.Phys.A827:187c-198c,2009
10.1016/j.nuclphysa.2009.05.034
CERN-PH-TH/2009-020
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model is in good shape, apart possibly from g_\mu - 2 and some niggling doubts about the electroweak data. Something like a Higgs boson is required to provide particle masses, but theorists are actively considering alternatives. The problems of flavour, unification and quantum gravity will require physics beyond the Standard Model, and astrophysics and cosmology also provide reasons to expect physics beyond the Standard Model, in particular to provide the dark matter and explain the origin of the matter in the Universe. Personally, I find supersymmetry to be the most attractive option for new physics at the TeV scale. The LHC should establish the origin of particle masses has good prospects for discovering dark matter, and might also cast light on unification and even quantum gravity. Important roles may also be played by lower-energy experiments, astrophysics and cosmology in the searches for new physics beyond the Standard Model.
[ { "created": "Mon, 2 Feb 2009 20:59:51 GMT", "version": "v1" } ]
2023-03-30
[ [ "Ellis", "John", "" ] ]
The Standard Model is in good shape, apart possibly from g_\mu - 2 and some niggling doubts about the electroweak data. Something like a Higgs boson is required to provide particle masses, but theorists are actively considering alternatives. The problems of flavour, unification and quantum gravity will require physics beyond the Standard Model, and astrophysics and cosmology also provide reasons to expect physics beyond the Standard Model, in particular to provide the dark matter and explain the origin of the matter in the Universe. Personally, I find supersymmetry to be the most attractive option for new physics at the TeV scale. The LHC should establish the origin of particle masses has good prospects for discovering dark matter, and might also cast light on unification and even quantum gravity. Important roles may also be played by lower-energy experiments, astrophysics and cosmology in the searches for new physics beyond the Standard Model.
hep-ph/0102210
Wolfgang Ochs
Peter Minkowski (Univ. Bern) and Wolfgang Ochs (MPI Munich)
Search for Gluonic Mesons in Gluon Jets
presented at the XXX Int. Symposium on Multiparticle Dynamics 2000, Tihany, Hungary, Oct. 2000; 6 pages in Latex + 2 figs. in ps
null
null
MPI-PhT/2000-53; BUTP-00/75
hep-ph
null
We present a short survey of the theoretical expectations on glueballs and hybrids as well as of the present phenomenological status. The possibility to obtain new information on gluonic mesons from the study of gluon jets in comparison to quark jets is discussed.
[ { "created": "Fri, 16 Feb 2001 20:34:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Minkowski", "Peter", "", "Univ. Bern" ], [ "Ochs", "Wolfgang", "", "MPI Munich" ] ]
We present a short survey of the theoretical expectations on glueballs and hybrids as well as of the present phenomenological status. The possibility to obtain new information on gluonic mesons from the study of gluon jets in comparison to quark jets is discussed.
0709.1931
Riccardo Catena
Riccardo Catena and Jan M\"oller
Axion-Dilaton Cosmology and Dark Energy
28 pages, 11 figures
JCAP0803:012,2008
10.1088/1475-7516/2008/03/012
DESY 07 - 145
hep-ph
null
We discuss a class of flat FRW cosmological models based on D=4 axion-dilaton gravity universally coupled to cosmological background fluids. In particular, we investigate the possibility of recurrent acceleration, which was recently shown to be generically realized in a wide class of axion-dilaton models, but in absence of cosmological background fluids. We observe that, once we impose the existence of radiation -and matter- dominated earlier stages of cosmic evolution, the axion-dilaton dynamics is altered significantly with respect to the case of pure axion-dilaton gravity. During the matter dominated epoch the scalar fields remain either frozen, due to the large expansion rate, or enter a cosmological scaling regime. In both cases, oscillations of the effective equation of state around the acceleration boundary value are impossible. Models which enter an oscillatory stage in the low redshift regime, on the other hand, are disfavored by observations. We also comment on the viability of the axion-dilaton system as a candidate for dynamical dark energy. In a certain subclass of models, an intermediate scaling regime is succeeded by eternal acceleration. We also briefly discuss the issue of dependence on initial conditions.
[ { "created": "Wed, 12 Sep 2007 17:08:37 GMT", "version": "v1" } ]
2008-11-26
[ [ "Catena", "Riccardo", "" ], [ "Möller", "Jan", "" ] ]
We discuss a class of flat FRW cosmological models based on D=4 axion-dilaton gravity universally coupled to cosmological background fluids. In particular, we investigate the possibility of recurrent acceleration, which was recently shown to be generically realized in a wide class of axion-dilaton models, but in absence of cosmological background fluids. We observe that, once we impose the existence of radiation -and matter- dominated earlier stages of cosmic evolution, the axion-dilaton dynamics is altered significantly with respect to the case of pure axion-dilaton gravity. During the matter dominated epoch the scalar fields remain either frozen, due to the large expansion rate, or enter a cosmological scaling regime. In both cases, oscillations of the effective equation of state around the acceleration boundary value are impossible. Models which enter an oscillatory stage in the low redshift regime, on the other hand, are disfavored by observations. We also comment on the viability of the axion-dilaton system as a candidate for dynamical dark energy. In a certain subclass of models, an intermediate scaling regime is succeeded by eternal acceleration. We also briefly discuss the issue of dependence on initial conditions.