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hep-ph/9401325
My Account
J. Lopez, D. Nanopoulos, G. Park, X. Wang and A. Zichichi
Experimental aspects of SU(5)xU(1) supergravity
latex, 36 pages, 25 figures (not included). Figures are available via anonymous ftp from hplaa02.cern.ch (/pub/lopez) as either 33 ps files (Easpects*.ps, 8.1MB) or one uuencoded file (AllFigures.uu, 3.7MB)
Phys.Rev.D50:2164-2190,1994
10.1103/PhysRevD.50.2164
CERN-TH.7139/94, CTP-TAMU-74/93
hep-ph
null
We study various aspects of $SU(5)\times U(1)$ supergravity as they relate to the experimental verification or falsification of this model. We consider two string-inspired, universal, one-parameter, no-scale soft-supersymmetry-breaking scenarios, driven by the $F$-terms of the moduli and dilaton fields. The model is described in terms of the supersymmetry mass scale (\ie, the chargino mass $m_{\chi^\pm_1}$), $\tan\beta$, and the top-quark mass. We first determine the combined effect on the parameter space of all presently available direct and indirect experimental constraints, including the LEP lower bounds on sparticle and Higgs-boson masses, the $b\to s\gamma$ rate, the anomalous magnetic moment of the muon, the high-precision electroweak parameters $\epsilon_1,\epsilon_b$ (which imply $m_t\lsim180\GeV$), and the muon fluxes in underground detectors (neutrino telescopes). For the still-allowed points in $(m_{\chi^\pm_1},\tan\beta)$ parameter space, we re-evaluate the experimental situation at the Tevatron, LEPII, and HERA. In the 1994 run, the Tevatron could probe chargino masses as high as 100 GeV. At LEPII the parameter space could be explored with probes of different resolutions: Higgs boson searches, selectron searches, and chargino searches. Moreover, for $m_t\lsim150\GeV$, these Higgs-boson searches could explore all of the allowed parameter space with $\sqrt{s}\lsim210\GeV$.
[ { "created": "Tue, 25 Jan 1994 16:24:59 GMT", "version": "v1" } ]
2009-09-25
[ [ "Lopez", "J.", "" ], [ "Nanopoulos", "D.", "" ], [ "Park", "G.", "" ], [ "Wang", "X.", "" ], [ "Zichichi", "A.", "" ] ]
We study various aspects of $SU(5)\times U(1)$ supergravity as they relate to the experimental verification or falsification of this model. We consider two string-inspired, universal, one-parameter, no-scale soft-supersymmetry-breaking scenarios, driven by the $F$-terms of the moduli and dilaton fields. The model is described in terms of the supersymmetry mass scale (\ie, the chargino mass $m_{\chi^\pm_1}$), $\tan\beta$, and the top-quark mass. We first determine the combined effect on the parameter space of all presently available direct and indirect experimental constraints, including the LEP lower bounds on sparticle and Higgs-boson masses, the $b\to s\gamma$ rate, the anomalous magnetic moment of the muon, the high-precision electroweak parameters $\epsilon_1,\epsilon_b$ (which imply $m_t\lsim180\GeV$), and the muon fluxes in underground detectors (neutrino telescopes). For the still-allowed points in $(m_{\chi^\pm_1},\tan\beta)$ parameter space, we re-evaluate the experimental situation at the Tevatron, LEPII, and HERA. In the 1994 run, the Tevatron could probe chargino masses as high as 100 GeV. At LEPII the parameter space could be explored with probes of different resolutions: Higgs boson searches, selectron searches, and chargino searches. Moreover, for $m_t\lsim150\GeV$, these Higgs-boson searches could explore all of the allowed parameter space with $\sqrt{s}\lsim210\GeV$.
hep-ph/0110314
Anna Kalliomaki
K. R. S. Balaji, Anna Kalliomaki, Jukka Maalampi
Revisiting pseudo-Dirac neutrinos
17 pages, no figures, references added, to be published in PLB
Phys.Lett.B524:153-160,2002
10.1016/S0370-2693(01)01356-9
HIP-2001-52/TH
hep-ph
null
We study the pseudo-Dirac mixing of left and right-handed neutrinos in the case where the Majorana masses M_L and M_R are small when compared with the Dirac mass, M_D. The light Majorana masses could be generated by a non-renormalizable operator reflecting effects of new physics at some high energy scale. In this context, we obtain a simple model independent closed bound for M_D. A phenomenologically consistent scenario is achieved with M_L,M_R ~ 10^{-7} eV and M_D ~ 10^{-5}-10^{-4} eV. This precludes the possibility of positive mass searches in the planned future experiments like GENIUS or in tritium decay experiments. If on the other hand, GENIUS does observe a positive signal for a Majorana mass \geq 10^{-3} eV, then with very little fine tuning of neutrino parameters, the scale of new physics could be in the TeV range, but pseudo-Dirac scenario in that case is excluded. We briefly discuss the constraints from cosmology when a fraction of the dark matter is composed of nearly degenerate neutrinos.
[ { "created": "Wed, 24 Oct 2001 16:29:47 GMT", "version": "v1" }, { "created": "Thu, 15 Nov 2001 20:26:13 GMT", "version": "v2" } ]
2011-07-19
[ [ "Balaji", "K. R. S.", "" ], [ "Kalliomaki", "Anna", "" ], [ "Maalampi", "Jukka", "" ] ]
We study the pseudo-Dirac mixing of left and right-handed neutrinos in the case where the Majorana masses M_L and M_R are small when compared with the Dirac mass, M_D. The light Majorana masses could be generated by a non-renormalizable operator reflecting effects of new physics at some high energy scale. In this context, we obtain a simple model independent closed bound for M_D. A phenomenologically consistent scenario is achieved with M_L,M_R ~ 10^{-7} eV and M_D ~ 10^{-5}-10^{-4} eV. This precludes the possibility of positive mass searches in the planned future experiments like GENIUS or in tritium decay experiments. If on the other hand, GENIUS does observe a positive signal for a Majorana mass \geq 10^{-3} eV, then with very little fine tuning of neutrino parameters, the scale of new physics could be in the TeV range, but pseudo-Dirac scenario in that case is excluded. We briefly discuss the constraints from cosmology when a fraction of the dark matter is composed of nearly degenerate neutrinos.
1005.0283
Luis Roca
L. Roca, E. Oset
A description of the f2(1270), rho3(1690), f4(2050), rho5(2350) and f6(2510) resonances as multi-rho(770) states
17 pages, 6 figures
Phys.Rev.D82:054013,2010
10.1103/PhysRevD.82.054013
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a previous work regarding the interaction of two $\rho(770)$ resonances, the $f_2(1270)$ ($J^{PC}=2^{++}$) resonance was obtained dynamically as a two-$\rho$ molecule with a very strong binding energy, 135~MeV per $\rho$ particle. In the present work we use the $\rho\rho$ interaction in spin 2 and isospin 0 channel to show that the resonances $\rho_3(1690)$ ($3^{--}$), $f_4(2050)$ ($4^{++}$), $\rho_5(2350)$ ($5^{--}$) and $f_6(2510)$ ($6^{++}$) are basically molecules of increasing number of $\rho(770)$ particles. We use the fixed center approximation of the Faddeev equations to write the multi-body interaction in terms of the two-body scattering amplitudes. We find the masses of the states very close to the experimental values and we get an increasing value of the binding energy per $\rho$ as the number of $\rho$ mesons is increased.
[ { "created": "Mon, 3 May 2010 13:15:33 GMT", "version": "v1" } ]
2014-11-20
[ [ "Roca", "L.", "" ], [ "Oset", "E.", "" ] ]
In a previous work regarding the interaction of two $\rho(770)$ resonances, the $f_2(1270)$ ($J^{PC}=2^{++}$) resonance was obtained dynamically as a two-$\rho$ molecule with a very strong binding energy, 135~MeV per $\rho$ particle. In the present work we use the $\rho\rho$ interaction in spin 2 and isospin 0 channel to show that the resonances $\rho_3(1690)$ ($3^{--}$), $f_4(2050)$ ($4^{++}$), $\rho_5(2350)$ ($5^{--}$) and $f_6(2510)$ ($6^{++}$) are basically molecules of increasing number of $\rho(770)$ particles. We use the fixed center approximation of the Faddeev equations to write the multi-body interaction in terms of the two-body scattering amplitudes. We find the masses of the states very close to the experimental values and we get an increasing value of the binding energy per $\rho$ as the number of $\rho$ mesons is increased.
hep-ph/9609333
null
E. Bagan, M. Lavelle, D. McMullan, B. Fiol, N. Roy
How do constituent quarks arise in QCD? Perturbation theory and the infra-red
5 pages, espcrc2.sty required, talk given at QDC-96, Montpellier, July 1996, A related simulation may be found at http://www.ifae.es/~roy/
Nucl.Phys.Proc.Suppl. 54A (1997) 208-212
10.1016/S0920-5632(97)00042-X
null
hep-ph hep-th
null
We motivate the use of dressed charges by arguing that such objects are needed to describe, e.g., constituent quarks and, in general, physical charged states in gauge theories. We give a short introduction to dressings in both QED and QCD. We put special emphasis on the infra-red properties of a moving dressed charge. To be more precise, we demonstrate that the one loop propagator of a relativistic dressed charge can be renormalized in the mass shell scheme with no infra-red divergence showing up.
[ { "created": "Thu, 12 Sep 1996 14:12:07 GMT", "version": "v1" } ]
2009-10-28
[ [ "Bagan", "E.", "" ], [ "Lavelle", "M.", "" ], [ "McMullan", "D.", "" ], [ "Fiol", "B.", "" ], [ "Roy", "N.", "" ] ]
We motivate the use of dressed charges by arguing that such objects are needed to describe, e.g., constituent quarks and, in general, physical charged states in gauge theories. We give a short introduction to dressings in both QED and QCD. We put special emphasis on the infra-red properties of a moving dressed charge. To be more precise, we demonstrate that the one loop propagator of a relativistic dressed charge can be renormalized in the mass shell scheme with no infra-red divergence showing up.
hep-ph/0412056
Magno Machado
A. Lengyel (IEP, National Academy of Sciences of Ukraine, Uzhgorod), M.V.T. Machado (GFPAE, IF UFRGS)
Revisiting the phenomenology on the QCD color dipole picture
Contribution to the ``International Workshop on Diffraction in High-Energy Physics'' (DIFFRACTION 2004), Cala Gonone (Sardinia, Italy), 18-23 September 2004; 3 pages, LaTeX file
null
10.1016/j.nuclphysbps.2005.02.098
null
hep-ph hep-ex
null
Using the QCD dipole picture of the hard BFKL Pomeron, we perform a 3 parameter fit analysis of the recent inclusive structure function experimental measurements at small-$x$ and intermediate $Q^2$. As a byproduct, the longitudinal structure function and the gluon distribution are predicted without further adjustments. The data description is quite reasonable, being timely a further study using resummed NLO BFKL kernels along the lines of recent theoretical developments.
[ { "created": "Fri, 3 Dec 2004 19:18:24 GMT", "version": "v1" } ]
2009-11-10
[ [ "Lengyel", "A.", "", "IEP, National Academy of Sciences of Ukraine, Uzhgorod" ], [ "Machado", "M. V. T.", "", "GFPAE, IF UFRGS" ] ]
Using the QCD dipole picture of the hard BFKL Pomeron, we perform a 3 parameter fit analysis of the recent inclusive structure function experimental measurements at small-$x$ and intermediate $Q^2$. As a byproduct, the longitudinal structure function and the gluon distribution are predicted without further adjustments. The data description is quite reasonable, being timely a further study using resummed NLO BFKL kernels along the lines of recent theoretical developments.
1111.1145
Ji Young Yu
K. Kovarik, I. Schienbein, F.I. Olness, J.Y. Yu, C. Keppel, J.G. Morfin, J.F. Owens, T. Stavreva
Compatibility of global NPDF analyses of neutrino DIS and charged-lepton DIS data
Contribution to the XXIst International Europhysics Conference on High Energy Physics, 21-27 July 2011, Grenoble, France
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The neutrino deep inelastic scattering (DIS) data is very interesting for global analyses of proton and nuclear parton distribution functions (PDFs) since they provide crucial information on the strange quark distribution in the proton and allow for a better flavor decompositon of the PDFs. In order to use neutrino DIS data in a global analysis of proton PDFs nuclear effects need to be understood. We study these effects with the help of nuclear PDFs extracted from global analyses of charged-lepton DIS, Drell-Yan and neutrino DIS data at next-to-leading order in QCD.
[ { "created": "Fri, 4 Nov 2011 14:50:43 GMT", "version": "v1" } ]
2011-11-07
[ [ "Kovarik", "K.", "" ], [ "Schienbein", "I.", "" ], [ "Olness", "F. I.", "" ], [ "Yu", "J. Y.", "" ], [ "Keppel", "C.", "" ], [ "Morfin", "J. G.", "" ], [ "Owens", "J. F.", "" ], [ "Stavreva", "T.", "" ] ]
The neutrino deep inelastic scattering (DIS) data is very interesting for global analyses of proton and nuclear parton distribution functions (PDFs) since they provide crucial information on the strange quark distribution in the proton and allow for a better flavor decompositon of the PDFs. In order to use neutrino DIS data in a global analysis of proton PDFs nuclear effects need to be understood. We study these effects with the help of nuclear PDFs extracted from global analyses of charged-lepton DIS, Drell-Yan and neutrino DIS data at next-to-leading order in QCD.
2009.04330
Masashi Aiko
Masashi Aiko and Shinya Kanemura
New scenario for aligned Higgs couplings originated from the twisted custodial symmetry at high energies
30 pages, 4 figures, version accepted by Journal of High Energy Physics
null
10.1007/JHEP02(2021)046
OU-HET 1066
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a new scenario of the two Higgs doublet model, where the current experimental data for the electroweak rho parameter and those for the Higgs boson couplings can be simultaneously explained. In this scenario, the two Higgs doublet model is supposed to be a low energy effective theory up to a high energy scale $\Lambda$, above which a fundamental theory should appear. It is assumed that the Higgs potential respects a global symmetry at $\Lambda$ (the twisted custodial symmetry), which is to be given as a consequence of the global symmetry structure of the fundamental theory above $\Lambda$. By the analysis using one-loop renormalization group equations, the above experimental data can be explained in a natural way even when the masses of the extra Higgs bosons are near the electroweak scale. We also discuss the predictions on the mass spectrum of the additional Higgs bosons and also those on coupling constants of the standard-model-like Higgs boson, which make it possible to test this scenario at current and future collider experiments.
[ { "created": "Wed, 9 Sep 2020 14:37:19 GMT", "version": "v1" }, { "created": "Mon, 14 Sep 2020 14:22:10 GMT", "version": "v2" }, { "created": "Sun, 27 Dec 2020 10:18:22 GMT", "version": "v3" } ]
2021-02-24
[ [ "Aiko", "Masashi", "" ], [ "Kanemura", "Shinya", "" ] ]
We investigate a new scenario of the two Higgs doublet model, where the current experimental data for the electroweak rho parameter and those for the Higgs boson couplings can be simultaneously explained. In this scenario, the two Higgs doublet model is supposed to be a low energy effective theory up to a high energy scale $\Lambda$, above which a fundamental theory should appear. It is assumed that the Higgs potential respects a global symmetry at $\Lambda$ (the twisted custodial symmetry), which is to be given as a consequence of the global symmetry structure of the fundamental theory above $\Lambda$. By the analysis using one-loop renormalization group equations, the above experimental data can be explained in a natural way even when the masses of the extra Higgs bosons are near the electroweak scale. We also discuss the predictions on the mass spectrum of the additional Higgs bosons and also those on coupling constants of the standard-model-like Higgs boson, which make it possible to test this scenario at current and future collider experiments.
1604.01886
Asako Murakami
Asako Murakami and Haruhiko Terao
Nonperturbative evaluation of quantum particle production in parametric resonance enhanced by noise
21 pages, 7 figures
null
null
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Numerical studies are reported to support the idea to explain the particle production in late inflationary era based on the parametric resonance with a noise effect. Two nonperturbative renormalization group formulations are used to numerically calculate the time evolution of particle numbers. Firstly, the dynamical renormalization group (DRG) method is applied to sum up the secular contributions. Secondly, we derive an exact evolution equation of the particle number which turned out to be possible surprisingly owing to the presence of the noise effect. Our numerical results show a drastic enhancement of the particle production in agreement with earlier works qualitatively. A comparison is made of numerical results based on two methods. Our work provides nonperturbative and quantitative methods to evaluate the particle production for the inflationary cosmology.
[ { "created": "Thu, 7 Apr 2016 06:33:27 GMT", "version": "v1" } ]
2016-04-08
[ [ "Murakami", "Asako", "" ], [ "Terao", "Haruhiko", "" ] ]
Numerical studies are reported to support the idea to explain the particle production in late inflationary era based on the parametric resonance with a noise effect. Two nonperturbative renormalization group formulations are used to numerically calculate the time evolution of particle numbers. Firstly, the dynamical renormalization group (DRG) method is applied to sum up the secular contributions. Secondly, we derive an exact evolution equation of the particle number which turned out to be possible surprisingly owing to the presence of the noise effect. Our numerical results show a drastic enhancement of the particle production in agreement with earlier works qualitatively. A comparison is made of numerical results based on two methods. Our work provides nonperturbative and quantitative methods to evaluate the particle production for the inflationary cosmology.
1809.01311
Matthias Lutz F.M.
Xiao-Yu Guo, Yonggoo Heo and Matthias F.M. Lutz
On chiral excitations with exotic quantum numbers
14 pages, three figures - published version
null
10.1016/j.physletb.2019.02.022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the flavour sextet of charmed meson resonances with J^P= 1^+ quantum numbers that is predicted by the leading order chiral Lagrangian with up, down and strange quarks. The effect of chiral correction terms as determined previously from QCD lattice data is worked out. Pole masses in the complex energy plane are derived. The most promising signal from such states accessible in experiments like Belle, LHCb and PANDA are foreseen in the s-wave pi D* phase shift and the eta D* invariant mass distribution. For physical quark masses a rapid variation of the phase shift in between the eta D* and the bar K Ds* thresholds is predicted.
[ { "created": "Wed, 5 Sep 2018 03:49:46 GMT", "version": "v1" }, { "created": "Wed, 20 Feb 2019 17:03:37 GMT", "version": "v2" } ]
2019-03-27
[ [ "Guo", "Xiao-Yu", "" ], [ "Heo", "Yonggoo", "" ], [ "Lutz", "Matthias F. M.", "" ] ]
We consider the flavour sextet of charmed meson resonances with J^P= 1^+ quantum numbers that is predicted by the leading order chiral Lagrangian with up, down and strange quarks. The effect of chiral correction terms as determined previously from QCD lattice data is worked out. Pole masses in the complex energy plane are derived. The most promising signal from such states accessible in experiments like Belle, LHCb and PANDA are foreseen in the s-wave pi D* phase shift and the eta D* invariant mass distribution. For physical quark masses a rapid variation of the phase shift in between the eta D* and the bar K Ds* thresholds is predicted.
1108.2834
Jin Min Yang
Junjie Cao, Wenyu Wang, Jin Min Yang
Split-SUSY dark matter in light of direct detection limits
Version in PLB (results updated)
Phys.Lett.B706:72-76,2011
10.1016/j.physletb.2011.11.003
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the present and future XENON limits on the neutralino dark matter in split supersymmetry (split-SUSY). Through a scan over the parameter space under the current constraints from collider experiments and the WMAP measurement of the dark matter relic density, we find that in the allowed parameter space a large part has been excluded by the present XENON100 limits and a further largish part can be covered by the future exposure (6000 kg-day). In case of unobservation of dark matter with such an exposure in the future, the lightest neutralino will remain bino-like and its annihilation is mainly through exchanging the SM-like Higgs boson in order to get the required relic density.
[ { "created": "Sun, 14 Aug 2011 02:25:20 GMT", "version": "v1" }, { "created": "Tue, 15 Nov 2011 07:47:35 GMT", "version": "v2" } ]
2011-11-16
[ [ "Cao", "Junjie", "" ], [ "Wang", "Wenyu", "" ], [ "Yang", "Jin Min", "" ] ]
We examine the present and future XENON limits on the neutralino dark matter in split supersymmetry (split-SUSY). Through a scan over the parameter space under the current constraints from collider experiments and the WMAP measurement of the dark matter relic density, we find that in the allowed parameter space a large part has been excluded by the present XENON100 limits and a further largish part can be covered by the future exposure (6000 kg-day). In case of unobservation of dark matter with such an exposure in the future, the lightest neutralino will remain bino-like and its annihilation is mainly through exchanging the SM-like Higgs boson in order to get the required relic density.
hep-ph/0102321
Michael Lublinsky
M. Lublinsky, E.Gotsman, E.Levin and U.Maor
Non-linear evolution and parton distributions at LHC and THERA energies
19 pages, 28 figures
Nucl.Phys.A696:851-869,2001
10.1016/S0375-9474(01)01150-2
TAUP-2667-2001
hep-ph
null
We suggest a new procedure for extrapolating the parton distributions from HERA energies to higher energies at THERA and LHC. The procedure suggested consists of two steps: first, we solve the non-linear evolution equation which includes the higher twists contributions, however this equation is deficient due to the low ($log(1/x)$) accuracy of our calculations. Second, we introduce a correcting function for which we write a DGLAP type linear evolution equation. We show that this correcting function is small in the whole kinematic region and decreases at low $x$. The nonlinear evolution equation is solved numerically and first estimates for the saturation scale, as well as for the value of the gluon density at THERA and LHC energies are made. We show that non-linear effects lead to damping of the gluon density by a factor of $2 \div 3$ at $x \approx 10^{-7}$.
[ { "created": "Tue, 27 Feb 2001 09:17:59 GMT", "version": "v1" } ]
2014-11-17
[ [ "Lublinsky", "M.", "" ], [ "Gotsman", "E.", "" ], [ "Levin", "E.", "" ], [ "Maor", "U.", "" ] ]
We suggest a new procedure for extrapolating the parton distributions from HERA energies to higher energies at THERA and LHC. The procedure suggested consists of two steps: first, we solve the non-linear evolution equation which includes the higher twists contributions, however this equation is deficient due to the low ($log(1/x)$) accuracy of our calculations. Second, we introduce a correcting function for which we write a DGLAP type linear evolution equation. We show that this correcting function is small in the whole kinematic region and decreases at low $x$. The nonlinear evolution equation is solved numerically and first estimates for the saturation scale, as well as for the value of the gluon density at THERA and LHC energies are made. We show that non-linear effects lead to damping of the gluon density by a factor of $2 \div 3$ at $x \approx 10^{-7}$.
1006.0669
Koloina A. Randrianarivony
D. Asner, M. Cunningham, S. Dejong, K. Randrianarivony, C. Santamarina Rios and M. Schram
Search for a Light Standard Model Higgs Boson Produced in Association with a Photon in Vector Boson Fusion
Presentation given at the Lake Louise Winter Institute 2010-Alberta, Canada
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the prospects for the discovery of a Standard Model Higgs boson decaying to $b\bar{b}$ pair through the Vector Boson Fusion mechanism in association with a central photon at the Large Hadron Collider (LHC). The photon provides a clean trigger and several advantages despite the fact that the cross section decreases by approximately a factor of $\alpha_{em}$. After applying various optimized selection criteria, we obtain a significance of $\sim$1.9 using ALPGEN interfaced with PYTHIA. The expected $b$-jet efficiency and fake rates and other detector acceptance cuts are taken into account to obtain a more realistic result.
[ { "created": "Thu, 3 Jun 2010 15:05:17 GMT", "version": "v1" } ]
2010-06-04
[ [ "Asner", "D.", "" ], [ "Cunningham", "M.", "" ], [ "Dejong", "S.", "" ], [ "Randrianarivony", "K.", "" ], [ "Rios", "C. Santamarina", "" ], [ "Schram", "M.", "" ] ]
We present the prospects for the discovery of a Standard Model Higgs boson decaying to $b\bar{b}$ pair through the Vector Boson Fusion mechanism in association with a central photon at the Large Hadron Collider (LHC). The photon provides a clean trigger and several advantages despite the fact that the cross section decreases by approximately a factor of $\alpha_{em}$. After applying various optimized selection criteria, we obtain a significance of $\sim$1.9 using ALPGEN interfaced with PYTHIA. The expected $b$-jet efficiency and fake rates and other detector acceptance cuts are taken into account to obtain a more realistic result.
hep-ph/9709288
Yuval Grossman
Yuval Grossman, Yosef Nir, Stephane Plaszczynski and Marie-Helene Schune
Implications of the Fleischer-Mannel Bound
24 pages, revtex, 6 figures included using psfig
Nucl.Phys. B511 (1998) 69-84
10.1016/S0550-3213(97)00736-0
SLAC-PUB-7622, WIS-97/27/Sep-PH, LAL 97-65
hep-ph
null
Fleischer and Mannel (FM) have shown that it may become possible to constrain the angle $\gamma$ of the unitarity triangle from measurements of various $B\to\pi K$ decays. This constraint is independent of hadronic uncertainties to the few percent level. We show that, within the Standard Model, the FM bound gives strong constraints on the CKM parameters. In particular, it could predict a well defined sign for $\sin2\gamma$ and $\sin2\alpha$. In a class of extensions of the Standard Model, where the New Physics affects only $\Delta B=2$ (and, in particular, not $\Delta B=1$) processes, the FM bound can lead to constraints on CP asymmetries in $B$ decays into final CP eigenstates even if $B-\bar B$ mixing is dominated by unknown New Physics. In our analysis, we use a new method to combine in a statistically meaningful way the various measurements that involve CKM parameters.
[ { "created": "Mon, 8 Sep 1997 21:09:31 GMT", "version": "v1" } ]
2009-10-30
[ [ "Grossman", "Yuval", "" ], [ "Nir", "Yosef", "" ], [ "Plaszczynski", "Stephane", "" ], [ "Schune", "Marie-Helene", "" ] ]
Fleischer and Mannel (FM) have shown that it may become possible to constrain the angle $\gamma$ of the unitarity triangle from measurements of various $B\to\pi K$ decays. This constraint is independent of hadronic uncertainties to the few percent level. We show that, within the Standard Model, the FM bound gives strong constraints on the CKM parameters. In particular, it could predict a well defined sign for $\sin2\gamma$ and $\sin2\alpha$. In a class of extensions of the Standard Model, where the New Physics affects only $\Delta B=2$ (and, in particular, not $\Delta B=1$) processes, the FM bound can lead to constraints on CP asymmetries in $B$ decays into final CP eigenstates even if $B-\bar B$ mixing is dominated by unknown New Physics. In our analysis, we use a new method to combine in a statistically meaningful way the various measurements that involve CKM parameters.
1102.5148
Ketan Patel
Anjan S. Joshipura, Ketan M. Patel
Fermion Masses in SO(10) Models
31 pages, 9 Tables, 4 figures
Phys.Rev.D83:095002,2011
10.1103/PhysRevD.83.095002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine many SO(10) models for their viability or otherwise in explaining all the fermion masses and mixing angles. This study is carried out for both supersymmetric and non-supersymmetric models and with minimal ($10+\bar{126}$) and non-minimal ($10+\bar{126}+120$) Higgs content. Extensive numerical fits to fermion masses and mixing are carried out in each case assuming dominance of type-II or type-I seesaw mechanism. Required scale of the B-L breaking is identified in each case. In supersymmetric case, several sets of data at the GUT scale with or without inclusion of finite supersymmetric corrections are used. All models studied provide quite good fits if the type-I seesaw mechanism dominates while many fail if the type-II seesaw dominates. This can be traced to the absence of the $b$-$\tau$ unification at the GUT scale in these models. The minimal non-supersymmetric model with type-I seesaw dominance gives excellent fits. In the presence of a $45_H$ and an intermediate scale, the model can also account for the gauge coupling unification making it potentially interesting model for the complete unification. Structure of the Yukawa coupling matrices obtained numerically in this specific case is shown to follow from a very simple U(1) symmetry and a Froggatt-Nielsen singlet.
[ { "created": "Fri, 25 Feb 2011 03:50:20 GMT", "version": "v1" } ]
2011-05-12
[ [ "Joshipura", "Anjan S.", "" ], [ "Patel", "Ketan M.", "" ] ]
We examine many SO(10) models for their viability or otherwise in explaining all the fermion masses and mixing angles. This study is carried out for both supersymmetric and non-supersymmetric models and with minimal ($10+\bar{126}$) and non-minimal ($10+\bar{126}+120$) Higgs content. Extensive numerical fits to fermion masses and mixing are carried out in each case assuming dominance of type-II or type-I seesaw mechanism. Required scale of the B-L breaking is identified in each case. In supersymmetric case, several sets of data at the GUT scale with or without inclusion of finite supersymmetric corrections are used. All models studied provide quite good fits if the type-I seesaw mechanism dominates while many fail if the type-II seesaw dominates. This can be traced to the absence of the $b$-$\tau$ unification at the GUT scale in these models. The minimal non-supersymmetric model with type-I seesaw dominance gives excellent fits. In the presence of a $45_H$ and an intermediate scale, the model can also account for the gauge coupling unification making it potentially interesting model for the complete unification. Structure of the Yukawa coupling matrices obtained numerically in this specific case is shown to follow from a very simple U(1) symmetry and a Froggatt-Nielsen singlet.
1511.09219
Joao Pacheco B. C. de Melo Dr.
J. P. B. C. de Melo, Kazuo Tsushima (Laborat\'orio de F\'isica Te\'orica e Computacional - LFTC - Universidade Cruzeiro do Sul), Tobias Frederico (Instituto Tecnol\'ogico da Aeron\'autica/DCTA)
Pion in the Medium with a Light-Front Model
To appear AIP PROCEEDINGS, XVI International Conference on Hadron Spectroscopy. HADRONS 2015, September 13-18, 2015, JLAB, Newport News, VA 6 pages, 4 figures eps, use AIP latex style
null
10.1063/1.4949459
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The pion properties in symmetric nuclear matter are investigated with the Quark-Meson Coupling (QMC) Model plus the light-front constituent quark model~(LFCQM). The LFCQM has been quite successful in describing the properties of pseudoscalar mesons in vacuum, such as the electromagnetic elastic form factors, electromagnetic radii, and decay constants. We study the pion properties in symmetric nuclear matter with the in-medium input recalculated through the QMC model, which provides the in-medium modification of the LFCQM.
[ { "created": "Mon, 30 Nov 2015 09:51:59 GMT", "version": "v1" } ]
2016-06-22
[ [ "de Melo", "J. P. B. C.", "", "Laboratório de Física\n Teórica e Computacional - LFTC - Universidade Cruzeiro do Sul" ], [ "Tsushima", "Kazuo", "", "Laboratório de Física\n Teórica e Computacional - LFTC - Universidade Cruzeiro do Sul" ], [ "Frederico", "Tobias", "", "Instituto Tecnológico da Aeronáutica/DCTA" ] ]
The pion properties in symmetric nuclear matter are investigated with the Quark-Meson Coupling (QMC) Model plus the light-front constituent quark model~(LFCQM). The LFCQM has been quite successful in describing the properties of pseudoscalar mesons in vacuum, such as the electromagnetic elastic form factors, electromagnetic radii, and decay constants. We study the pion properties in symmetric nuclear matter with the in-medium input recalculated through the QMC model, which provides the in-medium modification of the LFCQM.
2406.16281
Zeren Simon Wang
Zeren Simon Wang
Constraining long-lived particles from Higgs decays at the LHC with displaced vertices and jets
8 pages plus references, 5 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Long-lived particles (LLPs) originating from decays of the Standard-Model or Beyond-the-Standard-Model Higgs bosons are often featured with signatures of displaced vertices (DVs) and jets at colliders. In this work, we show that a recent ATLAS search for DVs plus jets, with its recast implementation, can efficiently place bounds on such hadronically or semi-leptonically decaying LLPs. In particular, we find the search is uniquely sensitive to LLP proper decay lengths of about $1-100$ mm, probing complementary regions in the parameter space of the relevant models compared to other prompt and LLP searches.
[ { "created": "Mon, 24 Jun 2024 03:02:59 GMT", "version": "v1" } ]
2024-06-25
[ [ "Wang", "Zeren Simon", "" ] ]
Long-lived particles (LLPs) originating from decays of the Standard-Model or Beyond-the-Standard-Model Higgs bosons are often featured with signatures of displaced vertices (DVs) and jets at colliders. In this work, we show that a recent ATLAS search for DVs plus jets, with its recast implementation, can efficiently place bounds on such hadronically or semi-leptonically decaying LLPs. In particular, we find the search is uniquely sensitive to LLP proper decay lengths of about $1-100$ mm, probing complementary regions in the parameter space of the relevant models compared to other prompt and LLP searches.
2206.10977
Bakar Chargeishvili
Bakar Chargeishvili, Maria Vittoria Garzelli, Sven-Olaf Moch
One-loop soft anomalous dimension matrices for $t\bar t j$ hadroproduction
29 pages, 13 figures
null
null
DESY-22-087
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the one-loop corrections to the soft anomalous dimension matrices for the production of a top-antitop quark pair in association with a jet at hadron colliders. This is a step forward towards implementing a procedure for the resummation of soft-gluon emission logarithms for the $t\bar{t}j + X$ hadroproduction process, that will enable the improvement of the accuracy of the $t\bar{t} j + X$ cross sections, beyond the current degree of knowledge. The latter, so far, has reached the next-to-leading order (NLO) level, complemented by the accuracy of the Shower Monte Carlo approaches used in matching the NLO computations to parton showers (PS) and by merging with matrix elements with a different number of light jets.
[ { "created": "Wed, 22 Jun 2022 11:00:41 GMT", "version": "v1" }, { "created": "Mon, 11 Jul 2022 15:11:09 GMT", "version": "v2" } ]
2022-07-12
[ [ "Chargeishvili", "Bakar", "" ], [ "Garzelli", "Maria Vittoria", "" ], [ "Moch", "Sven-Olaf", "" ] ]
We calculate the one-loop corrections to the soft anomalous dimension matrices for the production of a top-antitop quark pair in association with a jet at hadron colliders. This is a step forward towards implementing a procedure for the resummation of soft-gluon emission logarithms for the $t\bar{t}j + X$ hadroproduction process, that will enable the improvement of the accuracy of the $t\bar{t} j + X$ cross sections, beyond the current degree of knowledge. The latter, so far, has reached the next-to-leading order (NLO) level, complemented by the accuracy of the Shower Monte Carlo approaches used in matching the NLO computations to parton showers (PS) and by merging with matrix elements with a different number of light jets.
hep-ph/0008159
Xiao-Gang He
Xiao-Gang He (NTU), J.P. Ma (ITP) and Chung-Yi Wu (NTU)
$B\to \phi K$ and $B\to \phi X_s$ in the Heavy Quark Limit
11 pages, revtex
Phys.Rev. D63 (2001) 094004
10.1103/PhysRevD.63.094004
null
hep-ph hep-ex
null
We study $B\to \phi K$ and $B\to \phi X_s$ decays in the heavy quark limit using perturbative QCD. The next leading order corrections introduce substantial modifications to the naive factorization results (more than 50%). The branching ratio $Br(B\to \phi K)$ is predicted to be in the range $(F^{B\to K}_1(m^2_\phi)/0.33)^2(3.5\sim 4.2) \times 10^{-6}$ which is within the one $\sigma$ allowed region from the central value of $6.2\times 10^{-6}$ measured by CLEO, but outside the one $\sigma$ allowed region from the central value of $17.2\times 10^{-6}$ measured by BELLE for reasonable $F_1^{B\to K}$. For the semi-inclusive decay $B\to \phi X_s$ we also include initial bound state effect in the heavy quark limit which decreases the branching ratio by about 10%. $Br(B\to \phi X_s)$ is predicted to be in the range $(5.1\sim 6.3)\times 10^{-5}$.
[ { "created": "Wed, 16 Aug 2000 01:58:14 GMT", "version": "v1" }, { "created": "Sun, 20 Aug 2000 06:09:27 GMT", "version": "v2" } ]
2009-10-31
[ [ "He", "Xiao-Gang", "", "NTU" ], [ "Ma", "J. P.", "", "ITP" ], [ "Wu", "Chung-Yi", "", "NTU" ] ]
We study $B\to \phi K$ and $B\to \phi X_s$ decays in the heavy quark limit using perturbative QCD. The next leading order corrections introduce substantial modifications to the naive factorization results (more than 50%). The branching ratio $Br(B\to \phi K)$ is predicted to be in the range $(F^{B\to K}_1(m^2_\phi)/0.33)^2(3.5\sim 4.2) \times 10^{-6}$ which is within the one $\sigma$ allowed region from the central value of $6.2\times 10^{-6}$ measured by CLEO, but outside the one $\sigma$ allowed region from the central value of $17.2\times 10^{-6}$ measured by BELLE for reasonable $F_1^{B\to K}$. For the semi-inclusive decay $B\to \phi X_s$ we also include initial bound state effect in the heavy quark limit which decreases the branching ratio by about 10%. $Br(B\to \phi X_s)$ is predicted to be in the range $(5.1\sim 6.3)\times 10^{-5}$.
1212.4985
Kyohei Mukaida
Kyohei Mukaida, Kazunori Nakayama
Dissipative Effects on Reheating after Inflation
22 pages, 3 figures; v2: minor changes to reflect the published version
JCAP03(2013)002
10.1088/1475-7516/2013/03/002
UT-12-45
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The inflaton must convert its energy into radiation after inflation, which, in a conventional scenario, is caused by the perturbative inflaton decay. This reheating process would be much more complicated in some cases: the decay products obtain masses from an oscillating inflaton and thermal environment, and hence the conventional reheating scenario can be modified. We study in detail processes of particle production from the inflaton, their subsequent thermalization and evolution of inflaton/plasma system by taking dissipation of the inflaton in a hot plasma into account. It is shown that the reheating temperature is significantly affected by these effects.
[ { "created": "Thu, 20 Dec 2012 11:30:44 GMT", "version": "v1" }, { "created": "Sun, 3 Mar 2013 21:17:27 GMT", "version": "v2" } ]
2013-03-05
[ [ "Mukaida", "Kyohei", "" ], [ "Nakayama", "Kazunori", "" ] ]
The inflaton must convert its energy into radiation after inflation, which, in a conventional scenario, is caused by the perturbative inflaton decay. This reheating process would be much more complicated in some cases: the decay products obtain masses from an oscillating inflaton and thermal environment, and hence the conventional reheating scenario can be modified. We study in detail processes of particle production from the inflaton, their subsequent thermalization and evolution of inflaton/plasma system by taking dissipation of the inflaton in a hot plasma into account. It is shown that the reheating temperature is significantly affected by these effects.
1904.12938
Sadhana Dash
Pritam Chakraborty, Tulika Tripathy, Subhadip Pal and Sadhana Dash
Multiplicity dependence of strange and multi-strange hadrons in p$-$p, p$-$Pb and Pb$-$Pb collisions at LHC energies using Tsallis-Weibull Formalism
null
null
10.1140/epja/s10050-020-00081-4
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The transverse momentum ($p_{T}$) distribution of strange hadrons ($K_{S}^{0}$ and $\Lambda$) and multi-strange hadrons( $\Xi$ and $\Omega$) measured in p$-$p, p$-$Pb, and Pb$-$Pb collisions at LHC energies have been studied for different multiplicity classes using Tsallis-Weibull (or q$-$Weibull)formalism. The distribution describes the measured $p_{T}$ spectra for all multiplicity (or centrality)classes. The multiplicity dependence of the extracted parameters are studied for the mentioned collisions systems. The $\lambda$ parameter was observed to increase systematically with the collision multiplicity and follows a mass hierarchy for all collision system. This characteristic feature indicates that $\lambda$ can be associated to the strength of collectivity for heavy ion collisions. It can also be related to strength of dynamic effects such as multi-partonic interactions and color reconnections which mimic collectivity in smaller systems. The non-extensive $q$ parameter is found to be greater than one for all the particles suggesting that the strange particles are emitted from a source which is not fully equilibrated.
[ { "created": "Mon, 29 Apr 2019 20:29:29 GMT", "version": "v1" } ]
2020-04-22
[ [ "Chakraborty", "Pritam", "" ], [ "Tripathy", "Tulika", "" ], [ "Pal", "Subhadip", "" ], [ "Dash", "Sadhana", "" ] ]
The transverse momentum ($p_{T}$) distribution of strange hadrons ($K_{S}^{0}$ and $\Lambda$) and multi-strange hadrons( $\Xi$ and $\Omega$) measured in p$-$p, p$-$Pb, and Pb$-$Pb collisions at LHC energies have been studied for different multiplicity classes using Tsallis-Weibull (or q$-$Weibull)formalism. The distribution describes the measured $p_{T}$ spectra for all multiplicity (or centrality)classes. The multiplicity dependence of the extracted parameters are studied for the mentioned collisions systems. The $\lambda$ parameter was observed to increase systematically with the collision multiplicity and follows a mass hierarchy for all collision system. This characteristic feature indicates that $\lambda$ can be associated to the strength of collectivity for heavy ion collisions. It can also be related to strength of dynamic effects such as multi-partonic interactions and color reconnections which mimic collectivity in smaller systems. The non-extensive $q$ parameter is found to be greater than one for all the particles suggesting that the strange particles are emitted from a source which is not fully equilibrated.
1802.00821
Pedro Simoni Pasquini
Pedro Pasquini
Review: Long-baseline oscillation experiments as a tool to probe High Energy Models
13 pages, 6 figures, 4 tables. Invited Review for New Physics Landmarks: Dark Matter and Neutrino Masses at Advances in High Energy Physics
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the current status of neutrino oscillation experiments, mainly focussed on T2(H)K, NO$\nu$A and DUNE. Their capability to probe high energy physics is found in the precision measurement of the CP phase and $\theta_{23}$. In general, neutrino mass models predicts correlations among the mixing angles that can be used to scan and shrink down its parameter space. We updated previous analysis and presents a list of models that contain such structure.
[ { "created": "Fri, 2 Feb 2018 19:25:16 GMT", "version": "v1" } ]
2018-02-06
[ [ "Pasquini", "Pedro", "" ] ]
We review the current status of neutrino oscillation experiments, mainly focussed on T2(H)K, NO$\nu$A and DUNE. Their capability to probe high energy physics is found in the precision measurement of the CP phase and $\theta_{23}$. In general, neutrino mass models predicts correlations among the mixing angles that can be used to scan and shrink down its parameter space. We updated previous analysis and presents a list of models that contain such structure.
hep-ph/0612224
Damir Becirevic
Damir Becirevic, Svjetlana Fajfer and Jernej Kamenik
Chiral behavior of the B(s,d)-Bbar(s,d) mixing amplitude in the Standard Model and beyond
16 pages, 5 figures (published version)
JHEP 0706:003,2007
10.1088/1126-6708/2007/06/003
LPT Orsay, 06-94
hep-ph hep-lat
null
We compute the chiral logarithmic corrections to the Bd and Bs mixing amplitudes in the Standard Model and beyond. We then investigate the impact of the inclusion of the lowest-lying scalar heavy-light states to the decay constants and bag-parameters and show that this does not modify the pion chiral logarithms, but it does produce corrections which are competitive in size with the K- and eta-meson chiral logarithms. This conclusion is highly relevant to the lattice studies since the pion chiral logarithms represent the most important effect in guiding the chiral extrapolations of the lattice data for these quantities. Also important is to stress that the pion chiral logarithmic corrections are useful in guiding those extrapolations as long as Mpi << Delta, where Delta is the mass gap between the scalar and pseudoscalar heavy-light mesons.
[ { "created": "Tue, 19 Dec 2006 11:31:31 GMT", "version": "v1" }, { "created": "Wed, 31 Jan 2007 11:09:34 GMT", "version": "v2" }, { "created": "Fri, 1 Jun 2007 06:17:49 GMT", "version": "v3" } ]
2010-10-27
[ [ "Becirevic", "Damir", "" ], [ "Fajfer", "Svjetlana", "" ], [ "Kamenik", "Jernej", "" ] ]
We compute the chiral logarithmic corrections to the Bd and Bs mixing amplitudes in the Standard Model and beyond. We then investigate the impact of the inclusion of the lowest-lying scalar heavy-light states to the decay constants and bag-parameters and show that this does not modify the pion chiral logarithms, but it does produce corrections which are competitive in size with the K- and eta-meson chiral logarithms. This conclusion is highly relevant to the lattice studies since the pion chiral logarithms represent the most important effect in guiding the chiral extrapolations of the lattice data for these quantities. Also important is to stress that the pion chiral logarithmic corrections are useful in guiding those extrapolations as long as Mpi << Delta, where Delta is the mass gap between the scalar and pseudoscalar heavy-light mesons.
hep-ph/0201213
Yongjun Zhang
Yong-Jun Zhang, Bo-Qiang Ma, Li-Ming Yang
Flavor Asymmetry of Nucleon Sea from Detailed Balance
4 pages and no figures. Talk presented at the Third Circum-Pan-Pacific Symposium on "High Energy Spin Physics", Oct. 8-13, 2001, Beijing, China
Int.J.Mod.Phys. A18 (2003) 1465-1468
10.1142/S0217751X03014915
null
hep-ph hep-ex nucl-ex nucl-th
null
In this study, the proton is taken as an ensemble of quark-gluon Fock states. Using the principle of detailed balance, we find $\bar{d}-\bar{u} \approx 0.124$, which is in surprisingly agreement with the experimental observation.
[ { "created": "Wed, 23 Jan 2002 00:19:49 GMT", "version": "v1" } ]
2009-11-07
[ [ "Zhang", "Yong-Jun", "" ], [ "Ma", "Bo-Qiang", "" ], [ "Yang", "Li-Ming", "" ] ]
In this study, the proton is taken as an ensemble of quark-gluon Fock states. Using the principle of detailed balance, we find $\bar{d}-\bar{u} \approx 0.124$, which is in surprisingly agreement with the experimental observation.
2209.07690
Pawan Dhakal
Pawan Dhakal, Steven Prohira, Christopher V. Cappiello, John F. Beacom, Scott Palo, John Marino
New Constraints on Macroscopic Dark Matter Using Radar Meteor Detectors
Main text 15 pages and 11 figures, Appendix 2 pages and 3 figures; Typos and references corrected
null
10.1103/PhysRevD.107.043026
null
hep-ph astro-ph.CO astro-ph.EP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that dark-matter candidates with large masses and large nuclear interaction cross sections are detectable with terrestrial radar systems. We develop our results in close comparison to successful radar searches for tiny meteoroids, aggregates of ordinary matter. The path of a meteoroid (or suitable dark-matter particle) through the atmosphere produces ionization deposits that reflect incident radio waves. We calculate the equivalent radar echoing area or `radar cross section' for dark matter. By comparing the expected number of dark-matter-induced echoes with observations, we set new limits in the plane of dark-matter mass and cross section, complementary to pre-existing cosmological limits. Our results are valuable because (A) they open a new detection technique for which the reach can be greatly improved and (B) in case of a detection, the radar technique provides differential sensitivity to the mass and cross section, unlike cosmological probes.
[ { "created": "Fri, 16 Sep 2022 03:12:41 GMT", "version": "v1" }, { "created": "Thu, 13 Apr 2023 12:27:16 GMT", "version": "v2" } ]
2023-04-14
[ [ "Dhakal", "Pawan", "" ], [ "Prohira", "Steven", "" ], [ "Cappiello", "Christopher V.", "" ], [ "Beacom", "John F.", "" ], [ "Palo", "Scott", "" ], [ "Marino", "John", "" ] ]
We show that dark-matter candidates with large masses and large nuclear interaction cross sections are detectable with terrestrial radar systems. We develop our results in close comparison to successful radar searches for tiny meteoroids, aggregates of ordinary matter. The path of a meteoroid (or suitable dark-matter particle) through the atmosphere produces ionization deposits that reflect incident radio waves. We calculate the equivalent radar echoing area or `radar cross section' for dark matter. By comparing the expected number of dark-matter-induced echoes with observations, we set new limits in the plane of dark-matter mass and cross section, complementary to pre-existing cosmological limits. Our results are valuable because (A) they open a new detection technique for which the reach can be greatly improved and (B) in case of a detection, the radar technique provides differential sensitivity to the mass and cross section, unlike cosmological probes.
hep-ph/0409324
J\"org Raufeisen
J. Raufeisen
Probing the nuclear gluon distribution with heavy quarks
8 pages, 4 figures, invited talk at ISMD04, Sonoma State U., Rhonert Park, CA, July 26 - August 1, 2004
Acta Phys.Polon. B36 (2005) 235-242
null
null
hep-ph
null
The color dipole formulation provides an intuitive picture of hard processes in high energy scattering. Most importantly, this approach allows one to calculate nuclear effects in a parameter-free way. I review the relation between the dipole approach and transverse momentum factorization and present numerical results for open heavy flavor production in proton-proton and proton-nucleus collisions. The cross section for heavy quark production off nuclei is known to reflect gluon shadowing, but is also affected by higher twist effects and by finite coherence length effects.
[ { "created": "Tue, 28 Sep 2004 16:01:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Raufeisen", "J.", "" ] ]
The color dipole formulation provides an intuitive picture of hard processes in high energy scattering. Most importantly, this approach allows one to calculate nuclear effects in a parameter-free way. I review the relation between the dipole approach and transverse momentum factorization and present numerical results for open heavy flavor production in proton-proton and proton-nucleus collisions. The cross section for heavy quark production off nuclei is known to reflect gluon shadowing, but is also affected by higher twist effects and by finite coherence length effects.
1007.0981
Marcos Rodriguez Cardoso
M. C. Rodriguez
Mass Spectrum in the Minimal Supersymmetric 3-3-1 model
39 pages, 3 Tables and 9 figures
Journal of Modern Physics, 2011, 2, 1193-1214
10.4236/jmp.2011.210149
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the minimal supersymmetric extension of the 3-3-1 model. We study the mass spectra of this model in the fermionic and gauge bosons sectors without the antisextet. We also present some phenomenological consequences of this model at colliders such as Large Hadron Collider (LHC) and International Linear Collider(ILC).
[ { "created": "Tue, 6 Jul 2010 19:29:07 GMT", "version": "v1" } ]
2013-07-25
[ [ "Rodriguez", "M. C.", "" ] ]
We consider the minimal supersymmetric extension of the 3-3-1 model. We study the mass spectra of this model in the fermionic and gauge bosons sectors without the antisextet. We also present some phenomenological consequences of this model at colliders such as Large Hadron Collider (LHC) and International Linear Collider(ILC).
0904.2424
Jon Pumplin
Jon Pumplin, J. Huston, H.L. Lai, P. M. Nadolsky, Wu-Ki Tung, C.-P. Yuan
Collider Inclusive Jet Data and the Gluon Distribution
Published version
Phys.Rev.D80:014019,2009
10.1103/PhysRevD.80.014019
MSUHEP-090415
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inclusive jet production data are important for constraining the gluon distribution in the global QCD analysis of parton distribution functions. With the addition of recent CDF and D0 Run II jet data, we study a number of issues that play a role in determining the up-to-date gluon distribution and its uncertainty, and produce a new set of parton distributions that make use of that data. We present in detail the general procedures used to study the compatibility between new data sets and the previous body of data used in a global fit. We introduce a new method in which the Hessian matrix for uncertainties is ``rediagonalized'' to obtain eigenvector sets that conveniently characterize the uncertainty of a particular observable.
[ { "created": "Thu, 16 Apr 2009 04:27:47 GMT", "version": "v1" }, { "created": "Fri, 7 Aug 2009 21:02:10 GMT", "version": "v2" } ]
2010-04-23
[ [ "Pumplin", "Jon", "" ], [ "Huston", "J.", "" ], [ "Lai", "H. L.", "" ], [ "Nadolsky", "P. M.", "" ], [ "Tung", "Wu-Ki", "" ], [ "Yuan", "C. -P.", "" ] ]
Inclusive jet production data are important for constraining the gluon distribution in the global QCD analysis of parton distribution functions. With the addition of recent CDF and D0 Run II jet data, we study a number of issues that play a role in determining the up-to-date gluon distribution and its uncertainty, and produce a new set of parton distributions that make use of that data. We present in detail the general procedures used to study the compatibility between new data sets and the previous body of data used in a global fit. We introduce a new method in which the Hessian matrix for uncertainties is ``rediagonalized'' to obtain eigenvector sets that conveniently characterize the uncertainty of a particular observable.
1703.10845
Mureed Hussain
Mureed Hussain, Muhammad Usman, Muhammad Ali Paracha and Muhammad Jamil Aslam
Constraints on Two Higgs Doublet Model Parameters in the light of rare $B$-Decays
19 pages, 10 figures, added some references
null
10.1103/PhysRevD.95.075009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We established the allowed parameters of two-Higgs doublet model(2HDM) from flavor physics observables, precisely from rare $B$ meson decays. In our analysis most formidable constraints on the 2HDM parameters arise from the branching ratio of rare radiative $B$ meson decay i.e., $B\to X_{s}\gamma$. However, the constraints arising from the branching ratio of $B_{s}\to\mu^{+}\mu^{-}$ decay in $m_{H^{\pm}}-\tan\beta$ plane give $m_{H^{\pm}} >$ 80 GeV for the value of $\tan\beta\sim 2$, that is in agreement with large electron-positron collider (LEP) data. Furthermore, we also investigate the bounds on the $CP$-even $m_{H}$ and $CP$-odd $m_{A^{0}}$ Higgs boson not only from above mentioned physical observables, but also from the zero crossing of the forward-backward asymmetry of $B\to K^{\ast}\mu^{+}\mu^{-}$ decay. Therefore, these bounds on parameters of the 2HDM will provides a fertile ground to test the 2HDM at current and future $B$-physics experiments.
[ { "created": "Fri, 31 Mar 2017 10:48:57 GMT", "version": "v1" }, { "created": "Mon, 24 Apr 2017 07:23:30 GMT", "version": "v2" } ]
2017-04-25
[ [ "Hussain", "Mureed", "" ], [ "Usman", "Muhammad", "" ], [ "Paracha", "Muhammad Ali", "" ], [ "Aslam", "Muhammad Jamil", "" ] ]
We established the allowed parameters of two-Higgs doublet model(2HDM) from flavor physics observables, precisely from rare $B$ meson decays. In our analysis most formidable constraints on the 2HDM parameters arise from the branching ratio of rare radiative $B$ meson decay i.e., $B\to X_{s}\gamma$. However, the constraints arising from the branching ratio of $B_{s}\to\mu^{+}\mu^{-}$ decay in $m_{H^{\pm}}-\tan\beta$ plane give $m_{H^{\pm}} >$ 80 GeV for the value of $\tan\beta\sim 2$, that is in agreement with large electron-positron collider (LEP) data. Furthermore, we also investigate the bounds on the $CP$-even $m_{H}$ and $CP$-odd $m_{A^{0}}$ Higgs boson not only from above mentioned physical observables, but also from the zero crossing of the forward-backward asymmetry of $B\to K^{\ast}\mu^{+}\mu^{-}$ decay. Therefore, these bounds on parameters of the 2HDM will provides a fertile ground to test the 2HDM at current and future $B$-physics experiments.
hep-ph/0612069
Igor Mishustin
Igor N. Mishustin (1,2) and Konstantin A. Lyakhov (3) ((1) Frankfurt Institute for Advanced Studies, (2) Kurchatov Institute, Moscow, (3) Frankfurt International Graduate School for Science)
Baryon deceleration by strong chromofields in ultrarelativistic nuclear collisions
10 pages in revtex, 3 eps figures
Phys.Rev.C76:011603,2007
10.1103/PhysRevC.76.011603
null
hep-ph
null
It is assumed that strong chromofields are generated at early stages of ultrarelativistic heavy-ion collisions which give rise to a collective deceleration of net baryons from colliding nuclei. We have solved classical equations of motion for baryonic slabs under the action of a time-dependent longitudinal chromoelectric field. It is demonstrated that the slab final rapidities are rather sensitive to the strength and decay time of the chromofield as well as to the back reaction of the produced partonic plasma. The net-baryon rapidity loss of about 2 units, found for most central Au-Au collisions at RHIC, can be explained by the action of chromofields with the initial energy density of about 50 GeV/fm^3. Predictions for the baryon stopping at the LHC are made.
[ { "created": "Wed, 6 Dec 2006 14:15:37 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mishustin", "Igor N.", "" ], [ "Lyakhov", "Konstantin A.", "" ] ]
It is assumed that strong chromofields are generated at early stages of ultrarelativistic heavy-ion collisions which give rise to a collective deceleration of net baryons from colliding nuclei. We have solved classical equations of motion for baryonic slabs under the action of a time-dependent longitudinal chromoelectric field. It is demonstrated that the slab final rapidities are rather sensitive to the strength and decay time of the chromofield as well as to the back reaction of the produced partonic plasma. The net-baryon rapidity loss of about 2 units, found for most central Au-Au collisions at RHIC, can be explained by the action of chromofields with the initial energy density of about 50 GeV/fm^3. Predictions for the baryon stopping at the LHC are made.
hep-ph/9704222
Matthias Steinhauser
K.G. Chetyrkin, R. Harlander, J.H. Kuehn, M. Steinhauser
Mass Corrections to the Vector Current Correlator
16 pages, LaTeX, 11 postscript figures. The complete paper, including figures, is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
Nucl.Phys. B503 (1997) 339-353
10.1016/S0550-3213(97)00383-0
MPI/PhT/97-012, TTP97-11
hep-ph
null
Three-loop QCD corrections to the vector current correlator are considered. The large momentum procedure is applied in order to evaluate mass corrections up to order $(m^2/q^2)^6$. The inclusion of the first seven terms to the ratio $R=\sigma(e^+e^- \to hadrons)/\sigma(e^+e^- \to \mu^+\mu^-)$ leads to reliable predictions from the high energy region down to relatively close to threshold.
[ { "created": "Thu, 3 Apr 1997 12:33:55 GMT", "version": "v1" } ]
2009-10-30
[ [ "Chetyrkin", "K. G.", "" ], [ "Harlander", "R.", "" ], [ "Kuehn", "J. H.", "" ], [ "Steinhauser", "M.", "" ] ]
Three-loop QCD corrections to the vector current correlator are considered. The large momentum procedure is applied in order to evaluate mass corrections up to order $(m^2/q^2)^6$. The inclusion of the first seven terms to the ratio $R=\sigma(e^+e^- \to hadrons)/\sigma(e^+e^- \to \mu^+\mu^-)$ leads to reliable predictions from the high energy region down to relatively close to threshold.
1609.03052
Sasa Prelovsek
Sasa Prelovsek
Hadron spectroscopy and interactions from lattice QCD
8 pages, invited talk at QCD@Work 27-30 June 2016 Martina Franca, Italy, some overlap with 1508.07322, reference added. arXiv admin note: text overlap with arXiv:1508.07322
null
10.1051/epjconf/201612900018
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lattice QCD approach to study the hadronic resonances and exotic hadrons is described at an introductory level. The main challenge is that these states decay strongly via one or more decay channels, and they often lie near thersholds. Specific results for conventional and exotic hadrons are shown to illustrate the current status.
[ { "created": "Sat, 10 Sep 2016 13:37:47 GMT", "version": "v1" }, { "created": "Fri, 23 Sep 2016 12:31:30 GMT", "version": "v2" } ]
2016-12-21
[ [ "Prelovsek", "Sasa", "" ] ]
Lattice QCD approach to study the hadronic resonances and exotic hadrons is described at an introductory level. The main challenge is that these states decay strongly via one or more decay channels, and they often lie near thersholds. Specific results for conventional and exotic hadrons are shown to illustrate the current status.
hep-ph/9901258
Harald Anlauf
H. Anlauf (Siegen)
Deep Inelastic Scattering with a Tagged Photon: QED Corrections for the $\Sigma$ Method
28 pages, LaTeX2e, 7 figs. Labels of fig.6 fixed (correct in journal)
Eur.Phys.J.C9:69,1999
10.1007/s100520050514
SI-98-32
hep-ph
null
After a brief review of the kinematics of deep inelastic scattering (DIS) within the so-called $\Sigma$ method, we derive the necessary formulae for the treatment of QED radiative corrections to DIS originating from hard photon radiation. The results are applied to a calculation of the corrections to DIS with a tagged photon with next-to-leading logarithmic accuracy under HERA conditions. It turns out that the next-to-leading order corrections are quite important for the $\Sigma$ method. We also discuss the dependence of the corrections on the longitudinal structure function of the proton, $F_L$, in the region of low $Q^2$ and moderate $x$.
[ { "created": "Sat, 9 Jan 1999 18:12:37 GMT", "version": "v1" }, { "created": "Mon, 5 Jul 1999 16:48:22 GMT", "version": "v2" } ]
2011-09-13
[ [ "Anlauf", "H.", "", "Siegen" ] ]
After a brief review of the kinematics of deep inelastic scattering (DIS) within the so-called $\Sigma$ method, we derive the necessary formulae for the treatment of QED radiative corrections to DIS originating from hard photon radiation. The results are applied to a calculation of the corrections to DIS with a tagged photon with next-to-leading logarithmic accuracy under HERA conditions. It turns out that the next-to-leading order corrections are quite important for the $\Sigma$ method. We also discuss the dependence of the corrections on the longitudinal structure function of the proton, $F_L$, in the region of low $Q^2$ and moderate $x$.
hep-ph/0303047
Gabrijela
Glennys R. Farrar and Gabrijela Zaharijas
Transitions of two baryons to the H dibaryon in nuclei
7 pages, 3 figures
null
null
null
hep-ph
null
We calculate the suppression in the rate at which two baryons in a nucleus (viz., nucleons or $\Lambda$'s) convert to an H dibaryon, using an Isgur-Karl wavefunction for quarks in the baryons and H, and a Bethe-Goldstone wavefunction for the baryons in the nucleus. If $r_H \lsi 1/3~ r_N$, we find $\tau_{A_{\Lambda\Lambda}\to A'_H}\gsi \tau_\Lambda$ and the observation of $\Lambda$ decays from double-$\Lambda$ hypernuclei does not exclude the existence of the H. If $m_H < 2 m_p$, nuclei are unstable but have very long lifetimes. For reasonable values of $r_H$ and the nuclear wavefunction, the lifetime can be long enough to evade anticipated SuperK limits $\tau_{A_{NN}\to A'_H}\gsi {\rm few} 10^{29}$ yr, or short enough to be observed. An analysis of SuperK data to look for this possibility should be undertaken.
[ { "created": "Wed, 5 Mar 2003 22:46:21 GMT", "version": "v1" } ]
2016-09-06
[ [ "Farrar", "Glennys R.", "" ], [ "Zaharijas", "Gabrijela", "" ] ]
We calculate the suppression in the rate at which two baryons in a nucleus (viz., nucleons or $\Lambda$'s) convert to an H dibaryon, using an Isgur-Karl wavefunction for quarks in the baryons and H, and a Bethe-Goldstone wavefunction for the baryons in the nucleus. If $r_H \lsi 1/3~ r_N$, we find $\tau_{A_{\Lambda\Lambda}\to A'_H}\gsi \tau_\Lambda$ and the observation of $\Lambda$ decays from double-$\Lambda$ hypernuclei does not exclude the existence of the H. If $m_H < 2 m_p$, nuclei are unstable but have very long lifetimes. For reasonable values of $r_H$ and the nuclear wavefunction, the lifetime can be long enough to evade anticipated SuperK limits $\tau_{A_{NN}\to A'_H}\gsi {\rm few} 10^{29}$ yr, or short enough to be observed. An analysis of SuperK data to look for this possibility should be undertaken.
1910.05191
Christian Hohl
Stefan Antusch, Christian Hohl, Vasja Susic
Comparatively Light Extra Higgs States as Signature of SUSY $\mathrm{SO}(10)$ GUTs with 3rd Family Yukawa Unification
39 pages, 13 figures, 1 table, 2 appendices
null
10.1007/JHEP06(2020)014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study $3$rd family Yukawa unification in the context of supersymmetric (SUSY) $\mathrm{SO}(10)$ GUTs and $\mathrm{SO}(10)$-motivated boundary conditions for the SUSY-breaking soft terms. We consider $\mu<0$ such that the SUSY loop-threshold effects enable a good fit to all third family masses of the charged Standard Model (SM) fermions. We find that fitting the third family masses together with the mass of the SM-like Higgs particle, the scenario predicts the masses of the superpartner particles and of the extra Higgs states of the MSSM: while the sparticles are predicted to be comparatively heavy (above the present LHC bound but within reach of future colliders), the spectrum has the characteristic feature that the lightest new particles are the extra MSSM Higgses. We show that this effect is rather robust with respect to many deformations of the GUT boundary conditions, but turns out to be sensitive to the exactness of top-bottom Yukawa unification. Nevertheless, with moderate deviations of a few percent from exact top-bottom Yukawa unification (stemming e.g.\ from GUT-threshold corrections or higher-dimensional operators), the scenario still predicts extra MSSM Higgs particles with masses not much above $1.5\,\mathrm{TeV}$, which could be tested e.g.\ by future LHC searches for ditau decays $H^0/A^{0}\to\tau\tau$. Finding the extra MSSM Higges before the other new MSSM particles could thus be a smoking gun for a Yukawa unified $\mathrm{SO}(10)$ GUT.
[ { "created": "Fri, 11 Oct 2019 13:56:09 GMT", "version": "v1" } ]
2020-06-24
[ [ "Antusch", "Stefan", "" ], [ "Hohl", "Christian", "" ], [ "Susic", "Vasja", "" ] ]
We study $3$rd family Yukawa unification in the context of supersymmetric (SUSY) $\mathrm{SO}(10)$ GUTs and $\mathrm{SO}(10)$-motivated boundary conditions for the SUSY-breaking soft terms. We consider $\mu<0$ such that the SUSY loop-threshold effects enable a good fit to all third family masses of the charged Standard Model (SM) fermions. We find that fitting the third family masses together with the mass of the SM-like Higgs particle, the scenario predicts the masses of the superpartner particles and of the extra Higgs states of the MSSM: while the sparticles are predicted to be comparatively heavy (above the present LHC bound but within reach of future colliders), the spectrum has the characteristic feature that the lightest new particles are the extra MSSM Higgses. We show that this effect is rather robust with respect to many deformations of the GUT boundary conditions, but turns out to be sensitive to the exactness of top-bottom Yukawa unification. Nevertheless, with moderate deviations of a few percent from exact top-bottom Yukawa unification (stemming e.g.\ from GUT-threshold corrections or higher-dimensional operators), the scenario still predicts extra MSSM Higgs particles with masses not much above $1.5\,\mathrm{TeV}$, which could be tested e.g.\ by future LHC searches for ditau decays $H^0/A^{0}\to\tau\tau$. Finding the extra MSSM Higges before the other new MSSM particles could thus be a smoking gun for a Yukawa unified $\mathrm{SO}(10)$ GUT.
1606.06733
Ahmed Ismail
Marcela Carena, Peisi Huang, Ahmed Ismail, Ian Low, Nausheen R. Shah, Carlos E.M. Wagner
A Second Peak in Diphoton (or Diboson) Resonances
6 pages, 2 figures. v2: added discussion with updated figures, modified title and benchmark, conclusions unchanged, to appear in PRD
Phys. Rev. D 94, 115001 (2016)
null
EFI-16-14, NSF-KITP-16-089, WSU-HEP-1602
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many new physics models contain a neutral scalar resonance that can be predominantly produced via gluon fusion through loops. In such a case, there could be important effects of additional particles, that in turn may hadronize before decaying and form bound states. This interesting possibility may lead to novel signatures with double peaks that can be searched for at the LHC. We study the phenomenology of double peak searches in diboson final states from loop induced production and decay of a new neutral spin-0 resonance at the LHC. The loop-induced couplings should be mediated by particles carrying color and electroweak charge that after forming bound states will induce a second peak in the diboson invariant mass spectrum near twice their mass. A second peak could be present via loop-induced couplings into $gg$ (dijet), $\gamma\gamma$ and $Z\gamma$ final states as well as in the $WW$ and $ZZ$ channels for the case of a pseudo-scalar resonance or for scalars with suppressed tree-level coupling to gauge bosons.
[ { "created": "Tue, 21 Jun 2016 20:00:00 GMT", "version": "v1" }, { "created": "Thu, 10 Nov 2016 22:11:59 GMT", "version": "v2" } ]
2016-12-02
[ [ "Carena", "Marcela", "" ], [ "Huang", "Peisi", "" ], [ "Ismail", "Ahmed", "" ], [ "Low", "Ian", "" ], [ "Shah", "Nausheen R.", "" ], [ "Wagner", "Carlos E. M.", "" ] ]
Many new physics models contain a neutral scalar resonance that can be predominantly produced via gluon fusion through loops. In such a case, there could be important effects of additional particles, that in turn may hadronize before decaying and form bound states. This interesting possibility may lead to novel signatures with double peaks that can be searched for at the LHC. We study the phenomenology of double peak searches in diboson final states from loop induced production and decay of a new neutral spin-0 resonance at the LHC. The loop-induced couplings should be mediated by particles carrying color and electroweak charge that after forming bound states will induce a second peak in the diboson invariant mass spectrum near twice their mass. A second peak could be present via loop-induced couplings into $gg$ (dijet), $\gamma\gamma$ and $Z\gamma$ final states as well as in the $WW$ and $ZZ$ channels for the case of a pseudo-scalar resonance or for scalars with suppressed tree-level coupling to gauge bosons.
0810.0723
Bennie F. L. Ward
B.F.L. Ward (1), S. Joseph (1), S. Majhi (1), S.A. Yost (2) ((1) Department of Physics, Baylor University, Waco, TX, USA, (2) Department of Physics, The Citadel, Charleston, SC, USA)
Precision QED \otimes QCD Resummation Theory for LHC Physics: IR-Improved Scheme for Parton Distributions, Kernels, Reduced Cross Sections with Shower/ME Matching
4 pages, 1 figure, presented by BFLW at ICHEP08; updated style for proc
null
null
BU-HEPP-08-14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We summarize the recent progress in a new approach to precision LHC physics based on the IR-improved DGLAP-CS theory as it relates to a new MC friendly exponentiated scheme for precision calculation of higher order corrections to LHC physics in which IR singularities from both QED and QCD are canceled to all orders in \alpha and in \alpha_s simultaneously in the presence of rigorous shower/ME matching. We present the first MC data comparing the implied new showers themselves with the standard ones using the HERWIG6.5 MC event generator as a test case at LHC energies.
[ { "created": "Fri, 3 Oct 2008 21:48:10 GMT", "version": "v1" }, { "created": "Tue, 7 Oct 2008 18:49:46 GMT", "version": "v2" } ]
2008-10-07
[ [ "Ward", "B. F. L.", "" ], [ "Joseph", "S.", "" ], [ "Majhi", "S.", "" ], [ "Yost", "S. A.", "" ] ]
We summarize the recent progress in a new approach to precision LHC physics based on the IR-improved DGLAP-CS theory as it relates to a new MC friendly exponentiated scheme for precision calculation of higher order corrections to LHC physics in which IR singularities from both QED and QCD are canceled to all orders in \alpha and in \alpha_s simultaneously in the presence of rigorous shower/ME matching. We present the first MC data comparing the implied new showers themselves with the standard ones using the HERWIG6.5 MC event generator as a test case at LHC energies.
1508.01250
Zenro Hioki
Zenro Hioki
Decoupling theorem in top productions/decays revisited -- To what extent can we understand it visually?
LaTeX_2e, 16 pages, 7 figures, Version accepted for publication in Int. J. Mod. Phys. A
International Journal of Modern Physics A Vol. 31 (2016) 1650011
10.1142/S0217751X16500111
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I revisit here the decoupling theorem in top-quark productions/decays, which states that the angular distribution of any final-particle produced in those processes does not depend on any possible nonstandard top-quark decay interactions at their leading order when certain conditions are satisfied. Towards a simple, intuitive and visual understanding of this theorem, I will study to what extent we could explain why such a theorem holds without relying on any specific/detailed calculations.
[ { "created": "Thu, 6 Aug 2015 00:08:31 GMT", "version": "v1" }, { "created": "Wed, 30 Dec 2015 16:40:23 GMT", "version": "v2" } ]
2016-01-29
[ [ "Hioki", "Zenro", "" ] ]
I revisit here the decoupling theorem in top-quark productions/decays, which states that the angular distribution of any final-particle produced in those processes does not depend on any possible nonstandard top-quark decay interactions at their leading order when certain conditions are satisfied. Towards a simple, intuitive and visual understanding of this theorem, I will study to what extent we could explain why such a theorem holds without relying on any specific/detailed calculations.
hep-ph/9309256
Hans Eggers
H.C. Eggers and P. Lipa
Star Integrals and Unbiased Estimators
12 pages, LaTex, 2 figures in tar-compressed uuencoded .eps format, Regensburg preprint TPR--93--25
null
null
null
hep-ph
null
We review in brief the development and implementation of the Star integral, a tool yielding measurements of correlations much superior to conventional methods. A version for use in pion interferometry is explained. We also show how effects of non-poissonian overall multiplicity distributions may be eliminated if desired and quote results eliminating statistical biases arising in correlation measurements within small samples.
[ { "created": "Sun, 12 Sep 1993 15:49:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Eggers", "H. C.", "" ], [ "Lipa", "P.", "" ] ]
We review in brief the development and implementation of the Star integral, a tool yielding measurements of correlations much superior to conventional methods. A version for use in pion interferometry is explained. We also show how effects of non-poissonian overall multiplicity distributions may be eliminated if desired and quote results eliminating statistical biases arising in correlation measurements within small samples.
1902.08633
Rick Gupta
R.S. Gupta, J.Y. Reiness and M. Spannowsky
All-in-one Relaxion, a unified solution to five BSM puzzles
8 pages, 2 figures
Phys. Rev. D 100, 055003 (2019)
10.1103/PhysRevD.100.055003
IPPP/19/18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a unified relaxion solution to the five major outstanding issues in particle physics: the hierarchy problem, dark matter, matter-antimatter asymmetry, neutrino masses and the strong CP problem. The only additional field content in our construction with respect to standard relaxion models is an up-type vector-like fermion pair and three right-handed neutrinos charged under the relaxion shift symmetry. The observed dark matter abundance is generated automatically by oscillations of the relaxion field that begin once it is misaligned from its original stopping point after reheating. The matter-antimatter asymmetry arises from spontaneous baryogenesis induced by the CPT violation due to the rolling of the relaxion after reheating. The CPT violation is communicated to the baryons and leptons via an operator, $\partial_\mu \phi J^\mu$, where $J^\mu$ consists of right-handed neutrino currents arising naturally from a simple neutrino mass model. Finally, the strong CP problem is solved via the Nelson-Barr mechanism, i.e. by imposing CP as a symmetry of the Lagrangian that is broken only spontaneously by the relaxion. The CP breaking is such that although an ${\cal O}(1)$ strong CKM phase is generated, the induced strong CP phase is much smaller, i.e., within experimental bounds.
[ { "created": "Fri, 22 Feb 2019 19:00:33 GMT", "version": "v1" } ]
2019-09-11
[ [ "Gupta", "R. S.", "" ], [ "Reiness", "J. Y.", "" ], [ "Spannowsky", "M.", "" ] ]
We present a unified relaxion solution to the five major outstanding issues in particle physics: the hierarchy problem, dark matter, matter-antimatter asymmetry, neutrino masses and the strong CP problem. The only additional field content in our construction with respect to standard relaxion models is an up-type vector-like fermion pair and three right-handed neutrinos charged under the relaxion shift symmetry. The observed dark matter abundance is generated automatically by oscillations of the relaxion field that begin once it is misaligned from its original stopping point after reheating. The matter-antimatter asymmetry arises from spontaneous baryogenesis induced by the CPT violation due to the rolling of the relaxion after reheating. The CPT violation is communicated to the baryons and leptons via an operator, $\partial_\mu \phi J^\mu$, where $J^\mu$ consists of right-handed neutrino currents arising naturally from a simple neutrino mass model. Finally, the strong CP problem is solved via the Nelson-Barr mechanism, i.e. by imposing CP as a symmetry of the Lagrangian that is broken only spontaneously by the relaxion. The CP breaking is such that although an ${\cal O}(1)$ strong CKM phase is generated, the induced strong CP phase is much smaller, i.e., within experimental bounds.
hep-ph/0003157
Firooz Arash
Firooz Arash and Ali Naghi Khorramian
From Constituent Quark to Hadron Structure in the Next-to-Leading Order: Nucleon and Pion
The manuscript is a Tex file (9 pages) with nine PS figures
null
null
null
hep-ph
null
We calculate the partonic structure of constituent quark in the Next-to-Leading Order for the first time. The structure of any hadron can be obtained thereafter using a convolution method. Such a procedure is used to generate the structure function of proton and pion in NLO. It is shown that while the constituent quark structure is generated purely perturbatively and accounts to most part of the hadronic structure, there is a few percent contributions coming from the nonperturbative sector in the hadronic structure. This contribution plays the key role in explaining the SU(2) symmetry breaking of the nucleon sea and the observed violation of Gottfried sum rule. These effects are calculated. Excellent agreement with data in a wide range of $x=[10^{-6}, 1]$ and $Q^{2}=[0.5, 5000]$ $GeV^{2}$ is reached for proton structure function. We have also calculated Pion structure and compared it with the existing data. Again nice agreement is achieved.
[ { "created": "Thu, 16 Mar 2000 10:13:49 GMT", "version": "v1" }, { "created": "Tue, 18 Apr 2000 21:36:57 GMT", "version": "v2" } ]
2007-05-23
[ [ "Arash", "Firooz", "" ], [ "Khorramian", "Ali Naghi", "" ] ]
We calculate the partonic structure of constituent quark in the Next-to-Leading Order for the first time. The structure of any hadron can be obtained thereafter using a convolution method. Such a procedure is used to generate the structure function of proton and pion in NLO. It is shown that while the constituent quark structure is generated purely perturbatively and accounts to most part of the hadronic structure, there is a few percent contributions coming from the nonperturbative sector in the hadronic structure. This contribution plays the key role in explaining the SU(2) symmetry breaking of the nucleon sea and the observed violation of Gottfried sum rule. These effects are calculated. Excellent agreement with data in a wide range of $x=[10^{-6}, 1]$ and $Q^{2}=[0.5, 5000]$ $GeV^{2}$ is reached for proton structure function. We have also calculated Pion structure and compared it with the existing data. Again nice agreement is achieved.
hep-ph/0110296
Bernd Andreas Kniehl
Bernd A. Kniehl (Hamburg U.), Alberto Sirlin (New York U.)
On the Field Renormalization Constant for Unstable Particles
7 pages (Latex)
Phys.Lett. B530 (2002) 129-132
10.1016/S0370-2693(02)01331-X
DESY 01-146
hep-ph
null
A recently proposed normalization condition for the imaginary part of the self-energy of an unstable particle is shown to lead to a closed expression for the field renormalization constant Z. In turn, the exact expression for Z is necessary, in some important cases, in order to avoid power-like infrared divergences in high orders of perturbation theory. In the same examples, the width plays the r\^ole of an infrared cutoff and, consequently, Z is not an analytic function of the coupling constant.
[ { "created": "Tue, 23 Oct 2001 16:04:50 GMT", "version": "v1" } ]
2009-11-07
[ [ "Kniehl", "Bernd A.", "", "Hamburg U." ], [ "Sirlin", "Alberto", "", "New York U." ] ]
A recently proposed normalization condition for the imaginary part of the self-energy of an unstable particle is shown to lead to a closed expression for the field renormalization constant Z. In turn, the exact expression for Z is necessary, in some important cases, in order to avoid power-like infrared divergences in high orders of perturbation theory. In the same examples, the width plays the r\^ole of an infrared cutoff and, consequently, Z is not an analytic function of the coupling constant.
2011.03193
Martin Hentschinski
Martin Hentschinski, Krzysztof Kutak, Andreas van Hameren
Forward Higgs production within high energy factorization in the heavy quark limit at next-to-leading order accuracy
22 pages, 13 figures; version published in EPJC. Modified Abstract, added 2 figures, and added references
Eur. Phys. J. C 81, 112 (2021)
10.1140/epjc/s10052-021-08902-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use Lipatov's high energy effective action to determine the next-to-leading order corrections to Higgs production in the forward region within high energy factorization making use of the infinite top mass limit. Our result is based on an explicit calculation of real corrections combined with virtual corrections determined earlier by Nefedov. As a new element we provide a proper definition of the desired next-to-leading order coefficient within the high energy effective action framework, extending a previously proposed prescription. We further propose a subtraction mechanism to achieve for this coefficient a stable cancellation of real and virtual infra-red singularities in the presence of external off-shell legs. Apart from its relevance for direct phenomenological studies, such as high energy resummation of Higgs + jet configurations, our result will be further of use for the study of transverse momentum dependent factorization in the high energy limit.
[ { "created": "Fri, 6 Nov 2020 05:08:49 GMT", "version": "v1" }, { "created": "Wed, 10 Feb 2021 19:15:35 GMT", "version": "v2" } ]
2021-02-12
[ [ "Hentschinski", "Martin", "" ], [ "Kutak", "Krzysztof", "" ], [ "van Hameren", "Andreas", "" ] ]
We use Lipatov's high energy effective action to determine the next-to-leading order corrections to Higgs production in the forward region within high energy factorization making use of the infinite top mass limit. Our result is based on an explicit calculation of real corrections combined with virtual corrections determined earlier by Nefedov. As a new element we provide a proper definition of the desired next-to-leading order coefficient within the high energy effective action framework, extending a previously proposed prescription. We further propose a subtraction mechanism to achieve for this coefficient a stable cancellation of real and virtual infra-red singularities in the presence of external off-shell legs. Apart from its relevance for direct phenomenological studies, such as high energy resummation of Higgs + jet configurations, our result will be further of use for the study of transverse momentum dependent factorization in the high energy limit.
1105.1036
Koichi Kanazawa
Koichi Kanazawa and Yuji Koike
Hard- and soft-fermion-pole contributions to single transverse-spin asymmetry for Drell-Yan process
11 pages, 5 figures
Phys.Lett.B701:576-580,2011
10.1016/j.physletb.2011.06.021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the single transverse-spin asymmetry for the Drell-Yan lepton pair production based on the twist-3 mechanism in the collinear factorization. We calculate all the hard-pole (HP) and the soft-fermion-pole (SFP) contributions to the single-spin-dependent cross section originating from the quark-gluon correlation functions in the transversely polarized nucleon in the leading order with respect to the QCD coupling constant. Combined with the soft-gluon-pole (SGP) contribution, this completes the corresponding twist-3 cross section. In the real photon limit, where all the HP contributions are transformed into the SFP contribution, we find that the SFP partonic hard cross section for the two independent quark-gluon correlation functions coincides in each scattering channel, as in the case of the inclusive light-hadron production. Our result enables one to extract the quark-gluon correlation functions from the forthcoming experiments at several facilities such as RHIC and J-PARC.
[ { "created": "Thu, 5 May 2011 11:12:06 GMT", "version": "v1" } ]
2011-07-20
[ [ "Kanazawa", "Koichi", "" ], [ "Koike", "Yuji", "" ] ]
We study the single transverse-spin asymmetry for the Drell-Yan lepton pair production based on the twist-3 mechanism in the collinear factorization. We calculate all the hard-pole (HP) and the soft-fermion-pole (SFP) contributions to the single-spin-dependent cross section originating from the quark-gluon correlation functions in the transversely polarized nucleon in the leading order with respect to the QCD coupling constant. Combined with the soft-gluon-pole (SGP) contribution, this completes the corresponding twist-3 cross section. In the real photon limit, where all the HP contributions are transformed into the SFP contribution, we find that the SFP partonic hard cross section for the two independent quark-gluon correlation functions coincides in each scattering channel, as in the case of the inclusive light-hadron production. Our result enables one to extract the quark-gluon correlation functions from the forthcoming experiments at several facilities such as RHIC and J-PARC.
1802.06784
Kevin Kelly
Kevin J. Kelly, Stephen J. Parke
Matter Density Profile Shape Effects at DUNE
19 pages, 10 figures
Phys. Rev. D 98, 015025 (2018)
10.1103/PhysRevD.98.015025
NUHEP-TH/18-02, FERMILAB-PUB-18-019-T
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum mechanical interactions between neutrinos and matter along the path of propagation, the Wolfenstein matter effect, are of particular importance for the upcoming long-baseline neutrino oscillation experiments, specifically the Deep Underground Neutrino Experiment (DUNE). Here, we explore specifically what about the matter density profile can be measured by DUNE, considering both the shape and normalization of the profile between the neutrinos' origin and detection. Additionally, we explore the capability of a perturbative method for calculating neutrino oscillation probabilities and whether this method is suitable for DUNE. We also briefly quantitatively explore the ability of DUNE to measure the Earth's matter density, and the impact of performing this measurement on measuring standard neutrino oscillation parameters.
[ { "created": "Mon, 19 Feb 2018 19:00:00 GMT", "version": "v1" } ]
2018-07-25
[ [ "Kelly", "Kevin J.", "" ], [ "Parke", "Stephen J.", "" ] ]
Quantum mechanical interactions between neutrinos and matter along the path of propagation, the Wolfenstein matter effect, are of particular importance for the upcoming long-baseline neutrino oscillation experiments, specifically the Deep Underground Neutrino Experiment (DUNE). Here, we explore specifically what about the matter density profile can be measured by DUNE, considering both the shape and normalization of the profile between the neutrinos' origin and detection. Additionally, we explore the capability of a perturbative method for calculating neutrino oscillation probabilities and whether this method is suitable for DUNE. We also briefly quantitatively explore the ability of DUNE to measure the Earth's matter density, and the impact of performing this measurement on measuring standard neutrino oscillation parameters.
2110.05027
Chung-Lin Shan
Chung-Lin Shan
Annual modulations of the angular recoil-flux/energy distributions of WIMP-scattered target nuclei observed at an underground laboratory
9 pages, 7 figures, to be compacted for the proceedings of the 17th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2021), August 26 - September 3, Valencia, Spain
null
10.1088/1742-6596/2156/1/012173
null
hep-ph astro-ph.HE
http://creativecommons.org/licenses/by-sa/4.0/
In this article, we compare the target and WIMP-mass dependent "annual modulations" of the angular distributions of the recoil flux and energy of WIMP-scattered target nuclei observed at different underground laboratories. For readers' reference, simulation plots with different WIMP masses and frequently used target nuclei for all functionable underground laboratories can be found and downloaded on our online (interactive) demonstration webpage (http://www.tir.tw/phys/hep/dm/amidas-2d/).
[ { "created": "Mon, 11 Oct 2021 06:37:13 GMT", "version": "v1" } ]
2022-03-02
[ [ "Shan", "Chung-Lin", "" ] ]
In this article, we compare the target and WIMP-mass dependent "annual modulations" of the angular distributions of the recoil flux and energy of WIMP-scattered target nuclei observed at different underground laboratories. For readers' reference, simulation plots with different WIMP masses and frequently used target nuclei for all functionable underground laboratories can be found and downloaded on our online (interactive) demonstration webpage (http://www.tir.tw/phys/hep/dm/amidas-2d/).
hep-ph/0509061
Tomohiro Matsuda
Tomohiro Matsuda
Primordial black holes from monopoles connected by strings
19 pages, 2 figures, accepted for publication in Astroparticle Physics
Astropart.Phys.30:333-337,2009
10.1016/j.astropartphys.2008.10.006
null
hep-ph astro-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Primordial black holes (PBHs) are known to be produced from collapsing cosmic defects such as domain walls and strings. In this paper we show how PBHs are produced in monopole-string networks.
[ { "created": "Wed, 7 Sep 2005 11:14:59 GMT", "version": "v1" }, { "created": "Wed, 28 Sep 2005 10:56:46 GMT", "version": "v2" }, { "created": "Wed, 14 Jun 2006 10:55:35 GMT", "version": "v3" }, { "created": "Sun, 9 Jul 2006 07:58:46 GMT", "version": "v4" }, { "created": "Wed, 13 Jun 2007 05:56:49 GMT", "version": "v5" }, { "created": "Thu, 30 Oct 2008 07:07:01 GMT", "version": "v6" } ]
2009-01-14
[ [ "Matsuda", "Tomohiro", "" ] ]
Primordial black holes (PBHs) are known to be produced from collapsing cosmic defects such as domain walls and strings. In this paper we show how PBHs are produced in monopole-string networks.
hep-ph/9807358
Xiangdong Ji
Xiangdong Ji
Off-Forward Parton Distributions
null
J.Phys.G24:1181-1205,1998
10.1088/0954-3899/24/7/002
UMD PP#98-092
hep-ph
null
Recently, there have been some interesting developments involving off-forward parton distributions of the nucleon, deeply virtual Compton scattering, and hard diffractive vector-meson production. These developments are triggered by the realization that the off-forward distributions contain information about the internal spin structure of the nucleon and that diffractive electroproduction of vector mesons depends on these unconventional distributions. This paper gives a brief overview of the recent developments.
[ { "created": "Mon, 13 Jul 1998 14:34:43 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ji", "Xiangdong", "" ] ]
Recently, there have been some interesting developments involving off-forward parton distributions of the nucleon, deeply virtual Compton scattering, and hard diffractive vector-meson production. These developments are triggered by the realization that the off-forward distributions contain information about the internal spin structure of the nucleon and that diffractive electroproduction of vector mesons depends on these unconventional distributions. This paper gives a brief overview of the recent developments.
1205.1355
Mainak Chakraborty
Biswajit Adhikary, Mainak Chakraborty, Ambar Ghosal
Scaling ansatz, four zero Yukawa textures and large $\theta_{13}$
25 pages, 8 figures, Accepted for publication in Phys. Rev. D
Phys.Rev. D86 (2012) 013015
10.1103/PhysRevD.86.013015
SINP-APC-2012/02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate 'Scaling ansatz' in the neutrino sector within the framework of type I seesaw mechanism with diagonal charged lepton and right handed Majorana neutrino mass matrices ($M_R$). We also assume four zero texture of Dirac neutrino mass matrices ($m_D$) which severely constrain the phenomenological outcomes of such scheme. Scaling ansatz and the present neutrino data allow only Six such matrices out of 126 four zero Yukawa matrices. In this scheme, in order to generate large $\theta_{13}$ we break scaling ansatz in $m_D$ through a perturbation parameter and we also show our breaking scheme is radiatively stable. We further investigate CP violation and baryogenesis via leptogenesis in those surviving textures.
[ { "created": "Mon, 7 May 2012 11:58:07 GMT", "version": "v1" }, { "created": "Mon, 9 Jul 2012 08:23:01 GMT", "version": "v2" } ]
2013-10-18
[ [ "Adhikary", "Biswajit", "" ], [ "Chakraborty", "Mainak", "" ], [ "Ghosal", "Ambar", "" ] ]
We investigate 'Scaling ansatz' in the neutrino sector within the framework of type I seesaw mechanism with diagonal charged lepton and right handed Majorana neutrino mass matrices ($M_R$). We also assume four zero texture of Dirac neutrino mass matrices ($m_D$) which severely constrain the phenomenological outcomes of such scheme. Scaling ansatz and the present neutrino data allow only Six such matrices out of 126 four zero Yukawa matrices. In this scheme, in order to generate large $\theta_{13}$ we break scaling ansatz in $m_D$ through a perturbation parameter and we also show our breaking scheme is radiatively stable. We further investigate CP violation and baryogenesis via leptogenesis in those surviving textures.
0807.4412
Eric Laenen
Eric Laenen, Lorenzo Magnea, Gerben Stavenga
On next-to-eikonal corrections to threshold resummation for the Drell-Yan and DIS cross sections
17 pages
Phys.Lett.B669:173-179,2008
10.1016/j.physletb.2008.09.037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study corrections suppressed by one power of the soft gluon energy to the resummation of threshold logarithms for the Drell-Yan cross section and for Deep Inelastic structure functions. While no general factorization theorem is known for these next-to-eikonal (NE) corrections, it is conjectured that at least a subset will exponentiate, along with the logarithms arising at leading power. Here we develop some general tools to study NE logarithms, and we construct an ansatz for threshold resummation that includes various sources of NE corrections, implementing in this context the improved collinear evolution recently proposed by Dokshitzer, Marchesini and Salam (DMS). We compare our ansatz to existing exact results at two and three loops, finding evidence for the exponentiation of leading NE logarithms and confirming the predictivity of DMS evolution.
[ { "created": "Mon, 28 Jul 2008 11:35:41 GMT", "version": "v1" } ]
2008-11-26
[ [ "Laenen", "Eric", "" ], [ "Magnea", "Lorenzo", "" ], [ "Stavenga", "Gerben", "" ] ]
We study corrections suppressed by one power of the soft gluon energy to the resummation of threshold logarithms for the Drell-Yan cross section and for Deep Inelastic structure functions. While no general factorization theorem is known for these next-to-eikonal (NE) corrections, it is conjectured that at least a subset will exponentiate, along with the logarithms arising at leading power. Here we develop some general tools to study NE logarithms, and we construct an ansatz for threshold resummation that includes various sources of NE corrections, implementing in this context the improved collinear evolution recently proposed by Dokshitzer, Marchesini and Salam (DMS). We compare our ansatz to existing exact results at two and three loops, finding evidence for the exponentiation of leading NE logarithms and confirming the predictivity of DMS evolution.
1612.00041
Heikki M\"antysaari
H. M\"antysaari and B. Schenke
Constraints for proton structure fluctuations from exclusive scattering
4 pages, 4 figures. Talk given by H.M. at the 8th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2016), 22-27 September 2016, Wuhan, China
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We constrain the average density profile of the proton and the amount of event-by-event fluctuations by simultaneously calculating the coherent and incoherent exclusive diffractive vector meson production cross section in deep inelastic scattering. Working within the Color Glass Condensate picture, we find that the gluonic density of the proton must have large geometric fluctuations in order to describe the experimentally measured large incoherent cross section.
[ { "created": "Wed, 30 Nov 2016 21:34:00 GMT", "version": "v1" } ]
2016-12-02
[ [ "Mäntysaari", "H.", "" ], [ "Schenke", "B.", "" ] ]
We constrain the average density profile of the proton and the amount of event-by-event fluctuations by simultaneously calculating the coherent and incoherent exclusive diffractive vector meson production cross section in deep inelastic scattering. Working within the Color Glass Condensate picture, we find that the gluonic density of the proton must have large geometric fluctuations in order to describe the experimentally measured large incoherent cross section.
0810.1358
Yoshiharu Kawamura
Yoshiharu Kawamura
Topological Grand Unification
9 pages, version to appear in PTP
Prog.Theor.Phys.121:289-297,2009
10.1143/PTP.121.289
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new grand unification scenario for ensuring proton stability and triplet-doublet Higgs mass splitting with the help of topological symmetry and dynamics.
[ { "created": "Wed, 8 Oct 2008 05:24:48 GMT", "version": "v1" }, { "created": "Wed, 24 Dec 2008 05:48:19 GMT", "version": "v2" }, { "created": "Tue, 10 Feb 2009 07:23:30 GMT", "version": "v3" } ]
2014-11-18
[ [ "Kawamura", "Yoshiharu", "" ] ]
We propose a new grand unification scenario for ensuring proton stability and triplet-doublet Higgs mass splitting with the help of topological symmetry and dynamics.
hep-ph/0609060
Shigehiro Yasui
Kazuaki Ohnishi, Makoto Oka and Shigehiro Yasui
Possible Ferromagnetism in the Large N(c) and N(f) limit of quark matter
4 pages
Phys.Rev.D76:097501,2007
10.1103/PhysRevD.76.097501
null
hep-ph
null
We consider high density quark matter in the large $\N_c$ and $\N_f$ limit with $\N_f/\N_c$ fixed. In this limit, the color superconductivity disappears. We discuss that the chiral density wave state is also absent in the limit, if we assume the existence of the non-perturbative magnetic screening effect as indicated by recent lattice study. We argue that ferromagnetism can become a candidate for the ground state if quarks are massive.
[ { "created": "Wed, 6 Sep 2006 11:21:53 GMT", "version": "v1" }, { "created": "Tue, 14 Nov 2006 11:35:34 GMT", "version": "v2" }, { "created": "Fri, 4 May 2007 09:17:47 GMT", "version": "v3" }, { "created": "Sat, 4 Aug 2007 05:37:41 GMT", "version": "v4" } ]
2008-11-26
[ [ "Ohnishi", "Kazuaki", "" ], [ "Oka", "Makoto", "" ], [ "Yasui", "Shigehiro", "" ] ]
We consider high density quark matter in the large $\N_c$ and $\N_f$ limit with $\N_f/\N_c$ fixed. In this limit, the color superconductivity disappears. We discuss that the chiral density wave state is also absent in the limit, if we assume the existence of the non-perturbative magnetic screening effect as indicated by recent lattice study. We argue that ferromagnetism can become a candidate for the ground state if quarks are massive.
1104.3053
Rajarshi Ray
Supriya Das, Sanjay K. Ghosh, Sibaji Raha and Rajarshi Ray
Entropy scaling and thermalization in hadron-hadron collisions at LHC
4 pages, 5 figures
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent LHC data have once more brought the issue of the formation of thermalized state of matter in hadron-hadron collisions into the forefront. In this letter, we have shown that the scaling of the information entropy of the chaotically produced particles is valid up to recently available data from p+p collisions at $\sqrt{s}$ = 2.36 TeV obtained by ALICE experiment. We predict that at the highest energies projected for LHC, almost all the particles will be produced chaotically, indicating that a collective behavior should be observed in hadronic collisions, as indicated by one of present authors quite some time ago.
[ { "created": "Fri, 15 Apr 2011 13:44:42 GMT", "version": "v1" } ]
2011-04-18
[ [ "Das", "Supriya", "" ], [ "Ghosh", "Sanjay K.", "" ], [ "Raha", "Sibaji", "" ], [ "Ray", "Rajarshi", "" ] ]
The recent LHC data have once more brought the issue of the formation of thermalized state of matter in hadron-hadron collisions into the forefront. In this letter, we have shown that the scaling of the information entropy of the chaotically produced particles is valid up to recently available data from p+p collisions at $\sqrt{s}$ = 2.36 TeV obtained by ALICE experiment. We predict that at the highest energies projected for LHC, almost all the particles will be produced chaotically, indicating that a collective behavior should be observed in hadronic collisions, as indicated by one of present authors quite some time ago.
hep-ph/0512342
James Wells
James D. Wells
TASI Lecture Notes: Introduction to Precision Electroweak Analysis
26 pages, Presented at Theoretical Advanced Study Institute (TASI 2004), Boulder, Colorado, 6 Jun - 2 Jul, 2004
null
null
MCTP-04-74
hep-ph
null
I give a basic introduction to precision electroweak analysis, beginning with calculation at tree-level which most simply illustrates the procedure. I then work out the formalism for one-loop corrections to the vector boson self energies (oblique corrections). This is a tractable subset of the complete electroweak program. Not only does this exercise provide an analytically accessible demonstration of the theory involved in electroweak precision analyses, it also teaches students a useful technique to analyze a large class of theories beyond the Standard Model.
[ { "created": "Tue, 27 Dec 2005 17:18:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Wells", "James D.", "" ] ]
I give a basic introduction to precision electroweak analysis, beginning with calculation at tree-level which most simply illustrates the procedure. I then work out the formalism for one-loop corrections to the vector boson self energies (oblique corrections). This is a tractable subset of the complete electroweak program. Not only does this exercise provide an analytically accessible demonstration of the theory involved in electroweak precision analyses, it also teaches students a useful technique to analyze a large class of theories beyond the Standard Model.
hep-ph/0510020
Marcos Andre Betemps
M. A. Betemps, M. B. Gay Ducati (IF-Ufrgs)
Searching the Color Glass Condensate Through $p_T$ Suppression
Proceedings of the XIth Internation Conference on Elastic and Diffractive Scattering
null
null
null
hep-ph
null
In this work the rapidity and transverse momentum dependence of the nuclear modification ratio is evaluated for the dilepton production at RHIC and LHC, using the Color Glass Condensate (CGC) framework. The ratio is compared for two distinct dilepton mass values, concerning the transverse momentum distribution, and a suppression of the Cronin peak is verified even for large mass. The nuclear modification ratio suppression in the dilepton rapidity spectra, as obtained for hadrons at RHIC, is verified for LHC energies at large transverse momentum, although not present at RHIC energies. These results consolidate the dilepton as a most suitable observable for QCD high density approaches.
[ { "created": "Mon, 3 Oct 2005 13:30:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Betemps", "M. A.", "", "IF-Ufrgs" ], [ "Ducati", "M. B. Gay", "", "IF-Ufrgs" ] ]
In this work the rapidity and transverse momentum dependence of the nuclear modification ratio is evaluated for the dilepton production at RHIC and LHC, using the Color Glass Condensate (CGC) framework. The ratio is compared for two distinct dilepton mass values, concerning the transverse momentum distribution, and a suppression of the Cronin peak is verified even for large mass. The nuclear modification ratio suppression in the dilepton rapidity spectra, as obtained for hadrons at RHIC, is verified for LHC energies at large transverse momentum, although not present at RHIC energies. These results consolidate the dilepton as a most suitable observable for QCD high density approaches.
1106.5897
Aurore Courtoy
A. Courtoy, Alessandro Bacchetta, Marco Radici
The Dihadron fragmentation functions way to Transversity
To appear in the proceedings of XIX International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2011), April 11-15, 2011, Newport News, VA USA ; AIP style files included
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Observations of the transversity parton distribution based on an analysis of pion-pair production in deep inelastic scattering off transversely polarized targets are presented. This extraction relies on the knowledge of dihadron fragmentation functions, which are obtained from electron-positron annihilation measurements. This is the first attempt to determine the transversity distribution in the framework of collinear factorization.
[ { "created": "Wed, 29 Jun 2011 10:27:24 GMT", "version": "v1" } ]
2011-06-30
[ [ "Courtoy", "A.", "" ], [ "Bacchetta", "Alessandro", "" ], [ "Radici", "Marco", "" ] ]
Observations of the transversity parton distribution based on an analysis of pion-pair production in deep inelastic scattering off transversely polarized targets are presented. This extraction relies on the knowledge of dihadron fragmentation functions, which are obtained from electron-positron annihilation measurements. This is the first attempt to determine the transversity distribution in the framework of collinear factorization.
hep-ph/0202202
Reinhard Alkofer
C. S. Fischer and R. Alkofer
Infrared Exponents and Running Coupling of SU(N) Yang-Mills Theories
11 pages, 4 figures
Phys.Lett.B536:177-184,2002
10.1016/S0370-2693(02)01809-9
UNITUE-THEP-07/2002
hep-ph hep-lat hep-th nucl-th
null
We present approximate solutions for the gluon and ghost propagators as well as the running coupling in Landau gauge Yang-Mills theories. We solve the corresponding Dyson-Schwinger equations in flat Euclidean space-time without any angular approximation. This supplements recently obtained results employing a four-torus, i.e. a compact space-time manifold, as infrared regulator. We confirm previous findings deduced from an extrapolation with tori of different volumes: the gluon propagator is weakly vanishing in the infrared and the ghost propagator is highly singular. For non-vanishing momenta our propagators are in remarkable agreement with recent lattice calculations.
[ { "created": "Thu, 21 Feb 2002 16:24:32 GMT", "version": "v1" } ]
2008-11-26
[ [ "Fischer", "C. S.", "" ], [ "Alkofer", "R.", "" ] ]
We present approximate solutions for the gluon and ghost propagators as well as the running coupling in Landau gauge Yang-Mills theories. We solve the corresponding Dyson-Schwinger equations in flat Euclidean space-time without any angular approximation. This supplements recently obtained results employing a four-torus, i.e. a compact space-time manifold, as infrared regulator. We confirm previous findings deduced from an extrapolation with tori of different volumes: the gluon propagator is weakly vanishing in the infrared and the ghost propagator is highly singular. For non-vanishing momenta our propagators are in remarkable agreement with recent lattice calculations.
2406.13306
Jose Rodriguez-Quintero
Y.-Z. Xu, K. Raya, J. Segovia and J. Rodr\'iguez-Quintero
Charge distributions of pseudo-scalar and vector mesons from Dyson-Schwinger equations
14 pages, 9 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We combine the Dyson-Schwinger/Bethe-Salpeter equations framework with modern numerical reconstruction methods to derive the three-dimensional and transverse two-dimensional charge distribution of an array of ground-state pseudoscalar and vector mesons from their elastic electromagnetic form factor in the low-momentum region. The charge radii obtained by averaging over the reconstructed charge distributions have been checked to be consistent with those calculated from the slope of the elastic electromagnetic form factor at zero transferred momentum. The capability of the reconstruction procedure for capturing a reliable low-distance charge distribution is discussed and argued to work down to distances of around 0.1 fm, such that it might be potentially applied to extract, {\it e.g.}, mass densities from gravitational form factors.
[ { "created": "Wed, 19 Jun 2024 07:53:43 GMT", "version": "v1" } ]
2024-06-21
[ [ "Xu", "Y. -Z.", "" ], [ "Raya", "K.", "" ], [ "Segovia", "J.", "" ], [ "Rodríguez-Quintero", "J.", "" ] ]
We combine the Dyson-Schwinger/Bethe-Salpeter equations framework with modern numerical reconstruction methods to derive the three-dimensional and transverse two-dimensional charge distribution of an array of ground-state pseudoscalar and vector mesons from their elastic electromagnetic form factor in the low-momentum region. The charge radii obtained by averaging over the reconstructed charge distributions have been checked to be consistent with those calculated from the slope of the elastic electromagnetic form factor at zero transferred momentum. The capability of the reconstruction procedure for capturing a reliable low-distance charge distribution is discussed and argued to work down to distances of around 0.1 fm, such that it might be potentially applied to extract, {\it e.g.}, mass densities from gravitational form factors.
hep-ph/0512042
Sebastian Mendizabal
M. Loewe, S. Mendizabal, J. C. Rojas
Background field method at finite temperature and density
6 pages, no figures
Phys.Lett. B635 (2006) 213-217
10.1016/j.physletb.2006.03.001
null
hep-ph hep-th
null
In this letter we make use of the Background Field Method (BFM) to compute the effective potential of an SU(2) gauge field theory, in the presence of chemical potential and temperature. The main idea is to consider the chemical potential as the background field. The gauge fixing condition required by the BFM turns out to be exactly the one we found in a previous article in a different context.
[ { "created": "Fri, 2 Dec 2005 20:19:27 GMT", "version": "v1" } ]
2009-11-11
[ [ "Loewe", "M.", "" ], [ "Mendizabal", "S.", "" ], [ "Rojas", "J. C.", "" ] ]
In this letter we make use of the Background Field Method (BFM) to compute the effective potential of an SU(2) gauge field theory, in the presence of chemical potential and temperature. The main idea is to consider the chemical potential as the background field. The gauge fixing condition required by the BFM turns out to be exactly the one we found in a previous article in a different context.
1001.2977
Ted Rogers
Ted C. Rogers, Piet J. Mulders
No Generalized TMD-Factorization in the Hadro-Production of High Transverse Momentum Hadrons
19 pages, 11 figures, typos fixed and minor explanations added, version to appear in Physical Review D
Phys.Rev.D81:094006,2010
10.1103/PhysRevD.81.094006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has by now been established that standard QCD factorization using transverse momentum dependent parton distribution functions fails in hadro-production of nearly back-to-back hadrons with high transverse momentum. The essential problem is that gauge invariant transverse momentum dependent parton distribution functions cannot be defined with process-independent Wilson line operators, thus implying a breakdown of universality. This has led naturally to proposals that a correct approach is to instead use a type of "generalized" transverse momentum dependent factorization in which the basic factorized structure is assumed to remain valid, but with transverse momentum dependent parton distribution functions that contain non-standard, process dependent Wilson line structures. In other words, to recover a factorization formula, it has become common to assume that it is sufficient to simply modify the Wilson lines in the parton correlation functions for each separate hadron. In this paper, we will illustrate by direct counter-example that this is not possible in a non-Abelian gauge theory. Since a proof of generalized transverse momentum dependent factorization should apply generally to any hard hadro-production process, a single counter-example suffices to show that a general proof does not exist. Therefore, to make the counter-argument clear and explicit, we illustrate with a specific calculation for a double spin asymmetry in a spectator model with a non-Abelian gauge field. The observed breakdown of generalized transverse momentum dependent factorization challenges the notion that the role of parton transverse momentum in such processes can be described using separate correlation functions for each external hadron.
[ { "created": "Mon, 18 Jan 2010 09:14:29 GMT", "version": "v1" }, { "created": "Mon, 10 May 2010 08:36:50 GMT", "version": "v2" } ]
2010-05-19
[ [ "Rogers", "Ted C.", "" ], [ "Mulders", "Piet J.", "" ] ]
It has by now been established that standard QCD factorization using transverse momentum dependent parton distribution functions fails in hadro-production of nearly back-to-back hadrons with high transverse momentum. The essential problem is that gauge invariant transverse momentum dependent parton distribution functions cannot be defined with process-independent Wilson line operators, thus implying a breakdown of universality. This has led naturally to proposals that a correct approach is to instead use a type of "generalized" transverse momentum dependent factorization in which the basic factorized structure is assumed to remain valid, but with transverse momentum dependent parton distribution functions that contain non-standard, process dependent Wilson line structures. In other words, to recover a factorization formula, it has become common to assume that it is sufficient to simply modify the Wilson lines in the parton correlation functions for each separate hadron. In this paper, we will illustrate by direct counter-example that this is not possible in a non-Abelian gauge theory. Since a proof of generalized transverse momentum dependent factorization should apply generally to any hard hadro-production process, a single counter-example suffices to show that a general proof does not exist. Therefore, to make the counter-argument clear and explicit, we illustrate with a specific calculation for a double spin asymmetry in a spectator model with a non-Abelian gauge field. The observed breakdown of generalized transverse momentum dependent factorization challenges the notion that the role of parton transverse momentum in such processes can be described using separate correlation functions for each external hadron.
1612.01643
Shohei Okawa
Tomohiro Abe, Junichiro Kawamura, Shohei Okawa, Yuji Omura
Dark matter physics, flavor physics and LHC constraints in the dark matter model with a bottom partner
18 pages, 8 figures, 2 tables; some typos corrected, version published in JHEP
JHEP 1703 (2017) 058
10.1007/JHEP03(2017)058
WU-HEP-16-22
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the scenario that a dark matter (DM) is a weakly interacting massive particle, there are many possibilities of the interactions with the Standard Model (SM) particles to achieve the relic density of DM. In this paper, we consider one simple DM model where the DM candidate is a complex scalar and interacts with the SM particles via exchange of the Higgs particle and an extra quark, named bottom partner. The extra quark carries the same quantum number as the right-handed down-type quarks and has Yukawa couplings with the DM candidate and the right-handed down-type quarks. The Yukawa interactions are not only relevant to the thermal relic density of the DM, but also contribute to the flavor physics, such as the $\Delta F=2$ processes. In addition, the flavor alignment of the Yukawa couplings is related to the decay modes of the extra quark. Then, we can find the explicit correlations among the physical observables in DM physics, flavor physics and the signals at the LHC. Based on the numerical analyses of the thermal relic density, the direct detection of the DM and the current LHC bounds using the latest results, we survey our predictions for the $\Delta F=2$ processes. We investigate the perturbative bound on the Yukawa coupling, as well. Study of a fermionic DM model with extra scalar quarks is also given for comparison.
[ { "created": "Tue, 6 Dec 2016 02:56:00 GMT", "version": "v1" }, { "created": "Tue, 28 Mar 2017 05:57:57 GMT", "version": "v2" } ]
2017-03-29
[ [ "Abe", "Tomohiro", "" ], [ "Kawamura", "Junichiro", "" ], [ "Okawa", "Shohei", "" ], [ "Omura", "Yuji", "" ] ]
In the scenario that a dark matter (DM) is a weakly interacting massive particle, there are many possibilities of the interactions with the Standard Model (SM) particles to achieve the relic density of DM. In this paper, we consider one simple DM model where the DM candidate is a complex scalar and interacts with the SM particles via exchange of the Higgs particle and an extra quark, named bottom partner. The extra quark carries the same quantum number as the right-handed down-type quarks and has Yukawa couplings with the DM candidate and the right-handed down-type quarks. The Yukawa interactions are not only relevant to the thermal relic density of the DM, but also contribute to the flavor physics, such as the $\Delta F=2$ processes. In addition, the flavor alignment of the Yukawa couplings is related to the decay modes of the extra quark. Then, we can find the explicit correlations among the physical observables in DM physics, flavor physics and the signals at the LHC. Based on the numerical analyses of the thermal relic density, the direct detection of the DM and the current LHC bounds using the latest results, we survey our predictions for the $\Delta F=2$ processes. We investigate the perturbative bound on the Yukawa coupling, as well. Study of a fermionic DM model with extra scalar quarks is also given for comparison.
2208.09526
Gojko Vujanovic
Gojko Vujanovic
Electromagnetic probes of the Quark-Gluon Plasma
8 pages, 2 figures, Presented at the XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions (Quark Matter 2022)
null
null
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The penetrating nature of electromagnetic probes makes them an ideal candidate to study properties of the Quark-Gluon Plasma (QGP). A selection of recent developments in the theory and phenomenology of electromagnetic probes is discussed, with an emphasis given towards how these probes can be used to constrain QGP trapnsport coefficients. A Bayesian treatment of electromagnetic radiation, similar to the one of soft hadronic observables and jets, is suggested as a path towards imposing more stringent constraints on various transport coefficients of the QCD medium.
[ { "created": "Fri, 19 Aug 2022 19:22:34 GMT", "version": "v1" } ]
2022-08-23
[ [ "Vujanovic", "Gojko", "" ] ]
The penetrating nature of electromagnetic probes makes them an ideal candidate to study properties of the Quark-Gluon Plasma (QGP). A selection of recent developments in the theory and phenomenology of electromagnetic probes is discussed, with an emphasis given towards how these probes can be used to constrain QGP trapnsport coefficients. A Bayesian treatment of electromagnetic radiation, similar to the one of soft hadronic observables and jets, is suggested as a path towards imposing more stringent constraints on various transport coefficients of the QCD medium.
2111.13128
Dibya Chattopadhyay
Dibya S. Chattopadhyay, Kaustav Chakraborty, Amol Dighe, Srubabati Goswami, S. M. Lakshmi
Neutrino propagation when mass eigenstates and decay eigenstates mismatch
5 pages, 1 figure
null
10.1103/PhysRevLett.129.011802
TIFR/TH/21-21
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We point out that the Hermitian and anti-Hermitian components of the effective Hamiltonian for decaying neutrinos cannot be simultaneously diagonalized by unitary transformations for all matter densities. We develop a formalism for the two-flavor neutrino propagation through matter of uniform density, for neutrino decay to invisible states. Employing a resummation of the Zassenhaus expansion, we obtain compact analytic expressions for neutrino survival and conversion probabilities, to first and second order in the "mismatch parameter" $\bar{\gamma}$.
[ { "created": "Thu, 25 Nov 2021 15:35:10 GMT", "version": "v1" } ]
2022-07-13
[ [ "Chattopadhyay", "Dibya S.", "" ], [ "Chakraborty", "Kaustav", "" ], [ "Dighe", "Amol", "" ], [ "Goswami", "Srubabati", "" ], [ "Lakshmi", "S. M.", "" ] ]
We point out that the Hermitian and anti-Hermitian components of the effective Hamiltonian for decaying neutrinos cannot be simultaneously diagonalized by unitary transformations for all matter densities. We develop a formalism for the two-flavor neutrino propagation through matter of uniform density, for neutrino decay to invisible states. Employing a resummation of the Zassenhaus expansion, we obtain compact analytic expressions for neutrino survival and conversion probabilities, to first and second order in the "mismatch parameter" $\bar{\gamma}$.
hep-ph/0208117
J.-Alexis Rodriguez L.
Rodolfo A. Diaz, R. Martinez, and J.-Alexis Rodriguez
Phenomenology of lepton flavor violation in 2HDM(III) from (g-2)_mu and leptonic decays
Departamento de Fisica, Universidad Nacional de Colombia, Bogota, Colombia. 12 pages, 2 figures
Phys.Rev.D67:075011,2003
10.1103/PhysRevD.67.075011
null
hep-ph
null
We constrain some lepton flavor violating vertices in the context of the two Higgs doublet model type III, assuming that the lightest scalar Higgs mass $% m_{h^{0}} $is about $115 $GeV. Specifically, based on the $g-2 $muon factor and the decay width of$ \mu \to e\gamma $,$ $the following quite general bounds are obtained:$ 7.62\times 10^{-4}\lesssim \xi_{\mu \tau}^{2}\lesssim 4.44\times 10^{-2}, $ $\xi_{e\tau}^{2}\lesssim 2.77\times 10^{-14}$. Additionally, based on the processes $\tau \to \mu \gamma $, and $\tau \to \mu \mu \mu $, bounds on $\xi_{\tau \tau} $and $\xi_{\mu \mu} $are also gotten, such constraints on these parameters$ $still give enough room for either a strong suppression$ $or strong enhancement on the coupling of any Higgs boson to a pair of tau leptons or a pair of muons\textbf{.} Furthermore, upper limits on the decay widths of the leptonic decays $\tau \to e\gamma, $and $\tau \to eee $are calculated, finding them to stay far from the reach of near future experiments.
[ { "created": "Mon, 12 Aug 2002 22:55:22 GMT", "version": "v1" }, { "created": "Wed, 4 Sep 2002 23:41:29 GMT", "version": "v2" }, { "created": "Wed, 11 Dec 2002 23:06:57 GMT", "version": "v3" } ]
2014-11-17
[ [ "Diaz", "Rodolfo A.", "" ], [ "Martinez", "R.", "" ], [ "Rodriguez", "J. -Alexis", "" ] ]
We constrain some lepton flavor violating vertices in the context of the two Higgs doublet model type III, assuming that the lightest scalar Higgs mass $% m_{h^{0}} $is about $115 $GeV. Specifically, based on the $g-2 $muon factor and the decay width of$ \mu \to e\gamma $,$ $the following quite general bounds are obtained:$ 7.62\times 10^{-4}\lesssim \xi_{\mu \tau}^{2}\lesssim 4.44\times 10^{-2}, $ $\xi_{e\tau}^{2}\lesssim 2.77\times 10^{-14}$. Additionally, based on the processes $\tau \to \mu \gamma $, and $\tau \to \mu \mu \mu $, bounds on $\xi_{\tau \tau} $and $\xi_{\mu \mu} $are also gotten, such constraints on these parameters$ $still give enough room for either a strong suppression$ $or strong enhancement on the coupling of any Higgs boson to a pair of tau leptons or a pair of muons\textbf{.} Furthermore, upper limits on the decay widths of the leptonic decays $\tau \to e\gamma, $and $\tau \to eee $are calculated, finding them to stay far from the reach of near future experiments.
hep-ph/0107001
Iain W. Stewart
Christian W. Bauer and Iain W. Stewart
Invariant Operators in Collinear Effective Theory
11 pages, 2 figs, journal version
Phys.Lett.B516:134-142,2001
10.1016/S0370-2693(01)00902-9
UCSD/PTH 01-09
hep-ph
null
We consider processes which produce final state hadrons whose energy is much greater than their mass. In this limit interactions involving collinear fermions and gluons are constrained by a symmetry, and we give a general set of rules for constructing leading and subleading invariant operators. Wilson coefficients C(mu,P) are functions of a label operator P, and do not commute with collinear fields. The symmetry is used to reproduce a two-loop result for factorization in B -> D pi in a simple way.
[ { "created": "Mon, 2 Jul 2001 22:09:53 GMT", "version": "v1" }, { "created": "Wed, 29 Aug 2001 05:33:10 GMT", "version": "v2" } ]
2011-05-05
[ [ "Bauer", "Christian W.", "" ], [ "Stewart", "Iain W.", "" ] ]
We consider processes which produce final state hadrons whose energy is much greater than their mass. In this limit interactions involving collinear fermions and gluons are constrained by a symmetry, and we give a general set of rules for constructing leading and subleading invariant operators. Wilson coefficients C(mu,P) are functions of a label operator P, and do not commute with collinear fields. The symmetry is used to reproduce a two-loop result for factorization in B -> D pi in a simple way.
2011.11409
Zhenjun Xiao
Su-Ping Jin and Zhen-Jun Xiao
Study of $B_s\to \phi \ell^+ \ell^-$ decays in the PQCD factorization approach with lattice QCD input
32 pages, 4 figures and 12 tables. Some new corrections to the text. arXiv admin note: text overlap with arXiv:2003.12226
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In this paper, we studied systematically the semileptonic decays $B_s \to \phi l^+ l^-$ with $l^-=(e^-,\mu^-,\tau^-)$ by using the perturbative QCD (PQCD) and the "PQCD+Lattice" factorization approach, respectively. We first evaluated all relevant form factors $F_i(q^2)$ in the low $q^2$ region using the PQCD approach, and we also took the available lattice QCD results at the high-$q^2$ region as additional input to improve the extrapolation of $F_i(q^2)$ from the low-$q^2$ region to the endpoint $q^2_{max}$. We then calculated the branching ratios and many other physical observables: $A_{FB}^{l}$, $F_L^{\phi}$, $S_{3,4,7}$, $A_{5,6,8,9}$ and the clean angular observables $P_{1,2,3} $ and $P^{\prime}_{4,5,6,8}$.From our studies, we find the following points: (a) the PQCD and "PQCD+Lattice" predictions of ${\cal B}( B_s \to \phi \mu^+ \mu^-)$ are about $7\times 10^{-7}$, which agree well with the LHCb measured values and the QCD sum rule prediction within still large errors; (b) we defined and calculated the ratios of the branching ratios $R_\phi^{e\mu}$ and $R_\phi^{\mu\tau}$; (c) the PQCD and "PQCD+Lattice" predictions of the longitudinal polarization $F_L$, the CP averaged angular coefficients $S_{3,4,7} $ and the CP asymmetry angular coefficients $A_{5,6,8,9}$, agree with the LHCb measurements in all considered bins within the still large experimental errors; and (d) for those currently still unknown observables $R_\phi^{e\mu}, R_\phi^{\mu\tau}, A_{FB}^{l}, P_{1,2,3}$ and $P^{\prime}_{4,5,6,8}$, we suggest LHCb and Belle-II Collaboration to measure them in their experiments.
[ { "created": "Thu, 19 Nov 2020 22:24:15 GMT", "version": "v1" }, { "created": "Mon, 1 Feb 2021 06:35:16 GMT", "version": "v2" }, { "created": "Thu, 27 May 2021 03:08:21 GMT", "version": "v3" }, { "created": "Tue, 14 Sep 2021 11:25:12 GMT", "version": "v4" } ]
2021-09-15
[ [ "Jin", "Su-Ping", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
In this paper, we studied systematically the semileptonic decays $B_s \to \phi l^+ l^-$ with $l^-=(e^-,\mu^-,\tau^-)$ by using the perturbative QCD (PQCD) and the "PQCD+Lattice" factorization approach, respectively. We first evaluated all relevant form factors $F_i(q^2)$ in the low $q^2$ region using the PQCD approach, and we also took the available lattice QCD results at the high-$q^2$ region as additional input to improve the extrapolation of $F_i(q^2)$ from the low-$q^2$ region to the endpoint $q^2_{max}$. We then calculated the branching ratios and many other physical observables: $A_{FB}^{l}$, $F_L^{\phi}$, $S_{3,4,7}$, $A_{5,6,8,9}$ and the clean angular observables $P_{1,2,3} $ and $P^{\prime}_{4,5,6,8}$.From our studies, we find the following points: (a) the PQCD and "PQCD+Lattice" predictions of ${\cal B}( B_s \to \phi \mu^+ \mu^-)$ are about $7\times 10^{-7}$, which agree well with the LHCb measured values and the QCD sum rule prediction within still large errors; (b) we defined and calculated the ratios of the branching ratios $R_\phi^{e\mu}$ and $R_\phi^{\mu\tau}$; (c) the PQCD and "PQCD+Lattice" predictions of the longitudinal polarization $F_L$, the CP averaged angular coefficients $S_{3,4,7} $ and the CP asymmetry angular coefficients $A_{5,6,8,9}$, agree with the LHCb measurements in all considered bins within the still large experimental errors; and (d) for those currently still unknown observables $R_\phi^{e\mu}, R_\phi^{\mu\tau}, A_{FB}^{l}, P_{1,2,3}$ and $P^{\prime}_{4,5,6,8}$, we suggest LHCb and Belle-II Collaboration to measure them in their experiments.
hep-ph/0603041
Vajravelu Ravindran
V. Ravindran
Higher-Order threshold effects to inclusive processes in QCD
27 pages, two figures
Nucl.Phys.B752:173-196,2006
10.1016/j.nuclphysb.2006.06.025
null
hep-ph hep-th
null
We present threshold enhanced QCD corrections to inclusive processes such as Deep inelastic scattering, Drell-Yan process and Higgs productions through gluon fusion and bottom quark annihilation processes using the resummed cross sections. The resummed cross sections are derived using renormalisation group invariance and mass factorisation theorem that these hard scattering cross sections satisfy and Sudakov resummation of QCD amplitudes. We show how these higher order threshold QCD corrections improve the theoretical predictions for the Higgs production through gluon fusion at hadron colliders.
[ { "created": "Mon, 6 Mar 2006 08:58:09 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ravindran", "V.", "" ] ]
We present threshold enhanced QCD corrections to inclusive processes such as Deep inelastic scattering, Drell-Yan process and Higgs productions through gluon fusion and bottom quark annihilation processes using the resummed cross sections. The resummed cross sections are derived using renormalisation group invariance and mass factorisation theorem that these hard scattering cross sections satisfy and Sudakov resummation of QCD amplitudes. We show how these higher order threshold QCD corrections improve the theoretical predictions for the Higgs production through gluon fusion at hadron colliders.
hep-ph/0407227
Jochen Heitger
Jochen Heitger (Muenster U.), Andreas Juttner (Humboldt U., Berlin), Rainer Sommer (CERN) and Jan Wennekers (DESY)
Non-perturbative tests of Heavy Quark Effective Theory
28 pages including figures and tables, latex2e, uses JHEP3.cls; version published in JHEP, small additions and typos corrected, results unchanged
JHEP0411:048,2004
10.1088/1126-6708/2004/11/048
MS-TP-04-11, HU-EP-04/33, CERN-PH-TH/2004-114, DESY 04-102
hep-ph hep-lat
null
We consider QCD with one massless quark and one heavy quark in a finite volume of linear extent L_0 ~ 0.2 fm. In this situation, HQET represents an expansion in terms of 1/z=1/(m L_0), which we test by a non-perturbative computation of quenched current matrix elements and energies, taking the continuum limit of lattice results. These are seen to approach the corresponding renormalization group invariant matrix elements of the static effective theory as the quark mass becomes large. We are able to obtain estimates of the size of the 1/m-corrections to the static theory, which are also of practical relevance in our recent strategy to implement HQET non-perturbatively by matching to QCD in a finite volume.
[ { "created": "Tue, 20 Jul 2004 14:37:21 GMT", "version": "v1" }, { "created": "Mon, 3 Jan 2005 16:11:31 GMT", "version": "v2" } ]
2008-11-26
[ [ "Heitger", "Jochen", "", "Muenster U." ], [ "Juttner", "Andreas", "", "Humboldt U., Berlin" ], [ "Sommer", "Rainer", "", "CERN" ], [ "Wennekers", "Jan", "", "DESY" ] ]
We consider QCD with one massless quark and one heavy quark in a finite volume of linear extent L_0 ~ 0.2 fm. In this situation, HQET represents an expansion in terms of 1/z=1/(m L_0), which we test by a non-perturbative computation of quenched current matrix elements and energies, taking the continuum limit of lattice results. These are seen to approach the corresponding renormalization group invariant matrix elements of the static effective theory as the quark mass becomes large. We are able to obtain estimates of the size of the 1/m-corrections to the static theory, which are also of practical relevance in our recent strategy to implement HQET non-perturbatively by matching to QCD in a finite volume.
hep-ph/9803451
Emidio Gabrielli
Emidio Gabrielli, Uri Sarid
Imminent Phenomenology of a Minimal Gauge-Mediated Model
LaTeX, 31 pages, 3 (color) figures, few minor changes on section 4, a final note and new references added, conclusions unchanged
Phys. Rev. D 58, 115003 (1998)
10.1103/PhysRevD.58.115003
UND-HEP-97-US03, FTUAM 98/3
hep-ph
null
We calculate the inclusive branching ratio for B--> X_s gamma, the inclusive branching ratios and asymmetries for B--> X_s l+ l- and the anomalous magnetic moment g-2 of the muon, within a minimal gauge-mediated SUSY-breaking model which naturally generates a large ratio tan(beta) of Higgs field vacuum expectation values. These predictions are highly correlated with each other, depending on only two fundamental parameters: the superpartner mass scale and the logarithm of a common messenger mass. The predictions for B--> X_s gamma decay and g-2 are in somewhat better agreement with current experiments than the standard model, but a much sharper comparison will soon be possible using new measurements now in progress or under analysis. Moreover we predict large deviations in B--> X_s e+ e- and B--> X_s mu+ mu- asymmetries, and somewhat smaller ones in B--> X_s e+ e- and B--> X_s tau+ tau- branching ratios, which will be detectable in hadronic colliders.
[ { "created": "Wed, 25 Mar 1998 20:20:51 GMT", "version": "v1" }, { "created": "Mon, 11 May 1998 11:45:51 GMT", "version": "v2" } ]
2016-08-25
[ [ "Gabrielli", "Emidio", "" ], [ "Sarid", "Uri", "" ] ]
We calculate the inclusive branching ratio for B--> X_s gamma, the inclusive branching ratios and asymmetries for B--> X_s l+ l- and the anomalous magnetic moment g-2 of the muon, within a minimal gauge-mediated SUSY-breaking model which naturally generates a large ratio tan(beta) of Higgs field vacuum expectation values. These predictions are highly correlated with each other, depending on only two fundamental parameters: the superpartner mass scale and the logarithm of a common messenger mass. The predictions for B--> X_s gamma decay and g-2 are in somewhat better agreement with current experiments than the standard model, but a much sharper comparison will soon be possible using new measurements now in progress or under analysis. Moreover we predict large deviations in B--> X_s e+ e- and B--> X_s mu+ mu- asymmetries, and somewhat smaller ones in B--> X_s e+ e- and B--> X_s tau+ tau- branching ratios, which will be detectable in hadronic colliders.
hep-ph/9804454
Davison E. Soper
Davison E. Soper
QCD Calculations by Numerical Integration
9 pages including 2 figures. RevTeX
Phys.Rev.Lett. 81 (1998) 2638-2641
10.1103/PhysRevLett.81.2638
OITS 650
hep-ph
null
Calculations of observables in Quantum Chromodynamics are typically performed using a method that combines numerical integrations over the momenta of final state particles with analytical integrations over the momenta of virtual particles. I discuss a method for performing all of the integrations numerically.
[ { "created": "Thu, 30 Apr 1998 02:20:11 GMT", "version": "v1" } ]
2009-10-31
[ [ "Soper", "Davison E.", "" ] ]
Calculations of observables in Quantum Chromodynamics are typically performed using a method that combines numerical integrations over the momenta of final state particles with analytical integrations over the momenta of virtual particles. I discuss a method for performing all of the integrations numerically.
hep-ph/9804239
Stefan Leupold
Carsten Greiner and Stefan Leupold
Interpretation and resolution of pinch singularities in non-equilibrium quantum field theory
REVTeX, 11 pages, 3 eps-figures, minor changes, some remarks added
Eur.Phys.J.C8:517-522,1999
10.1007/s100529901095
UGI-98-17
hep-ph hep-th
null
Ill-defined pinch singularities arising in a perturbative expansion in out of equilibrium quantum field theory have a natural analogue to standard scattering theory. We explicitly demonstrate that the occurrence of such terms is directly related to Fermi's golden rule known from elementary scattering theory and is thus of no mystery. We further argue that within the process of thermalization of a plasma one has to resum such contributions to all orders as the process itself is of non-perturbative nature. In this way the resummed propagators obtain a finite width. Within the Markov approximation of kinetic theory the actual phase space distribution at a given time of the evolution enters explicitly.
[ { "created": "Mon, 6 Apr 1998 15:01:53 GMT", "version": "v1" }, { "created": "Tue, 8 Sep 1998 12:15:36 GMT", "version": "v2" } ]
2011-09-13
[ [ "Greiner", "Carsten", "" ], [ "Leupold", "Stefan", "" ] ]
Ill-defined pinch singularities arising in a perturbative expansion in out of equilibrium quantum field theory have a natural analogue to standard scattering theory. We explicitly demonstrate that the occurrence of such terms is directly related to Fermi's golden rule known from elementary scattering theory and is thus of no mystery. We further argue that within the process of thermalization of a plasma one has to resum such contributions to all orders as the process itself is of non-perturbative nature. In this way the resummed propagators obtain a finite width. Within the Markov approximation of kinetic theory the actual phase space distribution at a given time of the evolution enters explicitly.
1108.2872
Konstantin Kouzakov
Konstantin A. Kouzakov and Alexander I. Studenikin
Electromagnetic neutrino-atom collisions: The role of electron binding
4 pages, published in proceedings of NOW2010
Nuclear Physics B (Proc. Suppl.) 217 (2011) 353-356
10.1016/j.nuclphysbps.2011.04.137
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new theoretical approach to neutrino-impact atomic excitation and/or ionization due to neutrino magnetic moments. The differential cross section of the process is given by a sum of the longitudinal and transverse terms, which are induced by the corresponding components of the force that the neutrino magnetic moment imposes on electrons with respect to momentum transfer. In this context, the recent theoretical studies devoted to the magnetic neutrino scattering on atoms are critically examined.
[ { "created": "Sun, 14 Aug 2011 13:52:39 GMT", "version": "v1" } ]
2011-08-16
[ [ "Kouzakov", "Konstantin A.", "" ], [ "Studenikin", "Alexander I.", "" ] ]
We present a new theoretical approach to neutrino-impact atomic excitation and/or ionization due to neutrino magnetic moments. The differential cross section of the process is given by a sum of the longitudinal and transverse terms, which are induced by the corresponding components of the force that the neutrino magnetic moment imposes on electrons with respect to momentum transfer. In this context, the recent theoretical studies devoted to the magnetic neutrino scattering on atoms are critically examined.
1901.07488
Massimo Mannarelli
Luca Lepori and Massimo Mannarelli
Multicomponent meson superfluids in chiral perturbation theory
13 pages, 5 figures
Phys. Rev. D 99, 096011 (2019)
10.1103/PhysRevD.99.096011
null
hep-ph cond-mat.quant-gas cond-mat.str-el cond-mat.supr-con
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the multicomponent meson systems can be described by chiral perturbation theory. We chiefly focus on a system of two pion gases at different isospin chemical potential, deriving the general expression of the chiral Lagrangian, the ground state properties and the spectrum of the low-energy excitations. We consider two different kinds of interactions between the two meson gases: one which does not lock the two chiral symmetry groups and one which does lock them. The former is a kind of interaction that has already been discussed in mutlicomponent superfluids. The latter is perhaps more interesting, because seems to be related to an instability. Although the pressure of the system does not show any instability, we find that for sufficiently strong locking, the spectrum of one Bogolyubov mode becomes tachyonic. This unstable branch seems to indicate a transition to an inhomogeneous phase.
[ { "created": "Tue, 22 Jan 2019 18:04:52 GMT", "version": "v1" } ]
2019-05-22
[ [ "Lepori", "Luca", "" ], [ "Mannarelli", "Massimo", "" ] ]
We show that the multicomponent meson systems can be described by chiral perturbation theory. We chiefly focus on a system of two pion gases at different isospin chemical potential, deriving the general expression of the chiral Lagrangian, the ground state properties and the spectrum of the low-energy excitations. We consider two different kinds of interactions between the two meson gases: one which does not lock the two chiral symmetry groups and one which does lock them. The former is a kind of interaction that has already been discussed in mutlicomponent superfluids. The latter is perhaps more interesting, because seems to be related to an instability. Although the pressure of the system does not show any instability, we find that for sufficiently strong locking, the spectrum of one Bogolyubov mode becomes tachyonic. This unstable branch seems to indicate a transition to an inhomogeneous phase.
hep-ph/0112180
Lokhtin
I.P. Lokhtin, S.V. Petrushanko, L.I. Sarycheva, A.M. Snigirev
Azimuthal anisotropy of jet quenching at LHC
Talk given at Fourth International Conference "Physics and Astrophysics of Quark-Gluon Plasma", November 26-30, 2001; 4 pages including 4 eps-figures
Pramana60:1045-1050,2002
10.1007/BF02707028
null
hep-ph
null
We analyze the azimuthal anisotropy of jet spectra due to energy loss of hard partons in quark-gluon plasma, created initially in nuclear overlap zone in collisions with non-zero impact parameter. The calculations are performed for semi-central Pb-Pb collisions at LHC energy.
[ { "created": "Thu, 13 Dec 2001 13:49:07 GMT", "version": "v1" } ]
2016-09-06
[ [ "Lokhtin", "I. P.", "" ], [ "Petrushanko", "S. V.", "" ], [ "Sarycheva", "L. I.", "" ], [ "Snigirev", "A. M.", "" ] ]
We analyze the azimuthal anisotropy of jet spectra due to energy loss of hard partons in quark-gluon plasma, created initially in nuclear overlap zone in collisions with non-zero impact parameter. The calculations are performed for semi-central Pb-Pb collisions at LHC energy.
0810.4893
Sergey Alekhin
S. Alekhin, S. Kulagin, R. Petti
Update of the global fit of PDFs including the low-Q DIS data
4 pages, 3 figures. To appear in the proceedings of the 16th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2008), London, England, 7-11 April 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform the next-to-next-leading-order (NNLO) QCD global fit of PDFs using inclusive charged-lepton and neutrino DIS data down to Q = 1 GeV. We also consider the data on neutrino-nucleon dimuon production, that allows us to disentangle the strange sea distribution. The fit results in \chi^2/NDP = 5150/4338 = 1.2 that demonstrates a good consistency of the data sets used in analysis. The resulting value of \alpha_s(M_Z) = 0.1136+- 0.0007(exp.) is in a good agreement with the previous version of the fit with a more stringent cut on Q. This analysis allows us to improve the accuracy of PDFs. The HT terms of the neutrino-nucleon structure functions F_2 and xF_3 are determined, the former is found to be consistent with one for the charged-leptons if the charge factor is taken into account.
[ { "created": "Mon, 27 Oct 2008 18:28:24 GMT", "version": "v1" } ]
2008-10-28
[ [ "Alekhin", "S.", "" ], [ "Kulagin", "S.", "" ], [ "Petti", "R.", "" ] ]
We perform the next-to-next-leading-order (NNLO) QCD global fit of PDFs using inclusive charged-lepton and neutrino DIS data down to Q = 1 GeV. We also consider the data on neutrino-nucleon dimuon production, that allows us to disentangle the strange sea distribution. The fit results in \chi^2/NDP = 5150/4338 = 1.2 that demonstrates a good consistency of the data sets used in analysis. The resulting value of \alpha_s(M_Z) = 0.1136+- 0.0007(exp.) is in a good agreement with the previous version of the fit with a more stringent cut on Q. This analysis allows us to improve the accuracy of PDFs. The HT terms of the neutrino-nucleon structure functions F_2 and xF_3 are determined, the former is found to be consistent with one for the charged-leptons if the charge factor is taken into account.
1412.3953
Antonio Pich
Antonio Pich
Leptons and QCD
Invited talk at the 13th International Workshop on Tau Lepton Physics (Aachen, Germany, 15-19 September, 2014). 6 pages, 1 figure
null
null
IFIC/14-81, FTUV-14-1212
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Three important QCD-related aspects of the $\tau$ and $\mu$ dynamics are reviewed: the determination of the strong coupling from the hadronic tau decay width, leading to the updated value $\alpha_s(m_\tau^2) = 0.331 \pm 0.013$; the measurement of $|V_{us}|$ through the Cabibbo-suppressed decays of the $\tau$, and the Standard Model prediction for the muon anomalous magnetic moment.
[ { "created": "Fri, 12 Dec 2014 11:33:23 GMT", "version": "v1" } ]
2014-12-15
[ [ "Pich", "Antonio", "" ] ]
Three important QCD-related aspects of the $\tau$ and $\mu$ dynamics are reviewed: the determination of the strong coupling from the hadronic tau decay width, leading to the updated value $\alpha_s(m_\tau^2) = 0.331 \pm 0.013$; the measurement of $|V_{us}|$ through the Cabibbo-suppressed decays of the $\tau$, and the Standard Model prediction for the muon anomalous magnetic moment.
1308.5346
Tong Li
Yi Cai, Tong Li
Singlet Dark Matter in Type II Two Higgs Doublet Model
18 pages, 6 figures
Phys. Rev. D 88, 115004 (2013)
10.1103/PhysRevD.88.115004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the dark matter searches in the low mass region, we study the Type II two Higgs doublet model with a light gauge singlet WIMP stabilized by a Z_2 symmetry. The real singlet is required to only couple to the non-Standard Model Higgs. We investigate singlet candidates with different spins as well as isospin violating effect. The parameter space favored by LHC data in two Higgs doublet model and hadronic uncertainties in WIMP-nucleon elastic scattering are also taken into account. We find only the scalar singlet in the isospin conserving case leads to a major overlap with the region of interests of most direct detection experiments.
[ { "created": "Sat, 24 Aug 2013 16:36:52 GMT", "version": "v1" } ]
2013-12-16
[ [ "Cai", "Yi", "" ], [ "Li", "Tong", "" ] ]
Inspired by the dark matter searches in the low mass region, we study the Type II two Higgs doublet model with a light gauge singlet WIMP stabilized by a Z_2 symmetry. The real singlet is required to only couple to the non-Standard Model Higgs. We investigate singlet candidates with different spins as well as isospin violating effect. The parameter space favored by LHC data in two Higgs doublet model and hadronic uncertainties in WIMP-nucleon elastic scattering are also taken into account. We find only the scalar singlet in the isospin conserving case leads to a major overlap with the region of interests of most direct detection experiments.
2306.14298
Fernando Navarra
R. Terra and F. S. Navarra
Charmonium production in high multiplicity p p collisions and the structure of the proton
9 pages , 6 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work we study charmonium production in high multiplicity proton-proton collisions. We investigate the role of the spatial distribution of partons in the protons and assume that the proton has a Y shape. In this configuration quarks are more at the surface and gluons in the inner part of the proton. Going from peripheral to more central and then to ultra-central proton-proton collisions, we go from quark-quark collisions to gluon-gluon collisions. Since gluons are much more abundant, the cross sections grow. In the case of charm production this growth is enhanced by the fact that, $\sigma( g + g \to c + \bar{c}) >> \sigma( q + \bar{q} \to c + \bar{c})$. These effects can explain the growth seen in the data.
[ { "created": "Sun, 25 Jun 2023 17:16:37 GMT", "version": "v1" } ]
2023-06-27
[ [ "Terra", "R.", "" ], [ "Navarra", "F. S.", "" ] ]
In this work we study charmonium production in high multiplicity proton-proton collisions. We investigate the role of the spatial distribution of partons in the protons and assume that the proton has a Y shape. In this configuration quarks are more at the surface and gluons in the inner part of the proton. Going from peripheral to more central and then to ultra-central proton-proton collisions, we go from quark-quark collisions to gluon-gluon collisions. Since gluons are much more abundant, the cross sections grow. In the case of charm production this growth is enhanced by the fact that, $\sigma( g + g \to c + \bar{c}) >> \sigma( q + \bar{q} \to c + \bar{c})$. These effects can explain the growth seen in the data.
1703.09020
Ryusuke Jinno
Ryusuke Jinno and Kunio Kaneta
Hillclimbing inflation
5 pages, 3 figures
Phys. Rev. D 96, 043518 (2017)
10.1103/PhysRevD.96.043518
CTPU-17-11
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new class of inflationary models in which inflation takes place while the inflaton is climbing up a potential hill due to a coupling to gravity. We study their attractor behavior, and investigate its relation with known attractors. We also discuss a possible realization of this type of models with the natural inflation, and show that the inflationary predictions come well within the region consistent with the observation of the cosmic microwave background.
[ { "created": "Mon, 27 Mar 2017 11:49:41 GMT", "version": "v1" }, { "created": "Fri, 14 Apr 2017 02:40:30 GMT", "version": "v2" }, { "created": "Wed, 21 Jun 2017 08:26:16 GMT", "version": "v3" } ]
2017-08-30
[ [ "Jinno", "Ryusuke", "" ], [ "Kaneta", "Kunio", "" ] ]
We propose a new class of inflationary models in which inflation takes place while the inflaton is climbing up a potential hill due to a coupling to gravity. We study their attractor behavior, and investigate its relation with known attractors. We also discuss a possible realization of this type of models with the natural inflation, and show that the inflationary predictions come well within the region consistent with the observation of the cosmic microwave background.
1506.06986
Kazem Azizi
K. Azizi, N. Katirci
QCD nature of dark energy at finite temperature: cosmological implications
10 Pages and 6 Figures. Some references were rearranged
null
null
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Veneziano ghost field has been proposed as an alternative source of dark energy whose energy density is consistent with the cosmological observations. In this model, the energy density of QCD ghost field is expressed in terms of QCD degrees of freedom at zero temperature. We extend this model to finite temperature to search the model predictions from late time to early universe. We depict the variations of QCD parameters entering the calculations, dark energy density, equation of state, Hubble and deceleration parameters on temperature from zero to a critical temperature. We compare our results with the observations and theoretical predictions existing at different eras. It is found that this model safely defines the universe from quark condensation up to now and its predictions are not in tension with those of the standard cosmology. The EoS parameter of dark energy is dynamical and evolves from $-1/3$ in the presence of radiation to $-1$ at late time. The finite temperature ghost dark energy predictions on the Hubble parameter well fit to those of $\Lambda$CDM and observations at late time.
[ { "created": "Tue, 23 Jun 2015 13:34:24 GMT", "version": "v1" }, { "created": "Sun, 20 Sep 2015 20:22:19 GMT", "version": "v2" }, { "created": "Fri, 26 Feb 2016 13:53:32 GMT", "version": "v3" }, { "created": "Tue, 17 May 2016 08:39:14 GMT", "version": "v4" } ]
2016-05-18
[ [ "Azizi", "K.", "" ], [ "Katirci", "N.", "" ] ]
The Veneziano ghost field has been proposed as an alternative source of dark energy whose energy density is consistent with the cosmological observations. In this model, the energy density of QCD ghost field is expressed in terms of QCD degrees of freedom at zero temperature. We extend this model to finite temperature to search the model predictions from late time to early universe. We depict the variations of QCD parameters entering the calculations, dark energy density, equation of state, Hubble and deceleration parameters on temperature from zero to a critical temperature. We compare our results with the observations and theoretical predictions existing at different eras. It is found that this model safely defines the universe from quark condensation up to now and its predictions are not in tension with those of the standard cosmology. The EoS parameter of dark energy is dynamical and evolves from $-1/3$ in the presence of radiation to $-1$ at late time. The finite temperature ghost dark energy predictions on the Hubble parameter well fit to those of $\Lambda$CDM and observations at late time.
hep-ph/0009230
Motohiko Yoshimura
Sh. Matsumoto and M. Yoshimura
Resonance Enhanced Tunneling
12 pages, LATEX file with 5 PS figures
Phys.Lett. B495 (2000) 223-230
10.1016/S0370-2693(00)01225-9
TU/00/601
hep-ph
null
Time evolution of tunneling in thermal medium is examined using the real-time semiclassical formalism previously developed. Effect of anharmonic terms in the potential well is shown to give a new mechanism of resonance enhanced tunneling. If the friction from environment is small enough, this mechanism may give a very large enhancement for the tunneling rate. The case of the asymmetric wine bottle potential is worked out in detail.
[ { "created": "Wed, 20 Sep 2000 01:58:39 GMT", "version": "v1" } ]
2009-10-31
[ [ "Matsumoto", "Sh.", "" ], [ "Yoshimura", "M.", "" ] ]
Time evolution of tunneling in thermal medium is examined using the real-time semiclassical formalism previously developed. Effect of anharmonic terms in the potential well is shown to give a new mechanism of resonance enhanced tunneling. If the friction from environment is small enough, this mechanism may give a very large enhancement for the tunneling rate. The case of the asymmetric wine bottle potential is worked out in detail.
hep-ph/0104135
Vladimir Shevchenko
V.I.Shevchenko, Yu.A.Simonov (ITEP)
On Casimir scaling in QCD
RevTeX, 23 pages
null
null
null
hep-ph hep-lat
null
Recent lattice calculations have confirmed that QCD static potential for sources in different representations of the gauge group is proportional to eigenvalue of the corresponding quadratic Casimir operator with an accuracy of a few percents. We review the present theoretical status of the "Casimir scaling" phenomenon and stress its importance for analysis of nonperturbative QCD vacuum models and other field theories. It is argued that Casimir scaling strongly advocates the property of Gaussian dominance and we propose different lattice tests to improve our understanding of these phenomena.
[ { "created": "Fri, 13 Apr 2001 12:47:56 GMT", "version": "v1" }, { "created": "Sun, 3 Jun 2001 21:06:26 GMT", "version": "v2" } ]
2007-05-23
[ [ "Shevchenko", "V. I.", "", "ITEP" ], [ "Simonov", "Yu. A.", "", "ITEP" ] ]
Recent lattice calculations have confirmed that QCD static potential for sources in different representations of the gauge group is proportional to eigenvalue of the corresponding quadratic Casimir operator with an accuracy of a few percents. We review the present theoretical status of the "Casimir scaling" phenomenon and stress its importance for analysis of nonperturbative QCD vacuum models and other field theories. It is argued that Casimir scaling strongly advocates the property of Gaussian dominance and we propose different lattice tests to improve our understanding of these phenomena.
1204.0769
Carlos Merino
C. Merino and Yu.M. Shabelski
Elastic pp Scattering at LHC Energies
11 pages, 5 figures, and 1 table
null
10.1007/JHEP05(2012)013
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the first LHC data for elastic pp scattering in the framework of Regge theory with multiple Pomeron exchanges. The simplest eikonal approach allows one to describe differential elastic cross sections at LHC, as well as pp and $\bar{p}p$ scattering at lower collider energies, on a reasonable level.
[ { "created": "Tue, 3 Apr 2012 19:04:52 GMT", "version": "v1" } ]
2015-06-04
[ [ "Merino", "C.", "" ], [ "Shabelski", "Yu. M.", "" ] ]
We consider the first LHC data for elastic pp scattering in the framework of Regge theory with multiple Pomeron exchanges. The simplest eikonal approach allows one to describe differential elastic cross sections at LHC, as well as pp and $\bar{p}p$ scattering at lower collider energies, on a reasonable level.
2211.06729
Ritesh Ghosh
Ritesh Ghosh and Manu Kurian
Magnetic field-dependent electric charge transport in hadronic medium at finite temperature
22 pages, 7 figures
Phys. Rev. C 107, 034903 (2023)
10.1103/PhysRevC.107.034903
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Electric charge transport of hadronic matter at finite temperature and magnetic field is studied within the linear sigma model. Anisotropic transport coefficients associated with the charge transport are estimated both in the weak and strong regimes of the magnetic field using the transport theory approach. In a weakly magnetized medium, the magnetic field effects are incorporated through the Lorentz force term in the Boltzmann equation. Strong magnetic field puts further constraints on the motion of charged particles through Landau quantization. Magnetic field-dependent thermal relaxation time is obtained from interaction rates of hadrons with the S-matrix approach by considering the Landau level kinematics of the charged hadrons. Mean-field effects are embedded in the analysis through the temperature-dependent hadron masses. Further, the hadronic medium response to a time-varying external electric field is studied in weak and strong magnetic field regimes. It is seen that electromagnetic responses of the hadronic matter have a strong dependence on the mean-field effects, sigma mass, the strength of the external fields, and its evolution in the medium.
[ { "created": "Sat, 12 Nov 2022 19:16:14 GMT", "version": "v1" } ]
2023-03-07
[ [ "Ghosh", "Ritesh", "" ], [ "Kurian", "Manu", "" ] ]
Electric charge transport of hadronic matter at finite temperature and magnetic field is studied within the linear sigma model. Anisotropic transport coefficients associated with the charge transport are estimated both in the weak and strong regimes of the magnetic field using the transport theory approach. In a weakly magnetized medium, the magnetic field effects are incorporated through the Lorentz force term in the Boltzmann equation. Strong magnetic field puts further constraints on the motion of charged particles through Landau quantization. Magnetic field-dependent thermal relaxation time is obtained from interaction rates of hadrons with the S-matrix approach by considering the Landau level kinematics of the charged hadrons. Mean-field effects are embedded in the analysis through the temperature-dependent hadron masses. Further, the hadronic medium response to a time-varying external electric field is studied in weak and strong magnetic field regimes. It is seen that electromagnetic responses of the hadronic matter have a strong dependence on the mean-field effects, sigma mass, the strength of the external fields, and its evolution in the medium.
hep-ph/0008259
Wojciech Slominski
W. Slominski and J. Szwed
Phenomenology of the Electron Structure Function
6 pages, 4 figures New version, new figures added
Eur.Phys.J.C22:123-127,2001
10.1007/s100520100786
null
hep-ph
null
Advantages of introducing the electron structure function (ESF) in electron induced processes are demonstrated. Contrary to the photon structure function it is directly measured in such processes. At present energies a simultaneous analysis of both the electron and the photon structure functions gives an important test of the experimentally applied methods. Estimates of the ESF at currently measured momenta are given. At very high momenta contributions from $W$ and $Z$ bosons together with $\gamma$-$Z$ interference can be observed. Predictions for next generation of experiments are given.
[ { "created": "Thu, 24 Aug 2000 13:25:11 GMT", "version": "v1" }, { "created": "Thu, 17 May 2001 16:44:48 GMT", "version": "v2" } ]
2009-01-07
[ [ "Slominski", "W.", "" ], [ "Szwed", "J.", "" ] ]
Advantages of introducing the electron structure function (ESF) in electron induced processes are demonstrated. Contrary to the photon structure function it is directly measured in such processes. At present energies a simultaneous analysis of both the electron and the photon structure functions gives an important test of the experimentally applied methods. Estimates of the ESF at currently measured momenta are given. At very high momenta contributions from $W$ and $Z$ bosons together with $\gamma$-$Z$ interference can be observed. Predictions for next generation of experiments are given.
0711.0028
Antonio Pich
Antonio Pich
Selected topics on tau physics
Invited talk at the XXXI International Conference of Theoretical Physics, "Matter to the Deepest", Ustron, Poland, 5-11 September 2007
ActaPhys.Polon.B38:3449-3458,2007
null
FTUV/07-1031, IFIC/07-80
hep-ph hep-ex
null
The B Factories have generated a large amount of new results on the tau lepton. The present status of some selected topics on tau physics is presented: charged-current universality tests, bounds on lepton-flavour violation, the determination of alpha_s from the inclusive tau hadronic width, and the measurement of |V_{us}| through the Cabibbo-suppressed decays of the tau lepton.
[ { "created": "Wed, 31 Oct 2007 22:34:16 GMT", "version": "v1" } ]
2008-11-26
[ [ "Pich", "Antonio", "" ] ]
The B Factories have generated a large amount of new results on the tau lepton. The present status of some selected topics on tau physics is presented: charged-current universality tests, bounds on lepton-flavour violation, the determination of alpha_s from the inclusive tau hadronic width, and the measurement of |V_{us}| through the Cabibbo-suppressed decays of the tau lepton.
1502.03144
Igor Altsybeev
Grigory Feofilov, Igor Altsybeev, Olga Kochebina
Constraints on string percolation model from anomalous centrality evolution data in Au-Au collisions at $\mathbf{\sqrt{s_{NN}}=}$ 62 and 200 GeV
11 pages, 5 figures, proc. Baldin ISHEPP XXII; PoS (Baldin ISHEPP XXII) 067 (2015)
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Anomalous centrality evolution of two-particle angular correlations observed in Au-Au collisions at $\sqrt{s_{NN}} = 62$ and 200 GeV and the onset of ridge structures are considered in the model of interacting quark-gluon strings. We assume that at the given energy of nucleus-nucleus collisions the critical energy density may be reached at the specific centrality. In a string percolation model this might be treated equivalently to a formation of a large cluster of strings characterized by the critical string density, with a size comparable to the whole area of interaction of two nuclei. This hypothesis allows to define some constraints on the string percolation model using data on transitional centralities in Au-Au collisions at these two energies. Results are extrapolated to the LHC energy where high string densities (exceeding the critical value) are confirmed for all classes of centralities in Pb-Pb collisions. Interaction between strings inside large clusters formed in nucleus-nucleus collisions is considered in a simplified Monte Carlo model. This model is applied to the qualitative analysis of the onset of collectivity and the ridge formation in Pb-Pb collisions. It is shown that the approach of the repulsive string-string interaction is capable to explain the appearance of elliptic and triangular flow observed in nucleus-nucleus collisions at RHIC and LHC energies.
[ { "created": "Tue, 10 Feb 2015 22:48:04 GMT", "version": "v1" } ]
2015-02-12
[ [ "Feofilov", "Grigory", "" ], [ "Altsybeev", "Igor", "" ], [ "Kochebina", "Olga", "" ] ]
Anomalous centrality evolution of two-particle angular correlations observed in Au-Au collisions at $\sqrt{s_{NN}} = 62$ and 200 GeV and the onset of ridge structures are considered in the model of interacting quark-gluon strings. We assume that at the given energy of nucleus-nucleus collisions the critical energy density may be reached at the specific centrality. In a string percolation model this might be treated equivalently to a formation of a large cluster of strings characterized by the critical string density, with a size comparable to the whole area of interaction of two nuclei. This hypothesis allows to define some constraints on the string percolation model using data on transitional centralities in Au-Au collisions at these two energies. Results are extrapolated to the LHC energy where high string densities (exceeding the critical value) are confirmed for all classes of centralities in Pb-Pb collisions. Interaction between strings inside large clusters formed in nucleus-nucleus collisions is considered in a simplified Monte Carlo model. This model is applied to the qualitative analysis of the onset of collectivity and the ridge formation in Pb-Pb collisions. It is shown that the approach of the repulsive string-string interaction is capable to explain the appearance of elliptic and triangular flow observed in nucleus-nucleus collisions at RHIC and LHC energies.
hep-ph/9907559
Takehiko Asaka
T. Asaka, K. Hamaguchi, M. Kawasaki and T. Yanagida
Leptogenesis in Inflationary Universe
42 pages, 17 figures
Phys.Rev.D61:083512,2000
10.1103/PhysRevD.61.083512
null
hep-ph
null
We investigate the leptogenesis via decays of heavy Majorana neutrinos which are produced non-thermally in inflaton decays. We make a comprehensive study on the leptogenesis assuming various supersymmetric (SUSY) models for hybrid, new and topological inflations. For an estimation of the lepton asymmetry we adopt the Froggatt-Nielsen mechanism for mass matrices of quarks and leptons. We find that all of these models are successful to produce the lepton asymmetry enough to explain the baryon number in the present universe. Here we impose low reheating temperatures such as $T_R \lesssim 10^8$ GeV in order to suppress the abundance of gravitinos not to conflict with the big-bang nucleosynthesis. Furthermore, we find that the leptogenesis works very well even with $T_R \simeq 10^{6}$ GeV in the SUSY hybrid or new inflation model. It is known that such a reheating temperature is low enough to suppress the abundance of gravitinos of mass $m_{3/2} \simeq 100$ GeV--1 TeV. Thus, the leptogenesis is fully consistent with the big-bang nucleosynthesis in a wide region of the gravitino mass.
[ { "created": "Fri, 30 Jul 1999 07:36:45 GMT", "version": "v1" } ]
2014-11-17
[ [ "Asaka", "T.", "" ], [ "Hamaguchi", "K.", "" ], [ "Kawasaki", "M.", "" ], [ "Yanagida", "T.", "" ] ]
We investigate the leptogenesis via decays of heavy Majorana neutrinos which are produced non-thermally in inflaton decays. We make a comprehensive study on the leptogenesis assuming various supersymmetric (SUSY) models for hybrid, new and topological inflations. For an estimation of the lepton asymmetry we adopt the Froggatt-Nielsen mechanism for mass matrices of quarks and leptons. We find that all of these models are successful to produce the lepton asymmetry enough to explain the baryon number in the present universe. Here we impose low reheating temperatures such as $T_R \lesssim 10^8$ GeV in order to suppress the abundance of gravitinos not to conflict with the big-bang nucleosynthesis. Furthermore, we find that the leptogenesis works very well even with $T_R \simeq 10^{6}$ GeV in the SUSY hybrid or new inflation model. It is known that such a reheating temperature is low enough to suppress the abundance of gravitinos of mass $m_{3/2} \simeq 100$ GeV--1 TeV. Thus, the leptogenesis is fully consistent with the big-bang nucleosynthesis in a wide region of the gravitino mass.
2103.05658
Tyler Gorda
Tyler Gorda, Aleksi Kurkela, Risto Paatelainen, Saga S\"appi, Aleksi Vuorinen
Soft interactions in cold quark matter
6 pages, 4 figures; Companion letter for arXiv:2103.07427. Changes from v1: references added, further discussions added, half of final figure removed for space. Version published in PRL
null
10.1103/PhysRevLett.127.162003
HIP-2021-9/TH
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Accurate knowledge of the thermodynamic properties of zero-temperature, high-density quark matter plays an integral role in attempts to constrain the behavior of the dense QCD matter found inside neutron-star cores, irrespective of the phase realized inside the stars. In this Letter, we consider the weak-coupling expansion of the dense QCD equation of state and compute the next-to-next-to-next-to-leading-order contribution arising from the non-Abelian interactions among long-wavelength, dynamically screened gluonic fields. Accounting for these interactions requires an all-loop resummation, which can be performed using hard-thermal-loop (HTL) kinematic approximations. Concretely, we perform a full two-loop computation using the HTL effective theory, valid for the long-wavelength, or soft, modes. We find that the soft sector is well-behaved within cold quark matter, contrary to the case encountered at high temperatures, and find that the new contribution decreases the renormalization-scale dependence of the equation of state at high density.
[ { "created": "Tue, 9 Mar 2021 19:00:22 GMT", "version": "v1" }, { "created": "Thu, 16 Jun 2022 12:47:08 GMT", "version": "v2" } ]
2022-06-17
[ [ "Gorda", "Tyler", "" ], [ "Kurkela", "Aleksi", "" ], [ "Paatelainen", "Risto", "" ], [ "Säppi", "Saga", "" ], [ "Vuorinen", "Aleksi", "" ] ]
Accurate knowledge of the thermodynamic properties of zero-temperature, high-density quark matter plays an integral role in attempts to constrain the behavior of the dense QCD matter found inside neutron-star cores, irrespective of the phase realized inside the stars. In this Letter, we consider the weak-coupling expansion of the dense QCD equation of state and compute the next-to-next-to-next-to-leading-order contribution arising from the non-Abelian interactions among long-wavelength, dynamically screened gluonic fields. Accounting for these interactions requires an all-loop resummation, which can be performed using hard-thermal-loop (HTL) kinematic approximations. Concretely, we perform a full two-loop computation using the HTL effective theory, valid for the long-wavelength, or soft, modes. We find that the soft sector is well-behaved within cold quark matter, contrary to the case encountered at high temperatures, and find that the new contribution decreases the renormalization-scale dependence of the equation of state at high density.
hep-ph/0202205
Fabio Maltoni
F. Maltoni, D. Rainwater, S. Willenbrock
Measuring the top-quark Yukawa coupling at hadron colliders via tth, h->WW
11 pages, 3 figures
Phys.Rev.D66:034022,2002
10.1103/PhysRevD.66.034022
null
hep-ph
null
We study the signal and background for the process tth, h->WW at the LHC and a 100 TeV VLHC. Signals are studied in two-, three-, and four-lepton final states. We find a statistical uncertainty in the top-quark Yukawa coupling at the LHC of 16%, 8%, 12% for m_h = 130, 160, 190 GeV, respectively. The statistical uncertainty at the VLHC is likely to be negligible in comparison with the systematic uncertainty.
[ { "created": "Thu, 21 Feb 2002 22:40:28 GMT", "version": "v1" } ]
2014-11-17
[ [ "Maltoni", "F.", "" ], [ "Rainwater", "D.", "" ], [ "Willenbrock", "S.", "" ] ]
We study the signal and background for the process tth, h->WW at the LHC and a 100 TeV VLHC. Signals are studied in two-, three-, and four-lepton final states. We find a statistical uncertainty in the top-quark Yukawa coupling at the LHC of 16%, 8%, 12% for m_h = 130, 160, 190 GeV, respectively. The statistical uncertainty at the VLHC is likely to be negligible in comparison with the systematic uncertainty.
0705.3518
Nicolas Greiner
N.Greiner
Constraints On Unparticle Physics In Electroweak Gauge Boson Scattering
12 pages, 5 figures, typos corrected, references added
Phys.Lett.B653:75-80,2007
10.1016/j.physletb.2007.07.027
null
hep-ph
null
The existence of scale invariant physics would lead to new phenomena in particle physics that could be detected at the LHC. In this paper we exploit the effects of these unparticles in $WW \to WW$ scattering. From the requirement of unitarity we derive constraints on unparticle physics. We show that the existence of unparticles would lead to deviations in differential cross sections which can be measured. These deviations are sensitive on the scale dimension and on the spin characteristics of the unparticles.
[ { "created": "Thu, 24 May 2007 07:30:51 GMT", "version": "v1" }, { "created": "Mon, 4 Jun 2007 17:07:27 GMT", "version": "v2" } ]
2008-11-26
[ [ "Greiner", "N.", "" ] ]
The existence of scale invariant physics would lead to new phenomena in particle physics that could be detected at the LHC. In this paper we exploit the effects of these unparticles in $WW \to WW$ scattering. From the requirement of unitarity we derive constraints on unparticle physics. We show that the existence of unparticles would lead to deviations in differential cross sections which can be measured. These deviations are sensitive on the scale dimension and on the spin characteristics of the unparticles.
hep-ph/0608309
Shaouly Bar-Shalom
Shaouly Bar-Shalom, Nilendra G. Deshpande, Gad Eilam, Jing Jiang, Amarjit Soni
Majorana neutrinos and lepton-number-violating signals in top-quark and W-boson rare decays
latex, 7 pages, 2 figures. V2 as published in PLB
Phys.Lett.B643:342-347,2006
10.1016/j.physletb.2006.10.060
null
hep-ph
null
We discuss rare lepton-number-violating top-quark and W-boson four-body decays to final states containing a same-charge lepton pair, of the same or of different flavors: t -> b W- li^+ lj^+ and W+ -> J J' li^+ lj^+, where i \ne j or i=j and J J' stands for two light jets originating from a (u-bar d) or a (c-bar s) pair. These \Delta L=2 decays are forbidden in the Standard Model and may be mediated by exchanges of Majorana neutrinos. We adopt a model independent approach for the Majorana neutrinos mixing pattern and calculate the branching ratios (BR) for these decays. We find, for example, that for O(1) mixings between heavy and light Majorana neutrinos (not likely but not ruled out) and if at least one of the heavy Majorana neutrinos has a mass of ~100 GeV, then the BR's for these decays are: BR(t -> b li^+ lj^+ W-) ~ 10^{-4} and BR(W+ -> li^+ lj^+ J J') ~ 10^{-7} if m_N ~ 100 GeV and BR(t -> b li^+ lj^+ J J') ~ BR(W+ -> li^+ lj^+ J J') ~ 0.01 if m_N < 50 GeV. Taking into account the present limits on the neutrino mixing parameters, we obtain more realistic values for these BR's: BR(t -> b li^+ lj^+ W-) ~ 10^{-6} and BR(W+ -> li^+ lj^+ J J') ~ 10^{-10} for m_N ~ 100 GeV and BR(t -> b li^+ lj^+ J J') ~ BR(W+ -> li^+ lj^+ J J') ~ 10^{-6} for m_N < 50 GeV.
[ { "created": "Tue, 29 Aug 2006 17:59:50 GMT", "version": "v1" }, { "created": "Sun, 12 Nov 2006 20:16:14 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bar-Shalom", "Shaouly", "" ], [ "Deshpande", "Nilendra G.", "" ], [ "Eilam", "Gad", "" ], [ "Jiang", "Jing", "" ], [ "Soni", "Amarjit", "" ] ]
We discuss rare lepton-number-violating top-quark and W-boson four-body decays to final states containing a same-charge lepton pair, of the same or of different flavors: t -> b W- li^+ lj^+ and W+ -> J J' li^+ lj^+, where i \ne j or i=j and J J' stands for two light jets originating from a (u-bar d) or a (c-bar s) pair. These \Delta L=2 decays are forbidden in the Standard Model and may be mediated by exchanges of Majorana neutrinos. We adopt a model independent approach for the Majorana neutrinos mixing pattern and calculate the branching ratios (BR) for these decays. We find, for example, that for O(1) mixings between heavy and light Majorana neutrinos (not likely but not ruled out) and if at least one of the heavy Majorana neutrinos has a mass of ~100 GeV, then the BR's for these decays are: BR(t -> b li^+ lj^+ W-) ~ 10^{-4} and BR(W+ -> li^+ lj^+ J J') ~ 10^{-7} if m_N ~ 100 GeV and BR(t -> b li^+ lj^+ J J') ~ BR(W+ -> li^+ lj^+ J J') ~ 0.01 if m_N < 50 GeV. Taking into account the present limits on the neutrino mixing parameters, we obtain more realistic values for these BR's: BR(t -> b li^+ lj^+ W-) ~ 10^{-6} and BR(W+ -> li^+ lj^+ J J') ~ 10^{-10} for m_N ~ 100 GeV and BR(t -> b li^+ lj^+ J J') ~ BR(W+ -> li^+ lj^+ J J') ~ 10^{-6} for m_N < 50 GeV.
hep-ph/0504197
Mikhail Voloshin
M.B. Voloshin
The ${\bar c} c$ purity of $\psi(3770)$ and $\psi'$ challenged
13 pages
Phys.Rev.D71:114003,2005
10.1103/PhysRevD.71.114003
FTPI-MINN-05/12, UMN-TH-2354-05
hep-ph
null
It is suggested that the resonance $\psi(3770)$ may contain a sizeable ($O(10%)$ in terms of the probability weight factor) four-quark component with the up- and down- quarks and antiquarks in addition to the $c {\bar c}$ pair, which component in itself has a substantial part with the isospin I=1. Furthermore such four-quark part of the wave function should also affect the properties of the $\psi'$ charmonium resonance through the $\psi(3770) - \psi'$ mixing previously considered in the literature. It is argued that an admixture of extra light quark pairs can explain a possible discrepancy between the theoretical expectations and the recent data on the non-$D {\bar D}$ decay width of the $\psi(3770)$ and the ratio of the yield of charged and neutral $D$ meson pairs in its decays, as well as on the extra rate of the $\psi'$ direct decay into light hadrons and the rate of the decay $\psi' \to \pi^0 J/\psi$. It is further argued that the suggested four-quark component of the wave function of the $\psi(3770)$ should give rise to a measurable rate of the decays $\psi(3770) \to \eta J/\psi$ and $\psi(3770) \to \pi^0 J/\psi$.
[ { "created": "Thu, 21 Apr 2005 19:54:18 GMT", "version": "v1" } ]
2008-11-26
[ [ "Voloshin", "M. B.", "" ] ]
It is suggested that the resonance $\psi(3770)$ may contain a sizeable ($O(10%)$ in terms of the probability weight factor) four-quark component with the up- and down- quarks and antiquarks in addition to the $c {\bar c}$ pair, which component in itself has a substantial part with the isospin I=1. Furthermore such four-quark part of the wave function should also affect the properties of the $\psi'$ charmonium resonance through the $\psi(3770) - \psi'$ mixing previously considered in the literature. It is argued that an admixture of extra light quark pairs can explain a possible discrepancy between the theoretical expectations and the recent data on the non-$D {\bar D}$ decay width of the $\psi(3770)$ and the ratio of the yield of charged and neutral $D$ meson pairs in its decays, as well as on the extra rate of the $\psi'$ direct decay into light hadrons and the rate of the decay $\psi' \to \pi^0 J/\psi$. It is further argued that the suggested four-quark component of the wave function of the $\psi(3770)$ should give rise to a measurable rate of the decays $\psi(3770) \to \eta J/\psi$ and $\psi(3770) \to \pi^0 J/\psi$.
0812.0520
Zhi-Zhong Xing
Ping Ren and Zhi-zhong Xing
Lepton-number-violating decays of singly-charged Higgs bosons in the minimal type-(I+II) seesaw model at the TeV scale
RevTex 16 pages, 3 PS figures
Chin.Phys.C34:433-443,2010
10.1088/1674-1137/34/4/003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The lepton-number-violating decays of singly-charged Higgs bosons H^\pm are investigated in the minimal type-(I+II) seesaw model with one SU(2)_L Higgs triplet \Delta and one heavy Majorana neutrino N_1 at the TeV scale. We find that the branching ratios {\cal B}(H^+ \to l^+_\alpha{\bar \nu}) (for \alpha = e, \mu, \tau) depend not only on the mass and mixing parameters of three light neutrinos \nu_i (for i = 1, 2, 3) but also on those of N_1. Assuming the mass of N_1 to lie in the range of 200 GeV to 1 TeV, we figure out the generous interference bands for the contributions of \nu_i and N_1 to {\cal B}(H^+ \to l^+_\alpha{\bar \nu}). We illustrate some salient features of such interference effects by considering three typical mass patterns of \nu_i, and show that the relevant Majorana CP-violating phases can affect the magnitudes of {\cal B}(H^+ \to l^+_\alpha{\bar \nu}) in this parameter region.
[ { "created": "Tue, 2 Dec 2008 14:53:29 GMT", "version": "v1" } ]
2011-04-07
[ [ "Ren", "Ping", "" ], [ "Xing", "Zhi-zhong", "" ] ]
The lepton-number-violating decays of singly-charged Higgs bosons H^\pm are investigated in the minimal type-(I+II) seesaw model with one SU(2)_L Higgs triplet \Delta and one heavy Majorana neutrino N_1 at the TeV scale. We find that the branching ratios {\cal B}(H^+ \to l^+_\alpha{\bar \nu}) (for \alpha = e, \mu, \tau) depend not only on the mass and mixing parameters of three light neutrinos \nu_i (for i = 1, 2, 3) but also on those of N_1. Assuming the mass of N_1 to lie in the range of 200 GeV to 1 TeV, we figure out the generous interference bands for the contributions of \nu_i and N_1 to {\cal B}(H^+ \to l^+_\alpha{\bar \nu}). We illustrate some salient features of such interference effects by considering three typical mass patterns of \nu_i, and show that the relevant Majorana CP-violating phases can affect the magnitudes of {\cal B}(H^+ \to l^+_\alpha{\bar \nu}) in this parameter region.
0804.2180
Jean-Philippe Lansberg
J.P. Lansberg, T.N. Pham
Two-photon decay of pseudoscalar quarkonia
Presented by T.N. Pham at the Joint Meeting Heidelberg-Liege-Paris-Wroclaw (HLPW08), Spa, Belgium, 6-8 March 2008, 9 pages, 2 figures, LaTeX, uses aip-6s.clo, aipproc.cls and aipxfm.sty (included)
null
10.1063/1.2987179
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on our recent evaluation of the two-photon width of the pseudoscalar quarkonia, eta_c(nS) and eta_b(nS) in an approach based on Heavy-Quark Spin Symmetry (HQSS). To what concerns the 1S state eta_c, our parameter-free computation agrees with experiments, as well as most of other theoretical works. On the other hand, our computation for the 2S-state looks 2S like a confirmation that there may exist an anomaly related to the decay of eta_c(2S), especially in the light of the new preliminary result of the Belle collaboration. We also point out that the essentially model-independent ratio of eta_b two-photon width to the Upsilon leptonic width and the eta_b two-photon width could be used to extract the strong coupling constant alpha_s.
[ { "created": "Mon, 14 Apr 2008 13:34:25 GMT", "version": "v1" } ]
2009-11-13
[ [ "Lansberg", "J. P.", "" ], [ "Pham", "T. N.", "" ] ]
We report on our recent evaluation of the two-photon width of the pseudoscalar quarkonia, eta_c(nS) and eta_b(nS) in an approach based on Heavy-Quark Spin Symmetry (HQSS). To what concerns the 1S state eta_c, our parameter-free computation agrees with experiments, as well as most of other theoretical works. On the other hand, our computation for the 2S-state looks 2S like a confirmation that there may exist an anomaly related to the decay of eta_c(2S), especially in the light of the new preliminary result of the Belle collaboration. We also point out that the essentially model-independent ratio of eta_b two-photon width to the Upsilon leptonic width and the eta_b two-photon width could be used to extract the strong coupling constant alpha_s.
1105.3624
Alberto Guffanti
Nicolas Greiner, Alberto Guffanti, Thomas Reiter, J\"urgen Reuter
NLO QCD corrections to the production of two bottom-antibottom pairs at the LHC
4 pages, 3 figures
Phys.Rev.Lett. 107:102002,2011
10.1103/PhysRevLett.107.102002
FREIBURG-PHENO-2011-008, Nikhef 2011-014, MPP-2011-55, DESY 11-079
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report the results of a computation of the full next-to-leading order QCD corrections to the production of two $b\bar{b}$ pairs at the LHC. This calculation at the parton level provides predictions for well separated $b$-jets. The results show that the next-to-leading order corrections lead to an enhancement of the cross-section for the central scale choice by roughly 50% with respect to the leading order result. The theoretical uncertainty estimated by variation of the renormalization and factorization scales is strongly reduced by the inclusion of next-to-leading order corrections.
[ { "created": "Wed, 18 May 2011 13:32:52 GMT", "version": "v1" } ]
2011-09-29
[ [ "Greiner", "Nicolas", "" ], [ "Guffanti", "Alberto", "" ], [ "Reiter", "Thomas", "" ], [ "Reuter", "Jürgen", "" ] ]
We report the results of a computation of the full next-to-leading order QCD corrections to the production of two $b\bar{b}$ pairs at the LHC. This calculation at the parton level provides predictions for well separated $b$-jets. The results show that the next-to-leading order corrections lead to an enhancement of the cross-section for the central scale choice by roughly 50% with respect to the leading order result. The theoretical uncertainty estimated by variation of the renormalization and factorization scales is strongly reduced by the inclusion of next-to-leading order corrections.
hep-ph/0411026
Edmond Berger
Edmond L. Berger, Jianwei Qiu, and Yili Wang
Upsilon Transverse Momentum at Hadron Colliders
4 pages, 5 figures. Presented at the 2004 Meeting of the APS Division of Particles and Fields, University of California, Riverside, CA, Aug 26-31, 2004
Int.J.Mod.Phys.A20:3753-3755,2005
10.1142/S0217751X05027515
ANL-HEP-CP-04-110
hep-ph
null
We predict the shape of the transverse momentum p_T spectrum of Upsilon production. The distribution at low p_T is dominated by the region of small impact parameter b and may be computed reliably in perturbation theory. We resum to all orders in the strong coupling alpha_s the process-independent large logarithmic contributions that arise from initial-state gluon showers in the small p_T (< M_Upsilon) region. The cross section at large p_T is represented by the alpha_s^3 lowest-order non-vanishing perturbative contribution.
[ { "created": "Mon, 1 Nov 2004 21:39:01 GMT", "version": "v1" } ]
2014-11-18
[ [ "Berger", "Edmond L.", "" ], [ "Qiu", "Jianwei", "" ], [ "Wang", "Yili", "" ] ]
We predict the shape of the transverse momentum p_T spectrum of Upsilon production. The distribution at low p_T is dominated by the region of small impact parameter b and may be computed reliably in perturbation theory. We resum to all orders in the strong coupling alpha_s the process-independent large logarithmic contributions that arise from initial-state gluon showers in the small p_T (< M_Upsilon) region. The cross section at large p_T is represented by the alpha_s^3 lowest-order non-vanishing perturbative contribution.
0906.2473
Shi-Yuan Li
Wei Han, Shi-Yuan Li, Yong-Hui Shang, Feng-Lan Shao, Tao Yao
Exotic hadron production in quark combination model
5 pages, 1 figure, new version with minor corrections and one ref. added
Phys.Rev.C80:035202,2009
10.1103/PhysRevC.80.035202
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The philosophy on production of exotic hadrons (multi-quark states) in the framework of quark combination model is investigated, taking $f_0(980)$ as an example. The production rate and $p_T$ spectra of $f_0(980)$ considered as $(s\bar s)$ or $(s\bar q\bar s q)$ respectively, are calculated and compared in Au+Au collisions at $\sqrt{s_{NN}}=200GeV$. The unitarity of various combination models, when open for exotic hadron production, is addressed.
[ { "created": "Sat, 13 Jun 2009 12:58:05 GMT", "version": "v1" }, { "created": "Sat, 20 Jun 2009 13:48:33 GMT", "version": "v2" } ]
2009-11-06
[ [ "Han", "Wei", "" ], [ "Li", "Shi-Yuan", "" ], [ "Shang", "Yong-Hui", "" ], [ "Shao", "Feng-Lan", "" ], [ "Yao", "Tao", "" ] ]
The philosophy on production of exotic hadrons (multi-quark states) in the framework of quark combination model is investigated, taking $f_0(980)$ as an example. The production rate and $p_T$ spectra of $f_0(980)$ considered as $(s\bar s)$ or $(s\bar q\bar s q)$ respectively, are calculated and compared in Au+Au collisions at $\sqrt{s_{NN}}=200GeV$. The unitarity of various combination models, when open for exotic hadron production, is addressed.
hep-ph/9712214
Helmut Eberl
A. Bartl, H. Eberl, K. Hidaka, T. Kon, W. Majerotto, Y. Yamada
SUSY--QCD Corrections to Higgs Particle Decays into Quarks and Squarks
11 pages LaTex including 5 figures, style sprocl.sty, Talk presented by A. Bartl at the International Workshop on Quantum Effects in the MSSM, September 9 - 13, 1997, Barcelona, Spain
null
null
UWThPh-1997-47, HEPHY-PUB 680/97
hep-ph
null
We study the decays of the Higgs bosons $H^{\pm}$, $H^0$, and $A^0$ within the Minimal Supersymmetric Standard Model. For decays into quarks and squarks we include the supersymmetric QCD radiative corrections. We find that the corrections are significant and can go up to 50%. The supersymmetric decay modes $H^+ \to \tilde t \bar{\tilde b}$ and $H^0 (A^0) \to \tilde t \bar{\tilde t}$ can be dominant in a wide range of the model parameters due to the large Yukawa couplings and mixings of $\tilde t$ and $\tilde b$.
[ { "created": "Mon, 1 Dec 1997 14:31:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bartl", "A.", "" ], [ "Eberl", "H.", "" ], [ "Hidaka", "K.", "" ], [ "Kon", "T.", "" ], [ "Majerotto", "W.", "" ], [ "Yamada", "Y.", "" ] ]
We study the decays of the Higgs bosons $H^{\pm}$, $H^0$, and $A^0$ within the Minimal Supersymmetric Standard Model. For decays into quarks and squarks we include the supersymmetric QCD radiative corrections. We find that the corrections are significant and can go up to 50%. The supersymmetric decay modes $H^+ \to \tilde t \bar{\tilde b}$ and $H^0 (A^0) \to \tilde t \bar{\tilde t}$ can be dominant in a wide range of the model parameters due to the large Yukawa couplings and mixings of $\tilde t$ and $\tilde b$.
2009.09667
Mikhail Braun
M.A. Braun, C. Pajares
Flow coefficients in O-O Al-Al and Cu-Cu collisions at 200 GeV in the fusing color string model
11 pages, 4 figures
Phys. Rev. C 103, 054902 (2021)
10.1103/PhysRevC.103.054902
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In view of the planning experiments for collisions of light nuclei at RHIC the flow coefficients for O-O, Al-AL and Cu-Cu collisions are studied in the color string percolation model. Our results for $v_2$ are somewhat smaller than predicted by other groups although with the same dependence on centrality. Our obtained $v_3$ lie between predictions of other groups.
[ { "created": "Mon, 21 Sep 2020 08:06:11 GMT", "version": "v1" } ]
2021-05-12
[ [ "Braun", "M. A.", "" ], [ "Pajares", "C.", "" ] ]
In view of the planning experiments for collisions of light nuclei at RHIC the flow coefficients for O-O, Al-AL and Cu-Cu collisions are studied in the color string percolation model. Our results for $v_2$ are somewhat smaller than predicted by other groups although with the same dependence on centrality. Our obtained $v_3$ lie between predictions of other groups.