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1409.2627
Shinji Maedan
Shinji Maedan
Analytically expressed constraint on two Majorana phases in neutrinoless double beta decay
36 pages, Latex; revised Figures 1 and 2, added four references [16] [17] [18] [20]
null
null
TNCT-1401
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We assume that neutrinoless double beta decay is caused by the exchange of three light Majorana neutrinos. Under this assumption, we obtain, by the method of perturbation, the equation representing the isocontour of effective Majorana mass which is the function of two CP-violating Majorana phases. The equation representing the isocontour (constraint equation between two Majorana phases) is expressed analytically by six parameters: two lepton mixing angles, two kinds of neutrino mass squared differences, lightest neutrino mass scale, and the effective Majorana mass. We discuss how the constraint equation between two Majorana phases changes when the lightest neutrino mass scale is varied.
[ { "created": "Tue, 9 Sep 2014 08:02:21 GMT", "version": "v1" }, { "created": "Fri, 26 Sep 2014 00:53:53 GMT", "version": "v2" } ]
2014-09-29
[ [ "Maedan", "Shinji", "" ] ]
We assume that neutrinoless double beta decay is caused by the exchange of three light Majorana neutrinos. Under this assumption, we obtain, by the method of perturbation, the equation representing the isocontour of effective Majorana mass which is the function of two CP-violating Majorana phases. The equation representing the isocontour (constraint equation between two Majorana phases) is expressed analytically by six parameters: two lepton mixing angles, two kinds of neutrino mass squared differences, lightest neutrino mass scale, and the effective Majorana mass. We discuss how the constraint equation between two Majorana phases changes when the lightest neutrino mass scale is varied.
1901.06352
Bryan Larios
J. Lorenzo Diaz-Cruz and Bryan O. Larios
Very long-lived Stop NLSP in MSSM scenarios with Gravitino LSP
21 pages, 9 figures
null
null
CIFFU-19-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the calculation of the stop ($\tilde{t}$) lifetime that results from its decay into gravitinos ($\tilde{\Psi}^{\mu}$) in the final state, namely $\tilde{t}\to \tilde{\Psi}^{\mu} + X$, where $X=t, bW, b l\nu_l$ for the two-, three- and four-body decay modes. The full calculation is obtained using the Feynman rules for massive gravitino, which is compared with the results obtained employing the equivalence theorem, where the longitudinal component of the gravitino is replaced by the goldstino. The stop turns out to be very long-lived in these scenarios, with lifetimes of $\mathcal{O}$($10^8$s, $10^{14}$s, $10^{20}$s) for the corresponding 2-,3- and 4-body modes under consideration, and therefore all of them are safe from the big bang nucleosynthesis problem. However, the lifetime for the four body decay mode occurs during the epoch of galaxy formation. When the stop is produce at colliders, in these scenarios, it will hadronize and decay outside of the detector, even for the lowest values of stop lifetime.
[ { "created": "Fri, 18 Jan 2019 17:40:16 GMT", "version": "v1" }, { "created": "Wed, 11 Dec 2019 15:42:16 GMT", "version": "v2" } ]
2019-12-12
[ [ "Diaz-Cruz", "J. Lorenzo", "" ], [ "Larios", "Bryan O.", "" ] ]
We present the calculation of the stop ($\tilde{t}$) lifetime that results from its decay into gravitinos ($\tilde{\Psi}^{\mu}$) in the final state, namely $\tilde{t}\to \tilde{\Psi}^{\mu} + X$, where $X=t, bW, b l\nu_l$ for the two-, three- and four-body decay modes. The full calculation is obtained using the Feynman rules for massive gravitino, which is compared with the results obtained employing the equivalence theorem, where the longitudinal component of the gravitino is replaced by the goldstino. The stop turns out to be very long-lived in these scenarios, with lifetimes of $\mathcal{O}$($10^8$s, $10^{14}$s, $10^{20}$s) for the corresponding 2-,3- and 4-body modes under consideration, and therefore all of them are safe from the big bang nucleosynthesis problem. However, the lifetime for the four body decay mode occurs during the epoch of galaxy formation. When the stop is produce at colliders, in these scenarios, it will hadronize and decay outside of the detector, even for the lowest values of stop lifetime.
1606.06670
Aleksander Filip Zarnecki
Oleksii Turkot, Katarzyna Wichmann, Aleksander Filip Zarnecki
Simplified QCD fit method for BSM analysis of HERA data
11 pages, 6 figures
null
null
ZEUS-Note 2016-001
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The high-precision HERA data can be used as an input to a QCD analysis within the DGLAP formalism to obtain the detailed description of the proton structure in terms of the parton distribution functions (PDFs). However, when searching for Beyond Standard Model (BSM) contributions in the data one should take into account the possibility that the PDF set may already have been biased by partially or totally absorbing previously unrecognised new physics contributions. The ZEUS Collaboration has proposed a new approach to the BSM analysis of the inclusive $ep$ data based on the simultaneous QCD fits of parton distribution functions together with contributions of new physics processes. Unfortunately, limit setting procedure in the frequentist approach is very time consuming in this method, as full QCD analysis has to be repeated for numerous data replicas. We describe a simplified approach, based on the Taylor expansion of the cross section predictions in terms of PDF parameters, which allowed us to reduce the calculation time for the BSM limits by almost two orders of magnitude.
[ { "created": "Tue, 21 Jun 2016 17:19:43 GMT", "version": "v1" } ]
2016-06-22
[ [ "Turkot", "Oleksii", "" ], [ "Wichmann", "Katarzyna", "" ], [ "Zarnecki", "Aleksander Filip", "" ] ]
The high-precision HERA data can be used as an input to a QCD analysis within the DGLAP formalism to obtain the detailed description of the proton structure in terms of the parton distribution functions (PDFs). However, when searching for Beyond Standard Model (BSM) contributions in the data one should take into account the possibility that the PDF set may already have been biased by partially or totally absorbing previously unrecognised new physics contributions. The ZEUS Collaboration has proposed a new approach to the BSM analysis of the inclusive $ep$ data based on the simultaneous QCD fits of parton distribution functions together with contributions of new physics processes. Unfortunately, limit setting procedure in the frequentist approach is very time consuming in this method, as full QCD analysis has to be repeated for numerous data replicas. We describe a simplified approach, based on the Taylor expansion of the cross section predictions in terms of PDF parameters, which allowed us to reduce the calculation time for the BSM limits by almost two orders of magnitude.
1405.5685
Franz Herzog
Franz Herzog, Bernhard Mistlberger
The Soft-Virtual Higgs Cross-section at N3LO and the Convergence of the Threshold Expansion
Proceedings of Moriond QCD 2014; contains several interesting plots
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the validity of the soft-virtual approximation and the threshold expansion for the Higgs boson production cross-section at hadron colliders in perturbative QCD up to next-to- next-to-next-to-leading order (N3LO).
[ { "created": "Thu, 22 May 2014 09:38:24 GMT", "version": "v1" } ]
2014-05-23
[ [ "Herzog", "Franz", "" ], [ "Mistlberger", "Bernhard", "" ] ]
We discuss the validity of the soft-virtual approximation and the threshold expansion for the Higgs boson production cross-section at hadron colliders in perturbative QCD up to next-to- next-to-next-to-leading order (N3LO).
1410.2493
Loredana Bellantuono
Loredana Bellantuono
Hybrid exotic mesons in soft-wall AdS/QCD
LaTex, 5 pages, 2 figures. Poster presented at "QCD@Work 2014", International Workshop on QCD, Theory and Experiment, Giovinazzo (Bari), Italy, June 16-19, 2014. One reference added
null
10.1051/epjconf/20148000014
BARI-TH/2014-692
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hybrid mesons with exotic quantum numbers $J^{PC}=1^{-+}$ are examined in soft-wall AdS/QCD. The predicted mass spectrum is compared to the measured values of the candidates $\pi_1(1400)$, $\pi_1(1600)$ and $\pi_1(2015)$. Thermal effects are analysed through the spectral function in the AdS-Black Hole model, and the differences with the Hawking-Page description are discussed.
[ { "created": "Thu, 9 Oct 2014 14:50:08 GMT", "version": "v1" }, { "created": "Mon, 15 Dec 2014 16:03:54 GMT", "version": "v2" } ]
2015-06-23
[ [ "Bellantuono", "Loredana", "" ] ]
Hybrid mesons with exotic quantum numbers $J^{PC}=1^{-+}$ are examined in soft-wall AdS/QCD. The predicted mass spectrum is compared to the measured values of the candidates $\pi_1(1400)$, $\pi_1(1600)$ and $\pi_1(2015)$. Thermal effects are analysed through the spectral function in the AdS-Black Hole model, and the differences with the Hawking-Page description are discussed.
0905.2205
Anna Kaminska
Anna Kaminska (Warsaw U.), Pawel Pacholek (Warsaw U.)
Reheating in an early supersymmetric universe
Talk given at 44th Rencontres de Moriond on Electroweak Interactions and Unified Theories, 7-14 March 2009
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by a recent discussion about the role of flat directions, a typical feature of supersymmetric models, in the process of particle production in the early universe a consistent model of inflation and preheating in supergravity with MSSM fields has been built. It is based on a model proposed by M. Kawasaki, M. Yamaguchi and T. Yanagida. In the inflationary stage, the flat directions acquire large vacuum expectation values (VEVs) without spoiling the background of slow-roll, high-scale inflation consistent with the latest WMAP5 observational data. In the stage of particle production, naturally following inflation, the role of flat direction large VEVs depends strongly on effects connected with the supergravity framework and non-renormalizable terms in the superpotential, which have been neglected so far in the literature. Such effects turn out to be very important, changing the previous picture of preheating in the presence of large flat direction VEVs by allowing for efficient preheating from the inflaton.
[ { "created": "Wed, 13 May 2009 21:53:01 GMT", "version": "v1" } ]
2009-05-15
[ [ "Kaminska", "Anna", "", "Warsaw U." ], [ "Pacholek", "Pawel", "", "Warsaw U." ] ]
Motivated by a recent discussion about the role of flat directions, a typical feature of supersymmetric models, in the process of particle production in the early universe a consistent model of inflation and preheating in supergravity with MSSM fields has been built. It is based on a model proposed by M. Kawasaki, M. Yamaguchi and T. Yanagida. In the inflationary stage, the flat directions acquire large vacuum expectation values (VEVs) without spoiling the background of slow-roll, high-scale inflation consistent with the latest WMAP5 observational data. In the stage of particle production, naturally following inflation, the role of flat direction large VEVs depends strongly on effects connected with the supergravity framework and non-renormalizable terms in the superpotential, which have been neglected so far in the literature. Such effects turn out to be very important, changing the previous picture of preheating in the presence of large flat direction VEVs by allowing for efficient preheating from the inflaton.
2004.02921
Simone Biondini
Simone Biondini and K. Sravan Kumar
Dark matter and Standard Model reheating from conformal GUT inflation
38 pages, 9 figures, matches published version
J. High Energ. Phys. 2020, 39 (2020)
10.1007/JHEP07(2020)039
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spontaneous breaking of conformal symmetry has been widely exploited in successful model building of both inflationary cosmology and particle physics phenomenology. Conformal Grand Unified Theory (CGUT) inflation provides the same scalar tilt and tensor-to-scalar ratio as of Starobinsky and Higgs inflation. Moreover, it predicts a proton life time compatible with the current experimental bound. In this paper, we extend CGUT to account for the production of dark matter and the reheating of the Standard Model. To this end, we introduce a hidden sector directly coupled to the inflaton, whereas the reheating of the visible sector is realized through a portal coupling between the dark particles and the Higgs boson. The masses and interactions of the dark particles and the Higgs boson are determined by the form of the conformal potential and the non-vanishing VEV of the inflaton. We provide benchmark points in the parameter space of the model that give the observed dark matter relic density and reheating temperatures compatible with the Big Bang nucleosynthesis.
[ { "created": "Mon, 6 Apr 2020 18:18:36 GMT", "version": "v1" }, { "created": "Thu, 16 Apr 2020 18:57:07 GMT", "version": "v2" }, { "created": "Thu, 9 Jul 2020 11:28:01 GMT", "version": "v3" } ]
2020-07-28
[ [ "Biondini", "Simone", "" ], [ "Kumar", "K. Sravan", "" ] ]
Spontaneous breaking of conformal symmetry has been widely exploited in successful model building of both inflationary cosmology and particle physics phenomenology. Conformal Grand Unified Theory (CGUT) inflation provides the same scalar tilt and tensor-to-scalar ratio as of Starobinsky and Higgs inflation. Moreover, it predicts a proton life time compatible with the current experimental bound. In this paper, we extend CGUT to account for the production of dark matter and the reheating of the Standard Model. To this end, we introduce a hidden sector directly coupled to the inflaton, whereas the reheating of the visible sector is realized through a portal coupling between the dark particles and the Higgs boson. The masses and interactions of the dark particles and the Higgs boson are determined by the form of the conformal potential and the non-vanishing VEV of the inflaton. We provide benchmark points in the parameter space of the model that give the observed dark matter relic density and reheating temperatures compatible with the Big Bang nucleosynthesis.
hep-ph/0010060
Victor Goncalves
V. P. Goncalves (IFM - UFPel)
Searching Saturation in eA Processes
13 pages, 2 figures, 1 table
Phys.Lett. B495 (2000) 303-308
10.1016/S0370-2693(00)01258-2
null
hep-ph
null
The high density effects should be manifest at small x and/or large nuclei. In this letter we consider the behavior of nuclear structure function $F_2^A$ slope in the kinematic region which could be explored in the future eA colliders as a search of these effects. We verify that the high density implies that the maximum value of the slope occurs at large values of the photon virtuality, i.e. in a perturbative regime, and is dependent of the number of nucleons A and energy. Our conclusion is that the measurement of this observable will allow to explicit the saturation.
[ { "created": "Fri, 6 Oct 2000 18:07:23 GMT", "version": "v1" } ]
2009-10-31
[ [ "Goncalves", "V. P.", "", "IFM - UFPel" ] ]
The high density effects should be manifest at small x and/or large nuclei. In this letter we consider the behavior of nuclear structure function $F_2^A$ slope in the kinematic region which could be explored in the future eA colliders as a search of these effects. We verify that the high density implies that the maximum value of the slope occurs at large values of the photon virtuality, i.e. in a perturbative regime, and is dependent of the number of nucleons A and energy. Our conclusion is that the measurement of this observable will allow to explicit the saturation.
hep-ph/0311029
Ricardo Gonzalez Felipe
R. Gonzalez Felipe, F. R. Joaquim, B. M. Nobre
Radiatively induced leptogenesis in a minimal seesaw model
6 pages, 2 figures, uses RevTeX4, calculations improved, comments added
Phys.Rev.D70:085009,2004
10.1103/PhysRevD.70.085009
null
hep-ph
null
We study the possibility that the baryon asymmetry of the universe is generated in a minimal seesaw scenario where two right-handed Majorana neutrinos with degenerate masses are added to the standard model particle content. In the usual framework of thermal leptogenesis, a nonzero $CP$ asymmetry can be obtained through the mass splitting induced by the running of the heavy Majorana neutrino masses from their degeneracy scale down to the seesaw scale. Although, in the light of the present neutrino oscillation data, the produced baryon asymmetry turns out to be smaller than the experimental value, the present mechanism could be viable in simple extensions of the standard model.
[ { "created": "Tue, 4 Nov 2003 19:23:20 GMT", "version": "v1" }, { "created": "Fri, 16 Apr 2004 18:53:55 GMT", "version": "v2" }, { "created": "Wed, 15 Sep 2004 18:00:49 GMT", "version": "v3" } ]
2008-11-26
[ [ "Felipe", "R. Gonzalez", "" ], [ "Joaquim", "F. R.", "" ], [ "Nobre", "B. M.", "" ] ]
We study the possibility that the baryon asymmetry of the universe is generated in a minimal seesaw scenario where two right-handed Majorana neutrinos with degenerate masses are added to the standard model particle content. In the usual framework of thermal leptogenesis, a nonzero $CP$ asymmetry can be obtained through the mass splitting induced by the running of the heavy Majorana neutrino masses from their degeneracy scale down to the seesaw scale. Although, in the light of the present neutrino oscillation data, the produced baryon asymmetry turns out to be smaller than the experimental value, the present mechanism could be viable in simple extensions of the standard model.
1102.3251
Ru Peng
R Peng and C B Yang
Productions of Heavy Flavored Mesons in Relativistic Heavy Ion Collisions in the Recombination Model
15pages, 14 figures
Int.J.Mod.Phys.E20:1213-1226,2011
10.1142/S0218301311018356
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We get the distributions of shower partons initiated by heavy quarks $c$ and $b$ by studying the fragmentation functions in the framework of the recombination model. The transverse momentum spectra of heavy flavored mesons are predicted with these distributions. We find that the contribution from the recombination of thermal-shower partons is an important part in the total spectrum for the mesons. We predict the heavy flavored meson productions for different centralities with the heavy quark fugacities fitted by the experimental data of $J/\psi$ transverse momentum spectra in Au+Au collisions.
[ { "created": "Wed, 16 Feb 2011 06:43:44 GMT", "version": "v1" } ]
2011-06-13
[ [ "Peng", "R", "" ], [ "Yang", "C B", "" ] ]
We get the distributions of shower partons initiated by heavy quarks $c$ and $b$ by studying the fragmentation functions in the framework of the recombination model. The transverse momentum spectra of heavy flavored mesons are predicted with these distributions. We find that the contribution from the recombination of thermal-shower partons is an important part in the total spectrum for the mesons. We predict the heavy flavored meson productions for different centralities with the heavy quark fugacities fitted by the experimental data of $J/\psi$ transverse momentum spectra in Au+Au collisions.
hep-ph/9712375
Ljuba Rasdolskaya
E.Gedalin, A.Moalem and L.Razdolskaja
A Covariant OBE Model for $\eta$ Production in NN Collisions
40 pages, 15 figures
Nucl.Phys. A634 (1998) 368-392
10.1016/S0375-9474(98)00152-3
BGU PH-97/14
hep-ph
null
A relativistic covariant one boson exchange model, previously applied to describe elastic nucleon-nucleon scattering, is extended to study $\eta$ production in NN collisions. The transition amplitude for the elementary BN->$\eta$N process with B being the meson exchanged (B=$\pi$, $|sigma$,$\eta$, $\rho$, $\omega$ and $\delta$) are taken to be the sum of four terms corresponding to s and u-channels with a nucleon or a nucleon isobar N*(1535MeV) in the intermediate states. Taking the relative phases of the various exchange amplitudes to be +1, the model reproduces the cross sections for the $NN\to X\eta$ reactions in a consistent manner. In the limit where all $\eta$'s are produced via N^* excitations, interference terms between the overall contributions from the exchange of pseudoscalart and scalar mesons with that of vector mesons cancel out. Consequently, much of the ambiguities in the model predictions due to unknown relative phases of different vector pseudoscalar exchanges are strongly reduced.
[ { "created": "Mon, 15 Dec 1997 08:21:09 GMT", "version": "v1" }, { "created": "Thu, 18 Dec 1997 07:38:09 GMT", "version": "v2" } ]
2009-10-30
[ [ "Gedalin", "E.", "" ], [ "Moalem", "A.", "" ], [ "Razdolskaja", "L.", "" ] ]
A relativistic covariant one boson exchange model, previously applied to describe elastic nucleon-nucleon scattering, is extended to study $\eta$ production in NN collisions. The transition amplitude for the elementary BN->$\eta$N process with B being the meson exchanged (B=$\pi$, $|sigma$,$\eta$, $\rho$, $\omega$ and $\delta$) are taken to be the sum of four terms corresponding to s and u-channels with a nucleon or a nucleon isobar N*(1535MeV) in the intermediate states. Taking the relative phases of the various exchange amplitudes to be +1, the model reproduces the cross sections for the $NN\to X\eta$ reactions in a consistent manner. In the limit where all $\eta$'s are produced via N^* excitations, interference terms between the overall contributions from the exchange of pseudoscalart and scalar mesons with that of vector mesons cancel out. Consequently, much of the ambiguities in the model predictions due to unknown relative phases of different vector pseudoscalar exchanges are strongly reduced.
1504.05979
Nikolai Zerf
M. Baker, A.A. Penin, D. Seidel, N. Zerf
Bottomonium Hyperfine Splitting on the Lattice and in the Continuum
6 pages, 2 figures, journal version
Phys. Rev. D 92, 054502 (2015)
10.1103/PhysRevD.92.054502
ALBERTA-THY-03-15, QFET-2015-16, SI-HEP-2015-13
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revise the analysis of the bottomonium hyperfine splitting within the lattice nonrelativistic QCD. The Wilson coefficients of the radiatively improved lattice action are evaluated by a semianalytic approach based on the asymptotic expansion about the continuum limit. The nonrelativistic renormalization group is used to estimate the high-order radiative corrections. Our result for the $1S$ hyperfine splitting is $M_{\Upsilon(1S)}-M_{\eta_b(1S)}=52.9\pm 5.5~{\rm MeV}$. It reconciles the predictions of the continuum and lattice QCD and is in very good agreement with the most accurate experimental measurement by Belle collaboration.
[ { "created": "Wed, 22 Apr 2015 20:41:33 GMT", "version": "v1" }, { "created": "Mon, 21 Sep 2015 22:20:11 GMT", "version": "v2" } ]
2015-09-23
[ [ "Baker", "M.", "" ], [ "Penin", "A. A.", "" ], [ "Seidel", "D.", "" ], [ "Zerf", "N.", "" ] ]
We revise the analysis of the bottomonium hyperfine splitting within the lattice nonrelativistic QCD. The Wilson coefficients of the radiatively improved lattice action are evaluated by a semianalytic approach based on the asymptotic expansion about the continuum limit. The nonrelativistic renormalization group is used to estimate the high-order radiative corrections. Our result for the $1S$ hyperfine splitting is $M_{\Upsilon(1S)}-M_{\eta_b(1S)}=52.9\pm 5.5~{\rm MeV}$. It reconciles the predictions of the continuum and lattice QCD and is in very good agreement with the most accurate experimental measurement by Belle collaboration.
2405.13104
Benjamin Safdi
Nicholas L. Rodd, Benjamin R. Safdi, Weishuang Linda Xu
CTA and SWGO can Discover Higgsino Dark Matter Annihilation
42 pages, 38 figures, video abstract at https://youtu.be/8VxOuEDm16A
null
null
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Thermal higgsino dark matter (DM), with a mass near 1.1 TeV, is one of the most well-motivated and untested DM candidates. Leveraging recent hydrodynamic cosmological simulations that give DM density profiles in Milky Way analogue galaxies we show that the line-like gamma-ray signal predicted from higgsino annihilation in the Galactic Center could be detected at high significance with the upcoming Cherenkov Telescope Array (CTA) and Southern Wide-field Gamma-ray Observatory (SWGO) for all but the most pessimistic DM profiles. We perform the most sensitive search to-date for the line-like signal using 15 years of data from the Fermi Large Area Telescope, coming within an order one factor of the necessary sensitivity to detect the higgsino for some Milky Way analogue DM density profiles. We show that H.E.S.S. has sub-leading sensitivity relative to Fermi for the higgsino at present. In contrast, we analyze H.E.S.S. inner Galaxy data for the thermal wino model with a mass near 2.8 TeV; we find no evidence for a DM signal and exclude the wino by over a factor of two in cross-section for all DM profiles considered. In the process, we identify and attempt to correct what appears to be an inconsistency in previous H.E.S.S. inner Galaxy analyses for DM annihilation related to the analysis effective area, which may weaken the DM cross-section sensitivity claimed in those works by around an order of magnitude.
[ { "created": "Tue, 21 May 2024 18:00:00 GMT", "version": "v1" } ]
2024-05-24
[ [ "Rodd", "Nicholas L.", "" ], [ "Safdi", "Benjamin R.", "" ], [ "Xu", "Weishuang Linda", "" ] ]
Thermal higgsino dark matter (DM), with a mass near 1.1 TeV, is one of the most well-motivated and untested DM candidates. Leveraging recent hydrodynamic cosmological simulations that give DM density profiles in Milky Way analogue galaxies we show that the line-like gamma-ray signal predicted from higgsino annihilation in the Galactic Center could be detected at high significance with the upcoming Cherenkov Telescope Array (CTA) and Southern Wide-field Gamma-ray Observatory (SWGO) for all but the most pessimistic DM profiles. We perform the most sensitive search to-date for the line-like signal using 15 years of data from the Fermi Large Area Telescope, coming within an order one factor of the necessary sensitivity to detect the higgsino for some Milky Way analogue DM density profiles. We show that H.E.S.S. has sub-leading sensitivity relative to Fermi for the higgsino at present. In contrast, we analyze H.E.S.S. inner Galaxy data for the thermal wino model with a mass near 2.8 TeV; we find no evidence for a DM signal and exclude the wino by over a factor of two in cross-section for all DM profiles considered. In the process, we identify and attempt to correct what appears to be an inconsistency in previous H.E.S.S. inner Galaxy analyses for DM annihilation related to the analysis effective area, which may weaken the DM cross-section sensitivity claimed in those works by around an order of magnitude.
1507.03419
Gui-Jun Ding
Peng Chen, Chang-Yuan Yao, Gui-Jun Ding
Neutrino Mixing from CP Symmetry
18 pages, 2 figures
Phys. Rev. D 92, 073002 (2015)
10.1103/PhysRevD.92.073002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The neutrino mass matrix has remnant CP symmetry expressed in terms of the lepton mixing matrix, and vice versa the remnant CP transformations allow us to reconstruct the mixing matrix. We study the scenario that all the four remnant CP transformations are preserved by the neutrino mass matrix. The most general parameterization of remnant CP transformations is presented. The lepton mixing matrix is completely fixed by the remnant CP, and its explicit form is derived. The necessary and sufficient condition for conserved Dirac CP violating phase is found. If the Klein four flavor symmetry generated by the postulated remnant CP transformations arises from a finite flavor symmetry group, the phenomenologically viable lepton flavor mixing would be the trimaximal pattern, both Dirac CP phase $\delta_{CP}$ and Majorana phase $\alpha_{31}$ are either $0$ or $\pi$ while another Majorana phase $\alpha_{21}$ is a rational multiple of $\pi$. These general results are confirmed to be true in the case that the finite flavor symmetry group is $\Delta(6n^2)$.
[ { "created": "Mon, 13 Jul 2015 12:24:28 GMT", "version": "v1" } ]
2015-10-07
[ [ "Chen", "Peng", "" ], [ "Yao", "Chang-Yuan", "" ], [ "Ding", "Gui-Jun", "" ] ]
The neutrino mass matrix has remnant CP symmetry expressed in terms of the lepton mixing matrix, and vice versa the remnant CP transformations allow us to reconstruct the mixing matrix. We study the scenario that all the four remnant CP transformations are preserved by the neutrino mass matrix. The most general parameterization of remnant CP transformations is presented. The lepton mixing matrix is completely fixed by the remnant CP, and its explicit form is derived. The necessary and sufficient condition for conserved Dirac CP violating phase is found. If the Klein four flavor symmetry generated by the postulated remnant CP transformations arises from a finite flavor symmetry group, the phenomenologically viable lepton flavor mixing would be the trimaximal pattern, both Dirac CP phase $\delta_{CP}$ and Majorana phase $\alpha_{31}$ are either $0$ or $\pi$ while another Majorana phase $\alpha_{21}$ is a rational multiple of $\pi$. These general results are confirmed to be true in the case that the finite flavor symmetry group is $\Delta(6n^2)$.
1111.0182
Jacqueline A. Bonnet
J. A. Bonnet, C. S. Fischer and R. Williams
Effects of Anisotropy in (2+1)-dimensional QED
7 pages, 4 figures, contribution to the proceedings of the International School of Nuclear Physics, Erice 2011
null
10.1016/j.ppnp.2011.12.026
null
hep-ph cond-mat.supr-con
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We summarize our results for the impact of anisotropic fermionic velocities in (2+1)-dimensional QED on the critical number of fermion flavors, N^c_f, and dynamical mass generation. We apply different approximation schemes for the gauge boson vacuum polarization and the fermion-boson vertex to analyze the according Dyson-Schwinger equations in a finite volume. Our results point towards large variations of N^c_f away from the isotropic point in agreement with other approaches.
[ { "created": "Tue, 1 Nov 2011 12:08:25 GMT", "version": "v1" } ]
2015-06-03
[ [ "Bonnet", "J. A.", "" ], [ "Fischer", "C. S.", "" ], [ "Williams", "R.", "" ] ]
We summarize our results for the impact of anisotropic fermionic velocities in (2+1)-dimensional QED on the critical number of fermion flavors, N^c_f, and dynamical mass generation. We apply different approximation schemes for the gauge boson vacuum polarization and the fermion-boson vertex to analyze the according Dyson-Schwinger equations in a finite volume. Our results point towards large variations of N^c_f away from the isotropic point in agreement with other approaches.
1812.01633
Adarsh Pyarelal
Felix Kling, Honglei Li, Adarsh Pyarelal, Huayang Song, Shufang Su
Exotic Higgs Decays in Type-II 2HDMs at the LHC and Future 100 TeV Hadron Colliders
null
null
10.1007/JHEP06(2019)031
UCI-TR-2018-09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The exotic decay modes of non-Standard Model (SM) Higgses in models with extended Higgs sectors have the potential to serve as powerful search channels to explore the space of Two-Higgs Doublet Models (2HDMs) that cannot be studied effectively using conventional decay channels. Once kinematically allowed, heavy Higgses could decay into pairs of light non-SM Higgses, or a non-SM Higgs and a SM gauge boson, with branching fractions that dominate those of the conventional decay modes to SM particles. In this study, we focus on the prospects of probing exotic decay channels at the LHC and a future 100 TeV \emph{pp} collider in the context of Type-II 2HDMs. We study the three prominent exotic decay channels, A -> HZ, A -> H^+ W and H^+ -> HW, and find that a 100-TeV pp collider can probe the entire region of the Type-II 2HDM parameter space that survives current theoretical and experimental constraints with exotic decay branching fraction > 20%.
[ { "created": "Tue, 4 Dec 2018 19:14:41 GMT", "version": "v1" } ]
2019-06-26
[ [ "Kling", "Felix", "" ], [ "Li", "Honglei", "" ], [ "Pyarelal", "Adarsh", "" ], [ "Song", "Huayang", "" ], [ "Su", "Shufang", "" ] ]
The exotic decay modes of non-Standard Model (SM) Higgses in models with extended Higgs sectors have the potential to serve as powerful search channels to explore the space of Two-Higgs Doublet Models (2HDMs) that cannot be studied effectively using conventional decay channels. Once kinematically allowed, heavy Higgses could decay into pairs of light non-SM Higgses, or a non-SM Higgs and a SM gauge boson, with branching fractions that dominate those of the conventional decay modes to SM particles. In this study, we focus on the prospects of probing exotic decay channels at the LHC and a future 100 TeV \emph{pp} collider in the context of Type-II 2HDMs. We study the three prominent exotic decay channels, A -> HZ, A -> H^+ W and H^+ -> HW, and find that a 100-TeV pp collider can probe the entire region of the Type-II 2HDM parameter space that survives current theoretical and experimental constraints with exotic decay branching fraction > 20%.
1807.08401
Ivan Vitev
Ivan Vitev
Quarkonium tomography of heavy ion collisions at the LHC
4 pages, 4 figures; proceedings of the XXVIIth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2018)
null
10.1016/j.nuclphysa.2018.10.019
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quarkonium production in high-energy hadronic collisions provides a fundamental test of QCD. Its modification in a nuclear medium is a sensitive probe of the space-time temperature profile and transport properties of the QGP, yielding constraints complementary to the ones obtained from the quenching of light hadrons and jets, and open heavy flavor. In these proceedings, we report new results for the suppression of high transverse momentum charmonium [$J/\psi,\, \psi(2S)$] and bottomonium [$\Upsilon(1S),\, \Upsilon(2S),\, \Upsilon(3S)$] states in Pb+Pb collisions at the Large Hadron Collider. Our theoretical formalism combines the collisional dissociation of quarkonia, as they propagate in the quark-gluon plasma, with the thermal wavefunction effects due to the screening of the $Q\bar{Q}$ attractive potential in the medium. We find that a good description of the relative suppression of the ground and higher excited quarkonium states, transverse momentum and centrality distributions is achieved, when comparison to measurements at a center-of-mass energy of 2.76 TeV is performed. Theoretical predictions for the highest Pb+Pb center-of-mass energy of 5.02 TeV at the LHC, where new experimental results are being finalized are presented. Preliminary calculations for smaller systems, such as Xe+Xe are also shown. Last but not least, the potential of jet substructure to shed light in the mechanisms of heavy flavor production is discussed.
[ { "created": "Mon, 23 Jul 2018 02:05:33 GMT", "version": "v1" } ]
2019-02-20
[ [ "Vitev", "Ivan", "" ] ]
Quarkonium production in high-energy hadronic collisions provides a fundamental test of QCD. Its modification in a nuclear medium is a sensitive probe of the space-time temperature profile and transport properties of the QGP, yielding constraints complementary to the ones obtained from the quenching of light hadrons and jets, and open heavy flavor. In these proceedings, we report new results for the suppression of high transverse momentum charmonium [$J/\psi,\, \psi(2S)$] and bottomonium [$\Upsilon(1S),\, \Upsilon(2S),\, \Upsilon(3S)$] states in Pb+Pb collisions at the Large Hadron Collider. Our theoretical formalism combines the collisional dissociation of quarkonia, as they propagate in the quark-gluon plasma, with the thermal wavefunction effects due to the screening of the $Q\bar{Q}$ attractive potential in the medium. We find that a good description of the relative suppression of the ground and higher excited quarkonium states, transverse momentum and centrality distributions is achieved, when comparison to measurements at a center-of-mass energy of 2.76 TeV is performed. Theoretical predictions for the highest Pb+Pb center-of-mass energy of 5.02 TeV at the LHC, where new experimental results are being finalized are presented. Preliminary calculations for smaller systems, such as Xe+Xe are also shown. Last but not least, the potential of jet substructure to shed light in the mechanisms of heavy flavor production is discussed.
1702.03697
Oleksandr Novak
O. Novak
Pair production by an electron to excited levels in a magnetic field
4 pages, 1 figure
2015 Phys. Scr.90, 085305
10.1088/0031-8949/90/8/085305
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The resonant process of electron-positron pairproduction by an electron in a subcritical magnetic field has been studied when the pair is produced to exited Landau levels. The spin dependency of the process rate has been analyzed. In the spin state with the greatest rate the virtual photon is emitted with a flip of electron spin. This behavior is not suppressed for radiative transitions from a relativistic initial state to low energy levels.
[ { "created": "Mon, 13 Feb 2017 10:12:03 GMT", "version": "v1" } ]
2017-02-14
[ [ "Novak", "O.", "" ] ]
The resonant process of electron-positron pairproduction by an electron in a subcritical magnetic field has been studied when the pair is produced to exited Landau levels. The spin dependency of the process rate has been analyzed. In the spin state with the greatest rate the virtual photon is emitted with a flip of electron spin. This behavior is not suppressed for radiative transitions from a relativistic initial state to low energy levels.
hep-ph/9603217
Daniel Boyanovsky
D. Boyanovsky, I.D. Lawrie and D.S. Lee
Relaxation and Kinetics in Scalar Field Theories
28 pages, revtex 3.0, two figures available upon request
Phys.Rev. D54 (1996) 4013-4028
10.1103/PhysRevD.54.4013
PITT-96-172
hep-ph nucl-th
null
A new approach to the dynamics of relaxation and kinetics of thermalization in a scalar field theory is presented that incorporates the relevant time scales through the resummation of hard thermal loops. An alternative derivation of the kinetic equations for the ``quasiparticle'' distribution functions is obtained that allows a clear understanding of the different ``coarse graining'' approximations usually involved in a kinetic description. This method leads to a systematic perturbative expansion to obtain the kinetic equations including hard-thermal loop resummation and to an improvement including renormalization, off-shell effects and contributions that change chemical equilibrium on short time scales. As a byproduct of these methods we establish the relation between the relaxation time scale in the linearized equation of motion of the quasiparticles and the thermalization time scale of the quasiparticle distribution function in the ``relaxation time approximation''. Hard thermal loop resummation dramatically modifies the scattering rate for long wavelength modes as compared to the usual (semi) classical estimate. Relaxation and kinetics are studied both in the unbroken and broken symmetry phases of the theory. The broken symmetry phase also provides the setting to obtain the contribution to the kinetic equations from processes that involve decay of a heavy scalar into light scalar particles in the medium.
[ { "created": "Mon, 4 Mar 1996 14:58:09 GMT", "version": "v1" } ]
2009-10-28
[ [ "Boyanovsky", "D.", "" ], [ "Lawrie", "I. D.", "" ], [ "Lee", "D. S.", "" ] ]
A new approach to the dynamics of relaxation and kinetics of thermalization in a scalar field theory is presented that incorporates the relevant time scales through the resummation of hard thermal loops. An alternative derivation of the kinetic equations for the ``quasiparticle'' distribution functions is obtained that allows a clear understanding of the different ``coarse graining'' approximations usually involved in a kinetic description. This method leads to a systematic perturbative expansion to obtain the kinetic equations including hard-thermal loop resummation and to an improvement including renormalization, off-shell effects and contributions that change chemical equilibrium on short time scales. As a byproduct of these methods we establish the relation between the relaxation time scale in the linearized equation of motion of the quasiparticles and the thermalization time scale of the quasiparticle distribution function in the ``relaxation time approximation''. Hard thermal loop resummation dramatically modifies the scattering rate for long wavelength modes as compared to the usual (semi) classical estimate. Relaxation and kinetics are studied both in the unbroken and broken symmetry phases of the theory. The broken symmetry phase also provides the setting to obtain the contribution to the kinetic equations from processes that involve decay of a heavy scalar into light scalar particles in the medium.
hep-ph/9611207
null
Pervez Hoodbhoy
Wavefunction corrections and off-forward gluon distributions in diffractive J/psi electroproduction
14 pages, 3 figures (Latex)
Phys.Rev. D56 (1997) 388-393
10.1103/PhysRevD.56.388
null
hep-ph
null
Diffractive production of J/Psi particles by virtual photons on a proton target is studied with a view towards understanding two important corrections to the leading order result. First, the effect of Fermi motion of the heavy quarks is studied by performing a systematic expansion in the relative velocity, and a simple correction factor is derived. This is considerably less than estimated previously. Second, since the kinematics necessarily requires that non-zero momentum be transferred to the proton, off-forward gluon distributions are probed by the scattering process. To estimate the importance of the off-forwardness, we compute, in leading order perturbation theory, the extent of deviation from the usual forward gluon distribution in a quark.
[ { "created": "Fri, 1 Nov 1996 19:27:07 GMT", "version": "v1" } ]
2009-10-30
[ [ "Hoodbhoy", "Pervez", "" ] ]
Diffractive production of J/Psi particles by virtual photons on a proton target is studied with a view towards understanding two important corrections to the leading order result. First, the effect of Fermi motion of the heavy quarks is studied by performing a systematic expansion in the relative velocity, and a simple correction factor is derived. This is considerably less than estimated previously. Second, since the kinematics necessarily requires that non-zero momentum be transferred to the proton, off-forward gluon distributions are probed by the scattering process. To estimate the importance of the off-forwardness, we compute, in leading order perturbation theory, the extent of deviation from the usual forward gluon distribution in a quark.
hep-ph/0511009
Anders Tranberg
Anders Tranberg
The 2PI coupling expansion revisited
5 pages, 4 figures. To appear in the proceedings of XQCD, Swansea, 2-5 August 2005
null
null
null
hep-ph
null
Recently, out-of-equilibrium field theory has been studied using approximations based on truncations of the 2PI effective action. Although results are promising, the convergence of subsequent orders of the approximation is difficult to get a handle on, mainly because, generically, only the lowest non-trivial order is currently numerically tractable. We study one specific case, the broken phase of the phi^4 model, where the existence of an effective three point vertex makes it possible to compare a lowest and next-to-lowest non-trivial order.
[ { "created": "Tue, 1 Nov 2005 16:10:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tranberg", "Anders", "" ] ]
Recently, out-of-equilibrium field theory has been studied using approximations based on truncations of the 2PI effective action. Although results are promising, the convergence of subsequent orders of the approximation is difficult to get a handle on, mainly because, generically, only the lowest non-trivial order is currently numerically tractable. We study one specific case, the broken phase of the phi^4 model, where the existence of an effective three point vertex makes it possible to compare a lowest and next-to-lowest non-trivial order.
hep-ph/9503448
null
M. H. Friedman, Y. Srivastava and A. Widom
FERMIONS IN AN EXTERNAL SU(2) MAGNETIC FIELD
7 pages, Latex
J.Phys.G23:1061-1064,1997
10.1088/0954-3899/23/9/005
NUB 3114, March 1995
hep-ph
null
We consider Fermions in a constant and uniform external $SU(2)$ magnetic field. We find that the results for the energy levels depend on the choice of gauge potential. Choosing a Landau type gauge potential yields his results. On the other hand in another gauge potential, one obtains a different continuous eigenvalue spectrum.
[ { "created": "Mon, 27 Mar 1995 20:07:28 GMT", "version": "v1" } ]
2008-11-26
[ [ "Friedman", "M. H.", "" ], [ "Srivastava", "Y.", "" ], [ "Widom", "A.", "" ] ]
We consider Fermions in a constant and uniform external $SU(2)$ magnetic field. We find that the results for the energy levels depend on the choice of gauge potential. Choosing a Landau type gauge potential yields his results. On the other hand in another gauge potential, one obtains a different continuous eigenvalue spectrum.
hep-ph/0209108
Fabian Franke
T. Mayer, C. Bloechinger, F. Franke, H. Fraas
Chargino Production and Decay in Photon-Photon-Collisions
22 pages, 15 figures, version to be published in Eur. Phys. J. C
Eur.Phys.J.C27:135-143,2003
10.1140/epjc/s2002-01095-0
WUE-ITP-2002-022
hep-ph
null
We discuss the pair production of charginos in collisions of polarized photons $\gamma\gamma \to \tilde{\chi}_i^+ \tilde{\chi}_i^-$, ($i=1,2$) and the subsequent leptonic decay of the lighter chargino $\tilde{\chi}_1^+ \to \tilde{\chi}_1^0 e^+ \nu_e$ including the complete spin correlations. Analytical formulae are given for the polarization and the spin-spin correlations of the charginos. Since the production is a pure QED process the decay dynamics can be studied separately. For high energy photons from Compton backscattering of polarized laser pulses off polarized electron beams numerical results are presented for the cross section, the angular distribution and the forward-backward asymmetry of the decay positron. Finally we study the dependence on the gaugino mass parameter $M_1$ and on the sneutrino mass for a gaugino-like MSSM scenario.
[ { "created": "Tue, 10 Sep 2002 19:57:25 GMT", "version": "v1" }, { "created": "Tue, 10 Sep 2002 20:11:42 GMT", "version": "v2" }, { "created": "Mon, 4 Nov 2002 21:34:17 GMT", "version": "v3" } ]
2009-01-07
[ [ "Mayer", "T.", "" ], [ "Bloechinger", "C.", "" ], [ "Franke", "F.", "" ], [ "Fraas", "H.", "" ] ]
We discuss the pair production of charginos in collisions of polarized photons $\gamma\gamma \to \tilde{\chi}_i^+ \tilde{\chi}_i^-$, ($i=1,2$) and the subsequent leptonic decay of the lighter chargino $\tilde{\chi}_1^+ \to \tilde{\chi}_1^0 e^+ \nu_e$ including the complete spin correlations. Analytical formulae are given for the polarization and the spin-spin correlations of the charginos. Since the production is a pure QED process the decay dynamics can be studied separately. For high energy photons from Compton backscattering of polarized laser pulses off polarized electron beams numerical results are presented for the cross section, the angular distribution and the forward-backward asymmetry of the decay positron. Finally we study the dependence on the gaugino mass parameter $M_1$ and on the sneutrino mass for a gaugino-like MSSM scenario.
hep-ph/9301252
David Bowser-Chao
David Bowser-Chao and Kingman Cheung
Detection of the heavy Higgs boson at $\gamma\gamma$ colliders
18 pages (in RevTeX) plus Postscript figures (available by email or FAX), NUHEP-TH-92-29 and DOE-309-CPP-47. (Revised version: NO CHANGES to the manuscript, simply removed corrupted figure files)
Phys.Rev. D48 (1993) 89-95
10.1103/PhysRevD.48.89
null
hep-ph
null
We consider the possibility of detecting a heavy Higgs boson ($m_H>2m_Z$) in proposed $\gamma\gamma$ colliders through the semi-leptonic mode $\gamma\gamma \rightarrow H \rightarrow ZZ \rightarrow q\bar q \ell^+\ell^-$. We show that due to the non-monochromatic nature of the photon beams produced by the laser-backscattering method, the resultant cross section for Higgs production is much smaller than the on-resonance cross section and generally {\it decreases} with increasing collider energy. Although continuum $ZZ$ production is expected to be negligible, we demonstrate the presence of and calculate sizeable backgrounds from $\gamma\gamma\rightarrow \ell^+\ell^-Z,\,q\bar qZ$, with $Z\rightarrow q\bar q,\,\ell^+\ell^-$, respectively, and $\gamma\gamma\rightarrow t\bar t\rightarrow b\bar b\ell^+\ell^-\nu\bar\nu$. This channel may be used to detect a Higgs of mass $m_H$ up to around 350~GeV at a 0.5~TeV $e^+e^-$ collider, assuming a nominal yearly luminosity of 10--20~fb$^{-1}$.
[ { "created": "Wed, 20 Jan 1993 21:13:46 GMT", "version": "v1" }, { "created": "Thu, 21 Jan 1993 16:49:56 GMT", "version": "v2" } ]
2009-10-22
[ [ "Bowser-Chao", "David", "" ], [ "Cheung", "Kingman", "" ] ]
We consider the possibility of detecting a heavy Higgs boson ($m_H>2m_Z$) in proposed $\gamma\gamma$ colliders through the semi-leptonic mode $\gamma\gamma \rightarrow H \rightarrow ZZ \rightarrow q\bar q \ell^+\ell^-$. We show that due to the non-monochromatic nature of the photon beams produced by the laser-backscattering method, the resultant cross section for Higgs production is much smaller than the on-resonance cross section and generally {\it decreases} with increasing collider energy. Although continuum $ZZ$ production is expected to be negligible, we demonstrate the presence of and calculate sizeable backgrounds from $\gamma\gamma\rightarrow \ell^+\ell^-Z,\,q\bar qZ$, with $Z\rightarrow q\bar q,\,\ell^+\ell^-$, respectively, and $\gamma\gamma\rightarrow t\bar t\rightarrow b\bar b\ell^+\ell^-\nu\bar\nu$. This channel may be used to detect a Higgs of mass $m_H$ up to around 350~GeV at a 0.5~TeV $e^+e^-$ collider, assuming a nominal yearly luminosity of 10--20~fb$^{-1}$.
1104.4533
Nodoka Yamanaka
Nodoka Yamanaka, Toru Sato and Takahiro Kubota
Constraint on R-parity violating MSSM at the one-loop level from CP-odd N-N interaction
To appear in the proceedings of International conference on the structure of baryons: BARYONS'10, Osaka, Japan, 7-11 Dec 2010
null
10.1063/1.3647379
OU-HET-704
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Minimal supersymmetric standard model with R-parity violation (RPVMSSM) contributes to the P-, CP-odd four-quark interaction. The P-, CP-odd four-quark interaction is constrained by the new 199Hg EDM experimental data. It is then possible to constrain R-parity violating (RPV) couplings from the 199Hg EDM data. In this talk, we analyze the RPV contribution to the P-, CP-odd four- quark interaction at the one-loop level to give constraints on RPV parameters.
[ { "created": "Sat, 23 Apr 2011 06:15:05 GMT", "version": "v1" } ]
2015-05-27
[ [ "Yamanaka", "Nodoka", "" ], [ "Sato", "Toru", "" ], [ "Kubota", "Takahiro", "" ] ]
Minimal supersymmetric standard model with R-parity violation (RPVMSSM) contributes to the P-, CP-odd four-quark interaction. The P-, CP-odd four-quark interaction is constrained by the new 199Hg EDM experimental data. It is then possible to constrain R-parity violating (RPV) couplings from the 199Hg EDM data. In this talk, we analyze the RPV contribution to the P-, CP-odd four- quark interaction at the one-loop level to give constraints on RPV parameters.
1106.4545
Christoph Englert
Christoph Englert, Tuhin S. Roy, Michael Spannowsky
Ditau jets in Higgs searches
9 pages, 9 figures. References added, typos corrected, published version
null
10.1103/PhysRevD.84.075026
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Understanding and identifying ditau jets -- jets consisting of pairs of tau particles, can be of crucial importance and may even turn out to be a necessity if the Higgs boson decays dominantly to new light scalars which, on the other hand, decay to tau pairs. As often seen in various models of BSM such as in the NMSSM, Higgs portals etc., the lightness of these new states ensures their large transverse momenta and, as a consequence, the collinearity of their decay products. We show that the non-standard signatures of these objects, which can easily be missed by standard analysis techniques, can be superbly exploited in an analysis based on subjet observables. When combined with additional selection strategies, this analysis can even facilitate an early discovery of the Higgs boson. To be specific, a light Higgs can be found with $S/\sqrt{B} \gtrsim 5$ from $\mathcal {L} \simeq 12 fb^{-1}$ of data. We combine all these observables into a single discriminating likelihood that can be employed toward the construction of a realistic and standalone ditau tagger.
[ { "created": "Wed, 22 Jun 2011 20:00:01 GMT", "version": "v1" }, { "created": "Thu, 20 Oct 2011 09:29:52 GMT", "version": "v2" } ]
2013-05-29
[ [ "Englert", "Christoph", "" ], [ "Roy", "Tuhin S.", "" ], [ "Spannowsky", "Michael", "" ] ]
Understanding and identifying ditau jets -- jets consisting of pairs of tau particles, can be of crucial importance and may even turn out to be a necessity if the Higgs boson decays dominantly to new light scalars which, on the other hand, decay to tau pairs. As often seen in various models of BSM such as in the NMSSM, Higgs portals etc., the lightness of these new states ensures their large transverse momenta and, as a consequence, the collinearity of their decay products. We show that the non-standard signatures of these objects, which can easily be missed by standard analysis techniques, can be superbly exploited in an analysis based on subjet observables. When combined with additional selection strategies, this analysis can even facilitate an early discovery of the Higgs boson. To be specific, a light Higgs can be found with $S/\sqrt{B} \gtrsim 5$ from $\mathcal {L} \simeq 12 fb^{-1}$ of data. We combine all these observables into a single discriminating likelihood that can be employed toward the construction of a realistic and standalone ditau tagger.
hep-ph/9608430
David London
M. Gronau and D. London
New Physics in CP Asymmetries and Rare B Decays
42 pages, plain TeX (macros included), 1 figure (included). A few sentences added, references updated. Present manuscript is now identical to the version accepted for publication in Phys. Rev. D
Phys.Rev.D55:2845-2861,1997
10.1103/PhysRevD.55.2845
TECHNION-PH-96-37, UdeM-GPP-TH-96-39
hep-ph
null
We review and update the effects of physics beyond the standard model on CP asymmetries in B decays. These asymmetries can be significantly altered if there are important new-physics contributions to \bqbqbar mixing. This same new physics will therefore also contribute to rare, flavor-changing B decays. Through a study of such decays, we show that it is possible to partially distinguish the different models of new physics.
[ { "created": "Fri, 23 Aug 1996 19:42:35 GMT", "version": "v1" }, { "created": "Mon, 23 Dec 1996 02:46:23 GMT", "version": "v2" } ]
2014-11-17
[ [ "Gronau", "M.", "" ], [ "London", "D.", "" ] ]
We review and update the effects of physics beyond the standard model on CP asymmetries in B decays. These asymmetries can be significantly altered if there are important new-physics contributions to \bqbqbar mixing. This same new physics will therefore also contribute to rare, flavor-changing B decays. Through a study of such decays, we show that it is possible to partially distinguish the different models of new physics.
hep-ph/0501281
Gabor Domokos
S. Kovesi-Domokos, G. Domokos (Johns Hopkins University)
The Mysteries of the Highest Energy Cosmic Rays
LaTeX 2e, 9 pages, no figures. Invited talk given at XIII ISVHECRI, Pylos, Greece
null
10.1016/j.nuclphysbps.2005.07.007
null
hep-ph
null
We give a summary of the theoretical attempts to make sense of the observational data concerning the highest energy cosmic rays, (E > 3x10^{19} eV).
[ { "created": "Sun, 30 Jan 2005 19:05:43 GMT", "version": "v1" } ]
2015-06-25
[ [ "Kovesi-Domokos", "S.", "", "Johns Hopkins University" ], [ "Domokos", "G.", "", "Johns Hopkins University" ] ]
We give a summary of the theoretical attempts to make sense of the observational data concerning the highest energy cosmic rays, (E > 3x10^{19} eV).
2008.08002
Zhiguang Xiao
Zhi-Yong Zhou, Zhiguang Xiao
Two-pole structures in a relativistic Friedrichs-Lee-QPC scheme
9 pages, 4 figure; Major revisions, figures added, more discussions and references are added; Published version
Eur.Phys.J.C 81 (2021) 6, 551
10.1140/epjc/s10052-021-09329-9
null
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A general appearance of two-pole structures is exhibited in a relativistic Friedrichs-Lee model combined with a relativistic quark pair creation model in a consistent manner. This kind of two-pole structure could be found when a $q\bar q$ state couples to the open-flavor continuum state in the $S$ partial wave. We found that many enigmatic states, such as $f_0(500)/\sigma$, $K_0^*(700)/\kappa$, $a_0(980)$, $f_0(980)$, $D_0^*(2300)$, $D_{s0}^*(2317)$, and $X(3872)$, together with another higher state for each, all result from this kind of two-pole structures. Furthermore, an interesting observation is that this kind of two-pole structure will contribute roughly a total of 180$^\circ$ phase shift for the scattering process in a single channel approximation. This relativistic scheme may provide more insights into the understanding of the properties of non-$q\bar q$ state. It is also suggested that such two-pole structure could be a common phenomenon which deserves studying both from theoretical and experimental perspectives.
[ { "created": "Tue, 18 Aug 2020 16:17:03 GMT", "version": "v1" }, { "created": "Tue, 25 Aug 2020 17:02:43 GMT", "version": "v2" }, { "created": "Tue, 13 Jul 2021 14:16:59 GMT", "version": "v3" } ]
2021-07-21
[ [ "Zhou", "Zhi-Yong", "" ], [ "Xiao", "Zhiguang", "" ] ]
A general appearance of two-pole structures is exhibited in a relativistic Friedrichs-Lee model combined with a relativistic quark pair creation model in a consistent manner. This kind of two-pole structure could be found when a $q\bar q$ state couples to the open-flavor continuum state in the $S$ partial wave. We found that many enigmatic states, such as $f_0(500)/\sigma$, $K_0^*(700)/\kappa$, $a_0(980)$, $f_0(980)$, $D_0^*(2300)$, $D_{s0}^*(2317)$, and $X(3872)$, together with another higher state for each, all result from this kind of two-pole structures. Furthermore, an interesting observation is that this kind of two-pole structure will contribute roughly a total of 180$^\circ$ phase shift for the scattering process in a single channel approximation. This relativistic scheme may provide more insights into the understanding of the properties of non-$q\bar q$ state. It is also suggested that such two-pole structure could be a common phenomenon which deserves studying both from theoretical and experimental perspectives.
2306.13900
Gilberto Ramalho
G. Ramalho and M.T. Pe\~na
Electromagnetic Transition Form Factors of Baryon Resonances
Published in Prog.Part.Nucl.Phys. Version with larger fonts. 124 pages, 41 figures, 6 tables. Small corrections in the text. Updated bibliography
Prog.Part.Nucl.Phys. 136, 104097 (2024)
10.1016/j.ppnp.2024.104097
null
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent experimental and theoretical advancements have led to significant progress in our understanding of the electromagnetic structure of nucleons ($N$), nucleon excitations ($N^\ast$), and other baryons. These breakthroughs have been made possible by the capabilities of modern facilities, enabling the induction of photo- and electro-excitation of nucleon resonances. Recent experimental advances have sparked notable developments in theoretical approaches. New theoretical methods have been tested and proven to be robust, marking the beginning of a new era in our understanding on baryons. We present a comprehensive review of progress in experimental data on $\gamma^\ast N \to N^\ast$ reactions. Additionally, we discuss various analyses and theoretical results. Some of these methods have matured in their predictive power, offering new perspectives on exotic hadrons with multiquark components. We place special emphasis on both the low-$Q^2$ and large-$Q^2$ regions to reinforce crucial physical constraints on observables that hold in these limits. Furthermore, we illustrate that the combination of lattice QCD with chiral effective field theory and quark models, respectively, proves beneficial in interpreting data and applying constraints within those different regimes. As a practical contribution and for future reference, we review the formulas for helicity amplitudes, multipole form factors and the relations between these two sets of functions for transitions to resonances with general spin $J \geq \frac{1}{2}$. These formulas are ubiquitous and play a pivotal role in experimental and theoretical studies on baryon structure. Notably, the multipole transition form factors for $J \ge \frac{3}{2}$ resonances serve as valuable tools to test perturbative QCD results in the large-$Q^2$ region, thanks to the correlations between electric and magnetic transition form factors.
[ { "created": "Sat, 24 Jun 2023 08:29:55 GMT", "version": "v1" }, { "created": "Mon, 11 Mar 2024 09:10:19 GMT", "version": "v2" } ]
2024-03-12
[ [ "Ramalho", "G.", "" ], [ "Peña", "M. T.", "" ] ]
Recent experimental and theoretical advancements have led to significant progress in our understanding of the electromagnetic structure of nucleons ($N$), nucleon excitations ($N^\ast$), and other baryons. These breakthroughs have been made possible by the capabilities of modern facilities, enabling the induction of photo- and electro-excitation of nucleon resonances. Recent experimental advances have sparked notable developments in theoretical approaches. New theoretical methods have been tested and proven to be robust, marking the beginning of a new era in our understanding on baryons. We present a comprehensive review of progress in experimental data on $\gamma^\ast N \to N^\ast$ reactions. Additionally, we discuss various analyses and theoretical results. Some of these methods have matured in their predictive power, offering new perspectives on exotic hadrons with multiquark components. We place special emphasis on both the low-$Q^2$ and large-$Q^2$ regions to reinforce crucial physical constraints on observables that hold in these limits. Furthermore, we illustrate that the combination of lattice QCD with chiral effective field theory and quark models, respectively, proves beneficial in interpreting data and applying constraints within those different regimes. As a practical contribution and for future reference, we review the formulas for helicity amplitudes, multipole form factors and the relations between these two sets of functions for transitions to resonances with general spin $J \geq \frac{1}{2}$. These formulas are ubiquitous and play a pivotal role in experimental and theoretical studies on baryon structure. Notably, the multipole transition form factors for $J \ge \frac{3}{2}$ resonances serve as valuable tools to test perturbative QCD results in the large-$Q^2$ region, thanks to the correlations between electric and magnetic transition form factors.
hep-ph/9601241
Hans-Peter Nilles
Hans Peter Nilles
Dynamical Gauge Coupling Constants
Lectures given at the 1995 Trieste Summer School, LaTeX, 24 pages, 3 postscript figures included
null
null
TUM--HEP--234/96, SFB--375/28
hep-ph hep-th
null
In string theory the coupling parameters are functions of moduli fields. The actual values of the coupling constants are then dynamically determined through the vacuum expextation values of these fields. We review the attempts to connect such theories to low energy effective field theories with realistic gauge coupling constants. This includes a discussion of supersymmetry breakdown, the question of a running dilaton, string threshold calculations and the possibility of string unification.
[ { "created": "Thu, 11 Jan 1996 10:06:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nilles", "Hans Peter", "" ] ]
In string theory the coupling parameters are functions of moduli fields. The actual values of the coupling constants are then dynamically determined through the vacuum expextation values of these fields. We review the attempts to connect such theories to low energy effective field theories with realistic gauge coupling constants. This includes a discussion of supersymmetry breakdown, the question of a running dilaton, string threshold calculations and the possibility of string unification.
hep-ph/0312147
Jae-hyeon Park
P. Ko (1), Jungil Lee (2 and 3), Taekoon Lee (4), Jae-hyeon Park (1) ((1) KAIST, (2) KIAS, (3) Argonne, (4) SNU)
Chiral perturbation theory for pentaquark baryons and its applications
4 pages
Phys.Lett. B611 (2005) 87-92
10.1016/j.physletb.2005.02.031
ANL-HEP-PR-03-102, KAIST-TH 2003/11, KIAS-P03085
hep-ph hep-ex nucl-th
null
We construct a chiral lagrangian for pentaquark baryons assuming that the recently found Theta^+ (1540) state belongs to an antidecuplet of SU(3) flavor symmetry with J^P = (1/2)^(+-). We derive the Gell-Mann-Okubo formulae for the antidecuplet baryon masses, and a possible mixing between the antidecuplet and the pentaquark octet. Then we calculate the cross sections for pi^- p -> K^- Theta^+ and gamma n -> K^- Theta^+ using our chiral lagrangian. The resulting amplitudes respect the underlying chiral symmetry of QCD correctly. We also describe how to include the light vector mesons in the chiral lagrangian.
[ { "created": "Thu, 11 Dec 2003 03:27:45 GMT", "version": "v1" } ]
2009-11-10
[ [ "Ko", "P.", "", "KAIST" ], [ "Lee", "Jungil", "", "2 and 3" ], [ "Lee", "Taekoon", "", "SNU" ], [ "Park", "Jae-hyeon", "", "KAIST" ] ]
We construct a chiral lagrangian for pentaquark baryons assuming that the recently found Theta^+ (1540) state belongs to an antidecuplet of SU(3) flavor symmetry with J^P = (1/2)^(+-). We derive the Gell-Mann-Okubo formulae for the antidecuplet baryon masses, and a possible mixing between the antidecuplet and the pentaquark octet. Then we calculate the cross sections for pi^- p -> K^- Theta^+ and gamma n -> K^- Theta^+ using our chiral lagrangian. The resulting amplitudes respect the underlying chiral symmetry of QCD correctly. We also describe how to include the light vector mesons in the chiral lagrangian.
1607.01701
C. A. Dominguez
C. A. Dominguez, L. A. Hernandez, K. Schilcher, and H. Spiesberger
Quark-hadron duality: pinched kernel approch
Invited talk given by K. Schilcher at the International Workshop on Determination of the Fundamental Parameters in QCD. Mainz Institute of Theoretical Physics, Johannes Gutenberg University of Mainz, Mainz, Germany
null
10.1142/S0217732316300263
null
hep-ph hep-ex hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hadronic spectral functions measured by the ALEPH collaboration in the vector and axial-vector channels are used to study potential quark-hadron duality violations (DV). This is done entirely in the framework of pinched kernel finite energy sum rules (FESR), i.e. in a model independent fashion. The kinematical range of the ALEPH data is effectively extended up to $s = 10\; {\mbox{GeV}^2}$ by using an appropriate kernel, and assuming that in this region the spectral functions are given by perturbative QCD. Support for this assumption is obtained by using $e^+ e^-$ annihilation data in the vector channel. Results in both channels show a good saturation of the pinched FESR, without further need of explicit models of DV.
[ { "created": "Wed, 6 Jul 2016 16:32:42 GMT", "version": "v1" } ]
2016-09-21
[ [ "Dominguez", "C. A.", "" ], [ "Hernandez", "L. A.", "" ], [ "Schilcher", "K.", "" ], [ "Spiesberger", "H.", "" ] ]
Hadronic spectral functions measured by the ALEPH collaboration in the vector and axial-vector channels are used to study potential quark-hadron duality violations (DV). This is done entirely in the framework of pinched kernel finite energy sum rules (FESR), i.e. in a model independent fashion. The kinematical range of the ALEPH data is effectively extended up to $s = 10\; {\mbox{GeV}^2}$ by using an appropriate kernel, and assuming that in this region the spectral functions are given by perturbative QCD. Support for this assumption is obtained by using $e^+ e^-$ annihilation data in the vector channel. Results in both channels show a good saturation of the pinched FESR, without further need of explicit models of DV.
1109.1282
Ioannis Iatrakis Mr.
Ioannis Iatrakis, Elias Kiritsis
Vector-axial vector correlators in weak electric field and the holographic dynamics of the chiral condensate
17 pages, 5 figures, typos corrected
null
10.1007/JHEP02(2012)064
CCTP-2011-28
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The transverse part of the vector-axial vector flavor current correlator in the presence of weak external electric field is studied using holography. The correlator is calculated using a bottom-up model arxiv:1003.2377 {proposed recently}, that includes the non-linear dynamics of the chiral condensate. It is shown that for low momenta the result agrees with the relation proposed by arXiv:1010.0718 {Son and Yamamoto} motivated by a simpler holographic model. For large Euclidean momenta however, the two results diverge. In the process, the difference of the vector and axial vector two point functions is also calculated. At large Euclidean momenta it is found that the first non-perturbative contribution, decreases as $q^{-6}$ as expected from QCD.
[ { "created": "Tue, 6 Sep 2011 20:00:01 GMT", "version": "v1" }, { "created": "Thu, 22 Sep 2011 14:22:26 GMT", "version": "v2" } ]
2015-05-30
[ [ "Iatrakis", "Ioannis", "" ], [ "Kiritsis", "Elias", "" ] ]
The transverse part of the vector-axial vector flavor current correlator in the presence of weak external electric field is studied using holography. The correlator is calculated using a bottom-up model arxiv:1003.2377 {proposed recently}, that includes the non-linear dynamics of the chiral condensate. It is shown that for low momenta the result agrees with the relation proposed by arXiv:1010.0718 {Son and Yamamoto} motivated by a simpler holographic model. For large Euclidean momenta however, the two results diverge. In the process, the difference of the vector and axial vector two point functions is also calculated. At large Euclidean momenta it is found that the first non-perturbative contribution, decreases as $q^{-6}$ as expected from QCD.
1202.0740
Philippe Brax
Philippe Brax
Lorentz Invariance Violation in Modified Gravity
8 pages, extended discussion
null
10.1016/j.physletb.2012.05.005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider an environmentally dependent violation of Lorentz invariance in scalar-tensor models of modified gravity where General Relativity is retrieved locally thanks to a screening mechanism. We find that fermions have a modified dispersion relation and would go faster than light in an anisotropic and space-dependent way along the scalar field lines of force. Phenomenologically, these models are tightly restricted by the amount of Cerenkov radiation emitted by the superluminal particles, a constraint which is only satisfied by chameleons. Measuring the speed of neutrinos emitted radially from the surface of the earth and observed on the other side of the earth would probe the scalar field profile of modified gravity models in dense environments. We argue that the test of the equivalence principle provided by the Lunar ranging experiment implies that a deviation from the speed of light, for natural values of the coupling scale between the scalar field and fermions, would be below detectable levels, unless gravity is modified by camouflaged chameleons where the field normalisation is environmentally dependent.
[ { "created": "Fri, 3 Feb 2012 15:46:50 GMT", "version": "v1" }, { "created": "Tue, 14 Feb 2012 21:08:30 GMT", "version": "v2" }, { "created": "Mon, 27 Feb 2012 13:06:42 GMT", "version": "v3" }, { "created": "Thu, 10 May 2012 12:38:19 GMT", "version": "v4" } ]
2015-06-04
[ [ "Brax", "Philippe", "" ] ]
We consider an environmentally dependent violation of Lorentz invariance in scalar-tensor models of modified gravity where General Relativity is retrieved locally thanks to a screening mechanism. We find that fermions have a modified dispersion relation and would go faster than light in an anisotropic and space-dependent way along the scalar field lines of force. Phenomenologically, these models are tightly restricted by the amount of Cerenkov radiation emitted by the superluminal particles, a constraint which is only satisfied by chameleons. Measuring the speed of neutrinos emitted radially from the surface of the earth and observed on the other side of the earth would probe the scalar field profile of modified gravity models in dense environments. We argue that the test of the equivalence principle provided by the Lunar ranging experiment implies that a deviation from the speed of light, for natural values of the coupling scale between the scalar field and fermions, would be below detectable levels, unless gravity is modified by camouflaged chameleons where the field normalisation is environmentally dependent.
1101.5024
Barbara Sciascia
B. Sciascia (for the FlaviaNet Kaon Working Group)
Vus and precise Standard Model tests
5 pages, Proceedings of CKM2010, the 6th International Workshop on the CKM Unitarity Triangle, University of Warwick, UK, 6-10 September 2010
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent significant progress on both the experimental and theoretical sides on the study of leptonic and semileptonic kaon decays allows to precisely test the Standard Model. Here we present results for the determination of Vus from experimental data, the comparison between the values of Vus obtained from data on semileptonic and leptonic kaon decays, and tests of lepton universality in semileptonic kaon decays.
[ { "created": "Wed, 26 Jan 2011 11:07:49 GMT", "version": "v1" } ]
2019-08-14
[ [ "Sciascia", "B.", "", "for the FlaviaNet Kaon Working Group" ] ]
The recent significant progress on both the experimental and theoretical sides on the study of leptonic and semileptonic kaon decays allows to precisely test the Standard Model. Here we present results for the determination of Vus from experimental data, the comparison between the values of Vus obtained from data on semileptonic and leptonic kaon decays, and tests of lepton universality in semileptonic kaon decays.
hep-ph/0307294
Tancredi Carli
Tancredi Carli
Observation of Events with Isolated Charged Leptons and Large Missing Tra nsverse Momentum and of Events with Multi-Electrons at HERA
talk given at 38th Recontres de Moriond Electroweak Interactions and Unified Theories, Les Arc (France) 2003
null
null
null
hep-ph
null
Striking events with isolated charged leptons, large missing transverse momentum and large transverse momentum of the hadronic final state (PTX) have been observed at the electron proton collider HERA. In the full HERA-I data sample corresponding to an integrated luminosity of about 130 invpb, the H1 experiment observes 10 events with isolated electrons or muons and with PTX >25 GeV. Only 2.9 pm 0.4 events are expected from Standard Model (SM) processes. Six of these events have PTX >40 GeV, while 1.1 pm 0.2 events are expected. The ZEUS experiment observes good agreement with the SM. However, in a preliminary search ZEUS has found two events with a similar event topology, but tau-leptons instead of electrons or muons in the final state . Only 0.12 pm 0.02 events are expected from SM processes. Moreover, six events with two or more electrons forming an invariant mass bigger than 100 GeV have been observed by the H1 experiment. Three events have two electrons and three events have three electrons, while only 0.25 events are expected in each case. The ZEUS measurement is in agreement with the SM expectation.
[ { "created": "Wed, 23 Jul 2003 14:23:42 GMT", "version": "v1" }, { "created": "Thu, 31 Jul 2003 10:32:07 GMT", "version": "v2" } ]
2007-05-23
[ [ "Carli", "Tancredi", "" ] ]
Striking events with isolated charged leptons, large missing transverse momentum and large transverse momentum of the hadronic final state (PTX) have been observed at the electron proton collider HERA. In the full HERA-I data sample corresponding to an integrated luminosity of about 130 invpb, the H1 experiment observes 10 events with isolated electrons or muons and with PTX >25 GeV. Only 2.9 pm 0.4 events are expected from Standard Model (SM) processes. Six of these events have PTX >40 GeV, while 1.1 pm 0.2 events are expected. The ZEUS experiment observes good agreement with the SM. However, in a preliminary search ZEUS has found two events with a similar event topology, but tau-leptons instead of electrons or muons in the final state . Only 0.12 pm 0.02 events are expected from SM processes. Moreover, six events with two or more electrons forming an invariant mass bigger than 100 GeV have been observed by the H1 experiment. Three events have two electrons and three events have three electrons, while only 0.25 events are expected in each case. The ZEUS measurement is in agreement with the SM expectation.
1807.11498
Kyoungchul Kong
Jeong Han Kim, Kyoungchul Kong, Konstantin T. Matchev, Myeonghun Park
Probing the Triple Higgs Self-Interaction at the Large Hadron Collider
5 pages, 5 figures, matches the published version
Phys. Rev. Lett. 122, 091801 (2019)
10.1103/PhysRevLett.122.091801
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel kinematic method to expedite the discovery of the double Higgs ($hh$) production in the $\ell^+\ell^- b \bar{b} + E_T \hspace{-0.52cm} \big / ~$ final state. We make full use of recently developed kinematic variables, as well as the variables $\it Topness$ for the dominant background (top quark pair production) and $\it Higgsness$ for the signal. We obtain a significant increase in sensitivity compared to the previous analyses which used sophisticated algorithms like boosted decision trees or neutral networks. The method can be easily generalized to resonant $hh$ production as well as other non-resonant channels.
[ { "created": "Mon, 30 Jul 2018 18:00:16 GMT", "version": "v1" }, { "created": "Fri, 8 Mar 2019 15:51:59 GMT", "version": "v2" } ]
2019-03-13
[ [ "Kim", "Jeong Han", "" ], [ "Kong", "Kyoungchul", "" ], [ "Matchev", "Konstantin T.", "" ], [ "Park", "Myeonghun", "" ] ]
We propose a novel kinematic method to expedite the discovery of the double Higgs ($hh$) production in the $\ell^+\ell^- b \bar{b} + E_T \hspace{-0.52cm} \big / ~$ final state. We make full use of recently developed kinematic variables, as well as the variables $\it Topness$ for the dominant background (top quark pair production) and $\it Higgsness$ for the signal. We obtain a significant increase in sensitivity compared to the previous analyses which used sophisticated algorithms like boosted decision trees or neutral networks. The method can be easily generalized to resonant $hh$ production as well as other non-resonant channels.
2307.04396
Raghunath Sahoo
Kangkan Goswami, Kshitish Kumar Pradhan, Dushmanta Sahu, and Raghunath Sahoo
Diffusion and fluctuations of open charmed hadrons in an interacting hadronic medium
Same as the published version in Phys. Rev. D
Physical Review D 108, 074011 (2023)
10.1103/PhysRevD.108.074011
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by-sa/4.0/
Heavy quarks are excellent probes to understand the hot and dense medium formed in ultra-relativistic collisions. In a hadronic medium, studying the transport properties, e.g. the drag ($\gamma$), momentum diffusion ($B_{0}$), and spatial diffusion ($D_{s}$) coefficients of open charmed hadrons can provide useful information about the medium. Moreover, the fluctuations of charmed hadrons can help us to locate the onset of their deconfinement. In this work, we incorporate attractive and repulsive interactions in the well-established van der Waals hadron resonance gas model (VDWHRG) and study the diffusion and fluctuations of charmed hadrons. This study helps us understand the importance of interactions in the system, which affect both the diffusion and fluctuations of charmed hadrons.
[ { "created": "Mon, 10 Jul 2023 07:57:46 GMT", "version": "v1" }, { "created": "Tue, 31 Oct 2023 07:04:30 GMT", "version": "v2" } ]
2023-11-01
[ [ "Goswami", "Kangkan", "" ], [ "Pradhan", "Kshitish Kumar", "" ], [ "Sahu", "Dushmanta", "" ], [ "Sahoo", "Raghunath", "" ] ]
Heavy quarks are excellent probes to understand the hot and dense medium formed in ultra-relativistic collisions. In a hadronic medium, studying the transport properties, e.g. the drag ($\gamma$), momentum diffusion ($B_{0}$), and spatial diffusion ($D_{s}$) coefficients of open charmed hadrons can provide useful information about the medium. Moreover, the fluctuations of charmed hadrons can help us to locate the onset of their deconfinement. In this work, we incorporate attractive and repulsive interactions in the well-established van der Waals hadron resonance gas model (VDWHRG) and study the diffusion and fluctuations of charmed hadrons. This study helps us understand the importance of interactions in the system, which affect both the diffusion and fluctuations of charmed hadrons.
0906.1803
Michael Spannowsky
Tilman Plehn, Michael Rauch and Michael Spannowsky
Understanding Single Tops using Jets
null
Phys.Rev.D80:114027,2009
10.1103/PhysRevD.80.114027
KA-TP-07-2009; SFB/CPP-09-47
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Top plus jets production at hadron collider allows us to study the couplings of the top quark. In the Standard Model, two single top processes contribute to the top-jets final state. Beyond the Standard Model, additional direct top production can occur. All three processes probe top gauge couplings including flavor mixing. The structure of accompanying QCD jets allows us to separate the direct top signal from the QCD backgrounds as well as to disentangle the three top plus jets production mechanisms orthogonally to the usual bottom tags.
[ { "created": "Tue, 9 Jun 2009 19:08:01 GMT", "version": "v1" } ]
2010-01-07
[ [ "Plehn", "Tilman", "" ], [ "Rauch", "Michael", "" ], [ "Spannowsky", "Michael", "" ] ]
Top plus jets production at hadron collider allows us to study the couplings of the top quark. In the Standard Model, two single top processes contribute to the top-jets final state. Beyond the Standard Model, additional direct top production can occur. All three processes probe top gauge couplings including flavor mixing. The structure of accompanying QCD jets allows us to separate the direct top signal from the QCD backgrounds as well as to disentangle the three top plus jets production mechanisms orthogonally to the usual bottom tags.
1003.3230
Gilberto Tavares-Velasco
A. Moyotl, G. Tavares-Velasco
On-shell $WW\gamma$ vertex in the T-Parity and non T-Parity Littlest Higgs model
19 pages, 8 figures
J.Phys.G37:105012,2010
10.1088/0954-3899/37/10/105012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The static electromagnetic properties of the $W$ boson, $\Delta \kappa$ and $\Delta Q$, are calculated in the T-parity and non T-parity littlest Higgs model (LHM) including terms up to the order of $(v/f)^4$, with $v$ the standard model (SM) vacuum expectation value and $f$ the scale of the global symmetry breaking. There are contributions from the virtual effects of the new heavy particles and also from the new corrections to the SM vertices, which depend on the mixing parameter $c$ and decrease quickly as $f$ increases. Depending on the value of $c$, the partial contributions to $\Delta \kappa$ and $\Delta Q$ can add constructively or destructively. The terms of the order of $(v/f)^4$ are subdominant but they can add constructively and can enhance the $W$ form factors for $f < 1$ TeV. In general the size of the $W$ form factors is very suppressed in the LHM without T-parity as the constraints on the scale $f$ from electroweak precision measurements are very tight. The LHM with T-parity has no such constraints and it allows for values of $W$ form factors similar to those found in other weakly coupled SM extensions, though they are out of the expected sensitivity of future measurements at the LHC. We also discuss the possibility that there is some enhancement due to the interactions arising from the strongly interacting ultraviolet completion of the LHM.
[ { "created": "Tue, 16 Mar 2010 19:49:32 GMT", "version": "v1" }, { "created": "Thu, 17 Jun 2010 05:03:17 GMT", "version": "v2" } ]
2015-03-13
[ [ "Moyotl", "A.", "" ], [ "Tavares-Velasco", "G.", "" ] ]
The static electromagnetic properties of the $W$ boson, $\Delta \kappa$ and $\Delta Q$, are calculated in the T-parity and non T-parity littlest Higgs model (LHM) including terms up to the order of $(v/f)^4$, with $v$ the standard model (SM) vacuum expectation value and $f$ the scale of the global symmetry breaking. There are contributions from the virtual effects of the new heavy particles and also from the new corrections to the SM vertices, which depend on the mixing parameter $c$ and decrease quickly as $f$ increases. Depending on the value of $c$, the partial contributions to $\Delta \kappa$ and $\Delta Q$ can add constructively or destructively. The terms of the order of $(v/f)^4$ are subdominant but they can add constructively and can enhance the $W$ form factors for $f < 1$ TeV. In general the size of the $W$ form factors is very suppressed in the LHM without T-parity as the constraints on the scale $f$ from electroweak precision measurements are very tight. The LHM with T-parity has no such constraints and it allows for values of $W$ form factors similar to those found in other weakly coupled SM extensions, though they are out of the expected sensitivity of future measurements at the LHC. We also discuss the possibility that there is some enhancement due to the interactions arising from the strongly interacting ultraviolet completion of the LHM.
hep-ph/0612043
Francois Arleo
Francois Arleo and Vi-Nham Tram
A systematic study of J/psi suppression in cold nuclear matter
25 pages, 5 figures
Eur.Phys.J.C55:449-461,2008
10.1140/epjc/s10052-008-0604-8
CERN-PH-TH/2006-189, LAPTH-1163/06
hep-ph nucl-ex nucl-th
null
Based on a Glauber model, a statistical analysis of all mid-rapidity J/psi hadroproduction and leptoproduction data on nuclear targets is carried out. This allows us to determine the J/psi-nucleon inelastic cross section, whose knowledge is crucial to interpret the J/psi suppression observed in heavy-ion collisions, at SPS and at RHIC. The values of sigma are extracted from each experiment. A clear tension between the different data sets is reported. The global fit of all data gives sigma=3.4+/-0.2 mb, which is significantly smaller than previous estimates. A similar value, sigma=3.5+/-0.2 mb, is obtained when the nDS nuclear parton densities are included in the analysis, although we emphasize that the present uncertainties on gluon (anti)shadowing do not allow for a precise determination of sigma. Finally, no significant energy dependence of the J/psi-N interaction is observed, unless strong nuclear modifications of the parton densities are assumed.
[ { "created": "Tue, 5 Dec 2006 13:35:18 GMT", "version": "v1" } ]
2008-11-26
[ [ "Arleo", "Francois", "" ], [ "Tram", "Vi-Nham", "" ] ]
Based on a Glauber model, a statistical analysis of all mid-rapidity J/psi hadroproduction and leptoproduction data on nuclear targets is carried out. This allows us to determine the J/psi-nucleon inelastic cross section, whose knowledge is crucial to interpret the J/psi suppression observed in heavy-ion collisions, at SPS and at RHIC. The values of sigma are extracted from each experiment. A clear tension between the different data sets is reported. The global fit of all data gives sigma=3.4+/-0.2 mb, which is significantly smaller than previous estimates. A similar value, sigma=3.5+/-0.2 mb, is obtained when the nDS nuclear parton densities are included in the analysis, although we emphasize that the present uncertainties on gluon (anti)shadowing do not allow for a precise determination of sigma. Finally, no significant energy dependence of the J/psi-N interaction is observed, unless strong nuclear modifications of the parton densities are assumed.
1909.13804
Ken-Ichi Okumura
Ken-ichi Okumura
Hide and Seek with Massive Fields in Modulus Mediation
17 pages, 2 figures, accepted by Physical Review Letters
Phys. Rev. Lett. 123, 151801 (2019)
10.1103/PhysRevLett.123.151801
KYUSHU-RCAPP-2019-01, KYUSHU-HET-195
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the modulus mediation of supersymmetry breaking motivated by superstring theory. We show that the renormalization group running of the soft supersymmetry breaking parameters due to the interactions of massive fields is canceled by the threshold corrections at one-loop order, if their mass is given by nonperturbative dynamics controlled by the same modulus that mediates supersymmetry breaking and a sum rule of the modular weights holds for the Yukawa couplings. As an example, we discuss order reduction of lepton flavor violation in the supersymmetric seesaw mechanism, which revives the parameter space already excluded.
[ { "created": "Mon, 30 Sep 2019 16:00:03 GMT", "version": "v1" } ]
2019-10-16
[ [ "Okumura", "Ken-ichi", "" ] ]
We study the modulus mediation of supersymmetry breaking motivated by superstring theory. We show that the renormalization group running of the soft supersymmetry breaking parameters due to the interactions of massive fields is canceled by the threshold corrections at one-loop order, if their mass is given by nonperturbative dynamics controlled by the same modulus that mediates supersymmetry breaking and a sum rule of the modular weights holds for the Yukawa couplings. As an example, we discuss order reduction of lepton flavor violation in the supersymmetric seesaw mechanism, which revives the parameter space already excluded.
hep-ph/9805385
Oleg Kalashnikov
O.K. Kalashnikov
One-particle and collective electron spectra in hot and dense QED and their gauge dependence
9 pages, latex, no figures
Mod.Phys.Lett.A13:1719-1728,1998
10.1142/S0217732398001790
null
hep-ph
null
The one-particle electron spectrum is found for hot and dense QED and its properties are investigated in comparison with the collective spectrum. It is shown that the one-particle spectrum (in any case its zero momentum limit) is gauge invariant, but the collective spectrum, being qualitatively different, is always gauge dependent. The exception is the case $m,\mu=0$ for which the collective spectrum long wavelength limit demonstrates the gauge invariance as well.
[ { "created": "Wed, 20 May 1998 06:03:32 GMT", "version": "v1" } ]
2014-11-17
[ [ "Kalashnikov", "O. K.", "" ] ]
The one-particle electron spectrum is found for hot and dense QED and its properties are investigated in comparison with the collective spectrum. It is shown that the one-particle spectrum (in any case its zero momentum limit) is gauge invariant, but the collective spectrum, being qualitatively different, is always gauge dependent. The exception is the case $m,\mu=0$ for which the collective spectrum long wavelength limit demonstrates the gauge invariance as well.
0711.2364
Kenji Fukushima
Kenji Fukushima
Randomness in infinitesimal extent in the McLerran-Venugopalan model
11 pages, 11 figures, typos corrected; Introduction and Discussion sections extended
Phys.Rev.D77:074005,2008
10.1103/PhysRevD.77.074005
YITP-07-79
hep-ph
null
We study discrepancy between the analytical definition and the numerical implementation of the McLerran-Venugopalan (MV) model. The infinitesimal extent of a fast-moving nucleus should retain longitudinal randomness in the color source distribution even when the longitudinal extent approximates zero due to the Lorentz contraction, which is properly taken into account in the analytical treatment. We point out that the longitudinal randomness is lost in numerical simulations because of lack of the path-ordering of the Wilson line along the longitudinal direction. We quantitatively investigate how much the results with and without longitudinal randomness differ from each other. We finally mention that the discrepancy could be absorbed in a choice of the model parameter in the physical unit, and nevertheless, it is important for a full theory approach.
[ { "created": "Thu, 15 Nov 2007 18:15:08 GMT", "version": "v1" }, { "created": "Sun, 20 Jan 2008 15:00:03 GMT", "version": "v2" } ]
2008-11-26
[ [ "Fukushima", "Kenji", "" ] ]
We study discrepancy between the analytical definition and the numerical implementation of the McLerran-Venugopalan (MV) model. The infinitesimal extent of a fast-moving nucleus should retain longitudinal randomness in the color source distribution even when the longitudinal extent approximates zero due to the Lorentz contraction, which is properly taken into account in the analytical treatment. We point out that the longitudinal randomness is lost in numerical simulations because of lack of the path-ordering of the Wilson line along the longitudinal direction. We quantitatively investigate how much the results with and without longitudinal randomness differ from each other. We finally mention that the discrepancy could be absorbed in a choice of the model parameter in the physical unit, and nevertheless, it is important for a full theory approach.
hep-ph/9712343
Tony Gherghetta
Tony Gherghetta
The Role of Scalar and Pseudoscalar Fields in Determining Nucleosynthesis Bounds on the Scale of Supersymmetry Breaking
12 pages, 1 figure; Version to be published in Phys. Lett. B
Phys.Lett. B423 (1998) 311-318
10.1016/S0370-2693(98)00129-4
CERN-TH/97-361
hep-ph astro-ph
null
The effect of spin-0 goldstino superpartners is considered on the nucleosynthesis bounds arising when a superlight gravitino appears as an effective massless neutrino species. When the scalar and pseudoscalar superpartners are relativistic they will decouple at much later times than the goldstino and consequently will be the dominant effect when obtaining a nucleosynthesis bound on the scale of supersymmetry breaking. Assuming that the scalar and pseudoscalar fields decouple at a temperature no later than O(100) MeV, then typically the scale of supersymmetry breaking \sqrt{F} > 60 TeV. This corresponds to a lower bound on the gravitino mass m_{3/2} > 1 eV.
[ { "created": "Thu, 11 Dec 1997 11:23:31 GMT", "version": "v1" }, { "created": "Tue, 10 Feb 1998 14:26:41 GMT", "version": "v2" } ]
2009-10-30
[ [ "Gherghetta", "Tony", "" ] ]
The effect of spin-0 goldstino superpartners is considered on the nucleosynthesis bounds arising when a superlight gravitino appears as an effective massless neutrino species. When the scalar and pseudoscalar superpartners are relativistic they will decouple at much later times than the goldstino and consequently will be the dominant effect when obtaining a nucleosynthesis bound on the scale of supersymmetry breaking. Assuming that the scalar and pseudoscalar fields decouple at a temperature no later than O(100) MeV, then typically the scale of supersymmetry breaking \sqrt{F} > 60 TeV. This corresponds to a lower bound on the gravitino mass m_{3/2} > 1 eV.
hep-ph/0603067
J. A. R. Cembranos
Jose A. R. Cembranos, Jonathan L. Feng, Arvind Rajaraman, Bryan T. Smith, Fumihiro Takayama
Collider Signatures of SuperWIMP Warm Dark Matter
Contributed to the 2005 International Linear Collider Physics and Detector Workshop and 2nd ILC Accelerator Workshop, Snowmass, Colorado, 14-27 Aug 2005. 3 pages, LaTeX, 1 figure
ECONFC0508141:ALCPG0334,2005
null
UCI-TR-2005-43, SNOWMASS-2005-ALCPG0334
hep-ph
null
SuperWeakly-Interacting Massive Particles (superWIMPs) produced in the late decays of other particles are well-motivated dark matter candidates and may be favored over standard Weakly-Interacting Massive Particles (WIMPs) by small scale structure observations. Among the most promising frameworks that incorporate superWIMPs are R-parity conserving supersymmetry models in which the lightest supersymmetric particle (LSP) is the gravitino or the axino. In these well-defined particle models, astrophysical observations have direct implications for possible measurements at future colliders.
[ { "created": "Thu, 9 Mar 2006 01:52:45 GMT", "version": "v1" } ]
2008-11-26
[ [ "Cembranos", "Jose A. R.", "" ], [ "Feng", "Jonathan L.", "" ], [ "Rajaraman", "Arvind", "" ], [ "Smith", "Bryan T.", "" ], [ "Takayama", "Fumihiro", "" ] ]
SuperWeakly-Interacting Massive Particles (superWIMPs) produced in the late decays of other particles are well-motivated dark matter candidates and may be favored over standard Weakly-Interacting Massive Particles (WIMPs) by small scale structure observations. Among the most promising frameworks that incorporate superWIMPs are R-parity conserving supersymmetry models in which the lightest supersymmetric particle (LSP) is the gravitino or the axino. In these well-defined particle models, astrophysical observations have direct implications for possible measurements at future colliders.
1410.6434
Daniele Teresi
P.S. Bhupal Dev, Peter Millington, Apostolos Pilaftsis, Daniele Teresi
Kadanoff-Baym Approach to Flavour Mixing and Oscillations in Resonant Leptogenesis
35 pages, 4 figures; further discussion added and typos corrected; final published version
Nucl. Phys. B 891 (2015) 128-158
10.1016/j.nuclphysb.2014.12.003
MAN/HEP/2014/13, TUM-HEP-962-14
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe a loopwise perturbative truncation scheme for quantum transport equations in the Kadanoff-Baym formalism, which does not necessitate the use of the so-called Kadanoff-Baym or quasi-particle ansaetze for dressed propagators. This truncation scheme is used to study flavour effects in the context of Resonant Leptogenesis (RL), showing explicitly that, in the weakly-resonant regime, there exist two distinct and pertinent flavour effects in the heavy-neutrino sector: (i) the resonant mixing and (ii) the oscillations between different heavy-neutrino flavours. Moreover, we illustrate that Kadanoff-Baym and quasi-particle ansaetze, whilst appropriate for the flavour-singlet dressed charged-lepton and Higgs propagators of the RL scenario, should not be applied to the dressed heavy-neutrino propagators. The use of these approximations for the latter is shown to capture only flavour oscillations, whilst discarding the separate phenomenon of flavour mixing.
[ { "created": "Thu, 23 Oct 2014 18:01:06 GMT", "version": "v1" }, { "created": "Mon, 15 Dec 2014 16:25:42 GMT", "version": "v2" } ]
2014-12-23
[ [ "Dev", "P. S. Bhupal", "" ], [ "Millington", "Peter", "" ], [ "Pilaftsis", "Apostolos", "" ], [ "Teresi", "Daniele", "" ] ]
We describe a loopwise perturbative truncation scheme for quantum transport equations in the Kadanoff-Baym formalism, which does not necessitate the use of the so-called Kadanoff-Baym or quasi-particle ansaetze for dressed propagators. This truncation scheme is used to study flavour effects in the context of Resonant Leptogenesis (RL), showing explicitly that, in the weakly-resonant regime, there exist two distinct and pertinent flavour effects in the heavy-neutrino sector: (i) the resonant mixing and (ii) the oscillations between different heavy-neutrino flavours. Moreover, we illustrate that Kadanoff-Baym and quasi-particle ansaetze, whilst appropriate for the flavour-singlet dressed charged-lepton and Higgs propagators of the RL scenario, should not be applied to the dressed heavy-neutrino propagators. The use of these approximations for the latter is shown to capture only flavour oscillations, whilst discarding the separate phenomenon of flavour mixing.
1603.08786
Henry Tsz-King Wong
S. Kerman, V. Sharma, M. Deniz, H.T. Wong, J.-W. Chen, H.B. Li, S.T. Lin, C.-P. Liu, and Q. Yue (TEXONO Collaboration)
Coherency in Neutrino-Nucleus Elastic Scattering
5 pages, 4 figures, 3 tables. V2 -- Published Version
Phys. Rev. D 93, 113006 (2016)
10.1103/PhysRevD.93.113006
NCTS-ECP/1503
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino-nucleus elastic scattering provides a unique laboratory to study the quantum mechanical coherency effects in electroweak interactions, towards which several experimental programs are being actively pursued. We report results of our quantitative studies on the transitions towards decoherency. A parameter ($\alpha$) is identified to describe the degree of coherency, and its variations with incoming neutrino energy, detector threshold and target nucleus are studied. The ranges of $\alpha$ which can be probed with realistic neutrino experiments are derived, indicating complementarity between projects with different sources and targets. Uncertainties in nuclear physics and in $\alpha$ would constrain sensitivities in probing physics beyond the standard model. The maximum neutrino energies corresponding to $\alpha$>0.95 are derived.
[ { "created": "Tue, 29 Mar 2016 14:25:39 GMT", "version": "v1" }, { "created": "Thu, 9 Jun 2016 08:44:30 GMT", "version": "v2" } ]
2016-06-10
[ [ "Kerman", "S.", "", "TEXONO Collaboration" ], [ "Sharma", "V.", "", "TEXONO Collaboration" ], [ "Deniz", "M.", "", "TEXONO Collaboration" ], [ "Wong", "H. T.", "", "TEXONO Collaboration" ], [ "Chen", "J. -W.", "", "TEXONO Collaboration" ], [ "Li", "H. B.", "", "TEXONO Collaboration" ], [ "Lin", "S. T.", "", "TEXONO Collaboration" ], [ "Liu", "C. -P.", "", "TEXONO Collaboration" ], [ "Yue", "Q.", "", "TEXONO Collaboration" ] ]
Neutrino-nucleus elastic scattering provides a unique laboratory to study the quantum mechanical coherency effects in electroweak interactions, towards which several experimental programs are being actively pursued. We report results of our quantitative studies on the transitions towards decoherency. A parameter ($\alpha$) is identified to describe the degree of coherency, and its variations with incoming neutrino energy, detector threshold and target nucleus are studied. The ranges of $\alpha$ which can be probed with realistic neutrino experiments are derived, indicating complementarity between projects with different sources and targets. Uncertainties in nuclear physics and in $\alpha$ would constrain sensitivities in probing physics beyond the standard model. The maximum neutrino energies corresponding to $\alpha$>0.95 are derived.
hep-ph/0211278
Egle Tomasi-Gustafsson
Michail P. Rekalo and Egle Tomasi-Gustafsson
Sensitivity of pQCD deuteron structure to the nucleon form factors
null
Eur.Phys.J. A16 (2003) 563-567
null
null
hep-ph
null
We discuss the applicability of pQCD to the elastic scattering of electrons on protons and deuterons. We analyze the $Q^2$-dependence of the reduced deuteron form factor, taking into account the recent data on the electric proton form factor and we find that the value of the QCD-scale parameter $\Lambda$ differs essentially from the value $\Lambda=0.1$ GeV, previously found using the dipole parametrization of the electromagnetic nucleon form factors $G_E$ and $G_M$. Moreover the predicted scaling behavior of the reduced deuteron form factor can not be recovered in the Dirac and Pauli representations for the nucleon electromagnetic form factors.
[ { "created": "Mon, 18 Nov 2002 14:37:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rekalo", "Michail P.", "" ], [ "Tomasi-Gustafsson", "Egle", "" ] ]
We discuss the applicability of pQCD to the elastic scattering of electrons on protons and deuterons. We analyze the $Q^2$-dependence of the reduced deuteron form factor, taking into account the recent data on the electric proton form factor and we find that the value of the QCD-scale parameter $\Lambda$ differs essentially from the value $\Lambda=0.1$ GeV, previously found using the dipole parametrization of the electromagnetic nucleon form factors $G_E$ and $G_M$. Moreover the predicted scaling behavior of the reduced deuteron form factor can not be recovered in the Dirac and Pauli representations for the nucleon electromagnetic form factors.
1206.4908
Gudrun Heinrich
Sophia Borowka, Jonathon Carter, Gudrun Heinrich
SecDec: A tool for numerical multi-loop calculations
9 pages, Based on a talk given at the 14th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT), Uxbridge, London, UK, September 2011
J. Phys.: Conf. Ser. 368, 012051 (2012)
10.1088/1742-6596/368/1/012051
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The version 2.0 of the program SecDec is described, which can be used for the extraction of poles within dimensional regularisation from multi-loop integrals as well as phase space integrals. The numerical evaluation of the resulting finite functions is also done by the program in an automated way, with no restriction on the kinematics in the case of loop integrals.
[ { "created": "Thu, 21 Jun 2012 15:07:05 GMT", "version": "v1" } ]
2012-06-25
[ [ "Borowka", "Sophia", "" ], [ "Carter", "Jonathon", "" ], [ "Heinrich", "Gudrun", "" ] ]
The version 2.0 of the program SecDec is described, which can be used for the extraction of poles within dimensional regularisation from multi-loop integrals as well as phase space integrals. The numerical evaluation of the resulting finite functions is also done by the program in an automated way, with no restriction on the kinematics in the case of loop integrals.
1409.3502
Zahra Tabrizi
Arman Esmaili, O. L. G. Peres, and Zahra Tabrizi
Probing Large Extra Dimensions With IceCube
v2: 25 pages, 4 figures, matches the published version at JCAP
JCAP 12 (2014) 002
10.1088/1475-7516/2014/12/002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In models with Large Extra Dimensions the smallness of neutrino masses can be naturally explained by introducing gauge singlet fermions which propagate in the bulk. The Kaluza-Klein modes of these fermions appear as towers of sterile neutrino states on the brane. We study the phenomenological consequences of this picture for the high energy atmospheric neutrinos. For this purpose we construct a detailed equivalence between a model with large extra dimensions and a (3 + n) scenario consisting of three active and n extra sterile neutrino states, which provides a clear intuitive understanding of Kaluza-Klein modes. Finally, we analyze the collected data of high energy atmospheric neutrinos by IceCube experiment and obtain bounds on the radius of extra dimensions.
[ { "created": "Thu, 11 Sep 2014 17:07:22 GMT", "version": "v1" }, { "created": "Tue, 2 Dec 2014 01:27:07 GMT", "version": "v2" } ]
2014-12-03
[ [ "Esmaili", "Arman", "" ], [ "Peres", "O. L. G.", "" ], [ "Tabrizi", "Zahra", "" ] ]
In models with Large Extra Dimensions the smallness of neutrino masses can be naturally explained by introducing gauge singlet fermions which propagate in the bulk. The Kaluza-Klein modes of these fermions appear as towers of sterile neutrino states on the brane. We study the phenomenological consequences of this picture for the high energy atmospheric neutrinos. For this purpose we construct a detailed equivalence between a model with large extra dimensions and a (3 + n) scenario consisting of three active and n extra sterile neutrino states, which provides a clear intuitive understanding of Kaluza-Klein modes. Finally, we analyze the collected data of high energy atmospheric neutrinos by IceCube experiment and obtain bounds on the radius of extra dimensions.
2206.09717
Damir Becirevic
Damir Be\v{c}irevi\'c, Ilja Dor\v{s}ner, Svjetlana Fajfer, Darius A. Faroughy, Florentin Jaffredo, Nejc Ko\v{s}nik and Olcyr Sumensari
On a model with two scalar leptoquarks -- $R_2$ and $S_3$
11pages, 5 figures
null
null
ZU-TH 24/22
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a model that can accommodate the $B$-physics anomalies, based on combining two scalar leptoquarks, $R_2$ and $S_3$, of mass $\mathcal{O}(1\,\mathrm{TeV})$, and that we proposed in our previous paper. We update the analysis of its parameter space and show that a model remains viable and consistent with a number of low energy and high energy flavor physics constraints. Since the model predicts a non-zero New Physics phase, we discuss the possibility to test its contribution to the neutron electric dipole moment and to the angular distributions of the exclusive $b\to c\tau \bar \nu$ decays. We find that the model can provide a significant enhancement to $\mathcal{B}(B\to K^{(\ast)}\nu\nu)$ and provides both the upper and lower bounds to $\mathcal{B}(B\to K^{(\ast)}\mu\tau)$.
[ { "created": "Mon, 20 Jun 2022 11:25:07 GMT", "version": "v1" } ]
2022-06-22
[ [ "Bečirević", "Damir", "" ], [ "Doršner", "Ilja", "" ], [ "Fajfer", "Svjetlana", "" ], [ "Faroughy", "Darius A.", "" ], [ "Jaffredo", "Florentin", "" ], [ "Košnik", "Nejc", "" ], [ "Sumensari", "Olcyr", "" ] ]
We discuss a model that can accommodate the $B$-physics anomalies, based on combining two scalar leptoquarks, $R_2$ and $S_3$, of mass $\mathcal{O}(1\,\mathrm{TeV})$, and that we proposed in our previous paper. We update the analysis of its parameter space and show that a model remains viable and consistent with a number of low energy and high energy flavor physics constraints. Since the model predicts a non-zero New Physics phase, we discuss the possibility to test its contribution to the neutron electric dipole moment and to the angular distributions of the exclusive $b\to c\tau \bar \nu$ decays. We find that the model can provide a significant enhancement to $\mathcal{B}(B\to K^{(\ast)}\nu\nu)$ and provides both the upper and lower bounds to $\mathcal{B}(B\to K^{(\ast)}\mu\tau)$.
hep-ph/0004043
Konstantin Matchev
Jonathan L. Feng (IAS, Princeton), Konstantin T. Matchev (Fermilab) and Frank Wilczek (IAS, Princeton)
Neutralino Dark Matter in Focus Point Supersymmetry
15 pages, 6 figures, version to appear in Phys. Lett. B. References added, minor modifications of Figs. 2 and 4 due to a bug (sign error) in neutdriver
Phys.Lett.B482:388-399,2000
10.1016/S0370-2693(00)00512-8
IASSNS-HEP-00-24, FERMILAB-PUB-00/074-T
hep-ph astro-ph hep-ex
null
In recent work, it has been argued that multi-TeV masses for scalar superpartners are not unnatural. Indeed, they appear to have significant phenomenological virtues. Here we explore the implications of such `focus point' supersymmetry for the dark matter problem. We find that constraints on relic densities do not place upper bounds on neutralino or scalar masses. We demonstrate that, in the specific context of minimal supergravity, a cosmologically stable mixed gaugino-Higgsino state emerges as an excellent, robust dark matter candidate. We estimate that, over a wide range of the unknown parameters, the spin-independent proton-neutralino cross sections fall in the range accessible to planned search experiments.
[ { "created": "Thu, 6 Apr 2000 15:29:50 GMT", "version": "v1" }, { "created": "Wed, 3 May 2000 22:33:22 GMT", "version": "v2" } ]
2009-09-25
[ [ "Feng", "Jonathan L.", "", "IAS, Princeton" ], [ "Matchev", "Konstantin T.", "", "Fermilab" ], [ "Wilczek", "Frank", "", "IAS, Princeton" ] ]
In recent work, it has been argued that multi-TeV masses for scalar superpartners are not unnatural. Indeed, they appear to have significant phenomenological virtues. Here we explore the implications of such `focus point' supersymmetry for the dark matter problem. We find that constraints on relic densities do not place upper bounds on neutralino or scalar masses. We demonstrate that, in the specific context of minimal supergravity, a cosmologically stable mixed gaugino-Higgsino state emerges as an excellent, robust dark matter candidate. We estimate that, over a wide range of the unknown parameters, the spin-independent proton-neutralino cross sections fall in the range accessible to planned search experiments.
hep-ph/0201131
Bogdan A. Dobrescu
Thomas Appelquist, Bogdan A. Dobrescu, Eduardo Ponton, Ho-Ung Yee (Yale University)
Neutrinos Vis-a-vis the Six-Dimensional Standard Model
34 pages, Latex, 2 eps figures. Change in the normalization convention for the warp factor; other minor changes
Phys.Rev. D65 (2002) 105019
10.1103/PhysRevD.65.105019
YCTP-P1-02
hep-ph hep-th
null
We examine the origin of neutrino masses and oscillations in the context of the six-dimensional standard model. The space-time symmetries of this model explain proton stability and forbid Majorana neutrino masses. The consistency of the six-dimensional theory requires three right-handed neutrinos, and therefore Dirac neutrino masses are allowed. We employ the idea that the smallness of these masses is due to the propagation of the right-handed neutrinos in a seventh, warped dimension. We argue that this class of theories is free of gravitational anomalies. Although an exponential hierarchy arises between the neutrino masses and the electroweak scale, we find that the mass hierarchy among the three neutrino masses is limited by higher-dimension operators. All current neutrino oscillation data, except for the LSND result, are naturally accommodated by our model. In the case of the solar neutrinos, the model leads to the large mixing angle, MSW solution. The mechanism employed, involving three right-handed neutrinos coupled to a scalar in an extra dimension, may explain the features of the neutrino spectrum in a more general class of theories that forbid Majorana masses.
[ { "created": "Tue, 15 Jan 2002 20:17:38 GMT", "version": "v1" }, { "created": "Mon, 25 Mar 2002 22:56:37 GMT", "version": "v2" } ]
2009-11-07
[ [ "Appelquist", "Thomas", "", "Yale University" ], [ "Dobrescu", "Bogdan A.", "", "Yale University" ], [ "Ponton", "Eduardo", "", "Yale University" ], [ "Yee", "Ho-Ung", "", "Yale University" ] ]
We examine the origin of neutrino masses and oscillations in the context of the six-dimensional standard model. The space-time symmetries of this model explain proton stability and forbid Majorana neutrino masses. The consistency of the six-dimensional theory requires three right-handed neutrinos, and therefore Dirac neutrino masses are allowed. We employ the idea that the smallness of these masses is due to the propagation of the right-handed neutrinos in a seventh, warped dimension. We argue that this class of theories is free of gravitational anomalies. Although an exponential hierarchy arises between the neutrino masses and the electroweak scale, we find that the mass hierarchy among the three neutrino masses is limited by higher-dimension operators. All current neutrino oscillation data, except for the LSND result, are naturally accommodated by our model. In the case of the solar neutrinos, the model leads to the large mixing angle, MSW solution. The mechanism employed, involving three right-handed neutrinos coupled to a scalar in an extra dimension, may explain the features of the neutrino spectrum in a more general class of theories that forbid Majorana masses.
hep-ph/0310281
Roelof Bijker
R. Bijker, M.M. Giannini and E. Santopinto
Spectroscopy of pentaquark states
26 pages, 4 figures, 11 tables, revised version with 2 extra tables, an updated list of references and expanded discussion of the results. Accepted for publication in Eur. Phys. J. A
Eur.Phys.J. A22 (2004) 319-329
10.1140/epja/i2003-10232-x
null
hep-ph nucl-th
null
We construct a complete classification of pentaquark states in terms of the spin-flavour SU(6) representations. We find that only some definite SU(3) representations are allowed, singlets, octets, decuplets, anti-decuplets, 27-plets and 35-plets. The latter three contain exotic states, which cannot be constructed from three quarks only. This complete classification scheme is general and model independent and is useful both for model builders and experimentalists. The mass spectrum is obtained from a Gursey-Radicati type mass formula, whose coefficients have been determined previously by a study of qqq baryons. The ground state pentaquark which is identified with the recently observed Theta(1540) state, is predicted to be an isosinglet anti-decuplet state. Its parity depends on the interplay between the spin-flavour and orbital contributions to the mass operator.
[ { "created": "Thu, 23 Oct 2003 21:55:14 GMT", "version": "v1" }, { "created": "Fri, 14 Nov 2003 18:00:02 GMT", "version": "v2" }, { "created": "Tue, 18 May 2004 17:23:37 GMT", "version": "v3" } ]
2009-11-10
[ [ "Bijker", "R.", "" ], [ "Giannini", "M. M.", "" ], [ "Santopinto", "E.", "" ] ]
We construct a complete classification of pentaquark states in terms of the spin-flavour SU(6) representations. We find that only some definite SU(3) representations are allowed, singlets, octets, decuplets, anti-decuplets, 27-plets and 35-plets. The latter three contain exotic states, which cannot be constructed from three quarks only. This complete classification scheme is general and model independent and is useful both for model builders and experimentalists. The mass spectrum is obtained from a Gursey-Radicati type mass formula, whose coefficients have been determined previously by a study of qqq baryons. The ground state pentaquark which is identified with the recently observed Theta(1540) state, is predicted to be an isosinglet anti-decuplet state. Its parity depends on the interplay between the spin-flavour and orbital contributions to the mass operator.
1106.3942
Axel Maas
Axel Maas
Gauge bosons at zero and finite temperature
v2: 153 pages, 45 figures, revised, updated, and extended version submitted on invitation to Physics Reports; v3: Intermediate update, 152 pages, 45 figures, minor errors corrected, reference list extended; v3 minor typographical changes and corrections, added references, version to appear in Physics Reports
Physics Reports 524 (2013), pp. 203-300
10.1016/j.physrep.2012.11.002
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gauge theories of the Yang-Mills type are the single most important building block of the standard model and beyond. Since Yang-Mills theories are gauge theories their elementary particles, the gauge bosons, cannot be described without fixing a gauge. Beyond perturbation theory, gauge-fixing in non-Abelian gauge theories is obstructed by the Gribov-Singer ambiguity. The construction and implementation of a method-independent gauge-fixing prescription to resolve this ambiguity is the most important step to describe gauge bosons beyond perturbation theory. Proposals for such a procedure, generalizing the perturbative Landau gauge, are described here. Their implementation are discussed for two example methods, lattice gauge theory and the quantum equations of motion. The most direct access to the properties of the gauge bosons is provided by their correlation functions. The corresponding two- and three-point correlation functions are presented at all energy scales. These give access to the properties of the gauge bosons, like their absence from the asymptotic physical state space, the absence of an on-shell mass pole, particle-like properties at high energies, and their running couplings. Furthermore, auxiliary degrees of freedom are introduced during gauge-fixing, and their properties are discussed as well. These results are presented for two, three, and four dimensions, and for various gauge algebras. Finally, the modifications of the properties of gauge bosons at finite temperature are presented. Evidence is provided that these reflect the phase structure of Yang-Mills theory. However, it is found that the phase transition is not deconfining the gauge bosons, although the bulk thermodynamical behavior is of a Stefan-Boltzmann type. The resolution of this apparent contradiction is also presented. This resolution also provides an explicit and constructive solution to the Linde problem.
[ { "created": "Mon, 20 Jun 2011 15:27:07 GMT", "version": "v1" }, { "created": "Fri, 23 Dec 2011 13:39:34 GMT", "version": "v2" }, { "created": "Mon, 30 Jul 2012 14:21:41 GMT", "version": "v3" }, { "created": "Mon, 3 Dec 2012 17:02:26 GMT", "version": "v4" } ]
2013-03-12
[ [ "Maas", "Axel", "" ] ]
Gauge theories of the Yang-Mills type are the single most important building block of the standard model and beyond. Since Yang-Mills theories are gauge theories their elementary particles, the gauge bosons, cannot be described without fixing a gauge. Beyond perturbation theory, gauge-fixing in non-Abelian gauge theories is obstructed by the Gribov-Singer ambiguity. The construction and implementation of a method-independent gauge-fixing prescription to resolve this ambiguity is the most important step to describe gauge bosons beyond perturbation theory. Proposals for such a procedure, generalizing the perturbative Landau gauge, are described here. Their implementation are discussed for two example methods, lattice gauge theory and the quantum equations of motion. The most direct access to the properties of the gauge bosons is provided by their correlation functions. The corresponding two- and three-point correlation functions are presented at all energy scales. These give access to the properties of the gauge bosons, like their absence from the asymptotic physical state space, the absence of an on-shell mass pole, particle-like properties at high energies, and their running couplings. Furthermore, auxiliary degrees of freedom are introduced during gauge-fixing, and their properties are discussed as well. These results are presented for two, three, and four dimensions, and for various gauge algebras. Finally, the modifications of the properties of gauge bosons at finite temperature are presented. Evidence is provided that these reflect the phase structure of Yang-Mills theory. However, it is found that the phase transition is not deconfining the gauge bosons, although the bulk thermodynamical behavior is of a Stefan-Boltzmann type. The resolution of this apparent contradiction is also presented. This resolution also provides an explicit and constructive solution to the Linde problem.
hep-ph/0003284
Vicente Pleitez
J. C. Montero, C. A. de S. Pires and V. Pleitez
Neutrinoless double beta decay with and without Majoron-like boson emission in a 3-3-1 model
Revtex, 10 pages and 8 eps figures. Extended version to be published in Physical Review D
Phys.Rev. D64 (2001) 096001
10.1103/PhysRevD.64.096001
IFT-P.033/2000
hep-ph
null
We consider the contributions to the neutrinoless double beta decays in a $SU(3)_L\otimes U(1)_N$ electroweak model. We show that for a range of the parameters in the model there are diagrams involving vector-vector-scalar and trilinear scalar couplings which can be potentially as contributing as the light massive Majorana neutrino exchange one. We use these contributions to obtain constraints upon some mass scales of the model, like the masses of the new charged vector and scalar bosons. We also consider briefly the decay in which besides the two electrons a Majoron-like boson is emitted.
[ { "created": "Wed, 29 Mar 2000 14:06:47 GMT", "version": "v1" }, { "created": "Fri, 15 Dec 2000 18:12:13 GMT", "version": "v2" }, { "created": "Fri, 29 Jun 2001 16:58:54 GMT", "version": "v3" } ]
2009-10-31
[ [ "Montero", "J. C.", "" ], [ "Pires", "C. A. de S.", "" ], [ "Pleitez", "V.", "" ] ]
We consider the contributions to the neutrinoless double beta decays in a $SU(3)_L\otimes U(1)_N$ electroweak model. We show that for a range of the parameters in the model there are diagrams involving vector-vector-scalar and trilinear scalar couplings which can be potentially as contributing as the light massive Majorana neutrino exchange one. We use these contributions to obtain constraints upon some mass scales of the model, like the masses of the new charged vector and scalar bosons. We also consider briefly the decay in which besides the two electrons a Majoron-like boson is emitted.
2406.14602
Qinrui Liu
Qinrui Liu, Ningqiang Song, Aaron C. Vincent
Constraints on Heavy Asymmetric and Symmetric Dark Matter from the Glashow Resonance
10 pages, 3 figures
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay of asymmetric dark matter (ADM) can lead to distinct neutrino signatures characterized by an asymmetry between neutrinos and antineutrinos. In the high-energy regime, the Glashow resonant interaction $\bar{\nu}_{e} + e^{-} \rightarrow W^{-}$ yields an increase in sensitivity to the neutrino flux, and stands out as the only way of discerning the antineutrino component in the diffuse high-energy astrophysical neutrino flux. This offers a unique opportunity in the search for dark matter with masses above the PeV scale. We examine the neutrino signal stemming from ADM decay and set the first stringent constraints on ADM lifetime $\tau_X$. For ADM with mass $m_X\gtrsim 10$ PeV, we find $\tau_X\lesssim 10^{29}$s using the data from the recent IceCube search for Glashow resonance events. Our projections further show that sensitivities at the forthcoming IceCube-Gen2 could approach $10^{30}$s, depending on the decay channel. The current constraints on symmetric dark matter decay to neutrinos are also improved by up to a factor of 3 thanks to the Glashow resonance.
[ { "created": "Thu, 20 Jun 2024 18:00:00 GMT", "version": "v1" } ]
2024-06-24
[ [ "Liu", "Qinrui", "" ], [ "Song", "Ningqiang", "" ], [ "Vincent", "Aaron C.", "" ] ]
The decay of asymmetric dark matter (ADM) can lead to distinct neutrino signatures characterized by an asymmetry between neutrinos and antineutrinos. In the high-energy regime, the Glashow resonant interaction $\bar{\nu}_{e} + e^{-} \rightarrow W^{-}$ yields an increase in sensitivity to the neutrino flux, and stands out as the only way of discerning the antineutrino component in the diffuse high-energy astrophysical neutrino flux. This offers a unique opportunity in the search for dark matter with masses above the PeV scale. We examine the neutrino signal stemming from ADM decay and set the first stringent constraints on ADM lifetime $\tau_X$. For ADM with mass $m_X\gtrsim 10$ PeV, we find $\tau_X\lesssim 10^{29}$s using the data from the recent IceCube search for Glashow resonance events. Our projections further show that sensitivities at the forthcoming IceCube-Gen2 could approach $10^{30}$s, depending on the decay channel. The current constraints on symmetric dark matter decay to neutrinos are also improved by up to a factor of 3 thanks to the Glashow resonance.
hep-ph/0005115
Herbert Weigel
H. Weigel
Hyperon Beta-Decay and Axial Charges of the Lambda in view of Strongly Distorted Baryon Wave-Functions
14 pages, minor revisions, paper accepted for publication in Nucl. Phys. A
Nucl.Phys. A690 (2001) 595
10.1016/S0375-9474(01)00347-5
MIT-CTP-2982
hep-ph nucl-th
null
Within the collective coordinate approach to chiral soliton models we suggest that breaking of SU(3) flavor symmetry mainly resides in the baryon wave-functions while the charge operators maintain a symmetric structure. Sizable symmetry breaking in the wave-functions is required to reproduce the observed spacing in the spectrum of the (1/2)^+ baryons. The matrix elements of the flavor symmetric charge operators nevertheless yield g_A/g_V ratios for hyperon beta-decay which agree with the empirical data approximately as well as the successful F&D parameterization of the Cabibbo scheme. Demanding the strangeness component in the nucleon to vanish in the two flavor limit of the model, determines the structure of the singlet axial charge operator and yields the various quark flavor components of the axial charge of the \Lambda-hyperon. The suggested picture gains support from calculations in a realistic model using pion and vector meson degrees of freedom to build up the soliton.
[ { "created": "Thu, 11 May 2000 22:20:42 GMT", "version": "v1" }, { "created": "Wed, 20 Dec 2000 08:03:52 GMT", "version": "v2" } ]
2009-10-31
[ [ "Weigel", "H.", "" ] ]
Within the collective coordinate approach to chiral soliton models we suggest that breaking of SU(3) flavor symmetry mainly resides in the baryon wave-functions while the charge operators maintain a symmetric structure. Sizable symmetry breaking in the wave-functions is required to reproduce the observed spacing in the spectrum of the (1/2)^+ baryons. The matrix elements of the flavor symmetric charge operators nevertheless yield g_A/g_V ratios for hyperon beta-decay which agree with the empirical data approximately as well as the successful F&D parameterization of the Cabibbo scheme. Demanding the strangeness component in the nucleon to vanish in the two flavor limit of the model, determines the structure of the singlet axial charge operator and yields the various quark flavor components of the axial charge of the \Lambda-hyperon. The suggested picture gains support from calculations in a realistic model using pion and vector meson degrees of freedom to build up the soliton.
2010.04727
Arushi Bodas
Arushi Bodas, Soubhik Kumar, Raman Sundrum
The Scalar Chemical Potential in Cosmological Collider Physics
38 pages, 6 figures, v2: text added for clarification, figs. 2 and 3 changed to better represent the conclusions of our analysis, matches publication in JHEP
JHEP 2021, 79 (2021)
10.1007/JHEP02(2021)079
UMD-PP-020-09
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-analyticity in co-moving momenta within the non-Gaussian bispectrum is a distinctive sign of on-shell particle production during inflation, presenting a unique opportunity for the "direct detection" of particles with masses as large as the inflationary Hubble scale ($H$). However, the strength of such non-analyticity ordinarily drops exponentially by a Boltzmann-like factor as masses exceed $H$. In this paper, we study an exception provided by a dimension-5 derivative coupling of the inflaton to heavy-particle currents, applying it specifically to the case of two real scalars. The operator has a "chemical potential" form, which harnesses the large kinetic energy scale of the inflaton, $\dot{\phi}_{0}^{1/2} \approx 60H$, to act as an efficient source of scalar particle production. Derivative couplings of inflaton ensure radiative stability of the slow-roll potential, which in turn maintains (approximate) scale-invariance of the inflationary correlations. We show that a signal not suffering Boltzmann suppression can be obtained in the bispectrum with strength $f_{\mathrm{NL}} \sim \mathcal{O}(0.01-10)$ for an extended range of scalar masses, $M \lesssim \dot{\phi}_{0}^{1/2}$, potentially as high as $10^{15}$ GeV, within the sensitivity of upcoming LSS and more futuristic 21-cm experiments. The mechanism does not invoke any particular fine-tuning of parameters or breakdown of perturbation-theoretic control. The leading contribution appears at tree-level, which makes the calculation analytically tractable and removes the loop-suppression as compared to earlier chemical potential studies of non-zero spins. The steady particle production allows us to infer the effective mass of the heavy particles and the chemical potential from the variation in bispectrum oscillations as a function of co-moving momenta. Our analysis sets the stage for generalization to heavy bosons with non-zero spin.
[ { "created": "Fri, 9 Oct 2020 18:00:01 GMT", "version": "v1" }, { "created": "Sat, 20 Feb 2021 00:04:12 GMT", "version": "v2" } ]
2021-02-23
[ [ "Bodas", "Arushi", "" ], [ "Kumar", "Soubhik", "" ], [ "Sundrum", "Raman", "" ] ]
Non-analyticity in co-moving momenta within the non-Gaussian bispectrum is a distinctive sign of on-shell particle production during inflation, presenting a unique opportunity for the "direct detection" of particles with masses as large as the inflationary Hubble scale ($H$). However, the strength of such non-analyticity ordinarily drops exponentially by a Boltzmann-like factor as masses exceed $H$. In this paper, we study an exception provided by a dimension-5 derivative coupling of the inflaton to heavy-particle currents, applying it specifically to the case of two real scalars. The operator has a "chemical potential" form, which harnesses the large kinetic energy scale of the inflaton, $\dot{\phi}_{0}^{1/2} \approx 60H$, to act as an efficient source of scalar particle production. Derivative couplings of inflaton ensure radiative stability of the slow-roll potential, which in turn maintains (approximate) scale-invariance of the inflationary correlations. We show that a signal not suffering Boltzmann suppression can be obtained in the bispectrum with strength $f_{\mathrm{NL}} \sim \mathcal{O}(0.01-10)$ for an extended range of scalar masses, $M \lesssim \dot{\phi}_{0}^{1/2}$, potentially as high as $10^{15}$ GeV, within the sensitivity of upcoming LSS and more futuristic 21-cm experiments. The mechanism does not invoke any particular fine-tuning of parameters or breakdown of perturbation-theoretic control. The leading contribution appears at tree-level, which makes the calculation analytically tractable and removes the loop-suppression as compared to earlier chemical potential studies of non-zero spins. The steady particle production allows us to infer the effective mass of the heavy particles and the chemical potential from the variation in bispectrum oscillations as a function of co-moving momenta. Our analysis sets the stage for generalization to heavy bosons with non-zero spin.
1505.06469
Phung Van Dong
P. V. Dong
Unifying the electroweak and B-L interactions
25 pages, 2 figures; matches published version in PRD
Phys. Rev. D 92, 055026 (2015)
10.1103/PhysRevD.92.055026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that the gauge symmetry which includes SU(3)_L as a higher weak-isospin symmetry is manifestly given by SU(3)_C\otimes SU(3)_L\otimes U(1)_X\otimes U(1)_N, where the last two factors determine the electric charge and B-L, respectively. This theory not only provides a consistent unification of the electroweak and B-L interactions, but also gives insights in dark matter, neutrino masses, and inflation. The dark matter belongs to a class of new particles that have wrong B-L numbers, and is stabilized due to a newly-realized W-parity as residual gauge symmetry. The B-L breaking field is important to define the W-parity, seesaw scales, and inflaton. Furthermore, the number of fermion generations and the electric charge quantization are explained naturally. We also show that the previous 3-3-1 models are only an effective theory as the B-L charge and the unitarity argument are violated. This work substantially generalizes our recently-proposed 3-3-1-1 model.
[ { "created": "Sun, 24 May 2015 19:46:17 GMT", "version": "v1" }, { "created": "Mon, 21 Sep 2015 17:09:56 GMT", "version": "v2" } ]
2015-09-22
[ [ "Dong", "P. V.", "" ] ]
We argue that the gauge symmetry which includes SU(3)_L as a higher weak-isospin symmetry is manifestly given by SU(3)_C\otimes SU(3)_L\otimes U(1)_X\otimes U(1)_N, where the last two factors determine the electric charge and B-L, respectively. This theory not only provides a consistent unification of the electroweak and B-L interactions, but also gives insights in dark matter, neutrino masses, and inflation. The dark matter belongs to a class of new particles that have wrong B-L numbers, and is stabilized due to a newly-realized W-parity as residual gauge symmetry. The B-L breaking field is important to define the W-parity, seesaw scales, and inflaton. Furthermore, the number of fermion generations and the electric charge quantization are explained naturally. We also show that the previous 3-3-1 models are only an effective theory as the B-L charge and the unitarity argument are violated. This work substantially generalizes our recently-proposed 3-3-1-1 model.
hep-ph/0402097
Tim Gershon
Tim Gershon and Masashi Hazumi
Time-Dependent CP Violation in $B^0 \to P^0P^0X^0$ Decays
13 pages, 3 figures To appear in Physics Letters B
Phys.Lett. B596 (2004) 163-172
10.1016/j.physletb.2004.06.095
null
hep-ph hep-ex
null
We note that in decays of the type $B^0 \to P^0P^0X^0$, where $P^0$ and $X^0$ represent any CP eigenstate spin-0 neutral particles, the final state is a CP eigenstate. We consider the possibilities for studying time-dependent CP violation in decays of this type at $B$ factories with high luminosity, with particular attention to $B^0 \to \ks \ks \ks$. We also comment on some cases where $X^0$ has non-zero spin, and decays of the type $B^0 \to P^0 Q^0 X^0$, where the three final state particles are different spin-0 CP eigenstates.
[ { "created": "Tue, 10 Feb 2004 01:41:57 GMT", "version": "v1" }, { "created": "Thu, 6 May 2004 04:33:49 GMT", "version": "v2" }, { "created": "Wed, 30 Jun 2004 05:18:46 GMT", "version": "v3" } ]
2009-11-10
[ [ "Gershon", "Tim", "" ], [ "Hazumi", "Masashi", "" ] ]
We note that in decays of the type $B^0 \to P^0P^0X^0$, where $P^0$ and $X^0$ represent any CP eigenstate spin-0 neutral particles, the final state is a CP eigenstate. We consider the possibilities for studying time-dependent CP violation in decays of this type at $B$ factories with high luminosity, with particular attention to $B^0 \to \ks \ks \ks$. We also comment on some cases where $X^0$ has non-zero spin, and decays of the type $B^0 \to P^0 Q^0 X^0$, where the three final state particles are different spin-0 CP eigenstates.
1209.2490
M.I. Vyazovsky
M. A. Braun, M. Yu. Salykin, S. S. Pozdnyakov and M. I. Vyazovsky (Saint-Petersburg State University, Russia)
Production of a gluon with the exchange of three reggeized gluons in the Lipatov effective action approach
22 pages, 9 figures; submitted to Eur.Phys.Jour. C
null
10.1140/epjc/s10052-012-2223-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Regge kinematics the amplitude for gluon production off three scattering centers is found in the Lipatov effective action technique. The vertex for gluon emission with the reggeon splitting in three reggeons is calculated and its transversality is demonstrated. It is shown that in the sum of all contributions terms containing principal value singularities are cancelled and substituted by the standard Feynman poles. These results may be used for calculation of the inclusive cross-section for gluon production on two nucleons in the nucleus.
[ { "created": "Wed, 12 Sep 2012 04:12:16 GMT", "version": "v1" } ]
2015-06-11
[ [ "Braun", "M. A.", "", "Saint-Petersburg State University, Russia" ], [ "Salykin", "M. Yu.", "", "Saint-Petersburg State University, Russia" ], [ "Pozdnyakov", "S. S.", "", "Saint-Petersburg State University, Russia" ], [ "Vyazovsky", "M. I.", "", "Saint-Petersburg State University, Russia" ] ]
In the Regge kinematics the amplitude for gluon production off three scattering centers is found in the Lipatov effective action technique. The vertex for gluon emission with the reggeon splitting in three reggeons is calculated and its transversality is demonstrated. It is shown that in the sum of all contributions terms containing principal value singularities are cancelled and substituted by the standard Feynman poles. These results may be used for calculation of the inclusive cross-section for gluon production on two nucleons in the nucleus.
hep-ph/0009266
Robert Buras
R. Buras (MPP Munich), D.V. Semikoz (MPP Munich)
Maximum lepton asymmetry from active-sterile neutrino oscillations in the Early Universe
14 pp, 4 figures
Phys.Rev. D64 (2001) 017302
10.1103/PhysRevD.64.017302
null
hep-ph
null
A large lepton asymmetry could be generated in the Early Universe by oscillations of active to sterile neutrinos with a small mixing angle sin 2 \theta < 10^-2. The final order of magnitude of the lepton asymmetry \eta is mainly determined by its growth in the last stage of evolution when the MSW resonance dominates the kinetic equations. In this paper we present a simple way of calculating the maximum possible lepton asymmetry which can be created. Our results are in good agreement to previous calculations. Furthermore, we find that the growth of asymmetry does not obey any particular power law. We find that the maximum possible asymmetry at the freeze-out of the n/p ratio at T \sim 1 MeV strongly depends on the mass-squared difference \delta m^2: the asymmetry is negligible for \delta m^2 \ll 1 eV^2 and reaches asymptotically large values for \delta m^2 \ge 50 eV^2.
[ { "created": "Fri, 22 Sep 2000 12:50:49 GMT", "version": "v1" } ]
2009-10-31
[ [ "Buras", "R.", "", "MPP Munich" ], [ "Semikoz", "D. V.", "", "MPP Munich" ] ]
A large lepton asymmetry could be generated in the Early Universe by oscillations of active to sterile neutrinos with a small mixing angle sin 2 \theta < 10^-2. The final order of magnitude of the lepton asymmetry \eta is mainly determined by its growth in the last stage of evolution when the MSW resonance dominates the kinetic equations. In this paper we present a simple way of calculating the maximum possible lepton asymmetry which can be created. Our results are in good agreement to previous calculations. Furthermore, we find that the growth of asymmetry does not obey any particular power law. We find that the maximum possible asymmetry at the freeze-out of the n/p ratio at T \sim 1 MeV strongly depends on the mass-squared difference \delta m^2: the asymmetry is negligible for \delta m^2 \ll 1 eV^2 and reaches asymptotically large values for \delta m^2 \ge 50 eV^2.
1605.05116
Shaikh Saad
K.S. Babu, Borut Bajc, Shaikh Saad
New Class of SO(10) Models for Flavor
40 pages, Latex, 1 figure
Phys. Rev. D 94, 015030 (2016)
10.1103/PhysRevD.94.015030
OSU-HEP-16-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new class of unified models based on SO(10) symmetry which provides insights into the masses and mixings of quarks and leptons, including the neutrinos. The key feature of our proposal is the absence of Higgs boson 10_H belonging to the fundamental representation that is normally employed. Flavor mixing is induced via vector-like fermions in the 16 + 16-bar representation. A variety of scenarios, both supersymmetric and otherwise, are analyzed involving a 126_H along with either a 45_H or a 210_H of Higgs boson employed for symmetry breaking. It is shown that this framework, with only a limited number of parameters, provides an excellent fit to the full fermion spectrum, utilizing either type-I or type-II seesaw mechanism. These flavor models can be potentially tested and distinguished in their predictions for proton decay branching ratios, which are analyzed.
[ { "created": "Tue, 17 May 2016 11:19:52 GMT", "version": "v1" } ]
2016-08-03
[ [ "Babu", "K. S.", "" ], [ "Bajc", "Borut", "" ], [ "Saad", "Shaikh", "" ] ]
We present a new class of unified models based on SO(10) symmetry which provides insights into the masses and mixings of quarks and leptons, including the neutrinos. The key feature of our proposal is the absence of Higgs boson 10_H belonging to the fundamental representation that is normally employed. Flavor mixing is induced via vector-like fermions in the 16 + 16-bar representation. A variety of scenarios, both supersymmetric and otherwise, are analyzed involving a 126_H along with either a 45_H or a 210_H of Higgs boson employed for symmetry breaking. It is shown that this framework, with only a limited number of parameters, provides an excellent fit to the full fermion spectrum, utilizing either type-I or type-II seesaw mechanism. These flavor models can be potentially tested and distinguished in their predictions for proton decay branching ratios, which are analyzed.
hep-ph/9705424
GLin
Guey-Lin Lin
Like Sign Top Pair Production at LHC
9 pages, use sprocl.sty and psfig.tex; invited talk presented at the Third International Workshop on Particle Physics Phenomenology, Chinsan, Taipei, Taiwan, Nov. 14-17, 1996; to appear in the proceedings
null
null
NCTU-TH-97-02
hep-ph
null
Having a mass comparable to the weak scale, the top quark may have a sizable flavor changing couplings to Higgs bosons. We show that such couplings can be probed at the LHC through the parton subprocess $c(\bar c)g \to t (\bar t)A^0$, where the pseudoscalar $A^0$ subsequently decays into $t \bar c$ or ${\bar t} c$, giving rise to the intriguing final state of like sign top quark pairs. We also discuss major backgrounds to the above signal, in particular the QCD-Weak process $q\bar q' \to W^+(W^-) t \bar t$. The issue of background reduction is briefly discussed.
[ { "created": "Mon, 26 May 1997 10:19:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lin", "Guey-Lin", "" ] ]
Having a mass comparable to the weak scale, the top quark may have a sizable flavor changing couplings to Higgs bosons. We show that such couplings can be probed at the LHC through the parton subprocess $c(\bar c)g \to t (\bar t)A^0$, where the pseudoscalar $A^0$ subsequently decays into $t \bar c$ or ${\bar t} c$, giving rise to the intriguing final state of like sign top quark pairs. We also discuss major backgrounds to the above signal, in particular the QCD-Weak process $q\bar q' \to W^+(W^-) t \bar t$. The issue of background reduction is briefly discussed.
1207.3844
Ian Balitsky
Ian Balitsky and Giovanni A. Chirilli
Photon impact factor and $k_T$-factorization for DIS in the next-to-leading order
13 pages, 4 figures, typos corrected. arXiv admin note: substantial text overlap with arXiv:1009.4729
null
10.1103/PhysRevD.87.014013
JLAB-THY-12-1596; NT-LBL-12-014
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The photon impact factor for the BFKL pomeron is calculated in the next-to-leading order (NLO) approximation using the operator expansion in Wilson lines. The result is represented as a NLO $k_T$-factorization formula for the structure functions of small-$x$ deep inelastic scattering.
[ { "created": "Mon, 16 Jul 2012 23:18:21 GMT", "version": "v1" }, { "created": "Sun, 27 Jul 2014 16:56:05 GMT", "version": "v2" } ]
2014-07-29
[ [ "Balitsky", "Ian", "" ], [ "Chirilli", "Giovanni A.", "" ] ]
The photon impact factor for the BFKL pomeron is calculated in the next-to-leading order (NLO) approximation using the operator expansion in Wilson lines. The result is represented as a NLO $k_T$-factorization formula for the structure functions of small-$x$ deep inelastic scattering.
hep-ph/0012170
Altug Ozpineci
T. M. Aliev, A. Ozpineci, M. Savci
Meson-Baryon Couplings and the F/D ratio in Light Cone QCD
22 pages, 5 figures, LaTeX formatted
Phys.Rev. D64 (2001) 034001
10.1103/PhysRevD.64.034001
metu-phys-hep-00-21
hep-ph
null
Using the general form of the baryon currents, we calculate the meson-baryon coupling constants and the F/D ratio within the framework of light cone QCD sum rules in the SU(3) flavor symmetry limit. The dependence of the results on the Dirac structure and on the free parameter (b) appearing in the general baryon current is considered. Comparison of our results on F/D ratio with the existing results is presented.
[ { "created": "Thu, 14 Dec 2000 12:46:17 GMT", "version": "v1" }, { "created": "Tue, 13 Mar 2001 19:48:30 GMT", "version": "v2" }, { "created": "Mon, 10 Mar 2003 11:44:28 GMT", "version": "v3" } ]
2009-10-31
[ [ "Aliev", "T. M.", "" ], [ "Ozpineci", "A.", "" ], [ "Savci", "M.", "" ] ]
Using the general form of the baryon currents, we calculate the meson-baryon coupling constants and the F/D ratio within the framework of light cone QCD sum rules in the SU(3) flavor symmetry limit. The dependence of the results on the Dirac structure and on the free parameter (b) appearing in the general baryon current is considered. Comparison of our results on F/D ratio with the existing results is presented.
1511.06326
Leonard S. Kisslinger
Leonard S. Kisslinger, Zhou Li-juan, Ma Wei-xing
$\Psi(2S)$ Decay to $J/\Psi(1S)$ + 2$\pi$ or $J/\Psi(1S)$ +$\sigma$ + 2$\pi$
11 pages, 7 figures. arXiv admin note: substantial text overlap with arXiv:1509.08366
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The BES Collaboration has measured $\Psi(2S)$ decay to $J/\Psi \pi^+\pi^-$. Using the mixed hybrid theory for the $\Psi(2S)$ we estimate the decay to $J/\Psi(1S)$ + $\sigma$. Using the known $\sigma \rightarrow 2\pi$ coupling constant, we estimate the $\Psi(2S)$ to $J/\Psi(1S)$ + $2\pi$ decay rate and angular distribution. This is an extension of our previous research on $\Psi(2S)$ Decay to $J/\Psi(1S)$ +$\sigma$ + 2$\pi^o$, without the production of 2$\pi^o$, and with an estimate of the $\sigma \rightarrow \pi^+ + \pi^-$ transition.
[ { "created": "Tue, 17 Nov 2015 21:55:31 GMT", "version": "v1" }, { "created": "Mon, 31 Jul 2017 18:37:24 GMT", "version": "v2" }, { "created": "Mon, 3 Jun 2019 13:54:36 GMT", "version": "v3" } ]
2020-05-15
[ [ "Kisslinger", "Leonard S.", "" ], [ "Li-juan", "Zhou", "" ], [ "Wei-xing", "Ma", "" ] ]
The BES Collaboration has measured $\Psi(2S)$ decay to $J/\Psi \pi^+\pi^-$. Using the mixed hybrid theory for the $\Psi(2S)$ we estimate the decay to $J/\Psi(1S)$ + $\sigma$. Using the known $\sigma \rightarrow 2\pi$ coupling constant, we estimate the $\Psi(2S)$ to $J/\Psi(1S)$ + $2\pi$ decay rate and angular distribution. This is an extension of our previous research on $\Psi(2S)$ Decay to $J/\Psi(1S)$ +$\sigma$ + 2$\pi^o$, without the production of 2$\pi^o$, and with an estimate of the $\sigma \rightarrow \pi^+ + \pi^-$ transition.
1303.0659
Asmita Mukherjee
Asmita Mukherjee, Werner Vogelsang
Jet Production in $pp$ Collisions: Dependence on Jet Algorithm
Prepared for the Third Workshop on the QCD Structure of the Nucleon : QCD N'12, 22-26 October, 2012, Bilbao, Spain
null
10.1393/ncc/i2013-11589-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on a recent calculation of single-inclusive high-$p_T$ jet production in unpolarized and longitudinally polarized $pp$ collisions at RHIC, investigating the effect of the algorithm adopted to define the jets on the numerical results for cross sections and spin asymmetries.
[ { "created": "Mon, 4 Mar 2013 09:58:28 GMT", "version": "v1" } ]
2022-03-02
[ [ "Mukherjee", "Asmita", "" ], [ "Vogelsang", "Werner", "" ] ]
We report on a recent calculation of single-inclusive high-$p_T$ jet production in unpolarized and longitudinally polarized $pp$ collisions at RHIC, investigating the effect of the algorithm adopted to define the jets on the numerical results for cross sections and spin asymmetries.
2312.11320
Marek Matas
Jan Cepila, Jesus Guillermo Contreras, Marek Matas, Alexandra Ridzikova
Incoherent ${\rm J}/\psi$ production at large $|t|$ identifies the onset of saturation at the LHC
18 pages, 3 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We predict that the onset of gluon saturation can be uniquely identified using incoherent ${\rm J}/\psi$ production in Pb$\unicode{x2013}$Pb collisions at currently accessible energies of the LHC. The diffractive incoherent photo-production of a ${\rm J}/\psi$ vector meson off a hadron provides information on the partonic structure of the hadron. Within the Good-Walker approach it specifically measures the variance over possible target configurations of the hadronic colour field. For this process then, gluon saturation sets in when the cross section reaches a maximum, as a function of the centre-of-mass energy of the photon-hadron system ($W$), and then decreases. We benchmark the energy-dependent hot-spot model against data from HERA and the LHC and demonstrate a good description of the available data. We show that the study of the energy dependence of the incoherent production of ${\rm J}/\psi$ allows us to pinpoint the onset of saturation effects by selecting the region of Mandelstam-$t$ around 1 GeV$^2$ where the contribution of hot spots is dominant. We predict the onset of saturation in a Pb target to occur for $W$ around a few hundred GeV. This can be measured with current data in ultra-peripheral Pb$\unicode{x2013}$Pb collisions at the LHC.
[ { "created": "Mon, 18 Dec 2023 16:16:22 GMT", "version": "v1" }, { "created": "Wed, 27 Mar 2024 12:44:21 GMT", "version": "v2" } ]
2024-03-28
[ [ "Cepila", "Jan", "" ], [ "Contreras", "Jesus Guillermo", "" ], [ "Matas", "Marek", "" ], [ "Ridzikova", "Alexandra", "" ] ]
We predict that the onset of gluon saturation can be uniquely identified using incoherent ${\rm J}/\psi$ production in Pb$\unicode{x2013}$Pb collisions at currently accessible energies of the LHC. The diffractive incoherent photo-production of a ${\rm J}/\psi$ vector meson off a hadron provides information on the partonic structure of the hadron. Within the Good-Walker approach it specifically measures the variance over possible target configurations of the hadronic colour field. For this process then, gluon saturation sets in when the cross section reaches a maximum, as a function of the centre-of-mass energy of the photon-hadron system ($W$), and then decreases. We benchmark the energy-dependent hot-spot model against data from HERA and the LHC and demonstrate a good description of the available data. We show that the study of the energy dependence of the incoherent production of ${\rm J}/\psi$ allows us to pinpoint the onset of saturation effects by selecting the region of Mandelstam-$t$ around 1 GeV$^2$ where the contribution of hot spots is dominant. We predict the onset of saturation in a Pb target to occur for $W$ around a few hundred GeV. This can be measured with current data in ultra-peripheral Pb$\unicode{x2013}$Pb collisions at the LHC.
hep-ph/0101085
Allen Caldwell
Allen C. Caldwell and Mara S. Soares
Vector Meson Production in the Golec-Biernat Wuesthoff Model
null
Nucl.Phys. A696 (2001) 125-137
10.1016/S0375-9474(01)01117-4
null
hep-ph
null
We apply the Golec-Biernat Wuesthoff model in the calculation of vector meson photo- and electroproduction. Starting from very simple non-relativistic wave functions we show that the model provides a good description of $J/\Psi$ cross sections in wide $Q^2$ and $W$ ranges. For the light mesons one obtains the approximately correct $W$ dependence and ratio of longitudinal to transverse cross sections, although in this case the normalization, affected mainly by the wave function employed, is not in good agreement with data.
[ { "created": "Tue, 9 Jan 2001 18:00:16 GMT", "version": "v1" } ]
2009-11-07
[ [ "Caldwell", "Allen C.", "" ], [ "Soares", "Mara S.", "" ] ]
We apply the Golec-Biernat Wuesthoff model in the calculation of vector meson photo- and electroproduction. Starting from very simple non-relativistic wave functions we show that the model provides a good description of $J/\Psi$ cross sections in wide $Q^2$ and $W$ ranges. For the light mesons one obtains the approximately correct $W$ dependence and ratio of longitudinal to transverse cross sections, although in this case the normalization, affected mainly by the wave function employed, is not in good agreement with data.
hep-ph/0303063
Igor Ivanov
I.P. Ivanov (IM, Novosibirsk, Russia and IKP; KFA Juelich, Germany)
The hard scale in the exclusive rho-meson production in diffractive DIS
14 pages, 7 eps figures
Phys.Rev. D68 (2003) 032001
10.1103/PhysRevD.68.032001
FZJ-IKP(Th)-2003-XX
hep-ph hep-ex
null
We re-examine the issue of the pQCD factorization scale in the exclusive rho production in diffractive DIS from the k_t-factorization point of view. We find that this scale differs significantly from, and possesses much flatter Q^2 behavior than widely used value (Q^2 + m_\rho^2)/4. With these results in mind, we discuss the Q^2 shape of the rho meson production cross section. We introduce rescaled cross sections, which might provide further insight into the dynamics of rho production. We also comment on the recent ZEUS observation of energy-independent ratio sigma(gamma* p --> rho p) / sigma_{tot}(gamma*p).
[ { "created": "Fri, 7 Mar 2003 18:49:51 GMT", "version": "v1" } ]
2009-11-10
[ [ "Ivanov", "I. P.", "", "IM, Novosibirsk, Russia and IKP; KFA Juelich, Germany" ] ]
We re-examine the issue of the pQCD factorization scale in the exclusive rho production in diffractive DIS from the k_t-factorization point of view. We find that this scale differs significantly from, and possesses much flatter Q^2 behavior than widely used value (Q^2 + m_\rho^2)/4. With these results in mind, we discuss the Q^2 shape of the rho meson production cross section. We introduce rescaled cross sections, which might provide further insight into the dynamics of rho production. We also comment on the recent ZEUS observation of energy-independent ratio sigma(gamma* p --> rho p) / sigma_{tot}(gamma*p).
1407.6355
Yang Bai
Yang Bai and Wai-Yee Keung
Dips at Colliders
changed the conclusion for the existence of dips for the vanishing mass-on-shell interactions, added a section about dip structures with a zero in the vertex form factor
Int. J. Mod. Phys. A 30, 1550120 (2015)
10.1142/S0217751X15501201
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We categorize new physics signatures that manifest themselves as a "dip" structure at colliders. One potential way to realize a dip is to require interactions to be zero when all particles are mass on-shell, but not if one or more are mass off-shell. For three particle interactions, we have found three interesting cases: one massive gauge boson with two identical scalars; one massless gauge boson with two different scalars; one massive gauge boson with two identical massless gauge bosons. For each case, we identify the relevant effective operators to explore its dip signature at the LHC. Unfortunately, the unstable particle with a vanishing mass-on-shell interaction has a complex mass which is coincident with the complex pole in its propagator. As a result, a contact-like amplitude without a dip is produced. We then point out two other interesting ways that generate a dip in the cross section. The first way has a dip signature due to a zero in the vertex form factor of the time-like momentum in the s-channel. In the second way, the dip plus bump signature appears because there is destructive interference among processes of exchanging different s-channel particles.
[ { "created": "Wed, 23 Jul 2014 20:00:02 GMT", "version": "v1" }, { "created": "Thu, 14 Aug 2014 15:04:55 GMT", "version": "v2" } ]
2015-07-22
[ [ "Bai", "Yang", "" ], [ "Keung", "Wai-Yee", "" ] ]
We categorize new physics signatures that manifest themselves as a "dip" structure at colliders. One potential way to realize a dip is to require interactions to be zero when all particles are mass on-shell, but not if one or more are mass off-shell. For three particle interactions, we have found three interesting cases: one massive gauge boson with two identical scalars; one massless gauge boson with two different scalars; one massive gauge boson with two identical massless gauge bosons. For each case, we identify the relevant effective operators to explore its dip signature at the LHC. Unfortunately, the unstable particle with a vanishing mass-on-shell interaction has a complex mass which is coincident with the complex pole in its propagator. As a result, a contact-like amplitude without a dip is produced. We then point out two other interesting ways that generate a dip in the cross section. The first way has a dip signature due to a zero in the vertex form factor of the time-like momentum in the s-channel. In the second way, the dip plus bump signature appears because there is destructive interference among processes of exchanging different s-channel particles.
1504.06490
Rafal Maciula
Andreas van Hameren, Rafal Maciula and Antoni Szczurek
Production of two charm quark-antiquark pairs in single-parton scattering within the $k_t$-factorization approach
14 pages, 12 figures
null
10.1016/j.physletb.2015.06.061
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present first results for the $2 \to 4$ single-parton scattering $g g \to c \bar c c \bar c$ subprocess for the first time fully within the $k_t$-factorization approach. In this calculation we have used the Kimber-Martin-Ryskin unintegrated gluon distribution which effectively includes some class of higher-order gluon emissions, and an off-shell matrix element squared calculated using recently developed techniques. The results are compared with our earlier result obtained within the collinear-factorization approach. Only slightly larger cross sections are obtained than in the case of the collinear approach. Inclusion of transverse momenta of gluons entering the hard process leads to a much stronger azimuthal decorrelation between $c c$ and $\bar c \bar c$ than in the collinear-factorization approach. A comparison to predictions of double parton scattering (DPS) results and the LHCb data strongly suggests that the assumption of two fully independent DPS ($g g \to c \bar c \otimes g g \to c \bar c$) may be too approximate.
[ { "created": "Fri, 24 Apr 2015 13:01:29 GMT", "version": "v1" }, { "created": "Tue, 28 Apr 2015 11:01:55 GMT", "version": "v2" } ]
2015-07-01
[ [ "van Hameren", "Andreas", "" ], [ "Maciula", "Rafal", "" ], [ "Szczurek", "Antoni", "" ] ]
We present first results for the $2 \to 4$ single-parton scattering $g g \to c \bar c c \bar c$ subprocess for the first time fully within the $k_t$-factorization approach. In this calculation we have used the Kimber-Martin-Ryskin unintegrated gluon distribution which effectively includes some class of higher-order gluon emissions, and an off-shell matrix element squared calculated using recently developed techniques. The results are compared with our earlier result obtained within the collinear-factorization approach. Only slightly larger cross sections are obtained than in the case of the collinear approach. Inclusion of transverse momenta of gluons entering the hard process leads to a much stronger azimuthal decorrelation between $c c$ and $\bar c \bar c$ than in the collinear-factorization approach. A comparison to predictions of double parton scattering (DPS) results and the LHCb data strongly suggests that the assumption of two fully independent DPS ($g g \to c \bar c \otimes g g \to c \bar c$) may be too approximate.
hep-ph/9908505
Joseph D. Lykken
Joseph Lykken and Satyanarayan Nandi
Asymmetrical large extra dimensions
12 pages, 1 figure, improved discussion of collider signatures
Phys.Lett. B485 (2000) 224-230
10.1016/S0370-2693(00)00667-5
FERMILAB-PUB-99/242-T
hep-ph
null
We study scenarios in which there is a hierarchy of two sets of large compactified extra dimensions. One particularly interesting case has a single millimeter size extra dimension and five TeV^{-1} size dimensions. The Standard Model gauge bosons have Kaluza-Klein excitations with respect to one of the TeV scale dimensions. We discuss astrophysical constraints on this scenario, as well as prospects for signals at future high energy colliders.
[ { "created": "Mon, 30 Aug 1999 17:05:50 GMT", "version": "v1" }, { "created": "Mon, 22 May 2000 16:22:02 GMT", "version": "v2" } ]
2009-10-31
[ [ "Lykken", "Joseph", "" ], [ "Nandi", "Satyanarayan", "" ] ]
We study scenarios in which there is a hierarchy of two sets of large compactified extra dimensions. One particularly interesting case has a single millimeter size extra dimension and five TeV^{-1} size dimensions. The Standard Model gauge bosons have Kaluza-Klein excitations with respect to one of the TeV scale dimensions. We discuss astrophysical constraints on this scenario, as well as prospects for signals at future high energy colliders.
hep-ph/0608126
Tomo Takahashi
Junji Hisano, Kaiki Taro Inoue and Tomo Takahashi
Constraining SuperWIMPy and Warm Subhalos with Future Submillilensing
14 pages, 2 figures, revised version accepted for publication in PLB
Phys.Lett.B643:141-146,2006
10.1016/j.physletb.2006.10.050
null
hep-ph
null
We propose to observe QSO-galaxy strong lens systems to give a new constraint on the damping scale of the initial fluctuations. We find that the future observation of submilliarc scale astrometric shifts of the multiple lensed images of QSOs would find \sim 10^{(3-9)} M_{\odot} subhalos inside the macrolens halo. The superweakly interacting massive particles (superWIMPs) produced from a WIMP decay and the warm dark matter (WDM) particles that predict a comoving damping scale larger than \sim 2 kpc can be constrained if \sim 10^3 M_{\odot} subhalos are detected.
[ { "created": "Fri, 11 Aug 2006 05:31:47 GMT", "version": "v1" }, { "created": "Mon, 30 Oct 2006 08:22:44 GMT", "version": "v2" } ]
2008-11-26
[ [ "Hisano", "Junji", "" ], [ "Inoue", "Kaiki Taro", "" ], [ "Takahashi", "Tomo", "" ] ]
We propose to observe QSO-galaxy strong lens systems to give a new constraint on the damping scale of the initial fluctuations. We find that the future observation of submilliarc scale astrometric shifts of the multiple lensed images of QSOs would find \sim 10^{(3-9)} M_{\odot} subhalos inside the macrolens halo. The superweakly interacting massive particles (superWIMPs) produced from a WIMP decay and the warm dark matter (WDM) particles that predict a comoving damping scale larger than \sim 2 kpc can be constrained if \sim 10^3 M_{\odot} subhalos are detected.
2107.04242
Ruiyu Zhou
Wei Cheng, Tao Qian, Qing Yu, Hua Zhou, and Rui-Yu Zhou
Gravitational Wave From Axion-like Particle Inflation
7 pages, 5 figures
null
10.1103/PhysRevD.104.103502
null
hep-ph astro-ph.CO astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
In this paper, we investigate the Axion-like Particle inflation by applying the multi-nature inflation model, where the end of inflation is achieved through the phase transition (PT). The events of PT should not be less than $200$, which results in the free parameter $n\geq404$. Under the latest CMB restrictions, we found that the inflation energy is fixed at $10^{15} \rm{GeV}$. Then, we deeply discussed the corresponding stochastic background of the primordial gravitational wave (GW) during inflation. We study the two kinds of $n$ cases, i.e., $n=404, 2000$. We observe that the magnitude of $n$ is negligible for the physical observations, such as $n_s$, $r$, $\Lambda$, and $\Omega_{\rm{GW}}h^2$. In the low-frequency regions, the GW is dominated by the quantum fluctuations, and this GW can be detected by Decigo at $10^{-1}~\rm{Hz}$. However, GW generated by PT dominates the high-frequency regions, which is expected to be detected by future 3DSR detector.
[ { "created": "Fri, 9 Jul 2021 06:35:10 GMT", "version": "v1" } ]
2021-11-17
[ [ "Cheng", "Wei", "" ], [ "Qian", "Tao", "" ], [ "Yu", "Qing", "" ], [ "Zhou", "Hua", "" ], [ "Zhou", "Rui-Yu", "" ] ]
In this paper, we investigate the Axion-like Particle inflation by applying the multi-nature inflation model, where the end of inflation is achieved through the phase transition (PT). The events of PT should not be less than $200$, which results in the free parameter $n\geq404$. Under the latest CMB restrictions, we found that the inflation energy is fixed at $10^{15} \rm{GeV}$. Then, we deeply discussed the corresponding stochastic background of the primordial gravitational wave (GW) during inflation. We study the two kinds of $n$ cases, i.e., $n=404, 2000$. We observe that the magnitude of $n$ is negligible for the physical observations, such as $n_s$, $r$, $\Lambda$, and $\Omega_{\rm{GW}}h^2$. In the low-frequency regions, the GW is dominated by the quantum fluctuations, and this GW can be detected by Decigo at $10^{-1}~\rm{Hz}$. However, GW generated by PT dominates the high-frequency regions, which is expected to be detected by future 3DSR detector.
2305.17452
Shubham Mishra
Shubham Mishra, Sourav Pal, Aditya Srivastav, Anurag Tripathi
Multiparton Cwebs at five loops
The current version matches with the accepted JHEP version. The other details are: 51 pages, 32 figures, 28 tables and 1 ancillary file
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
Scattering amplitudes involving multiple partons are plagued with infrared singularities. The soft singularities of the amplitude are captured by the soft function which is defined as the vacuum expectation value of Wilson line correlators. Renormalization properties of soft function allows us to write it as an exponential of the finite soft anomalous dimension. An efficient way to study the soft function is through a set of Feynman diagrams known as Cwebs (webs). We present the mixing matrices and exponentiated colour factors (ECFs) for the Cwebs at five loops that connect six Wilson lines, except those that are related by relabeling of Wilson lines. Further, we express these ECFs in terms of 29 basis colour factors. We also find that this basis can be categorized into two colour structures. Our results are the first key ingredients for the calculation of the soft anomalous dimension at five loops.
[ { "created": "Sat, 27 May 2023 11:40:14 GMT", "version": "v1" }, { "created": "Mon, 1 Jul 2024 05:16:53 GMT", "version": "v2" } ]
2024-07-02
[ [ "Mishra", "Shubham", "" ], [ "Pal", "Sourav", "" ], [ "Srivastav", "Aditya", "" ], [ "Tripathi", "Anurag", "" ] ]
Scattering amplitudes involving multiple partons are plagued with infrared singularities. The soft singularities of the amplitude are captured by the soft function which is defined as the vacuum expectation value of Wilson line correlators. Renormalization properties of soft function allows us to write it as an exponential of the finite soft anomalous dimension. An efficient way to study the soft function is through a set of Feynman diagrams known as Cwebs (webs). We present the mixing matrices and exponentiated colour factors (ECFs) for the Cwebs at five loops that connect six Wilson lines, except those that are related by relabeling of Wilson lines. Further, we express these ECFs in terms of 29 basis colour factors. We also find that this basis can be categorized into two colour structures. Our results are the first key ingredients for the calculation of the soft anomalous dimension at five loops.
hep-ph/9909519
Stephane Peigne'
Paul Hoyer and Stephane Peigne
Psi' to J/Psi Ratio in Diffractive Photoproduction
4 pages, revtex
null
10.1103/PhysRevD.61.031501
NORDITA-1999/59 HE, LAPTH-749/99
hep-ph
null
We evaluate the Psi' to J/Psi ratio in diffractive photoproduction in a light-cone framework, using charmonium wave functions extracted from non-relativistic potential models. Contrary to current belief, we find that the best estimate for the ratio is a factor 2 to 5 below the data. The measured ratio constrains the distribution of the charm quark-antiquark component of the charmonium light-cone wave function and indicates that it is more compact than in potential models. We predict that the inelastic photoproduction ratio will be bigger than the elastic one, and will equal that measured in hadroproduction.
[ { "created": "Mon, 27 Sep 1999 11:54:33 GMT", "version": "v1" } ]
2009-10-31
[ [ "Hoyer", "Paul", "" ], [ "Peigne", "Stephane", "" ] ]
We evaluate the Psi' to J/Psi ratio in diffractive photoproduction in a light-cone framework, using charmonium wave functions extracted from non-relativistic potential models. Contrary to current belief, we find that the best estimate for the ratio is a factor 2 to 5 below the data. The measured ratio constrains the distribution of the charm quark-antiquark component of the charmonium light-cone wave function and indicates that it is more compact than in potential models. We predict that the inelastic photoproduction ratio will be bigger than the elastic one, and will equal that measured in hadroproduction.
hep-ph/9809353
Jun-ichi Kamoshita
Jun-ichi Kamoshita
Impact of Light Higgs Properties on the Determination of $\tan\beta$ and $m_{susy}$
7 pages with 10 figures, to be published in Prog. Theor. Phys
Prog.Theor.Phys. 100 (1998) 773-780
10.1143/PTP.100.773
OCHA-PP-123
hep-ph hep-ex
null
We examine whether parameters related to the Higgs sector of the minimal supersymmetric standard model can be determined by detailed study of the production cross section and decay branching ratios of the Higgs boson. Assuming that only the light Higgs boson will be observed at a future $e^+e^-$ linear collider with $\sqrt{s}=300\sim500$ GeV, we show that values of $m_{susy}$ and $\tan\beta$ are restricted within a narrow region in the $m_{susy}$ versus $\tan\beta$ plane by the combined analysis of the light Higgs properties. It is also pointed out that, in some case, $\tan\beta$ may be restricted to a relatively small value, $\tan\beta=1\sim5$.
[ { "created": "Sun, 13 Sep 1998 04:29:02 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kamoshita", "Jun-ichi", "" ] ]
We examine whether parameters related to the Higgs sector of the minimal supersymmetric standard model can be determined by detailed study of the production cross section and decay branching ratios of the Higgs boson. Assuming that only the light Higgs boson will be observed at a future $e^+e^-$ linear collider with $\sqrt{s}=300\sim500$ GeV, we show that values of $m_{susy}$ and $\tan\beta$ are restricted within a narrow region in the $m_{susy}$ versus $\tan\beta$ plane by the combined analysis of the light Higgs properties. It is also pointed out that, in some case, $\tan\beta$ may be restricted to a relatively small value, $\tan\beta=1\sim5$.
2308.00741
Yifan Chen
Yifan Chen, Xiao Xue, Vitor Cardoso
Black Holes as Neutrino Factories
17 pages, 3 figures
null
null
DESY-23-109
hep-ph astro-ph.CO astro-ph.HE gr-qc hep-ex
http://creativecommons.org/licenses/by/4.0/
Ultralight bosons near rotating black holes can grow significantly via superradiant energy extraction, potentially reaching field values close to the Planck scale, thereby turning black holes into effective transducers for these fields. The interaction between a boson field and fermions can initiate a parametric production of fermions, potentially halting the exponential growth and leading to a saturated state of the boson cloud. This dynamic offers a framework for establishing limits on boson-neutrino interactions, which have traditionally been restricted by neutrino self-interaction considerations. At the saturation phase, boson clouds have the capacity to propel neutrinos to TeV-scale energies, generating fluxes that surpass atmospheric neutrino fluxes from nearby black holes. This mechanism extends to dark sector fermions, leading to the generation of boosted dark matter. These fluxes open novel avenues for observation through high-energy neutrino detectors like IceCube, as well as through dark matter direct detection, by directing observational efforts towards targeted black holes.
[ { "created": "Tue, 1 Aug 2023 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 4 Mar 2024 13:25:27 GMT", "version": "v2" } ]
2024-03-05
[ [ "Chen", "Yifan", "" ], [ "Xue", "Xiao", "" ], [ "Cardoso", "Vitor", "" ] ]
Ultralight bosons near rotating black holes can grow significantly via superradiant energy extraction, potentially reaching field values close to the Planck scale, thereby turning black holes into effective transducers for these fields. The interaction between a boson field and fermions can initiate a parametric production of fermions, potentially halting the exponential growth and leading to a saturated state of the boson cloud. This dynamic offers a framework for establishing limits on boson-neutrino interactions, which have traditionally been restricted by neutrino self-interaction considerations. At the saturation phase, boson clouds have the capacity to propel neutrinos to TeV-scale energies, generating fluxes that surpass atmospheric neutrino fluxes from nearby black holes. This mechanism extends to dark sector fermions, leading to the generation of boosted dark matter. These fluxes open novel avenues for observation through high-energy neutrino detectors like IceCube, as well as through dark matter direct detection, by directing observational efforts towards targeted black holes.
hep-ph/0410322
Antonio Pich
A. Pich
Present Status of Chiral Perturbation Theory
6 pages. Invited talk at the 10th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2004), Beijing, China, August 29 - September 4, 2004
Int.J.Mod.Phys. A20 (2005) 1613-1618
10.1142/S0217751X05023074
IFIC/04-58, FTUV/04-1024
hep-ph nucl-th
null
The basic ideas and methods of chiral perturbation theory are briefly reviewed. I discuss the recent attempts to build an effective Lagrangian in the resonance region and summarize the known large-N_C constraints on the low-energy chiral couplings.
[ { "created": "Sun, 24 Oct 2004 18:25:27 GMT", "version": "v1" } ]
2009-11-10
[ [ "Pich", "A.", "" ] ]
The basic ideas and methods of chiral perturbation theory are briefly reviewed. I discuss the recent attempts to build an effective Lagrangian in the resonance region and summarize the known large-N_C constraints on the low-energy chiral couplings.
2012.11904
Zhi-Hui Guo
Zhi-Hui Guo, J. A. Oller
A unified description of the hidden-charm tetraquark states $Z_{cs}(3985)$, $Z_c(3900)$ and $X(4020)$
14 pages. To match the published version in PRD
Phys. Rev. D 103, 054021 (2021)
10.1103/PhysRevD.103.054021
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The newly observed hidden-charm tetraquark state $Z_{cs}(3985)$, together with $Z_c(3900)$ and $X(4020)$, are studied in the combined theoretical framework of the effective range expansion, compositeness relation and the decay width saturation. The elastic effective-range-expansion approach leads to sensible results for the scattering lengths, effective ranges and the compositeness coefficients, $i.e.$, the probabilities to find the two-charm-meson molecule components in the tetraquark states. The coupled-channel formalism by including the $J/\psi\pi$ and $D\bar{D}^*/\bar{D}D^*$ to fulfill the constraints of the compositeness relation and the decay width, confirms the elastic effective-range-expansion results for the $Z_c(3900)$, by using the experimental inputs for the ratios of the decay widths between $D\bar{D}^*/\bar{D}D^*$ and $J/\psi\pi$. With the results from the elastic effective-range-expansion study as input for the compositeness, we generalize the discussions to the $Z_{cs}(3985)$ by including the $J/\psi K^{-}$ and $D_s^{-}D^{*0}/D_s^{*-}D^{0}$, and predict the partial decay widths of the $J/\psi K^{-}$. Similar calculations are also carried out for the $X(4020)$ by including the $h_c\pi$ and $D^*\bar{D}^*$, and the partial decay widths of the $h_c\pi$ is predicted. Our results can provide useful guidelines for future experimental measurements.
[ { "created": "Tue, 22 Dec 2020 10:07:43 GMT", "version": "v1" }, { "created": "Thu, 25 Mar 2021 16:16:31 GMT", "version": "v2" } ]
2021-03-26
[ [ "Guo", "Zhi-Hui", "" ], [ "Oller", "J. A.", "" ] ]
The newly observed hidden-charm tetraquark state $Z_{cs}(3985)$, together with $Z_c(3900)$ and $X(4020)$, are studied in the combined theoretical framework of the effective range expansion, compositeness relation and the decay width saturation. The elastic effective-range-expansion approach leads to sensible results for the scattering lengths, effective ranges and the compositeness coefficients, $i.e.$, the probabilities to find the two-charm-meson molecule components in the tetraquark states. The coupled-channel formalism by including the $J/\psi\pi$ and $D\bar{D}^*/\bar{D}D^*$ to fulfill the constraints of the compositeness relation and the decay width, confirms the elastic effective-range-expansion results for the $Z_c(3900)$, by using the experimental inputs for the ratios of the decay widths between $D\bar{D}^*/\bar{D}D^*$ and $J/\psi\pi$. With the results from the elastic effective-range-expansion study as input for the compositeness, we generalize the discussions to the $Z_{cs}(3985)$ by including the $J/\psi K^{-}$ and $D_s^{-}D^{*0}/D_s^{*-}D^{0}$, and predict the partial decay widths of the $J/\psi K^{-}$. Similar calculations are also carried out for the $X(4020)$ by including the $h_c\pi$ and $D^*\bar{D}^*$, and the partial decay widths of the $h_c\pi$ is predicted. Our results can provide useful guidelines for future experimental measurements.
2404.10070
Halil Gams{\i}zkan
Halil Gams{\i}zkan
Microscopic Black Hole Events in Future Hadron Colliders
12 pages, 10 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Microscopic black hole production at future hadron colliders is a promising avenue to explore low scale gravity models like ADD. This study investigates production cross-sections and final state properties of these black holes using the BlackMax event generator. We analyze scenarios with varying proton-proton collision energies (27 TeV and 100 TeV), number of extra dimensions (2, 4, and 6), and black hole rotation. Black holes are found to decay to up to seventeen particles, which have high transverse momentum (up to 30 TeV) and concentrated in the central region. This unique signature allows them to be distinguished from background processes. The parameter space explored suggests future colliders like HE-LHC and FCC-hh have the potential to probe low scale gravity models.
[ { "created": "Mon, 15 Apr 2024 18:19:09 GMT", "version": "v1" } ]
2024-04-17
[ [ "Gamsızkan", "Halil", "" ] ]
Microscopic black hole production at future hadron colliders is a promising avenue to explore low scale gravity models like ADD. This study investigates production cross-sections and final state properties of these black holes using the BlackMax event generator. We analyze scenarios with varying proton-proton collision energies (27 TeV and 100 TeV), number of extra dimensions (2, 4, and 6), and black hole rotation. Black holes are found to decay to up to seventeen particles, which have high transverse momentum (up to 30 TeV) and concentrated in the central region. This unique signature allows them to be distinguished from background processes. The parameter space explored suggests future colliders like HE-LHC and FCC-hh have the potential to probe low scale gravity models.
1212.1281
Maciej Rybczynski
M. Rybczynski, Z. Wlodarczyk and G. Wilk
Scaling behavior of transverse momenta distributions in hadronic and nuclear collisions
6 pages, 8 figures, presented at the 42 International Symposium on Multiparticle Dynamics (ISMD 2012), Kielce, Poland
Acta Phys.Polon.Supp. 6 (2013) 507-512
10.5506/APhysPolBSupp.6.507
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been recently noticed that transverse momenta ($p_T$) distributions observed in high energy production processes exhibit remarkably universal scaling behavior. This is seen when they are in some suitable variable, replacing the usual $p_T$. On the other hand, it is also known that transverse momenta distributions in general follow a power-like Tsallis distribution, rather than an exponential Boltzmann-Gibbs, with a (generally energy dependent) nonextensivity parameter $q$. We now show that it is possible to choose a suitable variable such that $p_T$ distributions of particles produced in proton-proton interactions in a wide energy range can be fitted by the same Tsallis distribution (with the same, energy independent, value of the $q$-parameter). Similar scaling behavior in nucleus-nucleus collisions is also observed. The possible dynamical origin of the q parameter used in these fits will be discussed.
[ { "created": "Thu, 6 Dec 2012 10:40:55 GMT", "version": "v1" } ]
2015-04-03
[ [ "Rybczynski", "M.", "" ], [ "Wlodarczyk", "Z.", "" ], [ "Wilk", "G.", "" ] ]
It has been recently noticed that transverse momenta ($p_T$) distributions observed in high energy production processes exhibit remarkably universal scaling behavior. This is seen when they are in some suitable variable, replacing the usual $p_T$. On the other hand, it is also known that transverse momenta distributions in general follow a power-like Tsallis distribution, rather than an exponential Boltzmann-Gibbs, with a (generally energy dependent) nonextensivity parameter $q$. We now show that it is possible to choose a suitable variable such that $p_T$ distributions of particles produced in proton-proton interactions in a wide energy range can be fitted by the same Tsallis distribution (with the same, energy independent, value of the $q$-parameter). Similar scaling behavior in nucleus-nucleus collisions is also observed. The possible dynamical origin of the q parameter used in these fits will be discussed.
hep-ph/0109178
Stefano Forte
Guido Altarelli, Richard D. Ball, Stefano Forte
Factorization and Resummation of Small x Scaling Violations with Running Coupling
30 pages, 8 figures, plain TeX with harvmac
Nucl.Phys.B621:359-387,2002
10.1016/S0550-3213(01)00563-6
CERN-TH/2001-206, Edinburgh 2001-10, RM3-TH/01-08
hep-ph
null
We discuss the inclusion of running coupling effects in perturbative small x evolution equations. We show that a running coupling BFKL-like x-evolution equation is fully compatible, up to higher twist corrections, with the standard factorized perturbative evolution of parton distributions. We then use this result, combined with the well-known Airy asymptotics, to prove that the oscillations which are present in the running-coupling BFKL solution do not affect the associated splitting functions, which instead remain smooth in the small x limit. This allows us to give a prescription to include running-coupling corrections in the small-x resummation of scaling violations. We show that these corrections are small in the HERA region.
[ { "created": "Thu, 20 Sep 2001 09:27:22 GMT", "version": "v1" } ]
2008-11-26
[ [ "Altarelli", "Guido", "" ], [ "Ball", "Richard D.", "" ], [ "Forte", "Stefano", "" ] ]
We discuss the inclusion of running coupling effects in perturbative small x evolution equations. We show that a running coupling BFKL-like x-evolution equation is fully compatible, up to higher twist corrections, with the standard factorized perturbative evolution of parton distributions. We then use this result, combined with the well-known Airy asymptotics, to prove that the oscillations which are present in the running-coupling BFKL solution do not affect the associated splitting functions, which instead remain smooth in the small x limit. This allows us to give a prescription to include running-coupling corrections in the small-x resummation of scaling violations. We show that these corrections are small in the HERA region.
hep-ph/0401092
Karol Kovarik
K. Kovarik, C. Weber, H. Eberl, W. Majerotto
Complete one--loop corrections to e+e- -> sf_i sf_j
15 pages, 7 figures, shortened version for publication
Phys.Lett. B591 (2004) 242-254
10.1016/j.physletb.2004.04.036
HEPHY-PUB 784/04
hep-ph
null
We have calculated the complete one-loop corrections to the sfermion pair production process e+e- -> sf_i sf_j (f = t, b, tau, tau-neutrino) in the Minimal Supersymmetric Standard Model. Our results also include the previously calculated SUSY-QCD corrections. We present the details of the renormalization scheme used. It is found that the weak corrections are of the same magnitude as the SUSY-QCD corrections at higher energies (sqrt(s) ~ 1TeV). At these energies the main part of the weak corrections stems from the box contribution. This is best seen in sneutrino production.
[ { "created": "Tue, 13 Jan 2004 15:01:45 GMT", "version": "v1" }, { "created": "Tue, 25 May 2004 12:25:09 GMT", "version": "v2" } ]
2010-04-05
[ [ "Kovarik", "K.", "" ], [ "Weber", "C.", "" ], [ "Eberl", "H.", "" ], [ "Majerotto", "W.", "" ] ]
We have calculated the complete one-loop corrections to the sfermion pair production process e+e- -> sf_i sf_j (f = t, b, tau, tau-neutrino) in the Minimal Supersymmetric Standard Model. Our results also include the previously calculated SUSY-QCD corrections. We present the details of the renormalization scheme used. It is found that the weak corrections are of the same magnitude as the SUSY-QCD corrections at higher energies (sqrt(s) ~ 1TeV). At these energies the main part of the weak corrections stems from the box contribution. This is best seen in sneutrino production.
1011.1779
Elena Narynskaya
N.V.Mikheev, E.N.Narynskaya
Neutrino magnetic moment in a magnetized plasma
7 page, 1 figures, based on the talk presented by E.N.Narynskaya at the XVI International Seminar Quarks'2010, Kolomna, Moscow Region, June 6-12, 2010, to appear in the Proceedings
Phys.Atom.Nucl.73:2133-2138,2010
10.1134/S1063778810120197
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The contribution of a magnetized plasma to the neutrino magnetic moment is calculated. It is shown that only part of the additional neutrino energy in magnetized plasma connecting with its spin and magnetic field strength defines the neutrino magnetic moment. It is found that the presence of magnetized plasma does not lead to the considerable increase of the neutrino magnetic moment in contrast to the results presented in literature previously.
[ { "created": "Mon, 8 Nov 2010 11:57:11 GMT", "version": "v1" } ]
2011-01-27
[ [ "Mikheev", "N. V.", "" ], [ "Narynskaya", "E. N.", "" ] ]
The contribution of a magnetized plasma to the neutrino magnetic moment is calculated. It is shown that only part of the additional neutrino energy in magnetized plasma connecting with its spin and magnetic field strength defines the neutrino magnetic moment. It is found that the presence of magnetized plasma does not lead to the considerable increase of the neutrino magnetic moment in contrast to the results presented in literature previously.
1011.0269
Yadong Yang
Xin-Qiang Li, Fang Su, Ya-Dong Yang
Determination of the strong coupling $g_{B^* B\pi}$ from semi-leptonic $B\to \pi \ell \nu$ decay
19 pages, no figure. Revised
Phys.Rev.D83:054019,2011
10.1103/PhysRevD.83.054019
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
According to heavy-meson chiral perturbation theory, the vector form factor $f_+(q^2)$ of exclusive semi-leptonic decay $B\to \pi \ell \nu$ is closely related, at least in the soft-pion region (i.e., $q^{2} \sim (m_B-m_{\pi})^2$), to the strong coupling $g_{B^* B\pi}$ or the normalized coupling $\hat g$. Combining the precisely measured $q^2$ spectrum of $B\to \pi \ell \nu$ decay by the BaBar and Belle collaborations with several parametrizations of the form factor $f_+(q^2)$, we can extract these couplings from the residue of the form factor at the $B^*$ pole, which relies on an extrapolation of the form factor from the semi-leptonic region to the unphysical point $q^2=m_{B^*}^2$. Comparing the extracted values with the other experimental and theoretical estimates, we can test these various form-factor parametrizations, which differ from each other by the amount of physical information embedded in. It is found that the extracted values based on the BK, BZ and BCL parametrizations are consistent with each other and roughly in agreement with the other theoretical and lattice estimates, while the BGL ansatz, featured by a spurious, unwanted pole at the threshold of the cut, gives a neatly larger value.
[ { "created": "Mon, 1 Nov 2010 08:52:07 GMT", "version": "v1" }, { "created": "Fri, 5 Nov 2010 08:31:33 GMT", "version": "v2" }, { "created": "Tue, 25 Jan 2011 11:34:50 GMT", "version": "v3" } ]
2011-03-22
[ [ "Li", "Xin-Qiang", "" ], [ "Su", "Fang", "" ], [ "Yang", "Ya-Dong", "" ] ]
According to heavy-meson chiral perturbation theory, the vector form factor $f_+(q^2)$ of exclusive semi-leptonic decay $B\to \pi \ell \nu$ is closely related, at least in the soft-pion region (i.e., $q^{2} \sim (m_B-m_{\pi})^2$), to the strong coupling $g_{B^* B\pi}$ or the normalized coupling $\hat g$. Combining the precisely measured $q^2$ spectrum of $B\to \pi \ell \nu$ decay by the BaBar and Belle collaborations with several parametrizations of the form factor $f_+(q^2)$, we can extract these couplings from the residue of the form factor at the $B^*$ pole, which relies on an extrapolation of the form factor from the semi-leptonic region to the unphysical point $q^2=m_{B^*}^2$. Comparing the extracted values with the other experimental and theoretical estimates, we can test these various form-factor parametrizations, which differ from each other by the amount of physical information embedded in. It is found that the extracted values based on the BK, BZ and BCL parametrizations are consistent with each other and roughly in agreement with the other theoretical and lattice estimates, while the BGL ansatz, featured by a spurious, unwanted pole at the threshold of the cut, gives a neatly larger value.
1604.01189
Valery Schegelsky A
V.A. Schegelsky and M.G. Ryskin
Multiparticle production: an old-fashioned view
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the dynamics of high energy multiparticle production and discuss how the space-time picture of inelastic interaction may reveal itself in identical particles Bose-Einstein correlations.
[ { "created": "Tue, 5 Apr 2016 09:06:42 GMT", "version": "v1" } ]
2016-04-06
[ [ "Schegelsky", "V. A.", "" ], [ "Ryskin", "M. G.", "" ] ]
We consider the dynamics of high energy multiparticle production and discuss how the space-time picture of inelastic interaction may reveal itself in identical particles Bose-Einstein correlations.
2112.05052
Christoph Englert
Akanksha Bhardwaj, Christoph Englert, Robert Hankache, Andrew D. Pilkington
Machine-enhanced CP-asymmetries in the Higgs sector
10 pages, 7 figures, 2 tables, v2: added clarifications, references updated, v3: version published in PLB
null
10.1016/j.physletb.2022.137246
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Improving the sensitivity to CP-violation in the Higgs sector is one of the pillars of the precision Higgs programme at the Large Hadron Collider. We present a simple method that allows CP-sensitive observables to be directly constructed from the output of neural networks. We show that these observables have improved sensitivity to CP-violating effects in the production and decay of the Higgs boson, when compared to the use of traditional angular observables alone. The kinematic correlations identified by the neural networks can be used to design new analyses based on angular observables, with a similar improvement in sensitivity.
[ { "created": "Thu, 9 Dec 2021 17:24:44 GMT", "version": "v1" }, { "created": "Thu, 30 Dec 2021 00:13:02 GMT", "version": "v2" }, { "created": "Mon, 27 Jun 2022 10:09:02 GMT", "version": "v3" } ]
2022-06-28
[ [ "Bhardwaj", "Akanksha", "" ], [ "Englert", "Christoph", "" ], [ "Hankache", "Robert", "" ], [ "Pilkington", "Andrew D.", "" ] ]
Improving the sensitivity to CP-violation in the Higgs sector is one of the pillars of the precision Higgs programme at the Large Hadron Collider. We present a simple method that allows CP-sensitive observables to be directly constructed from the output of neural networks. We show that these observables have improved sensitivity to CP-violating effects in the production and decay of the Higgs boson, when compared to the use of traditional angular observables alone. The kinematic correlations identified by the neural networks can be used to design new analyses based on angular observables, with a similar improvement in sensitivity.
2201.07441
Utkarsh Patel
Sudhanwa Patra, Utkarsh Patel and Purushottam Sahu
LHC signatures of sterile neutrinos in a minimal radiative extended seesaw framework
arXiv admin note: text overlap with arXiv:1903.04905, arXiv:1801.03624 by other authors
International Journal of Modern Physics A (2021) 2150263, S0217751X21502638
10.1142/S0217751X21502638
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The presence of small neutrino masses and flavour mixings can be accounted for naturally in various models about extensions of the standard model, particularly in the seesaw mechanism models. In this work, we present a minimally extended seesaw framework with two right-handed neutrinos, where the active neutrino masses are derived in the radiative regime. Using the framework it can be shown that within certain mass limits, the light neutrino mass term can approach a form that is similar to its form under the type-I seesaw mechanism. Apart from this, we show that the decay width of right-handed neutrinos (produced through the decay of W boson in a particle collider) is short enough to cause a sufficiently long lifetime for the particles, thus ensuring an observable displacement in the LHC between the production and decay vertices. We comment on the fact that these displaced vertex signatures thus can serve as a means to verify the existence of these right-handed neutrinos in future experiments. Lastly, we line up the possibility of our future work where the vertex signatures of particles greater than the mass of W boson can be worked upon.
[ { "created": "Wed, 19 Jan 2022 06:55:47 GMT", "version": "v1" } ]
2022-01-20
[ [ "Patra", "Sudhanwa", "" ], [ "Patel", "Utkarsh", "" ], [ "Sahu", "Purushottam", "" ] ]
The presence of small neutrino masses and flavour mixings can be accounted for naturally in various models about extensions of the standard model, particularly in the seesaw mechanism models. In this work, we present a minimally extended seesaw framework with two right-handed neutrinos, where the active neutrino masses are derived in the radiative regime. Using the framework it can be shown that within certain mass limits, the light neutrino mass term can approach a form that is similar to its form under the type-I seesaw mechanism. Apart from this, we show that the decay width of right-handed neutrinos (produced through the decay of W boson in a particle collider) is short enough to cause a sufficiently long lifetime for the particles, thus ensuring an observable displacement in the LHC between the production and decay vertices. We comment on the fact that these displaced vertex signatures thus can serve as a means to verify the existence of these right-handed neutrinos in future experiments. Lastly, we line up the possibility of our future work where the vertex signatures of particles greater than the mass of W boson can be worked upon.
hep-ph/9706477
null
Tiehui (Ted) Liu
An Overview of $D^0\bar{D}^0$ Mixing Search Techniques
7 pages, talk given at Symposium on Flavor Changing Neutral Currents: Present and Future Studies, Santa Monica, Feb. 97
null
null
PRINCETON/HEP/97-5
hep-ph
null
The search for $D^0\bar{D}^0$ mixing may carry a large discovery potential for new physics since the $D^0\bar{D}^0$ mixing rate is expected to be small in the Standard Model. This paper gives a brief review of the experimental techniques which can be used to search for $D^0\bar{D}^0$ mixing in the future. Some ideas, applicable to future mixing searches at hadron machines (such as Tevatron and LHC), and fixed target experiments (such as HEAR-B) are introduced.
[ { "created": "Tue, 24 Jun 1997 00:36:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tiehui", "", "", "Ted" ], [ "Liu", "", "" ] ]
The search for $D^0\bar{D}^0$ mixing may carry a large discovery potential for new physics since the $D^0\bar{D}^0$ mixing rate is expected to be small in the Standard Model. This paper gives a brief review of the experimental techniques which can be used to search for $D^0\bar{D}^0$ mixing in the future. Some ideas, applicable to future mixing searches at hadron machines (such as Tevatron and LHC), and fixed target experiments (such as HEAR-B) are introduced.
hep-ph/0407195
Ruben Flores
J.J. Torres, Ruben Flores-Mendieta, M. Neri, A. Martinez, A. Garcia
Numerical precision radiative corrections to the Dalitz plot of baryon semileptonic decays including the spin-momentum correlation of the decaying and emitted baryons
34 pages, 4 tables, no figures. Some sections have been shortened. Conclusions remain unchanged
Phys.Rev.D70:093012,2004; Erratum-ibid.D75:019903,2007
10.1103/PhysRevD.70.093012 10.1103/PhysRevD.75.019903
null
hep-ph
null
We calculate the radiative corrections to the angular correlation between the polarization of the decaying and the direction of the emitted spin one-half baryons in the semileptonic decay mode. The final results are presented, first, with the triple integration of the bremsstrahlung photon ready to be performed numerically and, second, in an analytical form. A third presentation of our results in the form of numerical arrays of coefficients to be multiplied by the quadratic products of form factors is discussed. This latter may be the most practical one to use in Monte Carlo simulations. A series of crosschecks is performed. Previous results to order (alpha/pi)(q/M_1) for the decays of unpolarized baryons are reviewed, too, where q is the momentum transfer and M_1 is the mass of the decaying baryon. This paper is self-contained and organized to make it accessible and reliable in the analysis of the Dalitz plot of precision experiments involving heavy quarks and is not compromised to fixing the form factors at predetermined values. It is assumed that the real photons are kinematically discriminated. Otherwise, our results have a general model-independent applicability.
[ { "created": "Fri, 16 Jul 2004 20:27:27 GMT", "version": "v1" }, { "created": "Thu, 25 Nov 2004 18:57:48 GMT", "version": "v2" } ]
2014-11-17
[ [ "Torres", "J. J.", "" ], [ "Flores-Mendieta", "Ruben", "" ], [ "Neri", "M.", "" ], [ "Martinez", "A.", "" ], [ "Garcia", "A.", "" ] ]
We calculate the radiative corrections to the angular correlation between the polarization of the decaying and the direction of the emitted spin one-half baryons in the semileptonic decay mode. The final results are presented, first, with the triple integration of the bremsstrahlung photon ready to be performed numerically and, second, in an analytical form. A third presentation of our results in the form of numerical arrays of coefficients to be multiplied by the quadratic products of form factors is discussed. This latter may be the most practical one to use in Monte Carlo simulations. A series of crosschecks is performed. Previous results to order (alpha/pi)(q/M_1) for the decays of unpolarized baryons are reviewed, too, where q is the momentum transfer and M_1 is the mass of the decaying baryon. This paper is self-contained and organized to make it accessible and reliable in the analysis of the Dalitz plot of precision experiments involving heavy quarks and is not compromised to fixing the form factors at predetermined values. It is assumed that the real photons are kinematically discriminated. Otherwise, our results have a general model-independent applicability.
1805.11650
Sergei Chekanov V.
S. V. Chekanov
Imaging particle collision data for event classification using machine learning
20 pages, 4 figures
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 931 (2019) 92-99
10.1016/j.nima.2019.04.031
ANL-HEP-144006
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a method to organize experimental data from particle collision experiments in a general format which can enable a simple visualisation and effective classification of collision data using machine learning techniques. The method is based on sparse fixed-size matrices with single- and two-particle variables containing information on identified particles and jets. We illustrate this method using an example of searches for new physics at the LHC experiments.
[ { "created": "Tue, 29 May 2018 18:37:28 GMT", "version": "v1" }, { "created": "Fri, 15 Mar 2019 08:38:06 GMT", "version": "v2" } ]
2019-04-15
[ [ "Chekanov", "S. V.", "" ] ]
We propose a method to organize experimental data from particle collision experiments in a general format which can enable a simple visualisation and effective classification of collision data using machine learning techniques. The method is based on sparse fixed-size matrices with single- and two-particle variables containing information on identified particles and jets. We illustrate this method using an example of searches for new physics at the LHC experiments.
1304.7927
Paolo Torrielli
Stefano Frixione, Paolo Torrielli and Marco Zaro
Higgs production through vector-boson fusion at the NLO matched with parton showers
18 pages, 7 figures
null
10.1016/j.physletb.2013.08.030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a study of Higgs hadroproduction through vector-boson fusion at the NLO in QCD matched with parton showers. We discuss the matching systematics affecting this process through a comparison of the aMC@NLO predictions with the POWHEG and the pure-NLO ones.
[ { "created": "Tue, 30 Apr 2013 09:13:47 GMT", "version": "v1" }, { "created": "Thu, 26 Sep 2013 06:14:52 GMT", "version": "v2" } ]
2013-09-27
[ [ "Frixione", "Stefano", "" ], [ "Torrielli", "Paolo", "" ], [ "Zaro", "Marco", "" ] ]
We present a study of Higgs hadroproduction through vector-boson fusion at the NLO in QCD matched with parton showers. We discuss the matching systematics affecting this process through a comparison of the aMC@NLO predictions with the POWHEG and the pure-NLO ones.
1411.5669
Johannes Bl\"umlein
J. Bl\"umlein, A. De Freitas, and C. Schneider
Higher Order Heavy Quark Corrections to Deep-Inelastic Scattering
17 pages, 10 figures, 3 style files, Nucl. Phys. (Proc. Suppl.), Contribution to the Proceedings Final Meeting of DFG SFB-TR-9, to appear
null
null
DESY 14-159, DO--TH 14/22, SFB/CPP--14--73 , LPN 14--113
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The 3-loop heavy flavor corrections to deep-inelastic scattering are essential for consistent next-to-next-to-leading order QCD analyses. We report on the present status of the calculation of these corrections at large virtualities $Q^2$. We also describe a series of mathematical, computer-algebraic and combinatorial methods and special function spaces, needed to perform these calculations. Finally, we briefly discuss the status of measuring $\alpha_s(M_Z)$, the charm quark mass $m_c$, and the parton distribution functions at next-to-next-to-leading order from the world precision data on deep-inelastic scattering.
[ { "created": "Thu, 20 Nov 2014 20:41:41 GMT", "version": "v1" } ]
2014-11-21
[ [ "Blümlein", "J.", "" ], [ "De Freitas", "A.", "" ], [ "Schneider", "C.", "" ] ]
The 3-loop heavy flavor corrections to deep-inelastic scattering are essential for consistent next-to-next-to-leading order QCD analyses. We report on the present status of the calculation of these corrections at large virtualities $Q^2$. We also describe a series of mathematical, computer-algebraic and combinatorial methods and special function spaces, needed to perform these calculations. Finally, we briefly discuss the status of measuring $\alpha_s(M_Z)$, the charm quark mass $m_c$, and the parton distribution functions at next-to-next-to-leading order from the world precision data on deep-inelastic scattering.
hep-ph/0205271
Bei-Lok Hu
E. Calzetta and B. L. Hu
Thermalization of an Interacting Quantum Field in the CTP-2PI Next-to-leading-order Large N Scheme
Latex 31 pages with 10 figures, uses graphicx
null
null
umdpp02-052
hep-ph
null
In this paper we use an O(N)-invariant scalar field of unbroken symmetry to investigate whether an interacting quantum field at the next-to-leading order Large $N$ approximation may show signs of thermalization. We develop the closed time-path (CTP) two-particle irreducible (2PI) effective action in powers of 1/N, retaining up to next to leading order (O(1)) terms, and write down the corresponding (truncated) Schwinger-Dyson equations for its two point function. We show that in this approximation, the only translation invariant solutions to the Schwinger - Dyson equations are thermal. This provides a useful temperature concept without invoking a heat bath. When combined with the familiar Kadanoff-Baym approach to quantum kinetic theory our result shows that at this order of approximation thermalization can occur, at least if initial conditions are smooth enough that a derivative expansion is valid. Our analytic result provides support for similar claims in recent literature based on numerical evidence.
[ { "created": "Thu, 23 May 2002 22:10:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Calzetta", "E.", "" ], [ "Hu", "B. L.", "" ] ]
In this paper we use an O(N)-invariant scalar field of unbroken symmetry to investigate whether an interacting quantum field at the next-to-leading order Large $N$ approximation may show signs of thermalization. We develop the closed time-path (CTP) two-particle irreducible (2PI) effective action in powers of 1/N, retaining up to next to leading order (O(1)) terms, and write down the corresponding (truncated) Schwinger-Dyson equations for its two point function. We show that in this approximation, the only translation invariant solutions to the Schwinger - Dyson equations are thermal. This provides a useful temperature concept without invoking a heat bath. When combined with the familiar Kadanoff-Baym approach to quantum kinetic theory our result shows that at this order of approximation thermalization can occur, at least if initial conditions are smooth enough that a derivative expansion is valid. Our analytic result provides support for similar claims in recent literature based on numerical evidence.