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2106.01156
Juan M. Torres-Rincon
Juan M. Torres-Rincon, Gl\`oria Monta\~na, \`Angels Ramos, and Laura Tolos
In-medium kinetic theory of $D$ mesons and heavy-flavor transport coefficients
47 pages, 14 figures. Theoretical foundations largely abridged (we refer to v1 for details). Extended discussions and added new figures. Results unmodified. Version published by Physical Review C journal
Physical Review C 105, 025203 (2022)
10.1103/PhysRevC.105.025203
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the kinetic theory of $D$ mesons to accommodate thermal and off-shell effects due to the medium modification of the heavy-meson spectral functions. From the Kadanoff-Baym approach we derive the off-shell Fokker-Planck equation which encodes the heavy-flavor transport coefficients. We analyze the thermal width (damping rate) of $D$ mesons due to their scattering off light mesons, focusing on new in-medium effects: off-shell corrections, inelastic channels, and the contribution of the Landau cut. We obtain that the latter effect (absent for vacuum scattering amplitudes) brings sizable corrections at moderate temperatures. We discuss how the heavy-flavor transport coefficients, like the drag and diffusion coefficients, are modified in matter. We find that the $D$-meson spatial diffusion coefficient matches smoothly to the latest results of lattice-QCD calculations and Bayesian analyses at higher temperatures.
[ { "created": "Wed, 2 Jun 2021 13:45:15 GMT", "version": "v1" }, { "created": "Wed, 16 Feb 2022 17:32:52 GMT", "version": "v2" } ]
2022-02-17
[ [ "Torres-Rincon", "Juan M.", "" ], [ "Montaña", "Glòria", "" ], [ "Ramos", "Àngels", "" ], [ "Tolos", "Laura", "" ] ]
We extend the kinetic theory of $D$ mesons to accommodate thermal and off-shell effects due to the medium modification of the heavy-meson spectral functions. From the Kadanoff-Baym approach we derive the off-shell Fokker-Planck equation which encodes the heavy-flavor transport coefficients. We analyze the thermal width (damping rate) of $D$ mesons due to their scattering off light mesons, focusing on new in-medium effects: off-shell corrections, inelastic channels, and the contribution of the Landau cut. We obtain that the latter effect (absent for vacuum scattering amplitudes) brings sizable corrections at moderate temperatures. We discuss how the heavy-flavor transport coefficients, like the drag and diffusion coefficients, are modified in matter. We find that the $D$-meson spatial diffusion coefficient matches smoothly to the latest results of lattice-QCD calculations and Bayesian analyses at higher temperatures.
hep-ph/0603150
Richard F. Lebed
Richard F. Lebed
The Large N_c Baryon-Meson I_t = J_t Rule Holds for Three Flavors
12 pages, 0 figures, ReVTeX
Phys.Lett. B639 (2006) 68-73
10.1016/j.physletb.2006.06.014
null
hep-ph
null
It has long been known that nonstrange baryon-meson scattering in the 1/N_c expansion of QCD greatly simplifies when expressed in terms of t-channel exchanges: The leading-order amplitudes satisfy the selection rule I_t = J_t. We show that I_t = J_t, as well as Y_t = 0, also hold for the leading amplitudes when the baryon and/or meson contain strange quarks, and also characterize their 1/N_c corrections, thus opening a new front in the phenomenological study of baryon-meson scattering and baryon resonances.
[ { "created": "Mon, 20 Mar 2006 21:58:03 GMT", "version": "v1" } ]
2009-11-11
[ [ "Lebed", "Richard F.", "" ] ]
It has long been known that nonstrange baryon-meson scattering in the 1/N_c expansion of QCD greatly simplifies when expressed in terms of t-channel exchanges: The leading-order amplitudes satisfy the selection rule I_t = J_t. We show that I_t = J_t, as well as Y_t = 0, also hold for the leading amplitudes when the baryon and/or meson contain strange quarks, and also characterize their 1/N_c corrections, thus opening a new front in the phenomenological study of baryon-meson scattering and baryon resonances.
2305.02273
Vishnudath K. N.
A. E. C\'arcamo Hern\'andez, Vishnudath K. N., Jos\'e W. F. Valle
Linear seesaw mechanism from dark sector
Matches published version
null
10.1007/JHEP09(2023)046
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
We propose a minimal model where a dark sector seeds neutrino mass generation radiatively within the linear seesaw mechanism. Neutrino masses are calculable, since tree-level contributions are forbidden by symmetry. They arise from spontaneous lepton number violation by a small Higgs triplet vacuum expectation value. Lepton flavour violating processes e.g. $\mu \to e\gamma$ can be sizeable, despite the tiny neutrino masses. We comment also on dark-matter and collider implications.
[ { "created": "Wed, 3 May 2023 17:06:59 GMT", "version": "v1" }, { "created": "Sun, 14 May 2023 14:51:01 GMT", "version": "v2" }, { "created": "Mon, 11 Sep 2023 00:04:25 GMT", "version": "v3" } ]
2023-09-12
[ [ "Hernández", "A. E. Cárcamo", "" ], [ "N.", "Vishnudath K.", "" ], [ "Valle", "José W. F.", "" ] ]
We propose a minimal model where a dark sector seeds neutrino mass generation radiatively within the linear seesaw mechanism. Neutrino masses are calculable, since tree-level contributions are forbidden by symmetry. They arise from spontaneous lepton number violation by a small Higgs triplet vacuum expectation value. Lepton flavour violating processes e.g. $\mu \to e\gamma$ can be sizeable, despite the tiny neutrino masses. We comment also on dark-matter and collider implications.
1412.7658
Renata Jora
Amir H. Fariborz, Renata Jora, Joseph Schechter
Why are there three generations of fermions in the standard model?
3 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that by decomposing the gauge fields in fermion degrees of freedom and by saturating the remaining degrees of freedom as dynamical fields in the Lagrangian one might explain the proliferation of fermion states in the standard model Lagrangian. Thus the mere presence of the gauge symmetry $U(1)_Y \times SU(2)_L \times SU(3)_c$ is essential.
[ { "created": "Wed, 24 Dec 2014 13:05:23 GMT", "version": "v1" } ]
2014-12-25
[ [ "Fariborz", "Amir H.", "" ], [ "Jora", "Renata", "" ], [ "Schechter", "Joseph", "" ] ]
We show that by decomposing the gauge fields in fermion degrees of freedom and by saturating the remaining degrees of freedom as dynamical fields in the Lagrangian one might explain the proliferation of fermion states in the standard model Lagrangian. Thus the mere presence of the gauge symmetry $U(1)_Y \times SU(2)_L \times SU(3)_c$ is essential.
hep-ph/9607368
Lucchesi
C. Lucchesi (Neuchatel U.)
Finiteness in N=1 SYM Theories
3 pages, plain LaTex, no figures
Nucl.Phys.Proc.Suppl. 52A (1997) 195-200
10.1016/S0920-5632(96)00561-0
NEIP-96-003
hep-ph hep-th
null
I present a criterion for all-order finiteness in N=1 SYM theories. Three applications are given; they yield all-order finite N=1 SYM models with global symmetries of the superpotential.
[ { "created": "Thu, 18 Jul 1996 15:49:43 GMT", "version": "v1" } ]
2009-10-28
[ [ "Lucchesi", "C.", "", "Neuchatel U." ] ]
I present a criterion for all-order finiteness in N=1 SYM theories. Three applications are given; they yield all-order finite N=1 SYM models with global symmetries of the superpotential.
hep-ph/0609071
Leonard Lesniak
L. Lesniak, A. Furman, R. Kaminski, B. El-Bennich, B. Loiseau
Final state interactions in B --> pi pi K and B--> K antiK K decays
4 pages, 3 figures, contribution to MESON 2006, 9-th International Workshop on Meson Production, Properties and Interaction, Krakow, Poland, 9 - 13 June 2006
Int.J.Mod.Phys. A22 (2007) 645-648
10.1142/S0217751X07036038
null
hep-ph
null
Analysis of charged and neutral B meson decays into pi+ pi- K, K+ K- K and K0S K0S K0S is performed using a unitary representation of the pi pi and K anti- K final state interactions. Comparison of the theoretical model with the experimental data of the Belle and BaBar Collaborations indicates that charming penguin contributions are necessary to describe the B --> f0(980) K and B --> rho(770) K decays.
[ { "created": "Thu, 7 Sep 2006 09:35:57 GMT", "version": "v1" } ]
2015-06-25
[ [ "Lesniak", "L.", "" ], [ "Furman", "A.", "" ], [ "Kaminski", "R.", "" ], [ "El-Bennich", "B.", "" ], [ "Loiseau", "B.", "" ] ]
Analysis of charged and neutral B meson decays into pi+ pi- K, K+ K- K and K0S K0S K0S is performed using a unitary representation of the pi pi and K anti- K final state interactions. Comparison of the theoretical model with the experimental data of the Belle and BaBar Collaborations indicates that charming penguin contributions are necessary to describe the B --> f0(980) K and B --> rho(770) K decays.
hep-ph/9601300
null
Fabio Zwirner (CERN-TH and INFN,Padua)
Extensions of the Standard Model
LATEX, 5 figures, 15 A4 pages
null
null
CERN-TH/96-06
hep-ph
null
Rapporteur talk at the International Europhysics Conference on High Energy Physics, Brussels (Belgium), July 27-August 2, 1995. This talk begins with a brief general introduction to the extensions of the Standard Model, reviewing the ideology of effective field theories and its practical implications. The central part deals with candidate extensions near the Fermi scale, focusing on some phenomenological aspects of the Minimal Supersymmetric Standard Model. The final part discusses some possible low-energy implications of further extensions near the Planck scale, namely superstring theories.
[ { "created": "Fri, 19 Jan 1996 17:20:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zwirner", "Fabio", "", "CERN-TH and INFN,Padua" ] ]
Rapporteur talk at the International Europhysics Conference on High Energy Physics, Brussels (Belgium), July 27-August 2, 1995. This talk begins with a brief general introduction to the extensions of the Standard Model, reviewing the ideology of effective field theories and its practical implications. The central part deals with candidate extensions near the Fermi scale, focusing on some phenomenological aspects of the Minimal Supersymmetric Standard Model. The final part discusses some possible low-energy implications of further extensions near the Planck scale, namely superstring theories.
hep-ph/0111153
Ho-Meoyng Choi
Chueng-Ryong Ji (North Carolina State U.) and Ho-Meoyng Choi (Carnegie Mellon U.)
Light-Front QCD Hamiltonian Dynamics and Constituent Quark Picture in Exclusive Processes
5pages, Contributed to International Light-Cone Workshop "Light-cone Physics: Particles and Strings", Trento, Italy, 3-11 Sep. 2001
Nucl.Phys.Proc.Suppl. 108 (2002) 288-292
10.1016/S0920-5632(02)01346-4
null
hep-ph
null
After reviewing a connection between quantum chromodynamics and contituent quark model pictures in the light-front quantization with some comparison and contrast to the ordinary equal-time bridge a la Bogoliubov-Valatin transformation, we discuss some newer development of the light-front quark model phenomenology in exclusive processes including the embedded state. The skewed parton distribution appears to be a good testing ground for our new effective treatment of the light-front nonvalence contributions in timelike exclusive processes.
[ { "created": "Tue, 13 Nov 2001 01:51:07 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ji", "Chueng-Ryong", "", "North Carolina State U." ], [ "Choi", "Ho-Meoyng", "", "Carnegie\n Mellon U." ] ]
After reviewing a connection between quantum chromodynamics and contituent quark model pictures in the light-front quantization with some comparison and contrast to the ordinary equal-time bridge a la Bogoliubov-Valatin transformation, we discuss some newer development of the light-front quark model phenomenology in exclusive processes including the embedded state. The skewed parton distribution appears to be a good testing ground for our new effective treatment of the light-front nonvalence contributions in timelike exclusive processes.
2207.07757
Cheng-Ming Li
Cheng-Ming Li, Shu-Yu Zuo, Ya-Peng Zhao, Hui-Jun Mu, Yong-Feng Huang
The study of nonstrange quark stars within a modified NJL model
9 pages, 9 figures
null
10.1103/PhysRevD.106.116009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, a modified Nambu-Jona-Lasinio (NJL) model with proper-time regularization is employed to study the structure of nonstrange quark stars. The coupling constant of four-fermion interaction in the conventional NJL model is modified as $G=G_1+G_2\langle\bar{\psi}\psi\rangle$ to highlight the feedback of quark propagator to gluon propagator. To study the dependence of the equation of state (EOS) on this modification as well as the vacuum pressure, we choose nine representative EOSs for comparison. It is found that a smaller $G_1$ leads to a stiffer EOS, and a higher vacuum pressure (i.e., a smaller bag constant) yields a softer EOS at low energy density. It is further shown that the heaviest quark star under this modified NJL model satisfies not only the recent mass measurement of PSR J0740+6620, but also the radius constraints from X-ray timing observations. The corresponding tidal deformability is also in agreement with the observations of GW170817.
[ { "created": "Fri, 15 Jul 2022 21:19:48 GMT", "version": "v1" }, { "created": "Sat, 8 Oct 2022 13:08:12 GMT", "version": "v2" } ]
2022-12-28
[ [ "Li", "Cheng-Ming", "" ], [ "Zuo", "Shu-Yu", "" ], [ "Zhao", "Ya-Peng", "" ], [ "Mu", "Hui-Jun", "" ], [ "Huang", "Yong-Feng", "" ] ]
In this work, a modified Nambu-Jona-Lasinio (NJL) model with proper-time regularization is employed to study the structure of nonstrange quark stars. The coupling constant of four-fermion interaction in the conventional NJL model is modified as $G=G_1+G_2\langle\bar{\psi}\psi\rangle$ to highlight the feedback of quark propagator to gluon propagator. To study the dependence of the equation of state (EOS) on this modification as well as the vacuum pressure, we choose nine representative EOSs for comparison. It is found that a smaller $G_1$ leads to a stiffer EOS, and a higher vacuum pressure (i.e., a smaller bag constant) yields a softer EOS at low energy density. It is further shown that the heaviest quark star under this modified NJL model satisfies not only the recent mass measurement of PSR J0740+6620, but also the radius constraints from X-ray timing observations. The corresponding tidal deformability is also in agreement with the observations of GW170817.
1107.5238
Julian Heeck
Julian Heeck, Werner Rodejohann
Gauged L_mu - L_tau Symmetry at the Electroweak Scale
22 pages, 7 figures; matches published version
Phys.Rev.D84:075007,2011
10.1103/PhysRevD.84.075007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The extension of the Standard Model by a spontaneously broken abelian gauge group based on the L(mu)-L(tau) lepton number can resolve the longstanding discrepancy between experimental and theoretical values for the magnetic moment of the muon. It furthermore naturally generates mu-tau symmetric lepton mixing, introduces neutrino non-standard interactions, and the associated gauge boson Z' serves as a mediator to the right-handed neutrino sector. A detailed fit to electroweak data is performed to identify the allowed values for the mass of Z' and its mixing with the Standard Model Z. An economical new scalar sector is constructed that spontaneously breaks the new symmetry and leads to experimental consequences such as lepton flavor violation and collider signatures. Furthermore we discuss the non-abelian extension to an SU(2)', particularly the neutrino sector.
[ { "created": "Tue, 26 Jul 2011 15:16:46 GMT", "version": "v1" }, { "created": "Mon, 10 Oct 2011 15:58:08 GMT", "version": "v2" } ]
2011-10-11
[ [ "Heeck", "Julian", "" ], [ "Rodejohann", "Werner", "" ] ]
The extension of the Standard Model by a spontaneously broken abelian gauge group based on the L(mu)-L(tau) lepton number can resolve the longstanding discrepancy between experimental and theoretical values for the magnetic moment of the muon. It furthermore naturally generates mu-tau symmetric lepton mixing, introduces neutrino non-standard interactions, and the associated gauge boson Z' serves as a mediator to the right-handed neutrino sector. A detailed fit to electroweak data is performed to identify the allowed values for the mass of Z' and its mixing with the Standard Model Z. An economical new scalar sector is constructed that spontaneously breaks the new symmetry and leads to experimental consequences such as lepton flavor violation and collider signatures. Furthermore we discuss the non-abelian extension to an SU(2)', particularly the neutrino sector.
2209.10719
Ji Xu
Ji Xu, Xi-Ruo Zhang
Matching the B-meson quasidistribution amplitude in the RI/MOM scheme
19 pages, 4 figures
null
10.1103/PhysRevD.106.114019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the framework of large momentum effective theory (LaMET), the light-cone distribution amplitude of $B$-meson in heavy-quark effective theory (HQET) can be extracted from lattice calculations of quasidistribution amplitude through hard-collinear factorization formula. This quasiquantity can be renormalized in a regularization-independent momentum subtraction scheme (RI/MOM). In this work, we derive the matching coefficient which connects the renormalized quasiditribution amplitude in the RI/MOM scheme and standard LCDA in the $\overline{\textrm{MS}}$ scheme at one-loop accuracy. Our numerical analysis approves of the feasibility of RI/MOM scheme for renormalizing $B$-meson quasidistribution amplitude. These results will be crucial for exploring the partonic structure of heavy-quark hadrons.
[ { "created": "Thu, 22 Sep 2022 01:19:43 GMT", "version": "v1" } ]
2023-01-04
[ [ "Xu", "Ji", "" ], [ "Zhang", "Xi-Ruo", "" ] ]
Within the framework of large momentum effective theory (LaMET), the light-cone distribution amplitude of $B$-meson in heavy-quark effective theory (HQET) can be extracted from lattice calculations of quasidistribution amplitude through hard-collinear factorization formula. This quasiquantity can be renormalized in a regularization-independent momentum subtraction scheme (RI/MOM). In this work, we derive the matching coefficient which connects the renormalized quasiditribution amplitude in the RI/MOM scheme and standard LCDA in the $\overline{\textrm{MS}}$ scheme at one-loop accuracy. Our numerical analysis approves of the feasibility of RI/MOM scheme for renormalizing $B$-meson quasidistribution amplitude. These results will be crucial for exploring the partonic structure of heavy-quark hadrons.
1504.08042
Ashutosh V. Kotwal
A. V. Kotwal, S. Chekanov and M. Low
Double Higgs Production in the 4$\tau$ channel from resonances in longitudinal vector boson scattering at a 100 TeV collider
null
Phys. Rev. D 91, 114018 (2015)
10.1103/PhysRevD.91.114018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the sensitivity of a 100 TeV $pp$ collider to heavy resonances produced in longitudinal vector boson scattering and decaying to a pair of Higgs bosons. A Monte Carlo study has been performed using the $H \to \tau \tau$ decay channel for both Higgs bosons, comparing the kinematics of such a signal to the irreducible Standard Model backgrounds. The results are presented in the context of a phenomenological model of a resonance ($\eta$) coupling to goldstone modes, $V_L V_L \to \eta \to HH$, as can arise in composite Higgs models. With a fractional width of 70% (20%), the $5 \sigma$ discovery reach is 4.2 (2.9) TeV in resonance mass for 10 ab$^{-1}$ of integrated luminosity. We also discuss the dependence of the mass reach on the collider energy and integrated luminosity.
[ { "created": "Wed, 29 Apr 2015 22:57:57 GMT", "version": "v1" }, { "created": "Sat, 1 Aug 2015 15:57:38 GMT", "version": "v2" } ]
2015-08-04
[ [ "Kotwal", "A. V.", "" ], [ "Chekanov", "S.", "" ], [ "Low", "M.", "" ] ]
We discuss the sensitivity of a 100 TeV $pp$ collider to heavy resonances produced in longitudinal vector boson scattering and decaying to a pair of Higgs bosons. A Monte Carlo study has been performed using the $H \to \tau \tau$ decay channel for both Higgs bosons, comparing the kinematics of such a signal to the irreducible Standard Model backgrounds. The results are presented in the context of a phenomenological model of a resonance ($\eta$) coupling to goldstone modes, $V_L V_L \to \eta \to HH$, as can arise in composite Higgs models. With a fractional width of 70% (20%), the $5 \sigma$ discovery reach is 4.2 (2.9) TeV in resonance mass for 10 ab$^{-1}$ of integrated luminosity. We also discuss the dependence of the mass reach on the collider energy and integrated luminosity.
2407.01663
Dorival Goncalves
Zhongtian Dong, Dorival Gon\c{c}alves, Kyoungchul Kong, Andrew J. Larkoski, Alberto Navarro
Hadronic Top Quark Polarimetry with ParticleNet
7 pages and 3 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Precision studies for top quark physics are a cornerstone of the Large Hadron Collider program. Polarization, probed through decay kinematics, provides a unique tool to scrutinize the top quark across its various production modes and to explore potential new physics effects. However, the top quark most often decays hadronically, for which unambiguous identification of its decay products sensitive to top quark polarization is not possible. In this Letter, we introduce a jet flavor tagging method to significantly improve spin analyzing power in hadronic decays, going beyond exclusive kinematic information employed in previous studies. We provide parametric estimates of the improvement from flavor tagging with any set of measured observables and demonstrate this in practice on simulated data using a Graph Neural Network (GNN). We find that the spin analyzing power in hadronic decays can improve by approximately 20% (40%) compared to the kinematic approach, assuming an efficiency of 0.5 (0.2) for the network.
[ { "created": "Mon, 1 Jul 2024 18:00:00 GMT", "version": "v1" } ]
2024-07-03
[ [ "Dong", "Zhongtian", "" ], [ "Gonçalves", "Dorival", "" ], [ "Kong", "Kyoungchul", "" ], [ "Larkoski", "Andrew J.", "" ], [ "Navarro", "Alberto", "" ] ]
Precision studies for top quark physics are a cornerstone of the Large Hadron Collider program. Polarization, probed through decay kinematics, provides a unique tool to scrutinize the top quark across its various production modes and to explore potential new physics effects. However, the top quark most often decays hadronically, for which unambiguous identification of its decay products sensitive to top quark polarization is not possible. In this Letter, we introduce a jet flavor tagging method to significantly improve spin analyzing power in hadronic decays, going beyond exclusive kinematic information employed in previous studies. We provide parametric estimates of the improvement from flavor tagging with any set of measured observables and demonstrate this in practice on simulated data using a Graph Neural Network (GNN). We find that the spin analyzing power in hadronic decays can improve by approximately 20% (40%) compared to the kinematic approach, assuming an efficiency of 0.5 (0.2) for the network.
0709.0979
Haibo Li
Hai-Bo Li and Mao-Zhi Yang
Rare Semileptonic Decays of Heavy Mesons with Flavor SU(3) Symmetry
4 pages and 1 figure, accepted by European Physical Journal C
null
10.1140/epjc/s10052-008-0828-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we calculate the decay rates of $D^+ \to D^0 e^+ \nu$, $D^+_S \to D^0 e^+ \nu$, $B^0_S \to B^+ e^- \bar{\nu}$, $D^+_S \to D^+ e^- e^+$ and $B^0_S \to B^0 e^-e^+$ semileptonic decay processes, in which only the light quarks decay, while the heavy flavors remain unchanged. The branching ratios of these decay processes are calculated with the flavor SU(3) symmetry. The uncertainties are estimated by considering the SU(3) breaking effect. We find that the decay rates are very tiny in the framework of the Standard Model. We also estimate the sensitivities of the measurements of these rare decays at the future experiments, such as BES-III, super-$B$ and LHC-$b$.
[ { "created": "Fri, 7 Sep 2007 01:39:49 GMT", "version": "v1" }, { "created": "Tue, 26 Feb 2008 02:45:43 GMT", "version": "v2" }, { "created": "Mon, 1 Dec 2008 01:04:53 GMT", "version": "v3" } ]
2015-05-13
[ [ "Li", "Hai-Bo", "" ], [ "Yang", "Mao-Zhi", "" ] ]
In this paper, we calculate the decay rates of $D^+ \to D^0 e^+ \nu$, $D^+_S \to D^0 e^+ \nu$, $B^0_S \to B^+ e^- \bar{\nu}$, $D^+_S \to D^+ e^- e^+$ and $B^0_S \to B^0 e^-e^+$ semileptonic decay processes, in which only the light quarks decay, while the heavy flavors remain unchanged. The branching ratios of these decay processes are calculated with the flavor SU(3) symmetry. The uncertainties are estimated by considering the SU(3) breaking effect. We find that the decay rates are very tiny in the framework of the Standard Model. We also estimate the sensitivities of the measurements of these rare decays at the future experiments, such as BES-III, super-$B$ and LHC-$b$.
hep-ph/9502320
null
Pyungwon Ko, Kang Young Lee and Jae Kwan Kim
$K_{L e5}$ decay as a background in search for $K_{L} \to \pi^{0} \mu^{\pm} e^{\mp}$
RevTeX, 10 pages, 1 figure available upon request, to appear in Phys. Rev. D
Phys.Rev. D51 (1995) 3455-3458
10.1103/PhysRevD.51.3455
SNUTP-94-62, KAIST-CHEP-94/04
hep-ph
null
We consider a process $K_{L e5} ( K_{L} \rightarrow \pi^{0} \pi^{0} \pi^{\pm} e^{\mp} \nu )$ as a standard model background to the experiment $K_{L} \rightarrow \pi^{0} \mu^{\pm} e^{\mp}$, which seeks for possible violation of lepton family number. Using the lowest order chiral lagrangian, we find that the branching ratio for $K_{L} \rightarrow \pi^{0} \pi^{0} \pi^{\pm} e^{\mp} \nu $ to be $6.2 \times 10^{-12}$. A similar decay $K_{L} \rightarrow \pi^{\mp} \pi^{\mp} \pi^{\pm} e^{\pm} \nu$ has a branching ratio, $1.7 \times 10^{-11}$.
[ { "created": "Thu, 16 Feb 1995 22:15:59 GMT", "version": "v1" }, { "created": "Sat, 18 Feb 1995 11:00:33 GMT", "version": "v2" } ]
2016-09-01
[ [ "Ko", "Pyungwon", "" ], [ "Lee", "Kang Young", "" ], [ "Kim", "Jae Kwan", "" ] ]
We consider a process $K_{L e5} ( K_{L} \rightarrow \pi^{0} \pi^{0} \pi^{\pm} e^{\mp} \nu )$ as a standard model background to the experiment $K_{L} \rightarrow \pi^{0} \mu^{\pm} e^{\mp}$, which seeks for possible violation of lepton family number. Using the lowest order chiral lagrangian, we find that the branching ratio for $K_{L} \rightarrow \pi^{0} \pi^{0} \pi^{\pm} e^{\mp} \nu $ to be $6.2 \times 10^{-12}$. A similar decay $K_{L} \rightarrow \pi^{\mp} \pi^{\mp} \pi^{\pm} e^{\pm} \nu$ has a branching ratio, $1.7 \times 10^{-11}$.
1403.6393
Helen Matskevich
S.M. Gerasyuta and E.E. Matskevich
Molecular state $\Sigma_b \Sigma_b^*$ in the coupled-channel formalism
5 pages. arXiv admin note: text overlap with arXiv:1012.3812 by other authors
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of the dispersion relation technique the relativistic six-quark equations for the molecule $\Sigma_b \Sigma_b^*$ are found. The relativistic six-quark amplitudes of the hexaquark including the quarks of three flavors ($u$, $d$, $b$) are calculated. The pole of these amplitudes determines the mass of $\Sigma_b \Sigma_b^*$ state $M=11620\, MeV$. The binding energy is equal to $27\, MeV$.
[ { "created": "Tue, 25 Mar 2014 15:38:56 GMT", "version": "v1" } ]
2014-03-26
[ [ "Gerasyuta", "S. M.", "" ], [ "Matskevich", "E. E.", "" ] ]
In the framework of the dispersion relation technique the relativistic six-quark equations for the molecule $\Sigma_b \Sigma_b^*$ are found. The relativistic six-quark amplitudes of the hexaquark including the quarks of three flavors ($u$, $d$, $b$) are calculated. The pole of these amplitudes determines the mass of $\Sigma_b \Sigma_b^*$ state $M=11620\, MeV$. The binding energy is equal to $27\, MeV$.
1112.0075
Teiji Kunihiro
Teiji Kunihiro and Zhao Zhang
Axial Anomaly, Mismatched Fermi Surfaces and Vector Interaction in Dense Neutral Quark Matter
A typos is corrected. Definitions of some coupling constants are added
null
10.1143/PTPS.193.20
KUNS-2376
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on effects of the q-$\bar{\rm q}$ vector interaction and/or the U(1)$_A$-anomaly-induced chiral-diquark coupling on the charge-neutral quark matter in $\beta$-equilibrium. We show that when the vector coupling is absent, there can appear a cross-over region sandwiched by two critical points in the intermediate temperature ($T$) region, while the phase transition in the low-$T$ region including zero temperature keeps being first order until the strength of the anomaly term is increased to have a critical value. On the other hand, when the vector coupling is also present, there appears a crossover region in the low-$T$ area including zero temperature with a new critical point, as was first demonstrated by Kitazawa et al and the present authors without and with the charge-neutral condition, respectively. We remark that the possible chromomagnetic instability is suppressed and can be even completely absent owing to the enhanced diquark coupling due to the anomaly term and/or by the vector interaction.
[ { "created": "Thu, 1 Dec 2011 03:34:49 GMT", "version": "v1" }, { "created": "Fri, 9 Dec 2011 12:00:03 GMT", "version": "v2" } ]
2015-06-03
[ [ "Kunihiro", "Teiji", "" ], [ "Zhang", "Zhao", "" ] ]
We report on effects of the q-$\bar{\rm q}$ vector interaction and/or the U(1)$_A$-anomaly-induced chiral-diquark coupling on the charge-neutral quark matter in $\beta$-equilibrium. We show that when the vector coupling is absent, there can appear a cross-over region sandwiched by two critical points in the intermediate temperature ($T$) region, while the phase transition in the low-$T$ region including zero temperature keeps being first order until the strength of the anomaly term is increased to have a critical value. On the other hand, when the vector coupling is also present, there appears a crossover region in the low-$T$ area including zero temperature with a new critical point, as was first demonstrated by Kitazawa et al and the present authors without and with the charge-neutral condition, respectively. We remark that the possible chromomagnetic instability is suppressed and can be even completely absent owing to the enhanced diquark coupling due to the anomaly term and/or by the vector interaction.
hep-ph/9501224
Tom Browder
T.E. Browder and S. Pakvasa (University of Hawaii)
A Comment on the Experimental Determination of $|V_{ts}/V_{td}|^2$.
6 pages, LATEX format
Phys.Rev.D52:3123-3124,1995
10.1103/PhysRevD.52.3123
UH 511-814-95, BELLE-46
hep-ph
null
We propose a method to extract the ratio $|V_{ts}/V_{td}|^2$ from a measurement of $\Delta \Gamma/\Gamma$ for the $B_s$ meson. This method is experimentally more sensitive than the conventional method for large values of $|V_{ts}|$ but depends on the accuracy of parton level calculations.
[ { "created": "Fri, 6 Jan 1995 08:47:38 GMT", "version": "v1" } ]
2016-09-01
[ [ "Browder", "T. E.", "", "University of Hawaii" ], [ "Pakvasa", "S.", "", "University of Hawaii" ] ]
We propose a method to extract the ratio $|V_{ts}/V_{td}|^2$ from a measurement of $\Delta \Gamma/\Gamma$ for the $B_s$ meson. This method is experimentally more sensitive than the conventional method for large values of $|V_{ts}|$ but depends on the accuracy of parton level calculations.
hep-ph/9808386
Yakov Azimov
Ya. Azimov (PNPI, St.Petersburg, Russia)
Phenomenology of Neutral D-meson Decays and Double-Flavor Oscillations
22 pages, LATEX, no figures. Misprint in bibliography is corrected; publication reference is appended
Eur.Phys.J.A4:21-31,1999
10.1007/s100500050200
null
hep-ph hep-ex
null
Decays of neutral D-mesons are considered phenomenologically without invoking any particular models. Special attention is given to cascade decays with intermediate neutral kaons where coherent double-flavor oscillations (CDFO) become possible. We show necessity and unique possibilities of experiments on CDFO. They allow to relate with each other widths and masses of D-meson eigenstates, to separate interference effects due to $D^0 - \bar D^0$ mixing and/or Cabibbo-favored vs. doubly-suppressed transitions. Such experiments provide the only known ways to unambiguous model-independent measurements of all CP-violating parameters and of Cabibbo-doubly-suppressed amplitudes, where the New Physics may have more prominent manifestations. Similar experiments would be useful and interesting also for charged $D$-meson decays to neutral kaons.
[ { "created": "Sun, 23 Aug 1998 14:08:58 GMT", "version": "v1" }, { "created": "Tue, 23 Feb 1999 14:57:28 GMT", "version": "v2" } ]
2008-11-26
[ [ "Azimov", "Ya.", "", "PNPI, St.Petersburg, Russia" ] ]
Decays of neutral D-mesons are considered phenomenologically without invoking any particular models. Special attention is given to cascade decays with intermediate neutral kaons where coherent double-flavor oscillations (CDFO) become possible. We show necessity and unique possibilities of experiments on CDFO. They allow to relate with each other widths and masses of D-meson eigenstates, to separate interference effects due to $D^0 - \bar D^0$ mixing and/or Cabibbo-favored vs. doubly-suppressed transitions. Such experiments provide the only known ways to unambiguous model-independent measurements of all CP-violating parameters and of Cabibbo-doubly-suppressed amplitudes, where the New Physics may have more prominent manifestations. Similar experiments would be useful and interesting also for charged $D$-meson decays to neutral kaons.
1005.5651
Shigeki Matsumoto
Shinya Kanemura, Shigeki Matsumoto, Takehiro Nabeshima, Nobuchika Okada
Can WIMP Dark Matter overcome the Nightmare Scenario?
14 pages, 10 figures
Phys.Rev.D82:055026,2010
10.1103/PhysRevD.82.055026
UT-HET 039
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Even if new physics beyond the Standard Model (SM) indeed exists, the energy scale of new physics might be beyond the reach at the Large Hadron Collider (LHC) and the LHC could find only the Higgs boson but nothing else. This is the so-called "nightmare scenario". On the other hand, the existence of the dark matter has been established from various observations. One of the promising candidates for thermal relic dark matter is a stable and electric charge-neutral Weakly Interacting Massive Particle (WIMP) with the mass below the TeV scale. In the nightmare scenario, we introduce a WIMP dark matter singlet under the SM gauge group, which only couples to the Higgs doublet at the lowest order, and investigate a possibility that such WIMP dark matter can be a clue to overcome the nightmare scenario via various phenomenological tests such as the dark matter relic abundance, the direct detection experiments for the dark matter particle, and the production of the dark matter particle at the LHC.
[ { "created": "Mon, 31 May 2010 10:17:24 GMT", "version": "v1" } ]
2014-11-21
[ [ "Kanemura", "Shinya", "" ], [ "Matsumoto", "Shigeki", "" ], [ "Nabeshima", "Takehiro", "" ], [ "Okada", "Nobuchika", "" ] ]
Even if new physics beyond the Standard Model (SM) indeed exists, the energy scale of new physics might be beyond the reach at the Large Hadron Collider (LHC) and the LHC could find only the Higgs boson but nothing else. This is the so-called "nightmare scenario". On the other hand, the existence of the dark matter has been established from various observations. One of the promising candidates for thermal relic dark matter is a stable and electric charge-neutral Weakly Interacting Massive Particle (WIMP) with the mass below the TeV scale. In the nightmare scenario, we introduce a WIMP dark matter singlet under the SM gauge group, which only couples to the Higgs doublet at the lowest order, and investigate a possibility that such WIMP dark matter can be a clue to overcome the nightmare scenario via various phenomenological tests such as the dark matter relic abundance, the direct detection experiments for the dark matter particle, and the production of the dark matter particle at the LHC.
hep-ph/0211356
T. Melde
T. Melde, R. F. Wagenbrunn, W. Plessas
Relativistic Study of Mesonic Baryon Resonance Decays
4 pages, contribution to XVIII European Conference on Few-Body Problems in Physics, September 2002, Bled, Slovenia
Few Body Syst.Suppl. 14 (2003) 37-40
null
null
hep-ph
null
Mesonic baryon resonance decays are calculated from constituent quark models along a Poincar\'e-invariant generalization of the elementary emission model. Covariant results of pionic decay widths are presented for the Goldstone-boson-exchange constituent quark model.
[ { "created": "Fri, 22 Nov 2002 15:04:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Melde", "T.", "" ], [ "Wagenbrunn", "R. F.", "" ], [ "Plessas", "W.", "" ] ]
Mesonic baryon resonance decays are calculated from constituent quark models along a Poincar\'e-invariant generalization of the elementary emission model. Covariant results of pionic decay widths are presented for the Goldstone-boson-exchange constituent quark model.
1008.5049
Aikaterini Katsikatsou
A. Katsikatsou
Collective treatment of High Energy Thresholds in SUSY - GUTs
21 pages, 8 figures, UA-NPPS/BSM-10/02 (added)
Int.J.Mod.Phys.A26:2027-2046,2011
10.1142/S0217751X11053055
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supersymmetric GUTs are the most natural extension of the Standard model unifying electroweak and strong forces. Despite their indubitable virtues, among these the gauge coupling unification and the quantization of the electric charge, one of their shortcomings is the large number of parameters used to describe the high energy thresholds (HET), which are hard to handle. We present a new method according to which the effects of the HET, in any GUT model, can be described by fewer parameters that are randomly produced from the original set of the parameters of the model. In this way, regions favoured by the experimental data are easier to locate, avoiding a detailed and time consuming exploration of the parameter space, which is multidimensional even in the most economic unifying schemes. To check the efficiency of this method, we directly apply it to a SUSY SO(10) GUT model in which the doublet-triplet splitting is realized through the Dimopoulos-Wilczek mechanism. We show that the demand of gauge coupling unification, in conjunction with precision data, locates regions of the parameter space in which values of the strong coupling \astrong are within the experimental limits, along with a suppressed nucleon decay, mediated by a higgsino driven dimension five operators, yielding lifetimes that are comfortably above the current experimental bounds. These regions open up for values of the SUSY breaking parameters m_0, M_1/2 < 1 TeV being therefore accessible to LHC.
[ { "created": "Mon, 30 Aug 2010 10:55:25 GMT", "version": "v1" }, { "created": "Thu, 16 Sep 2010 08:55:22 GMT", "version": "v2" } ]
2011-05-12
[ [ "Katsikatsou", "A.", "" ] ]
Supersymmetric GUTs are the most natural extension of the Standard model unifying electroweak and strong forces. Despite their indubitable virtues, among these the gauge coupling unification and the quantization of the electric charge, one of their shortcomings is the large number of parameters used to describe the high energy thresholds (HET), which are hard to handle. We present a new method according to which the effects of the HET, in any GUT model, can be described by fewer parameters that are randomly produced from the original set of the parameters of the model. In this way, regions favoured by the experimental data are easier to locate, avoiding a detailed and time consuming exploration of the parameter space, which is multidimensional even in the most economic unifying schemes. To check the efficiency of this method, we directly apply it to a SUSY SO(10) GUT model in which the doublet-triplet splitting is realized through the Dimopoulos-Wilczek mechanism. We show that the demand of gauge coupling unification, in conjunction with precision data, locates regions of the parameter space in which values of the strong coupling \astrong are within the experimental limits, along with a suppressed nucleon decay, mediated by a higgsino driven dimension five operators, yielding lifetimes that are comfortably above the current experimental bounds. These regions open up for values of the SUSY breaking parameters m_0, M_1/2 < 1 TeV being therefore accessible to LHC.
1412.0124
Wojciech Broniowski
Wojciech Broniowski, Enrique Ruiz Arriola, Pere Masjuan
Large-Nc Regge spectroscopy
6 pages, 7 figures, talk presented by WB at EEF70, Workshop on Unquenched Hadron Spectroscopy: Non-Perturbative Models and Methods of QCD vs. Experiment, Coimbra, Portugal, 1-5 September 2014
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This talk, dedicated to Eef van Beveren on the occasion of his birthday, reviews some of our results concerning the hadron spectroscopy, Regge trajectories, and the large-Nc meson-dominance of hadronic form factors.
[ { "created": "Sat, 29 Nov 2014 16:49:34 GMT", "version": "v1" } ]
2014-12-02
[ [ "Broniowski", "Wojciech", "" ], [ "Arriola", "Enrique Ruiz", "" ], [ "Masjuan", "Pere", "" ] ]
This talk, dedicated to Eef van Beveren on the occasion of his birthday, reviews some of our results concerning the hadron spectroscopy, Regge trajectories, and the large-Nc meson-dominance of hadronic form factors.
2112.00042
Kalliopi Petraki
Tobias Binder, Anastasiia Filimonova, Kalliopi Petraki and Graham White
Saha equilibrium for metastable bound states and dark matter freeze-out
v2: toy model added, discussion on validity of steady-state approximation improved; published in PLB
Phys.Lett.B 833 (2022) 137323
10.1016/j.physletb.2022.137323
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The formation and decay of metastable bound states can significantly decrease the thermal-relic dark matter density, particularly for dark matter masses around and above the TeV scale. Incorporating bound-state effects in the dark matter thermal decoupling requires in principle a set of coupled Boltzmann equations for the bound and unbound species. However, decaying bound states attain and remain in a quasi-steady state. Here we prove in generality that this reduces the coupled system into a single Boltzmann equation of the standard form, with an effective cross-section that describes the interplay among bound-state formation, ionisation, transitions and decays. We derive a closed-form expression for the effective cross-section for an arbitrary number of bound states, and show that bound-to-bound transitions can only increase it. Excited bound levels may thus decrease the dark matter density more significantly than otherwise estimated. Our results generalise the Saha ionisation equilibrium to metastable bound states, potentially with applications beyond the dark matter thermal decoupling.
[ { "created": "Tue, 30 Nov 2021 19:05:14 GMT", "version": "v1" }, { "created": "Wed, 31 Aug 2022 10:41:31 GMT", "version": "v2" } ]
2022-09-01
[ [ "Binder", "Tobias", "" ], [ "Filimonova", "Anastasiia", "" ], [ "Petraki", "Kalliopi", "" ], [ "White", "Graham", "" ] ]
The formation and decay of metastable bound states can significantly decrease the thermal-relic dark matter density, particularly for dark matter masses around and above the TeV scale. Incorporating bound-state effects in the dark matter thermal decoupling requires in principle a set of coupled Boltzmann equations for the bound and unbound species. However, decaying bound states attain and remain in a quasi-steady state. Here we prove in generality that this reduces the coupled system into a single Boltzmann equation of the standard form, with an effective cross-section that describes the interplay among bound-state formation, ionisation, transitions and decays. We derive a closed-form expression for the effective cross-section for an arbitrary number of bound states, and show that bound-to-bound transitions can only increase it. Excited bound levels may thus decrease the dark matter density more significantly than otherwise estimated. Our results generalise the Saha ionisation equilibrium to metastable bound states, potentially with applications beyond the dark matter thermal decoupling.
hep-ph/0607094
Fayet
Pierre Fayet
U-boson detectability, and Light Dark Matter
4 pages
null
null
LPTENS-06/24
hep-ph astro-ph
null
The possible existence of a new gauge boson U, light and very weakly coupled, allows for Light Dark Matter particles, which could also be at the origin of the 511 keV line from the galactic bulge. Independently of dark matter, and taking into account possible Z-U mixing effects, we show that, even under favorable circumstances (no axial couplings leading to an axionlike behavior or extra parity-violation effects, very small coupling to neutrinos), and using reasonable assumptions (no cancellation effect in g(mu)-2, lepton universality), the U coupling to electrons can be at most as large as ~ 1.5 10^-3 (for m(U) < m(mu)), and is likely to be smaller (e.g. <~ 3 10^-6 m(U) (MeV), if the U couplings to neutrinos and electrons are similar). This restricts significantly the detectability of a light U in e+e- --> gamma U, in particular. U exchanges can still provide annihilation cross sections of LDM particles of the appropriate size, even if this may require that light dark matter be relatively strongly self-interacting.
[ { "created": "Sun, 9 Jul 2006 16:20:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fayet", "Pierre", "" ] ]
The possible existence of a new gauge boson U, light and very weakly coupled, allows for Light Dark Matter particles, which could also be at the origin of the 511 keV line from the galactic bulge. Independently of dark matter, and taking into account possible Z-U mixing effects, we show that, even under favorable circumstances (no axial couplings leading to an axionlike behavior or extra parity-violation effects, very small coupling to neutrinos), and using reasonable assumptions (no cancellation effect in g(mu)-2, lepton universality), the U coupling to electrons can be at most as large as ~ 1.5 10^-3 (for m(U) < m(mu)), and is likely to be smaller (e.g. <~ 3 10^-6 m(U) (MeV), if the U couplings to neutrinos and electrons are similar). This restricts significantly the detectability of a light U in e+e- --> gamma U, in particular. U exchanges can still provide annihilation cross sections of LDM particles of the appropriate size, even if this may require that light dark matter be relatively strongly self-interacting.
0910.5049
Harry Lipkin J
Harry J. Lipkin
Theoretical Analysis Supports Darmstadt Oscillations Crucial Roles of Wave Function Collapse and Dicke Superradiance
19 pages, no figures, introduction and abstract revised for clarification
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Darmstadt $\nu$ oscillations in decay of radioactive ion can only come from initial state wave function. Causality forbids any influence on transition probability by detection of $\nu$ or final state interference after decay. Energy-time uncertainty allows two initial state components with different energies to decay into combination of two orthogonal states with same energy, different momenta and different $\nu$ masses. Final amplitudes completely separated at long times have broadened energy spectra overlapping at short times. Their interference produces oscillations between Dicke superradiant and subradiant states having different transition probabilities. Repeated monitoring by interactions with laboratory environment at regular time intervals and same space point in laboratory collapses wave function and destroys entanglement. First-order time dependent perturbation theory gives probability for initial state decay during small interval between two monitoring events. Experiment measures momentum difference between two contributing coherent initial states and obtains information about $\nu$ masses without detecting $\nu$. Simple model relates observed oscillation to squared $\nu$ mass difference and gives value differing by less than factor of three from values calculated from KAMLAND experiment. Monitoring simply expressed in laboratory frame not easily transformed to other frames and missed in Lorentz-covariant descriptions based on relativistic quantum field theory.
[ { "created": "Tue, 27 Oct 2009 07:20:12 GMT", "version": "v1" }, { "created": "Fri, 20 Nov 2009 20:05:33 GMT", "version": "v2" } ]
2009-11-20
[ [ "Lipkin", "Harry J.", "" ] ]
Darmstadt $\nu$ oscillations in decay of radioactive ion can only come from initial state wave function. Causality forbids any influence on transition probability by detection of $\nu$ or final state interference after decay. Energy-time uncertainty allows two initial state components with different energies to decay into combination of two orthogonal states with same energy, different momenta and different $\nu$ masses. Final amplitudes completely separated at long times have broadened energy spectra overlapping at short times. Their interference produces oscillations between Dicke superradiant and subradiant states having different transition probabilities. Repeated monitoring by interactions with laboratory environment at regular time intervals and same space point in laboratory collapses wave function and destroys entanglement. First-order time dependent perturbation theory gives probability for initial state decay during small interval between two monitoring events. Experiment measures momentum difference between two contributing coherent initial states and obtains information about $\nu$ masses without detecting $\nu$. Simple model relates observed oscillation to squared $\nu$ mass difference and gives value differing by less than factor of three from values calculated from KAMLAND experiment. Monitoring simply expressed in laboratory frame not easily transformed to other frames and missed in Lorentz-covariant descriptions based on relativistic quantum field theory.
1505.04168
Estela A. Garces
R. Gaitan, E. A. Garc\'es, J.H. Montes de Oca and R. Martinez
Top quark Chromoelectric and Chromomagnetic Dipole Moments in a Two Higgs Doublet Model with CP violation
9 Pages, 2 tables, 4 figures
Phys. Rev. D 92, 094025 (2015)
10.1103/PhysRevD.92.094025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study the anomalous top quark-gluon couplings Chromoelectric Dipole Moment (CEDM) and Chromomagnetic Dipole Moment (CMDM) in a general THDM with CP violation. We find that this model provides an important contribution from the $Y_{tt}$ Yukawa coupling that needs to be taken into account. The CMDM and CEDM obtained are $-0.03<\Delta\tilde{k} < 0.005}$ and $|\Delta \tilde{d}| < 0.005$, respectively.
[ { "created": "Fri, 15 May 2015 19:14:33 GMT", "version": "v1" }, { "created": "Wed, 27 May 2015 21:33:55 GMT", "version": "v2" }, { "created": "Mon, 19 Oct 2015 17:38:37 GMT", "version": "v3" } ]
2015-12-02
[ [ "Gaitan", "R.", "" ], [ "Garcés", "E. A.", "" ], [ "de Oca", "J. H. Montes", "" ], [ "Martinez", "R.", "" ] ]
In this work we study the anomalous top quark-gluon couplings Chromoelectric Dipole Moment (CEDM) and Chromomagnetic Dipole Moment (CMDM) in a general THDM with CP violation. We find that this model provides an important contribution from the $Y_{tt}$ Yukawa coupling that needs to be taken into account. The CMDM and CEDM obtained are $-0.03<\Delta\tilde{k} < 0.005}$ and $|\Delta \tilde{d}| < 0.005$, respectively.
hep-ph/9908297
Jochum van der Bij
J. J. van der Bij
Large rescaling of the scalar condensate, towards a Higgs-gravity connection ?
6 pages
null
null
Freiburg-THEP 99/09
hep-ph
null
In the Standard Model the Fermi constant is associated with the vacuum expectation value of the Higgs field $<\Phi>$, `the condensate', usually believed to be a nearly cut-off independent quantity. General arguments related to the `triviality' of $\lambda\Phi^4$ theory in 4 space-time dimensions suggest, however, a dramatic renormalization effect in the continuum theory. This effect is visible on the relatively large lattices (such as $32^4$) available today. The result is suggestive of a certain `Higgs-gravity connection', as discussed some years ago. The space-time structure is determined by symmetry breaking and the Planck scale is essentially a rescaling of the Fermi scale. The resulting picture may lead to quite substantial changes in the usual phenomenology associated with the Higgs particle.
[ { "created": "Sun, 8 Aug 1999 13:58:06 GMT", "version": "v1" } ]
2015-07-22
[ [ "van der Bij", "J. J.", "" ] ]
In the Standard Model the Fermi constant is associated with the vacuum expectation value of the Higgs field $<\Phi>$, `the condensate', usually believed to be a nearly cut-off independent quantity. General arguments related to the `triviality' of $\lambda\Phi^4$ theory in 4 space-time dimensions suggest, however, a dramatic renormalization effect in the continuum theory. This effect is visible on the relatively large lattices (such as $32^4$) available today. The result is suggestive of a certain `Higgs-gravity connection', as discussed some years ago. The space-time structure is determined by symmetry breaking and the Planck scale is essentially a rescaling of the Fermi scale. The resulting picture may lead to quite substantial changes in the usual phenomenology associated with the Higgs particle.
1607.07236
Mina Ketan Parida
M. K. Parida, Bidyut Prava Nayak (Siksha 'O' Anusandhan Univ., Bhubaneswar)
Singlet Fermion Assisted Dominant Seesaw with Lepton Flavor and Number Violations and Leptogenesis
66 pages pdfLatex, 9 figures; Review Artile on Neutrino Physics, Seesaw Mechanisms, and Beyond SM Physics Including GUTs
Advances in High Energy Physics, Volume 2017 (2017), Article ID 4023493, 24 pages
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent review Mohapatra has discussed how type-I seesaw mechanism suppressed by fine tuning of Yukawa couplings, or specific textures of associated fermion mass matrices, can form the basis of neutrino masses in TeV scale $W_R$ boson models. In this paper we review recent works in another class of theories where the added presence of fermion singlets manifesting as sterile neutrinos render the type-I seesaw contribution vanishing but extended seesaw dominant where the light neutrino mass formula is same as the classic inverse seesaw but all massive neutrinos are Majorana fermions. We also show domunance of linear seesaw, or double seesaw, or type-II seesaw in due to cancellation of type-I seesaw. Embeddings of this mechnism in supersymmetric as well as non-supersymmetric SO(10) with low or intermediate masses of $W_R$ or $Z_R$ bosons are discussed. We also discuss how this cancellation criteria has led to a new mechanism of type-II seesaw dominance which permits $U(1)_{B-L}$ breaking scale much smaller than the left-handed triplet mass. Out of a number of new observable predictions, the most visible ones are the dominant contribution to LFV decays and neutrinoless double beta decay mediated by light sterile neutrinos in the $W_L-W_L$ channel. These seesaw dominance mechanisms are applicable in the extensions of the SM and high, intermediate, or low scale left-right gauge theories with or without their SO(10) origin. Other recent works on the applications of this mechanism covering dark matter and leptogenesis are noted..
[ { "created": "Mon, 25 Jul 2016 12:23:10 GMT", "version": "v1" }, { "created": "Thu, 28 Jul 2016 12:23:57 GMT", "version": "v2" }, { "created": "Thu, 16 Feb 2017 12:17:44 GMT", "version": "v3" }, { "created": "Tue, 21 Mar 2017 12:03:58 GMT", "version": "v4" } ]
2017-03-22
[ [ "Parida", "M. K.", "", "Siksha 'O' Anusandhan Univ.,\n Bhubaneswar" ], [ "Nayak", "Bidyut Prava", "", "Siksha 'O' Anusandhan Univ.,\n Bhubaneswar" ] ]
In a recent review Mohapatra has discussed how type-I seesaw mechanism suppressed by fine tuning of Yukawa couplings, or specific textures of associated fermion mass matrices, can form the basis of neutrino masses in TeV scale $W_R$ boson models. In this paper we review recent works in another class of theories where the added presence of fermion singlets manifesting as sterile neutrinos render the type-I seesaw contribution vanishing but extended seesaw dominant where the light neutrino mass formula is same as the classic inverse seesaw but all massive neutrinos are Majorana fermions. We also show domunance of linear seesaw, or double seesaw, or type-II seesaw in due to cancellation of type-I seesaw. Embeddings of this mechnism in supersymmetric as well as non-supersymmetric SO(10) with low or intermediate masses of $W_R$ or $Z_R$ bosons are discussed. We also discuss how this cancellation criteria has led to a new mechanism of type-II seesaw dominance which permits $U(1)_{B-L}$ breaking scale much smaller than the left-handed triplet mass. Out of a number of new observable predictions, the most visible ones are the dominant contribution to LFV decays and neutrinoless double beta decay mediated by light sterile neutrinos in the $W_L-W_L$ channel. These seesaw dominance mechanisms are applicable in the extensions of the SM and high, intermediate, or low scale left-right gauge theories with or without their SO(10) origin. Other recent works on the applications of this mechanism covering dark matter and leptogenesis are noted..
1211.1542
Christopher Gorham Lester
Colin H. Lally and Christopher G. Lester
Properties of MT2 in the massless limit
16 pages, 11 figures. V2 - small corrections to appendix and acknowledgements, V3 - small typographical corrections (thank you RWD Nickalls) to text relating to polynomial root properties
null
null
CAV-HEP-12/17
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although numerical methods are required to evaluate the stransverse mass, MT2, for general input momenta, non-numerical methods have been proposed for some special clases of input momenta. One special case, considered in this note, is the so-called `massless limit' in which all four daughter objects (comprising one invisible particle and one visible system from each `side' of the event) have zero mass. This note establishes that it is possible to construct a stable and accurate implementation for evaluating MT2 based on an analytic expression valid in that massless limit. Although this implementation is found to have no significant speed improvements over existing evaluation strategies, it leads to an unexpected by-product: namely a secondary variable, that is found to be very similar to MT2 for much of its input-space and yet is much faster to calculate. This is potentially of interest for hardware applications that require very fast estimation of a mass scale (or QCD background discriminant) based on a hypothesis of pair production -- as might be required by a high luminosity trigger for a search for pair production of new massive states undergoing few subsequent decays (eg di-squark or di-slepton production). This is an application to which the contransverse mass MCT has previously been well suited due to its simplicity and ease of evaluation. Though the new variable requires a quadratic root to be found, it (like MCT) does not require iteration to compute, and is found to perform better then MCT in circumstances in which the information from the missing transverse momentum (which the former retains and the latter discards) is both reliable and useful.
[ { "created": "Wed, 7 Nov 2012 13:25:46 GMT", "version": "v1" }, { "created": "Mon, 21 Jan 2013 10:10:16 GMT", "version": "v2" }, { "created": "Tue, 10 Sep 2013 08:58:04 GMT", "version": "v3" } ]
2013-09-11
[ [ "Lally", "Colin H.", "" ], [ "Lester", "Christopher G.", "" ] ]
Although numerical methods are required to evaluate the stransverse mass, MT2, for general input momenta, non-numerical methods have been proposed for some special clases of input momenta. One special case, considered in this note, is the so-called `massless limit' in which all four daughter objects (comprising one invisible particle and one visible system from each `side' of the event) have zero mass. This note establishes that it is possible to construct a stable and accurate implementation for evaluating MT2 based on an analytic expression valid in that massless limit. Although this implementation is found to have no significant speed improvements over existing evaluation strategies, it leads to an unexpected by-product: namely a secondary variable, that is found to be very similar to MT2 for much of its input-space and yet is much faster to calculate. This is potentially of interest for hardware applications that require very fast estimation of a mass scale (or QCD background discriminant) based on a hypothesis of pair production -- as might be required by a high luminosity trigger for a search for pair production of new massive states undergoing few subsequent decays (eg di-squark or di-slepton production). This is an application to which the contransverse mass MCT has previously been well suited due to its simplicity and ease of evaluation. Though the new variable requires a quadratic root to be found, it (like MCT) does not require iteration to compute, and is found to perform better then MCT in circumstances in which the information from the missing transverse momentum (which the former retains and the latter discards) is both reliable and useful.
2110.14687
Moha Ouali
M. Ouali, M. Ouhammou, S. Taj, R. Benbrik, and B. Manaut
Muon pair production via $e^{+}e^{-}$ annihilation in the presence of a circularly polarized laser field
17 pages, 10 figures
null
10.1088/1555-6611/ac8fe8
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we have investigated the elementary particle reaction ${e}^{+} {e}^{-} \rightarrow{\mu}^{+} {\mu}^{-}$ that results from the electron-positron interaction, at the leading order, with an intense laser wave of circular polarization. We have derived, by annalytical means, the laser-assisted differential cross section expression by using the scattering matrix approach. We have analyzed the energy and the number of exchanged photons dependence of muon pair production in electron-positron annihilation at different centre of mass energies including the $Z$-boson peak. For this reason, a wide range of high centre of mass energies relevant to future $e^{+}e^{-}$ collider were covered to study the cross section behavior. We have found that, for a given number of exchanged photons, laser field strength and frequency, the circularly polarized laser field decreases the total cross section by several orders of magnitudes.
[ { "created": "Wed, 27 Oct 2021 18:13:01 GMT", "version": "v1" } ]
2022-10-05
[ [ "Ouali", "M.", "" ], [ "Ouhammou", "M.", "" ], [ "Taj", "S.", "" ], [ "Benbrik", "R.", "" ], [ "Manaut", "B.", "" ] ]
In this paper, we have investigated the elementary particle reaction ${e}^{+} {e}^{-} \rightarrow{\mu}^{+} {\mu}^{-}$ that results from the electron-positron interaction, at the leading order, with an intense laser wave of circular polarization. We have derived, by annalytical means, the laser-assisted differential cross section expression by using the scattering matrix approach. We have analyzed the energy and the number of exchanged photons dependence of muon pair production in electron-positron annihilation at different centre of mass energies including the $Z$-boson peak. For this reason, a wide range of high centre of mass energies relevant to future $e^{+}e^{-}$ collider were covered to study the cross section behavior. We have found that, for a given number of exchanged photons, laser field strength and frequency, the circularly polarized laser field decreases the total cross section by several orders of magnitudes.
1001.2396
Radja Boughezal
Radja Boughezal, Aude Gehrmann-De Ridder, Mathias Ritzmann
NNLO antenna subtraction with two hadronic initial states
7 pages, 3 figures, talk given at RADCOR 2009 - 9th International Symposium on Radiative Corrections (Applications of Quantum Field Theory to Phenomenology) October 25 - 30 2009
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the extension of the antenna subtraction method to include two hadrons in the initial state (initial-initial antennae) at next-to-next-to-leading order. We sketch the construction of the subtraction terms and the required phase space transformations. We discuss the integration of the subtraction terms in detail.
[ { "created": "Thu, 14 Jan 2010 10:07:56 GMT", "version": "v1" } ]
2010-01-15
[ [ "Boughezal", "Radja", "" ], [ "Ridder", "Aude Gehrmann-De", "" ], [ "Ritzmann", "Mathias", "" ] ]
We discuss the extension of the antenna subtraction method to include two hadrons in the initial state (initial-initial antennae) at next-to-next-to-leading order. We sketch the construction of the subtraction terms and the required phase space transformations. We discuss the integration of the subtraction terms in detail.
hep-ph/9506242
Alexander Khodjamirian
A. Khodjamirian, G. Stoll, D. Wyler
Calculation of Long-Distance Effects in Exclusive Weak Radiative Decays of B-Mesons
14 pages, Latex, two figures added as an uuencoded .ps file
Phys.Lett. B358 (1995) 129-138
10.1016/0370-2693(95)00972-N
ZU-TH 8/95 , LMU-06/95
hep-ph
null
We calculate the contribution of the weak annihilation to the $B\rightarrow \rho\gamma$ decay amplitude by means of QCD sum rules using the photon light-cone wave function. We find that this long-distance contribution amounts to about 10\% of the leading short-distance effect in $B^-\rightarrow \rho^-\gamma$. On the other hand, weak annihilation is the dominant source of the corresponding $D$ meson decays and according to our estimates, yields branching ratios of $O(10^{-4})$ for $D^0\rightarrow \bar{K}^{*0}\gamma$, $O(10^{-5})$ for $D_s\rightarrow \rho^+\gamma$, and $O(10^{-6})$ for $D^-\rightarrow \rho^-\gamma$ and for $D^0\rightarrow \rho^0\gamma$.
[ { "created": "Tue, 6 Jun 1995 00:45:16 GMT", "version": "v1" } ]
2009-10-28
[ [ "Khodjamirian", "A.", "" ], [ "Stoll", "G.", "" ], [ "Wyler", "D.", "" ] ]
We calculate the contribution of the weak annihilation to the $B\rightarrow \rho\gamma$ decay amplitude by means of QCD sum rules using the photon light-cone wave function. We find that this long-distance contribution amounts to about 10\% of the leading short-distance effect in $B^-\rightarrow \rho^-\gamma$. On the other hand, weak annihilation is the dominant source of the corresponding $D$ meson decays and according to our estimates, yields branching ratios of $O(10^{-4})$ for $D^0\rightarrow \bar{K}^{*0}\gamma$, $O(10^{-5})$ for $D_s\rightarrow \rho^+\gamma$, and $O(10^{-6})$ for $D^-\rightarrow \rho^-\gamma$ and for $D^0\rightarrow \rho^0\gamma$.
0710.3109
Sven Heinemeyer
S. Heinemeyer, A. Nikitenko, G. Weiglein
Heavy MSSM Higgs Bosons at CMS: "LHC wedge" and Higgs-Mass Precision
Talk given by G.W. at EPS07 (Manchester, July 2007) and talk given by S.H. at SUSY07 (Karlsruhe, July 2007). 4 pages, 2 figures
J.Phys.Conf.Ser.110:072047,2008
10.1088/1742-6596/110/7/072047
IPPP/07/59, DCPT/07/118
hep-ph
null
The search for MSSM Higgs bosons will be an important goal at the LHC. In order to analyze the search reach of the CMS experiment for the heavy neutral MSSM Higgs bosons, we combine the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The experimental analyses are done assuming an integrated luminosity of 30 or 60 fb^-1. The results are interpreted as 5$ \si$ discovery contours in MSSM M_A-tan_beta benchmark scenarios. Special emphasis is put on the variation of the Higgs mixing parameter mu. While the variation of mu can shift the prospective discovery reach (and correspondingly the ``LHC wedge'' region) by about Delta tan_beta= 10, the discovery reach is rather stable with respect to the impact of other supersymmetric parameters. Within the discovery region we analyze the accuracy with which the masses of the heavy neutral Higgs bosons can be determined. An accuracy of 1-4% should be achievable, depending on M_A and tan_beta.
[ { "created": "Tue, 16 Oct 2007 16:21:54 GMT", "version": "v1" } ]
2008-11-26
[ [ "Heinemeyer", "S.", "" ], [ "Nikitenko", "A.", "" ], [ "Weiglein", "G.", "" ] ]
The search for MSSM Higgs bosons will be an important goal at the LHC. In order to analyze the search reach of the CMS experiment for the heavy neutral MSSM Higgs bosons, we combine the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The experimental analyses are done assuming an integrated luminosity of 30 or 60 fb^-1. The results are interpreted as 5$ \si$ discovery contours in MSSM M_A-tan_beta benchmark scenarios. Special emphasis is put on the variation of the Higgs mixing parameter mu. While the variation of mu can shift the prospective discovery reach (and correspondingly the ``LHC wedge'' region) by about Delta tan_beta= 10, the discovery reach is rather stable with respect to the impact of other supersymmetric parameters. Within the discovery region we analyze the accuracy with which the masses of the heavy neutral Higgs bosons can be determined. An accuracy of 1-4% should be achievable, depending on M_A and tan_beta.
hep-ph/0006103
Alexander Dolgov
A.D. Dolgov
Restrictions on neutrino oscillations from BBN. Non-resonant case
10 pages; latex
Phys.Lett. B506 (2001) 7-12
10.1016/S0370-2693(01)00402-6
null
hep-ph
null
New nucleosynthesis bounds on the oscillation parameters of active neutrinos mixed with a sterile one are derived for the non-resonant case. The controversy in the literature whether to use the annihilation rate or the total reaction rate for the estimates of sterile neutrino production is resolved in favor of the annihilation rate. In contrast to previous papers, the restrictions on oscillations of electronic neutrinos are weaker than those of muonic and tauonic ones.
[ { "created": "Sat, 10 Jun 2000 16:19:26 GMT", "version": "v1" } ]
2009-10-31
[ [ "Dolgov", "A. D.", "" ] ]
New nucleosynthesis bounds on the oscillation parameters of active neutrinos mixed with a sterile one are derived for the non-resonant case. The controversy in the literature whether to use the annihilation rate or the total reaction rate for the estimates of sterile neutrino production is resolved in favor of the annihilation rate. In contrast to previous papers, the restrictions on oscillations of electronic neutrinos are weaker than those of muonic and tauonic ones.
0712.2793
Peihong Gu
Pei-Hong Gu, Utpal Sarkar
B-L Conserved Baryogenesis
3 pages. References added
Mod.Phys.Lett.A23:2047-2051,2008
10.1142/S0217732308027357
null
hep-ph
null
In the presence of anomaly induced sphaleron process, only a B-L asymmetry can be partially converted to the baryon asymmetry while any B+L asymmetry would be completely erased. Thus in any successful baryogenesis theories, B-L is usually violated above the electroweak scale to explain the observed matter-antimatter asymmetry of the universe. However, if any lepton asymmetry is not affected by the sphaleron processes, a B-L conserved theory can still realize the baryogenesis. We present here an SU(5) GUT realization of this scenario, which naturally accommodates small masses of Dirac neutrinos.
[ { "created": "Mon, 17 Dec 2007 19:07:53 GMT", "version": "v1" }, { "created": "Tue, 18 Dec 2007 17:07:34 GMT", "version": "v2" } ]
2008-11-26
[ [ "Gu", "Pei-Hong", "" ], [ "Sarkar", "Utpal", "" ] ]
In the presence of anomaly induced sphaleron process, only a B-L asymmetry can be partially converted to the baryon asymmetry while any B+L asymmetry would be completely erased. Thus in any successful baryogenesis theories, B-L is usually violated above the electroweak scale to explain the observed matter-antimatter asymmetry of the universe. However, if any lepton asymmetry is not affected by the sphaleron processes, a B-L conserved theory can still realize the baryogenesis. We present here an SU(5) GUT realization of this scenario, which naturally accommodates small masses of Dirac neutrinos.
hep-ph/9809583
null
Arjun Berera, Marcelo Gleiser, Rudnei O. Ramos
A First Principles Warm Inflation Model that Solves the Cosmological Horizon/Flatness Problems
In Press Physical Review Letters 1999, 5 pgs, 1 fig., latex
Phys.Rev.Lett.83:264-267,1999
10.1103/PhysRevLett.83.264
VAND-TH-98-16,DART-HEP-98/04,IF/UERJ-13/98
hep-ph astro-ph gr-qc hep-th
null
A quantum field theory warm inflation model is presented that solves the horizon/flatness problems. The model obtains, from the elementary dynamics of particle physics, cosmological scale factor trajectories that begin in a radiation dominated regime, enter an inflationary regime and then smoothly exit back into a radiation dominated regime, with nonnegligible radiation throughout the evolution.
[ { "created": "Tue, 29 Sep 1998 21:26:04 GMT", "version": "v1" }, { "created": "Mon, 26 Oct 1998 22:55:19 GMT", "version": "v2" }, { "created": "Tue, 18 May 1999 21:35:56 GMT", "version": "v3" } ]
2008-11-26
[ [ "Berera", "Arjun", "" ], [ "Gleiser", "Marcelo", "" ], [ "Ramos", "Rudnei O.", "" ] ]
A quantum field theory warm inflation model is presented that solves the horizon/flatness problems. The model obtains, from the elementary dynamics of particle physics, cosmological scale factor trajectories that begin in a radiation dominated regime, enter an inflationary regime and then smoothly exit back into a radiation dominated regime, with nonnegligible radiation throughout the evolution.
1311.0884
Kuver Sinha
Kuver Sinha
Non-thermal Dark Matter: A Selective Apercu
16 Pages, 1 Figure. References and discussion on dark radiation updated. Based on plenary talk at PPC 2013
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I provide a review of some recent work on non-thermal dark matter.
[ { "created": "Mon, 4 Nov 2013 21:00:19 GMT", "version": "v1" }, { "created": "Wed, 10 Dec 2014 18:27:40 GMT", "version": "v2" } ]
2014-12-11
[ [ "Sinha", "Kuver", "" ] ]
I provide a review of some recent work on non-thermal dark matter.
hep-ph/0106182
Masamichi Ishihara
Masamichi Ishihara
Parametric resonance at the critical temperature in high energy heavy ion collisions
8 pages, 1 figure Some statements and equations are modified to clarify
Phys.Rev. C64 (2001) 064903
10.1103/PhysRevC.64.064903
null
hep-ph nucl-th
null
Parametric resonance in soft modes at the critical temperature ($T_{c}$) in high energy heavy ion collisions is studied in the case when the temperature ($T$) of the system is almost constant for a long time. By deviding the fields into three parts, zero mode (condensate), soft modes and hard modes and assuming that the hard modes are in thermal equilibrium, we derive the equation of motion for soft modes at $T=T_{c}$. Enhanced modes are extracted by comparing with the Mathieu equation for the condensate oscillating along the sigma axis at $T=T_{c}$. It is found that the soft mode of $\pi$ fields at about 174 MeV is enhanced.
[ { "created": "Mon, 18 Jun 2001 04:58:44 GMT", "version": "v1" }, { "created": "Tue, 26 Jun 2001 11:32:46 GMT", "version": "v2" }, { "created": "Wed, 22 Aug 2001 04:40:57 GMT", "version": "v3" } ]
2009-11-07
[ [ "Ishihara", "Masamichi", "" ] ]
Parametric resonance in soft modes at the critical temperature ($T_{c}$) in high energy heavy ion collisions is studied in the case when the temperature ($T$) of the system is almost constant for a long time. By deviding the fields into three parts, zero mode (condensate), soft modes and hard modes and assuming that the hard modes are in thermal equilibrium, we derive the equation of motion for soft modes at $T=T_{c}$. Enhanced modes are extracted by comparing with the Mathieu equation for the condensate oscillating along the sigma axis at $T=T_{c}$. It is found that the soft mode of $\pi$ fields at about 174 MeV is enhanced.
hep-ph/0010261
K. Oganessyan
K.A. Oganessyan, N. Bianchi, E. De Sanctis, W.-D. Nowak
Investigation of single spin asymmetries in pi^{+} electroproduction
11 pages with 4 figures, LaTeX
Nucl.Phys. A689 (2001) 784-792
10.1016/S0375-9474(00)00609-6
null
hep-ph hep-ex
null
The azimuthal single target-spin asymmetries for pi^{+} production in semi-inclusive deep inelastic scattering of leptons off longitudinally polarized protons are evaluated using two main approaches available in the literature. It is shown that the approximation where the twist-2 transverse quark spin distribution in the longitudinally polarized nucleon is small enough to be neglected leads to a consistent description of all existing asymmetries observed by the HERMES experiment.
[ { "created": "Sun, 22 Oct 2000 19:08:12 GMT", "version": "v1" } ]
2016-09-06
[ [ "Oganessyan", "K. A.", "" ], [ "Bianchi", "N.", "" ], [ "De Sanctis", "E.", "" ], [ "Nowak", "W. -D.", "" ] ]
The azimuthal single target-spin asymmetries for pi^{+} production in semi-inclusive deep inelastic scattering of leptons off longitudinally polarized protons are evaluated using two main approaches available in the literature. It is shown that the approximation where the twist-2 transverse quark spin distribution in the longitudinally polarized nucleon is small enough to be neglected leads to a consistent description of all existing asymmetries observed by the HERMES experiment.
1304.4308
Mark Strikman
Leonid Frankfurt and Mark Strikman
Diffractive phenomena in high energy processes
79 pages, 11 figures. To be published as a chapter of the book "100 Years of Subatomic Physics"
null
10.1142/9789814425810_0014
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the evolution of the studies of diffractive processes in the strong interaction over the last 60 years. First, we briefly outline the early developments of the theory based on analyticity and unitarity of the S-matrix, including the derivation and exploration of the Regge trajectories and related moving cuts. Special attention is paid to the concept of the Pomeron trajectory introduced for description of total, elastic and diffractive cross sections at high energies and to the emergence of the dynamics of multi-Pomeron interactions.The role of large longitudinal distances and color coherent phenomena for the understanding of inelastic diffraction in hadron-hadron scattering and deep inelastic scattering is emphasized. The connection of these phenomena to the cancellation of the contribution of the Glauber approximation in hadron-nucleus collisions and to the understanding of the Gribov-Glauber approximation is explained. The presence of different scales in perturbative QCD due to masses of heavy quarks has led to the emergence of numerous new phenomena including non-universality of the slopes of Regge trajectories made of light and heavy quarks and non-universal energy dependence of elastic cross sections. The application of the perturbative QCD techniques allowed us to calculate from the first principles the interaction of small transverse size color singlets with hadrons leading to the development of the quantitative theory of hard exclusive reactions and to the successful prediction of many regularities in hard large mass diffraction. It also led to the prediction of the phenomenon of complete transparency of nuclear matter in QCD in special processes. The conflict of perturbative QCD with probability conservation for high energy processes of virtual photon-nucleon scattering is explained. Some properties of the new QCD regime are outlined.
[ { "created": "Tue, 16 Apr 2013 02:12:46 GMT", "version": "v1" } ]
2017-08-23
[ [ "Frankfurt", "Leonid", "" ], [ "Strikman", "Mark", "" ] ]
We review the evolution of the studies of diffractive processes in the strong interaction over the last 60 years. First, we briefly outline the early developments of the theory based on analyticity and unitarity of the S-matrix, including the derivation and exploration of the Regge trajectories and related moving cuts. Special attention is paid to the concept of the Pomeron trajectory introduced for description of total, elastic and diffractive cross sections at high energies and to the emergence of the dynamics of multi-Pomeron interactions.The role of large longitudinal distances and color coherent phenomena for the understanding of inelastic diffraction in hadron-hadron scattering and deep inelastic scattering is emphasized. The connection of these phenomena to the cancellation of the contribution of the Glauber approximation in hadron-nucleus collisions and to the understanding of the Gribov-Glauber approximation is explained. The presence of different scales in perturbative QCD due to masses of heavy quarks has led to the emergence of numerous new phenomena including non-universality of the slopes of Regge trajectories made of light and heavy quarks and non-universal energy dependence of elastic cross sections. The application of the perturbative QCD techniques allowed us to calculate from the first principles the interaction of small transverse size color singlets with hadrons leading to the development of the quantitative theory of hard exclusive reactions and to the successful prediction of many regularities in hard large mass diffraction. It also led to the prediction of the phenomenon of complete transparency of nuclear matter in QCD in special processes. The conflict of perturbative QCD with probability conservation for high energy processes of virtual photon-nucleon scattering is explained. Some properties of the new QCD regime are outlined.
1101.4471
Azad Inshalla oglu Ahmadov
A.I. Ahmadov, Yu.M. Bystritskiy, E.A. Kuraev
Peripherical processes 2 $\to$ 3 and 2 $\to$ 4 in QED and QCD in $p(\bar p)p$ high energy collisions
17 pages, 6 figures
null
10.1134/S1063776111130012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Differential cross section of processes with high energy $p(\bar p)p$ collisions in frames of QED: creation of scalar, pseudoscalar and lepton pair - are considered in Weizs\"acker - Williams approximation. In frames of QCD processes with conversion of initial proton (antiproton) to fermionic jets accompanied with one gluon jet as well as the state of two gluons and quark-antiquark pair (with out rapidity gap) are considered in frames of effective Reggion action of theory of Lipatov. Process of creation of a Higgs boson accompanied with two fermionic jets is considered. The azimuthal correlation in process of two gluon jet separated by rapidity gap is investigated. Effects of gluon reggeization are taken into account. Some distributions are illustrated by numerical calculations.
[ { "created": "Mon, 24 Jan 2011 09:13:26 GMT", "version": "v1" }, { "created": "Wed, 27 Apr 2011 11:00:10 GMT", "version": "v2" } ]
2015-05-27
[ [ "Ahmadov", "A. I.", "" ], [ "Bystritskiy", "Yu. M.", "" ], [ "Kuraev", "E. A.", "" ] ]
Differential cross section of processes with high energy $p(\bar p)p$ collisions in frames of QED: creation of scalar, pseudoscalar and lepton pair - are considered in Weizs\"acker - Williams approximation. In frames of QCD processes with conversion of initial proton (antiproton) to fermionic jets accompanied with one gluon jet as well as the state of two gluons and quark-antiquark pair (with out rapidity gap) are considered in frames of effective Reggion action of theory of Lipatov. Process of creation of a Higgs boson accompanied with two fermionic jets is considered. The azimuthal correlation in process of two gluon jet separated by rapidity gap is investigated. Effects of gluon reggeization are taken into account. Some distributions are illustrated by numerical calculations.
2405.17611
Gabriel Massoni Salla
Enrico Bertuzzo, Yuber F. Perez-Gonzalez, Gabriel M. Salla, Renata Zukanovich Funchal
Gravitationally produced Dark Matter and primordial black holes
22 pages + 2 apendices
null
null
IPPP/24/25
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine how the existence of a population of primordial black holes (PBHs) influences cosmological gravitational particle production (CGPP) for spin-0 and spin-1 particles. In addition to the known effects of particle production and entropy dilution resulting from PBH evaporation, we find that the generation of dark matter (DM) through CGPP is profoundly influenced by a possible era of PBH matter domination. This early matter dominated era results in an enhancement of the particle spectrum from CGPP. Specifically, it amplifies the peak comoving momentum $k_\star$ for spin-1 DM, while enhancing the plateau of the spectrum for minimally coupled spin-0 particles for low comoving momenta. At the same time, the large entropy dilution may partially or completely compensate for the increase of the spectrum and strongly mitigates the DM abundance produced by CGPP. Our results show that, in the computation of the final abundance, CGPP and PBH evaporation cannot be disentangled, but the parameters of both sectors must be considered together to obtain the final result. Furthermore, we explore the potential formation of PBHs from density fluctuations arising from CGPP and the associated challenges in such a scenario.
[ { "created": "Mon, 27 May 2024 19:19:20 GMT", "version": "v1" } ]
2024-05-29
[ [ "Bertuzzo", "Enrico", "" ], [ "Perez-Gonzalez", "Yuber F.", "" ], [ "Salla", "Gabriel M.", "" ], [ "Funchal", "Renata Zukanovich", "" ] ]
We examine how the existence of a population of primordial black holes (PBHs) influences cosmological gravitational particle production (CGPP) for spin-0 and spin-1 particles. In addition to the known effects of particle production and entropy dilution resulting from PBH evaporation, we find that the generation of dark matter (DM) through CGPP is profoundly influenced by a possible era of PBH matter domination. This early matter dominated era results in an enhancement of the particle spectrum from CGPP. Specifically, it amplifies the peak comoving momentum $k_\star$ for spin-1 DM, while enhancing the plateau of the spectrum for minimally coupled spin-0 particles for low comoving momenta. At the same time, the large entropy dilution may partially or completely compensate for the increase of the spectrum and strongly mitigates the DM abundance produced by CGPP. Our results show that, in the computation of the final abundance, CGPP and PBH evaporation cannot be disentangled, but the parameters of both sectors must be considered together to obtain the final result. Furthermore, we explore the potential formation of PBHs from density fluctuations arising from CGPP and the associated challenges in such a scenario.
hep-ph/9311295
Andreas Schaale
A.A.Bel'kov, G.Bohm, F.Matth\"ai, A.V.Lanyov, A.Schaale
What can we learn from new measurements of Dalitz plot parameters for K $\rightarrow 3 \pi$ decays ?
(DESY Int. Rep. 93-05, 16 p., 5 fig.)
null
null
null
hep-ph
null
We give a simple expression in linear and quadratic Dalitz--plot slopes which does not depend on the charge combination of the $3\pi$ state $(K^\pm \to \pi^{\pm}\pi^{+}\pi^{-}$ or $\pi^{\pm}\pi^{0}\pi^{0}$ and $K_L^{0} \to \pi^{+}\pi^{-}\pi^{0}$ or $\pi^{0}\pi^{0}\pi^{0})$, if all phases between final states are negligible. After investigating the influence of radiative corrections, it is shown how new measurements, especially of quadratic slopes in the $\pi^{\pm} \pi^{0} \pi^{0}$ channel, could help to test theoretical predictions more stringently. A FORTRAN code for the radiatiative corrections is available on request.
[ { "created": "Mon, 15 Nov 1993 19:34:18 GMT", "version": "v1" } ]
2009-09-25
[ [ "Bel'kov", "A. A.", "" ], [ "Bohm", "G.", "" ], [ "Matthäi", "F.", "" ], [ "Lanyov", "A. V.", "" ], [ "Schaale", "A.", "" ] ]
We give a simple expression in linear and quadratic Dalitz--plot slopes which does not depend on the charge combination of the $3\pi$ state $(K^\pm \to \pi^{\pm}\pi^{+}\pi^{-}$ or $\pi^{\pm}\pi^{0}\pi^{0}$ and $K_L^{0} \to \pi^{+}\pi^{-}\pi^{0}$ or $\pi^{0}\pi^{0}\pi^{0})$, if all phases between final states are negligible. After investigating the influence of radiative corrections, it is shown how new measurements, especially of quadratic slopes in the $\pi^{\pm} \pi^{0} \pi^{0}$ channel, could help to test theoretical predictions more stringently. A FORTRAN code for the radiatiative corrections is available on request.
1805.04477
J.D. Vergados
H. Ejiri (RCNP, Osaka University, Osaka, Japan), J.D. Vergados (University of Ioannina, Ioannina, Greece)
Neutron disappearance inside the nucleus
3 figures, 1 table. References added.To appear 2018 J. Phys. G: Nucl. Part. Phys. https://doi.org/10.1088/1361-6471/aaf55b arXiv admin note: text overlap with arXiv:1801.01124, arXiv:1203.3081 by other authors
null
10.1088/1361-6471/aaf55b
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the possibility that a neutron may disappear inside the nucleus, which will demonstrate the existence of baryon violating $\Delta B=1$ interactions. It has recently been proposed that such a process may have an effect on the free neutron decay life time. We evaluate the widths for $n\rightarrow \chi$ and $n\rightarrow \chi \gamma$, with $\chi$ being a light dark matter particle emitted by a loosely bound neutron in various light nuclei. We find that, assuming a mass $m_{\chi}$ close to 938 MeV, the obtained width for $n\rightarrow \chi$ in $^{11}$Be is much larger than the corresponding beta decay width. This suggests a severe limit on the possible decay channel of $n \rightarrow \chi \gamma $ for free neutron.
[ { "created": "Thu, 10 May 2018 11:51:08 GMT", "version": "v1" }, { "created": "Wed, 23 May 2018 10:01:01 GMT", "version": "v2" }, { "created": "Tue, 4 Dec 2018 11:44:08 GMT", "version": "v3" } ]
2019-01-30
[ [ "Ejiri", "H.", "", "RCNP, Osaka University, Osaka, Japan" ], [ "Vergados", "J. D.", "", "University of Ioannina, Ioannina, Greece" ] ]
We consider the possibility that a neutron may disappear inside the nucleus, which will demonstrate the existence of baryon violating $\Delta B=1$ interactions. It has recently been proposed that such a process may have an effect on the free neutron decay life time. We evaluate the widths for $n\rightarrow \chi$ and $n\rightarrow \chi \gamma$, with $\chi$ being a light dark matter particle emitted by a loosely bound neutron in various light nuclei. We find that, assuming a mass $m_{\chi}$ close to 938 MeV, the obtained width for $n\rightarrow \chi$ in $^{11}$Be is much larger than the corresponding beta decay width. This suggests a severe limit on the possible decay channel of $n \rightarrow \chi \gamma $ for free neutron.
1610.00666
Christoph Borschensky
Christoph Borschensky and Anna Kulesza
Double parton scattering in pair-production of $J/\psi$ mesons at the LHC revisited
22 pages, 10 figures
Phys. Rev. D 95, 034029 (2017)
10.1103/PhysRevD.95.034029
MS-TP-16-21
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Double parton scattering (DPS) is studied at the example of $J/\psi$ pair-production in the LHCb and ATLAS experiments of the Large Hadron Collider (LHC) at centre-of-mass energies of $\sqrt{S}=$ 7, 8, and 13 TeV. We report theoretical predictions delivered to the LHCb and ATLAS collaborations adjusted for the fiducial volumes of the corresponding measurements during Run I and provide new predictions at 13 TeV collision energy. It is shown that DPS can lead to noticeable contributions in the distributions of longitudinal variables of the di-$J/\psi$ system, especially at 13 TeV. The increased DPS rate in double $J/\psi$ production at high energies will open up more possibilities for the separation of single parton scattering (SPS) and DPS contributions in future studies.
[ { "created": "Mon, 3 Oct 2016 18:33:57 GMT", "version": "v1" } ]
2017-03-01
[ [ "Borschensky", "Christoph", "" ], [ "Kulesza", "Anna", "" ] ]
Double parton scattering (DPS) is studied at the example of $J/\psi$ pair-production in the LHCb and ATLAS experiments of the Large Hadron Collider (LHC) at centre-of-mass energies of $\sqrt{S}=$ 7, 8, and 13 TeV. We report theoretical predictions delivered to the LHCb and ATLAS collaborations adjusted for the fiducial volumes of the corresponding measurements during Run I and provide new predictions at 13 TeV collision energy. It is shown that DPS can lead to noticeable contributions in the distributions of longitudinal variables of the di-$J/\psi$ system, especially at 13 TeV. The increased DPS rate in double $J/\psi$ production at high energies will open up more possibilities for the separation of single parton scattering (SPS) and DPS contributions in future studies.
1107.1087
Dmitry Zhuridov Dr.
Dmitry V. Zhuridov
Freed Leptogenesis
15 pages, 3 figures. Minor corrections, Ref. [46] added
Mod.Phys.Lett. A26 (2011) 2983-2996
10.1142/S0217732311037340
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Economical extensions of the Standard Model (SM), in which the famous Davidson-Ibarra bound on the CP asymmetry relevant for leptogenesis may be significantly relaxed by the loop effects, comparing to predictions of the SM extended only by right-handed neutrinos with hierarchical masses, are discussed. This leads to decreasing of the lower bound on the heavy neutrino masses and increasing of the upper bound on the light neutrino masses. In addition, the considered theory may help to solve the dark matter problem.
[ { "created": "Wed, 6 Jul 2011 10:44:32 GMT", "version": "v1" }, { "created": "Thu, 28 Jul 2011 10:51:45 GMT", "version": "v2" }, { "created": "Thu, 17 Nov 2011 08:59:22 GMT", "version": "v3" }, { "created": "Mon, 23 Apr 2012 17:07:12 GMT", "version": "v4" }, { "created": "Fri, 29 Mar 2013 19:28:58 GMT", "version": "v5" } ]
2016-03-22
[ [ "Zhuridov", "Dmitry V.", "" ] ]
Economical extensions of the Standard Model (SM), in which the famous Davidson-Ibarra bound on the CP asymmetry relevant for leptogenesis may be significantly relaxed by the loop effects, comparing to predictions of the SM extended only by right-handed neutrinos with hierarchical masses, are discussed. This leads to decreasing of the lower bound on the heavy neutrino masses and increasing of the upper bound on the light neutrino masses. In addition, the considered theory may help to solve the dark matter problem.
2007.07167
M\'at\'e Csan\'ad
Mate Csanad, Antal Jakovac, Sandor Lokos, Ayon Mukherjee, Srikanta Kumar Tripathy
Multi-particle quantum-statistical correlation functions in a Hubble-expanding hadron gas
This research was supported by the NKFIH grants K-128713, FK-123842 and 2019-2.1.11-TET-2019-0008
Gribov-90 Memorial Volume, pp. 261-273 (2021)
10.1142/9789811238406_0023
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum-statistical correlation measurements in high-energy physics represent an important tool to obtain information about the space-time structure of the particle-emitting source. There are several final state effects which may modify the measured femtoscopic correlation functions. One of these may be the interaction of the investigated particles with the expanding hadron gas, consisting of the other final state particles. This may cause the trajectories - and hence the phases - of the quantum-correlated pairs to be modified compared to free streaming. The resulting effect and could be interpreted as an Aharonov-Bohm-like phenomenon, in the sense that the possible paths of a quantum-correlated pair represent a closed loop, with an internally present field caused by the hadron gas. In this paper, the possible role of the effect in heavy-ion experiments is presented with analytical calculations and a simple numerical model. The modification of the strength of multi-particle Bose-Einstein correlation functions is investigated, and the is found that in case of sufficiently large source density, this effect may play a non-negligible role.
[ { "created": "Tue, 14 Jul 2020 16:36:30 GMT", "version": "v1" }, { "created": "Tue, 26 Sep 2023 09:43:34 GMT", "version": "v2" } ]
2023-09-27
[ [ "Csanad", "Mate", "" ], [ "Jakovac", "Antal", "" ], [ "Lokos", "Sandor", "" ], [ "Mukherjee", "Ayon", "" ], [ "Tripathy", "Srikanta Kumar", "" ] ]
Quantum-statistical correlation measurements in high-energy physics represent an important tool to obtain information about the space-time structure of the particle-emitting source. There are several final state effects which may modify the measured femtoscopic correlation functions. One of these may be the interaction of the investigated particles with the expanding hadron gas, consisting of the other final state particles. This may cause the trajectories - and hence the phases - of the quantum-correlated pairs to be modified compared to free streaming. The resulting effect and could be interpreted as an Aharonov-Bohm-like phenomenon, in the sense that the possible paths of a quantum-correlated pair represent a closed loop, with an internally present field caused by the hadron gas. In this paper, the possible role of the effect in heavy-ion experiments is presented with analytical calculations and a simple numerical model. The modification of the strength of multi-particle Bose-Einstein correlation functions is investigated, and the is found that in case of sufficiently large source density, this effect may play a non-negligible role.
0801.0804
Mihai L. Ion
D. B. Ion (1 and 2) and M. L. Ion (3) ((1) National Institute for Physics and Nuclear Engineering Horia Hulubei, Bucharest, Magurele Romania, (2) TH-Division, CERN, (3) Bucharest University, Bucharest, Romania)
From Cherenkov Radiation to Generalized Super-Cherenkov Exotic Decays
14 pages, 15 figures
null
null
null
hep-ph
null
Generalized Super-Cherenkov Radiations (SCR), as well as their SCR-signatures are investigated. Two general SCR-coherence conditions are found as two natural extremes of the same spontaneous particles decays in (dielectric, nuclear or hadronic) media. The main results on the experimental test of the super-coherence conditions, obtained by using the experimental data from BNL, are presented. The interpretation of the observed anomalous Cherenkov rings as experimental evidence for the HE-component of the SCR is discussed.
[ { "created": "Sat, 5 Jan 2008 12:36:14 GMT", "version": "v1" } ]
2008-01-08
[ [ "Ion", "D. B.", "", "1 and 2" ], [ "Ion", "M. L.", "" ] ]
Generalized Super-Cherenkov Radiations (SCR), as well as their SCR-signatures are investigated. Two general SCR-coherence conditions are found as two natural extremes of the same spontaneous particles decays in (dielectric, nuclear or hadronic) media. The main results on the experimental test of the super-coherence conditions, obtained by using the experimental data from BNL, are presented. The interpretation of the observed anomalous Cherenkov rings as experimental evidence for the HE-component of the SCR is discussed.
1205.5061
Suchita Kulkarni Miss
Suchita Kulkarni
Effective couplings approach to neutralino dark matter relic density
Moriond EW 2012 proceedings, 4 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we analyze the electroweak loop corrections to the Neutralino dark matter relic density in the framework of effective coupling. In the first part, we comment on the generic features of the corrections and quantitative changes to the predicted relic density. We analyze the correlation between the characteristics of effective couplings to the nature of neutralino. Effective couplings, however, absorb only the most dominant one loop corrections and are not an exact calculation. In the second part, we assess the validity of effective couplings by comparing them to the full one loop calculations in various regions of parameter space.
[ { "created": "Tue, 22 May 2012 21:18:15 GMT", "version": "v1" } ]
2012-05-24
[ [ "Kulkarni", "Suchita", "" ] ]
In this work, we analyze the electroweak loop corrections to the Neutralino dark matter relic density in the framework of effective coupling. In the first part, we comment on the generic features of the corrections and quantitative changes to the predicted relic density. We analyze the correlation between the characteristics of effective couplings to the nature of neutralino. Effective couplings, however, absorb only the most dominant one loop corrections and are not an exact calculation. In the second part, we assess the validity of effective couplings by comparing them to the full one loop calculations in various regions of parameter space.
hep-ph/0408299
Axel Maas
Axel Maas, Jochen Wambach, Burghard Gruter, Reinhard Alkofer
Residual Confinement in High-Temperature Yang-Mills Theory
5 pages, 4 figures, poster presented by A.Maas at the Strong and Electroweak Matter 2004 Conference, Helsinki, Finland, 16th-19th June 2004; to appear in the proceedings
null
10.1142/9789812702159_0062
null
hep-ph hep-lat nucl-th
null
The infrared behavior of Landau gauge gluon and ghost propagators are investigated in Yang-Mills theory at non-vanishing temperatures. Self-consistent solutions are presented for temperatures below the presumed phase transition and in the infinite temperature limit. Gluon confinement is manifest in the infrared behavior of these propagators. As expected confinement prevails below the phase transition. In the infinite-temperature limit a qualitative change is observed: the chromoelectric sector exhibits a near-perturbative behavior while long-range chromomagnetic interactions, mediated by soft ghost modes, are still present. The latter behavior is in agreement with corresponding lattice results. It furthermore implies that part of the gluons are still confined.
[ { "created": "Thu, 26 Aug 2004 11:42:53 GMT", "version": "v1" } ]
2017-08-23
[ [ "Maas", "Axel", "" ], [ "Wambach", "Jochen", "" ], [ "Gruter", "Burghard", "" ], [ "Alkofer", "Reinhard", "" ] ]
The infrared behavior of Landau gauge gluon and ghost propagators are investigated in Yang-Mills theory at non-vanishing temperatures. Self-consistent solutions are presented for temperatures below the presumed phase transition and in the infinite temperature limit. Gluon confinement is manifest in the infrared behavior of these propagators. As expected confinement prevails below the phase transition. In the infinite-temperature limit a qualitative change is observed: the chromoelectric sector exhibits a near-perturbative behavior while long-range chromomagnetic interactions, mediated by soft ghost modes, are still present. The latter behavior is in agreement with corresponding lattice results. It furthermore implies that part of the gluons are still confined.
hep-ph/0507158
Sandro Uccirati
W. Hollik, U. Meier, S. Uccirati (MPI, Munich)
The effective electroweak mixing angle $\sin^2\theta_{eff}$ with two-loop fermionic contributions
15 pages, 5 figures, reference added, few typos corrected
Nucl.Phys. B731 (2005) 213-224
10.1016/j.nuclphysb.2005.10.015
MPP-2005-77
hep-ph
null
We present the results from a calculation of the full electroweak two-loop fermionic contributions to the effective leptonic mixing angle of the $Z$ boson, $\sin^2\theta_{eff}$, in the Standard Model. On-shell renormalization and analytic calculations are performed for the three-point vertex functions at zero external momenta, whereas irreducible three-point integrals for non-vanishing external momenta are evaluated semi-analytically applying two different methods. Comparisons with a previous calculation show complete agreement.
[ { "created": "Wed, 13 Jul 2005 15:34:38 GMT", "version": "v1" }, { "created": "Thu, 20 Oct 2005 11:49:39 GMT", "version": "v2" } ]
2009-11-11
[ [ "Hollik", "W.", "", "MPI, Munich" ], [ "Meier", "U.", "", "MPI, Munich" ], [ "Uccirati", "S.", "", "MPI, Munich" ] ]
We present the results from a calculation of the full electroweak two-loop fermionic contributions to the effective leptonic mixing angle of the $Z$ boson, $\sin^2\theta_{eff}$, in the Standard Model. On-shell renormalization and analytic calculations are performed for the three-point vertex functions at zero external momenta, whereas irreducible three-point integrals for non-vanishing external momenta are evaluated semi-analytically applying two different methods. Comparisons with a previous calculation show complete agreement.
1507.07768
Floriana Giannuzzi
L. Bellantuono, P. Colangelo, F. Giannuzzi
Holographic Oddballs
16 pages, 9 figures, 3 tables
null
null
BARI-TH/2015-697
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spectrum of the glueball with $J^{PC}=0^{--}$ is computed using different bottom-up holographic models of QCD. The results indicate a lowest-lying state lighter than in the determination by other methods, with mass $m \simeq 2.8$ GeV. The in-medium properties of this gluonium are investigated, and stability against thermal and density effects is compared to other hadronic systems. Production and decay modes are identified, useful for searching the $J^{PC}=0^{--}$ glueball.
[ { "created": "Tue, 28 Jul 2015 13:47:23 GMT", "version": "v1" } ]
2015-07-29
[ [ "Bellantuono", "L.", "" ], [ "Colangelo", "P.", "" ], [ "Giannuzzi", "F.", "" ] ]
The spectrum of the glueball with $J^{PC}=0^{--}$ is computed using different bottom-up holographic models of QCD. The results indicate a lowest-lying state lighter than in the determination by other methods, with mass $m \simeq 2.8$ GeV. The in-medium properties of this gluonium are investigated, and stability against thermal and density effects is compared to other hadronic systems. Production and decay modes are identified, useful for searching the $J^{PC}=0^{--}$ glueball.
2110.08183
Jeremy Dalseno
J. Dalseno
Rescaling the isospin triangle argument for constraining $\phi_2$ ($\alpha$): consolidating Belle II and a potential path forward for LHCb
10 pages, 7 figures, replaced with journal version. This article should be considered in conjunction with arXiv:2108.06182
Eur. Phys. J. Plus 137 (2022) 806
10.1140/epjp/s13360-022-03008-8
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A rescaling of the SU(2) isospin triangles constraining $\phi_2$ ($\alpha$) that relies on measurements of the experimentally cleaner relative branching fractions, as opposed to those absolute, is proposed. Paving the way towards more systematically sustainable analysis, this method promises to eliminate a dominant systematic at Belle II amongst others, namely the uncertainty on the number of $B \bar B$ pairs in data. Furthermore, a $\phi_2$ constraint in the $B \to \rho \rho$ system at LHCb that is more independent of Belle II input is shown to become viable even without a measurement of $C\!P$ violation in $B^0 \to \rho^+\rho^-$.
[ { "created": "Fri, 15 Oct 2021 16:30:03 GMT", "version": "v1" }, { "created": "Tue, 12 Jul 2022 16:48:20 GMT", "version": "v2" } ]
2022-07-13
[ [ "Dalseno", "J.", "" ] ]
A rescaling of the SU(2) isospin triangles constraining $\phi_2$ ($\alpha$) that relies on measurements of the experimentally cleaner relative branching fractions, as opposed to those absolute, is proposed. Paving the way towards more systematically sustainable analysis, this method promises to eliminate a dominant systematic at Belle II amongst others, namely the uncertainty on the number of $B \bar B$ pairs in data. Furthermore, a $\phi_2$ constraint in the $B \to \rho \rho$ system at LHCb that is more independent of Belle II input is shown to become viable even without a measurement of $C\!P$ violation in $B^0 \to \rho^+\rho^-$.
hep-ph/9603271
Glennys Farrar
Glennys R. Farrar (Rutgers University)
Detecting Gluino-Containing Hadrons
13 pp, 1 figure (uuencoded). Descendant of hep-ph/9504295, hep-ph/9508291, and hep-ph/9508292, focused on experimental search techniques. To be published in Phys Rev Lett
Phys.Rev.Lett.76:4111-4114,1996
10.1103/PhysRevLett.76.4111
RU-96-05
hep-ph
null
When SUSY breaking produces only dimension-2 operators, gluino and photino masses are of order 1 GeV or less. The gluon-gluino bound state has mass 1.3-2.2 GeV and lifetime > 10^{-5} - 10^{-10} s. This range of mass and lifetime is largely unconstrained because missing energy and beam dump techniques are ineffective. With only small modifications, upcoming K^0 decay experiments can study most of the interesting range. The lightest gluino-containing baryon (uds-gluino) is long-lived or stable; experiments to find it and the uud-gluino are also discussed.
[ { "created": "Mon, 11 Mar 1996 19:30:07 GMT", "version": "v1" } ]
2008-11-26
[ [ "Farrar", "Glennys R.", "", "Rutgers University" ] ]
When SUSY breaking produces only dimension-2 operators, gluino and photino masses are of order 1 GeV or less. The gluon-gluino bound state has mass 1.3-2.2 GeV and lifetime > 10^{-5} - 10^{-10} s. This range of mass and lifetime is largely unconstrained because missing energy and beam dump techniques are ineffective. With only small modifications, upcoming K^0 decay experiments can study most of the interesting range. The lightest gluino-containing baryon (uds-gluino) is long-lived or stable; experiments to find it and the uud-gluino are also discussed.
1012.2708
Eugenio Javier Garzon Alama
A. Mart\'inez Torres, E.J. Garzon, E. Oset, L. R. Dai
Limits to the Fixed Center Approximation to Faddeev equations: the case of the $\phi(2170)$
null
Phys.Rev.D83:116002,2011
10.1103/PhysRevD.83.116002
YITP-10-95
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Fixed Center Approximation to the Faddeev equations (FCA) has been used lately with success in the study of bound systems of three hadrons. It is also important to set the limits of the approach in those problems to prevent proliferation of inaccurate predictions. In this paper we study the case of the $\phi(2170)$, which has been described by means of Faddeev equations as a resonant state of $\phi$ and $K \bar{K}$, and show the problems derived from the use of the FCA in its study. At the same time we also expose the limitations of an alternative approach recently proposed.
[ { "created": "Mon, 13 Dec 2010 12:14:05 GMT", "version": "v1" }, { "created": "Fri, 11 Mar 2011 11:04:01 GMT", "version": "v2" } ]
2015-03-17
[ [ "Torres", "A. Martínez", "" ], [ "Garzon", "E. J.", "" ], [ "Oset", "E.", "" ], [ "Dai", "L. R.", "" ] ]
The Fixed Center Approximation to the Faddeev equations (FCA) has been used lately with success in the study of bound systems of three hadrons. It is also important to set the limits of the approach in those problems to prevent proliferation of inaccurate predictions. In this paper we study the case of the $\phi(2170)$, which has been described by means of Faddeev equations as a resonant state of $\phi$ and $K \bar{K}$, and show the problems derived from the use of the FCA in its study. At the same time we also expose the limitations of an alternative approach recently proposed.
hep-ph/9911407
Dennys A. Lopez Falcon
J. L. Diaz Cruz and D. A. Lopez Falcon (Puebla U., Mexico)
Testing models with non-minimal Higgs sector through the decay t->q+WZ
Typeset using REVTEX and EPSF, 5 pag, 2 figures
Phys.Rev.D61:051701,2000
10.1103/PhysRevD.61.051701
HEP-IFUAP-99-03
hep-ph
null
We study the contribution of charged Higgs boson to the rare decay of the top quark t->q+WZ (q=d,s,b) in models with Higgs sector that includes doublets and triplets. Higgs doublets are needed to couple charged Higgs with quarks, whereas the Higgs triplets are required to generate the non-standard vertex HWZ at tree-level. It is found that within a model that respect the custodial SU(2) symmetry and avoids flavour changing neutral currents by imposing discrete symmetries, the decay mode t->b+WZ, can reach a branching ratio of order 0.0178, whereas the decay modes t->(d,s)+WZ, can reach a similar branching ratio in models where flavour changing neutral currents are suppressed by flavour symmetries.
[ { "created": "Fri, 19 Nov 1999 03:18:06 GMT", "version": "v1" }, { "created": "Fri, 18 Feb 2000 01:28:12 GMT", "version": "v2" } ]
2009-12-30
[ [ "Cruz", "J. L. Diaz", "", "Puebla U., Mexico" ], [ "Falcon", "D. A. Lopez", "", "Puebla U., Mexico" ] ]
We study the contribution of charged Higgs boson to the rare decay of the top quark t->q+WZ (q=d,s,b) in models with Higgs sector that includes doublets and triplets. Higgs doublets are needed to couple charged Higgs with quarks, whereas the Higgs triplets are required to generate the non-standard vertex HWZ at tree-level. It is found that within a model that respect the custodial SU(2) symmetry and avoids flavour changing neutral currents by imposing discrete symmetries, the decay mode t->b+WZ, can reach a branching ratio of order 0.0178, whereas the decay modes t->(d,s)+WZ, can reach a similar branching ratio in models where flavour changing neutral currents are suppressed by flavour symmetries.
2306.09056
John Gracey
J.A. Gracey, R.H. Mason, Thomas A. Ryttov, R.M. Simms
Scheme and gauge dependence of QCD fixed points at five loops
56 latex pages, 11 figures, 34 tables, anc directory contains pdf of additional tables, minor text additions
null
null
LTH 1341
hep-ph
http://creativecommons.org/licenses/by/4.0/
We analyse the fixed points of QCD at high loop order in a variety of renormalization schemes and gauges across the conformal window. We observe that in the minimal momentum subtraction scheme solutions for the Banks-Zaks fixed point persist for values of Nf below that of the MSbar scheme in the canonical linear covariant gauge. By treating the parameter of the linear covariant gauge as a second coupling constant we confirm the existence of a second Banks-Zaks twin critical point, which is infrared stable, to five loops. Moreover a similar and parallel infrared stable fixed point is present in the Curci-Ferrari and maximal abelian gauges which persists in different schemes including kinematic ones. We verify that with the increased available loop order critical exponent estimates show an improvement in convergence and agreement in the various schemes.
[ { "created": "Thu, 15 Jun 2023 11:30:54 GMT", "version": "v1" }, { "created": "Thu, 13 Jul 2023 09:00:33 GMT", "version": "v2" } ]
2023-07-14
[ [ "Gracey", "J. A.", "" ], [ "Mason", "R. H.", "" ], [ "Ryttov", "Thomas A.", "" ], [ "Simms", "R. M.", "" ] ]
We analyse the fixed points of QCD at high loop order in a variety of renormalization schemes and gauges across the conformal window. We observe that in the minimal momentum subtraction scheme solutions for the Banks-Zaks fixed point persist for values of Nf below that of the MSbar scheme in the canonical linear covariant gauge. By treating the parameter of the linear covariant gauge as a second coupling constant we confirm the existence of a second Banks-Zaks twin critical point, which is infrared stable, to five loops. Moreover a similar and parallel infrared stable fixed point is present in the Curci-Ferrari and maximal abelian gauges which persists in different schemes including kinematic ones. We verify that with the increased available loop order critical exponent estimates show an improvement in convergence and agreement in the various schemes.
1910.02014
Ben Stefanek
Admir Greljo, Toby Opferkuch, Ben A. Stefanek
Gravitational Imprints of Flavor Hierarchies
6 pages, 4 figures
Phys. Rev. Lett. 124, 171802 (2020)
10.1103/PhysRevLett.124.171802
CERN-TH-2019-162
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The mass hierarchy among the three generations of quarks and charged leptons is one of the greatest mysteries in particle physics. In various flavor models, the origin of this phenomenon is attributed to a series of hierarchical spontaneous symmetry breakings, most of which are beyond the reach of particle colliders. We point out that the observation of a multi-peaked stochastic gravitational wave signal from a series of cosmological phase transitions could well be a unique probe of the mechanism behind flavor hierarchies. To illustrate this point, we show how near future ground- and space-based gravitational wave observatories could detect up to three peaks in the recently proposed $PS^3$ model.
[ { "created": "Fri, 4 Oct 2019 16:13:57 GMT", "version": "v1" } ]
2020-05-06
[ [ "Greljo", "Admir", "" ], [ "Opferkuch", "Toby", "" ], [ "Stefanek", "Ben A.", "" ] ]
The mass hierarchy among the three generations of quarks and charged leptons is one of the greatest mysteries in particle physics. In various flavor models, the origin of this phenomenon is attributed to a series of hierarchical spontaneous symmetry breakings, most of which are beyond the reach of particle colliders. We point out that the observation of a multi-peaked stochastic gravitational wave signal from a series of cosmological phase transitions could well be a unique probe of the mechanism behind flavor hierarchies. To illustrate this point, we show how near future ground- and space-based gravitational wave observatories could detect up to three peaks in the recently proposed $PS^3$ model.
hep-ph/0208042
A. Cooper-Sarkar
V. Chekelian, A.M. Cooper-Sarkar, R. Thorne
The Structure Function Working Group Summary: DIS2002
Summary of WG1:Structure Function Group at Deep Inelastic Scattering 2002 (DIS2002), Krakow, Apr30-May4 2002
Acta Phys.Polon.B33:3075-3098,2002
null
null
hep-ph
null
A summary of the experimental and theoretical presentations in the Structure Function Working Group on the proton and photon unpolarized structure functions is given.
[ { "created": "Mon, 5 Aug 2002 16:00:28 GMT", "version": "v1" } ]
2010-11-30
[ [ "Chekelian", "V.", "" ], [ "Cooper-Sarkar", "A. M.", "" ], [ "Thorne", "R.", "" ] ]
A summary of the experimental and theoretical presentations in the Structure Function Working Group on the proton and photon unpolarized structure functions is given.
2402.14069
Ana Alexandre
Ana Alexandre, Gia Dvali, Emmanouil Koutsangelas
New Mass Window for Primordial Black Holes as Dark Matter from Memory Burden Effect
null
null
null
null
hep-ph astro-ph.CO gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
The mass ranges allowed for Primordial Black Holes (PBHs) to constitute all of Dark Matter (DM) are broadly constrained. However, these constraints rely on the standard semiclassical approximation which assumes that the evaporation process is self-similar. Quantum effects such as memory burden take the evaporation process out of the semiclassical regime latest by half-decay time. What happens beyond this time is currently not known. However, theoretical evidence based on prototype models indicates that the evaporation slows down thereby extending the lifetime of a black hole. This modifies the mass ranges constrained, in particular, by BBN and CMB spectral distortions. We show that previous constraints are largely relaxed when the PBH lifetime is extended, making it possible for PBHs to constitute all of DM in previously excluded mass ranges. In particular, this is the case for PBHs lighter than $10^9$g which enter the memory burden stage before BBN and are still present today as DM.
[ { "created": "Wed, 21 Feb 2024 19:00:20 GMT", "version": "v1" } ]
2024-02-23
[ [ "Alexandre", "Ana", "" ], [ "Dvali", "Gia", "" ], [ "Koutsangelas", "Emmanouil", "" ] ]
The mass ranges allowed for Primordial Black Holes (PBHs) to constitute all of Dark Matter (DM) are broadly constrained. However, these constraints rely on the standard semiclassical approximation which assumes that the evaporation process is self-similar. Quantum effects such as memory burden take the evaporation process out of the semiclassical regime latest by half-decay time. What happens beyond this time is currently not known. However, theoretical evidence based on prototype models indicates that the evaporation slows down thereby extending the lifetime of a black hole. This modifies the mass ranges constrained, in particular, by BBN and CMB spectral distortions. We show that previous constraints are largely relaxed when the PBH lifetime is extended, making it possible for PBHs to constitute all of DM in previously excluded mass ranges. In particular, this is the case for PBHs lighter than $10^9$g which enter the memory burden stage before BBN and are still present today as DM.
hep-ph/9702201
null
Mark W\"usthoff
Large Rapidity Gap Events in Deep Inelastic Scattering
20 pages with 6 ps-figures in the text
Phys.Rev.D56:4311-4321,1997
10.1103/PhysRevD.56.4311
ANL-HEP-PR-97-03
hep-ph
null
Large Rapidity Gap Events in Deep Inelastic Scattering are discussed in terms of lightcone wave functions for quarks and gluons inside the photon. It is shown that this approach is consistent with earlier, conventional Feynman diagram calculations. An updated parametrization for the cross section is given and a numerical analysis presented.
[ { "created": "Fri, 31 Jan 1997 01:19:34 GMT", "version": "v1" } ]
2011-07-19
[ [ "Wüsthoff", "Mark", "" ] ]
Large Rapidity Gap Events in Deep Inelastic Scattering are discussed in terms of lightcone wave functions for quarks and gluons inside the photon. It is shown that this approach is consistent with earlier, conventional Feynman diagram calculations. An updated parametrization for the cross section is given and a numerical analysis presented.
0904.0425
Diogo Rodrigues Boito
Diogo R. Boito, Rafel Escribano, and Matthias Jamin
Dispersive representation of the K pi vector form factor and fits to tau -> K pi nu(tau) and Ke3 data
Talk given at "International Workshop on Effective Field Theories: from the pion to the upsilon", February 2009, Valencia, Spain. 7 pages, 2 figures. PoS style. Minor correction in figure 2
PoS EFT09:064,2009
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, we introduced several dispersive representations for the vector $K\pi$ form factor and fitted them to the Belle spectrum of $\tau \to K \pi \nu_\tau$. Here, we briefly present the model and discuss the results for the slope and curvature of $F_+(s)$ arising from the best fit. Furthermore, we compare the pole position of the charged $K^*(892)$ computed from our model with other results in the literature. Finally, we discuss the prospects of a simultaneous fit to $\tau \to K \pi \nu_\tau$ and $K_{e3}$ spectra.
[ { "created": "Thu, 2 Apr 2009 16:43:24 GMT", "version": "v1" }, { "created": "Wed, 6 May 2009 09:05:51 GMT", "version": "v2" } ]
2009-11-24
[ [ "Boito", "Diogo R.", "" ], [ "Escribano", "Rafel", "" ], [ "Jamin", "Matthias", "" ] ]
Recently, we introduced several dispersive representations for the vector $K\pi$ form factor and fitted them to the Belle spectrum of $\tau \to K \pi \nu_\tau$. Here, we briefly present the model and discuss the results for the slope and curvature of $F_+(s)$ arising from the best fit. Furthermore, we compare the pole position of the charged $K^*(892)$ computed from our model with other results in the literature. Finally, we discuss the prospects of a simultaneous fit to $\tau \to K \pi \nu_\tau$ and $K_{e3}$ spectra.
hep-ph/9510336
Meng Ta-chung
Meng Ta-chung
Theoretical aspects of singly polarized hadron-hadron collisions
Invited talk given at the Workshop on the Prospects of Spin Physics at HERA, DESY Zeuthen, August 28-31, 1995
null
null
FUB-HEP/95-15
hep-ph
null
The special role played by singly polarized high-energy hadron-hadron collisions in Spin Physics is discussed: In such processes, the measured and the calculated quantities can be and have been directly compared with each other --- without data-extrapolation and without sum rules. It is in this kind of processes, where significant asymmetries (up to 30-40\%) have been observed. It is also in this kind of processes, where the obtained data and the predictions of the conventional theories dramatically disagree with each other. Attempts to understand the existing data are briefly summarized. Predictions for further experiments are presented.
[ { "created": "Wed, 18 Oct 1995 14:03:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ta-chung", "Meng", "" ] ]
The special role played by singly polarized high-energy hadron-hadron collisions in Spin Physics is discussed: In such processes, the measured and the calculated quantities can be and have been directly compared with each other --- without data-extrapolation and without sum rules. It is in this kind of processes, where significant asymmetries (up to 30-40\%) have been observed. It is also in this kind of processes, where the obtained data and the predictions of the conventional theories dramatically disagree with each other. Attempts to understand the existing data are briefly summarized. Predictions for further experiments are presented.
hep-ph/0601158
Alain Blondel P
Alain Blondel
Future neutrino oscillation facilities: physics priorities and open issues
based on an Invited plenary presentation at NUFACT05, Frascati, June 2005
Nucl.Phys.Proc.Suppl.155:131-142,2006
10.1016/j.nuclphysbps.2006.02.024
null
hep-ph
null
The recent discovery that neutrinos have mass opens a wide new field of experimentation. Accelerator-made neutrinos are essential. Ideas for future facilities include superbeams beta-beams and neutrino factories, each associated with one or several options for detector systems. A summary of the perceived virtues and shortcomings of these options, and a number of open questions, are presented.
[ { "created": "Thu, 19 Jan 2006 14:40:10 GMT", "version": "v1" }, { "created": "Fri, 20 Jan 2006 18:13:16 GMT", "version": "v2" } ]
2008-11-26
[ [ "Blondel", "Alain", "" ] ]
The recent discovery that neutrinos have mass opens a wide new field of experimentation. Accelerator-made neutrinos are essential. Ideas for future facilities include superbeams beta-beams and neutrino factories, each associated with one or several options for detector systems. A summary of the perceived virtues and shortcomings of these options, and a number of open questions, are presented.
0711.3396
Thomas Walcher
Dieter Drechsel and Thomas Walcher
Hadron structure at low Q^2
55 pages, 47 figures, review
Rev.Mod.Phys.80:731-785,2008
10.1103/RevModPhys.80.731
null
hep-ph
null
This review deals with the structure of hadrons, strongly interacting many-body systems consisting of quarks and gluons. These systems have a size of about 1 fm, which shows up in scattering experiments at low momentum transfers $Q$ in the GeV region. At this scale the running coupling constant of Quantum Chromodynamics (QCD), the established theory of the strong interactions, becomes divergent. It is therefore highly intriguing to explore this theory in the realm of its strong interaction regime. However, the quarks and gluons can not be resolved at the GeV scale but have to be studied through their manifestations in the bound many-body systems, for instance pions, nucleons and their resonances. The review starts with a short overview of QCD at low momentum transfer and a summary of the theoretical apparatus describing the interaction of hadrons with electrons and photons. In the following sections we present the experimental results for the most significant observables studied with the electromagnetic probe: form factors, polarizabilities, excitation spectra, and sum rules. These experimental findings are compared and interpreted with various theoretical approaches to QCD, such as phenomenological models with quarks and pions, dispersion relations as a means to connect observables from different experiments, and, directly based on the QCD lagrangian, chiral perturbation theory and lattice gauge theory.
[ { "created": "Tue, 20 Nov 2007 14:59:29 GMT", "version": "v1" } ]
2009-09-29
[ [ "Drechsel", "Dieter", "" ], [ "Walcher", "Thomas", "" ] ]
This review deals with the structure of hadrons, strongly interacting many-body systems consisting of quarks and gluons. These systems have a size of about 1 fm, which shows up in scattering experiments at low momentum transfers $Q$ in the GeV region. At this scale the running coupling constant of Quantum Chromodynamics (QCD), the established theory of the strong interactions, becomes divergent. It is therefore highly intriguing to explore this theory in the realm of its strong interaction regime. However, the quarks and gluons can not be resolved at the GeV scale but have to be studied through their manifestations in the bound many-body systems, for instance pions, nucleons and their resonances. The review starts with a short overview of QCD at low momentum transfer and a summary of the theoretical apparatus describing the interaction of hadrons with electrons and photons. In the following sections we present the experimental results for the most significant observables studied with the electromagnetic probe: form factors, polarizabilities, excitation spectra, and sum rules. These experimental findings are compared and interpreted with various theoretical approaches to QCD, such as phenomenological models with quarks and pions, dispersion relations as a means to connect observables from different experiments, and, directly based on the QCD lagrangian, chiral perturbation theory and lattice gauge theory.
1401.5355
Sanjin Beni\'c
S. Benic, D. Horvatic, J. Klaric
Recovering the chiral critical end-point via delocalization of quark interactions
title changed, minor changes in text, version to match the one published in PRD
null
10.1103/PhysRevD.89.054025
ZTF-EP-14-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that for the lower branch of the quark condensate and values higher than approximately $-(250 \, \mathrm{MeV})^3$ the chiral critical end-point in the Nambu--Jona-Lasinio model does not occur in the phase diagram. By using lattice motivated non-local quark interactions, we demonstrate that the critical end-point can be recovered. We study this behavior for a range of condensate values and find that the variation in the position of the critical end-point is more pronounced as the condensate is increased.
[ { "created": "Tue, 21 Jan 2014 15:49:02 GMT", "version": "v1" }, { "created": "Thu, 6 Mar 2014 16:54:35 GMT", "version": "v2" } ]
2014-04-01
[ [ "Benic", "S.", "" ], [ "Horvatic", "D.", "" ], [ "Klaric", "J.", "" ] ]
We show that for the lower branch of the quark condensate and values higher than approximately $-(250 \, \mathrm{MeV})^3$ the chiral critical end-point in the Nambu--Jona-Lasinio model does not occur in the phase diagram. By using lattice motivated non-local quark interactions, we demonstrate that the critical end-point can be recovered. We study this behavior for a range of condensate values and find that the variation in the position of the critical end-point is more pronounced as the condensate is increased.
0704.1392
James Libby
J.F. Libby (on behalf of the LHCb Collaboration)
Measuring CP violation in Bs->phi phi with LHCb
Presented at the CKM2006, 4th International Workshop on the CKM Unitarity Triangle
null
null
null
hep-ph
null
Sensitivity studies to the CP-violating parameters of the decay Bs->phi phi with the LHCb experiment are presented. The decay proceeds via a b->s s anti-s gluonic-penguin quark transition, which is sensitive to contributions from beyond the Standard Model particles. A time-dependent angular analysis of simulated data leads to an expected statistical uncertainty of 6 degrees on any new physics induced CP-violating phase for a sample corresponding to 2 fb^{-1} of integrated luminosity. The expected precision on sin2beta from the related decay Bd->phi K0S is also discussed.
[ { "created": "Wed, 11 Apr 2007 10:53:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Libby", "J. F.", "", "on behalf of the LHCb Collaboration" ] ]
Sensitivity studies to the CP-violating parameters of the decay Bs->phi phi with the LHCb experiment are presented. The decay proceeds via a b->s s anti-s gluonic-penguin quark transition, which is sensitive to contributions from beyond the Standard Model particles. A time-dependent angular analysis of simulated data leads to an expected statistical uncertainty of 6 degrees on any new physics induced CP-violating phase for a sample corresponding to 2 fb^{-1} of integrated luminosity. The expected precision on sin2beta from the related decay Bd->phi K0S is also discussed.
hep-ph/0605215
Maxim Pospelov
Maxim Pospelov
Particle physics catalysis of thermal Big Bang Nucleosynthesis
Some typos corrected
Phys.Rev.Lett.98:231301,2007
10.1103/PhysRevLett.98.231301
UVIC-TH-2006-05
hep-ph astro-ph nucl-th
null
We point out that the existence of metastable, tau > 10^3 s, negatively charged electroweak-scale particles (X^-) alters the predictions for lithium and other primordial elemental abundances for A>4 via the formation of bound states with nuclei during BBN. In particular, we show that the bound states of X^- with helium, formed at temperatures of about T=10^8K, lead to the catalytic enhancement of Li6 production, which is eight orders of magnitude more efficient than the standard channel. In particle physics models where subsequent decay of X^- does not lead to large non-thermal BBN effects, this directly translates to the level of sensitivity to the number density of long-lived X^-, particles (\tau>10^5 s) relative to entropy of n_{X^-}/s < 3\times 10^{-17}, which is one of the most stringent probes of electroweak scale remnants known to date.
[ { "created": "Fri, 19 May 2006 19:13:03 GMT", "version": "v1" }, { "created": "Sun, 2 Jul 2006 00:03:40 GMT", "version": "v2" }, { "created": "Thu, 9 Nov 2006 20:48:42 GMT", "version": "v3" }, { "created": "Thu, 15 Mar 2007 07:17:36 GMT", "version": "v4" } ]
2008-11-26
[ [ "Pospelov", "Maxim", "" ] ]
We point out that the existence of metastable, tau > 10^3 s, negatively charged electroweak-scale particles (X^-) alters the predictions for lithium and other primordial elemental abundances for A>4 via the formation of bound states with nuclei during BBN. In particular, we show that the bound states of X^- with helium, formed at temperatures of about T=10^8K, lead to the catalytic enhancement of Li6 production, which is eight orders of magnitude more efficient than the standard channel. In particle physics models where subsequent decay of X^- does not lead to large non-thermal BBN effects, this directly translates to the level of sensitivity to the number density of long-lived X^-, particles (\tau>10^5 s) relative to entropy of n_{X^-}/s < 3\times 10^{-17}, which is one of the most stringent probes of electroweak scale remnants known to date.
1403.0733
Takuya Morozumi
Ryuichi Hotta, Takuya Morozumi, Hiroyuki Takata
Time variation of particle and anti-particle asymmetry in an expanding universe
27pages, 10 figures, The title of the paper is slightly changed. All the formulas including the asymmetry is extended to the case of the scale factor with arbitrary time dependence. The discussion of the application to asymmetric dark matter is also added
Phys. Rev. D 90, 016008 (2014)
10.1103/PhysRevD.90.016008
HUPD1307
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Particle number violating interactions wash out the primordial asymmetry of particle number density generated by some interaction satisfying Sakharov conditions for baryogenesis. In this paper, we study how the primordial asymmetry evolves in time under the presence of particle number violating interactions and in the environment of expanding universe. We introduce a complex scalar model with particle number violating mass terms and calculate the time evolution of the particle number density with non-equilibrium quantum field theory. We show how the time evolution of the number density depends on parameters, including the chemical potential related with the particle number, temperature, size of the particle number violating mass terms, and the expansion rate of the universe. Depending upon whether the chemical potential is larger or smaller than the rest mass of the scalar particle, behaviors of the number density are very different to each other. When the chemical potential is smaller than the mass, the interference among the contribution of oscillators with various momenta reduces the number density in addition to the dilution due to the expansion of universe. In opposite case, the oscillation of the particle number density lasts for a long time and the cancellation due to the interference does not occur.
[ { "created": "Tue, 4 Mar 2014 10:21:45 GMT", "version": "v1" }, { "created": "Wed, 25 Jun 2014 09:51:19 GMT", "version": "v2" } ]
2014-07-23
[ [ "Hotta", "Ryuichi", "" ], [ "Morozumi", "Takuya", "" ], [ "Takata", "Hiroyuki", "" ] ]
Particle number violating interactions wash out the primordial asymmetry of particle number density generated by some interaction satisfying Sakharov conditions for baryogenesis. In this paper, we study how the primordial asymmetry evolves in time under the presence of particle number violating interactions and in the environment of expanding universe. We introduce a complex scalar model with particle number violating mass terms and calculate the time evolution of the particle number density with non-equilibrium quantum field theory. We show how the time evolution of the number density depends on parameters, including the chemical potential related with the particle number, temperature, size of the particle number violating mass terms, and the expansion rate of the universe. Depending upon whether the chemical potential is larger or smaller than the rest mass of the scalar particle, behaviors of the number density are very different to each other. When the chemical potential is smaller than the mass, the interference among the contribution of oscillators with various momenta reduces the number density in addition to the dilution due to the expansion of universe. In opposite case, the oscillation of the particle number density lasts for a long time and the cancellation due to the interference does not occur.
2407.02324
Phung Van Dong
Phung Van Dong, Duong Van Loi, Do Thi Huong, Nguyen Tuan Duy, Dang Van Soa
Dark symmetry implication for right-handed neutrinos
14 pages, 2 figures, 1 table
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We argue that the long-standing issues of neutrino mass and dark matter can be manifestly solved in a dark gauge symmetry $U(1)_D$ that transforms nontrivially only for three right-handed neutrinos $\nu_{1,2,3R}$ -- the counterparts of known left-handed neutrinos. This theory assigns $\nu_{1,2,3R}$ dark charge to be $D=0$, $-1$, and $+1$, respectively, in order for anomaly cancelation. Additionally, it imposes an inert Higgs doublet $\eta$ and two Higgs singlets $\xi,\phi$ with dark charge $D=+1$, $-1$, and $+2$, respectively. That said, the dark symmetry is broken by $\phi$ (by two units) down to a dark parity $P_D=(-1)^D$, for which $\nu_{2,3R}$ and $\eta,\xi$ are odd, whereas all other fields are even due to $D=0$. The lightest of these odd fields is stabilized by $P_D$, responsible for dark matter. Neutrino masses are generated by a scotoseesaw scheme, in which the seesaw part is mediated by $\nu_{1R}$, while the scotogenic part is mediated by $\nu_{2,3R}$, for which the hierarchy of atmospheric and solar neutrino mass splittings is explained.
[ { "created": "Tue, 2 Jul 2024 14:53:03 GMT", "version": "v1" } ]
2024-07-03
[ [ "Van Dong", "Phung", "" ], [ "Van Loi", "Duong", "" ], [ "Huong", "Do Thi", "" ], [ "Duy", "Nguyen Tuan", "" ], [ "Van Soa", "Dang", "" ] ]
We argue that the long-standing issues of neutrino mass and dark matter can be manifestly solved in a dark gauge symmetry $U(1)_D$ that transforms nontrivially only for three right-handed neutrinos $\nu_{1,2,3R}$ -- the counterparts of known left-handed neutrinos. This theory assigns $\nu_{1,2,3R}$ dark charge to be $D=0$, $-1$, and $+1$, respectively, in order for anomaly cancelation. Additionally, it imposes an inert Higgs doublet $\eta$ and two Higgs singlets $\xi,\phi$ with dark charge $D=+1$, $-1$, and $+2$, respectively. That said, the dark symmetry is broken by $\phi$ (by two units) down to a dark parity $P_D=(-1)^D$, for which $\nu_{2,3R}$ and $\eta,\xi$ are odd, whereas all other fields are even due to $D=0$. The lightest of these odd fields is stabilized by $P_D$, responsible for dark matter. Neutrino masses are generated by a scotoseesaw scheme, in which the seesaw part is mediated by $\nu_{1R}$, while the scotogenic part is mediated by $\nu_{2,3R}$, for which the hierarchy of atmospheric and solar neutrino mass splittings is explained.
2405.18755
Giampiero Passarino
Giampiero Passarino (Turin U. and INFN, Turin)
Feynman integrals and Fox functions
99 pages, 4 figures
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we discuss the connection between Feynman integrals and Fox functions. Illustrative examples are given.
[ { "created": "Wed, 29 May 2024 04:41:54 GMT", "version": "v1" } ]
2024-05-30
[ [ "Passarino", "Giampiero", "", "Turin U. and INFN, Turin" ] ]
In this work we discuss the connection between Feynman integrals and Fox functions. Illustrative examples are given.
hep-ph/9507464
null
Yung Su Tsai
Addendum to the Test of CP Violation in Tau Decay
6 page LaTeX file - To obtain a copy, send e-mail to techpub@slac.stanford.edu
null
10.1063/1.49259
SLAC-PUB-95-6967
hep-ph
null
We discuss the test of CP and CPT violation in $\tau$ decay without using the polarized electron beam by comparing partial fractions of $\tau^-$ and $\tau^+$ decay into channels with strong final state interactions. For example, $\Gamma(\tau^-\rarrow \pi^-+\pi^0+\nu) \ne \Gamma(\tau^+\rarrow \pi^++\pi^0+\nu)$ signifies violation of CP. The optimum energy to investigatge CP violation in $\tau$ decay is discussed. We conclude that this energy is a few MeV below $\psi(2s)$ in order to avoid the charm contribution and over abundance of hadrons at the $\psi(2s)$ peak.
[ { "created": "Mon, 31 Jul 1995 22:02:20 GMT", "version": "v1" } ]
2015-06-25
[ [ "Tsai", "Yung Su", "" ] ]
We discuss the test of CP and CPT violation in $\tau$ decay without using the polarized electron beam by comparing partial fractions of $\tau^-$ and $\tau^+$ decay into channels with strong final state interactions. For example, $\Gamma(\tau^-\rarrow \pi^-+\pi^0+\nu) \ne \Gamma(\tau^+\rarrow \pi^++\pi^0+\nu)$ signifies violation of CP. The optimum energy to investigatge CP violation in $\tau$ decay is discussed. We conclude that this energy is a few MeV below $\psi(2s)$ in order to avoid the charm contribution and over abundance of hadrons at the $\psi(2s)$ peak.
2306.02168
Reza Ebadi
Reza Ebadi, David E. Kaplan, Surjeet Rajendran, and Ronald L. Walsworth
Galactic Axion Laser Interferometer Leveraging Electro-Optics: GALILEO
6+4 pages, 2 figures
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We propose a novel experimental method for probing light dark matter candidates. We show that an electro-optical material's refractive index is modified in the presence of a coherently oscillating dark matter background. A high-precision resonant Michelson interferometer can be used to read out this signal. The proposed detection scheme allows for the exploration of an uncharted parameter space of dark matter candidates over a wide range of masses -- including masses exceeding a few tens of microelectronvolts, which is a challenging parameter space for microwave cavity haloscopes.
[ { "created": "Sat, 3 Jun 2023 18:19:44 GMT", "version": "v1" } ]
2023-06-06
[ [ "Ebadi", "Reza", "" ], [ "Kaplan", "David E.", "" ], [ "Rajendran", "Surjeet", "" ], [ "Walsworth", "Ronald L.", "" ] ]
We propose a novel experimental method for probing light dark matter candidates. We show that an electro-optical material's refractive index is modified in the presence of a coherently oscillating dark matter background. A high-precision resonant Michelson interferometer can be used to read out this signal. The proposed detection scheme allows for the exploration of an uncharted parameter space of dark matter candidates over a wide range of masses -- including masses exceeding a few tens of microelectronvolts, which is a challenging parameter space for microwave cavity haloscopes.
1410.4310
Shouhua Zhu
Shou-hua Zhu (Peking U)
Charged Higgs Boson: Tracer of the Physics beyond Standard Model
ICHEP2014 talk, 5 pages
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charged Higgs boson can exist in many physics beyond the standard models (BSM) and it is the obvious BSM signal. We briefly describe why the 125GeV scalar discovered at the LHC must have (heavy) companion: the charged Higgs boson, in a new paradigm. We then focus on the charged Higgs phenomenology, especially on how to measure $\tan\beta$ precisely utilizing the top quark polarization information.
[ { "created": "Thu, 16 Oct 2014 06:43:46 GMT", "version": "v1" } ]
2014-10-17
[ [ "Zhu", "Shou-hua", "", "Peking U" ] ]
Charged Higgs boson can exist in many physics beyond the standard models (BSM) and it is the obvious BSM signal. We briefly describe why the 125GeV scalar discovered at the LHC must have (heavy) companion: the charged Higgs boson, in a new paradigm. We then focus on the charged Higgs phenomenology, especially on how to measure $\tan\beta$ precisely utilizing the top quark polarization information.
hep-ph/0002154
Pierre Sikivie
P. Sikivie (U. of Florida)
Axion Searches
12 pages, 2 figures, based on talks at the TAUP99 Conference (Sept. 6-10, 1999, Paris, France) and at Adrianfest (Sept. 24-25, 1999, Rochester, NY)
Nucl.Phys.Proc.Suppl.87:41-52,2000
10.1016/S0920-5632(00)00628-9
UFIFT-HEP-00-2
hep-ph
null
The strong CP problem and its resolution through the existence of an axion are briefly reviewed. The constraints on the axion from accelerator searches, from the evolution of red giants and from supernova SN1987a combine to require $m_a < 3 \cdot 10^{-3}$ eV, where $m_a$ is the axion mass. On the other hand, the constraint that axions do not overclose the universe implies $m_a \gtwid 10^{-6}$ eV. If $m_a \sim 10^{-5}$ eV, axions contribute significantly to the cosmological energy density in the form of cold dark matter. Dark matter axions can be detected by resonant conversion to microwave photons in a cavity permeated by a static magnetic field and tuned to the axion mass. Experiments using this effect are described, as well as several other types of axion searches.
[ { "created": "Mon, 14 Feb 2000 20:30:06 GMT", "version": "v1" } ]
2014-11-17
[ [ "Sikivie", "P.", "", "U. of Florida" ] ]
The strong CP problem and its resolution through the existence of an axion are briefly reviewed. The constraints on the axion from accelerator searches, from the evolution of red giants and from supernova SN1987a combine to require $m_a < 3 \cdot 10^{-3}$ eV, where $m_a$ is the axion mass. On the other hand, the constraint that axions do not overclose the universe implies $m_a \gtwid 10^{-6}$ eV. If $m_a \sim 10^{-5}$ eV, axions contribute significantly to the cosmological energy density in the form of cold dark matter. Dark matter axions can be detected by resonant conversion to microwave photons in a cavity permeated by a static magnetic field and tuned to the axion mass. Experiments using this effect are described, as well as several other types of axion searches.
1112.3647
Antonio Racioppi
M. Kadastik, K. Kannike, A. Racioppi, and M. Raidal
Implications of the 125 GeV Higgs boson for scalar dark matter and for the CMSSM phenomenology
17 pages, 7 figures. v3: same as published version
JHEP 1205 (2012) 061
10.1007/JHEP05(2012)061
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study phenomenological implications of the ATLAS and CMS hint of a $125\pm 1$ GeV Higgs boson for the singlet, and singlet plus doublet non-supersymmetric dark matter models, and for the phenomenology of the CMSSM. We show that in scalar dark matter models the vacuum stability bound on Higgs boson mass is lower than in the standard model and the 125 GeV Higgs boson is consistent with the models being valid up the GUT or Planck scale. We perform a detailed study of the full CMSSM parameter space keeping the Higgs boson mass fixed to $125\pm 1$ GeV, and study in detail the freeze-out processes that imply the observed amount of dark matter. After imposing all phenomenological constraints except for the muon $(g-2)_\mu,$ we show that the CMSSM parameter space is divided into well separated regions with distinctive but in general heavy sparticle mass spectra. Imposing the $(g-2)_\mu$ constraint introduces severe tension between the high SUSY scale and the experimental measurements -- only the slepton co-annihilation region survives with potentially testable sparticle masses at the LHC. In the latter case the spin-independent DM-nucleon scattering cross section is predicted to be below detectable limit at the XENON100 but might be of measurable magnitude in the general case of light dark matter with large bino-higgsino mixing and unobservably large scalar masses.
[ { "created": "Thu, 15 Dec 2011 20:51:38 GMT", "version": "v1" }, { "created": "Wed, 4 Jan 2012 20:13:58 GMT", "version": "v2" }, { "created": "Thu, 17 Jan 2013 16:45:04 GMT", "version": "v3" } ]
2013-01-18
[ [ "Kadastik", "M.", "" ], [ "Kannike", "K.", "" ], [ "Racioppi", "A.", "" ], [ "Raidal", "M.", "" ] ]
We study phenomenological implications of the ATLAS and CMS hint of a $125\pm 1$ GeV Higgs boson for the singlet, and singlet plus doublet non-supersymmetric dark matter models, and for the phenomenology of the CMSSM. We show that in scalar dark matter models the vacuum stability bound on Higgs boson mass is lower than in the standard model and the 125 GeV Higgs boson is consistent with the models being valid up the GUT or Planck scale. We perform a detailed study of the full CMSSM parameter space keeping the Higgs boson mass fixed to $125\pm 1$ GeV, and study in detail the freeze-out processes that imply the observed amount of dark matter. After imposing all phenomenological constraints except for the muon $(g-2)_\mu,$ we show that the CMSSM parameter space is divided into well separated regions with distinctive but in general heavy sparticle mass spectra. Imposing the $(g-2)_\mu$ constraint introduces severe tension between the high SUSY scale and the experimental measurements -- only the slepton co-annihilation region survives with potentially testable sparticle masses at the LHC. In the latter case the spin-independent DM-nucleon scattering cross section is predicted to be below detectable limit at the XENON100 but might be of measurable magnitude in the general case of light dark matter with large bino-higgsino mixing and unobservably large scalar masses.
hep-ph/9609511
James Wells
Robert Garisto (BNL) and James D. Wells (SLAC)
Constraints on supersymmetric soft phases from renormalization group relations
25 pages, REVTEX.
Phys.Rev.D55:1611-1622,1997
10.1103/PhysRevD.55.1611
SLAC-PUB-7286
hep-ph
null
By using relations derived from renormalization group equations (RGEs), we find that strong indirect constraints can be placed on the top squark mixing phase in At from the electric dipole moment of the neutron (dn). Since mtop is large, any GUT-scale phase in At feeds into other weak scale phases through RGEs, which in turn contribute to dn. Thus CP-violating effects due to a weak-scale At are strongly constrained. We find that |Im At(mz)| must be smaller than or of order |Im B(mz)|, making the electric dipole moment of the top quark unobservably small in most models. Quantitative estimates of the contributions to dn from Au, Ad and B show that substantial fine-tuning is still required to satisfy the experimental bound on dn. While the low energy phases of the A's are not as strongly constrained as the phase of B(mz), we note that the phase of a universal A(GUT) induces large contributions in the phase of B(mz) through RGEs, and is thus still strongly constrained in most models with squark masses below a TeV.
[ { "created": "Sun, 29 Sep 1996 23:54:31 GMT", "version": "v1" } ]
2014-11-17
[ [ "Garisto", "Robert", "", "BNL" ], [ "Wells", "James D.", "", "SLAC" ] ]
By using relations derived from renormalization group equations (RGEs), we find that strong indirect constraints can be placed on the top squark mixing phase in At from the electric dipole moment of the neutron (dn). Since mtop is large, any GUT-scale phase in At feeds into other weak scale phases through RGEs, which in turn contribute to dn. Thus CP-violating effects due to a weak-scale At are strongly constrained. We find that |Im At(mz)| must be smaller than or of order |Im B(mz)|, making the electric dipole moment of the top quark unobservably small in most models. Quantitative estimates of the contributions to dn from Au, Ad and B show that substantial fine-tuning is still required to satisfy the experimental bound on dn. While the low energy phases of the A's are not as strongly constrained as the phase of B(mz), we note that the phase of a universal A(GUT) induces large contributions in the phase of B(mz) through RGEs, and is thus still strongly constrained in most models with squark masses below a TeV.
hep-ph/0509145
Johann Haidenbauer
A. Sibirtsev, J. Haidenbauer, S. Krewald, Ulf-G. Mei{\ss}ner, A.W. Thomas
KKbar photoproduction from protons
updated version, analysis of new CLAS data included, 11 pages, 11 figures
Eur.Phys.J.A31:221-232,2007
10.1140/epja/i2006-10216-4
null
hep-ph nucl-th
null
We study the contribution of the Drell mechanism driven by K^+ and K^- exchange to the reaction gamma N -> KKbar N. Our calculation implements the full KN and KbarN reaction amplitudes in the form of partial wave amplitudes taken from a meson-exchange model (KN) and a partial wave analysis (KbarN), respectively. Comparing our results to data of the LAMP2 collaboration we observe that the Drell mechanism alone cannot describe the large Lambda(1520) photoproduction rate observed experimentally. We argue that the discrepancy could be due to significant contributions from K*-meson exchange with subsequent excitation of the Lambda(1520) resonance. After adding such contributions to our model a good agreement of the LAMP2 experiment is achieved. When applying the same model to the recent SAPHIR data we find an excellent description of the K^+p spectrum and can determine the parameters of the Lambda(1600) P01 resonance, M_R = 1617 +/- 2 MeV and Gamma_R = 117 +/- 4 MeV, from the K^-p mass distribution.
[ { "created": "Wed, 14 Sep 2005 11:56:08 GMT", "version": "v1" }, { "created": "Tue, 26 Sep 2006 13:14:26 GMT", "version": "v2" } ]
2008-11-26
[ [ "Sibirtsev", "A.", "" ], [ "Haidenbauer", "J.", "" ], [ "Krewald", "S.", "" ], [ "Meißner", "Ulf-G.", "" ], [ "Thomas", "A. W.", "" ] ]
We study the contribution of the Drell mechanism driven by K^+ and K^- exchange to the reaction gamma N -> KKbar N. Our calculation implements the full KN and KbarN reaction amplitudes in the form of partial wave amplitudes taken from a meson-exchange model (KN) and a partial wave analysis (KbarN), respectively. Comparing our results to data of the LAMP2 collaboration we observe that the Drell mechanism alone cannot describe the large Lambda(1520) photoproduction rate observed experimentally. We argue that the discrepancy could be due to significant contributions from K*-meson exchange with subsequent excitation of the Lambda(1520) resonance. After adding such contributions to our model a good agreement of the LAMP2 experiment is achieved. When applying the same model to the recent SAPHIR data we find an excellent description of the K^+p spectrum and can determine the parameters of the Lambda(1600) P01 resonance, M_R = 1617 +/- 2 MeV and Gamma_R = 117 +/- 4 MeV, from the K^-p mass distribution.
hep-ph/0602125
Vladimir Kopeliovich Benedikt
Vladimir B. Kopeliovich, Andrei M. Shunderuk (Moscow, INR)
Baryon Spectrum in Large N(C) Chiral Soliton and in Quark Models
28 pages, 3 figures. Language and stylistic amendments, added references, misprints removed. Version prepared for Phys. Rev. D
Phys.Rev. D73 (2006) 094018
10.1103/PhysRevD.73.094018
null
hep-ph
null
Strangeness contents of baryons are calculated within rigid rotator model for arbitrary number of colors $N_c$. The problem of extrapolation to realistic value $N_c=3$ is noted, based on explicit calculations and comparison of rigid rotator and rigid oscillator variants of the model. Some features of exotic baryon spectra ($\{\bar{10}\}, \{27\}$-and $\{35\}$-plets of baryons) obtained in the chiral soliton approach can be understood in terms of simplified quark $(4q\bar{q})$ wave functions. The effective mass of strange antiquark in different SU(3) multiplets of pentaquarks should depend on the particular multiplet, to link the predictions of soliton and quark models. The estimate of the $6_F$ and $\bar{3}_F$ diquarks mass difference can be made from comparison with chiral soliton model results for masses of exotic baryons from different SU(3)-multiplets. The masses of baryons partners with different values of spin $J$ are also estimated.
[ { "created": "Tue, 14 Feb 2006 15:41:15 GMT", "version": "v1" }, { "created": "Tue, 6 Jun 2006 19:18:40 GMT", "version": "v2" } ]
2009-11-11
[ [ "Kopeliovich", "Vladimir B.", "", "Moscow, INR" ], [ "Shunderuk", "Andrei M.", "", "Moscow, INR" ] ]
Strangeness contents of baryons are calculated within rigid rotator model for arbitrary number of colors $N_c$. The problem of extrapolation to realistic value $N_c=3$ is noted, based on explicit calculations and comparison of rigid rotator and rigid oscillator variants of the model. Some features of exotic baryon spectra ($\{\bar{10}\}, \{27\}$-and $\{35\}$-plets of baryons) obtained in the chiral soliton approach can be understood in terms of simplified quark $(4q\bar{q})$ wave functions. The effective mass of strange antiquark in different SU(3) multiplets of pentaquarks should depend on the particular multiplet, to link the predictions of soliton and quark models. The estimate of the $6_F$ and $\bar{3}_F$ diquarks mass difference can be made from comparison with chiral soliton model results for masses of exotic baryons from different SU(3)-multiplets. The masses of baryons partners with different values of spin $J$ are also estimated.
1503.00028
Wei Chao
Wei Chao and Michael J. Ramsey-Musolf
Catalysis of Electroweak Baryogenesis via Fermionic Higgs Portal Dark Matter
6 pages, 1 figure
null
null
ACFI-T15-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate catalysis of electroweak baryogenesis by fermionic Higgs portal dark matter using a two Higgs doublet model augmented by vector-like fermions. The lightest neutral fermion mass eigenstate provides a viable dark matter candidate in the presence of a stabilizing symmetry Z_2 or gauged U(1)_D symmetry. Allowing for a non-vanishing CP-violating phase in the lowest-dimension Higgs portal dark matter interactions allows generation of the observed dark matter relic density while evading direct detection bounds. The same phase provides a source for electroweak baryogenesis. We show that it is possible to obtain the observed abundances of visible and dark matter while satisfying present bounds from electric dipole moment (EDM) searches and direct detection experiments. Improving the present electron (neutron) EDM sensitivity by one (two) orders of magnitude would provide a conclusive test of this scenario.
[ { "created": "Fri, 27 Feb 2015 22:25:29 GMT", "version": "v1" } ]
2015-03-03
[ [ "Chao", "Wei", "" ], [ "Ramsey-Musolf", "Michael J.", "" ] ]
We investigate catalysis of electroweak baryogenesis by fermionic Higgs portal dark matter using a two Higgs doublet model augmented by vector-like fermions. The lightest neutral fermion mass eigenstate provides a viable dark matter candidate in the presence of a stabilizing symmetry Z_2 or gauged U(1)_D symmetry. Allowing for a non-vanishing CP-violating phase in the lowest-dimension Higgs portal dark matter interactions allows generation of the observed dark matter relic density while evading direct detection bounds. The same phase provides a source for electroweak baryogenesis. We show that it is possible to obtain the observed abundances of visible and dark matter while satisfying present bounds from electric dipole moment (EDM) searches and direct detection experiments. Improving the present electron (neutron) EDM sensitivity by one (two) orders of magnitude would provide a conclusive test of this scenario.
1206.4512
Xiao-Gang Wu
Xiao-Gang Wu and Qiang Zhao
The study of Ds1(2460) and Ds1(2536) mixing
6 pages, 4 figures, talk presented by Xiao-Gang Wu at the Sixth International Conference on Quarks and Nuclear Physics (QNP2012), April 16-20, 2012, Palaiseau, France
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this proceeding, we report our recent study of the mixing mechanism between $D_{s1}(2460)$ and $D_{s1}(2536)$. On the basis of Godfrey-Isgur model, we consider the $D^*K$ hadron loop effect on the ${}^3P_1$ and ${}^1P_1$ $c\bar{s}$ states. We construct the propagator matrix of these two-state system, from which we can extract the poles as well as the mixing angles. Through this method, we simultaneously determine the masses, widths and mixing angle of these two physical states and the results agree well with the experimental measurement. Besides the mass shift, we also find that the hadron loop effects can cause a significant shift for the mixing angles from the value determined in the heavy quark symmetry limit.
[ { "created": "Wed, 20 Jun 2012 14:29:44 GMT", "version": "v1" } ]
2012-06-21
[ [ "Wu", "Xiao-Gang", "" ], [ "Zhao", "Qiang", "" ] ]
In this proceeding, we report our recent study of the mixing mechanism between $D_{s1}(2460)$ and $D_{s1}(2536)$. On the basis of Godfrey-Isgur model, we consider the $D^*K$ hadron loop effect on the ${}^3P_1$ and ${}^1P_1$ $c\bar{s}$ states. We construct the propagator matrix of these two-state system, from which we can extract the poles as well as the mixing angles. Through this method, we simultaneously determine the masses, widths and mixing angle of these two physical states and the results agree well with the experimental measurement. Besides the mass shift, we also find that the hadron loop effects can cause a significant shift for the mixing angles from the value determined in the heavy quark symmetry limit.
1106.2433
Fukano Hidenori S
Hidenori S. Fukano, Matti Heikinheimo, Kimmo Tuominen
Flavor constraints in a Bosonic Technicolor model
16 pages, 13 figures
null
10.1103/PhysRevD.84.035017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavor constraints in a bosonic Technicolor model are considered. We illustrate different sources for their origin, and emphasize in particular the role played by the vector states present in the Technicolor model. This feature is the essential difference in comparison to an analogous model with two fundamental Higgs scalar doublets.
[ { "created": "Mon, 13 Jun 2011 13:02:00 GMT", "version": "v1" } ]
2013-05-29
[ [ "Fukano", "Hidenori S.", "" ], [ "Heikinheimo", "Matti", "" ], [ "Tuominen", "Kimmo", "" ] ]
Flavor constraints in a bosonic Technicolor model are considered. We illustrate different sources for their origin, and emphasize in particular the role played by the vector states present in the Technicolor model. This feature is the essential difference in comparison to an analogous model with two fundamental Higgs scalar doublets.
1503.08817
Ibragim Alikhanov
I. Alikhanov
Hidden Glashow resonance in neutrino-nucleus collisions
32 pages, 8 figures. Version accepted for publication in PLB
Phys.Lett.B756:247-253,2016
10.1016/j.physletb.2016.03.009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Today it is widely believed that $s$-channel excitation of an on-shell~$W$ boson, commonly known as the Glashow resonance, can be initiated in matter only by the electron antineutrino in the process $\bar\nu_ee^-\rightarrow W^-$ at the laboratory energy around~6.3~PeV. In this paper we argue that the Glashow resonance within the Standard Model also occurs in neutrino--nucleus collisions. The main conclusions are as follows. 1)~The Glashow resonance can be excited by both~neutrinos and~antineutrinos of all the three flavors scattering in the Coulomb field of a nucleus. 2)~The Glashow resonance in a neutrino--nucleus reaction does not manifest itself as a Breit--Wigner-like peak in the cross section but the latter exhibits instead a slow logarithmic-law growth with the neutrino energy. The resonance turns thus out to be hidden. 3)~More than~$98\%$ of~$W$ bosons produced in the sub-PeV region in neutrino-initiated reactions in water/ice will be from the Glashow resonance. 4)~The vast majority of the Glashow resonance events in a neutrino detector is expected at energies from a few TeV to a few tens of TeV, being mostly initiated by the conventional atmospheric neutrinos dominant in this energy range. Calculations of the cross sections for Glashow resonance excitation on the oxygen nucleus as well as on the proton are carried out in detail. The results of this paper can be useful for studies of neutrino interactions at large volume water/ice neutrino detectors. For example, in the IceCube detector one can expect~0.3 Glashow resonance events with shower-like topologies and the deposited energies above~$300~\text{TeV}$ per year. It is therefore likely already to have at least one Glashow resonance event in the IceCube data set.
[ { "created": "Mon, 30 Mar 2015 19:52:50 GMT", "version": "v1" }, { "created": "Wed, 9 Mar 2016 21:44:06 GMT", "version": "v2" } ]
2016-03-22
[ [ "Alikhanov", "I.", "" ] ]
Today it is widely believed that $s$-channel excitation of an on-shell~$W$ boson, commonly known as the Glashow resonance, can be initiated in matter only by the electron antineutrino in the process $\bar\nu_ee^-\rightarrow W^-$ at the laboratory energy around~6.3~PeV. In this paper we argue that the Glashow resonance within the Standard Model also occurs in neutrino--nucleus collisions. The main conclusions are as follows. 1)~The Glashow resonance can be excited by both~neutrinos and~antineutrinos of all the three flavors scattering in the Coulomb field of a nucleus. 2)~The Glashow resonance in a neutrino--nucleus reaction does not manifest itself as a Breit--Wigner-like peak in the cross section but the latter exhibits instead a slow logarithmic-law growth with the neutrino energy. The resonance turns thus out to be hidden. 3)~More than~$98\%$ of~$W$ bosons produced in the sub-PeV region in neutrino-initiated reactions in water/ice will be from the Glashow resonance. 4)~The vast majority of the Glashow resonance events in a neutrino detector is expected at energies from a few TeV to a few tens of TeV, being mostly initiated by the conventional atmospheric neutrinos dominant in this energy range. Calculations of the cross sections for Glashow resonance excitation on the oxygen nucleus as well as on the proton are carried out in detail. The results of this paper can be useful for studies of neutrino interactions at large volume water/ice neutrino detectors. For example, in the IceCube detector one can expect~0.3 Glashow resonance events with shower-like topologies and the deposited energies above~$300~\text{TeV}$ per year. It is therefore likely already to have at least one Glashow resonance event in the IceCube data set.
0705.0689
Chuan Hung Chen
Chuan-Hung Chen, Chao-Qiang Geng
Unparticle physics on direct CP violation
4 pages, 3 figures, paper revised, references added, new T-odd observables are introduced, published version
Phys.Rev.D76:115003,2007
10.1103/PhysRevD.76.115003
null
hep-ph hep-ex
null
The effects of the peculiar CP conserving phases in unparticle propagators are explored. We find that the phases have a great impact on CP-violation. We adopt the decays $B_{d}\to \pi^{+} \pi^{-}$ and $B_{d}\to \ell^{-}\ell^{+}$ as the illustrators to demonstrate the influences of these phases on the direct CP asymmetries. In particular, we emphasize that unparticle physics is the only model suggested to date that could give the direct CP asymmetries in $B_d\to \ell^{-} \ell^{+}$ as large as 15%. We also point out that the unparticle phases could be probed in $B\to K^* \ell^{+} \ell^{-}$ decays by using T-odd correlations.
[ { "created": "Fri, 4 May 2007 18:32:05 GMT", "version": "v1" }, { "created": "Sat, 14 Jul 2007 16:43:53 GMT", "version": "v2" }, { "created": "Wed, 28 Nov 2007 12:30:16 GMT", "version": "v3" }, { "created": "Thu, 29 Nov 2007 14:38:16 GMT", "version": "v4" } ]
2008-11-26
[ [ "Chen", "Chuan-Hung", "" ], [ "Geng", "Chao-Qiang", "" ] ]
The effects of the peculiar CP conserving phases in unparticle propagators are explored. We find that the phases have a great impact on CP-violation. We adopt the decays $B_{d}\to \pi^{+} \pi^{-}$ and $B_{d}\to \ell^{-}\ell^{+}$ as the illustrators to demonstrate the influences of these phases on the direct CP asymmetries. In particular, we emphasize that unparticle physics is the only model suggested to date that could give the direct CP asymmetries in $B_d\to \ell^{-} \ell^{+}$ as large as 15%. We also point out that the unparticle phases could be probed in $B\to K^* \ell^{+} \ell^{-}$ decays by using T-odd correlations.
1408.1120
Margarete Muhlleitner
S.F. King, M. Muhlleitner, R. Nevzorov and K. Walz
Discovery Prospects for NMSSM Higgs Bosons at the High-Energy Large Hadron Collider
null
Phys. Rev. D 90, 095014 (2014)
10.1103/PhysRevD.90.095014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the discovery prospects for NMSSM Higgs bosons during the 13~TeV run of the LHC. While one of the neutral Higgs bosons is demanded to have a mass around 125~GeV and Standard Model (SM)-like properties, there can be substantially lighter, nearby or heavier Higgs bosons, that have not been excluded yet by LEP, Tevatron or the 8~TeV run of the LHC. The challenge consists in discovering the whole NMSSM Higgs mass spectrum. We present the rates for production and subsequent decay of the neutral NMSSM Higgs bosons in the most promising final states and discuss their possible discovery. The prospects for pinning down the Higgs sector of the Natural NMSSM will be analysed taking into account alternative search channels. We give a series of benchmark scenarios compatible with the experimental constraints, that feature Higgs-to-Higgs decays and entail (exotic) signatures with multi-fermion and/or multi-photon final states. These decay chains furthermore give access to the trilinear Higgs self-couplings. We briefly discuss the possibility of exploiting coupling sum rules in case not all the NMSSM Higgs bosons are discovered.
[ { "created": "Tue, 5 Aug 2014 21:30:50 GMT", "version": "v1" } ]
2014-11-19
[ [ "King", "S. F.", "" ], [ "Muhlleitner", "M.", "" ], [ "Nevzorov", "R.", "" ], [ "Walz", "K.", "" ] ]
We investigate the discovery prospects for NMSSM Higgs bosons during the 13~TeV run of the LHC. While one of the neutral Higgs bosons is demanded to have a mass around 125~GeV and Standard Model (SM)-like properties, there can be substantially lighter, nearby or heavier Higgs bosons, that have not been excluded yet by LEP, Tevatron or the 8~TeV run of the LHC. The challenge consists in discovering the whole NMSSM Higgs mass spectrum. We present the rates for production and subsequent decay of the neutral NMSSM Higgs bosons in the most promising final states and discuss their possible discovery. The prospects for pinning down the Higgs sector of the Natural NMSSM will be analysed taking into account alternative search channels. We give a series of benchmark scenarios compatible with the experimental constraints, that feature Higgs-to-Higgs decays and entail (exotic) signatures with multi-fermion and/or multi-photon final states. These decay chains furthermore give access to the trilinear Higgs self-couplings. We briefly discuss the possibility of exploiting coupling sum rules in case not all the NMSSM Higgs bosons are discovered.
1201.5936
Chung-Lin Shan
Chung-Lin Shan
Background effects on reconstructed WIMP couplings
4 pages, 5 eps figures, to appear in the proceedings of the 12th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2011), September 5-9, 2011, Munich, Germany
null
10.1088/1742-6596/375/1/012007
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, I presented effects of small, but non-negligible unrejected background events on the determinations of WIMP couplings/cross sections.
[ { "created": "Sat, 28 Jan 2012 08:32:39 GMT", "version": "v1" } ]
2015-06-03
[ [ "Shan", "Chung-Lin", "" ] ]
In this talk, I presented effects of small, but non-negligible unrejected background events on the determinations of WIMP couplings/cross sections.
hep-ph/0506160
Muneyuki Ishida
Muneyuki Ishida (Meisei university)
Ground State Baryons in U(12) Scheme
11 pages, uses elsart.cls
Phys.Lett. B627 (2005) 105-112
10.1016/j.physletb.2005.08.100
null
hep-ph
null
The properties of ground-state baryons of light-quarks are investigated in U(12)-classification scheme of hadrons, recently proposed by us. In U(12), in addition to the ordinary 56 of SU(6)SF, the existence of the extra 56 with positive-parity and 70 with negative-parity appear as ground-states in lower mass region. The N(1440), Lambda(1600) and Sigma(1660) have the plausible properties of masses and strong decay widths as the flavor-octet of extra 56, while the ordinary radially-excited octet states are expected not to be observed as resonances because of their large predicted widths of the decays to extra 70 baryons. The extra 70 baryons are not observed directly as resonances for the same reason, except for only the Lambda(1406), of which properties are consistently explained through the singlet-octet mixing. The baryon properties in lower mass regions are consistently explained in U(12) scheme.
[ { "created": "Thu, 16 Jun 2005 09:11:03 GMT", "version": "v1" }, { "created": "Tue, 9 Aug 2005 03:02:46 GMT", "version": "v2" } ]
2009-11-11
[ [ "Ishida", "Muneyuki", "", "Meisei university" ] ]
The properties of ground-state baryons of light-quarks are investigated in U(12)-classification scheme of hadrons, recently proposed by us. In U(12), in addition to the ordinary 56 of SU(6)SF, the existence of the extra 56 with positive-parity and 70 with negative-parity appear as ground-states in lower mass region. The N(1440), Lambda(1600) and Sigma(1660) have the plausible properties of masses and strong decay widths as the flavor-octet of extra 56, while the ordinary radially-excited octet states are expected not to be observed as resonances because of their large predicted widths of the decays to extra 70 baryons. The extra 70 baryons are not observed directly as resonances for the same reason, except for only the Lambda(1406), of which properties are consistently explained through the singlet-octet mixing. The baryon properties in lower mass regions are consistently explained in U(12) scheme.
1804.00184
Gabriel Cozzella
Gabriel Cozzella, Carlo Giunti
Mixed states for mixing neutrinos
11 pages, new discussions about heavy neutrinos and added references
Phys. Rev. D 98, 096010 (2018)
10.1103/PhysRevD.98.096010
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Here we discuss the description of flavor neutrinos produced or detected in processes which involve more than one neutrino. We show that in these cases flavor neutrinos cannot be separately described by pure states, but require a density matrix description. We consider explicitly the examples of $\nu_{e}$ and $\bar\nu_{\mu}$ production in $\mu^{+}$ decay and $\nu_{\mu}$ detection through scattering on electrons. We show that the density matrix which describes a flavor neutrino can be approximated with a density matrix of a pure state only when the differences of the neutrino masses are neglected in the interaction process. In this approximation, the pure states are the standard flavor states and one recovers the standard expression for the neutrino oscillation probability. We discuss also the effects of mixing of the three standard light neutrinos with heavy neutrinos which can be either decoupled because their masses are much larger than the maximum neutrino energy in the neutrino production process or because they are produced and detected incoherently. Finally, we discuss the more complicated case of neutrino-electron elastic scattering, in which the initial and final neutrinos do not have determined flavors, but there is a flavor dependence due to the different contributions of charged-current and neutral-current interactions.
[ { "created": "Sat, 31 Mar 2018 15:31:58 GMT", "version": "v1" }, { "created": "Fri, 6 Apr 2018 19:59:03 GMT", "version": "v2" }, { "created": "Thu, 4 Oct 2018 16:32:39 GMT", "version": "v3" } ]
2018-11-20
[ [ "Cozzella", "Gabriel", "" ], [ "Giunti", "Carlo", "" ] ]
Here we discuss the description of flavor neutrinos produced or detected in processes which involve more than one neutrino. We show that in these cases flavor neutrinos cannot be separately described by pure states, but require a density matrix description. We consider explicitly the examples of $\nu_{e}$ and $\bar\nu_{\mu}$ production in $\mu^{+}$ decay and $\nu_{\mu}$ detection through scattering on electrons. We show that the density matrix which describes a flavor neutrino can be approximated with a density matrix of a pure state only when the differences of the neutrino masses are neglected in the interaction process. In this approximation, the pure states are the standard flavor states and one recovers the standard expression for the neutrino oscillation probability. We discuss also the effects of mixing of the three standard light neutrinos with heavy neutrinos which can be either decoupled because their masses are much larger than the maximum neutrino energy in the neutrino production process or because they are produced and detected incoherently. Finally, we discuss the more complicated case of neutrino-electron elastic scattering, in which the initial and final neutrinos do not have determined flavors, but there is a flavor dependence due to the different contributions of charged-current and neutral-current interactions.
hep-ph/9603213
Martin Hirsch
M. Hirsch, H.V. Klapdor-Kleingrothaus and S.G. Kovalenko
New Leptoquark Mechanism of Neutrinoless Double Beta Decay
LaTeX, 6 pages, 1 figure
Phys.Rev.D54:4207-4210,1996
10.1103/PhysRevD.54.R4207
null
hep-ph
null
A new mechanism for neutrinoless double beta ($\znbb$) decay based on leptoquark exchange is discussed. Due to the specific helicity structure of the effective four-fermion interaction this contribution is strongly enhanced compared to the well-known mass mechanism of $\znbb$ decay. As a result the corresponding leptoquark parameters are severely constrained from non-observation of $\znbb$-decay. These constraints are more stringent than those derived from other experiments.
[ { "created": "Mon, 4 Mar 1996 10:40:19 GMT", "version": "v1" } ]
2009-12-30
[ [ "Hirsch", "M.", "" ], [ "Klapdor-Kleingrothaus", "H. V.", "" ], [ "Kovalenko", "S. G.", "" ] ]
A new mechanism for neutrinoless double beta ($\znbb$) decay based on leptoquark exchange is discussed. Due to the specific helicity structure of the effective four-fermion interaction this contribution is strongly enhanced compared to the well-known mass mechanism of $\znbb$ decay. As a result the corresponding leptoquark parameters are severely constrained from non-observation of $\znbb$-decay. These constraints are more stringent than those derived from other experiments.
1111.7264
Luis Anchordoqui
Luis Alfredo Anchordoqui and Haim Goldberg
Neutrino Cosmology after WMAP and LHC7
References added; to be published in PRL
null
10.1103/PhysRevLett.108.081805
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gauge-extended U(1)_C \times SU(2)_L \times U(1)_{I_R} \times U(1)_L model has the attractive property of elevating the two major global symmetries of the standard model (baryon number B and lepton number L) to local gauge symmetries. The U(1)_L symmetry prevents the generation of Majorana masses, leading to three superweakly interacting right-handed neutrinos. This also renders a B-L symmetry non-anomalous. We show that the superweak interactions of these Dirac states (through their coupling to the TeV-scale B-L gauge boson) permit right-handed neutrino decoupling just above the QCD phase transition: 175 MeV < T_{\nu_R}^{dec} < 250 MeV. In this transitional region, the residual temperature ratio between \nu_L and \nu_R generates extra relativistic degrees of freedom at BBN and at the CMB epochs. Consistency (within 1\sigma) with both WMAP 7-year data and the most recent estimate of the primordial ^4He mass fraction is achieved for 3 TeV < M_{B-L} < 6 TeV. The model is fully predictive, and can be confronted with dijet and dilepton data (or lack thereof) from LHC7 and, eventually, LHC14.
[ { "created": "Wed, 30 Nov 2011 18:27:44 GMT", "version": "v1" }, { "created": "Fri, 30 Dec 2011 15:23:36 GMT", "version": "v2" } ]
2013-05-30
[ [ "Anchordoqui", "Luis Alfredo", "" ], [ "Goldberg", "Haim", "" ] ]
The gauge-extended U(1)_C \times SU(2)_L \times U(1)_{I_R} \times U(1)_L model has the attractive property of elevating the two major global symmetries of the standard model (baryon number B and lepton number L) to local gauge symmetries. The U(1)_L symmetry prevents the generation of Majorana masses, leading to three superweakly interacting right-handed neutrinos. This also renders a B-L symmetry non-anomalous. We show that the superweak interactions of these Dirac states (through their coupling to the TeV-scale B-L gauge boson) permit right-handed neutrino decoupling just above the QCD phase transition: 175 MeV < T_{\nu_R}^{dec} < 250 MeV. In this transitional region, the residual temperature ratio between \nu_L and \nu_R generates extra relativistic degrees of freedom at BBN and at the CMB epochs. Consistency (within 1\sigma) with both WMAP 7-year data and the most recent estimate of the primordial ^4He mass fraction is achieved for 3 TeV < M_{B-L} < 6 TeV. The model is fully predictive, and can be confronted with dijet and dilepton data (or lack thereof) from LHC7 and, eventually, LHC14.
2004.13127
Dmitri Melikhov
Anastasiia Kozachuk and Dmitri Melikhov
Constraints on the anomalous $Wtb$ couplings from $B$-physics experiments
7 pages, extended version. The present analysis involves also exclusive B-decays resulting in more stringent constraints on the anomalous couplings
Symmetry 12, 1506 (2020)
10.3390/sym12091506
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze constraints on the anomalous $Wtb$ couplings from $B$-physics experiments, performing a correlated analysis and allowing all anomalous couplings to differ simultaneously from their Standard-Model (SM) values. The $B$-physics observables allow one to probe three linear combinations out of the four anomalous couplings, which parameterize the $Wtb$ vertex under the assumption that the SM symmetries remain the symmetries of the effective theory. The constraints in this work are obtained by taking into account the following $B$-physics observables: the $\bar B^0-B^0$ oscillations, the leptonic $B\to \mu^+\mu^-$ decays, the inclusive radiative $B\to X_s\gamma$ decays, and the differential branching fractions in the semileptonic inclusive $B\to X_s \mu^+ \mu^-$ and exclusive $B\to (K,K^*)\mu^+\mu^-$ decays at small $q^2$, $q$ the momentum of the $\mu^+\mu^-$ pair. We find that the SM values of the anomalous couplings belong to the 95\% CL allowed region obtained this way but lie beyond the 68\% allowed region. We also report that the distributions of the anomalous couplings obtained within our scenario differ from the results of the 1D scenario, when only one of the couplings is allowed to deviate from its SM value.
[ { "created": "Mon, 27 Apr 2020 19:52:40 GMT", "version": "v1" }, { "created": "Wed, 10 Jun 2020 14:54:17 GMT", "version": "v2" }, { "created": "Thu, 10 Sep 2020 08:38:19 GMT", "version": "v3" } ]
2020-09-15
[ [ "Kozachuk", "Anastasiia", "" ], [ "Melikhov", "Dmitri", "" ] ]
We analyze constraints on the anomalous $Wtb$ couplings from $B$-physics experiments, performing a correlated analysis and allowing all anomalous couplings to differ simultaneously from their Standard-Model (SM) values. The $B$-physics observables allow one to probe three linear combinations out of the four anomalous couplings, which parameterize the $Wtb$ vertex under the assumption that the SM symmetries remain the symmetries of the effective theory. The constraints in this work are obtained by taking into account the following $B$-physics observables: the $\bar B^0-B^0$ oscillations, the leptonic $B\to \mu^+\mu^-$ decays, the inclusive radiative $B\to X_s\gamma$ decays, and the differential branching fractions in the semileptonic inclusive $B\to X_s \mu^+ \mu^-$ and exclusive $B\to (K,K^*)\mu^+\mu^-$ decays at small $q^2$, $q$ the momentum of the $\mu^+\mu^-$ pair. We find that the SM values of the anomalous couplings belong to the 95\% CL allowed region obtained this way but lie beyond the 68\% allowed region. We also report that the distributions of the anomalous couplings obtained within our scenario differ from the results of the 1D scenario, when only one of the couplings is allowed to deviate from its SM value.
2107.03634
Yu-Kuo Hsiao
Shang-Yuu Tsai and Yu-Kuo Hsiao
Semileptonic $B^{-}\to\pi^{+}\pi^{-}\ell^{-}\bar\nu_\ell$ decay with $\pi\pi$ invariant mass spectrum
10 pages, 4 figures, 1 table
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
BELLE has recently reported the measurement of the branching fraction of the semileptonic $B^{-}\to\pi^{+}\pi^{-}\ell^{-}\bar\nu_\ell$ decay, where $\ell$ represents an electron or a muon. With the new information on the $\pi\pi$ invariant mass spectrum, we extract $|V_{ub}|=(3.31\pm 0.61)\times 10^{-3}$ in agreement with those from the other exclusive $B$ decays. In particular, we determine the non-resonant $B\to\pi\pi$ transition form factors, and predict the non-resonant branching fraction ${\cal B}(B^{-}\to\pi^{+}\pi^{-}\ell^{-}\bar\nu_\ell)=(3.5\pm 1.4^{+4.3}_{-2.4})\times 10^{-5}$, which is accessible to the BELLEII and LHCb experiments.
[ { "created": "Thu, 8 Jul 2021 06:59:29 GMT", "version": "v1" } ]
2021-07-09
[ [ "Tsai", "Shang-Yuu", "" ], [ "Hsiao", "Yu-Kuo", "" ] ]
BELLE has recently reported the measurement of the branching fraction of the semileptonic $B^{-}\to\pi^{+}\pi^{-}\ell^{-}\bar\nu_\ell$ decay, where $\ell$ represents an electron or a muon. With the new information on the $\pi\pi$ invariant mass spectrum, we extract $|V_{ub}|=(3.31\pm 0.61)\times 10^{-3}$ in agreement with those from the other exclusive $B$ decays. In particular, we determine the non-resonant $B\to\pi\pi$ transition form factors, and predict the non-resonant branching fraction ${\cal B}(B^{-}\to\pi^{+}\pi^{-}\ell^{-}\bar\nu_\ell)=(3.5\pm 1.4^{+4.3}_{-2.4})\times 10^{-5}$, which is accessible to the BELLEII and LHCb experiments.
0712.4355
Toshimitsu Yamazaki
Toshimitsu Yamazaki
Interplay between Yukawa and Tomonaga in the Birth of Mesons
Invited tals at the Yukawa Centennial Session at INPC07, June, 2007, Tokyo. to be published in NPA. Nucl. Phys. A, in press
Nucl.Phys.A805:29-35,2008; Erratum-ibid.A808:220,2008
10.1016/j.nuclphysa.2008.02.228 10.1016/j.nuclphysa.2008.05.010
null
hep-ph
null
Light is shed on the early stage in the birth of Yukawa's meson theory, particularly on the interplay between Yukawa and Tomonaga in 1933. The discovery of the muon by Nishina' group in 1937 is also reviewed. It is pointed out that Heisenberg's attempt to explain the nuclear force in terms of the Heitler-London scheme, overcome by Yukawa and abandoned since then, is now being revived as a mechanism for a super strong nuclear force caused by a migrating real Kbar meson.
[ { "created": "Thu, 27 Dec 2007 23:42:29 GMT", "version": "v1" }, { "created": "Wed, 19 Mar 2008 15:13:00 GMT", "version": "v2" } ]
2008-11-26
[ [ "Yamazaki", "Toshimitsu", "" ] ]
Light is shed on the early stage in the birth of Yukawa's meson theory, particularly on the interplay between Yukawa and Tomonaga in 1933. The discovery of the muon by Nishina' group in 1937 is also reviewed. It is pointed out that Heisenberg's attempt to explain the nuclear force in terms of the Heitler-London scheme, overcome by Yukawa and abandoned since then, is now being revived as a mechanism for a super strong nuclear force caused by a migrating real Kbar meson.
1711.01801
Arnab Chaudhuri
Arnab Chaudhuri and Alexander Dolgov
Electroweak phase transition and entropy release in the early universe
Main text (10 pages, 1 figure)
null
10.1088/1475-7516/2018/01/032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that the vacuum-like energy of the Higgs potential at non-zero temperatures leads, in the course of the cosmological expansion, to a small but non-negligible rise of the entropy density in the comoving volume. This increase is calculated in the frameworks of the minimal standard model. The result can have a noticeable effect on the outcome of baryo-through-leptogenesis.
[ { "created": "Mon, 6 Nov 2017 09:36:36 GMT", "version": "v1" } ]
2018-01-31
[ [ "Chaudhuri", "Arnab", "" ], [ "Dolgov", "Alexander", "" ] ]
It is shown that the vacuum-like energy of the Higgs potential at non-zero temperatures leads, in the course of the cosmological expansion, to a small but non-negligible rise of the entropy density in the comoving volume. This increase is calculated in the frameworks of the minimal standard model. The result can have a noticeable effect on the outcome of baryo-through-leptogenesis.
hep-ph/0110282
Krzysztof Turzynski
Krzysztof Turzynski
On suppressing the Higgsino-mediated proton decay in SUSY SO(10) GUT's
19 pages, 3 Postscript figures, 2 mpost figures, rearranged plots, corrected typos
JHEP 0210 (2002) 044
10.1088/1126-6708/2002/10/044
IFT 01/29
hep-ph
null
Using the freedom in SO(10) GUT's one can generalize the existing models without changing the mass spectrum of fermions to obtain a significant suppression of proton decay resulting from the baryon number violating operators of dimension 5. In some limiting cases, their contributions can be made negligible compared to the dimension 6 operators resulting from the heavy gauge bosons exchange.
[ { "created": "Mon, 22 Oct 2001 14:02:29 GMT", "version": "v1" }, { "created": "Sun, 13 Jan 2002 17:50:59 GMT", "version": "v2" } ]
2009-11-07
[ [ "Turzynski", "Krzysztof", "" ] ]
Using the freedom in SO(10) GUT's one can generalize the existing models without changing the mass spectrum of fermions to obtain a significant suppression of proton decay resulting from the baryon number violating operators of dimension 5. In some limiting cases, their contributions can be made negligible compared to the dimension 6 operators resulting from the heavy gauge bosons exchange.
1007.1040
Hye-Sung Lee
Hye-Sung Lee
Minimal gauge origin of baryon triality and flavorful signatures at the LHC
Version to appear in PLB
null
10.1016/j.physletb.2011.09.040
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Baryon triality (B3) is a Z3 discrete symmetry that can protect the proton from decay. Although its realization does not require supersymmetry, it is particularly appealing in the supersymmetry as an alternative to the popular R-parity. We discuss the issues in gauging B3, and present the minimal supersymmetric model with B3 as the remnant discrete symmetry of a TeV scale U(1) gauge symmetry. A flavor-dependent U(1) charge is necessary to achieve this, and it results in very distinguishable and flavorful predictions for the LHC experiments. We find a complementarity between a 2-lepton sneutrino resonance and a 4-lepton Z' resonance in the supersymmetry search. In addition, we introduce baryon tetrality (B4), which would play an equivalent role if there are four fermion generations.
[ { "created": "Wed, 7 Jul 2010 03:24:59 GMT", "version": "v1" }, { "created": "Thu, 30 Jun 2011 16:56:58 GMT", "version": "v2" }, { "created": "Mon, 19 Sep 2011 20:30:08 GMT", "version": "v3" } ]
2015-05-19
[ [ "Lee", "Hye-Sung", "" ] ]
Baryon triality (B3) is a Z3 discrete symmetry that can protect the proton from decay. Although its realization does not require supersymmetry, it is particularly appealing in the supersymmetry as an alternative to the popular R-parity. We discuss the issues in gauging B3, and present the minimal supersymmetric model with B3 as the remnant discrete symmetry of a TeV scale U(1) gauge symmetry. A flavor-dependent U(1) charge is necessary to achieve this, and it results in very distinguishable and flavorful predictions for the LHC experiments. We find a complementarity between a 2-lepton sneutrino resonance and a 4-lepton Z' resonance in the supersymmetry search. In addition, we introduce baryon tetrality (B4), which would play an equivalent role if there are four fermion generations.
hep-ph/9901286
Channa B. Paranavitane
C.B. Paranavitane, B.H.J. McKellar and J.P. Ma
The Color Singlet Relativistic Correction in $J/\psi$ Photoproduction
12 pages, 5 figures, LaTex, new figures
null
10.1103/PhysRevD.61.114502
null
hep-ph
null
The $O(v^2)$ relativistic correction for inelastic $J/\psi$ photoproduction, in which heavy quark pairs are in the dominant Fock state of the quarkonium, is studied in the framework of NRQCD factorization. An assessment of its significance, particularly in comparison to the color octet contributions, is made. It is found that the impact on the energy distribution is negative in certain regions of phase space. The predictions are compared with photoproduction data from DESY-HERA.
[ { "created": "Wed, 13 Jan 1999 07:29:36 GMT", "version": "v1" }, { "created": "Mon, 17 Jul 2000 10:01:26 GMT", "version": "v2" }, { "created": "Tue, 18 Jul 2000 04:33:01 GMT", "version": "v3" } ]
2009-10-31
[ [ "Paranavitane", "C. B.", "" ], [ "McKellar", "B. H. J.", "" ], [ "Ma", "J. P.", "" ] ]
The $O(v^2)$ relativistic correction for inelastic $J/\psi$ photoproduction, in which heavy quark pairs are in the dominant Fock state of the quarkonium, is studied in the framework of NRQCD factorization. An assessment of its significance, particularly in comparison to the color octet contributions, is made. It is found that the impact on the energy distribution is negative in certain regions of phase space. The predictions are compared with photoproduction data from DESY-HERA.
1204.3622
Basudeb Dasgupta
Gary Steigman, Basudeb Dasgupta, John F. Beacom
Precise Relic WIMP Abundance and its Impact on Searches for Dark Matter Annihilation
12 Pages, 6 figures. Matches published PRD version. Data for the relic annihilation cross section vs. mass is available as an ancillary file
Phys.Rev. D86 (2012) 023506
10.1103/PhysRevD.86.023506
null
hep-ph astro-ph.CO astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If dark matter (DM) is a weakly interacting massive particle (WIMP) that is a thermal relic of the early Universe, then its total self-annihilation cross section is revealed by its present-day mass density. The canonical thermally averaged cross section for a generic WIMP is usually stated as 3*10^-26 cm^3s^-1, with unspecified uncertainty, and taken to be independent of WIMP mass. Recent searches for annihilation products of DM annihilation have just reached the sensitivity to exclude this canonical cross section for 100% branching ratio to certain final states and small WIMP masses. The ultimate goal is to probe all kinematically allowed final states as a function of mass and, if all states are adequately excluded, set a lower limit to the WIMP mass. Probing the low-mass region is further motivated due to recent hints for a light WIMP in direct and indirect searches. We revisit the thermal relic abundance calculation for a generic WIMP and show that the required cross section can be calculated precisely. It varies significantly with mass at masses below 10 GeV, reaching a maximum of 5.2*10^-26 cm^3s^-1 at masses around 0.3 GeV, and is 2.2*10^-26 cm^3s^-1 with feeble mass-dependence for masses above 10 GeV. These results, which differ significantly from the canonical value and have not been taken into account in searches for annihilation products from generic WIMPs, have a noticeable impact on the interpretation of present limits from Fermi-LAT and WMAP+ACT.
[ { "created": "Mon, 16 Apr 2012 20:00:00 GMT", "version": "v1" }, { "created": "Mon, 30 Apr 2012 17:19:59 GMT", "version": "v2" }, { "created": "Fri, 10 Aug 2012 02:38:16 GMT", "version": "v3" } ]
2012-08-13
[ [ "Steigman", "Gary", "" ], [ "Dasgupta", "Basudeb", "" ], [ "Beacom", "John F.", "" ] ]
If dark matter (DM) is a weakly interacting massive particle (WIMP) that is a thermal relic of the early Universe, then its total self-annihilation cross section is revealed by its present-day mass density. The canonical thermally averaged cross section for a generic WIMP is usually stated as 3*10^-26 cm^3s^-1, with unspecified uncertainty, and taken to be independent of WIMP mass. Recent searches for annihilation products of DM annihilation have just reached the sensitivity to exclude this canonical cross section for 100% branching ratio to certain final states and small WIMP masses. The ultimate goal is to probe all kinematically allowed final states as a function of mass and, if all states are adequately excluded, set a lower limit to the WIMP mass. Probing the low-mass region is further motivated due to recent hints for a light WIMP in direct and indirect searches. We revisit the thermal relic abundance calculation for a generic WIMP and show that the required cross section can be calculated precisely. It varies significantly with mass at masses below 10 GeV, reaching a maximum of 5.2*10^-26 cm^3s^-1 at masses around 0.3 GeV, and is 2.2*10^-26 cm^3s^-1 with feeble mass-dependence for masses above 10 GeV. These results, which differ significantly from the canonical value and have not been taken into account in searches for annihilation products from generic WIMPs, have a noticeable impact on the interpretation of present limits from Fermi-LAT and WMAP+ACT.
2407.01395
Fabian Lange
Fabian Lange, Johann Usovitsch and Zihao Wu
Towards the next Kira release
13 pages, 5 figures, 4 tables, contribution to the proceedings of Loops and Legs in Quantum Field Theory (LL2024), Wittenberg, Germany
null
null
ZU-TH 32/24, PSI-PR-24-14, CERN-TH-2024-096
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
The reduction of Feynman integrals to a basis of master integrals plays a crucial role for many high-precision calculations and Kira is one of the leading tools for this task. In these proceedings we discuss some of the new features and improvements currently being developed for the next release.
[ { "created": "Mon, 1 Jul 2024 15:47:05 GMT", "version": "v1" } ]
2024-07-02
[ [ "Lange", "Fabian", "" ], [ "Usovitsch", "Johann", "" ], [ "Wu", "Zihao", "" ] ]
The reduction of Feynman integrals to a basis of master integrals plays a crucial role for many high-precision calculations and Kira is one of the leading tools for this task. In these proceedings we discuss some of the new features and improvements currently being developed for the next release.