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2312.13349
Pablo Quilez
Benjam\'in Grinstein, Xiaochuan Lu, Luca Merlo and Pablo Qu\'ilez
Hilbert series for covariants and their applications to Minimal Flavor Violation
96 pages, 16 tables
null
null
IFT-UAM-CSIC-23-67
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We elaborate how to apply the Hilbert series method to enumerating group covariants, which transform under any given representation, including but going beyond group invariants. Mathematically, group covariants form a module over the ring of the invariants. The number of independent covariants is given by the rank of the module, which can be computed by taking a ratio of two Hilbert series. In many cases, the rank equals the dimension of the group covariant representation. When this happens, we say that there is a \textit{rank saturation}. We apply this technology to revisit the hypothesis of Minimal Flavor Violation in constructing Effective Field Theories beyond the Standard Model. We find that rank saturation is guaranteed in this case, leading to the important consequence that the MFV symmetry principle does not impose any restriction on the EFT, \textit{i.e.} MFV SMEFT = SMEFT, in the absence of additional assumptions.
[ { "created": "Wed, 20 Dec 2023 19:00:01 GMT", "version": "v1" } ]
2023-12-22
[ [ "Grinstein", "Benjamín", "" ], [ "Lu", "Xiaochuan", "" ], [ "Merlo", "Luca", "" ], [ "Quílez", "Pablo", "" ] ]
We elaborate how to apply the Hilbert series method to enumerating group covariants, which transform under any given representation, including but going beyond group invariants. Mathematically, group covariants form a module over the ring of the invariants. The number of independent covariants is given by the rank of the module, which can be computed by taking a ratio of two Hilbert series. In many cases, the rank equals the dimension of the group covariant representation. When this happens, we say that there is a \textit{rank saturation}. We apply this technology to revisit the hypothesis of Minimal Flavor Violation in constructing Effective Field Theories beyond the Standard Model. We find that rank saturation is guaranteed in this case, leading to the important consequence that the MFV symmetry principle does not impose any restriction on the EFT, \textit{i.e.} MFV SMEFT = SMEFT, in the absence of additional assumptions.
1804.10468
Yusuke Shimizu
Sin Kyu Kang, Yusuke Shimizu, Kenta Takagi, Shunya Takahashi, Morimitsu Tanimoto
Revisiting $A_4$ model for leptons in light of NuFIT 3.2
21 pages, 14 figures
Prog Theor Exp Phys (2018)
10.1093/ptep/pty080
HUPD1801
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the $A_4$ model for leptons in light of new result of NuFIT 3.2. We introduce a new flavon $\eta$ transforming as $A_4$ singlet $1'$ or $1"$ which couples to both charged leptons and neutrinos in next-leading order operators. The model consists of the five parameters: the lightest neutrino mass $m_1$, the vacuum expectation value of $\eta$ and three CP violating phases after inputting the experimental values of $\Delta m_{\rm atm}^2$ and $\Delta m_{\rm sol}^2$. The model with the $1"$ singlet flavon gives the prediction of $\sin^2 \theta_{12}$ around the best fit of NuFIT 3.2 while keeping near the maximal mixing of $\theta_{23}$. Inputting the experimental mixing angles with the $1\,\sigma$ error-bar, the Dirac CP violating phase is clearly predicted to be $|\delta_\text{CP}|=50^\circ- 120^\circ$, which will be tested by the precise observed value in the future. In order to get the best fit value $\sin^2\theta_{23}=0.538$, the sum of three neutrino masses is predicted to be larger than $90\,$meV. The cosmological observation for the sum of neutrino masses will also provide a crucial test of our predictions. It is remarked that the model is consistent with the experimental data only for the normal hierarchy of neutrino masses.
[ { "created": "Fri, 27 Apr 2018 12:34:30 GMT", "version": "v1" } ]
2019-12-06
[ [ "Kang", "Sin Kyu", "" ], [ "Shimizu", "Yusuke", "" ], [ "Takagi", "Kenta", "" ], [ "Takahashi", "Shunya", "" ], [ "Tanimoto", "Morimitsu", "" ] ]
We revisit the $A_4$ model for leptons in light of new result of NuFIT 3.2. We introduce a new flavon $\eta$ transforming as $A_4$ singlet $1'$ or $1"$ which couples to both charged leptons and neutrinos in next-leading order operators. The model consists of the five parameters: the lightest neutrino mass $m_1$, the vacuum expectation value of $\eta$ and three CP violating phases after inputting the experimental values of $\Delta m_{\rm atm}^2$ and $\Delta m_{\rm sol}^2$. The model with the $1"$ singlet flavon gives the prediction of $\sin^2 \theta_{12}$ around the best fit of NuFIT 3.2 while keeping near the maximal mixing of $\theta_{23}$. Inputting the experimental mixing angles with the $1\,\sigma$ error-bar, the Dirac CP violating phase is clearly predicted to be $|\delta_\text{CP}|=50^\circ- 120^\circ$, which will be tested by the precise observed value in the future. In order to get the best fit value $\sin^2\theta_{23}=0.538$, the sum of three neutrino masses is predicted to be larger than $90\,$meV. The cosmological observation for the sum of neutrino masses will also provide a crucial test of our predictions. It is remarked that the model is consistent with the experimental data only for the normal hierarchy of neutrino masses.
hep-ph/0212010
Howard E. Haber
Howard E. Haber
Decoupling and the radiatively-corrected MSSM Higgs sector
6 pages, 1 figure, LaTeX with npb.sty, talk at RADCOR-2002 - Loops and Legs 2002, Kloster Banz, Germany, 8-13 September 2002
Nucl.Phys.Proc.Suppl. 116 (2003) 291-295
10.1016/S0920-5632(03)80186-X
SCIPP-02/27
hep-ph
null
In the decoupling limit of a non-minimal Higgs sector, the lightest CP-even Higgs boson (h) is indistinguishable from the Standard Model (SM) Higgs boson. In the two-Higgs-doublet sector of the MSSM, the approach to the decoupling limit (for m_A>>m_Z) persists, even in the presence of potentially large (tan(beta)-enhanced) radiative corrections to the hbb coupling. Radiative corrections can also generate an accidental cancellation between tree-level and one-loop terms, resulting in a SM-like Higgs boson for moderate m_A outside the decoupling regime.
[ { "created": "Sun, 1 Dec 2002 10:26:01 GMT", "version": "v1" } ]
2009-11-07
[ [ "Haber", "Howard E.", "" ] ]
In the decoupling limit of a non-minimal Higgs sector, the lightest CP-even Higgs boson (h) is indistinguishable from the Standard Model (SM) Higgs boson. In the two-Higgs-doublet sector of the MSSM, the approach to the decoupling limit (for m_A>>m_Z) persists, even in the presence of potentially large (tan(beta)-enhanced) radiative corrections to the hbb coupling. Radiative corrections can also generate an accidental cancellation between tree-level and one-loop terms, resulting in a SM-like Higgs boson for moderate m_A outside the decoupling regime.
2010.06458
Bindu Anubha Bambah
Abhishek Kumar Jha, Akshay Chatla and Bindu A. Bambah
Quantum simulation of oscillating neutrinos
8 pages, 6 figures, Prepared for the proceedings of The 5th International Conference on Particle Physics and Astrophysics (ICPPA-2020), Moscow, Russia, 5th-9th October,2020. New version has new references in introduction
null
null
null
hep-ph hep-ex quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Two and three flavor oscillating neutrinos are shown to exhibit the properties bipartite and tripartite quantum entanglement. The two and three flavor neutrinos are mapped to qubit states used in quantum information theory. Such quantum bits of the neutrino state can be encoded on a IBMQ computer using quantum computing as a tool. We show the implementation of entanglement in the two neutrino system on the IBM quantum processor.
[ { "created": "Tue, 13 Oct 2020 15:12:31 GMT", "version": "v1" }, { "created": "Sun, 25 Oct 2020 07:56:20 GMT", "version": "v2" } ]
2020-10-27
[ [ "Jha", "Abhishek Kumar", "" ], [ "Chatla", "Akshay", "" ], [ "Bambah", "Bindu A.", "" ] ]
Two and three flavor oscillating neutrinos are shown to exhibit the properties bipartite and tripartite quantum entanglement. The two and three flavor neutrinos are mapped to qubit states used in quantum information theory. Such quantum bits of the neutrino state can be encoded on a IBMQ computer using quantum computing as a tool. We show the implementation of entanglement in the two neutrino system on the IBM quantum processor.
2012.07761
Alexander Parkhomenko
Ahmed Ali, Luciano Maiani, Alexander Parkhomenko, Wei Wang
Tetraquark Interpretation and Production Mechanism of the Belle $Y_b (10750)$-Resonance
6 pages, 1 figure. Contribution to the Proceedings of the 40th ICHEP2020 Conference, Prague, Czech Republic (Virtual Conference)
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Recently, the Belle Collaboration has updated the analysis of the cross sections for the processes $e^+ e^- \to \Upsilon(nS)\, \pi^+ \pi^-$ ($n = 1,\, 2,\, 3$) in the $e^+ e^-$ center-of-mass energy range from 10.52 to 11.02~GeV. A new structure, called $Y_b (10750)$, with the mass $M (Y_b) = (10752.7 \pm 5.9^{+0.7}_{-1.1})$~MeV and the Breit-Wigner width $\Gamma (Y_b) = (35.5^{+17.6 +3.9}_{-11.3 -3.3})$~MeV was observed. We interpret $Y_b (10750)$ as a compact $J^{PC} = 1^{--}$ state with a dominant tetraquark component. The mass eigenstate $Y_b (10750)$ is treated as a linear combination of the diquark-antidiquark and $b \bar b$ components due to the mixing via gluonic exchanges shown recently to arise in the limit of large number of quark colors. The mixing angle between $Y_b$ and $\Upsilon(5S)$ can be estimated from the electronic width, recently determined to be $\Gamma_{ee} (Y_b) = (13.7 \pm 1.8)$~eV. The mixing provides a plausible mechanism for $Y_b (10750)$ production in high energy collisions from its $b \bar b$ component and we work out the Drell-Yan and prompt production cross sections for $p p \to Y_b (10750) \to \Upsilon (nS)\, \pi^+ \pi^-$ at the LHC. The resonant part of the dipion invariant mass spectrum in $Y_b (10750) \to \Upsilon (1S)\, \pi^+ \pi^-$ and the corresponding angular distribution of $\pi^+$-meson in the dipion rest frame are presented.
[ { "created": "Mon, 14 Dec 2020 17:58:28 GMT", "version": "v1" } ]
2020-12-15
[ [ "Ali", "Ahmed", "" ], [ "Maiani", "Luciano", "" ], [ "Parkhomenko", "Alexander", "" ], [ "Wang", "Wei", "" ] ]
Recently, the Belle Collaboration has updated the analysis of the cross sections for the processes $e^+ e^- \to \Upsilon(nS)\, \pi^+ \pi^-$ ($n = 1,\, 2,\, 3$) in the $e^+ e^-$ center-of-mass energy range from 10.52 to 11.02~GeV. A new structure, called $Y_b (10750)$, with the mass $M (Y_b) = (10752.7 \pm 5.9^{+0.7}_{-1.1})$~MeV and the Breit-Wigner width $\Gamma (Y_b) = (35.5^{+17.6 +3.9}_{-11.3 -3.3})$~MeV was observed. We interpret $Y_b (10750)$ as a compact $J^{PC} = 1^{--}$ state with a dominant tetraquark component. The mass eigenstate $Y_b (10750)$ is treated as a linear combination of the diquark-antidiquark and $b \bar b$ components due to the mixing via gluonic exchanges shown recently to arise in the limit of large number of quark colors. The mixing angle between $Y_b$ and $\Upsilon(5S)$ can be estimated from the electronic width, recently determined to be $\Gamma_{ee} (Y_b) = (13.7 \pm 1.8)$~eV. The mixing provides a plausible mechanism for $Y_b (10750)$ production in high energy collisions from its $b \bar b$ component and we work out the Drell-Yan and prompt production cross sections for $p p \to Y_b (10750) \to \Upsilon (nS)\, \pi^+ \pi^-$ at the LHC. The resonant part of the dipion invariant mass spectrum in $Y_b (10750) \to \Upsilon (1S)\, \pi^+ \pi^-$ and the corresponding angular distribution of $\pi^+$-meson in the dipion rest frame are presented.
2307.07476
Alessandro Granelli
Alessandro Granelli, Silvia Pascoli and Serguey T. Petcov
Low-Scale Leptogenesis with Low-Energy Dirac CP-Violation
7 pages, 2 figures; matches version published in PRD
Phys. Rev. D 108 (2023) L101302
10.1103/PhysRevD.108.L101302
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the freeze-in scenario of leptogenesis via oscillations within the type-I seesaw model with two quasi-degenerate heavy Majorana neutrinos $N_{1,\,2}$ having masses $M_2 > M_1 \sim (0.1-100)\,\text{GeV}$, $(M_2-M_1)/M_1 \ll 1$, focusing on the role of the CP-violation provided by the Dirac phase $\delta$ of the Pontecorvo-Maki-Nakagawa-Sakata lepton mixing matrix. We find that viable leptogenesis can be due solely to CP-violating values of $\delta$ and that the $N_{1,\,2}$ total mixing squared $\Theta^2=\sum_\alpha\Theta^2_\alpha$ needed is within the reach of future experiments, $\Theta_\alpha$ parameterising the coupling to the charged lepton $\alpha=e,\,\mu,\,\tau$. Furthermore, the required parameter space differs from that associated with additional Casas-Ibarra sources of CP-violation. Future determination of $\delta$, $\Theta^2$ and/or the ratios $\Theta_\tau^2:\Theta^2_\mu:\Theta^2_e$ would provide a critical test of the considered scenario.
[ { "created": "Fri, 14 Jul 2023 16:56:06 GMT", "version": "v1" }, { "created": "Wed, 8 Nov 2023 17:45:46 GMT", "version": "v2" } ]
2023-11-09
[ [ "Granelli", "Alessandro", "" ], [ "Pascoli", "Silvia", "" ], [ "Petcov", "Serguey T.", "" ] ]
We study the freeze-in scenario of leptogenesis via oscillations within the type-I seesaw model with two quasi-degenerate heavy Majorana neutrinos $N_{1,\,2}$ having masses $M_2 > M_1 \sim (0.1-100)\,\text{GeV}$, $(M_2-M_1)/M_1 \ll 1$, focusing on the role of the CP-violation provided by the Dirac phase $\delta$ of the Pontecorvo-Maki-Nakagawa-Sakata lepton mixing matrix. We find that viable leptogenesis can be due solely to CP-violating values of $\delta$ and that the $N_{1,\,2}$ total mixing squared $\Theta^2=\sum_\alpha\Theta^2_\alpha$ needed is within the reach of future experiments, $\Theta_\alpha$ parameterising the coupling to the charged lepton $\alpha=e,\,\mu,\,\tau$. Furthermore, the required parameter space differs from that associated with additional Casas-Ibarra sources of CP-violation. Future determination of $\delta$, $\Theta^2$ and/or the ratios $\Theta_\tau^2:\Theta^2_\mu:\Theta^2_e$ would provide a critical test of the considered scenario.
hep-ph/9303233
null
Peter N. Maher, Loyal Durand, and Kurt Riesselmann
Two-loop renormalization constants and high energy $2\rightarrow 2$ scattering amplitudes in the Higgs sector of the standard model
47 pages, 7 figures available by request to LD, RevTEX 3.0, MAD/TH/93-1
Phys.Rev.D48:1061,1993; Erratum-ibid.D52:553,1995; Phys.Rev.D52:553,1995
10.1103/PhysRevD.48.1061 10.1103/PhysRevD.52.553
null
hep-ph
null
We calculate the complete matrix of two-body scattering amplitudes for the scattering of longitudinally polarized gauge bosons $W_L^\pm$, $Z_L$ and Higgs bosons to two loops in the high-energy, heavy-Higgs limit $\sqrt{s}\gg M_H\gg M_W$. Use of the Goldstone boson equivalence theorem reduces the problem to one involving only the scalar fields $w^\pm$, $z$ (the Goldstone bosons of the original theory) and the Higgs boson. Renormalization of the scattering amplitudes requires the calculation of the self-energy functions $\Pi _i^0(M_i^2)$, the renormalization constants $Z_i$, and the bare quartic Higgs coupling $\lambda _0$ to two loops. The results will be useful in other calculations. To facilitate the calculations, we introduce a powerful new technique for evaluating integrals over Feynman parameters in dimensional regularization which is based on a Barnes' type representation of the binomial expansion. We also collect some useful integrals which extend the tables given by Devoto and Duke.
[ { "created": "Tue, 9 Mar 1993 14:38:00 GMT", "version": "v1" } ]
2014-11-17
[ [ "Maher", "Peter N.", "" ], [ "Durand", "Loyal", "" ], [ "Riesselmann", "Kurt", "" ] ]
We calculate the complete matrix of two-body scattering amplitudes for the scattering of longitudinally polarized gauge bosons $W_L^\pm$, $Z_L$ and Higgs bosons to two loops in the high-energy, heavy-Higgs limit $\sqrt{s}\gg M_H\gg M_W$. Use of the Goldstone boson equivalence theorem reduces the problem to one involving only the scalar fields $w^\pm$, $z$ (the Goldstone bosons of the original theory) and the Higgs boson. Renormalization of the scattering amplitudes requires the calculation of the self-energy functions $\Pi _i^0(M_i^2)$, the renormalization constants $Z_i$, and the bare quartic Higgs coupling $\lambda _0$ to two loops. The results will be useful in other calculations. To facilitate the calculations, we introduce a powerful new technique for evaluating integrals over Feynman parameters in dimensional regularization which is based on a Barnes' type representation of the binomial expansion. We also collect some useful integrals which extend the tables given by Devoto and Duke.
0904.3360
Hiroshi Nunokawa
A. M. Gago, H. Minakata, H. Nunokawa, S. Uchinami and R. Zukanovich Funchal
Resolving CP Violation by Standard and Nonstandard Interactions and Parameter Degeneracy in Neutrino Oscillations
43 pages, 28 figures, version accepted for publication in JHEP
JHEP 1001:049,2010
10.1007/JHEP01(2010)049
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In neutrino oscillation with non-standard interactions (NSI) the system is enriched with CP violation caused by phases due to NSI in addition to the standard lepton Kobayashi-Maskawa phase \delta. In this paper we show that it is possible to disentangle the two CP violating effects by measurement of muon neutrino appearance by a near-far two detector setting in neutrino factory experiments. Prior to the quantitative analysis we investigate in detail the various features of the neutrino oscillations with NSI, but under the assumption that only one of the NSI elements, \epsilon_{e \mu} or \epsilon_{e \tau}, is present. They include synergy between the near and the far detectors, the characteristic differences between the \epsilon_{e \mu} and \epsilon_{e\tau} systems, and in particular, the parameter degeneracy. Finally, we use a concrete setting with the muon energy of 50 GeV and magnetized iron detectors at two baselines, one at L=3000 km and the other at L=7000 km, each having a fiducial mass of 50 kton to study the discovery potential of NSI and its CP violation effects. We demonstrate, by assuming 4 \times 10^{21} useful muon decays for both polarities, that one can identify non-standard CP violation down to | epsilon_{e \mu} | \simeq \text{a few} \times 10^{-3}, and | \epsilon_{e \tau} | \simeq 10^{-2} at 3\sigma CL for \theta_{13} down to \sin^2 2\theta_{13} = 10^{-4} in most of the region of \delta. The impact of the existence of NSI on the measurement of \delta and the mass hierarchy is also worked out.
[ { "created": "Tue, 21 Apr 2009 22:53:31 GMT", "version": "v1" }, { "created": "Mon, 4 May 2009 21:29:29 GMT", "version": "v2" }, { "created": "Wed, 23 Dec 2009 20:12:09 GMT", "version": "v3" } ]
2010-01-22
[ [ "Gago", "A. M.", "" ], [ "Minakata", "H.", "" ], [ "Nunokawa", "H.", "" ], [ "Uchinami", "S.", "" ], [ "Funchal", "R. Zukanovich", "" ] ]
In neutrino oscillation with non-standard interactions (NSI) the system is enriched with CP violation caused by phases due to NSI in addition to the standard lepton Kobayashi-Maskawa phase \delta. In this paper we show that it is possible to disentangle the two CP violating effects by measurement of muon neutrino appearance by a near-far two detector setting in neutrino factory experiments. Prior to the quantitative analysis we investigate in detail the various features of the neutrino oscillations with NSI, but under the assumption that only one of the NSI elements, \epsilon_{e \mu} or \epsilon_{e \tau}, is present. They include synergy between the near and the far detectors, the characteristic differences between the \epsilon_{e \mu} and \epsilon_{e\tau} systems, and in particular, the parameter degeneracy. Finally, we use a concrete setting with the muon energy of 50 GeV and magnetized iron detectors at two baselines, one at L=3000 km and the other at L=7000 km, each having a fiducial mass of 50 kton to study the discovery potential of NSI and its CP violation effects. We demonstrate, by assuming 4 \times 10^{21} useful muon decays for both polarities, that one can identify non-standard CP violation down to | epsilon_{e \mu} | \simeq \text{a few} \times 10^{-3}, and | \epsilon_{e \tau} | \simeq 10^{-2} at 3\sigma CL for \theta_{13} down to \sin^2 2\theta_{13} = 10^{-4} in most of the region of \delta. The impact of the existence of NSI on the measurement of \delta and the mass hierarchy is also worked out.
hep-ph/0210085
Matthias Neubert
Martin Beneke (Aachen) and Matthias Neubert (Cornell)
Flavor-Singlet B-Decay Amplitudes in QCD Factorization
25 pages, 5 figures
Nucl.Phys.B651:225-248,2003
10.1016/S0550-3213(02)01091-X
CLNS-02/1802, PITHA-02/14
hep-ph
null
Exclusive hadronic B-meson decays into two-body final states consisting of a light pseudoscalar or vector meson along with an eta or eta' meson are of great phenomenological interest. Their theoretical analysis involves decay mechanisms that are unique to flavor-singlet states, such as their coupling to gluons or their ``intrinsic charm'' content. These issues are studied systematically in the context of QCD factorization and the heavy-quark expansion. Theory can account for the experimental data on the B->K^{(*)} eta^{(')} branching fractions, albeit within large uncertainties.
[ { "created": "Fri, 4 Oct 2002 20:35:41 GMT", "version": "v1" } ]
2011-01-27
[ [ "Beneke", "Martin", "", "Aachen" ], [ "Neubert", "Matthias", "", "Cornell" ] ]
Exclusive hadronic B-meson decays into two-body final states consisting of a light pseudoscalar or vector meson along with an eta or eta' meson are of great phenomenological interest. Their theoretical analysis involves decay mechanisms that are unique to flavor-singlet states, such as their coupling to gluons or their ``intrinsic charm'' content. These issues are studied systematically in the context of QCD factorization and the heavy-quark expansion. Theory can account for the experimental data on the B->K^{(*)} eta^{(')} branching fractions, albeit within large uncertainties.
hep-ph/9407227
Asher Gotsman
E. Gotsman, E.M. Levin and U. Maor
The Role of Screening Corrections in High Energy Photoproduction
12 pages (Replacement due to PostScript file problem in previous posting)
Phys.Lett. B347 (1995) 424-430
10.1016/0370-2693(95)00075-V
null
hep-ph
null
The role of screening corrections, calculated using the eikonal model, is discussed in the context of soft photoproduction. We present a comprehensive calculation considering the total,elastic and diffractive cross sections jointly. We examine the differences between our results and those obtained from the supercritical Pomeron-Reggeon model with no unitarity corrections.
[ { "created": "Tue, 5 Jul 1994 12:57:47 GMT", "version": "v1" }, { "created": "Sun, 10 Jul 1994 13:20:57 GMT", "version": "v2" }, { "created": "Mon, 11 Jul 1994 14:40:32 GMT", "version": "v3" } ]
2009-10-28
[ [ "Gotsman", "E.", "" ], [ "Levin", "E. M.", "" ], [ "Maor", "U.", "" ] ]
The role of screening corrections, calculated using the eikonal model, is discussed in the context of soft photoproduction. We present a comprehensive calculation considering the total,elastic and diffractive cross sections jointly. We examine the differences between our results and those obtained from the supercritical Pomeron-Reggeon model with no unitarity corrections.
hep-ph/0412298
Paul Romatschke
Eduardo S. Fraga and Paul Romatschke
The role of quark mass in cold and dense perturbative QCD
5 pages REVTEX4, 4 figures; minor changes, matches published version
Phys.Rev. D71 (2005) 105014
10.1103/PhysRevD.71.105014
BI-TP 2004/39
hep-ph astro-ph nucl-th
null
We consider the equation of state of QCD at high density and zero temperature in perturbation theory to first order in the coupling constant $\alpha_s$. We compute the thermodynamic potential including the effect of a non-vanishing mass for the strange quark and show that corrections are sizable. Renormalization group running of the coupling and the strange quark mass plays a crucial role. The structure of quark stars is dramatically modified.
[ { "created": "Tue, 21 Dec 2004 07:02:41 GMT", "version": "v1" }, { "created": "Fri, 27 May 2005 12:56:42 GMT", "version": "v2" } ]
2009-11-10
[ [ "Fraga", "Eduardo S.", "" ], [ "Romatschke", "Paul", "" ] ]
We consider the equation of state of QCD at high density and zero temperature in perturbation theory to first order in the coupling constant $\alpha_s$. We compute the thermodynamic potential including the effect of a non-vanishing mass for the strange quark and show that corrections are sizable. Renormalization group running of the coupling and the strange quark mass plays a crucial role. The structure of quark stars is dramatically modified.
hep-ph/9602313
Alexander Moroz
Alexander Moroz and Jan Fischer
A Surprise in Sum Rules - Modulating Factors
12 pp, plain latex + 1 ps figure uuencoded
null
null
TH-CERN/96-39, TPBU-95-06
hep-ph cond-mat hep-th quant-ph
null
A generic physical situation is considered where Im $\Pi$, the imaginary part of polarization operator (generalized susceptibility), can be measured on a finite interval and the high frequency asymptotics (up to a few orders) of $\Pi$ can be calculated theoretically. In such a case, it is desirable to derive an equivalent form of the Kramers-Kronig dispersion relation, the so-called sum rule, in which both the high-frequency part of Im $\Pi$ in the dispersion integral and the high-order contribution to $\Pi$ are suppressed. We provide a general framework for derivation of such sum rules, without any recourse to an infinite-order differential operator. We derive sum rules for a wide set of weight functions and show that any departure from the $e^{-t}$ behaviour of the weight function in sum rules leads to modulating factors on the theoretical side of sum rules, providing its low frequency regularization. We argue that by including modulating factors one can extend the domain of validity of sum rules further to an intermediate region of frequencies and can account for ``bumps" which were observed numerically on the phenomenological side of sum rules at ``intermediate'' frequencies.
[ { "created": "Wed, 14 Feb 1996 19:22:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Moroz", "Alexander", "" ], [ "Fischer", "Jan", "" ] ]
A generic physical situation is considered where Im $\Pi$, the imaginary part of polarization operator (generalized susceptibility), can be measured on a finite interval and the high frequency asymptotics (up to a few orders) of $\Pi$ can be calculated theoretically. In such a case, it is desirable to derive an equivalent form of the Kramers-Kronig dispersion relation, the so-called sum rule, in which both the high-frequency part of Im $\Pi$ in the dispersion integral and the high-order contribution to $\Pi$ are suppressed. We provide a general framework for derivation of such sum rules, without any recourse to an infinite-order differential operator. We derive sum rules for a wide set of weight functions and show that any departure from the $e^{-t}$ behaviour of the weight function in sum rules leads to modulating factors on the theoretical side of sum rules, providing its low frequency regularization. We argue that by including modulating factors one can extend the domain of validity of sum rules further to an intermediate region of frequencies and can account for ``bumps" which were observed numerically on the phenomenological side of sum rules at ``intermediate'' frequencies.
0801.1662
Yang Bai
Yang Bai
Mini Little Higgs and Dark Matter
5 pages, 2 figures; added references; final version in PLB
Phys.Lett.B666:332-335,2008
10.1016/j.physletb.2008.07.082
FERMILAB-PUB-08-001-T
hep-ph astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a little Higgs model with the most minimal extension of the standard model gauge group by an extra U(1) gauge symmetry. For specific charge assignments of scalars, an approximate U(3) global symmetry appears in the cutoff-squared scalar mass terms generated from gauge bosons at one-loop level. Hence, the Higgs boson, identified as a pseudo-Goldstone boson of the broken global symmetry, has its mass radiatively protected up to scales of 5-10 TeV. In this model, a Z2 symmetry, ensuring the two U(1) gauge groups to be identical, also makes the extra massive neutral gauge boson stable and a viable dark matter candidate with a promising prospect of direct detection.
[ { "created": "Thu, 10 Jan 2008 20:30:20 GMT", "version": "v1" }, { "created": "Mon, 25 Aug 2008 04:40:10 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bai", "Yang", "" ] ]
We construct a little Higgs model with the most minimal extension of the standard model gauge group by an extra U(1) gauge symmetry. For specific charge assignments of scalars, an approximate U(3) global symmetry appears in the cutoff-squared scalar mass terms generated from gauge bosons at one-loop level. Hence, the Higgs boson, identified as a pseudo-Goldstone boson of the broken global symmetry, has its mass radiatively protected up to scales of 5-10 TeV. In this model, a Z2 symmetry, ensuring the two U(1) gauge groups to be identical, also makes the extra massive neutral gauge boson stable and a viable dark matter candidate with a promising prospect of direct detection.
2402.15673
Xingyu Guo
Xingyu Guo, Jinfeng Liao, and Hongxi Xing
Studying exotic hadrons in high energy nuclear collisions
4 pages, 4 figures, contribution to the proceeding of Quark Matter 2023. arXiv admin note: text overlap with arXiv:2302.03828
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Studies of exotic hadrons such as the $\chi_{cl}(3872)$ state provide crucial insights into the fundamental force governing the strong interaction dynamics, with an emerging new frontier to investigate their production in high energy nuclear collisions where a partonic medium is present. This contribution discusses the production mechanisms of exotic hadrons in such collisions and analyzes novel effects from the partonic medium, demonstrating the potential to use heavy ion measurements for deciphering their internal structure and understanding their in-medium evolutions.
[ { "created": "Sat, 24 Feb 2024 01:12:33 GMT", "version": "v1" } ]
2024-02-27
[ [ "Guo", "Xingyu", "" ], [ "Liao", "Jinfeng", "" ], [ "Xing", "Hongxi", "" ] ]
Studies of exotic hadrons such as the $\chi_{cl}(3872)$ state provide crucial insights into the fundamental force governing the strong interaction dynamics, with an emerging new frontier to investigate their production in high energy nuclear collisions where a partonic medium is present. This contribution discusses the production mechanisms of exotic hadrons in such collisions and analyzes novel effects from the partonic medium, demonstrating the potential to use heavy ion measurements for deciphering their internal structure and understanding their in-medium evolutions.
hep-ph/0105072
Per Osland
A.I. Davydychev (Mainz), P. Osland, L. Saks (Bergen)
Quark mass dependence of the one-loop three-gluon vertex in arbitrary dimension
21 pages, including 2 figures
JHEP 0108:050,2001
10.1088/1126-6708/2001/08/050
MZ-TH/01-14
hep-ph
null
The one-loop off-shell massive quark contribution to the three-gluon vertex is calculated in an arbitrary space-time dimension. The results for all relevant on-shell and symmetric limits are obtained directly from the general off-shell results. The analytic structure of the results for the relevant massive scalar integrals is also discussed.
[ { "created": "Tue, 8 May 2001 16:57:02 GMT", "version": "v1" } ]
2010-02-03
[ [ "Davydychev", "A. I.", "", "Mainz" ], [ "Osland", "P.", "", "Bergen" ], [ "Saks", "L.", "", "Bergen" ] ]
The one-loop off-shell massive quark contribution to the three-gluon vertex is calculated in an arbitrary space-time dimension. The results for all relevant on-shell and symmetric limits are obtained directly from the general off-shell results. The analytic structure of the results for the relevant massive scalar integrals is also discussed.
hep-ph/9209239
null
Peter Cho and Howard Georgi
Electromagnetic Interactions in Heavy Hadron Chiral Theory
12 pages, 0 figures
Phys.Lett.B296:408-414,1992; ERRATUM-ibid.B300:410,1993
10.1016/0370-2693(92)91340-F
HUTP-92/A043
hep-ph
null
Electromagnetic interactions are incorporated into Heavy Hadron Chiral Perturbation Theory. Short and long distance magnetic moment contributions to the chiral Lagrangian are identified, and $M1$ radiative decays of heavy vector mesons and sextet baryons are studied. Using recent CLEO $D^*$ branching fraction ratio data, we fit the meson coupling to the axial vector Goldstone current and find $g_1^2 = 0.34 \pm 0.48$ for $\mc = 1700 \MeV$. Finally, we obtain model independent predictions for total and partial widths of charm and bottom vector mesons.
[ { "created": "Tue, 15 Sep 1992 21:37:04 GMT", "version": "v1" } ]
2009-09-11
[ [ "Cho", "Peter", "" ], [ "Georgi", "Howard", "" ] ]
Electromagnetic interactions are incorporated into Heavy Hadron Chiral Perturbation Theory. Short and long distance magnetic moment contributions to the chiral Lagrangian are identified, and $M1$ radiative decays of heavy vector mesons and sextet baryons are studied. Using recent CLEO $D^*$ branching fraction ratio data, we fit the meson coupling to the axial vector Goldstone current and find $g_1^2 = 0.34 \pm 0.48$ for $\mc = 1700 \MeV$. Finally, we obtain model independent predictions for total and partial widths of charm and bottom vector mesons.
hep-ph/9705356
Yuval Grossman
Yuval Grossman and Helen R. Quinn
Removing Discrete Ambiguities in CP Asymmetry Measurements
23 pages, revtex, no figures
Phys. Rev. D 56, 7259 (1997)
10.1103/PhysRevD.56.7259
SLAC-PUB-7454
hep-ph
null
We discuss methods to resolve the ambiguities in CP violating phase angles $\phi$ that are left when a measurement of $\sin 2 \phi$ is made. We show what knowledge of hadronic quantities will be needed to fully resolve all such ambiguities.
[ { "created": "Mon, 19 May 1997 20:06:00 GMT", "version": "v1" } ]
2016-08-25
[ [ "Grossman", "Yuval", "" ], [ "Quinn", "Helen R.", "" ] ]
We discuss methods to resolve the ambiguities in CP violating phase angles $\phi$ that are left when a measurement of $\sin 2 \phi$ is made. We show what knowledge of hadronic quantities will be needed to fully resolve all such ambiguities.
0810.5443
Carlo Giunti
H.L. Ge, C. Giunti, Q.Y. Liu
Bayesian Constraints on theta_{13} from Solar and KamLAND Neutrino Data
21 pages. Final version published in Phys. Rev. D 80 (2009) 053009
Phys.Rev.D80:053009,2009
10.1103/PhysRevD.80.053009
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the results of a Bayesian analysis of solar and KamLAND neutrino data in the framework of three-neutrino mixing. We adopt two approaches for the prior probability distribution of the oscillation parameters Delta m^2_{21}, sin^2 theta_{12}, sin^2 theta_{13}: 1) a traditional flat uninformative prior; 2) an informative prior which describes the limits on sin^2 theta_{13} obtained in atmospheric and long-baseline accelerator and reactor neutrino experiments. In both approaches, we present the allowed regions in the sin^2 theta_{13} - Delta m^2_{21} and sin^2 theta_{12} - sin^2 theta_{13} planes, as well as the marginal posterior probability distribution of sin^2 theta_{13}. We confirm the 1.2 sigma hint of theta_{13} > 0 found in hep-ph/0806.2649 from the analysis of solar and KamLAND neutrino data. We found that the statistical significance of the hint is reduced to about 0.8 sigma by the constraints on sin^2 theta_{13} coming from atmospheric and long-baseline accelerator and reactor neutrino data, in agreement with arXiv:0808.2016.
[ { "created": "Thu, 30 Oct 2008 08:43:15 GMT", "version": "v1" }, { "created": "Mon, 30 Mar 2009 12:10:12 GMT", "version": "v2" }, { "created": "Wed, 30 Sep 2009 11:58:04 GMT", "version": "v3" } ]
2010-04-28
[ [ "Ge", "H. L.", "" ], [ "Giunti", "C.", "" ], [ "Liu", "Q. Y.", "" ] ]
We present the results of a Bayesian analysis of solar and KamLAND neutrino data in the framework of three-neutrino mixing. We adopt two approaches for the prior probability distribution of the oscillation parameters Delta m^2_{21}, sin^2 theta_{12}, sin^2 theta_{13}: 1) a traditional flat uninformative prior; 2) an informative prior which describes the limits on sin^2 theta_{13} obtained in atmospheric and long-baseline accelerator and reactor neutrino experiments. In both approaches, we present the allowed regions in the sin^2 theta_{13} - Delta m^2_{21} and sin^2 theta_{12} - sin^2 theta_{13} planes, as well as the marginal posterior probability distribution of sin^2 theta_{13}. We confirm the 1.2 sigma hint of theta_{13} > 0 found in hep-ph/0806.2649 from the analysis of solar and KamLAND neutrino data. We found that the statistical significance of the hint is reduced to about 0.8 sigma by the constraints on sin^2 theta_{13} coming from atmospheric and long-baseline accelerator and reactor neutrino data, in agreement with arXiv:0808.2016.
1209.1866
Masaki Yasue
Masaki Yasue
Generalized Scaling in Flavor Neutrino Masses
12 pages, 8 figures, Abstract modified, Sec.2 and Sec.3 reconstructed, 3 figures removed
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scaling in flavor neutrino masses $M_{ij}$ ($i,j$=$e,\mu,\tau$) can be described by two angles: $\theta_{SC}$ and the atmospheric neutrino mixing angle $\theta_{23}$. For $A$=${\cos ^2}{\theta_{SC}}+{\sin ^2}{\theta_{SC}}t_{23}^4$ and B=${\cos ^2}{\theta_{SC}}-{\sin ^2}{\theta_{SC}}t_{23}^2$, where $t_{23}=\tan\theta_{23}$, our scaling ansatz dictates that $M_{i\tau}/M_{i\mu}$ = $- \kappa_it_{23}$ ($i$=$e,\mu,\tau$) with $\kappa_e$=1, $\kappa_\mu$=B/A and $\kappa_\tau$=1/B and leads to the vanishing reactor neutrino mixing angle $\theta_{13}=0$. This generalized scaling is naturally realized in seesaw textures. To obtain $\theta_{13}\neq 0$ as required by the recent experimental results, we introduce breaking terms of scaling ansatz, which are taken to keep $M_{\mu\tau}/M_{\mu\mu}$ = $- \kappa_\mu t_{23}$ intact even at $\theta_{13}\neq 0$. We derive relations that connect CP violating phases with phases of flavor neutrino masses, which are found to be numerically supported. The angle $\theta_{SC}$ is observed to be $0.91 \lesssim\sin^2\theta_{SC}\lesssim 0.93$ for the normal mass hierarchy and $\sin^2\theta_{SC}\lesssim 0.33$ for the inverted mass hierarchy. Also observed is the size of $|M_{ee}|$ to be measured in neutrinoless double beta decay, which is 0.001-0.004 eV (0.02 eV-0.05 eV) in the normal (inverted) mass hierarchy.
[ { "created": "Mon, 10 Sep 2012 02:04:34 GMT", "version": "v1" }, { "created": "Sun, 7 Oct 2012 13:02:17 GMT", "version": "v2" } ]
2012-10-09
[ [ "Yasue", "Masaki", "" ] ]
Scaling in flavor neutrino masses $M_{ij}$ ($i,j$=$e,\mu,\tau$) can be described by two angles: $\theta_{SC}$ and the atmospheric neutrino mixing angle $\theta_{23}$. For $A$=${\cos ^2}{\theta_{SC}}+{\sin ^2}{\theta_{SC}}t_{23}^4$ and B=${\cos ^2}{\theta_{SC}}-{\sin ^2}{\theta_{SC}}t_{23}^2$, where $t_{23}=\tan\theta_{23}$, our scaling ansatz dictates that $M_{i\tau}/M_{i\mu}$ = $- \kappa_it_{23}$ ($i$=$e,\mu,\tau$) with $\kappa_e$=1, $\kappa_\mu$=B/A and $\kappa_\tau$=1/B and leads to the vanishing reactor neutrino mixing angle $\theta_{13}=0$. This generalized scaling is naturally realized in seesaw textures. To obtain $\theta_{13}\neq 0$ as required by the recent experimental results, we introduce breaking terms of scaling ansatz, which are taken to keep $M_{\mu\tau}/M_{\mu\mu}$ = $- \kappa_\mu t_{23}$ intact even at $\theta_{13}\neq 0$. We derive relations that connect CP violating phases with phases of flavor neutrino masses, which are found to be numerically supported. The angle $\theta_{SC}$ is observed to be $0.91 \lesssim\sin^2\theta_{SC}\lesssim 0.93$ for the normal mass hierarchy and $\sin^2\theta_{SC}\lesssim 0.33$ for the inverted mass hierarchy. Also observed is the size of $|M_{ee}|$ to be measured in neutrinoless double beta decay, which is 0.001-0.004 eV (0.02 eV-0.05 eV) in the normal (inverted) mass hierarchy.
1609.01018
Yi Liao
Shu-Yuan Guo (Nankai U.), Zhi-Long Han (Nankai U.), Yi Liao (Nankai U., ITP, Beijing, CHEP, Peking U.)
Testing Type II Radiative Seesaw Model: from Dark Matter Detection to LHC Signatures
v1: 27 pages, 10 figures, 5 tables; v2: added a few refs, without other changes
Phys. Rev. D 94, 115014 (2016)
10.1103/PhysRevD.94.115014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse the testability of the type II radiative seesaw in which neutrino mass and dark matter (DM) are related at one-loop level. Under the constraints from DM relic density, direct and indirect detection, and invisible Higgs decays, we find three possible regions of DM mass $M_{s_1}$ that can survive the present and even the future experiments: (1) the Higgs resonance region with $M_{s_1}\sim M_h/2$, (2) the Higgs region with $M_{s_1}\sim M_h$, and (3) the coannihilation region with $M_{s_2}\sim M_{s_1}$. Here $s_{1,2}$ are two scalar singlets with the lighter $s_1$ being the DM candidate. Based on DM properties and direct collider constraints, we choose three benchmark points to illustrate the testability of this model at LHC. We perform a detailed simulation of the four-lepton and tri-lepton signatures at 13 (14) TeV LHC. While both signatures are found to be promising at all benchmark points, the tri-lepton one is even better: it is possible to reach the $5\sigma$ significance with an integrated luminosity of 100/fb.
[ { "created": "Mon, 5 Sep 2016 02:19:58 GMT", "version": "v1" }, { "created": "Sun, 11 Sep 2016 14:24:16 GMT", "version": "v2" } ]
2016-12-14
[ [ "Guo", "Shu-Yuan", "", "Nankai U." ], [ "Han", "Zhi-Long", "", "Nankai U." ], [ "Liao", "Yi", "", "Nankai\n U., ITP, Beijing, CHEP, Peking U." ] ]
We analyse the testability of the type II radiative seesaw in which neutrino mass and dark matter (DM) are related at one-loop level. Under the constraints from DM relic density, direct and indirect detection, and invisible Higgs decays, we find three possible regions of DM mass $M_{s_1}$ that can survive the present and even the future experiments: (1) the Higgs resonance region with $M_{s_1}\sim M_h/2$, (2) the Higgs region with $M_{s_1}\sim M_h$, and (3) the coannihilation region with $M_{s_2}\sim M_{s_1}$. Here $s_{1,2}$ are two scalar singlets with the lighter $s_1$ being the DM candidate. Based on DM properties and direct collider constraints, we choose three benchmark points to illustrate the testability of this model at LHC. We perform a detailed simulation of the four-lepton and tri-lepton signatures at 13 (14) TeV LHC. While both signatures are found to be promising at all benchmark points, the tri-lepton one is even better: it is possible to reach the $5\sigma$ significance with an integrated luminosity of 100/fb.
hep-ph/0309180
Carsten van de Bruck
Ph. Brax, C. van de Bruck, A.-C. Davis and C.S. Rhodes
Branes at low energy
5 pages, one figure; contribution to the proceedings of the Marseille conference "Where cosmology and fundamental physics meet"
null
null
null
hep-ph astro-ph hep-th
null
Brane models at low energy are described by an effective action involving gravity and two moduli fields associated with the brane positions. The scalar-tensor nature of the effective theory and the coupling to matter are explicitly spelt out. We discuss the post-Newtonian gravitational constraints on the models, some applications to quintessence and the variations of constants.
[ { "created": "Tue, 16 Sep 2003 10:32:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Brax", "Ph.", "" ], [ "van de Bruck", "C.", "" ], [ "Davis", "A. -C.", "" ], [ "Rhodes", "C. S.", "" ] ]
Brane models at low energy are described by an effective action involving gravity and two moduli fields associated with the brane positions. The scalar-tensor nature of the effective theory and the coupling to matter are explicitly spelt out. We discuss the post-Newtonian gravitational constraints on the models, some applications to quintessence and the variations of constants.
0807.4598
Vali Bashiry
K. Zeynali, V. Bashiry
Exclusive $B \rar \rho \ell^+ \ell^-$ Decay in the Standard Model with Fourth--Generation
17 pages, 7 figures
Phys.Rev.D78:033001,2008
10.1103/PhysRevD.78.033001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the influence of the fourth generation of quarks on the branching ratio, the CP-asymmetry and the polarization asymmetries in $B \rar \rho \ell^+ \ell^-$ decay. Taking $|V_{t'd}V_{t'b}|\sim 0.001$ with phase about $10^\circ$, which is consistent with the $sin2\phi_1$ of the CKM and the $B_d$ mixing parameter $\Delta m_{B_d}$, we obtain that for both ($\mu, \tau$) channels the branching ratio is increased and the magnitude of CP-asymmetry and polarization asymmetries decreased by the mass and mixing parameters of the 4th generation of quarks . These results can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation of quarks($t', b')$ via its indirect manifestations in loop diagrams.
[ { "created": "Tue, 29 Jul 2008 08:11:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Zeynali", "K.", "" ], [ "Bashiry", "V.", "" ] ]
We investigate the influence of the fourth generation of quarks on the branching ratio, the CP-asymmetry and the polarization asymmetries in $B \rar \rho \ell^+ \ell^-$ decay. Taking $|V_{t'd}V_{t'b}|\sim 0.001$ with phase about $10^\circ$, which is consistent with the $sin2\phi_1$ of the CKM and the $B_d$ mixing parameter $\Delta m_{B_d}$, we obtain that for both ($\mu, \tau$) channels the branching ratio is increased and the magnitude of CP-asymmetry and polarization asymmetries decreased by the mass and mixing parameters of the 4th generation of quarks . These results can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation of quarks($t', b')$ via its indirect manifestations in loop diagrams.
2105.12018
Andres Daniel Perez
Ernesto Arganda, Anibal D. Medina, Andres D. Perez, Alejandro Szynkman
Towards a method to anticipate dark matter signals with deep learning at the LHC
52 pages, 29 figures, 3 tables. v2: Added a subsection to briefly discuss and compare event-by-event combination versus histogram or ensemble classifiers. v3: minor changes
SciPost Phys. 12, 063 (2022)
10.21468/SciPostPhys.12.2.063
null
hep-ph cs.LG hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study several simplified dark matter (DM) models and their signatures at the LHC using neural networks. We focus on the usual monojet plus missing transverse energy channel, but to train the algorithms we organize the data in 2D histograms instead of event-by-event arrays. This results in a large performance boost to distinguish between standard model (SM) only and SM plus new physics signals. We use the kinematic monojet features as input data which allow us to describe families of models with a single data sample. We found that the neural network performance does not depend on the simulated number of background events if they are presented as a function of $S/\sqrt{B}$, where $S$ and $B$ are the number of signal and background events per histogram, respectively. This provides flexibility to the method, since testing a particular model in that case only requires knowing the new physics monojet cross section. Furthermore, we also discuss the network performance under incorrect assumptions about the true DM nature. Finally, we propose multimodel classifiers to search and identify new signals in a more general way, for the next LHC run.
[ { "created": "Tue, 25 May 2021 15:38:13 GMT", "version": "v1" }, { "created": "Sat, 7 Aug 2021 01:13:19 GMT", "version": "v2" }, { "created": "Fri, 3 Dec 2021 15:46:24 GMT", "version": "v3" } ]
2022-03-09
[ [ "Arganda", "Ernesto", "" ], [ "Medina", "Anibal D.", "" ], [ "Perez", "Andres D.", "" ], [ "Szynkman", "Alejandro", "" ] ]
We study several simplified dark matter (DM) models and their signatures at the LHC using neural networks. We focus on the usual monojet plus missing transverse energy channel, but to train the algorithms we organize the data in 2D histograms instead of event-by-event arrays. This results in a large performance boost to distinguish between standard model (SM) only and SM plus new physics signals. We use the kinematic monojet features as input data which allow us to describe families of models with a single data sample. We found that the neural network performance does not depend on the simulated number of background events if they are presented as a function of $S/\sqrt{B}$, where $S$ and $B$ are the number of signal and background events per histogram, respectively. This provides flexibility to the method, since testing a particular model in that case only requires knowing the new physics monojet cross section. Furthermore, we also discuss the network performance under incorrect assumptions about the true DM nature. Finally, we propose multimodel classifiers to search and identify new signals in a more general way, for the next LHC run.
hep-ph/0108004
Youngjoon Kwon
C.S. Kim, Y. Kwon, Jake Lee, and W. Namgung
Test of Factorization Hypothesis from Exclusive Non-leptonic B decays
11 pages; submitted to PRD
Phys.Rev. D65 (2002) 097503
10.1103/PhysRevD.65.097503
null
hep-ph
null
We investigate the possibility of testing factorization hypothesis in non-leptonic exclusive decays of B-meson. In particular, we considered the non factorizable \bar{B^0} -> D^{(*)+} D_s^{(*)-} modes and \bar{B^0} -> D^{(*)+} (\pi^-, \rho^-) known as well-factorizable modes. By taking the ratios BR(\bar{B^0}-> D^{(*)+}D_s^{(*)-})/BR(\bar{B^0}-> D^{(*)+}(\pi^-,\rho^-)), we found that under the present theoretical and experimental uncertainties there's no evidence for the breakdown of factorization description to heavy-heavy decays of the B meson.
[ { "created": "Wed, 1 Aug 2001 15:40:01 GMT", "version": "v1" } ]
2009-11-07
[ [ "Kim", "C. S.", "" ], [ "Kwon", "Y.", "" ], [ "Lee", "Jake", "" ], [ "Namgung", "W.", "" ] ]
We investigate the possibility of testing factorization hypothesis in non-leptonic exclusive decays of B-meson. In particular, we considered the non factorizable \bar{B^0} -> D^{(*)+} D_s^{(*)-} modes and \bar{B^0} -> D^{(*)+} (\pi^-, \rho^-) known as well-factorizable modes. By taking the ratios BR(\bar{B^0}-> D^{(*)+}D_s^{(*)-})/BR(\bar{B^0}-> D^{(*)+}(\pi^-,\rho^-)), we found that under the present theoretical and experimental uncertainties there's no evidence for the breakdown of factorization description to heavy-heavy decays of the B meson.
2204.00543
Patrick Barry
P. C. Barry, C. Egerer, J. Karpie, W. Melnitchouk, C. Monahan, K. Orginos, Jian-Wei Qiu, D. Richards, N. Sato, R. S. Sufian, S. Zafeiropoulos
Complementarity of experimental and lattice QCD data on pion parton distributions
47 pages, 15 figures
null
10.1103/PhysRevD.105.114051
JLAB-THY-22-3592
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extract pion parton distribution functions (PDFs) in a Monte Carlo global QCD analysis of experimental data together with reduced Ioffe time pseudo-distributions and matrix elements of current-current correlators generated from lattice QCD. By including both experimental and lattice QCD data, our analysis rigorously quantifies both the uncertainties of the pion PDFs and systematic effects intrinsic to the lattice QCD observables. The reduced Ioffe time pseudo-distributions significantly decrease the uncertainties on the PDFs, while the current-current correlators are limited by the systematic effects associated with the lattice. Consistent with recent phenomenological determinations, the behavior of the valence quark distribution of the pion at large momentum fraction is found to be $\sim (1-x)^{ \beta_{\rm eff}}$ with $\beta_{\rm eff} \approx 1.0-1.2$.
[ { "created": "Fri, 1 Apr 2022 16:12:15 GMT", "version": "v1" }, { "created": "Fri, 10 Jun 2022 19:30:55 GMT", "version": "v2" } ]
2022-07-13
[ [ "Barry", "P. C.", "" ], [ "Egerer", "C.", "" ], [ "Karpie", "J.", "" ], [ "Melnitchouk", "W.", "" ], [ "Monahan", "C.", "" ], [ "Orginos", "K.", "" ], [ "Qiu", "Jian-Wei", "" ], [ "Richards", "D.", "" ], [ "Sato", "N.", "" ], [ "Sufian", "R. S.", "" ], [ "Zafeiropoulos", "S.", "" ] ]
We extract pion parton distribution functions (PDFs) in a Monte Carlo global QCD analysis of experimental data together with reduced Ioffe time pseudo-distributions and matrix elements of current-current correlators generated from lattice QCD. By including both experimental and lattice QCD data, our analysis rigorously quantifies both the uncertainties of the pion PDFs and systematic effects intrinsic to the lattice QCD observables. The reduced Ioffe time pseudo-distributions significantly decrease the uncertainties on the PDFs, while the current-current correlators are limited by the systematic effects associated with the lattice. Consistent with recent phenomenological determinations, the behavior of the valence quark distribution of the pion at large momentum fraction is found to be $\sim (1-x)^{ \beta_{\rm eff}}$ with $\beta_{\rm eff} \approx 1.0-1.2$.
2207.02718
Mauro Giannini
M. M. Giannini
An improved upper limit for the (muon based) neutrino mass
5 pages, 2 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
The width for the mu decay is calculated in the V-A theory leaving open the possibility of non zero neutrino masses. It is shown that not only the agreement with the experimental data is kept, but the smallness of the experimental error allows to improve the constraint of nu mass (muon based) down to 0.021 MeV, provided that nu mass (electron based) is as low as indicated by the 3H beta decay. An analogous constraint for the nu mass (tau based) is not possible since in this case the decay width has a larger experimental error.
[ { "created": "Wed, 6 Jul 2022 14:44:13 GMT", "version": "v1" } ]
2022-07-07
[ [ "Giannini", "M. M.", "" ] ]
The width for the mu decay is calculated in the V-A theory leaving open the possibility of non zero neutrino masses. It is shown that not only the agreement with the experimental data is kept, but the smallness of the experimental error allows to improve the constraint of nu mass (muon based) down to 0.021 MeV, provided that nu mass (electron based) is as low as indicated by the 3H beta decay. An analogous constraint for the nu mass (tau based) is not possible since in this case the decay width has a larger experimental error.
hep-ph/9811438
Alessandro Strumia
Alessandro Strumia and Nikolaos Tetradis
Bubble-nucleation rates for radiatively induced first-order phase transitions
19 pages, 5 figures. Misprint fixed
Nucl.Phys.B554:697-718,1999
10.1016/S0550-3213(99)00285-0
IFUP-TH/98-54 and SNS-PH/98-24
hep-ph
null
We present a consistent calculation of bubble-nucleation rates in theories of two scalar fields. Our approach is based on the notion of a coarse-grained free energy that incorporates the effects of fluctuations with momenta above a given scale k. We establish the reliability of the method for a variety of two-scalar models and confirm the conclusions of previous studies in one-field theories: Langer's theory of homogeneous nucleation is applicable as long as the expansion around the semiclassical saddle point associated with tunnelling is convergent. This expansion breaks down when the exponential suppression of the rate by the saddle-point action becomes comparable to the pre-exponential factor associated with fluctuations around the saddle point. We reconfirm that Langer's theory is not applicable to the case of weakly first-oder phase transitions. We also find that the same is true in general for radiatively induced first-order phase transitions. We discuss the relevance of our results for the electroweak phase transition and the metastability bound on the Higgs-boson mass.
[ { "created": "Mon, 23 Nov 1998 11:41:13 GMT", "version": "v1" }, { "created": "Mon, 3 May 1999 11:48:04 GMT", "version": "v2" }, { "created": "Thu, 3 Jun 1999 10:28:27 GMT", "version": "v3" } ]
2009-10-09
[ [ "Strumia", "Alessandro", "" ], [ "Tetradis", "Nikolaos", "" ] ]
We present a consistent calculation of bubble-nucleation rates in theories of two scalar fields. Our approach is based on the notion of a coarse-grained free energy that incorporates the effects of fluctuations with momenta above a given scale k. We establish the reliability of the method for a variety of two-scalar models and confirm the conclusions of previous studies in one-field theories: Langer's theory of homogeneous nucleation is applicable as long as the expansion around the semiclassical saddle point associated with tunnelling is convergent. This expansion breaks down when the exponential suppression of the rate by the saddle-point action becomes comparable to the pre-exponential factor associated with fluctuations around the saddle point. We reconfirm that Langer's theory is not applicable to the case of weakly first-oder phase transitions. We also find that the same is true in general for radiatively induced first-order phase transitions. We discuss the relevance of our results for the electroweak phase transition and the metastability bound on the Higgs-boson mass.
0708.3351
Shunji Yoshimoto
Masayasu Harada, Yukio Nemoto and Shunji Yoshimoto (Nagoya Univ.)
Quasi-quark spectrum in the chiral symmetric phase from the Schwinger-Dyson equation
21 pages, 11 figures; This is the version published in Prog.Theor.Phys
Prog.Theor.Phys. 119 (2008) 117-137
10.1143/PTP.119.117
null
hep-ph
null
We non-perturbatively study the fermion spectrum in the chiral symmetric phase from the Schwinger-Dyson equation with the Feynman gauge, in which we perform an analytic continuation of the solution on the imaginary time axis to the real time axis with a method employing an integral equation. It is shown that the fermion spectrum has two peaks, which correspond to the normal quasi-fermion and the plasmino, although these peaks in the strong coupling region are very broad, owing to multiple scatterings with gauge bosons. We find that the thermal mass of the quasi-fermion saturates at some value of the gauge coupling, beyond which the thermal (pole) mass satisfies $M \sim T$, independently of the value of the gauge coupling. We also comment on the appearance of a three-peak structure in the fermion spectrum as a non-perturbative effect.
[ { "created": "Fri, 24 Aug 2007 14:44:22 GMT", "version": "v1" }, { "created": "Fri, 19 Oct 2007 13:55:13 GMT", "version": "v2" }, { "created": "Thu, 24 Jan 2008 15:10:43 GMT", "version": "v3" } ]
2008-01-24
[ [ "Harada", "Masayasu", "", "Nagoya Univ." ], [ "Nemoto", "Yukio", "", "Nagoya Univ." ], [ "Yoshimoto", "Shunji", "", "Nagoya Univ." ] ]
We non-perturbatively study the fermion spectrum in the chiral symmetric phase from the Schwinger-Dyson equation with the Feynman gauge, in which we perform an analytic continuation of the solution on the imaginary time axis to the real time axis with a method employing an integral equation. It is shown that the fermion spectrum has two peaks, which correspond to the normal quasi-fermion and the plasmino, although these peaks in the strong coupling region are very broad, owing to multiple scatterings with gauge bosons. We find that the thermal mass of the quasi-fermion saturates at some value of the gauge coupling, beyond which the thermal (pole) mass satisfies $M \sim T$, independently of the value of the gauge coupling. We also comment on the appearance of a three-peak structure in the fermion spectrum as a non-perturbative effect.
1512.04545
Eric Kuflik
Eric Kuflik, Maxim Perelstein, Nicolas Rey-Le Lorier, Yu-Dai Tsai
Elastically Decoupling Dark Matter
6 pages, 3 figures
Phys. Rev. Lett. 116, 221302 (2016)
10.1103/PhysRevLett.116.221302
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel dark matter candidate, an Elastically Decoupling Relic (ELDER), which is a cold thermal relic whose present abundance is determined by the cross-section of its elastic scattering on Standard Model particles. The dark matter candidate is predicted to have a mass ranging from a few to a few hundred MeV, and an elastic scattering cross-section with electrons, photons and/or neutrinos in the $10^{-3}-1$ fb range.
[ { "created": "Mon, 14 Dec 2015 21:01:04 GMT", "version": "v1" } ]
2016-06-08
[ [ "Kuflik", "Eric", "" ], [ "Perelstein", "Maxim", "" ], [ "Lorier", "Nicolas Rey-Le", "" ], [ "Tsai", "Yu-Dai", "" ] ]
We present a novel dark matter candidate, an Elastically Decoupling Relic (ELDER), which is a cold thermal relic whose present abundance is determined by the cross-section of its elastic scattering on Standard Model particles. The dark matter candidate is predicted to have a mass ranging from a few to a few hundred MeV, and an elastic scattering cross-section with electrons, photons and/or neutrinos in the $10^{-3}-1$ fb range.
2103.02058
Daniel Moreno Torres
Th. Mannel, D. Moreno, and A. A. Pivovarov
The Heavy Quark Expansion for the Charm Quark
4 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that one can re-arrange the Heavy Quark Expansion for inclusive weak decays of charmed hadrons in such a way that the resulting expansion is an expansion in $\Lambda_{\rm QCD} / m_c$ and $\alpha_s (m_c)$ with order-one coefficients. Unlike in the case of the bottom quark, the leading term includes not only the contribution of the free-quark decay, but also a tower of terms related to matrix elements of four quark operators.
[ { "created": "Tue, 2 Mar 2021 22:13:29 GMT", "version": "v1" } ]
2021-03-04
[ [ "Mannel", "Th.", "" ], [ "Moreno", "D.", "" ], [ "Pivovarov", "A. A.", "" ] ]
We show that one can re-arrange the Heavy Quark Expansion for inclusive weak decays of charmed hadrons in such a way that the resulting expansion is an expansion in $\Lambda_{\rm QCD} / m_c$ and $\alpha_s (m_c)$ with order-one coefficients. Unlike in the case of the bottom quark, the leading term includes not only the contribution of the free-quark decay, but also a tower of terms related to matrix elements of four quark operators.
hep-ph/0109049
Walter Grimus
G.V. Dass, W. Grimus
Testing the Wigner - Weisskopf approximation by using neutral-meson - antimeson correlated states
9 pages, latex, no figures
Phys.Lett. B521 (2001) 267-272
10.1016/S0370-2693(01)01196-0
UWThPh-2001-35
hep-ph
null
We phenomenologically decompose the Weisskopf--Wigner approximation, as applied to the neutral flavoured meson complexes, into three pieces and propose tests for these pieces. Our tests hold for general decay amplitudes and $M^0$--$\bar M^0$ mixing parameters. We concentrate on C-odd $M^0 \bar M^0$ states and stress the importance of such tests in view of the variety of physics extracted from measurements on such complexes. Studying the feasibility of the tests confines one to the $K^0 \bar K^0$ system at present. In particular, we show that the time dependence of the correlated decay $\phi \to K^0 \bar K^0 \to 2 (\pi^+ \pi^-)$ is determined solely by the WWA and provides thus a clean test of it.
[ { "created": "Thu, 6 Sep 2001 13:02:53 GMT", "version": "v1" } ]
2009-11-07
[ [ "Dass", "G. V.", "" ], [ "Grimus", "W.", "" ] ]
We phenomenologically decompose the Weisskopf--Wigner approximation, as applied to the neutral flavoured meson complexes, into three pieces and propose tests for these pieces. Our tests hold for general decay amplitudes and $M^0$--$\bar M^0$ mixing parameters. We concentrate on C-odd $M^0 \bar M^0$ states and stress the importance of such tests in view of the variety of physics extracted from measurements on such complexes. Studying the feasibility of the tests confines one to the $K^0 \bar K^0$ system at present. In particular, we show that the time dependence of the correlated decay $\phi \to K^0 \bar K^0 \to 2 (\pi^+ \pi^-)$ is determined solely by the WWA and provides thus a clean test of it.
hep-ph/0207189
Fabrizio Gabbiani
F. Gabbiani and G. Valencia
Vector-meson contributions do not explain the rate and spectrum in K_L -> pi0 gamma gamma
Version accepted for publication on Phys. Rev. D. 19 pages, LaTeX, 8 figures, uses epsf.sty
Phys.Rev. D66 (2002) 074006
10.1103/PhysRevD.66.074006
null
hep-ph hep-ex
null
We analyze the recent NA48 data for the reaction K_L -> pi0 gamma gamma with and without the assumption of vector meson dominance (VMD). We find that the data is well described by a three-parameter expression inspired by O(p^6) chiral perturbation theory. We also find that it is impossible to fit the shape of the decay distribution and the overall rate simultaneously if one imposes the VMD constraints on the three parameters. We comment on the different fits and their implications for the CP-conserving component of the decay K_L -> pi0 e+ e-.
[ { "created": "Mon, 15 Jul 2002 18:57:03 GMT", "version": "v1" }, { "created": "Tue, 16 Jul 2002 01:25:09 GMT", "version": "v2" }, { "created": "Mon, 12 Aug 2002 16:19:00 GMT", "version": "v3" } ]
2009-11-07
[ [ "Gabbiani", "F.", "" ], [ "Valencia", "G.", "" ] ]
We analyze the recent NA48 data for the reaction K_L -> pi0 gamma gamma with and without the assumption of vector meson dominance (VMD). We find that the data is well described by a three-parameter expression inspired by O(p^6) chiral perturbation theory. We also find that it is impossible to fit the shape of the decay distribution and the overall rate simultaneously if one imposes the VMD constraints on the three parameters. We comment on the different fits and their implications for the CP-conserving component of the decay K_L -> pi0 e+ e-.
hep-ph/0312155
Yann Mambrini
Pierre Binetruy, Yann Mambrini, Emmanuel Nezri
Direct and Indirect Detection of Dark Matter in Heterotic Orbifold Models
29 pages, 13 figures. Notations clarified, figures improved, typos and english corrected
Astropart.Phys.22:1-18,2004
10.1016/j.astropartphys.2004.05.010
null
hep-ph astro-ph
null
We study the neutralino dark matter phenomenology in the context of effective field theories derived from the weakly--coupled heterotic string. We consider in particular direct detection and indirect detection with neutrino telescopes rates. The two cases of moduli dominated and dilaton dominated SUSY breaking lead to completely different phenomenologies. Even if in both cases relic density constraints can be fulfilled, moduli domination generically leads to detection rates which are much below the present and future experimental sensitivities, whereas dilaton domination gives high detection rates accessible to the next generation of experiments. This could make dark matter searches an alternative way to constrain high energy fundamental parameters.
[ { "created": "Thu, 11 Dec 2003 16:22:46 GMT", "version": "v1" }, { "created": "Wed, 12 May 2004 09:32:05 GMT", "version": "v2" } ]
2011-05-23
[ [ "Binetruy", "Pierre", "" ], [ "Mambrini", "Yann", "" ], [ "Nezri", "Emmanuel", "" ] ]
We study the neutralino dark matter phenomenology in the context of effective field theories derived from the weakly--coupled heterotic string. We consider in particular direct detection and indirect detection with neutrino telescopes rates. The two cases of moduli dominated and dilaton dominated SUSY breaking lead to completely different phenomenologies. Even if in both cases relic density constraints can be fulfilled, moduli domination generically leads to detection rates which are much below the present and future experimental sensitivities, whereas dilaton domination gives high detection rates accessible to the next generation of experiments. This could make dark matter searches an alternative way to constrain high energy fundamental parameters.
1402.0162
G.R. Boroun
G.R. Boroun and M. Amiri
Laguerre polynomials method in the valon model
arXiv admin note: text overlap with arXiv:hep-ph/9904264 by other authors
Phys. Scr. 88 (2013) 035102
10.1088/0031-8949/88/03/035102
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We used the Laguerre polynomials method for determination of the proton structure function in the valon model. We have examined the applicability of the valon model with respect to a very elegant method, where the structure of the proton is determined by expanding valon distributions and valon structure functions on Laguerre polynomials. We compared our results with the experimental data, GJR parameterization and DL model. Having checked, this method gives a good description for the proton structure function in valon model.
[ { "created": "Sun, 2 Feb 2014 09:25:19 GMT", "version": "v1" }, { "created": "Thu, 20 Feb 2014 10:24:07 GMT", "version": "v2" }, { "created": "Fri, 11 Nov 2016 04:56:53 GMT", "version": "v3" }, { "created": "Tue, 15 Nov 2016 15:35:31 GMT", "version": "v4" } ]
2016-11-16
[ [ "Boroun", "G. R.", "" ], [ "Amiri", "M.", "" ] ]
We used the Laguerre polynomials method for determination of the proton structure function in the valon model. We have examined the applicability of the valon model with respect to a very elegant method, where the structure of the proton is determined by expanding valon distributions and valon structure functions on Laguerre polynomials. We compared our results with the experimental data, GJR parameterization and DL model. Having checked, this method gives a good description for the proton structure function in valon model.
1811.08183
Susana Coito
Susana Coito
Radially excited $\psi$ mesons and the $Y$ enhancements
7 pages, 4 figures, Conference Proceedings of "XIIIth Quark Confinement and Hadron Spectrum", 31 July - 6 August 2018 Maynooth University, Ireland
null
10.22323/1.336.0105
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While many properties of the vector charmonium first excitations are yet to be measured, enhancements at unexpected energies are intriguing, alias the $Y$ states. In order to understand the naturally unquenched mesonic line-shapes, the influence of the most relevant hadronic decay channels must be taken into account. Within an unitary effective approach we present results where mesonic loops are included in an equivalent manner to coupled-channels. We show results for the $\psi(3770)$ and $\psi(4160)$ systems, where we find the nonperturbative effects of dynamical generation of poles and line-shape distortion.
[ { "created": "Tue, 20 Nov 2018 11:20:21 GMT", "version": "v1" } ]
2022-09-21
[ [ "Coito", "Susana", "" ] ]
While many properties of the vector charmonium first excitations are yet to be measured, enhancements at unexpected energies are intriguing, alias the $Y$ states. In order to understand the naturally unquenched mesonic line-shapes, the influence of the most relevant hadronic decay channels must be taken into account. Within an unitary effective approach we present results where mesonic loops are included in an equivalent manner to coupled-channels. We show results for the $\psi(3770)$ and $\psi(4160)$ systems, where we find the nonperturbative effects of dynamical generation of poles and line-shape distortion.
hep-ph/9605280
A. Dolgov
A.D. Dolgov
Antimatter in Different Baryogenesis Scenarios
Latex, 9 pages, presented at International Workshop on Baryon Instability, Oak Ridge, Tennessee, March 28-39, 1996. (to be published in the Proceedings)
null
null
TAC-1996-010
hep-ph astro-ph
null
Possible mechanisms of abundant creation of antimatter in the universe are reviewed. The necessary conditions for that are: baryonic charge nonconservation, spontaneous breaking of charge symmetry or nonequilibrium initial state, and the formation of appropriate initial conditions during inflation. In this case the universe may be populated with domains, cells, or even stellar size objects consisting of antimatter.
[ { "created": "Sat, 11 May 1996 22:13:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dolgov", "A. D.", "" ] ]
Possible mechanisms of abundant creation of antimatter in the universe are reviewed. The necessary conditions for that are: baryonic charge nonconservation, spontaneous breaking of charge symmetry or nonequilibrium initial state, and the formation of appropriate initial conditions during inflation. In this case the universe may be populated with domains, cells, or even stellar size objects consisting of antimatter.
hep-ph/0004088
Shinji Tsujikawa
S. Tsujikawa (Waseda University)
Power-law inflation with a nonminimally coupled scalar field
12 pages, 6 figures, to appear in Phys. Rev. D
Phys.Rev. D62 (2000) 043512
10.1103/PhysRevD.62.043512
WU-AP/95/00
hep-ph astro-ph gr-qc hep-th
null
We consider the dynamics of power-law inflation with a nonminimally coupled scalar field $\phi$. It is well known that multiple scalar fields with exponential potentials $V(\phi)=V_0 {\rm exp}(-\sqrt{16\pi/p m_{\rm pl}^2} \phi)$ lead to an inflationary solution even if the each scalar field is not capable to sustain inflation. In this paper, we show that inflation can be assisted even in the one-field case by the effect of nonminimal coupling. When $\xi$ is positive, since an effective potential which arises by a conformal transformation becomes flatter compared with the case of $\xi=0$ for $\phi>0$, we have an inflationary solution even when the universe evolves as non-inflationary in the minimally coupled case. For the negative $\xi$, the assisted inflation can take place when $\phi$ evolves in the region of $\phi<0$ \.
[ { "created": "Mon, 10 Apr 2000 08:04:15 GMT", "version": "v1" } ]
2009-10-31
[ [ "Tsujikawa", "S.", "", "Waseda University" ] ]
We consider the dynamics of power-law inflation with a nonminimally coupled scalar field $\phi$. It is well known that multiple scalar fields with exponential potentials $V(\phi)=V_0 {\rm exp}(-\sqrt{16\pi/p m_{\rm pl}^2} \phi)$ lead to an inflationary solution even if the each scalar field is not capable to sustain inflation. In this paper, we show that inflation can be assisted even in the one-field case by the effect of nonminimal coupling. When $\xi$ is positive, since an effective potential which arises by a conformal transformation becomes flatter compared with the case of $\xi=0$ for $\phi>0$, we have an inflationary solution even when the universe evolves as non-inflationary in the minimally coupled case. For the negative $\xi$, the assisted inflation can take place when $\phi$ evolves in the region of $\phi<0$ \.
0801.3456
Sunghoon Jung
Shrihari Gopalakrishna, Sunghoon Jung, James D. Wells
Higgs boson decays to four fermions through an abelian hidden sector
5 pages, 3 figures
Phys.Rev.D78:055002,2008
10.1103/PhysRevD.78.055002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a generic abelian hidden sector that couples to the Standard Model only through gauge-invariant renormalizable operators. This allows the exotic Higgs boson to mix with the Standard Model Higgs boson, and the exotic abelian gauge boson to mix with the Standard Model hypercharge gauge boson. One immediate consequence of spontaneous breaking of the hidden sector gauge group is the possible decay of the lightest Higgs boson into four fermions through intermediate exotic gauge bosons. We study the implications of this decay for Higgs boson phenomenology at the Fermilab Tevatron Collider and the CERN Large Hadron Collider. Our emphasis is on the four lepton final state.
[ { "created": "Wed, 23 Jan 2008 13:44:41 GMT", "version": "v1" }, { "created": "Tue, 2 Sep 2008 21:07:54 GMT", "version": "v2" } ]
2008-11-26
[ [ "Gopalakrishna", "Shrihari", "" ], [ "Jung", "Sunghoon", "" ], [ "Wells", "James D.", "" ] ]
We consider a generic abelian hidden sector that couples to the Standard Model only through gauge-invariant renormalizable operators. This allows the exotic Higgs boson to mix with the Standard Model Higgs boson, and the exotic abelian gauge boson to mix with the Standard Model hypercharge gauge boson. One immediate consequence of spontaneous breaking of the hidden sector gauge group is the possible decay of the lightest Higgs boson into four fermions through intermediate exotic gauge bosons. We study the implications of this decay for Higgs boson phenomenology at the Fermilab Tevatron Collider and the CERN Large Hadron Collider. Our emphasis is on the four lepton final state.
2108.13214
Carlos Garcia Canal
C.A. Garc\'ia Canal
Neutrinos and strong interactions: QCD (and beyond?)
invited talk at LISHEP 2021
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
In this talk the answer to the question: what neutrinos have to do with QCD, the present theory of strong interactions? is presented. The answer is positive as some strong arguments on this assertion that are presented bring out.
[ { "created": "Mon, 30 Aug 2021 13:08:17 GMT", "version": "v1" } ]
2021-08-31
[ [ "Canal", "C. A. García", "" ] ]
In this talk the answer to the question: what neutrinos have to do with QCD, the present theory of strong interactions? is presented. The answer is positive as some strong arguments on this assertion that are presented bring out.
hep-ph/0407264
Otavio Socolowski Jr.
Y. Hama, T. Kodama and O. Socolowski Jr
Topics on Hydrodynamic Model of Nucleus-Nucleus Collisions
30 pages, 29 figures; corrected typos
Braz.J.Phys.35:24-51,2005
10.1590/S0103-97332005000100003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A survey is given on the applications of hydrodynamic model of nucleus-nucleus collisons, focusing especially on i) the resolution of hydrodynamic equations for arbitrary configurations, by using the smoothed-particle hydrodynamic approach; ii) effects of the event-by-event fluctuation of the initial conditions on the observables; iii) decoupling criteria; iv) analytical solutions; and others.
[ { "created": "Thu, 22 Jul 2004 04:40:42 GMT", "version": "v1" }, { "created": "Fri, 12 Nov 2004 03:54:49 GMT", "version": "v2" }, { "created": "Sun, 10 Mar 2013 16:41:41 GMT", "version": "v3" } ]
2015-06-25
[ [ "Hama", "Y.", "" ], [ "Kodama", "T.", "" ], [ "Socolowski", "O.", "Jr" ] ]
A survey is given on the applications of hydrodynamic model of nucleus-nucleus collisons, focusing especially on i) the resolution of hydrodynamic equations for arbitrary configurations, by using the smoothed-particle hydrodynamic approach; ii) effects of the event-by-event fluctuation of the initial conditions on the observables; iii) decoupling criteria; iv) analytical solutions; and others.
1403.2204
C. A. Dominguez
C. A. Dominguez, M. Loewe and M. Lushozi
Scalar form factor of the pion in the Kroll-Lee-Zumino field theory
null
null
null
UCT-TP-299/14
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The renormalizable Kroll-Lee-Zumino field theory of pions and a neutral rho-meson is used to determine the scalar form factor of the pion in the space-like region at next-to-leading order. Perturbative calculations in this framework are parameter free, as the masses and the rho-pion-pion coupling are known from experiment. Results compare favourably with lattice QCD calculations.
[ { "created": "Mon, 10 Mar 2014 10:08:59 GMT", "version": "v1" } ]
2014-03-11
[ [ "Dominguez", "C. A.", "" ], [ "Loewe", "M.", "" ], [ "Lushozi", "M.", "" ] ]
The renormalizable Kroll-Lee-Zumino field theory of pions and a neutral rho-meson is used to determine the scalar form factor of the pion in the space-like region at next-to-leading order. Perturbative calculations in this framework are parameter free, as the masses and the rho-pion-pion coupling are known from experiment. Results compare favourably with lattice QCD calculations.
hep-ph/9907436
B. F. L. Ward
S. Jadach (1 and 2), W. Placzek (2 and 3), M. Skrzypek (1 and 2), B.F.L. Ward (2 and 4 and 5), Z. Was (1 and 2) ((1) Institute of Nuclear Physics, Krak\'ow, Poland, (2) CERN, Theory Division, Geneva, Switzerland, (3) Institute of Computer Science, Jagellonian University, Krak\'ow, Poland, (4) Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee, (5) SLAC, Stanford University, Stanford, California)
Final State Radiative Effects for the Exact O(alpha) YFS Exponentiated (Un)Stable W+W- Production At and Beyond LEP2 Energies
16 pages, 8 figures, 2 tables
Phys.Rev.D61:113010,2000
10.1103/PhysRevD.61.113010
UTHEP-98-0502
hep-ph
null
We present the LL final state radiative effects for the exact O(alpha) YFS exponentiated (un)stable WW pair production at LEP2/NLC energies using Monte Carlo event generator methods. The respective event generator, version 1.12 of the program YFSWW3, wherein both Standard Model and anomalous triple gauge boson couplings are allowed, generates n(\gamma) radiation both from the initial state and from the intermediate W+ W- and generates the LL final state W decay radiative effects. Sample Monte Carlo data are illustrated.
[ { "created": "Tue, 20 Jul 1999 20:41:13 GMT", "version": "v1" }, { "created": "Wed, 19 Jan 2000 14:24:32 GMT", "version": "v2" } ]
2009-09-25
[ [ "Jadach", "S.", "", "1 and 2" ], [ "Placzek", "W.", "", "2 and 3" ], [ "Skrzypek", "M.", "", "1 and 2" ], [ "Ward", "B. F. L.", "", "2 and 4 and 5" ], [ "Was", "Z.", "", "1 and 2" ] ]
We present the LL final state radiative effects for the exact O(alpha) YFS exponentiated (un)stable WW pair production at LEP2/NLC energies using Monte Carlo event generator methods. The respective event generator, version 1.12 of the program YFSWW3, wherein both Standard Model and anomalous triple gauge boson couplings are allowed, generates n(\gamma) radiation both from the initial state and from the intermediate W+ W- and generates the LL final state W decay radiative effects. Sample Monte Carlo data are illustrated.
1506.03924
Jonathan Davis
Jonathan H. Davis
The Past and Future of Light Dark Matter Direct Detection
Invited review article for the International Journal of Modern Physics A. 20 pages, 3 figures
Int. J. Mod. Phys. A, 30, 1530038 (2015)
10.1142/S0217751X15300380
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the status and future of direct searches for light dark matter. We start by answering the question: `Whatever happened to the light dark matter anomalies?' i.e. the fate of the potential dark matter signals observed by the CoGeNT, CRESST-II, CDMS-Si and DAMA/LIBRA experiments. We discuss how the excess events in the first two of these experiments have been explained by previously underestimated backgrounds. For DAMA we summarise the progress and future of mundane explanations for the annual modulation reported in its event rate. Concerning the future of direct detection we focus on the irreducible background from solar neutrinos. We explain broadly how it will affect future searches and summarise efforts to mitigate its effects.
[ { "created": "Fri, 12 Jun 2015 08:02:03 GMT", "version": "v1" } ]
2015-06-15
[ [ "Davis", "Jonathan H.", "" ] ]
We review the status and future of direct searches for light dark matter. We start by answering the question: `Whatever happened to the light dark matter anomalies?' i.e. the fate of the potential dark matter signals observed by the CoGeNT, CRESST-II, CDMS-Si and DAMA/LIBRA experiments. We discuss how the excess events in the first two of these experiments have been explained by previously underestimated backgrounds. For DAMA we summarise the progress and future of mundane explanations for the annual modulation reported in its event rate. Concerning the future of direct detection we focus on the irreducible background from solar neutrinos. We explain broadly how it will affect future searches and summarise efforts to mitigate its effects.
1504.07848
Takaaki Nomura
Chuan-Hung Chen, Cheng-Wei Chiang, Takaaki Nomura
Dark matter for excess of AMS-02 positrons and antiprotons
12 pages, 3 figures, references and comments added, version to appear in Phys. Lett. B
Phys.Lett. B747 (2015) 495-499
10.1016/j.physletb.2015.06.035
IPMU15-0060
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a dark matter explanation to simultaneously account for the excess of antiproton-to-proton and positron power spectra observed in the AMS-02 experiment while having the right dark matter relic abundance and satisfying the current direct search bounds. We extend the Higgs triplet model with a hidden gauge symmetry of $SU(2)_X$ that is broken to $Z_3$ by a quadruplet scalar field, rendering the associated gauge bosons stable weakly-interacting massive particle dark matter candidates. By coupling the complex Higgs triplet and the $SU(2)_X$ quadruplet, the dark matter candidates can annihilate into triplet Higgs bosons each of which in turn decays into lepton or gauge boson final states. Such a mechanism gives rise to correct excess of positrons and antiprotons with an appropriate choice of the triplet vacuum expectation value. Besides, the model provides a link between neutrino mass and dark matter phenomenology.
[ { "created": "Wed, 29 Apr 2015 13:11:59 GMT", "version": "v1" }, { "created": "Tue, 23 Jun 2015 02:16:01 GMT", "version": "v2" } ]
2015-06-24
[ [ "Chen", "Chuan-Hung", "" ], [ "Chiang", "Cheng-Wei", "" ], [ "Nomura", "Takaaki", "" ] ]
We propose a dark matter explanation to simultaneously account for the excess of antiproton-to-proton and positron power spectra observed in the AMS-02 experiment while having the right dark matter relic abundance and satisfying the current direct search bounds. We extend the Higgs triplet model with a hidden gauge symmetry of $SU(2)_X$ that is broken to $Z_3$ by a quadruplet scalar field, rendering the associated gauge bosons stable weakly-interacting massive particle dark matter candidates. By coupling the complex Higgs triplet and the $SU(2)_X$ quadruplet, the dark matter candidates can annihilate into triplet Higgs bosons each of which in turn decays into lepton or gauge boson final states. Such a mechanism gives rise to correct excess of positrons and antiprotons with an appropriate choice of the triplet vacuum expectation value. Besides, the model provides a link between neutrino mass and dark matter phenomenology.
2003.08892
Xiao Wang
Xiao Wang, Fa Peng Huang, and Xinmin Zhang
Phase transition dynamics and gravitational wave spectra of strong first-order phase transition in supercooled universe
Published version in JCAP, 58 pages, 34 figures, 8 tables
JCAP05(2020)045
10.1088/1475-7516/2020/05/045
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Phase transition dynamics may play important roles in the evolution history of the early universe, such as its possible roles in electroweak baryogenesis and dark matter.We systematically discuss and clarify the important details of the phase transition dynamics during a strong first-order phase transition (SFOPT). We classify the SFOPT into four types: slight supercooling, mild supercooling, strong supercooling, and ultra supercooling. Using different characteristic temperatures, length scales and bubble wall velocities, the corresponding gravitational wave (GW) spectra are investigated in details. We emphasize the essential importance of using the correct characteristic temperature and length scale when the phase transition dynamics and GW spectra are calculated. Especially, for strong supercooling and ultra supercooling cases, there are obvious differences of the phase transition strength and GW spectra between the results calculated at the nucleation temperature and those derived at the percolation temperature. For ultra supercooling case, we propose a criterion to quantify whether the phase transition can terminate. Besides the model-independent discussions, we also study three representative models as concrete examples to clearly show the subtle points therein.
[ { "created": "Thu, 19 Mar 2020 16:38:30 GMT", "version": "v1" }, { "created": "Tue, 31 Mar 2020 16:55:10 GMT", "version": "v2" }, { "created": "Wed, 27 May 2020 15:45:41 GMT", "version": "v3" } ]
2020-05-28
[ [ "Wang", "Xiao", "" ], [ "Huang", "Fa Peng", "" ], [ "Zhang", "Xinmin", "" ] ]
Phase transition dynamics may play important roles in the evolution history of the early universe, such as its possible roles in electroweak baryogenesis and dark matter.We systematically discuss and clarify the important details of the phase transition dynamics during a strong first-order phase transition (SFOPT). We classify the SFOPT into four types: slight supercooling, mild supercooling, strong supercooling, and ultra supercooling. Using different characteristic temperatures, length scales and bubble wall velocities, the corresponding gravitational wave (GW) spectra are investigated in details. We emphasize the essential importance of using the correct characteristic temperature and length scale when the phase transition dynamics and GW spectra are calculated. Especially, for strong supercooling and ultra supercooling cases, there are obvious differences of the phase transition strength and GW spectra between the results calculated at the nucleation temperature and those derived at the percolation temperature. For ultra supercooling case, we propose a criterion to quantify whether the phase transition can terminate. Besides the model-independent discussions, we also study three representative models as concrete examples to clearly show the subtle points therein.
hep-ph/9610254
Tsuneki Matsuki
T. Matsuki and K. Yazaki (Univ. of Tokyo)
QCD Sum Rules and the Validity of Effective Models
10 pages, 2 Postscript figures, uses revtex.sty, epsf.sty
null
null
null
hep-ph
null
The consistency of effective models with QCD is investigated through the use of the QCD sum rule. Taking the potential model for the heavy quark system, we apply the method to two phenomenologically successful parameter sets, and obtain the dependences of the model parameters on the QCD scale $\Lambda$. Comparison with the expected scaling laws allows us to reject one of the two sets. The method is applicable to any model which reproduces the low lying spectra of hadronic systems.
[ { "created": "Sat, 5 Oct 1996 12:18:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Matsuki", "T.", "", "Univ. of Tokyo" ], [ "Yazaki", "K.", "", "Univ. of Tokyo" ] ]
The consistency of effective models with QCD is investigated through the use of the QCD sum rule. Taking the potential model for the heavy quark system, we apply the method to two phenomenologically successful parameter sets, and obtain the dependences of the model parameters on the QCD scale $\Lambda$. Comparison with the expected scaling laws allows us to reject one of the two sets. The method is applicable to any model which reproduces the low lying spectra of hadronic systems.
0706.2678
Samoil Bilenky M.
S.M. Bilenky
CP-violation and unitarity triangle test of the Standard Model
On the basis of the lectures given to the students of SISSA (Trieste) in 2006
Phys.Part.Nucl.39:641-673,2008
10.1134/S1063779608050018
null
hep-ph
null
Phenomenological issues of the CP violation in the quark sector of the Standard Model are discussed. We consider quark mixing in the SM, standard and Wolfenstein parametrization of the $CKM$ mixing matrix and unitarity triangle. We discuss the phenomenology of the CP violation in $K^{0}_{L}$ and $B_{d}^{0} (\bar B_{d}^{0})$-decays. The standard unitarity triangle fit of the existing data is discussed. In appendix A we compare the $K^{0}\leftrightarrows \bar K^{0}$, $B_{d,s}^{0}\leftrightarrows \bar B^{0}_{d,s}$ etc oscillations with neutrino oscillations. In Appendix B we derive the evolution equation for $M^{0}- \bar M^{0}$ system in the Weisskopf-Wigner approximation.
[ { "created": "Mon, 18 Jun 2007 22:28:52 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bilenky", "S. M.", "" ] ]
Phenomenological issues of the CP violation in the quark sector of the Standard Model are discussed. We consider quark mixing in the SM, standard and Wolfenstein parametrization of the $CKM$ mixing matrix and unitarity triangle. We discuss the phenomenology of the CP violation in $K^{0}_{L}$ and $B_{d}^{0} (\bar B_{d}^{0})$-decays. The standard unitarity triangle fit of the existing data is discussed. In appendix A we compare the $K^{0}\leftrightarrows \bar K^{0}$, $B_{d,s}^{0}\leftrightarrows \bar B^{0}_{d,s}$ etc oscillations with neutrino oscillations. In Appendix B we derive the evolution equation for $M^{0}- \bar M^{0}$ system in the Weisskopf-Wigner approximation.
hep-ph/0609147
Jonathan Roberts
S. F. King, J. P. Roberts
Natural Dark Matter
Reference added. Based on talk given at Physics at the LHC 2006, Cracow, Poland, 3-8 Jul 2006
ActaPhys.Polon.B38:607-616,2007
null
null
hep-ph
null
In this talk we analyse the claim that supersymmetry (SUSY) naturally accounts for the observed dark matter density. In many cases, it is necessary to tune the parameters of a SUSY model to fit the WMAP data. We provide a quantitative analysis of the degree of tuning required for different annihilation channels. Some regions are natural, requiring no tuning at all, whereas others require tuning at the 0.1% level.
[ { "created": "Fri, 15 Sep 2006 12:06:12 GMT", "version": "v1" }, { "created": "Mon, 25 Sep 2006 09:00:32 GMT", "version": "v2" } ]
2008-11-26
[ [ "King", "S. F.", "" ], [ "Roberts", "J. P.", "" ] ]
In this talk we analyse the claim that supersymmetry (SUSY) naturally accounts for the observed dark matter density. In many cases, it is necessary to tune the parameters of a SUSY model to fit the WMAP data. We provide a quantitative analysis of the degree of tuning required for different annihilation channels. Some regions are natural, requiring no tuning at all, whereas others require tuning at the 0.1% level.
1507.08252
Xiao-Gang He
Guan-Nan Li, Min He, Xiao-Gang He
Some Predictions of Diquark Model for Hidden Charm Pentaquark Discovered at the LHCb
revtex, 19 pages, 3 figures. one reference added and some typos corrected
null
10.1007/JHEP12(2015)128
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHCb has discovered two new states with preferred $J^P$ quantum numbers $3/2^-$ and $5/2^+$ from $\Lambda_b$ decays. These new states can be interpreted as hidden charm pentaquarks. It has been argued that the main features of these pentaquarks can be described by diquark model. The diquark model predicts that the $3/2^-$ and $5/2^+$ are in two separate octet multiplets of flavor $SU(3)$ and there is also an additional decuplet pentaquark multiplet. Finding the states in these multiplets can provide crucial evidence for this model. The weak decays of b-baryon to a light meson and a pentaquark can have Cabibbo allowed and suppressed decay channels. We find that in the $SU(3)$ limit, for $U$-spin related decay modes the ratio of the decay rates of Cabibbo suppressed to Cabibbo allowed decay channels is given by $|V_{cd}|^2/|V_{cs}|^2$. There are also other testable relations for b-baryon weak decays into a pentaquark and a light pseudoscalar. These relations can be used as tests for the diquark model for pentaquark.
[ { "created": "Wed, 29 Jul 2015 18:34:34 GMT", "version": "v1" }, { "created": "Sun, 2 Aug 2015 01:51:12 GMT", "version": "v2" }, { "created": "Mon, 21 Sep 2015 01:54:15 GMT", "version": "v3" }, { "created": "Thu, 8 Oct 2015 15:40:48 GMT", "version": "v4" } ]
2016-01-27
[ [ "Li", "Guan-Nan", "" ], [ "He", "Min", "" ], [ "He", "Xiao-Gang", "" ] ]
The LHCb has discovered two new states with preferred $J^P$ quantum numbers $3/2^-$ and $5/2^+$ from $\Lambda_b$ decays. These new states can be interpreted as hidden charm pentaquarks. It has been argued that the main features of these pentaquarks can be described by diquark model. The diquark model predicts that the $3/2^-$ and $5/2^+$ are in two separate octet multiplets of flavor $SU(3)$ and there is also an additional decuplet pentaquark multiplet. Finding the states in these multiplets can provide crucial evidence for this model. The weak decays of b-baryon to a light meson and a pentaquark can have Cabibbo allowed and suppressed decay channels. We find that in the $SU(3)$ limit, for $U$-spin related decay modes the ratio of the decay rates of Cabibbo suppressed to Cabibbo allowed decay channels is given by $|V_{cd}|^2/|V_{cs}|^2$. There are also other testable relations for b-baryon weak decays into a pentaquark and a light pseudoscalar. These relations can be used as tests for the diquark model for pentaquark.
0908.1750
Sheung Tsun Tsou
J. Bordes, H.M. Chan, S.T. Tsou
Possible Anomalies in Higgs Decay: Charm Suppression and Flavour-Violation
12 pages, 3 figures
Eur.Phys.J.C65:537-542,2010
10.1140/epjc/s10052-009-1186-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is suggested that the Higgs boson may have a branching ratio into the $c \bar{c}$ mode suppressed by several orders of magnitude compared with conventional predictions and in addition some small but detectable flavour-violating modes such as $b \bar{s}$ and $\tau \bar{\mu}$. The suggestion is based on a scheme proposed and tested earlier for explaining the mixing pattern and mass hierarchy of fermions in terms of a rotating mass matrix. If confirmed, the effects would cast new light on the geometric origin of fermion generations and of the Higgs field itself.
[ { "created": "Wed, 12 Aug 2009 16:48:18 GMT", "version": "v1" } ]
2010-02-11
[ [ "Bordes", "J.", "" ], [ "Chan", "H. M.", "" ], [ "Tsou", "S. T.", "" ] ]
It is suggested that the Higgs boson may have a branching ratio into the $c \bar{c}$ mode suppressed by several orders of magnitude compared with conventional predictions and in addition some small but detectable flavour-violating modes such as $b \bar{s}$ and $\tau \bar{\mu}$. The suggestion is based on a scheme proposed and tested earlier for explaining the mixing pattern and mass hierarchy of fermions in terms of a rotating mass matrix. If confirmed, the effects would cast new light on the geometric origin of fermion generations and of the Higgs field itself.
1907.10698
Moinul Hossain Rahat
M. Jay P\'erez, Moinul Hossain Rahat, Pierre Ramond, Alexander J. Stuart, Bin Xu
Stitching an Asymmetric Texture with $\mathcal{T}_{13} \times \mathcal{Z}_5$ Family Symmetry
Major change from previous version: the symmetry $\mathcal{Z}_4$ has been changed to $\mathcal{Z}_5$ to prohibit a new unwanted vertex, 26 pages, version accepted for publication in Physical Review D
Phys. Rev. D 100, 075008 (2019)
10.1103/PhysRevD.100.075008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose $\mathcal{T}_{13} = \mathcal{Z}_{13} \rtimes \mathcal{Z}_3$ as the underlying non-Abelian discrete family symmetry of the asymmetric texture presented in arXiv:1805.10684 [hep-ph]. Its mod 13 arithmetic distinguishes each Yukawa matrix element of the texture. We construct a model of effective interactions that singles out the asymmetry and equates, without fine-tuning, the products of down-quark and charged-lepton masses at a GUT-like scale.
[ { "created": "Wed, 24 Jul 2019 20:12:04 GMT", "version": "v1" }, { "created": "Tue, 1 Oct 2019 17:48:33 GMT", "version": "v2" } ]
2019-10-16
[ [ "Pérez", "M. Jay", "" ], [ "Rahat", "Moinul Hossain", "" ], [ "Ramond", "Pierre", "" ], [ "Stuart", "Alexander J.", "" ], [ "Xu", "Bin", "" ] ]
We propose $\mathcal{T}_{13} = \mathcal{Z}_{13} \rtimes \mathcal{Z}_3$ as the underlying non-Abelian discrete family symmetry of the asymmetric texture presented in arXiv:1805.10684 [hep-ph]. Its mod 13 arithmetic distinguishes each Yukawa matrix element of the texture. We construct a model of effective interactions that singles out the asymmetry and equates, without fine-tuning, the products of down-quark and charged-lepton masses at a GUT-like scale.
1410.2042
Shouhua Zhu
Shou-hua Zhu (Peking U)
A New Paradigm: Role of Electron-positron and Hadron Colliders
Invited talk at HF2014, 5 pages
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In 2012, a light scalar boson (denoted as H(125) in this paper) was discovered at the LHC. We explore the possible correlation between the lightness of H(125) and the smallness of CP-violation based on the Lee model, namely the spontaneous CP-violation two-Higgs-doublet-model. It is a new way to understand why H(125) is light. Based on this we propose that it is the much heavier scalar bosons, instead of the H(125), which need to be understood. This opens a new paradigm that one tries to understand the electro-weak symmetry breaking and CP violation. For the new paradigm, similar to many other physics beyond the standard model, one need both electron-positron and higher energy hadron collider, as well as the low energy experiments, in order to pin down the whole picture.
[ { "created": "Wed, 8 Oct 2014 09:55:31 GMT", "version": "v1" } ]
2014-10-09
[ [ "Zhu", "Shou-hua", "", "Peking U" ] ]
In 2012, a light scalar boson (denoted as H(125) in this paper) was discovered at the LHC. We explore the possible correlation between the lightness of H(125) and the smallness of CP-violation based on the Lee model, namely the spontaneous CP-violation two-Higgs-doublet-model. It is a new way to understand why H(125) is light. Based on this we propose that it is the much heavier scalar bosons, instead of the H(125), which need to be understood. This opens a new paradigm that one tries to understand the electro-weak symmetry breaking and CP violation. For the new paradigm, similar to many other physics beyond the standard model, one need both electron-positron and higher energy hadron collider, as well as the low energy experiments, in order to pin down the whole picture.
hep-ph/0401188
Iain W. Stewart
Christian W. Bauer, Dan Pirjol, Ira Z. Rothstein, Iain W. Stewart
B -> M1 M2: Factorization, Charming Penguins, Strong Phases, and Polarization
10 pages, v2 phenomenological analysis of B->pi pi added
Phys.Rev. D70 (2004) 054015
10.1103/PhysRevD.70.054015
MIT-CTP 3469, CMU-HEP-04-01, CALT-68-2475
hep-ph hep-ex
null
Using the soft-collinear effective theory we derive the factorization theorem for the decays B-> M1 M2 with M{1,2}= pi,K, rho,K*, at leading order in Lambda/E_M and Lambda/mb. The results derived here apply even if alpha_s(E_M Lambda) is not perturbative, and we prove that the physics sensitive to the E*Lambda scale is the same in B-> M1 M2 and B-> M form factors. We argue that c-cbar penguins could give long-distance effects at leading order. Decays to two transversely polarized vector mesons are discussed. Analyzing B-> pi pi we find predictions for B^0 -> pi^0 pi^0 and |V_{ub}| f_+(0) as a function of gamma.
[ { "created": "Mon, 26 Jan 2004 20:27:26 GMT", "version": "v1" }, { "created": "Wed, 2 Jun 2004 04:24:50 GMT", "version": "v2" } ]
2009-11-10
[ [ "Bauer", "Christian W.", "" ], [ "Pirjol", "Dan", "" ], [ "Rothstein", "Ira Z.", "" ], [ "Stewart", "Iain W.", "" ] ]
Using the soft-collinear effective theory we derive the factorization theorem for the decays B-> M1 M2 with M{1,2}= pi,K, rho,K*, at leading order in Lambda/E_M and Lambda/mb. The results derived here apply even if alpha_s(E_M Lambda) is not perturbative, and we prove that the physics sensitive to the E*Lambda scale is the same in B-> M1 M2 and B-> M form factors. We argue that c-cbar penguins could give long-distance effects at leading order. Decays to two transversely polarized vector mesons are discussed. Analyzing B-> pi pi we find predictions for B^0 -> pi^0 pi^0 and |V_{ub}| f_+(0) as a function of gamma.
hep-ph/0211339
Aleksey I. Alekseev
Aleksey I. Alekseev
Strong coupling constant to four loops in the analytic approach to QCD
30 pages, LATEX, 4 tables, 8 figures
Few Body Syst. 32 (2003) 193-217
10.1007/s00601-003-0005-3
null
hep-ph
null
The QCD analytic running coupling alpha_{an} which has no nonphysical singularities for all Q^2>0 is considered for the initial perturbation theory approximations up to four loop order. The finiteness of the analytic coupling at zero is shown to be a consequence of the asymptotic freedom property of the initial theory. The nonperturbative contributions to the analytic coupling are extracted explicitly. For all Q>Lambda they are represented in the form of an expansion in inverse powers of Euclidean momentum squared. The effective method for a precise calculation of the analytic running coupling is developed on the basis of the stated expansion. The energy scale evolution of the analytic running coupling for the one- to four-loop cases is studied and the higher loop stability and low dependence on the quark threshold matching conditions in comparison with the perturbative running coupling were found. Normalizing the analytic running coupling at the scale of the rest mass of the Z boson with the world average value of the strong coupling constant, alpha_{an}(M_Z^2)=0.1181^{+0.002}_{-0.002}, one obtains as a result of the energy scale evolution of the analytic running coupling alpha_{an}(M_tau^2)= 0.2943^{+0.0111}_{-0.0106} that is notably lower than the estimations of the coupling strength available at the scale of the mass of the tau lepton.
[ { "created": "Thu, 21 Nov 2002 18:35:51 GMT", "version": "v1" } ]
2009-11-07
[ [ "Alekseev", "Aleksey I.", "" ] ]
The QCD analytic running coupling alpha_{an} which has no nonphysical singularities for all Q^2>0 is considered for the initial perturbation theory approximations up to four loop order. The finiteness of the analytic coupling at zero is shown to be a consequence of the asymptotic freedom property of the initial theory. The nonperturbative contributions to the analytic coupling are extracted explicitly. For all Q>Lambda they are represented in the form of an expansion in inverse powers of Euclidean momentum squared. The effective method for a precise calculation of the analytic running coupling is developed on the basis of the stated expansion. The energy scale evolution of the analytic running coupling for the one- to four-loop cases is studied and the higher loop stability and low dependence on the quark threshold matching conditions in comparison with the perturbative running coupling were found. Normalizing the analytic running coupling at the scale of the rest mass of the Z boson with the world average value of the strong coupling constant, alpha_{an}(M_Z^2)=0.1181^{+0.002}_{-0.002}, one obtains as a result of the energy scale evolution of the analytic running coupling alpha_{an}(M_tau^2)= 0.2943^{+0.0111}_{-0.0106} that is notably lower than the estimations of the coupling strength available at the scale of the mass of the tau lepton.
hep-ph/9703369
Debajyoti Choudhury
Debajyoti Choudhury and Sreerup Raychaudhuri (CERN)
Like-Sign Dileptons at the Fermilab Tevatron Revisited in the Light of the HERA High-$Q^2$ Anomaly
Minor changes made and references updated
Phys.Rev.D56:1778-1782,1997
10.1103/PhysRevD.56.1778
CERN-TH/97-51
hep-ph
null
We re-examine like-sign dilepton signals at the Fermilab Tevatron assuming that the excess high-$Q^2$ events recently seen at HERA are due to scalar resonances such as squarks of $R$-parity-violating supersymmetry. For gluinos in the mass range of 200--350 GeV, the like-sign dilepton signal can help to make the crucial distinction between the most favoured squark explanation and other proposed solutions.
[ { "created": "Wed, 19 Mar 1997 19:06:35 GMT", "version": "v1" }, { "created": "Wed, 9 Apr 1997 15:46:58 GMT", "version": "v2" } ]
2011-08-11
[ [ "Choudhury", "Debajyoti", "", "CERN" ], [ "Raychaudhuri", "Sreerup", "", "CERN" ] ]
We re-examine like-sign dilepton signals at the Fermilab Tevatron assuming that the excess high-$Q^2$ events recently seen at HERA are due to scalar resonances such as squarks of $R$-parity-violating supersymmetry. For gluinos in the mass range of 200--350 GeV, the like-sign dilepton signal can help to make the crucial distinction between the most favoured squark explanation and other proposed solutions.
2209.08100
Edward D. Ramirez
Edward D. Ramirez, Matthew R. Buckley
Constraining Dark Matter Substructure With Gaia Wide Binaries
21 pages, 23 figures
null
null
null
hep-ph astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use a catalogue of stellar binaries with wide separations (up to 1 pc) identified by the Gaia satellite to constrain the presence of extended substructure within the Milky Way galaxy. Heating of the binaries through repeated encounters with substructure results in a characteristic distribution of binary separations, allowing constraints to be placed independent of the formation mechanism of wide binaries. Across a wide range of subhalo density profiles, we show that subhalos with masses $\gtrsim 65 \ M_\odot$ and characteristic length scales similar to the separation of these wide binaries cannot make up 100% of the Galaxy's dark matter. Constraints weaken for subhalos with larger length scales and are dependent on their density profiles. For such large subhalos, higher central densities lead to stronger constraints. Subhalos with density profiles similar to those expected from cold dark matter must be at least $\sim 5,000$ times denser than predicted by simulation to be constrained by the wide binary catalogue.
[ { "created": "Fri, 16 Sep 2022 18:00:00 GMT", "version": "v1" } ]
2022-09-20
[ [ "Ramirez", "Edward D.", "" ], [ "Buckley", "Matthew R.", "" ] ]
We use a catalogue of stellar binaries with wide separations (up to 1 pc) identified by the Gaia satellite to constrain the presence of extended substructure within the Milky Way galaxy. Heating of the binaries through repeated encounters with substructure results in a characteristic distribution of binary separations, allowing constraints to be placed independent of the formation mechanism of wide binaries. Across a wide range of subhalo density profiles, we show that subhalos with masses $\gtrsim 65 \ M_\odot$ and characteristic length scales similar to the separation of these wide binaries cannot make up 100% of the Galaxy's dark matter. Constraints weaken for subhalos with larger length scales and are dependent on their density profiles. For such large subhalos, higher central densities lead to stronger constraints. Subhalos with density profiles similar to those expected from cold dark matter must be at least $\sim 5,000$ times denser than predicted by simulation to be constrained by the wide binary catalogue.
1806.01129
Subhaditya Bhattacharya
Basabendu Barman, Subhaditya Bhattacharya and Mohammadreza Zakeri
Multipartite Dark Matter in $SU(2)_N$ extension of Standard Model and signatures at the LHC
35 pages, 29 figures and 4 tables, Version published in JCAP
null
10.1088/1475-7516/2018/09/023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An $SU(2)_N$ extension ($N$ stands for neutral) of the Standard Model (SM) is proposed with an additional $U(1)=S^{'}$ global symmetry, which stabilizes the lightest of the vector boson ($X,\bar{X}$) as dark matter (DM) through unbroken $S=T_{3N}+S^{'}$. The field content of the model is motivated to address neutrino mass generation, a possible unification to $SU(7)$, along with spontaneous symmetry breaking of $SU(2)_N$ resulting in massive gauge bosons. None of the SM particles are charged under $SU(2)_N$ and therefore $X,\bar{X}$ do not have a direct coupling to the visible sector besides a Higgs portal, which is tiny to avoid any conflict with Higgs data. We show that, a large kinematic region of this model allows the neutral component of $SU(2)_N$ scalar triplet and heavy neutrinos introduced here to become additional DM components. In this paper we explore the viability of such multipartite DM parameter space, including non-zero DM-DM interactions, to comply with relic density and direct search constraints. We also demonstrate that the model may yield hadronically quiet single lepton and two lepton signatures with missing energy at the Large Hadron Collider (LHC) that can be accessed with high luminosity.
[ { "created": "Mon, 4 Jun 2018 14:04:33 GMT", "version": "v1" }, { "created": "Thu, 20 Sep 2018 06:39:36 GMT", "version": "v2" } ]
2018-09-26
[ [ "Barman", "Basabendu", "" ], [ "Bhattacharya", "Subhaditya", "" ], [ "Zakeri", "Mohammadreza", "" ] ]
An $SU(2)_N$ extension ($N$ stands for neutral) of the Standard Model (SM) is proposed with an additional $U(1)=S^{'}$ global symmetry, which stabilizes the lightest of the vector boson ($X,\bar{X}$) as dark matter (DM) through unbroken $S=T_{3N}+S^{'}$. The field content of the model is motivated to address neutrino mass generation, a possible unification to $SU(7)$, along with spontaneous symmetry breaking of $SU(2)_N$ resulting in massive gauge bosons. None of the SM particles are charged under $SU(2)_N$ and therefore $X,\bar{X}$ do not have a direct coupling to the visible sector besides a Higgs portal, which is tiny to avoid any conflict with Higgs data. We show that, a large kinematic region of this model allows the neutral component of $SU(2)_N$ scalar triplet and heavy neutrinos introduced here to become additional DM components. In this paper we explore the viability of such multipartite DM parameter space, including non-zero DM-DM interactions, to comply with relic density and direct search constraints. We also demonstrate that the model may yield hadronically quiet single lepton and two lepton signatures with missing energy at the Large Hadron Collider (LHC) that can be accessed with high luminosity.
2004.11915
Jonathan Gaunt
Jonathan R. Gaunt, Maximilian Stahlhofen
The Fully-Differential Gluon Beam Function at NNLO
21 pages, 0 figures
null
10.1007/JHEP07(2020)234
CERN-TH-2020-065, FR-PHENO-2020-003
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The fully-differential beam function (dBF) is a universal ingredient in resummed predictions of hadron collider observables that probe the full kinematics of the incoming parton from each colliding proton -- the virtuality and transverse momentum as well as the light-cone momentum fraction $x$. In this paper we compute the matching coefficients between the unpolarized gluon dBF and the usual parton distribution functions (PDFs) at the two-loop order. For observables probing both the virtuality and transverse momentum of incoming gluons, our results provide the part of the NNLO singular cross section related to collinear initial-state radiation, and are required for the resummation of large logarithms through N$^3$LL. Further to this, the dBF is closely linked to the beam function appearing in a generalized version of threshold factorization, via a simple integration. By performing this integration for the two-loop gluon matching coefficients, we also obtain the corresponding quantities for the generalized threshold beam function.
[ { "created": "Fri, 24 Apr 2020 18:00:03 GMT", "version": "v1" } ]
2020-08-26
[ [ "Gaunt", "Jonathan R.", "" ], [ "Stahlhofen", "Maximilian", "" ] ]
The fully-differential beam function (dBF) is a universal ingredient in resummed predictions of hadron collider observables that probe the full kinematics of the incoming parton from each colliding proton -- the virtuality and transverse momentum as well as the light-cone momentum fraction $x$. In this paper we compute the matching coefficients between the unpolarized gluon dBF and the usual parton distribution functions (PDFs) at the two-loop order. For observables probing both the virtuality and transverse momentum of incoming gluons, our results provide the part of the NNLO singular cross section related to collinear initial-state radiation, and are required for the resummation of large logarithms through N$^3$LL. Further to this, the dBF is closely linked to the beam function appearing in a generalized version of threshold factorization, via a simple integration. By performing this integration for the two-loop gluon matching coefficients, we also obtain the corresponding quantities for the generalized threshold beam function.
hep-ph/0112122
Ismd31
Nu Xu
Recent results from heavy ion collisions
8 pages, 4 figures (2 in ps, 2 in eps) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China see http://ismd31.ccnu.edu.cn/
null
10.1142/9789812778048_0027
null
hep-ph
null
Systematic trends of baryon transport, chemical freeze-out, and kinetic freeze-out in high energy nuclear collisions are presented. Further measurements of particles with heavy flavors are proposed in order to shed light on collision dynamics at parton level.
[ { "created": "Sat, 8 Dec 2001 04:55:43 GMT", "version": "v1" } ]
2017-08-23
[ [ "Xu", "Nu", "" ] ]
Systematic trends of baryon transport, chemical freeze-out, and kinetic freeze-out in high energy nuclear collisions are presented. Further measurements of particles with heavy flavors are proposed in order to shed light on collision dynamics at parton level.
1905.08577
Marius H\"ofer
X. Chen, T. Gehrmann, N. Glover, M. H\"ofer, A. Huss
Isolated photon and photon+jet production at NNLO QCD accuracy and the ratio $R_{13/8}^\gamma$
4 pages, 1 figure. Contribution to the 2019 QCD session of the 54th Rencontres de Moriond
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss different approaches to photon isolation in fixed-order calculations and present a new next-to-next-to-leading order (NNLO) QCD calculation of $R_{13/8}^\gamma$, the ratio of the inclusive isolated photon cross section at 8 TeV and 13 TeV, differential in the photon transverse momentum, which was recently measured by the ATLAS collaboration.
[ { "created": "Tue, 21 May 2019 12:22:48 GMT", "version": "v1" } ]
2019-05-22
[ [ "Chen", "X.", "" ], [ "Gehrmann", "T.", "" ], [ "Glover", "N.", "" ], [ "Höfer", "M.", "" ], [ "Huss", "A.", "" ] ]
We discuss different approaches to photon isolation in fixed-order calculations and present a new next-to-next-to-leading order (NNLO) QCD calculation of $R_{13/8}^\gamma$, the ratio of the inclusive isolated photon cross section at 8 TeV and 13 TeV, differential in the photon transverse momentum, which was recently measured by the ATLAS collaboration.
hep-ph/0012015
Andriy Kostyuk
M.I. Gorenstein, A.P. Kostyuk, H. Stoecker and W. Greiner
Open Charm Enhancement in Pb+Pb Collisions at SPS
4 pages, Latex
J.Phys. G27 (2001) L47-L52
10.1088/0954-3899/27/7/101
null
hep-ph
null
The statistical coalescence model for the production of open and hidden charm is considered within the canonical ensemble formulation. The data for the J/\psi multiplicity in Pb+Pb collisions at 158 A GeV are used for the model prediction of the open charm yield. We find a strong enhancement of the open charm production, by a factor of about 2--4, over the standard hard-collision model extrapolation from nucleon-nucleon to nucleus-nucleus collisions. A possible mechanism of the open charm enhancement in A+A collisions at the SPS energies is proposed.
[ { "created": "Fri, 1 Dec 2000 19:37:04 GMT", "version": "v1" } ]
2009-10-31
[ [ "Gorenstein", "M. I.", "" ], [ "Kostyuk", "A. P.", "" ], [ "Stoecker", "H.", "" ], [ "Greiner", "W.", "" ] ]
The statistical coalescence model for the production of open and hidden charm is considered within the canonical ensemble formulation. The data for the J/\psi multiplicity in Pb+Pb collisions at 158 A GeV are used for the model prediction of the open charm yield. We find a strong enhancement of the open charm production, by a factor of about 2--4, over the standard hard-collision model extrapolation from nucleon-nucleon to nucleus-nucleus collisions. A possible mechanism of the open charm enhancement in A+A collisions at the SPS energies is proposed.
1601.06163
Cen Zhang
Cen Zhang
Single Top Production at Next-to-Leading Order in the Standard Model Effective Field Theory
Typos corrected; refs. added
Phys. Rev. Lett. 116, 162002 (2016)
10.1103/PhysRevLett.116.162002
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Single top production processes at hadron colliders provide information on the relation between the top quark and the electroweak sector of the standard model. We compute the next-to-leading order QCD corrections to the three main production channels: $t$-channel, $s$-channel and $tW$ associated production, in the standard model including operators up to dimension-six. The calculation can be matched to parton shower programs and can therefore be directly used in experimental analyses. The QCD corrections are found to significantly impact the extraction of the current limits on the operators, because both of an improved accuracy and a better precision of the theoretical predictions. In addition, the distributions of some of the key discriminating observables are modified in a nontrivial way, which could change the interpretation of measurements in terms of UV complete models.
[ { "created": "Fri, 22 Jan 2016 21:00:01 GMT", "version": "v1" }, { "created": "Fri, 15 Apr 2016 19:04:43 GMT", "version": "v2" } ]
2016-04-27
[ [ "Zhang", "Cen", "" ] ]
Single top production processes at hadron colliders provide information on the relation between the top quark and the electroweak sector of the standard model. We compute the next-to-leading order QCD corrections to the three main production channels: $t$-channel, $s$-channel and $tW$ associated production, in the standard model including operators up to dimension-six. The calculation can be matched to parton shower programs and can therefore be directly used in experimental analyses. The QCD corrections are found to significantly impact the extraction of the current limits on the operators, because both of an improved accuracy and a better precision of the theoretical predictions. In addition, the distributions of some of the key discriminating observables are modified in a nontrivial way, which could change the interpretation of measurements in terms of UV complete models.
2401.06214
Marco Ardu
Marco Ardu, Sacha Davidson, St\'ephane Lavignac
Constraining New Physics models from $\mu\to e$ observables in bottom-up EFT
22 Pages + Appendix, 18 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Upcoming experiments will improve the sensitivity to $\mu\to e$ processes by several orders of magnitude, and could observe lepton flavour-changing contact interactions for the first time. In this paper, we investigate what could be learned about New Physics from the measurements of these $\mu\to e$ observables, using a bottom-up effective field theory (EFT) approach and focusing on three popular models with new particles around the TeV scale (the type II seesaw, the inverse seesaw and a scalar leptoquark). We showed in a previous publication that $\mu\to e$ observables have the ability to rule out these models because none can fill the whole experimentally accessible parameter space. In this work, we give more details on our EFT formalism and present more complete results. We discuss the impact of some observables complementary to $\mu\to e$ transitions (such as the neutrino mass scale and ordering, and LFV $\tau$ decays) and draw attention to the interesting appearance of Jarlskog-like invariants in our expressions for the low-energy Wilson coefficients.
[ { "created": "Thu, 11 Jan 2024 19:00:02 GMT", "version": "v1" } ]
2024-01-15
[ [ "Ardu", "Marco", "" ], [ "Davidson", "Sacha", "" ], [ "Lavignac", "Stéphane", "" ] ]
Upcoming experiments will improve the sensitivity to $\mu\to e$ processes by several orders of magnitude, and could observe lepton flavour-changing contact interactions for the first time. In this paper, we investigate what could be learned about New Physics from the measurements of these $\mu\to e$ observables, using a bottom-up effective field theory (EFT) approach and focusing on three popular models with new particles around the TeV scale (the type II seesaw, the inverse seesaw and a scalar leptoquark). We showed in a previous publication that $\mu\to e$ observables have the ability to rule out these models because none can fill the whole experimentally accessible parameter space. In this work, we give more details on our EFT formalism and present more complete results. We discuss the impact of some observables complementary to $\mu\to e$ transitions (such as the neutrino mass scale and ordering, and LFV $\tau$ decays) and draw attention to the interesting appearance of Jarlskog-like invariants in our expressions for the low-energy Wilson coefficients.
hep-ph/0508144
Ramazan Sever
Sameer M. Ikhdair and Ramazan Sever
A Systematic Study on Nonrelativistic Quarkonium Interaction
24 pages
Int.J.Mod.Phys. A21 (2006) 3989-4002
10.1142/S0217751X06030953
null
hep-ph
null
recently proposed strictly phenomenological static quark-antiquark potential belonging to the generality $V(r)=-Ar^{-\alpha}+\kappa r^{\beta}+V_{0}$ is tested with heavy quarkonia in the context of the shifted large N-expansion method. This nonrelativistic potential model fits the spin-averaged mass spectra of the $c\bar{c},$ $b\bar{b}$ and $c% \bar{b}$ quarkonia within a few ${\rm MeV}$ and also the five experimentally known leptonic decay widths of the $c\bar{c}$ and $b% \bar{b}$ vector states. Further, we compute the hyperfine splittings of the bottomonium spectrum as well as the fine and hyperfine splittings of the charmonium spectrum. We give predictions for not yet observed $B_{c}$ splittings. The model is then used to predict the masses of the remaining quarkonia and the leptonic decay widths of the two pseudoscalar $c\bar{b%}$ states. Our results are compared with other models to gauge the reliability of the predictions and point out differences.
[ { "created": "Fri, 12 Aug 2005 06:00:48 GMT", "version": "v1" } ]
2009-11-11
[ [ "Ikhdair", "Sameer M.", "" ], [ "Sever", "Ramazan", "" ] ]
recently proposed strictly phenomenological static quark-antiquark potential belonging to the generality $V(r)=-Ar^{-\alpha}+\kappa r^{\beta}+V_{0}$ is tested with heavy quarkonia in the context of the shifted large N-expansion method. This nonrelativistic potential model fits the spin-averaged mass spectra of the $c\bar{c},$ $b\bar{b}$ and $c% \bar{b}$ quarkonia within a few ${\rm MeV}$ and also the five experimentally known leptonic decay widths of the $c\bar{c}$ and $b% \bar{b}$ vector states. Further, we compute the hyperfine splittings of the bottomonium spectrum as well as the fine and hyperfine splittings of the charmonium spectrum. We give predictions for not yet observed $B_{c}$ splittings. The model is then used to predict the masses of the remaining quarkonia and the leptonic decay widths of the two pseudoscalar $c\bar{b%}$ states. Our results are compared with other models to gauge the reliability of the predictions and point out differences.
2003.03817
Vladimir Petrov A.
V. V. Ezhela, V. A. Petrov and N. P. Tkachenko
On the $ \rho $ and $ \sigma_{tot} $ measurement by the TOTEM Collaboration: in the wake of recent discoveries
A small edit of the drawing
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that extraction of the quantities} $\rho(s)=\mbox{Re}[T_{N}(s,0)]/\mbox{Im}[T_{N}(s,0)]$ {\it and} $\sigma_{\mbox{tot}}(s)$ {\it from the data on the $pp$ differential cross-section at $\sqrt{s} = 13$} TeV {\it obtained by the} TOTEM {\it Collaboration gives results essentially different from those presented in publication} \cite{Ant} {\it if to use a modified formula for Coulomb-nuclear interference. The physical interpretation of these data changes accordingly.
[ { "created": "Sun, 8 Mar 2020 17:34:50 GMT", "version": "v1" }, { "created": "Tue, 10 Mar 2020 09:03:41 GMT", "version": "v2" } ]
2020-03-11
[ [ "Ezhela", "V. V.", "" ], [ "Petrov", "V. A.", "" ], [ "Tkachenko", "N. P.", "" ] ]
We show that extraction of the quantities} $\rho(s)=\mbox{Re}[T_{N}(s,0)]/\mbox{Im}[T_{N}(s,0)]$ {\it and} $\sigma_{\mbox{tot}}(s)$ {\it from the data on the $pp$ differential cross-section at $\sqrt{s} = 13$} TeV {\it obtained by the} TOTEM {\it Collaboration gives results essentially different from those presented in publication} \cite{Ant} {\it if to use a modified formula for Coulomb-nuclear interference. The physical interpretation of these data changes accordingly.
1708.04012
Tomasz Skwarnicki
Stephen Lars Olsen, Tomasz Skwarnicki, Daria Zieminska
Non-Standard Heavy Mesons and Baryons, an Experimental Review
null
Rev. Mod. Phys. 90, 15003 (2018)
10.1103/RevModPhys.90.015003
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Quantum Chromodynamics (QCD), the generally accepted theory for the strong interactions, describes the interactions between quarks and gluons. The strongly interacting particles that are seen in nature are hadrons, which are composites of quarks and gluons. Since QCD is a strongly coupled theory at distance scales that are characteristic of observable hadrons, there are no rigorous, first-principle methods to derive the spectrum and properties of the hadrons from the QCD Lagrangian, except for Lattice QCD simulations that are not yet able to cope with all aspects of complex and short-lived states. Instead, a variety of "QCD inspired" phenomenological models have been proposed. Common features of these models are predictions for the existence of hadrons with substructures that are more complex than the standard quark-antiquark mesons and the three quark baryons of the original quark model that provides a concise description of most of the low-mass hadrons. Recently, an assortment of candidates for non-standard multi-quark mesons, meson-gluon hybrids and pentaquark baryons that contain heavy (charm or bottom) quarks have been discovered. Here we review the experimental evidence for these states and make some general comparisons of their measured properties with standard quark-model expectations and predictions of various models for non-standard hadrons. We conclude that the spectroscopy of all but simplest hadrons is not yet understood.
[ { "created": "Mon, 14 Aug 2017 05:06:19 GMT", "version": "v1" } ]
2018-02-14
[ [ "Olsen", "Stephen Lars", "" ], [ "Skwarnicki", "Tomasz", "" ], [ "Zieminska", "Daria", "" ] ]
Quantum Chromodynamics (QCD), the generally accepted theory for the strong interactions, describes the interactions between quarks and gluons. The strongly interacting particles that are seen in nature are hadrons, which are composites of quarks and gluons. Since QCD is a strongly coupled theory at distance scales that are characteristic of observable hadrons, there are no rigorous, first-principle methods to derive the spectrum and properties of the hadrons from the QCD Lagrangian, except for Lattice QCD simulations that are not yet able to cope with all aspects of complex and short-lived states. Instead, a variety of "QCD inspired" phenomenological models have been proposed. Common features of these models are predictions for the existence of hadrons with substructures that are more complex than the standard quark-antiquark mesons and the three quark baryons of the original quark model that provides a concise description of most of the low-mass hadrons. Recently, an assortment of candidates for non-standard multi-quark mesons, meson-gluon hybrids and pentaquark baryons that contain heavy (charm or bottom) quarks have been discovered. Here we review the experimental evidence for these states and make some general comparisons of their measured properties with standard quark-model expectations and predictions of various models for non-standard hadrons. We conclude that the spectroscopy of all but simplest hadrons is not yet understood.
1902.01355
Steven D. Bass
Steven D. Bass
QED and Fundamental Symmetries in Positronium Decays
15 pages, to appear in Acta Physica Polonica B, based on a lecture presented at the 3rd Symposium on Positron Emission Tomography, Cracow, September 10-13 2018
Acta Phys. Polon. B50 (2019) 1319
10.5506/APhysPolB.50.1319
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss positronium decays with emphasis on tests of fundamental symmetries and the constraints from measurements of other precision observables involving electrons and photons.
[ { "created": "Mon, 4 Feb 2019 18:19:20 GMT", "version": "v1" }, { "created": "Mon, 6 May 2019 09:36:30 GMT", "version": "v2" } ]
2019-07-12
[ [ "Bass", "Steven D.", "" ] ]
We discuss positronium decays with emphasis on tests of fundamental symmetries and the constraints from measurements of other precision observables involving electrons and photons.
hep-ph/0005134
Osamu Yasuda
Osamu Yasuda
Phenomenology of Neutrino Oscillations at a Neutrino Factory
12 pages, 6 sets of figures, uses epsfig. Talk presented at KEK International Workshop on High Intensity Muon Sources (HIMUS99), to appear in Proceedings published by World Scientific Publishing Co
null
10.1142/9789812791849_0009
TMUP-HEL-0008
hep-ph
null
It is shown in the three flavor framework that neutrino factories enable us to measure some of the oscillation parameters, such as the sign of $\Delta m_{32}^2$, $\theta_{13}$, $\delta$. Some efforts are made to determine the parameters (the muon energy and the neutrino path length) of a neutrino factory to optimize the signals.
[ { "created": "Mon, 15 May 2000 04:04:34 GMT", "version": "v1" } ]
2016-11-23
[ [ "Yasuda", "Osamu", "" ] ]
It is shown in the three flavor framework that neutrino factories enable us to measure some of the oscillation parameters, such as the sign of $\Delta m_{32}^2$, $\theta_{13}$, $\delta$. Some efforts are made to determine the parameters (the muon energy and the neutrino path length) of a neutrino factory to optimize the signals.
1408.3811
Eugene Levin
E. Gotsman (Tel AvivU.), E.Levin (Tel Aviv U./UTFSM) and U. Maor (Tel Aviv U.)
A model for strong interactions at high energy based on the CGC/saturation approach
21 pp. 16 figures in eps files
null
10.1140/epjc/s10052-014-3205-8
TAUP - 2985/14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present our first attempt to develop a model for soft interactions at high energy, based on the BFKL Pomeron and the CGC/saturation approach. We construct an eikonal-type model, whose opacity is determined by the exchange of the dressed BFKL Pomeron. The Green's function of the Pomeron is calculated in the framework of the CGC/saturation approach. Using five parameters we achieve a good description of the experimental data at high energies ( $W\,\geq\,0.546\,TeV$). The model results in different behaviour for the single and double diffraction cross sections at high energies. The single diffraction cross section reaches a saturated value (about 10 mb) at high energies, while the double diffraction cross section continues growing slowly
[ { "created": "Sun, 17 Aug 2014 11:13:19 GMT", "version": "v1" }, { "created": "Sun, 24 Aug 2014 08:00:56 GMT", "version": "v2" }, { "created": "Tue, 2 Dec 2014 12:00:11 GMT", "version": "v3" } ]
2015-06-22
[ [ "Gotsman", "E.", "", "Tel AvivU." ], [ "Levin", "E.", "", "Tel Aviv U./UTFSM" ], [ "Maor", "U.", "", "Tel\n Aviv U." ] ]
We present our first attempt to develop a model for soft interactions at high energy, based on the BFKL Pomeron and the CGC/saturation approach. We construct an eikonal-type model, whose opacity is determined by the exchange of the dressed BFKL Pomeron. The Green's function of the Pomeron is calculated in the framework of the CGC/saturation approach. Using five parameters we achieve a good description of the experimental data at high energies ( $W\,\geq\,0.546\,TeV$). The model results in different behaviour for the single and double diffraction cross sections at high energies. The single diffraction cross section reaches a saturated value (about 10 mb) at high energies, while the double diffraction cross section continues growing slowly
hep-ph/9902438
K. Sridhar
K. Sridhar (TIFR)
Issues in Quarkonium Production
9 pages, latex, 2 ps figures. Invited talk presented at the 13th International Conference on Hadron Collider Physics, Mumbai, India, 14-20 January 1999
null
null
TIFR/TH/99-09
hep-ph
null
In this talk, I start with a brief introduction to Non-Relativistic QCD (NRQCD) and its applications to quarkonium physics. This theory has provided a consistent framework for the physics of quarkonia, in particular, the colour-octet Fock components predicted by NRQCD have important implications for the phenomenology of charmonium production in experiments. The applications of NRQCD to $J/\psi$ production at Tevatron and the tests of the theory in other experiments is discussed. In particular, the apparent disagreement of NRQCD with results from HERA on inelastic photoproduction of $J/\psi$ is discussed and it is shown that the results are rather susceptible to intrinsic transverse momentum smearing. The photoproduction data, therefore, do not provide a good test of NRQCD. It is argued that NRQCD may be tested stringently by looking for the production of other charmonium resonances at the Tevatron, because the production rates for these resonances can be predicted within the NRQCD framework.
[ { "created": "Tue, 23 Feb 1999 11:00:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sridhar", "K.", "", "TIFR" ] ]
In this talk, I start with a brief introduction to Non-Relativistic QCD (NRQCD) and its applications to quarkonium physics. This theory has provided a consistent framework for the physics of quarkonia, in particular, the colour-octet Fock components predicted by NRQCD have important implications for the phenomenology of charmonium production in experiments. The applications of NRQCD to $J/\psi$ production at Tevatron and the tests of the theory in other experiments is discussed. In particular, the apparent disagreement of NRQCD with results from HERA on inelastic photoproduction of $J/\psi$ is discussed and it is shown that the results are rather susceptible to intrinsic transverse momentum smearing. The photoproduction data, therefore, do not provide a good test of NRQCD. It is argued that NRQCD may be tested stringently by looking for the production of other charmonium resonances at the Tevatron, because the production rates for these resonances can be predicted within the NRQCD framework.
hep-ph/9805501
Nita Sinha
Nita Sinha and Rahul Sinha (Institute of Mathematical Sciences)
CP Violation and Lifetime Differences of Neutral B Mesons from Correlated B^0-B^0bar Pairs
11 Pages Revtex
Phys.Rev. D59 (1999) 116001
10.1103/PhysRevD.59.116001
IMSc-98/05/23
hep-ph
null
We present a technique to determine the CP violating phases, as well as, the lifetime differences of the mass eigenstates for both $B_d$ and $B_s$, by considering correlated $B\bar{B}$ pairs produced at the $\Upsilon$ resonances. We do not require a detailed time dependent study, but only partial time integrated rates, with the tag time, either preceding or following the decay of the other $B$ meson to a final state f. f may be a CP eigenstate or a non-CP eigenstate.
[ { "created": "Fri, 29 May 1998 11:26:31 GMT", "version": "v1" } ]
2009-10-31
[ [ "Sinha", "Nita", "", "Institute of Mathematical Sciences" ], [ "Sinha", "Rahul", "", "Institute of Mathematical Sciences" ] ]
We present a technique to determine the CP violating phases, as well as, the lifetime differences of the mass eigenstates for both $B_d$ and $B_s$, by considering correlated $B\bar{B}$ pairs produced at the $\Upsilon$ resonances. We do not require a detailed time dependent study, but only partial time integrated rates, with the tag time, either preceding or following the decay of the other $B$ meson to a final state f. f may be a CP eigenstate or a non-CP eigenstate.
2407.03524
Vidya Manian
Jairo Orozco Sandoval, Vidya Manian, Sudhir Malik
A multicategory jet image classification framework using deep neural network
9 pages, y figures
null
null
null
hep-ph cs.LG
http://creativecommons.org/licenses/by/4.0/
Jet point cloud images are high dimensional data structures that needs to be transformed to a separable feature space for machine learning algorithms to distinguish them with simple decision boundaries. In this article, the authors focus on jet category separability by particle and jet feature extraction, resulting in more efficient training of a simple deep neural network, resulting in a computational efficient interpretable model for jet classification. The methodology is tested with three to five categories of jets from the JetNet benchmark jet tagging dataset, resulting in comparable performance to particle flow network. This work demonstrates that high dimensional datasets represented in separable latent spaces lead to simpler architectures for jet classification.
[ { "created": "Wed, 3 Jul 2024 22:00:35 GMT", "version": "v1" } ]
2024-07-08
[ [ "Sandoval", "Jairo Orozco", "" ], [ "Manian", "Vidya", "" ], [ "Malik", "Sudhir", "" ] ]
Jet point cloud images are high dimensional data structures that needs to be transformed to a separable feature space for machine learning algorithms to distinguish them with simple decision boundaries. In this article, the authors focus on jet category separability by particle and jet feature extraction, resulting in more efficient training of a simple deep neural network, resulting in a computational efficient interpretable model for jet classification. The methodology is tested with three to five categories of jets from the JetNet benchmark jet tagging dataset, resulting in comparable performance to particle flow network. This work demonstrates that high dimensional datasets represented in separable latent spaces lead to simpler architectures for jet classification.
hep-ph/0506235
Gian Paolo Vacca
J. bartels, L.N. Lipatov, M. Salvadore and G.P. Vacca
Deformed Spectral Representation of the BFKL Kernel and the Bootstrap for Gluon Reggeization
22 pages, 1 figure
Nucl.Phys. B726 (2005) 53-74
10.1016/j.nuclphysb.2005.07.033
preprint DESY 05-103
hep-ph hep-th
null
We investigate the space of functions in which the BFKL kernel acts. For the amplitudes which describe the scattering of colorless projectiles it is convenient to define, in transverse coordinates, the Moebius space in which the solutions to the BFKL equation vanish as the coordinates of the two reggeized gluons coincide. However, in order to fulfill the bootstrap relation for the BFKL kernel it is necessary to modify the space of functions. We define and investigate a new space of functions and show explicitly that the bootstrap relation is valid for the corresponding spectral form of the kernel. We calculate the generators of the resulting deformed representation of the sl(2,C) algebra.
[ { "created": "Thu, 23 Jun 2005 15:21:41 GMT", "version": "v1" } ]
2009-11-11
[ [ "bartels", "J.", "" ], [ "Lipatov", "L. N.", "" ], [ "Salvadore", "M.", "" ], [ "Vacca", "G. P.", "" ] ]
We investigate the space of functions in which the BFKL kernel acts. For the amplitudes which describe the scattering of colorless projectiles it is convenient to define, in transverse coordinates, the Moebius space in which the solutions to the BFKL equation vanish as the coordinates of the two reggeized gluons coincide. However, in order to fulfill the bootstrap relation for the BFKL kernel it is necessary to modify the space of functions. We define and investigate a new space of functions and show explicitly that the bootstrap relation is valid for the corresponding spectral form of the kernel. We calculate the generators of the resulting deformed representation of the sl(2,C) algebra.
1803.10247
Rahul Srivastava
Rahul Srivastava, Christoph A. Ternes, Mariam T\'ortola, Jos\'e W. F. Valle
Zooming in on neutrino oscillations with DUNE
20 pages, 8 figures, Published Version
Phys. Rev. D 97, 095025 (2018)
10.1103/PhysRevD.97.095025
IFIC/18-xxx
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the capabilities of the DUNE experiment as a probe of the neutrino mixing paradigm. Taking the current status of neutrino oscillations and the design specifications of DUNE, we determine the experiment's potential to probe the structure of neutrino mixing and CP violation. We focus on the poorly determined parameters $\theta_{23}$ and $\delta_{CP}$ and consider both two and seven years of run. We take various benchmarks as our true values, such as the current preferred values of $\theta_{23}$ and $\delta_{CP}$, as well as several theory-motivated choices. We determine quantitatively DUNE's potential to perform a precision measurement of $\theta_{23}$, as well as to test the CP violation hypothesis in a model-independent way. We find that, after running for seven years, DUNE will make a substantial step in the precise determination of these parameters, bringing to quantitative test the predictions of various theories of neutrino mixing.
[ { "created": "Tue, 27 Mar 2018 18:00:17 GMT", "version": "v1" }, { "created": "Tue, 22 May 2018 13:58:31 GMT", "version": "v2" } ]
2018-05-23
[ [ "Srivastava", "Rahul", "" ], [ "Ternes", "Christoph A.", "" ], [ "Tórtola", "Mariam", "" ], [ "Valle", "José W. F.", "" ] ]
We examine the capabilities of the DUNE experiment as a probe of the neutrino mixing paradigm. Taking the current status of neutrino oscillations and the design specifications of DUNE, we determine the experiment's potential to probe the structure of neutrino mixing and CP violation. We focus on the poorly determined parameters $\theta_{23}$ and $\delta_{CP}$ and consider both two and seven years of run. We take various benchmarks as our true values, such as the current preferred values of $\theta_{23}$ and $\delta_{CP}$, as well as several theory-motivated choices. We determine quantitatively DUNE's potential to perform a precision measurement of $\theta_{23}$, as well as to test the CP violation hypothesis in a model-independent way. We find that, after running for seven years, DUNE will make a substantial step in the precise determination of these parameters, bringing to quantitative test the predictions of various theories of neutrino mixing.
1611.00543
Chuwen Xiao
C. W. Xiao
Investigations of the $D$-multi-$\rho$ interactions
References added; welcome to comment
null
10.1140/epja/i2017-12366-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present work, which aims at searching for bound sates, the interactions of the $D$-multi-$\rho$ systems are investigated by means of the formalism of the fixed-center-approximation to Faddeev equations. Reproducing the states of $f_2 (1270)$ and $D_1 (2420)$ dynamically in the two-body $\rho\rho$ and $\rho D$ interactions, respectively, as the clusters of the fixed center approximation, the state of $D(3000)^0$ is found as a molecule of $D-f_2$ or $\rho-D_1$ structures in the three-body interactions, where we determine its quantum number $J^P = 2^-$ and find another possible state of $D_2 (3100)$ with isospin $I=3/2$. In our results, there are some other predictions with uncertainties, a $D_3 (3160)$ state with $I(J^P) = \frac{1}{2} (3^+)$ in the four-body interactions, a narrow $D_4 (3730)$ state with $I(J^P) = \frac{1}{2} (4^-)$, a wide $D_4 (3410)$ state of $I(J^P) = \frac{1}{2} (4^-)$, and another wide $D_4 (3770)$ state but with $I(J^P) = \frac{3}{2} (4^-)$ in the five-body interactions, and a $D_5 (3570)$ state with $I(J^P) = \frac{1}{2} (5^+)$ in the six-body interactions. Our results are consistent with the findings of quark models.
[ { "created": "Wed, 2 Nov 2016 10:44:59 GMT", "version": "v1" }, { "created": "Thu, 10 Nov 2016 10:41:19 GMT", "version": "v2" } ]
2017-09-20
[ [ "Xiao", "C. W.", "" ] ]
In the present work, which aims at searching for bound sates, the interactions of the $D$-multi-$\rho$ systems are investigated by means of the formalism of the fixed-center-approximation to Faddeev equations. Reproducing the states of $f_2 (1270)$ and $D_1 (2420)$ dynamically in the two-body $\rho\rho$ and $\rho D$ interactions, respectively, as the clusters of the fixed center approximation, the state of $D(3000)^0$ is found as a molecule of $D-f_2$ or $\rho-D_1$ structures in the three-body interactions, where we determine its quantum number $J^P = 2^-$ and find another possible state of $D_2 (3100)$ with isospin $I=3/2$. In our results, there are some other predictions with uncertainties, a $D_3 (3160)$ state with $I(J^P) = \frac{1}{2} (3^+)$ in the four-body interactions, a narrow $D_4 (3730)$ state with $I(J^P) = \frac{1}{2} (4^-)$, a wide $D_4 (3410)$ state of $I(J^P) = \frac{1}{2} (4^-)$, and another wide $D_4 (3770)$ state but with $I(J^P) = \frac{3}{2} (4^-)$ in the five-body interactions, and a $D_5 (3570)$ state with $I(J^P) = \frac{1}{2} (5^+)$ in the six-body interactions. Our results are consistent with the findings of quark models.
1309.1681
Mikhail Voloshin
Xin Li and M.B.Voloshin
Y(4260) and Y(4360) as mixed hadrocharmonium
9 pages, 2 figures. Note added including a comparison of our model with the new BESIII data which became available after the initial version of our paper
null
10.1142/S0217732314500606
FTPI-MINN-13/32, UMN-TH-3303/13
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent BESIII data indicate a significant rate of the process $e^+e^- \to h_c \pi^+ \pi^-$ at the Y(4260) and Y(4360) resonances, implying a substantial breaking of the heavy quark spin symmetry. We consider these resonances within the picture of hadrocharmonium, i.e. of (relatively) compact charmonium embedded in a light quark mesonic excitation. We suggest that the resonances Y(4260) and Y(4360) are a mixture, with mixing close to maximal, of two states of hadrochamonium, one containing a spin-triplet $c \bar c$ pair and the other containing a spin-singlet heavy quark pair. We argue that this model is in a reasonable agreement with the available data and produces distinctive and verifiable predictions for the energy dependence of the production rate in $e^+e^-$ annihilation of the final states $J/\psi \pi \pi$, $\psi' \pi \pi$ and $h_c \pi \pi$, including the pattern of interference between the two resonances.
[ { "created": "Fri, 6 Sep 2013 15:49:29 GMT", "version": "v1" }, { "created": "Wed, 18 Sep 2013 17:39:56 GMT", "version": "v2" }, { "created": "Wed, 5 Feb 2014 18:28:15 GMT", "version": "v3" } ]
2015-06-17
[ [ "Li", "Xin", "" ], [ "Voloshin", "M. B.", "" ] ]
Recent BESIII data indicate a significant rate of the process $e^+e^- \to h_c \pi^+ \pi^-$ at the Y(4260) and Y(4360) resonances, implying a substantial breaking of the heavy quark spin symmetry. We consider these resonances within the picture of hadrocharmonium, i.e. of (relatively) compact charmonium embedded in a light quark mesonic excitation. We suggest that the resonances Y(4260) and Y(4360) are a mixture, with mixing close to maximal, of two states of hadrochamonium, one containing a spin-triplet $c \bar c$ pair and the other containing a spin-singlet heavy quark pair. We argue that this model is in a reasonable agreement with the available data and produces distinctive and verifiable predictions for the energy dependence of the production rate in $e^+e^-$ annihilation of the final states $J/\psi \pi \pi$, $\psi' \pi \pi$ and $h_c \pi \pi$, including the pattern of interference between the two resonances.
1407.4101
Katarzyna Krajewska
K. Krajewska, J. Z. Kami\'nski
Coherent combs of anti-matter from nonlinear electron-positron pair creation
9 pages, 5 figures
Phys. Rev. A 90, 052108 (2014)
10.1103/PhysRevA.90.052108
null
hep-ph physics.acc-ph physics.atom-ph physics.plasm-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electron-positron pair creation in collisions of a modulated laser pulse with a high-energy photon (nonlinear Breit-Wheeler process) is studied by means of strong-field quantum electrodynamics. It is shown that the driving pulse modulations lead to appearance of comb structures in the energy spectra of produced positrons (electrons). It is demonstrated that these combs result from a coherent enhancement of probability amplitudes of pair creation from different modulations of the laser pulse. Thus, resembling the Young-double slit experiment for anti-matter (matter) waves.
[ { "created": "Tue, 15 Jul 2014 19:31:07 GMT", "version": "v1" } ]
2015-06-22
[ [ "Krajewska", "K.", "" ], [ "Kamiński", "J. Z.", "" ] ]
Electron-positron pair creation in collisions of a modulated laser pulse with a high-energy photon (nonlinear Breit-Wheeler process) is studied by means of strong-field quantum electrodynamics. It is shown that the driving pulse modulations lead to appearance of comb structures in the energy spectra of produced positrons (electrons). It is demonstrated that these combs result from a coherent enhancement of probability amplitudes of pair creation from different modulations of the laser pulse. Thus, resembling the Young-double slit experiment for anti-matter (matter) waves.
2401.01323
Ren-You Zhang
Zhe Li, Ren-You Zhang, Shu-Xiang Li, Xiao-Feng Wang, Wen-Jie He, Liang Han, Yi Jiang, Qing-hai Wang
Mixed QCD-EW corrections to $W$-pair production at electron-positron colliders
32 pages, 9 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discrepancy between the CDF measurement and the Standard Model theoretical prediction for the $W$-boson mass underscores the importance of conducting high-precision studies on the $W$ boson, which is one of the predominant objectives of proposed future $e^+e^-$ colliders. We investigate in detail the production of $W$-boson pairs at $e^+e^-$ colliders, and compute the next-to-next-to-leading order mixed QCD-EW corrections to both the integrated cross section and various kinematic distributions. By employing the method of differential equations, we analytically calculate the two-loop master integrals for the mixed QCD-EW virtual corrections to $e^+e^- \rightarrow W^+W^-$. Utilizing the Magnus transformation, we derive a set of canonical master integrals for each integral family. This canonical basis satisfies a system of differential equations in which the dependence on the dimensional regulator is linearly factorized from the kinematics. We then express all these canonical master integrals as Taylor series in $\epsilon$ up to $\epsilon^4$, with coefficients articulated in terms of Goncharov polylogarithms up to weight four. Upon applying our analytic expressions of these master integrals to the phenomenological analysis of $W$-pair production, we observe that the $\mathcal{O}(\alpha\alpha_s)$ corrections are significantly impactful in the $\alpha(0)$ scheme, particularly in certain phase-space regions. However, these mixed QCD-EW corrections can be heavily suppressed by adopting the $G_{\mu}$ scheme.
[ { "created": "Tue, 2 Jan 2024 18:26:30 GMT", "version": "v1" }, { "created": "Tue, 16 Jul 2024 14:11:01 GMT", "version": "v2" } ]
2024-07-17
[ [ "Li", "Zhe", "" ], [ "Zhang", "Ren-You", "" ], [ "Li", "Shu-Xiang", "" ], [ "Wang", "Xiao-Feng", "" ], [ "He", "Wen-Jie", "" ], [ "Han", "Liang", "" ], [ "Jiang", "Yi", "" ], [ "Wang", "Qing-hai", "" ] ]
The discrepancy between the CDF measurement and the Standard Model theoretical prediction for the $W$-boson mass underscores the importance of conducting high-precision studies on the $W$ boson, which is one of the predominant objectives of proposed future $e^+e^-$ colliders. We investigate in detail the production of $W$-boson pairs at $e^+e^-$ colliders, and compute the next-to-next-to-leading order mixed QCD-EW corrections to both the integrated cross section and various kinematic distributions. By employing the method of differential equations, we analytically calculate the two-loop master integrals for the mixed QCD-EW virtual corrections to $e^+e^- \rightarrow W^+W^-$. Utilizing the Magnus transformation, we derive a set of canonical master integrals for each integral family. This canonical basis satisfies a system of differential equations in which the dependence on the dimensional regulator is linearly factorized from the kinematics. We then express all these canonical master integrals as Taylor series in $\epsilon$ up to $\epsilon^4$, with coefficients articulated in terms of Goncharov polylogarithms up to weight four. Upon applying our analytic expressions of these master integrals to the phenomenological analysis of $W$-pair production, we observe that the $\mathcal{O}(\alpha\alpha_s)$ corrections are significantly impactful in the $\alpha(0)$ scheme, particularly in certain phase-space regions. However, these mixed QCD-EW corrections can be heavily suppressed by adopting the $G_{\mu}$ scheme.
hep-ph/9403214
null
D.A. Morris and A. Ringwald
Astrophysical Searches For Exotic Phenomena In Ultrahigh Energy Neutrino-Nucleon Scattering
Invited talk presented by A. Ringwald at the 3rd NESTOR International Conference, 19-21 October 1993, Pylos, Greece. 24 pages, LaTeX, 10 figures appended as uu-encoded file. DESY 94-026, UCLA/94/TEP/9
null
null
null
hep-ph
null
We investigate the potential of near-future neutrino telescopes like NESTOR for searches for exotic processes in ultrahigh energy neutrino-quark scattering. (NESTOR is the acronym for NEutrinos, from Supernovae and TeV sources, Ocean Range ... a water Cherenkov detector to be constructed in the Mediterranean off the coast of Greece). We consider signatures such as muon bundles and/or contained cascades from the nonperturbative production of multiple weak gauge bosons in the Standard Model, compositeness and leptoquark production.
[ { "created": "Wed, 2 Mar 1994 22:17:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Morris", "D. A.", "" ], [ "Ringwald", "A.", "" ] ]
We investigate the potential of near-future neutrino telescopes like NESTOR for searches for exotic processes in ultrahigh energy neutrino-quark scattering. (NESTOR is the acronym for NEutrinos, from Supernovae and TeV sources, Ocean Range ... a water Cherenkov detector to be constructed in the Mediterranean off the coast of Greece). We consider signatures such as muon bundles and/or contained cascades from the nonperturbative production of multiple weak gauge bosons in the Standard Model, compositeness and leptoquark production.
1112.5108
Renata Zukanovich Funchal
O. J. P. Eboli (Sao Paulo U.), C. A. Savoy (Saclay, SPhT), R. Zukanovich Funchal (Sao Paulo, U.)
A Rationale for Long-lived Quarks and Leptons at the LHC: Low Energy Flavour Theory
10 pages, 1 figure
null
10.1007/JHEP02(2012)123
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of gauged flavour symmetries, new fermions in parity symmetric representations of the standard model are generically needed for the compensation of mixed anomalies. The key point is that their masses are also protected by flavour symmetries and some of them are expected to lie way below the flavour symmetry breaking scale(s), which has to occur many orders of magnitude above the electroweak scale to be compatible with the available data from flavour changing neutral currents and CP violation experiments. We argue that, actually, some of these fermions would plausibly get masses within the LHC range. If they are taken to be heavy quarks and leptons, in (bi)-fundamental representations of the standard model symmetries, their mixings with the light ones are strongly constrained to be very small by electroweak precision data. The alternative chosen here is to exactly forbid such mixings by breaking of flavour symmetries into an exact discrete symmetry, the so-called proton-hexality, primarily suggested to avoid proton decay. As a consequence of the large value needed for the flavour breaking scale, those heavy particles are long-lived and rather appropriate for the current and future searches at the LHC for quasi-stable hadrons and leptons. In fact, the LHC experiments have already started to look for them.
[ { "created": "Wed, 21 Dec 2011 17:40:04 GMT", "version": "v1" } ]
2015-06-03
[ [ "Eboli", "O. J. P.", "", "Sao Paulo U." ], [ "Savoy", "C. A.", "", "Saclay, SPhT" ], [ "Funchal", "R. Zukanovich", "", "Sao Paulo, U." ] ]
In the framework of gauged flavour symmetries, new fermions in parity symmetric representations of the standard model are generically needed for the compensation of mixed anomalies. The key point is that their masses are also protected by flavour symmetries and some of them are expected to lie way below the flavour symmetry breaking scale(s), which has to occur many orders of magnitude above the electroweak scale to be compatible with the available data from flavour changing neutral currents and CP violation experiments. We argue that, actually, some of these fermions would plausibly get masses within the LHC range. If they are taken to be heavy quarks and leptons, in (bi)-fundamental representations of the standard model symmetries, their mixings with the light ones are strongly constrained to be very small by electroweak precision data. The alternative chosen here is to exactly forbid such mixings by breaking of flavour symmetries into an exact discrete symmetry, the so-called proton-hexality, primarily suggested to avoid proton decay. As a consequence of the large value needed for the flavour breaking scale, those heavy particles are long-lived and rather appropriate for the current and future searches at the LHC for quasi-stable hadrons and leptons. In fact, the LHC experiments have already started to look for them.
2403.20017
Nanako Kato
Nanako Kato, Luca Maxia, Cristian Pisano
Spin asymmetries for $C$-even quarkonium production as a probe of gluon distributions
14 pages, 5 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Within the framework of transverse momentum dependent factorization in combination with nonrelativistic QCD, we study charmonium and bottomonium production in hadronic collisions. We focus on quarkonium states with even charge conjugation, for which the color-singlet production mechanism is expected to be also dominant in the small transverse momentum region, $q_T^2 \ll 4 M_{c,b}^2$. It is shown that the distributions of linearly polarized gluons inside unpolarized, longitudinally and transversely polarized protons contribute to the cross sections for scalar and pseudoscalar quarkonia in a very distinctive, parity-dependent way, whereas their effects on higher angular momentum states are strongly suppressed. We derive analytical expressions for single and double spin asymmetries, which would allow for the direct extraction of the gluon transverse momentum dependent distributions, mirroring the phenomenological studies of the Drell-Yan processes aimed at the extraction of their quark counterparts. By adopting Gaussian models for the gluon TMDs, which fulfill without saturating everywhere their positivity bounds, we provide numerical predictions for the transverse single-spin asymmetries. These observables could be measured at LHCSpin, the fixed target experiment planned at the LHC.
[ { "created": "Fri, 29 Mar 2024 07:05:21 GMT", "version": "v1" } ]
2024-04-01
[ [ "Kato", "Nanako", "" ], [ "Maxia", "Luca", "" ], [ "Pisano", "Cristian", "" ] ]
Within the framework of transverse momentum dependent factorization in combination with nonrelativistic QCD, we study charmonium and bottomonium production in hadronic collisions. We focus on quarkonium states with even charge conjugation, for which the color-singlet production mechanism is expected to be also dominant in the small transverse momentum region, $q_T^2 \ll 4 M_{c,b}^2$. It is shown that the distributions of linearly polarized gluons inside unpolarized, longitudinally and transversely polarized protons contribute to the cross sections for scalar and pseudoscalar quarkonia in a very distinctive, parity-dependent way, whereas their effects on higher angular momentum states are strongly suppressed. We derive analytical expressions for single and double spin asymmetries, which would allow for the direct extraction of the gluon transverse momentum dependent distributions, mirroring the phenomenological studies of the Drell-Yan processes aimed at the extraction of their quark counterparts. By adopting Gaussian models for the gluon TMDs, which fulfill without saturating everywhere their positivity bounds, we provide numerical predictions for the transverse single-spin asymmetries. These observables could be measured at LHCSpin, the fixed target experiment planned at the LHC.
hep-ph/9409253
null
Ina Sarcevic
Charm Production at RHIC and LHC to $O(\alpha_{s}^3)$
Presented at Annual Meeting of Division of Particles and Fields of the APS (DPF'94), Albuquerque, NM, August 2-6, 1994; University of Arizona preprint, Latex, 6 pages, 4 figs.(not included, (available upon request), AZPH-TH/94-21
Phys. Lett. B338 (1994) 426
null
null
hep-ph
null
We present results on rapidity and transverse momentum distributions of inclusive charm quark production in hadronic and heavy-ion collisions at RHIC and LHC energies, including the next-to-leading order, $O(\alpha_s^3)$, radiative corrections and the nuclear shadowing effect. We determine hadronic and nuclear K-factor for the differential and total inclusive cross sections for the charm production. We discuss theoretical uncertainties inherent in our calculation. In particular, we find that different extrapolations of gluon density to low-$x$ region introduce large theoretical uncertainty in the calculation of charm production at LHC energies. Finally, we comment on the possibility of detecting the quark-gluon plasma signal as an enhanced charm production in heavy-ion collisions at RHIC.
[ { "created": "Wed, 7 Sep 1994 22:06:32 GMT", "version": "v1" } ]
2009-09-25
[ [ "Sarcevic", "Ina", "" ] ]
We present results on rapidity and transverse momentum distributions of inclusive charm quark production in hadronic and heavy-ion collisions at RHIC and LHC energies, including the next-to-leading order, $O(\alpha_s^3)$, radiative corrections and the nuclear shadowing effect. We determine hadronic and nuclear K-factor for the differential and total inclusive cross sections for the charm production. We discuss theoretical uncertainties inherent in our calculation. In particular, we find that different extrapolations of gluon density to low-$x$ region introduce large theoretical uncertainty in the calculation of charm production at LHC energies. Finally, we comment on the possibility of detecting the quark-gluon plasma signal as an enhanced charm production in heavy-ion collisions at RHIC.
hep-ph/9302252
Gye Park
T.K. Kuo, Gye T. Park, and M. Zralek
Boson Pair Productions In $e^+$ $e^-$ Annihilation
10 pages, LaTeX, 3 figs not included, CTP-TAMU-08/93, PURD-TH-93-1
NuovoCim.A107:757-764,1994
10.1007/BF02732083
null
hep-ph
null
We examine the processes $e^+ e^-\longrightarrow W^+ W^-$ and $Z^0 Z^0$ in the context of the $SP(6)_L\otimes U(1)_Y$ model. We find that there are significant deviations in the total cross sections $\sigma (s)$ from the standard model results due to the presence of additional gauge bosons $Z^\prime$ and $W^\prime$ in the model. These deviations could be detected at LEP.
[ { "created": "Thu, 11 Feb 1993 19:37:46 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kuo", "T. K.", "" ], [ "Park", "Gye T.", "" ], [ "Zralek", "M.", "" ] ]
We examine the processes $e^+ e^-\longrightarrow W^+ W^-$ and $Z^0 Z^0$ in the context of the $SP(6)_L\otimes U(1)_Y$ model. We find that there are significant deviations in the total cross sections $\sigma (s)$ from the standard model results due to the presence of additional gauge bosons $Z^\prime$ and $W^\prime$ in the model. These deviations could be detected at LEP.
hep-ph/0010187
Jochum van der Bij
R. Akhoury, J.J. van der Bij, H. Wang
Interplay between perturbative and non-perturbative effects in the stealthy Higgs model
31 pages, Latex, 11 figures
Eur.Phys.J.C20:497-505,2001
10.1007/s100520100680
UM-TH-00-14, Freiburg-THEP-00/15
hep-ph
null
We study corrections to electroweak precision variables in a model with strongly interacting singlet Higgs particles.
[ { "created": "Tue, 17 Oct 2000 14:29:02 GMT", "version": "v1" } ]
2009-01-07
[ [ "Akhoury", "R.", "" ], [ "van der Bij", "J. J.", "" ], [ "Wang", "H.", "" ] ]
We study corrections to electroweak precision variables in a model with strongly interacting singlet Higgs particles.
0804.3409
Samoil Bilenky M.
S. M. Bilenky, F. von Feilitzsch and W. Potzel
Different Schemes of Neutrino Oscillations in M\"Ossbauer Neutrino Experiment
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We comment on the paper "On application of the time-energy uncertainty relation to M\"ossbauer neutrino experiments" (see arXiv: 0803.1424) in which our paper "Time-energy uncertainty relations for neutrino oscillation and M\"ossbauer neutrino experiment" (see arXiv: 0803.0527) has been criticized. We argue that this critique is a result of misinterpretation: The authors of (arXiv: 0803.1424) do not take into account (or do not accept) the fact that at present there exist different schemes of neutrino oscillations which can not be distinguished in usual neutrino oscillation experiments. We stress that a recently proposed M\"ossbauer neutrino experiment provides the unique possibility to discriminate basically different approaches to oscillations of flavor neutrinos.
[ { "created": "Mon, 21 Apr 2008 20:51:15 GMT", "version": "v1" } ]
2008-04-23
[ [ "Bilenky", "S. M.", "" ], [ "von Feilitzsch", "F.", "" ], [ "Potzel", "W.", "" ] ]
We comment on the paper "On application of the time-energy uncertainty relation to M\"ossbauer neutrino experiments" (see arXiv: 0803.1424) in which our paper "Time-energy uncertainty relations for neutrino oscillation and M\"ossbauer neutrino experiment" (see arXiv: 0803.0527) has been criticized. We argue that this critique is a result of misinterpretation: The authors of (arXiv: 0803.1424) do not take into account (or do not accept) the fact that at present there exist different schemes of neutrino oscillations which can not be distinguished in usual neutrino oscillation experiments. We stress that a recently proposed M\"ossbauer neutrino experiment provides the unique possibility to discriminate basically different approaches to oscillations of flavor neutrinos.
0902.1316
Adam Szczepaniak
Peng Guo and Adam P. Szczepaniak
Chiral symmetry restoration and deconfinement in Coulomb Gauge QCD
7 pages, 8 figures
Phys.Rev.D79:116006,2009
10.1103/PhysRevD.79.116006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of Coulomb Gauge QCD we explore dynamical breaking of chiral symmetry and screening of the confinement potential at finite density. The screened potential is applied in study of charmonium dissociation.
[ { "created": "Sun, 8 Feb 2009 15:49:01 GMT", "version": "v1" } ]
2010-04-23
[ [ "Guo", "Peng", "" ], [ "Szczepaniak", "Adam P.", "" ] ]
In the framework of Coulomb Gauge QCD we explore dynamical breaking of chiral symmetry and screening of the confinement potential at finite density. The screened potential is applied in study of charmonium dissociation.
2401.04681
Shuai Zhao
Jian-Ping Dai, Shuai Zhao
Production of true para-muonium in linearly polarized photon fusions
7 pages, 10 figures, 1 table. Accepted for publication in Physical Review D
Phys. Rev. D 109, 054022 (2024)
10.1103/PhysRevD.109.054022
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
True muonium (TM) -- the bound state of $\mu^+\mu^-$ -- has not been discovered yet. It was demonstrated that searching for TM via $\gamma\gamma$ fusions in heavy ion collisions is feasible due to the enhancement of the atom number. We study the production of the true para-muonium (pTM) in the collisions of linearly polarized photons in the experiments of heavy-ion collisions, calculate the production rate as well as the transverse spectrum of pTM, and explore the discovery potential in nuclear experiments. Our results show that there is a significant correlation between the linearly polarized photon distribution and the transverse momentum distribution of pTM. The optimal kinematic region of the generated pTM is identified, which can provide a theoretical guide to the detection of pTM in experiments.
[ { "created": "Tue, 9 Jan 2024 17:14:11 GMT", "version": "v1" }, { "created": "Wed, 13 Mar 2024 15:11:02 GMT", "version": "v2" } ]
2024-03-14
[ [ "Dai", "Jian-Ping", "" ], [ "Zhao", "Shuai", "" ] ]
True muonium (TM) -- the bound state of $\mu^+\mu^-$ -- has not been discovered yet. It was demonstrated that searching for TM via $\gamma\gamma$ fusions in heavy ion collisions is feasible due to the enhancement of the atom number. We study the production of the true para-muonium (pTM) in the collisions of linearly polarized photons in the experiments of heavy-ion collisions, calculate the production rate as well as the transverse spectrum of pTM, and explore the discovery potential in nuclear experiments. Our results show that there is a significant correlation between the linearly polarized photon distribution and the transverse momentum distribution of pTM. The optimal kinematic region of the generated pTM is identified, which can provide a theoretical guide to the detection of pTM in experiments.
hep-ph/0103025
Ivan Dadic
I. Dadic
Pinching phenomenon: Central feature in out of equilibrium thermal field theories
18 pages, 1 Postscript figure, Latex
null
null
BI-TP 2000/14, IRB-TH-5/00
hep-ph
null
We continue to study out of equilibrium TFT with switching on the interaction occurring at finite time. We exploit the concept of projected function (PF) and Wigner transform of projected function (WTPF). WTPF's are bare propagators, one-loop self-energies, retarded and advanced components of the resummed propagator. Among WTPF's convolution product is very simple, one does not need gradient expansion. However, WTPF's are completely determined by their infinite time limit and, thus, cannot be the carriers of relaxation phenomena. Furthermore, we observe that the functions capable of carrying relaxation phenomena (non-WTPF) emerge in the mixed ("ill-defined") products of retarded and advanced propagators and self-energies. In particular, only non-WTPF's contribute to time variation of equal-time Green functions (particle number, etc.); contributions from WTPF will be constant in time. As these are generated in mixed products, the pinching phenomenon is being promoted from an obstacle to the central feature of out of equilibrium TFT. We analyze the pinching phenomenon. In the case of naive pinching we reproduce known results. In Schwinger-Dyson equations the Keldysh component of self-energy is well defined even for multiple self-energy insertion contributions. We calaculate explicitly single self-energy contribution to Keldysh component of propagator which generates nontrivial time dependence. For photon production from QCD plasma (finite-lifetime effect) our approximate analytic results agree with the results by S. -Y. Wang and D. Boyanovsky obtained within dynamical renormalisation group approach.
[ { "created": "Fri, 2 Mar 2001 14:11:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dadic", "I.", "" ] ]
We continue to study out of equilibrium TFT with switching on the interaction occurring at finite time. We exploit the concept of projected function (PF) and Wigner transform of projected function (WTPF). WTPF's are bare propagators, one-loop self-energies, retarded and advanced components of the resummed propagator. Among WTPF's convolution product is very simple, one does not need gradient expansion. However, WTPF's are completely determined by their infinite time limit and, thus, cannot be the carriers of relaxation phenomena. Furthermore, we observe that the functions capable of carrying relaxation phenomena (non-WTPF) emerge in the mixed ("ill-defined") products of retarded and advanced propagators and self-energies. In particular, only non-WTPF's contribute to time variation of equal-time Green functions (particle number, etc.); contributions from WTPF will be constant in time. As these are generated in mixed products, the pinching phenomenon is being promoted from an obstacle to the central feature of out of equilibrium TFT. We analyze the pinching phenomenon. In the case of naive pinching we reproduce known results. In Schwinger-Dyson equations the Keldysh component of self-energy is well defined even for multiple self-energy insertion contributions. We calaculate explicitly single self-energy contribution to Keldysh component of propagator which generates nontrivial time dependence. For photon production from QCD plasma (finite-lifetime effect) our approximate analytic results agree with the results by S. -Y. Wang and D. Boyanovsky obtained within dynamical renormalisation group approach.
hep-ph/9508345
Lu Cai-dian
Cai-Dian Lu
$b\to s \gamma$ Decay in the Two Higgs Doublet Model
3 pages (no figure). Talk given at the first International Conference on Fronties of Physics, Shantou, China. To appear in the proceedings, World Scientific, Singapore
null
null
As-ITP 95-25
hep-ph
null
QCD corrections to $b \to s \gamma$ decay in the two Higgs doublet model are calculated from the energy scale of top quark to that of bottom. The constraints on the two Higgs doublet model from the new experimental bounds of $b\to s\gamma$ by CLEO and the latest top quark mass by CDF and D0 are reanalyzed. It shows that the constraints become more stringent than that of the earlier analysis, i.e. a bigger region of the parameter space of the model is ruled out.
[ { "created": "Tue, 22 Aug 1995 14:04:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lu", "Cai-Dian", "" ] ]
QCD corrections to $b \to s \gamma$ decay in the two Higgs doublet model are calculated from the energy scale of top quark to that of bottom. The constraints on the two Higgs doublet model from the new experimental bounds of $b\to s\gamma$ by CLEO and the latest top quark mass by CDF and D0 are reanalyzed. It shows that the constraints become more stringent than that of the earlier analysis, i.e. a bigger region of the parameter space of the model is ruled out.
1805.00070
Jilberto Zamora-Sa\'a
Gorazd Cvetic, Arindam Das, Jilberto Zamora-Saa
Probing heavy neutrino oscillations in rare W boson decays
Accepted Manuscript
Journal of Physics G: Nuclear and Particle Physics, Volume 46, Number 7 (2019)
10.1088/1361-6471/ab1212
0954-3899; 1361-6471
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we study the lepton number violating W boson and top quark decays via intermediate on-shell Majorana neutrinos Nj into three charged leptons and a light neutrino. We discuss the neutrino oscillation effects present in the decay due to the small mass gap between the heavy neutrino states. We focus on a scenario that contains at least two heavy Majorana neutrinos in the mass range 2-80 GeV. The results indicate that the modulation of the branching ratios as a function of the distance between the vertices may be detected in a future experiment such as High-Luminosity Large Hadron Collider. As a secondary result, the CP-violating phases could be explored.
[ { "created": "Mon, 30 Apr 2018 19:27:28 GMT", "version": "v1" }, { "created": "Tue, 26 Mar 2019 23:45:45 GMT", "version": "v2" } ]
2019-05-17
[ [ "Cvetic", "Gorazd", "" ], [ "Das", "Arindam", "" ], [ "Zamora-Saa", "Jilberto", "" ] ]
In this work, we study the lepton number violating W boson and top quark decays via intermediate on-shell Majorana neutrinos Nj into three charged leptons and a light neutrino. We discuss the neutrino oscillation effects present in the decay due to the small mass gap between the heavy neutrino states. We focus on a scenario that contains at least two heavy Majorana neutrinos in the mass range 2-80 GeV. The results indicate that the modulation of the branching ratios as a function of the distance between the vertices may be detected in a future experiment such as High-Luminosity Large Hadron Collider. As a secondary result, the CP-violating phases could be explored.
1208.5508
A. Tureanu
Masud Chaichian, Kazuo Fujikawa and Anca Tureanu
On neutrino masses via CPT violating Higgs interaction in the Standard Model
8 pages
null
10.1016/j.physletb.2012.09.071
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Lorentz invariant $CPT$ violation by using non-local interactions is naturally incorporated in the Higgs coupling to neutrinos in the Standard Model, without spoiling the basic $SU(2)_{L}\times U(1)$ gauge symmetry. The neutrino--antineutrino mass splitting is thus realized by the mechanism which was proposed recently, assuming the neutrino masses to be predominantly Dirac-type in the Standard Model.
[ { "created": "Mon, 27 Aug 2012 21:16:27 GMT", "version": "v1" } ]
2015-06-11
[ [ "Chaichian", "Masud", "" ], [ "Fujikawa", "Kazuo", "" ], [ "Tureanu", "Anca", "" ] ]
The Lorentz invariant $CPT$ violation by using non-local interactions is naturally incorporated in the Higgs coupling to neutrinos in the Standard Model, without spoiling the basic $SU(2)_{L}\times U(1)$ gauge symmetry. The neutrino--antineutrino mass splitting is thus realized by the mechanism which was proposed recently, assuming the neutrino masses to be predominantly Dirac-type in the Standard Model.
0911.1086
Philippe Brax
Philippe Brax, Carsten van de Bruck, Anne-Christine Davis and Douglas Shaw
Laboratory Tests of Chameleon Models
Contribution to the "5th Patras Workshop on Axions, WIMPs and WISPs", Durham 13-17 July 2009
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a cursory overview of chameleon models of dark energy and their laboratory tests with an emphasis on optical and Casimir experiments. Optical experiments measuring the ellipticity of an initially polarised laser beam are sensitive to the coupling of chameleons to photons. The next generation of Casimir experiments may be able to unravel the nature of the scalar force mediated by the chameleon between parallel plates.
[ { "created": "Thu, 5 Nov 2009 17:33:16 GMT", "version": "v1" } ]
2009-11-06
[ [ "Brax", "Philippe", "" ], [ "van de Bruck", "Carsten", "" ], [ "Davis", "Anne-Christine", "" ], [ "Shaw", "Douglas", "" ] ]
We present a cursory overview of chameleon models of dark energy and their laboratory tests with an emphasis on optical and Casimir experiments. Optical experiments measuring the ellipticity of an initially polarised laser beam are sensitive to the coupling of chameleons to photons. The next generation of Casimir experiments may be able to unravel the nature of the scalar force mediated by the chameleon between parallel plates.
1012.4868
Amir Fariborz
Amir H. Fariborz, Renata Jora, Joseph Schechter and M. Naeem Shahid
Are three flavors special?
null
Phys.Rev.D83:034018,2011
10.1103/PhysRevD.83.034018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has become clearer recently that the regular pattern of three flavor nonets describing the low spin meson multiplets seems to require some modification for the case of the spin 0 scalar mesons. One picture which has had some success, treats the scalars in a chiral Lagrangian framework and considers them to populate two nonets. These are, in turn, taken to result from the mixing of two "bare" nonets, one of which is of quark- antiquark type and the other of two quark- two antiquark type. Here we show that such a mixing is, before chiral symmetry breaking terms are included, only possible for three flavors. In other cases, the two types of structure can not have the same chiral symmetry transformation property. Specifically, our criterion would lead one to believe that scalar and pseudoscalar states containing charm would not have "four quark" admixtures. This work is of potential interest for constructing chiral Lagrangians based on exact chiral symmetry which is then broken by well known specific terms. It may also be of interest in studying some kinds of technicolor theories.
[ { "created": "Wed, 22 Dec 2010 03:00:42 GMT", "version": "v1" } ]
2011-02-23
[ [ "Fariborz", "Amir H.", "" ], [ "Jora", "Renata", "" ], [ "Schechter", "Joseph", "" ], [ "Shahid", "M. Naeem", "" ] ]
It has become clearer recently that the regular pattern of three flavor nonets describing the low spin meson multiplets seems to require some modification for the case of the spin 0 scalar mesons. One picture which has had some success, treats the scalars in a chiral Lagrangian framework and considers them to populate two nonets. These are, in turn, taken to result from the mixing of two "bare" nonets, one of which is of quark- antiquark type and the other of two quark- two antiquark type. Here we show that such a mixing is, before chiral symmetry breaking terms are included, only possible for three flavors. In other cases, the two types of structure can not have the same chiral symmetry transformation property. Specifically, our criterion would lead one to believe that scalar and pseudoscalar states containing charm would not have "four quark" admixtures. This work is of potential interest for constructing chiral Lagrangians based on exact chiral symmetry which is then broken by well known specific terms. It may also be of interest in studying some kinds of technicolor theories.
hep-ph/9510304
Evan Reidell
X. Ji and J. Tang (MIT) and P. Hoodbhoy (Quaid-e-Azam, Pakistan)
The Spin Structure of the Nucleon in the Asymptotic Limit
8 pages in REVTEX
Phys.Rev.Lett.76:740-743,1996
10.1103/PhysRevLett.76.740
MIT-CTP-2476
hep-ph nucl-th
null
In analogy to the Altarelli-Parisi equation for the quark and gluon helicity contributions to the nucleon spin, we derive an evolution equation for the quark and gluon orbital angular momenta. The solution of the combined equations yields the asymptotic fractions of the nucleon spin carried by quarks and gluons: $3n_f/(16+3n_f)$ and $16/(16+3n_f)$, respectively, where $n_f$ is the number of active quark flavors. These are identical to the well-known asymptotic partitions of the nucleon momentum between quark and gluon contributions. We show that the axial-anomaly contribution to the quark helicity is cancelled by a similar contribution to the quark orbital angular momentum, making the total quark contribution to the nucleon spin anomaly-free.
[ { "created": "Mon, 16 Oct 1995 17:29:00 GMT", "version": "v1" } ]
2014-11-17
[ [ "Ji", "X.", "", "MIT" ], [ "Tang", "J.", "", "MIT" ], [ "Hoodbhoy", "P.", "", "Quaid-e-Azam, Pakistan" ] ]
In analogy to the Altarelli-Parisi equation for the quark and gluon helicity contributions to the nucleon spin, we derive an evolution equation for the quark and gluon orbital angular momenta. The solution of the combined equations yields the asymptotic fractions of the nucleon spin carried by quarks and gluons: $3n_f/(16+3n_f)$ and $16/(16+3n_f)$, respectively, where $n_f$ is the number of active quark flavors. These are identical to the well-known asymptotic partitions of the nucleon momentum between quark and gluon contributions. We show that the axial-anomaly contribution to the quark helicity is cancelled by a similar contribution to the quark orbital angular momentum, making the total quark contribution to the nucleon spin anomaly-free.
1410.0918
Chuan-Ren Chen
Chuan-Ren Chen, Yu-Kuang Chu and Ho-Chin Tsai
An Elusive Vector Dark Matter
11 pages, 5 figures
null
10.1016/j.physletb.2014.12.043
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Even though the sensitivity of direct dark matter search experiments reach the level about $10^{-45}~{\rm cm}^2$, there is no confident signal of dark matter been observed. We point out that, if dark matter is a vector boson, the null result in direct dark matter search experiments may due to the destructive effects in dark-matter-nucleon elastic scattering. We illustrate the scenario using a modified Higgs portal model that includes exotic quarks. The significant cancellation can occur for certain mass gap between heavy quark and dark matter. As a result, the spin-independent dark-matter-nucleon elastic scattering is so suppressed that the future direct search experiments can hardly observe the signal of dark matter.
[ { "created": "Fri, 3 Oct 2014 17:24:30 GMT", "version": "v1" } ]
2018-05-09
[ [ "Chen", "Chuan-Ren", "" ], [ "Chu", "Yu-Kuang", "" ], [ "Tsai", "Ho-Chin", "" ] ]
Even though the sensitivity of direct dark matter search experiments reach the level about $10^{-45}~{\rm cm}^2$, there is no confident signal of dark matter been observed. We point out that, if dark matter is a vector boson, the null result in direct dark matter search experiments may due to the destructive effects in dark-matter-nucleon elastic scattering. We illustrate the scenario using a modified Higgs portal model that includes exotic quarks. The significant cancellation can occur for certain mass gap between heavy quark and dark matter. As a result, the spin-independent dark-matter-nucleon elastic scattering is so suppressed that the future direct search experiments can hardly observe the signal of dark matter.
2310.02763
Jacek Ciborowski
Jakub Rembielinski and Jacek Ciborowski
Possible explanation of not observing ultra-high energy cosmic neutrinos
null
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Assuming that neutrinos are spacelike (tachyonic) fermions, we calculate width for the kinematically allowed, lepton number conserving, three-body decay $\nu_{\alpha}\rightarrow \nu_{\alpha} \; \nu_{\beta} \bar{\nu}_{\beta}$ in the Standard Model. Decays of tachyonic neutrinos over cosmological distances can lead to a reduction of the neutrino flux in the high-energy end of the spectrum. We estimate upper limits on the spacelike neutrino mass based on the PeV-energy cosmological neutrino events observed in the IceCube experiment. These limits are close to those deduced from the measurements of $m_{\nu}^2$ in the tritium-decay experiment KATRIN.
[ { "created": "Wed, 4 Oct 2023 12:20:29 GMT", "version": "v1" } ]
2023-10-05
[ [ "Rembielinski", "Jakub", "" ], [ "Ciborowski", "Jacek", "" ] ]
Assuming that neutrinos are spacelike (tachyonic) fermions, we calculate width for the kinematically allowed, lepton number conserving, three-body decay $\nu_{\alpha}\rightarrow \nu_{\alpha} \; \nu_{\beta} \bar{\nu}_{\beta}$ in the Standard Model. Decays of tachyonic neutrinos over cosmological distances can lead to a reduction of the neutrino flux in the high-energy end of the spectrum. We estimate upper limits on the spacelike neutrino mass based on the PeV-energy cosmological neutrino events observed in the IceCube experiment. These limits are close to those deduced from the measurements of $m_{\nu}^2$ in the tritium-decay experiment KATRIN.
hep-ph/0411077
Luis. A. Sanchez
Diego A. Gutierrez, William A. Ponce, Luis A. Sanchez
Phenomenology of the SU(3)_c X SU(3)_L X U(1)_X model with right-handed neutrinos
RevTeX, 10 pages, 4 figures. v2: 13 pages. Substantial changes. New section about RGE analysis. Experimental data updated. v3: Discussions about bounds from unitarity violation of the CKM matrix and from FCNC included. Accepted for publication in Eur. Phys. J. C
Eur.Phys.J.C46:497-509,2006
10.1140/epjc/s2006-02513-y
null
hep-ph
null
A phenomenological analysis of the three-family local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ with right-handed neutrinos is carried out. Instead of using the minimal scalar sector able to break the symmetry in a proper way, we introduce an alternative set of four Higgs scalar triplets, which combined with an anomaly-free discrete symmetry, produces a quark mass spectrum without hierarchies in the Yukawa coupling contants. We also embed the structure into a simple gauge group and show some conditions to achieve a low energy gauge coupling unification, avoiding possible conflict with proton decay bounds. By using experimental results from the CERN-LEP, SLAC linear collider and atomic parity violation data, we update constraints on several parameters of the model.
[ { "created": "Fri, 5 Nov 2004 02:08:15 GMT", "version": "v1" }, { "created": "Sat, 29 Oct 2005 05:57:01 GMT", "version": "v2" }, { "created": "Thu, 16 Feb 2006 18:55:03 GMT", "version": "v3" } ]
2009-01-07
[ [ "Gutierrez", "Diego A.", "" ], [ "Ponce", "William A.", "" ], [ "Sanchez", "Luis A.", "" ] ]
A phenomenological analysis of the three-family local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ with right-handed neutrinos is carried out. Instead of using the minimal scalar sector able to break the symmetry in a proper way, we introduce an alternative set of four Higgs scalar triplets, which combined with an anomaly-free discrete symmetry, produces a quark mass spectrum without hierarchies in the Yukawa coupling contants. We also embed the structure into a simple gauge group and show some conditions to achieve a low energy gauge coupling unification, avoiding possible conflict with proton decay bounds. By using experimental results from the CERN-LEP, SLAC linear collider and atomic parity violation data, we update constraints on several parameters of the model.
hep-ph/9211279
null
Eric D. Carlson and Meng Yuan Wang
Trinification and the Strong P Problem
null
null
10.1063/1.43438
Harvard Preprint HUTP-92/A057
hep-ph
null
Models with spontaneously broken parity symmetry can solve the strong $CP$ problem in a natural way. We construct such a model in the context of $\SU3^3$ unification. Parity has the conventional meaning in this model, and the gauge group is unified.
[ { "created": "Thu, 19 Nov 1992 21:12:20 GMT", "version": "v1" } ]
2009-10-22
[ [ "Carlson", "Eric D.", "" ], [ "Wang", "Meng Yuan", "" ] ]
Models with spontaneously broken parity symmetry can solve the strong $CP$ problem in a natural way. We construct such a model in the context of $\SU3^3$ unification. Parity has the conventional meaning in this model, and the gauge group is unified.
hep-ph/9401329
null
Debajyoti Choudhury, Raj Gandhi, J.A. Gracey and Biswarup Mukhopadhyaya
Two-Loop Neutrino Masses and the Solar Neutrino Problem
24 pages, Two figures, attached as postscript files at the end, Latex, CTP-TAMU-76/93, MRI-PHY-12/93, LTH-326
Phys.Rev.D50:3468-3476,1994
10.1103/PhysRevD.50.3468
null
hep-ph
null
The addition of $m$ singlet right-handed neutrinos to the Standard Model leads to radiatively generated mass corrections for the $SU(2)_L $ doublet neutrinos. For those neutrinos which are massless at the tree level after this addition, this implies a small mass generated at the two-loop level via $W^{\pm}$ exchange. We calculate these mass corrections exactly by obtaining an analytic form for the general case of $n$ doublets and $m$ singlets. As a phenomenological application, we consider the $m=1$ case and examine the masses and mixings of the doublet neutrinos which arise as a result of the two-loop correction in the light of experimental data from two sources which may shed light on the question of neutrino masses. These are(a) the neutrino detectors reporting a solar neutrino deficit (and its resolution via Mikheyev-Smirnov-Wolfenstein matter oscillations), and (b) the COBE satellite data on the non-zero angular variations of the cosmic microwave background temperature (and its possible implications for hot dark matter). Within the framework of the extension considered here, which leaves the gauge group structure of the Standard Model intact, we show that it is possible for neutrinos to acquire small masses naturally, with values which are compatible with current theoretical bias and experimental data.
[ { "created": "Tue, 25 Jan 1994 23:03:42 GMT", "version": "v1" } ]
2011-09-21
[ [ "Choudhury", "Debajyoti", "" ], [ "Gandhi", "Raj", "" ], [ "Gracey", "J. A.", "" ], [ "Mukhopadhyaya", "Biswarup", "" ] ]
The addition of $m$ singlet right-handed neutrinos to the Standard Model leads to radiatively generated mass corrections for the $SU(2)_L $ doublet neutrinos. For those neutrinos which are massless at the tree level after this addition, this implies a small mass generated at the two-loop level via $W^{\pm}$ exchange. We calculate these mass corrections exactly by obtaining an analytic form for the general case of $n$ doublets and $m$ singlets. As a phenomenological application, we consider the $m=1$ case and examine the masses and mixings of the doublet neutrinos which arise as a result of the two-loop correction in the light of experimental data from two sources which may shed light on the question of neutrino masses. These are(a) the neutrino detectors reporting a solar neutrino deficit (and its resolution via Mikheyev-Smirnov-Wolfenstein matter oscillations), and (b) the COBE satellite data on the non-zero angular variations of the cosmic microwave background temperature (and its possible implications for hot dark matter). Within the framework of the extension considered here, which leaves the gauge group structure of the Standard Model intact, we show that it is possible for neutrinos to acquire small masses naturally, with values which are compatible with current theoretical bias and experimental data.
hep-ph/9510300
Arnd Brandenburg
Werner Bernreuther, Arnd Brandenburg, and Peter Uwer (Institut f\"ur Theoretische Physik, Physikzentrum, Rheinisch-Westf\"alische Technische Hochschule Aachen, Aachen, Germany)
Transverse Polarization of Top Quark Pairs at the Tevatron and the Large Hadron Collider
14 pages, LaTeX; 8 uuencoded, tar-compressed figures added separately
Phys.Lett. B368 (1996) 153-162
10.1016/0370-2693(95)01475-6
PITHA 95/26
hep-ph
null
We investigate the prospects to observe effects of transverse polarization of top quarks in $pp,p\bar{p}\to t\bar{t}X$. QCD absorptive parts generate a polarization of top quarks and antiquarks transverse to the production plane in the partonic processes $q\bar{q}\to t\bar{t}$ and $gg\to t\bar{t}$, which reaches values of a few percent. These perturbative QCD effects are decreased at the hadronic level. A measurement through momentum correlations among the $t$ and $\bar{t}$ decay products will be difficult both at an upgraded Tevatron and at the LHC.
[ { "created": "Mon, 16 Oct 1995 10:36:22 GMT", "version": "v1" } ]
2009-10-28
[ [ "Bernreuther", "Werner", "", "Institut für\n Theoretische Physik, Physikzentrum, Rheinisch-Westfälische Technische\n Hochschule Aachen, Aachen, Germany" ], [ "Brandenburg", "Arnd", "", "Institut für\n Theoretische Physik, Physikzentrum, Rheinisch-Westfälische Technische\n Hochschule Aachen, Aachen, Germany" ], [ "Uwer", "Peter", "", "Institut für\n Theoretische Physik, Physikzentrum, Rheinisch-Westfälische Technische\n Hochschule Aachen, Aachen, Germany" ] ]
We investigate the prospects to observe effects of transverse polarization of top quarks in $pp,p\bar{p}\to t\bar{t}X$. QCD absorptive parts generate a polarization of top quarks and antiquarks transverse to the production plane in the partonic processes $q\bar{q}\to t\bar{t}$ and $gg\to t\bar{t}$, which reaches values of a few percent. These perturbative QCD effects are decreased at the hadronic level. A measurement through momentum correlations among the $t$ and $\bar{t}$ decay products will be difficult both at an upgraded Tevatron and at the LHC.