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1312.2837
Elaine Fortes
Elaine C. F. S. Fortes and M. D. Tonasse
Low Mass Pseudoscalar Dark Matter in an Extended B - L Model
Version submitted and accepted for publication in PRD
null
10.1103/PhysRevD.89.016015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study an extended B-L model, which has in its structure four neutral scalars. In this model, a representative set of parameters enable us to conclude that one of these scalars is a promising candidate for low-mass dark matter. We introduce an Z_2 symmetry, which ensure the stability of the dark matter. The dominant annihilation process will be through $s$-channel exchange of a scalar in $b\overline{b}$. So, this is also a Higgs portal dark matter model, but the Higgs decay to dark matter is suppressed and meets the constraints from invisible decays of Higgs boson. The model is also in agreement with the constraints established by XENON100, CoGeNT and CDMS experiments, maching the relic abundance and the cross section with nucleon.
[ { "created": "Tue, 10 Dec 2013 15:43:45 GMT", "version": "v1" } ]
2015-06-18
[ [ "Fortes", "Elaine C. F. S.", "" ], [ "Tonasse", "M. D.", "" ] ]
We study an extended B-L model, which has in its structure four neutral scalars. In this model, a representative set of parameters enable us to conclude that one of these scalars is a promising candidate for low-mass dark matter. We introduce an Z_2 symmetry, which ensure the stability of the dark matter. The dominant annihilation process will be through $s$-channel exchange of a scalar in $b\overline{b}$. So, this is also a Higgs portal dark matter model, but the Higgs decay to dark matter is suppressed and meets the constraints from invisible decays of Higgs boson. The model is also in agreement with the constraints established by XENON100, CoGeNT and CDMS experiments, maching the relic abundance and the cross section with nucleon.
0903.5228
Paul Frampton
Paul H. Frampton
T' and the Cabibbo Angle
8 pages, Talk at 75 Years Since Solvay. Singapore. November 2008
Int.J.Mod.Phys.A24:3359-3365,2009
10.1142/S0217751X09046953
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The use of the binary tetrahedral group ($T^{'}$) as flavor symmetry is discussed. I emphasize the CKM quark and PMNS neutrino mixings. I present a novel formula for the Cabibbo angle.
[ { "created": "Mon, 30 Mar 2009 14:12:52 GMT", "version": "v1" } ]
2009-08-20
[ [ "Frampton", "Paul H.", "" ] ]
The use of the binary tetrahedral group ($T^{'}$) as flavor symmetry is discussed. I emphasize the CKM quark and PMNS neutrino mixings. I present a novel formula for the Cabibbo angle.
1303.3752
Alka Upadhyay
M. Batra, A. Upadhyay
Sea Quark and Gluon contributions to Strange Baryons and their Properties
4 pages, IOP Proceedings(2013)
Journal of Physics: Conference Series 481 (2014) 012024
10.1088/1742-6596/481/1/012024
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We treat the hadrons as an ensemble of quark-gluon Fock states where contributions from sea-quarks and gluons can be studied in detail for the properties of low lying baryons. Statistical model is applied to calculate individual probabilities from various scalar, vector and tensor sea components in flavor, spin and color subspaces for each quark-gluon Fock state. The mass of strange quark is imposed in terms of constraints to the availability of strange quarks in the sea and free energy of gluons in conformity with experimental indications. We calculate multiplicities for different sets of Fock states to compute the role of strange sea for cascade doublet {\Xi}+, and {\Xi}-.The low energy properties like magnetic moment, weak decay matrix elements and axial coupling constant ratios have been studied. The incorporation of strange quark gluon sea is discussed and they found to affect the results by almost 46% . The results provide deeper understanding for baryon structure thereby motivating experiments for further inspection, especially the spin distribution among the quarks and gluons.
[ { "created": "Fri, 15 Mar 2013 12:18:24 GMT", "version": "v1" }, { "created": "Sat, 16 Nov 2013 03:46:48 GMT", "version": "v2" } ]
2014-03-07
[ [ "Batra", "M.", "" ], [ "Upadhyay", "A.", "" ] ]
We treat the hadrons as an ensemble of quark-gluon Fock states where contributions from sea-quarks and gluons can be studied in detail for the properties of low lying baryons. Statistical model is applied to calculate individual probabilities from various scalar, vector and tensor sea components in flavor, spin and color subspaces for each quark-gluon Fock state. The mass of strange quark is imposed in terms of constraints to the availability of strange quarks in the sea and free energy of gluons in conformity with experimental indications. We calculate multiplicities for different sets of Fock states to compute the role of strange sea for cascade doublet {\Xi}+, and {\Xi}-.The low energy properties like magnetic moment, weak decay matrix elements and axial coupling constant ratios have been studied. The incorporation of strange quark gluon sea is discussed and they found to affect the results by almost 46% . The results provide deeper understanding for baryon structure thereby motivating experiments for further inspection, especially the spin distribution among the quarks and gluons.
1108.1206
Daniel Almeida Fagundes
D. A. Fagundes, E. G. S. Luna, M. J. Menon, A. A. Natale
Testing parameters in an eikonalized dynamical gluon mass model
misprints corrected, one reference updated and minor changes
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of a dynamical gluon mass model recently developed, we investigate the effects of two essential parameters in the description of elastic $pp$ and $\bar{p}p$ data at high energies: the soft Pomeron intercept and the dynamical gluon mass. By considering relevant numerical intervals for both parameters and fits to the experimental data up to 1.8 TeV, with good statistical results, we discuss the predictions of the physical quantities at the LHC energies (7 and 14 TeV). We conclude that these quantities are sensitive to those variations and the predictions are correlated with the intervals considered for both parameters. This conclusion puts limits on the reliability of QCD inspired models predictions at the LHC energies, mainly those models with ad hoc fixed values for the mass scale and the Pomeron intercept.
[ { "created": "Thu, 4 Aug 2011 20:10:18 GMT", "version": "v1" }, { "created": "Wed, 17 Aug 2011 15:52:00 GMT", "version": "v2" }, { "created": "Tue, 17 Jan 2012 15:15:43 GMT", "version": "v3" } ]
2012-01-18
[ [ "Fagundes", "D. A.", "" ], [ "Luna", "E. G. S.", "" ], [ "Menon", "M. J.", "" ], [ "Natale", "A. A.", "" ] ]
In the framework of a dynamical gluon mass model recently developed, we investigate the effects of two essential parameters in the description of elastic $pp$ and $\bar{p}p$ data at high energies: the soft Pomeron intercept and the dynamical gluon mass. By considering relevant numerical intervals for both parameters and fits to the experimental data up to 1.8 TeV, with good statistical results, we discuss the predictions of the physical quantities at the LHC energies (7 and 14 TeV). We conclude that these quantities are sensitive to those variations and the predictions are correlated with the intervals considered for both parameters. This conclusion puts limits on the reliability of QCD inspired models predictions at the LHC energies, mainly those models with ad hoc fixed values for the mass scale and the Pomeron intercept.
2102.03598
Sourav Pal
Neelima Agarwal, Lorenzo Magnea, Sourav Pal, Anurag Tripathi
Cwebs beyond three loops in multiparton amplitudes
51 pages, 37 figures, Published version, published in JHEP
null
10.1007/JHEP03(2021)188
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
Correlators of Wilson-line operators in non-abelian gauge theories are known to exponentiate, and their logarithms can be organised in terms of collections of Feynman diagrams called webs. In [1] we introduced the concept of Cweb, or correlator web, which is a set of skeleton diagrams built with connected gluon correlators, and we computed the mixing matrices for all Cwebs connecting four or five Wilson lines at four loops. Here we complete the evaluation of four-loop mixing matrices, presenting the results for all Cwebs connecting two and three Wilson lines. We observe that the conjuctured column sum rule is obeyed by all the mixing matrices that appear at four-loops. We also show how low-dimensional mixing matrices can be uniquely determined from their known combinatorial properties, and provide some all-order results for selected classes of mixing matrices. Our results complete the required colour building blocks for the calculation of the soft anomalous dimension matrix at four-loop order.
[ { "created": "Sat, 6 Feb 2021 15:31:54 GMT", "version": "v1" }, { "created": "Mon, 21 Jun 2021 06:57:35 GMT", "version": "v2" } ]
2021-06-22
[ [ "Agarwal", "Neelima", "" ], [ "Magnea", "Lorenzo", "" ], [ "Pal", "Sourav", "" ], [ "Tripathi", "Anurag", "" ] ]
Correlators of Wilson-line operators in non-abelian gauge theories are known to exponentiate, and their logarithms can be organised in terms of collections of Feynman diagrams called webs. In [1] we introduced the concept of Cweb, or correlator web, which is a set of skeleton diagrams built with connected gluon correlators, and we computed the mixing matrices for all Cwebs connecting four or five Wilson lines at four loops. Here we complete the evaluation of four-loop mixing matrices, presenting the results for all Cwebs connecting two and three Wilson lines. We observe that the conjuctured column sum rule is obeyed by all the mixing matrices that appear at four-loops. We also show how low-dimensional mixing matrices can be uniquely determined from their known combinatorial properties, and provide some all-order results for selected classes of mixing matrices. Our results complete the required colour building blocks for the calculation of the soft anomalous dimension matrix at four-loop order.
hep-ph/0401009
BingAn Li
Bing An Li
Correction of the low energy theorem of \gamma\to2\pi anomaly
14 pages
null
null
null
hep-ph
null
A correction of the low energy theorem of the \gamma\to3\pi anomaly has been found. A_{3\pi}(0,0,0) and the cross section are calculated. Theory agrees with data. There is no new adjustable parameter.
[ { "created": "Fri, 2 Jan 2004 17:19:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Li", "Bing An", "" ] ]
A correction of the low energy theorem of the \gamma\to3\pi anomaly has been found. A_{3\pi}(0,0,0) and the cross section are calculated. Theory agrees with data. There is no new adjustable parameter.
2309.16755
Manuel Reichert
Roman Pasechnik, Manuel Reichert, Francesco Sannino, Zhi-Wei Wang
Gravitational Waves from Composite Dark Sectors
19 pages, 8 figures
null
null
null
hep-ph astro-ph.CO hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study under which conditions a first-order phase transition in a composite dark sector can yield an observable stochastic gravitational-wave signal. To this end, we employ the Linear-Sigma model featuring $N_f=3,4,5$ flavours and perform a Cornwall-Jackiw-Tomboulis computation also accounting for the effects of the Polyakov loop. The model allows us to investigate the chiral phase transition in regimes that can mimic QCD-like theories incorporating in addition composite dynamics associated with the effects of confinement-deconfinement phase transition. A further benefit of this approach is that it allows to study the limit in which the effective interactions are weak. We show that strong first-order phase transitions occur for weak effective couplings of the composite sector leading to gravitational-wave signals potentially detectable at future experimental facilities.
[ { "created": "Thu, 28 Sep 2023 18:00:04 GMT", "version": "v1" } ]
2023-10-02
[ [ "Pasechnik", "Roman", "" ], [ "Reichert", "Manuel", "" ], [ "Sannino", "Francesco", "" ], [ "Wang", "Zhi-Wei", "" ] ]
We study under which conditions a first-order phase transition in a composite dark sector can yield an observable stochastic gravitational-wave signal. To this end, we employ the Linear-Sigma model featuring $N_f=3,4,5$ flavours and perform a Cornwall-Jackiw-Tomboulis computation also accounting for the effects of the Polyakov loop. The model allows us to investigate the chiral phase transition in regimes that can mimic QCD-like theories incorporating in addition composite dynamics associated with the effects of confinement-deconfinement phase transition. A further benefit of this approach is that it allows to study the limit in which the effective interactions are weak. We show that strong first-order phase transitions occur for weak effective couplings of the composite sector leading to gravitational-wave signals potentially detectable at future experimental facilities.
1903.12177
Xing-Gang Wu
Xing-Gang Wu, Jian-Ming Shen, Bo-Lun Du, Xu-Dong Huang, Sheng-Quan Wang and Stanley J. Brodsky
The QCD Renormalization Group Equation and the Elimination of Fixed-Order Scheme-and-Scale Ambiguities Using the Principle of Maximum Conformality
67 pages, 26 figures. Updated version which has been published as an invited review for Prog.Part.Nucl.Phys. arXiv admin note: text overlap with arXiv:1802.09154
Prog. Part. Nucl. Phys. 108, 103706 (2019)
10.1016/j.ppnp.2019.05.003
SLAC-PUB-17403
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The conventional approach to fixed-order perturbative QCD predictions is based on an arbitrary choice of the renormalization scale, together with an arbitrary range. This {\it ad hoc} assignment of the renormalization scale causes the coefficients of the QCD running coupling at each perturbative order to be strongly dependent on the choice of both the renormalization scale and the renormalization scheme. However, such ambiguities are not necessary, since as a basic requirement of renormalization group invariance (RGI), any physical observable must be independent of the choice of both the renormalization scheme and the renormalization scale. In fact, if one uses the {\it Principle of Maximum Conformality} (PMC) to fix the renormalization scale, the coefficients of the pQCD series match the series of conformal theory, and they are thus scheme independent. It has been found that the elimination of the scale and scheme ambiguities at all orders relies heavily on how precisely we know the analytic form of the QCD running coupling $\alpha_s$. In this review, we summarize the known properties of the QCD running coupling and its recent progresses, especially for its behavior within the asymptotic region. We also summarize the current progress on the PMC and some of its typical applications, showing to what degree the conventional renormalization scheme-and-scale ambiguities can be eliminated after applying the PMC. We also compare the PA approach for the conventional scale-dependent pQCD series and the PMC scale-independent conformal series. We observe that by using the conformal series, the PA approach can provide a more reliable estimate of the magnitude of the uncalculated terms. And if the conformal series for an observable has been calculated up to $n_{\rm th}$-order level, then the $[N/M]=[0/n-1]$-type PA series provides an important estimate for the higher-order terms.
[ { "created": "Wed, 27 Mar 2019 12:21:35 GMT", "version": "v1" }, { "created": "Sat, 25 May 2019 09:42:17 GMT", "version": "v2" }, { "created": "Wed, 6 Nov 2019 09:37:17 GMT", "version": "v3" } ]
2019-12-19
[ [ "Wu", "Xing-Gang", "" ], [ "Shen", "Jian-Ming", "" ], [ "Du", "Bo-Lun", "" ], [ "Huang", "Xu-Dong", "" ], [ "Wang", "Sheng-Quan", "" ], [ "Brodsky", "Stanley J.", "" ] ]
The conventional approach to fixed-order perturbative QCD predictions is based on an arbitrary choice of the renormalization scale, together with an arbitrary range. This {\it ad hoc} assignment of the renormalization scale causes the coefficients of the QCD running coupling at each perturbative order to be strongly dependent on the choice of both the renormalization scale and the renormalization scheme. However, such ambiguities are not necessary, since as a basic requirement of renormalization group invariance (RGI), any physical observable must be independent of the choice of both the renormalization scheme and the renormalization scale. In fact, if one uses the {\it Principle of Maximum Conformality} (PMC) to fix the renormalization scale, the coefficients of the pQCD series match the series of conformal theory, and they are thus scheme independent. It has been found that the elimination of the scale and scheme ambiguities at all orders relies heavily on how precisely we know the analytic form of the QCD running coupling $\alpha_s$. In this review, we summarize the known properties of the QCD running coupling and its recent progresses, especially for its behavior within the asymptotic region. We also summarize the current progress on the PMC and some of its typical applications, showing to what degree the conventional renormalization scheme-and-scale ambiguities can be eliminated after applying the PMC. We also compare the PA approach for the conventional scale-dependent pQCD series and the PMC scale-independent conformal series. We observe that by using the conformal series, the PA approach can provide a more reliable estimate of the magnitude of the uncalculated terms. And if the conformal series for an observable has been calculated up to $n_{\rm th}$-order level, then the $[N/M]=[0/n-1]$-type PA series provides an important estimate for the higher-order terms.
hep-ph/0410092
Roberto Bonciani
R. Bonciani
Two-loop QCD corrections to the vector form factors for the heavy-quark photo-production
Talk presented at the 11th International QCD Conference: QCD04, Montpellier, France, 5-10 July 2004; 4 pages, 4 figures
null
10.1016/j.nuclphysbps.2005.08.032
null
hep-ph
null
We review on the calculation of the heavy-quark photo-production vector form factors, with the full dependence on the mass of the heavy-quark. The Feynman diagrams are evaluated within the dimensional regularization scheme and expressed in Laurent series of $\epsilon=(4-D)/2$, where $D$ is the space-time dimension. The coefficients of the expansion are expressed in terms of harmonic polylogarithms. The numerical evaluation of the analytical formulas and the threshold limit of our results are presented.
[ { "created": "Wed, 6 Oct 2004 14:55:44 GMT", "version": "v1" } ]
2015-06-25
[ [ "Bonciani", "R.", "" ] ]
We review on the calculation of the heavy-quark photo-production vector form factors, with the full dependence on the mass of the heavy-quark. The Feynman diagrams are evaluated within the dimensional regularization scheme and expressed in Laurent series of $\epsilon=(4-D)/2$, where $D$ is the space-time dimension. The coefficients of the expansion are expressed in terms of harmonic polylogarithms. The numerical evaluation of the analytical formulas and the threshold limit of our results are presented.
hep-ph/0110057
Nikolai Achasov
N.N. Achasov (Sobolev Institute for Mathematics SB RAS, Novosibirsk)
Relative phase between the three-gluon and one-photon amplitudes of the J/psi decays
Parallel session talk at HADRON 2001, Protvino, Russia, August 30, 4 pages, revtex, tightlines
AIP Conf.Proc. 619 (2002) 649-652
10.1063/1.1482510
null
hep-ph hep-ex nucl-th
null
It is shown that the study of the \omega-\rho interference pattern in the J/psi -> (rho+omega)eta -> pi+pi-eta decay provides evidence for the large (nearly 90 degrees) relative phase between the isovector one-photon and three-gluon decay amplitudes.
[ { "created": "Thu, 4 Oct 2001 09:51:33 GMT", "version": "v1" } ]
2009-11-07
[ [ "Achasov", "N. N.", "", "Sobolev Institute for Mathematics SB RAS, Novosibirsk" ] ]
It is shown that the study of the \omega-\rho interference pattern in the J/psi -> (rho+omega)eta -> pi+pi-eta decay provides evidence for the large (nearly 90 degrees) relative phase between the isovector one-photon and three-gluon decay amplitudes.
2110.02234
Cristian Gaidau
Cristian Gaidau and Jessie Shelton
Singularities in the Gravitational Capture of Dark Matter through Long-Range Interactions
v2: version accepted for publication in JCAP; 30 pages, 5 figures
null
10.1088/1475-7516/2022/01/016
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We re-examine the gravitational capture of dark matter (DM) through long-range interactions. We demonstrate that neglecting the thermal motion of target particles, which is often a good approximation for short-range capture, results in parametrically inaccurate results for long-range capture. When the particle mediating the scattering process has a mass that is small in comparison to the momentum transfer in scattering events, correctly incorporating the thermal motion of target particles results in a quadratic, rather than logarithmic, sensitivity to the mediator mass, which substantially enhances the capture rate. We quantitatively assess the impact of this finite temperature effect on the captured DM population in the Sun as a function of mediator mass. We find that capture of DM through light dark photons, as in e.g. mirror DM, can be powerfully enhanced, with self-capture attaining a geometric limit over much of parameter space. For visibly-decaying dark photons, thermal corrections are not large in the Sun, but may be important in understanding long-range DM capture in more massive bodies such as Population III stars. We additionally provide the first calculation of the long-range DM self-evaporation rate.
[ { "created": "Tue, 5 Oct 2021 18:00:03 GMT", "version": "v1" }, { "created": "Wed, 22 Dec 2021 04:15:37 GMT", "version": "v2" } ]
2022-01-19
[ [ "Gaidau", "Cristian", "" ], [ "Shelton", "Jessie", "" ] ]
We re-examine the gravitational capture of dark matter (DM) through long-range interactions. We demonstrate that neglecting the thermal motion of target particles, which is often a good approximation for short-range capture, results in parametrically inaccurate results for long-range capture. When the particle mediating the scattering process has a mass that is small in comparison to the momentum transfer in scattering events, correctly incorporating the thermal motion of target particles results in a quadratic, rather than logarithmic, sensitivity to the mediator mass, which substantially enhances the capture rate. We quantitatively assess the impact of this finite temperature effect on the captured DM population in the Sun as a function of mediator mass. We find that capture of DM through light dark photons, as in e.g. mirror DM, can be powerfully enhanced, with self-capture attaining a geometric limit over much of parameter space. For visibly-decaying dark photons, thermal corrections are not large in the Sun, but may be important in understanding long-range DM capture in more massive bodies such as Population III stars. We additionally provide the first calculation of the long-range DM self-evaporation rate.
2401.13896
Sarira Sahu
Jos\'e F. Nieves and Sarira Sahu
Photon propagation in a charged Bose-Einstein condensate
19 pages, 7 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider the propagation of photons in a model of a charged scalar Bose-Einstein (BE) condensate. We determine the dispersion relations of the collective modes, as well as the photon polarization tensor and the dielectric constant in the model. Two modes correspond to the transverse photon polarizations, with dispersion relations of the usual form for transverse photons in a plasma. The other two modes, denoted as the $(\pm)$ modes, are combinations of the longitudinal photon and the massive scalar field. Their dispersion relations behave very differently as functions of momentum. The $(+)$ mode dispersion relation increases steadily and remains greater than the momentum as the momentum increases. The dispersion relation of the $(-)$ mode decreases in a given momentum range, with the group velocity being negative in that range, while in another range it increases steadily but remains smaller than the momentum, akin to the situation in a medium with an index of refraction greater than 1. We consider the non-relativistic limit of the $(\pm)$ dispersion relations and discuss some aspects of the results. We also determine the wavefunctions of the $(\pm)$ modes, which are useful to obtain the corrections to the dispersion relations, e.g., imaginary parts due to the damping effects and/or the effects of scattering, due to the interactions with the excitations of the system. The results can be useful in various physical contexts that have been considered in the literature involving the electrodynamics of a charged scalar BE condensate.
[ { "created": "Thu, 25 Jan 2024 02:23:50 GMT", "version": "v1" }, { "created": "Tue, 30 Jul 2024 18:52:27 GMT", "version": "v2" } ]
2024-08-01
[ [ "Nieves", "José F.", "" ], [ "Sahu", "Sarira", "" ] ]
We consider the propagation of photons in a model of a charged scalar Bose-Einstein (BE) condensate. We determine the dispersion relations of the collective modes, as well as the photon polarization tensor and the dielectric constant in the model. Two modes correspond to the transverse photon polarizations, with dispersion relations of the usual form for transverse photons in a plasma. The other two modes, denoted as the $(\pm)$ modes, are combinations of the longitudinal photon and the massive scalar field. Their dispersion relations behave very differently as functions of momentum. The $(+)$ mode dispersion relation increases steadily and remains greater than the momentum as the momentum increases. The dispersion relation of the $(-)$ mode decreases in a given momentum range, with the group velocity being negative in that range, while in another range it increases steadily but remains smaller than the momentum, akin to the situation in a medium with an index of refraction greater than 1. We consider the non-relativistic limit of the $(\pm)$ dispersion relations and discuss some aspects of the results. We also determine the wavefunctions of the $(\pm)$ modes, which are useful to obtain the corrections to the dispersion relations, e.g., imaginary parts due to the damping effects and/or the effects of scattering, due to the interactions with the excitations of the system. The results can be useful in various physical contexts that have been considered in the literature involving the electrodynamics of a charged scalar BE condensate.
2110.07517
Chun-Wei Su
Chuan-Hung Chen, Cheng-Wei Chiang, Chun-Wei Su
Ultra-high-energy neutrino scattering in an anomalous U(1) effective field theory
18 pages, 6 figures, version published in Physics Letters B
null
10.1016/j.physletb.2022.136988
null
hep-ph astro-ph.HE hep-ex
http://creativecommons.org/licenses/by-sa/4.0/
A unique characteristic of exponentially growing scattering amplitude arises in an anomalous Abelian effective field theory when an extremely light Dirac neutrino mass is introduced to break the symmetry. We show that the low energy effective Lagrangian can be made explicitly gauge invariant with the help of a nonlinear representation of the Goldstone or Stueckelberg field. We study the peculiar feature of exponential growth in the ultra-high-energy neutrino-nucleon inelastic scattering. It is found that the inelastic scattering cross section is highly sensitive to the ratio of gauge coupling to the gauge boson mass, $g_X/m_X$. When the IceCube measurement of ultra-high-energy neutrinos, which is consistent with the standard model prediction up to $E_\nu \sim 6$ PeV, is taken into account, the inferred constraint on $g_X/m_X$ is more severe than that obtained from the events of mono-lepton$+$missing transverse energy at the LHC. A muon collider with a collision energy of $10$ TeV can be a good environment other than hadron colliders to probe the novel effect.
[ { "created": "Thu, 14 Oct 2021 16:40:32 GMT", "version": "v1" }, { "created": "Fri, 22 Oct 2021 16:00:57 GMT", "version": "v2" }, { "created": "Mon, 21 Feb 2022 17:09:45 GMT", "version": "v3" }, { "created": "Wed, 5 Oct 2022 15:39:39 GMT", "version": "v4" } ]
2022-10-06
[ [ "Chen", "Chuan-Hung", "" ], [ "Chiang", "Cheng-Wei", "" ], [ "Su", "Chun-Wei", "" ] ]
A unique characteristic of exponentially growing scattering amplitude arises in an anomalous Abelian effective field theory when an extremely light Dirac neutrino mass is introduced to break the symmetry. We show that the low energy effective Lagrangian can be made explicitly gauge invariant with the help of a nonlinear representation of the Goldstone or Stueckelberg field. We study the peculiar feature of exponential growth in the ultra-high-energy neutrino-nucleon inelastic scattering. It is found that the inelastic scattering cross section is highly sensitive to the ratio of gauge coupling to the gauge boson mass, $g_X/m_X$. When the IceCube measurement of ultra-high-energy neutrinos, which is consistent with the standard model prediction up to $E_\nu \sim 6$ PeV, is taken into account, the inferred constraint on $g_X/m_X$ is more severe than that obtained from the events of mono-lepton$+$missing transverse energy at the LHC. A muon collider with a collision energy of $10$ TeV can be a good environment other than hadron colliders to probe the novel effect.
1805.09182
Herschel A. Chawdhry
Herschel A. Chawdhry, Matthew A. Lim and Alexander Mitov
Two-loop five-point massless QCD amplitudes within the IBP approach
6 pages, 1 ancillary file, results available from "http://www.precision.hep.phy.cam.ac.uk/results/amplitudes/". v2 (published version): added references
Phys. Rev. D 99, 076011 (2019)
10.1103/PhysRevD.99.076011
Cavendish-HEP-18/11
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We solve the integration-by-parts (IBP) identities needed for the computation of any planar two-loop five-point massless amplitude in QCD. We also derive some new results for the most complicated non-planar topology with irreducible numerators of power as high as six. We do this by applying a new strategy for solving the IBP identities which scales better for problems with a large number of scales and/or master integrals. Our results are a proof of principle that the remaining non-planar contributions for all two-loop five-point massless QCD amplitudes can be computed in analytic form.
[ { "created": "Wed, 23 May 2018 14:01:45 GMT", "version": "v1" }, { "created": "Sun, 11 Aug 2019 17:24:02 GMT", "version": "v2" } ]
2019-08-13
[ [ "Chawdhry", "Herschel A.", "" ], [ "Lim", "Matthew A.", "" ], [ "Mitov", "Alexander", "" ] ]
We solve the integration-by-parts (IBP) identities needed for the computation of any planar two-loop five-point massless amplitude in QCD. We also derive some new results for the most complicated non-planar topology with irreducible numerators of power as high as six. We do this by applying a new strategy for solving the IBP identities which scales better for problems with a large number of scales and/or master integrals. Our results are a proof of principle that the remaining non-planar contributions for all two-loop five-point massless QCD amplitudes can be computed in analytic form.
2001.09487
Helen Matskevich
S.M. Gerasyuta and E.E. Matskevich
Baryonia with open and hidden strange
9 pages. arXiv admin note: substantial text overlap with arXiv:1009.3365, arXiv:1105.0824, arXiv:1105.0817, arXiv:1109.2338, arXiv:1211.0667, arXiv:1212.0444
null
10.1142/S0218301320500354
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The relativistic six-quark equations are found in the framework of the dispersion relation technique. The strange baryonia are constructed without the mixing of the quarks and antiquarks. The relativistic six-quark amplitudes of the strange baryonia with the open and hidden strange are calculated. The poles of these amplitudes determine the masses of strange baryonia. 17 masses of baryonia are predicted.
[ { "created": "Sun, 26 Jan 2020 17:14:42 GMT", "version": "v1" } ]
2020-08-26
[ [ "Gerasyuta", "S. M.", "" ], [ "Matskevich", "E. E.", "" ] ]
The relativistic six-quark equations are found in the framework of the dispersion relation technique. The strange baryonia are constructed without the mixing of the quarks and antiquarks. The relativistic six-quark amplitudes of the strange baryonia with the open and hidden strange are calculated. The poles of these amplitudes determine the masses of strange baryonia. 17 masses of baryonia are predicted.
hep-ph/0307119
M. N. Rebelo
G. C. Branco, P. A. Parada and M. N. Rebelo
A Common Origin for all CP Violations
4 pages, no figures, uses revtex4
null
null
CERN-TH/2003-153
hep-ph
null
We put forward the conjecture that all CP violating phenomena may have a common origin. In order to illustrate our idea, we present a minimal model where CP is spontaneously broken at a high energy scale, through the phase in the vacuum expectation value of a complex scalar singlet. This single phase is the origin of both low energy CP violation in the quark and leptonic sectors, as well as leptogenesis. We also show that in this framework the strong CP problem may be solved in a simple way through the introduction of a Z_4 symmetry which allows for the implementation of the Nelson-Barr mechanism.
[ { "created": "Tue, 8 Jul 2003 18:59:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Branco", "G. C.", "" ], [ "Parada", "P. A.", "" ], [ "Rebelo", "M. N.", "" ] ]
We put forward the conjecture that all CP violating phenomena may have a common origin. In order to illustrate our idea, we present a minimal model where CP is spontaneously broken at a high energy scale, through the phase in the vacuum expectation value of a complex scalar singlet. This single phase is the origin of both low energy CP violation in the quark and leptonic sectors, as well as leptogenesis. We also show that in this framework the strong CP problem may be solved in a simple way through the introduction of a Z_4 symmetry which allows for the implementation of the Nelson-Barr mechanism.
1902.05614
Istv\'an Szanyi
L\'aszl\'o Jenkovszky, Rainer Schicker, Istv\'an Szanyi
Elastic and diffractive scattering in the LHC era
45 pages, 38 figures, 2 tables
International Journal of Modern Physics E Vol. 27, No. 08, 1830005 (2018)
10.1142/S0218301318300059
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review elastic and diffractive scattering of protons (called also "forward physics") with emphasis on the LHC data, especially those deviating from the expectations based on extrapolations from earlier measurements at the ISR, Fermilab and thus triggering searches for new ideas, models and theories. We list these new data and provide a brief introduction of available theoretical approaches, mainly those based on analyticity, crossing symmetry and unitarity, particularly the Regge-pole model realizing these concepts. Fits to the data are presented and tensions between theoretical predictions and the data that may indicate the way to further progress are in the focus of our paper.
[ { "created": "Thu, 14 Feb 2019 21:47:27 GMT", "version": "v1" } ]
2019-02-18
[ [ "Jenkovszky", "László", "" ], [ "Schicker", "Rainer", "" ], [ "Szanyi", "István", "" ] ]
We review elastic and diffractive scattering of protons (called also "forward physics") with emphasis on the LHC data, especially those deviating from the expectations based on extrapolations from earlier measurements at the ISR, Fermilab and thus triggering searches for new ideas, models and theories. We list these new data and provide a brief introduction of available theoretical approaches, mainly those based on analyticity, crossing symmetry and unitarity, particularly the Regge-pole model realizing these concepts. Fits to the data are presented and tensions between theoretical predictions and the data that may indicate the way to further progress are in the focus of our paper.
1905.10537
Yi-Peng Wu
Yi-Peng Wu, Louis Yang, Alexander Kusenko
Leptogenesis from spontaneous symmetry breaking during inflation
21 + 2 pages, 13 + 1 figures; added discussion on non-perturbative Higgs decay; references updated; version matched with publication
null
10.1007/JHEP12(2019)088
RESCEU 6/19, IPMU19-0079
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Symmetry breaking in the Higgs field via a non-minimal coupling to gravity or higher-dimensional interactions with the inflaton can lead to condensation at a large vacuum expectation value (VEV) during inflation. After inflation is over, the Higgs field must relax to the minimum of its effective potential, creating an era in which the CPT is effectively broken by the time-depended VEV. We show that the matter-antimatter asymmetry can be generated during this relaxation epoch.
[ { "created": "Sat, 25 May 2019 07:05:06 GMT", "version": "v1" }, { "created": "Fri, 26 Jul 2019 07:09:13 GMT", "version": "v2" }, { "created": "Fri, 17 Jan 2020 16:59:53 GMT", "version": "v3" } ]
2020-01-20
[ [ "Wu", "Yi-Peng", "" ], [ "Yang", "Louis", "" ], [ "Kusenko", "Alexander", "" ] ]
Symmetry breaking in the Higgs field via a non-minimal coupling to gravity or higher-dimensional interactions with the inflaton can lead to condensation at a large vacuum expectation value (VEV) during inflation. After inflation is over, the Higgs field must relax to the minimum of its effective potential, creating an era in which the CPT is effectively broken by the time-depended VEV. We show that the matter-antimatter asymmetry can be generated during this relaxation epoch.
0808.3977
Brian Batell
Brian Batell, Tony Gherghetta, Daniel Sword
The Soft-Wall Standard Model
32 pages, 3 figures
Phys.Rev.D78:116011,2008
10.1103/PhysRevD.78.116011
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the possibility of modeling electroweak physics in a warped extra dimension with a soft wall. The infrared boundary is replaced with a smoothly varying dilaton field that provides a dynamical spacetime cutoff. We analyze gravity, gauge fields, and fermions in the soft-wall background and obtain a discrete spectrum of Kaluza-Klein states which can exhibit linear Regge-like behavior. Bulk Yukawa interactions give rise to nonconstant fermion mass terms, leading to fermion localization in the soft-wall background and a possible explanation of the Standard Model flavor structure. Furthermore we construct electroweak models with custodial symmetry, where the gauge symmetry is broken with a bulk Higgs condensate. The electroweak constraints are not as stringent as in hard-wall models, allowing Kaluza-Klein masses of order the TeV scale.
[ { "created": "Thu, 28 Aug 2008 19:38:26 GMT", "version": "v1" } ]
2008-12-30
[ [ "Batell", "Brian", "" ], [ "Gherghetta", "Tony", "" ], [ "Sword", "Daniel", "" ] ]
We explore the possibility of modeling electroweak physics in a warped extra dimension with a soft wall. The infrared boundary is replaced with a smoothly varying dilaton field that provides a dynamical spacetime cutoff. We analyze gravity, gauge fields, and fermions in the soft-wall background and obtain a discrete spectrum of Kaluza-Klein states which can exhibit linear Regge-like behavior. Bulk Yukawa interactions give rise to nonconstant fermion mass terms, leading to fermion localization in the soft-wall background and a possible explanation of the Standard Model flavor structure. Furthermore we construct electroweak models with custodial symmetry, where the gauge symmetry is broken with a bulk Higgs condensate. The electroweak constraints are not as stringent as in hard-wall models, allowing Kaluza-Klein masses of order the TeV scale.
hep-ph/0612334
Hirotaka Sugawara
Hirotaka Sugawara
Space-Time Duality and Vacuum Energy
23 pages total with 2 figures
null
null
null
hep-ph astro-ph hep-th
null
The concept of Euclidean time is proposed which is dual to the usual Minkowski time. The De Sitter solution is shown to be dual to the anti-De Sitter solution under the dual transformation in which Euclidean time and Minkowski time are interchanged. This observation enables us to make a proposal in which supersymmetry is broken, but the four dimensional cosmological constant remains zero. An explicit model is proposed in which we calculate the cosmological constant. The phenomenology based on this model is presented, including the issue of the quark-lepton-Higgs mass matrix.
[ { "created": "Wed, 27 Dec 2006 03:54:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sugawara", "Hirotaka", "" ] ]
The concept of Euclidean time is proposed which is dual to the usual Minkowski time. The De Sitter solution is shown to be dual to the anti-De Sitter solution under the dual transformation in which Euclidean time and Minkowski time are interchanged. This observation enables us to make a proposal in which supersymmetry is broken, but the four dimensional cosmological constant remains zero. An explicit model is proposed in which we calculate the cosmological constant. The phenomenology based on this model is presented, including the issue of the quark-lepton-Higgs mass matrix.
1112.2659
Isabella Masina
Isabella Masina, Alessio Notari
The Higgs mass range from Standard Model false vacuum Inflation in scalar-tensor gravity
v1: 14 pages, 4 figures; v2: 18 pages, 8 figures, text improved, new section and figures added
null
10.1103/PhysRevD.85.123506
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If the Standard Model is valid up to very high energies it is known that the Higgs potential can develop a local minimum at field values around $10^{15}-10^{17}$ GeV, for a narrow band of values of the top quark and Higgs masses. We show that in a scalar-tensor theory of gravity such Higgs false vacuum can give rise to viable inflation if the potential barrier is very shallow, allowing for tunneling and relaxation into the electroweak scale true vacuum. The amplitude of cosmological density perturbations from inflation is directly linked to the value of the Higgs potential at the false minimum. Requiring the top quark mass, the amplitude and spectral index of density perturbations to be compatible with observations, selects a narrow range of values for the Higgs mass, $m_H=126.0\pm 3.5$ GeV, where the error is mostly due to the theoretical uncertainty of the 2-loop RGE. This prediction could be soon tested at the Large Hadron Collider. Our inflationary scenario could also be further checked by better constraining the spectral index and the tensor-to-scalar ratio.
[ { "created": "Mon, 12 Dec 2011 19:19:19 GMT", "version": "v1" }, { "created": "Mon, 5 Mar 2012 18:41:21 GMT", "version": "v2" } ]
2013-05-30
[ [ "Masina", "Isabella", "" ], [ "Notari", "Alessio", "" ] ]
If the Standard Model is valid up to very high energies it is known that the Higgs potential can develop a local minimum at field values around $10^{15}-10^{17}$ GeV, for a narrow band of values of the top quark and Higgs masses. We show that in a scalar-tensor theory of gravity such Higgs false vacuum can give rise to viable inflation if the potential barrier is very shallow, allowing for tunneling and relaxation into the electroweak scale true vacuum. The amplitude of cosmological density perturbations from inflation is directly linked to the value of the Higgs potential at the false minimum. Requiring the top quark mass, the amplitude and spectral index of density perturbations to be compatible with observations, selects a narrow range of values for the Higgs mass, $m_H=126.0\pm 3.5$ GeV, where the error is mostly due to the theoretical uncertainty of the 2-loop RGE. This prediction could be soon tested at the Large Hadron Collider. Our inflationary scenario could also be further checked by better constraining the spectral index and the tensor-to-scalar ratio.
2303.13979
Piotr Lebiedowicz
Piotr Lebiedowicz, Otto Nachtmann, Antoni Szczurek
Exclusive diffractive bremsstrahlung of one and two photons at forward rapidities: Possibilities for experimental studies in $pp$ collisions at the LHC
18 pages, 9 figures. In v2 we discussed the role of the $p p \to p p \pi^0$ background for single photon production
Phys.Lett.B 843 (2023) 138053
10.1016/j.physletb.2023.138053
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We evaluate the cross section for diffractive bremsstrahlung of a single photon in the $pp \to pp \gamma$ reaction at high energies and at forward photon rapidities. Several differential distributions, for instance, in $y$, $k_{\perp}$ and $\omega$, the rapidity, the absolute value of the transverse momentum, and the energy of the photon, respectively, are presented. We compare the results for our standard approach, based on QFT and the tensor-pomeron model, with two versions of soft-photon-approximations, SPA1 and SPA2, where the radiative amplitudes contain only the leading terms proportional to $\omega^{-1}$. The SPA1, which does not have the correct energy-momentum relations, performs surprisingly well in the kinematic range considered. We discuss also azimuthal correlations between outgoing particles. The azimuthal distributions are not isotropic and are different for our standard model and SPAs. We discuss also the possibility of a measurement of two-photon-bremsstrahlung in the $pp \to pp \gamma \gamma$ reaction. In our calculations we impose a cut on the relative energy loss ($0.02 < \xi_{i} < 0.1$, $i = 1,2$) of the protons where measurements by the ATLAS Forward Proton (AFP) detectors are possible. The AFP requirement for both diffractively scattered protons and one forward photon (measured at LHCf) reduces the cross section for $p p \to p p \gamma$ almost to zero. On the other hand, much less cross-section reduction occurs for $pp \to pp \gamma \gamma$ when photons are emitted in opposite sides of the ATLAS interaction point and can be measured by two different arms of LHCf. For the SPA1 ansatz we find $\sigma(pp \to pp \gamma \gamma) \simeq 0.03$ nb at $\sqrt{s} = 13$ TeV and with the cuts $0.02 < \xi_{i} < 0.1$, $8.5 < y_{3} < 9$, $-9 < y_{4} < -8.5$. Our predictions can be verified by ATLAS and LHCf combined experiments.
[ { "created": "Fri, 24 Mar 2023 13:05:53 GMT", "version": "v1" }, { "created": "Mon, 10 Jul 2023 05:56:57 GMT", "version": "v2" } ]
2023-07-11
[ [ "Lebiedowicz", "Piotr", "" ], [ "Nachtmann", "Otto", "" ], [ "Szczurek", "Antoni", "" ] ]
We evaluate the cross section for diffractive bremsstrahlung of a single photon in the $pp \to pp \gamma$ reaction at high energies and at forward photon rapidities. Several differential distributions, for instance, in $y$, $k_{\perp}$ and $\omega$, the rapidity, the absolute value of the transverse momentum, and the energy of the photon, respectively, are presented. We compare the results for our standard approach, based on QFT and the tensor-pomeron model, with two versions of soft-photon-approximations, SPA1 and SPA2, where the radiative amplitudes contain only the leading terms proportional to $\omega^{-1}$. The SPA1, which does not have the correct energy-momentum relations, performs surprisingly well in the kinematic range considered. We discuss also azimuthal correlations between outgoing particles. The azimuthal distributions are not isotropic and are different for our standard model and SPAs. We discuss also the possibility of a measurement of two-photon-bremsstrahlung in the $pp \to pp \gamma \gamma$ reaction. In our calculations we impose a cut on the relative energy loss ($0.02 < \xi_{i} < 0.1$, $i = 1,2$) of the protons where measurements by the ATLAS Forward Proton (AFP) detectors are possible. The AFP requirement for both diffractively scattered protons and one forward photon (measured at LHCf) reduces the cross section for $p p \to p p \gamma$ almost to zero. On the other hand, much less cross-section reduction occurs for $pp \to pp \gamma \gamma$ when photons are emitted in opposite sides of the ATLAS interaction point and can be measured by two different arms of LHCf. For the SPA1 ansatz we find $\sigma(pp \to pp \gamma \gamma) \simeq 0.03$ nb at $\sqrt{s} = 13$ TeV and with the cuts $0.02 < \xi_{i} < 0.1$, $8.5 < y_{3} < 9$, $-9 < y_{4} < -8.5$. Our predictions can be verified by ATLAS and LHCf combined experiments.
1805.03475
Abdulkadir Senol
A. Senol, H. Denizli, A. Yilmaz, I. Turk Cakir, K.Y. Oyulmaz, O. Karadeniz and O. Cakir
Probing the Effects of Dimension-eight Operators Describing Anomalous Neutral Triple Gauge Boson Interactions at FCC-hh
16 pages, 9 figures, 8 Tables, accepted for publication in Nuclear Physics B
Nucl. Phys. B935 (2018) 365-376
10.1016/j.nuclphysb.2018.08.018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effects of dimension-eight operators giving rise to anomalous neutral triple gauge boson interactions of $Z\gamma\gamma$ and $Z\gamma Z$ vertices in $pp\to l^-l^+\gamma$ and $pp\to \nu\bar \nu \gamma$ are investigated at 100 TeV centre of mass energy of future circular hadron collider (FCC-hh). The transverse momentum of photon, invariant mass of $l^-l^+\gamma$ and angular distribution of charged lepton in the rest frame of $l^-l^+$ and Missing Energy Transverse (MET) are considered in the analysis. The realistic detector effects are also included with Delphes simulation. Sensitivity limits obtained at 95\% C.L. for $C_{\widetilde B W}/\Lambda^4$ and $C_{B B}/\Lambda^4$ couplings are $[-0.52;0.52] ([-0.40;0.40])$ TeV$^{-4}$, $[-0.43;0.43] ([-0.33;0.33])$ TeV$^{-4}$ in the dilepton+photon channel and $[-0.11;0.11] ([-0.084;0.084])$ TeV$^{-4}$, $[-0.092;0.092] ([-0.072;0.072])$ TeV$^{-4}$ in the MET+photon channel with $L_{int}$=1 (3) ab$^{-1}$, respectively.
[ { "created": "Wed, 9 May 2018 12:27:39 GMT", "version": "v1" }, { "created": "Tue, 4 Sep 2018 14:15:53 GMT", "version": "v2" } ]
2018-09-12
[ [ "Senol", "A.", "" ], [ "Denizli", "H.", "" ], [ "Yilmaz", "A.", "" ], [ "Cakir", "I. Turk", "" ], [ "Oyulmaz", "K. Y.", "" ], [ "Karadeniz", "O.", "" ], [ "Cakir", "O.", "" ] ]
The effects of dimension-eight operators giving rise to anomalous neutral triple gauge boson interactions of $Z\gamma\gamma$ and $Z\gamma Z$ vertices in $pp\to l^-l^+\gamma$ and $pp\to \nu\bar \nu \gamma$ are investigated at 100 TeV centre of mass energy of future circular hadron collider (FCC-hh). The transverse momentum of photon, invariant mass of $l^-l^+\gamma$ and angular distribution of charged lepton in the rest frame of $l^-l^+$ and Missing Energy Transverse (MET) are considered in the analysis. The realistic detector effects are also included with Delphes simulation. Sensitivity limits obtained at 95\% C.L. for $C_{\widetilde B W}/\Lambda^4$ and $C_{B B}/\Lambda^4$ couplings are $[-0.52;0.52] ([-0.40;0.40])$ TeV$^{-4}$, $[-0.43;0.43] ([-0.33;0.33])$ TeV$^{-4}$ in the dilepton+photon channel and $[-0.11;0.11] ([-0.084;0.084])$ TeV$^{-4}$, $[-0.092;0.092] ([-0.072;0.072])$ TeV$^{-4}$ in the MET+photon channel with $L_{int}$=1 (3) ab$^{-1}$, respectively.
1901.05213
Maximilian Delto
Maximilian Delto, Kirill Melnikov
Integrated triple-collinear counter-terms for the nested soft-collinear subtraction scheme
published version
null
10.1007/JHEP05(2019)148
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain analytic results for integrated triple-collinear splitting functions that emerge as collinear counter-terms in the context of the nested soft-collinear subtraction scheme arXiv:1702.01352 . With these results, all integrated subtraction terms required for NNLO QCD computations within this scheme are known analytically. In addition to improving efficiency and numerical stability of practical computations, the availability of these results will contribute towards establishing a general NNLO QCD subtraction formula for generic hard scattering processes in hadron collisions, similar to Catani-Seymour and FKS subtractions at NLO.
[ { "created": "Wed, 16 Jan 2019 10:26:06 GMT", "version": "v1" }, { "created": "Thu, 17 Jan 2019 18:17:10 GMT", "version": "v2" }, { "created": "Fri, 16 Aug 2019 09:25:24 GMT", "version": "v3" } ]
2019-08-19
[ [ "Delto", "Maximilian", "" ], [ "Melnikov", "Kirill", "" ] ]
We obtain analytic results for integrated triple-collinear splitting functions that emerge as collinear counter-terms in the context of the nested soft-collinear subtraction scheme arXiv:1702.01352 . With these results, all integrated subtraction terms required for NNLO QCD computations within this scheme are known analytically. In addition to improving efficiency and numerical stability of practical computations, the availability of these results will contribute towards establishing a general NNLO QCD subtraction formula for generic hard scattering processes in hadron collisions, similar to Catani-Seymour and FKS subtractions at NLO.
1206.6537
Kyle Huggins
Kyle Huggins, Ralf Rapp
A T-Matrix Calculation for in-Medium Heavy-Quark Gluon Scattering
null
null
10.1016/j.nuclphysa.2012.09.008
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The interactions of charm and bottom quarks in a Quark-Gluon Plasma (QGP) are evaluated using a thermodynamic 2-body T-matrix. We specifically focus on heavy-quark (HQ) interactions with thermal gluons with an input potential motivated by lattice-QCD computations of the HQ free energy. The latter is implemented into a field-theoretic ansatz for color-Coulomb and (remnants of) confining interactions. This, in particular, enables to discuss corrections to the potential approach, specifically hard-thermal-loop corrections to the vertices, relativistic corrections deduced from pertinent Feynman diagrams, and a suitable projection on transverse thermal gluons. The resulting potentials are applied to compute scattering amplitudes in different color channels and utilized for a calculation of the corresponding HQ drag coefficient in the QGP. A factor of ~2-3 enhancement over perturbative results is obtained, mainly driven by the resummation in the attractive color-channels.
[ { "created": "Wed, 27 Jun 2012 23:03:53 GMT", "version": "v1" } ]
2015-06-05
[ [ "Huggins", "Kyle", "" ], [ "Rapp", "Ralf", "" ] ]
The interactions of charm and bottom quarks in a Quark-Gluon Plasma (QGP) are evaluated using a thermodynamic 2-body T-matrix. We specifically focus on heavy-quark (HQ) interactions with thermal gluons with an input potential motivated by lattice-QCD computations of the HQ free energy. The latter is implemented into a field-theoretic ansatz for color-Coulomb and (remnants of) confining interactions. This, in particular, enables to discuss corrections to the potential approach, specifically hard-thermal-loop corrections to the vertices, relativistic corrections deduced from pertinent Feynman diagrams, and a suitable projection on transverse thermal gluons. The resulting potentials are applied to compute scattering amplitudes in different color channels and utilized for a calculation of the corresponding HQ drag coefficient in the QGP. A factor of ~2-3 enhancement over perturbative results is obtained, mainly driven by the resummation in the attractive color-channels.
1102.4562
Sacha Davidson
Sacha Davidson, Patrice Verdier
Leptoquarks decaying to a top quark and a charged lepton at hadron colliders
13 pages, 6 figures, minor changes (typos)
Phys.Rev.D83:115016,2011
10.1103/PhysRevD.83.115016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the sensitivity of the Tevatron and the 7 TeV LHC to a leptoquark S coupling to a top quark and a charged lepton L (= e, mu, or tau). For the Tevatron, we focus on the case m_S < m_t, where the leptoquark pair production cross section is large, and the decay is three-body: S --> W b L^{\pm}. We argue that existing Tevatron observations could exclude m_S \lsim 160 GeV. For m_S > m_t, we show that the LHC experiments with low integrated luminosity could be sensitive to such leptoquarks decaying to tl^{\pm} with l= mu or tau.
[ { "created": "Tue, 22 Feb 2011 17:22:46 GMT", "version": "v1" }, { "created": "Tue, 15 Mar 2011 14:05:53 GMT", "version": "v2" } ]
2011-07-04
[ [ "Davidson", "Sacha", "" ], [ "Verdier", "Patrice", "" ] ]
We study the sensitivity of the Tevatron and the 7 TeV LHC to a leptoquark S coupling to a top quark and a charged lepton L (= e, mu, or tau). For the Tevatron, we focus on the case m_S < m_t, where the leptoquark pair production cross section is large, and the decay is three-body: S --> W b L^{\pm}. We argue that existing Tevatron observations could exclude m_S \lsim 160 GeV. For m_S > m_t, we show that the LHC experiments with low integrated luminosity could be sensitive to such leptoquarks decaying to tl^{\pm} with l= mu or tau.
2005.12493
Robert Shrock
Shmuel Nussinov and Robert Shrock
Using $\bar p p$ and $e^+e^-$ Annihilation Data to Refine Bounds on the Baryon-Number-Violating Dinucleon Decays $nn \to e^+e^-$ and $nn \to \mu^+\mu^-$
5 pages, latex
Phys. Rev. D 102, 035003 (2020)
10.1103/PhysRevD.102.035003
Tel Aviv - Stony Brook preprint YITP-SB-2020-10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use $\bar p p$ and $e^+e^-$ annihilation data to further strengthen lower bounds on the partial lifetimes for the baryon-number-violating dinucleon decays $nn \to e^+ e^-$ and $nn \to \mu^+\mu^-$.
[ { "created": "Tue, 26 May 2020 03:01:42 GMT", "version": "v1" } ]
2020-08-07
[ [ "Nussinov", "Shmuel", "" ], [ "Shrock", "Robert", "" ] ]
We use $\bar p p$ and $e^+e^-$ annihilation data to further strengthen lower bounds on the partial lifetimes for the baryon-number-violating dinucleon decays $nn \to e^+ e^-$ and $nn \to \mu^+\mu^-$.
2101.11160
Wen-Chen Chang
Wen-Chen Chang, Randall Evan McClellan, Jen-Chieh Peng and Oleg Teryaev
QCD effects in lepton angular distributions of Drell-Yan/$Z$ production and jet discrimination
7 pages, 2 figures; contribution to the proceedings of 40th International Conference on High Energy physics (ICHEP2020), 28 July - 6 August 2020, Prague, Czech. arXiv admin note: text overlap with arXiv:1907.11356
null
10.22323/1.390.0465
null
hep-ph hep-ex nucl-ex
http://creativecommons.org/licenses/by/4.0/
We present a comparison of data of lepton angular distributions of Drell-Yan/$Z$ production with the fixed-order pQCD calculations by which the baseline of pQCD effects is illustrated. As for the $Z$ production, we predict that $A_0$ and $A_2$ for $Z$ plus single gluon-jet events are very different from that of $Z$ plus single quark-jet events, allowing a new experimental tool for checking various algorithms which attempt to discriminate quark jets from gluon jets. Using an intuitive geometric approach, we show that the violation of the Lam-Tung relation, appearing at large transverse-momentum region, is attributed to the presence of a non-coplanarity effect. This interpretation is consistent with the appearance of violation beyond LO-QCD effect.
[ { "created": "Wed, 27 Jan 2021 01:37:51 GMT", "version": "v1" } ]
2022-09-21
[ [ "Chang", "Wen-Chen", "" ], [ "McClellan", "Randall Evan", "" ], [ "Peng", "Jen-Chieh", "" ], [ "Teryaev", "Oleg", "" ] ]
We present a comparison of data of lepton angular distributions of Drell-Yan/$Z$ production with the fixed-order pQCD calculations by which the baseline of pQCD effects is illustrated. As for the $Z$ production, we predict that $A_0$ and $A_2$ for $Z$ plus single gluon-jet events are very different from that of $Z$ plus single quark-jet events, allowing a new experimental tool for checking various algorithms which attempt to discriminate quark jets from gluon jets. Using an intuitive geometric approach, we show that the violation of the Lam-Tung relation, appearing at large transverse-momentum region, is attributed to the presence of a non-coplanarity effect. This interpretation is consistent with the appearance of violation beyond LO-QCD effect.
1002.0410
Kenji Yamada
Kenji Yamada
A Novel View of Exotic Hadrons and the Covariant ~U(12)-Classification Scheme
5 pages, To appear in proceedings of the XIII International Conference on Hadron Spectroscopy, Nov. 29 - Dec. 4, 2009, Florida State University
null
10.1063/1.3483369
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I classify exotic hadrons into two types, "genuine" and "hidden" exotics, and propose that the "hidden" exotics would be interpreted as "chiralons" in the ~U(12)_SF times O(3,1)_L-classification scheme of hadrons. Based upon this conjecture I investigate the mass spectrum of 1S, 1P, and 2S states for the ccbar system by use of a phenomenological mass formula with the spin-dependent interactions and present possible assignments for exotic neutral charmonium-like states which were recently discovered. It is also mentioned that some J^PC-exotic states predicted in this scheme might correspond to those found in a recent lattice QCD calculation of the charmonium spectrum.
[ { "created": "Tue, 2 Feb 2010 07:53:42 GMT", "version": "v1" } ]
2015-05-18
[ [ "Yamada", "Kenji", "" ] ]
I classify exotic hadrons into two types, "genuine" and "hidden" exotics, and propose that the "hidden" exotics would be interpreted as "chiralons" in the ~U(12)_SF times O(3,1)_L-classification scheme of hadrons. Based upon this conjecture I investigate the mass spectrum of 1S, 1P, and 2S states for the ccbar system by use of a phenomenological mass formula with the spin-dependent interactions and present possible assignments for exotic neutral charmonium-like states which were recently discovered. It is also mentioned that some J^PC-exotic states predicted in this scheme might correspond to those found in a recent lattice QCD calculation of the charmonium spectrum.
hep-ph/0106163
Kawamura
Tetsuaki Kawamoto and Yoshiharu Kawamura
Symmetry Reduction, Gauge Transformation and Orbifold
11 pages, Latex
null
null
null
hep-ph
null
We study a mechanism of symmetry reduction in a higher-dimensional field theory upon orbifold compactification. Split multiplets appear unless all components in a multiplet of a symmetry group have a common parity on an orbifold. A gauge transformation property is also examined.
[ { "created": "Fri, 15 Jun 2001 08:17:51 GMT", "version": "v1" }, { "created": "Mon, 18 Jun 2001 06:00:27 GMT", "version": "v2" } ]
2007-05-23
[ [ "Kawamoto", "Tetsuaki", "" ], [ "Kawamura", "Yoshiharu", "" ] ]
We study a mechanism of symmetry reduction in a higher-dimensional field theory upon orbifold compactification. Split multiplets appear unless all components in a multiplet of a symmetry group have a common parity on an orbifold. A gauge transformation property is also examined.
0903.0356
Roberto Pittau
P. Draggiotis, M.V. Garzelli, C.G. Papadopoulos, R. Pittau
Feynman Rules for the Rational Part of the QCD 1-loop amplitudes
18 pages, 11 figures. Misprints corrected in Appendix A. Version to be published in JHEP
JHEP 0904:072,2009
10.1088/1126-6708/2009/04/072
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the complete set of Feynman Rules producing the Rational Terms of kind R_2 needed to perform any QCD 1-loop calculation. We also explicitly check that in order to account for the entire R_2 contribution, even in case of processes with more than four external legs, only up to four-point vertices are needed. Our results are expressed both in the 't Hooft Veltman regularization scheme and in the Four Dimensional Helicity scheme, using explicit color configurations as well as the color connection language.
[ { "created": "Mon, 2 Mar 2009 18:57:08 GMT", "version": "v1" }, { "created": "Mon, 13 Apr 2009 09:22:40 GMT", "version": "v2" } ]
2009-11-25
[ [ "Draggiotis", "P.", "" ], [ "Garzelli", "M. V.", "" ], [ "Papadopoulos", "C. G.", "" ], [ "Pittau", "R.", "" ] ]
We compute the complete set of Feynman Rules producing the Rational Terms of kind R_2 needed to perform any QCD 1-loop calculation. We also explicitly check that in order to account for the entire R_2 contribution, even in case of processes with more than four external legs, only up to four-point vertices are needed. Our results are expressed both in the 't Hooft Veltman regularization scheme and in the Four Dimensional Helicity scheme, using explicit color configurations as well as the color connection language.
hep-ph/9602229
H. Holtmann
H. Holtmann, G. Levman, N.N. Nikolaev, A. Szczurek and J. Speth
How to measure the pion structure function at HERA
12 pages written in ReVTeX and 4 Postscript figures
Phys.Lett.B338:393,1995
null
KFA-IKP-(TH)-12-1995
hep-ph
null
We suggest a method of determination of the pion structure function down to x \simeq 10^{-4} based on semi-exclusive deep inelastic scattering off protons. The idea is to exploit the nonperturbative \pi N$ and \pi\Delta Fock components of the nucleon, which contribute significantly to deep inelastic scattering and dominate the fragmentation of protons into fast neutrons and deltas. The intrinsic factorization properties of the semi-exclusive cross section give a good test for the validity of this approach.
[ { "created": "Tue, 6 Feb 1996 11:12:50 GMT", "version": "v1" } ]
2014-11-17
[ [ "Holtmann", "H.", "" ], [ "Levman", "G.", "" ], [ "Nikolaev", "N. N.", "" ], [ "Szczurek", "A.", "" ], [ "Speth", "J.", "" ] ]
We suggest a method of determination of the pion structure function down to x \simeq 10^{-4} based on semi-exclusive deep inelastic scattering off protons. The idea is to exploit the nonperturbative \pi N$ and \pi\Delta Fock components of the nucleon, which contribute significantly to deep inelastic scattering and dominate the fragmentation of protons into fast neutrons and deltas. The intrinsic factorization properties of the semi-exclusive cross section give a good test for the validity of this approach.
1306.6372
Cristina Volpe
D. V\"a\"an\"anen, C. Volpe
Linearizing neutrino evolution equations including neutrino-antineutrino pairing correlations
16 pages, 1 figure, minor corrections
null
10.1103/PhysRevD.88.065003
null
hep-ph astro-ph.SR nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We linearize the neutrino mean-field evolution equations describing the neutrino propagation in a background of matter and of neutrinos, using techniques from many-body microscopic approaches. The procedure leads to an eigenvalue equation that allows to identify instabilities in the evolution, associated with a change of the curvature of the neutrino energy-density surface. Our result includes all contributions from the neutrino Hamiltonian and is generalizable to linearize the equations of motion at an arbitrary point of the evolution. We then consider the extended equations that comprise the normal mean field as well as the abnormal mean field that is associated with neutrino-antineutrino pairing correlations. We first re-derive the extended neutrino Hamiltonian and show that such a Hamiltonian can be diagonalized by introducing a generalized Bogoliubov-Valatin transformation with quasi-particle operators that mix neutrinos and antineutrinos. We give the eigenvalue equations that determine the energies of the quasi-particles eigenstates. Finally we derive the eigenvalue equation of the extended equations of motion, valid in the small amplitude approximation. Our results apply to an arbitrary number of neutrino families.
[ { "created": "Wed, 26 Jun 2013 22:37:04 GMT", "version": "v1" }, { "created": "Fri, 29 Nov 2013 23:01:31 GMT", "version": "v2" } ]
2015-06-16
[ [ "Väänänen", "D.", "" ], [ "Volpe", "C.", "" ] ]
We linearize the neutrino mean-field evolution equations describing the neutrino propagation in a background of matter and of neutrinos, using techniques from many-body microscopic approaches. The procedure leads to an eigenvalue equation that allows to identify instabilities in the evolution, associated with a change of the curvature of the neutrino energy-density surface. Our result includes all contributions from the neutrino Hamiltonian and is generalizable to linearize the equations of motion at an arbitrary point of the evolution. We then consider the extended equations that comprise the normal mean field as well as the abnormal mean field that is associated with neutrino-antineutrino pairing correlations. We first re-derive the extended neutrino Hamiltonian and show that such a Hamiltonian can be diagonalized by introducing a generalized Bogoliubov-Valatin transformation with quasi-particle operators that mix neutrinos and antineutrinos. We give the eigenvalue equations that determine the energies of the quasi-particles eigenstates. Finally we derive the eigenvalue equation of the extended equations of motion, valid in the small amplitude approximation. Our results apply to an arbitrary number of neutrino families.
2010.11222
Arkaitz Rodas
J.R. Pel\'aez, A. Rodas
Dispersive $\pi K\to \pi K$ and $\pi \pi \to K \bar{K}$ amplitudes from scattering data, threshold parameters and the lightest strange resonance $\kappa$ or $K^*_0(700)$
148 pages, 53 figures. Further clarifications, discussions and references added. Version published in Physics Reports
Phys.Rept. 969 (2022) 1-126
10.1016/j.physrep.2022.03.004
JLAB-THY-20-3276
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the simultaneous dispersive analyses of $\pi K\to \pi K$ and $\pi \pi \to K \bar{K}$ scattering data and the $\kappa/K^*_0(700)$ resonance. The unprecedented statistics of present and future Hadron Experiments, modern Lattice QCD calculations, and the wealth of new states and decays, require such precise and model-independent analyses to describe final state interactions. We review the existing and often conflicting data and explain in detail the derivation of the relevant dispersion relations, maximizing their applicability range. Next, we review and extend the caveats on some data, showing their inconsistency with dispersion relations. Our main result is the derivation and compilation of precise amplitude parameterizations constrained by several $\pi K\to \pi K$ and $\pi \pi \to K \bar{K}$ dispersion relations. These constrained parameterizations are easily implementable and provide the rigor and accuracy needed for modern experimental and phenomenological Hadron Physics. As applications, after reviewing their status and interest, we will provide new precise threshold and subthreshold parameters and review our dispersive determination of the controversial $\kappa/K^*_0(700)$ resonance and other light-strange resonances.
[ { "created": "Wed, 21 Oct 2020 18:04:07 GMT", "version": "v1" }, { "created": "Fri, 10 Jun 2022 23:36:34 GMT", "version": "v2" } ]
2022-06-14
[ [ "Peláez", "J. R.", "" ], [ "Rodas", "A.", "" ] ]
We discuss the simultaneous dispersive analyses of $\pi K\to \pi K$ and $\pi \pi \to K \bar{K}$ scattering data and the $\kappa/K^*_0(700)$ resonance. The unprecedented statistics of present and future Hadron Experiments, modern Lattice QCD calculations, and the wealth of new states and decays, require such precise and model-independent analyses to describe final state interactions. We review the existing and often conflicting data and explain in detail the derivation of the relevant dispersion relations, maximizing their applicability range. Next, we review and extend the caveats on some data, showing their inconsistency with dispersion relations. Our main result is the derivation and compilation of precise amplitude parameterizations constrained by several $\pi K\to \pi K$ and $\pi \pi \to K \bar{K}$ dispersion relations. These constrained parameterizations are easily implementable and provide the rigor and accuracy needed for modern experimental and phenomenological Hadron Physics. As applications, after reviewing their status and interest, we will provide new precise threshold and subthreshold parameters and review our dispersive determination of the controversial $\kappa/K^*_0(700)$ resonance and other light-strange resonances.
1601.04284
Flavio Pereira
F. I. M. Pereira
On the anomalous mass defect of strange stars in the Field Correlator Method
24 pages, 6 figures
null
10.1016/j.nuclphysa.2016.04.020
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate general aspects of the mass defects of strange stars in the context of the Field Correlator Method, without magnetic field. The main parameters of the model that enter the corresponding nonperturbative equation of state of the quark gluon plasma are the gluon condensate $G_2$ and the large distance static $Q{\bar Q}$ potential $V_1$. We calculate mass defects of stellar configurations in the central density range $11<\log\rho_c<18$. In general, the mass defects are strongly dependent on the model parameters. For a large range of values of $G_2$ and $V_1$, we obtain anomalous mass defects with magnitudes around $10^{53}\,$erg\,, of the same order of the observed energies of gamma-ray bursts and neutrino emissions in SN1987A, and of the theoretically predicted energies of the quark-novae explosions.
[ { "created": "Sun, 17 Jan 2016 12:35:44 GMT", "version": "v1" }, { "created": "Mon, 18 Apr 2016 17:50:22 GMT", "version": "v2" } ]
2023-05-17
[ [ "Pereira", "F. I. M.", "" ] ]
We investigate general aspects of the mass defects of strange stars in the context of the Field Correlator Method, without magnetic field. The main parameters of the model that enter the corresponding nonperturbative equation of state of the quark gluon plasma are the gluon condensate $G_2$ and the large distance static $Q{\bar Q}$ potential $V_1$. We calculate mass defects of stellar configurations in the central density range $11<\log\rho_c<18$. In general, the mass defects are strongly dependent on the model parameters. For a large range of values of $G_2$ and $V_1$, we obtain anomalous mass defects with magnitudes around $10^{53}\,$erg\,, of the same order of the observed energies of gamma-ray bursts and neutrino emissions in SN1987A, and of the theoretically predicted energies of the quark-novae explosions.
hep-ph/9907514
Johan Bijnens
Johan Bijnens (Lund)
I : Chiral Perturbation for Kaons II: The $\Delta I=1/2$-rule in the Chiral Limit
Talk presented at Kaon99, Chicago, June 20-27, 1999, 11 pages
null
null
LU TP 99-19
hep-ph
null
I : Chiral Perturbation Theory is introduced and its applications to semileptonic and nonleptonic kaon decays are discussed. II: The method of large $N_c$ is used to calculate $K\to\pi\pi$ nonleptonic matrix elements, in particular the matching procedure between long and short-distance evolution that takes all scheme dependence correctly into account is discussed. Numerical results reproduce the $\Delta I=1/2$ rule without the introduction of any free parameters.
[ { "created": "Tue, 27 Jul 1999 14:39:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bijnens", "Johan", "", "Lund" ] ]
I : Chiral Perturbation Theory is introduced and its applications to semileptonic and nonleptonic kaon decays are discussed. II: The method of large $N_c$ is used to calculate $K\to\pi\pi$ nonleptonic matrix elements, in particular the matching procedure between long and short-distance evolution that takes all scheme dependence correctly into account is discussed. Numerical results reproduce the $\Delta I=1/2$ rule without the introduction of any free parameters.
hep-ph/9811222
Dmitri Kharzeev
John Ellis and Dmitri Kharzeev
The Glueball Filter in Central Production and Broken Scale Invariance
9 pages, 2 figures, LaTeX2e
null
null
CERN-TH/98-349
hep-ph
null
We propose a possible explanation of the kinematical dependence of the central production of the scalar glueball candidate observed recently by the WA91 and WA102 Collaborations, and discussed by Close and Kirk, in the context of the broken scale invariance of QCD. The dependences of glueball production on the transverse momenta and azimuthal angles of the final-state protons may be related to the structure of the trace anomaly in QCD.
[ { "created": "Mon, 2 Nov 1998 20:31:00 GMT", "version": "v1" }, { "created": "Thu, 17 Dec 1998 21:34:00 GMT", "version": "v2" } ]
2007-05-23
[ [ "Ellis", "John", "" ], [ "Kharzeev", "Dmitri", "" ] ]
We propose a possible explanation of the kinematical dependence of the central production of the scalar glueball candidate observed recently by the WA91 and WA102 Collaborations, and discussed by Close and Kirk, in the context of the broken scale invariance of QCD. The dependences of glueball production on the transverse momenta and azimuthal angles of the final-state protons may be related to the structure of the trace anomaly in QCD.
2310.19881
So Chigusa
Christian W. Bauer, So Chigusa, Masahito Yamazaki
Quantum Parton Shower with Kinematics
14 pages, 8 figures
null
null
null
hep-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
Parton showers which can efficiently incorporate quantum interference effects have been shown to be run efficiently on quantum computers. However, so far these quantum parton showers did not include the full kinematical information required to reconstruct an event, which in classical parton showers requires the use of a veto algorithm. In this work, we show that adding one extra assumption about the discretization of the evolution variable allows to construct a quantum veto algorithm, which reproduces the full quantum interference in the event, and allows to include kinematical effects. We finally show that for certain initial states the quantum interference effects generated in this veto algorithm are classically tractable, such that an efficient classical algorithm can be devised.
[ { "created": "Mon, 30 Oct 2023 18:00:03 GMT", "version": "v1" } ]
2023-11-01
[ [ "Bauer", "Christian W.", "" ], [ "Chigusa", "So", "" ], [ "Yamazaki", "Masahito", "" ] ]
Parton showers which can efficiently incorporate quantum interference effects have been shown to be run efficiently on quantum computers. However, so far these quantum parton showers did not include the full kinematical information required to reconstruct an event, which in classical parton showers requires the use of a veto algorithm. In this work, we show that adding one extra assumption about the discretization of the evolution variable allows to construct a quantum veto algorithm, which reproduces the full quantum interference in the event, and allows to include kinematical effects. We finally show that for certain initial states the quantum interference effects generated in this veto algorithm are classically tractable, such that an efficient classical algorithm can be devised.
hep-ph/9607332
Hai-Yang Cheng
Hai-Yang Cheng, Chi-Yee Cheung, Chien-Wen Hwang
Mesonic Form Factors and the Isgur-Wise Function on the Light-Front
49 pages, 11 figures
Phys.Rev. D55 (1997) 1559-1577
10.1103/PhysRevD.55.1559
IP-ASTP-04-96
hep-ph
null
Within the light-front framework, form factors for $P\to P$ and $P\to V$ transitions ($P$: pseudoscalar meson, $V$: vector meson) due to the valence-quark configuration are calculated directly in the entire physical range of momentum transfer. The behavior of form factors in the infinite quark mass limit are examined to see if the requirements of heavy-quark symmetry are fulfilled. We find that the Bauer-Stech-Wirbel type of light-front wave function fails to give a correct normalization for the Isgur-Wise function at zero recoil in $P\to V$ transition. Some of the $P\to V$ form factors are found to depend on the recoiling direction of the daughter mesons relative to their parents. Thus, the inclusion of the non-valence configuration arising from quark-pair creation is mandatory in order to ensure that the physical form factors are independent of the recoiling direction. The main feature of the non-valence contribution is discussed.
[ { "created": "Tue, 16 Jul 1996 20:24:11 GMT", "version": "v1" } ]
2009-10-28
[ [ "Cheng", "Hai-Yang", "" ], [ "Cheung", "Chi-Yee", "" ], [ "Hwang", "Chien-Wen", "" ] ]
Within the light-front framework, form factors for $P\to P$ and $P\to V$ transitions ($P$: pseudoscalar meson, $V$: vector meson) due to the valence-quark configuration are calculated directly in the entire physical range of momentum transfer. The behavior of form factors in the infinite quark mass limit are examined to see if the requirements of heavy-quark symmetry are fulfilled. We find that the Bauer-Stech-Wirbel type of light-front wave function fails to give a correct normalization for the Isgur-Wise function at zero recoil in $P\to V$ transition. Some of the $P\to V$ form factors are found to depend on the recoiling direction of the daughter mesons relative to their parents. Thus, the inclusion of the non-valence configuration arising from quark-pair creation is mandatory in order to ensure that the physical form factors are independent of the recoiling direction. The main feature of the non-valence contribution is discussed.
2106.12582
Marco Fedele
Luc Darm\'e, Marco Fedele, Kamila Kowalska, Enrico Maria Sessolo
Flavour anomalies and the muon $g-2$ from feebly interacting particles
32 pages, 4 figures. Typos corrected, published version
JHEP 03 (2022) 085
10.1007/JHEP03(2022)085
TTP21-020, P3H-21-047
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a phenomenological analysis of simplified models of light, feebly interacting particles~(FIPs)that can provide a combined explanation of the anomalies in $b\to s l^+ l ^-$ transitions at LHCb and the anomalous magnetic moment of the muon. Different scenarios are categorised according to the explicit momentum dependence of the FIP coupling to the $b-s$ and $\mu-\mu$ vector currents and they are subject to several constraints from flavour and precision physics. We show that viable combined solutions to the muon $g-2$ and flavour anomalies exist with the exchange of a vector FIP with mass larger than $4 \,\textrm{GeV}$. Interestingly, the LHC has the potential to probe this region of the parameter space by increasing the precision of the $Z\to 4\mu$ cross-section measurement. Conversely, we find that solutions based on the exchange of a lighter vector, in the $m_V < 1\,\textrm{GeV}$ range, are essentially excluded by a combination of $B\to K +\textrm{invisible}$ and $W$-decay precision bounds.
[ { "created": "Wed, 23 Jun 2021 18:00:00 GMT", "version": "v1" }, { "created": "Fri, 26 Nov 2021 10:58:18 GMT", "version": "v2" }, { "created": "Sun, 20 Mar 2022 16:51:57 GMT", "version": "v3" } ]
2022-03-22
[ [ "Darmé", "Luc", "" ], [ "Fedele", "Marco", "" ], [ "Kowalska", "Kamila", "" ], [ "Sessolo", "Enrico Maria", "" ] ]
We perform a phenomenological analysis of simplified models of light, feebly interacting particles~(FIPs)that can provide a combined explanation of the anomalies in $b\to s l^+ l ^-$ transitions at LHCb and the anomalous magnetic moment of the muon. Different scenarios are categorised according to the explicit momentum dependence of the FIP coupling to the $b-s$ and $\mu-\mu$ vector currents and they are subject to several constraints from flavour and precision physics. We show that viable combined solutions to the muon $g-2$ and flavour anomalies exist with the exchange of a vector FIP with mass larger than $4 \,\textrm{GeV}$. Interestingly, the LHC has the potential to probe this region of the parameter space by increasing the precision of the $Z\to 4\mu$ cross-section measurement. Conversely, we find that solutions based on the exchange of a lighter vector, in the $m_V < 1\,\textrm{GeV}$ range, are essentially excluded by a combination of $B\to K +\textrm{invisible}$ and $W$-decay precision bounds.
hep-ph/9711508
Andrzej Bialas
A. Bialas, W. Czyz (Jagellonian University)
Shadowing of Virtual Photons in Nuclei at Small $x_{Bj}$ in the QCD Dipole Picture
17 pages Latex2e file, To be published in Acta Physica Polonica B, no. 3 (1998)
Acta Phys.Polon. B29 (1998) 651-666
null
TPJU-10/97
hep-ph
null
Compact and well defined formulae for the shadow of the virtual photon interacting with a large nucleus at small $x_{Bj}$ are given in the QCD dipole picture. Two classes of contributions are considered: (a) quasi-elastic interaction of the $q\bar{q}$ dipole and (b) multi-pomeron coupling.
[ { "created": "Fri, 28 Nov 1997 12:00:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bialas", "A.", "", "Jagellonian University" ], [ "Czyz", "W.", "", "Jagellonian University" ] ]
Compact and well defined formulae for the shadow of the virtual photon interacting with a large nucleus at small $x_{Bj}$ are given in the QCD dipole picture. Two classes of contributions are considered: (a) quasi-elastic interaction of the $q\bar{q}$ dipole and (b) multi-pomeron coupling.
2109.13779
Hiroshi Okada
Hiroshi Okada, Yong-hui Qi
Zee-Babu model in modular $A_4$ symmetry
22 pages, 4 tables, 3 figures. arXiv admin note: text overlap with arXiv:2012.11156
null
null
APCTP Pre2021-022
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
We study a Zee-Babu model in a modular $A_4$ flavor symmetry, in which we search for several predictions such as phases, sum of neutrino masses, and neutrinoless double beta decay, satisfying neutrino oscillation data in a minimum framework of the charge assignments of modular weight. We perform $\Delta \chi^2$ analysis to get our results and find $\tau$ is localized nearby at one of the fixed points of $i\times \infty$ for both of normal and inverted mass hierarchies.
[ { "created": "Tue, 28 Sep 2021 14:58:10 GMT", "version": "v1" }, { "created": "Sat, 16 Oct 2021 06:34:22 GMT", "version": "v2" } ]
2022-01-18
[ [ "Okada", "Hiroshi", "" ], [ "Qi", "Yong-hui", "" ] ]
We study a Zee-Babu model in a modular $A_4$ flavor symmetry, in which we search for several predictions such as phases, sum of neutrino masses, and neutrinoless double beta decay, satisfying neutrino oscillation data in a minimum framework of the charge assignments of modular weight. We perform $\Delta \chi^2$ analysis to get our results and find $\tau$ is localized nearby at one of the fixed points of $i\times \infty$ for both of normal and inverted mass hierarchies.
hep-ph/9905564
Sergey Troshin
S. M. Troshin, N. E. Tyurin
Unitarity and nonperturbative effects in the spin structure functions at small $x$
4 pages, 1 figure, talk given by S. Troshin at the DESY Workshop: Polarized Protons at High Energies - Accelerator Challenges and Physics Opportunities, Hamburg 17-20 May 1999
null
null
null
hep-ph
null
We consider low-$x$ behavior of the spin structure functions $g_1(x)$ and $h_1(x)$ in the unitarized chiral quark model that combines the ideas on constituent quark structure of hadrons with a geometrical scattering picture and unitarity. A nondiffractive singular low-$x$ dependence of $g^p_1(x)$ and $g_1^n(x)$ is obtained and a diffractive type smooth behavior of $h_1(x)$ is predicted at small $x$.
[ { "created": "Mon, 31 May 1999 12:36:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Troshin", "S. M.", "" ], [ "Tyurin", "N. E.", "" ] ]
We consider low-$x$ behavior of the spin structure functions $g_1(x)$ and $h_1(x)$ in the unitarized chiral quark model that combines the ideas on constituent quark structure of hadrons with a geometrical scattering picture and unitarity. A nondiffractive singular low-$x$ dependence of $g^p_1(x)$ and $g_1^n(x)$ is obtained and a diffractive type smooth behavior of $h_1(x)$ is predicted at small $x$.
0906.4052
Gizo Nanava
G. Nanava (1), Qingjun Xu (2) and Z. Was (2 and 3) ((1) Bonn U., (2) Cracow, INP, (3) CERN)
Matching NLO parton shower matrix element with exact phase space: case of W -> l nu (gamma) and gamma^* -> pi^+pi^-(gamma)
24 pages
Eur.Phys.J.C70:673-688,2010
10.1140/epjc/s10052-010-1454-8
IFJPAN-IV-2009-1, CERN-PH-TH/2009-092
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The PHOTOS Monte Carlo is often used for simulation of QED effects in decay of intermediate particles and resonances. Momenta are generated in such a way that samples of events cover the whole bremsstrahlung phase space. With the help of selection cuts, experimental acceptance can be then taken into account. The program is based on an exact multiphoton phase space. Crude matrix element is obtained by iteration of a universal multidimensional kernel. It ensures exact distribution in the soft photon region. Algorithm is compatible with exclusive exponentiation. To evaluate the program's precision, it is necessary to control the kernel with the help of perturbative results. If available, kernel is constructed from the exact first order matrix element. This ensures that all terms necessary for non-leading logarithms are taken into account. In the present paper we will focus on the W -> l nu and gamma^* -> pi^+ pi^- decays. The Born level cross sections for both processes approach zero in some points of the phase space. A process dependent compensating weight is constructed to incorporate the exact matrix element, but is recommended for use in tests only. In the hard photon region, where scalar QED is not expected to be reliable, the compensating weight for gamma^* decay can be large. With respect to the total rate, the effect remains at the permille level. It is nonetheless of interest. The terms leading to the effect are analogous to some terms appearing in QCD. The present paper can be understood either as a contribution to discussion on how to match two collinear emission chains resulting from charged sources in a way compatible with the exact and complete phase space, exclusive exponentiation and the first order matrix element of QED (scalar QED), or as the practical study of predictions for accelerator experiments.
[ { "created": "Mon, 22 Jun 2009 16:33:44 GMT", "version": "v1" }, { "created": "Sun, 30 May 2010 16:31:08 GMT", "version": "v2" } ]
2010-12-15
[ [ "Nanava", "G.", "", "2 and 3" ], [ "Xu", "Qingjun", "", "2 and 3" ], [ "Was", "Z.", "", "2 and 3" ] ]
The PHOTOS Monte Carlo is often used for simulation of QED effects in decay of intermediate particles and resonances. Momenta are generated in such a way that samples of events cover the whole bremsstrahlung phase space. With the help of selection cuts, experimental acceptance can be then taken into account. The program is based on an exact multiphoton phase space. Crude matrix element is obtained by iteration of a universal multidimensional kernel. It ensures exact distribution in the soft photon region. Algorithm is compatible with exclusive exponentiation. To evaluate the program's precision, it is necessary to control the kernel with the help of perturbative results. If available, kernel is constructed from the exact first order matrix element. This ensures that all terms necessary for non-leading logarithms are taken into account. In the present paper we will focus on the W -> l nu and gamma^* -> pi^+ pi^- decays. The Born level cross sections for both processes approach zero in some points of the phase space. A process dependent compensating weight is constructed to incorporate the exact matrix element, but is recommended for use in tests only. In the hard photon region, where scalar QED is not expected to be reliable, the compensating weight for gamma^* decay can be large. With respect to the total rate, the effect remains at the permille level. It is nonetheless of interest. The terms leading to the effect are analogous to some terms appearing in QCD. The present paper can be understood either as a contribution to discussion on how to match two collinear emission chains resulting from charged sources in a way compatible with the exact and complete phase space, exclusive exponentiation and the first order matrix element of QED (scalar QED), or as the practical study of predictions for accelerator experiments.
hep-ph/0201262
Danny Marfatia
V. Barger, S.L. Glashow, D. Marfatia and K. Whisnant
Neutrinoless double beta decay can constrain neutrino dark matter
Version to appear in PLB
Phys.Lett.B532:15-18,2002
10.1016/S0370-2693(02)01531-9
MADPH-02-1254, AMES-HET-02-01
hep-ph astro-ph hep-ex
null
We examine how constraints can be placed on the neutrino component of dark matter by an accurate measurement of neutrinoless double beta ($0\nu\beta\beta$) decay and the solar oscillation amplitude. We comment on the alleged evidence for $0\nu\beta\beta$ decay.
[ { "created": "Mon, 28 Jan 2002 22:49:34 GMT", "version": "v1" }, { "created": "Tue, 26 Feb 2002 19:35:23 GMT", "version": "v2" } ]
2017-08-23
[ [ "Barger", "V.", "" ], [ "Glashow", "S. L.", "" ], [ "Marfatia", "D.", "" ], [ "Whisnant", "K.", "" ] ]
We examine how constraints can be placed on the neutrino component of dark matter by an accurate measurement of neutrinoless double beta ($0\nu\beta\beta$) decay and the solar oscillation amplitude. We comment on the alleged evidence for $0\nu\beta\beta$ decay.
0807.1008
Bernd Kniehl
Joachim Brod, Frank Fugel, Bernd A. Kniehl
Two-Loop Electroweak Corrections to the A^0 gamma gamma and A^0 g g Couplings of the CP-Odd Higgs Boson
27 pages, 11 figures
Nucl.Phys.B807:188-209,2009
10.1016/j.nuclphysb.2008.08.021
DESY 08-071, TTP 08-20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the asymptotic-expansion technique, we compute the dominant two-loop electroweak corrections, of O(G_F m_t^2), to production and decay via a pair of photons or gluons of the CP-odd Higgs boson A^0 in a two-Higgs-doublet model with low- to intermediate values of the Higgs-boson masses and ratio tan(beta)=v_2/v_1 of the vacuum expectation values. We also study the influence of a sequential heavy-fermion generation. The appearance of three gamma_5 matrices in closed fermion loops requires special care in the dimensional regularisation of ultraviolet divergences. The finite renormalisation constant for the pseudoscalar current effectively restoring the anticommutativity of the gamma_5 matrix, familiar from perturbative quantum chromodynamics, is found not to receive a correction in this order. We also revisit the dominant two-loop electroweak correction to the H -> gamma gamma decay width in the standard model with a fourth fermion generation.
[ { "created": "Mon, 7 Jul 2008 13:05:26 GMT", "version": "v1" } ]
2008-11-26
[ [ "Brod", "Joachim", "" ], [ "Fugel", "Frank", "" ], [ "Kniehl", "Bernd A.", "" ] ]
Using the asymptotic-expansion technique, we compute the dominant two-loop electroweak corrections, of O(G_F m_t^2), to production and decay via a pair of photons or gluons of the CP-odd Higgs boson A^0 in a two-Higgs-doublet model with low- to intermediate values of the Higgs-boson masses and ratio tan(beta)=v_2/v_1 of the vacuum expectation values. We also study the influence of a sequential heavy-fermion generation. The appearance of three gamma_5 matrices in closed fermion loops requires special care in the dimensional regularisation of ultraviolet divergences. The finite renormalisation constant for the pseudoscalar current effectively restoring the anticommutativity of the gamma_5 matrix, familiar from perturbative quantum chromodynamics, is found not to receive a correction in this order. We also revisit the dominant two-loop electroweak correction to the H -> gamma gamma decay width in the standard model with a fourth fermion generation.
2009.14295
Avi Friedlander
Avi Friedlander, Ian Banta, James M. Cline, David Tucker-Smith
Wall speed and shape in singlet-assisted strong electroweak phase transitions
19 pages, 15 figures
Phys. Rev. D 103, 055020 (2021)
10.1103/PhysRevD.103.055020
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Models with singlet fields coupling to the Higgs can enable a strongly first order electroweak phase transition, of interest for baryogenesis and gravity waves. We improve on previous attempts to self-consistently solve for the bubble wall properties -- wall speed $v_w$ and shape -- in a highly predictive class of models with $Z_2$-symmetric singlet potentials. A new algorithm is implemented to determine $v_w$ and the wall profiles throughout the singlet parameter space in the case of subsonic walls, focusing on models with strong enough phase transitions to satisfy the sphaleron washout constraint for electroweak baryogenesis. We find speeds as low as $v_w \cong 0.1$ in our scan over parameter space, and the singlet must be relatively light to have a subsonic wall, $m_s \lesssim 135$ GeV.
[ { "created": "Tue, 29 Sep 2020 20:36:01 GMT", "version": "v1" }, { "created": "Sun, 28 Feb 2021 17:36:09 GMT", "version": "v2" } ]
2021-03-31
[ [ "Friedlander", "Avi", "" ], [ "Banta", "Ian", "" ], [ "Cline", "James M.", "" ], [ "Tucker-Smith", "David", "" ] ]
Models with singlet fields coupling to the Higgs can enable a strongly first order electroweak phase transition, of interest for baryogenesis and gravity waves. We improve on previous attempts to self-consistently solve for the bubble wall properties -- wall speed $v_w$ and shape -- in a highly predictive class of models with $Z_2$-symmetric singlet potentials. A new algorithm is implemented to determine $v_w$ and the wall profiles throughout the singlet parameter space in the case of subsonic walls, focusing on models with strong enough phase transitions to satisfy the sphaleron washout constraint for electroweak baryogenesis. We find speeds as low as $v_w \cong 0.1$ in our scan over parameter space, and the singlet must be relatively light to have a subsonic wall, $m_s \lesssim 135$ GeV.
hep-ph/0103044
Frank Daniel Steffen
Frank D. Steffen and Markus H. Thoma
Hard Thermal Photon Production in Relativistic Heavy Ion Collisions
20 pages with 8 figures. v3: Erratum to [Phys. Lett. B 510 (2001) 98] with correctly labeled Figs. 2, 4, and 5 added
Phys.Lett.B510:98-106,2001; Erratum-ibid.B660:604-606,2008
10.1016/S0370-2693(01)00525-1 10.1016/j.physletb.2007.11.020
CERN-TH/2001-080, HD-THEP-01-13, MPP-2007-113
hep-ph nucl-th
null
The recent status of hard thermal photon production in relativistic heavy ion collisions is reviewed and the current rates are presented with emphasis on corrected bremsstrahlung processes in the quark-gluon plasma (QGP) and quark-hadron duality. Employing Bjorken hydrodynamics with an EOS supporting the phase transition from QGP to hot hadron gas (HHG), thermal photon spectra are computed. For SPS 158 GeV Pb+Pb collisions, comparison with other theoretical results and the WA98 direct photon data indicates significant contributions due to prompt photons. Extrapolating the presented approach to RHIC and LHC experiments, predictions of the thermal photon spectrum show a QGP outshining the HHG in the high-pT-region.
[ { "created": "Sun, 4 Mar 2001 22:54:24 GMT", "version": "v1" }, { "created": "Wed, 28 Mar 2001 10:34:00 GMT", "version": "v2" }, { "created": "Mon, 27 Aug 2007 16:39:05 GMT", "version": "v3" } ]
2008-11-26
[ [ "Steffen", "Frank D.", "" ], [ "Thoma", "Markus H.", "" ] ]
The recent status of hard thermal photon production in relativistic heavy ion collisions is reviewed and the current rates are presented with emphasis on corrected bremsstrahlung processes in the quark-gluon plasma (QGP) and quark-hadron duality. Employing Bjorken hydrodynamics with an EOS supporting the phase transition from QGP to hot hadron gas (HHG), thermal photon spectra are computed. For SPS 158 GeV Pb+Pb collisions, comparison with other theoretical results and the WA98 direct photon data indicates significant contributions due to prompt photons. Extrapolating the presented approach to RHIC and LHC experiments, predictions of the thermal photon spectrum show a QGP outshining the HHG in the high-pT-region.
1205.1438
Rahul Sinha
Diganta Das, Rahul Sinha
New Physics Effects and Hadronic Form Factor Uncertainties in B -> K^* l^+ l^-
26 pages, 9 figures (20 pdf figure files). Several typos corrected
null
10.1103/PhysRevD.86.056006
IMSc-2012-5-10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that New Physics can contribute to weak decays of heavy mesons via virtual processes during its decays. The discovery of New Physics, using such decays is made difficult due to intractable strong interaction effects needed to describe it. Modes such as B -> K^* l^+ l^- offer an advantage as they provide a multitude of observables via angular analysis. We show how the multitude of "related observables" obtained from B -> K^* l^+ l^-, can provide many new "clean tests" of the Standard Model. The hallmark of these tests is that several of them are independent of the unknown universal form factors in heavy quark effective theory. We derive a relation between observables that is free of form factors and Wilson coefficients, the violation of which will be an unambiguous signal of New Physics. We also derive relations between observables and form factors that are independent of Wilson coefficients and enable verification of hadronic estimates. We show how form factor ratios can be measured directly from helicity fraction with out any assumptions what so ever. We find that the allowed parameter space for observables is very tightly constrained in Standard Model, thereby providing clean signals of New Physics. We examine both the large-recoil and low-recoil regions of the K^* meson and point out special features and derive relations between observables valid in the two limits. In the large-recoil regions several of the relations are unaffected by corrections to all orders in \alpha_s. We present yet another new relation involving only observables that would verify the validity of the relations between form-factors assumed in the low-recoil region. The several relations and constraints derived will provide unambiguous signals of New Physics if it contributes to these decays.
[ { "created": "Mon, 7 May 2012 15:54:12 GMT", "version": "v1" }, { "created": "Tue, 15 May 2012 09:38:12 GMT", "version": "v2" } ]
2013-05-30
[ [ "Das", "Diganta", "" ], [ "Sinha", "Rahul", "" ] ]
It is well known that New Physics can contribute to weak decays of heavy mesons via virtual processes during its decays. The discovery of New Physics, using such decays is made difficult due to intractable strong interaction effects needed to describe it. Modes such as B -> K^* l^+ l^- offer an advantage as they provide a multitude of observables via angular analysis. We show how the multitude of "related observables" obtained from B -> K^* l^+ l^-, can provide many new "clean tests" of the Standard Model. The hallmark of these tests is that several of them are independent of the unknown universal form factors in heavy quark effective theory. We derive a relation between observables that is free of form factors and Wilson coefficients, the violation of which will be an unambiguous signal of New Physics. We also derive relations between observables and form factors that are independent of Wilson coefficients and enable verification of hadronic estimates. We show how form factor ratios can be measured directly from helicity fraction with out any assumptions what so ever. We find that the allowed parameter space for observables is very tightly constrained in Standard Model, thereby providing clean signals of New Physics. We examine both the large-recoil and low-recoil regions of the K^* meson and point out special features and derive relations between observables valid in the two limits. In the large-recoil regions several of the relations are unaffected by corrections to all orders in \alpha_s. We present yet another new relation involving only observables that would verify the validity of the relations between form-factors assumed in the low-recoil region. The several relations and constraints derived will provide unambiguous signals of New Physics if it contributes to these decays.
1704.08158
Peter Cox
Rodrigo Alonso, Peter Cox, Chengcheng Han, Tsutomu T. Yanagida
Anomaly-free local horizontal symmetry and anomaly-full rare B-decays
7 pages, 2 figures; v2: version published in PRD
Phys. Rev. D 96, 071701 (2017)
10.1103/PhysRevD.96.071701
IPMU17-0068, CERN-TH-2017-094
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The largest global symmetry that can be made local in the Standard Model + 3$\nu_R$ while being compatible with Pati-Salam unification is $SU(3)_H\times U(1)_{B-L}$. The gauge bosons of this theory would induce flavour effects involving both quarks and leptons, and are a potential candidate to explain the recent reports of lepton universality violation in rare B meson decays. In this letter we characterise this type of models and show how they can accommodate the data and naturally be within reach of direct searches.
[ { "created": "Wed, 26 Apr 2017 15:14:27 GMT", "version": "v1" }, { "created": "Tue, 24 Oct 2017 04:09:39 GMT", "version": "v2" } ]
2017-10-25
[ [ "Alonso", "Rodrigo", "" ], [ "Cox", "Peter", "" ], [ "Han", "Chengcheng", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
The largest global symmetry that can be made local in the Standard Model + 3$\nu_R$ while being compatible with Pati-Salam unification is $SU(3)_H\times U(1)_{B-L}$. The gauge bosons of this theory would induce flavour effects involving both quarks and leptons, and are a potential candidate to explain the recent reports of lepton universality violation in rare B meson decays. In this letter we characterise this type of models and show how they can accommodate the data and naturally be within reach of direct searches.
1110.1451
Riazuddin Riazuddin
Riazuddin, Sidra Shafiq
Spin-orbit splittings in heavy-light mesons and Dirac equation
9 pages, 1 fig
null
10.1140/epjc/s10052-012-1925-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spin-orbit splitting in heavy-light mesons is seen to be suppressed experimentally. It is shown that it can be understood qualitatively in the frame work of Dirac theory. An alternative derivation of a relativistic dynamical symmetry for the Dirac Hamiltonian, which suppresses spin orbit splitting, is also given. However it is shown that such a symmetry is not needed since the spin-orbit splitting in Dirac theory with Coulomb like potential (as is the case for the one gluon exchange potential in pQCD) is small anyway.
[ { "created": "Fri, 7 Oct 2011 08:04:35 GMT", "version": "v1" } ]
2015-05-30
[ [ "Riazuddin", "", "" ], [ "Shafiq", "Sidra", "" ] ]
The spin-orbit splitting in heavy-light mesons is seen to be suppressed experimentally. It is shown that it can be understood qualitatively in the frame work of Dirac theory. An alternative derivation of a relativistic dynamical symmetry for the Dirac Hamiltonian, which suppresses spin orbit splitting, is also given. However it is shown that such a symmetry is not needed since the spin-orbit splitting in Dirac theory with Coulomb like potential (as is the case for the one gluon exchange potential in pQCD) is small anyway.
1904.10543
Ping-Han Chu
P.-H. Chu and Y. J. Kim and I. Savukov
Comment on "Search for an axion-induced oscillating electric dipole moment for electrons using atomic magnetometers"
null
null
null
LA-UR-19-23854
hep-ph nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the recent work arXiv:1809.02446, the authors proposed a new method measuring the electron oscillating electric dipole moment (eOEDM) using atomic magnetomaters. This eOEDM is induced by the interaction between the electron magnetic dipole moment, electric field and axion field. The result is sensitive to the axion-photon coupling according to [Hill, PRD 91, 111702 (2015)]. Here we want to describe that the same experimental method can be also sensitive to the axion-electron coupling according to [Alexander and Sims, PRD 98, 015011 (2018)]. In this article, we will show the corresponding sensitivity plot and compare with other constraints.
[ { "created": "Tue, 23 Apr 2019 21:35:13 GMT", "version": "v1" } ]
2019-04-30
[ [ "Chu", "P. -H.", "" ], [ "Kim", "Y. J.", "" ], [ "Savukov", "I.", "" ] ]
In the recent work arXiv:1809.02446, the authors proposed a new method measuring the electron oscillating electric dipole moment (eOEDM) using atomic magnetomaters. This eOEDM is induced by the interaction between the electron magnetic dipole moment, electric field and axion field. The result is sensitive to the axion-photon coupling according to [Hill, PRD 91, 111702 (2015)]. Here we want to describe that the same experimental method can be also sensitive to the axion-electron coupling according to [Alexander and Sims, PRD 98, 015011 (2018)]. In this article, we will show the corresponding sensitivity plot and compare with other constraints.
hep-ph/0505209
Ernest Ma
Ernest Ma (UC Riverside)
Aspects of the Tetrahedral Neutrino Mass Matrix
5 pages, no figure, important new equations added
Phys.Rev.D72:037301,2005
10.1103/PhysRevD.72.037301
UCRHEP-T390 (May 2005)
hep-ph
null
The four-parameter tetrahedral neutrino mass matrix introduced earlier by the author is studied in two specific limits, both having only two parameters and resulting in theta_13=0, theta_23=pi/4, and tan^2 theta_12=1/2. One limit corresponds to a recent proposal which predicts a normal ordering of neutrino masses; the other is new and allows both inverted and normal ordering.
[ { "created": "Tue, 24 May 2005 19:39:28 GMT", "version": "v1" }, { "created": "Wed, 25 May 2005 18:22:08 GMT", "version": "v2" } ]
2010-04-06
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
The four-parameter tetrahedral neutrino mass matrix introduced earlier by the author is studied in two specific limits, both having only two parameters and resulting in theta_13=0, theta_23=pi/4, and tan^2 theta_12=1/2. One limit corresponds to a recent proposal which predicts a normal ordering of neutrino masses; the other is new and allows both inverted and normal ordering.
2107.02302
Lipei Du
Lipei Du (Ohio State U.), Xin An (North Carolina U.), Ulrich Heinz (Ohio State U.)
Baryon transport and the QCD critical point
26 pages, 17 figures; v2: Fig.14 moved to Fig.1, Sec.IIIC included more clarifications; published on PRC
null
10.1103/PhysRevC.104.064904
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fireballs created in relativistic heavy-ion collisions at different beam energies have been argued to follow different trajectories in the QCD phase diagram in which the QCD critical point serves as a landmark. Using a (1+1)-dimensional model setting with transverse homogeneity, we study the complexities introduced by the fact that the evolution history of each fireball cannot be characterized by a single trajectory but rather covers an entire swath of the phase diagram, with the finally emitted hadron spectra integrating over contributions from many different trajectories. Studying the phase diagram trajectories of fluid cells at different space-time rapidities, we explore how baryon diffusion shuffles them around, and how they are affected by critical dynamics near the QCD critical point. We find a striking insensitivity of baryon diffusion to critical effects. Its origins are analyzed and possible implications discussed.
[ { "created": "Mon, 5 Jul 2021 22:28:13 GMT", "version": "v1" }, { "created": "Sun, 16 Jan 2022 16:46:51 GMT", "version": "v2" } ]
2022-01-19
[ [ "Du", "Lipei", "", "Ohio State U." ], [ "An", "Xin", "", "North Carolina U." ], [ "Heinz", "Ulrich", "", "Ohio State U." ] ]
Fireballs created in relativistic heavy-ion collisions at different beam energies have been argued to follow different trajectories in the QCD phase diagram in which the QCD critical point serves as a landmark. Using a (1+1)-dimensional model setting with transverse homogeneity, we study the complexities introduced by the fact that the evolution history of each fireball cannot be characterized by a single trajectory but rather covers an entire swath of the phase diagram, with the finally emitted hadron spectra integrating over contributions from many different trajectories. Studying the phase diagram trajectories of fluid cells at different space-time rapidities, we explore how baryon diffusion shuffles them around, and how they are affected by critical dynamics near the QCD critical point. We find a striking insensitivity of baryon diffusion to critical effects. Its origins are analyzed and possible implications discussed.
2209.04753
Nestor Quintero
Cristian H. Garc\'ia-Duque, J. M. Cabarcas, J. H. Mu\~noz, N\'estor Quintero, and Eduardo Rojas
Singlet vector leptoquark model facing recent LHCb and BABAR measurements
15 pages, 3 figures. V2: Typos fixed. New References added. Recent LHCb result on the LFV decay B^0 to K^{*0} mu^{+} tau^- (mu^{-} tau^+) included. Phenomenology analysis improved. Overall conclusions unchanged
Nuclear Physics B 988 (2023) 116115
10.1016/j.nuclphysb.2023.116115
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Very recently the LHCb experiment released the first measurement of the ratio $R(\Lambda_c) = {\rm BR}(\Lambda_b \to \Lambda_c\tau\bar{\nu}_\tau)/{\rm BR}(\Lambda_b \to \Lambda_c\mu\bar{\nu}_\mu)$. Moreover, the BABAR experiment reported a new result of the leptonic decay ratio of Upsilon meson $\Upsilon(3S)$, namely, $R_{\Upsilon(3S)} = {\rm BR}(\Upsilon(3S) \to \tau^+\tau^-)/{\rm BR}(\Upsilon(3S) \to \mu^+\mu^-)$. Both measurements are below their corresponding Standard Model predictions (deficit), deviating by $\sim 1.1\sigma$ and $\sim 1.8\sigma$, respectively. Moreover, the LHCb recently presented the first search of the lepton flavor violating decay $B^0 \to K^{\ast 0}\mu^\pm\tau^\mp$. Motivated by these new data, in this work we study their impact on the phenomenology of the singlet vector leptoquark ($U_1$) model addressing the hints of lepton flavor universality violation in the semileptonic decays of $B$ mesons ($B$ meson anomalies), by carrying out a global fit analysis. In general, we found that a minimal version of the $U_1$ model with a mass of 1.8 TeV can successfully explain the $B$ meson anomalies, while being compatible with all other flavor observables and LHC bounds. Interestingly, our study shows that the new observables $R(\Lambda_c)$ and $R_{\Upsilon(3S)}$ generate strong tension, leading to non-trivial effects on the global fit. Future improvements at the LHCb and Belle II experiments would help to understand their complementarity. Moreover, we also analyze the impact of the expected sensitivity on flavor observables at Belle II to provide a further test of the $U_1$ model. Finally, we study the minimal assumptions under which the $U_1$ model could, in addition, provide a combined explanation of the anomalous magnetic moment of the muon.
[ { "created": "Sat, 10 Sep 2022 22:22:42 GMT", "version": "v1" }, { "created": "Sun, 25 Sep 2022 21:28:47 GMT", "version": "v2" } ]
2023-02-21
[ [ "García-Duque", "Cristian H.", "" ], [ "Cabarcas", "J. M.", "" ], [ "Muñoz", "J. H.", "" ], [ "Quintero", "Néstor", "" ], [ "Rojas", "Eduardo", "" ] ]
Very recently the LHCb experiment released the first measurement of the ratio $R(\Lambda_c) = {\rm BR}(\Lambda_b \to \Lambda_c\tau\bar{\nu}_\tau)/{\rm BR}(\Lambda_b \to \Lambda_c\mu\bar{\nu}_\mu)$. Moreover, the BABAR experiment reported a new result of the leptonic decay ratio of Upsilon meson $\Upsilon(3S)$, namely, $R_{\Upsilon(3S)} = {\rm BR}(\Upsilon(3S) \to \tau^+\tau^-)/{\rm BR}(\Upsilon(3S) \to \mu^+\mu^-)$. Both measurements are below their corresponding Standard Model predictions (deficit), deviating by $\sim 1.1\sigma$ and $\sim 1.8\sigma$, respectively. Moreover, the LHCb recently presented the first search of the lepton flavor violating decay $B^0 \to K^{\ast 0}\mu^\pm\tau^\mp$. Motivated by these new data, in this work we study their impact on the phenomenology of the singlet vector leptoquark ($U_1$) model addressing the hints of lepton flavor universality violation in the semileptonic decays of $B$ mesons ($B$ meson anomalies), by carrying out a global fit analysis. In general, we found that a minimal version of the $U_1$ model with a mass of 1.8 TeV can successfully explain the $B$ meson anomalies, while being compatible with all other flavor observables and LHC bounds. Interestingly, our study shows that the new observables $R(\Lambda_c)$ and $R_{\Upsilon(3S)}$ generate strong tension, leading to non-trivial effects on the global fit. Future improvements at the LHCb and Belle II experiments would help to understand their complementarity. Moreover, we also analyze the impact of the expected sensitivity on flavor observables at Belle II to provide a further test of the $U_1$ model. Finally, we study the minimal assumptions under which the $U_1$ model could, in addition, provide a combined explanation of the anomalous magnetic moment of the muon.
hep-ph/0211394
Boris Kayser
Andre de Gouvea, Boris Kayser and Rabindra Mohapatra
Manifest CP Violation from Majorana Phases
16 pages, 3 eps figures
Phys.Rev. D67 (2003) 053004
10.1103/PhysRevD.67.053004
Fermilab-Pub-02/298-T, UMD-PP-03-027
hep-ph
null
We hunt for and discuss manifestly CP-violating effects which are mediated by Majorana phases. These phases are present if the Standard Model neutrinos are Majorana particles. We argue that while Majorana phases do affect the strength of neutrinoless double beta decay (a well known fact), they do so in a way that involves no manifest violation of CP. The conditions for manifestly CP-violating phenomena -- differences between the rates for CP-mirror-image processes -- are presented, and three examples are discussed: (i) neutrino-antineutrino oscillation; (ii) rare decays of K and B mesons and their antiparticles and (iii) the lepton asymmetry generated by the decay of hypothetical very heavy right-handed "see-saw" neutrinos. We also find that, for the case of degenerate light neutrinos, manifestly CP-violating effects in neutrino-antineutrino oscillation vanish, although flavor-changing transitions do not. Finally, we comment on leptogenesis with degenerate right-handed neutrinos, and contrast it to the neutrino-antineutrino oscillation case.
[ { "created": "Tue, 26 Nov 2002 20:21:32 GMT", "version": "v1" } ]
2009-11-07
[ [ "de Gouvea", "Andre", "" ], [ "Kayser", "Boris", "" ], [ "Mohapatra", "Rabindra", "" ] ]
We hunt for and discuss manifestly CP-violating effects which are mediated by Majorana phases. These phases are present if the Standard Model neutrinos are Majorana particles. We argue that while Majorana phases do affect the strength of neutrinoless double beta decay (a well known fact), they do so in a way that involves no manifest violation of CP. The conditions for manifestly CP-violating phenomena -- differences between the rates for CP-mirror-image processes -- are presented, and three examples are discussed: (i) neutrino-antineutrino oscillation; (ii) rare decays of K and B mesons and their antiparticles and (iii) the lepton asymmetry generated by the decay of hypothetical very heavy right-handed "see-saw" neutrinos. We also find that, for the case of degenerate light neutrinos, manifestly CP-violating effects in neutrino-antineutrino oscillation vanish, although flavor-changing transitions do not. Finally, we comment on leptogenesis with degenerate right-handed neutrinos, and contrast it to the neutrino-antineutrino oscillation case.
hep-ph/0102110
Dr. Alex Finch
A.Finch
Tests of QCD in Two Photon PHysics
Contribution to ISMD 2000, Tihany, Hungary
null
null
null
hep-ph
null
Recent developments in the field of Two Photon Physics at LEP, and their contribution to QCD are reviewed.
[ { "created": "Fri, 9 Feb 2001 10:18:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Finch", "A.", "" ] ]
Recent developments in the field of Two Photon Physics at LEP, and their contribution to QCD are reviewed.
hep-ph/0409253
Edward Shuryak
Dmitry Ostrovsky and Edward Shuryak
Instanton-induced Azimuthal Spin Asymmetry in Deep Inelastic Scattering
version 2 includes few refs and new fig.5 which contains comparison to recent data
Phys.Rev.D71:014037,2005
10.1103/PhysRevD.71.014037
null
hep-ph
null
It is by now well understood that spin asymmetry in deep inelastic scattering (DIS) can appear if two things are both present: (i) a chirality flip of the struck quark; (ii) a nonzero T-odd phase due to its final state interaction. So far (i) was attributed to a new structure/wave function of the nucleon and (ii) to some gluon exchanges. We propose a new mechanism utilizing strong vacuum fluctuations of the gluon field described semiclasically by instantons, and show that both (i) and (ii) are present. The magnitude of the effect is estimated using known parameters of the instanton ensemble in the QCD vacuum and known structure and fragmentation functions, without any new free parameters. The result agrees in sign and (roughly) in magnitude with the available data on single particle inclusive DIS. Furthermore, our predictions uniquely relate effects for longitudinally and transversely polarized targets.
[ { "created": "Tue, 21 Sep 2004 21:26:01 GMT", "version": "v1" }, { "created": "Thu, 30 Sep 2004 14:45:24 GMT", "version": "v2" } ]
2011-02-01
[ [ "Ostrovsky", "Dmitry", "" ], [ "Shuryak", "Edward", "" ] ]
It is by now well understood that spin asymmetry in deep inelastic scattering (DIS) can appear if two things are both present: (i) a chirality flip of the struck quark; (ii) a nonzero T-odd phase due to its final state interaction. So far (i) was attributed to a new structure/wave function of the nucleon and (ii) to some gluon exchanges. We propose a new mechanism utilizing strong vacuum fluctuations of the gluon field described semiclasically by instantons, and show that both (i) and (ii) are present. The magnitude of the effect is estimated using known parameters of the instanton ensemble in the QCD vacuum and known structure and fragmentation functions, without any new free parameters. The result agrees in sign and (roughly) in magnitude with the available data on single particle inclusive DIS. Furthermore, our predictions uniquely relate effects for longitudinally and transversely polarized targets.
hep-ph/0211384
Sven Heinemeyer
T. Hahn, S. Heinemeyer, G. Weiglein
Very Heavy MSSM Higgs-Boson Production at the Linear Collider
6 pages, 7 figures, invited talk at the RADCOR 2002 - Loops & Legs 2002, Kloster Banz, Germany, Sept. 2002
Nucl.Phys.Proc.Suppl. 116 (2003) 336-340
10.1016/S0920-5632(03)80195-0
DCPT/02/124, IPPP/02/62, LMU 13/02, MPI-PhT/2002-72
hep-ph
null
In the Minimal Supersymmetric Standard Model (MSSM) we present the corrections to the heavy neutral CP-even Higgs-boson production in the WW-fusion and Higgs-strahlung channel, e+e- -> \bar nu nu H, taking into account all O(\alpha) corrections arising from loops of fermions and sfermions. While the H boson shows decoupling behavior at the tree-level, we find non-negligible loop corrections that can enhance the cross section considerably. At a center-of-mass energy of \sqrt{s} = 1000 GeV, masses of up to M_H <= 750 GeV are accessible at the LC in favorable regions of the MSSM parameter space.
[ { "created": "Mon, 25 Nov 2002 13:41:19 GMT", "version": "v1" } ]
2009-11-07
[ [ "Hahn", "T.", "" ], [ "Heinemeyer", "S.", "" ], [ "Weiglein", "G.", "" ] ]
In the Minimal Supersymmetric Standard Model (MSSM) we present the corrections to the heavy neutral CP-even Higgs-boson production in the WW-fusion and Higgs-strahlung channel, e+e- -> \bar nu nu H, taking into account all O(\alpha) corrections arising from loops of fermions and sfermions. While the H boson shows decoupling behavior at the tree-level, we find non-negligible loop corrections that can enhance the cross section considerably. At a center-of-mass energy of \sqrt{s} = 1000 GeV, masses of up to M_H <= 750 GeV are accessible at the LC in favorable regions of the MSSM parameter space.
hep-ph/0202244
Liliana Micu
L. Micu
A stationary relativistic representation of the bound state
12 pages
null
null
null
hep-ph
null
We show that a bound system in momentum space can be treated like a gas of free elementary constituents and a collective excitation of a background field which represents the countless quantum fluctuations generating the binding potential. The distribution function of the internal momenta in the bound system at rest is given by the projection of the solution of a relativistic bound state equation on the free wave functions of the elementary constituents. The 4-momentum carried by the collective excitation is the difference between the bound state 4-momentum and the sum of the free 4-momenta. This definiton ensures the explicit fulfilment of Lorentz covariance, mass-shell constraints and single particle normalizability of the bound state function. The discussion is made for a two particle bound state and can be easily generalized to the case of three or more particles.
[ { "created": "Tue, 26 Feb 2002 13:19:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Micu", "L.", "" ] ]
We show that a bound system in momentum space can be treated like a gas of free elementary constituents and a collective excitation of a background field which represents the countless quantum fluctuations generating the binding potential. The distribution function of the internal momenta in the bound system at rest is given by the projection of the solution of a relativistic bound state equation on the free wave functions of the elementary constituents. The 4-momentum carried by the collective excitation is the difference between the bound state 4-momentum and the sum of the free 4-momenta. This definiton ensures the explicit fulfilment of Lorentz covariance, mass-shell constraints and single particle normalizability of the bound state function. The discussion is made for a two particle bound state and can be easily generalized to the case of three or more particles.
hep-ph/9505335
Hussain Faheem
F. Hussain, J.G. K\"orner, J. Landgraf and Salam Tawfiq
$SU(2N_{f})\otimes O(3)$ light diquark symmetry and current-induced heavy baryon transition form factors
Corrected spelling mistake in title, 19 pages, latex, no figures
Z.Phys.C69:655-662,1996
10.1007/s002880050069
IC/95/45, MZ-TH/95-15
hep-ph
null
We study the current-induced bottom baryon to charm baryon transitions in the Heavy Quark Symmetry limit as $m_{q}\rightarrow \infty$. Our discussion involves $s$-wave to $s$-wave as well as $s$-wave to $p$-wave transitions. Using a constituent quark model picture for the light diquark system with an underlying $SU(2N_{f})\otimes O(3)$ symmetry and the heavy quark symmetry we arrive at a number of new predictions for the reduced form factors that describe these transitions.
[ { "created": "Thu, 18 May 1995 14:55:27 GMT", "version": "v1" }, { "created": "Fri, 19 May 1995 10:14:23 GMT", "version": "v2" } ]
2014-11-17
[ [ "Hussain", "F.", "" ], [ "Körner", "J. G.", "" ], [ "Landgraf", "J.", "" ], [ "Tawfiq", "Salam", "" ] ]
We study the current-induced bottom baryon to charm baryon transitions in the Heavy Quark Symmetry limit as $m_{q}\rightarrow \infty$. Our discussion involves $s$-wave to $s$-wave as well as $s$-wave to $p$-wave transitions. Using a constituent quark model picture for the light diquark system with an underlying $SU(2N_{f})\otimes O(3)$ symmetry and the heavy quark symmetry we arrive at a number of new predictions for the reduced form factors that describe these transitions.
1603.07739
Matthew Buckley
James Brooke, Matthew R. Buckley, Patrick Dunne, Bjoern Penning, John Tamanas, and Miha Zgubic
Vector Boson Fusion Searches for Dark Matter at the LHC
16 pages, 2 tables, 12 figures
Phys. Rev. D 93, 113013 (2016)
10.1103/PhysRevD.93.113013
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The vector boson fusion (VBF) event topology at the Large Hadron Collider (LHC) allows efficient suppression of dijet backgrounds and is therefore a promising target for new physics searches. We consider dark matter models which interact with the Standard Model through the electroweak sector: either through new scalar and pseudoscalar mediators which can be embedded into the Higgs sector, or via effective operators suppressed by some higher scale, and therefore have significant VBF production cross-sections. Using realistic simulations of the ATLAS and CMS analysis chain, including estimates of major error sources, we project the discovery and exclusion potential of the LHC for these models over the next decade.
[ { "created": "Thu, 24 Mar 2016 20:11:57 GMT", "version": "v1" } ]
2016-06-29
[ [ "Brooke", "James", "" ], [ "Buckley", "Matthew R.", "" ], [ "Dunne", "Patrick", "" ], [ "Penning", "Bjoern", "" ], [ "Tamanas", "John", "" ], [ "Zgubic", "Miha", "" ] ]
The vector boson fusion (VBF) event topology at the Large Hadron Collider (LHC) allows efficient suppression of dijet backgrounds and is therefore a promising target for new physics searches. We consider dark matter models which interact with the Standard Model through the electroweak sector: either through new scalar and pseudoscalar mediators which can be embedded into the Higgs sector, or via effective operators suppressed by some higher scale, and therefore have significant VBF production cross-sections. Using realistic simulations of the ATLAS and CMS analysis chain, including estimates of major error sources, we project the discovery and exclusion potential of the LHC for these models over the next decade.
2103.08586
Hua-Xing Chen
Hua-Xing Chen
Hadronic molecules in B decays
30 pages, 5 figures, 4 tables, accepted by PRD. arXiv admin note: text overlap with arXiv:2011.07187
Phys. Rev. D 105, 094003 (2022)
10.1103/PhysRevD.105.094003
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
There are eighteen possibly existing $D^{(*)} \bar D^{(*)}$, $D^{(*)} \bar K^{(*)}$, and $D^{(*)} D_s^{(*)-}$ hadronic molecular states. We construct their corresponding interpolating currents, and calculate their masses and decay constants using QCD sum rules. Based on these results, we calculate their relative production rates in $B$ and $B^*$ decays through the current algebra, and calculate their relative branching ratios through the Fierz rearrangement, as summarized in Table III. Our results support the interpretations of the $X(3872)$, $Z_c(3900)$, $Z_c(4020)$, and $X_0(2900)$ as the molecular states $D \bar D^*$ of $J^{PC} = 1^{++}$, $D \bar D^*$ of $J^{PC} = 1^{+-}$, $D^* \bar D^*$ of $J^{PC} = 1^{+-}$, and $D^* \bar K^*$ of $J^P = 0^{+}$, respectively. Our results also suggest that the $Z_{cs}(3985)$, $Z_{cs}(4000)$, and $Z_{cs}(4220)$ are strange partners of the $X(3872)$, $Z_c(3900)$, and $Z_c(4020)$, respectively. In the calculations we estimate the lifetime of a weakly-coupled composite particle $A = |BC\rangle$ to be $1/t_A \approx 1/t_B + 1/t_C + \Gamma_{A \to BC} + \cdots$, with $\cdots$ partial widths of other possible decay channels.
[ { "created": "Mon, 15 Mar 2021 17:56:19 GMT", "version": "v1" }, { "created": "Thu, 21 Apr 2022 01:39:18 GMT", "version": "v2" } ]
2022-05-09
[ [ "Chen", "Hua-Xing", "" ] ]
There are eighteen possibly existing $D^{(*)} \bar D^{(*)}$, $D^{(*)} \bar K^{(*)}$, and $D^{(*)} D_s^{(*)-}$ hadronic molecular states. We construct their corresponding interpolating currents, and calculate their masses and decay constants using QCD sum rules. Based on these results, we calculate their relative production rates in $B$ and $B^*$ decays through the current algebra, and calculate their relative branching ratios through the Fierz rearrangement, as summarized in Table III. Our results support the interpretations of the $X(3872)$, $Z_c(3900)$, $Z_c(4020)$, and $X_0(2900)$ as the molecular states $D \bar D^*$ of $J^{PC} = 1^{++}$, $D \bar D^*$ of $J^{PC} = 1^{+-}$, $D^* \bar D^*$ of $J^{PC} = 1^{+-}$, and $D^* \bar K^*$ of $J^P = 0^{+}$, respectively. Our results also suggest that the $Z_{cs}(3985)$, $Z_{cs}(4000)$, and $Z_{cs}(4220)$ are strange partners of the $X(3872)$, $Z_c(3900)$, and $Z_c(4020)$, respectively. In the calculations we estimate the lifetime of a weakly-coupled composite particle $A = |BC\rangle$ to be $1/t_A \approx 1/t_B + 1/t_C + \Gamma_{A \to BC} + \cdots$, with $\cdots$ partial widths of other possible decay channels.
2403.15387
Fernando Arias-Arag\'on
Fernando Arias-Arag\'on, Luc Darm\'e, Giovanni Grilli di Cortona, Enrico Nardi
Production of dark sector particles via resonant positron annihilation on atomic electrons
11 pages, 3 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Resonant positron annihilation on atomic electrons provides a powerful method to search for light new particles coupled to $e^+e^-$. Reliable estimates of production rates require a detailed characterization of electron momentum distributions. We describe a general method that harnesses the target material Compton profile to properly include electron velocity effects in resonant annihilation cross-sections. We additionally find that high $Z$ atoms can efficiently act as particle physics accelerators, providing a density of relativistic electrons that allows to extend by several times the experimental mass reach.
[ { "created": "Fri, 22 Mar 2024 17:59:43 GMT", "version": "v1" } ]
2024-03-25
[ [ "Arias-Aragón", "Fernando", "" ], [ "Darmé", "Luc", "" ], [ "di Cortona", "Giovanni Grilli", "" ], [ "Nardi", "Enrico", "" ] ]
Resonant positron annihilation on atomic electrons provides a powerful method to search for light new particles coupled to $e^+e^-$. Reliable estimates of production rates require a detailed characterization of electron momentum distributions. We describe a general method that harnesses the target material Compton profile to properly include electron velocity effects in resonant annihilation cross-sections. We additionally find that high $Z$ atoms can efficiently act as particle physics accelerators, providing a density of relativistic electrons that allows to extend by several times the experimental mass reach.
hep-ph/9211214
Jim Pantaleone
J. Pantaleone, A. Halprin, C.N. Leung
Neutrino Mixing due to a Violation of the Equivalence Principle
13 pages
Phys.Rev.D47:4199-4202,1993
10.1103/PhysRevD.47.R4199
null
hep-ph
null
Massless neutrinos will mix if their couplings to gravity are flavor dependent, i.e., violate the principle of equivalence. Because the gravitational interaction grows with neutrino energy, the solar neutrino problem and the recent atmospheric neutrino data may be simultaneously explained by violations at the level of 1E-14 to 1E-17 or smaller. This possibility is severely constrained by present accelerator neutrino experiments and will be preeminently tested in proposed long baseline accelerator neutrino experiments.
[ { "created": "Thu, 5 Nov 1992 21:04:50 GMT", "version": "v1" } ]
2008-11-26
[ [ "Pantaleone", "J.", "" ], [ "Halprin", "A.", "" ], [ "Leung", "C. N.", "" ] ]
Massless neutrinos will mix if their couplings to gravity are flavor dependent, i.e., violate the principle of equivalence. Because the gravitational interaction grows with neutrino energy, the solar neutrino problem and the recent atmospheric neutrino data may be simultaneously explained by violations at the level of 1E-14 to 1E-17 or smaller. This possibility is severely constrained by present accelerator neutrino experiments and will be preeminently tested in proposed long baseline accelerator neutrino experiments.
1810.04689
Yongcheng Wu
Ning Chen, Chun Du, Yongcheng Wu, Xun-Jie Xu
Further study of the global minimum constraint on the two-Higgs-doublet models: LHC searches for heavy Higgs bosons
19 pages, 9 figures, 2 tables; v2: Refs added, one-loop level results added, conclusion doesn't change, matches to published version
Phys. Rev. D 99, 035011 (2019)
10.1103/PhysRevD.99.035011
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The usually considered vacuum of the two-Higgs-doublet model (2HDM) could be unstable if it locates at a local but not global minimum (GM) of the scalar potential. By requiring the vacuum to be a GM, we obtain an additional constraint, namely the GM constraint, on the scalar potential. In this work, we explore the GM constraint on the $CP$-conserving general 2HDM. This constraint is found to put limits on the soft $\mathbb{Z}_2$ breaking mass parameter $m_{12}^2$ and also squeeze the heavy $CP$-even Higgs boson mass into larger values for the $m_{12}^2< 0$ case. Combined with the current global signal fits from the LHC measurements of the 125 GeV Higgs boson, we discuss the phenomenological implications for the heavy Higgs boson searches at the LHC.
[ { "created": "Wed, 10 Oct 2018 18:01:53 GMT", "version": "v1" }, { "created": "Sun, 17 Feb 2019 14:08:07 GMT", "version": "v2" } ]
2019-02-20
[ [ "Chen", "Ning", "" ], [ "Du", "Chun", "" ], [ "Wu", "Yongcheng", "" ], [ "Xu", "Xun-Jie", "" ] ]
The usually considered vacuum of the two-Higgs-doublet model (2HDM) could be unstable if it locates at a local but not global minimum (GM) of the scalar potential. By requiring the vacuum to be a GM, we obtain an additional constraint, namely the GM constraint, on the scalar potential. In this work, we explore the GM constraint on the $CP$-conserving general 2HDM. This constraint is found to put limits on the soft $\mathbb{Z}_2$ breaking mass parameter $m_{12}^2$ and also squeeze the heavy $CP$-even Higgs boson mass into larger values for the $m_{12}^2< 0$ case. Combined with the current global signal fits from the LHC measurements of the 125 GeV Higgs boson, we discuss the phenomenological implications for the heavy Higgs boson searches at the LHC.
1206.1923
Mikhail Mikhasenko
Mikhail Mikhasenko
A proton-pentaquark mixing and the~intrinsic charm model
5 pages, 1 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new interpretation of intrinsic charm phenomenon based on the assumption of pentaquark $\left| u u d c\bar{c} \right>$ mixing with a proton is offered. The structure function of the $c$-quark in the pentaquark is constructed. Mixing different states is considered theoretically and using experiment data on $D$-meson production and inclusive production of the hidden charm particles.
[ { "created": "Sat, 9 Jun 2012 09:36:33 GMT", "version": "v1" }, { "created": "Tue, 26 Nov 2013 11:26:39 GMT", "version": "v2" } ]
2013-11-27
[ [ "Mikhasenko", "Mikhail", "" ] ]
A new interpretation of intrinsic charm phenomenon based on the assumption of pentaquark $\left| u u d c\bar{c} \right>$ mixing with a proton is offered. The structure function of the $c$-quark in the pentaquark is constructed. Mixing different states is considered theoretically and using experiment data on $D$-meson production and inclusive production of the hidden charm particles.
1503.02597
Wei Chen
Hua-Xing Chen, Er-Liang Cui, Wei Chen, T. G. Steele, Xiang Liu and Shi-Lin Zhu
$a_1(1420)$ resonance as a tetraquark state and its isospin partner
15 pages, 8 figures. Accepted by Phys. Rev. D
Phys. Rev. D 91, 094022 (2015)
10.1103/PhysRevD.91.094022
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We systematically construct tetraquark currents of $I^GJ^{PC}=1^-1^{++}$ and classify them into types $\mathbf{A}$ (antisymmetric), $\mathbf{S}$ (symmetric) and $\mathbf{M}$ (mixed), based on flavor symmetries of diquarks and antidiquarks composing the tetra quark currents. We use tetraquark currents of type $\mathbf{M}$ to perform QCD sum rule analyses, and find a tetraquark current $\eta^M_{5\mu}$ with quark contents $q s\bar q \bar s$($q=u$ or $d$) leading to a mass of $1.44 \pm 0.08$ GeV consistent with the $a_1(1420)$ state recently observed by the COMPASS collaboration. Our results support tetraquark explanations for both $a_1(1420)$ and $f_1(1420)$, assuming that they are isospin partners. We also study their possible decay patterns. As tetraquark candidates, the possible decay modes of $a_1(1420)$ are $S$-wave $a_1(1420) \rightarrow K^*(892)K$ and $P$-wave $a_1(1420)\rightarrow f_0(980) \pi$ while the possible decay patterns of $f_1(1420)$ are $S$-wave $f_1(1420) \rightarrow K^*(892)K$ and $P$-wave $f_1(1420) \rightarrow a_0(980) \pi$. We speculate that $a_1(1420)$ is partly responsible for the large isospin violation in the $\eta(1405)\to f_0(980)\pi_0$ decay mode which is reported by BESIII collaboration in the $J/\psi\to\gamma 3\pi$ process.
[ { "created": "Mon, 9 Mar 2015 18:14:30 GMT", "version": "v1" }, { "created": "Thu, 21 May 2015 18:19:32 GMT", "version": "v2" } ]
2015-05-25
[ [ "Chen", "Hua-Xing", "" ], [ "Cui", "Er-Liang", "" ], [ "Chen", "Wei", "" ], [ "Steele", "T. G.", "" ], [ "Liu", "Xiang", "" ], [ "Zhu", "Shi-Lin", "" ] ]
We systematically construct tetraquark currents of $I^GJ^{PC}=1^-1^{++}$ and classify them into types $\mathbf{A}$ (antisymmetric), $\mathbf{S}$ (symmetric) and $\mathbf{M}$ (mixed), based on flavor symmetries of diquarks and antidiquarks composing the tetra quark currents. We use tetraquark currents of type $\mathbf{M}$ to perform QCD sum rule analyses, and find a tetraquark current $\eta^M_{5\mu}$ with quark contents $q s\bar q \bar s$($q=u$ or $d$) leading to a mass of $1.44 \pm 0.08$ GeV consistent with the $a_1(1420)$ state recently observed by the COMPASS collaboration. Our results support tetraquark explanations for both $a_1(1420)$ and $f_1(1420)$, assuming that they are isospin partners. We also study their possible decay patterns. As tetraquark candidates, the possible decay modes of $a_1(1420)$ are $S$-wave $a_1(1420) \rightarrow K^*(892)K$ and $P$-wave $a_1(1420)\rightarrow f_0(980) \pi$ while the possible decay patterns of $f_1(1420)$ are $S$-wave $f_1(1420) \rightarrow K^*(892)K$ and $P$-wave $f_1(1420) \rightarrow a_0(980) \pi$. We speculate that $a_1(1420)$ is partly responsible for the large isospin violation in the $\eta(1405)\to f_0(980)\pi_0$ decay mode which is reported by BESIII collaboration in the $J/\psi\to\gamma 3\pi$ process.
2304.07682
Xiao-Yun Wang
Xiao-Yun Wang, Chen Dong, Xiang Liu
Analysis of strong coupling constant with machine learning and its application
10 pages, 7 figures
Chin.Phys.Lett. 41 (2023) 031201
10.1088/0256-307X/41/3/031201
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, we investigate the nature of the strong coupling constant and related physics. Through the analysis of accumulated experimental data from around the world, we employ the ability of machine learning to unravel its physical laws. The result of our efforts is a formula that captures the expansive panorama of the distribution of the strong coupling constant across the entire energy range. Importantly, this newly derived expression is very similar to the formula derived from the Dyson-Schwinger equations based on the framework of Yang-Mills theory. By introducing the Euler number, $e$, into the functional formula of the strong coupling constant at high energies, we have successfully solved the puzzle of the infrared divergence, which allows for a seamless transition of the strong coupling constant from the perturbative to the non-perturbative energy regime. Moreover, the obtained ghost and gluon dressing function distribution results confirm that the obtained strong coupling constant formula can well describe the physical properties of the non-perturbed regime. In addition, we investigate the QCD strong coupling constant result of the Bjorken sum rule $\Gamma_1^{p-n}$ and the quark-quark static energy $E_0(r)$, and find that the global energy scale can effectively interpret the experimental data. The results presented in this work shed light on the puzzling properties of quantum chromodynamics and the intricate interplay of strong coupling constants at both low and high energy scales.
[ { "created": "Sun, 16 Apr 2023 03:23:33 GMT", "version": "v1" }, { "created": "Sun, 28 May 2023 03:41:55 GMT", "version": "v2" }, { "created": "Fri, 6 Oct 2023 05:59:57 GMT", "version": "v3" }, { "created": "Thu, 29 Feb 2024 02:06:29 GMT", "version": "v4" } ]
2024-03-06
[ [ "Wang", "Xiao-Yun", "" ], [ "Dong", "Chen", "" ], [ "Liu", "Xiang", "" ] ]
In this work, we investigate the nature of the strong coupling constant and related physics. Through the analysis of accumulated experimental data from around the world, we employ the ability of machine learning to unravel its physical laws. The result of our efforts is a formula that captures the expansive panorama of the distribution of the strong coupling constant across the entire energy range. Importantly, this newly derived expression is very similar to the formula derived from the Dyson-Schwinger equations based on the framework of Yang-Mills theory. By introducing the Euler number, $e$, into the functional formula of the strong coupling constant at high energies, we have successfully solved the puzzle of the infrared divergence, which allows for a seamless transition of the strong coupling constant from the perturbative to the non-perturbative energy regime. Moreover, the obtained ghost and gluon dressing function distribution results confirm that the obtained strong coupling constant formula can well describe the physical properties of the non-perturbed regime. In addition, we investigate the QCD strong coupling constant result of the Bjorken sum rule $\Gamma_1^{p-n}$ and the quark-quark static energy $E_0(r)$, and find that the global energy scale can effectively interpret the experimental data. The results presented in this work shed light on the puzzling properties of quantum chromodynamics and the intricate interplay of strong coupling constants at both low and high energy scales.
hep-ph/0009050
Lev Leinson
L. B. Leinson
Neutrino emission due to Cooper pairing of protons in cooling neutron stars: Collective effects
11 pages, 2 figures
Phys.Lett. B473 (2000) 318
10.1016/S0370-2693(99)01473-2
null
hep-ph
null
The process of neutrino-pair radiation due to formation and breaking of Cooper pairs of protons in superconducting cores of neutron stars is considered with taking into account of the electromagnetic coupling of protons to ambient electrons. It is shown that plasma polarization strongly modifies the effective vector weak current of protons. Collective response of ambient electrons to the proton quantum transition contributes coherently to the complete interaction with the neutrino field and enhances the rate of neutrino-pair production by two orders of magnitude.
[ { "created": "Tue, 5 Sep 2000 10:22:29 GMT", "version": "v1" }, { "created": "Mon, 11 Sep 2000 08:08:52 GMT", "version": "v2" } ]
2009-10-31
[ [ "Leinson", "L. B.", "" ] ]
The process of neutrino-pair radiation due to formation and breaking of Cooper pairs of protons in superconducting cores of neutron stars is considered with taking into account of the electromagnetic coupling of protons to ambient electrons. It is shown that plasma polarization strongly modifies the effective vector weak current of protons. Collective response of ambient electrons to the proton quantum transition contributes coherently to the complete interaction with the neutrino field and enhances the rate of neutrino-pair production by two orders of magnitude.
1707.02517
Zhou Rui
Zhou Rui, Ya Li, and Zhen-Jun Xiao
Branching ratios, $CP$ asymmetries and polarizations of $B\rightarrow \psi(2S) V$ decays
14 pages, 1 figure, 6 tables
Eur. Phys. J. C (2017) 77:610
10.1140/epjc/s10052-017-5193-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyzed the nonleptonic decays $B/B_s\to \psi(2S) V $ with $V=(\rho, \omega, K^{*}, \phi)$ by employing the perturbative QCD (PQCD) factorization approach. Here the branching ratios, the $CP$ asymmetries and the complete set of polarization observables are investigated systematically. Besides the traditional contributions from the factorizable and nonfactorizable diagrams at the leading order, the next-to-leading order (NLO) vertex corrections could also provide considerable contributions. The PQCD predictions for the branching ratios of the $B_{(s)}\to \psi(2S)K^{*}, \psi(2S) \phi$ decays are consistent with the measured values within errors. As for $B\to \psi(2S) \rho, \psi(2S) \omega$ decays, the branching ratios can reach the order of $10^{-5}$ and could be measured in the LHCb and Belle-II experiments. The numerical results show that the direct $CP$ asymmetries of the considered decays are very small. Thus the observation of any large direct $CP$ asymmetry for these decays will be a signal for new physics. The mixing induced $CP$ asymmetries in the neutral modes are very close to $\sin 2\beta_{(s)}$, which suggests that these channels can give a cross-check on the measurement of the Cabbibo-Kobayashi-Maskawa (CKM) angle $\beta$ and $\beta_s$. We found that the longitudinal polarization fractions $f_0$ are suppressed to $\sim 50\%$ due to the large nonfactorizable contributions. The magnitudes and phases of the two transverse amplitudes $\mathcal {A}_{\parallel}$ and $\mathcal {A}_{\perp}$ are roughly equal, which is an indication for the approximate light quark helicity conservation in these decays. The overall polarization observables of $B\to \psi(2S) K^{*0}$ and $B_s\to \psi(2S) \phi$ channels are also in good agreement with the experimental measurements as reported by LHCb and BaBar. Other results can also be tested by the LHCb and Belle-II experiments.
[ { "created": "Sun, 9 Jul 2017 02:09:16 GMT", "version": "v1" } ]
2017-09-18
[ [ "Rui", "Zhou", "" ], [ "Li", "Ya", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
We analyzed the nonleptonic decays $B/B_s\to \psi(2S) V $ with $V=(\rho, \omega, K^{*}, \phi)$ by employing the perturbative QCD (PQCD) factorization approach. Here the branching ratios, the $CP$ asymmetries and the complete set of polarization observables are investigated systematically. Besides the traditional contributions from the factorizable and nonfactorizable diagrams at the leading order, the next-to-leading order (NLO) vertex corrections could also provide considerable contributions. The PQCD predictions for the branching ratios of the $B_{(s)}\to \psi(2S)K^{*}, \psi(2S) \phi$ decays are consistent with the measured values within errors. As for $B\to \psi(2S) \rho, \psi(2S) \omega$ decays, the branching ratios can reach the order of $10^{-5}$ and could be measured in the LHCb and Belle-II experiments. The numerical results show that the direct $CP$ asymmetries of the considered decays are very small. Thus the observation of any large direct $CP$ asymmetry for these decays will be a signal for new physics. The mixing induced $CP$ asymmetries in the neutral modes are very close to $\sin 2\beta_{(s)}$, which suggests that these channels can give a cross-check on the measurement of the Cabbibo-Kobayashi-Maskawa (CKM) angle $\beta$ and $\beta_s$. We found that the longitudinal polarization fractions $f_0$ are suppressed to $\sim 50\%$ due to the large nonfactorizable contributions. The magnitudes and phases of the two transverse amplitudes $\mathcal {A}_{\parallel}$ and $\mathcal {A}_{\perp}$ are roughly equal, which is an indication for the approximate light quark helicity conservation in these decays. The overall polarization observables of $B\to \psi(2S) K^{*0}$ and $B_s\to \psi(2S) \phi$ channels are also in good agreement with the experimental measurements as reported by LHCb and BaBar. Other results can also be tested by the LHCb and Belle-II experiments.
0911.1942
Riccardo Torre
Riccardo Barbieri, Antonio E. Carcamo, Gennaro Corcella, Riccardo Torre, Enrico Trincherini
Composite Vectors at the Large Hadron Collider
17 pages, 4 figures, 2 tables
JHEP 1003:068,2010
10.1007/JHEP03(2010)068
IFUP-TH/2009-24
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An unspecified strong dynamics may give rise to composite vectors sufficiently light that their interactions, among themselves or with the electroweak gauge bosons, be approximately described by an effective Lagrangian invariant under $SU(2)_L\times SU(2)_R/ SU(2)_{L+R}$. We study the production at the LHC of two such states by vector boson fusion or by the Drell--Yan process in this general framework and we compare it with the case of gauge vectors from a $SU(2)_L\times SU(2)_R\times SU(2)^N$ gauge model spontaneously broken to the diagonal SU(2) subgroup by a generic $\sigma$-model. Special attention is payed to the asymptotic behaviour of the different amplitudes in both cases. The expected rates of multi-lepton events from the decay of the composite vectors are also given. A thorough phenomenological analysis and the evaluation of the backgrounds to such signals, aiming at assessing the visibility of composite-vector pairs at the LHC, is instead deferred to future work.
[ { "created": "Tue, 10 Nov 2009 16:36:29 GMT", "version": "v1" }, { "created": "Tue, 16 Mar 2010 18:01:36 GMT", "version": "v2" }, { "created": "Wed, 31 Mar 2010 12:20:16 GMT", "version": "v3" } ]
2015-03-13
[ [ "Barbieri", "Riccardo", "" ], [ "Carcamo", "Antonio E.", "" ], [ "Corcella", "Gennaro", "" ], [ "Torre", "Riccardo", "" ], [ "Trincherini", "Enrico", "" ] ]
An unspecified strong dynamics may give rise to composite vectors sufficiently light that their interactions, among themselves or with the electroweak gauge bosons, be approximately described by an effective Lagrangian invariant under $SU(2)_L\times SU(2)_R/ SU(2)_{L+R}$. We study the production at the LHC of two such states by vector boson fusion or by the Drell--Yan process in this general framework and we compare it with the case of gauge vectors from a $SU(2)_L\times SU(2)_R\times SU(2)^N$ gauge model spontaneously broken to the diagonal SU(2) subgroup by a generic $\sigma$-model. Special attention is payed to the asymptotic behaviour of the different amplitudes in both cases. The expected rates of multi-lepton events from the decay of the composite vectors are also given. A thorough phenomenological analysis and the evaluation of the backgrounds to such signals, aiming at assessing the visibility of composite-vector pairs at the LHC, is instead deferred to future work.
1901.03256
Renato Zamora
M. Loewe, L. Monje, E. Mu\~noz, A. Raya and R. Zamora
A new perspective for the magnetic corrections to $\pi$-$\pi$ Scattering Lengths in the Linear Sigma Model
7 pages, 3 figures
Phys. Rev. D 99, 056002 (2019)
10.1103/PhysRevD.99.056002
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, a new perspective for obtaining the magnetic evolution of $\pi-\pi $ scattering lengths in the frame of the linear sigma model is presented. When computing the relevant one-loop diagrams that contribute to these parameters, the sum over Landau levels --emerging from the expansion of the Schwinger propagator-- is handled in a novel way that could also be applied to the calculation of other magnetic-type corrections. Essentially, we have obtained an expansion in terms of Hurwitz Zeta functions. It is necessary to regularize our expressions by an appropriate physical subtraction when $|qB| \rightarrow 0$ ($q$ the meson charge and $B$ the magnetic field strength). In this way, we are able to interpolate between the very high magnetic field strength region, usually handled in terms of the Lowest Landau Level (LLA) approximation, and the weak field region, discussed in a previous paper by some of us, which is based on an appropriate expansion of the Schwinger propagator up to order $|qB|^{2}$. Our results for the scattering lengths parameters produce a soft evolution in a wide region of magnetic field strengths, reducing to the previously found expressions in both limits.
[ { "created": "Thu, 10 Jan 2019 16:34:14 GMT", "version": "v1" } ]
2019-03-13
[ [ "Loewe", "M.", "" ], [ "Monje", "L.", "" ], [ "Muñoz", "E.", "" ], [ "Raya", "A.", "" ], [ "Zamora", "R.", "" ] ]
In this article, a new perspective for obtaining the magnetic evolution of $\pi-\pi $ scattering lengths in the frame of the linear sigma model is presented. When computing the relevant one-loop diagrams that contribute to these parameters, the sum over Landau levels --emerging from the expansion of the Schwinger propagator-- is handled in a novel way that could also be applied to the calculation of other magnetic-type corrections. Essentially, we have obtained an expansion in terms of Hurwitz Zeta functions. It is necessary to regularize our expressions by an appropriate physical subtraction when $|qB| \rightarrow 0$ ($q$ the meson charge and $B$ the magnetic field strength). In this way, we are able to interpolate between the very high magnetic field strength region, usually handled in terms of the Lowest Landau Level (LLA) approximation, and the weak field region, discussed in a previous paper by some of us, which is based on an appropriate expansion of the Schwinger propagator up to order $|qB|^{2}$. Our results for the scattering lengths parameters produce a soft evolution in a wide region of magnetic field strengths, reducing to the previously found expressions in both limits.
hep-ph/9705470
Wojciech Florkowski
A. Bialas, W. Czyz, W. Florkowski
Total $\gamma^{\star}\gamma^{\star}$ cross section and the BFKL pomeron
16 pages, latex, uses psfig, 2 figures
Eur.Phys.J.C2:683-689,1998
10.1007/s100520050171
TPJU - 6/97
hep-ph
null
In the framework of the dipole picture of the BFKL pomeron we discuss a few possibilities of calculating the total $\gamma^{\star}\gamma^{\star}$ cross section of the virtual photons. We argue that the existing successful fits of the dipole picture formulae to the measured structure functions $F_2(Q^2,x)$ favor one of the possible extensions of the dipole picture of the BFKL pomeron formulated recently by one of us.
[ { "created": "Fri, 30 May 1997 08:10:49 GMT", "version": "v1" } ]
2011-09-13
[ [ "Bialas", "A.", "" ], [ "Czyz", "W.", "" ], [ "Florkowski", "W.", "" ] ]
In the framework of the dipole picture of the BFKL pomeron we discuss a few possibilities of calculating the total $\gamma^{\star}\gamma^{\star}$ cross section of the virtual photons. We argue that the existing successful fits of the dipole picture formulae to the measured structure functions $F_2(Q^2,x)$ favor one of the possible extensions of the dipole picture of the BFKL pomeron formulated recently by one of us.
hep-ph/9301274
Claudio Coriano
Claudio Coriano', Anatoly Radyushkin and George Sterman
QCD Sum Rules and Compton Scattering
30 pages in Latex, 6 figures not included, available upon request (send email to: claudio@max.physics.sunysb.edu), ITP-SB-92-70, CEBAF-TH-92-32
Nucl.Phys.B405:481-506,1993
10.1016/0550-3213(93)90556-5
null
hep-ph
null
We extend QCD sum rule analysis to moderate energy fixed angle Compton scattering. In this kinematic region there is a strong similarity to the sum rule treatment of electromagnetic form factors, although the four-point amplitude requires a modification of the Borel transform. To illustrate our method, we derive the sum rules for helicity amplitudes in pion Compton scattering and estimate their large-$t$ behavior in the local duality approximation.
[ { "created": "Tue, 26 Jan 1993 15:48:11 GMT", "version": "v1" } ]
2014-11-17
[ [ "Coriano'", "Claudio", "" ], [ "Radyushkin", "Anatoly", "" ], [ "Sterman", "George", "" ] ]
We extend QCD sum rule analysis to moderate energy fixed angle Compton scattering. In this kinematic region there is a strong similarity to the sum rule treatment of electromagnetic form factors, although the four-point amplitude requires a modification of the Borel transform. To illustrate our method, we derive the sum rules for helicity amplitudes in pion Compton scattering and estimate their large-$t$ behavior in the local duality approximation.
1410.5274
Zhenjun Xiao
Zhen-Jun Xiao, Ya Li, Dong-Ting Lin, Ying-Ying Fan and Ai-Jun Ma
$\bar{B}^0_s \to (\pi^0 \eta^{(*)}, \eta^{(*)}\eta^{(*)})$ decays and the effects of next-to-leading order contributions in the perturbative QCD approach
12 pages, 2figures and 3 tables
Phys. Rev. D 90, 114028 (2014)
10.1103/PhysRevD.90.114028
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we calculate the branching ratios and CP violating asymmetries of the five $\bar{B}^0_s \to (\pi^0\eta^{(*)},\eta^{(*)}\eta^{(*)})$ decays, by employing the perturbative QCD (pQCD) factorization approach and with the inclusion of all currently known next-to-leading order (NLO) contributions. We find that (a) the NLO contributions can provide about 100% enhancements to the LO pQCD predictions for the decay rates of $\bar{B}_s^0 \to \eta\eta^\prime$ and $\eta^\prime \eta^\prime$ decays, but result in small changes to $Br(\bar{B}_s \to \pi^0 \eta^{(*)})$ and $Br(\bar{B}_s \to \eta\eta)$; (b) the newly known NLO twist-2 and twist-3 contributions to the relevant form factors can provide about 10% enhancements to the decay rates of the considered decays; (c) for $\bar{B}_s \to \pi^0 \eta^{(*)}$ decays, their direct CP-violating asymmetries $\cala_f^{dir}$ could be enhanced significantly by the inclusion of the NLO contributions; and (d) the pQCD predictions for $Br(\bar{B}_s \to \eta \eta^{(*)})$ and $Br(\bar{B}_s \to \eta^\prime \eta^\prime)$ can be as large as $4\times 10^{-5}$, which may be measurable at LHCb or the forthcoming super-B experiments.
[ { "created": "Mon, 20 Oct 2014 13:44:57 GMT", "version": "v1" } ]
2014-12-31
[ [ "Xiao", "Zhen-Jun", "" ], [ "Li", "Ya", "" ], [ "Lin", "Dong-Ting", "" ], [ "Fan", "Ying-Ying", "" ], [ "Ma", "Ai-Jun", "" ] ]
In this paper, we calculate the branching ratios and CP violating asymmetries of the five $\bar{B}^0_s \to (\pi^0\eta^{(*)},\eta^{(*)}\eta^{(*)})$ decays, by employing the perturbative QCD (pQCD) factorization approach and with the inclusion of all currently known next-to-leading order (NLO) contributions. We find that (a) the NLO contributions can provide about 100% enhancements to the LO pQCD predictions for the decay rates of $\bar{B}_s^0 \to \eta\eta^\prime$ and $\eta^\prime \eta^\prime$ decays, but result in small changes to $Br(\bar{B}_s \to \pi^0 \eta^{(*)})$ and $Br(\bar{B}_s \to \eta\eta)$; (b) the newly known NLO twist-2 and twist-3 contributions to the relevant form factors can provide about 10% enhancements to the decay rates of the considered decays; (c) for $\bar{B}_s \to \pi^0 \eta^{(*)}$ decays, their direct CP-violating asymmetries $\cala_f^{dir}$ could be enhanced significantly by the inclusion of the NLO contributions; and (d) the pQCD predictions for $Br(\bar{B}_s \to \eta \eta^{(*)})$ and $Br(\bar{B}_s \to \eta^\prime \eta^\prime)$ can be as large as $4\times 10^{-5}$, which may be measurable at LHCb or the forthcoming super-B experiments.
hep-ph/9811451
Takehiko Asaka
T. Asaka and Masahiro Yamaguchi
Hadronic Axion Model in Gauge-Mediated Supersymmetry Breaking and Cosmology of Saxion
24 pages, 3 figures
Phys.Rev. D59 (1999) 125003
10.1103/PhysRevD.59.125003
null
hep-ph
null
Recently we have proposed a simple hadronic axion model within gauge-mediated supersymmetry breaking. In this paper we discuss various cosmological consequences of the model in great detail. A particular attention is paid to a saxion, a scalar partner of an axion, which is produced as a coherent oscillation in the early universe. We show that our model is cosmologically viable, if the reheating temperature of inflation is sufficiently low. We also discuss the late decay of the saxion which gives a preferable power spectrum of the density fluctuation in the standard cold dark matter model when compared with the observation.
[ { "created": "Tue, 24 Nov 1998 08:50:08 GMT", "version": "v1" } ]
2009-10-31
[ [ "Asaka", "T.", "" ], [ "Yamaguchi", "Masahiro", "" ] ]
Recently we have proposed a simple hadronic axion model within gauge-mediated supersymmetry breaking. In this paper we discuss various cosmological consequences of the model in great detail. A particular attention is paid to a saxion, a scalar partner of an axion, which is produced as a coherent oscillation in the early universe. We show that our model is cosmologically viable, if the reheating temperature of inflation is sufficiently low. We also discuss the late decay of the saxion which gives a preferable power spectrum of the density fluctuation in the standard cold dark matter model when compared with the observation.
hep-ph/9607450
Thomas
Savas Dimopoulos, Michael Dine, Stuart Raby, Scott Thomas, James D. Wells
Phenomenological Implications of Low Energy Supersymmetry Breaking
5 pages, Latex, requires espcrc2.sty, to appear in the proceedings of SUSY96
Nucl.Phys.Proc.Suppl. 52A (1997) 38-42
10.1016/S0920-5632(96)00530-0
SLAC-PUB-7236
hep-ph hep-ex
null
The experimental signatures for low energy supersymmetry breaking are presented. The lightest standard model superpartner is unstable and decays to its partner plus a Goldstino, $G$. For a supersymmetry breaking scale below a few 1000 TeV this decay can take place within a detector, leading to very distinctive signatures. If a neutralino is the lightest standard model superpartner it decays by $\chi_1^0 \to \gamma + G$, and if kinematically accessible by $\chi_1^0 \to (Z^0, h^0, H^0, A^0) + G$. These decays can give rise to displaced vertices. Alternately, if a slepton is the lightest standard model superpartner it decays by $\tilde{l} \to l + G$. This can be seen as a greater than minimum ionizing charged particle track, possibly with a kink to a minimum ionizing track.
[ { "created": "Sat, 27 Jul 1996 18:45:42 GMT", "version": "v1" } ]
2009-10-28
[ [ "Dimopoulos", "Savas", "" ], [ "Dine", "Michael", "" ], [ "Raby", "Stuart", "" ], [ "Thomas", "Scott", "" ], [ "Wells", "James D.", "" ] ]
The experimental signatures for low energy supersymmetry breaking are presented. The lightest standard model superpartner is unstable and decays to its partner plus a Goldstino, $G$. For a supersymmetry breaking scale below a few 1000 TeV this decay can take place within a detector, leading to very distinctive signatures. If a neutralino is the lightest standard model superpartner it decays by $\chi_1^0 \to \gamma + G$, and if kinematically accessible by $\chi_1^0 \to (Z^0, h^0, H^0, A^0) + G$. These decays can give rise to displaced vertices. Alternately, if a slepton is the lightest standard model superpartner it decays by $\tilde{l} \to l + G$. This can be seen as a greater than minimum ionizing charged particle track, possibly with a kink to a minimum ionizing track.
hep-ph/0405291
Roberto Sghedoni
Roberto Sghedoni
Transverse Momentum Distribution in B Decays
Ph.D. Thesis, 141pp
null
null
null
hep-ph
null
We derive the strange quark transverse momentum distribution for the $% b\to s\gamma $ decay. A resummed formula is presented showing the singularity structure in the impact parameter $b$. We observe the appearance of a new next-to-leading soft singularity. The first term of the coefficient function is calculated to complete the evaluation of the distribution with next-to-leading accuracy and the constant term. The connection with the shape function for the mass spectrum is briefly discussed. The extension of the shape function interpretation to the transverse momentum distribution seems not to be longer possible. The complete perturbative $O(\alpha)$ transverse momentum distribution formula for the $b \to s \gamma$ process is given. The coefficient function, the double and single logarithmic terms together with the remainder function are explicitely evaluated and presented in analytic form. A resummed expression is also shown.
[ { "created": "Fri, 28 May 2004 21:17:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sghedoni", "Roberto", "" ] ]
We derive the strange quark transverse momentum distribution for the $% b\to s\gamma $ decay. A resummed formula is presented showing the singularity structure in the impact parameter $b$. We observe the appearance of a new next-to-leading soft singularity. The first term of the coefficient function is calculated to complete the evaluation of the distribution with next-to-leading accuracy and the constant term. The connection with the shape function for the mass spectrum is briefly discussed. The extension of the shape function interpretation to the transverse momentum distribution seems not to be longer possible. The complete perturbative $O(\alpha)$ transverse momentum distribution formula for the $b \to s \gamma$ process is given. The coefficient function, the double and single logarithmic terms together with the remainder function are explicitely evaluated and presented in analytic form. A resummed expression is also shown.
hep-ph/9301257
Slava Belyaev
V.M.Belyaev
Delta-Isobar Magnetic Form Factor in QCD
13 pages, CEBAF-TH-93-02, Latex, 1 Figure
null
null
null
hep-ph
null
We consider the QCD sum rules approach for Delta-isobar magnetic form factor in the infra-red region $0<Q^2<1GeV^2$. The QCD sum rules in external variable field are used. The obtained formfactor is in agreement with quark model predictions for the Delta-isobar magnetic moment.
[ { "created": "Thu, 21 Jan 1993 16:59:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Belyaev", "V. M.", "" ] ]
We consider the QCD sum rules approach for Delta-isobar magnetic form factor in the infra-red region $0<Q^2<1GeV^2$. The QCD sum rules in external variable field are used. The obtained formfactor is in agreement with quark model predictions for the Delta-isobar magnetic moment.
1207.2199
Christian Sturm
P. A. Baikov, K. G. Chetyrkin, J. H. Kuhn, C. Sturm
The relation between the QED charge renormalized in MSbar and on-shell schemes at four loops, the QED on-shell beta-function at five loops and asymptotic contributions to the muon anomaly at five and six loops
25 pages, 6 figures; v2: final published version
Nucl.Phys.B 867 (2013) 182-202
10.1016/j.nuclphysb.2012.09.018
MPP-2012-105; SFB/CPP-12-40; TTP12--12-021
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we compute the four-loop corrections to the QED photon self-energy Pi(Q^2) in the two limits of q=0 and Q^2->infinity. These results are used to explicitly construct the conversion relations between the QED charge renormalized in on-shell(OS) and MSbar scheme. Using these relations and results of Baikov et al. [1] we construct the momentum dependent part of Pi(Q^2,m,alpha) at large Q^2 at five loops in both MSbar and OS schemes. As a direct consequence we arrive at the full result for the QED beta-function in the OS scheme at five loops. These results are applied, in turn, to analytically evaluate a class of asymptotic contributions to the muon anomaly at five and six loops.
[ { "created": "Tue, 10 Jul 2012 00:15:40 GMT", "version": "v1" }, { "created": "Fri, 9 Nov 2012 22:28:35 GMT", "version": "v2" } ]
2012-11-13
[ [ "Baikov", "P. A.", "" ], [ "Chetyrkin", "K. G.", "" ], [ "Kuhn", "J. H.", "" ], [ "Sturm", "C.", "" ] ]
In this paper we compute the four-loop corrections to the QED photon self-energy Pi(Q^2) in the two limits of q=0 and Q^2->infinity. These results are used to explicitly construct the conversion relations between the QED charge renormalized in on-shell(OS) and MSbar scheme. Using these relations and results of Baikov et al. [1] we construct the momentum dependent part of Pi(Q^2,m,alpha) at large Q^2 at five loops in both MSbar and OS schemes. As a direct consequence we arrive at the full result for the QED beta-function in the OS scheme at five loops. These results are applied, in turn, to analytically evaluate a class of asymptotic contributions to the muon anomaly at five and six loops.
hep-ph/0312043
Peschanski
R. B. Peschanski
Beyond BFKL
12 pages, 6 figures, Invited Talk at the Ringberg Workshop ``New Trends in HERA Physics 2003''September 28 - October 3, 2003
null
10.1142/9789812702722_0022
Publication SPhT-T03/188 (Saclay)
hep-ph
null
The Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution equation is known to be ``unstable'' with respect to fluctuations in gluon virtuality, transverse momentum and energy requiring to go beyond the leading order BFKL. Still, these instabilities point to fruitful improvements of our deep understanding of QCD. Recent applications to next-leading order and to saturation problems are outlined.
[ { "created": "Wed, 3 Dec 2003 09:28:34 GMT", "version": "v1" } ]
2017-08-23
[ [ "Peschanski", "R. B.", "" ] ]
The Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution equation is known to be ``unstable'' with respect to fluctuations in gluon virtuality, transverse momentum and energy requiring to go beyond the leading order BFKL. Still, these instabilities point to fruitful improvements of our deep understanding of QCD. Recent applications to next-leading order and to saturation problems are outlined.
1004.5250
David Ireland
D. G. Ireland
Information Content of Polarization Measurements
19 pages, 4 figures; figures updated, minor textual corrections
Phys.Rev.C82:025204,2010
10.1103/PhysRevC.82.025204
null
hep-ph hep-ex physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Information entropy is applied to the state of knowledge of reaction amplitudes in pseudoscalar meson photoproduction, and a scheme is developed that quantifies the information content of a measured set of polarization observables. It is shown that this definition of information is a more practical measure of the quality of a set of measured observables than whether the combination is a mathematically complete set. It is also shown that when experimental uncertainty is introduced, complete sets of measurements do not necessarily remove ambiguities, and that experiments should strive to measure as many observables as practical in order to extract amplitudes.
[ { "created": "Thu, 29 Apr 2010 11:23:38 GMT", "version": "v1" }, { "created": "Thu, 22 Jul 2010 10:46:46 GMT", "version": "v2" } ]
2010-09-02
[ [ "Ireland", "D. G.", "" ] ]
Information entropy is applied to the state of knowledge of reaction amplitudes in pseudoscalar meson photoproduction, and a scheme is developed that quantifies the information content of a measured set of polarization observables. It is shown that this definition of information is a more practical measure of the quality of a set of measured observables than whether the combination is a mathematically complete set. It is also shown that when experimental uncertainty is introduced, complete sets of measurements do not necessarily remove ambiguities, and that experiments should strive to measure as many observables as practical in order to extract amplitudes.
1108.1391
James Cline
James M. Cline, Andrew R. Frey
Minimal hidden sector models for CoGeNT/DAMA events
15 pages, 1 figure; v4: published version; added references on PAMELA constraint and discussion of gauge boson mixing; v3: clarified role of inelastic couplings, added discussion of astrophysical constraints, added references; v2: added references and corrected analysis of exothermic dark matter
null
10.1103/PhysRevD.84.075003
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by recent attempts to reconcile hints of direct dark matter detection by the CoGeNT and DAMA experiments, we construct simple particle physics models that can accommodate the constraints. We point out challenges for building reasonable models and identify the most promising scenarios for getting isospin violation and inelasticity, as indicated by some phenomenological studies. If inelastic scattering is demanded, we need two new light gauge bosons, one of which kinetically mixes with the standard model hypercharge and has mass < 2 GeV, and another which couples to baryon number and has mass 6.8 +/- 0.2 GeV. Their interference gives the desired amount of isospin violation. The dark matter is nearly Dirac, but with small Majorana masses induced by spontaneous symmetry breaking, so that the gauge boson couplings become exactly off-diagonal in the mass basis, and the small mass splitting needed for inelasticity is simultaneously produced. If only elastic scattering is demanded, then an alternative model, with interference between the kinetically mixed gauge boson and a hidden sector scalar Higgs, is adequate to give the required isospin violation. In both cases, the light kinetically mixed gauge boson is in the range of interest for currently running fixed target experiments.
[ { "created": "Fri, 5 Aug 2011 19:59:56 GMT", "version": "v1" }, { "created": "Mon, 15 Aug 2011 15:58:40 GMT", "version": "v2" }, { "created": "Sat, 3 Sep 2011 03:12:33 GMT", "version": "v3" }, { "created": "Mon, 19 Sep 2011 16:03:42 GMT", "version": "v4" } ]
2013-05-29
[ [ "Cline", "James M.", "" ], [ "Frey", "Andrew R.", "" ] ]
Motivated by recent attempts to reconcile hints of direct dark matter detection by the CoGeNT and DAMA experiments, we construct simple particle physics models that can accommodate the constraints. We point out challenges for building reasonable models and identify the most promising scenarios for getting isospin violation and inelasticity, as indicated by some phenomenological studies. If inelastic scattering is demanded, we need two new light gauge bosons, one of which kinetically mixes with the standard model hypercharge and has mass < 2 GeV, and another which couples to baryon number and has mass 6.8 +/- 0.2 GeV. Their interference gives the desired amount of isospin violation. The dark matter is nearly Dirac, but with small Majorana masses induced by spontaneous symmetry breaking, so that the gauge boson couplings become exactly off-diagonal in the mass basis, and the small mass splitting needed for inelasticity is simultaneously produced. If only elastic scattering is demanded, then an alternative model, with interference between the kinetically mixed gauge boson and a hidden sector scalar Higgs, is adequate to give the required isospin violation. In both cases, the light kinetically mixed gauge boson is in the range of interest for currently running fixed target experiments.
hep-ph/0612223
Thomas Schwetz
Thomas Schwetz
What is the probability that $\theta_{13}$ and CP violation will be discovered in future neutrino oscillation experiments?
11 pages, 5 figures
Phys.Lett.B648:54-59,2007
10.1016/j.physletb.2007.02.053
CERN-PH-TH/2006-266
hep-ph hep-ex
null
The sensitivity of future neutrino oscillation experiments is determined within a frequentist framework by using a statistical procedure based on Monte Carlo simulations. I consider the search for a non-zero value of the mixing angle $\theta_{13}$ at the T2K and Double-Chooz experiments, as well as the discovery of CP violation at the example of the T2HK experiment. The probability that a discovery will be made at a given confidence level is calculated as a function of the true parameter values by generating large ensembles of artificial experiments. The interpretation of the commonly used sensitivity limits is clarified.
[ { "created": "Tue, 19 Dec 2006 10:31:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Schwetz", "Thomas", "" ] ]
The sensitivity of future neutrino oscillation experiments is determined within a frequentist framework by using a statistical procedure based on Monte Carlo simulations. I consider the search for a non-zero value of the mixing angle $\theta_{13}$ at the T2K and Double-Chooz experiments, as well as the discovery of CP violation at the example of the T2HK experiment. The probability that a discovery will be made at a given confidence level is calculated as a function of the true parameter values by generating large ensembles of artificial experiments. The interpretation of the commonly used sensitivity limits is clarified.
hep-ph/9608272
Nikolaos Tetradis
N. Tetradis (CERN)
The Electroweak Phase Transition through the Renormalization Group
48 pages, 17 figures (some additions to the labels included in the captions), LaTeX file
Nucl.Phys. B488 (1997) 92-140
10.1016/S0550-3213(97)00037-0
CERN-TH/96-190
hep-ph hep-lat hep-th
null
We study the high-temperature phase transitions for the Abelian and $SU(2)$ Higgs models, using the exact renormalization group. The evolution equation for a properly-defined coarse-grained free energy is solved. The phase diagram of the Abelian Higgs model has a region of second-order phase transitions governed by fixed points, for which we calculate critical exponents and crossover curves. It also has a region of first-order phase transitions, which we discuss in terms of the coarse-grained free energy. The $SU(2)$ Higgs model for small Higgs field masses has only first-order phase transitions. We derive their properties and compare with lattice and perturbative results. For larger Higgs field masses the strength of the first-order phase transitions diminishes. For masses larger than 80-100 GeV we find evidence that they are replaced by analytical crossovers.
[ { "created": "Thu, 8 Aug 1996 16:51:32 GMT", "version": "v1" } ]
2009-10-28
[ [ "Tetradis", "N.", "", "CERN" ] ]
We study the high-temperature phase transitions for the Abelian and $SU(2)$ Higgs models, using the exact renormalization group. The evolution equation for a properly-defined coarse-grained free energy is solved. The phase diagram of the Abelian Higgs model has a region of second-order phase transitions governed by fixed points, for which we calculate critical exponents and crossover curves. It also has a region of first-order phase transitions, which we discuss in terms of the coarse-grained free energy. The $SU(2)$ Higgs model for small Higgs field masses has only first-order phase transitions. We derive their properties and compare with lattice and perturbative results. For larger Higgs field masses the strength of the first-order phase transitions diminishes. For masses larger than 80-100 GeV we find evidence that they are replaced by analytical crossovers.
hep-ph/0209153
Yakov Azimov
Ya. I. Azimov
Mixing and decays of rho- and omega-mesons
22 pages, 1 eps fig
Eur.Phys.J.A16:209-219,2003
10.1140/epja/i2002-10084-x
null
hep-ph hep-ex nucl-th
null
Isospin violating mixing of \rho- and \omega-mesons is reconsidered in terms of propagators. Its influence on various pairs of (\rho^0,\omega)-decays to the same final states is demonstrated. Some of them, (\rho^0,\omega)\to\pi^+\pi^- and (\rho^0,\omega)\to\pi^0\gamma, have been earlier discussed in the literature, others (e.g., (\rho^0,\omega)\to\eta\gamma and (\rho^0,\omega)\to e^+e^-) are new in this context. Changes in partial widths for all the decay pairs are shown to be correlated. The set of present experimental data, though yet inconclusive, provides some limits for the direct (\rho\omega)-coupling and indirectly supports enhancement of \rho^0\to\pi^0\gamma in comparison with \rho^{\pm}\to\pi^{\pm}\gamma, though not so large as in some previous estimates.
[ { "created": "Fri, 13 Sep 2002 16:20:19 GMT", "version": "v1" } ]
2008-11-26
[ [ "Azimov", "Ya. I.", "" ] ]
Isospin violating mixing of \rho- and \omega-mesons is reconsidered in terms of propagators. Its influence on various pairs of (\rho^0,\omega)-decays to the same final states is demonstrated. Some of them, (\rho^0,\omega)\to\pi^+\pi^- and (\rho^0,\omega)\to\pi^0\gamma, have been earlier discussed in the literature, others (e.g., (\rho^0,\omega)\to\eta\gamma and (\rho^0,\omega)\to e^+e^-) are new in this context. Changes in partial widths for all the decay pairs are shown to be correlated. The set of present experimental data, though yet inconclusive, provides some limits for the direct (\rho\omega)-coupling and indirectly supports enhancement of \rho^0\to\pi^0\gamma in comparison with \rho^{\pm}\to\pi^{\pm}\gamma, though not so large as in some previous estimates.
hep-ph/0509338
Jamal Jalilian-Marian
Jamal Jalilian-Marian
Photon $+$ Hadron Production in High Energy Deuteron (Proton)-Nucleus Collisions
10 pages, 5 figures
Nucl.Phys.A770:210-220,2006
10.1016/j.nuclphysa.2006.02.013
INT-PUB 05-21
hep-ph nucl-ex nucl-th
null
We apply the Color Glass Condensate formalism to photon $+$ hadron production cross section in high energy deuteron (proton)-gold collisions at RHIC. We investigate the dependence of the production cross section on the angle between the produced hadron and photon for various rapidities and transverse momenta. It is shown that the angular correlation between the produced hadron and photon is a sensitive probe of the saturation dynamics.
[ { "created": "Thu, 29 Sep 2005 01:34:41 GMT", "version": "v1" } ]
2008-11-26
[ [ "Jalilian-Marian", "Jamal", "" ] ]
We apply the Color Glass Condensate formalism to photon $+$ hadron production cross section in high energy deuteron (proton)-gold collisions at RHIC. We investigate the dependence of the production cross section on the angle between the produced hadron and photon for various rapidities and transverse momenta. It is shown that the angular correlation between the produced hadron and photon is a sensitive probe of the saturation dynamics.
1305.2641
Kirtiman Ghosh
Shreyashi Chakdar, Kirtiman Ghosh, S. Nandi and Santosh Kumar Rai
Collider signatures of mirror fermions in the framework of Left Right Mirror Model
26 pages, 11 figures
Phys. Rev. D 88,095005(2013)
10.1103/PhysRevD.88.095005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The idea of left-right symmetry with mirror fermions is very appealing from the symmetry point of view. In this picture, unlike the Standard Model, the symmetry is not only left-right symmetric, but each left handed fermion multiplet is accompanied by new right handed fermion multiplet of opposite chirality. In this work, we consider a gauge symmetry, $SU(3)_c \otimes SU(2)_L\otimes SU(2)_R \otimes U(1)_{Y^\prime}$ supplemented by a discrete $Z_2$ symmetry. Instead of having right handed multiplets for each left handed multiplets of the same fermions as in the usual left-right model, the mirror model include right handed doublets involving new fermions (called mirrors), and similarly for each right handed singlet, there are corresponding mirror singlets. Thus the gauge anomaly is naturally absent in this model, and the model also provide a solution for the strong CP problem because of parity conservation. The first stage of symmetry breaking is achieved by a doublet mirror Higgs with a vacuum expectation value $\simeq 10^7$ GeV, needed to explain the neutrino mass $\simeq 10^{-11}$ GeV. The mirror fermions can mix with the ordinary fermions via a scalar which is singlet under the gauge symmetry. In this model, only light mirror particles, having masses in the few hundred GeV range are $\hat{e}, \hat{u}, \hat{d}$ with well-defined spectrum. $\hat{u}$ and $\hat{d}$ can be pair produced at the LHC, and can be detected as ($u Z$) and ($d Z$) resonances. We discuss the signals of these mirror fermions at the LHC, and find that the reach at the LHC can be as large as $m_{\hat q}\simeq 800$ GeV.
[ { "created": "Sun, 12 May 2013 22:31:03 GMT", "version": "v1" } ]
2013-11-20
[ [ "Chakdar", "Shreyashi", "" ], [ "Ghosh", "Kirtiman", "" ], [ "Nandi", "S.", "" ], [ "Rai", "Santosh Kumar", "" ] ]
The idea of left-right symmetry with mirror fermions is very appealing from the symmetry point of view. In this picture, unlike the Standard Model, the symmetry is not only left-right symmetric, but each left handed fermion multiplet is accompanied by new right handed fermion multiplet of opposite chirality. In this work, we consider a gauge symmetry, $SU(3)_c \otimes SU(2)_L\otimes SU(2)_R \otimes U(1)_{Y^\prime}$ supplemented by a discrete $Z_2$ symmetry. Instead of having right handed multiplets for each left handed multiplets of the same fermions as in the usual left-right model, the mirror model include right handed doublets involving new fermions (called mirrors), and similarly for each right handed singlet, there are corresponding mirror singlets. Thus the gauge anomaly is naturally absent in this model, and the model also provide a solution for the strong CP problem because of parity conservation. The first stage of symmetry breaking is achieved by a doublet mirror Higgs with a vacuum expectation value $\simeq 10^7$ GeV, needed to explain the neutrino mass $\simeq 10^{-11}$ GeV. The mirror fermions can mix with the ordinary fermions via a scalar which is singlet under the gauge symmetry. In this model, only light mirror particles, having masses in the few hundred GeV range are $\hat{e}, \hat{u}, \hat{d}$ with well-defined spectrum. $\hat{u}$ and $\hat{d}$ can be pair produced at the LHC, and can be detected as ($u Z$) and ($d Z$) resonances. We discuss the signals of these mirror fermions at the LHC, and find that the reach at the LHC can be as large as $m_{\hat q}\simeq 800$ GeV.
hep-ph/9312272
Christopher Kolda
G. L. Kane, Chris Kolda, Leszek Roszkowski and James D. Wells
Study of Constrained Minimal Supersymmetry
Michigan preprint UM-TH-93-24, LaTeX, 60 pages without figures. Complete paper with inline figures available by anonymous ftp to williams.physics.lsa.umich.edu in /pub/preprints/UM-TH-93-24.ps.Z (uncompresses to 10MB / 77 pages), or by e-mailing request
Phys.Rev.D49:6173-6210,1994
10.1103/PhysRevD.49.6173
null
hep-ph
null
Taking seriously phenomenological indications for supersymmetry, we have made a detailed study of unified minimal SUSY, including effects at the few percent level in a consistent fashion. We report here a general analysis without choosing a particular unification gauge group. We find that the encouraging SUSY unification results of recent years do survive the challenge of a more complete and accurate analysis. Taking into account effects at the 5-10% level leads to several improvements of previous results, and allows us to sharpen our predictions for SUSY in the light of unification. We perform a thorough study of the parameter space. The results form a well-defined basis for comparing the physics potential of different facilities. Very little of the acceptable parameter space has been excluded by LEP or FNAL so far, but a significant fraction can be covered when these accelerators are upgraded. A number of initial applications to the understanding of the SUSY spectrum, detectability of SUSY at LEP II or FNAL, BR($b\to s\gamma$), Width($Z\to b\bar b$), dark matter, etc, are included in a separate section. We formulate an approach to extracting SUSY parameters from data when superpartners are detected. For small tan(beta) or large $m_top$ both $M_half$ and $M_0$ are entirely bounded from above at O(1 tev) without having to use a fine-tuning constraint.
[ { "created": "Mon, 13 Dec 1993 19:41:22 GMT", "version": "v1" } ]
2009-09-15
[ [ "Kane", "G. L.", "" ], [ "Kolda", "Chris", "" ], [ "Roszkowski", "Leszek", "" ], [ "Wells", "James D.", "" ] ]
Taking seriously phenomenological indications for supersymmetry, we have made a detailed study of unified minimal SUSY, including effects at the few percent level in a consistent fashion. We report here a general analysis without choosing a particular unification gauge group. We find that the encouraging SUSY unification results of recent years do survive the challenge of a more complete and accurate analysis. Taking into account effects at the 5-10% level leads to several improvements of previous results, and allows us to sharpen our predictions for SUSY in the light of unification. We perform a thorough study of the parameter space. The results form a well-defined basis for comparing the physics potential of different facilities. Very little of the acceptable parameter space has been excluded by LEP or FNAL so far, but a significant fraction can be covered when these accelerators are upgraded. A number of initial applications to the understanding of the SUSY spectrum, detectability of SUSY at LEP II or FNAL, BR($b\to s\gamma$), Width($Z\to b\bar b$), dark matter, etc, are included in a separate section. We formulate an approach to extracting SUSY parameters from data when superpartners are detected. For small tan(beta) or large $m_top$ both $M_half$ and $M_0$ are entirely bounded from above at O(1 tev) without having to use a fine-tuning constraint.
hep-ph/9511422
Eric S. Swanson
Adam Szczepaniak, Eric S. Swanson, Chueng-Ryong Ji, and Stephen R. Cotanch
Glueball Spectroscopy in a Relativistic Many-Body Approach to Hadron Structure
12 pages, 1 uuencoded ps figure, RevTex
Phys.Rev.Lett. 76 (1996) 2011-2014
10.1103/PhysRevLett.76.2011
null
hep-ph hep-lat
null
A comprehensive, relativistic many-body approach to hadron structure is advanced based on the Coulomb gauge QCD Hamiltonian. Our method incorporates standard many-body techniques which render the approximations amenable to systematic improvement. Using BCS variational methods, dynamic chiral symmetry breaking naturally emerges and both quarks and gluons acquire constituent masses. Gluonia are studied both in the valence and in the collective, random phase approximations. Using representative values for the strong coupling constant and string tension, calculated quenched glueball masses are found to be in remarkable agreement with lattice gauge theory.
[ { "created": "Mon, 27 Nov 1995 15:34:32 GMT", "version": "v1" } ]
2009-10-28
[ [ "Szczepaniak", "Adam", "" ], [ "Swanson", "Eric S.", "" ], [ "Ji", "Chueng-Ryong", "" ], [ "Cotanch", "Stephen R.", "" ] ]
A comprehensive, relativistic many-body approach to hadron structure is advanced based on the Coulomb gauge QCD Hamiltonian. Our method incorporates standard many-body techniques which render the approximations amenable to systematic improvement. Using BCS variational methods, dynamic chiral symmetry breaking naturally emerges and both quarks and gluons acquire constituent masses. Gluonia are studied both in the valence and in the collective, random phase approximations. Using representative values for the strong coupling constant and string tension, calculated quenched glueball masses are found to be in remarkable agreement with lattice gauge theory.
1201.2281
Bodo Lampe
Bodo Lampe
Chirality and Symmetry Breaking in a discrete internal Space
42 pages, 3 tables
null
10.1007/s10773-012-1190-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In previous papers the permutation group S_4 has been suggested as an ordering scheme for elementary particles, and the appearance of this finite symmetry group was taken as indication for the existence of a discrete inner symmetry space underlying elementary particle interactions. Here it is pointed out that a more suitable choice than the tetrahedral group S_4 is the pyritohedral group A_4 x Z_2 because its vibrational spectrum exhibits exactly the mass multiplet structure of the 3 fermion generations. Furthermore it is noted that the same structure can also be obtained from a primordial symmetry breaking S_4 --> A_4. Since A_4 is a chiral group, while S_4 is achiral, an argument can be given why the chirality of the inner pyritohedral symmetry leads to parity violation of the weak interactions.
[ { "created": "Wed, 11 Jan 2012 11:16:27 GMT", "version": "v1" } ]
2015-06-03
[ [ "Lampe", "Bodo", "" ] ]
In previous papers the permutation group S_4 has been suggested as an ordering scheme for elementary particles, and the appearance of this finite symmetry group was taken as indication for the existence of a discrete inner symmetry space underlying elementary particle interactions. Here it is pointed out that a more suitable choice than the tetrahedral group S_4 is the pyritohedral group A_4 x Z_2 because its vibrational spectrum exhibits exactly the mass multiplet structure of the 3 fermion generations. Furthermore it is noted that the same structure can also be obtained from a primordial symmetry breaking S_4 --> A_4. Since A_4 is a chiral group, while S_4 is achiral, an argument can be given why the chirality of the inner pyritohedral symmetry leads to parity violation of the weak interactions.
hep-ph/9609506
Haim Goldberg
Haim Goldberg
Thermodynamics of Hidden Sector Gaugino Condensation in the Expanding Universe
13 pages LaTex, no figures
Phys.Lett. B394 (1997) 43-48
10.1016/S0370-2693(96)01678-4
NUB-3144/96-Th
hep-ph
null
This work examines the confining-deconfining phase transition in a hidden Yang Mills sector with scale $\Lambda \sim 10^{14}$ GeV appropriate to dilaton stabilization and SUSY-breaking via formation of a gaugino consensate. If the transition is assumed to take place through homogenous nucleation, then under reasonable assumptions it is found that a critical bubble, formed at a temperature which provides enough supercooling, is not large enough to accommodate an adequate number $(\gsim 100)$ of quanta of the confined phase (`hidden hadrons') to allow a consistent thermodynamic description. Thus, a first order transition in the hidden sector may not be possible in the expanding universe.
[ { "created": "Fri, 27 Sep 1996 16:45:47 GMT", "version": "v1" } ]
2009-10-28
[ [ "Goldberg", "Haim", "" ] ]
This work examines the confining-deconfining phase transition in a hidden Yang Mills sector with scale $\Lambda \sim 10^{14}$ GeV appropriate to dilaton stabilization and SUSY-breaking via formation of a gaugino consensate. If the transition is assumed to take place through homogenous nucleation, then under reasonable assumptions it is found that a critical bubble, formed at a temperature which provides enough supercooling, is not large enough to accommodate an adequate number $(\gsim 100)$ of quanta of the confined phase (`hidden hadrons') to allow a consistent thermodynamic description. Thus, a first order transition in the hidden sector may not be possible in the expanding universe.
1904.12882
Ted Rogers
M. Boglione, A. Dotson, L. Gamberg, S. Gordon, J. O. Gonzalez-Hernandez, A. Prokudin, T. C. Rogers, N. Sato
Mapping the Kinematical Regimes of Semi-Inclusive Deep Inelastic Scattering
37 pages, 11 Figures
JHEP10(2019)122
10.1007/JHEP10(2019)122
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a language for identifying kinematical regions of transversely differential semi-inclusive deep inelastic scattering cross sections with particular underlying partonic pictures, especially in regions of moderate to low $Q$ where sensitivity to kinematical effects outside the usual very high energy limit becomes non-trivial. The partonic pictures map to power law expansions whose leading contributions ultimately lead to well-known QCD factorization theorems. We propose methods for estimating the consistency of any particular region of overall hadronic kinematics with the kinematics of a given underlying partonic picture. The basic setup of kinematics of semi-inclusive deep inelastic scattering is also reviewed in some detail.
[ { "created": "Mon, 29 Apr 2019 18:01:44 GMT", "version": "v1" } ]
2019-11-01
[ [ "Boglione", "M.", "" ], [ "Dotson", "A.", "" ], [ "Gamberg", "L.", "" ], [ "Gordon", "S.", "" ], [ "Gonzalez-Hernandez", "J. O.", "" ], [ "Prokudin", "A.", "" ], [ "Rogers", "T. C.", "" ], [ "Sato",...
We construct a language for identifying kinematical regions of transversely differential semi-inclusive deep inelastic scattering cross sections with particular underlying partonic pictures, especially in regions of moderate to low $Q$ where sensitivity to kinematical effects outside the usual very high energy limit becomes non-trivial. The partonic pictures map to power law expansions whose leading contributions ultimately lead to well-known QCD factorization theorems. We propose methods for estimating the consistency of any particular region of overall hadronic kinematics with the kinematics of a given underlying partonic picture. The basic setup of kinematics of semi-inclusive deep inelastic scattering is also reviewed in some detail.
0803.0497
Ben Gripaios
Ben Gripaios
Anomaly Holography, the Wess-Zumino-Witten Term, and Electroweak Symmetry Breaking
7 pp
Phys.Lett.B663:419-423,2008
10.1016/j.physletb.2008.04.046
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I consider anomalies in effective field theories (EFTs) of gauge fields coupled to fermions on an interval in AdS_5, and their holographic duals. The anomalies give rise to constraints on the consistent EFT description, which are stronger than the usual four-dimensional anomaly cancellation condition for the zero modes. Even though the anomalies occur on both boundaries of the interval, corresponding to both the UV and the IR of the holographic dual, they are nevertheless consistent with the non-renormalization of the anomaly and the 't Hooft matching condition. They give rise, in general, to a Wess-Zumino-Witten (WZW) term in the four-dimensional, low-energy effective action, whose form I compute. Finally I discuss the relevance to holographic models of electroweak symmetry breaking. I show that the so-called `minimal composite Higgs models' have a consistent EFT description without a WZW term. In contrast, a variant of an earlier model of Contino, Nomura, and Pomarol does have a WZW term.
[ { "created": "Tue, 4 Mar 2008 17:02:07 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gripaios", "Ben", "" ] ]
I consider anomalies in effective field theories (EFTs) of gauge fields coupled to fermions on an interval in AdS_5, and their holographic duals. The anomalies give rise to constraints on the consistent EFT description, which are stronger than the usual four-dimensional anomaly cancellation condition for the zero modes. Even though the anomalies occur on both boundaries of the interval, corresponding to both the UV and the IR of the holographic dual, they are nevertheless consistent with the non-renormalization of the anomaly and the 't Hooft matching condition. They give rise, in general, to a Wess-Zumino-Witten (WZW) term in the four-dimensional, low-energy effective action, whose form I compute. Finally I discuss the relevance to holographic models of electroweak symmetry breaking. I show that the so-called `minimal composite Higgs models' have a consistent EFT description without a WZW term. In contrast, a variant of an earlier model of Contino, Nomura, and Pomarol does have a WZW term.
hep-ph/0209159
Iain W. Stewart
Iain W. Stewart
Factorization, Effective Field Theory, and B-> D^(*) X Decays
7 pages, 3 figs, Invited plenary talk at the 5th International Conference on Hyperons, Charm, and Beauty Hadrons, Vancouver, June 2002
Nucl.Phys.Proc.Suppl. 115 (2003) 107-113
10.1016/S0920-5632(02)01964-3
INT-PUB 02-45
hep-ph
null
In this proceedings I review the soft-collinear effective theory (SCET), an effective theory for energetic particles. I also discuss factorization in exclusive and inclusive B-> D^(*)X decays, and tests which can help distinguish whether factorization is a result of a large energy limit, the large N_c limit, or a combination of the two.
[ { "created": "Sat, 14 Sep 2002 02:37:42 GMT", "version": "v1" }, { "created": "Thu, 21 Nov 2002 01:02:05 GMT", "version": "v2" } ]
2009-11-07
[ [ "Stewart", "Iain W.", "" ] ]
In this proceedings I review the soft-collinear effective theory (SCET), an effective theory for energetic particles. I also discuss factorization in exclusive and inclusive B-> D^(*)X decays, and tests which can help distinguish whether factorization is a result of a large energy limit, the large N_c limit, or a combination of the two.
hep-ph/9602206
Nir Polonsky
Nir Polonsky
On Supersymmetric b-tau Unification, Gauge Unification, and Fixed Points
17 pages + 7 postscript figures (packaged as a .uu file), LaTex + RevTex 3
Phys.Rev. D54 (1996) 4537-4547
10.1103/PhysRevD.54.4537
LMU-TPW-96-04
hep-ph
null
The equality assumption of the b and tau Yukawa couplings at the grand-unification scale can strongly constrain the allowed parameter space of supersymmetric models. We examine the constraints in the case that there is a discrepancy > 10% in the gauge coupling unification assumption (which necessarily implies large perturbations at the grand scale). The constraints are shown to diminish in that case [most significantly so if alpha_{s}(M_{Z}) \approx 0.11]. In particular, the requirement that the t Yukawa coupling, h_{t}, is near its quasi-fixed point may not be necessary. We discuss the colored-triplet threshold as a simple example of a source for the discrepancies, and comment on its possible implications. In addition, we point out that supersymmetric (as well as unification-scale) threshold corrections to h_{t} shift the fixed-point curve in the m_{t} - \tan\beta plane. The implications for the prediction of the Higgs boson mass are briefly discussed.
[ { "created": "Thu, 1 Feb 1996 19:32:49 GMT", "version": "v1" } ]
2009-10-28
[ [ "Polonsky", "Nir", "" ] ]
The equality assumption of the b and tau Yukawa couplings at the grand-unification scale can strongly constrain the allowed parameter space of supersymmetric models. We examine the constraints in the case that there is a discrepancy > 10% in the gauge coupling unification assumption (which necessarily implies large perturbations at the grand scale). The constraints are shown to diminish in that case [most significantly so if alpha_{s}(M_{Z}) \approx 0.11]. In particular, the requirement that the t Yukawa coupling, h_{t}, is near its quasi-fixed point may not be necessary. We discuss the colored-triplet threshold as a simple example of a source for the discrepancies, and comment on its possible implications. In addition, we point out that supersymmetric (as well as unification-scale) threshold corrections to h_{t} shift the fixed-point curve in the m_{t} - \tan\beta plane. The implications for the prediction of the Higgs boson mass are briefly discussed.
1405.6050
A. Tolga Tasci
A. Senol, A. T. Tasci, I. T. Cakir and O. Cakir
Anomalous $HZ\gamma$ couplings in photon-induced collisions at the LHC
10 pages, 7 figures, 3 tables
Mod. Phys. Lett. A, Vol. 29, No. 36 (2014) 1450186
10.1142/S0217732314501867
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have examined $HZ\gamma$ vertex to obtain the limits on anomalous $a_\gamma$, $b_\gamma$ and $\tilde b_\gamma$ couplings in a model independent way through the $\gamma p$ collisions via the process $pp\to p \gamma p\to pHqX$. The sensitivities to the anomalous couplings can be obtained as $|b_\gamma|$, $|\tilde{b}_\gamma|\sim 10^{-3}$ for the integrated luminosity of $L_{int}=100 ~\mathrm{fb}^{-1}$ at the LHC with $\sqrt{s}=14$ TeV.
[ { "created": "Fri, 23 May 2014 12:57:24 GMT", "version": "v1" } ]
2014-11-14
[ [ "Senol", "A.", "" ], [ "Tasci", "A. T.", "" ], [ "Cakir", "I. T.", "" ], [ "Cakir", "O.", "" ] ]
We have examined $HZ\gamma$ vertex to obtain the limits on anomalous $a_\gamma$, $b_\gamma$ and $\tilde b_\gamma$ couplings in a model independent way through the $\gamma p$ collisions via the process $pp\to p \gamma p\to pHqX$. The sensitivities to the anomalous couplings can be obtained as $|b_\gamma|$, $|\tilde{b}_\gamma|\sim 10^{-3}$ for the integrated luminosity of $L_{int}=100 ~\mathrm{fb}^{-1}$ at the LHC with $\sqrt{s}=14$ TeV.
1809.01063
Maria Manuela Saez
M.M. Saez and M.E. Mosquera and O. Civitarese
Effects of neutrino mixing upon electron fraction in core collapse supernovae
null
Boletin de la Asociacion Argentina de Astronomia. Volumen 60. 2018
null
ISSN 1669-9521
hep-ph astro-ph.SR nucl-th physics.space-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The inclusion of massive neutrinos affects the cross sections involved in the formation of heavy nuclei, modifying their abundances. Rapid neutron capture processes (r-process) are often associated with explosive events such as core-collapse supernovae. In this work we study the effects of active and sterile neutrino oscillations and interactions, upon the calculation of neutrino fluxes, the baryonic density and the electron fraction of the material. We have considered two different initial distribution functions of the neutrinos and different combinations of mixing parameters (including {\theta} 34 = 0). We use the formalism of density matrices for the calculations and included the effects of neutrino oscillations, interactions with matter and self-neutrino interactions. We found that the interactions of the neutrinos with matter and with themselves change the electron fraction, affecting the onset of the r-process.
[ { "created": "Tue, 4 Sep 2018 16:12:10 GMT", "version": "v1" }, { "created": "Thu, 6 Sep 2018 22:07:46 GMT", "version": "v2" } ]
2018-09-10
[ [ "Saez", "M. M.", "" ], [ "Mosquera", "M. E.", "" ], [ "Civitarese", "O.", "" ] ]
The inclusion of massive neutrinos affects the cross sections involved in the formation of heavy nuclei, modifying their abundances. Rapid neutron capture processes (r-process) are often associated with explosive events such as core-collapse supernovae. In this work we study the effects of active and sterile neutrino oscillations and interactions, upon the calculation of neutrino fluxes, the baryonic density and the electron fraction of the material. We have considered two different initial distribution functions of the neutrinos and different combinations of mixing parameters (including {\theta} 34 = 0). We use the formalism of density matrices for the calculations and included the effects of neutrino oscillations, interactions with matter and self-neutrino interactions. We found that the interactions of the neutrinos with matter and with themselves change the electron fraction, affecting the onset of the r-process.
hep-ph/0204094
Fernando Monti Steffens
F. M. Steffens
A Constraint on the x Dependence of the Light Antiquarks Ratio
no figures
Phys.Lett.B541:346-349,2002
10.1016/S0370-2693(02)02273-6
null
hep-ph hep-ex
null
We perform a careful study on the effect of the Pauli blocking to the light antiquark structure of the proton sea. We develop the formal expressions for the antiquark distributions, highlighting the role played by quark statistics and the vacuum structure. Ratios involving the antiquarks are calculated. In particular, it is found that $\Delta\bar{d}(x)/\Delta\bar{u}(x)$ should be negative and x independent.
[ { "created": "Tue, 9 Apr 2002 11:20:55 GMT", "version": "v1" } ]
2014-11-17
[ [ "Steffens", "F. M.", "" ] ]
We perform a careful study on the effect of the Pauli blocking to the light antiquark structure of the proton sea. We develop the formal expressions for the antiquark distributions, highlighting the role played by quark statistics and the vacuum structure. Ratios involving the antiquarks are calculated. In particular, it is found that $\Delta\bar{d}(x)/\Delta\bar{u}(x)$ should be negative and x independent.