id
stringlengths
9
14
submitter
stringlengths
1
56
authors
stringlengths
5
7.68k
title
stringlengths
3
299
comments
stringlengths
1
1.15k
journal-ref
stringlengths
9
298
doi
stringlengths
12
97
report-no
stringlengths
3
341
categories
stringclasses
869 values
license
stringclasses
9 values
orig_abstract
stringlengths
16
2.44k
versions
listlengths
1
39
update_date
stringlengths
10
10
authors_parsed
listlengths
1
565
abstract
stringlengths
13
2.44k
1203.0207
Yu-Jie Zhang Dr.
Guang-Zhi Xu, Yi-Jie Li, Kui-Yong Liu, Yu-Jie Zhang
Relativistic Correction to Color Octet J/psi Production at Hadron Colliders
Published version. Figures and Equations are added
Phys.Rev. D86 (2012) 094017
10.1103/PhysRevD.86.094017
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/3.0/
The relativistic corrections to the color-octet $J/\psi$ hadroproduction at the Tevatron and LHC are calculated up to $\mathcal{O}(v^2)$ in nonrelativistic QCD factorization frame. The short distance coefficients are obtained by matching full QCD with NRQCD results for the partonic subprocess $g+g\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+g$, $q+\bar{q}\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+g$ and $g+q({\bar{q}})\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+q({\bar{q}})$. The short distance coefficient ratios of relativistic correction to leading order for color-octet states ${^1}S_{0}^{[8]}$, ${^3}S_{1}^{[8]}$, and ${^3}P_{J}^{[8]}$ at large $p_T$ are approximately -5/6, -11/6, and -31/30, respectively, for each subprocess, and it is 1/6 for color-singlet state ${^3}S_{1}^{[1]}$. If the higher order long distance matrix elements are estimated through velocity scaling rule with adopting $v^2=0.23$ and the lower order long distance matrix elements are fixed, the leading order cross sections of color-octet states are reduced by about a factor of $20\sim40%$ at large $p_T$ at both the Tevatron and the LHC. Comparing with QCD radiative corrections to color-octet states, relativistic correction is ignored along with $p_T$ increasing. Using long distance matrix elements extracted from the fit to $J/\psi$ production at the Tevatron, we can find the unpolarization cross sections of $J/\psi$ production at the LHC taking into account both QCD and relativistic corrections are changed by about $20\sim50%$ of that considering only QCD corrections. These results indicate that relativistic corrections may play an important role in $J/\psi$ production at the Tevatron and the LHC.
[ { "created": "Thu, 1 Mar 2012 15:12:04 GMT", "version": "v1" }, { "created": "Mon, 4 Mar 2013 21:27:28 GMT", "version": "v2" } ]
2013-03-06
[ [ "Xu", "Guang-Zhi", "" ], [ "Li", "Yi-Jie", "" ], [ "Liu", "Kui-Yong", "" ], [ "Zhang", "Yu-Jie", "" ] ]
The relativistic corrections to the color-octet $J/\psi$ hadroproduction at the Tevatron and LHC are calculated up to $\mathcal{O}(v^2)$ in nonrelativistic QCD factorization frame. The short distance coefficients are obtained by matching full QCD with NRQCD results for the partonic subprocess $g+g\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+g$, $q+\bar{q}\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+g$ and $g+q({\bar{q}})\to J/\psi ({}^1S_0^{[8]},{}^3S_1^{[8]}, {}^3P_J^{[8]})+q({\bar{q}})$. The short distance coefficient ratios of relativistic correction to leading order for color-octet states ${^1}S_{0}^{[8]}$, ${^3}S_{1}^{[8]}$, and ${^3}P_{J}^{[8]}$ at large $p_T$ are approximately -5/6, -11/6, and -31/30, respectively, for each subprocess, and it is 1/6 for color-singlet state ${^3}S_{1}^{[1]}$. If the higher order long distance matrix elements are estimated through velocity scaling rule with adopting $v^2=0.23$ and the lower order long distance matrix elements are fixed, the leading order cross sections of color-octet states are reduced by about a factor of $20\sim40%$ at large $p_T$ at both the Tevatron and the LHC. Comparing with QCD radiative corrections to color-octet states, relativistic correction is ignored along with $p_T$ increasing. Using long distance matrix elements extracted from the fit to $J/\psi$ production at the Tevatron, we can find the unpolarization cross sections of $J/\psi$ production at the LHC taking into account both QCD and relativistic corrections are changed by about $20\sim50%$ of that considering only QCD corrections. These results indicate that relativistic corrections may play an important role in $J/\psi$ production at the Tevatron and the LHC.
hep-ph/0312327
Yong Zhou
Yong Zhou, Cai-dian L\"u
The Gauge Dependence of Imaginary Part of physical amplitude $W^{+}\to u_i \bar{d}_j$ in Quark Mixing Matrix Renormalization
The contents has been moved to hep-ph/0312134
null
null
null
hep-ph
null
We investigate the current renormalization prescriptions of quark mixing matrix and found that there is gauge dependence in the imaginary part of physical amplitude $W^{+}\to u_i \bar{d}_j$ in two main renormalization prescriptions. Our conclusion may affect the renormalization of the quark mixing matrix and indicates that it needs more investigation about the gauge independence in quark mixing matrix renormalization.
[ { "created": "Tue, 23 Dec 2003 04:22:38 GMT", "version": "v1" }, { "created": "Fri, 5 Mar 2004 03:47:21 GMT", "version": "v2" } ]
2007-05-23
[ [ "Zhou", "Yong", "" ], [ "Lü", "Cai-dian", "" ] ]
We investigate the current renormalization prescriptions of quark mixing matrix and found that there is gauge dependence in the imaginary part of physical amplitude $W^{+}\to u_i \bar{d}_j$ in two main renormalization prescriptions. Our conclusion may affect the renormalization of the quark mixing matrix and indicates that it needs more investigation about the gauge independence in quark mixing matrix renormalization.
2310.06526
Zhi-Peng Xing
Jin Sun and Zhi-Peng Xing
Dark photon effects with the kinetic and mass mixing in Z boson decay processes
10 pages,3 figures, 2 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the most recent measurement of tau polarization in $Z\to \tau^+\tau^-$ by CMS, we have introduced a new $U(1)_X$ gauge boson field X, which can have renormalizable kinetic mixing with the standard model $U(1)_Y$ gauge boson field Y. In addition to the kinetic mixing of the dark photon, denoted as $\sigma$, there may also be mass mixing introduced by the additional Higgs doublet with a vacuum expectation value (vev) participating in $U(1)_X$ and electroweak symmetry breaking simultaneously. The interaction of the Z boson with the SM leptons is modified by the introduction of the mixing ratio parameter $\epsilon$, which quantifies the magnitude of both the mass and kinetic mixing of the dark photon. Initially, we use the tau lepton as an example to explore the Z boson phenomenology of the dark photon model with both kinetic and mass mixing. The goal is to determine the allowed parameter regions by taking into account constraints from the vector and axial-vector couplings $g_{V,A}^\tau$, the decay branching ratio $Br(Z\to \tau^- \tau^+)$ and tau lepton polarization in $Z\to \tau^-\tau^+$. We found that the mixing ratio plays important role in the Z boson features by choosing different $\epsilon$ values. Furthermore, we aim to generalize our analysis from the tau-lepton case to include all fermions by conducting global fits. This allows us to identify viable regions by incorporating relevant fermion constraints and the W/Z mass ratio. Correspondingly, we obtain the fit results with the kinetic mixing parameter $\sigma=0.074\pm0.021$, mixing ratio $\epsilon=-1.37\pm0.46$, and dark photon mass $m_X=275\pm39$ GeV. Our global analysis indicates a preference for a dark photon mass larger than $m_Z$.
[ { "created": "Tue, 10 Oct 2023 11:17:11 GMT", "version": "v1" }, { "created": "Wed, 13 Dec 2023 06:26:23 GMT", "version": "v2" } ]
2023-12-14
[ [ "Sun", "Jin", "" ], [ "Xing", "Zhi-Peng", "" ] ]
Motivated by the most recent measurement of tau polarization in $Z\to \tau^+\tau^-$ by CMS, we have introduced a new $U(1)_X$ gauge boson field X, which can have renormalizable kinetic mixing with the standard model $U(1)_Y$ gauge boson field Y. In addition to the kinetic mixing of the dark photon, denoted as $\sigma$, there may also be mass mixing introduced by the additional Higgs doublet with a vacuum expectation value (vev) participating in $U(1)_X$ and electroweak symmetry breaking simultaneously. The interaction of the Z boson with the SM leptons is modified by the introduction of the mixing ratio parameter $\epsilon$, which quantifies the magnitude of both the mass and kinetic mixing of the dark photon. Initially, we use the tau lepton as an example to explore the Z boson phenomenology of the dark photon model with both kinetic and mass mixing. The goal is to determine the allowed parameter regions by taking into account constraints from the vector and axial-vector couplings $g_{V,A}^\tau$, the decay branching ratio $Br(Z\to \tau^- \tau^+)$ and tau lepton polarization in $Z\to \tau^-\tau^+$. We found that the mixing ratio plays important role in the Z boson features by choosing different $\epsilon$ values. Furthermore, we aim to generalize our analysis from the tau-lepton case to include all fermions by conducting global fits. This allows us to identify viable regions by incorporating relevant fermion constraints and the W/Z mass ratio. Correspondingly, we obtain the fit results with the kinetic mixing parameter $\sigma=0.074\pm0.021$, mixing ratio $\epsilon=-1.37\pm0.46$, and dark photon mass $m_X=275\pm39$ GeV. Our global analysis indicates a preference for a dark photon mass larger than $m_Z$.
2109.07130
Bing-Dong Wan
Bing-Dong Wan, Sheng-Qi Zhang, Cong-Feng Qiao
Light baryonium spectrum
32 pages, 4 figures, accepted by PRD
null
10.1103/PhysRevD.105.014016
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We evaluate the light baryonium spectrum, viz. the baryon-antibaryon states, in the framework of QCD sum rules. The nonperturbative contributions up to dimension 12 are taken into account. Numerical results indicate that there might exist eight possible light baryonium states, i.e. $p$-$\bar{p}$, $\Lambda$-$\bar{\Lambda}$, $\Sigma$-$\bar{\Sigma}$, and $\Xi$-$\bar{\Xi}$ with quantum numbers of $0^{-+}$ and $1^{--}$. For the $\Lambda$-$\bar{\Lambda}$, $\Sigma$-$\bar{\Sigma}$, and $\Xi$-$\bar{\Xi}$ states, their masses are found above the corresponding dibaryon thresholds, while the masses of $p$-$\bar{p}$ states are not. The possible baryonium decay modes are analyzed, which are hopefully measurable in BESIII, BELLEII, and LHCb experiments.
[ { "created": "Wed, 15 Sep 2021 07:26:36 GMT", "version": "v1" }, { "created": "Thu, 13 Jan 2022 10:46:59 GMT", "version": "v2" } ]
2022-02-02
[ [ "Wan", "Bing-Dong", "" ], [ "Zhang", "Sheng-Qi", "" ], [ "Qiao", "Cong-Feng", "" ] ]
We evaluate the light baryonium spectrum, viz. the baryon-antibaryon states, in the framework of QCD sum rules. The nonperturbative contributions up to dimension 12 are taken into account. Numerical results indicate that there might exist eight possible light baryonium states, i.e. $p$-$\bar{p}$, $\Lambda$-$\bar{\Lambda}$, $\Sigma$-$\bar{\Sigma}$, and $\Xi$-$\bar{\Xi}$ with quantum numbers of $0^{-+}$ and $1^{--}$. For the $\Lambda$-$\bar{\Lambda}$, $\Sigma$-$\bar{\Sigma}$, and $\Xi$-$\bar{\Xi}$ states, their masses are found above the corresponding dibaryon thresholds, while the masses of $p$-$\bar{p}$ states are not. The possible baryonium decay modes are analyzed, which are hopefully measurable in BESIII, BELLEII, and LHCb experiments.
1909.09561
\'Alvaro Hern\'andez-Cabezudo
Oliver Fischer, Alvaro Hernandez-Cabezudo, and Thomas Schwetz
Explaining the MiniBooNE excess by a decaying sterile neutrino with mass in the 250 MeV range
26 pages, 9 figures. New references, supernova bound and an appendix about the impact of the timing cut are added
Phys. Rev. D 101, 075045 (2020)
10.1103/PhysRevD.101.075045
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The MiniBooNE collaboration has reported an excess of $460.5\pm 95.8$ electron-like events ($4.8\sigma$). We propose an explanation of these events in terms of a sterile neutrino decaying into a photon and a light neutrino. The sterile neutrino has a mass around 250 MeV and it is produced from kaon decays in the proton beam target via mixing with the muon or the electron in the range $10^{-11} \lesssim |U_{\ell 4}|^2 \lesssim 10^{-7}$ ($\ell = e,\mu$). The model can be tested by considering the time distribution of the events in MiniBooNE and by looking for single-photon events in running or upcoming neutrino experiments, in particular by the suite of liquid argon detectors in the short-baseline neutrino program at Fermilab.
[ { "created": "Fri, 20 Sep 2019 15:32:56 GMT", "version": "v1" }, { "created": "Tue, 1 Oct 2019 12:52:04 GMT", "version": "v2" } ]
2020-05-06
[ [ "Fischer", "Oliver", "" ], [ "Hernandez-Cabezudo", "Alvaro", "" ], [ "Schwetz", "Thomas", "" ] ]
The MiniBooNE collaboration has reported an excess of $460.5\pm 95.8$ electron-like events ($4.8\sigma$). We propose an explanation of these events in terms of a sterile neutrino decaying into a photon and a light neutrino. The sterile neutrino has a mass around 250 MeV and it is produced from kaon decays in the proton beam target via mixing with the muon or the electron in the range $10^{-11} \lesssim |U_{\ell 4}|^2 \lesssim 10^{-7}$ ($\ell = e,\mu$). The model can be tested by considering the time distribution of the events in MiniBooNE and by looking for single-photon events in running or upcoming neutrino experiments, in particular by the suite of liquid argon detectors in the short-baseline neutrino program at Fermilab.
1008.4531
Per Osland
P. Osland, A. A. Pankov, A. V. Tsytrinov, N. Paver
Signals of Warped Extra Dimensions at the LHC
8 pages, Talk given at QCD@Work - International Workshop on QCD - Theory and Experiment, 20 - 23 June, 2010, Martina Franca Italy
AIP Conf.Proc.1317:201-208,2011
10.1063/1.3536560
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the signatures of the spin-2 graviton excitations predicted by the Randall-Sundrum model with one warped extra dimension, in dilepton and diphoton production at LHC. By using a specific angular analysis, we assess the ranges in mass and coupling constant where such gravitons can be discriminated against competitor spin-1 and spin-0 objects, that potentially could manifest themselves in these processes with the same mass and rate of events. Depending on the value of the coupling constant to quarks and leptons, the numerical results indicate graviton identification mass ranges up to 1.1-2.4 TeV and 1.6-3.2 TeV for LHC nominal energy of 14 TeV and time-integrated luminosity of 10 and 100~${\rm fb}^{-1}$, respectively.
[ { "created": "Thu, 26 Aug 2010 15:32:30 GMT", "version": "v1" } ]
2011-02-01
[ [ "Osland", "P.", "" ], [ "Pankov", "A. A.", "" ], [ "Tsytrinov", "A. V.", "" ], [ "Paver", "N.", "" ] ]
We discuss the signatures of the spin-2 graviton excitations predicted by the Randall-Sundrum model with one warped extra dimension, in dilepton and diphoton production at LHC. By using a specific angular analysis, we assess the ranges in mass and coupling constant where such gravitons can be discriminated against competitor spin-1 and spin-0 objects, that potentially could manifest themselves in these processes with the same mass and rate of events. Depending on the value of the coupling constant to quarks and leptons, the numerical results indicate graviton identification mass ranges up to 1.1-2.4 TeV and 1.6-3.2 TeV for LHC nominal energy of 14 TeV and time-integrated luminosity of 10 and 100~${\rm fb}^{-1}$, respectively.
1508.07201
Wolfgang Hollik
Wolfgang Gregor Hollik
Charge and color breaking constraints in the Minimal Supersymmetric Standard Model associated with the bottom Yukawa coupling
14 pages, 3 figures; v4 version accepted by PLB, RG-improvement added
Phys. Lett. B752 (2016) 7-12
10.1016/j.physletb.2015.11.028
TTP15-033
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Testing the stability of the electroweak vacuum in any extension of the Standard Model Higgs sector is of great importance to verify the consistency of the theory. Multi-scalar extensions as the Minimal Supersymmetric Standard Model generically lead to unstable configurations in certain regions of parameter space. An exact minimization of the scalar potential is rather an impossible analytic task. To give handy analytic constraints, a specific direction in field space has to be considered which is a simplification that tends to miss excluded regions, however good to quickly check parameter points. We describe a yet undescribed class of charge and color breaking minima as they appear in the Minimal Supersymmetric Standard Model, exemplarily for the case of non-vanishing bottom squark vacuum expectation values constraining the combination mu Yb in a non-trivial way. Contrary to famous A-parameter bounds, we relate the bottom Yukawa coupling with the supersymmetry breaking masses. Another bound can be found relating soft breaking masses and mu only. The exclusions follow from the tree-level minimization and can change dramatically using the one-loop potential. Estimates of the lifetime of unstable configurations show that they are either extremely short- or long-lived.
[ { "created": "Fri, 28 Aug 2015 13:23:49 GMT", "version": "v1" }, { "created": "Wed, 2 Sep 2015 13:21:49 GMT", "version": "v2" }, { "created": "Fri, 9 Oct 2015 12:34:55 GMT", "version": "v3" }, { "created": "Wed, 11 Nov 2015 17:23:57 GMT", "version": "v4" } ]
2015-11-24
[ [ "Hollik", "Wolfgang Gregor", "" ] ]
Testing the stability of the electroweak vacuum in any extension of the Standard Model Higgs sector is of great importance to verify the consistency of the theory. Multi-scalar extensions as the Minimal Supersymmetric Standard Model generically lead to unstable configurations in certain regions of parameter space. An exact minimization of the scalar potential is rather an impossible analytic task. To give handy analytic constraints, a specific direction in field space has to be considered which is a simplification that tends to miss excluded regions, however good to quickly check parameter points. We describe a yet undescribed class of charge and color breaking minima as they appear in the Minimal Supersymmetric Standard Model, exemplarily for the case of non-vanishing bottom squark vacuum expectation values constraining the combination mu Yb in a non-trivial way. Contrary to famous A-parameter bounds, we relate the bottom Yukawa coupling with the supersymmetry breaking masses. Another bound can be found relating soft breaking masses and mu only. The exclusions follow from the tree-level minimization and can change dramatically using the one-loop potential. Estimates of the lifetime of unstable configurations show that they are either extremely short- or long-lived.
2303.09015
Xiaoyu Wang
Shuailiang Yang, Jianxi Song, Xiaoyu Wang, De-Min Li, Zhun Lu
The Sivers asymmetry in charged Kaon and $\Lambda$ hyperon produced SIDIS process at electron ion colliders
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate the single transverse-spin asymmetry with a $\sin (\phi_h-\phi_S)$ modulation in the charged Kaon produced and in $\Lambda$ hyperon produced SIDIS process within the theoretical framework of transverse momentum dependent (TMD) factorization at the next-to-leading-logarithmic order. The asymmetry is contributed by the convolution of Sivers function and the unpolarized fragmentation function $D_1$ for the produced hadron. The parametrization for the proton Qiu-Sterman function, which is closely related to the Sivers function, is adopted to numerically estimate the Sivers asymmetry at the kinematical region of Electron Ion Collider (EIC) and Electron Ion Collider in China (EicC). The TMD evolution of the TMD parton distribution functions are considered by employing the nonperturbative Sudakov form factor. It is found that the predicted Sivers asymmetries $A_{UT}^{\sin (\phi_h-\phi_S)}$ as functions of $x$, $z$ and $P_{hT}$ are sizable at the kinematical configurations of both EIC and EicC. The strange constituent of the produced charged Kaon and $\Lambda$ hyperon in the final state can be a promising probe of the sea quark Sivers function as well as the flavor dependence in the proton target. Therefore, it is important to utilize the future EIC facilities to constrain the sea quark distribution functions as well as the validity of the generalized universality of the Sivers function.
[ { "created": "Thu, 16 Mar 2023 01:05:07 GMT", "version": "v1" } ]
2023-03-17
[ [ "Yang", "Shuailiang", "" ], [ "Song", "Jianxi", "" ], [ "Wang", "Xiaoyu", "" ], [ "Li", "De-Min", "" ], [ "Lu", "Zhun", "" ] ]
We investigate the single transverse-spin asymmetry with a $\sin (\phi_h-\phi_S)$ modulation in the charged Kaon produced and in $\Lambda$ hyperon produced SIDIS process within the theoretical framework of transverse momentum dependent (TMD) factorization at the next-to-leading-logarithmic order. The asymmetry is contributed by the convolution of Sivers function and the unpolarized fragmentation function $D_1$ for the produced hadron. The parametrization for the proton Qiu-Sterman function, which is closely related to the Sivers function, is adopted to numerically estimate the Sivers asymmetry at the kinematical region of Electron Ion Collider (EIC) and Electron Ion Collider in China (EicC). The TMD evolution of the TMD parton distribution functions are considered by employing the nonperturbative Sudakov form factor. It is found that the predicted Sivers asymmetries $A_{UT}^{\sin (\phi_h-\phi_S)}$ as functions of $x$, $z$ and $P_{hT}$ are sizable at the kinematical configurations of both EIC and EicC. The strange constituent of the produced charged Kaon and $\Lambda$ hyperon in the final state can be a promising probe of the sea quark Sivers function as well as the flavor dependence in the proton target. Therefore, it is important to utilize the future EIC facilities to constrain the sea quark distribution functions as well as the validity of the generalized universality of the Sivers function.
1507.05096
Andi Hektor
Andi Hektor, Kristjan Kannike, Luca Marzola
Muon g-2 and galactic centre $\gamma$-ray excess in a scalar extension of the 2HDM type-X
23 pages, 8 figures, references added
null
10.1088/1475-7516/2015/10/025
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider an extension of the lepto-specific 2HDM with an extra singlet $S$ as a dark matter candidate. Taking into account theoretical and experimental constraints, we investigate the possibility to address both the $\gamma$-ray excess detected at the Galactic centre and the discrepancy between the Standard Model prediction and experimental results of the anomalous magnetic moment of the muon. Our analyses reveal that the $SS \to \tau^+ \tau^-$ and $SS \to b \bar b$ channels reproduce the Galactic centre excess, with an emerging dark matter candidate which complies with the bounds from direct detection experiments, measurements of the Higgs boson invisible decay width and observations of the dark matter relic abundance. Addressing the anomalous magnetic moment of the muon imposes further strong constraints on the model. Remarkably, under these conditions, the $SS \to b \bar b$ channel still allows for the fitting of the Galactic centre. We also comment on a scenario allowed by the model where the $SS \to \tau^+ \tau^-$ and $SS \to b \bar b$ channels have comparable branching ratios, which possibly yield an improved fitting of the Galactic centre excess.
[ { "created": "Fri, 17 Jul 2015 20:01:03 GMT", "version": "v1" }, { "created": "Thu, 30 Jul 2015 17:11:08 GMT", "version": "v2" } ]
2015-10-21
[ [ "Hektor", "Andi", "" ], [ "Kannike", "Kristjan", "" ], [ "Marzola", "Luca", "" ] ]
We consider an extension of the lepto-specific 2HDM with an extra singlet $S$ as a dark matter candidate. Taking into account theoretical and experimental constraints, we investigate the possibility to address both the $\gamma$-ray excess detected at the Galactic centre and the discrepancy between the Standard Model prediction and experimental results of the anomalous magnetic moment of the muon. Our analyses reveal that the $SS \to \tau^+ \tau^-$ and $SS \to b \bar b$ channels reproduce the Galactic centre excess, with an emerging dark matter candidate which complies with the bounds from direct detection experiments, measurements of the Higgs boson invisible decay width and observations of the dark matter relic abundance. Addressing the anomalous magnetic moment of the muon imposes further strong constraints on the model. Remarkably, under these conditions, the $SS \to b \bar b$ channel still allows for the fitting of the Galactic centre. We also comment on a scenario allowed by the model where the $SS \to \tau^+ \tau^-$ and $SS \to b \bar b$ channels have comparable branching ratios, which possibly yield an improved fitting of the Galactic centre excess.
hep-ph/9803387
null
Edmond L. Berger(ANL), Lionel E. Gordon(TJNL), and Michael Klasen(ANL)
Massive Lepton Pairs as a Prompt Photon Surrogate
36 pages, RevTeX, including 16 ps files of figures; minor changes in wording; one reference added. Version to appear in Phys Rev D
Phys.Rev.D58:074012,1998
10.1103/PhysRevD.58.074012
ANL-HEP-PR-98-27, JLAB-THY-98-11
hep-ph
null
We discuss the transverse momentum distribution for the production of massive lepton-pairs in hadron reactions at fixed target and collider energies within the context of next-to-leading order perturbative quantum chromodynamics. For values of the transverse momentum $Q_T$ greater than the pair mass $Q$, $Q_T > Q$, we show that the differential cross section is dominated by subprocesses initiated by incident gluons. Massive lepton-pair differential cross sections are an advantageous source of constraints on the gluon density, free from the experimental and theoretical complications of photon isolation that beset studies of prompt photon production. We compare calculations with data and provide predictions for the differential cross section as a function of $Q_T$ in proton-antiproton reactions at center-of-mass energies of 1.8 TeV, and in proton-nucleon reactions at fixed target and LHC energies.
[ { "created": "Wed, 18 Mar 1998 23:02:58 GMT", "version": "v1" }, { "created": "Thu, 25 Jun 1998 22:14:54 GMT", "version": "v2" } ]
2014-11-17
[ [ "Berger", "Edmond L.", "", "ANL" ], [ "Gordon", "Lionel E.", "", "TJNL" ], [ "Klasen", "Michael", "", "ANL" ] ]
We discuss the transverse momentum distribution for the production of massive lepton-pairs in hadron reactions at fixed target and collider energies within the context of next-to-leading order perturbative quantum chromodynamics. For values of the transverse momentum $Q_T$ greater than the pair mass $Q$, $Q_T > Q$, we show that the differential cross section is dominated by subprocesses initiated by incident gluons. Massive lepton-pair differential cross sections are an advantageous source of constraints on the gluon density, free from the experimental and theoretical complications of photon isolation that beset studies of prompt photon production. We compare calculations with data and provide predictions for the differential cross section as a function of $Q_T$ in proton-antiproton reactions at center-of-mass energies of 1.8 TeV, and in proton-nucleon reactions at fixed target and LHC energies.
1106.4137
Mina Ketan Parida
Mina K. Parida (HRI, Allahabad)
Radiative Seesaw in SO(10) with Dark Matter
11 pages LaTex, no figures.hep-ph, astro-ph, hep-th; Version accepted in Phys. Lett. B
Phys. Lett. B 704 (2011) 206-210
10.1016/j.physletb.2011.09.016
null
hep-ph astro-ph.HE hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High energy accelerators may probe into dark matter and the seesaw neutrino mass scales if they are not much heavier than ~O(TeV). In the absence of supersymmetry, we extend a class of SO(10) models to predict well known cold dark matter candidates while achieving precision unification with experimentally testable proton lifetime. The most important prediction is a new radiative seesaw formula of Ma type accessible to accelerator tests while the essential small value of its quartic coupling also emerges naturally. This dominates over the high-scale seesaw contributions making a major impact on neutrino physics and dark matter, opening up high prospects as a theory of fermion masses.
[ { "created": "Tue, 21 Jun 2011 08:59:20 GMT", "version": "v1" }, { "created": "Wed, 7 Sep 2011 16:47:29 GMT", "version": "v2" } ]
2011-09-27
[ [ "Parida", "Mina K.", "", "HRI, Allahabad" ] ]
High energy accelerators may probe into dark matter and the seesaw neutrino mass scales if they are not much heavier than ~O(TeV). In the absence of supersymmetry, we extend a class of SO(10) models to predict well known cold dark matter candidates while achieving precision unification with experimentally testable proton lifetime. The most important prediction is a new radiative seesaw formula of Ma type accessible to accelerator tests while the essential small value of its quartic coupling also emerges naturally. This dominates over the high-scale seesaw contributions making a major impact on neutrino physics and dark matter, opening up high prospects as a theory of fermion masses.
2010.07941
Yu-Dai Tsai
Saeid Foroughi-Abari, Felix Kling, Yu-Dai Tsai
FORMOSA: Looking Forward to Millicharged Dark Sectors
9 pages, 3 figures. Para uma FORMOSA aventura!
Phys. Rev. D 104, 035014 (2021)
10.1103/PhysRevD.104.035014
FERMILAB-PUB-20-477-AE-PPD-T
hep-ph astro-ph.CO hep-ex
http://creativecommons.org/licenses/by-nc-sa/4.0/
We identify potentially the world's most sensitive location to search for millicharged particles in the 10 MeV to 100 GeV mass range: the forward region at the LHC. We propose constructing a scintillator-based experiment, FORward MicrOcharge SeArch (FORMOSA) in this location, and estimate the corresponding sensitivity projection. We show that FORMOSA can discover millicharged particles in a large and unexplored parameter space, and study strongly interacting dark matter that cannot be detected by ground-based direct-detection experiments. The newly proposed LHC Forward Physics Facility (FPF) provides an ideal structure to host the full FORMOSA experiment.
[ { "created": "Thu, 15 Oct 2020 18:00:00 GMT", "version": "v1" } ]
2021-08-25
[ [ "Foroughi-Abari", "Saeid", "" ], [ "Kling", "Felix", "" ], [ "Tsai", "Yu-Dai", "" ] ]
We identify potentially the world's most sensitive location to search for millicharged particles in the 10 MeV to 100 GeV mass range: the forward region at the LHC. We propose constructing a scintillator-based experiment, FORward MicrOcharge SeArch (FORMOSA) in this location, and estimate the corresponding sensitivity projection. We show that FORMOSA can discover millicharged particles in a large and unexplored parameter space, and study strongly interacting dark matter that cannot be detected by ground-based direct-detection experiments. The newly proposed LHC Forward Physics Facility (FPF) provides an ideal structure to host the full FORMOSA experiment.
0903.4201
Roman Pasechnik
V. A. Beylin, V. I. Kuksa, R. S. Pasechnik, G. M. Vereshkov
Neutralino-nucleon interaction in the Split SUSY scenario of the Dark Matter
18 pages, 4 figures, minor corrections made, references revised
Int.J.Mod.Phys.A24:6051-6069,2009
10.1142/S0217751X09047697
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Split SUSY scenario with light Higgsino states is treated as an application to the Dark Matter problem. We have considered the structure of the neutralino-nucleon interaction and calculated cross-section of the neutralino-nucleon scattering. The decay properties of the lightest chargino and next lightest neutralino are analyzed in details.
[ { "created": "Wed, 25 Mar 2009 17:19:32 GMT", "version": "v1" }, { "created": "Sat, 21 Nov 2009 14:51:13 GMT", "version": "v2" } ]
2010-01-21
[ [ "Beylin", "V. A.", "" ], [ "Kuksa", "V. I.", "" ], [ "Pasechnik", "R. S.", "" ], [ "Vereshkov", "G. M.", "" ] ]
The Split SUSY scenario with light Higgsino states is treated as an application to the Dark Matter problem. We have considered the structure of the neutralino-nucleon interaction and calculated cross-section of the neutralino-nucleon scattering. The decay properties of the lightest chargino and next lightest neutralino are analyzed in details.
2101.01226
Soumya Bhattacharyya
Soumya Bhattacharyya and Basudeb Dasgupta
Fast Flavor Oscillations of Astrophysical Neutrinos with $1,\,2,\,\ldots,\,\infty$ Crossings
25 pages, 6 figures
JCAP07(2021)023
10.1088/1475-7516/2021/07/023
TIFR/TH/20-47
hep-ph astro-ph.CO astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the early Universe, as well as in supernovae and merging neutron stars, neutrinos have such high densities that they affect each other and exhibit collective flavor oscillations. A crucial ingredient for fast collective flavor oscillations is that the electron lepton number (ELN) distribution changes its sign as a function of direction, i.e., has a zero crossing. We present a study in two dimensions and show how fast flavor oscillations depend on the ELN and its crossings. We show that a large number of crossings can inhibit flavor oscillations. This may be a natural self-limiting mechanism that stabilizes the flavor content of the dense neutrino gas in a vast majority of scenarios, especially the early Universe, where the angular distributions for all flavors are very similar and crossings occur mainly due to fluctuations.
[ { "created": "Mon, 4 Jan 2021 20:25:46 GMT", "version": "v1" } ]
2022-12-06
[ [ "Bhattacharyya", "Soumya", "" ], [ "Dasgupta", "Basudeb", "" ] ]
In the early Universe, as well as in supernovae and merging neutron stars, neutrinos have such high densities that they affect each other and exhibit collective flavor oscillations. A crucial ingredient for fast collective flavor oscillations is that the electron lepton number (ELN) distribution changes its sign as a function of direction, i.e., has a zero crossing. We present a study in two dimensions and show how fast flavor oscillations depend on the ELN and its crossings. We show that a large number of crossings can inhibit flavor oscillations. This may be a natural self-limiting mechanism that stabilizes the flavor content of the dense neutrino gas in a vast majority of scenarios, especially the early Universe, where the angular distributions for all flavors are very similar and crossings occur mainly due to fluctuations.
0805.0442
Giorgio Torrieri
Giorgio Torrieri, Igor Mishustin
Instability of Boost-invariant hydrodynamics with a QCD inspired bulk viscosity
Accepted for publication, Rapid Communication in Physical Review C Discussion extended, derivation and conclusions not changed
Phys.Rev.C78:021901,2008
10.1103/PhysRevC.78.021901
null
hep-ph astro-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We solve the relativistic Navier-Stokes equations with homogeneous boost-invariant boundary conditions, and perform a stability analysis of the solution. We show that, if the bulk viscosity has a peak around $T_c$ as inferred from QCD-based arguments, the background solution "freezes" at $T_c$ to a nearly constant temperature state. This state is however highly unstable with respect to certain inhomogeneous modes. Calculations show that these modes have enough time to blow up and tear the system into droplets. We conjecture that this is how freeze-out occurs in the QGP created in heavy ion collisions, and perhaps similar transitions in the early universe.
[ { "created": "Sun, 4 May 2008 20:35:13 GMT", "version": "v1" }, { "created": "Sat, 26 Jul 2008 09:32:26 GMT", "version": "v2" } ]
2008-11-26
[ [ "Torrieri", "Giorgio", "" ], [ "Mishustin", "Igor", "" ] ]
We solve the relativistic Navier-Stokes equations with homogeneous boost-invariant boundary conditions, and perform a stability analysis of the solution. We show that, if the bulk viscosity has a peak around $T_c$ as inferred from QCD-based arguments, the background solution "freezes" at $T_c$ to a nearly constant temperature state. This state is however highly unstable with respect to certain inhomogeneous modes. Calculations show that these modes have enough time to blow up and tear the system into droplets. We conjecture that this is how freeze-out occurs in the QGP created in heavy ion collisions, and perhaps similar transitions in the early universe.
0901.2693
Lianshou Liu
Yu Meiling, Xu Mingmei, Liu Zhengyou, Liu Lianshou
Model investigation on the probability of QGP formation in relativistic heavy ion collisions
4 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The formation probability of quark-gluon plasma in relativistic heavy ion collisions for colliding nuclei of different sizes is investigated in the framework of a bond percolation model. The results show that nuclei with sizes smaller than that of Pb or Au produce QGP with probability less than unity even at very high collision energies. The dependence of the QGP-formation probability on different nuclear sizes and on various centralities of Au-Au collision are presented.
[ { "created": "Sun, 18 Jan 2009 10:33:36 GMT", "version": "v1" } ]
2009-01-20
[ [ "Meiling", "Yu", "" ], [ "Mingmei", "Xu", "" ], [ "Zhengyou", "Liu", "" ], [ "Lianshou", "Liu", "" ] ]
The formation probability of quark-gluon plasma in relativistic heavy ion collisions for colliding nuclei of different sizes is investigated in the framework of a bond percolation model. The results show that nuclei with sizes smaller than that of Pb or Au produce QGP with probability less than unity even at very high collision energies. The dependence of the QGP-formation probability on different nuclear sizes and on various centralities of Au-Au collision are presented.
1309.6986
C. Pallis
R. Armillis, G. Lazarides, C. Pallis
Inflation, Leptogenesis, and Yukawa Quasi-Unification within a Supersymmetric Left-Right Model
20 pages including 4 figures
Phys. Rev. D 89, 065032 (2014)
10.1103/PhysRevD.89.065032
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A simple extension of the minimal left-right symmetric supersymmetric grand unified theory model is constructed by adding two pairs of superfields. This naturally violates the partial Yukawa unification predicted by the minimal model. After including supergravity corrections, we find that this extended model naturally supports hilltop F-term hybrid inflation along its trivial inflationary path with only a very mild tuning of the initial conditions. With a convenient choice of signs of the terms in the Kahler potential, we can reconcile the inflationary scale with the supersymmetric grand unified theory scale. All the current data on the inflationary observables are readily reproduced. Inflation is followed by non-thermal leptogenesis via the decay of the right-handed neutrinos emerging from the decay of the inflaton and any possible washout of the lepton asymmetry is avoided thanks to the violation of partial Yukawa unification. The extra superfields also assist us in reducing the reheat temperature so as to satisfy the gravitino constraint. The observed baryon asymmetry of the universe is naturally reproduced consistently with the neutrino oscillation parameters.
[ { "created": "Thu, 26 Sep 2013 17:38:55 GMT", "version": "v1" } ]
2014-03-26
[ [ "Armillis", "R.", "" ], [ "Lazarides", "G.", "" ], [ "Pallis", "C.", "" ] ]
A simple extension of the minimal left-right symmetric supersymmetric grand unified theory model is constructed by adding two pairs of superfields. This naturally violates the partial Yukawa unification predicted by the minimal model. After including supergravity corrections, we find that this extended model naturally supports hilltop F-term hybrid inflation along its trivial inflationary path with only a very mild tuning of the initial conditions. With a convenient choice of signs of the terms in the Kahler potential, we can reconcile the inflationary scale with the supersymmetric grand unified theory scale. All the current data on the inflationary observables are readily reproduced. Inflation is followed by non-thermal leptogenesis via the decay of the right-handed neutrinos emerging from the decay of the inflaton and any possible washout of the lepton asymmetry is avoided thanks to the violation of partial Yukawa unification. The extra superfields also assist us in reducing the reheat temperature so as to satisfy the gravitino constraint. The observed baryon asymmetry of the universe is naturally reproduced consistently with the neutrino oscillation parameters.
1602.06384
Ajay Kumar Rai
Zalak Shah, Kaushal Thakkar, Ajay Kumar Rai and P. C. Vinodkumar
Excited State Mass spectra of Singly Charmed Baryons
23 pages
Eur. Phys. J. A 52 (2016) 313
10.1140/epja/i2016-16313-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mass spectra of excited states of the singly charmed baryons are calculated using the hypercentral description of three body system. The baryon consist of a charm quark and light quarks (u, d and s) are studied in the framework of QCD motivated constituent quark model. The form of confinement potential is hyper coloumb plus power potential with potential index $\nu$, varying from 0.5 to 2.0. The first order correction to the confinement potential is also incorporated in this approach. The radial as well as orbital excited state masses of $\Sigma_{c}^{++}, \Sigma_{c}^+, \Sigma_{c}^0, \Xi_c^+, \Xi_c^0, \Lambda_c^+, \Omega_c^0$ baryons, are reported in this paper. We have incorporated spin-spin, spin-orbit and tensor interactions perturbatively in the present study. The semi-electronic decay of $\Omega_c$ and $\Xi_c$ are also calculated using the spectroscopic parameters of these baryons. The computed results are compared with other theoretical predictions as well as with the available experimental observations. We also construct the Regge trajectory in ($n_r$, $M^{2}$) and (J, $M^{2}$) plane for these baryons.
[ { "created": "Sat, 20 Feb 2016 09:09:18 GMT", "version": "v1" }, { "created": "Sat, 27 Feb 2016 08:35:58 GMT", "version": "v2" }, { "created": "Wed, 31 Aug 2016 07:12:01 GMT", "version": "v3" } ]
2016-10-13
[ [ "Shah", "Zalak", "" ], [ "Thakkar", "Kaushal", "" ], [ "Rai", "Ajay Kumar", "" ], [ "Vinodkumar", "P. C.", "" ] ]
Mass spectra of excited states of the singly charmed baryons are calculated using the hypercentral description of three body system. The baryon consist of a charm quark and light quarks (u, d and s) are studied in the framework of QCD motivated constituent quark model. The form of confinement potential is hyper coloumb plus power potential with potential index $\nu$, varying from 0.5 to 2.0. The first order correction to the confinement potential is also incorporated in this approach. The radial as well as orbital excited state masses of $\Sigma_{c}^{++}, \Sigma_{c}^+, \Sigma_{c}^0, \Xi_c^+, \Xi_c^0, \Lambda_c^+, \Omega_c^0$ baryons, are reported in this paper. We have incorporated spin-spin, spin-orbit and tensor interactions perturbatively in the present study. The semi-electronic decay of $\Omega_c$ and $\Xi_c$ are also calculated using the spectroscopic parameters of these baryons. The computed results are compared with other theoretical predictions as well as with the available experimental observations. We also construct the Regge trajectory in ($n_r$, $M^{2}$) and (J, $M^{2}$) plane for these baryons.
2211.08211
Manuel Pavon Valderrama
Zi-Ying Yang, Fang-Zheng Peng, Mao-Jun Yan, Mario S\'anchez S\'anchez, Manuel Pavon Valderrama
Molecular $P_{\psi}$ pentaquarks from light-meson exchange saturation
8 pages, 3 tables
null
null
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Theoretical predictions for the spectrum of heavy meson-baryon bound states are a fundamental tool for disentangling the nature of the different pentaquark states that have been observed in experimental facilities. Here we explore this spectrum in a phenomenological model that describes the heavy meson-baryon interaction in terms of a contact-range interaction, where the coupling strength is saturated by the exchange of light scalar and vector mesons, i.e. $\sigma$, $\rho$ and $\omega$ exchanges. Saturation determines the couplings modulo an unknown proportionality constant that can be calibrated from a molecular candidate. If we use the $P_{\psi}^N(4312)$ as input, we predict a series of molecular pentaquarks including the $P_{\psi}^N(4440)$ and $P_{\psi}^N(4457)$, the recent $P_{\psi s}^{\Lambda}(4338)$ and the $P_{\psi s}^{\Lambda}(4459)$.
[ { "created": "Tue, 15 Nov 2022 15:25:19 GMT", "version": "v1" } ]
2022-11-16
[ [ "Yang", "Zi-Ying", "" ], [ "Peng", "Fang-Zheng", "" ], [ "Yan", "Mao-Jun", "" ], [ "Sánchez", "Mario Sánchez", "" ], [ "Valderrama", "Manuel Pavon", "" ] ]
Theoretical predictions for the spectrum of heavy meson-baryon bound states are a fundamental tool for disentangling the nature of the different pentaquark states that have been observed in experimental facilities. Here we explore this spectrum in a phenomenological model that describes the heavy meson-baryon interaction in terms of a contact-range interaction, where the coupling strength is saturated by the exchange of light scalar and vector mesons, i.e. $\sigma$, $\rho$ and $\omega$ exchanges. Saturation determines the couplings modulo an unknown proportionality constant that can be calibrated from a molecular candidate. If we use the $P_{\psi}^N(4312)$ as input, we predict a series of molecular pentaquarks including the $P_{\psi}^N(4440)$ and $P_{\psi}^N(4457)$, the recent $P_{\psi s}^{\Lambda}(4338)$ and the $P_{\psi s}^{\Lambda}(4459)$.
hep-ph/9504252
Kim Maltman
Kim Maltman
Comparison of Chiral Perturbation Theory and QCD Sum Rule Results for Pseudoscalar Isoscalar-Isovector Mixing
14 pages, uses REVTEX Entire manuscript available as a ps file at http://www.physics.adelaide.edu.au/theory/home.html . Also available via anonymous ftp at ftp://adelphi.adelaide.edu.au/pub/theory/ADP-95-2.T169.ps To appear in Physics Letters B
Phys.Lett. B351 (1995) 56-63
10.1016/0370-2693(95)00319-G
ADP-95-2/T169
hep-ph nucl-th
null
The forms of the neutral, non-strange pseudoscalar propagator matrix and mixed axial current correlator, $\lngle0|T(A_\mu^3 A_\nu^8)|0\rangle$, are discussed at next-to-leading (one-loop) order in chiral perturbation theory, and the results compared to those obtained using QCD sum rules. This comparison provides a check of the truncations employed in the sum rule treatment of the current correlator. Values for the slope of the correlator with $q^2$ in the two approaches are found to differ by more than an order of magnitude and the source of this discrepancy is shown to be the incorrect chiral behavior of the sum rule result.
[ { "created": "Fri, 7 Apr 1995 03:32:46 GMT", "version": "v1" } ]
2009-10-28
[ [ "Maltman", "Kim", "" ] ]
The forms of the neutral, non-strange pseudoscalar propagator matrix and mixed axial current correlator, $\lngle0|T(A_\mu^3 A_\nu^8)|0\rangle$, are discussed at next-to-leading (one-loop) order in chiral perturbation theory, and the results compared to those obtained using QCD sum rules. This comparison provides a check of the truncations employed in the sum rule treatment of the current correlator. Values for the slope of the correlator with $q^2$ in the two approaches are found to differ by more than an order of magnitude and the source of this discrepancy is shown to be the incorrect chiral behavior of the sum rule result.
1204.1914
Dremin
I. M. Dremin
The real part of the elastic scattering amplitude at nonzero transferred momenta
8 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The model-independent solution of the s-channel unitarity condition for the imaginary part of the hadronic elastic scattering amplitude outside the diffraction peak allows to make conclusions about its real part at nonzero transferred momenta. The asymptotical properties of the ratio of the real to imaginary part of the amplitude are discussed. In particular, it is explicitly shown that the ratio changes its sign at a defnite value of the transferred momentum. Some comments concerning the present day experimental results about the behavior of the differential cross-section of elastic scattering outside the diffraction cone are given.
[ { "created": "Mon, 9 Apr 2012 16:10:48 GMT", "version": "v1" } ]
2012-04-10
[ [ "Dremin", "I. M.", "" ] ]
The model-independent solution of the s-channel unitarity condition for the imaginary part of the hadronic elastic scattering amplitude outside the diffraction peak allows to make conclusions about its real part at nonzero transferred momenta. The asymptotical properties of the ratio of the real to imaginary part of the amplitude are discussed. In particular, it is explicitly shown that the ratio changes its sign at a defnite value of the transferred momentum. Some comments concerning the present day experimental results about the behavior of the differential cross-section of elastic scattering outside the diffraction cone are given.
hep-ph/0403282
Mustafa Savci
T. M. Aliev, V. Bashiry, M. Savci
Polarized lepton pair forward-backward asymmetries in (B -> K^* l^+ l^-) decay beyond the standard model
29 pages, 18 figures, LaTeX formatted
JHEP 0405 (2004) 037
10.1088/1126-6708/2004/05/037
metu-phys-hep-0403011
hep-ph
null
We study the polarized lepton pair forward-backward asymmetries in (B -> K^* l^+ l^-) decay using a general, model independent form of the effective Hamiltonian. We present the general expression for nine double-polarization forward-backward asymmetries. It is shown that, the study of the forward-backward asymmetries of the doubly-polarized lepton pair is a very useful tool for establishing new physics beyond the standard model.
[ { "created": "Mon, 29 Mar 2004 16:48:14 GMT", "version": "v1" }, { "created": "Mon, 31 May 2004 14:08:13 GMT", "version": "v2" }, { "created": "Wed, 2 Jun 2004 09:50:03 GMT", "version": "v3" } ]
2009-11-10
[ [ "Aliev", "T. M.", "" ], [ "Bashiry", "V.", "" ], [ "Savci", "M.", "" ] ]
We study the polarized lepton pair forward-backward asymmetries in (B -> K^* l^+ l^-) decay using a general, model independent form of the effective Hamiltonian. We present the general expression for nine double-polarization forward-backward asymmetries. It is shown that, the study of the forward-backward asymmetries of the doubly-polarized lepton pair is a very useful tool for establishing new physics beyond the standard model.
2011.04694
Alexander Lind
Alexander Lind, Andrea Banfi
H1jet, a fast program to compute transverse momentum distributions
25 pages, 8 figures, published version
Eur. Phys. J. C 81, 72 (2021)
10.1140/epjc/s10052-020-08815-w
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present H1jet, a fast code that computes the total cross section and differential distribution in the transverse momentum of a colour singlet. In its current version, the program implements only leading-order $2\to 1$ and $2\to 2$ processes, but could be extended to higher orders. We discuss the processes implemented in H1jet, give detailed instructions on how to implement new processes, and perform comparisons to existing codes. This tool, mainly designed for theorists, can be fruitfully used to assess deviations of selected new physics models from the Standard Model behaviour, as well as to quickly obtain distributions of relevance for Standard Model phenomenology.
[ { "created": "Mon, 9 Nov 2020 19:18:49 GMT", "version": "v1" }, { "created": "Tue, 24 Nov 2020 16:51:02 GMT", "version": "v2" }, { "created": "Sat, 23 Jan 2021 18:18:28 GMT", "version": "v3" } ]
2021-01-26
[ [ "Lind", "Alexander", "" ], [ "Banfi", "Andrea", "" ] ]
We present H1jet, a fast code that computes the total cross section and differential distribution in the transverse momentum of a colour singlet. In its current version, the program implements only leading-order $2\to 1$ and $2\to 2$ processes, but could be extended to higher orders. We discuss the processes implemented in H1jet, give detailed instructions on how to implement new processes, and perform comparisons to existing codes. This tool, mainly designed for theorists, can be fruitfully used to assess deviations of selected new physics models from the Standard Model behaviour, as well as to quickly obtain distributions of relevance for Standard Model phenomenology.
0712.3732
Yuri V. Kovchegov
Yuri V. Kovchegov, Heribert Weigert
Collinear Singularities and Running Coupling Corrections to Gluon Production in CGC
35 pages, 16 figures; v2: minor corrections, references and figures added
Nucl.Phys.A807:158-189,2008
10.1016/j.nuclphysa.2008.04.008
null
hep-ph
null
We analyze the structure of running coupling corrections to the gluon production cross section in the projectile-nucleus collisions calculated in the Color Glass Condensate (CGC) framework. We argue that for the gluon production cross section (and for gluon transverse momentum spectra and multiplicity) the inclusion of running coupling corrections brings in collinear singularities due to final state splittings completely unaffected by CGC resummations. Hence, despite the saturation/CGC dynamics, the gluon production cross section is not infrared-safe. As usual, regularizing the singularities requires an infrared cutoff Lambda_coll that defines a resolution scale for gluons. We specifically show that the cutoff enters the gluon production cross section in the argument of the strong coupling constant alpha_s(Lambda_coll^2). We argue that for hadron production calculations one should be able to absorb the collinear divergence into a fragmentation function. The singular collinear terms in the gluon production cross section are shown not to contribute to the energy density of the produced matter, which is indeed an infrared-finite quantity.
[ { "created": "Fri, 21 Dec 2007 16:39:50 GMT", "version": "v1" }, { "created": "Fri, 25 Apr 2008 13:56:39 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kovchegov", "Yuri V.", "" ], [ "Weigert", "Heribert", "" ] ]
We analyze the structure of running coupling corrections to the gluon production cross section in the projectile-nucleus collisions calculated in the Color Glass Condensate (CGC) framework. We argue that for the gluon production cross section (and for gluon transverse momentum spectra and multiplicity) the inclusion of running coupling corrections brings in collinear singularities due to final state splittings completely unaffected by CGC resummations. Hence, despite the saturation/CGC dynamics, the gluon production cross section is not infrared-safe. As usual, regularizing the singularities requires an infrared cutoff Lambda_coll that defines a resolution scale for gluons. We specifically show that the cutoff enters the gluon production cross section in the argument of the strong coupling constant alpha_s(Lambda_coll^2). We argue that for hadron production calculations one should be able to absorb the collinear divergence into a fragmentation function. The singular collinear terms in the gluon production cross section are shown not to contribute to the energy density of the produced matter, which is indeed an infrared-finite quantity.
hep-ph/0012093
Yvonne Wong
Yvonne Y. Y. Wong
Relic neutrino asymmetry generation from $\nu_{\alpha}- \nu_s$ oscillations
3 pages, no figures, uses espcrc2.sty; Talk given at the Europhysics Neutrino Oscillation Workshop, Otranto, Italy, September 9-16, 2000, to appear in the Proceedings
Nucl.Phys.Proc.Suppl. 100 (2001) 363-365
10.1016/S0920-5632(01)01474-8
null
hep-ph
null
Active--sterile neutrino oscillations provide a mechanism by which large differences in the neutrino and antineutrino number densities can be created in the early universe. The quantum kinetic equations are employed in the study of these asymmetries, which, when solved analytically in the adiabatic limit, generate physically transparent evolution equations that are very useful for the understanding of the nature of the asymmetry growth.
[ { "created": "Fri, 8 Dec 2000 05:42:22 GMT", "version": "v1" } ]
2009-10-31
[ [ "Wong", "Yvonne Y. Y.", "" ] ]
Active--sterile neutrino oscillations provide a mechanism by which large differences in the neutrino and antineutrino number densities can be created in the early universe. The quantum kinetic equations are employed in the study of these asymmetries, which, when solved analytically in the adiabatic limit, generate physically transparent evolution equations that are very useful for the understanding of the nature of the asymmetry growth.
0706.4259
Paul Frampton
Paul H. Frampton and Thomas W. Kephart
Quiver Gauge Theory and Conformality at the TeV Scale
175 pages latex. Changes suggested by Physics Reports reviewer. Bibliography extended to include colleagues' suggestions
Phys.Rept.454:203-269,2008
10.1016/j.physrep.2007.09.005
null
hep-ph astro-ph gr-qc hep-th
null
This review describes the conformality approach to extending the standard model of particle phenomenology using an assumption of no conformal anomaly at high energy. Topics include quiver gauge theory, the conformality approach to phenomenology, strong-electroweak unification at 4 TeV, cancellation of quadratic divergences, cancellation of U(1) anomalies, and a dark matter candidate.
[ { "created": "Thu, 28 Jun 2007 15:56:26 GMT", "version": "v1" }, { "created": "Mon, 10 Sep 2007 18:55:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Frampton", "Paul H.", "" ], [ "Kephart", "Thomas W.", "" ] ]
This review describes the conformality approach to extending the standard model of particle phenomenology using an assumption of no conformal anomaly at high energy. Topics include quiver gauge theory, the conformality approach to phenomenology, strong-electroweak unification at 4 TeV, cancellation of quadratic divergences, cancellation of U(1) anomalies, and a dark matter candidate.
hep-ph/0611051
Takashi Inoue
Takahi Inoue
A pentaquark model for Lambda(1405)
4 pages, 2 figures, espcrc1, Proceedings of the 18th International IUPAP Conference on Few-Body Problems in Physics, FB18, held in Santos, Brazil, on August 21-16, 2006
null
10.1016/j.nuclphysa.2007.03.172
null
hep-ph
null
We study a pentaquark model of the negative parity hyperon Lambda(1405). We choose a specific quark configuration for trial, and use the perturbative chiral quark model extended to four quarks and one anti-quark system. We calculate a sigma-term and a scalar form factor of the hyperon and demonstrate their usefulness to study the nature of the hyperon.
[ { "created": "Sat, 4 Nov 2006 08:24:36 GMT", "version": "v1" } ]
2009-11-11
[ [ "Inoue", "Takahi", "" ] ]
We study a pentaquark model of the negative parity hyperon Lambda(1405). We choose a specific quark configuration for trial, and use the perturbative chiral quark model extended to four quarks and one anti-quark system. We calculate a sigma-term and a scalar form factor of the hyperon and demonstrate their usefulness to study the nature of the hyperon.
1610.04489
Mateo Garcia Pepin
Mateo Garcia-Pepin
Light Stops from extra dimensions
4 pages, 2 figures. To appear in the proceedings of the 28th Rencontres de Blois on Particle Physics and Cosmology, May 29 - June 03, 2016. Based on arXiv:1608.06470
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In supersymmetric models the mass of the stops can be considered as the naturalness measure of the theory. Roughly, the lighter the stops are, the more natural the theory is. Both, the absence of supersymmetric signals at experiment and the measurement of the Higgs mass, put scenarios with light stops under increasing tension. I will present a supersymmetry breaking mechanism of the Scherk-Schwarz type that, by introducing extra $SU(2)_L$ triplets in the Higgs sector, is able to generate the correct Higgs mass while keeping stops light.
[ { "created": "Fri, 14 Oct 2016 14:58:29 GMT", "version": "v1" } ]
2016-10-17
[ [ "Garcia-Pepin", "Mateo", "" ] ]
In supersymmetric models the mass of the stops can be considered as the naturalness measure of the theory. Roughly, the lighter the stops are, the more natural the theory is. Both, the absence of supersymmetric signals at experiment and the measurement of the Higgs mass, put scenarios with light stops under increasing tension. I will present a supersymmetry breaking mechanism of the Scherk-Schwarz type that, by introducing extra $SU(2)_L$ triplets in the Higgs sector, is able to generate the correct Higgs mass while keeping stops light.
1805.09345
Eric Kuflik
Yonit Hochberg, Eric Kuflik, Hitoshi Murayama
Twin SIMPs
7 pages, 4 figures
Phys. Rev. D 99, 015005 (2019)
10.1103/PhysRevD.99.015005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hierarchy problem and the identity of dark matter are two of the central driving forces in particle physics. Twin Higgs models provide an elegant solution to the little hierarchy problem, while Strongly Interacting Massive Particles (SIMPs) provide an appealing dark matter candidate. Here we show that SIMPs can easily be embedded in the Twin Higgs setup, such that dark matter and the hierarchy problem can be addressed in a single framework. This also provides a natural explanation to the proximity between the confinement scale of SIMP dark matter and the strong scale of QCD.
[ { "created": "Wed, 23 May 2018 18:00:11 GMT", "version": "v1" } ]
2019-01-09
[ [ "Hochberg", "Yonit", "" ], [ "Kuflik", "Eric", "" ], [ "Murayama", "Hitoshi", "" ] ]
The hierarchy problem and the identity of dark matter are two of the central driving forces in particle physics. Twin Higgs models provide an elegant solution to the little hierarchy problem, while Strongly Interacting Massive Particles (SIMPs) provide an appealing dark matter candidate. Here we show that SIMPs can easily be embedded in the Twin Higgs setup, such that dark matter and the hierarchy problem can be addressed in a single framework. This also provides a natural explanation to the proximity between the confinement scale of SIMP dark matter and the strong scale of QCD.
1701.06877
Peter H. L. Christiansen
Peter Christiansen
High $p_{\rm T}$ spectra and anisotropy of light and heavy hadrons
5 pages, 2 figures, proceeding for Hard Probes 2016
null
null
null
hep-ph nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Data driven studies of heavy-ion results has played a big role in highlighting interesting features of these complex systems. In this proceeding, a simple QGP-brick interpretation of the $R_{\rm AA}$ and $v_{2}$ at high $p_{\rm T}$ ($p_{\rm T} \approx 10$ GeV/c) is presented. This interpretation draws attention to two fundamental questions: is there an effect of the asymmetric QGP expansion on the $v_{2}$ at high $p_{\rm T}$? is there an energy loss difference between quarks and gluons? Finally, it is discussed how these studies can be extended using Event-Shape Engineering and how they can be applied to compare the energy loss of light and heavy quarks.
[ { "created": "Tue, 24 Jan 2017 14:00:24 GMT", "version": "v1" } ]
2017-01-25
[ [ "Christiansen", "Peter", "" ] ]
Data driven studies of heavy-ion results has played a big role in highlighting interesting features of these complex systems. In this proceeding, a simple QGP-brick interpretation of the $R_{\rm AA}$ and $v_{2}$ at high $p_{\rm T}$ ($p_{\rm T} \approx 10$ GeV/c) is presented. This interpretation draws attention to two fundamental questions: is there an effect of the asymmetric QGP expansion on the $v_{2}$ at high $p_{\rm T}$? is there an energy loss difference between quarks and gluons? Finally, it is discussed how these studies can be extended using Event-Shape Engineering and how they can be applied to compare the energy loss of light and heavy quarks.
1110.0843
Wolfgang Altmannshofer
Wolfgang Altmannshofer and Marcela Carena
B Meson Mixing in Effective Theories of Supersymmetric Higgs Bosons
14 pages, 3 figures. v2: discussion on EDMs and MFV expansion extended, references added, version to be published in PRD
null
10.1103/PhysRevD.85.075006
FERMILAB-PUB-11-509-T, EFI-11-29
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a minimal flavor violating extension of the MSSM, where higher dimensional operators in the Kahler potential induce tree level non-holomorphic Higgs couplings that are controlled by the scale of the physics beyond the MSSM, and analyze their possible impact on CP violation in Bs and Bd mixing. We consider results on the time dependent CP asymmetries in Bs --> psi phi and Bs --> psi f_0 from LHCb, in Bs --> psi phi from CDF and D0 and in B --> psi K_S from the B factories as well as the measurement of an anomalous like-sign dimuon charge asymmetry at D0. Taking into account the stringent bounds on the branching ratio of the rare Bs --> mu+mu- decay, we investigate to which extent the framework allows to address the observed (2-3)sigma discrepancies in fits of the unitarity triangle. We find that a non-standard Bd mixing phase, that is in agreement with the current bounds on CP violation in Bs mixing, requires the presence of higher dimensional operators both in the Kahler potential and the superpotential. The corresponding region of parameter space is characterized by small tan(beta)~5, a light Higgs spectrum with masses below ~400 GeV and will be probed by future measurements at LHCb.
[ { "created": "Tue, 4 Oct 2011 20:29:43 GMT", "version": "v1" }, { "created": "Mon, 12 Mar 2012 20:06:29 GMT", "version": "v2" } ]
2013-05-30
[ [ "Altmannshofer", "Wolfgang", "" ], [ "Carena", "Marcela", "" ] ]
We study a minimal flavor violating extension of the MSSM, where higher dimensional operators in the Kahler potential induce tree level non-holomorphic Higgs couplings that are controlled by the scale of the physics beyond the MSSM, and analyze their possible impact on CP violation in Bs and Bd mixing. We consider results on the time dependent CP asymmetries in Bs --> psi phi and Bs --> psi f_0 from LHCb, in Bs --> psi phi from CDF and D0 and in B --> psi K_S from the B factories as well as the measurement of an anomalous like-sign dimuon charge asymmetry at D0. Taking into account the stringent bounds on the branching ratio of the rare Bs --> mu+mu- decay, we investigate to which extent the framework allows to address the observed (2-3)sigma discrepancies in fits of the unitarity triangle. We find that a non-standard Bd mixing phase, that is in agreement with the current bounds on CP violation in Bs mixing, requires the presence of higher dimensional operators both in the Kahler potential and the superpotential. The corresponding region of parameter space is characterized by small tan(beta)~5, a light Higgs spectrum with masses below ~400 GeV and will be probed by future measurements at LHCb.
2303.13551
Sergey Salnikov
S.G. Salnikov, A.I. Milstein
Natural explanation of recent results on $e^{+}e^{-}\to\Lambda\bar{\Lambda}$
3 pages, 1 figure
JETP Lett. 117, 905 (2023)
10.1134/S0021364023601471
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the recent experimental data on the cross section of the process $e^{+}e^{-}\to\Lambda\bar{\Lambda}$ near the threshold can be perfectly explained by the final-state interaction of $\Lambda$ and $\bar{\Lambda}$. The enhancement of the cross section is related to the existence of low-energy real or virtual state in the corresponding potential. We present a simple analytical formula that fits the experimental data very well.
[ { "created": "Wed, 22 Mar 2023 04:11:11 GMT", "version": "v1" }, { "created": "Fri, 12 May 2023 09:59:03 GMT", "version": "v2" } ]
2023-10-03
[ [ "Salnikov", "S. G.", "" ], [ "Milstein", "A. I.", "" ] ]
We show that the recent experimental data on the cross section of the process $e^{+}e^{-}\to\Lambda\bar{\Lambda}$ near the threshold can be perfectly explained by the final-state interaction of $\Lambda$ and $\bar{\Lambda}$. The enhancement of the cross section is related to the existence of low-energy real or virtual state in the corresponding potential. We present a simple analytical formula that fits the experimental data very well.
hep-ph/9812229
Seungwon Baek
Seungwon Baek and Pyungwon Ko
Probing SUSY-induced CP violations at B factories
4 pages, 2 figures. Version to appear in Phys. Rev. Lett
Phys.Rev.Lett.83:488-491,1999
10.1103/PhysRevLett.83.488
KAIST-TH 98/20, SNUTP 98-139
hep-ph
null
In the minimal supersymmetric standard model (MSSM), the \mu-parameter and the trilinear coupling A_t may be generically complex and can affect various observables at B factories. Imposing the edm constraints, we find that there is no new large phase shift in the B^0 - \bar{B^0} mixing, CP violating dilepton asymmetry is smaller than 0.1 %, and the direct CP violation in B\to X_s \gamma can be as large as \sim \pm 16 %.
[ { "created": "Wed, 2 Dec 1998 14:18:34 GMT", "version": "v1" }, { "created": "Wed, 9 Dec 1998 01:49:57 GMT", "version": "v2" }, { "created": "Fri, 9 Apr 1999 11:41:13 GMT", "version": "v3" }, { "created": "Sun, 13 Jun 1999 09:56:49 GMT", "version": "v4" } ]
2008-11-26
[ [ "Baek", "Seungwon", "" ], [ "Ko", "Pyungwon", "" ] ]
In the minimal supersymmetric standard model (MSSM), the \mu-parameter and the trilinear coupling A_t may be generically complex and can affect various observables at B factories. Imposing the edm constraints, we find that there is no new large phase shift in the B^0 - \bar{B^0} mixing, CP violating dilepton asymmetry is smaller than 0.1 %, and the direct CP violation in B\to X_s \gamma can be as large as \sim \pm 16 %.
hep-ph/0307277
Gustavo C. Branco
Gustavo C. Branco
CP Violation and New Physics
Invited talk at Workshop on the CKM Unitarity Triangle, IPPP Durham, April 2003. 8 pages, 1 figure
eConf C0304052 (2003) WG301
null
null
hep-ph
null
We describe some of the extensions of the SM, including models with spontaneous CP violation, where New Physics relevant for CP violation may arise. It is emphasized that the SM predicts a series of exact relations among various measurable quantities, such as moduli of CKM matrix elements and rephasing invariant phases. These exact relations provide a stringent test of the SM, with the potential to reveal New Physics.
[ { "created": "Tue, 22 Jul 2003 13:00:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Branco", "Gustavo C.", "" ] ]
We describe some of the extensions of the SM, including models with spontaneous CP violation, where New Physics relevant for CP violation may arise. It is emphasized that the SM predicts a series of exact relations among various measurable quantities, such as moduli of CKM matrix elements and rephasing invariant phases. These exact relations provide a stringent test of the SM, with the potential to reveal New Physics.
1205.5326
Frank Ndili Ph.D.
F. N. Ndili
Hierarchies of the 4 Texture Zero Quark Mass Matrices and their equal spacing rule
22 pages, no figures, no tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the parameters of the quark mass matrices M_u and M_d of a 4 texture zero model, exhibit an interesting hierarchical regularity we have called equal spacing rule, and that this regularity leads us to a further observation that the quark mass matrices (M_u, M_d) appear to exist in a plurality of states, each state labelled by two numbers (N,k). We give interpretation to these observations.
[ { "created": "Thu, 24 May 2012 04:17:16 GMT", "version": "v1" } ]
2012-05-25
[ [ "Ndili", "F. N.", "" ] ]
We show that the parameters of the quark mass matrices M_u and M_d of a 4 texture zero model, exhibit an interesting hierarchical regularity we have called equal spacing rule, and that this regularity leads us to a further observation that the quark mass matrices (M_u, M_d) appear to exist in a plurality of states, each state labelled by two numbers (N,k). We give interpretation to these observations.
hep-ph/9708360
Dietrich Bodeker
D. B"odeker
Real Time Correlation Functions at Finite Temperature and their Classical Limit
6 pages, Talk given at the E"otv"os Conference in Science: Strong and Electroweak Matter, Eger, Hungary, 21-25 May 1997
null
null
HD-THEP-97-43
hep-ph
null
In order to investigate the reliability of the classical approximation for non-perturbative real time correlation functions at finite temperature we study the two-point correlator for the anharmonic oscillator. For moderately large times the classical limit gives a good approximation of the quantum result but after some time $t_*$ the classical approximation breaks down even at high temperature.
[ { "created": "Fri, 15 Aug 1997 09:10:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "B\"odeker", "D.", "" ] ]
In order to investigate the reliability of the classical approximation for non-perturbative real time correlation functions at finite temperature we study the two-point correlator for the anharmonic oscillator. For moderately large times the classical limit gives a good approximation of the quantum result but after some time $t_*$ the classical approximation breaks down even at high temperature.
hep-ph/0311069
Kunihiko Terasaki
K. Terasaki
On the charmed scalar resonances
4 pages, 0 figures, Revtex
null
null
YITP-03-75
hep-ph
null
It is discussed that a newly observed broad bump around 2.3 GeV in the D\pi mass distribution can include two scalar resonances, and is predicted that a broad scalar resonance can be observed around 2.45 GeV in the DK channels.
[ { "created": "Thu, 6 Nov 2003 05:14:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Terasaki", "K.", "" ] ]
It is discussed that a newly observed broad bump around 2.3 GeV in the D\pi mass distribution can include two scalar resonances, and is predicted that a broad scalar resonance can be observed around 2.45 GeV in the DK channels.
1408.0278
Adam Kardos
Adam Kardos and Zolt\'an Tr\'ocs\'anyi
Hadroproduction of t anti-t pair with two isolated photons with PowHel
18 pages, 11 figures, minor changes, version submitted for publication
null
10.1016/j.nuclphysb.2015.05.032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We simulate the hadroproduction of a t anti-t pair in association with two isolated hard photons at 13 TeV LHC using the PowHel package. We use the generated events, stored according to the Les-Houches event format, to make predictions for differential distributions formally at the next-to-leading order (NLO) accuracy. We present predictions at the hadron level employing the cone-type isolation of the photons used by experiments. We also compare the kinematic distributions to the same distributions obtained in the t anti-t H final state when the Higgs-boson decays into a photon pair, to which the process discussed here is an irreducible background.
[ { "created": "Fri, 1 Aug 2014 19:59:57 GMT", "version": "v1" }, { "created": "Mon, 18 May 2015 21:26:32 GMT", "version": "v2" } ]
2015-12-09
[ [ "Kardos", "Adam", "" ], [ "Trócsányi", "Zoltán", "" ] ]
We simulate the hadroproduction of a t anti-t pair in association with two isolated hard photons at 13 TeV LHC using the PowHel package. We use the generated events, stored according to the Les-Houches event format, to make predictions for differential distributions formally at the next-to-leading order (NLO) accuracy. We present predictions at the hadron level employing the cone-type isolation of the photons used by experiments. We also compare the kinematic distributions to the same distributions obtained in the t anti-t H final state when the Higgs-boson decays into a photon pair, to which the process discussed here is an irreducible background.
2407.19355
Selcuk Bilmis
T.M.Aliev, S.Bilmis, M.Savci
Determination of the multipole moments of the $J^P = 3^-$ mesons via QCD sum rules
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The multipole moments of the $J^P = 3^-$ tensor mesons are obtained using the light cone sum rules. Our results on multipole moments are compared with the predictions of light-cone helicity formalism within SU(3) flavor symmetry, and it is observed that the results in both approaches are quite compatible with each other. The obtained multipole moments of tensor mesons provide deeper insights into their properties and understanding of the strong and electromagnetic decay channels of these mesons.
[ { "created": "Sun, 28 Jul 2024 00:31:51 GMT", "version": "v1" } ]
2024-07-30
[ [ "Aliev", "T. M.", "" ], [ "Bilmis", "S.", "" ], [ "Savci", "M.", "" ] ]
The multipole moments of the $J^P = 3^-$ tensor mesons are obtained using the light cone sum rules. Our results on multipole moments are compared with the predictions of light-cone helicity formalism within SU(3) flavor symmetry, and it is observed that the results in both approaches are quite compatible with each other. The obtained multipole moments of tensor mesons provide deeper insights into their properties and understanding of the strong and electromagnetic decay channels of these mesons.
2011.13946
Lorenzo Tancredi
Fabrizio Caola, Andreas von Manteuffel, Lorenzo Tancredi
Di-photon amplitudes in three-loop Quantum Chromodynamics
10 pages, 2 figures, results in the ancillary files
Phys. Rev. Lett. 126, 112004 (2021)
10.1103/PhysRevLett.126.112004
MSUHEP-20-018, OUTP-20-12P
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the three-loop scattering amplitudes for the production of a pair of photons in quark-antiquark annihilation in Quantum Chromodynamics (QCD). We use suitably defined projectors to efficiently calculate all helicity amplitudes. We obtain relatively compact analytic results, that we write in terms of harmonic polylogarithms or, alternatively, multiple polylogarithms of up to depth three. This is the first calculation of a three-loop four-point scattering amplitude in full QCD.
[ { "created": "Fri, 27 Nov 2020 19:00:03 GMT", "version": "v1" } ]
2021-03-24
[ [ "Caola", "Fabrizio", "" ], [ "von Manteuffel", "Andreas", "" ], [ "Tancredi", "Lorenzo", "" ] ]
We consider the three-loop scattering amplitudes for the production of a pair of photons in quark-antiquark annihilation in Quantum Chromodynamics (QCD). We use suitably defined projectors to efficiently calculate all helicity amplitudes. We obtain relatively compact analytic results, that we write in terms of harmonic polylogarithms or, alternatively, multiple polylogarithms of up to depth three. This is the first calculation of a three-loop four-point scattering amplitude in full QCD.
hep-ph/0306032
Andrei I. Onishchenko
J.G.Korner, A.I.Onishchenko, A.A.Petrov, A.A.Pivovarov
B0 - anti-B0 mixing beyond factorization
4 pages, 3 figures, LaTeX2e
Phys.Rev.Lett.91:192002,2003
10.1103/PhysRevLett.91.192002
MZ-TH/03-08, WSU-HEP-0305
hep-ph
null
We present a calculation of the B0 - anti-B0 mixing matrix element in the framework of QCD sum rules for three-point functions. We compute alpha_s corrections to a three-point function at the three-loop level in QCD perturbation theory, which allows one to extract the matrix element with next-to-leading order (NLO) accuracy. This calculation is imperative for a consistent evaluation of experimentally-measured mixing parameters since the coefficient functions of the effective Hamiltonian for B0 - anti-B0 mixing are known at NLO. We find that radiative corrections violate factorization at NLO; this violation is under full control and amounts to 10%.
[ { "created": "Tue, 3 Jun 2003 21:27:15 GMT", "version": "v1" } ]
2014-11-17
[ [ "Korner", "J. G.", "" ], [ "Onishchenko", "A. I.", "" ], [ "Petrov", "A. A.", "" ], [ "Pivovarov", "A. A.", "" ] ]
We present a calculation of the B0 - anti-B0 mixing matrix element in the framework of QCD sum rules for three-point functions. We compute alpha_s corrections to a three-point function at the three-loop level in QCD perturbation theory, which allows one to extract the matrix element with next-to-leading order (NLO) accuracy. This calculation is imperative for a consistent evaluation of experimentally-measured mixing parameters since the coefficient functions of the effective Hamiltonian for B0 - anti-B0 mixing are known at NLO. We find that radiative corrections violate factorization at NLO; this violation is under full control and amounts to 10%.
hep-ph/0602176
Ma Yong-Liang
Yong-Liang Ma, Qing Wang and Yue-Liang Wu
Anomalous Action of QCD from the General Quark Propagator
25 pages
null
null
null
hep-ph
null
The anomalous action of the chiral effective theory to $\mathcal{O}(p^4)$ is investigated by generalizing the consideration in \cite{ma02} with including the wave function part in the general quark propagator. It is found that the QCD dynamics dependence of the Wess-Zumino term is explicit and this dependence means that the QCD chiral symmetry must be broken dynamically in the low energy region for dynamically generating the Wess-Zumino term. In addition, we found that the next to leading order anomalous action in the momentum expansion of the chiral perturbation theory is gauge invariant and QCD dynamics dependent.
[ { "created": "Mon, 20 Feb 2006 04:19:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ma", "Yong-Liang", "" ], [ "Wang", "Qing", "" ], [ "Wu", "Yue-Liang", "" ] ]
The anomalous action of the chiral effective theory to $\mathcal{O}(p^4)$ is investigated by generalizing the consideration in \cite{ma02} with including the wave function part in the general quark propagator. It is found that the QCD dynamics dependence of the Wess-Zumino term is explicit and this dependence means that the QCD chiral symmetry must be broken dynamically in the low energy region for dynamically generating the Wess-Zumino term. In addition, we found that the next to leading order anomalous action in the momentum expansion of the chiral perturbation theory is gauge invariant and QCD dynamics dependent.
0710.5274
Zhi-Gang Wang
Zhi-Gang Wang, Zhi-Bin Wang
Analysis of the vertex $D^*D^* \rho$ with the light-cone QCD sum rules
6 pages, 1 figure, revised version
Chin.Phys.Lett.25:444-446,2008
10.1088/0256-307X/25/2/025
null
hep-ph
null
In this article, we analyze the vertex $D^*D^*\rho$ with the light-cone QCD sum rules. The strong coupling constant $g_{D^*D^*\rho}$ is an important parameter in evaluating the charmonium absorption cross sections in searching for the quark-gluon plasmas. Our numerical value for the $g_{D^*D^*\rho}$ is consistent with the prediction of the effective SU(4) symmetry and vector meson dominance theory.
[ { "created": "Sun, 28 Oct 2007 09:45:03 GMT", "version": "v1" }, { "created": "Sat, 15 Dec 2007 08:30:48 GMT", "version": "v2" } ]
2008-11-26
[ [ "Wang", "Zhi-Gang", "" ], [ "Wang", "Zhi-Bin", "" ] ]
In this article, we analyze the vertex $D^*D^*\rho$ with the light-cone QCD sum rules. The strong coupling constant $g_{D^*D^*\rho}$ is an important parameter in evaluating the charmonium absorption cross sections in searching for the quark-gluon plasmas. Our numerical value for the $g_{D^*D^*\rho}$ is consistent with the prediction of the effective SU(4) symmetry and vector meson dominance theory.
1504.08093
Sibo Zheng
Sibo Zheng
Can Higgs Inflation be Saved with High-scale Supersymmetry ?
Revtex, 5 page; journal version, references added
Eur. Phys. J. C 75 (2015) 489
10.1140/epjc/s10052-015-3721-1
null
hep-ph astro-ph.CO hep-ex
http://creativecommons.org/licenses/by/4.0/
It is shown whether Higgs inflation can be saved with high-scale supersymmetry critically depends on the magnitude of non-minimal coupling constant $\xi$. For small $\xi \leq 500$, the threshold correction at scale $M_{P}/\xi$ is constrained in high precision.Its magnitude is in the narrow range of $(-0.03, -0.02)$ and $(-0.05, -0.04)$ for the wino and higgsino/singlino dark matter, respectively. While in the large $\xi$-region with $\xi \geq 10^{4}$, such high-scale supersymmetry is excluded by too large threshold correction as required by Higgs inflation.
[ { "created": "Thu, 30 Apr 2015 06:48:44 GMT", "version": "v1" }, { "created": "Wed, 7 Oct 2015 08:10:17 GMT", "version": "v2" } ]
2015-10-16
[ [ "Zheng", "Sibo", "" ] ]
It is shown whether Higgs inflation can be saved with high-scale supersymmetry critically depends on the magnitude of non-minimal coupling constant $\xi$. For small $\xi \leq 500$, the threshold correction at scale $M_{P}/\xi$ is constrained in high precision.Its magnitude is in the narrow range of $(-0.03, -0.02)$ and $(-0.05, -0.04)$ for the wino and higgsino/singlino dark matter, respectively. While in the large $\xi$-region with $\xi \geq 10^{4}$, such high-scale supersymmetry is excluded by too large threshold correction as required by Higgs inflation.
hep-ph/0510303
Joseph Towe
J. Towe
SUGRA interactions within flavor triplets
5 pages, 2 figures
null
null
null
hep-ph
null
A specific new quark permits that flavor generations constitute a representation of the 3-dimensional SU(3) symmetry that characterizes the Z(3) orbifold. In this context, color and supergravity bind triplets and 4-tuplets into composite fields of spin 3/2 and spin 2; and the symmetry E(8) that characterizes (the observable sector of) 10-spacetime is interpreted as having reduced to SU(5)XSU(3), where SU(3) refers to the 3-dimensional symmetry described above and SU(5) consists of colors and of isotopic spin classes that are devoid of color and hypercharge. In this context, supergravity interactions occur to color bound quarks that are experiencing asymptotic freedom within triplets. Quark-lepton transitions are produced, but quickly reverse, preserving the triplets. The symmetry consisting of six quark classes and six lepton classes is also maintained because the predicted quark is an anomalous, left-handed version of the strange quark.
[ { "created": "Sun, 23 Oct 2005 04:13:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Towe", "J.", "" ] ]
A specific new quark permits that flavor generations constitute a representation of the 3-dimensional SU(3) symmetry that characterizes the Z(3) orbifold. In this context, color and supergravity bind triplets and 4-tuplets into composite fields of spin 3/2 and spin 2; and the symmetry E(8) that characterizes (the observable sector of) 10-spacetime is interpreted as having reduced to SU(5)XSU(3), where SU(3) refers to the 3-dimensional symmetry described above and SU(5) consists of colors and of isotopic spin classes that are devoid of color and hypercharge. In this context, supergravity interactions occur to color bound quarks that are experiencing asymptotic freedom within triplets. Quark-lepton transitions are produced, but quickly reverse, preserving the triplets. The symmetry consisting of six quark classes and six lepton classes is also maintained because the predicted quark is an anomalous, left-handed version of the strange quark.
hep-ph/9904226
Valeri Yudichev
M. K. Volkov, V. L. Yudichev (JINR, Russia)
Excited scalar mesons in a chiral quark model
LaTeX, 1 figure, minor misprints eradicated
Int.J.Mod.Phys. A14 (1999) 4621-4640
10.1142/S0217751X99002165
E2-99-89
hep-ph
null
First radial excitations of the isoscalar and isovector scalar mesons f_0(400-1200), f_0(980) and a_0(980) are investigated in the framework of a nonlocal version of a chiral quark model of the Nambu--Jona-Lasinio type. It is shown that f_0(1370), f_J(1710) and a_0(1450) are the first radially excited states of f_0(400-1200), f_0(980) and a_0(980) which are ground states of the scalar meson nonet. The mesons' masses and strong decay widths are calculated. The scalar resonance f_0(1500) is supposed to be a glueball. The status of K_0^*(1430) is discussed.
[ { "created": "Mon, 5 Apr 1999 13:09:24 GMT", "version": "v1" }, { "created": "Wed, 7 Apr 1999 17:21:17 GMT", "version": "v2" } ]
2009-10-31
[ [ "Volkov", "M. K.", "", "JINR, Russia" ], [ "Yudichev", "V. L.", "", "JINR, Russia" ] ]
First radial excitations of the isoscalar and isovector scalar mesons f_0(400-1200), f_0(980) and a_0(980) are investigated in the framework of a nonlocal version of a chiral quark model of the Nambu--Jona-Lasinio type. It is shown that f_0(1370), f_J(1710) and a_0(1450) are the first radially excited states of f_0(400-1200), f_0(980) and a_0(980) which are ground states of the scalar meson nonet. The mesons' masses and strong decay widths are calculated. The scalar resonance f_0(1500) is supposed to be a glueball. The status of K_0^*(1430) is discussed.
2405.19399
Richard Ruiz
Benjamin Fuks, Fotis Marugas, Richard Ruiz, Alicja Sztandera
Hard processes in multi-TeV ion collisions
44 pages total, 18 figures (54 eps and pdf files), 4 long tables. comments welcome!
null
null
IFJPAN-IV-2024-7, COMETA-2024-09
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Motivated by the ion-collision program at the Large Hadron Collider, plans for its high-luminosity upgrade, and on-going discussions for multi-TeV future hadron colliders, we systematically investigate hard-scattering, Standard Model processes in many-TeV ion-ion collisions. We focus on the symmetric beam configurations $^{208}$Pb-$^{208}$Pb, $^{131}$Xe-$^{131}$Xe, $^{12}$C-$^{12}$C, and $pp$, and we catalog total and fiducial cross sections for dozens of processes, ranging from associated-Higgs and multiboson production to associated-top pair production, at next-to-leading order in QCD for nucleon-nucleon collision energies from $\sqrt{s_{NN}}=1$ to $100$ TeV. We report the residual scale uncertainties at this order as well as the uncertainties originating from fits of nuclear parton densities. We also discuss the propagation of nuclear dynamics (as encoded in nuclear parton densities) into parton luminosities, and ultimately into predictions for cross sections. Finally, we report on the emergence of trends and the reliability of extrapolating cross sections across different nuclei.
[ { "created": "Wed, 29 May 2024 18:00:01 GMT", "version": "v1" } ]
2024-05-31
[ [ "Fuks", "Benjamin", "" ], [ "Marugas", "Fotis", "" ], [ "Ruiz", "Richard", "" ], [ "Sztandera", "Alicja", "" ] ]
Motivated by the ion-collision program at the Large Hadron Collider, plans for its high-luminosity upgrade, and on-going discussions for multi-TeV future hadron colliders, we systematically investigate hard-scattering, Standard Model processes in many-TeV ion-ion collisions. We focus on the symmetric beam configurations $^{208}$Pb-$^{208}$Pb, $^{131}$Xe-$^{131}$Xe, $^{12}$C-$^{12}$C, and $pp$, and we catalog total and fiducial cross sections for dozens of processes, ranging from associated-Higgs and multiboson production to associated-top pair production, at next-to-leading order in QCD for nucleon-nucleon collision energies from $\sqrt{s_{NN}}=1$ to $100$ TeV. We report the residual scale uncertainties at this order as well as the uncertainties originating from fits of nuclear parton densities. We also discuss the propagation of nuclear dynamics (as encoded in nuclear parton densities) into parton luminosities, and ultimately into predictions for cross sections. Finally, we report on the emergence of trends and the reliability of extrapolating cross sections across different nuclei.
1012.3527
Edmond Iancu
Edmond Iancu
Parton branching and medium-induced radiation in a strongly coupled plasma
4 pages, based on a talk presented at Hard Probes 2010, October 10-15, Eilat, Israel
null
10.1016/j.nuclphysa.2011.02.072
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review the parton picture at strong coupling emerging from the gauge/gravity duality together with its consequences for the energy loss and momentum broadening of a heavy quark moving through a strongly coupled plasma.
[ { "created": "Thu, 16 Dec 2010 07:46:10 GMT", "version": "v1" } ]
2015-05-20
[ [ "Iancu", "Edmond", "" ] ]
I review the parton picture at strong coupling emerging from the gauge/gravity duality together with its consequences for the energy loss and momentum broadening of a heavy quark moving through a strongly coupled plasma.
2312.14119
Drona Vatsyayan
Alessio Giarnetti, Juan Herrero-Garcia, Simone Marciano, Davide Meloni, Drona Vatsyayan
Neutrino masses from new seesaw models: Low-scale variants and phenomenological implications
30 pages, 6 figures, 9 tables. Submitted with a companion paper; v2: Typos corrected, matches published version
Eur. Phys. J. C 84, 803 (2024)
10.1140/epjc/s10052-024-13149-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With just the Standard Model Higgs doublet, there are only three types of seesaw models that generate light Majorana neutrino masses at tree level after electroweak spontaneous symmetry breaking. However, if there exist additional TeV scalars acquiring vacuum expectation values, coupled with heavier fermionic multiplets, several new seesaw models become possible. These new seesaws are the primary focus of this study and correspond to the tree-level ultraviolet completions of the effective operators studied in a companion publication. We are interested in the genuine cases, in which the standard seesaw contributions are absent. In addition to the tree-level generation of neutrino masses, we also consider the one-loop contributions. Furthermore, we construct low-energy versions that exhibit a very rich phenomenology. Specifically, we scrutinise the generation of dimension-6 operators and explore their implications, including non-unitarity of the leptonic mixing matrix, non-universal $Z-$boson interactions, and lepton flavor violation. Finally, we provide (Generalised) Scotogenic-like variants that incorporate viable dark matter candidates.
[ { "created": "Thu, 21 Dec 2023 18:42:52 GMT", "version": "v1" }, { "created": "Mon, 12 Aug 2024 15:47:59 GMT", "version": "v2" } ]
2024-08-13
[ [ "Giarnetti", "Alessio", "" ], [ "Herrero-Garcia", "Juan", "" ], [ "Marciano", "Simone", "" ], [ "Meloni", "Davide", "" ], [ "Vatsyayan", "Drona", "" ] ]
With just the Standard Model Higgs doublet, there are only three types of seesaw models that generate light Majorana neutrino masses at tree level after electroweak spontaneous symmetry breaking. However, if there exist additional TeV scalars acquiring vacuum expectation values, coupled with heavier fermionic multiplets, several new seesaw models become possible. These new seesaws are the primary focus of this study and correspond to the tree-level ultraviolet completions of the effective operators studied in a companion publication. We are interested in the genuine cases, in which the standard seesaw contributions are absent. In addition to the tree-level generation of neutrino masses, we also consider the one-loop contributions. Furthermore, we construct low-energy versions that exhibit a very rich phenomenology. Specifically, we scrutinise the generation of dimension-6 operators and explore their implications, including non-unitarity of the leptonic mixing matrix, non-universal $Z-$boson interactions, and lepton flavor violation. Finally, we provide (Generalised) Scotogenic-like variants that incorporate viable dark matter candidates.
hep-ph/9504424
Arnd Brandenburg
H. Anlauf, W. Bernreuther and A. Brandenburg
Probing Higgs Sector CP Violation with Top Quarks at a Photon Linear Collider
13 pages, plain TeX; 6 figures available upon request from arndb@axpwb.physik.rwth-aachen.de
Phys.Rev.D52:3803,1995; Erratum-ibid.D53:1725,1996; Phys.Rev.D53:1725,1996
10.1103/PhysRevD.52.3803 10.1103/PhysRevD.53.1725
null
hep-ph
null
We investigate for two-Higgs doublet models with intrinsic CP violation in the scalar potential CP-nonconserving effects in unpolarized $\gamma \gamma \rightarrow t \bar{t} $ for a range of neutral Higgs boson masses which includes resonant $\varphi$ production and the subsequent decay of $\varphi \rightarrow t \bar{t}$. The importance of taking into account, even in the resonant case, the interference with the nonresonant background is shown. Further, we propose and calculate three asymmetries which efficiently trace CP-violating effects in $\gamma \gamma \rightarrow t \bar{t} $ using semileptonic $t \bar{t}$ decays.
[ { "created": "Fri, 28 Apr 1995 13:53:00 GMT", "version": "v1" } ]
2014-11-17
[ [ "Anlauf", "H.", "" ], [ "Bernreuther", "W.", "" ], [ "Brandenburg", "A.", "" ] ]
We investigate for two-Higgs doublet models with intrinsic CP violation in the scalar potential CP-nonconserving effects in unpolarized $\gamma \gamma \rightarrow t \bar{t} $ for a range of neutral Higgs boson masses which includes resonant $\varphi$ production and the subsequent decay of $\varphi \rightarrow t \bar{t}$. The importance of taking into account, even in the resonant case, the interference with the nonresonant background is shown. Further, we propose and calculate three asymmetries which efficiently trace CP-violating effects in $\gamma \gamma \rightarrow t \bar{t} $ using semileptonic $t \bar{t}$ decays.
hep-ph/9312247
Gunter Sigl
Xiangdong Shi and Guenter Sigl
A Type II Supernovae Constraint on $\nu_e$-$\nu_s$
plain Tex 11 pages, 3 figures available upon request from the authors. (shi6@oddjob.uchicago.edu, sigl@oddjob)
Phys.Lett.B323:360-366,1994; ERRATUM-ibid.B324:516,1994
10.1016/0370-2693(94)91232-7
null
hep-ph astro-ph
null
The role of a resonant $\nu_e$-$\nu_s$ oscillation is discussed in the event of a supernova explosion. It is concluded that a significant $\nu_e$-$\nu_s$ mixing may hinder the ability of the supernova to explode. It may also cool the proto-neutron star too quickly with respect to the observed cooling time of several seconds. The constraints on the $\nu_e$-$\nu_s$ mixing parameters based on the above arguments are calculated.
[ { "created": "Wed, 8 Dec 1993 22:19:21 GMT", "version": "v1" } ]
2011-06-10
[ [ "Shi", "Xiangdong", "" ], [ "Sigl", "Guenter", "" ] ]
The role of a resonant $\nu_e$-$\nu_s$ oscillation is discussed in the event of a supernova explosion. It is concluded that a significant $\nu_e$-$\nu_s$ mixing may hinder the ability of the supernova to explode. It may also cool the proto-neutron star too quickly with respect to the observed cooling time of several seconds. The constraints on the $\nu_e$-$\nu_s$ mixing parameters based on the above arguments are calculated.
0811.1387
Michael Kuchiev
Michael Kuchiev, Victor Flambaum, and Edward Shuryak
Light bound states of heavy fermions
null
Phys.Lett.B693:485-488,2010
10.1016/j.physletb.2010.08.076
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Standard Model, a group of heavy fermions, e.g. top quarks, can collectively strongly affect the Higgs field and create relatively long-lived bound states. If there exist new generations of fermions with masses beyond 1 TeV, strong binding of several of them can make them lighter than even a single heavy fermion. Using the mean field approximation we find multi-fermion states with masses M ~ 5 v N^{1/2} ~ 1.2 N^{1/2} TeV, with N=2,3... being the total number of heavy fermions bound together, and v=246 GeV the Higgs VEV. The experimental search for multi-fermions within the range of energies 2-3 Tev would either discover them, or suggest absence of new Standard Model fermions with larger masses. Possible implications related to multi-top states and baryonic asymmetry of the Universe are discussed.
[ { "created": "Mon, 10 Nov 2008 01:38:18 GMT", "version": "v1" } ]
2014-11-18
[ [ "Kuchiev", "Michael", "" ], [ "Flambaum", "Victor", "" ], [ "Shuryak", "Edward", "" ] ]
In the Standard Model, a group of heavy fermions, e.g. top quarks, can collectively strongly affect the Higgs field and create relatively long-lived bound states. If there exist new generations of fermions with masses beyond 1 TeV, strong binding of several of them can make them lighter than even a single heavy fermion. Using the mean field approximation we find multi-fermion states with masses M ~ 5 v N^{1/2} ~ 1.2 N^{1/2} TeV, with N=2,3... being the total number of heavy fermions bound together, and v=246 GeV the Higgs VEV. The experimental search for multi-fermions within the range of energies 2-3 Tev would either discover them, or suggest absence of new Standard Model fermions with larger masses. Possible implications related to multi-top states and baryonic asymmetry of the Universe are discussed.
0803.0494
Stefan Dittmaier
Z.Bern, S.Dittmaier, L.Dixon, G.Heinrich, J.Huston, B.Kersevan, Z.Kunszt, D.E.Soper (conveners), C.Bernicot, T.Binoth, F.Boudjema, R.Britto, J.Campbell, M.Czakon, A.Denner, G.Dissertori, G.Duplancic, R.K.Ellis, R.Frederix, T.Gehrmann, A.Gehrmann-De Ridder, W.T.Giele, E.W.N.Glover, J.P.Guillet, S.Kallweit, S.Karg, N.Kauer, D.A.Kosower, F.Krauss, N.D.Le, P.Mastrolia, A.Mitov, S.Moch, S.Odaka, G.Ossola, C.G.Papadopoulos, E.Pilon, R.Pittau, T.Reiter, G.Sanguinetti, S.Schumann, C.Schwinn, P.Z.Skands, H.Stenzel, P.Uwer, S.Weinzierl, G.Zanderighi
The NLO multileg working group: summary report
119 pages, latex, many figures, summary report of the NLO multileg working group of the Les Houches 2007 workshop "Physics at TeV Colliders", Les Houches, France, 11-29 June, 2007; some references added or corrected
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This report summarizes the activities of the NLM working group of the Workshop "Physics at TeV Colliders", Les Houches, France, 11-29 June, 2007.
[ { "created": "Tue, 4 Mar 2008 16:31:25 GMT", "version": "v1" }, { "created": "Mon, 10 Mar 2008 13:18:55 GMT", "version": "v2" } ]
2008-03-10
[ [ "Bern", "Z.", "", "conveners" ], [ "Dittmaier", "S.", "", "conveners" ], [ "Dixon", "L.", "", "conveners" ], [ "Heinrich", "G.", "", "conveners" ], [ "Huston", "J.", "", "conveners" ], [ "Kersevan", "B.", "", "conveners" ], [ "Kunszt", "Z.", "", "conveners" ], [ "Soper", "D. E.", "", "conveners" ], [ "Bernicot", "C.", "" ], [ "Binoth", "T.", "" ], [ "Boudjema", "F.", "" ], [ "Britto", "R.", "" ], [ "Campbell", "J.", "" ], [ "Czakon", "M.", "" ], [ "Denner", "A.", "" ], [ "Dissertori", "G.", "" ], [ "Duplancic", "G.", "" ], [ "Ellis", "R. K.", "" ], [ "Frederix", "R.", "" ], [ "Gehrmann", "T.", "" ], [ "Ridder", "A. Gehrmann-De", "" ], [ "Giele", "W. T.", "" ], [ "Glover", "E. W. N.", "" ], [ "Guillet", "J. P.", "" ], [ "Kallweit", "S.", "" ], [ "Karg", "S.", "" ], [ "Kauer", "N.", "" ], [ "Kosower", "D. A.", "" ], [ "Krauss", "F.", "" ], [ "Le", "N. D.", "" ], [ "Mastrolia", "P.", "" ], [ "Mitov", "A.", "" ], [ "Moch", "S.", "" ], [ "Odaka", "S.", "" ], [ "Ossola", "G.", "" ], [ "Papadopoulos", "C. G.", "" ], [ "Pilon", "E.", "" ], [ "Pittau", "R.", "" ], [ "Reiter", "T.", "" ], [ "Sanguinetti", "G.", "" ], [ "Schumann", "S.", "" ], [ "Schwinn", "C.", "" ], [ "Skands", "P. Z.", "" ], [ "Stenzel", "H.", "" ], [ "Uwer", "P.", "" ], [ "Weinzierl", "S.", "" ], [ "Zanderighi", "G.", "" ] ]
This report summarizes the activities of the NLM working group of the Workshop "Physics at TeV Colliders", Les Houches, France, 11-29 June, 2007.
1206.6764
Andrius Bernotas
Andrius Bernotas and Vytautas \v{S}imonis
Effect of the Casimir energy on the bag model phenomenology of light hadrons
23 pages, 4 figures and 7 tables
null
10.3952/lithjphys.52310
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The dependence of light hadron masses and baryon magnetic moments on the magnitude of the Casimir energy is examined in the bag model with center-of-mass corrections. There are seven free parameters in the model. Six of them are determined from the fit to the masses of certain hadrons, and the last one (Casimir energy parameter) from the best fit to the magnetic moments of light baryons. The predicted magnetic moments are compared with the results obtained in various other models and with experiment data.
[ { "created": "Thu, 28 Jun 2012 17:07:39 GMT", "version": "v1" }, { "created": "Mon, 30 Jul 2012 11:26:06 GMT", "version": "v2" } ]
2015-06-05
[ [ "Bernotas", "Andrius", "" ], [ "Šimonis", "Vytautas", "" ] ]
The dependence of light hadron masses and baryon magnetic moments on the magnitude of the Casimir energy is examined in the bag model with center-of-mass corrections. There are seven free parameters in the model. Six of them are determined from the fit to the masses of certain hadrons, and the last one (Casimir energy parameter) from the best fit to the magnetic moments of light baryons. The predicted magnetic moments are compared with the results obtained in various other models and with experiment data.
hep-ph/0302017
Luis G. Cabral-Rosetti
Alexis A. Aguilar-Arevalo, L. G. Cabral-Rosetti and J. C. D'Olivo
Magnus Expansion and Three-Neutrino Oscillations in Matter
RevTex4 style, 5 pages including 5 figures. Presented at Mexican School of Astrophysics 2002, Guanajuato, Mexico, 31 Jul - 7 Aug 2002. Final version to appear in the Proceedings of IX Mexican Workshop on Particles and Fields Physics Beyond the Standard Model, Colima Col. Mexico, November 17-22, 2003
J.Phys.Conf.Ser. 37 (2006) 161
10.1088/1742-6596/37/1/028
null
hep-ph
null
We present a semi-analytical derivation of the survival probability of solar neutrinos in the three generation scheme, based on the Magnus approximation of the evolution operator of a three level system, and assuming a mass hierarchy among neutrino mass eigenstates. We have used an exponential profile for the solar electron density in our approximation. The different interesting density regions that appear throughout the propagation are analyzed. Finally, some comments on the allowed regions in the solar neutrino parameter space are addressed.
[ { "created": "Mon, 3 Feb 2003 23:08:03 GMT", "version": "v1" }, { "created": "Fri, 7 Feb 2003 22:48:34 GMT", "version": "v2" }, { "created": "Sat, 12 Nov 2005 17:27:23 GMT", "version": "v3" } ]
2009-11-10
[ [ "Aguilar-Arevalo", "Alexis A.", "" ], [ "Cabral-Rosetti", "L. G.", "" ], [ "D'Olivo", "J. C.", "" ] ]
We present a semi-analytical derivation of the survival probability of solar neutrinos in the three generation scheme, based on the Magnus approximation of the evolution operator of a three level system, and assuming a mass hierarchy among neutrino mass eigenstates. We have used an exponential profile for the solar electron density in our approximation. The different interesting density regions that appear throughout the propagation are analyzed. Finally, some comments on the allowed regions in the solar neutrino parameter space are addressed.
hep-ph/0004155
null
G. Cvetic, S. K. Kang, C. S. Kim, K. Lee
No CPT Violation from Tilted Brane in Neutral Meson--Antimeson Systems
5 pages, RevTex
Phys.Rev.D62:057901,2000
10.1103/PhysRevD.62.057901
null
hep-ph gr-qc hep-ex hep-th
null
Tilted brane in theories with large compact extra dimensions leads to spontaneous symmetry breaking of the Lorentz and rotational invariance in four dimensions, as shown by Dvali and Shifman. In this brief report, we point out that the mentioned Lorentz symmetry breaking, although leading to the CPT--violating interaction terms, cannot lead to the CPT violation in the experimentally interesting $K$--${\bar K}$ and analogous systems.
[ { "created": "Mon, 17 Apr 2000 05:21:19 GMT", "version": "v1" } ]
2008-12-18
[ [ "Cvetic", "G.", "" ], [ "Kang", "S. K.", "" ], [ "Kim", "C. S.", "" ], [ "Lee", "K.", "" ] ]
Tilted brane in theories with large compact extra dimensions leads to spontaneous symmetry breaking of the Lorentz and rotational invariance in four dimensions, as shown by Dvali and Shifman. In this brief report, we point out that the mentioned Lorentz symmetry breaking, although leading to the CPT--violating interaction terms, cannot lead to the CPT violation in the experimentally interesting $K$--${\bar K}$ and analogous systems.
2404.04644
Zhang Liang
Tingfei Li, Yuekai Song, Liang Zhang
Solve arbitrary one-loop reduction with generating function
30 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, the concept of generating function has been employed in one-loop reduction. For one-loop integrals encompassing arbitrary tensor ranks and higher-pole contributions, the generating function can be decomposed into a tensor part and a higher-pole part. While the tensor component has been thoroughly addressed in recent studies, there remains a lack of satisfactory investigations regarding the higher-pole part. In this work, we completely solve the problem. We first establish the partial differential equations governing the higher-pole generating function. Based on these equations, we derive an integration recursion relation and solve it iteratively. This approach enables us to explore the analytical structure of higher-pole reduction and provides a valuable tool for generating reduction coefficients efficiently.
[ { "created": "Sat, 6 Apr 2024 14:34:35 GMT", "version": "v1" }, { "created": "Wed, 10 Apr 2024 10:51:32 GMT", "version": "v2" } ]
2024-04-11
[ [ "Li", "Tingfei", "" ], [ "Song", "Yuekai", "" ], [ "Zhang", "Liang", "" ] ]
Recently, the concept of generating function has been employed in one-loop reduction. For one-loop integrals encompassing arbitrary tensor ranks and higher-pole contributions, the generating function can be decomposed into a tensor part and a higher-pole part. While the tensor component has been thoroughly addressed in recent studies, there remains a lack of satisfactory investigations regarding the higher-pole part. In this work, we completely solve the problem. We first establish the partial differential equations governing the higher-pole generating function. Based on these equations, we derive an integration recursion relation and solve it iteratively. This approach enables us to explore the analytical structure of higher-pole reduction and provides a valuable tool for generating reduction coefficients efficiently.
1601.04241
Wei Wang
Cai-Dian L\"u, Wei Wang, Fu-Sheng Yu
Test Flavor SU(3) symmetry in Exclusive $\Lambda_c$ decays
8 pages, 1 figure
Phys. Rev. D 93, 056008 (2016)
10.1103/PhysRevD.93.056008
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavor SU(3) symmetry is a powerful tool to analyze charmed baryon decays, however its applicability remains to be experimentally validated. Since there is not much data on $\Xi_c$ decays, various exclusive $\Lambda_c$ decays especially the ones into a neutron state are essential for the test of flavor symmetry. These decay modes are also helpful to investigate final state interactions in charmed baryon decays. In this work, we discuss the explicit roles of $\Lambda_c$ decays into a neutron in testing the flavor symmetry and exploring final state interactions. The involved decay modes include semileptonic decays, two-body and three-body non-leptonic decays, but all of them have not been experimentally observed to date.
[ { "created": "Sun, 17 Jan 2016 03:35:19 GMT", "version": "v1" } ]
2016-03-30
[ [ "Lü", "Cai-Dian", "" ], [ "Wang", "Wei", "" ], [ "Yu", "Fu-Sheng", "" ] ]
Flavor SU(3) symmetry is a powerful tool to analyze charmed baryon decays, however its applicability remains to be experimentally validated. Since there is not much data on $\Xi_c$ decays, various exclusive $\Lambda_c$ decays especially the ones into a neutron state are essential for the test of flavor symmetry. These decay modes are also helpful to investigate final state interactions in charmed baryon decays. In this work, we discuss the explicit roles of $\Lambda_c$ decays into a neutron in testing the flavor symmetry and exploring final state interactions. The involved decay modes include semileptonic decays, two-body and three-body non-leptonic decays, but all of them have not been experimentally observed to date.
2312.11045
Nguyen Hua Thanh Nha
T.T. Hong, V. K. Le, L. T. T. Phuong, N .C. Hoi, N. T. K. Ngan, N. H. T. Nha
Decays of Standard Model like Higgs boson $h \rightarrow\gamma\gamma, Z \gamma$ in a minimal left-right symmetric model
23 pages, 6 figures
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
Two decay channels $h\rightarrow \gamma \gamma, Z\gamma$ of the Standard Model-like Higgs in a left-right symmetry model are investigated under recent experimental data. We will show there exist one-loop contributions that affect the $h\rightarrow Z\gamma$ amplitude, but not the $h\rightarrow \gamma\gamma$ amplitude. From numerical investigations, we show that the signal strength $\mu_{Z \gamma}$ of the decay $h\rightarrow Z\gamma$ is still constrained strictly by that of $h\rightarrow \gamma\gamma$, namely $|\Delta \mu_{\gamma \gamma}|<38\%$ results in max $|\Delta \mu_{Z \gamma}|<46\%$. On the other hand, the future experimental sensitivity $|\Delta \mu_{\gamma \gamma}|=4\%$ still allows $|\Delta \mu_{Z \gamma}|$ reaches to values larger than the expected sensitivity $|\Delta \mu_{Z \gamma}|=23\%$.
[ { "created": "Mon, 18 Dec 2023 09:19:43 GMT", "version": "v1" }, { "created": "Tue, 12 Mar 2024 01:53:58 GMT", "version": "v2" } ]
2024-03-13
[ [ "Hong", "T. T.", "" ], [ "Le", "V. K.", "" ], [ "Phuong", "L. T. T.", "" ], [ "Hoi", "N . C.", "" ], [ "Ngan", "N. T. K.", "" ], [ "Nha", "N. H. T.", "" ] ]
Two decay channels $h\rightarrow \gamma \gamma, Z\gamma$ of the Standard Model-like Higgs in a left-right symmetry model are investigated under recent experimental data. We will show there exist one-loop contributions that affect the $h\rightarrow Z\gamma$ amplitude, but not the $h\rightarrow \gamma\gamma$ amplitude. From numerical investigations, we show that the signal strength $\mu_{Z \gamma}$ of the decay $h\rightarrow Z\gamma$ is still constrained strictly by that of $h\rightarrow \gamma\gamma$, namely $|\Delta \mu_{\gamma \gamma}|<38\%$ results in max $|\Delta \mu_{Z \gamma}|<46\%$. On the other hand, the future experimental sensitivity $|\Delta \mu_{\gamma \gamma}|=4\%$ still allows $|\Delta \mu_{Z \gamma}|$ reaches to values larger than the expected sensitivity $|\Delta \mu_{Z \gamma}|=23\%$.
0909.0520
Rose Lerner
Rose N. Lerner and John McDonald
Gauge singlet scalar as inflaton and thermal relic dark matter
13 pages, 7 figures. Published version
Phys.Rev.D80:123507,2009
10.1103/PhysRevD.80.123507
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that, by adding a gauge singlet scalar S to the standard model which is nonminimally coupled to gravity, S can act both as the inflaton and as thermal relic dark matter. We obtain the allowed region of the (m_s, m_h) parameter space which gives a spectral index in agreement with observational bounds and also produces the observed dark matter density while not violating vacuum stability or nonperturbativity constraints. We show that, in contrast to the case of Higgs inflation, once quantum corrections are included the spectral index is significantly larger than the classical value (n = 0.966 for N = 60) for all allowed values of the Higgs mass m_h. The range of Higgs mass compatible with the constraints is 145 GeV < m_h < 170 GeV. The S mass lies in the range 45 GeV < ms < 1 TeV for the case of a real S scalar with large quartic self-coupling lambdas, with a smaller upper bound for smaller lambdas. A region of the parameter space is accessible to direct searches at the LHC via h-->SS, while future direct dark matter searches should be able to significantly constrain the model.
[ { "created": "Thu, 3 Sep 2009 15:44:02 GMT", "version": "v1" }, { "created": "Tue, 22 Sep 2009 14:48:48 GMT", "version": "v2" }, { "created": "Tue, 22 Dec 2009 12:51:31 GMT", "version": "v3" } ]
2009-12-22
[ [ "Lerner", "Rose N.", "" ], [ "McDonald", "John", "" ] ]
We show that, by adding a gauge singlet scalar S to the standard model which is nonminimally coupled to gravity, S can act both as the inflaton and as thermal relic dark matter. We obtain the allowed region of the (m_s, m_h) parameter space which gives a spectral index in agreement with observational bounds and also produces the observed dark matter density while not violating vacuum stability or nonperturbativity constraints. We show that, in contrast to the case of Higgs inflation, once quantum corrections are included the spectral index is significantly larger than the classical value (n = 0.966 for N = 60) for all allowed values of the Higgs mass m_h. The range of Higgs mass compatible with the constraints is 145 GeV < m_h < 170 GeV. The S mass lies in the range 45 GeV < ms < 1 TeV for the case of a real S scalar with large quartic self-coupling lambdas, with a smaller upper bound for smaller lambdas. A region of the parameter space is accessible to direct searches at the LHC via h-->SS, while future direct dark matter searches should be able to significantly constrain the model.
1308.5784
Christoph Englert
S. Y. Choi, C. Englert, and P. M. Zerwas
Multiple Higgs-Portal and Gauge-Kinetic Mixings
22 pages, 8 figures, published version
null
10.1140/epjc/s10052-013-2643-z
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a phenomenological formalism for mixing effects between the Standard Model and hidden-sector fields, motivated by dark matter in the Universe as well as string theories. The scheme includes multiple Higgs-portal interactions in the scalar sector as well as multiple gauge-kinetic mixings in the abelian gauge sector. While some of the mixing effects can be cast in closed form, other elements can be controlled analytically only by means of perturbative expansions in the ratio of standard scales over large hidden scales. Higgs and vector-boson masses and mixings are illustrated numerically for characteristic processes.
[ { "created": "Tue, 27 Aug 2013 07:55:05 GMT", "version": "v1" }, { "created": "Tue, 29 Oct 2013 10:02:26 GMT", "version": "v2" } ]
2015-06-17
[ [ "Choi", "S. Y.", "" ], [ "Englert", "C.", "" ], [ "Zerwas", "P. M.", "" ] ]
We develop a phenomenological formalism for mixing effects between the Standard Model and hidden-sector fields, motivated by dark matter in the Universe as well as string theories. The scheme includes multiple Higgs-portal interactions in the scalar sector as well as multiple gauge-kinetic mixings in the abelian gauge sector. While some of the mixing effects can be cast in closed form, other elements can be controlled analytically only by means of perturbative expansions in the ratio of standard scales over large hidden scales. Higgs and vector-boson masses and mixings are illustrated numerically for characteristic processes.
1712.05312
Dave Dunbar
David C. Dunbar, John H Godwin, Guy R. Jehu and Warren B. Perkins
Analytic results for two-loop Yang-Mills
Talk presented at 13th International Symposium on Radiative Corrections, 24-29 September, 2017,St. Gilgen, Austria, 9 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent Developments in computing very specific helicity amplitudes in two loop QCD are presented. The techniques focus upon the singular structure of the amplitude rather than on a diagramatic and integration approach
[ { "created": "Thu, 14 Dec 2017 16:13:32 GMT", "version": "v1" } ]
2017-12-15
[ [ "Dunbar", "David C.", "" ], [ "Godwin", "John H", "" ], [ "Jehu", "Guy R.", "" ], [ "Perkins", "Warren B.", "" ] ]
Recent Developments in computing very specific helicity amplitudes in two loop QCD are presented. The techniques focus upon the singular structure of the amplitude rather than on a diagramatic and integration approach
2206.01575
Geng Li
Geng Li, Chia-Wei Liu, Chao-Qiang Geng
Bottomed baryon decays with invisible Majorana fermions
18 pages, 29 figures
null
10.1103/PhysRevD.106.115007
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the invisible Majorana fermions of $\chi$ in bottomed baryon decays with flavor-changing neutral currents (FCNCs) based on the model-independent effective Lagrangian between the quarks and invisible particles. From the bounds of the coupling constants extracted from the experiments, we examine the decay branching ratios of $\Lambda_b\to\Lambda\chi\chi$, $\Xi_b^{0(-)}\to\Xi^{0(-)}\chi\chi$, $\Lambda_b\to n \chi\chi$, $\Xi_b^{-}\to \Sigma^{-} \chi\chi$, $\Xi_b^{0}\to \Sigma^{0} \chi\chi$, and $\Xi_b^{0}\to \Lambda \chi\chi$, which can be as large as $6.3,~9.2,~5.7,~5.8,~2.7$, and $1.0\times10^{-5}$ for $m_\chi=2$ GeV, respectively. Some of these decays are accessible to the future experimental searches, such as Belle II.
[ { "created": "Fri, 3 Jun 2022 13:57:29 GMT", "version": "v1" }, { "created": "Sat, 10 Dec 2022 03:55:09 GMT", "version": "v2" } ]
2022-12-13
[ [ "Li", "Geng", "" ], [ "Liu", "Chia-Wei", "" ], [ "Geng", "Chao-Qiang", "" ] ]
We study the invisible Majorana fermions of $\chi$ in bottomed baryon decays with flavor-changing neutral currents (FCNCs) based on the model-independent effective Lagrangian between the quarks and invisible particles. From the bounds of the coupling constants extracted from the experiments, we examine the decay branching ratios of $\Lambda_b\to\Lambda\chi\chi$, $\Xi_b^{0(-)}\to\Xi^{0(-)}\chi\chi$, $\Lambda_b\to n \chi\chi$, $\Xi_b^{-}\to \Sigma^{-} \chi\chi$, $\Xi_b^{0}\to \Sigma^{0} \chi\chi$, and $\Xi_b^{0}\to \Lambda \chi\chi$, which can be as large as $6.3,~9.2,~5.7,~5.8,~2.7$, and $1.0\times10^{-5}$ for $m_\chi=2$ GeV, respectively. Some of these decays are accessible to the future experimental searches, such as Belle II.
hep-ph/0506245
Matthias Neubert
Matthias Neubert (Cornell University)
Advanced Predictions for Moments of the B->X_s+gamma Photon Spectrum
28 pages, 3 figures. Experimental data updated and correlations included in the fit; typos in eqs. (38) and (47) corrected. Version to appear in Phys. Rev. D
Phys.Rev. D72 (2005) 074025
10.1103/PhysRevD.72.074025
CLNS-04/1904
hep-ph
null
Based on a new, exact QCD factorization formula for the partial B->X_s+gamma decay rate with a restriction on large photon energy, improved predictions are presented for the partial moments <E_gamma> and <E_gamma^2>-<E_gamma>^2 of the photon spectrum defined with a cut E_gamma>E_0. In the region where Delta=m_b-2E_0 is large compared with Lambda_{QCD}, a theoretical description without recourse to shape functions can be obtained. However, for Delta<<m_b it is important to separate short-distance contributions arising from different scales. The leading terms in the heavy-quark expansion of the moments receive contributions from the scales Delta and \sqrt{m_b Delta} only, but not from the hard scale m_b. For these terms, a complete scale separation is achieved at next-to-next-to-leading order in renormalization-group improved perturbation theory, including two-loop matching contributions and three-loop running. The results presented here can be used to extract the b-quark mass and the quantity mu_pi^2 with excellent theoretical precision. A fit to experimental data reported by the Belle Collaboration yields m_b^{SF}=(4.62+-0.10_{exp}+-0.03_{th})GeV and mu_pi^{2,SF}=(0.11+-0.19_{exp}+-0.08_{th})GeV^2 in the shape-function scheme at a scale mu_f=1.5GeV, while m_b^{kin}=(4.54+-0.11_{exp}+-0.04_{th})GeV and mu_pi^{2,kin}=(0.49+-0.18_{exp}+-0.09_{th})GeV^2 in the kinetic scheme at a scale mu_f=1GeV.
[ { "created": "Fri, 24 Jun 2005 00:47:36 GMT", "version": "v1" }, { "created": "Fri, 23 Sep 2005 08:18:25 GMT", "version": "v2" } ]
2009-11-11
[ [ "Neubert", "Matthias", "", "Cornell University" ] ]
Based on a new, exact QCD factorization formula for the partial B->X_s+gamma decay rate with a restriction on large photon energy, improved predictions are presented for the partial moments <E_gamma> and <E_gamma^2>-<E_gamma>^2 of the photon spectrum defined with a cut E_gamma>E_0. In the region where Delta=m_b-2E_0 is large compared with Lambda_{QCD}, a theoretical description without recourse to shape functions can be obtained. However, for Delta<<m_b it is important to separate short-distance contributions arising from different scales. The leading terms in the heavy-quark expansion of the moments receive contributions from the scales Delta and \sqrt{m_b Delta} only, but not from the hard scale m_b. For these terms, a complete scale separation is achieved at next-to-next-to-leading order in renormalization-group improved perturbation theory, including two-loop matching contributions and three-loop running. The results presented here can be used to extract the b-quark mass and the quantity mu_pi^2 with excellent theoretical precision. A fit to experimental data reported by the Belle Collaboration yields m_b^{SF}=(4.62+-0.10_{exp}+-0.03_{th})GeV and mu_pi^{2,SF}=(0.11+-0.19_{exp}+-0.08_{th})GeV^2 in the shape-function scheme at a scale mu_f=1.5GeV, while m_b^{kin}=(4.54+-0.11_{exp}+-0.04_{th})GeV and mu_pi^{2,kin}=(0.49+-0.18_{exp}+-0.09_{th})GeV^2 in the kinetic scheme at a scale mu_f=1GeV.
hep-ph/0506171
Christian Weiss
M. Diehl, W. Kugler, A. Schaefer, C. Weiss
Exclusive channels in semi-inclusive production of pions and kaons
33 pages, 18 figures
Phys.Rev.D72:034034,2005; Erratum-ibid.D72:059902,2005
10.1103/PhysRevD.72.034034 10.1103/PhysRevD.72.059902
DESY-05-094, JLAB-THY-05-375
hep-ph
null
We investigate the role of exclusive channels in semi-inclusive electroproduction of pions and kaons. Using the QCD factorization theorem for hard exclusive processes we evaluate the cross sections for exclusive pseudoscalar and vector meson production in terms of generalized parton distributions and meson distribution amplitudes. We investigate the uncertainties arising from the modeling of the nonperturbative input quantities. Combining these results with available experimental data, we compare the cross sections for exclusive channels to that obtained from quark fragmentation in semi-inclusive deep inelastic scattering. We find that rho^0 production is the only exclusive channel with significant contributions to semi-inclusive pion production at large z and moderate Q^2. The corresponding contribution to kaon production from the decay of exclusively produced phi and K^* is rather small.
[ { "created": "Thu, 16 Jun 2005 21:48:40 GMT", "version": "v1" } ]
2014-11-18
[ [ "Diehl", "M.", "" ], [ "Kugler", "W.", "" ], [ "Schaefer", "A.", "" ], [ "Weiss", "C.", "" ] ]
We investigate the role of exclusive channels in semi-inclusive electroproduction of pions and kaons. Using the QCD factorization theorem for hard exclusive processes we evaluate the cross sections for exclusive pseudoscalar and vector meson production in terms of generalized parton distributions and meson distribution amplitudes. We investigate the uncertainties arising from the modeling of the nonperturbative input quantities. Combining these results with available experimental data, we compare the cross sections for exclusive channels to that obtained from quark fragmentation in semi-inclusive deep inelastic scattering. We find that rho^0 production is the only exclusive channel with significant contributions to semi-inclusive pion production at large z and moderate Q^2. The corresponding contribution to kaon production from the decay of exclusively produced phi and K^* is rather small.
hep-ph/0305264
Vicari
Francesco Parisen Toldin, Andrea Pelissetto, Ettore Vicari
The 3-D O(4) universality class and the phase transition in two-flavor QCD
19 pages, 5 figs
JHEP 0307:029,2003
10.1088/1126-6708/2003/07/029
null
hep-ph hep-lat
null
We determine the critical equation of state of the three-dimensional O(4) universality class. We first consider the small-field expansion of the effective potential (Helmholtz free energy). Then, we apply a systematic approximation scheme based on polynomial parametric representations that are valid in the whole critical regime, satisfy the correct analytic properties (Griffiths' analyticity), take into account the Goldstone singularities at the coexistence curve, and match the small-field expansion of the effective potential. From the approximate representations of the equation of state, we obtain estimates of several universal amplitude ratios. The three-dimensional O(4) universality class is expected to describe the finite-temperature chiral transition of quantum chromodynamics with two light flavors. Within this picture, the O(4) critical equation of state relates the reduced temperature, the quark masses, and the condensates around T_c in the limit of vanishing quark masses.
[ { "created": "Fri, 23 May 2003 13:18:35 GMT", "version": "v1" }, { "created": "Sat, 24 May 2003 06:39:54 GMT", "version": "v2" } ]
2014-11-17
[ [ "Toldin", "Francesco Parisen", "" ], [ "Pelissetto", "Andrea", "" ], [ "Vicari", "Ettore", "" ] ]
We determine the critical equation of state of the three-dimensional O(4) universality class. We first consider the small-field expansion of the effective potential (Helmholtz free energy). Then, we apply a systematic approximation scheme based on polynomial parametric representations that are valid in the whole critical regime, satisfy the correct analytic properties (Griffiths' analyticity), take into account the Goldstone singularities at the coexistence curve, and match the small-field expansion of the effective potential. From the approximate representations of the equation of state, we obtain estimates of several universal amplitude ratios. The three-dimensional O(4) universality class is expected to describe the finite-temperature chiral transition of quantum chromodynamics with two light flavors. Within this picture, the O(4) critical equation of state relates the reduced temperature, the quark masses, and the condensates around T_c in the limit of vanishing quark masses.
1805.09815
Sida Lu
Yang Bai, Sida Lu and Qian-Fei Xiang
Hexapod Coloron at the LHC
18 pages, 10 figures
null
10.1007/JHEP08(2018)200
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Instead of the usual dijet decay, the coloron may mainly decay into its own "Higgs bosons", which subsequently decay into many jets. This is a general feature of the renormalizable coloron model, where the corresponding "Higgs bosons" are a color-octet $\Theta$ and a color-singlet $\phi_I$. In this paper, we perform a detailed collider study for the signature of $pp \rightarrow G' \rightarrow (\Theta \rightarrow gg) (\phi_I \rightarrow gg q\bar{q})$ with the coloron $G'$ as a six-jet resonance. For a light $\phi_I$ below around 0.5 TeV, it may be boosted and behave as a four-prong fat jet. We also develop a jet-substructure-based search strategy to cover this boosted $\phi_I$ case. Independent of whether $\phi_I$ is boosted or not, the 13 TeV LHC with 100 fb$^{-1}$ has great discovery potential for a coloron with the mass sensitivity up to 5 TeV.
[ { "created": "Thu, 24 May 2018 17:55:45 GMT", "version": "v1" } ]
2018-09-26
[ [ "Bai", "Yang", "" ], [ "Lu", "Sida", "" ], [ "Xiang", "Qian-Fei", "" ] ]
Instead of the usual dijet decay, the coloron may mainly decay into its own "Higgs bosons", which subsequently decay into many jets. This is a general feature of the renormalizable coloron model, where the corresponding "Higgs bosons" are a color-octet $\Theta$ and a color-singlet $\phi_I$. In this paper, we perform a detailed collider study for the signature of $pp \rightarrow G' \rightarrow (\Theta \rightarrow gg) (\phi_I \rightarrow gg q\bar{q})$ with the coloron $G'$ as a six-jet resonance. For a light $\phi_I$ below around 0.5 TeV, it may be boosted and behave as a four-prong fat jet. We also develop a jet-substructure-based search strategy to cover this boosted $\phi_I$ case. Independent of whether $\phi_I$ is boosted or not, the 13 TeV LHC with 100 fb$^{-1}$ has great discovery potential for a coloron with the mass sensitivity up to 5 TeV.
1810.04048
Alper Hayreter
Alper Hayreter, German Valencia
Color-octet scalar decays to a gluon and an electroweak gauge boson in the Manohar-Wise model
17 pages, 7 Figures
Phys. Rev. D 102, 115033 (2020)
10.1103/PhysRevD.102.115033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present one loop results for the amplitudes giving rise to couplings between a color octet scalar, a gluon, and an electroweak gauge boson. These amplitudes could signal new physics in $\gamma$ jet, $Z$ jet and $W$ jet production at the LHC. We compute the relevant branching ratios and identify regions of parameter space where these decay modes become important. This can happen for scalar masses below the threshold for decay into heavy quark pairs ($t\bar t$ and $t\bar b$); or for small Yukawa couplings in which case the colored scalars are fermiophobic. In the case of light scalars, ${\cal B}(S\to \gamma g)$ can reach up to 10\% whereas ${\cal B}(S\to Z g)$ can reach a few percent. In the fermiophobic region of parameter space, ${\cal B}(S\to \gamma g)$ and ${\cal B}(S\to Z g)$ can reach up to 72\% and 28\% respectively, whereas ${\cal B}(S\to g g)$ can be 100\%. For the charged scalar, the decay mode ${\cal B}(S^\pm \to W^\pm g)$ can become dominant in both scenarios.
[ { "created": "Mon, 8 Oct 2018 09:56:50 GMT", "version": "v1" }, { "created": "Mon, 15 Oct 2018 11:05:04 GMT", "version": "v2" }, { "created": "Fri, 9 Oct 2020 11:15:44 GMT", "version": "v3" } ]
2021-01-04
[ [ "Hayreter", "Alper", "" ], [ "Valencia", "German", "" ] ]
We present one loop results for the amplitudes giving rise to couplings between a color octet scalar, a gluon, and an electroweak gauge boson. These amplitudes could signal new physics in $\gamma$ jet, $Z$ jet and $W$ jet production at the LHC. We compute the relevant branching ratios and identify regions of parameter space where these decay modes become important. This can happen for scalar masses below the threshold for decay into heavy quark pairs ($t\bar t$ and $t\bar b$); or for small Yukawa couplings in which case the colored scalars are fermiophobic. In the case of light scalars, ${\cal B}(S\to \gamma g)$ can reach up to 10\% whereas ${\cal B}(S\to Z g)$ can reach a few percent. In the fermiophobic region of parameter space, ${\cal B}(S\to \gamma g)$ and ${\cal B}(S\to Z g)$ can reach up to 72\% and 28\% respectively, whereas ${\cal B}(S\to g g)$ can be 100\%. For the charged scalar, the decay mode ${\cal B}(S^\pm \to W^\pm g)$ can become dominant in both scenarios.
hep-ph/0611160
HongWei Ke
Yan-Ming Yu, Hong-Wei Ke, Yi-Bing Ding, Xin-Heng Guo, Hong-Ying Jin, Xue-Qian Li, Peng-Nian Shen, and Guo-Li Wang
Study on the Form Factors at Effective Vertices of Diqarks Interacting with Gauge Bosons
16 pages, 6 figures
Int.J.Mod.Phys.A23:2975-2990,2008
10.1142/S0217751X08039815
null
hep-ph
null
The diquark structure in baryons is commonly accepted as a reasonable approximation which can much simplify the picture and reduce the length of calculations. However, a diquark by no means is a point-like particle, even though it is treated as a whole object. Therefore, to apply the diquark picture to the phenomenological calculations, at the effective vertices for the diquark-gauge boson interactions, suitable form factors must be introduced to compensate the effects caused by the inner structure of the diquark. It is crucial to derive the appropriate form factors for various interactions. In this work, we use the Bethe-Salpeter equation to derive such form factors and numerically evaluate their magnitudes.
[ { "created": "Sun, 12 Nov 2006 06:33:25 GMT", "version": "v1" }, { "created": "Tue, 26 Dec 2006 10:43:23 GMT", "version": "v2" } ]
2014-11-18
[ [ "Yu", "Yan-Ming", "" ], [ "Ke", "Hong-Wei", "" ], [ "Ding", "Yi-Bing", "" ], [ "Guo", "Xin-Heng", "" ], [ "Jin", "Hong-Ying", "" ], [ "Li", "Xue-Qian", "" ], [ "Shen", "Peng-Nian", "" ], [ "Wang", "Guo-Li", "" ] ]
The diquark structure in baryons is commonly accepted as a reasonable approximation which can much simplify the picture and reduce the length of calculations. However, a diquark by no means is a point-like particle, even though it is treated as a whole object. Therefore, to apply the diquark picture to the phenomenological calculations, at the effective vertices for the diquark-gauge boson interactions, suitable form factors must be introduced to compensate the effects caused by the inner structure of the diquark. It is crucial to derive the appropriate form factors for various interactions. In this work, we use the Bethe-Salpeter equation to derive such form factors and numerically evaluate their magnitudes.
0710.0343
Matti Jarvinen
M. Jarvinen
Spin asymmetry at large x_F and k_T
3 pages, 1 figure. Talk given at EPS HEP 2007, Manchester
J.Phys.Conf.Ser.110:022021,2008
10.1088/1742-6596/110/2/022021
null
hep-ph
null
We suggest that the large single spin asymmetries observed at high momentum fractions x_F and transverse momenta k_T of the pion in p^\uparrow p -> \pi(x_F,k_T)+X arise from the coherence of the soft interactions with the hard parton scattering process. Such coherence can be maintained if x_F -> 1 as k_T -> \infty, while k_T^2(1-x_F) ~ \Lambda_{QCD}^2 stays fixed. Analogous coherence effects have been seen experimentally in the Drell-Yan process at high x_F. We find that the p^\uparrow p -> \pi X production amplitudes have large dynamic phases and that helicity flip contributions are unsuppressed in this limit, giving rise to potentially large single spin asymmetries.
[ { "created": "Mon, 1 Oct 2007 17:30:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Jarvinen", "M.", "" ] ]
We suggest that the large single spin asymmetries observed at high momentum fractions x_F and transverse momenta k_T of the pion in p^\uparrow p -> \pi(x_F,k_T)+X arise from the coherence of the soft interactions with the hard parton scattering process. Such coherence can be maintained if x_F -> 1 as k_T -> \infty, while k_T^2(1-x_F) ~ \Lambda_{QCD}^2 stays fixed. Analogous coherence effects have been seen experimentally in the Drell-Yan process at high x_F. We find that the p^\uparrow p -> \pi X production amplitudes have large dynamic phases and that helicity flip contributions are unsuppressed in this limit, giving rise to potentially large single spin asymmetries.
hep-ph/0004012
Jens D. Noritzsch
Jens D. Noritzsch
Off-forward parton distributions and Shuvaev's transformations
13 pages, 7 eps-figures, LaTeX2e, added references, corrected typos
Phys.Rev. D62 (2000) 054015
10.1103/PhysRevD.62.054015
DO-TH 00/08
hep-ph
null
We review Shuvaev's transformations, that relate off-forward parton distributions (OFPDs) to so-called effective forward parton distributions (EFPDs). The latter evolve like conventional forward partons. We express nonforward amplitudes, depending on OFPDs, directly in terms of EFPDs and construct a model for the EFPDs, which allows to consistently express them in terms of the conventional forward parton distributions and nucleon form factors. Our model is self-consistent for arbitrary x, xi, mu, and t.
[ { "created": "Mon, 3 Apr 2000 13:28:34 GMT", "version": "v1" }, { "created": "Thu, 3 Aug 2000 15:27:50 GMT", "version": "v2" } ]
2009-10-31
[ [ "Noritzsch", "Jens D.", "" ] ]
We review Shuvaev's transformations, that relate off-forward parton distributions (OFPDs) to so-called effective forward parton distributions (EFPDs). The latter evolve like conventional forward partons. We express nonforward amplitudes, depending on OFPDs, directly in terms of EFPDs and construct a model for the EFPDs, which allows to consistently express them in terms of the conventional forward parton distributions and nucleon form factors. Our model is self-consistent for arbitrary x, xi, mu, and t.
2401.00931
Anjie Gao
Anjie Gao, Ian Moult, Sanjay Raman, Gregory Ridgway, Iain W. Stewart
A Collinear Perspective on the Regge Limit
48 pages + references, 10 figures; v2: JHEP version
null
10.1007/JHEP05(2024)328
MIT-CTP 5628
hep-ph hep-th nucl-th
http://creativecommons.org/licenses/by/4.0/
The high energy (Regge) limit provides a playground for understanding all loop structures of scattering amplitudes, and plays an important role in the description of many phenomenologically relevant cross-sections. While well understood in the planar limit, the structure of non-planar corrections introduces many fascinating complexities, for which a general organizing principle is still lacking. We study the structure of multi-reggeon exchanges in the context of the effective field theory for forward scattering, and derive their factorization into collinear operators (impact factors) and soft operators. We derive the structure of the renormalization group consistency equations in the effective theory, showing how the anomalous dimensions of the soft operators are related to those of the collinear operators, allowing us to derive renormalization group equations in the Regge limit purely from a collinear perspective. The rigidity of the consistency equations provides considerable insight into the all orders organization of Regge amplitudes in the effective theory, as well as its relation to other approaches. Along the way we derive a number of technical results that improve the understanding of the effective theory. We illustrate this collinear perspective by re-deriving all the standard BFKL equations for two-Glauber exchange from purely collinear calculations, and we show that this perspective provides a number of conceptual and computational advantages as compared to the standard view from soft or Glauber physics. We anticipate that this formulation in terms of collinear operators will enable a better understanding of the relation between BFKL and DGLAP in gauge theories, and facilitate the analysis of renormalization group evolution equations describing Reggeization beyond next-to-leading order.
[ { "created": "Mon, 1 Jan 2024 19:00:00 GMT", "version": "v1" }, { "created": "Mon, 22 Jul 2024 18:09:02 GMT", "version": "v2" } ]
2024-07-24
[ [ "Gao", "Anjie", "" ], [ "Moult", "Ian", "" ], [ "Raman", "Sanjay", "" ], [ "Ridgway", "Gregory", "" ], [ "Stewart", "Iain W.", "" ] ]
The high energy (Regge) limit provides a playground for understanding all loop structures of scattering amplitudes, and plays an important role in the description of many phenomenologically relevant cross-sections. While well understood in the planar limit, the structure of non-planar corrections introduces many fascinating complexities, for which a general organizing principle is still lacking. We study the structure of multi-reggeon exchanges in the context of the effective field theory for forward scattering, and derive their factorization into collinear operators (impact factors) and soft operators. We derive the structure of the renormalization group consistency equations in the effective theory, showing how the anomalous dimensions of the soft operators are related to those of the collinear operators, allowing us to derive renormalization group equations in the Regge limit purely from a collinear perspective. The rigidity of the consistency equations provides considerable insight into the all orders organization of Regge amplitudes in the effective theory, as well as its relation to other approaches. Along the way we derive a number of technical results that improve the understanding of the effective theory. We illustrate this collinear perspective by re-deriving all the standard BFKL equations for two-Glauber exchange from purely collinear calculations, and we show that this perspective provides a number of conceptual and computational advantages as compared to the standard view from soft or Glauber physics. We anticipate that this formulation in terms of collinear operators will enable a better understanding of the relation between BFKL and DGLAP in gauge theories, and facilitate the analysis of renormalization group evolution equations describing Reggeization beyond next-to-leading order.
2311.18209
Luis Hidalgo
Luis Hidalgo and Patrick Draper
Quantum Simulations for Strong-Field QED
null
null
null
null
hep-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
Quantum field theory in the presence of strong background fields contains interesting problems where quantum computers may someday provide a valuable computational resource. In the NISQ era it is useful to consider simpler benchmark problems in order to develop feasible approaches, identify critical limitations of current hardware, and build new simulation tools. Here we perform quantum simulations of strong-field QED (SFQED) in $3+1$ dimensions, using real-time nonlinear Breit-Wheeler pair-production as a prototypical process. The strong-field QED Hamiltonian is derived and truncated in the Furry-Volkov mode expansion, and the interactions relevant for Breit-Wheeler are transformed into a quantum circuit. Quantum simulations of a "null double slit" experiment are found to agree well with classical simulations following the application of various error mitigation strategies, including an asymmetric depolarization algorithm which we develop and adapt to the case of Trotterization with a time-dependent Hamiltonian. We also discuss longer-term goals for the quantum simulation of SFQED.
[ { "created": "Thu, 30 Nov 2023 03:05:26 GMT", "version": "v1" } ]
2023-12-01
[ [ "Hidalgo", "Luis", "" ], [ "Draper", "Patrick", "" ] ]
Quantum field theory in the presence of strong background fields contains interesting problems where quantum computers may someday provide a valuable computational resource. In the NISQ era it is useful to consider simpler benchmark problems in order to develop feasible approaches, identify critical limitations of current hardware, and build new simulation tools. Here we perform quantum simulations of strong-field QED (SFQED) in $3+1$ dimensions, using real-time nonlinear Breit-Wheeler pair-production as a prototypical process. The strong-field QED Hamiltonian is derived and truncated in the Furry-Volkov mode expansion, and the interactions relevant for Breit-Wheeler are transformed into a quantum circuit. Quantum simulations of a "null double slit" experiment are found to agree well with classical simulations following the application of various error mitigation strategies, including an asymmetric depolarization algorithm which we develop and adapt to the case of Trotterization with a time-dependent Hamiltonian. We also discuss longer-term goals for the quantum simulation of SFQED.
1506.02593
Gouranga Nayak
Gouranga C. Nayak
Proof of NRQCD Factorization at All Order in Coupling Constant in Heavy Quarkonium Production
Final Version, Accepted for Publication in Eur. Phys. J. C, 37 Pages Latex
Eur. Phys. J. C (2016) 76:448
10.1140/epjc/s10052-016-4297-0
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently the proof of factorization in heavy quarkonium production in NRQCD color octet mechanism is given at next-to-next-to-leading order (NNLO) in coupling constant by using diagrammatic method of QCD. In this paper we prove factorization in heavy quarkonium production in NRQCD color octet mechanism at all order in coupling constant by using path integral method of QCD. Our proof is valid to all powers in the heavy quark relative velocity. We find that the gauge invariance and the factorization at all order in coupling constant require gauge-completed non-perturbative NRQCD matrix elements that were introduced previously to prove factorization at NNLO.
[ { "created": "Mon, 8 Jun 2015 17:37:21 GMT", "version": "v1" }, { "created": "Mon, 1 Aug 2016 23:47:36 GMT", "version": "v2" } ]
2016-08-12
[ [ "Nayak", "Gouranga C.", "" ] ]
Recently the proof of factorization in heavy quarkonium production in NRQCD color octet mechanism is given at next-to-next-to-leading order (NNLO) in coupling constant by using diagrammatic method of QCD. In this paper we prove factorization in heavy quarkonium production in NRQCD color octet mechanism at all order in coupling constant by using path integral method of QCD. Our proof is valid to all powers in the heavy quark relative velocity. We find that the gauge invariance and the factorization at all order in coupling constant require gauge-completed non-perturbative NRQCD matrix elements that were introduced previously to prove factorization at NNLO.
1207.6517
Georg Wolschin
David Roehrscheid and Georg Wolschin
Centrality dependence of charged-hadron pseudorapidity distributions in PbPb collisions at LHC energies in the RDM
8 Pages, 5 figures, Phys. Rev. C, in press
Phys. Rev. C 86, 024902 (2012)
10.1103/PhysRevC.86.024902
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The centrality dependence of charged-hadron production in relativistic heavy-ion collisions at LHC energies is investigated in a nonequilibrium-statistical relativistic diffusion model (RDM) with three sources. Theoretical pseudorapidity distributions are compared with preliminary PbPb ALICE data at LHC energy of sqrt(s_NN) = 2.76 TeV for seven centralities, and a previous RDM prediction for this energy is confronted with the data. Refined predictions for 5.52 TeV PbPb based on RDM parameter extrapolations are presented.
[ { "created": "Fri, 27 Jul 2012 11:30:37 GMT", "version": "v1" } ]
2012-08-07
[ [ "Roehrscheid", "David", "" ], [ "Wolschin", "Georg", "" ] ]
The centrality dependence of charged-hadron production in relativistic heavy-ion collisions at LHC energies is investigated in a nonequilibrium-statistical relativistic diffusion model (RDM) with three sources. Theoretical pseudorapidity distributions are compared with preliminary PbPb ALICE data at LHC energy of sqrt(s_NN) = 2.76 TeV for seven centralities, and a previous RDM prediction for this energy is confronted with the data. Refined predictions for 5.52 TeV PbPb based on RDM parameter extrapolations are presented.
hep-ph/9501363
null
M. A. Ivanov, T. Mizutani (Department of Physics, Virginia Polytechnic Institute and State University)
Self-energy of Heavy Quark
17 pages, figures are included at the end (FEYNMAN.* macros are needed.)
Z.Phys.C68:639-646,1995
10.1007/BF01565263
null
hep-ph
null
We demonstrate that to calculate the self-energy of a heavy quark in the heavy quark limit (or the heavy fermion limit in what is called the Baryon Chiral Perturbation Theory), the use of standard dimensional regularization provides only the quantum limit: opposite to the heavy quark (or classical) limit that one wishes to obtain. We thus devised a standard ultraviolet/infrared regularization procedure in calculating the one- and two-loop contributions to the heavy quark self-energy in this limit. Then the one-loop result is shown to provide the standard classical Coulomb self-energy of a static colour source that is linearly proportional to the untraviolet cutoff $\Lambda$. All the two-loop contributions are found to be proportional to $\Lambda \ln(\Lambda/\lambda)$ where $\lambda$ is the infrared cutoff. Often only the contribution from the bubble (light quarks, gluon and ghost) insertion to the gluon propagator has been considered as the $O(\alpha_s)$ correction to the Coulomb energy to this order. Our result shows that other contributions are of the same magnitude, thus have to be taken into account.
[ { "created": "Tue, 24 Jan 1995 16:56:49 GMT", "version": "v1" } ]
2010-11-01
[ [ "Ivanov", "M. A.", "", "Department of Physics, Virginia Polytechnic\n Institute and State University" ], [ "Mizutani", "T.", "", "Department of Physics, Virginia Polytechnic\n Institute and State University" ] ]
We demonstrate that to calculate the self-energy of a heavy quark in the heavy quark limit (or the heavy fermion limit in what is called the Baryon Chiral Perturbation Theory), the use of standard dimensional regularization provides only the quantum limit: opposite to the heavy quark (or classical) limit that one wishes to obtain. We thus devised a standard ultraviolet/infrared regularization procedure in calculating the one- and two-loop contributions to the heavy quark self-energy in this limit. Then the one-loop result is shown to provide the standard classical Coulomb self-energy of a static colour source that is linearly proportional to the untraviolet cutoff $\Lambda$. All the two-loop contributions are found to be proportional to $\Lambda \ln(\Lambda/\lambda)$ where $\lambda$ is the infrared cutoff. Often only the contribution from the bubble (light quarks, gluon and ghost) insertion to the gluon propagator has been considered as the $O(\alpha_s)$ correction to the Coulomb energy to this order. Our result shows that other contributions are of the same magnitude, thus have to be taken into account.
0707.0103
Sergey Slabospitsky
A.A. Ashimova (1), S.R. Slabospitsky (2) ((1) Moscow State University, Moscow, Russia, (2) Institute for High Energy Physics, Protvino, Russia)
Simulation of the Polarized Fermion Decay
4 pages, 2 EPS figures
null
null
null
hep-ph
null
In this paper the modification of the method conventionally used for the modeling of the massive fermions production and decays is proposed. The step by step algorithm is presented. Under the strict conditions the proposed method of modeling allow distinctly raise the efficiency of the computations.
[ { "created": "Sun, 1 Jul 2007 11:18:25 GMT", "version": "v1" }, { "created": "Wed, 2 Apr 2008 06:45:03 GMT", "version": "v2" } ]
2008-04-02
[ [ "Ashimova", "A. A.", "" ], [ "Slabospitsky", "S. R.", "" ] ]
In this paper the modification of the method conventionally used for the modeling of the massive fermions production and decays is proposed. The step by step algorithm is presented. Under the strict conditions the proposed method of modeling allow distinctly raise the efficiency of the computations.
hep-ph/0504251
Yoshimasa Kurihara
Y. Kurihara
Dimensionally regularized one-loop tensor-integrals with massless internal particles
28 pages, 0 figure
Eur.Phys.J.C45:427-444,2006
10.1140/epjc/s2005-02428-1
KEK-CP-160
hep-ph
null
A set of one-loop vertex and box tensor-integrals with massless internal particles has been obtained directly without any reduction method to scalar-integrals. The results with one or two massive external lines for the vertex integral and zero or one massive external lines for the box integral are shown in this report. Dimensional regularization is employed to treat any soft and collinear (IR) divergence. A series expansion of tensor-integrals with respect to an extra space-time dimension for the dimensional regularization is also given. The results are expressed by very short formulas in a suitable manner for a numerical calculation.
[ { "created": "Wed, 27 Apr 2005 07:45:06 GMT", "version": "v1" }, { "created": "Tue, 10 May 2005 13:51:58 GMT", "version": "v2" }, { "created": "Thu, 28 Jul 2005 05:51:32 GMT", "version": "v3" } ]
2009-01-07
[ [ "Kurihara", "Y.", "" ] ]
A set of one-loop vertex and box tensor-integrals with massless internal particles has been obtained directly without any reduction method to scalar-integrals. The results with one or two massive external lines for the vertex integral and zero or one massive external lines for the box integral are shown in this report. Dimensional regularization is employed to treat any soft and collinear (IR) divergence. A series expansion of tensor-integrals with respect to an extra space-time dimension for the dimensional regularization is also given. The results are expressed by very short formulas in a suitable manner for a numerical calculation.
hep-ph/0006015
John F. Beacom
J.F. Beacom (Caltech), R.N. Boyd (Ohio State University), A. Mezzacappa (Oak Ridge National Laboratory)
Technique for Direct eV-Scale Measurements of the Mu and Tau Neutrino Masses Using Supernova Neutrinos
4 pages including 3 inline figures. Submitted to Physical Review Letters
Phys.Rev.Lett. 85 (2000) 3568-3571
10.1103/PhysRevLett.85.3568
null
hep-ph astro-ph gr-qc hep-ex nucl-ex nucl-th
null
Early black hole formation in a core-collapse supernova will abruptly truncate the neutrino fluxes. The sharp cutoff can be used to make model-independent time-of-flight neutrino mass tests. Assuming a neutrino luminosity of $10^{52}$ erg/s per flavor at cutoff and a distance of 10 kpc, SuperKamiokande can detect an electron neutrino mass as small as 1.8 eV, and the proposed OMNIS detector can detect mu and tau neutrino masses as small as 6 eV. This {\it Letter} presents the first technique with direct sensitivity to eV-scale mu and tau neutrino masses.
[ { "created": "Thu, 1 Jun 2000 17:54:52 GMT", "version": "v1" } ]
2009-10-31
[ [ "Beacom", "J. F.", "", "Caltech" ], [ "Boyd", "R. N.", "", "Ohio State University" ], [ "Mezzacappa", "A.", "", "Oak Ridge National Laboratory" ] ]
Early black hole formation in a core-collapse supernova will abruptly truncate the neutrino fluxes. The sharp cutoff can be used to make model-independent time-of-flight neutrino mass tests. Assuming a neutrino luminosity of $10^{52}$ erg/s per flavor at cutoff and a distance of 10 kpc, SuperKamiokande can detect an electron neutrino mass as small as 1.8 eV, and the proposed OMNIS detector can detect mu and tau neutrino masses as small as 6 eV. This {\it Letter} presents the first technique with direct sensitivity to eV-scale mu and tau neutrino masses.
1609.08157
Duccio Pappadopulo
Marco Farina, Giuliano Panico, Duccio Pappadopulo, Joshua T. Ruderman, Riccardo Torre, and Andrea Wulzer
Energy helps accuracy: electroweak precision tests at hadron colliders
8 pages, 5 figures, 2 tables. Added: CEPC reach, projected reach on heavy vector triplets
null
10.1016/j.physletb.2017.06.043
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that high energy measurements of Drell-Yan at the LHC can serve as electroweak precision tests. Dimension-6 operators, from the Standard Model Effective Field Theory, modify the high energy behavior of electroweak gauge boson propagators. Existing measurements of the dilepton invariant mass spectrum, from neutral current Drell-Yan at 8 TeV, have comparable sensitivity to LEP. We propose measuring the transverse mass spectrum of charged current Drell-Yan, which can surpass LEP already with 8 TeV data. The 13 TeV LHC will elevate electroweak tests to a new precision frontier.
[ { "created": "Mon, 26 Sep 2016 20:00:00 GMT", "version": "v1" }, { "created": "Mon, 26 Jun 2017 15:51:57 GMT", "version": "v2" } ]
2017-06-27
[ [ "Farina", "Marco", "" ], [ "Panico", "Giuliano", "" ], [ "Pappadopulo", "Duccio", "" ], [ "Ruderman", "Joshua T.", "" ], [ "Torre", "Riccardo", "" ], [ "Wulzer", "Andrea", "" ] ]
We show that high energy measurements of Drell-Yan at the LHC can serve as electroweak precision tests. Dimension-6 operators, from the Standard Model Effective Field Theory, modify the high energy behavior of electroweak gauge boson propagators. Existing measurements of the dilepton invariant mass spectrum, from neutral current Drell-Yan at 8 TeV, have comparable sensitivity to LEP. We propose measuring the transverse mass spectrum of charged current Drell-Yan, which can surpass LEP already with 8 TeV data. The 13 TeV LHC will elevate electroweak tests to a new precision frontier.
hep-ph/0412409
Boris Blankleider
A. N. Kvinikhidze and B. Blankleider
Generalized parton distributions for dynamical equation models
23 pages, 9 figures, revtex4, feynmf
Nucl.Phys.A784:259-281,2007
10.1016/j.nuclphysa.2006.11.161
null
hep-ph nucl-th
null
We show how generalized parton distributions (GPDs) can be determined in the case where hadrons are described in terms of their partonic degrees of freedom through solutions of dynamical equations. We demonstrate our approach on the example of two-quark bound states described by the Bethe-Salpeter equation, and three-quark bound states described by three- and four-dimensional Faddeev-like equations. Within the model of strong interactions defined by the dynamical equations, all possible mechanisms contributing to the GPDs are taken into account, and all GPD sum rules are satisfied automatically. The formulation is general and can be applied to determine generalized quark distributions, generalized gluon distributions, transition GPDs, nucleon distributions in nuclei, etc. Our approach is based on the gauging of equations method.
[ { "created": "Wed, 29 Dec 2004 17:27:48 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kvinikhidze", "A. N.", "" ], [ "Blankleider", "B.", "" ] ]
We show how generalized parton distributions (GPDs) can be determined in the case where hadrons are described in terms of their partonic degrees of freedom through solutions of dynamical equations. We demonstrate our approach on the example of two-quark bound states described by the Bethe-Salpeter equation, and three-quark bound states described by three- and four-dimensional Faddeev-like equations. Within the model of strong interactions defined by the dynamical equations, all possible mechanisms contributing to the GPDs are taken into account, and all GPD sum rules are satisfied automatically. The formulation is general and can be applied to determine generalized quark distributions, generalized gluon distributions, transition GPDs, nucleon distributions in nuclei, etc. Our approach is based on the gauging of equations method.
0709.2457
Kazutaka Sudoh
M. Hirai, S. Kumano, T.-H. Nagai, M. Oka, and K. Sudoh
Global analysis of hadron-production data in e^+ e^- annihilation for determining fragmentation functions
3 pages, 3 eps figures, to appear in the proceedings of INPC2007 (International Nuclear Physics Conference), Tokyo, Japan, June 3-8, 2007
null
null
KEK-TH-1179
hep-ph hep-ex nucl-ex nucl-th
null
Fragmentation functions of pion, kaon, and nucleon are determined by global analyses of hadron-production data in $e^+e^-$ annihilation. It is particularly important that uncertainties of the fragmentation functions are estimated for the first time. We found that light-quark and gluon fragmentation functions have large uncertainties, so that one should be careful in using these functions for hadron-production processes in heavy-ion collisions and lepton scattering. The analysis is extended to possible exotic hadron search by fragmentation functions. We found that internal structure of $f_0 (980)$, such as $s\bar s$ or tetraquark configuration, can be determined by noting differences between favored and disfavored fragmentation functions.
[ { "created": "Sun, 16 Sep 2007 04:46:16 GMT", "version": "v1" } ]
2007-09-25
[ [ "Hirai", "M.", "" ], [ "Kumano", "S.", "" ], [ "Nagai", "T. -H.", "" ], [ "Oka", "M.", "" ], [ "Sudoh", "K.", "" ] ]
Fragmentation functions of pion, kaon, and nucleon are determined by global analyses of hadron-production data in $e^+e^-$ annihilation. It is particularly important that uncertainties of the fragmentation functions are estimated for the first time. We found that light-quark and gluon fragmentation functions have large uncertainties, so that one should be careful in using these functions for hadron-production processes in heavy-ion collisions and lepton scattering. The analysis is extended to possible exotic hadron search by fragmentation functions. We found that internal structure of $f_0 (980)$, such as $s\bar s$ or tetraquark configuration, can be determined by noting differences between favored and disfavored fragmentation functions.
1305.7055
Kin-ya Oda
Yuta Hamada, Hikaru Kawai, and Kin-ya Oda
Bare Higgs mass and potential at ultraviolet cutoff
6 pages, 2 figures. Prceedings for Toyama International Workshop on Higgs as a Probe of New Physics 2013, 13--16, February, 2013
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/3.0/
We first review the current status of the top mass determination paying attention to the difference between the MS-bar and pole masses. Then we present our recent result on the bare Higgs mass at a very high ultraviolet cutoff scale.
[ { "created": "Thu, 30 May 2013 10:24:22 GMT", "version": "v1" } ]
2013-06-03
[ [ "Hamada", "Yuta", "" ], [ "Kawai", "Hikaru", "" ], [ "Oda", "Kin-ya", "" ] ]
We first review the current status of the top mass determination paying attention to the difference between the MS-bar and pole masses. Then we present our recent result on the bare Higgs mass at a very high ultraviolet cutoff scale.
0808.1034
Yu Jia
Bin Gong, Yu Jia, and Jian-Xiong Wang
Exclusive $eta_b$ decay to double $J/\psi$ at next-to-leading order in $alpha_s$
v2,16 pages, 3 figures; References added/updated, presentation refined, minor mistakes corrected. The absence of Coulomb divergences in Figure 1b) is stressed
Phys.Lett.B670:350-355,2009
10.1016/j.physletb.2008.10.063
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the nonrelativistic QCD (NRQCD) factorization framework, we calculate the exclusive decay process \eta_b \to J/\psi J/\psi to next-to-leading order in the strong coupling constant, while at leading order in charm quark relative velocity. It is found that this new contribution to the amplitude is comparable in magnitude with the previously calculated relativistic correction piece, but differs by a phase about 90^\circ. Including this new contribution will increase the previous prediction to B(\eta_b \to J/\psi J/\psi) substantially, thus brightening the discovery potential of this clean hadronic decay channel of \eta_b in the forthcoming LHC experiment.
[ { "created": "Thu, 7 Aug 2008 17:29:56 GMT", "version": "v1" }, { "created": "Thu, 9 Oct 2008 19:18:14 GMT", "version": "v2" } ]
2009-01-16
[ [ "Gong", "Bin", "" ], [ "Jia", "Yu", "" ], [ "Wang", "Jian-Xiong", "" ] ]
Within the nonrelativistic QCD (NRQCD) factorization framework, we calculate the exclusive decay process \eta_b \to J/\psi J/\psi to next-to-leading order in the strong coupling constant, while at leading order in charm quark relative velocity. It is found that this new contribution to the amplitude is comparable in magnitude with the previously calculated relativistic correction piece, but differs by a phase about 90^\circ. Including this new contribution will increase the previous prediction to B(\eta_b \to J/\psi J/\psi) substantially, thus brightening the discovery potential of this clean hadronic decay channel of \eta_b in the forthcoming LHC experiment.
hep-ph/0510278
Jordi Burguet-Castell
J. Bernabeu, J. Burguet-Castell, C. Espinoza, M. Lindroos
Physics Reach of Electron-Capture Neutrino Beams
5 pages, 3 png figures. Talk given at the 7th International Workshop on Neutrino Factories and Superbeams (NuFact 05), Frascati, Italy, June 2005
null
10.1016/j.nuclphysbps.2006.02.054
null
hep-ph
null
To complete the picture of neutrino oscillations two fundamental parameters need to be measured, theta13 and delta. The next generation of long baseline neutrino oscillation experiments -superbeams, betabeams and neutrino factories- indeed take aim at measuring them. Here we explore the physics reach of a new candidate: an electron-capture neutrino beam. Emphasis is made on its feasibility thanks to the recent discovery of nuclei that decay fast through electron capture, and on the interplay with a betabeam (its closest relative).
[ { "created": "Fri, 21 Oct 2005 02:03:14 GMT", "version": "v1" } ]
2009-11-11
[ [ "Bernabeu", "J.", "" ], [ "Burguet-Castell", "J.", "" ], [ "Espinoza", "C.", "" ], [ "Lindroos", "M.", "" ] ]
To complete the picture of neutrino oscillations two fundamental parameters need to be measured, theta13 and delta. The next generation of long baseline neutrino oscillation experiments -superbeams, betabeams and neutrino factories- indeed take aim at measuring them. Here we explore the physics reach of a new candidate: an electron-capture neutrino beam. Emphasis is made on its feasibility thanks to the recent discovery of nuclei that decay fast through electron capture, and on the interplay with a betabeam (its closest relative).
2103.09827
Gregory Ridgway
Pouya Asadi, Eric David Kramer, Eric Kuflik, Gregory W. Ridgway, Tracy R. Slatyer, Juri Smirnov
Thermal Squeezeout of Dark Matter
38+30 pages, 14 figures
null
10.1103/PhysRevD.104.095013
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We carry out a detailed study of the confinement phase transition in a dark sector with a $SU(N)$ gauge group and a single generation of dark heavy quark. We focus on heavy enough quarks such that their abundance freezes out before the phase transition and the phase transition is of first-order. We find that during this phase transition the quarks are trapped inside contracting pockets of the deconfined phase and are compressed enough to interact at a significant rate, giving rise to a second stage of annihilation that can dramatically change the resulting dark matter abundance. As a result, the dark matter can be heavier than the often-quoted unitarity bound of $\sim100~$TeV. Our findings are almost completely independent of the details of the portal between the dark sector and the Standard Model. We comment briefly on possible signals of such a sector. Our main findings are summarized in a companion letter, while here we provide further details on different parts of the calculation.
[ { "created": "Wed, 17 Mar 2021 18:00:01 GMT", "version": "v1" }, { "created": "Mon, 18 Apr 2022 15:38:09 GMT", "version": "v2" } ]
2022-04-19
[ [ "Asadi", "Pouya", "" ], [ "Kramer", "Eric David", "" ], [ "Kuflik", "Eric", "" ], [ "Ridgway", "Gregory W.", "" ], [ "Slatyer", "Tracy R.", "" ], [ "Smirnov", "Juri", "" ] ]
We carry out a detailed study of the confinement phase transition in a dark sector with a $SU(N)$ gauge group and a single generation of dark heavy quark. We focus on heavy enough quarks such that their abundance freezes out before the phase transition and the phase transition is of first-order. We find that during this phase transition the quarks are trapped inside contracting pockets of the deconfined phase and are compressed enough to interact at a significant rate, giving rise to a second stage of annihilation that can dramatically change the resulting dark matter abundance. As a result, the dark matter can be heavier than the often-quoted unitarity bound of $\sim100~$TeV. Our findings are almost completely independent of the details of the portal between the dark sector and the Standard Model. We comment briefly on possible signals of such a sector. Our main findings are summarized in a companion letter, while here we provide further details on different parts of the calculation.
hep-ph/0107315
Sven Zschocke
Sven Zschocke, Guenter Plunien, Gerhard Soff
Renormalization of the two-photon vacuum polarization and the self energy vacuum polarization for a tightly bound electron
25 pages, latex, 12 figures
Eur.Phys.J.D19:147-156,2002
10.1007/s10053-002-8865-5
null
hep-ph
null
The renormalization method of Bogoljubov-Parasiuk-Hepp-Zimmermann (BPHZ) is used in order to derive the renormalized energy shift due to the gauge invariant K\"all\'en-Sabry diagram of the two-photon vacuum polarization (VPVP) as well as the self energy vacuum polarization S(VP)E beyond the Uehling approximation. It is outlined, that no outer renormalization is required for the two-photon vacuum polarization and that only the inner renormalization has to b e accomplished. It is shown that the so-called nongauge invariant spurious term is absent for a wide class of vacuum polarization (VP) diagrams if one applies the widely used spherical expansion of bound and free-electron propagat or. This simplifies significantly calculations in bound state quantum electrodynamis . As one result of our paper the use of the BPHZ-approach in bound state QED is established.
[ { "created": "Tue, 31 Jul 2001 07:03:49 GMT", "version": "v1" }, { "created": "Wed, 10 Apr 2002 09:21:36 GMT", "version": "v2" } ]
2011-08-17
[ [ "Zschocke", "Sven", "" ], [ "Plunien", "Guenter", "" ], [ "Soff", "Gerhard", "" ] ]
The renormalization method of Bogoljubov-Parasiuk-Hepp-Zimmermann (BPHZ) is used in order to derive the renormalized energy shift due to the gauge invariant K\"all\'en-Sabry diagram of the two-photon vacuum polarization (VPVP) as well as the self energy vacuum polarization S(VP)E beyond the Uehling approximation. It is outlined, that no outer renormalization is required for the two-photon vacuum polarization and that only the inner renormalization has to b e accomplished. It is shown that the so-called nongauge invariant spurious term is absent for a wide class of vacuum polarization (VP) diagrams if one applies the widely used spherical expansion of bound and free-electron propagat or. This simplifies significantly calculations in bound state quantum electrodynamis . As one result of our paper the use of the BPHZ-approach in bound state QED is established.
1210.4561
Joel Jones-Perez
Gianluca Blankenburg and Joel Jones-Perez
RGE Behaviour of SUSY with a U(2)^3 symmetry
22 pages, 9 Figures; v2: minor corrections, improved discussion on (LL)(RR) operators, main results unchanged
null
10.1140/epjc/s10052-013-2289-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The first LHC results seem to disfavour, from the point of view of naturalness, any constrained MSSM realization with universal conditions at the SUSY-breaking scale. A more motivated scenario is given by split-family SUSY, in which the first two generations of squarks are heavy, compatible with a U(2)^3 flavour symmetry. We consider this flavour symmetry to be broken at a very high scale and study the consequences at low energies through its RGE evolution. Initial conditions compatible with a split scenario are found, and the preservation of correlations from minimal U(2)^3 breaking are checked. The various chiral operators in $\Delta F=2$ processes are analyzed, and we show that, due to LHC gluino bounds, the (LL)(RR) operators can not always be neglected. Finally, we also study a possible extension of the U(2)^3 model compatible with the lepton sector.
[ { "created": "Tue, 16 Oct 2012 20:03:24 GMT", "version": "v1" }, { "created": "Fri, 18 Jan 2013 18:33:39 GMT", "version": "v2" } ]
2015-06-11
[ [ "Blankenburg", "Gianluca", "" ], [ "Jones-Perez", "Joel", "" ] ]
The first LHC results seem to disfavour, from the point of view of naturalness, any constrained MSSM realization with universal conditions at the SUSY-breaking scale. A more motivated scenario is given by split-family SUSY, in which the first two generations of squarks are heavy, compatible with a U(2)^3 flavour symmetry. We consider this flavour symmetry to be broken at a very high scale and study the consequences at low energies through its RGE evolution. Initial conditions compatible with a split scenario are found, and the preservation of correlations from minimal U(2)^3 breaking are checked. The various chiral operators in $\Delta F=2$ processes are analyzed, and we show that, due to LHC gluino bounds, the (LL)(RR) operators can not always be neglected. Finally, we also study a possible extension of the U(2)^3 model compatible with the lepton sector.
1412.3221
Chunsheng An
Gang Li, Chun-Sheng An, Peng-Yu Li, Di Liu, Xiao Zhang and Zhu Zhou
Investigations on the charmless decays of $Y(4260)$
6 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Apart from the charmful decay channels of $Y(4260)$, the charmless decay channels of $Y(4260)$ also provide us a good platform to study the nature and the decay mechanism of $Y(4260)$. In this paper, we propose to probe the structure of $Y(4260)$ through the charmless decays $Y(4260)\to VP$ via intermediate $D_1\bar D+c.c.$ meson loops, where $V$ and $P$ stand for light vector and pseudoscalar mesons, respectively. Under the molecule ansatz of $Y(4260)$, the predicted total branching ratio $BR_{VP}$ for all $Y(4260)\to VP$ processes are about $(0.34^{+0.32}_{-0.23})%$ to $(0.75^{+0.72}_{-0.52})%$ with the cutoff parameter $\alpha=2\sim 3$. Numerical results show that the intermediate $D_1 \bar D+c.c.$ meson loops may be a possible transition mechanism in the $Y(4260)\to VP$ decays. These predicted branching ratios are the same order to that of $Y(4260) \to Z_c^+(3900) \pi^-$, which may be an evidence of $D_1D$ molecule and can be examined by the forthcoming BESIII data in the near future.
[ { "created": "Wed, 10 Dec 2014 07:59:40 GMT", "version": "v1" } ]
2014-12-11
[ [ "Li", "Gang", "" ], [ "An", "Chun-Sheng", "" ], [ "Li", "Peng-Yu", "" ], [ "Liu", "Di", "" ], [ "Zhang", "Xiao", "" ], [ "Zhou", "Zhu", "" ] ]
Apart from the charmful decay channels of $Y(4260)$, the charmless decay channels of $Y(4260)$ also provide us a good platform to study the nature and the decay mechanism of $Y(4260)$. In this paper, we propose to probe the structure of $Y(4260)$ through the charmless decays $Y(4260)\to VP$ via intermediate $D_1\bar D+c.c.$ meson loops, where $V$ and $P$ stand for light vector and pseudoscalar mesons, respectively. Under the molecule ansatz of $Y(4260)$, the predicted total branching ratio $BR_{VP}$ for all $Y(4260)\to VP$ processes are about $(0.34^{+0.32}_{-0.23})%$ to $(0.75^{+0.72}_{-0.52})%$ with the cutoff parameter $\alpha=2\sim 3$. Numerical results show that the intermediate $D_1 \bar D+c.c.$ meson loops may be a possible transition mechanism in the $Y(4260)\to VP$ decays. These predicted branching ratios are the same order to that of $Y(4260) \to Z_c^+(3900) \pi^-$, which may be an evidence of $D_1D$ molecule and can be examined by the forthcoming BESIII data in the near future.
hep-ph/0602184
Roman Pasechnik
R. S. Pasechnik, V. A. Beylin, V. I. Kuksa and G. M. Vereshkov
High energy Gamma-Ray Bursts as a result of the collapse and total annihilation of neutralino clumps
9 pages, 4 figures
null
null
null
hep-ph
null
Rare astrophysical events - cosmological gamma-ray bursts with energies over GeV - are considered as an origin of information about some SUSY parameters. The model of generation of the powerful gamma-ray bursts is proposed. According to this model the gamma-ray burst represents as a result of the collapse and the total annihilation of the neutralino clump. About 80 % of the clump mass radiates during about 100 second at the final stage of annihilation. The annihilation spectrum and its characteristic energies are calculated in the framework of Split Higgsino model.
[ { "created": "Mon, 20 Feb 2006 17:59:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pasechnik", "R. S.", "" ], [ "Beylin", "V. A.", "" ], [ "Kuksa", "V. I.", "" ], [ "Vereshkov", "G. M.", "" ] ]
Rare astrophysical events - cosmological gamma-ray bursts with energies over GeV - are considered as an origin of information about some SUSY parameters. The model of generation of the powerful gamma-ray bursts is proposed. According to this model the gamma-ray burst represents as a result of the collapse and the total annihilation of the neutralino clump. About 80 % of the clump mass radiates during about 100 second at the final stage of annihilation. The annihilation spectrum and its characteristic energies are calculated in the framework of Split Higgsino model.
1501.04455
Yuta Hamada
Yuta Hamada, Hikaru Kawai, Kin-ya Oda
Eternal Higgs inflation and cosmological constant problem
52 pages, 14 figures; Version to appear in PRD (v2)
Phys. Rev. D 92, 045009 (2015)
10.1103/PhysRevD.92.045009
KUNS-2538, OU-HET/850
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the Higgs potential beyond the Planck scale in the superstring theory, under the assumption that the supersymmetry is broken at the string scale. We identify the Higgs field as a massless state of the string, which is indicated by the fact that the bare Higgs mass can be zero around the string scale. We find that, in the large field region, the Higgs potential is connected to a runaway vacuum with vanishing energy, which corresponds to opening up an extra dimension. We verify that such universal behavior indeed follows from the toroidal compactification of the non-supersymmetric $SO(16)\times SO(16)$ heterotic string theory. We show that this behavior fits in the picture that the Higgs field is the source of the eternal inflation. The observed small value of the cosmological constant of our universe may be understood as the degeneracy with this runaway vacuum, which has vanishing energy, as is suggested by the multiple point criticality principle.
[ { "created": "Mon, 19 Jan 2015 11:21:15 GMT", "version": "v1" }, { "created": "Tue, 21 Jul 2015 16:18:30 GMT", "version": "v2" } ]
2015-08-13
[ [ "Hamada", "Yuta", "" ], [ "Kawai", "Hikaru", "" ], [ "Oda", "Kin-ya", "" ] ]
We investigate the Higgs potential beyond the Planck scale in the superstring theory, under the assumption that the supersymmetry is broken at the string scale. We identify the Higgs field as a massless state of the string, which is indicated by the fact that the bare Higgs mass can be zero around the string scale. We find that, in the large field region, the Higgs potential is connected to a runaway vacuum with vanishing energy, which corresponds to opening up an extra dimension. We verify that such universal behavior indeed follows from the toroidal compactification of the non-supersymmetric $SO(16)\times SO(16)$ heterotic string theory. We show that this behavior fits in the picture that the Higgs field is the source of the eternal inflation. The observed small value of the cosmological constant of our universe may be understood as the degeneracy with this runaway vacuum, which has vanishing energy, as is suggested by the multiple point criticality principle.
hep-ph/0011299
Vladislav Korotkov
The TESLA-N Study Group: M. Anselmino, E.C. Aschenauer, S. Belostotski, W. Bialowons, J. Bluemlein, V. Braun, R. Brinkmann, M. Dueren, F. Ellinghaus, K. Goeke, St. Goertz, A. Gute, J. Harmsen, D. v.Harrach, R. Jakob, E.M. Kabuss, R. Kaiser, V. Korotkov, P. Kroll, E. Leader, B. Lehmann-Dronke, L. Mankiewicz, A. Meier, W. Meyer, N. Meyners, D. Mueller, P.J. Mulders, W.-D. Nowak, L. Niedermeier, K. Oganessyan, P.V. Pobilitsa, M.V. Polyakov, G. Reicherz, K. Rith, D. Ryckbosch, A. Schaefer, K. Sinram, G. v.d.Steenhoven, E. Steffens, J. Steijger, C. Weiss
Electron Scattering with Polarized Targets at TESLA
24 pages, 10 figures
null
null
DESY 00-160, TPR-00-20
hep-ph
null
Measurements of polarized electron-nucleon scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e+ arm of TESLA, can be directed onto a solid state target that may be either longitudinally or transversely polarized. A large variety of polarized parton distribution and fragmentation functions can be determined with unprecedented accuracy, many of them for the first time. A main goal of the experiment is the precise measurement of the x- and Q^2-dependence of the experimentally totally unknown quark transversity distributions that will complete the information on the nucleon's quark spin structure as relevant for high energy processes. Comparing their Q^2-evolution to that of the corresponding helicity distributions constitutes an important precision test of the predictive power of QCD in the spin sector. Measuring transversity distributions and tensor charges allows access to the hitherto unmeasured chirally odd operators in QCD which are of great importance to understand the role of chiral symmetry. The possibilities of using unpolarized targets and of experiments with a real photon beam turn TESLA-N into a versatile next-generation facility at the intersection of particle and nuclear physics.
[ { "created": "Fri, 24 Nov 2000 14:05:05 GMT", "version": "v1" } ]
2012-08-27
[ [ "N Study Group", "", "" ], [ "Anselmino", "M.", "" ], [ "Aschenauer", "E. C.", "" ], [ "Belostotski", "S.", "" ], [ "Bialowons", "W.", "" ], [ "Bluemlein", "J.", "" ], [ "Braun", "V.", "" ], [ "Brinkmann", "R.", "" ], [ "Dueren", "M.", "" ], [ "Ellinghaus", "F.", "" ], [ "Goeke", "K.", "" ], [ "Goertz", "St.", "" ], [ "Gute", "A.", "" ], [ "Harmsen", "J.", "" ], [ "Harrach", "D. v.", "" ], [ "Jakob", "R.", "" ], [ "Kabuss", "E. M.", "" ], [ "Kaiser", "R.", "" ], [ "Korotkov", "V.", "" ], [ "Kroll", "P.", "" ], [ "Leader", "E.", "" ], [ "Lehmann-Dronke", "B.", "" ], [ "Mankiewicz", "L.", "" ], [ "Meier", "A.", "" ], [ "Meyer", "W.", "" ], [ "Meyners", "N.", "" ], [ "Mueller", "D.", "" ], [ "Mulders", "P. J.", "" ], [ "Nowak", "W. -D.", "" ], [ "Niedermeier", "L.", "" ], [ "Oganessyan", "K.", "" ], [ "Pobilitsa", "P. V.", "" ], [ "Polyakov", "M. V.", "" ], [ "Reicherz", "G.", "" ], [ "Rith", "K.", "" ], [ "Ryckbosch", "D.", "" ], [ "Schaefer", "A.", "" ], [ "Sinram", "K.", "" ], [ "Steenhoven", "G. v. d.", "" ], [ "Steffens", "E.", "" ], [ "Steijger", "J.", "" ], [ "Weiss", "C.", "" ] ]
Measurements of polarized electron-nucleon scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e+ arm of TESLA, can be directed onto a solid state target that may be either longitudinally or transversely polarized. A large variety of polarized parton distribution and fragmentation functions can be determined with unprecedented accuracy, many of them for the first time. A main goal of the experiment is the precise measurement of the x- and Q^2-dependence of the experimentally totally unknown quark transversity distributions that will complete the information on the nucleon's quark spin structure as relevant for high energy processes. Comparing their Q^2-evolution to that of the corresponding helicity distributions constitutes an important precision test of the predictive power of QCD in the spin sector. Measuring transversity distributions and tensor charges allows access to the hitherto unmeasured chirally odd operators in QCD which are of great importance to understand the role of chiral symmetry. The possibilities of using unpolarized targets and of experiments with a real photon beam turn TESLA-N into a versatile next-generation facility at the intersection of particle and nuclear physics.
0805.2502
Satoshi Shirai
Koichi Hamaguchi, Eita Nakamura and Satoshi Shirai
A Measurement of Neutralino Mass at the LHC in Light Gravitino Scenarios
12 pages, 6 figures
Phys.Lett.B666:57-61,2008
10.1016/j.physletb.2008.07.010
UT-08-17, IPMU-08-0029
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider supersymmetric (SUSY) models in which a very light gravitino is the lightest SUSY particle. Assuming that a neutralino is the next-to-lightest SUSY particle, we present a measurement of the neutralino mass at the LHC in two photons + missing energy events, which is based on the MT2 method. It is a direct measurement of the neutralino mass itself, independent of other SUSY particle masses and patterns of cascade decays before the neutralino is produced.
[ { "created": "Fri, 16 May 2008 11:39:36 GMT", "version": "v1" } ]
2010-05-12
[ [ "Hamaguchi", "Koichi", "" ], [ "Nakamura", "Eita", "" ], [ "Shirai", "Satoshi", "" ] ]
We consider supersymmetric (SUSY) models in which a very light gravitino is the lightest SUSY particle. Assuming that a neutralino is the next-to-lightest SUSY particle, we present a measurement of the neutralino mass at the LHC in two photons + missing energy events, which is based on the MT2 method. It is a direct measurement of the neutralino mass itself, independent of other SUSY particle masses and patterns of cascade decays before the neutralino is produced.
2304.11480
G\"oran F\"aldt
G\"oran F\"aldt
Initial state radiation in $e^+e^-$ annihilation
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
In two earlier papers it was demonstrated that Lorentzian and Galilean symmetries could both be useful in the analysis of the annihilation reaction $e^+ e^- \to \gamma \Lambda(\rightarrow p\pi^-) \bar{\Lambda}(\rightarrow \bar{p}\pi^+)$. It was also demonstrated that any pair of hyperon form factors would be acceptable, but that the $\{G_E, G_M\}$ pair would probably be the simplest one to handle.
[ { "created": "Sat, 22 Apr 2023 20:52:55 GMT", "version": "v1" } ]
2023-04-25
[ [ "Fäldt", "Göran", "" ] ]
In two earlier papers it was demonstrated that Lorentzian and Galilean symmetries could both be useful in the analysis of the annihilation reaction $e^+ e^- \to \gamma \Lambda(\rightarrow p\pi^-) \bar{\Lambda}(\rightarrow \bar{p}\pi^+)$. It was also demonstrated that any pair of hyperon form factors would be acceptable, but that the $\{G_E, G_M\}$ pair would probably be the simplest one to handle.
2008.04016
Suman Kumbhakar
Suman Kumbhakar, Rukmani Mohanta
Investigating the effect of $U_1$ vector leptoquark on $b\to u \tau\bar{\nu}$ mediated $B$ decays
23 pages, 6 figures
J. Phys. G: Nucl. Part. Phys. 48 (2021) 075006
10.1088/1361-6471/abdc02
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent measurements of lepton flavor university (LFU) violating observables in semileptonic $b \to c \ell \bar{\nu} $ and $b\to s\ell^+ \ell^-$ transitions by various experiments exhibit $(2-3)\sigma$ deviations from their corresponding Standard Model (SM) predictions. These tantalizing signals hint towards the possible role of new physics (NP) in $b \to c \tau \bar{\nu}$ and $b\to s\mu^+\mu^-$ decay channels. This in turn indicates that the same class of NP as appeared in $b \to c \tau \bar{\nu}$, might also show up in other tree level processes involving $b \to u \tau \bar{\nu}$ transition. Since these charged current transitions are doubly Cabibbo suppressed, the NP contributions could be significant enough leading to sizeable effects in some of the observables. In this paper, we study the implications of the vector leptoquark $U_1(3,1,2/3)$, which is one of the few scenarios that can simultaneously explain the LFU violation signals both in the charged-current as well as neutral-current sectors, on the semileptonic decays $B \to (\pi, \rho, \omega)\tau \bar{\nu}$ and $B_s \to (K, K^*) \tau \bar{\nu}$. In particular, we pay our attention to the branching fraction, lepton flavor non-universality (LNU) observable, forward-backward asymmetry and the polarization asymmetry parameters of these modes. We find substantial deviations in the branching fractions as well as LNU observables of these decay modes due to the $U_1$ contributions, which can be probed by the currently running experiments LHCb and Belle-II.
[ { "created": "Mon, 10 Aug 2020 10:52:33 GMT", "version": "v1" } ]
2021-06-08
[ [ "Kumbhakar", "Suman", "" ], [ "Mohanta", "Rukmani", "" ] ]
The recent measurements of lepton flavor university (LFU) violating observables in semileptonic $b \to c \ell \bar{\nu} $ and $b\to s\ell^+ \ell^-$ transitions by various experiments exhibit $(2-3)\sigma$ deviations from their corresponding Standard Model (SM) predictions. These tantalizing signals hint towards the possible role of new physics (NP) in $b \to c \tau \bar{\nu}$ and $b\to s\mu^+\mu^-$ decay channels. This in turn indicates that the same class of NP as appeared in $b \to c \tau \bar{\nu}$, might also show up in other tree level processes involving $b \to u \tau \bar{\nu}$ transition. Since these charged current transitions are doubly Cabibbo suppressed, the NP contributions could be significant enough leading to sizeable effects in some of the observables. In this paper, we study the implications of the vector leptoquark $U_1(3,1,2/3)$, which is one of the few scenarios that can simultaneously explain the LFU violation signals both in the charged-current as well as neutral-current sectors, on the semileptonic decays $B \to (\pi, \rho, \omega)\tau \bar{\nu}$ and $B_s \to (K, K^*) \tau \bar{\nu}$. In particular, we pay our attention to the branching fraction, lepton flavor non-universality (LNU) observable, forward-backward asymmetry and the polarization asymmetry parameters of these modes. We find substantial deviations in the branching fractions as well as LNU observables of these decay modes due to the $U_1$ contributions, which can be probed by the currently running experiments LHCb and Belle-II.
2006.08985
Abhijit Bhattacharyya Prof.
Somenath Pal, Abhijit Bhattacharyya and Rajarshi Ray
Modified Excluded Volume Hadron Resonance Gas Model with Lorentz Contraction
null
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we discuss a modified version of Excluded Volume Hadron Resonance Gas model and also study the effect of Lorentz contraction of the excluded volume on scaled pressure and susceptibilities of conserved charges. We find that the Lorentz contraction, coupled with the variety of excluded volume parameters reproduce the lattice QCD data quite satisfactorily.
[ { "created": "Tue, 16 Jun 2020 08:30:15 GMT", "version": "v1" }, { "created": "Tue, 9 Mar 2021 07:10:30 GMT", "version": "v2" } ]
2021-03-10
[ [ "Pal", "Somenath", "" ], [ "Bhattacharyya", "Abhijit", "" ], [ "Ray", "Rajarshi", "" ] ]
In this work we discuss a modified version of Excluded Volume Hadron Resonance Gas model and also study the effect of Lorentz contraction of the excluded volume on scaled pressure and susceptibilities of conserved charges. We find that the Lorentz contraction, coupled with the variety of excluded volume parameters reproduce the lattice QCD data quite satisfactorily.
hep-ph/9603358
null
A.Barducci, R.Casalbuoni, M.Modugno, G.Pettini, R.Gatto
1/N_c expansion for the partition function in four fermion models
9 pages, latex, no figures
Mod.Phys.Lett.A11:1579-1587,1996
10.1142/S0217732396001570
UGVA-DPT 1996/03-916
hep-ph hep-th nucl-th
null
We present a derivation of the bosonic contribution to the thermodynamical potential of four fermion models by means of a $1/N_c$-expansion of the functional integral defining the partition function. This expansion turns out to be particularly useful to correct the mean field approximation expecially at low temperatures, where the relevant degrees of freedom are low-mass bosonic excitations (pseudogoldstones).
[ { "created": "Wed, 20 Mar 1996 10:17:11 GMT", "version": "v1" } ]
2008-11-26
[ [ "Barducci", "A.", "" ], [ "Casalbuoni", "R.", "" ], [ "Modugno", "M.", "" ], [ "Pettini", "G.", "" ], [ "Gatto", "R.", "" ] ]
We present a derivation of the bosonic contribution to the thermodynamical potential of four fermion models by means of a $1/N_c$-expansion of the functional integral defining the partition function. This expansion turns out to be particularly useful to correct the mean field approximation expecially at low temperatures, where the relevant degrees of freedom are low-mass bosonic excitations (pseudogoldstones).
1608.04785
Kazem Azizi
S. S. Agaev, K. Azizi, B. Barsbay, H. Sundu
Resonance $X(5568)$ as an exotic axial-vector state
10 Pages, 5 Figures and 1 Table
null
10.1140/epja/i2017-12201-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The mass and meson-current coupling constant of the resonance $X(5568)$, as well as the width of the decay $X(5568)\to B_s^{\ast}\pi$ are calculated by modeling the exotic $X(5568)$ resonance as a diquark-antidiquark state $% X_b=[su][bd]$ with quantum numbers $J^{P}=1^{+}$. The calculations are made employing QCD two-point sum rule method, where the quark, gluon and mixed vacuum condensates up to dimension eight are taken into account. The sum rule approach on the light-cone in its soft-meson approximation is used to explore the vertex $X_bB_{s}^{\ast}\pi$ and extract the strong coupling $% g_{X_bB_{s}^{\ast}\pi}$, which is a necessary ingredient to find the width of the $X_b \to B_s^{\ast}\pi^{+}$ decay process. The obtained predictions are compared with the experimental data of the D0 Collaboration, and results of other theoretical works.
[ { "created": "Tue, 16 Aug 2016 21:30:43 GMT", "version": "v1" }, { "created": "Tue, 27 Sep 2016 09:35:15 GMT", "version": "v2" }, { "created": "Fri, 20 Jan 2017 13:30:10 GMT", "version": "v3" } ]
2017-03-08
[ [ "Agaev", "S. S.", "" ], [ "Azizi", "K.", "" ], [ "Barsbay", "B.", "" ], [ "Sundu", "H.", "" ] ]
The mass and meson-current coupling constant of the resonance $X(5568)$, as well as the width of the decay $X(5568)\to B_s^{\ast}\pi$ are calculated by modeling the exotic $X(5568)$ resonance as a diquark-antidiquark state $% X_b=[su][bd]$ with quantum numbers $J^{P}=1^{+}$. The calculations are made employing QCD two-point sum rule method, where the quark, gluon and mixed vacuum condensates up to dimension eight are taken into account. The sum rule approach on the light-cone in its soft-meson approximation is used to explore the vertex $X_bB_{s}^{\ast}\pi$ and extract the strong coupling $% g_{X_bB_{s}^{\ast}\pi}$, which is a necessary ingredient to find the width of the $X_b \to B_s^{\ast}\pi^{+}$ decay process. The obtained predictions are compared with the experimental data of the D0 Collaboration, and results of other theoretical works.
hep-ph/0202105
Xin-Nian Wang
Enke Wang and Xin-Nian Wang
Jet Tomography of Hot and Cold Nuclear Matter
4 pages in RevTex with 3 ps figures, final version published in Phys. Rev. Letters
Phys.Rev.Lett.89:162301,2002
10.1103/PhysRevLett.89.162301
LBNL-49561
hep-ph hep-ex nucl-ex nucl-th
null
Medium modification of parton fragmentation functions induced by multiple scattering and gluon bremsstrahlung is shown to describe the recent HERMES data in deeply inelastic scattering (DIS) very well, providing the first evidence of $A^{2/3}$-dependence of the modification. The energy loss is found to be $<dE/dL> \approx 0.5$ GeV/fm for a 10-GeV quark in a $Au$ nucleus. Including the effect of expansion, analysis of the $\pi^0$ spectra in central $Au+Au$ collisions at $\sqrt{s}=130$ GeV yields an averaged energy loss equivalent to $<dE/dL> \approx 7.3$ GeV/fm in a static medium. Predictions for central $Au+Au$ collisions at $\sqrt{s}=200$ GeV are also given.
[ { "created": "Tue, 12 Feb 2002 01:46:04 GMT", "version": "v1" }, { "created": "Mon, 18 Feb 2002 04:51:14 GMT", "version": "v2" }, { "created": "Mon, 21 Oct 2002 03:47:19 GMT", "version": "v3" } ]
2014-11-17
[ [ "Wang", "Enke", "" ], [ "Wang", "Xin-Nian", "" ] ]
Medium modification of parton fragmentation functions induced by multiple scattering and gluon bremsstrahlung is shown to describe the recent HERMES data in deeply inelastic scattering (DIS) very well, providing the first evidence of $A^{2/3}$-dependence of the modification. The energy loss is found to be $<dE/dL> \approx 0.5$ GeV/fm for a 10-GeV quark in a $Au$ nucleus. Including the effect of expansion, analysis of the $\pi^0$ spectra in central $Au+Au$ collisions at $\sqrt{s}=130$ GeV yields an averaged energy loss equivalent to $<dE/dL> \approx 7.3$ GeV/fm in a static medium. Predictions for central $Au+Au$ collisions at $\sqrt{s}=200$ GeV are also given.
0810.3779
Ashutosh Alok
Ashutosh Kumar Alok, Amol Dighe, S. Uma Sankar
Large forward-backward asymmetry in B --> K mu+ mu- from new physics tensor operators
19 pages, 5 figures
Phys.Rev.D78:114025,2008
10.1103/PhysRevD.78.114025
TIFR/TH/08-41
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the constraints on possible new physics contribution to the forward-backward asymmetry of muons, A_{FB}(q^2), in B --> K mu+ mu-. New physics in the form of vector/axial-vector operators does not contribute to A_{FB}(q^2) whereas new physics in the form of scalar/pseudoscalar operators can enhance A_{FB}(q^2) only by a few per cent. However new physics the form of tensor operators can take the peak value of A_{FB}(q^2) to as high as 40% near the high-q^2 end point. In addition, if both scalar/pseudoscalar and tensor operators are present, then A_{FB}(q^2) can be more than 15% for the entire high-q^2 region q^2 > 15 GeV^2. The observation of significant A_{FB} would imply the presence of new physics tensor operators, whereas its q^2 dependence could further indicate the presence of new scalar/pseudoscalar physics.
[ { "created": "Tue, 21 Oct 2008 09:18:00 GMT", "version": "v1" } ]
2010-04-15
[ [ "Alok", "Ashutosh Kumar", "" ], [ "Dighe", "Amol", "" ], [ "Sankar", "S. Uma", "" ] ]
We study the constraints on possible new physics contribution to the forward-backward asymmetry of muons, A_{FB}(q^2), in B --> K mu+ mu-. New physics in the form of vector/axial-vector operators does not contribute to A_{FB}(q^2) whereas new physics in the form of scalar/pseudoscalar operators can enhance A_{FB}(q^2) only by a few per cent. However new physics the form of tensor operators can take the peak value of A_{FB}(q^2) to as high as 40% near the high-q^2 end point. In addition, if both scalar/pseudoscalar and tensor operators are present, then A_{FB}(q^2) can be more than 15% for the entire high-q^2 region q^2 > 15 GeV^2. The observation of significant A_{FB} would imply the presence of new physics tensor operators, whereas its q^2 dependence could further indicate the presence of new scalar/pseudoscalar physics.