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hep-ph/9712398
Luca Silvestrini
A.J. Buras, A. Romanino and L. Silvestrini
$K \to \pi \nu \bar \nu$: A Model Independent Analysis and Supersymmetry
LaTeX, 32 pages, 14 figures. Constraints in Table 1 and related text changed due to a previously overlooked constraint. Figures 13 and 14 slightly modified, general conclusions unchanged. Final version to appear in Nucl. Phys. B
Nucl.Phys. B520 (1998) 3-30
10.1016/S0550-3213(98)00169-2
TUM-HEP-302/97
hep-ph
null
We present a model independent analysis of new-physics contributions to the decays K^+ \to \pi^+ \nu \bar \nu and K_L \to \pi^0 \nu \bar \nu. We parameterize the effects of new physics in these decays by two parameters: r_K and \theta_K, with r_K=1 and \theta_K=0 in the Standard Model (SM). We show how these parameters can be extracted from future data. This analysis offers some insight in a possible violation of a "golden relation" between K \to \pi \nu \bar \nu decays and the CP asymmetry in B \to \psi K_S in the SM pointed out some time ago. We illustrate these ideas by considering a general class of supersymmetric models. We find that in the "constrained" MSSM, in which \theta_K=0, the measurements of Br(K^+ \to \pi^+ \nu \bar \nu) and Br(K_L \to \pi^0 \nu \bar \nu) directly determine the angle \beta. Moreover, the "golden relation" remains unaffected. On the other hand, in general SUSY models with unbroken R-parity the present experimental constraints still allow for substantial deviations from r_K=1 and \theta_K=0. Typically 0.5 < r_K < 1.3 and -25^0 < \theta_K < 25^0. Consequently, in these models the violation of the "golden relation" is possible and values for Br(K^+ \to \pi^+ \nu \bar \nu) and Br(K_L \to \pi^0 \nu \bar \nu) departing from the SM expectations by factors 2-3 cannot be excluded. Our conclusions differ in certain aspects from the ones reached in previous analyses. In particular, we stress the possible importance of left-right flavour-violating mass insertions that were not considered before.
[ { "created": "Tue, 16 Dec 1997 17:51:48 GMT", "version": "v1" }, { "created": "Mon, 9 Mar 1998 10:19:11 GMT", "version": "v2" } ]
2009-10-30
[ [ "Buras", "A. J.", "" ], [ "Romanino", "A.", "" ], [ "Silvestrini", "L.", "" ] ]
We present a model independent analysis of new-physics contributions to the decays K^+ \to \pi^+ \nu \bar \nu and K_L \to \pi^0 \nu \bar \nu. We parameterize the effects of new physics in these decays by two parameters: r_K and \theta_K, with r_K=1 and \theta_K=0 in the Standard Model (SM). We show how these parameters can be extracted from future data. This analysis offers some insight in a possible violation of a "golden relation" between K \to \pi \nu \bar \nu decays and the CP asymmetry in B \to \psi K_S in the SM pointed out some time ago. We illustrate these ideas by considering a general class of supersymmetric models. We find that in the "constrained" MSSM, in which \theta_K=0, the measurements of Br(K^+ \to \pi^+ \nu \bar \nu) and Br(K_L \to \pi^0 \nu \bar \nu) directly determine the angle \beta. Moreover, the "golden relation" remains unaffected. On the other hand, in general SUSY models with unbroken R-parity the present experimental constraints still allow for substantial deviations from r_K=1 and \theta_K=0. Typically 0.5 < r_K < 1.3 and -25^0 < \theta_K < 25^0. Consequently, in these models the violation of the "golden relation" is possible and values for Br(K^+ \to \pi^+ \nu \bar \nu) and Br(K_L \to \pi^0 \nu \bar \nu) departing from the SM expectations by factors 2-3 cannot be excluded. Our conclusions differ in certain aspects from the ones reached in previous analyses. In particular, we stress the possible importance of left-right flavour-violating mass insertions that were not considered before.
hep-ph/9705261
Yang Ya-Dong
Dongsheng Du, Hongying Jin, Yadong Yang
Probe New Physics in Leptonic $ B_c$ Decays at CERN LHC
LaTeX file, 9 pages, 3 figures, final version to be published in Phys.Lett.B
Phys.Lett. B414 (1997) 130-133
10.1016/S0370-2693(97)01151-9
BIHEP-Th/97-007
hep-ph
null
With respect to large samples of $B_c$ mesons expected to be produced at CERN Large Hadron Collider(LHC) and the large branching ratios $Br(B_{c}\to \tau\bar\nu)$ and $Br(B_{c}\to \mu\bar\nu)$, we suggest that $B_c$ purely leptonic decays could offer an unique probe of the standard model and its extensions such as two Higgs doublet models and models involving supersymmetry, and also the structure of charged weak currents.
[ { "created": "Thu, 8 May 1997 20:17:55 GMT", "version": "v1" }, { "created": "Tue, 16 Sep 1997 03:35:35 GMT", "version": "v2" } ]
2009-10-30
[ [ "Du", "Dongsheng", "" ], [ "Jin", "Hongying", "" ], [ "Yang", "Yadong", "" ] ]
With respect to large samples of $B_c$ mesons expected to be produced at CERN Large Hadron Collider(LHC) and the large branching ratios $Br(B_{c}\to \tau\bar\nu)$ and $Br(B_{c}\to \mu\bar\nu)$, we suggest that $B_c$ purely leptonic decays could offer an unique probe of the standard model and its extensions such as two Higgs doublet models and models involving supersymmetry, and also the structure of charged weak currents.
2107.02801
TaeHun Kim
Sunghoon Jung, TaeHun Kim
Hubble selection of the weak scale from QCD quantum critical point
v3: matched with the published version; discussions improved
Phys. Rev. Research 4, L022048 (2022)
10.1103/PhysRevResearch.4.L022048
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
There is growing evidence that the small weak scale may be related to self-organized criticality. In this regard, we note that if the strange quark were lighter, the QCD phase transition could have been first order, possibly exhibiting quantum critical points at zero temperature as a function of the Higgs vacuum expectation value $v_h$ smaller than (but near) the weak scale. We show that these quantum critical points allow a dynamical selection of the observed weak scale, via quantum-dominated stochastic evolutions of the value of $v_h$ during eternal inflation. Although the values of $v_h$ in different Hubble patches are described by a probability distribution in the multiverse, inflationary quantum dynamics ensures that the peak of the distribution evolves toward critical points (self-organized criticality), driven mainly by the largest Hubble expansion rate there -- the Hubble selection of the universe. To this end, we first explore the quantum critical points of the three-flavor QCD linear sigma model, parametrized by $v_h$ at zero temperature, and we present a relaxion model for the weak scale. Among the patches that have reached reheating, it results in a sharp probability distribution of $v_h$ near the observed weak scale, which is critical not to the crossover at $v_h=0$ but to the sharp transition at ${\sim}\Lambda_{\rm QCD}$.
[ { "created": "Tue, 6 Jul 2021 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 3 Aug 2021 19:14:21 GMT", "version": "v2" }, { "created": "Fri, 3 Jun 2022 18:04:33 GMT", "version": "v3" } ]
2022-06-07
[ [ "Jung", "Sunghoon", "" ], [ "Kim", "TaeHun", "" ] ]
There is growing evidence that the small weak scale may be related to self-organized criticality. In this regard, we note that if the strange quark were lighter, the QCD phase transition could have been first order, possibly exhibiting quantum critical points at zero temperature as a function of the Higgs vacuum expectation value $v_h$ smaller than (but near) the weak scale. We show that these quantum critical points allow a dynamical selection of the observed weak scale, via quantum-dominated stochastic evolutions of the value of $v_h$ during eternal inflation. Although the values of $v_h$ in different Hubble patches are described by a probability distribution in the multiverse, inflationary quantum dynamics ensures that the peak of the distribution evolves toward critical points (self-organized criticality), driven mainly by the largest Hubble expansion rate there -- the Hubble selection of the universe. To this end, we first explore the quantum critical points of the three-flavor QCD linear sigma model, parametrized by $v_h$ at zero temperature, and we present a relaxion model for the weak scale. Among the patches that have reached reheating, it results in a sharp probability distribution of $v_h$ near the observed weak scale, which is critical not to the crossover at $v_h=0$ but to the sharp transition at ${\sim}\Lambda_{\rm QCD}$.
2206.02503
Hua Zhou
Hua Zhou, Qing Yu, Xu-Chang Zheng, Hai-Bing Fu, Xing-Gang Wu
New determination of $|V_{\rm cb}|$ using the three-loop QCD corrections for the $B\to D^{\ast}$ semi-leptonic decays
7 pages,2 figures
null
10.1016/j.nuclphysa.2022.122595
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{\rm cb}|$ by using the three-loop perturbative QCD corrections for the $B\to D^{\ast}$ semi-leptonic decay. The decay width of $B\to D^{\ast}$ semi-leptonic decay can be factorized as perturbatively calculable short-distance part and the non-perturbative but universal long-distance part. We adopt the principle of maximum conformality (PMC) single-scale setting approach to deal with the perturbative series so as to achieve a precise fixed-order prediction for the short-distance parameter $\eta_{A}$. By applying the PMC, an overall effective $\alpha_s$ value is achieved by recursively using the renormalization group equation, which inversely results in a precise scale-invariant pQCD series. Such scale-invariant series also provides a reliable basis for predicting the contributions from uncalculated perturbative terms. We then obtain $\eta_{A}=0.9225^{+0.0117}_{-0.0168}$, where the error is the squared average of those from $\Delta\alpha_{s}(M_Z)=\pm0.0010$ and the uncertainties caused by the uncalculated higher-order perturbative terms. By using the data of $B\to D^{\ast}\ell\bar{\nu}_{\ell}$, we finally obtain $|V_{\rm cb}|_{\rm PMC} =(40.60^{+0.53}_{-0.57})\times10^{-3}$, which is consistent with the PDG value within errors.
[ { "created": "Mon, 6 Jun 2022 11:28:22 GMT", "version": "v1" }, { "created": "Mon, 26 Dec 2022 05:40:26 GMT", "version": "v2" }, { "created": "Fri, 6 Jan 2023 11:09:19 GMT", "version": "v3" } ]
2023-01-25
[ [ "Zhou", "Hua", "" ], [ "Yu", "Qing", "" ], [ "Zheng", "Xu-Chang", "" ], [ "Fu", "Hai-Bing", "" ], [ "Wu", "Xing-Gang", "" ] ]
We present a new determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{\rm cb}|$ by using the three-loop perturbative QCD corrections for the $B\to D^{\ast}$ semi-leptonic decay. The decay width of $B\to D^{\ast}$ semi-leptonic decay can be factorized as perturbatively calculable short-distance part and the non-perturbative but universal long-distance part. We adopt the principle of maximum conformality (PMC) single-scale setting approach to deal with the perturbative series so as to achieve a precise fixed-order prediction for the short-distance parameter $\eta_{A}$. By applying the PMC, an overall effective $\alpha_s$ value is achieved by recursively using the renormalization group equation, which inversely results in a precise scale-invariant pQCD series. Such scale-invariant series also provides a reliable basis for predicting the contributions from uncalculated perturbative terms. We then obtain $\eta_{A}=0.9225^{+0.0117}_{-0.0168}$, where the error is the squared average of those from $\Delta\alpha_{s}(M_Z)=\pm0.0010$ and the uncertainties caused by the uncalculated higher-order perturbative terms. By using the data of $B\to D^{\ast}\ell\bar{\nu}_{\ell}$, we finally obtain $|V_{\rm cb}|_{\rm PMC} =(40.60^{+0.53}_{-0.57})\times10^{-3}$, which is consistent with the PDG value within errors.
hep-ph/9704370
Zoltan Ligeti
Zoltan Ligeti
Nonperturbative effects in inclusive $B\to X_s\gamma$
Talk given at the FCNC'97 workshop, February 19-21, 1997, Santa Monica
null
null
CALT-68-2111
hep-ph
null
Uncertainties in the theoretical prediction for the inclusive $\bar B\to X_s\gamma$ decay rate are examined. Certain nonperturbative effects involving a virtual $c\bar c$ loop, which are calculable using the operator product expansion, are discussed.
[ { "created": "Mon, 21 Apr 1997 22:51:22 GMT", "version": "v1" } ]
2016-09-06
[ [ "Ligeti", "Zoltan", "" ] ]
Uncertainties in the theoretical prediction for the inclusive $\bar B\to X_s\gamma$ decay rate are examined. Certain nonperturbative effects involving a virtual $c\bar c$ loop, which are calculable using the operator product expansion, are discussed.
1307.7186
Xiao-Gang He
Dong Xu, Guan-Nan Li, Xiao-Gang He
Large SU(3) breaking effects and CP violation in $B^+ $ decays into three charged SU(3) octet pseudoscalar mesons
Review Tex, 20 pages, no figure. Materials extensively extended to include momentum dependent decay amplitudes
null
10.1142/S0217751X14500110
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
TThe LHCb collaboration has recently reported evidence for non-zero CP asymmetries in $B^+$ decays into $\pi^+ K^+ K^-,\; \pi^+\pi^+\pi^-,\; K^+ K^+ K^- $ and $K^+\pi^+\pi^-$. The branching ratios for these decays have also been measured with different values ranging from $5\times 10^{-6}$ to $51\times 10^{-6}$. If flavor $SU(3)$ symmetry is a good symmetry for $B$ decays, in the case that the dominant amplitude is momentum independent it is expected that branching ratios $Br$ and CP violating rate differences $\Delta_{CP} = \Gamma - \overline{\Gamma}$ satisfy, $Br(\pi^+\pi^+\pi^-) = 2Br(\pi^+ K^+ K^-)$, $Br(K^+K^+K^-) = 2 Br(K^+\pi^+\pi^-)$, and $\Delta_{CP}(\pi^+\pi^+\pi^-) = 2\Delta_{CP}(\pi^+ K^+K^-) = - \Delta_{CP}(K^+K^+K^-) = -2\Delta_{CP}(K^+\pi^+\pi^-)$. The experimental data do not exhibit the expected pattern for the branching ratios. The rate differences for $B^+\to \pi^+\pi^+\pi^-$ and $B^+\to K^+ K^+ K^-$ satisfy the relation between $\Delta S =0$ and $\Delta S=1$ well, but the other two do not, with the CP asymmetries having different signs than expected. In this work we study how to including momentum dependent and also $SU(3)$ breaking effects on these decays to explain experimental data. We find that only including lowest order derivative terms, in the $SU(3)$ limit, the decay patterns cannot be explained. Large $SU(3)$ breaking effects are needed to explain the data.
[ { "created": "Fri, 26 Jul 2013 22:42:34 GMT", "version": "v1" }, { "created": "Wed, 31 Jul 2013 16:46:47 GMT", "version": "v2" }, { "created": "Mon, 18 Nov 2013 05:21:01 GMT", "version": "v3" } ]
2015-06-16
[ [ "Xu", "Dong", "" ], [ "Li", "Guan-Nan", "" ], [ "He", "Xiao-Gang", "" ] ]
TThe LHCb collaboration has recently reported evidence for non-zero CP asymmetries in $B^+$ decays into $\pi^+ K^+ K^-,\; \pi^+\pi^+\pi^-,\; K^+ K^+ K^- $ and $K^+\pi^+\pi^-$. The branching ratios for these decays have also been measured with different values ranging from $5\times 10^{-6}$ to $51\times 10^{-6}$. If flavor $SU(3)$ symmetry is a good symmetry for $B$ decays, in the case that the dominant amplitude is momentum independent it is expected that branching ratios $Br$ and CP violating rate differences $\Delta_{CP} = \Gamma - \overline{\Gamma}$ satisfy, $Br(\pi^+\pi^+\pi^-) = 2Br(\pi^+ K^+ K^-)$, $Br(K^+K^+K^-) = 2 Br(K^+\pi^+\pi^-)$, and $\Delta_{CP}(\pi^+\pi^+\pi^-) = 2\Delta_{CP}(\pi^+ K^+K^-) = - \Delta_{CP}(K^+K^+K^-) = -2\Delta_{CP}(K^+\pi^+\pi^-)$. The experimental data do not exhibit the expected pattern for the branching ratios. The rate differences for $B^+\to \pi^+\pi^+\pi^-$ and $B^+\to K^+ K^+ K^-$ satisfy the relation between $\Delta S =0$ and $\Delta S=1$ well, but the other two do not, with the CP asymmetries having different signs than expected. In this work we study how to including momentum dependent and also $SU(3)$ breaking effects on these decays to explain experimental data. We find that only including lowest order derivative terms, in the $SU(3)$ limit, the decay patterns cannot be explained. Large $SU(3)$ breaking effects are needed to explain the data.
hep-ph/0602117
Edmond Berger
Edmond L. Berger (Argonne)
Overview and Charge -- Snowmass Workshop 2005
8 pages; to be published in the Proceedings of the 2005 International Linear Collider Workshop, Snowmass, CO, August 14 - 27, 2005
null
null
ANL-HEP-CP-06-1; PLEN0001
hep-ph
null
This contribution to the published Proceedings records the opening talk I presented on the first morning of the 2005 International Linear Collider Workshop in Snowmass, CO, August 14 - 27, 2005. It includes a summary of the motivation for the workshop, the scientific goals and charges for the working groups, the initial plans of the accelerator, detector, and physics groups, and the activities of the communication, education, and outreach group. This document also describes organizational aspects of the meeting, particularly the scientific committee structure, the self-organization of the working groups, the composition of the indispensable secretariat and computer support teams, and the sources of funding support. The report serves as an introduction to the proceedings whose individual papers and summary documents must be consulted for an appreciation of the accomplishments and progress made at Snowmass in 2005 toward the realization of an International Linear Collider.
[ { "created": "Mon, 13 Feb 2006 23:51:20 GMT", "version": "v1" } ]
2007-05-23
[ [ "Berger", "Edmond L.", "", "Argonne" ] ]
This contribution to the published Proceedings records the opening talk I presented on the first morning of the 2005 International Linear Collider Workshop in Snowmass, CO, August 14 - 27, 2005. It includes a summary of the motivation for the workshop, the scientific goals and charges for the working groups, the initial plans of the accelerator, detector, and physics groups, and the activities of the communication, education, and outreach group. This document also describes organizational aspects of the meeting, particularly the scientific committee structure, the self-organization of the working groups, the composition of the indispensable secretariat and computer support teams, and the sources of funding support. The report serves as an introduction to the proceedings whose individual papers and summary documents must be consulted for an appreciation of the accomplishments and progress made at Snowmass in 2005 toward the realization of an International Linear Collider.
2206.10132
En Wang
Xue-Chao Feng, Zheng-Ya Li, De-Min Li, Qin-Tao Song, En Wang, and Wen-Chen Yan
Mass spectra and decay properties of the higher excited $\rho$ mesons
9 pages, 3 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Although there are some experimental hints for the higher excited $\rho$ mesons, our knowledge of their properties is much poor theoretically. Based on our recent work about excited $\rho$ mesons [Phys.Rev.D104(2021)034013], we present the mass spectra and decay properties of the higher excited $\rho$ mesons with the modified Godfrey-Isgur quark model and the $^3P_0$ strong decay model, and compare our predictions with the experimental hints, which should be helpful to search for these higher excited $\rho$ mesons.
[ { "created": "Tue, 21 Jun 2022 06:30:56 GMT", "version": "v1" } ]
2022-06-22
[ [ "Feng", "Xue-Chao", "" ], [ "Li", "Zheng-Ya", "" ], [ "Li", "De-Min", "" ], [ "Song", "Qin-Tao", "" ], [ "Wang", "En", "" ], [ "Yan", "Wen-Chen", "" ] ]
Although there are some experimental hints for the higher excited $\rho$ mesons, our knowledge of their properties is much poor theoretically. Based on our recent work about excited $\rho$ mesons [Phys.Rev.D104(2021)034013], we present the mass spectra and decay properties of the higher excited $\rho$ mesons with the modified Godfrey-Isgur quark model and the $^3P_0$ strong decay model, and compare our predictions with the experimental hints, which should be helpful to search for these higher excited $\rho$ mesons.
2101.10749
Eduardo Saul-Sala
E. Saul-Sala, J. E. Sobczyk, M. Rafi Alam, L. Alvarez-Ruso, J. Nieves
Weak Kaon Production off the nucleon and Watson's theorem
8 pages, 5 figures
null
10.1016/j.physletb.2021.136349
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
We have improved the tree-level model of Ref arXiv:1004.5484 [hep-ph] for weak production of kaons off nucleons by partially restoring unitarity. This is achieved by imposing Watson's theorem to the dominant vector and axial-vector contributions in appropriate angular momentum and isospin quantum number sectors. The observable consequences of this procedure are investigated.
[ { "created": "Tue, 26 Jan 2021 12:41:51 GMT", "version": "v1" } ]
2021-05-12
[ [ "Saul-Sala", "E.", "" ], [ "Sobczyk", "J. E.", "" ], [ "Alam", "M. Rafi", "" ], [ "Alvarez-Ruso", "L.", "" ], [ "Nieves", "J.", "" ] ]
We have improved the tree-level model of Ref arXiv:1004.5484 [hep-ph] for weak production of kaons off nucleons by partially restoring unitarity. This is achieved by imposing Watson's theorem to the dominant vector and axial-vector contributions in appropriate angular momentum and isospin quantum number sectors. The observable consequences of this procedure are investigated.
1206.5909
Kalpana Bora
Kalpana Bora
Updated values of running quark and lepton masses at GUT scale in SM, 2HDM and MSSM
6 pages, 6 tables
Horizon, A Journal of Physics, Vol 2, 2013 (ISSN 2250-0871)
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Updated values of running quark and lepton masses at GUT (Grand unified theories) scales are important for fermion mass model building, and to calculate neutrino masses, in GUTs . We present their values at GUT scales, in SM, MSSM and 2HDM theories, using the latest values of running quark and lepton masses.
[ { "created": "Tue, 26 Jun 2012 08:10:10 GMT", "version": "v1" } ]
2014-07-28
[ [ "Bora", "Kalpana", "" ] ]
Updated values of running quark and lepton masses at GUT (Grand unified theories) scales are important for fermion mass model building, and to calculate neutrino masses, in GUTs . We present their values at GUT scales, in SM, MSSM and 2HDM theories, using the latest values of running quark and lepton masses.
hep-ph/0609067
Andreas Weiler
Gustavo C. Branco, Andrzej J. Buras, Sebastian Jager, Selma Uhlig, Andreas Weiler
Another Look at Minimal Lepton Flavour Violation, l_i -> l_j gamma, Leptogenesis, and the Ratio M_nu/ Lambda_LFV
48 pages, 9 figures
JHEP 0709:004,2007
10.1088/1126-6708/2007/09/004
TUM-HEP-645/06, PITHA-06/08
hep-ph
null
We analyze lepton flavour violation (LFV), as well as generation of the observed baryon-antibaryon asymmetry of the Universe (BAU) within a generalized minimal lepton flavour violation (MLFV) framework where we allow for CP violation both at low and high energies. The generation of BAU is obtained through radiative resonant leptogenesis (RRL), where starting with three exactly degenerate right-handed neutrinos at Lambda_GUT, we demonstrate explicitly within the SM and the MSSM that the splittings between their masses at the see-saw scale M_nu, generated by renormalization group effects, are sufficient for a successful leptogenesis for M_nu even as low as 10^6 GeV. The inclusion of flavour effects plays an important role in this result and can lead to the observed BAU even in the absence of CP violation beyond the PMNS phases. The absence of a stringent lower bound on M_nu in this type of leptogenesis allows to easily satisfy present and near future upper bounds on mu -> e gamma and other charged lepton flavour violating (LFV) processes even for Lambda_LFV = O(1 TeV). We find, that the MLFV framework in the presence of heavy right-handed neutrinos and leptogenesis is not as predictive as MFV in the quark sector and point out that without a specific MLFV model, there is a rich spectrum of possibilities for charged LFV processes and for their correlation with low energy neutrino physics and the LHC physics, even if the constraint from the observed BAU is taken into account. While certain qualitative features of our analysis confirm findings of Cirigliano et al., at the quantitative level we find phenomenologically important differences. We explain the origin of these differences.
[ { "created": "Wed, 6 Sep 2006 18:53:05 GMT", "version": "v1" }, { "created": "Mon, 19 Mar 2007 18:48:39 GMT", "version": "v2" } ]
2010-10-27
[ [ "Branco", "Gustavo C.", "" ], [ "Buras", "Andrzej J.", "" ], [ "Jager", "Sebastian", "" ], [ "Uhlig", "Selma", "" ], [ "Weiler", "Andreas", "" ] ]
We analyze lepton flavour violation (LFV), as well as generation of the observed baryon-antibaryon asymmetry of the Universe (BAU) within a generalized minimal lepton flavour violation (MLFV) framework where we allow for CP violation both at low and high energies. The generation of BAU is obtained through radiative resonant leptogenesis (RRL), where starting with three exactly degenerate right-handed neutrinos at Lambda_GUT, we demonstrate explicitly within the SM and the MSSM that the splittings between their masses at the see-saw scale M_nu, generated by renormalization group effects, are sufficient for a successful leptogenesis for M_nu even as low as 10^6 GeV. The inclusion of flavour effects plays an important role in this result and can lead to the observed BAU even in the absence of CP violation beyond the PMNS phases. The absence of a stringent lower bound on M_nu in this type of leptogenesis allows to easily satisfy present and near future upper bounds on mu -> e gamma and other charged lepton flavour violating (LFV) processes even for Lambda_LFV = O(1 TeV). We find, that the MLFV framework in the presence of heavy right-handed neutrinos and leptogenesis is not as predictive as MFV in the quark sector and point out that without a specific MLFV model, there is a rich spectrum of possibilities for charged LFV processes and for their correlation with low energy neutrino physics and the LHC physics, even if the constraint from the observed BAU is taken into account. While certain qualitative features of our analysis confirm findings of Cirigliano et al., at the quantitative level we find phenomenologically important differences. We explain the origin of these differences.
hep-ph/9209274
null
Volker Rieckert
Note on Tests of the Factorization Hypothesis and the Determination of Meson Decay Constants
(9 pages, ReVTeX, no figures), HD-THEP-92-32
Phys.Rev. D47 (1993) 3053-3056
10.1103/PhysRevD.47.3053
null
hep-ph
null
We discuss various tests of the factorization hypothesis making use of the close relationship between semi-leptonic and factorized nonleptonic decay amplitudes. It is pointed out that factorization leads to truely model-independent predictions for the ratio of nonleptonic to semi-leptonic decay rates, if in the nonleptonic decay a spin one meson of arbitrary mass or a pion take the place of the lepton pair. Where the decay constants of those mesons are known, these predictions represent ideal tests of the factorization hypothesis. In other cases they may be used to extract the decay constants. Currently available data on the decays $\bar B^0 \to D^+\pi^-,\, D^{*+}\pi^-,\, D^+\varrho^-,\, D^{*+}\varrho^-$ are shown to be in excellent agreement with the factorization results. A weighted average of the four independent values for the QCD coefficient $a_1$ extracted from the data gives $a_1=1.15\pm 0.06$ suggesting that it may be equal to the Wilson coefficient $c_1(\mu)$ evaluated at the scale $\mu = m_b$.
[ { "created": "Thu, 24 Sep 1992 05:52:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Rieckert", "Volker", "" ] ]
We discuss various tests of the factorization hypothesis making use of the close relationship between semi-leptonic and factorized nonleptonic decay amplitudes. It is pointed out that factorization leads to truely model-independent predictions for the ratio of nonleptonic to semi-leptonic decay rates, if in the nonleptonic decay a spin one meson of arbitrary mass or a pion take the place of the lepton pair. Where the decay constants of those mesons are known, these predictions represent ideal tests of the factorization hypothesis. In other cases they may be used to extract the decay constants. Currently available data on the decays $\bar B^0 \to D^+\pi^-,\, D^{*+}\pi^-,\, D^+\varrho^-,\, D^{*+}\varrho^-$ are shown to be in excellent agreement with the factorization results. A weighted average of the four independent values for the QCD coefficient $a_1$ extracted from the data gives $a_1=1.15\pm 0.06$ suggesting that it may be equal to the Wilson coefficient $c_1(\mu)$ evaluated at the scale $\mu = m_b$.
2404.01244
Yoshini Bailung
Yoshini Bailung, Neha Shah, Ankhi Roy
Searching for enhancement in coalescence of in-jet (anti-)deuterons in proton-proton collisions
11 pages, 9 figures, To appear in Physical Review C
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Recent measurements from ALICE report that $``$in-jet'' nucleons carry a higher probability of forming a deuteron via coalescence than the nucleons from the underlying event (UE). This study makes use of an event shape classifier to separate the $``$in-jet'' deuterons and the deuterons in the UE produced in high multiplicity proton-proton collisions at $\sqrt{s} = 13$ TeV. Event shape variables such as transverse spherocity allow the categorization of hard and soft components of an event, which can be divided into two respective classes; $``$jetty'' and $``$isotropic''. The $``$jetty'' deuterons minus the contribution of the deuterons from the $``$isotropic'' event are taken as $``$in-jet'' deuterons, and the coalescence mechanism is tested. The coalescence is performed with a Wigner function formalism, augmented as an afterburner to \textsc{pythia}8. The possible enhancement of the coalescence probability of $``$in-jet'' deuterons is investigated by calculating the coalescence parameter ($B_{2}$) in different spherocity classes in high-multiplicity $pp$ collisions.
[ { "created": "Mon, 1 Apr 2024 17:03:30 GMT", "version": "v1" } ]
2024-04-02
[ [ "Bailung", "Yoshini", "" ], [ "Shah", "Neha", "" ], [ "Roy", "Ankhi", "" ] ]
Recent measurements from ALICE report that $``$in-jet'' nucleons carry a higher probability of forming a deuteron via coalescence than the nucleons from the underlying event (UE). This study makes use of an event shape classifier to separate the $``$in-jet'' deuterons and the deuterons in the UE produced in high multiplicity proton-proton collisions at $\sqrt{s} = 13$ TeV. Event shape variables such as transverse spherocity allow the categorization of hard and soft components of an event, which can be divided into two respective classes; $``$jetty'' and $``$isotropic''. The $``$jetty'' deuterons minus the contribution of the deuterons from the $``$isotropic'' event are taken as $``$in-jet'' deuterons, and the coalescence mechanism is tested. The coalescence is performed with a Wigner function formalism, augmented as an afterburner to \textsc{pythia}8. The possible enhancement of the coalescence probability of $``$in-jet'' deuterons is investigated by calculating the coalescence parameter ($B_{2}$) in different spherocity classes in high-multiplicity $pp$ collisions.
hep-ph/9607462
Peter Gosdzinsky
J. Bijnens and P. Gosdzinsky
Electromagnetic Contributions to Vector Meson Masses and Mixings
null
Phys.Lett. B388 (1996) 203-210
10.1016/0370-2693(96)01147-1
null
hep-ph
null
We use the 1/N_c method to estimate electromagnetic contributions to vector meson masses and mixings. We identify several new sources of rho-omega mixing coming from short-distance effects. We comment on the extraction of quark masses from the vector meson masses. We also present a simple group theoretical discussion of the electromagnetic mass differences.
[ { "created": "Mon, 29 Jul 1996 15:11:30 GMT", "version": "v1" } ]
2009-10-28
[ [ "Bijnens", "J.", "" ], [ "Gosdzinsky", "P.", "" ] ]
We use the 1/N_c method to estimate electromagnetic contributions to vector meson masses and mixings. We identify several new sources of rho-omega mixing coming from short-distance effects. We comment on the extraction of quark masses from the vector meson masses. We also present a simple group theoretical discussion of the electromagnetic mass differences.
0712.1644
Masahiro Imachi
Masahiro Imachi, Fumihiko Toyoda, Shoichiro Otsuki
String Junction Model, Cluster Hypothesis, Penta-Quark Baryon and Tetra-Quark Meson
17 pages, 4 figures, correction is made, extensively revised
null
10.1143/PTP.120.723
null
hep-ph hep-ex
null
Thirty years ago we proposed string junction model of hadrons and examined structure and reaction of hadrons including exotic ones. Mass $m$ of exotic hadrons of light quarks is roughly given by $m \sim N_J\cdot m_B$, where $N_J$ is the total number of junctions and $m_B \sim 1$ GeV is the ordinary light baryon mass. In this paper we introduce "cluster hypothesis" into the model by which mass of a complex hadron is given by the sum of masses of clusters composing it. The hypothesis guarantees the established picture that mass differences of hadrons of the same string junction structure are due to those of the constituent quarks. A candidate for penta-quark baryon $\Theta$(1530 MeV, $S=+1)$ including a strange anti-quark ${\sb}$ and that for tetra-quark meson $Z^+$(4430 MeV) recently reported by the Bell collaboration are examined in parallel. $\Theta $ is considered to have non-strange partners, which are lighter by the mass difference $\Delta_s$ between strange and non-strange quarks. Mass of such light penta-quark baryons with $N_J=3$ is expected to be about 3 GeV. Several parameters of the model are estimated such as mass of junction of $m_J \sim O(10)$ MeV. While mass of light tetra-quark meson with $N_J=2$ is expected to be about 2 GeV, $Z^+$(4430 MeV) containing $(u,c,{\db},{\cb})$ gives a clue to determine some parameters of the model, e.g., inter-junction string energy $m_{IJ}$.
[ { "created": "Tue, 11 Dec 2007 04:33:29 GMT", "version": "v1" }, { "created": "Fri, 21 Dec 2007 13:34:51 GMT", "version": "v2" }, { "created": "Thu, 24 Apr 2008 16:27:37 GMT", "version": "v3" } ]
2009-11-13
[ [ "Imachi", "Masahiro", "" ], [ "Toyoda", "Fumihiko", "" ], [ "Otsuki", "Shoichiro", "" ] ]
Thirty years ago we proposed string junction model of hadrons and examined structure and reaction of hadrons including exotic ones. Mass $m$ of exotic hadrons of light quarks is roughly given by $m \sim N_J\cdot m_B$, where $N_J$ is the total number of junctions and $m_B \sim 1$ GeV is the ordinary light baryon mass. In this paper we introduce "cluster hypothesis" into the model by which mass of a complex hadron is given by the sum of masses of clusters composing it. The hypothesis guarantees the established picture that mass differences of hadrons of the same string junction structure are due to those of the constituent quarks. A candidate for penta-quark baryon $\Theta$(1530 MeV, $S=+1)$ including a strange anti-quark ${\sb}$ and that for tetra-quark meson $Z^+$(4430 MeV) recently reported by the Bell collaboration are examined in parallel. $\Theta $ is considered to have non-strange partners, which are lighter by the mass difference $\Delta_s$ between strange and non-strange quarks. Mass of such light penta-quark baryons with $N_J=3$ is expected to be about 3 GeV. Several parameters of the model are estimated such as mass of junction of $m_J \sim O(10)$ MeV. While mass of light tetra-quark meson with $N_J=2$ is expected to be about 2 GeV, $Z^+$(4430 MeV) containing $(u,c,{\db},{\cb})$ gives a clue to determine some parameters of the model, e.g., inter-junction string energy $m_{IJ}$.
0901.3184
Alexander Lenz
V. M. Braun, D. Yu. Ivanov, A. Lenz and A. Peters
Threshold Pion Production at Large Momentum Transfers
3 pages, talkpresented at PANIC 2008
null
null
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider threshold pion electroproduction on a proton target for photon virtualities in the region 1-10 GeV$^2$. The S-wave multipoles at threshold, $E_{0+}$ and $L_{0+}$, are calculated using light-cone sum rules.
[ { "created": "Wed, 21 Jan 2009 15:53:18 GMT", "version": "v1" } ]
2009-02-18
[ [ "Braun", "V. M.", "" ], [ "Ivanov", "D. Yu.", "" ], [ "Lenz", "A.", "" ], [ "Peters", "A.", "" ] ]
We consider threshold pion electroproduction on a proton target for photon virtualities in the region 1-10 GeV$^2$. The S-wave multipoles at threshold, $E_{0+}$ and $L_{0+}$, are calculated using light-cone sum rules.
hep-ph/9906296
Yuri Shirman
E. Katz, Y. Shadmi, and Y. Shirman
Heavy Thresholds, Slepton Masses and the $\mu$ Term in Anomaly Mediated Supersymmetry Breaking
25 pages, latex
JHEP 9908 (1999) 015
10.1088/1126-6708/1999/08/015
PUPT-1868, MIT-CTP-2875
hep-ph hep-th
null
The effects of heavy mass thresholds on anomaly-mediated soft supersymmetry breaking terms are discussed. While heavy thresholds completely decouple to lowest order in the supersymmetry breaking, it is argued that they do affect the breaking terms at higher orders. The relevant contributions typically occur at lower order in the loop expansion compared to purely anomaly mediated contributions. The non decoupling contributions may be used to render models in which the only source of supersymmetry breaking is anomaly mediation viable, by generating positive contributions to the sleptons' masses squared. They can also be used to generate acceptable mu- and B-terms.
[ { "created": "Tue, 8 Jun 1999 21:27:10 GMT", "version": "v1" } ]
2009-10-31
[ [ "Katz", "E.", "" ], [ "Shadmi", "Y.", "" ], [ "Shirman", "Y.", "" ] ]
The effects of heavy mass thresholds on anomaly-mediated soft supersymmetry breaking terms are discussed. While heavy thresholds completely decouple to lowest order in the supersymmetry breaking, it is argued that they do affect the breaking terms at higher orders. The relevant contributions typically occur at lower order in the loop expansion compared to purely anomaly mediated contributions. The non decoupling contributions may be used to render models in which the only source of supersymmetry breaking is anomaly mediation viable, by generating positive contributions to the sleptons' masses squared. They can also be used to generate acceptable mu- and B-terms.
1105.3846
Jernej Kamenik
Jernej F. Kamenik
Top, Polarization, LHC and New Physics
6 pages, 1 figure; To appear in the proceedings of Rencontres de Moriond EW 2011, 13-20 Mar 2011, La Thuile
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Polarization observables in top quark decays are sensitive probes of possible new physics contributions to the interactions of the heavy third generation quarks. Within an effective theory approach such new physics contributions can be classified in terms of several higher dimensional operators. We investigate the interplay between indirect constraints on such operators, coming mainly from rare B physics processes, and direct measurements of top polarization observables at the LHC.
[ { "created": "Thu, 19 May 2011 11:54:53 GMT", "version": "v1" } ]
2011-05-20
[ [ "Kamenik", "Jernej F.", "" ] ]
Polarization observables in top quark decays are sensitive probes of possible new physics contributions to the interactions of the heavy third generation quarks. Within an effective theory approach such new physics contributions can be classified in terms of several higher dimensional operators. We investigate the interplay between indirect constraints on such operators, coming mainly from rare B physics processes, and direct measurements of top polarization observables at the LHC.
hep-ph/0208197
Kanchan Khemchandani
N. G. Kelkar, M. Nowakowski, K. P. Khemchandani, and Sudhir R. Jain
Time Delay Plots of Unflavoured Baryons
28 pages, 5 figures and 3 tables, title changed, references added, manuscript revised
Nucl.Phys. A730 (2004) 121-140
10.1016/j.nuclphysa.2003.10.018
null
hep-ph hep-ex nucl-th
null
We explore the usefulness of the existing relations between the $S$-matrix and time delay in characterizing baryon resonances in pion-nucleon scattering. We draw attention to the fact that the existence of a positive maximum in time delay is a necessary criterion for the existence of a resonance and should be used as a constraint in conventional analyses which locate resonances from poles of the $S$-matrix and Argand diagrams. The usefulness of the time delay plots of resonances is demonstrated through a detailed analysis of the time delay in several partial waves of $\pi N$ elastic scattering.
[ { "created": "Thu, 22 Aug 2002 09:28:13 GMT", "version": "v1" }, { "created": "Sat, 10 Jan 2004 17:31:07 GMT", "version": "v2" } ]
2015-06-25
[ [ "Kelkar", "N. G.", "" ], [ "Nowakowski", "M.", "" ], [ "Khemchandani", "K. P.", "" ], [ "Jain", "Sudhir R.", "" ] ]
We explore the usefulness of the existing relations between the $S$-matrix and time delay in characterizing baryon resonances in pion-nucleon scattering. We draw attention to the fact that the existence of a positive maximum in time delay is a necessary criterion for the existence of a resonance and should be used as a constraint in conventional analyses which locate resonances from poles of the $S$-matrix and Argand diagrams. The usefulness of the time delay plots of resonances is demonstrated through a detailed analysis of the time delay in several partial waves of $\pi N$ elastic scattering.
hep-ph/9505379
Michelangelo Mangano
M. Cacciari, M. Greco, M.L. Mangano and A. Petrelli
Charmonium Production at the Tevatron
12 pages, Latex, epsfig, 4 tar-gzip-uuencoded figures
Phys.Lett. B356 (1995) 553-560
10.1016/0370-2693(95)00868-L
CERN-TH/95-129, FNT/T-95/17, IFUP-TH 25/95
hep-ph
null
We present in this work a study of large-\pt\ charmonium production in hadronic collisions. We work in the framework of the factorization model of Bodwin Braaten and Lepage, thereby including the color octet production mechanism, and extract the values of the necessary nonperturbative parameters from a comparison with the most recent data from the Fermilab 1.8 TeV $p\bar p$ hadron collider. We extend the calculation to 630 \gev, and compare the results with data published by the UA1 Collaboration. The global agreement is satisfactory, indicating that the largest components of the production mechanisms for charmonium production at high \pt\ have been isolated.
[ { "created": "Thu, 25 May 1995 09:11:59 GMT", "version": "v1" } ]
2009-10-28
[ [ "Cacciari", "M.", "" ], [ "Greco", "M.", "" ], [ "Mangano", "M. L.", "" ], [ "Petrelli", "A.", "" ] ]
We present in this work a study of large-\pt\ charmonium production in hadronic collisions. We work in the framework of the factorization model of Bodwin Braaten and Lepage, thereby including the color octet production mechanism, and extract the values of the necessary nonperturbative parameters from a comparison with the most recent data from the Fermilab 1.8 TeV $p\bar p$ hadron collider. We extend the calculation to 630 \gev, and compare the results with data published by the UA1 Collaboration. The global agreement is satisfactory, indicating that the largest components of the production mechanisms for charmonium production at high \pt\ have been isolated.
2304.04513
Masaki J.S. Yang
Masaki J. S. Yang
Chiral perturbative relation for neutrino masses in the type-I seesaw mechanism
6 pages, final version to be published in PLB
null
10.1016/j.physletb.2023.138061
STUPP-23-262
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this letter, we perform a perturbative analysis by the lightest singular value $m_{D1}$ of the Dirac mass matrix $m_{D}$ in the type-I seesaw mechanism. A mass relation $M_{1} = m_{D1}^{2}/ |(m_{\nu})_{11}|$ is obtained for the lightest mass $M_{1}$ of the right-handed neutrino $\nu_{R1}$ and the mass matrix of the left-handed neutrinos $m_{\nu}$ in the diagonal basis of $m_{D}$. This relation is rather stable under renormalization because it is gauge-invariant in the SM and associates with the approximate chiral symmetry of $\nu_{R1}$. If diagonalization of the Yukawa matrices of leptons $Y_{\nu, e}$ has only small mixings, the element $(m_{\nu})_{11}$ is close to the effective mass $m_{ee}$ of the neutrinoless double beta decay. By assuming $m_{D1} \simeq m_{u,e} \simeq 0.5$ MeV, the lightest mass is about $M_{1} \gtrsim O(100)$ TeV in the normal hierarchy and $M_{1} \sim O(10)$ TeV in the inverted hierarchy. Such a $\nu_{R1}$ with a tiny Yukawa coupling $y_{\nu 1} \sim O(10^{-5})$ can indirectly influence various observations. On the other hand, the famous bound of the thermal leptogenesis $M_{1} \gtrsim 10^{9}$ GeV that requires $m_{D1} \gtrsim 30$ MeV seems to be difficult to reconcile with a simple unified theory without a special condition.
[ { "created": "Mon, 10 Apr 2023 11:05:22 GMT", "version": "v1" }, { "created": "Sun, 9 Jul 2023 01:39:08 GMT", "version": "v2" } ]
2023-08-09
[ [ "Yang", "Masaki J. S.", "" ] ]
In this letter, we perform a perturbative analysis by the lightest singular value $m_{D1}$ of the Dirac mass matrix $m_{D}$ in the type-I seesaw mechanism. A mass relation $M_{1} = m_{D1}^{2}/ |(m_{\nu})_{11}|$ is obtained for the lightest mass $M_{1}$ of the right-handed neutrino $\nu_{R1}$ and the mass matrix of the left-handed neutrinos $m_{\nu}$ in the diagonal basis of $m_{D}$. This relation is rather stable under renormalization because it is gauge-invariant in the SM and associates with the approximate chiral symmetry of $\nu_{R1}$. If diagonalization of the Yukawa matrices of leptons $Y_{\nu, e}$ has only small mixings, the element $(m_{\nu})_{11}$ is close to the effective mass $m_{ee}$ of the neutrinoless double beta decay. By assuming $m_{D1} \simeq m_{u,e} \simeq 0.5$ MeV, the lightest mass is about $M_{1} \gtrsim O(100)$ TeV in the normal hierarchy and $M_{1} \sim O(10)$ TeV in the inverted hierarchy. Such a $\nu_{R1}$ with a tiny Yukawa coupling $y_{\nu 1} \sim O(10^{-5})$ can indirectly influence various observations. On the other hand, the famous bound of the thermal leptogenesis $M_{1} \gtrsim 10^{9}$ GeV that requires $m_{D1} \gtrsim 30$ MeV seems to be difficult to reconcile with a simple unified theory without a special condition.
2107.09679
Isaac Wang
Keisuke Harigaya and Isaac R. Wang
Axiogenesis from $SU(2)_R$ phase transition
30 pages, 1 figure
null
10.1007/JHEP10(2021)022
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The baryon asymmetry of the universe may be explained by rotations of the QCD axion in field space and baryon number violating processes. We consider the minimal extension of the Standard Model by a non-Abelian gauge interaction, $SU(2)_R$, whose sphaleron process violates baryon number. Assuming that axion dark matter is also created from the axion rotation by the kinetic misalignment mechanism, the mass scale of the $SU(2)_R$ gauge boson is fixed as a function of the QCD axion decay constant, and vise versa. Significant portion of the parameter space has already been excluded by new gauge boson searches, and the high-luminocity LHC will further probe the viable parameter space.
[ { "created": "Tue, 20 Jul 2021 18:00:02 GMT", "version": "v1" }, { "created": "Thu, 5 Aug 2021 22:29:42 GMT", "version": "v2" }, { "created": "Thu, 23 Dec 2021 00:09:07 GMT", "version": "v3" } ]
2021-12-24
[ [ "Harigaya", "Keisuke", "" ], [ "Wang", "Isaac R.", "" ] ]
The baryon asymmetry of the universe may be explained by rotations of the QCD axion in field space and baryon number violating processes. We consider the minimal extension of the Standard Model by a non-Abelian gauge interaction, $SU(2)_R$, whose sphaleron process violates baryon number. Assuming that axion dark matter is also created from the axion rotation by the kinetic misalignment mechanism, the mass scale of the $SU(2)_R$ gauge boson is fixed as a function of the QCD axion decay constant, and vise versa. Significant portion of the parameter space has already been excluded by new gauge boson searches, and the high-luminocity LHC will further probe the viable parameter space.
1706.01379
Vladimir Galkin
R. N. Faustov, V. O. Galkin
Rare $\Lambda_b\to n l^+l^-$ decays in the relativistic quark-diquark picture
7 pages, 4 figures
Mod. Phys. Lett. A, Vol. 32, No. 24 (2017) 1750125
10.1142/S0217732317501255
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The form factors of the rare $\Lambda_b\to n l^+l^-$ decays are calculated in the framework of the relativistic quark-diquark picture of baryons with the consistent account of the relativistic effects. Their momentum transfer squared dependence is determined explicitly in the whole accessible kinematical range. The decay branching fractions, forward-backward asymmetries and the fractions of longitudinally polarized dileptons are determined. The branching fraction of the rare $\Lambda_b\to n\mu^+\mu^-$ decay are found to be ${\rm Br}(\Lambda_b\to n\mu^+\mu^-)=(3.75\pm0.38)\times10^{-8}$ and thus could be measured at the LHC. Prediction for the branching fraction of the rare radiative $\Lambda_b\to n \gamma$ decay is also given.
[ { "created": "Mon, 5 Jun 2017 15:37:46 GMT", "version": "v1" } ]
2017-07-19
[ [ "Faustov", "R. N.", "" ], [ "Galkin", "V. O.", "" ] ]
The form factors of the rare $\Lambda_b\to n l^+l^-$ decays are calculated in the framework of the relativistic quark-diquark picture of baryons with the consistent account of the relativistic effects. Their momentum transfer squared dependence is determined explicitly in the whole accessible kinematical range. The decay branching fractions, forward-backward asymmetries and the fractions of longitudinally polarized dileptons are determined. The branching fraction of the rare $\Lambda_b\to n\mu^+\mu^-$ decay are found to be ${\rm Br}(\Lambda_b\to n\mu^+\mu^-)=(3.75\pm0.38)\times10^{-8}$ and thus could be measured at the LHC. Prediction for the branching fraction of the rare radiative $\Lambda_b\to n \gamma$ decay is also given.
hep-ph/9606484
Fred Jegerlehner
F. Jegerlehner (DESY-IFH, Zeuthen)
Hadronic Vacuum Polarization Contribution to g-2 of the Leptons and alpha(M_Z)
11 pages, 11 postscript figures, uses espcrc2.sty. Postscript version available at http://www.ifh.de/~fjeger/desy-96-121.ps.gz To be published in the proceedings of Zeuthen Workshop on Elementary Particle Theory: QCD and QED in Higher Orders, Rheinsberg, Germany, 21-26 Apr 1996
Nucl.Phys.Proc.Suppl. 51C (1996) 131-141
10.1016/S0920-5632(96)90017-1
DESY-96-121
hep-ph
null
We review and compare recent calculations of hadronic vacuum polarization effects. In particular, we consider the anomalous magnetic moments g-2 of the leptons and alpha(M_Z), the effective fine structure constant at the Z--resonance.
[ { "created": "Sun, 30 Jun 1996 23:52:21 GMT", "version": "v1" } ]
2015-06-25
[ [ "Jegerlehner", "F.", "", "DESY-IFH, Zeuthen" ] ]
We review and compare recent calculations of hadronic vacuum polarization effects. In particular, we consider the anomalous magnetic moments g-2 of the leptons and alpha(M_Z), the effective fine structure constant at the Z--resonance.
1411.0865
Wolfgang Lucha
Wolfgang Lucha, Dmitri Melikhov, Silvano Simula
QCD Sum Rules for Heavy-Meson Decay Constants: Impact of Renormalization Scale and Scheme
5 pages, 3 figures, contributed to "Quark Confinement and the Hadron Spectrum XI" (8 - 12 September 2014, St. Petersburg, Russia)
AIP Conf. Proc 1701 (2016) 100013
10.1063/1.4938722
HEPHY-PUB 939/14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the realm of QCD sum rules, one of the most important areas of application of this nonperturbative approach is the prediction of the decay constants of heavy mesons. However, in spite of the fact that, indisputably, the adopted techniques are, of course, very similar, we encounter rather dissimilar challenges, or obstacles, when extracting from two-point correlators of appropriate heavy-light currents interpolating the mesons, the characteristics of charmed mesons with different spin. In view of this, it seems worthwhile to us to revisit this issue for the case of charmed pseudoscalar mesons $D_{(s)}$ and vector mesons $D^*_{(s)}.$
[ { "created": "Tue, 4 Nov 2014 11:38:58 GMT", "version": "v1" } ]
2016-01-26
[ [ "Lucha", "Wolfgang", "" ], [ "Melikhov", "Dmitri", "" ], [ "Simula", "Silvano", "" ] ]
Within the realm of QCD sum rules, one of the most important areas of application of this nonperturbative approach is the prediction of the decay constants of heavy mesons. However, in spite of the fact that, indisputably, the adopted techniques are, of course, very similar, we encounter rather dissimilar challenges, or obstacles, when extracting from two-point correlators of appropriate heavy-light currents interpolating the mesons, the characteristics of charmed mesons with different spin. In view of this, it seems worthwhile to us to revisit this issue for the case of charmed pseudoscalar mesons $D_{(s)}$ and vector mesons $D^*_{(s)}.$
1412.1552
G.R. Boroun
G.R. Boroun, B. Rezaei, J.K.Sarma
A Phenomenological Solution Small $x$ to the Longitudinal Structure Function Dynamical Behavior
10 pages, 5 figures, 1 table
International Journal of Modern Physics A, Vol. 29 (2014) 1450189
10.1142/S0217751X14501899
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, the evolutions of longitudinal proton structure function have been obtained at small-$x$ up to next-to-next-to-leading order using a hard Pomeron behavior. In our paper, evolutions of gluonic as well as heavy longitudinal structure functions have been obtained separately and the total contributions have been calculated. The total longitudinal structure functions have been compared with results of Donnachie-Landshoff (DL) model, Color Dipole (CD) model, $k_{T}$ factorization and H1 data.
[ { "created": "Thu, 4 Dec 2014 04:35:15 GMT", "version": "v1" } ]
2014-12-05
[ [ "Boroun", "G. R.", "" ], [ "Rezaei", "B.", "" ], [ "Sarma", "J. K.", "" ] ]
In this paper, the evolutions of longitudinal proton structure function have been obtained at small-$x$ up to next-to-next-to-leading order using a hard Pomeron behavior. In our paper, evolutions of gluonic as well as heavy longitudinal structure functions have been obtained separately and the total contributions have been calculated. The total longitudinal structure functions have been compared with results of Donnachie-Landshoff (DL) model, Color Dipole (CD) model, $k_{T}$ factorization and H1 data.
1205.6606
Miguel Albaladejo
M. Albaladejo and J.A. Oller
On the size of the sigma meson and its nature
31 pages, 21 figures
null
10.1103/PhysRevD.86.034003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work the nature of the \sigma or f_0(600) resonance is discussed by evaluating its quadratic scalar radius, \la r^2\ra_s^\sigma. This allows one to have a quantitative estimate for the size of this resonance. We obtain that the \sigma resonance is a compact object with $\la r^2\ra_s^\sigma=(0.19\pm0.02)-i(0.06\pm0.02)$ fm^2. Within our approach, employing unitary chiral perturbation theory, the \sigma is a dynamically generated resonance that stems from the pion-pion interactions. Given its small size we conclude that the two pions inside the resonance are merged. A four-quark picture is then more appropriate. However, when the pion mass increases, for pion masses somewhat above 400 MeV, the picture of a two-pion molecule is the appropriate one. The \sigma is then a spread \pi\pi bound state. These results are connected with other recent works that support a non standard nature of the \sigma as well, while fulfilling strong QCD constraints, as well as with lattice QCD. We offer a detailed study of the low-energy S-wave \pi\pi scattering data from where we extract our values for the threshold parameters of S-wave \pi\pi phase shifts, the {\cal O}(p^4) chiral perturbation theory low energy constants as well as the \sigma pole position. From the comparison with other accurate determinations in the literature we obtain the average values for the isospin 0 S-wave \pi\pi threshold parameters, $a_0^0=0.220\pm0.003$, $b_0^0=0.279\pm 0.003 M_\pi^{-2}$, and for the real and imaginary parts of the \sigma pole position in \sqrt{s}, $458\pm14-i(261\pm17)$ MeV. The quark mass dependence of the size of the \sigma, its mass and width are considered too. The latter agree accurately with a previous lattice QCD calculation. The fact that the mass of this resonance tends to follow the threshold of two pions is a clear indication that the \sigma is a dynamically generated meson-meson resonance.
[ { "created": "Wed, 30 May 2012 09:45:17 GMT", "version": "v1" } ]
2013-05-30
[ [ "Albaladejo", "M.", "" ], [ "Oller", "J. A.", "" ] ]
In this work the nature of the \sigma or f_0(600) resonance is discussed by evaluating its quadratic scalar radius, \la r^2\ra_s^\sigma. This allows one to have a quantitative estimate for the size of this resonance. We obtain that the \sigma resonance is a compact object with $\la r^2\ra_s^\sigma=(0.19\pm0.02)-i(0.06\pm0.02)$ fm^2. Within our approach, employing unitary chiral perturbation theory, the \sigma is a dynamically generated resonance that stems from the pion-pion interactions. Given its small size we conclude that the two pions inside the resonance are merged. A four-quark picture is then more appropriate. However, when the pion mass increases, for pion masses somewhat above 400 MeV, the picture of a two-pion molecule is the appropriate one. The \sigma is then a spread \pi\pi bound state. These results are connected with other recent works that support a non standard nature of the \sigma as well, while fulfilling strong QCD constraints, as well as with lattice QCD. We offer a detailed study of the low-energy S-wave \pi\pi scattering data from where we extract our values for the threshold parameters of S-wave \pi\pi phase shifts, the {\cal O}(p^4) chiral perturbation theory low energy constants as well as the \sigma pole position. From the comparison with other accurate determinations in the literature we obtain the average values for the isospin 0 S-wave \pi\pi threshold parameters, $a_0^0=0.220\pm0.003$, $b_0^0=0.279\pm 0.003 M_\pi^{-2}$, and for the real and imaginary parts of the \sigma pole position in \sqrt{s}, $458\pm14-i(261\pm17)$ MeV. The quark mass dependence of the size of the \sigma, its mass and width are considered too. The latter agree accurately with a previous lattice QCD calculation. The fact that the mass of this resonance tends to follow the threshold of two pions is a clear indication that the \sigma is a dynamically generated meson-meson resonance.
hep-ph/9712448
Qing Di
Di Qing, Xiang-Song Chen and Fan Wang
Spin content of the nucleon in a valence and sea quark mixing model
11 pages, Latex, one figure, to be published in Phys. Rev. C57
Phys.Rev.C57:31-34,1998
10.1103/PhysRevC.57.31
null
hep-ph
null
A dynamical valence and sea quark mixing model is shown to fit the baryon ground state properties as well as the spin content of the nucleon. The relativistic correction and the $q^3{\leftrightarrow} q^3q\bar{q}$ transition terms induced by the quark axial vector current $\bar{\psi}\vec{\gamma}\gamma^5\psi$ in this model space is responsible for the quark spin reduction.
[ { "created": "Fri, 19 Dec 1997 06:30:39 GMT", "version": "v1" } ]
2008-11-26
[ [ "Qing", "Di", "" ], [ "Chen", "Xiang-Song", "" ], [ "Wang", "Fan", "" ] ]
A dynamical valence and sea quark mixing model is shown to fit the baryon ground state properties as well as the spin content of the nucleon. The relativistic correction and the $q^3{\leftrightarrow} q^3q\bar{q}$ transition terms induced by the quark axial vector current $\bar{\psi}\vec{\gamma}\gamma^5\psi$ in this model space is responsible for the quark spin reduction.
1006.0973
Eder Izaguirre
Anson Hook, Eder Izaguirre, Jay G. Wacker
Model Independent Bounds on Kinetic Mixing
4 pages, 2 figures
null
null
SLAC-PUB-14131
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New Abelian vector bosons can kinetically mix with the hypercharge gauge boson of the Standard Model. This letter computes the model independent limits on vector bosons with masses from 1 GeV to 1 TeV. The limits arise from the numerous e+e- experiments that have been performed in this energy range and bound the kinetic mixing by epsilon < 0.03 for most of the mass range studied, regardless of any additional interactions that the new vector boson may have.
[ { "created": "Fri, 4 Jun 2010 20:00:01 GMT", "version": "v1" } ]
2010-06-08
[ [ "Hook", "Anson", "" ], [ "Izaguirre", "Eder", "" ], [ "Wacker", "Jay G.", "" ] ]
New Abelian vector bosons can kinetically mix with the hypercharge gauge boson of the Standard Model. This letter computes the model independent limits on vector bosons with masses from 1 GeV to 1 TeV. The limits arise from the numerous e+e- experiments that have been performed in this energy range and bound the kinetic mixing by epsilon < 0.03 for most of the mass range studied, regardless of any additional interactions that the new vector boson may have.
hep-ph/9906270
J. Gunion
J.F. Gunion and S. Mrenna (U.C. Davis)
A study of SUSY signatures at the Tevatron in models with near mass degeneracy of the lightest chargino and neutralino
44 pages, equations.sty, submitted to Phys. Rev. D
Phys.Rev. D62 (2000) 015002
10.1103/PhysRevD.62.015002
UCD-99-11
hep-ph hep-ex
null
For some choices of soft SUSY-breaking parameters, the LSP is a stable neutralino $\cnone$, the NLSP is a chargino $\cpmone$ almost degenerate in mass with the LSP ($\dmchi\equiv\mcpmone-\mcnone\sim \mpi-$few GeV), and all other sparticles are relatively heavy. In this case, detection of sparticles in the usual, mSUGRA-motivated signals will be difficult, since the decay products in $\cpmone\to\cnone...$ will be very soft, and alternative signals must be considered. Here, we study the viability of signatures at the Tevatron based on highly-ionizing charged tracks, disappearing charged tracks, large impact parameters, missing transverse energy and a jet or a photon, and determine the mass reach of such signatures assuming that only the $\cpmone$ and $\cnone$ are light. We also consider the jet+$\etmiss$ and $\gamma+\etmiss$ signatures assuming that the gluino is also light with $\mgl\sim \mcpmone$. We find that the mass reach is critically dependent upon $\dmchi$ and $\mgl-\mcpmone$. If $\dmchi$ is sufficiently big that $c\tau(\cpmone)\lsim$few cm and $\mgl$ is large, there is a significant possibility that the limits on $\mcpmone$ based on LEP2 data cannot be extended at the Tevatron. If $c\tau(\cpmone)>$few cm, relatively background-free signals exist that will give a clear signal of $\cpmone$ production (for some range of $\mcpmone$) even if $\mgl$ is very large.
[ { "created": "Sun, 6 Jun 1999 23:56:53 GMT", "version": "v1" }, { "created": "Tue, 8 Jun 1999 01:24:21 GMT", "version": "v2" } ]
2009-10-31
[ [ "Gunion", "J. F.", "", "U.C. Davis" ], [ "Mrenna", "S.", "", "U.C. Davis" ] ]
For some choices of soft SUSY-breaking parameters, the LSP is a stable neutralino $\cnone$, the NLSP is a chargino $\cpmone$ almost degenerate in mass with the LSP ($\dmchi\equiv\mcpmone-\mcnone\sim \mpi-$few GeV), and all other sparticles are relatively heavy. In this case, detection of sparticles in the usual, mSUGRA-motivated signals will be difficult, since the decay products in $\cpmone\to\cnone...$ will be very soft, and alternative signals must be considered. Here, we study the viability of signatures at the Tevatron based on highly-ionizing charged tracks, disappearing charged tracks, large impact parameters, missing transverse energy and a jet or a photon, and determine the mass reach of such signatures assuming that only the $\cpmone$ and $\cnone$ are light. We also consider the jet+$\etmiss$ and $\gamma+\etmiss$ signatures assuming that the gluino is also light with $\mgl\sim \mcpmone$. We find that the mass reach is critically dependent upon $\dmchi$ and $\mgl-\mcpmone$. If $\dmchi$ is sufficiently big that $c\tau(\cpmone)\lsim$few cm and $\mgl$ is large, there is a significant possibility that the limits on $\mcpmone$ based on LEP2 data cannot be extended at the Tevatron. If $c\tau(\cpmone)>$few cm, relatively background-free signals exist that will give a clear signal of $\cpmone$ production (for some range of $\mcpmone$) even if $\mgl$ is very large.
hep-ph/9704280
Istvan Montvay
I. Montvay
Leptoquarks and vector-like strong interactions at the TeV scale
latex, 8 pages, 1 figure with epsfig. Revised version to be published, including a few clarifying remarks
Phys.Lett. B407 (1997) 22-26
10.1016/S0370-2693(97)00720-X
DESY 97-058
hep-ph
null
In a vector-like extension of the minimal standard model with mirror fermions leptoquarks can be bound states of fermion-mirror-fermion pairs held together by a new strong interaction at the TeV scale. The small couplings of leptoquarks to light fermion pairs arise due to mixing. The large $Q^2$ event excess at HERA and also the high $E_T$ jet excess at Tevatron can potentially be explained.
[ { "created": "Thu, 10 Apr 1997 08:43:38 GMT", "version": "v1" }, { "created": "Wed, 28 May 1997 14:35:04 GMT", "version": "v2" } ]
2009-10-30
[ [ "Montvay", "I.", "" ] ]
In a vector-like extension of the minimal standard model with mirror fermions leptoquarks can be bound states of fermion-mirror-fermion pairs held together by a new strong interaction at the TeV scale. The small couplings of leptoquarks to light fermion pairs arise due to mixing. The large $Q^2$ event excess at HERA and also the high $E_T$ jet excess at Tevatron can potentially be explained.
hep-ph/0610014
Gennady Kozlov
G.A. Kozlov and G. Khoriauli
The flux-tube phase transition
Based on the talk presented at the Conference "Quark Confinement and Hadron Spectrum VII", Ponta Delgada, Azores, Portugal, September 2-7, 2006. To be published in AIP. (9 pages, 4 figures)
AIP Conf.Proc.892:391-395,2007
10.1063/1.2714426
null
hep-ph
null
We consider the phase transition in the "hot" dual long-distances Yang-Mills theory at finite temperature $T$. This phase transition is associated with a change of symmetry. The dual model is formulated in terms of two-point Wightman functions with equations of motion involving higher derivatives. The effective mass of the dual gauge field is derived as a function of $T$-dependent gauge coupling constant.
[ { "created": "Mon, 2 Oct 2006 06:31:32 GMT", "version": "v1" } ]
2010-05-27
[ [ "Kozlov", "G. A.", "" ], [ "Khoriauli", "G.", "" ] ]
We consider the phase transition in the "hot" dual long-distances Yang-Mills theory at finite temperature $T$. This phase transition is associated with a change of symmetry. The dual model is formulated in terms of two-point Wightman functions with equations of motion involving higher derivatives. The effective mass of the dual gauge field is derived as a function of $T$-dependent gauge coupling constant.
1610.06487
Gerry McKeon Dr.
F.A. Chishtie, D.G.C. McKeon
Renormalization Scheme Dependence and Renormalization Group Summation
16 pages, 3 figures, LaTeX format
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider logarithmic contributions to the free energy, instanton effective action and Laplace sum rules in QCD that are a consequence of radiative corrections. Upon summing these contributions by using the renormalization group, all dependence on the renormalization scale parameter $\mu$ cancels. The renormalization scheme dependence in these processes is examined, and a renormalization scheme is found in which the effect of higher order radiative corrections is absorbed by the behaviour of the running coupling.
[ { "created": "Thu, 20 Oct 2016 16:29:31 GMT", "version": "v1" }, { "created": "Fri, 13 Jan 2017 11:25:53 GMT", "version": "v2" }, { "created": "Wed, 14 Jun 2017 22:05:56 GMT", "version": "v3" } ]
2017-06-16
[ [ "Chishtie", "F. A.", "" ], [ "McKeon", "D. G. C.", "" ] ]
We consider logarithmic contributions to the free energy, instanton effective action and Laplace sum rules in QCD that are a consequence of radiative corrections. Upon summing these contributions by using the renormalization group, all dependence on the renormalization scale parameter $\mu$ cancels. The renormalization scheme dependence in these processes is examined, and a renormalization scheme is found in which the effect of higher order radiative corrections is absorbed by the behaviour of the running coupling.
hep-ph/9212251
John Collins
John C. Collins
Spin in Perturbative QCD; Coherent Hard Diffraction
To appear in Proceedings of annual meeting of Division of Particles and Fields of American Physical Society, Fermilab 10--14 November 1992; 4 pages, no figures, LaTeX, PSU/TH/118
null
null
null
hep-ph
null
I briefly review: (a) some recent developments in the theory of hard scattering in QCD with polarized beams, and (b) coherent hard diffraction (that is, hard scattering in diffractive events, with the Pomeron behaving in an apparently point-like fashion).
[ { "created": "Thu, 10 Dec 1992 20:26:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Collins", "John C.", "" ] ]
I briefly review: (a) some recent developments in the theory of hard scattering in QCD with polarized beams, and (b) coherent hard diffraction (that is, hard scattering in diffractive events, with the Pomeron behaving in an apparently point-like fashion).
hep-ph/9708331
Randall J. Scalise
Marcel Demarteau, Vassilis Koulovassilopoulos, Joseph Lykken, Fredrick I. Olness, Stephen Parke, Randall J. Scalise, Erich Varnes, and G. P. Yeh
Precision Measurements Of Heavy Objects Working Group Summary
6 pages, LaTeX2e, 11 PostScript figures, uses epsf.sty and snow2e.cls. Contribution to Very Large Hadron Collider (VLHC) Physics and Detector Workshop, 13-15 March 1997, Fermilab
null
null
null
hep-ph
null
We report on the activities of the Precision Measurements Of Heavy Objects working group of the Very Large Hadron Collider Physics and Detector Workshop.
[ { "created": "Wed, 13 Aug 1997 03:33:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Demarteau", "Marcel", "" ], [ "Koulovassilopoulos", "Vassilis", "" ], [ "Lykken", "Joseph", "" ], [ "Olness", "Fredrick I.", "" ], [ "Parke", "Stephen", "" ], [ "Scalise", "Randall J.", "" ], [ "Varnes", "Erich", "" ], [ "Yeh", "G. P.", "" ] ]
We report on the activities of the Precision Measurements Of Heavy Objects working group of the Very Large Hadron Collider Physics and Detector Workshop.
1712.06002
D\'aniel Ber\'enyi
D\'aniel Ber\'enyi and P\'eter L\'evai
Chiral Magnetic Effect in the Dirac-Heisenberg-Wigner formalism
4 pages, 2 figures, to appear in the proceedings of The European Physical Society Conference on High Energy Physics, 5-12 July 2017, Venice, Italy
null
10.22323/1.314.0172
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The emergence of the Chiral Magnetic Effect (CME) and the related anomalous current is investigated using the real time Dirac-Heisenberg-Wigner formalism. This method is widely used for describing strong field physics and QED vacuum tunneling phenomena as well as pair-production in heavy-ion collisions. We extend earlier investigations of the CME in constant fluxtube configuration by considering time dependent fields. In our model we can follow the formation of axial charge separation, formation of axial current and then the emergence of the anomalous electric current. Qualitative results are shown for special field configurations that help interpret the predictions of CME related effects in heavy-ion collisions in the RHIC Beam Energy Scan program.
[ { "created": "Sat, 16 Dec 2017 18:13:06 GMT", "version": "v1" } ]
2018-08-08
[ [ "Berényi", "Dániel", "" ], [ "Lévai", "Péter", "" ] ]
The emergence of the Chiral Magnetic Effect (CME) and the related anomalous current is investigated using the real time Dirac-Heisenberg-Wigner formalism. This method is widely used for describing strong field physics and QED vacuum tunneling phenomena as well as pair-production in heavy-ion collisions. We extend earlier investigations of the CME in constant fluxtube configuration by considering time dependent fields. In our model we can follow the formation of axial charge separation, formation of axial current and then the emergence of the anomalous electric current. Qualitative results are shown for special field configurations that help interpret the predictions of CME related effects in heavy-ion collisions in the RHIC Beam Energy Scan program.
1612.09537
Gilberto Tavares-Velasco
M. A. Arroyo-Ure\~na, G. Hern\'andez-Tom\'e, G. Tavares-Velasco
Anomalous magnetic and weak magnetic dipole moments of the $\tau$ lepton in the simplest little Higgs model
23 pages, 11 figures, new analysis and References added
Eur. Phys. J. C (2017) 77:227
10.1140/epjc/s10052-017-4803-z
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain analytical expressions, both in terms of parametric integrals and Passarino-Veltman scalar functions, for the one-loop contributions to the anomalous weak magnetic dipole moment (AWMDM) of a charged lepton in the framework of the simplest little Higgs model (SLHM). Our results are general and can be useful to compute the weak properties of a charged lepton in other extensions of the standard model (SM). As a by-product we obtain generic contributions to the anomalous magnetic dipole moment (AMDM), which agree with previous results. We then study numerically the potential contributions from this model to the $\tau$ lepton AMDM and AWMDM for values of the parameter space consistent with current experimental data. It is found that they depend mainly on the energy scale $f$ at which the global symmetry is broken and the $t_\beta$ parameter, whereas there is little sensitivity to a mild change in the values of other parameters of the model. While the $\tau$ AMDM is of the order of $10^{-9}$, the real (imaginary) part of its AWMDM is of the order of $10^{-9}$ ($10^{-10}$). These values seem to be out of the reach of the expected experimental sensitivity of future experiments.
[ { "created": "Fri, 30 Dec 2016 17:13:56 GMT", "version": "v1" }, { "created": "Sat, 7 Jan 2017 21:43:36 GMT", "version": "v2" }, { "created": "Fri, 17 Mar 2017 01:08:10 GMT", "version": "v3" } ]
2017-04-13
[ [ "Arroyo-Ureña", "M. A.", "" ], [ "Hernández-Tomé", "G.", "" ], [ "Tavares-Velasco", "G.", "" ] ]
We obtain analytical expressions, both in terms of parametric integrals and Passarino-Veltman scalar functions, for the one-loop contributions to the anomalous weak magnetic dipole moment (AWMDM) of a charged lepton in the framework of the simplest little Higgs model (SLHM). Our results are general and can be useful to compute the weak properties of a charged lepton in other extensions of the standard model (SM). As a by-product we obtain generic contributions to the anomalous magnetic dipole moment (AMDM), which agree with previous results. We then study numerically the potential contributions from this model to the $\tau$ lepton AMDM and AWMDM for values of the parameter space consistent with current experimental data. It is found that they depend mainly on the energy scale $f$ at which the global symmetry is broken and the $t_\beta$ parameter, whereas there is little sensitivity to a mild change in the values of other parameters of the model. While the $\tau$ AMDM is of the order of $10^{-9}$, the real (imaginary) part of its AWMDM is of the order of $10^{-9}$ ($10^{-10}$). These values seem to be out of the reach of the expected experimental sensitivity of future experiments.
1007.5355
Masashi Wakamatsu
M. Wakamatsu
Gauge- and frame-independent decomposition of nucleon spin
A slightly extended version to appear in Physical Review D
Phys.Rev.D83:014012,2011
10.1103/PhysRevD.83.014012
OU-HET-675
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent paper, we have shown that the way of gauge-invariant decomposition of the nucleon spin is not necessarily unique, but there still exists a preferable decomposition from the observational viewpoint. What was not complete in this argument is a fully satisfactory answer to the following questions. Does the proposed gauge-invariant decomposition, especially the decomposition of the gluon total angular momentum into its spin and orbital parts, correspond to observables which can be extracted from high-energy deep-inelastic-scattering measurements ? Is this decomposition not only gauge-invariant but also Lorentz frame-independent, so that it is legitimately thought to reflect an intrinsic property of the nucleon ? We show that we can answer both of these questions affirmatively, by making full use of a gauge-invariant decomposition of covariant angular momentum tensor of QCD in an arbitrary Lorentz frame.
[ { "created": "Fri, 30 Jul 2010 00:44:50 GMT", "version": "v1" }, { "created": "Tue, 21 Dec 2010 00:55:47 GMT", "version": "v2" } ]
2011-02-16
[ [ "Wakamatsu", "M.", "" ] ]
In a recent paper, we have shown that the way of gauge-invariant decomposition of the nucleon spin is not necessarily unique, but there still exists a preferable decomposition from the observational viewpoint. What was not complete in this argument is a fully satisfactory answer to the following questions. Does the proposed gauge-invariant decomposition, especially the decomposition of the gluon total angular momentum into its spin and orbital parts, correspond to observables which can be extracted from high-energy deep-inelastic-scattering measurements ? Is this decomposition not only gauge-invariant but also Lorentz frame-independent, so that it is legitimately thought to reflect an intrinsic property of the nucleon ? We show that we can answer both of these questions affirmatively, by making full use of a gauge-invariant decomposition of covariant angular momentum tensor of QCD in an arbitrary Lorentz frame.
hep-ph/0605316
Krishna Rajagopal
Krishna Rajagopal (MIT and LBNL), Rishi Sharma (MIT)
The Crystallography of Three-Flavor Quark Matter
41 pages, 8 figures, 2 tables
Phys.Rev. D74 (2006) 094019
10.1103/PhysRevD.74.094019
MIT-CTP-3749
hep-ph astro-ph cond-mat.supr-con nucl-th
null
We analyze and compare candidate crystal structures for the crystalline color superconducting phase that may arise in cold, dense but not asymptotically dense, three-flavor quark matter. We determine the gap parameter Delta and free energy Omega(Delta) for many possible crystal structures within a Ginzburg-Landau approximation, evaluating Omega(Delta) to order Delta^6. In contrast to the two-flavor case, we find a positive Delta^6 term and hence an Omega(Delta) that is bounded from below for all the structures that we analyze. This means that we are able to evaluate Delta and Omega as a function of the splitting between Fermi surfaces for all the structures we consider. We find two structures with particularly robust values of Delta and the condensation energy, within a factor of two of those for the CFL phase which is known to characterize QCD at asymptotically large densities. The robustness of these phases results in their being favored over wide ranges of density. However, it also implies that the Ginzburg-Landau approximation is not quantitatively reliable. We develop qualitative insights into what makes a crystal structure favorable, and use these to winnow the possibilities. The two structures that we find to be most favorable are both built from condensates with face-centered cubic symmetry: in one case, the <ud> and <us> condensates are separately face centered cubic; in the other case <ud> and <us> combined make up a face centered cube.
[ { "created": "Mon, 29 May 2006 15:24:10 GMT", "version": "v1" }, { "created": "Tue, 30 May 2006 18:26:32 GMT", "version": "v2" } ]
2009-11-11
[ [ "Rajagopal", "Krishna", "", "MIT and LBNL" ], [ "Sharma", "Rishi", "", "MIT" ] ]
We analyze and compare candidate crystal structures for the crystalline color superconducting phase that may arise in cold, dense but not asymptotically dense, three-flavor quark matter. We determine the gap parameter Delta and free energy Omega(Delta) for many possible crystal structures within a Ginzburg-Landau approximation, evaluating Omega(Delta) to order Delta^6. In contrast to the two-flavor case, we find a positive Delta^6 term and hence an Omega(Delta) that is bounded from below for all the structures that we analyze. This means that we are able to evaluate Delta and Omega as a function of the splitting between Fermi surfaces for all the structures we consider. We find two structures with particularly robust values of Delta and the condensation energy, within a factor of two of those for the CFL phase which is known to characterize QCD at asymptotically large densities. The robustness of these phases results in their being favored over wide ranges of density. However, it also implies that the Ginzburg-Landau approximation is not quantitatively reliable. We develop qualitative insights into what makes a crystal structure favorable, and use these to winnow the possibilities. The two structures that we find to be most favorable are both built from condensates with face-centered cubic symmetry: in one case, the <ud> and <us> condensates are separately face centered cubic; in the other case <ud> and <us> combined make up a face centered cube.
hep-ph/0409011
Alejandro Lorca
J. Gluza, A. Lorca, T. Riemann
Automated use of DIANA for two-fermion production at colliders
To appear in the proceedings of ACAT03, Dec 2003, KEK, Japan
Nucl.Instrum.Meth. A534 (2004) 289-292
10.1016/j.nima.2004.07.103
SFB/CPP-04-03
hep-ph
null
We describe packages for the calculation of radiative corrections to two-fermion production at colliders. The packages use DIANA, and also QGRAF, FORM, Fortran, and further unix/linux tools. The one-loop calculations in the Standard Model are highly automatized with the package aITALC. Further, the automatic determination of all the matrix elements for two-loop corrections to massive Bhabha scattering in QED and the classification of their topologies and prototypes is done with DIANA. A generalization to the Standard Model is straightforward.
[ { "created": "Wed, 1 Sep 2004 15:45:40 GMT", "version": "v1" } ]
2009-11-10
[ [ "Gluza", "J.", "" ], [ "Lorca", "A.", "" ], [ "Riemann", "T.", "" ] ]
We describe packages for the calculation of radiative corrections to two-fermion production at colliders. The packages use DIANA, and also QGRAF, FORM, Fortran, and further unix/linux tools. The one-loop calculations in the Standard Model are highly automatized with the package aITALC. Further, the automatic determination of all the matrix elements for two-loop corrections to massive Bhabha scattering in QED and the classification of their topologies and prototypes is done with DIANA. A generalization to the Standard Model is straightforward.
1108.0482
Francois-Xavier Josse-Michaux
Fran\c{c}ois-Xavier Josse-Michaux and Emiliano Molinaro
A Common Framework for Dark Matter, Leptogenesis and Neutrino Masses
v4: Published version. No changes w.r.t. v3
Phys. Rev. D 84, 125021 (2011)
10.1103/PhysRevD.84.125021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a seesaw-type extension of the Standard Model in which the symmetry group is enlarged by a global U(1). We introduce adequate scalar and fermion representations which naturally explain the smallness of neutrino masses. With the addition of a viable scalar Dark Matter candidate, an original scenario of leptogenesis emerges. We solve the relevant set of Boltzmann equations and show how leptogenesis can be successfully implemented at the TeV scale. The constraints on the scalar mass spectrum are derived and the Dark Matter phenomenology is discussed.
[ { "created": "Tue, 2 Aug 2011 05:19:10 GMT", "version": "v1" }, { "created": "Wed, 31 Aug 2011 13:56:25 GMT", "version": "v2" }, { "created": "Fri, 30 Sep 2011 15:55:20 GMT", "version": "v3" }, { "created": "Fri, 16 Dec 2011 14:05:15 GMT", "version": "v4" } ]
2011-12-19
[ [ "Josse-Michaux", "François-Xavier", "" ], [ "Molinaro", "Emiliano", "" ] ]
We study a seesaw-type extension of the Standard Model in which the symmetry group is enlarged by a global U(1). We introduce adequate scalar and fermion representations which naturally explain the smallness of neutrino masses. With the addition of a viable scalar Dark Matter candidate, an original scenario of leptogenesis emerges. We solve the relevant set of Boltzmann equations and show how leptogenesis can be successfully implemented at the TeV scale. The constraints on the scalar mass spectrum are derived and the Dark Matter phenomenology is discussed.
hep-ph/0102051
Stanley J. Brodsky
Stanley J. Brodsky
Hadronic Light-Front Wavefunctions and QCD Phenomenology
Invited Lectures presented at the Fifth International Workshop on Particle Physics Phenomenology, Chi-Pen, Taitung, Taiwan, 8-11 Nov 2000
null
10.1142/9789812799982_0001
SLAC-PUB-8770
hep-ph
null
A fundamental goal in QCD is to understand the non-perturbative structure of hadrons at the amplitude level--not just the single-particle flavor, momentum, and helicity distributions of the quark constituents, but also the multi-quark, gluonic, and hidden-color correlations intrinsic to hadronic and nuclear wavefunctions. A natural calculus for describing the bound-state structure of relativistic composite systems in quantum field theory is the light-front Fock expansion which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Light-front quantization in the doubly-transverse light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. A number of applications are discussed in these lectures, including semileptonic B decays, two-photon exclusive reactions, and deeply virtual Compton scattering. The relation of the intrinsic sea to the light-front wavefunctions is discussed. A new type of jet production reaction, "self-resolving diffractive interactions" can provide direct information on the light-front wavefunctions of hadrons in terms of their quark and gluon degrees of freedom as well as the composition of nuclei in terms of their nucleon and mesonic degrees of freedom.
[ { "created": "Mon, 5 Feb 2001 20:13:36 GMT", "version": "v1" } ]
2017-08-23
[ [ "Brodsky", "Stanley J.", "" ] ]
A fundamental goal in QCD is to understand the non-perturbative structure of hadrons at the amplitude level--not just the single-particle flavor, momentum, and helicity distributions of the quark constituents, but also the multi-quark, gluonic, and hidden-color correlations intrinsic to hadronic and nuclear wavefunctions. A natural calculus for describing the bound-state structure of relativistic composite systems in quantum field theory is the light-front Fock expansion which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Light-front quantization in the doubly-transverse light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. A number of applications are discussed in these lectures, including semileptonic B decays, two-photon exclusive reactions, and deeply virtual Compton scattering. The relation of the intrinsic sea to the light-front wavefunctions is discussed. A new type of jet production reaction, "self-resolving diffractive interactions" can provide direct information on the light-front wavefunctions of hadrons in terms of their quark and gluon degrees of freedom as well as the composition of nuclei in terms of their nucleon and mesonic degrees of freedom.
0910.4462
Chao-Hsi Chang
Chao-Hsi Chang, Jian-Xiong Wang and Xing-Gang Wu
GENXICC2.0: An Upgraded Version of the Generator for Hadronic Production of Double Heavy Baryons $\Xi_{cc}$, $\Xi_{bc}$ and $\Xi_{bb}$
15 pages, 2 figures
Comput.Phys.Commun.181:1144-1149,2010
10.1016/j.cpc.2010.02.008
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An upgraded (second) version of the package GENXICC ({\bf A Generator for Hadronic Production of the Double Heavy Baryons $\Xi_{cc}$, $\Xi_{bc}$ and $\Xi_{bb}$ by C.H. Chang, J.X. Wang and X.G. Wu,} [its first version: in Comput. Phys. Commun. {\bf 177} (2007) 467-478]) is presented. Users, with this version being implemented in PYTHIA and a GNU C compiler, may simulate full events of the production in various experimental environments conveniently. In comparison with the previous version, in order to implement it in PYTHIA properly, a subprogram for the fragmentation of the produced double heavy diquark to the relevant baryon is complemented and the interphase of the generator to PYTHIA is changed accordingly. In the subprogram, with explanation, certain necessary assumptions (approximations) are made so as to conserve the momenta and the QCD `color' flow for the fragmentation.
[ { "created": "Fri, 23 Oct 2009 09:11:03 GMT", "version": "v1" }, { "created": "Tue, 8 Dec 2009 22:51:47 GMT", "version": "v2" } ]
2010-04-22
[ [ "Chang", "Chao-Hsi", "" ], [ "Wang", "Jian-Xiong", "" ], [ "Wu", "Xing-Gang", "" ] ]
An upgraded (second) version of the package GENXICC ({\bf A Generator for Hadronic Production of the Double Heavy Baryons $\Xi_{cc}$, $\Xi_{bc}$ and $\Xi_{bb}$ by C.H. Chang, J.X. Wang and X.G. Wu,} [its first version: in Comput. Phys. Commun. {\bf 177} (2007) 467-478]) is presented. Users, with this version being implemented in PYTHIA and a GNU C compiler, may simulate full events of the production in various experimental environments conveniently. In comparison with the previous version, in order to implement it in PYTHIA properly, a subprogram for the fragmentation of the produced double heavy diquark to the relevant baryon is complemented and the interphase of the generator to PYTHIA is changed accordingly. In the subprogram, with explanation, certain necessary assumptions (approximations) are made so as to conserve the momenta and the QCD `color' flow for the fragmentation.
hep-ph/9802214
null
M. Shifman
Snapshots of Hadrons, or the Story of How the Vacuum Medium Determines the Properties of the Classical Mesons Which Are Produced, Live and Die in the QCD Vacuum
Lecture given at the 1997 Yukawa International Seminar Non-Perturbative QCD -- Structure of the QCD Vacuum, Kyoto, December 2 -- 12, 1997. 80 pages, LATEX, 23 eps figures
Prog.Theor.Phys.Suppl.131:1-71,1998
10.1143/PTPS.131.1
TPI-MINN-98/01-T, UMN-TH-1622-98
hep-ph
null
1. QCD Sum Rules: 20 Years After; 2. QCD Vacuum and Basics of the SVZ Method: 2.1 General ideas; 2.2. Getting started/Playing with toy models; 3. Vacuum Condensates; 4. Rho Meson in QCD; 5. Basic Theoretical Instrument -- Wilson's OPE; 6. Practical Version of OPE; 7. Low Energy Theorems; 8. Are All Hadrons Alike? 9. Ecological Niche; 10. New Developments: 10.1 Light-cone sum rules; 10.2 Heavy flavor sum rules; 11. Sum Rules and Lattices; 12. Vacuum Fluctuations are Subtle Creatures; 13. Instead of Conclusions.
[ { "created": "Mon, 2 Feb 1998 18:53:48 GMT", "version": "v1" } ]
2008-11-26
[ [ "Shifman", "M.", "" ] ]
1. QCD Sum Rules: 20 Years After; 2. QCD Vacuum and Basics of the SVZ Method: 2.1 General ideas; 2.2. Getting started/Playing with toy models; 3. Vacuum Condensates; 4. Rho Meson in QCD; 5. Basic Theoretical Instrument -- Wilson's OPE; 6. Practical Version of OPE; 7. Low Energy Theorems; 8. Are All Hadrons Alike? 9. Ecological Niche; 10. New Developments: 10.1 Light-cone sum rules; 10.2 Heavy flavor sum rules; 11. Sum Rules and Lattices; 12. Vacuum Fluctuations are Subtle Creatures; 13. Instead of Conclusions.
1411.0553
Matteo Giordano
Matteo Giordano, Enrico Meggiolaro
Comments on high-energy total cross sections in QCD
Revised version; matches published version
Phys. Lett. B 744 (2015) 263
10.1016/j.physletb.2015.03.060
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss how hadronic total cross sections at high energy depend on the details of QCD, namely on the number of colours $N_c$ and the quark masses. We find that while a "Froissart"-type behaviour $\sigma_{\rm tot}\sim B\log^2s$ is rather general, relying only on the presence of higher-spin stable particles in the spectrum, the value of $B$ depends quite strongly on the quark masses. Moreover, we argue that $B$ is of order ${\cal O}(N_c^0)$ at large $N_c$, and we discuss a bound for $B$ which does not become singular in the $N_f=2$ chiral limit, unlike the Froissart-\L ukaszuk-Martin bound.
[ { "created": "Mon, 3 Nov 2014 16:42:10 GMT", "version": "v1" }, { "created": "Mon, 11 May 2015 10:35:18 GMT", "version": "v2" } ]
2015-06-23
[ [ "Giordano", "Matteo", "" ], [ "Meggiolaro", "Enrico", "" ] ]
We discuss how hadronic total cross sections at high energy depend on the details of QCD, namely on the number of colours $N_c$ and the quark masses. We find that while a "Froissart"-type behaviour $\sigma_{\rm tot}\sim B\log^2s$ is rather general, relying only on the presence of higher-spin stable particles in the spectrum, the value of $B$ depends quite strongly on the quark masses. Moreover, we argue that $B$ is of order ${\cal O}(N_c^0)$ at large $N_c$, and we discuss a bound for $B$ which does not become singular in the $N_f=2$ chiral limit, unlike the Froissart-\L ukaszuk-Martin bound.
1703.03114
Jihn E. Kim
Jihn E. Kim
Strong CP problem, axions, and cosmological implications of CP violation
21 pages of LaTeX file with 12 figures. Talk presented at Corfu, Greece
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, I present a pedagogical and historical review related to the CP symmetry. It includes the weak CP violation, the strong CP problem, "invisible" axions and cosmology, and Type-II leptogenesis.
[ { "created": "Thu, 9 Mar 2017 02:55:10 GMT", "version": "v1" }, { "created": "Tue, 21 Mar 2017 15:28:00 GMT", "version": "v2" } ]
2017-03-22
[ [ "Kim", "Jihn E.", "" ] ]
In this talk, I present a pedagogical and historical review related to the CP symmetry. It includes the weak CP violation, the strong CP problem, "invisible" axions and cosmology, and Type-II leptogenesis.
hep-ph/9802219
Kingman Cheung
Kingman Cheung
Muon-proton Colliders: Leptoquarks and Contact Interactions
7 pages, LaTeX, in the proceedings of the 4th Int. Conf. on Physics Potential and Development of Muon Colliders, San Francisco, December 1997
null
10.1063/1.56424
UCD-97-XX
hep-ph
null
The muon-proton ($\mu p$) collider is an interesting option of the muon collider. Here we discuss the physics potential of the $\mu p$ collider; especially, leptoquarks and contact interactions. We calculate the sensitivity reach for the second generation leptoquarks and leptogluons, $R$-parity violating squarks, and $\mu q$ contact interactions for the $\mu p$ colliders of various energies and luminosities.
[ { "created": "Mon, 2 Feb 1998 23:48:26 GMT", "version": "v1" } ]
2009-10-31
[ [ "Cheung", "Kingman", "" ] ]
The muon-proton ($\mu p$) collider is an interesting option of the muon collider. Here we discuss the physics potential of the $\mu p$ collider; especially, leptoquarks and contact interactions. We calculate the sensitivity reach for the second generation leptoquarks and leptogluons, $R$-parity violating squarks, and $\mu q$ contact interactions for the $\mu p$ colliders of various energies and luminosities.
2405.02482
Dominik Fuchs
A. Bento, A. Bertolini, L. Canonica, S. Di Lorenzo, F. Dominksky, N. Ferreiro Iachellini, D. Fuchs, A. Garai, D. Hauff, A. Langenk\"amper, M. Mancuso, B. Mauri, F. Petricca, F. Pr\"obst, F. Pucci, L. Stodolsky
Solar Neutrinos in Cryogenic Detectors
12 pages, 16 figures
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) poses an irreducible background in the search for dark matter-nucleus elastic scatterings, which is commonly known as the neutrino floor. As direct dark matter search experiments keep improving their sensitivity into so far unexplored regions, they face the challenge of approaching this neutrino floor. A precise description of the CE$\nu$NS signal is therefore crucial for the description of backgrounds for future DM searches. In this work we discuss the scenario of detecting neutrinos in low-threshold, high-exposure cryogenic solid state experiments optimized for the search of low-mass dark matter. The energy range considered is completely dominated by solar neutrinos. In absence of any dark matter events, we treat solar neutrinos as the main signal of interest. We show that sensitivity to the flux of neutrinos from different production mechanisms can be achieved. In particular we investigate the sensitivity to the flux of pp and $^{7}$Be neutrinos, as well as CNO neutrinos. Furthermore, we investigate the sensitivity to dark matter signals in the presence of a solar neutrino background for different experimental scenarios, which are defined by three parameters: the target material, the energy threshold and the exposure. We show that experiments with thresholds of $\mathcal{O}$(eV) and exposures of $\mathcal{O}$(tonne-years), using CaWO$_{4}$ or Al$_{2}$O$_{3}$ targets, have discovery potential for dark matter interaction cross sections in the neutrino floor.
[ { "created": "Fri, 3 May 2024 21:13:11 GMT", "version": "v1" } ]
2024-05-07
[ [ "Bento", "A.", "" ], [ "Bertolini", "A.", "" ], [ "Canonica", "L.", "" ], [ "Di Lorenzo", "S.", "" ], [ "Dominksky", "F.", "" ], [ "Iachellini", "N. Ferreiro", "" ], [ "Fuchs", "D.", "" ], [ "Garai", "A.", "" ], [ "Hauff", "D.", "" ], [ "Langenkämper", "A.", "" ], [ "Mancuso", "M.", "" ], [ "Mauri", "B.", "" ], [ "Petricca", "F.", "" ], [ "Pröbst", "F.", "" ], [ "Pucci", "F.", "" ], [ "Stodolsky", "L.", "" ] ]
Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) poses an irreducible background in the search for dark matter-nucleus elastic scatterings, which is commonly known as the neutrino floor. As direct dark matter search experiments keep improving their sensitivity into so far unexplored regions, they face the challenge of approaching this neutrino floor. A precise description of the CE$\nu$NS signal is therefore crucial for the description of backgrounds for future DM searches. In this work we discuss the scenario of detecting neutrinos in low-threshold, high-exposure cryogenic solid state experiments optimized for the search of low-mass dark matter. The energy range considered is completely dominated by solar neutrinos. In absence of any dark matter events, we treat solar neutrinos as the main signal of interest. We show that sensitivity to the flux of neutrinos from different production mechanisms can be achieved. In particular we investigate the sensitivity to the flux of pp and $^{7}$Be neutrinos, as well as CNO neutrinos. Furthermore, we investigate the sensitivity to dark matter signals in the presence of a solar neutrino background for different experimental scenarios, which are defined by three parameters: the target material, the energy threshold and the exposure. We show that experiments with thresholds of $\mathcal{O}$(eV) and exposures of $\mathcal{O}$(tonne-years), using CaWO$_{4}$ or Al$_{2}$O$_{3}$ targets, have discovery potential for dark matter interaction cross sections in the neutrino floor.
hep-ph/0012190
Francesca Rosati
Francesca Rosati
Supergravity models of Quintessence and Supersymmetry breaking
4 pages, Proceedings of Euresco conference 'Frontiers in Particle Astrophysics and Cosmology', San Feliu de Guixols, Spain, 30 Sept - 5 Oct 2000
Nucl.Phys.Proc.Suppl. 95 (2001) 74-77
10.1016/S0920-5632(01)01059-3
null
hep-ph astro-ph gr-qc hep-th
null
The issue of Supersymmetry breaking in the context of Supergravity models of Quintessence is discussed.
[ { "created": "Fri, 15 Dec 2000 12:25:12 GMT", "version": "v1" } ]
2009-10-31
[ [ "Rosati", "Francesca", "" ] ]
The issue of Supersymmetry breaking in the context of Supergravity models of Quintessence is discussed.
1408.0530
Vladyslav Libov
Roberto Fiore and Laszlo Jenkovszky and Vladyslav Libov and Magno Machado
Vector meson production in ultra-peripheral collisions at the LHC
null
null
10.1007/s11232-015-0252-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By using a Regge-pole model for vector meson production (VMP), successfully describing the HERA data, we analyse the correlation between VMP cross sections in photon-induced reactions at HERA and those in ultra-peripheral collisions at the Large Hadron Collider (LHC). Predictions for future experiments on production of $J/\psi$ and $\psi(2S)$ are presented.
[ { "created": "Sun, 3 Aug 2014 19:29:08 GMT", "version": "v1" } ]
2015-06-22
[ [ "Fiore", "Roberto", "" ], [ "Jenkovszky", "Laszlo", "" ], [ "Libov", "Vladyslav", "" ], [ "Machado", "Magno", "" ] ]
By using a Regge-pole model for vector meson production (VMP), successfully describing the HERA data, we analyse the correlation between VMP cross sections in photon-induced reactions at HERA and those in ultra-peripheral collisions at the Large Hadron Collider (LHC). Predictions for future experiments on production of $J/\psi$ and $\psi(2S)$ are presented.
1810.05371
Peter Athron
Peter Athron, Markus Bach, Dylan Harries, Wojciech Kotlarski, Thomas Kwasnitza, Jae-hyeon Park, Tom Steudtner, Dominik St\"ockinger, Alexander Voigt and Jobst Ziebell
FlexibleSUSY: Precise automated calculations in any BSM theory
4 pages plus title page, 1 figure. Contribution to proceedings of ICHEP 2018, the 39th International Conference on High Energy Physics
null
null
CoEPP-MN-18-8
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
FlexibleSUSY is a software package for various calculations in any model of physics beyond the standard model (not just any supersymmetric model). FlexibleSUSY can solve boundary value problems and uses this to find $\overline{DR}/\overline{MS}$ parameters and calculate the Higgs and BSM particle masses, as well as other observables. FlexibleSUSY is designed to be adaptable, fast, precise and reliable. We describe FlexibleSUSY with particular emphasis on recent developments and the state of the art Higgs mass calculations it can perform. We also show some applications to illustrate how it can be used to obtain interesting physics results with the highest precision possible and with remarkable speed.
[ { "created": "Fri, 12 Oct 2018 06:28:15 GMT", "version": "v1" } ]
2018-10-15
[ [ "Athron", "Peter", "" ], [ "Bach", "Markus", "" ], [ "Harries", "Dylan", "" ], [ "Kotlarski", "Wojciech", "" ], [ "Kwasnitza", "Thomas", "" ], [ "Park", "Jae-hyeon", "" ], [ "Steudtner", "Tom", "" ], [ "Stöckinger", "Dominik", "" ], [ "Voigt", "Alexander", "" ], [ "Ziebell", "Jobst", "" ] ]
FlexibleSUSY is a software package for various calculations in any model of physics beyond the standard model (not just any supersymmetric model). FlexibleSUSY can solve boundary value problems and uses this to find $\overline{DR}/\overline{MS}$ parameters and calculate the Higgs and BSM particle masses, as well as other observables. FlexibleSUSY is designed to be adaptable, fast, precise and reliable. We describe FlexibleSUSY with particular emphasis on recent developments and the state of the art Higgs mass calculations it can perform. We also show some applications to illustrate how it can be used to obtain interesting physics results with the highest precision possible and with remarkable speed.
1705.09760
Surjeet Rajendran
Surjeet Rajendran, Nicholas Zobrist, Alexander O. Sushkov, Ronald Walsworth and Mikhail Lukin
Directional Detection of Dark Matter using Spectroscopy of Crystal Defects
9 pages, 3 figures
Phys. Rev. D 96, 035009 (2017)
10.1103/PhysRevD.96.035009
null
hep-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a method to identify the direction of an incident Weakly Interacting Massive Particle (WIMP) via induced nuclear recoil. Our method is based on spectroscopic interrogation of quantum defects in macroscopic solid-state crystals . When a WIMP scatters in a crystal, the induced nuclear recoil creates a tell-tale damage cluster, localized to within about 50 nm, with an orientation to the damage trail that correlates well with the direction of the recoil and hence the incoming WIMP. This damage cluster induces strain in the crystal, shifting the energy levels of nearby quantum defects. These level shifts can be measured optically (or through paramagnetic resonance) making it possible to detect the strain environment around the defect in a solid sample. As a specific example, we consider nitrogen vacancy centers in diamond, for which high defect densities and nanoscale localization of individual defects have been demonstrated. To localize the millimeter-scale region of a nuclear recoil within the crystal due to a potential dark matter event, we can use conventional WIMP detection techniques such as the collection of ionization/scintillation. Once an event is identified, the quantum defects in the vicinity of the event can be interrogated to map the strain environment, thus determining the direction of the recoil. In principle, this approach should be able to identify the recoil direction with an efficiency greater than 70% at a false positive rate less than 5% for 10 keV recoil energies. If successful, this method would allow for directional detection of WIMP-induced nuclear recoils at solid state densities, enabling probes of WIMP parameter space below the solar neutrino floor. This technique could also potentially be applied to identify the direction of particles such as neutrons whose low scattering cross-section requires detectors with a large target mass.
[ { "created": "Sat, 27 May 2017 03:41:05 GMT", "version": "v1" } ]
2017-08-23
[ [ "Rajendran", "Surjeet", "" ], [ "Zobrist", "Nicholas", "" ], [ "Sushkov", "Alexander O.", "" ], [ "Walsworth", "Ronald", "" ], [ "Lukin", "Mikhail", "" ] ]
We propose a method to identify the direction of an incident Weakly Interacting Massive Particle (WIMP) via induced nuclear recoil. Our method is based on spectroscopic interrogation of quantum defects in macroscopic solid-state crystals . When a WIMP scatters in a crystal, the induced nuclear recoil creates a tell-tale damage cluster, localized to within about 50 nm, with an orientation to the damage trail that correlates well with the direction of the recoil and hence the incoming WIMP. This damage cluster induces strain in the crystal, shifting the energy levels of nearby quantum defects. These level shifts can be measured optically (or through paramagnetic resonance) making it possible to detect the strain environment around the defect in a solid sample. As a specific example, we consider nitrogen vacancy centers in diamond, for which high defect densities and nanoscale localization of individual defects have been demonstrated. To localize the millimeter-scale region of a nuclear recoil within the crystal due to a potential dark matter event, we can use conventional WIMP detection techniques such as the collection of ionization/scintillation. Once an event is identified, the quantum defects in the vicinity of the event can be interrogated to map the strain environment, thus determining the direction of the recoil. In principle, this approach should be able to identify the recoil direction with an efficiency greater than 70% at a false positive rate less than 5% for 10 keV recoil energies. If successful, this method would allow for directional detection of WIMP-induced nuclear recoils at solid state densities, enabling probes of WIMP parameter space below the solar neutrino floor. This technique could also potentially be applied to identify the direction of particles such as neutrons whose low scattering cross-section requires detectors with a large target mass.
hep-ph/9804302
null
Sergio Scopetta, Vicente Vento (Valencia) and Marco Traini (Trento)
Polarized structure functions in a constituent quark scenario
18 pages; latex; 4 ps figures. Final version to appear in Phys. Lett. B; discussion about the polarized sea slightly changed
Phys.Lett.B442:28-37,1998
10.1016/S0370-2693(98)01218-0
FTUV/98-8; IFIC/98-8
hep-ph
null
Using a simple picture of the constituent quark as a composite system of point-like partons, we construct the polarized parton distributions by a convolution between constituent quark momentum distributions and constituent quark structure functions. Using unpolarized data to fix the parameters we achieve good agreement with the polarization experiments for the proton, while not so for the neutron. By relaxing our assumptions for the sea distributions, we define new quark functions for the polarized case, which reproduce well the proton data and are in better agreement with the neutron data. When our results are compared with similar calculations using non-composite constituent quarks the accord with the experiments of the present scheme is impressive. We conclude that, also in the polarized case, DIS data are consistent with a low energy scenario dominated by composite constituents of the nucleon.
[ { "created": "Thu, 16 Apr 1998 11:14:19 GMT", "version": "v1" }, { "created": "Mon, 31 Aug 1998 13:51:30 GMT", "version": "v2" } ]
2011-07-19
[ [ "Scopetta", "Sergio", "", "Valencia" ], [ "Vento", "Vicente", "", "Valencia" ], [ "Traini", "Marco", "", "Trento" ] ]
Using a simple picture of the constituent quark as a composite system of point-like partons, we construct the polarized parton distributions by a convolution between constituent quark momentum distributions and constituent quark structure functions. Using unpolarized data to fix the parameters we achieve good agreement with the polarization experiments for the proton, while not so for the neutron. By relaxing our assumptions for the sea distributions, we define new quark functions for the polarized case, which reproduce well the proton data and are in better agreement with the neutron data. When our results are compared with similar calculations using non-composite constituent quarks the accord with the experiments of the present scheme is impressive. We conclude that, also in the polarized case, DIS data are consistent with a low energy scenario dominated by composite constituents of the nucleon.
hep-ph/0101148
Hisakazu Minakata
Hisakazu Minakata (Tokyo Metropolitan U. and RCCN at ICRR, U. Tokyo)
Degenerate and Other Neutrino Mass Scenarios and Dark Matter
23 pages, Latex, 5 figures. Talk presented at Third International Conference on Dark Matter in Astro and Particle Physics, Dark2000, July 10-15, 2000, Heidelberg, Germany
null
null
null
hep-ph
null
I discuss in this talk mainly three topics related with dark matter motivated neutrino mass spectrum and a generic issue of mass pattern, the normal versus the inverted mass hierarchies. In the first part, by describing failure of a nontrivial potential counter example, I argue that the standard 3 $\nu$ mixing scheme with the solar and the atmospheric $\Delta m^2$'s is robust. In the second part, I discuss the almost degenerate neutrino (ADN) scenario as the unique possibility of accommodating dark matter mass neutrinos into the 3 $\nu$ scheme. I review a cosmological bound and then reanalyze the constraints imposed on the ADN scenario with the new data of double beta decay experiment. In the last part, I discuss the 3 $\nu$ flavor transformation in supernova (SN) and point out the possibility that neutrinos from SN may distinguish the normal versus inverted hierarchies of neutrino masses. By analyzing the neutrino data from SN1987A, I argue that the inverted mass hierarchy is disfavored by the data.
[ { "created": "Mon, 15 Jan 2001 09:08:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Minakata", "Hisakazu", "", "Tokyo Metropolitan U. and RCCN at ICRR, U. Tokyo" ] ]
I discuss in this talk mainly three topics related with dark matter motivated neutrino mass spectrum and a generic issue of mass pattern, the normal versus the inverted mass hierarchies. In the first part, by describing failure of a nontrivial potential counter example, I argue that the standard 3 $\nu$ mixing scheme with the solar and the atmospheric $\Delta m^2$'s is robust. In the second part, I discuss the almost degenerate neutrino (ADN) scenario as the unique possibility of accommodating dark matter mass neutrinos into the 3 $\nu$ scheme. I review a cosmological bound and then reanalyze the constraints imposed on the ADN scenario with the new data of double beta decay experiment. In the last part, I discuss the 3 $\nu$ flavor transformation in supernova (SN) and point out the possibility that neutrinos from SN may distinguish the normal versus inverted hierarchies of neutrino masses. By analyzing the neutrino data from SN1987A, I argue that the inverted mass hierarchy is disfavored by the data.
hep-ph/9309216
J. Gunion
J.F. Gunion
Detecting an Invisibly Decaying Higgs Boson at a Hadron Supercollider
7 pages, requires phyzzx.tex and tables.tex, revised to convert results from SSC to LHC and include additional top quark mass cases, full postscript file including embedded figure available via anonymous ftp at ucdhep.ucdavis.edu as [anonymous.gunion]hinvisible_revised.ps, preprint UCD-93-28
Phys.Rev.Lett. 72 (1994) 199-202
10.1103/PhysRevLett.72.199
null
hep-ph
null
We demonstrate that an invisibly decaying Higgs boson with Standard Model coupling strength to top--anti-top can be detected at the LHC for masses up to about 250 GeV.
[ { "created": "Thu, 2 Sep 1993 18:38:00 GMT", "version": "v1" }, { "created": "Thu, 2 Dec 1993 21:55:00 GMT", "version": "v2" } ]
2009-10-22
[ [ "Gunion", "J. F.", "" ] ]
We demonstrate that an invisibly decaying Higgs boson with Standard Model coupling strength to top--anti-top can be detected at the LHC for masses up to about 250 GeV.
0908.0502
Marc Sher
Sean Litsey (Yale) and Marc Sher (William and Mary)
Higgs Masses in the Four Generation MSSM
4 pages, 3 figures
Phys.Rev.D80:057701,2009
10.1103/PhysRevD.80.057701
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Minimal Supersymmetric Standard Model (MSSM) with three generations of fermions, there is a stringent upper bound on the mass of the lightest neutral Higgs h, and the mass of the charged Higgs H^+, must be close (within tens of GeV) to the heavier neutral Higgs, H, and the pseudoscalar Higgs A. In this Brief Report, we show that in the four generation MSSM, the upper bound on the h mass is much higher, as high as 400 GeV, and H^+ is generally much heavier than the A, allowing the H^+ -> A W^+ decay, potentially changing search strategies for both the charged Higgs and the pseudoscalar. The H mass, on the other hand, remains within tens of GeV of the charged Higgs mass.
[ { "created": "Tue, 4 Aug 2009 17:53:23 GMT", "version": "v1" }, { "created": "Thu, 6 Aug 2009 15:57:43 GMT", "version": "v2" } ]
2009-10-20
[ [ "Litsey", "Sean", "", "Yale" ], [ "Sher", "Marc", "", "William and Mary" ] ]
In the Minimal Supersymmetric Standard Model (MSSM) with three generations of fermions, there is a stringent upper bound on the mass of the lightest neutral Higgs h, and the mass of the charged Higgs H^+, must be close (within tens of GeV) to the heavier neutral Higgs, H, and the pseudoscalar Higgs A. In this Brief Report, we show that in the four generation MSSM, the upper bound on the h mass is much higher, as high as 400 GeV, and H^+ is generally much heavier than the A, allowing the H^+ -> A W^+ decay, potentially changing search strategies for both the charged Higgs and the pseudoscalar. The H mass, on the other hand, remains within tens of GeV of the charged Higgs mass.
hep-ph/0309133
Sean Fleming
Sean Fleming
The Large Energy Expansion for B Decays: Soft Collinear Effective Theory
Proceedings for the 2003 conference on Flavor Physics and CP violation (FPCP2003). Requires fpcp03.sty
ECONF C030603:MEC03,2003
null
CMU-HEP-03-11
hep-ph
null
I this talk I give an introduction to the soft collinear effective theory by considering in detail the decay rate for $B \to X_s \gamma$ near the endpoint.
[ { "created": "Thu, 11 Sep 2003 22:14:16 GMT", "version": "v1" } ]
2011-07-19
[ [ "Fleming", "Sean", "" ] ]
I this talk I give an introduction to the soft collinear effective theory by considering in detail the decay rate for $B \to X_s \gamma$ near the endpoint.
2304.07180
Gramos Qerimi
Simone Biondini, Nora Brambilla, Gramos Qerimi, Antonio Vairo
Effective Field Theories for Dark Matter Pairs in the Early Universe
Discussion about hierarchies of scales improved with respect to the published version in the conference proceedings. 4 pages, 2 figures, conference proceeding of "NuDM-2022"
Letters in High Energy Physics 2023
10.31526/LHEP.2023.375
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this conference paper, we consider effective field theories of non-relativistic dark matter particles interacting with a light force mediator in the early expanding universe. We present a general framework, where to account in a systematic way for the relevant processes that may affect the dynamics during thermal freeze-out. In the temperature regime where near-threshold effects, most notably the formation of bound states and Sommerfeld enhancement, have a large impact on the dark matter relic density, we scrutinize possible contributions from higher excited states and radiative corrections in the annihilations and decays of dark-matter pairs.
[ { "created": "Fri, 14 Apr 2023 14:54:32 GMT", "version": "v1" } ]
2023-04-18
[ [ "Biondini", "Simone", "" ], [ "Brambilla", "Nora", "" ], [ "Qerimi", "Gramos", "" ], [ "Vairo", "Antonio", "" ] ]
In this conference paper, we consider effective field theories of non-relativistic dark matter particles interacting with a light force mediator in the early expanding universe. We present a general framework, where to account in a systematic way for the relevant processes that may affect the dynamics during thermal freeze-out. In the temperature regime where near-threshold effects, most notably the formation of bound states and Sommerfeld enhancement, have a large impact on the dark matter relic density, we scrutinize possible contributions from higher excited states and radiative corrections in the annihilations and decays of dark-matter pairs.
2109.11875
Francesco Giovanni Celiberto
Francesco Giovanni Celiberto, Michael Fucilla, Dmitry Yu. Ivanov, Mohammed M.A. Mohammed, Alessandro Papa
Bottom-flavored inclusive emissions in the variable-flavor number scheme: A high-energy analysis
40 pages, 10 figures; improved layout of 3D surface plots in Figs. 7 and 8, small text improvements, added four more reference, version published in Phys. Rev. D
Phys. Rev. D 104 (2021) 11, 114007
10.1103/PhysRevD.104.114007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose the inclusive semi-hard production, in proton-proton collisions, of two bottom-flavored hadrons, as well as of a single bottom-flavored hadron accompanied by a light jet, as novel channels for the manifestation of stabilization effects of the high-energy resummation under next-to-leading-order corrections. Our formalism relies on a hybrid high-energy and collinear factorization, where the BFKL resummation of leading and next-to-leading energy logarithms is used together with collinear factorization. We present results for cross sections and azimuthal correlations differential in rapidity, which are widely recognized as standard observables where to hunt for distinctive signals of the BFKL dynamics. We propose the study of double differential distributions in the transverse momenta of final-state particles as a common basis to investigate the interplay of different kinds of resummation mechanisms.
[ { "created": "Fri, 24 Sep 2021 10:40:32 GMT", "version": "v1" }, { "created": "Wed, 8 Dec 2021 18:13:53 GMT", "version": "v2" } ]
2021-12-09
[ [ "Celiberto", "Francesco Giovanni", "" ], [ "Fucilla", "Michael", "" ], [ "Ivanov", "Dmitry Yu.", "" ], [ "Mohammed", "Mohammed M. A.", "" ], [ "Papa", "Alessandro", "" ] ]
We propose the inclusive semi-hard production, in proton-proton collisions, of two bottom-flavored hadrons, as well as of a single bottom-flavored hadron accompanied by a light jet, as novel channels for the manifestation of stabilization effects of the high-energy resummation under next-to-leading-order corrections. Our formalism relies on a hybrid high-energy and collinear factorization, where the BFKL resummation of leading and next-to-leading energy logarithms is used together with collinear factorization. We present results for cross sections and azimuthal correlations differential in rapidity, which are widely recognized as standard observables where to hunt for distinctive signals of the BFKL dynamics. We propose the study of double differential distributions in the transverse momenta of final-state particles as a common basis to investigate the interplay of different kinds of resummation mechanisms.
0810.3871
William Ponce A.
Johana A. Herrera, Richard H. Benavides, and William A. Ponce
Flavor changing neutral currents with a fourth family of quarks
7 pages, one figure. Published on Physical Review D
Phys.Rev.D78:073008,2008
10.1103/PhysRevD.78.073008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For a model with a fourth family of quarks, new sources of flavor changing neutral currents are identified by confronting the unitary 4x4 quark mixing matrix with the experimental measured values of the familiar 3x3 quark mixing matrix. By imposing as experimental constraints the known bounds for the flavor changing neutral currents, the largest mixing of the known quarks with the fourth family ones is established. The predictions are: a value for |V_{tb}| significantly different from unity, large rates for rare top decays as t->c\gamma and t->cZ, the last one reachable at the Large Hadrion Collider, and large rates for rare strange decays s->d\gamma and s->dg, where g stands for the gluon field.
[ { "created": "Tue, 21 Oct 2008 16:05:42 GMT", "version": "v1" } ]
2010-04-15
[ [ "Herrera", "Johana A.", "" ], [ "Benavides", "Richard H.", "" ], [ "Ponce", "William A.", "" ] ]
For a model with a fourth family of quarks, new sources of flavor changing neutral currents are identified by confronting the unitary 4x4 quark mixing matrix with the experimental measured values of the familiar 3x3 quark mixing matrix. By imposing as experimental constraints the known bounds for the flavor changing neutral currents, the largest mixing of the known quarks with the fourth family ones is established. The predictions are: a value for |V_{tb}| significantly different from unity, large rates for rare top decays as t->c\gamma and t->cZ, the last one reachable at the Large Hadrion Collider, and large rates for rare strange decays s->d\gamma and s->dg, where g stands for the gluon field.
2212.10800
A. Bashir
A.S. Miramontes and Adnan Bashir
The time-like electromagnetic kaon form factor
11 pages, 5 figures
null
10.1103/PhysRevD.107.014016
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We compute the electromagnetic charged kaon form factor in the time-like region by employing a Poincar\'e covariant formalism of the Bethe-Salpeter equation to study quark-antiquark bound states in conjunction with the Schwinger-Dyson equation for the quark propagator. Following a recent kindred calculation of the time-like electromagnetic pion form factor, we include the most relevant intermediate composite particles permitted by their quantum numbers in the interaction kernel to allow for a decay mechanism for the resonances involved. This term augments the usual gluon mediated interaction between quarks. For a sufficiently low energy time-like probing photon, the electromagnetic form factor is saturated by the $\rho(770)$ and $\phi(1020)$ resonances. We assume $SU(2)$ isospin symmetry throughout. Our results for the absolute value squared of the electromagnetic form factor agree qualitatively rather well and quantitatively moderately so with available experimental data.
[ { "created": "Wed, 21 Dec 2022 06:46:03 GMT", "version": "v1" } ]
2023-02-01
[ [ "Miramontes", "A. S.", "" ], [ "Bashir", "Adnan", "" ] ]
We compute the electromagnetic charged kaon form factor in the time-like region by employing a Poincar\'e covariant formalism of the Bethe-Salpeter equation to study quark-antiquark bound states in conjunction with the Schwinger-Dyson equation for the quark propagator. Following a recent kindred calculation of the time-like electromagnetic pion form factor, we include the most relevant intermediate composite particles permitted by their quantum numbers in the interaction kernel to allow for a decay mechanism for the resonances involved. This term augments the usual gluon mediated interaction between quarks. For a sufficiently low energy time-like probing photon, the electromagnetic form factor is saturated by the $\rho(770)$ and $\phi(1020)$ resonances. We assume $SU(2)$ isospin symmetry throughout. Our results for the absolute value squared of the electromagnetic form factor agree qualitatively rather well and quantitatively moderately so with available experimental data.
hep-ph/0303005
Robert Foot
R. Foot
Some comments on Super-Kamiokande's multi-ring analysis
About 8 pages long
null
10.1142/S0217732303011927
null
hep-ph
null
The super-Kamiokande collaboration have used multi-ring events to discriminate between the $\nu_\mu --> \nu_\tau$ and $\nu_\mu --> \nu_s$ solutions to the atmospheric neutrino anomaly. We show that the effect of systematic uncertainties in cross sections are so significant that the usefulness of multi-ring data to distinguish between these two solutions is doubtful.
[ { "created": "Mon, 3 Mar 2003 00:31:50 GMT", "version": "v1" }, { "created": "Fri, 18 Jul 2003 00:31:36 GMT", "version": "v2" } ]
2009-11-10
[ [ "Foot", "R.", "" ] ]
The super-Kamiokande collaboration have used multi-ring events to discriminate between the $\nu_\mu --> \nu_\tau$ and $\nu_\mu --> \nu_s$ solutions to the atmospheric neutrino anomaly. We show that the effect of systematic uncertainties in cross sections are so significant that the usefulness of multi-ring data to distinguish between these two solutions is doubtful.
hep-ph/9907357
Mike Seymour
Stefano Catani, Michael H. Seymour
The Forward-Backward Asymmetry in NNLO QCD
14 pages, LaTeX, uses lathuile.sty (included). Talk given by M. Seymour at 13th Rencontres de Physique de la Vallee d'Aoste, Results and Perspectives in Particle Physics, La Thuile, Aosta Valley, Italy, February 28th-March 6th, 1999
null
null
RAL-TR-1999-048, CERN-TH/99-204
hep-ph
null
We have recently calculated the second-order QCD corrections to the forward-backward asymmetry in e+e- annihilation (hep-ph/9905424). Here we recall the results and compare them to others in the literature.
[ { "created": "Wed, 14 Jul 1999 16:14:08 GMT", "version": "v1" } ]
2007-05-23
[ [ "Catani", "Stefano", "" ], [ "Seymour", "Michael H.", "" ] ]
We have recently calculated the second-order QCD corrections to the forward-backward asymmetry in e+e- annihilation (hep-ph/9905424). Here we recall the results and compare them to others in the literature.
hep-ph/9610309
Nuss Eric
Eric NUSS (University of Montpellier II)
Di-Boson production at Hadron Colliders with General 3 Gauge Boson Couplings. Analytic Expressions of Helicity Amplitudes and Cross-Section
23 pages of LaTeX file and 2 Postscript files to be printed separately. 47 pages in total
Z.Phys. C76 (1997) 701-719
null
PM/96-30
hep-ph
null
We discuss the tests of general Three Gauge Boson Vertices (TGV) through bosonic pair production at present and future hadron colliders. All bosonic final states are reviewed via the tree level quark-antiquark annihilation sub-process. The full analytic expressions of the helicity amplitudes and cross-sections are given. These expressions should be useful in any attempt to disentangle the effects of the most general non standard $WWV (V=\gamma,Z)$ vertices including 14 free parameters. We investigate the sensitivity of the invariant mass and transverse momentum distributions to the full set of anomalous couplings including final state polarization structures. We particularly consider these features at the projected CERN Large Hadron Collider (LHC) energy scale.
[ { "created": "Thu, 10 Oct 1996 09:52:51 GMT", "version": "v1" } ]
2016-09-06
[ [ "NUSS", "Eric", "", "University of Montpellier II" ] ]
We discuss the tests of general Three Gauge Boson Vertices (TGV) through bosonic pair production at present and future hadron colliders. All bosonic final states are reviewed via the tree level quark-antiquark annihilation sub-process. The full analytic expressions of the helicity amplitudes and cross-sections are given. These expressions should be useful in any attempt to disentangle the effects of the most general non standard $WWV (V=\gamma,Z)$ vertices including 14 free parameters. We investigate the sensitivity of the invariant mass and transverse momentum distributions to the full set of anomalous couplings including final state polarization structures. We particularly consider these features at the projected CERN Large Hadron Collider (LHC) energy scale.
1208.5446
Boris Kopeliovich
B. Z. Kopeliovich, I. K. Potashnikova, and B. Povh
Two-scale hadronic structure and elastic pp scattering: predicted and measured
6 pages, 6 figures
null
10.1103/PhysRevD.86.051502
USM-TH-304
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We update the comparison with experiment of the dynamical model of high-energy hadron interactions based on the two scale structure of hadrons. All predictions made over decade ago are confirmed with a high precision by the TOTEM experiment at LHC.
[ { "created": "Mon, 27 Aug 2012 17:00:11 GMT", "version": "v1" } ]
2013-05-30
[ [ "Kopeliovich", "B. Z.", "" ], [ "Potashnikova", "I. K.", "" ], [ "Povh", "B.", "" ] ]
We update the comparison with experiment of the dynamical model of high-energy hadron interactions based on the two scale structure of hadrons. All predictions made over decade ago are confirmed with a high precision by the TOTEM experiment at LHC.
0711.4727
Michal Malinsky
Stefan Antusch, Stephen F. King, Michal Malinsky
Third Family Corrections to Tri-bimaximal Lepton Mixing and a New Sum Rule
4 pages, 1 figure; v2:references added, minor clarifications
Phys.Lett.B671:263-266,2009
10.1016/j.physletb.2008.12.013
null
hep-ph
null
We investigate the theoretical stability of the predictions of tri-bimaximal neutrino mixing with respect to third family wave-function corrections. Such third family wave-function corrections can arise from either the canonical normalisation of the kinetic terms or renormalisation group running effects. At leading order both sorts of corrections can be subsumed into a single universal parameter. For hierarchical neutrinos, this leads to a new testable lepton mixing sum rule 's = r cos delta + 2/3 a' (where s, r, a describe the deviations of solar, reactor and atmospheric mixing angles from their tri-bimaximal values, and 'delta' is the observable Dirac CP phase) which is stable under all leading order third family wave-function corrections, as well as Cabibbo-like charged lepton mixing effects.
[ { "created": "Thu, 29 Nov 2007 14:54:36 GMT", "version": "v1" }, { "created": "Wed, 5 Dec 2007 21:06:16 GMT", "version": "v2" } ]
2009-01-14
[ [ "Antusch", "Stefan", "" ], [ "King", "Stephen F.", "" ], [ "Malinsky", "Michal", "" ] ]
We investigate the theoretical stability of the predictions of tri-bimaximal neutrino mixing with respect to third family wave-function corrections. Such third family wave-function corrections can arise from either the canonical normalisation of the kinetic terms or renormalisation group running effects. At leading order both sorts of corrections can be subsumed into a single universal parameter. For hierarchical neutrinos, this leads to a new testable lepton mixing sum rule 's = r cos delta + 2/3 a' (where s, r, a describe the deviations of solar, reactor and atmospheric mixing angles from their tri-bimaximal values, and 'delta' is the observable Dirac CP phase) which is stable under all leading order third family wave-function corrections, as well as Cabibbo-like charged lepton mixing effects.
1702.07809
Vincent Cheung
Vincent Cheung and Ramona Vogt
Polarized Heavy Quarkonium Production in the Color Evaporation Model
null
Phys. Rev. D 95, 074021 (2017)
10.1103/PhysRevD.95.074021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore polarized heavy quarkonium production using the color evaporation model at leading order. We present the polarized to total yield ratio as a function of center of mass energy and rapidity in $p+p$ collisions. At energies far above the $Q \overline Q$ production threshold, we find charmonium and bottomonium production to be longitudinally polarized ($J_z=0$). The quarkonium states are also longitudinally polarized at central rapidity, becoming transversely polarized ($J_z=\pm1$) at the most forward rapidities.
[ { "created": "Sat, 25 Feb 2017 00:04:38 GMT", "version": "v1" }, { "created": "Thu, 17 Aug 2017 16:56:22 GMT", "version": "v2" } ]
2017-08-18
[ [ "Cheung", "Vincent", "" ], [ "Vogt", "Ramona", "" ] ]
We explore polarized heavy quarkonium production using the color evaporation model at leading order. We present the polarized to total yield ratio as a function of center of mass energy and rapidity in $p+p$ collisions. At energies far above the $Q \overline Q$ production threshold, we find charmonium and bottomonium production to be longitudinally polarized ($J_z=0$). The quarkonium states are also longitudinally polarized at central rapidity, becoming transversely polarized ($J_z=\pm1$) at the most forward rapidities.
1912.12322
Andreas Windisch
Andreas Windisch, Thomas Gallien, Christopher Schwarzlmueller
Deep reinforcement learning for complex evaluation of one-loop diagrams in quantum field theory
null
Phys. Rev. E 101, 033305 (2020)
10.1103/PhysRevE.101.033305
null
hep-ph cs.LG physics.comp-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a novel technique based on deep reinforcement learning that allows for numerical analytic continuation of integrals that are often encountered in one-loop diagrams in quantum field theory. In order to extract certain quantities of two-point functions, such as spectral densities, mass poles or multi-particle thresholds, it is necessary to perform an analytic continuation of the correlator in question. At one-loop level in Euclidean space, this results in the necessity to deform the integration contour of the loop integral in the complex plane of the square of the loop momentum, in order to avoid non-analyticities in the integration plane. Using a toy model for which an exact solution is known, we train a reinforcement learning agent to perform the required contour deformations. Our study shows great promise for an agent to be deployed in iterative numerical approaches used to compute non-perturbative 2-point functions, such as the quark propagator Dyson-Schwinger equation, or more generally, Fredholm equations of the second kind, in the complex domain.
[ { "created": "Fri, 27 Dec 2019 19:45:24 GMT", "version": "v1" } ]
2020-03-25
[ [ "Windisch", "Andreas", "" ], [ "Gallien", "Thomas", "" ], [ "Schwarzlmueller", "Christopher", "" ] ]
In this paper we present a novel technique based on deep reinforcement learning that allows for numerical analytic continuation of integrals that are often encountered in one-loop diagrams in quantum field theory. In order to extract certain quantities of two-point functions, such as spectral densities, mass poles or multi-particle thresholds, it is necessary to perform an analytic continuation of the correlator in question. At one-loop level in Euclidean space, this results in the necessity to deform the integration contour of the loop integral in the complex plane of the square of the loop momentum, in order to avoid non-analyticities in the integration plane. Using a toy model for which an exact solution is known, we train a reinforcement learning agent to perform the required contour deformations. Our study shows great promise for an agent to be deployed in iterative numerical approaches used to compute non-perturbative 2-point functions, such as the quark propagator Dyson-Schwinger equation, or more generally, Fredholm equations of the second kind, in the complex domain.
1310.0164
Mikko Laine
M. Laine
NLO thermal dilepton rate at non-zero momentum
21 pages
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The vector channel spectral function and the dilepton production rate from a QCD plasma at a temperature above a few hundred MeV are evaluated up to next-to-leading order (NLO) including their dependence on a non-zero momentum with respect to the heat bath. The invariant mass of the virtual photon is taken to be in the range K^2 ~ (pi T)^2 ~ (1 GeV)^2, generalizing previous NLO results valid for K^2 >> (pi T)^2. In the opposite regime 0 < K^2 << (pi T)^2 the loop expansion breaks down, but agrees nevertheless in order of magnitude with a previous result obtained through resummations. Ways to test the vector spectral function through comparisons with imaginary-time correlators measured on the lattice are discussed.
[ { "created": "Tue, 1 Oct 2013 07:18:14 GMT", "version": "v1" } ]
2013-10-02
[ [ "Laine", "M.", "" ] ]
The vector channel spectral function and the dilepton production rate from a QCD plasma at a temperature above a few hundred MeV are evaluated up to next-to-leading order (NLO) including their dependence on a non-zero momentum with respect to the heat bath. The invariant mass of the virtual photon is taken to be in the range K^2 ~ (pi T)^2 ~ (1 GeV)^2, generalizing previous NLO results valid for K^2 >> (pi T)^2. In the opposite regime 0 < K^2 << (pi T)^2 the loop expansion breaks down, but agrees nevertheless in order of magnitude with a previous result obtained through resummations. Ways to test the vector spectral function through comparisons with imaginary-time correlators measured on the lattice are discussed.
0712.1523
C. Q. Geng
Kazuharu Bamba, C. Q. Geng and S. H. Ho
Hypermagnetic Baryogenesis
8 pages, no figure, accepted in Phys. Lett. B
Phys.Lett.B664:154-156,2008
10.1016/j.physletb.2008.05.027
null
hep-ph astro-ph hep-th
null
We study a new scenario for baryogenesis due to the spontaneous breaking of the $CPT$ invariance through the interaction between a baryon current and a hypermagnetic helicity. The hypermagnetic helicity (Chern-Simons number) of $U(1)_Y$ provides a $CPT$ violation background for the generation of baryons via sphaleron processes, which protects these baryons from the sphaleron wash-out effect in thermal equilibrium. It is shown that if the present amplitude of the resultant magnetic fields are sufficiently large, for a wide range mass scale (from TeV to the Planck scale), the observational magnitude of the baryon asymmetry of the Universe can be realized.
[ { "created": "Mon, 10 Dec 2007 16:03:36 GMT", "version": "v1" }, { "created": "Thu, 13 Dec 2007 08:04:16 GMT", "version": "v2" }, { "created": "Sun, 25 May 2008 10:55:06 GMT", "version": "v3" } ]
2008-11-26
[ [ "Bamba", "Kazuharu", "" ], [ "Geng", "C. Q.", "" ], [ "Ho", "S. H.", "" ] ]
We study a new scenario for baryogenesis due to the spontaneous breaking of the $CPT$ invariance through the interaction between a baryon current and a hypermagnetic helicity. The hypermagnetic helicity (Chern-Simons number) of $U(1)_Y$ provides a $CPT$ violation background for the generation of baryons via sphaleron processes, which protects these baryons from the sphaleron wash-out effect in thermal equilibrium. It is shown that if the present amplitude of the resultant magnetic fields are sufficiently large, for a wide range mass scale (from TeV to the Planck scale), the observational magnitude of the baryon asymmetry of the Universe can be realized.
hep-ph/0206054
Christian Brouder
Christian Brouder and Robert Oeckl
Quantum fields and quantum groups
4 pages, no figure
null
null
null
hep-ph hep-th math.QA
null
Quantum fields are shown to provide an example of infinite-dimensional quantum groups. A dictionary is established between quantum field and quantum group concepts: the expectation value over the vacuum is the counit, Wick's theorem is the definition of a twisted product, operator and time-ordered products are examples of twisted products. Through this dictionary, coquasitriangular structures are introduced in quantum field theory. These structures are the origin of Wick's theorem and quasifree states. Renormalization becomes the replacement of a coquasitriangular structure by a 2-coboundary. Quantum groups provide a second quantization without commutators which can second-quantize noncommutative algebras.
[ { "created": "Wed, 5 Jun 2002 16:58:35 GMT", "version": "v1" }, { "created": "Wed, 3 Jul 2002 18:16:05 GMT", "version": "v2" } ]
2007-05-23
[ [ "Brouder", "Christian", "" ], [ "Oeckl", "Robert", "" ] ]
Quantum fields are shown to provide an example of infinite-dimensional quantum groups. A dictionary is established between quantum field and quantum group concepts: the expectation value over the vacuum is the counit, Wick's theorem is the definition of a twisted product, operator and time-ordered products are examples of twisted products. Through this dictionary, coquasitriangular structures are introduced in quantum field theory. These structures are the origin of Wick's theorem and quasifree states. Renormalization becomes the replacement of a coquasitriangular structure by a 2-coboundary. Quantum groups provide a second quantization without commutators which can second-quantize noncommutative algebras.
hep-ph/9604384
Patrick O'Donnell
Patrick J. O'Donnell, Q.P. Xu and Humphrey K.K. Tung
The Spin--Symmetry of the Quark Model
null
Eur.Phys.J.C9:313-317,1999
10.1007/s100529900043
UTPT--96--08
hep-ph
null
Corrections to the exact heavy--quark symmetry results are expected to follow the $1/m_{Q}$ mass effect of the heavy--quark. We show, by an explicit calculation, that there is something other than the mass effect that suppresses the breaking of the spin symmetry.
[ { "created": "Mon, 22 Apr 1996 16:21:57 GMT", "version": "v1" } ]
2014-11-17
[ [ "O'Donnell", "Patrick J.", "" ], [ "Xu", "Q. P.", "" ], [ "Tung", "Humphrey K. K.", "" ] ]
Corrections to the exact heavy--quark symmetry results are expected to follow the $1/m_{Q}$ mass effect of the heavy--quark. We show, by an explicit calculation, that there is something other than the mass effect that suppresses the breaking of the spin symmetry.
1805.04917
Darius Faroughy
Jos\'e Eliel Camargo-Molina, Alejandro Celis, Darius A. Faroughy
Anomalies in Bottom from new physics in Top
13 pages, 10 figures, 4 tables -- v2: Overview section removed, added Table IV, added B meson mixing discussion, added refs, version accepted for publication in Phys. Lett. B
null
10.1016/j.physletb.2018.07.051
Imperial-TP-2018-JECM-01, LMU-ASC 18/18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the possibility to accommodate current $b \to s \ell^+ \ell^-$ anomalies with TeV-scale mediators that couple to right-handed top quarks and muons, contributing to $b \to s \ell^+ \ell^-\,$ at the one-loop level. We use the Standard Model Effective Field Theory (SMEFT) framework but also look at specific scenarios by taking into account all possible irreducible representations of the Lorentz and Standard Model gauge group for the mediators. From a global fit of $b \to s \ell^+ \ell^-$ data and LEP-I observables we find that the Wilson coefficients of two SMEFT operators: $\mathcal{O}_{\ell u}= (\bar \ell_{ L \mu} \gamma^{\alpha} \ell_{ L \mu}) (\bar t_R \gamma_{\alpha} t_R )$ and $\mathcal{O}_{e u}= (\bar \mu_{R} \gamma^{\alpha} \mu_{R}) (\bar t_R \gamma_{\alpha} t_R )$ need to satisfy $\mathcal{C}_{eu} \sim \mathcal{C}_{\ell u}$. New physics enters then in $b \to s \ell^+ \ell^-$ mainly through the operator $\mathcal{O}_9 = ( \bar s \gamma_{\mu} P_{L} b )( \bar \ell \gamma^{\mu} \ell )$ of the Weak Effective Theory. After discussing all possible mediators, we concentrate on two scenarios: A vector boson in the irreducible representation $Z_{\mu}^{\prime} \sim (1,1,0)$ of the Standard Model gauge group with vectorial coupling to muons, and a combination of two leptoquarks: the scalar $R_2 \sim (3,2,7/6)$ and the vector $\widetilde U_{1 \mu} \sim (3,1,5/3)$. We derive LHC constraints by recasting di-muon resonance, $pp \to t \bar t t \bar t$ and SUSY searches. Additionally, we analyze the prospects for discovering these mediators during the high-luminosity phase of the LHC.
[ { "created": "Sun, 13 May 2018 17:20:27 GMT", "version": "v1" }, { "created": "Mon, 6 Aug 2018 17:46:25 GMT", "version": "v2" } ]
2018-08-07
[ [ "Camargo-Molina", "José Eliel", "" ], [ "Celis", "Alejandro", "" ], [ "Faroughy", "Darius A.", "" ] ]
We analyze the possibility to accommodate current $b \to s \ell^+ \ell^-$ anomalies with TeV-scale mediators that couple to right-handed top quarks and muons, contributing to $b \to s \ell^+ \ell^-\,$ at the one-loop level. We use the Standard Model Effective Field Theory (SMEFT) framework but also look at specific scenarios by taking into account all possible irreducible representations of the Lorentz and Standard Model gauge group for the mediators. From a global fit of $b \to s \ell^+ \ell^-$ data and LEP-I observables we find that the Wilson coefficients of two SMEFT operators: $\mathcal{O}_{\ell u}= (\bar \ell_{ L \mu} \gamma^{\alpha} \ell_{ L \mu}) (\bar t_R \gamma_{\alpha} t_R )$ and $\mathcal{O}_{e u}= (\bar \mu_{R} \gamma^{\alpha} \mu_{R}) (\bar t_R \gamma_{\alpha} t_R )$ need to satisfy $\mathcal{C}_{eu} \sim \mathcal{C}_{\ell u}$. New physics enters then in $b \to s \ell^+ \ell^-$ mainly through the operator $\mathcal{O}_9 = ( \bar s \gamma_{\mu} P_{L} b )( \bar \ell \gamma^{\mu} \ell )$ of the Weak Effective Theory. After discussing all possible mediators, we concentrate on two scenarios: A vector boson in the irreducible representation $Z_{\mu}^{\prime} \sim (1,1,0)$ of the Standard Model gauge group with vectorial coupling to muons, and a combination of two leptoquarks: the scalar $R_2 \sim (3,2,7/6)$ and the vector $\widetilde U_{1 \mu} \sim (3,1,5/3)$. We derive LHC constraints by recasting di-muon resonance, $pp \to t \bar t t \bar t$ and SUSY searches. Additionally, we analyze the prospects for discovering these mediators during the high-luminosity phase of the LHC.
2405.07923
Benedetta Belfatto
Zurab Berezhiani, Benedetta Belfatto
Towards understanding fermion masses and mixings
Contribution to the volume in memory of Harald Fritzsch. arXiv admin note: text overlap with arXiv:2305.00069
null
null
TTP24-012, P3H-24-029
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model does not constrain the form of the Yukawa matrices and thus the origin of fermion mass hierarchies and mixing pattern remains puzzling. On the other hand, there are intriguing relations between the quark masses and their weak mixing angles, such as the well-known one $\tan \theta_C= \sqrt{m_d/m_s}$ for the Cabibbo angle, which may point towards specific textures of Yukawa matrices hypothesized by Harald Fritzsch at the end of the 70's. Though the original ansatz of Fritzsch is excluded by the experimental data, one can consider its minimal modification which consists in introducing an asymmetry between the 23 and 32 entries in the down-quark Yukawa matrix. We show that this structure is perfectly compatible with the present precision data on quark masses and CKM mixing matrix, and theoretically it can be obtained in the context of $SU(5)$ model with inter-family $SU(3)_H$ symmetry. We also discuss some alternative approaches which could give a natural description of the fermion mass spectrum and weak mixing pattern.
[ { "created": "Mon, 13 May 2024 16:54:45 GMT", "version": "v1" } ]
2024-05-14
[ [ "Berezhiani", "Zurab", "" ], [ "Belfatto", "Benedetta", "" ] ]
The Standard Model does not constrain the form of the Yukawa matrices and thus the origin of fermion mass hierarchies and mixing pattern remains puzzling. On the other hand, there are intriguing relations between the quark masses and their weak mixing angles, such as the well-known one $\tan \theta_C= \sqrt{m_d/m_s}$ for the Cabibbo angle, which may point towards specific textures of Yukawa matrices hypothesized by Harald Fritzsch at the end of the 70's. Though the original ansatz of Fritzsch is excluded by the experimental data, one can consider its minimal modification which consists in introducing an asymmetry between the 23 and 32 entries in the down-quark Yukawa matrix. We show that this structure is perfectly compatible with the present precision data on quark masses and CKM mixing matrix, and theoretically it can be obtained in the context of $SU(5)$ model with inter-family $SU(3)_H$ symmetry. We also discuss some alternative approaches which could give a natural description of the fermion mass spectrum and weak mixing pattern.
2108.12207
Shuyun Yang
Shuyun Yang, Meng Jin, and Defu Hou
Mass Spectra and Decay of Mesons under Strong External Magnetic Field
15 pages, 7 figures
Chinese Phys. C 46 043107(2022)
10.1088/1674-1137/ac4694
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the mass spectra and decay process of $\sigma$ and $\pi_0$ mesons under strong external magnetic field. For this purpose, we deduce the thermodynamic potential in a two-flavor, hot and magnetized Nambu-Jona-Lasinio model. We calculate the energy gap equation through the random phase approximation(RPA). Then we use Ritus method to calculate the decay triangle diagram and self-energy in the presence of a constant magnetic field B. Our results indicate that the magnetic field has little influence on the mass of $\pi_0$ at low temperatures. While for quarks and $\sigma$ mesons, their mass changes obviously, which reflects the influence of magnetic catalysis(MC). The presence of magnetic field accelerates the decay of the meson while the presence of chemical potential will decrease the decay process.
[ { "created": "Fri, 27 Aug 2021 10:06:13 GMT", "version": "v1" }, { "created": "Sun, 19 Dec 2021 07:01:02 GMT", "version": "v2" }, { "created": "Wed, 13 Apr 2022 03:32:13 GMT", "version": "v3" } ]
2022-04-14
[ [ "Yang", "Shuyun", "" ], [ "Jin", "Meng", "" ], [ "Hou", "Defu", "" ] ]
We study the mass spectra and decay process of $\sigma$ and $\pi_0$ mesons under strong external magnetic field. For this purpose, we deduce the thermodynamic potential in a two-flavor, hot and magnetized Nambu-Jona-Lasinio model. We calculate the energy gap equation through the random phase approximation(RPA). Then we use Ritus method to calculate the decay triangle diagram and self-energy in the presence of a constant magnetic field B. Our results indicate that the magnetic field has little influence on the mass of $\pi_0$ at low temperatures. While for quarks and $\sigma$ mesons, their mass changes obviously, which reflects the influence of magnetic catalysis(MC). The presence of magnetic field accelerates the decay of the meson while the presence of chemical potential will decrease the decay process.
1605.09376
Kevin Kelly
Andr\'e de Gouv\^ea and Kevin J. Kelly
False Signals of CP-Invariance Violation at DUNE
13 pages, 8 figures
null
null
NUHEP-TH/16-03
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the main goals of the Deep Underground Neutrino Experiment (DUNE) is to look for new sources of CP-invariance violation. Another is to significantly test the three-massive-neutrinos paradigm. Here, we show that there are CP-invariant new physics scenarios which, as far as DUNE data are concerned, cannot be distinguished from the three-massive-neutrinos paradigm with very large CP-invariance violating effects. We discuss examples with non-standard neutrino interactions and with a fourth neutrino mass eigenstate. We briefly discuss how ambiguities can be resolved by combining DUNE data with data from other long-baseline experiments, including Hyper-Kamiokande.
[ { "created": "Mon, 30 May 2016 20:00:00 GMT", "version": "v1" } ]
2016-06-01
[ [ "de Gouvêa", "André", "" ], [ "Kelly", "Kevin J.", "" ] ]
One of the main goals of the Deep Underground Neutrino Experiment (DUNE) is to look for new sources of CP-invariance violation. Another is to significantly test the three-massive-neutrinos paradigm. Here, we show that there are CP-invariant new physics scenarios which, as far as DUNE data are concerned, cannot be distinguished from the three-massive-neutrinos paradigm with very large CP-invariance violating effects. We discuss examples with non-standard neutrino interactions and with a fourth neutrino mass eigenstate. We briefly discuss how ambiguities can be resolved by combining DUNE data with data from other long-baseline experiments, including Hyper-Kamiokande.
1907.12835
Alexander John Macleod
Anton Ilderton, Ben King, Alexander John Macleod
Absorption cross section in an intense plane wave background
15 pages, 6 pdf figures. V2 updated to match published version
Phys. Rev. D 100, 076002 (2019)
10.1103/PhysRevD.100.076002
null
hep-ph physics.plasm-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the absorption of probe photons by electrons in the presence of an intense, pulsed, background field. Our analysis reveals an interplay between regularisation and gauge invariance which distinguishes absorption from its crossing-symmetric processes, as well as a physical interpretation of absorption in terms of degenerate processes in the weak field limit. In the strong field limit we develop a locally constant field approximation (LCFA) for absorption which also exhibits new features. We benchmark the LCFA against exact analytical calculations and explore its regime of validity. Pulse shape effects are also investigated, as well as infra-red and collinear limits of the absorption process.
[ { "created": "Tue, 30 Jul 2019 11:24:14 GMT", "version": "v1" }, { "created": "Tue, 8 Oct 2019 09:51:29 GMT", "version": "v2" } ]
2019-10-09
[ [ "Ilderton", "Anton", "" ], [ "King", "Ben", "" ], [ "Macleod", "Alexander John", "" ] ]
We consider the absorption of probe photons by electrons in the presence of an intense, pulsed, background field. Our analysis reveals an interplay between regularisation and gauge invariance which distinguishes absorption from its crossing-symmetric processes, as well as a physical interpretation of absorption in terms of degenerate processes in the weak field limit. In the strong field limit we develop a locally constant field approximation (LCFA) for absorption which also exhibits new features. We benchmark the LCFA against exact analytical calculations and explore its regime of validity. Pulse shape effects are also investigated, as well as infra-red and collinear limits of the absorption process.
0711.2859
Bo-Young Han
Arie Bodek, Yeonsei Chung, Eva Halkiadakis, Bo-Young Han, Kevin McFarland
A new analysis technique to measure the W Production Charge Asymmetry at the Tevatron
5 pages, 5 figures, to be published in PRD rapid communications
Phys.Rev.D77:111301,2008
10.1103/PhysRevD.77.111301
null
hep-ph
null
We propose an analysis technique to directly measure W production charge asymmetry from W leptonic decay events at the Tevatron and show the feasibility for new analysis method using Monte Carlo simulations.
[ { "created": "Mon, 19 Nov 2007 08:15:04 GMT", "version": "v1" }, { "created": "Tue, 25 Mar 2008 03:21:08 GMT", "version": "v2" }, { "created": "Wed, 28 May 2008 15:47:03 GMT", "version": "v3" } ]
2008-11-26
[ [ "Bodek", "Arie", "" ], [ "Chung", "Yeonsei", "" ], [ "Halkiadakis", "Eva", "" ], [ "Han", "Bo-Young", "" ], [ "McFarland", "Kevin", "" ] ]
We propose an analysis technique to directly measure W production charge asymmetry from W leptonic decay events at the Tevatron and show the feasibility for new analysis method using Monte Carlo simulations.
hep-ph/0110210
Bilenky Samoil
S. M. Bilenky
On the Status of Three-Neutrino Mixing
11 pages, Report at the Meeting NO-VE, Neutrino oscillations at Venice, 24-26 July 2001
null
null
TUM-HEP-440/01
hep-ph
null
All existing solar and atmospheric neutrino oscillation data are described by the standard two-neutrino formulas with neutrino mass squared differences that satisfy the hierarchy relation $\Delta m^{2}_{sol} \ll \Delta m^{2}_{atm}$. We discuss this phenomenon from the point of view of three-neutrino mixing. Possibilities to see effects of three-neutrino mixing and, in particular, effects of CP-violation in the lepton sector depend on the values of $|U_{e3}|^2 $ and $\Delta m^{2}_{sol}$. We present an upper bound of $|U_{e3}|^2 $, which was obtained from a three-neutrino analysis of CHOOZ data in the case if the solar neutrino oscillation parameters lie in the LMA allowed region.
[ { "created": "Tue, 16 Oct 2001 09:45:21 GMT", "version": "v1" }, { "created": "Wed, 17 Oct 2001 15:59:11 GMT", "version": "v2" } ]
2007-05-23
[ [ "Bilenky", "S. M.", "" ] ]
All existing solar and atmospheric neutrino oscillation data are described by the standard two-neutrino formulas with neutrino mass squared differences that satisfy the hierarchy relation $\Delta m^{2}_{sol} \ll \Delta m^{2}_{atm}$. We discuss this phenomenon from the point of view of three-neutrino mixing. Possibilities to see effects of three-neutrino mixing and, in particular, effects of CP-violation in the lepton sector depend on the values of $|U_{e3}|^2 $ and $\Delta m^{2}_{sol}$. We present an upper bound of $|U_{e3}|^2 $, which was obtained from a three-neutrino analysis of CHOOZ data in the case if the solar neutrino oscillation parameters lie in the LMA allowed region.
hep-ph/0508253
Stefano Pozzorini
Johann H. Kuhn, A. Kulesza, S. Pozzorini, M. Schulze
Electroweak corrections to hadronic photon production at large transverse momenta
20 pages, 8 figures
JHEP0603:059,2006
10.1088/1126-6708/2006/03/059
TTP05-16, SFB/CPP-05-44
hep-ph
null
We study the impact of electroweak radiative corrections on direct production of photons with high transverse momenta at hadron colliders. Analytic results for the weak one-loop corrections to the parton scattering reaction $\bar q q \to \gamma g$ and its crossed variants are presented. For the high-energy region, where the corrections are strongly enhanced by logarithms of $\hat s/M_W^2$, we derive simple asymptotic expressions which approximate the exact one-loop results with high precision. The dominant two-loop electroweak contributions are also calculated. Numerical results are presented for the LHC and the Tevatron. The corrections are negative and their size increases with transverse momentum. For the LHC, where transverse momenta of 2 TeV or more can be reached, the size of the one- and two-loop effects amounts up to -17% and +3%, respectively. At the Tevatron, with transverse momenta up to 400 GeV, the one-loop corrections do not exceed -4% and the two-loop effects are negligible. Finally we compare the cross sections for hadronic production of photons and Z bosons and find that the electroweak corrections have an important impact on their ratio.
[ { "created": "Wed, 24 Aug 2005 16:39:56 GMT", "version": "v1" } ]
2009-11-11
[ [ "Kuhn", "Johann H.", "" ], [ "Kulesza", "A.", "" ], [ "Pozzorini", "S.", "" ], [ "Schulze", "M.", "" ] ]
We study the impact of electroweak radiative corrections on direct production of photons with high transverse momenta at hadron colliders. Analytic results for the weak one-loop corrections to the parton scattering reaction $\bar q q \to \gamma g$ and its crossed variants are presented. For the high-energy region, where the corrections are strongly enhanced by logarithms of $\hat s/M_W^2$, we derive simple asymptotic expressions which approximate the exact one-loop results with high precision. The dominant two-loop electroweak contributions are also calculated. Numerical results are presented for the LHC and the Tevatron. The corrections are negative and their size increases with transverse momentum. For the LHC, where transverse momenta of 2 TeV or more can be reached, the size of the one- and two-loop effects amounts up to -17% and +3%, respectively. At the Tevatron, with transverse momenta up to 400 GeV, the one-loop corrections do not exceed -4% and the two-loop effects are negligible. Finally we compare the cross sections for hadronic production of photons and Z bosons and find that the electroweak corrections have an important impact on their ratio.
0811.1202
Yoshimasa Hidaka
Yoshimasa Hidaka and Robert D. Pisarski
Suppression of the shear viscosity near the critical temperature in hot QCD
4 pages, 2 figures, talk given at SEWM 2008, August 26-29, Amsterdam
null
10.1016/j.nuclphysa.2009.01.023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider QCD near but above critical temperature Tc. The pressure, susceptibilities and the renormalized Polyakov loop -- which is an order parameter for the deconfining phase transition -- dramatically change up to temperatures a few times Tc. We refer to this region as a "semi"-QGP, where partial confinement plays important role. We show that the shear viscosity ,eta, is suppressed by two powers of the Polyakov loop. This suggests that eta/T^3 decreases markedly as QCD cools down to temperatures near Tc. We also show a ratio of the viscosity to the entropy becomes small near Tc.
[ { "created": "Fri, 7 Nov 2008 19:01:03 GMT", "version": "v1" } ]
2009-11-13
[ [ "Hidaka", "Yoshimasa", "" ], [ "Pisarski", "Robert D.", "" ] ]
We consider QCD near but above critical temperature Tc. The pressure, susceptibilities and the renormalized Polyakov loop -- which is an order parameter for the deconfining phase transition -- dramatically change up to temperatures a few times Tc. We refer to this region as a "semi"-QGP, where partial confinement plays important role. We show that the shear viscosity ,eta, is suppressed by two powers of the Polyakov loop. This suggests that eta/T^3 decreases markedly as QCD cools down to temperatures near Tc. We also show a ratio of the viscosity to the entropy becomes small near Tc.
hep-ph/0410178
Jonathan Feng
Jonathan L. Feng, Arvind Rajaraman, Bryan T. Smith, Shufang Su, Fumihiro Takayama
SuperWIMP Cosmology and Collider Physics
12 pages, to appear in the proceedings of SUSY2004, the 12th International Conference on Supersymmetry and Unification of Fundamental Interactions, Tsukuba, Japan, 17-23 June 2004
null
null
UCI-TR-2004-36
hep-ph astro-ph hep-ex hep-th
null
Dark matter may be composed of superWIMPs, superweakly-interacting massive particles produced in the late decays of other particles. We focus here on the well-motivated supersymmetric example of gravitino LSPs. Gravitino superWIMPs share several virtues with the well-known case of neutralino dark matter: they are present in the same supersymmetric frameworks (supergravity with R-parity conservation) and naturally have the desired relic density. In contrast to neutralinos, however, gravitino superWIMPs are impossible to detect by conventional dark matter searches, may explain an existing discrepancy in Big Bang nucleosynthesis, predict observable distortions in the cosmic microwave background, and imply spectacular signals at future particle colliders.
[ { "created": "Tue, 12 Oct 2004 21:15:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Feng", "Jonathan L.", "" ], [ "Rajaraman", "Arvind", "" ], [ "Smith", "Bryan T.", "" ], [ "Su", "Shufang", "" ], [ "Takayama", "Fumihiro", "" ] ]
Dark matter may be composed of superWIMPs, superweakly-interacting massive particles produced in the late decays of other particles. We focus here on the well-motivated supersymmetric example of gravitino LSPs. Gravitino superWIMPs share several virtues with the well-known case of neutralino dark matter: they are present in the same supersymmetric frameworks (supergravity with R-parity conservation) and naturally have the desired relic density. In contrast to neutralinos, however, gravitino superWIMPs are impossible to detect by conventional dark matter searches, may explain an existing discrepancy in Big Bang nucleosynthesis, predict observable distortions in the cosmic microwave background, and imply spectacular signals at future particle colliders.
hep-ph/9412308
Claudio Coriano
M. Block (Northwestern Univ.)
A Test of the Standard Model, Using Da$\Phi$ne
8 pages in latex, 1 figure uuencoded, (NUHEP 388)
null
null
null
hep-ph
null
Both the light hypernucleus ${}_\Lambda {\rm H}^4$ and the nucleus ${\rm He}^4$ have spin 0. The ratio $R$ of the electron to muon rates for the pure Fermi transitions \begin{equation} R=\frac{\Gamma\left({}_\Lambda {\rm H}^4\rightarrow {\rm e}^- + \bar \nu +{\rm He}^4\right)} {\Gamma\left({}_\Lambda {\rm H}^4\rightarrow {\mu}^- + \bar \nu +{\rm He}^4\right)} \end{equation} is a sensitive measure of the presence of a {\em second-class} weak current (to the extent that SU(3) is valid in strong interactions), and hence, is a test of the Standard Model. Rates and sensitivities, using Da$\Phi$ne, the $e^+e^-$ machine under construction at Frascati, are discussed.
[ { "created": "Thu, 15 Dec 1994 20:04:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Block", "M.", "", "Northwestern Univ." ] ]
Both the light hypernucleus ${}_\Lambda {\rm H}^4$ and the nucleus ${\rm He}^4$ have spin 0. The ratio $R$ of the electron to muon rates for the pure Fermi transitions \begin{equation} R=\frac{\Gamma\left({}_\Lambda {\rm H}^4\rightarrow {\rm e}^- + \bar \nu +{\rm He}^4\right)} {\Gamma\left({}_\Lambda {\rm H}^4\rightarrow {\mu}^- + \bar \nu +{\rm He}^4\right)} \end{equation} is a sensitive measure of the presence of a {\em second-class} weak current (to the extent that SU(3) is valid in strong interactions), and hence, is a test of the Standard Model. Rates and sensitivities, using Da$\Phi$ne, the $e^+e^-$ machine under construction at Frascati, are discussed.
hep-ph/0006165
Yashar Aghababaie
Y. Aghababaie and C.P. Burgess
Two-Neutrino Five-Photon Scattering at Low Energies
14 pages, plain tex, no figures. Two references added
Phys.Rev. D63 (2001) 113006
10.1103/PhysRevD.63.113006
McGill-00/18
hep-ph
null
We extend earlier constructions of the effective action for neutrino-photon scattering, using the connection between low-energy neutrino-photon and photon-photon scattering together with the known effective Lagrangian describing low-energy photon scattering in QED. We use this effective action to calculate analytic expressions for the low-energy cross section for the (unpolarised) processes $\nu \nubar \to 5 \gamma$, $\nu \gamma \to \nu + 4 \gamma$ and $\gamma \gamma \to \nu \nubar + 3 \gamma$. As a byproduct we derive compact expressions for the $N$-body phase-space integrals for massless particles, including those having non-trivial tensor-structure.
[ { "created": "Thu, 15 Jun 2000 07:18:55 GMT", "version": "v1" }, { "created": "Mon, 3 Jul 2000 06:08:08 GMT", "version": "v2" } ]
2009-10-31
[ [ "Aghababaie", "Y.", "" ], [ "Burgess", "C. P.", "" ] ]
We extend earlier constructions of the effective action for neutrino-photon scattering, using the connection between low-energy neutrino-photon and photon-photon scattering together with the known effective Lagrangian describing low-energy photon scattering in QED. We use this effective action to calculate analytic expressions for the low-energy cross section for the (unpolarised) processes $\nu \nubar \to 5 \gamma$, $\nu \gamma \to \nu + 4 \gamma$ and $\gamma \gamma \to \nu \nubar + 3 \gamma$. As a byproduct we derive compact expressions for the $N$-body phase-space integrals for massless particles, including those having non-trivial tensor-structure.
2102.13120
Miguel Pedra Bento
M. P. Bento
The invariant space of multi-Higgs doublet models
Added references. Conjecture now a theorem. Added details
null
10.1007/JHEP05(2021)146
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a model with more than one scalar doublet, the parameter space encloses both physical and unphysical information. Invariant theory provides a detailed description of the counting and characterization of the physical parameter space. The Hilbert series for the 3HDM is computed for the first time using partition analysis, in particular Omega calculus, giving rise to the possibility of a full description of its physical parameters. A rigorous counting of the physical parameters is given for the full class of models with $N$ scalar doublets as well as a decomposition of the Lagrangian into irreducible representations of $\mathrm{SU}(N)$. For the first time we derive a basis-invariant technique for counting parameters in a Lagrangian with both basis-invariant redundancies and global symmetries.
[ { "created": "Thu, 25 Feb 2021 19:00:03 GMT", "version": "v1" }, { "created": "Mon, 8 Mar 2021 18:39:20 GMT", "version": "v2" }, { "created": "Fri, 23 Apr 2021 17:46:49 GMT", "version": "v3" }, { "created": "Thu, 27 May 2021 16:09:07 GMT", "version": "v4" } ]
2021-05-28
[ [ "Bento", "M. P.", "" ] ]
In a model with more than one scalar doublet, the parameter space encloses both physical and unphysical information. Invariant theory provides a detailed description of the counting and characterization of the physical parameter space. The Hilbert series for the 3HDM is computed for the first time using partition analysis, in particular Omega calculus, giving rise to the possibility of a full description of its physical parameters. A rigorous counting of the physical parameters is given for the full class of models with $N$ scalar doublets as well as a decomposition of the Lagrangian into irreducible representations of $\mathrm{SU}(N)$. For the first time we derive a basis-invariant technique for counting parameters in a Lagrangian with both basis-invariant redundancies and global symmetries.
hep-ph/9503415
Chung Kao
Chung Kao and Nikita Stepanov
DISCOVERING THE HIGGS BOSONS OF MINIMAL SUPERSYMMETRY WITH MUONS
14 pages, LaTeX, 5 figures
Phys.Rev. D52 (1995) 5025-5030
10.1103/PhysRevD.52.5025
UR-1407, ER-40685-854
hep-ph
null
The prospects of detecting neutral Higgs bosons in the minimal supersymmetric model via their decays into muon pairs at the LHC are investigated. The CMS detector performance is adopted for a realistic study of observability. It is found that the muon pair decay mode might provide a very promising channel to search for the neutral Higgs bosons of minimal supersymmetry. This channel will allow precise mass reconstruction for neutral Higgs bosons.
[ { "created": "Wed, 22 Mar 1995 21:49:30 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kao", "Chung", "" ], [ "Stepanov", "Nikita", "" ] ]
The prospects of detecting neutral Higgs bosons in the minimal supersymmetric model via their decays into muon pairs at the LHC are investigated. The CMS detector performance is adopted for a realistic study of observability. It is found that the muon pair decay mode might provide a very promising channel to search for the neutral Higgs bosons of minimal supersymmetry. This channel will allow precise mass reconstruction for neutral Higgs bosons.
2112.06264
Ju-Jun Xie
An-Xin Dai, Zhong-Yi Li, Lei Chang, and Ju-Jun Xie
Electromagnetic form factors of neutron and neutral stange hyperons in the oscillating view of point
4 figures, 5 pages. Experimental data on $\Xi^0$ are included, title is slightly modified
null
10.1088/1674-1137/ac5f9c
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Based on the recently precise measurements of the electron-positron annihilation reactions into a neutron and anti-neutron pair by BESIII collaboration, the effective form factor of neutron was determined in the time like region, and it was found that the effective form factor of neutron is smaller than the ones of proton. The effective form factors of neutron shows a periodic behaviour, similar to the case of proton. Here, a compared analysis for $\Lambda$, $\Sigma^0$ and $\Xi^0$ is performed. Fits of the available data on the effective form factors of $\Lambda$, $\Sigma^0$ and $\Xi^0$ with charge zero, allow to show a universal phenomenon of the oscillation behavior in their effective form factors. However, this needs to be confirmed by future precise experiments. Both theoretical and experimental investigations of this phenomenon can shed light on the reaction mechanisms of the electron-positron annihilation process.
[ { "created": "Sun, 12 Dec 2021 15:56:09 GMT", "version": "v1" }, { "created": "Wed, 22 Dec 2021 02:35:23 GMT", "version": "v2" } ]
2022-07-13
[ [ "Dai", "An-Xin", "" ], [ "Li", "Zhong-Yi", "" ], [ "Chang", "Lei", "" ], [ "Xie", "Ju-Jun", "" ] ]
Based on the recently precise measurements of the electron-positron annihilation reactions into a neutron and anti-neutron pair by BESIII collaboration, the effective form factor of neutron was determined in the time like region, and it was found that the effective form factor of neutron is smaller than the ones of proton. The effective form factors of neutron shows a periodic behaviour, similar to the case of proton. Here, a compared analysis for $\Lambda$, $\Sigma^0$ and $\Xi^0$ is performed. Fits of the available data on the effective form factors of $\Lambda$, $\Sigma^0$ and $\Xi^0$ with charge zero, allow to show a universal phenomenon of the oscillation behavior in their effective form factors. However, this needs to be confirmed by future precise experiments. Both theoretical and experimental investigations of this phenomenon can shed light on the reaction mechanisms of the electron-positron annihilation process.
2304.06750
Jack Shergold
Guillaume Rostagni, Jack D. Shergold
The dark Stodolsky effect: constraining effective dark matter operators with spin-dependent interactions
34 pages, 2 figures
null
10.1088/1475-7516/2023/07/018
IPPP/23/21
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a comprehensive discussion of the Stodolsky effect for dark matter (DM), and discuss two techniques to measure the effect and constrain the DM parameter space. The Stodolsky effect is the spin-dependent shift in the energy of a Standard Model (SM) fermion sitting in a bath of neutrinos. This effect, which scales linearly in the effective coupling, manifests as a small torque on the SM fermion spin and has historically been proposed as a method of detecting the cosmic neutrino background. We generalise this effect to DM, and give expressions for the induced energy shifts for DM candidates from spin-$0$ to spin-$\frac 32$, considering all effective operators up to mass dimension-6. In all cases, the effect scales inversely with the DM mass, but requires an asymmetric background. We show that a torsion balance experiment is sensitive to energy shifts of $\Delta E \gtrsim 10^{-28}\,\mathrm{eV}$, whilst a more intricate setup using a SQUID magnetometer is sensitive to shifts of $\Delta E \gtrsim 10^{-32}\,\mathrm{eV}$. Finally, we compute the energy shifts for a model of scalar DM, and demonstrate that the Stodolsky effect can be used to constrain regions of parameter space that are not presently excluded.
[ { "created": "Thu, 13 Apr 2023 18:00:03 GMT", "version": "v1" }, { "created": "Thu, 25 May 2023 14:55:49 GMT", "version": "v2" } ]
2023-07-11
[ [ "Rostagni", "Guillaume", "" ], [ "Shergold", "Jack D.", "" ] ]
We present a comprehensive discussion of the Stodolsky effect for dark matter (DM), and discuss two techniques to measure the effect and constrain the DM parameter space. The Stodolsky effect is the spin-dependent shift in the energy of a Standard Model (SM) fermion sitting in a bath of neutrinos. This effect, which scales linearly in the effective coupling, manifests as a small torque on the SM fermion spin and has historically been proposed as a method of detecting the cosmic neutrino background. We generalise this effect to DM, and give expressions for the induced energy shifts for DM candidates from spin-$0$ to spin-$\frac 32$, considering all effective operators up to mass dimension-6. In all cases, the effect scales inversely with the DM mass, but requires an asymmetric background. We show that a torsion balance experiment is sensitive to energy shifts of $\Delta E \gtrsim 10^{-28}\,\mathrm{eV}$, whilst a more intricate setup using a SQUID magnetometer is sensitive to shifts of $\Delta E \gtrsim 10^{-32}\,\mathrm{eV}$. Finally, we compute the energy shifts for a model of scalar DM, and demonstrate that the Stodolsky effect can be used to constrain regions of parameter space that are not presently excluded.
hep-ph/0505232
Fabio Cossutti
F. Cossutti
Electroweak corrections uncertainty on the W mass measurement at LEP
34 pages, 3 figures
Eur.Phys.J.C44:383-393,2005
10.1140/epjc/s2005-02378-6
INFN/AE-05/03
hep-ph
null
The systematic uncertainty on the W mass and width measurement resulting from the imperfect knowledge of electroweak radiative corrections is discussed. The intrinsic uncertainty in the 4-f generator used by the DELPHI Collaboration is studied following the guidelines of the authors of YFSWW, on which its radiative corrections part is based. The full DELPHI simulation, reconstruction and analysis chain is used for the uncertainty assessment. A comparison with the other available 4-f calculation implementing DPA O(alpha) corrections, RacoonWW, is also presented. The uncertainty on the W mass is found to be below 10 MeV for all the WW decay channels used in the measurement.
[ { "created": "Fri, 27 May 2005 09:02:46 GMT", "version": "v1" } ]
2009-01-07
[ [ "Cossutti", "F.", "" ] ]
The systematic uncertainty on the W mass and width measurement resulting from the imperfect knowledge of electroweak radiative corrections is discussed. The intrinsic uncertainty in the 4-f generator used by the DELPHI Collaboration is studied following the guidelines of the authors of YFSWW, on which its radiative corrections part is based. The full DELPHI simulation, reconstruction and analysis chain is used for the uncertainty assessment. A comparison with the other available 4-f calculation implementing DPA O(alpha) corrections, RacoonWW, is also presented. The uncertainty on the W mass is found to be below 10 MeV for all the WW decay channels used in the measurement.
hep-ph/0102050
Michael Eides
Michael I. Eides (University of Kentucky, USA, and Petersburg Nuclear Physics Institute, St.Petersburg, Russia) and Valery A. Shelyuto (D. I. Mendeleev Institute of Metrology, Russia)
One-Loop Electron Vertex in Yennie Gauge
Revtex, 12 pp., 1 fig., one reference added. Two misprints in intermediate formulae corrected
Eur.Phys.J.C21:489-494,2001
10.1007/s100520100745
UK/01-01
hep-ph
null
We derive a compact Yennie gauge representation for the off-shell one-loop electron-photon vertex, and discuss it properties. This expression is explicitly infrared finite, and it has proved to be extremely useful in multiloop calculations in the QED bound state problem.
[ { "created": "Mon, 5 Feb 2001 18:58:34 GMT", "version": "v1" }, { "created": "Sun, 11 Feb 2001 17:53:15 GMT", "version": "v2" }, { "created": "Thu, 1 Mar 2001 21:24:44 GMT", "version": "v3" } ]
2009-01-07
[ [ "Eides", "Michael I.", "", "University of Kentucky, USA, and Petersburg Nuclear\n Physics Institute, St.Petersburg, Russia" ], [ "Shelyuto", "Valery A.", "", "D. I.\n Mendeleev Institute of Metrology, Russia" ] ]
We derive a compact Yennie gauge representation for the off-shell one-loop electron-photon vertex, and discuss it properties. This expression is explicitly infrared finite, and it has proved to be extremely useful in multiloop calculations in the QED bound state problem.
hep-ph/0605337
Muneyuki Ishida
Keiji Igi (RIKEN), Muneyuki Ishida (Meisei Univ.)
Proposing a new constraint for predictions of pp, pbar p total cross sections and rho ratio at LHC
8 pages, 1 figure
null
null
null
hep-ph
null
We propose a new constraint(1) corresponding to the FESR (with the moment n=-1) free from unphysical regions. Using this constraint(1) together with the constraint(2) (with the moment n=1), we search for the simultaneous best fit to the data points of sigma-tot and rho ratio up to the SPS energies to determine those values at higher energies. We then predict sigma-tot=107.1 +- 2.6 mb, rho=0.127 +- 0.004 at the LHC energy(E=14 TeV).
[ { "created": "Wed, 31 May 2006 16:00:23 GMT", "version": "v1" }, { "created": "Thu, 20 Jul 2006 07:26:14 GMT", "version": "v2" } ]
2007-05-23
[ [ "Igi", "Keiji", "", "RIKEN" ], [ "Ishida", "Muneyuki", "", "Meisei Univ." ] ]
We propose a new constraint(1) corresponding to the FESR (with the moment n=-1) free from unphysical regions. Using this constraint(1) together with the constraint(2) (with the moment n=1), we search for the simultaneous best fit to the data points of sigma-tot and rho ratio up to the SPS energies to determine those values at higher energies. We then predict sigma-tot=107.1 +- 2.6 mb, rho=0.127 +- 0.004 at the LHC energy(E=14 TeV).
2001.03499
Siamak Sadat Gousheh
S. Abbaslu, S. Rostam Zadeh, M. Mehraeen, S. S. Gousheh
The generation of matter-antimatter asymmetries and hypermagnetic fields by the chiral vortical effect of transient fluctuations
22 pages, 6 figures
null
10.1140/epjc/s10052-021-09272-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the contribution of temperature-dependent chiral vortical effect to the generation and evolution of the hypermagnetic fields and the matter-antimatter asymmetries, in the symmetric phase of the early Universe, in the temperature range $100\mbox{GeV} \le T\le 10\mbox{TeV}$. Our most important result is that, due to the chiral vortical effect, small overlapping transient fluctuations in the vorticity field in the plasma and temperature of matter degrees of freedom can lead to the generation of strong hypermagnetic fields and matter-antimatter asymmetries, all starting from zero initial values. We show that, either an increase in the amplitudes of the fluctuations of vorticity or temperature, or a decrease in their widths, leads to the production of stronger hypermagnetic fields, and therefore, larger matter-antimatter asymmetries. We have the interesting result that fluctuating vorticity fields are more productive, by many orders of magnitude, as compared to vorticities that are constant in time.
[ { "created": "Fri, 10 Jan 2020 15:13:10 GMT", "version": "v1" }, { "created": "Sat, 22 Feb 2020 11:00:44 GMT", "version": "v2" }, { "created": "Mon, 19 Oct 2020 13:12:50 GMT", "version": "v3" }, { "created": "Tue, 22 Jun 2021 08:39:11 GMT", "version": "v4" } ]
2021-06-30
[ [ "Abbaslu", "S.", "" ], [ "Zadeh", "S. Rostam", "" ], [ "Mehraeen", "M.", "" ], [ "Gousheh", "S. S.", "" ] ]
We study the contribution of temperature-dependent chiral vortical effect to the generation and evolution of the hypermagnetic fields and the matter-antimatter asymmetries, in the symmetric phase of the early Universe, in the temperature range $100\mbox{GeV} \le T\le 10\mbox{TeV}$. Our most important result is that, due to the chiral vortical effect, small overlapping transient fluctuations in the vorticity field in the plasma and temperature of matter degrees of freedom can lead to the generation of strong hypermagnetic fields and matter-antimatter asymmetries, all starting from zero initial values. We show that, either an increase in the amplitudes of the fluctuations of vorticity or temperature, or a decrease in their widths, leads to the production of stronger hypermagnetic fields, and therefore, larger matter-antimatter asymmetries. We have the interesting result that fluctuating vorticity fields are more productive, by many orders of magnitude, as compared to vorticities that are constant in time.
1108.1538
Li-gong Bian
Li-Gong Bian, Zheng-Tao Wei
Constraints of unparticle physics parameters from $K^0-\bar K^0$ mixing
13 pages, 5 figures, one author is added, the paper will appear in Chinese Physics C
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The neutral kaon meson mixing plays an important role in test of the Standard Model (SM) and new physics beyond it. Scale invariant unparticle physics induces a flavor changing neutral current (FCNC) transition of $K^0-\bar K^0$ oscillation at the tree level. In this study, we investigate the scale invariant unparticle physics effects on the $K^0-\bar K^0$ mixing. Based on the current experimental data, we give constraints of $K^0-\bar K^0$ mixing on the unparticle parameters.
[ { "created": "Sun, 7 Aug 2011 10:22:00 GMT", "version": "v1" }, { "created": "Sat, 13 Aug 2011 09:04:35 GMT", "version": "v2" }, { "created": "Mon, 1 Apr 2013 01:43:50 GMT", "version": "v3" } ]
2015-03-19
[ [ "Bian", "Li-Gong", "" ], [ "Wei", "Zheng-Tao", "" ] ]
The neutral kaon meson mixing plays an important role in test of the Standard Model (SM) and new physics beyond it. Scale invariant unparticle physics induces a flavor changing neutral current (FCNC) transition of $K^0-\bar K^0$ oscillation at the tree level. In this study, we investigate the scale invariant unparticle physics effects on the $K^0-\bar K^0$ mixing. Based on the current experimental data, we give constraints of $K^0-\bar K^0$ mixing on the unparticle parameters.
hep-ph/0411188
Gilberto Tavares-Velasco
Adriana Cordero-Cid, J.M. Hernandez, G. Tavares-Velasco, J.J. Toscano
Rare top quark decay t --> u_1 \bar{u}_2 u_2 in the standard model
8 pages, 3 figures, branching ratio is evaluated using the running quark masses at the top quark mass scale, results and conclusion changes slightly, new results agree with those presented in hep-ph/0601151, missing references are added
Phys.Rev.D73:094005,2006
10.1103/PhysRevD.73.094005
null
hep-ph
null
The one-loop induced top quark decay $t\to u_1\bar{u}_2u_2$ ($u_i=u,c$) is calculated in the context of the standard model. The dominant contribution to this top quark decay arises from the Feynman diagrams induced by the off-shell $tu_1g^*$ vertex, whereas the box diagrams are negligibly small. In contrast with the on-shell $tu_1g$ vertex, which only gives rise to a pure dipolar effect, the off-shell $tu_1g^*$ coupling also involves a monopolar term, which gives a larger contribution than the dipolar one. It is found that the branching ratio for the three-body decay $t\to u_1\bar{u}_2u_2$ is about of the same order of magnitude of the two-body decay $t\to u_1 g$, the latter being slightly larger, which stems from the fact that the three-body decay is dominated by a monopolar term.
[ { "created": "Sun, 14 Nov 2004 21:38:11 GMT", "version": "v1" }, { "created": "Tue, 14 Mar 2006 19:23:48 GMT", "version": "v2" } ]
2011-03-23
[ [ "Cordero-Cid", "Adriana", "" ], [ "Hernandez", "J. M.", "" ], [ "Tavares-Velasco", "G.", "" ], [ "Toscano", "J. J.", "" ] ]
The one-loop induced top quark decay $t\to u_1\bar{u}_2u_2$ ($u_i=u,c$) is calculated in the context of the standard model. The dominant contribution to this top quark decay arises from the Feynman diagrams induced by the off-shell $tu_1g^*$ vertex, whereas the box diagrams are negligibly small. In contrast with the on-shell $tu_1g$ vertex, which only gives rise to a pure dipolar effect, the off-shell $tu_1g^*$ coupling also involves a monopolar term, which gives a larger contribution than the dipolar one. It is found that the branching ratio for the three-body decay $t\to u_1\bar{u}_2u_2$ is about of the same order of magnitude of the two-body decay $t\to u_1 g$, the latter being slightly larger, which stems from the fact that the three-body decay is dominated by a monopolar term.
2303.10947
Sudhir Pandurang Rode
Sudhir Pandurang Rode, Partha Pratim Bhaduri, and Amaresh Jaiswal
Flow fluctuations and kinetic freeze-out of identified hadrons at energies available at the CERN Super Proton Synchrotron
11 pages, 8 figures, Accepted in Phys. Rev. C, Version to appear in the journal
Phys. Rev. C 108, 014906 (2023)
10.1103/PhysRevC.108.014906
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate the effect of flow fluctuations, incorporated in non boost-invariant blast-wave model, on kinetic freeze-out parameters of identified hadrons in low energy relativistic heavy-ion collisions. For the purpose of this study, we use the transverse momentum spectra of the identified hadrons produced in central Pb--Pb collisions, at SPS energies ranging from $\rm E_{Lab}=20A-158A $ GeV, and analyze them within a modified non boost-invariant blast wave model. We perform simultaneous fits of the transverse momentum spectra for light hadrons ($\pi^{-}$, $K^{\pm}$, $p$) and heavy strange hadrons ($\Lambda$, $\bar{\Lambda}$, $\phi$, $\Xi^{\pm}$, $\Omega^{\pm}$) seperately. We also fit the transverse momentum spectra of charmonia ($J/\Psi$, $\Psi'$) at $\rm E_{Lab}=158A $ GeV. Our findings suggest that the inclusion of flow fluctuations enhances kinetic freeze-out temperature in case of light and heavy strange hadrons and reduces the corresponding transverse flow velocities. Moreover, we find that the kinetic freeze-out parameters of the charmonia at $\rm E_{Lab}=158A $ GeV are least affected by inclusion of flow fluctuations. Based on this, we make predictions which can provide further insights on the role of flow fluctuations in relativistic heavy-ion collisions.
[ { "created": "Mon, 20 Mar 2023 09:12:36 GMT", "version": "v1" }, { "created": "Mon, 3 Jul 2023 17:26:57 GMT", "version": "v2" } ]
2023-07-12
[ [ "Rode", "Sudhir Pandurang", "" ], [ "Bhaduri", "Partha Pratim", "" ], [ "Jaiswal", "Amaresh", "" ] ]
We investigate the effect of flow fluctuations, incorporated in non boost-invariant blast-wave model, on kinetic freeze-out parameters of identified hadrons in low energy relativistic heavy-ion collisions. For the purpose of this study, we use the transverse momentum spectra of the identified hadrons produced in central Pb--Pb collisions, at SPS energies ranging from $\rm E_{Lab}=20A-158A $ GeV, and analyze them within a modified non boost-invariant blast wave model. We perform simultaneous fits of the transverse momentum spectra for light hadrons ($\pi^{-}$, $K^{\pm}$, $p$) and heavy strange hadrons ($\Lambda$, $\bar{\Lambda}$, $\phi$, $\Xi^{\pm}$, $\Omega^{\pm}$) seperately. We also fit the transverse momentum spectra of charmonia ($J/\Psi$, $\Psi'$) at $\rm E_{Lab}=158A $ GeV. Our findings suggest that the inclusion of flow fluctuations enhances kinetic freeze-out temperature in case of light and heavy strange hadrons and reduces the corresponding transverse flow velocities. Moreover, we find that the kinetic freeze-out parameters of the charmonia at $\rm E_{Lab}=158A $ GeV are least affected by inclusion of flow fluctuations. Based on this, we make predictions which can provide further insights on the role of flow fluctuations in relativistic heavy-ion collisions.
hep-ph/9906473
Mustafa Savci
T. M. Aliev, M. Savci (Middle East Technical University-Ankara-Turkey)
Exclusive Lambda_b -> Lambda l^+ l^- decay in two Higgs doublet model
16 pages, 3 figures, LaTeX formatted
J.Phys.G26:997-1010,2000
10.1088/0954-3899/26/7/302
metu-phys-hep-99-20
hep-ph
null
Rare Lambda_b -> Lambda l^+ l^- decay is investigated in framework of general two Higgs doublet model, in which a new source of CP violation exists (model III). The polarization parameter, CP asymmetry and decay width are calculated. It is shown that CP asymmetry is a very sensitive tool for establishing model III.
[ { "created": "Wed, 23 Jun 1999 19:45:07 GMT", "version": "v1" } ]
2008-11-26
[ [ "Aliev", "T. M.", "", "Middle East Technical University-Ankara-Turkey" ], [ "Savci", "M.", "", "Middle East Technical University-Ankara-Turkey" ] ]
Rare Lambda_b -> Lambda l^+ l^- decay is investigated in framework of general two Higgs doublet model, in which a new source of CP violation exists (model III). The polarization parameter, CP asymmetry and decay width are calculated. It is shown that CP asymmetry is a very sensitive tool for establishing model III.
1111.0177
Apoorva Patel
Apoorva Patel
Flux Tube Model Signals for Baryon Correlations in Heavy Ion Collisions
LaTeX, 9 pages, 5 figures, (v2) Several arguments expanded for clarity, (v3) Minor typesetting changes, published version
Phys. Rev. D 85 (2012) 114019
10.1103/PhysRevD.85.114019
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The flux tube model offers a pictorial description of what happens during the deconfinement phase transition in QCD. The 3-point vertices of a flux tube network lead to formation of baryons upon hadronisation. Therefore, correlations in the baryon number distribution at the last scattering surface are related to the preceding pattern of the flux tube vertices, and provide a signature of the nearby deconfinement phase transition. I discuss the nature of the expected signal, which should be observable in heavy ion collisions at RHIC and LHC.
[ { "created": "Tue, 1 Nov 2011 11:43:14 GMT", "version": "v1" }, { "created": "Wed, 21 Mar 2012 14:03:24 GMT", "version": "v2" }, { "created": "Wed, 13 Jun 2012 09:42:05 GMT", "version": "v3" } ]
2013-05-30
[ [ "Patel", "Apoorva", "" ] ]
The flux tube model offers a pictorial description of what happens during the deconfinement phase transition in QCD. The 3-point vertices of a flux tube network lead to formation of baryons upon hadronisation. Therefore, correlations in the baryon number distribution at the last scattering surface are related to the preceding pattern of the flux tube vertices, and provide a signature of the nearby deconfinement phase transition. I discuss the nature of the expected signal, which should be observable in heavy ion collisions at RHIC and LHC.
hep-ph/0106157
Carl Albright
Carl H. Albright (Fermilab)
GUT Implications from Neutrino Mass
9 pages, 1 figure, invited talk at the NUFACT'01 Workshop in Tsukuba, Japan, 24-30 May 2001
Nucl.Instrum.Meth.A503:47-52,2001
10.1016/S0168-9002(03)00640-5
FERMILAB-Conf-01/120-T
hep-ph hep-ex
null
An overview is given of the experimental neutrino mixing results and types of neutrino models proposed, with special attention to the general features of various GUT models involving intra-family symmetries and horizontal flavor symmetries. Many of the features are then illustrated by a specific SO(10) SUSY GUT model formulated by S.M. Barr and the author which can explain all four types of solar neutrino mixing solutions by various choices of the right-handed Majorana mass matrix. The quantitative nature of the model's large mixing angle solution is used to compare the reaches of a neutrino super beam and a neutrino factory for determining the small U_{e3} mixing matrix element.
[ { "created": "Thu, 14 Jun 2001 21:21:55 GMT", "version": "v1" } ]
2008-11-26
[ [ "Albright", "Carl H.", "", "Fermilab" ] ]
An overview is given of the experimental neutrino mixing results and types of neutrino models proposed, with special attention to the general features of various GUT models involving intra-family symmetries and horizontal flavor symmetries. Many of the features are then illustrated by a specific SO(10) SUSY GUT model formulated by S.M. Barr and the author which can explain all four types of solar neutrino mixing solutions by various choices of the right-handed Majorana mass matrix. The quantitative nature of the model's large mixing angle solution is used to compare the reaches of a neutrino super beam and a neutrino factory for determining the small U_{e3} mixing matrix element.
0903.4703
Yun Guo
Adrian Dumitru, Yun Guo and Michael Strickland
The imaginary part of the static gluon propagator in an anisotropic (viscous) QCD plasma
11 pages, 1 figure, final version, to appear in PRD
Phys.Rev.D79:114003,2009
10.1103/PhysRevD.79.114003
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine viscosity corrections to the retarded, advanced and symmetric gluon self energies and to the static propagator in the weak-coupling "hard loop" approximation to high-temperature QCD. We apply these results to calculate the imaginary part of the heavy-quark potential which is found to be smaller (in magnitude) than at vanishing viscosity. This implies a smaller decay width of quarkonium bound states in an anisotropic plasma.
[ { "created": "Thu, 26 Mar 2009 21:28:30 GMT", "version": "v1" }, { "created": "Tue, 2 Jun 2009 09:55:34 GMT", "version": "v2" } ]
2009-06-30
[ [ "Dumitru", "Adrian", "" ], [ "Guo", "Yun", "" ], [ "Strickland", "Michael", "" ] ]
We determine viscosity corrections to the retarded, advanced and symmetric gluon self energies and to the static propagator in the weak-coupling "hard loop" approximation to high-temperature QCD. We apply these results to calculate the imaginary part of the heavy-quark potential which is found to be smaller (in magnitude) than at vanishing viscosity. This implies a smaller decay width of quarkonium bound states in an anisotropic plasma.
1303.7056
Hiroshi Okada
Yasuhiro Daikoku, Hiroshi Okada
Phenomenology of S_4 Flavor Symmetric extra U(1) model
33 pages, 7 tables, no figures; version accepted for publication in Physical Review D
null
10.1103/PhysRevD.88.015034
KIAS-P13019
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study several phenomenologies of an E_6 inspired extra U(1) model with S_4 flavor symmetry. With the assignment of left-handed quarks and leptons to S_4-doublet, SUSY flavor problem is softened. As the extra Higgs bosons are neutrinophilic, baryon number asymmetry in the universe is realized by leptogenesis without causing gravitino overproduction. We find that the allowed region for the lightest chargino mass is given by 100-140 GeV, if the dark matter is a singlino dominated neutralino whose mass is about 36 GeV.
[ { "created": "Thu, 28 Mar 2013 07:22:05 GMT", "version": "v1" }, { "created": "Wed, 26 Jun 2013 16:50:27 GMT", "version": "v2" } ]
2013-08-09
[ [ "Daikoku", "Yasuhiro", "" ], [ "Okada", "Hiroshi", "" ] ]
We study several phenomenologies of an E_6 inspired extra U(1) model with S_4 flavor symmetry. With the assignment of left-handed quarks and leptons to S_4-doublet, SUSY flavor problem is softened. As the extra Higgs bosons are neutrinophilic, baryon number asymmetry in the universe is realized by leptogenesis without causing gravitino overproduction. We find that the allowed region for the lightest chargino mass is given by 100-140 GeV, if the dark matter is a singlino dominated neutralino whose mass is about 36 GeV.