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1204.3762
Jerzy Kami\'nski
K. Krajewska and J. Z. Kaminski
Symmetries in nonlinear Bethe-Heitler process
4 pages, 4 figures
null
10.1103/PhysRevA.86.021402
null
hep-ph physics.acc-ph physics.atom-ph physics.plasm-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Nonlinear Bethe-Heitler process in a bichromatic laser field is investigated using strong-field QED formalism. Symmetry properties of angular distributions of created $e^-e^+$ pairs are analyzed. These properties are showed to be governed by a behavior of the vector potential characterizing the laser field, rather than by the respective electric field component.
[ { "created": "Tue, 17 Apr 2012 11:22:08 GMT", "version": "v1" } ]
2015-06-04
[ [ "Krajewska", "K.", "" ], [ "Kaminski", "J. Z.", "" ] ]
Nonlinear Bethe-Heitler process in a bichromatic laser field is investigated using strong-field QED formalism. Symmetry properties of angular distributions of created $e^-e^+$ pairs are analyzed. These properties are showed to be governed by a behavior of the vector potential characterizing the laser field, rather than by the respective electric field component.
1101.2431
Farida Iddir
F. Iddir and L. Semlala
The hybrid meson: new results from the updated mg and alpha_s parameters
10 pages, 8 tables
null
10.1142/S0217751X11054097
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present new results concerning the masses and the decay widths of the most interesting hybrid meson states taking as inputs the gluon mass mg and the non-perturbative QCD running coupling constant ?alpha_s(0) comming from both LQCD and SDE recent estimations.
[ { "created": "Wed, 12 Jan 2011 19:38:18 GMT", "version": "v1" }, { "created": "Tue, 2 Aug 2011 22:30:16 GMT", "version": "v2" } ]
2015-05-27
[ [ "Iddir", "F.", "" ], [ "Semlala", "L.", "" ] ]
We present new results concerning the masses and the decay widths of the most interesting hybrid meson states taking as inputs the gluon mass mg and the non-perturbative QCD running coupling constant ?alpha_s(0) comming from both LQCD and SDE recent estimations.
0705.3047
T. Lappi
H. Kowalski, T. Lappi, R. Venugopalan
Nuclear enhancement of universal dynamics of high parton densities
4 pages, 5 figures, RevTeX V2: Clarifications, figs 1 and 3 modified to include bCGC model and NMC Sn/C data. Published in PRL
Phys.Rev.Lett.100:022303,2008
10.1103/PhysRevLett.100.022303
null
hep-ph nucl-ex nucl-th
null
We show that the enhancement of the saturation scale in large nuclei relative to the proton is significantly influenced by the effects of quantum evolution and the impact parameter dependence of dipole cross sections in high energy QCD. We demonstrate that there is a strong A dependence in diffractive deeply inelastic scattering and discuss its sensitivity to the measurement of the recoil nucleus.
[ { "created": "Tue, 22 May 2007 15:00:38 GMT", "version": "v1" }, { "created": "Fri, 18 Jan 2008 07:54:00 GMT", "version": "v2" } ]
2010-03-25
[ [ "Kowalski", "H.", "" ], [ "Lappi", "T.", "" ], [ "Venugopalan", "R.", "" ] ]
We show that the enhancement of the saturation scale in large nuclei relative to the proton is significantly influenced by the effects of quantum evolution and the impact parameter dependence of dipole cross sections in high energy QCD. We demonstrate that there is a strong A dependence in diffractive deeply inelastic scattering and discuss its sensitivity to the measurement of the recoil nucleus.
hep-ph/9802379
Kirill Melnikov
Kirill Melnikov and Alexander Yelkhovsky
Top quark production at threshold with O(alpha_s^2) accuracy
15 pages, Latex, one figure, some misprints corrected
Nucl.Phys. B528 (1998) 59-72
10.1016/S0550-3213(98)00348-4
BudkerINP-98-7, TTP98-10
hep-ph
null
We calculate the next-to-next-to-leading order correction to the cross section for top quark pair production in e+e- annihilation in the threshold region, resumming all O [ (alpha_s/beta)^n (alpha_s^2, beta^2, alpha_s beta) ] terms of perturbation series. We find that the magnitude of the NNLO correction is comparable to the size of the NLO corrections.
[ { "created": "Fri, 20 Feb 1998 17:23:09 GMT", "version": "v1" }, { "created": "Sat, 21 Feb 1998 15:49:41 GMT", "version": "v2" }, { "created": "Sat, 9 May 1998 09:21:26 GMT", "version": "v3" } ]
2009-10-31
[ [ "Melnikov", "Kirill", "" ], [ "Yelkhovsky", "Alexander", "" ] ]
We calculate the next-to-next-to-leading order correction to the cross section for top quark pair production in e+e- annihilation in the threshold region, resumming all O [ (alpha_s/beta)^n (alpha_s^2, beta^2, alpha_s beta) ] terms of perturbation series. We find that the magnitude of the NNLO correction is comparable to the size of the NLO corrections.
hep-ph/0005302
V. Gogohia
V. Gogohia
Can instantons saturate the large mass of the $\eta'$ meson in the chiral limit?
14 pages, essential clarification is introduced, some numerical numbers are corrected
Phys.Lett. B501 (2001) 60-68
10.1016/S0370-2693(01)00107-1
null
hep-ph
null
Using the trace anomaly and low energy relations, as well as Witten-Veneziano formula for the mass of the $\eta'$ meson, the chiral topology of the QCD nonperturbative instanton vacuum has been numerically evaluated. Our formalism makes it possible to express the topological susceptibility and the mass of the $\eta'$ meson as a functions of the instanton number density in the chiral limit. We have explicitly shown that the topological susceptibility in this case is approximately one fours and one half of its phenomenological value at instanton number densities in the chiral limit, 0.5 fm^{-4} and 1.0 fm^{-4}, respectively. Thus the instanton contributions substantially underestimate the mass of the $\eta'$ meson which still remains large in the chiral limit. With the help of the above-mentioned Witten-Veneziano formula, we derived an absolute lower bounds for the pion decay constant and the mass of the $\eta'$ meson in the chiral limit.
[ { "created": "Tue, 30 May 2000 14:06:14 GMT", "version": "v1" }, { "created": "Tue, 7 Nov 2000 12:12:27 GMT", "version": "v2" }, { "created": "Wed, 15 Nov 2000 16:38:22 GMT", "version": "v3" } ]
2009-10-31
[ [ "Gogohia", "V.", "" ] ]
Using the trace anomaly and low energy relations, as well as Witten-Veneziano formula for the mass of the $\eta'$ meson, the chiral topology of the QCD nonperturbative instanton vacuum has been numerically evaluated. Our formalism makes it possible to express the topological susceptibility and the mass of the $\eta'$ meson as a functions of the instanton number density in the chiral limit. We have explicitly shown that the topological susceptibility in this case is approximately one fours and one half of its phenomenological value at instanton number densities in the chiral limit, 0.5 fm^{-4} and 1.0 fm^{-4}, respectively. Thus the instanton contributions substantially underestimate the mass of the $\eta'$ meson which still remains large in the chiral limit. With the help of the above-mentioned Witten-Veneziano formula, we derived an absolute lower bounds for the pion decay constant and the mass of the $\eta'$ meson in the chiral limit.
hep-ph/9807373
Sreerup Raychaudhuri
Debajyoti Choudhury and Sreerup Raychaudhuri
Signals of R-Parity Violation at a Muon Collider
29 pages LaTeX, 12 postscript figures, macros included
null
null
CERN-TH/98-222, MRI-PHY/P980756
hep-ph
null
We investigate the effects of R-parity-violating $LL\bar E$ and $LQ\bar D$ operators on the production of fermion pairs at a $\mu^+ \mu^-$ collider with high energy and luminosity. We show that comparison of angular distributions leads to useful discovery limits for the R-parity-violating couplings, especially if the exchanged sfermions turn out to be heavy. Products of these couplings can also be probed well beyond present experimental limits, especially for the second and third generations. Finally, we compare results at a muon collider with those obtainable from an $e^+ e^-$ linear collider with similar energy and luminosity.
[ { "created": "Tue, 14 Jul 1998 19:21:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Choudhury", "Debajyoti", "" ], [ "Raychaudhuri", "Sreerup", "" ] ]
We investigate the effects of R-parity-violating $LL\bar E$ and $LQ\bar D$ operators on the production of fermion pairs at a $\mu^+ \mu^-$ collider with high energy and luminosity. We show that comparison of angular distributions leads to useful discovery limits for the R-parity-violating couplings, especially if the exchanged sfermions turn out to be heavy. Products of these couplings can also be probed well beyond present experimental limits, especially for the second and third generations. Finally, we compare results at a muon collider with those obtainable from an $e^+ e^-$ linear collider with similar energy and luminosity.
hep-ph/0302259
Anja Werthenbach
J. Fleischer, A. Leike, T. Riemann and A. Werthenbach
Elektroweak one-loop corrections for e^+e^- annihilation into t\bar{t} including hard bremsstrahlung
34 pages
Eur.Phys.J. C31 (2003) 37-56
10.1140/epjc/s2003-01263-8
null
hep-ph
null
We present the complete electroweak one-loop corrections to top-pair production at a linear e^+e^- collider in the continuum region. Besides weak and photonic virtual corrections, real hard bremsstrahlung with simple realistic kinematical cuts is included. For the bremsstrahlung we advocate a semi-analytical approach with a high numerical accuracy. The virtual corrections are parametrized through six independent form factors, suitable for Monte-Carlo implementation. Alternatively, our numerical package topfit, a stand-alone code, can be utilized for the calculation of both differential and integrated cross sections as well as forward--backward asymmetries.
[ { "created": "Thu, 27 Feb 2003 17:36:16 GMT", "version": "v1" } ]
2009-11-10
[ [ "Fleischer", "J.", "" ], [ "Leike", "A.", "" ], [ "Riemann", "T.", "" ], [ "Werthenbach", "A.", "" ] ]
We present the complete electroweak one-loop corrections to top-pair production at a linear e^+e^- collider in the continuum region. Besides weak and photonic virtual corrections, real hard bremsstrahlung with simple realistic kinematical cuts is included. For the bremsstrahlung we advocate a semi-analytical approach with a high numerical accuracy. The virtual corrections are parametrized through six independent form factors, suitable for Monte-Carlo implementation. Alternatively, our numerical package topfit, a stand-alone code, can be utilized for the calculation of both differential and integrated cross sections as well as forward--backward asymmetries.
hep-ph/9803323
Piotr Chankowski
W. Krolikowski (Inst. of Theor. Phys., Warsaw University)
Texture dynamics including potential sterile neutrino
LaTeX, 20 pages, no figures
Nuovo Cim. A111 (1998) 1257-1273
10.1007/BF03545793
IFT/98-25
hep-ph
null
A unified form of mass matrix proposed previously for all fundamental fermions is extended to include the sterile neutrino $\nu_s$, presumed to mix mainly with $\nu_e$, while $\nu_\tau$ mixes strongly with $\nu_\mu$ (and both $\nu_\mu$ and $\nu_\tau$ weakly with $\nu_e$ and $\nu_s$). It turns out that the former mixing can be responsible for oscillations of solar neutrinos, while the latter for those of atmospheric neutrinos. It is mentioned in a footnote that $\nu_s$ is one of two sterile neutrinos, possible from a viewpoint of an algebraic construction. The charged-lepton factor $U^{(e)}$ in the leptonic four-dimensional CKM matrix $V=U^{(\nu) \dagger}U^{(e)}$ is determined through the small deviation of our previous prediction $m_\tau=1776.80$ MeV (valid at the level of $ U^{(e)} = {\bf 1}$) from the experimental value $m_\tau=1777.00^{+0.30}_{-0.27}$ MeV. Then, it gives corrections to the four-dimensional mixing of $\nu_e$, $\nu_\mu$, $\nu_\tau$, $\nu_s$ leading, in particular, to small $\nu_e\to\nu_\mu$, $\nu_e\to \nu_\tau$ and $\nu_\mu\to\nu_s$ oscillations (absent at the level of $U^{(e)}= 1$). However, the LSND estimates of $\bar{\nu}_\mu \to \bar{\nu}_e$ and $\nu_\mu\to\nu_e$ oscillations are too large to be explained by these corrections, though in the case of $\nu_\mu \to\nu_e$ they seem to be at the edge of such possible explanation.
[ { "created": "Thu, 12 Mar 1998 15:44:25 GMT", "version": "v1" } ]
2022-03-02
[ [ "Krolikowski", "W.", "", "Inst. of Theor. Phys., Warsaw University" ] ]
A unified form of mass matrix proposed previously for all fundamental fermions is extended to include the sterile neutrino $\nu_s$, presumed to mix mainly with $\nu_e$, while $\nu_\tau$ mixes strongly with $\nu_\mu$ (and both $\nu_\mu$ and $\nu_\tau$ weakly with $\nu_e$ and $\nu_s$). It turns out that the former mixing can be responsible for oscillations of solar neutrinos, while the latter for those of atmospheric neutrinos. It is mentioned in a footnote that $\nu_s$ is one of two sterile neutrinos, possible from a viewpoint of an algebraic construction. The charged-lepton factor $U^{(e)}$ in the leptonic four-dimensional CKM matrix $V=U^{(\nu) \dagger}U^{(e)}$ is determined through the small deviation of our previous prediction $m_\tau=1776.80$ MeV (valid at the level of $ U^{(e)} = {\bf 1}$) from the experimental value $m_\tau=1777.00^{+0.30}_{-0.27}$ MeV. Then, it gives corrections to the four-dimensional mixing of $\nu_e$, $\nu_\mu$, $\nu_\tau$, $\nu_s$ leading, in particular, to small $\nu_e\to\nu_\mu$, $\nu_e\to \nu_\tau$ and $\nu_\mu\to\nu_s$ oscillations (absent at the level of $U^{(e)}= 1$). However, the LSND estimates of $\bar{\nu}_\mu \to \bar{\nu}_e$ and $\nu_\mu\to\nu_e$ oscillations are too large to be explained by these corrections, though in the case of $\nu_\mu \to\nu_e$ they seem to be at the edge of such possible explanation.
hep-ph/0505242
Konstantinos Dimopoulos
Anne-Christine Davis and Konstantinos Dimopoulos
Cosmic Superstrings and Primordial Magnetogenesis
RevTex, 9 pages, no figures
Phys.Rev. D72 (2005) 043517
10.1103/PhysRevD.72.043517
null
hep-ph astro-ph hep-th
null
Cosmic superstrings are produced at the end of brane inflation. Their properties are similar to cosmic strings arising in grand unified theories. Like cosmic strings they can give rise to a primordial magnetic field, as a result of vortical motions stirred in the ionised plasma by the gravitational pull of moving string segments. The resulting magnetic field is both strong enough and coherent enough to seed the galactic dynamo and explain the observed magnetic fields of the galaxies.
[ { "created": "Fri, 27 May 2005 17:13:23 GMT", "version": "v1" } ]
2009-11-11
[ [ "Davis", "Anne-Christine", "" ], [ "Dimopoulos", "Konstantinos", "" ] ]
Cosmic superstrings are produced at the end of brane inflation. Their properties are similar to cosmic strings arising in grand unified theories. Like cosmic strings they can give rise to a primordial magnetic field, as a result of vortical motions stirred in the ionised plasma by the gravitational pull of moving string segments. The resulting magnetic field is both strong enough and coherent enough to seed the galactic dynamo and explain the observed magnetic fields of the galaxies.
1902.06510
Jian-Hua Gao
Jian-Hua Gao and Zuo-Tang Liang
Relativistic Quantum Kinetic Theory for Massive Fermions and Spin Effects
5 pages, Typos fixed and references updated
Phys. Rev. D 100, 056021 (2019)
10.1103/PhysRevD.100.056021
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the complete first order relativistic quantum kinetic theory with spin for massive fermions derived from the Wigner function formalism in a concise form that shows explicitly how the 32 Wigner equations reduce to 4 independent transport equations. We solve modified on-shell conditions to obtain the general solution and present the corresponding transport equations in three different forms that are suitable for different purposes. We demonstrate how different spin effects arise from the kinetic theory by calculating the chiral separation effect with mass correction, the chiral anomaly from the axial current and the quantum magnetic moment density induced by vorticity and magnetic field. We also show how to generate the global polarization effect due to spin vorticity coupling. The formalism presented may serve as a practical theoretical framework to study different spin effects in relativistic fermion systems encountered in different areas such as heavy ion, astro-particle and condensed matter physics as well.
[ { "created": "Mon, 18 Feb 2019 11:06:19 GMT", "version": "v1" }, { "created": "Tue, 26 Feb 2019 05:59:20 GMT", "version": "v2" } ]
2019-10-02
[ [ "Gao", "Jian-Hua", "" ], [ "Liang", "Zuo-Tang", "" ] ]
We present the complete first order relativistic quantum kinetic theory with spin for massive fermions derived from the Wigner function formalism in a concise form that shows explicitly how the 32 Wigner equations reduce to 4 independent transport equations. We solve modified on-shell conditions to obtain the general solution and present the corresponding transport equations in three different forms that are suitable for different purposes. We demonstrate how different spin effects arise from the kinetic theory by calculating the chiral separation effect with mass correction, the chiral anomaly from the axial current and the quantum magnetic moment density induced by vorticity and magnetic field. We also show how to generate the global polarization effect due to spin vorticity coupling. The formalism presented may serve as a practical theoretical framework to study different spin effects in relativistic fermion systems encountered in different areas such as heavy ion, astro-particle and condensed matter physics as well.
1208.6262
Jens Erler
Jens Erler
Electroweak tests of the Standard Model
8 pages, 5 figures, plenary talk presented at the Eleventh Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2012), St. Petersburg, FL, May 29-June 3, 2012
null
10.1063/1.4826727
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electroweak precision tests of the Standard Model of the fundamental interactions are reviewed ranging from the lowest to the highest energy experiments. Results from global fits are presented with particular emphasis on the extraction of fundamental parameters such as the Fermi constant, the strong coupling constant, the electroweak mixing angle, and the mass of the Higgs boson. Constraints on physics beyond the Standard Model are also discussed.
[ { "created": "Thu, 30 Aug 2012 18:47:36 GMT", "version": "v1" } ]
2015-06-11
[ [ "Erler", "Jens", "" ] ]
Electroweak precision tests of the Standard Model of the fundamental interactions are reviewed ranging from the lowest to the highest energy experiments. Results from global fits are presented with particular emphasis on the extraction of fundamental parameters such as the Fermi constant, the strong coupling constant, the electroweak mixing angle, and the mass of the Higgs boson. Constraints on physics beyond the Standard Model are also discussed.
1711.07243
Qin Qin
Qin Qin, Qiang Li, Cai-Dian L\"u, Fu-Sheng Yu and Si-Hong Zhou
Charged lepton flavor violating Higgs decays at future $e^+e^-$ colliders
20 pages, 2 figures (extend the CEPC study to the FCC-ee and the ILC, and to match the published version)
Eur. Phys. J. C (2018) 78: 835
10.1140/epjc/s10052-018-6298-7
SI-HEP-2017-25, QFET-2017-22
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After the discovery of the Higgs boson, several future experiments have been proposed to study the Higgs boson properties, including two circular lepton colliders, the CEPC and the FCC-ee, and one linear lepton collider, the ILC. We evaluate the precision reach of these colliders in measuring the branching ratios of the charged lepton flavor violating Higgs decays $H\to e^\pm\mu^\mp$, $e^\pm\tau^\mp$ and $\mu^\pm\tau^\mp$. The expected upper bounds on the branching ratios given by the circular (linear) colliders are found to be $\mathcal{B}(H\to e^\pm\mu^\mp) < 1.2\ (2.1) \times 10^{-5}$, $\mathcal{B}(H\to e^\pm\tau^\mp) < 1.6\ (2.4) \times 10^{-4}$ and $\mathcal{B}(H\to \mu^\pm\tau^\mp) < 1.4\ (2.3) \times 10^{-4}$ at 95\% CL, which are improved by one to two orders compared to the current experimental bounds. We also discuss the constraints that these upper bounds set on certain theory parameters, including the charged lepton flavor violating Higgs couplings, the corresponding parameters in the type-III 2HDM, and the new physics cut-off scales in the SMEFT, in RS models and in models with heavy neutrinos.
[ { "created": "Mon, 20 Nov 2017 10:26:23 GMT", "version": "v1" }, { "created": "Wed, 10 Oct 2018 18:33:45 GMT", "version": "v2" } ]
2018-10-23
[ [ "Qin", "Qin", "" ], [ "Li", "Qiang", "" ], [ "Lü", "Cai-Dian", "" ], [ "Yu", "Fu-Sheng", "" ], [ "Zhou", "Si-Hong", "" ] ]
After the discovery of the Higgs boson, several future experiments have been proposed to study the Higgs boson properties, including two circular lepton colliders, the CEPC and the FCC-ee, and one linear lepton collider, the ILC. We evaluate the precision reach of these colliders in measuring the branching ratios of the charged lepton flavor violating Higgs decays $H\to e^\pm\mu^\mp$, $e^\pm\tau^\mp$ and $\mu^\pm\tau^\mp$. The expected upper bounds on the branching ratios given by the circular (linear) colliders are found to be $\mathcal{B}(H\to e^\pm\mu^\mp) < 1.2\ (2.1) \times 10^{-5}$, $\mathcal{B}(H\to e^\pm\tau^\mp) < 1.6\ (2.4) \times 10^{-4}$ and $\mathcal{B}(H\to \mu^\pm\tau^\mp) < 1.4\ (2.3) \times 10^{-4}$ at 95\% CL, which are improved by one to two orders compared to the current experimental bounds. We also discuss the constraints that these upper bounds set on certain theory parameters, including the charged lepton flavor violating Higgs couplings, the corresponding parameters in the type-III 2HDM, and the new physics cut-off scales in the SMEFT, in RS models and in models with heavy neutrinos.
2404.15113
Marco Vitti
Giuseppe Degrassi, Ramona Gr\"ober and Marco Vitti
Virtual QCD corrections to $gg \to ZZ$: top-quark loops from a transverse-momentum expansion
30 pages, 7 figures, 2 tables, 2 appendices
null
null
COMETA-2024-06; TTP24-010
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present the virtual corrections due to the top-quark loops for the process $gg \to ZZ$ at next-to-leading order in QCD. The associated two-loop box diagrams are computed using a small-transverse-momentum expansion. Our results are then merged with those available in the complementary energy region, obtained via a high-energy expansion, in order to provide an analytic result that is valid in the whole phase space. The results presented allow for an efficient modelling of the signal--background interference as well as the irreducible background in off-shell Higgs production.
[ { "created": "Tue, 23 Apr 2024 15:06:48 GMT", "version": "v1" } ]
2024-04-24
[ [ "Degrassi", "Giuseppe", "" ], [ "Gröber", "Ramona", "" ], [ "Vitti", "Marco", "" ] ]
We present the virtual corrections due to the top-quark loops for the process $gg \to ZZ$ at next-to-leading order in QCD. The associated two-loop box diagrams are computed using a small-transverse-momentum expansion. Our results are then merged with those available in the complementary energy region, obtained via a high-energy expansion, in order to provide an analytic result that is valid in the whole phase space. The results presented allow for an efficient modelling of the signal--background interference as well as the irreducible background in off-shell Higgs production.
1112.5922
Chung Kao
Howard Baer, Chung Kao, and Joshua Sayre
Prospects for Higgs Searches with the Tri-bottom Channel in Unified SUSY Models
REVTEX, 23 pages, 4 figures
null
10.1103/PhysRevD.85.035021
OUHEP-111212
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the prospects for the discovery of a neutral Higgs boson produced in association with a $b$ quark, followed by the Higgs decay into a pair of bottom quarks, $pp \to b\phi^0 \to b b\bar{b} +X$, at the CERN Large Hadron Collider (LHC) within the framework of unified supersymmetric models. The Higgs boson $\phi^0$ can be a heavy scalar $H^0$ or a pseudoscalar $A^0$. Furthermore, this direct discovery channel is compared with the indirect Higgs searches in the rare decay $B_s \to \mu^+\mu^-$ at hadron colliders. Promising results are found for the minimal supergravity (mSUGRA) model, the anomaly mediated supersymmetry breaking (AMSB) model, and the gauge mediated supersymmetry breaking (GMSB) model. We find that the indirect search for $B(B_s \to \mu^+\mu^-) \ge 5\times 10^{-9}$ is complementary to the direct search for $b\phi^0 \to bb\bar{b}$ with $\sqrt{s} = 14$ TeV and an integrated luminosity ($L$) of 300 fb$^{-1}$. In the AMSB and GMSB models, $b\phi^0 \to bb\bar{b}$ with $L = 300$ fb$^{-1}$ covers a larger area in the parameter space than $B(B_s \to \mu^+\mu^-) \ge 5\times 10^{-9}$. In addition, we present constraints from $b \to s\gamma$ and muon anomalous dipole moment ($\Delta a_\mu$) on the parameter space.
[ { "created": "Tue, 27 Dec 2011 04:48:57 GMT", "version": "v1" } ]
2013-05-30
[ [ "Baer", "Howard", "" ], [ "Kao", "Chung", "" ], [ "Sayre", "Joshua", "" ] ]
We investigate the prospects for the discovery of a neutral Higgs boson produced in association with a $b$ quark, followed by the Higgs decay into a pair of bottom quarks, $pp \to b\phi^0 \to b b\bar{b} +X$, at the CERN Large Hadron Collider (LHC) within the framework of unified supersymmetric models. The Higgs boson $\phi^0$ can be a heavy scalar $H^0$ or a pseudoscalar $A^0$. Furthermore, this direct discovery channel is compared with the indirect Higgs searches in the rare decay $B_s \to \mu^+\mu^-$ at hadron colliders. Promising results are found for the minimal supergravity (mSUGRA) model, the anomaly mediated supersymmetry breaking (AMSB) model, and the gauge mediated supersymmetry breaking (GMSB) model. We find that the indirect search for $B(B_s \to \mu^+\mu^-) \ge 5\times 10^{-9}$ is complementary to the direct search for $b\phi^0 \to bb\bar{b}$ with $\sqrt{s} = 14$ TeV and an integrated luminosity ($L$) of 300 fb$^{-1}$. In the AMSB and GMSB models, $b\phi^0 \to bb\bar{b}$ with $L = 300$ fb$^{-1}$ covers a larger area in the parameter space than $B(B_s \to \mu^+\mu^-) \ge 5\times 10^{-9}$. In addition, we present constraints from $b \to s\gamma$ and muon anomalous dipole moment ($\Delta a_\mu$) on the parameter space.
0708.1977
Asan Damanik
Asan Damanik, Mirza Satriawan, Arief Hermanto, Pramudita Anggraita
Truly Minimal Left-Right Symmetry Model for Electroweak Interaction
6 pages, no figure
null
null
null
hep-ph
null
By using two primary doublets and one induced bidoublet Higgs fields as a result of the interactions of the two doublets, we evaluate the predictive power of the left-right symmetry model based on $SU(2)_{L}\otimes SU(2)_{R}\otimes U(1)$ gauge group to the gauge bosons masses, leptons masses, and the structure of electroweak interactions. We found that the contribution of the right charge-current to the electroweak interaction is only around 0.0073 percent. The neutrino mass emerges naturally without introducing exotic particles. We obtain that the mixing angle $\theta = 45^{0}$ for boson sector, $\theta \approx 45^{0}$ for neutrino sector, and $\theta = 0^{0}$ for electron sector. The parity violation in our model could be associated with the mass mixing in the bosons and leptons masses arise from the induced bidoublet Higgs via symmetry breaking. PACs: 12.60.Cn; 12.60.Fr
[ { "created": "Wed, 15 Aug 2007 01:56:44 GMT", "version": "v1" } ]
2007-08-16
[ [ "Damanik", "Asan", "" ], [ "Satriawan", "Mirza", "" ], [ "Hermanto", "Arief", "" ], [ "Anggraita", "Pramudita", "" ] ]
By using two primary doublets and one induced bidoublet Higgs fields as a result of the interactions of the two doublets, we evaluate the predictive power of the left-right symmetry model based on $SU(2)_{L}\otimes SU(2)_{R}\otimes U(1)$ gauge group to the gauge bosons masses, leptons masses, and the structure of electroweak interactions. We found that the contribution of the right charge-current to the electroweak interaction is only around 0.0073 percent. The neutrino mass emerges naturally without introducing exotic particles. We obtain that the mixing angle $\theta = 45^{0}$ for boson sector, $\theta \approx 45^{0}$ for neutrino sector, and $\theta = 0^{0}$ for electron sector. The parity violation in our model could be associated with the mass mixing in the bosons and leptons masses arise from the induced bidoublet Higgs via symmetry breaking. PACs: 12.60.Cn; 12.60.Fr
2009.03316
Quinn Brodsky
Jasmine Brewer, Quinn Brodsky, Krishna Rajagopal
Disentangling Jet Modification
4 pages; 3 figures; proceedings of Hard Probes 2020
null
null
MIT-CTP-5231
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Jet modification in heavy-ion collisions is an important probe of the nature and structure of the quark-gluon plasma (QGP) produced in these collisions and also encodes information about how the wakes that jets excite in a droplet of QGP form and relax. However, in experiment, one cannot know what a particular jet in a heavy ion collision would have looked like without quenching, making it difficult to interpret measurements in terms of individual jet modification. The goal of this Monte Carlo study is to gain insight into the modification of jet observables using the hybrid strong/weak coupling model of jet quenching as a test bed. In this Monte Carlo study (but not in experiment) it is possible to watch $\textit{the same jet}$ as it evolves in vacuum or in QGP. We use this ability to disentangle the effects of modification of individual jets in heavy ion collisions vs. the effects of differing selection bias on the distribution of two observables: fractional energy loss and groomed $\Delta R$. We find that in the hybrid model the distribution of groomed $\Delta R$ appears to be unmodified in a sample of jets selected after quenching, as in heavy ion collisions, and confirm that this lack of modification arises because of a selection bias toward jets that lose only a small fraction of their energy. If instead we select jets in a way that avoids this bias, and then follow these selected jets as they are quenched, we show that there is, in fact, a substantial modification of the $\Delta R$ of individual jets. We show that this jet modification is principally due to the incorporation of particles coming from the wake that the parton shower excites in the plasma as a component of what an experimentalist reconstructs as a jet. The effects we discuss are substantial in magnitude, suggesting that our qualitative conclusions are more general than the Monte Carlo study in which we obtain them.
[ { "created": "Mon, 7 Sep 2020 18:00:00 GMT", "version": "v1" } ]
2020-09-09
[ [ "Brewer", "Jasmine", "" ], [ "Brodsky", "Quinn", "" ], [ "Rajagopal", "Krishna", "" ] ]
Jet modification in heavy-ion collisions is an important probe of the nature and structure of the quark-gluon plasma (QGP) produced in these collisions and also encodes information about how the wakes that jets excite in a droplet of QGP form and relax. However, in experiment, one cannot know what a particular jet in a heavy ion collision would have looked like without quenching, making it difficult to interpret measurements in terms of individual jet modification. The goal of this Monte Carlo study is to gain insight into the modification of jet observables using the hybrid strong/weak coupling model of jet quenching as a test bed. In this Monte Carlo study (but not in experiment) it is possible to watch $\textit{the same jet}$ as it evolves in vacuum or in QGP. We use this ability to disentangle the effects of modification of individual jets in heavy ion collisions vs. the effects of differing selection bias on the distribution of two observables: fractional energy loss and groomed $\Delta R$. We find that in the hybrid model the distribution of groomed $\Delta R$ appears to be unmodified in a sample of jets selected after quenching, as in heavy ion collisions, and confirm that this lack of modification arises because of a selection bias toward jets that lose only a small fraction of their energy. If instead we select jets in a way that avoids this bias, and then follow these selected jets as they are quenched, we show that there is, in fact, a substantial modification of the $\Delta R$ of individual jets. We show that this jet modification is principally due to the incorporation of particles coming from the wake that the parton shower excites in the plasma as a component of what an experimentalist reconstructs as a jet. The effects we discuss are substantial in magnitude, suggesting that our qualitative conclusions are more general than the Monte Carlo study in which we obtain them.
1301.5631
Jonathan Rosner
Bhubanjyoti Bhattacharya, David London, Michael Gronau, and Jonathan L. Rosner
Shift in weak phase $\gamma$ due to CP asymmetries in $D$ decays to two pseudoscalar mesons
15 pages, 3 figures, submitted to Phys. Rev. D. More text and references added
null
10.1103/PhysRevD.87.074002
EFI 12-36; UdeM-GPP-TH-13-219; TECHNION-PH-13-1
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A difference of several tenths of a percent has been observed between the direct CP asymmetries of $D^0\to K^+K^-$ and $D^0\to \pi^+\pi^-$. It has been noted recently that CP asymmetries in such singly-Cabibbo-suppressed (SCS) decays can affect the determination of the weak phase $\gamma$ using the Gronau-London-Wyler method of comparing rates for $B^+ \to D K^+$ and $B^- \to D K^-$, where $D$ is a superposition of $D^0$ and $\od$ decaying to a CP eigenstate. Using an analysis of the CP asymmetries in SCS decays based on a $c \to u$ penguin amplitude with standard model weak phase but enhanced by CP-conserving strong interactions, we estimate typical shifts in $\gamma$ of several degrees and pinpoint measurements which would reduce uncertainties to an acceptable level.
[ { "created": "Wed, 23 Jan 2013 20:48:13 GMT", "version": "v1" }, { "created": "Mon, 28 Jan 2013 19:59:33 GMT", "version": "v2" }, { "created": "Thu, 31 Jan 2013 17:49:54 GMT", "version": "v3" }, { "created": "Thu, 28 Feb 2013 16:35:03 GMT", "version": "v4" } ]
2013-04-10
[ [ "Bhattacharya", "Bhubanjyoti", "" ], [ "London", "David", "" ], [ "Gronau", "Michael", "" ], [ "Rosner", "Jonathan L.", "" ] ]
A difference of several tenths of a percent has been observed between the direct CP asymmetries of $D^0\to K^+K^-$ and $D^0\to \pi^+\pi^-$. It has been noted recently that CP asymmetries in such singly-Cabibbo-suppressed (SCS) decays can affect the determination of the weak phase $\gamma$ using the Gronau-London-Wyler method of comparing rates for $B^+ \to D K^+$ and $B^- \to D K^-$, where $D$ is a superposition of $D^0$ and $\od$ decaying to a CP eigenstate. Using an analysis of the CP asymmetries in SCS decays based on a $c \to u$ penguin amplitude with standard model weak phase but enhanced by CP-conserving strong interactions, we estimate typical shifts in $\gamma$ of several degrees and pinpoint measurements which would reduce uncertainties to an acceptable level.
1204.3435
Jochum van der Bij
J. J. van der Bij
New Spectra in the Heidi Models
Rencontres de Moriond EW 2012, 8 pages, 6 figures
null
null
FR-PHENO-2012-08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the so-called HEIDI models, which are renormalizable extensions of the standard model with a higher-dimensional scalar singlet field. We compare their predictions with the recent results from the LHC. We show that the data can easily be described by the HEIDI models. However more data are necessary in order to distinguish these models from the standard model. A particular prediction is that the width of the Higgs could be in the GeV range. Such a width could be difficult to establish at the LHC. Suggestions for experiments beyond the LHC are made.
[ { "created": "Mon, 16 Apr 2012 10:43:50 GMT", "version": "v1" } ]
2012-04-17
[ [ "van der Bij", "J. J.", "" ] ]
We study the so-called HEIDI models, which are renormalizable extensions of the standard model with a higher-dimensional scalar singlet field. We compare their predictions with the recent results from the LHC. We show that the data can easily be described by the HEIDI models. However more data are necessary in order to distinguish these models from the standard model. A particular prediction is that the width of the Higgs could be in the GeV range. Such a width could be difficult to establish at the LHC. Suggestions for experiments beyond the LHC are made.
2009.02118
Abdulla Abdulsalam
Abdulla Abdulsalam (Department of Physics, King Abdulaziz University, Jeddah)
Calculating the rates of charmonium dissociation and recombination reactions in heavy-ion collisions using Bateman equation
15 pages, 7 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The charmonium states with their different binding energies and radii dissolve at different temperatures of the medium produced in relativistic heavy-ion collisions. Relative yields of charmonium and thus their survival have potential to map the properties of Quark Gluon Plasma. In this study, we estimate the combined effect of color screening, gluon-induced dissociation and recombination on charmonium production in heavy-ion collisions (Pb+Pb ions) at centre of mass energy ($\sqrt{s_{\rm NN}}$) = 5.02 TeV. The rate equations of dissociation and recombination are solved separately with a 2-dimensional accelerated expansion of fireball volume. To solve the recombination rate equation, we have used an approach of Bateman solution which ensures the dissociation of the recombined charmonium in the QGP medium. The modifications of charmonium states are estimated in an expanding QGP with the conditions relevant for Pb+Pb collisions at LHC.
[ { "created": "Fri, 4 Sep 2020 11:38:11 GMT", "version": "v1" }, { "created": "Tue, 8 Sep 2020 09:19:44 GMT", "version": "v2" }, { "created": "Tue, 17 Nov 2020 19:31:47 GMT", "version": "v3" } ]
2022-02-23
[ [ "Abdulsalam", "Abdulla", "", "Department of Physics, King Abdulaziz University,\n Jeddah" ] ]
The charmonium states with their different binding energies and radii dissolve at different temperatures of the medium produced in relativistic heavy-ion collisions. Relative yields of charmonium and thus their survival have potential to map the properties of Quark Gluon Plasma. In this study, we estimate the combined effect of color screening, gluon-induced dissociation and recombination on charmonium production in heavy-ion collisions (Pb+Pb ions) at centre of mass energy ($\sqrt{s_{\rm NN}}$) = 5.02 TeV. The rate equations of dissociation and recombination are solved separately with a 2-dimensional accelerated expansion of fireball volume. To solve the recombination rate equation, we have used an approach of Bateman solution which ensures the dissociation of the recombined charmonium in the QGP medium. The modifications of charmonium states are estimated in an expanding QGP with the conditions relevant for Pb+Pb collisions at LHC.
hep-ph/9902323
Pran Nath
Pran Nath and Masahiro Yamaguchi
Effects of Extra Space-time Dimensions on the Fermi Constant
12 pages including one figure
Phys.Rev.D60:116004,1999
10.1103/PhysRevD.60.116004
null
hep-ph hep-th
null
Effects of Kaluza-Klein excitations associated with extra dimensions with large radius compactifications on the Fermi constant are explored. It is shown that the current precision determinations of the Fermi constant, of the fine structure constant, and of the W and Z mass put stringent constraints on the compactification radius. The analysis excludes one extra space time dimension below $\sim 1.6$ TeV, and excludes 2, 3 and 4 extra space dimensions opening simultaneously below $\sim$ 3.5 TeV, 5.7 TeV and 7.8 TeV at the $90% CL$. Implications of these results for future collider experiments are discussed.
[ { "created": "Thu, 11 Feb 1999 17:26:53 GMT", "version": "v1" } ]
2008-11-26
[ [ "Nath", "Pran", "" ], [ "Yamaguchi", "Masahiro", "" ] ]
Effects of Kaluza-Klein excitations associated with extra dimensions with large radius compactifications on the Fermi constant are explored. It is shown that the current precision determinations of the Fermi constant, of the fine structure constant, and of the W and Z mass put stringent constraints on the compactification radius. The analysis excludes one extra space time dimension below $\sim 1.6$ TeV, and excludes 2, 3 and 4 extra space dimensions opening simultaneously below $\sim$ 3.5 TeV, 5.7 TeV and 7.8 TeV at the $90% CL$. Implications of these results for future collider experiments are discussed.
hep-ph/0012053
Andrzej Czarnecki
Andrzej Czarnecki and Kirill Melnikov
Expansion of bound-state energies in powers of m/M
4 pages, revtex
Phys.Rev.Lett. 87 (2001) 013001
10.1103/PhysRevLett.87.013001
Alberta Thy 12-00 and SLAC-PUB-8730
hep-ph
null
We describe a new approach to computing energy levels of a non-relativistic bound-state of two constituents with masses M and m, by a systematic expansion in powers of m/M. After discussing the method, we demonstrate its potential with an example of the radiative recoil corrections to the Lamb shift and hyperfine splitting relevant for the hydrogen, muonic hydrogen, and muonium. A discrepancy between two previous calculations of O(alpha(Zalpha)^5 m^2/M) radiative recoil corrections to the Lamb shift is resolved and several new terms of O(alpha(Zalpha)^5 m^4/M^3) and higher are obtained.
[ { "created": "Tue, 5 Dec 2000 18:44:36 GMT", "version": "v1" } ]
2009-10-31
[ [ "Czarnecki", "Andrzej", "" ], [ "Melnikov", "Kirill", "" ] ]
We describe a new approach to computing energy levels of a non-relativistic bound-state of two constituents with masses M and m, by a systematic expansion in powers of m/M. After discussing the method, we demonstrate its potential with an example of the radiative recoil corrections to the Lamb shift and hyperfine splitting relevant for the hydrogen, muonic hydrogen, and muonium. A discrepancy between two previous calculations of O(alpha(Zalpha)^5 m^2/M) radiative recoil corrections to the Lamb shift is resolved and several new terms of O(alpha(Zalpha)^5 m^4/M^3) and higher are obtained.
1501.04660
Andrea Addazi AndAdd
Andrea Addazi
'Exotic vector-like pair' of color-triplet scalars
Sections 2.1 and 3 revisited; New Fig.5 of jj+Missing Energy channel; more references about LHC and FCNCs. Essential results on Neutron-Antineutron oscillations and Post-Sphaleron Baryogenesis are the same. More comments about string-inspred models. Accepted by JHEP
null
10.1007/JHEP04(2015)153
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a minimal extension of Standard Model, generating a Majorana mass for neutron, connected with a mechanism of Post-Sphaleron Baryogenesis. We consider an `exotic vector-like pair' of color-triplet scalars, an extra Majorana fermion $\psi$, and a scalar field $\phi$, giving mass to $\psi$. The vector-like pair is defined `exotic' because of a peculiar mass term of the color-triplet scalars, violating Baryon number as $\Delta B=1$. A Post-Sphaleron Baryogenesis is realized through $\phi$-decays into six quarks (antiquarks), or through $\psi$-decays into three quarks (antiquarks). This model suggests some intriguing B-violating signatures, testable in the next future, in Neutron-Antineutron physics and LHC. We also discuss limits from FCNC. Sterile fermion can also be light as $1-100\, \rm GeV$. In this case, the sterile fermion could be (meta)-stable and $n-\bar{n}$ oscillation can be indirectly generated by two $n-\psi$, $\psi-\bar{n}$ oscillations, without needing of an effective Majorana mass for neutron. Majorana fermion $\psi$ can be a good candidate for WIMP-like dark matter.
[ { "created": "Mon, 19 Jan 2015 22:31:37 GMT", "version": "v1" }, { "created": "Sat, 31 Jan 2015 18:21:39 GMT", "version": "v2" }, { "created": "Sun, 26 Apr 2015 07:48:17 GMT", "version": "v3" } ]
2015-05-20
[ [ "Addazi", "Andrea", "" ] ]
We propose a minimal extension of Standard Model, generating a Majorana mass for neutron, connected with a mechanism of Post-Sphaleron Baryogenesis. We consider an `exotic vector-like pair' of color-triplet scalars, an extra Majorana fermion $\psi$, and a scalar field $\phi$, giving mass to $\psi$. The vector-like pair is defined `exotic' because of a peculiar mass term of the color-triplet scalars, violating Baryon number as $\Delta B=1$. A Post-Sphaleron Baryogenesis is realized through $\phi$-decays into six quarks (antiquarks), or through $\psi$-decays into three quarks (antiquarks). This model suggests some intriguing B-violating signatures, testable in the next future, in Neutron-Antineutron physics and LHC. We also discuss limits from FCNC. Sterile fermion can also be light as $1-100\, \rm GeV$. In this case, the sterile fermion could be (meta)-stable and $n-\bar{n}$ oscillation can be indirectly generated by two $n-\psi$, $\psi-\bar{n}$ oscillations, without needing of an effective Majorana mass for neutron. Majorana fermion $\psi$ can be a good candidate for WIMP-like dark matter.
0901.3491
Bob McElrath
Bob McElrath
Laboratory tests for the cosmic neutrino background using beta-decaying nuclei
4 pages, 2 figures, contribution to procedings of PANIC 2008
null
null
null
hep-ph astro-ph.CO hep-ex
http://creativecommons.org/licenses/by/3.0/
We point out that the Pauli blocking of neutrinos by cosmological relic neutrinos can be a significant effect. For zero-energy neutrinos, the standard parameters for the neutrino background temperature and density give a suppression of approximately 1/2. We show the effect this has on three-body beta decays. The size of the effect is of the same order as the recently suggested neutrino capture on beta-decaying nuclei.
[ { "created": "Thu, 22 Jan 2009 15:07:11 GMT", "version": "v1" } ]
2009-01-23
[ [ "McElrath", "Bob", "" ] ]
We point out that the Pauli blocking of neutrinos by cosmological relic neutrinos can be a significant effect. For zero-energy neutrinos, the standard parameters for the neutrino background temperature and density give a suppression of approximately 1/2. We show the effect this has on three-body beta decays. The size of the effect is of the same order as the recently suggested neutrino capture on beta-decaying nuclei.
hep-ph/9806347
Jerome Charles
J. Charles, A. Le Yaouanc, L. Oliver, O. P\`ene and J.-C. Raynal
New CP observables in B0(t) -> hyperon + antihyperon from parity violation in the sequential decay
LaTeX, 35 pages, 4 figures in a separate postscript file
Phys.Rev. D58 (1998) 114021
10.1103/PhysRevD.58.114021
LPTHE-Orsay 98-21
hep-ph hep-ex
null
We consider the decay B0(t) -> hyperon + antihyperon, followed by hyperon weak decay. We show that parity violation in the latter allows to reach new CP observables: not only Im(lambda_f) but also Re(lambda_f) can be measured. In the decay B0_d(t) -> Lambda LambdaBar (BR ~ 10-6), Lambda -> p pi- these observables reduce to sin(2alpha) and cos(2alpha) in the small Penguin limit, the latter solving the discrete ambiguity alpha -> pi/2 -alpha. For beta one could consider the Cabibbo suppressed mode B0_d(t) -> Lambda_c Lambda_cBar (BR \~ 10-4), Lambda_c -> Lambda pi+, p K0bar, ... (with BR ~ 10-2). The pure Penguin modes B0_s(t)->Sigma-Sigma-Bar, Xi-Xi-Bar, Omega-Omega-Bar (BR ~ 10-7) can be useful in the search of CP violation beyond the Standard Model. Because of the small total rates, the study of these modes could only be done in future high statistics experiments. Also, in the most interesting case Lambda LambdaBar the time dependence of the asymmetry can be difficult to reconstruct. On the other hand, we show that B_d mesons, being a coherent source of Lambda LambdaBar, is useful to look for CP violation in Lambda decay. We also discuss B0_d(t) -> J/Psi K*0 -> l+ l- K_S pi0 where the secondary decays conserve parity, and angular correlations allow to determine terms of the form cos(delta)cos(2beta), delta being a strong phase. This phase has been measured by CLEO, but we point out that a discrete ambiguity prevents to determine sign(cos(2beta)). However, if one assumes small strong phases, like in factorization and as supported by CLEO data, one could have information on sign(cos(2beta)). Similar remarks can be done for cos(2alpha) in the decay B_d0(t) -> rho rho -> 4pi.
[ { "created": "Thu, 11 Jun 1998 20:45:22 GMT", "version": "v1" } ]
2009-10-31
[ [ "Charles", "J.", "" ], [ "Yaouanc", "A. Le", "" ], [ "Oliver", "L.", "" ], [ "Pène", "O.", "" ], [ "Raynal", "J. -C.", "" ] ]
We consider the decay B0(t) -> hyperon + antihyperon, followed by hyperon weak decay. We show that parity violation in the latter allows to reach new CP observables: not only Im(lambda_f) but also Re(lambda_f) can be measured. In the decay B0_d(t) -> Lambda LambdaBar (BR ~ 10-6), Lambda -> p pi- these observables reduce to sin(2alpha) and cos(2alpha) in the small Penguin limit, the latter solving the discrete ambiguity alpha -> pi/2 -alpha. For beta one could consider the Cabibbo suppressed mode B0_d(t) -> Lambda_c Lambda_cBar (BR \~ 10-4), Lambda_c -> Lambda pi+, p K0bar, ... (with BR ~ 10-2). The pure Penguin modes B0_s(t)->Sigma-Sigma-Bar, Xi-Xi-Bar, Omega-Omega-Bar (BR ~ 10-7) can be useful in the search of CP violation beyond the Standard Model. Because of the small total rates, the study of these modes could only be done in future high statistics experiments. Also, in the most interesting case Lambda LambdaBar the time dependence of the asymmetry can be difficult to reconstruct. On the other hand, we show that B_d mesons, being a coherent source of Lambda LambdaBar, is useful to look for CP violation in Lambda decay. We also discuss B0_d(t) -> J/Psi K*0 -> l+ l- K_S pi0 where the secondary decays conserve parity, and angular correlations allow to determine terms of the form cos(delta)cos(2beta), delta being a strong phase. This phase has been measured by CLEO, but we point out that a discrete ambiguity prevents to determine sign(cos(2beta)). However, if one assumes small strong phases, like in factorization and as supported by CLEO data, one could have information on sign(cos(2beta)). Similar remarks can be done for cos(2alpha) in the decay B_d0(t) -> rho rho -> 4pi.
hep-ph/0612011
Bjorn Garbrecht
Bjorn Garbrecht
Radiative Lifting of Flat Directions of the MSSM in de Sitter Background
14 pages
Nucl.Phys.B784:118-131,2007
10.1016/j.nuclphysb.2007.06.013
MAN/HEP/2006/35
hep-ph
null
The one-loop effective potential for a charged scalar field in de Sitter background is studied. We derive an approximate form for the gauge boson propagator with a general covariant gauge-fixing parameter \xi. This expression is used to derive an explicitly gauge-invariant effective potential, which agrees with earlier results obtained in Landau gauge. Adding the scalar- and fermion-loop contributions, that arise in a supersymmetric Higgs model, we find that the effective potential is vanishing to first order in the Hubble rate H^2. The contribution due to a chiral multiplet running in the loop is however non-vanishing. When applied to a flat direction of the MSSM with VEV w, a logarithmically running correction of order $h^2 H^2 w^2$ arises, where h is Yukawa coupling. This is of particular importance for D-term inflation or models endowed with a Heisenberg symmetry, where Hubble scale mass terms for flat directions from supergravity corrections are absent.
[ { "created": "Fri, 1 Dec 2006 15:04:12 GMT", "version": "v1" }, { "created": "Sun, 3 Dec 2006 01:07:35 GMT", "version": "v2" } ]
2008-11-26
[ [ "Garbrecht", "Bjorn", "" ] ]
The one-loop effective potential for a charged scalar field in de Sitter background is studied. We derive an approximate form for the gauge boson propagator with a general covariant gauge-fixing parameter \xi. This expression is used to derive an explicitly gauge-invariant effective potential, which agrees with earlier results obtained in Landau gauge. Adding the scalar- and fermion-loop contributions, that arise in a supersymmetric Higgs model, we find that the effective potential is vanishing to first order in the Hubble rate H^2. The contribution due to a chiral multiplet running in the loop is however non-vanishing. When applied to a flat direction of the MSSM with VEV w, a logarithmically running correction of order $h^2 H^2 w^2$ arises, where h is Yukawa coupling. This is of particular importance for D-term inflation or models endowed with a Heisenberg symmetry, where Hubble scale mass terms for flat directions from supergravity corrections are absent.
hep-ph/9909566
Gautam Bhattacharyya
Gautam Bhattacharyya
Direct CP violation in B decays in R-parity violating models
7 pages, Latex, requires iopconf1.sty which is included. Invited talk presented at `Beyond the Desert 1999', Castle Ringberg, Tegernsee, Germany, 6-12 June 1999
null
null
SINP/TNP/99-30
hep-ph
null
In the standard model, CP asymmetries in the $B^\pm \to \pi^\pm K$ channels are about 2% based on perturbative calculation. Rescattering effects might enhance it to at most (20-25)%. We show that lepton-number-violating $\lambda'$ couplings in supersymmetric models are capable of enhancing it to as large as 100%. Upcoming B factories will test this scenario.
[ { "created": "Thu, 30 Sep 1999 11:20:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bhattacharyya", "Gautam", "" ] ]
In the standard model, CP asymmetries in the $B^\pm \to \pi^\pm K$ channels are about 2% based on perturbative calculation. Rescattering effects might enhance it to at most (20-25)%. We show that lepton-number-violating $\lambda'$ couplings in supersymmetric models are capable of enhancing it to as large as 100%. Upcoming B factories will test this scenario.
1909.05336
Quentin Bonnefoy
Q. Bonnefoy, E. Dudas and S. Pokorski
Chiral Froggatt-Nielsen models, gauge anomalies and flavourful axions
24 pages + appendices, 7 figures. v2: refs added, minor clarifications, matches the version accepted in JHEP
null
10.1007/JHEP01(2020)191
DESY 19-154, CPHT-RR051.082019
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study UV-complete Froggatt-Nielsen-like models for the generation of mass and mixing hierarchies, assuming that the integrated heavy fields are chiral with respect to an abelian Froggatt-Nielsen symmetry. It modifies the mixed anomalies with respect to the Standard Model gauge group, which opens up the possibility to gauge the Froggatt-Nielsen symmetry without the need to introduce additional spectator fermions, while keeping mass matrices usually associated to anomalous flavour symmetries. We give specific examples where this happens, and we study the flavourful axion which arises from an accidental Peccei-Quinn symmetry in some of those models. Such an axion is typically more coupled to matter than in models with spectator fermions.
[ { "created": "Wed, 11 Sep 2019 20:07:40 GMT", "version": "v1" }, { "created": "Mon, 20 Jan 2020 11:31:08 GMT", "version": "v2" } ]
2020-02-19
[ [ "Bonnefoy", "Q.", "" ], [ "Dudas", "E.", "" ], [ "Pokorski", "S.", "" ] ]
We study UV-complete Froggatt-Nielsen-like models for the generation of mass and mixing hierarchies, assuming that the integrated heavy fields are chiral with respect to an abelian Froggatt-Nielsen symmetry. It modifies the mixed anomalies with respect to the Standard Model gauge group, which opens up the possibility to gauge the Froggatt-Nielsen symmetry without the need to introduce additional spectator fermions, while keeping mass matrices usually associated to anomalous flavour symmetries. We give specific examples where this happens, and we study the flavourful axion which arises from an accidental Peccei-Quinn symmetry in some of those models. Such an axion is typically more coupled to matter than in models with spectator fermions.
1806.11152
Mario E. Gomez
M.E. Gomez, S. Lola, R. Ruiz de Austri, Q. Shafi
Confronting SUSY GUT with Dark Matter, Sparticle Spectroscopy and Muon $(g-2)$
12 pages, 6 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the implications of LHC and cold dark matter searches for supersymmetric particle mass spectra in two different grand unified models with left-right symmetry, $SO(10)$ and $ SU(4)_c \times SU(2)_L \times SU(2)_R$ (4-2-2). We identify characteristic differences between the two scenarios, which imply distinct correlations between experimental measurements and the particular structure of the GUT group. The gauge structure of 4-2-2 enhances significantly the allowed parameter space as compared to $SO(10)$, giving rise to a variety of coannihilation scenarios compatible with the LHC data, LSP dark matter and the ongoing muon g-2 experiment.
[ { "created": "Thu, 28 Jun 2018 19:30:21 GMT", "version": "v1" } ]
2018-07-02
[ [ "Gomez", "M. E.", "" ], [ "Lola", "S.", "" ], [ "de Austri", "R. Ruiz", "" ], [ "Shafi", "Q.", "" ] ]
We explore the implications of LHC and cold dark matter searches for supersymmetric particle mass spectra in two different grand unified models with left-right symmetry, $SO(10)$ and $ SU(4)_c \times SU(2)_L \times SU(2)_R$ (4-2-2). We identify characteristic differences between the two scenarios, which imply distinct correlations between experimental measurements and the particular structure of the GUT group. The gauge structure of 4-2-2 enhances significantly the allowed parameter space as compared to $SO(10)$, giving rise to a variety of coannihilation scenarios compatible with the LHC data, LSP dark matter and the ongoing muon g-2 experiment.
hep-ph/9905241
Michael R. Pennington
M.R. Pennington
Riddle of the scalars: where is the sigma?
20 pages, 12 figures Talk at the Workshop on Hadron Spectroscopy, WHS99, Frascati, March 1999. Revised version has the word "triangles" replaced by "circles"!
null
null
DPT-99/40
hep-ph
null
The riddle of the sigma is recast in a way that tries to differentiate fact from fiction as a basis for future/further discussion. By doing this, it is hoped that the role of the sigma as dominating the ubiquitous $\pi\pi$ interactions below 1 GeV and its relation to the QCD vacuum can be clarified.
[ { "created": "Tue, 4 May 1999 16:47:02 GMT", "version": "v1" }, { "created": "Thu, 13 May 1999 09:39:06 GMT", "version": "v2" } ]
2007-05-23
[ [ "Pennington", "M. R.", "" ] ]
The riddle of the sigma is recast in a way that tries to differentiate fact from fiction as a basis for future/further discussion. By doing this, it is hoped that the role of the sigma as dominating the ubiquitous $\pi\pi$ interactions below 1 GeV and its relation to the QCD vacuum can be clarified.
hep-ph/9508382
Hai-Yang Cheng
Ling-Lie Chau, Hai-Yang Cheng, and B. Tseng
Analysis of Two-Body Decays of Charmed Baryons Using the Quark-Diagram Scheme
28 pages, 20 Tables in landscape form, 4 figures. Main changes are: (i) some errors in the Tables and in the relations between the quark-diagram amplitudes of this paper and those of Ref.[10] are corrected, (ii) improvements are made in the presentation so that comparisons with previous works and what have been done to include SU(3) breaking and final-state interactions are more clearly stated; to appear in the Physical Review D
Phys.Rev. D54 (1996) 2132-2160
10.1103/PhysRevD.54.2132
UCDPHY-PUB-95-26
hep-ph
null
We give a general formulation of the quark-diagram scheme for the nonleptonic weak decays of baryons. We apply it to all the decays of the antitriplet and sextet charmed baryons and express their decay amplitudes in terms of the quark-diagram amplitudes. We have also given parametrizations for the effects of final-state interactions. For SU(3) violation effects, we only parametrize those in the horizontal $W$-loop quark diagrams whose contributions are solely due to SU(3)-violation effects. In the absence of all these effects, there are many relations among various decay modes. Some of the relations are valid even in the presence of final-state interactions when each decay amplitude in the relation contains only a single phase shift. All these relations provide useful frameworks to compare with future experiments and to find out the effects of final-state interactions and SU(3) symmetry violations.
[ { "created": "Mon, 28 Aug 1995 08:07:35 GMT", "version": "v1" }, { "created": "Mon, 8 Apr 1996 05:10:08 GMT", "version": "v2" } ]
2009-10-28
[ [ "Chau", "Ling-Lie", "" ], [ "Cheng", "Hai-Yang", "" ], [ "Tseng", "B.", "" ] ]
We give a general formulation of the quark-diagram scheme for the nonleptonic weak decays of baryons. We apply it to all the decays of the antitriplet and sextet charmed baryons and express their decay amplitudes in terms of the quark-diagram amplitudes. We have also given parametrizations for the effects of final-state interactions. For SU(3) violation effects, we only parametrize those in the horizontal $W$-loop quark diagrams whose contributions are solely due to SU(3)-violation effects. In the absence of all these effects, there are many relations among various decay modes. Some of the relations are valid even in the presence of final-state interactions when each decay amplitude in the relation contains only a single phase shift. All these relations provide useful frameworks to compare with future experiments and to find out the effects of final-state interactions and SU(3) symmetry violations.
1610.02904
Martin Hansen
Martin Hansen, Kasper Langaeble, Francesco Sannino
Extending Chiral Perturbation Theory with an Isosinglet Scalar
18 pages, 2 figures, accepted version for Physical Review D
Phys. Rev. D 95, 036005 (2017)
10.1103/PhysRevD.95.036005
CP3-Origins-2016-041 DNRF90
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We augment the chiral Lagrangian by an isosinglet scalar and compute the one-loop radiative corrections to the pion mass and decay constant, as well as the scalar mass. The calculations are carried out for different patterns of chiral symmetry breaking of immediate relevance for phenomenology and lattice investigations. By construction our results encompass several interesting limits, ranging from the dilaton to the linear sigma model.
[ { "created": "Mon, 10 Oct 2016 13:26:21 GMT", "version": "v1" }, { "created": "Mon, 30 Jan 2017 11:26:48 GMT", "version": "v2" } ]
2017-02-15
[ [ "Hansen", "Martin", "" ], [ "Langaeble", "Kasper", "" ], [ "Sannino", "Francesco", "" ] ]
We augment the chiral Lagrangian by an isosinglet scalar and compute the one-loop radiative corrections to the pion mass and decay constant, as well as the scalar mass. The calculations are carried out for different patterns of chiral symmetry breaking of immediate relevance for phenomenology and lattice investigations. By construction our results encompass several interesting limits, ranging from the dilaton to the linear sigma model.
hep-ph/9411427
Serguei Khlebnikov
S.Yu. Khlebnikov
The current of fermions scattered off a bubble wall
7 pages, latex, no figures; misprint in eq.(12) corrected
Phys.Rev.D52:702-704,1995
10.1103/PhysRevD.52.702
PURD-TH-94-11
hep-ph
null
Proceeding from WKB quantization conditions, we derive a semiclassical expression for the current of fermions scattered off a propagating bubble wall in the presence of longitudinal gauge field. It agrees with the expression used by Nasser and Turok in semiclassical analysis of instability of electroweak bubble walls with respect to longitudinal $Z$ condensation. We discuss the resulting dispersion relation for longitudinal $Z$ field and show that light species are important for the analysis of stability, because of their large contribution to plasma frequency.
[ { "created": "Tue, 29 Nov 1994 22:19:16 GMT", "version": "v1" }, { "created": "Wed, 30 Nov 1994 05:00:28 GMT", "version": "v2" }, { "created": "Fri, 9 Dec 1994 23:41:47 GMT", "version": "v3" }, { "created": "Thu, 22 Dec 1994 00:42:33 GMT", "version": "v4" } ]
2010-11-01
[ [ "Khlebnikov", "S. Yu.", "" ] ]
Proceeding from WKB quantization conditions, we derive a semiclassical expression for the current of fermions scattered off a propagating bubble wall in the presence of longitudinal gauge field. It agrees with the expression used by Nasser and Turok in semiclassical analysis of instability of electroweak bubble walls with respect to longitudinal $Z$ condensation. We discuss the resulting dispersion relation for longitudinal $Z$ field and show that light species are important for the analysis of stability, because of their large contribution to plasma frequency.
2204.01130
Howard Baer
Howard Baer, Vernon Barger and Robert Wiley Deal
On dark radiation from string moduli decay to ALPs
18 pages with 9 .png figures
null
null
OU-HEP-220401
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We examine the issue of dark radiation (DR) from string moduli decay into axion-like particles (ALPs). In KKLT-type models of moduli stabilization, the axionlike phases of moduli fields are expected to decouple whilst in LVS-type moduli stabilization some can remain light and may constitute dark radiation. We evaluate modulus decay to Minimal Supersymmetric Standard Model (MSSM) particles and dark radiation for more general compactifications. In spite of tightening error bars on \Delta N_{eff}, we find only mild constraints on modulus-ALP couplings due to the somewhat suppressed modulus branching fraction to DR owing to the large number of MSSM decay modes. We anticipate that future CMB experiments with greater precision on \Delta N_{eff} may still turn up evidence for DR if the ALP associated with the lightest modulus field is indeed light.
[ { "created": "Sun, 3 Apr 2022 18:10:43 GMT", "version": "v1" } ]
2022-04-05
[ [ "Baer", "Howard", "" ], [ "Barger", "Vernon", "" ], [ "Deal", "Robert Wiley", "" ] ]
We examine the issue of dark radiation (DR) from string moduli decay into axion-like particles (ALPs). In KKLT-type models of moduli stabilization, the axionlike phases of moduli fields are expected to decouple whilst in LVS-type moduli stabilization some can remain light and may constitute dark radiation. We evaluate modulus decay to Minimal Supersymmetric Standard Model (MSSM) particles and dark radiation for more general compactifications. In spite of tightening error bars on \Delta N_{eff}, we find only mild constraints on modulus-ALP couplings due to the somewhat suppressed modulus branching fraction to DR owing to the large number of MSSM decay modes. We anticipate that future CMB experiments with greater precision on \Delta N_{eff} may still turn up evidence for DR if the ALP associated with the lightest modulus field is indeed light.
0901.3040
Jeff Forshaw
J.R. Forshaw
Central Exclusive Production at the LHC
Talk presented at the workshop "New Trends in HERA Physics", Ringberg Castle, Tegernsee, 5-10 October 2008
null
10.1016/j.nuclphysbps.2009.03.132
MAN/HEP/2009/5
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After a brief resume of the theory underpinning the central exclusive process (CEP) pp \to p+H+p, attention is focussed upon Higgs bosons produced in the Standard Model, the MSSM and the NMSSM. In all cases, CEP adds significantly to the physics potential of the LHC and in some scenarios it may be crucial.
[ { "created": "Tue, 20 Jan 2009 12:23:15 GMT", "version": "v1" } ]
2015-05-13
[ [ "Forshaw", "J. R.", "" ] ]
After a brief resume of the theory underpinning the central exclusive process (CEP) pp \to p+H+p, attention is focussed upon Higgs bosons produced in the Standard Model, the MSSM and the NMSSM. In all cases, CEP adds significantly to the physics potential of the LHC and in some scenarios it may be crucial.
hep-ph/0105137
Poonam Mehta
Anindya Datta, Raj Gandhi, Biswarup Mukhopadhyaya (H.R.I.), Poonam Mehta (University of Delhi)
Signals of R-parity Violating Supersymmetry at a Muon Storage Ring
Latex, 4 pages, 2 ps figures, uses axodraw.sty . Talk presented by P.Mehta at the XIV DAE Symposium on HEP, University of Hyderabad, India, 18-22 December 2000. To be published in the Proceedings of the XIV DAE Symposium on HEP
null
null
null
hep-ph
null
Neutrino oscillation signals at muon storage rings (MSR) can be mimicked by Supersymmetric (SUSY) interactions in an R-parity violating scenario. We have investigated the $\tau$-appearance signals for both long-baseline and near-site experiments, and concluded that the latter is of great use in distinguishing between oscillation and SUSY effects. On the other hand, SUSY can cause a manifold increase in the event rate for wrong-sign muons at a long-baseline setting, thereby providing us with signatures of new physics.
[ { "created": "Tue, 15 May 2001 11:29:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Datta", "Anindya", "", "H.R.I." ], [ "Gandhi", "Raj", "", "H.R.I." ], [ "Mukhopadhyaya", "Biswarup", "", "H.R.I." ], [ "Mehta", "Poonam", "", "University of Delhi" ] ]
Neutrino oscillation signals at muon storage rings (MSR) can be mimicked by Supersymmetric (SUSY) interactions in an R-parity violating scenario. We have investigated the $\tau$-appearance signals for both long-baseline and near-site experiments, and concluded that the latter is of great use in distinguishing between oscillation and SUSY effects. On the other hand, SUSY can cause a manifold increase in the event rate for wrong-sign muons at a long-baseline setting, thereby providing us with signatures of new physics.
2011.13335
Erasmo Ferreira
E. Ferreira, A. K. Kohara and T. Kodama
Analytical representation for amplitudes and differential cross section of pp elastic scattering at 13 TeV
22 pages, 26 figures
null
10.1140/epjc/s10052-021-09056-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With analytical representation for the pp scattering amplitudes introduced and tested at lower energies, a description of high precision is given of the $d\sigma/dt$ data at $\sqrt{s}$= 13 TeV for all values of the momentum transfer, with explicit identification of the real and imaginary parts. In both $t$ and $b$ coordinates the amplitudes have terms identified as of non-perturbative and perturbative nature, with distinction of their influences in forward and large $|t|$ ranges and in central and peripheral regions respectively. In the forward range, the role of the Coulomb-nuclear interference phase is investigated. The energy dependence of the parameters of the amplitudes are reviewed and updated, revealing a possible emergence of a peculiar behavior of elastic and inelastic profiles in b-space for central collisions, which seems to be enhanced quickly at higher energies. Some other models are also briefly discussed in comparison, including the above mentioned behavior in b-space.
[ { "created": "Thu, 26 Nov 2020 15:04:58 GMT", "version": "v1" }, { "created": "Tue, 23 Mar 2021 22:28:07 GMT", "version": "v2" } ]
2021-03-25
[ [ "Ferreira", "E.", "" ], [ "Kohara", "A. K.", "" ], [ "Kodama", "T.", "" ] ]
With analytical representation for the pp scattering amplitudes introduced and tested at lower energies, a description of high precision is given of the $d\sigma/dt$ data at $\sqrt{s}$= 13 TeV for all values of the momentum transfer, with explicit identification of the real and imaginary parts. In both $t$ and $b$ coordinates the amplitudes have terms identified as of non-perturbative and perturbative nature, with distinction of their influences in forward and large $|t|$ ranges and in central and peripheral regions respectively. In the forward range, the role of the Coulomb-nuclear interference phase is investigated. The energy dependence of the parameters of the amplitudes are reviewed and updated, revealing a possible emergence of a peculiar behavior of elastic and inelastic profiles in b-space for central collisions, which seems to be enhanced quickly at higher energies. Some other models are also briefly discussed in comparison, including the above mentioned behavior in b-space.
1306.6693
J. P. Ma
J.P. Ma, C. Wang and G.P. Zhang
Azimuthal Dependence of DIS with Spin-1 Target
improved representation to avoid possible confusions, conclusion unchanged
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study DIS with a spin-1 hadron or a nucleus polarized in arbitrary direction. The differential cross-section in this case will have an azimuthal dependence. We derive the dependence by including contributions from twist-2- and twist-3 QCD operators. The twist-3 contribution is computed at tree-level. A spin-1 hadron or nucleus can have nonzero tensor polarization. We find that all structure functions related to the tensor-polarization of the initial hadron can be extracted by study the azimuthal dependence. A nonzero result of the structure functions of a nucleus from experiment will indicate nontrivial inner structure of the nucleus.
[ { "created": "Fri, 28 Jun 2013 02:00:29 GMT", "version": "v1" }, { "created": "Mon, 9 Dec 2013 01:43:40 GMT", "version": "v2" } ]
2013-12-10
[ [ "Ma", "J. P.", "" ], [ "Wang", "C.", "" ], [ "Zhang", "G. P.", "" ] ]
We study DIS with a spin-1 hadron or a nucleus polarized in arbitrary direction. The differential cross-section in this case will have an azimuthal dependence. We derive the dependence by including contributions from twist-2- and twist-3 QCD operators. The twist-3 contribution is computed at tree-level. A spin-1 hadron or nucleus can have nonzero tensor polarization. We find that all structure functions related to the tensor-polarization of the initial hadron can be extracted by study the azimuthal dependence. A nonzero result of the structure functions of a nucleus from experiment will indicate nontrivial inner structure of the nucleus.
hep-ph/0001069
Jose F. Nieves
H. Athar and Jose F. Nieves
Matter effects on neutrino oscillations in gravitational and magnetic fields
Latex, 12 pages
Phys.Rev.D61:103001,2000
10.1103/PhysRevD.61.103001
null
hep-ph
null
When neutrinos propagate in a background, their gravitational couplings are modified by their weak interactions with the particles in the background. In a medium that contains electrons but no muons or taons, the matter-induced gravitational couplings of neutrinos are different for the various neutrino flavors, and they must be taken into account in describing the phenomena associated with the neutrino oscillations in the presence of strong gravitational fields. Here we incorporate those couplings in that description, including also the effects of a magnetic field, and consider the implications that they have for the emission of high energy neutrinos in the vicinity of Active Galactic Nuclei.
[ { "created": "Mon, 10 Jan 2000 17:37:39 GMT", "version": "v1" } ]
2010-12-03
[ [ "Athar", "H.", "" ], [ "Nieves", "Jose F.", "" ] ]
When neutrinos propagate in a background, their gravitational couplings are modified by their weak interactions with the particles in the background. In a medium that contains electrons but no muons or taons, the matter-induced gravitational couplings of neutrinos are different for the various neutrino flavors, and they must be taken into account in describing the phenomena associated with the neutrino oscillations in the presence of strong gravitational fields. Here we incorporate those couplings in that description, including also the effects of a magnetic field, and consider the implications that they have for the emission of high energy neutrinos in the vicinity of Active Galactic Nuclei.
1509.07114
Abdel Nasser Tawfik
Abdel Nasser Tawfik (Egyptian Ctr. Theor. Phys., Cairo and WLCAPP, Cairo), Niseem Magdy (WLCAPP, Cairo)
On SU(3) effective models and chiral phase-transition
19 pages, 3 eps-figures accepted for publication in AHEP
Adv.High Energy Phys. 2015 (2015) 563428
10.1155/2015/563428
ECTP-2014-01, WLCAPP-2014-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The sensitivity of Polyakov Nambu-Jona-Lasinio (PNJL) model as an effective theory of quark dynamics to chiral symmetry has been utilized in studying the QCD phase-diagram. Also, Poyakov linear sigma-model (PLSM), in which information about the confining glue sector of the theory was included through Polyakov-loop potential. Furthermore, from quasi-particle model (QPM), the gluonic sector of QPM is integrated to LSM in order to reproduce recent lattice calculations. We review PLSM, QLSM, PNJL and HRG with respect to their descriptions for the chiral phase-transition. We analyse chiral order-parameter M(T), normalized net-strange condensate Delta_{q,s}(T) and chiral phase-diagram and compare the results with lattice QCD. We conclude that PLSM works perfectly in reproducing M(T) and Delta_{q,s}(T). HRG model reproduces Delta_{q,s}(T), while PNJL and QLSM seem to fail. These differences are present in QCD chiral phase-diagram. PLSM chiral boundary is located in upper band of lattice QCD calculations and agree well with freeze-out results deduced from high-energy experiments and thermal models. Also, we find that the chiral temperature calculated from from HRG model is larger than that from PLSM. This is also larger than the freeze-out temperatures calculated in lattice QCD and deduced from experiments and thermal models. The corresponding temperature T and chemical potential mu sets are very similar to that of PLSM. This might be explained, because the chiral T and mu are calculated using different order parameters; in HRG vanishing quark-antiquark condensate but in PLSM crossing (equaling) chiral condensates and Polyakov loop potentials. The latter assumed that the two phase transitions; chiral and deconfinement, take place at the same temperature.
[ { "created": "Wed, 23 Sep 2015 20:11:19 GMT", "version": "v1" } ]
2015-09-30
[ [ "Tawfik", "Abdel Nasser", "", "Egyptian Ctr. Theor. Phys., Cairo and WLCAPP,\n Cairo" ], [ "Magdy", "Niseem", "", "WLCAPP, Cairo" ] ]
The sensitivity of Polyakov Nambu-Jona-Lasinio (PNJL) model as an effective theory of quark dynamics to chiral symmetry has been utilized in studying the QCD phase-diagram. Also, Poyakov linear sigma-model (PLSM), in which information about the confining glue sector of the theory was included through Polyakov-loop potential. Furthermore, from quasi-particle model (QPM), the gluonic sector of QPM is integrated to LSM in order to reproduce recent lattice calculations. We review PLSM, QLSM, PNJL and HRG with respect to their descriptions for the chiral phase-transition. We analyse chiral order-parameter M(T), normalized net-strange condensate Delta_{q,s}(T) and chiral phase-diagram and compare the results with lattice QCD. We conclude that PLSM works perfectly in reproducing M(T) and Delta_{q,s}(T). HRG model reproduces Delta_{q,s}(T), while PNJL and QLSM seem to fail. These differences are present in QCD chiral phase-diagram. PLSM chiral boundary is located in upper band of lattice QCD calculations and agree well with freeze-out results deduced from high-energy experiments and thermal models. Also, we find that the chiral temperature calculated from from HRG model is larger than that from PLSM. This is also larger than the freeze-out temperatures calculated in lattice QCD and deduced from experiments and thermal models. The corresponding temperature T and chemical potential mu sets are very similar to that of PLSM. This might be explained, because the chiral T and mu are calculated using different order parameters; in HRG vanishing quark-antiquark condensate but in PLSM crossing (equaling) chiral condensates and Polyakov loop potentials. The latter assumed that the two phase transitions; chiral and deconfinement, take place at the same temperature.
hep-ph/0703187
Rafel Escribano
R. Escribano (UAB and IFAE, Barcelona), J. Nadal (IFAE, Barcelona)
On the gluon content of the eta and eta' mesons
16 pages, 3 figures, JHEP style. First part of data fitting changed, conclusions not modified
JHEP 0705:006,2007
10.1088/1126-6708/2007/05/006
UAB-FT-628
hep-ph hep-ex
null
A phenomenological analysis of radiative $V\to P\gamma$ and $P\to V\gamma$ decays is performed with the purpose of determining the gluonic content of the $\eta$ and $\eta^\prime$ wave functions. Our results show that within our model there is no evidence for a gluonium contribution in the $\eta$, $Z_\eta^2=0.00\pm 0.12$, or the $\eta^\prime$, $Z_{\eta^\prime}^2=0.04\pm 0.09$. In terms of a mixing angle description this corresponds to $\phi_P=(41.4\pm 1.3)^\circ$ and $|\phi_{\eta^\prime G}|=(12\pm 13)^\circ$. In addition, the $\eta$-$\eta^\prime$ mixing angle is found to be $\phi_P=(41.5\pm 1.2)^\circ$ if we don't allow for a gluonium component.
[ { "created": "Sat, 17 Mar 2007 22:56:24 GMT", "version": "v1" }, { "created": "Mon, 7 May 2007 09:43:38 GMT", "version": "v2" } ]
2010-10-27
[ [ "Escribano", "R.", "", "UAB and IFAE, Barcelona" ], [ "Nadal", "J.", "", "IFAE, Barcelona" ] ]
A phenomenological analysis of radiative $V\to P\gamma$ and $P\to V\gamma$ decays is performed with the purpose of determining the gluonic content of the $\eta$ and $\eta^\prime$ wave functions. Our results show that within our model there is no evidence for a gluonium contribution in the $\eta$, $Z_\eta^2=0.00\pm 0.12$, or the $\eta^\prime$, $Z_{\eta^\prime}^2=0.04\pm 0.09$. In terms of a mixing angle description this corresponds to $\phi_P=(41.4\pm 1.3)^\circ$ and $|\phi_{\eta^\prime G}|=(12\pm 13)^\circ$. In addition, the $\eta$-$\eta^\prime$ mixing angle is found to be $\phi_P=(41.5\pm 1.2)^\circ$ if we don't allow for a gluonium component.
1012.4735
Lisa M. Haas
Lisa M. Haas, Jens Braun, Jan M. Pawlowski
On the QCD phase diagram at finite chemical potential
3 pages, 5 figures; Contribution to the proceedings 'Quark Confinement and the Hadron Spectrum IX', 2010, Madrid
null
10.1063/1.3575061
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results for the phase diagram of QCD with two massless quark flavours as obtained from a first-principles functional renormalisation group approach. In particular we compute order parameters for chiral symmetry breaking and quark confinement at vanishing and non-zero imaginary chemical potential. Our analytical and numerical results suggest a close relation between the chiral and the deconfinement phase transition. We discuss the properties of dual order parameters at imaginary and real chemical potential.
[ { "created": "Tue, 21 Dec 2010 17:19:42 GMT", "version": "v1" } ]
2015-05-20
[ [ "Haas", "Lisa M.", "" ], [ "Braun", "Jens", "" ], [ "Pawlowski", "Jan M.", "" ] ]
We present results for the phase diagram of QCD with two massless quark flavours as obtained from a first-principles functional renormalisation group approach. In particular we compute order parameters for chiral symmetry breaking and quark confinement at vanishing and non-zero imaginary chemical potential. Our analytical and numerical results suggest a close relation between the chiral and the deconfinement phase transition. We discuss the properties of dual order parameters at imaginary and real chemical potential.
1901.05225
Susmita Bhaduri
Susmita Bhaduri, Anirban Bhaduri and Dipak Ghosh
Symmetry-Scaling Based Complex Network Approach to Explore Exotic Hadronic States in High-Energy Collision
null
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Conventionally invariant mass or transverse momentum techniques have been used to probe for any formation of some exotic or unusual resonance states in high energy collision. In this work, we have applied symmetry scaling based complex network approach to study exotic resonance/hadronic states utilizing the clustering coefficients and associated scaling parameter extracted with the complex network based technique of Visibility Graph. We have analyzed the data of Pb-Pb collision data sample at 2.76 TeV from ALICE Collaboration and analyzed different patterns of symmetry scaling, scale-freeness, correlation and clustering among the produced particles. This is a chaos-based complex network technique where simple parameters like Average Clustering Coefficient and Power of Scale-freeness of Visibility Graph(PSVG) may hint at formation of some exotic or unusual resonance states without using conventional methods. From this experiment we may infer that highest range of Average clustering coefficient, might be the resonance states/clusters from where the hadronic decay might have occurred and few clusters with highest value of this parameter may indicate that those clusters may be the ancestors of some strange particles. There have also been extensive study of dilepton production since the study of lepton pair generation in Drell-Yan processes is immensely important as these processes enable us to validate the Standard Model-SM predictions for the fundamental particles interaction at the new energy region and also to probe for new physics beyond SM. Hence we have applied the same methodology and extracted the same parameters for p-p collision data at 8TeV from CMS, to detect possible resonance states eventually generating lepton pairs.
[ { "created": "Wed, 16 Jan 2019 10:52:03 GMT", "version": "v1" }, { "created": "Thu, 17 Jan 2019 11:03:27 GMT", "version": "v2" } ]
2019-01-18
[ [ "Bhaduri", "Susmita", "" ], [ "Bhaduri", "Anirban", "" ], [ "Ghosh", "Dipak", "" ] ]
Conventionally invariant mass or transverse momentum techniques have been used to probe for any formation of some exotic or unusual resonance states in high energy collision. In this work, we have applied symmetry scaling based complex network approach to study exotic resonance/hadronic states utilizing the clustering coefficients and associated scaling parameter extracted with the complex network based technique of Visibility Graph. We have analyzed the data of Pb-Pb collision data sample at 2.76 TeV from ALICE Collaboration and analyzed different patterns of symmetry scaling, scale-freeness, correlation and clustering among the produced particles. This is a chaos-based complex network technique where simple parameters like Average Clustering Coefficient and Power of Scale-freeness of Visibility Graph(PSVG) may hint at formation of some exotic or unusual resonance states without using conventional methods. From this experiment we may infer that highest range of Average clustering coefficient, might be the resonance states/clusters from where the hadronic decay might have occurred and few clusters with highest value of this parameter may indicate that those clusters may be the ancestors of some strange particles. There have also been extensive study of dilepton production since the study of lepton pair generation in Drell-Yan processes is immensely important as these processes enable us to validate the Standard Model-SM predictions for the fundamental particles interaction at the new energy region and also to probe for new physics beyond SM. Hence we have applied the same methodology and extracted the same parameters for p-p collision data at 8TeV from CMS, to detect possible resonance states eventually generating lepton pairs.
hep-ph/0512262
Ulrich Baur
U. Baur (Buffalo), A. Juste (Fermilab), D. Rainwater (Rochester) and L.H. Orr (Rochester)
Improved Measurement of ttZ Couplings at the LHC
revtex4, 16 pages, 4 figures, 1 table
Phys.Rev.D73:034016,2006
10.1103/PhysRevD.73.034016
FERMILAB-PUB-05-542-T
hep-ph
null
We consider QCD tt~Z production at the LHC with Z->\bar\nu\nu and all-hadronic tt~ decays, i.e. pp -> p_T(miss)bb~+4 jets, as a tool to measure ttZ couplings. This channel has a significantly larger cross section than those where the Z boson decays leptonically. However, tt~, bb~+4 jet, tt~j and tt~jj production give rise to potentially large backgrounds. We show that these processes can be suppressed to an acceptable level with suitable cuts, and find that adding the p_T(miss)bb~+4 jet channel to the final states used in previous ttZ couplings analyses will improve the sensitivity by 10-60%. We also discuss how the measurement of the ttZ couplings may constrain Little Higgs models.
[ { "created": "Tue, 20 Dec 2005 20:44:10 GMT", "version": "v1" } ]
2008-11-26
[ [ "Baur", "U.", "", "Buffalo" ], [ "Juste", "A.", "", "Fermilab" ], [ "Rainwater", "D.", "", "Rochester" ], [ "Orr", "L. H.", "", "Rochester" ] ]
We consider QCD tt~Z production at the LHC with Z->\bar\nu\nu and all-hadronic tt~ decays, i.e. pp -> p_T(miss)bb~+4 jets, as a tool to measure ttZ couplings. This channel has a significantly larger cross section than those where the Z boson decays leptonically. However, tt~, bb~+4 jet, tt~j and tt~jj production give rise to potentially large backgrounds. We show that these processes can be suppressed to an acceptable level with suitable cuts, and find that adding the p_T(miss)bb~+4 jet channel to the final states used in previous ttZ couplings analyses will improve the sensitivity by 10-60%. We also discuss how the measurement of the ttZ couplings may constrain Little Higgs models.
2101.01527
Xu-Chang Zheng
Xu-Chang Zheng, Ze-Yang Zhang, Xing-Gang Wu
Fragmentation functions for a quark into a spin-singlet quarkonium: Different flavor case
10 pages, 8 figures
Phys. Rev. D 103, 074004 (2021)
10.1103/PhysRevD.103.074004
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In the paper, we calculate the fragmentation functions for a quark to fragment into a spin-singlet quarkonium, where the flavor of the initial quark is different from that of the constituent quark in the quarkonium. The ultraviolet divergences in the phase space integral are removed through the operator renormalization under the modified minimal subtraction scheme. The fragmentation function $D_{q \to \eta_Q}(z,\mu_F)$ is expressed as a two-dimensional integral. Numerical results for the fragmentation functions of a light quark or a bottom quark to fragment into the $\eta_c$ are presented. As an application of those fragmentation functions, we study the processes $Z \to \eta_c+q\bar{q}g(q=u,d,s)$ and $Z \to \eta_c+b\bar{b}g$ under the fragmentation and the direct nonrelativistic QCD approaches.
[ { "created": "Tue, 5 Jan 2021 14:20:14 GMT", "version": "v1" }, { "created": "Wed, 7 Apr 2021 15:13:59 GMT", "version": "v2" } ]
2021-04-08
[ [ "Zheng", "Xu-Chang", "" ], [ "Zhang", "Ze-Yang", "" ], [ "Wu", "Xing-Gang", "" ] ]
In the paper, we calculate the fragmentation functions for a quark to fragment into a spin-singlet quarkonium, where the flavor of the initial quark is different from that of the constituent quark in the quarkonium. The ultraviolet divergences in the phase space integral are removed through the operator renormalization under the modified minimal subtraction scheme. The fragmentation function $D_{q \to \eta_Q}(z,\mu_F)$ is expressed as a two-dimensional integral. Numerical results for the fragmentation functions of a light quark or a bottom quark to fragment into the $\eta_c$ are presented. As an application of those fragmentation functions, we study the processes $Z \to \eta_c+q\bar{q}g(q=u,d,s)$ and $Z \to \eta_c+b\bar{b}g$ under the fragmentation and the direct nonrelativistic QCD approaches.
1003.2204
Eric Kuflik
Timothy Cohen, Eric Kuflik, and Kathryn M. Zurek
Extracting the Dark Matter Mass from Single Stage Cascade Decays at the LHC
23 Pages, 14 Figures, 2 Appendices
JHEP 1011:008,2010
10.1007/JHEP11(2010)008
MCTP-10-09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore a variant on the MT2 kinematic variable which enables dark matter mass measurements for simple, one stage, cascade decays. This will prove useful for constraining a subset of supersymmetric processes, or a class of leptophilic dark matter models at the LHC. We investigate the statistical reach of these measurements and discuss which sources of error have the largest effects. For example, we find that using only single stage cascade decays with initial state radiation, a measurement of a 150 GeV dark matter candidate can be made to O(10%) for a parent mass of 300 GeV with a production cross section of 100 fb and 100 fb^(-1) of integrated luminosity.
[ { "created": "Wed, 10 Mar 2010 21:00:38 GMT", "version": "v1" }, { "created": "Mon, 19 Apr 2010 18:59:39 GMT", "version": "v2" } ]
2010-12-01
[ [ "Cohen", "Timothy", "" ], [ "Kuflik", "Eric", "" ], [ "Zurek", "Kathryn M.", "" ] ]
We explore a variant on the MT2 kinematic variable which enables dark matter mass measurements for simple, one stage, cascade decays. This will prove useful for constraining a subset of supersymmetric processes, or a class of leptophilic dark matter models at the LHC. We investigate the statistical reach of these measurements and discuss which sources of error have the largest effects. For example, we find that using only single stage cascade decays with initial state radiation, a measurement of a 150 GeV dark matter candidate can be made to O(10%) for a parent mass of 300 GeV with a production cross section of 100 fb and 100 fb^(-1) of integrated luminosity.
2111.04723
Antonio Bouzas
Antonio O. Bouzas and F. Larios
Top quark effective couplings from top-pair tagged photoproduction in $pe^-$ collisions
40 pages, some minor typos corrected
null
10.1103/PhysRevD.105.115002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a detailed study, at the fast detector simulation level, of top-pair photoproduction in semileptonic mode at the LHeC and FCC-he future colliders. We work in full tree-level QED, not relying on the equivalent-photon approximation, taking into account the complete photoproduction kinematics. This allows us to define three photoproduction regions based on the angular acceptance range of the electron tagger. Those regions provide different degrees of sensitivity to top-quark effective couplings. We focus on the $t\bar{t}\gamma$ dipole couplings and the left-handed vector $tbW$ coupling for which we determine limits at both energies and in different photoproduction regions. We find that the LHeC and FCC-he will yield tight direct bounds on top dipole moments, greatly improving on current direct limits from hadron colliders, and direct limits on the $tbW$ coupling as restrictive as those expected from the HL-LHC. We also consider indirect limits from $b\to s \gamma$ branching ratio and $CP$ asymmetry, that are well known to be very sensitive probes of top electromagnetic dipole moments.
[ { "created": "Mon, 8 Nov 2021 18:58:19 GMT", "version": "v1" }, { "created": "Wed, 1 Jun 2022 16:31:11 GMT", "version": "v2" }, { "created": "Thu, 23 Mar 2023 19:14:39 GMT", "version": "v3" } ]
2023-03-27
[ [ "Bouzas", "Antonio O.", "" ], [ "Larios", "F.", "" ] ]
We present a detailed study, at the fast detector simulation level, of top-pair photoproduction in semileptonic mode at the LHeC and FCC-he future colliders. We work in full tree-level QED, not relying on the equivalent-photon approximation, taking into account the complete photoproduction kinematics. This allows us to define three photoproduction regions based on the angular acceptance range of the electron tagger. Those regions provide different degrees of sensitivity to top-quark effective couplings. We focus on the $t\bar{t}\gamma$ dipole couplings and the left-handed vector $tbW$ coupling for which we determine limits at both energies and in different photoproduction regions. We find that the LHeC and FCC-he will yield tight direct bounds on top dipole moments, greatly improving on current direct limits from hadron colliders, and direct limits on the $tbW$ coupling as restrictive as those expected from the HL-LHC. We also consider indirect limits from $b\to s \gamma$ branching ratio and $CP$ asymmetry, that are well known to be very sensitive probes of top electromagnetic dipole moments.
hep-ph/9605262
Mauro
M. Napsuciale and J. L. Lucio
Spin $3/2$ Interacting Fields and Heavy Baryon Chiral Perturbation Theory
12 pages, Latex
Phys.Lett.B384:227-232,1996
10.1016/0370-2693(96)00812-X
NL1-96
hep-ph
null
We analyze the consistency of the Chiral Lagrangian approach to the description of the spin 3/2 interacting theory. We argue that to lowest order in the 1/m expansion, the formalism leads to the appropriated constraints and the theory is free of the so called ``off shell" ambiguities.
[ { "created": "Wed, 8 May 1996 22:33:49 GMT", "version": "v1" } ]
2016-09-01
[ [ "Napsuciale", "M.", "" ], [ "Lucio", "J. L.", "" ] ]
We analyze the consistency of the Chiral Lagrangian approach to the description of the spin 3/2 interacting theory. We argue that to lowest order in the 1/m expansion, the formalism leads to the appropriated constraints and the theory is free of the so called ``off shell" ambiguities.
hep-ph/0609049
Jesse Thaler
Aaron Pierce, Jesse Thaler, Lian-Tao Wang
Disentangling Dimension Six Operators through Di-Higgs Boson Production
20 pages, 7 figures; v2: to match JHEP version
JHEP 0705:070,2007
10.1088/1126-6708/2007/05/070
HUTP-06/A0037, MCTP-06-20
hep-ph
null
New physics near the TeV scale can generate dimension-six operators that modify the production rate and branching ratios of the Higgs boson. Here, we show how Higgs boson pair production can yield complementary information on dimension-six operators involving the gluon field strength. For example, the invariant mass distribution of the Higgs boson pair can show the extent to which the masses of exotic TeV-scale quarks come from electroweak symmetry breaking. We discuss both the current Tevatron bounds on these operators and the most promising LHC measurement channels for two different Higgs masses: 120 GeV and 180 GeV. We argue that the operators considered in this paper are the ones most likely to yield interesting Higgs pair physics at the LHC.
[ { "created": "Tue, 5 Sep 2006 16:30:17 GMT", "version": "v1" }, { "created": "Thu, 21 Jun 2007 01:57:13 GMT", "version": "v2" } ]
2010-10-27
[ [ "Pierce", "Aaron", "" ], [ "Thaler", "Jesse", "" ], [ "Wang", "Lian-Tao", "" ] ]
New physics near the TeV scale can generate dimension-six operators that modify the production rate and branching ratios of the Higgs boson. Here, we show how Higgs boson pair production can yield complementary information on dimension-six operators involving the gluon field strength. For example, the invariant mass distribution of the Higgs boson pair can show the extent to which the masses of exotic TeV-scale quarks come from electroweak symmetry breaking. We discuss both the current Tevatron bounds on these operators and the most promising LHC measurement channels for two different Higgs masses: 120 GeV and 180 GeV. We argue that the operators considered in this paper are the ones most likely to yield interesting Higgs pair physics at the LHC.
hep-ph/0310045
Bachir Moussallam
S. Descotes-Genon (LPT, Orsay), P. Buttiker (U. of Bonn), B. Moussallam (IPN, Orsay)
pi K scattering inputs to ChPT
Talk given at QCD'03 conference, 2-9 July 2003, Montpellier
null
null
null
hep-ph
null
Experimental information on low energy $\pi K$ scattering would shed light on the poorly known OZI suppressed sector of ChPT. I describe recent work aimed at generating such information based on available experimental data by setting up and then solving with appropriate boundary conditions a non linear system of equations of the Roy and Steiner type. First results of this analysis are presented.
[ { "created": "Fri, 3 Oct 2003 10:30:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Descotes-Genon", "S.", "", "LPT, Orsay" ], [ "Buttiker", "P.", "", "U. of Bonn" ], [ "Moussallam", "B.", "", "IPN, Orsay" ] ]
Experimental information on low energy $\pi K$ scattering would shed light on the poorly known OZI suppressed sector of ChPT. I describe recent work aimed at generating such information based on available experimental data by setting up and then solving with appropriate boundary conditions a non linear system of equations of the Roy and Steiner type. First results of this analysis are presented.
1603.06580
JiJi Fan
JiJi Fan
Ultralight Repulsive Dark Matter and BEC
minor modifications; references added
null
null
null
hep-ph astro-ph.CO astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ultralight scalar dark matter with mass at or below the eV scale and pressure from repulsive self-interaction could form a Bose-Einstein condensate in the early Universe and maybe in galaxies as well. It has been suggested to be a possible solution to the cusp/core problem or even to explain MOND phenomenology. In this paper, I initiate a study of possible self-interactions of ultralight scalar dark matter from the particle physics point of view. To protect its mass, the scalar dark matter is identified as a pseudo Nambu-Goldstone boson (pNGB). Quite a few pNGB models with different potentials such as the QCD axion and the dilaton lead to attractive self-interactions. Yet if an axion is a remnant of a 5D gauged U(1) symmetry, its self-interactions could be repulsive provided the masses and charges of the 5D matter contributing to its potential satisfy certain constraints. Collective symmetry breaking could also lead to a repulsive self-interaction yet with too large a strength that is ruled out by Bullet Cluster constraints. I also discuss cosmological and astrophysical constraints on ultralight repulsive dark matter in terms of a parametrization motivated by particle physics considerations.
[ { "created": "Mon, 21 Mar 2016 20:00:02 GMT", "version": "v1" }, { "created": "Fri, 15 Apr 2016 00:26:40 GMT", "version": "v2" } ]
2016-04-21
[ [ "Fan", "JiJi", "" ] ]
Ultralight scalar dark matter with mass at or below the eV scale and pressure from repulsive self-interaction could form a Bose-Einstein condensate in the early Universe and maybe in galaxies as well. It has been suggested to be a possible solution to the cusp/core problem or even to explain MOND phenomenology. In this paper, I initiate a study of possible self-interactions of ultralight scalar dark matter from the particle physics point of view. To protect its mass, the scalar dark matter is identified as a pseudo Nambu-Goldstone boson (pNGB). Quite a few pNGB models with different potentials such as the QCD axion and the dilaton lead to attractive self-interactions. Yet if an axion is a remnant of a 5D gauged U(1) symmetry, its self-interactions could be repulsive provided the masses and charges of the 5D matter contributing to its potential satisfy certain constraints. Collective symmetry breaking could also lead to a repulsive self-interaction yet with too large a strength that is ruled out by Bullet Cluster constraints. I also discuss cosmological and astrophysical constraints on ultralight repulsive dark matter in terms of a parametrization motivated by particle physics considerations.
hep-ph/0008181
U. Meissner
Nadia Fettes, Ulf-G. Mei{\ss}ner
Towards an understanding of isospin violation in pion-nucleon scattering
12 pp, REVTeX, 8 figs, FZJ-IKP(TH)-2000-20
Phys.Rev. C63 (2001) 045201
10.1103/PhysRevC.63.045201
null
hep-ph nucl-th
null
We investigate isospin breaking in low-energy pion-nucleon scattering in the framework of chiral perturbation theory. This work extends the systematic analysis of [1] to the energy range above threshold. Various relations, which identically vanish in the limit of isospin symmetry, are used to quantify isospin breaking effects. We study the energy dependence of the S- and P-wave projections of these ratios and find dramatic effects in the S-waves of those two relations which are given in terms of isoscalar quantities only. This effect drops rather quickly with growing center-of-mass energy.
[ { "created": "Thu, 17 Aug 2000 11:28:40 GMT", "version": "v1" } ]
2009-10-31
[ [ "Fettes", "Nadia", "" ], [ "Meißner", "Ulf-G.", "" ] ]
We investigate isospin breaking in low-energy pion-nucleon scattering in the framework of chiral perturbation theory. This work extends the systematic analysis of [1] to the energy range above threshold. Various relations, which identically vanish in the limit of isospin symmetry, are used to quantify isospin breaking effects. We study the energy dependence of the S- and P-wave projections of these ratios and find dramatic effects in the S-waves of those two relations which are given in terms of isoscalar quantities only. This effect drops rather quickly with growing center-of-mass energy.
hep-ph/0510325
Jure Zupan
A. Soni and J. Zupan
Semi-inclusive hadronic B decays as null tests of the Standard Model
8 pages, significantly expanded after the observation that both neutral and charged B decays can be used, calculation for decays involving eta' added
Phys.Rev.D75:014024,2007
10.1103/PhysRevD.75.014024
BNL-HET-05/26, CMU-TH-05-09
hep-ph
null
We propose a new set of observables that can be used as experimental null tests of the Standard Model in charged and neutral B decays. The CP asymmetries in hadronic decays of charged B mesons into inclusive final states containing at least one of the following mesons: K_{S,L}, eta', c\bar c bound states or neutral K^* or D mesons, for all of which a U-spin rotation is equivalent to a CP conjugation, are CKM suppressed and furthermore vanish in the exact U-spin limit. We show how this reduces the theoretical error by using Soft Collinear Effective Theory to calculate the CP asymmetries for K_{S,L} X_{s+d}, K^* X_{s+d} and eta' X_{s+d} final states in the endpoint region. For these CP asymmetries only the flavor and not the charge of the decaying B meson needs to be tagged up to corrections of NLO in 1/m_b, making the measurements more accessible experimentally.
[ { "created": "Mon, 24 Oct 2005 22:37:30 GMT", "version": "v1" }, { "created": "Tue, 1 Nov 2005 13:42:40 GMT", "version": "v2" }, { "created": "Tue, 7 Feb 2006 02:47:55 GMT", "version": "v3" }, { "created": "Sun, 27 Aug 2006 19:06:36 GMT", "version": "v4" } ]
2008-11-26
[ [ "Soni", "A.", "" ], [ "Zupan", "J.", "" ] ]
We propose a new set of observables that can be used as experimental null tests of the Standard Model in charged and neutral B decays. The CP asymmetries in hadronic decays of charged B mesons into inclusive final states containing at least one of the following mesons: K_{S,L}, eta', c\bar c bound states or neutral K^* or D mesons, for all of which a U-spin rotation is equivalent to a CP conjugation, are CKM suppressed and furthermore vanish in the exact U-spin limit. We show how this reduces the theoretical error by using Soft Collinear Effective Theory to calculate the CP asymmetries for K_{S,L} X_{s+d}, K^* X_{s+d} and eta' X_{s+d} final states in the endpoint region. For these CP asymmetries only the flavor and not the charge of the decaying B meson needs to be tagged up to corrections of NLO in 1/m_b, making the measurements more accessible experimentally.
1112.6351
Benjamin Koch
Giovanna Cottin, Marco Aurelio Diaz, and Benjamin Koch
Non-diagonal Charged Lepton Yukawa Matrix: Effects on Neutrino Mixing in Supersymmetry
22 pages 8 figures
null
10.1103/PhysRevD.85.095019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Generally the diagonalization of the mass matrix of the charged leptons is a part of the neutrino UPMNS matrix. However, usually this contribution is ignored by assuming a diagonal mass matrix for charged leptons. In this letter we test this common assumption in the context of neutrino physics. Our analytical and numerical results for two supersymmetric models reveal that such a simplification is not justified. Especially for the solar and reactor mixing angles important modifications are found.
[ { "created": "Thu, 29 Dec 2011 17:10:11 GMT", "version": "v1" } ]
2015-06-03
[ [ "Cottin", "Giovanna", "" ], [ "Diaz", "Marco Aurelio", "" ], [ "Koch", "Benjamin", "" ] ]
Generally the diagonalization of the mass matrix of the charged leptons is a part of the neutrino UPMNS matrix. However, usually this contribution is ignored by assuming a diagonal mass matrix for charged leptons. In this letter we test this common assumption in the context of neutrino physics. Our analytical and numerical results for two supersymmetric models reveal that such a simplification is not justified. Especially for the solar and reactor mixing angles important modifications are found.
1403.2971
Leonard Lesniak
J.-P. Dedonder, R. Kaminski, L. Lesniak, and B. Loiseau
Dalitz plot studies of D0 --> K0S pi+ pi- decays in a factorization approach
34 pages, 14 figures
Physical Review D 89, 094018 (2014)
10.1103/PhysRevD.89.094018
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The presently available high-statistics data of the D0 --> K0S pi+ pi- processes measured by the Belle and BABAR Collaborations are analyzed within a quasi two-body QCD factorization framework. Starting from the weak effective Hamiltonian, tree and annihilation amplitudes build up the D0 --> K0S pi+ pi- decay amplitude. Two of the three final-state mesons are assumed to form a single scalar, vector or tensor state originating from a quark-antiquark pair so that the factorization hypothesis can be applied. The meson-meson final state interactions are described by K pi and pi pi scalar and vector form factors for the S and P waves and by relativistic Breit-Wigner formulae for the D waves. A combined chi^2 fit to a Belle Dalitz plot density distribution, to the total experimental branching fraction and to the tau^- --> K0S pi- nu_tau decay data is carried out to fix the 33 free parameters. These are mainly related to the strengths of the scalar form factors and to unknown meson to meson transition form factors at a large momentum transfer squared equal to the D0 mass squared. A good overall agreement to the Belle Dalitz plot density distribution is achieved. Another set of parameters fits equally well the BABAR Collaboration Dalitz plot model. The branching fractions of the dominant channels compare well with those of the isobar Belle or BABAR models.The lower-limit values of the branching fractions of the annihilation amplitudes are significant. Built upon experimental data from other processes, the unitary K pi and pi pi scalar form factors, entering our decay amplitude and satisfying analyticity and chiral symmetry constraints, are furthermore constrained by the present Dalitz plot analysis. Our decay amplitude could be a useful input for determinations of D0-D0bar mixing parameters and of the CKM angle gamma (or phi3).
[ { "created": "Wed, 12 Mar 2014 15:27:12 GMT", "version": "v1" }, { "created": "Tue, 23 Sep 2014 12:54:47 GMT", "version": "v2" } ]
2014-09-24
[ [ "Dedonder", "J. -P.", "" ], [ "Kaminski", "R.", "" ], [ "Lesniak", "L.", "" ], [ "Loiseau", "B.", "" ] ]
The presently available high-statistics data of the D0 --> K0S pi+ pi- processes measured by the Belle and BABAR Collaborations are analyzed within a quasi two-body QCD factorization framework. Starting from the weak effective Hamiltonian, tree and annihilation amplitudes build up the D0 --> K0S pi+ pi- decay amplitude. Two of the three final-state mesons are assumed to form a single scalar, vector or tensor state originating from a quark-antiquark pair so that the factorization hypothesis can be applied. The meson-meson final state interactions are described by K pi and pi pi scalar and vector form factors for the S and P waves and by relativistic Breit-Wigner formulae for the D waves. A combined chi^2 fit to a Belle Dalitz plot density distribution, to the total experimental branching fraction and to the tau^- --> K0S pi- nu_tau decay data is carried out to fix the 33 free parameters. These are mainly related to the strengths of the scalar form factors and to unknown meson to meson transition form factors at a large momentum transfer squared equal to the D0 mass squared. A good overall agreement to the Belle Dalitz plot density distribution is achieved. Another set of parameters fits equally well the BABAR Collaboration Dalitz plot model. The branching fractions of the dominant channels compare well with those of the isobar Belle or BABAR models.The lower-limit values of the branching fractions of the annihilation amplitudes are significant. Built upon experimental data from other processes, the unitary K pi and pi pi scalar form factors, entering our decay amplitude and satisfying analyticity and chiral symmetry constraints, are furthermore constrained by the present Dalitz plot analysis. Our decay amplitude could be a useful input for determinations of D0-D0bar mixing parameters and of the CKM angle gamma (or phi3).
1702.06634
Alexandr Pimikov
Alexandr Pimikov, Hee-Jung Lee and Nikolai Kochelev
Comment on "Finding the $0^{--}$ Glueball" [arXiv:1408.3995]
null
Phys. Rev. Lett. 119, 079101 (2017)
10.1103/PhysRevLett.119.079101
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A Comment on the Letter by C. F. Qiao and L. Tang, Phys. Rev. Lett. 113, 221601 (2014) [arXiv:1408.3995]
[ { "created": "Wed, 22 Feb 2017 01:09:28 GMT", "version": "v1" }, { "created": "Sat, 29 Apr 2017 00:42:08 GMT", "version": "v2" } ]
2017-08-23
[ [ "Pimikov", "Alexandr", "" ], [ "Lee", "Hee-Jung", "" ], [ "Kochelev", "Nikolai", "" ] ]
A Comment on the Letter by C. F. Qiao and L. Tang, Phys. Rev. Lett. 113, 221601 (2014) [arXiv:1408.3995]
1310.2499
Karol Kolodziej
Karol Kolodziej
The top--Higgs coupling at the LHC
9 pages, 4 figures, presented at the XXXVII International Conference of Theoretical Physics, " Matter to the Deepest", Ustron, Poland, September 1-6, 2013
null
10.5506/APhysPolB.44.2189
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The factorization scale dependence of the anomalous top-Higgs coupling effects in the leading order differential cross sections and distributions of the secondary lepton in the process of associated production of the top quark pair and the Higgs boson at the LHC is discussed. It is also shown that the differential cross section as a function of the rapidity of the secondary lepton in the process is practically not sensitive to a sign of the anomalous pseudoscalar coupling.
[ { "created": "Wed, 9 Oct 2013 14:36:43 GMT", "version": "v1" } ]
2015-06-17
[ [ "Kolodziej", "Karol", "" ] ]
The factorization scale dependence of the anomalous top-Higgs coupling effects in the leading order differential cross sections and distributions of the secondary lepton in the process of associated production of the top quark pair and the Higgs boson at the LHC is discussed. It is also shown that the differential cross section as a function of the rapidity of the secondary lepton in the process is practically not sensitive to a sign of the anomalous pseudoscalar coupling.
hep-ph/9212304
Philip Mannheim
Philip D. Mannheim
Linear Potentials and Galactic Rotation Curves
13 pages (1 figure requestable), UCONN-92-3
Astrophys.J. 419 (1993) 150-154
10.1086/173468
null
hep-ph
null
We derive a simple, closed form expression for the potential of a thin exponential disk of stars interacting through gravitational potentials of the form $V(r)=-\beta /r+\gamma r/2$, the potential associated with fundamental sources in the fourth order conformal invariant theory of gravity which has recently been advanced by Mannheim and Kazanas as a candidate alternative to the standard second order Einstein theory. Using the model, we obtain a reasonable fit (flat to within $\pm3\%$) to the (prototypical) NGC3198 $HI$ rotation curve data without the need for any non-luminous or dark matter. Our study suggests that th observed flatness of rotation curves may only be an intermediate phenomenon, and an asymptotic one.
[ { "created": "Tue, 22 Dec 1992 23:50:54 GMT", "version": "v1" } ]
2009-10-22
[ [ "Mannheim", "Philip D.", "" ] ]
We derive a simple, closed form expression for the potential of a thin exponential disk of stars interacting through gravitational potentials of the form $V(r)=-\beta /r+\gamma r/2$, the potential associated with fundamental sources in the fourth order conformal invariant theory of gravity which has recently been advanced by Mannheim and Kazanas as a candidate alternative to the standard second order Einstein theory. Using the model, we obtain a reasonable fit (flat to within $\pm3\%$) to the (prototypical) NGC3198 $HI$ rotation curve data without the need for any non-luminous or dark matter. Our study suggests that th observed flatness of rotation curves may only be an intermediate phenomenon, and an asymptotic one.
1211.3140
Michael Spannowsky
Davison E. Soper and Michael Spannowsky
Finding top quarks with shower deconstruction
21 pages, 8 figures
null
10.1103/PhysRevD.87.054012
IPPP/12/83; DCPT/12/166
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a new method for tagging jets produced by hadronically decaying top quarks. The method is an application of shower deconstruction, a maximum information approach that was previously applied to identifying jets produced by Higgs bosons that decay to bottom quarks. We tag an observed jet as a top jet based on a cut on a calculated variable that is an approximation to the ratio of the likelihood that a top jet would have the structure of the observed jet to the likelihood that a non-top QCD jet would have this structure. We find that the shower deconstruction based tagger can perform better in discriminating boosted top quark jets from QCD jets than other publicly available tagging algorithms.
[ { "created": "Tue, 13 Nov 2012 21:26:28 GMT", "version": "v1" }, { "created": "Tue, 20 Dec 2016 20:01:13 GMT", "version": "v2" } ]
2016-12-21
[ [ "Soper", "Davison E.", "" ], [ "Spannowsky", "Michael", "" ] ]
We develop a new method for tagging jets produced by hadronically decaying top quarks. The method is an application of shower deconstruction, a maximum information approach that was previously applied to identifying jets produced by Higgs bosons that decay to bottom quarks. We tag an observed jet as a top jet based on a cut on a calculated variable that is an approximation to the ratio of the likelihood that a top jet would have the structure of the observed jet to the likelihood that a non-top QCD jet would have this structure. We find that the shower deconstruction based tagger can perform better in discriminating boosted top quark jets from QCD jets than other publicly available tagging algorithms.
1110.2064
Guillaume Chalons
G. Chalons, A. Semenov
Loop-induced photon spectral lines from neutralino annihilation in the NMSSM
18 pages, 3 figures. Minor clarifications added in the text. Typing mistakes and references corrected. Matches published version
JHEP 1112:055,2011
10.1007/JHEP12(2011)055
TTP11-28; LAPTH-038/11
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have computed the loop-induced processes of neutralino annihilation into two photons and, for the first time, into a photon and a Z boson in the framework of the NMSSM. The photons produced from these radiative modes are monochromatic and possess a clear "smoking gun" experimental signature. This numerical analysis has been done with the help of the SloopS code, initially developed for automatic one-loop calculation in the MSSM. We have computed the rates for different benchmark points coming from SUGRA and GMSB soft SUSY breaking scenarios and compared them with the MSSM. We comment on how this signal can be enhanced, with respect to the MSSM, especially in the low mass region of the neutralino. We also discuss the possibility of this observable to constrain the NMSSM parameter space, taking into account the latest limits from the FERMI collaboration on these two modes.
[ { "created": "Mon, 10 Oct 2011 15:04:17 GMT", "version": "v1" }, { "created": "Tue, 13 Dec 2011 08:29:59 GMT", "version": "v2" }, { "created": "Mon, 19 Dec 2011 13:30:11 GMT", "version": "v3" } ]
2011-12-20
[ [ "Chalons", "G.", "" ], [ "Semenov", "A.", "" ] ]
We have computed the loop-induced processes of neutralino annihilation into two photons and, for the first time, into a photon and a Z boson in the framework of the NMSSM. The photons produced from these radiative modes are monochromatic and possess a clear "smoking gun" experimental signature. This numerical analysis has been done with the help of the SloopS code, initially developed for automatic one-loop calculation in the MSSM. We have computed the rates for different benchmark points coming from SUGRA and GMSB soft SUSY breaking scenarios and compared them with the MSSM. We comment on how this signal can be enhanced, with respect to the MSSM, especially in the low mass region of the neutralino. We also discuss the possibility of this observable to constrain the NMSSM parameter space, taking into account the latest limits from the FERMI collaboration on these two modes.
hep-ph/0607252
Charanjit S. Aulakh
Charanjit S. Aulakh
Msgut Reborn ?
Typos corrected, coefficient notation simplified slightly
null
null
null
hep-ph
null
We present examples of fits of fermion mass data using the $\mathbf{10-120-\oot}$ FM Higgs system in Susy SO(10) GUTs that follow the scenario\cite{blmdoom,nmsgutI} in which the $\mathbf{120}$ -plet collaborates with the $ \mathbf{10}$-plet to fit the charged fermion masses while small $\mathbf{\oot} $-plet couplings enhance the Type I seesaw neutrino masses to viable values and make the fit to light fermions accurate. Restricting ourselves to the CP conserving case we use a linear perturbative technique to obtain accurate charged fermion fits ($\chi^2_{tot} < .2 $) to all the charged fermion masses and angles. The resulting fits imply Type I neutrino masses that are generically $10^2- 10^3$ times larger than those obtained in the $\mathbf{10-\oot}$ scenario precisely because of the small $\mathbf{\oot} $ coupling. Thus the difficulty of obtaining sufficiently large neutrino masses in the context of these Next to Minimal Susy GUTs is essentially removed. The remaining free parameters allow one to obtain the correct ratio of neutrino mass squared splitting and a large($\theta_{23}^{PMNS}$) and small($\theta_{13}^{PMNS}$) mixing angle. The $\theta_{12}^{PMNS}$ is however small and this indicates that -as in the Type I $\mathbf{10-\oot}$ case - a fully realistic fit to the lepton mixing data also \emph{requires} CP violation.
[ { "created": "Sun, 23 Jul 2006 13:14:55 GMT", "version": "v1" }, { "created": "Thu, 10 Aug 2006 14:53:16 GMT", "version": "v2" } ]
2007-05-23
[ [ "Aulakh", "Charanjit S.", "" ] ]
We present examples of fits of fermion mass data using the $\mathbf{10-120-\oot}$ FM Higgs system in Susy SO(10) GUTs that follow the scenario\cite{blmdoom,nmsgutI} in which the $\mathbf{120}$ -plet collaborates with the $ \mathbf{10}$-plet to fit the charged fermion masses while small $\mathbf{\oot} $-plet couplings enhance the Type I seesaw neutrino masses to viable values and make the fit to light fermions accurate. Restricting ourselves to the CP conserving case we use a linear perturbative technique to obtain accurate charged fermion fits ($\chi^2_{tot} < .2 $) to all the charged fermion masses and angles. The resulting fits imply Type I neutrino masses that are generically $10^2- 10^3$ times larger than those obtained in the $\mathbf{10-\oot}$ scenario precisely because of the small $\mathbf{\oot} $ coupling. Thus the difficulty of obtaining sufficiently large neutrino masses in the context of these Next to Minimal Susy GUTs is essentially removed. The remaining free parameters allow one to obtain the correct ratio of neutrino mass squared splitting and a large($\theta_{23}^{PMNS}$) and small($\theta_{13}^{PMNS}$) mixing angle. The $\theta_{12}^{PMNS}$ is however small and this indicates that -as in the Type I $\mathbf{10-\oot}$ case - a fully realistic fit to the lepton mixing data also \emph{requires} CP violation.
hep-ph/0604254
Matthew Wingate
Matthew Wingate
B Physics on the Lattice: Present and Future
Invited brief review for Mod. Phys. Lett. A. 15 pages. v2: typos corrected, references added
Mod.Phys.Lett. A21 (2006) 1167-1182
10.1142/S0217732306020688
INT-PUB 06-07
hep-ph hep-lat
null
Recent experimental measurements and lattice QCD calculations are now reaching the precision (and accuracy) needed to over-constrain the CKM parameters $\bar\rho$ and $\bar\eta$. In this brief review, I discuss the current status of lattice QCD calculations needed to connect the experimental measurements of $B$ meson properties to quark flavor-changing parameters. Special attention is given to $B\to\pi\ell\nu$, which is becoming a competitive way to determine $|V_{ub}|$, and to $B^0-\bar{B^0}$ mixings, which now include reliable extrapolation to the physical light quark mass. The combination of the recent measurement of the $B_s$ mass difference and current lattice calculations dramatically reduces the uncertainty in $|V_{td}|$. I present an outlook for reducing dominant lattice QCD uncertainties entering CKM fits, and I remark on lattice calculations for other decay channels.
[ { "created": "Fri, 28 Apr 2006 19:24:46 GMT", "version": "v1" }, { "created": "Tue, 16 May 2006 03:15:47 GMT", "version": "v2" } ]
2009-11-11
[ [ "Wingate", "Matthew", "" ] ]
Recent experimental measurements and lattice QCD calculations are now reaching the precision (and accuracy) needed to over-constrain the CKM parameters $\bar\rho$ and $\bar\eta$. In this brief review, I discuss the current status of lattice QCD calculations needed to connect the experimental measurements of $B$ meson properties to quark flavor-changing parameters. Special attention is given to $B\to\pi\ell\nu$, which is becoming a competitive way to determine $|V_{ub}|$, and to $B^0-\bar{B^0}$ mixings, which now include reliable extrapolation to the physical light quark mass. The combination of the recent measurement of the $B_s$ mass difference and current lattice calculations dramatically reduces the uncertainty in $|V_{td}|$. I present an outlook for reducing dominant lattice QCD uncertainties entering CKM fits, and I remark on lattice calculations for other decay channels.
0910.5095
Gautam Bhattacharyya
Gautam Bhattacharyya
A Pedagogical Review of Electroweak Symmetry Breaking Scenarios
45 pages, Review based on a series of lectures; v2: 63 pages, substantially expanded, references added, to appear in `Reports on Progress in Physics'
Rept.Prog.Phys.74:026201,2011
10.1088/0034-4885/74/2/026201
SINP/TNP/2009/23
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review different avenues of electroweak symmetry breaking explored over the years. This constitutes a timely exercise as the world's largest and the highest energy particle accelerator, namely, the Large Hadron Collider (LHC) at CERN near Geneva, has started running whose primary mission is to find the Higgs or some phenomena that mimic the effects of the Higgs, i.e. to unravel the mysteries of electroweak phase transition. In the beginning, we discuss the Standard Model Higgs mechanism. After that we review the Higgs sector of the Minimal Supersymmetric Standard Model. Then we take up three relatively recent ideas: Little Higgs, Gauge-Higgs Unification, and Higgsless scenarios. For the latter three cases, we first present the basic ideas and restrict our illustration to some instructive toy models to provide an intuitive feel of the underlying dynamics, and then discuss, for each of the three cases, how more realistic scenarios are constructed and how to decipher their experimental signatures. Wherever possible, we provide enough pedagogical details, which the beginners might find useful.
[ { "created": "Tue, 27 Oct 2009 11:37:06 GMT", "version": "v1" }, { "created": "Wed, 15 Dec 2010 10:37:17 GMT", "version": "v2" } ]
2011-02-02
[ [ "Bhattacharyya", "Gautam", "" ] ]
We review different avenues of electroweak symmetry breaking explored over the years. This constitutes a timely exercise as the world's largest and the highest energy particle accelerator, namely, the Large Hadron Collider (LHC) at CERN near Geneva, has started running whose primary mission is to find the Higgs or some phenomena that mimic the effects of the Higgs, i.e. to unravel the mysteries of electroweak phase transition. In the beginning, we discuss the Standard Model Higgs mechanism. After that we review the Higgs sector of the Minimal Supersymmetric Standard Model. Then we take up three relatively recent ideas: Little Higgs, Gauge-Higgs Unification, and Higgsless scenarios. For the latter three cases, we first present the basic ideas and restrict our illustration to some instructive toy models to provide an intuitive feel of the underlying dynamics, and then discuss, for each of the three cases, how more realistic scenarios are constructed and how to decipher their experimental signatures. Wherever possible, we provide enough pedagogical details, which the beginners might find useful.
hep-ph/9911425
Michail Ivanov
M.A. Ivanov, J.G. Korner, V.E. Lyubovitskij, M.A. Pisarev, A.G. Rusetsky
On the choice of heavy baryon currents in the relativistic three-quark model
revtex, 9 pages
Phys.Rev. D61 (2000) 114010
10.1103/PhysRevD.61.114010
Mainz University preprint MZ-TH/99-51
hep-ph
null
We test the sensitivity of bottom baryon observables with regard to the choice of the interpolating three-quark currents within the relativistic three-quark model. We have found that the semileptonic decay rates are clearly affected by the choice of currents, whereas the asymmetry parameters show only a very weak dependence on the choice of current.
[ { "created": "Sun, 21 Nov 1999 12:21:46 GMT", "version": "v1" } ]
2009-10-31
[ [ "Ivanov", "M. A.", "" ], [ "Korner", "J. G.", "" ], [ "Lyubovitskij", "V. E.", "" ], [ "Pisarev", "M. A.", "" ], [ "Rusetsky", "A. G.", "" ] ]
We test the sensitivity of bottom baryon observables with regard to the choice of the interpolating three-quark currents within the relativistic three-quark model. We have found that the semileptonic decay rates are clearly affected by the choice of currents, whereas the asymmetry parameters show only a very weak dependence on the choice of current.
hep-ph/0212109
Ivan Vitev
Ivan Vitev
Leading order pQCD hadron production and nuclear modification factors at RHIC and the LHC
Contribution to the CERN Yellow Report on Hard Probes in Heavy Ion Collisions at the LHC, 10 pages, uses cernrep.cls
null
null
null
hep-ph nucl-th
null
Hadron production in leading order pQCD is reviewed. The shape of the single inclusive particle spectra is well described for $p_T \geq 2-3$ GeV at center of mass energies from 20 GeV to 2 TeV. The phenomenological K-factor is found to decrease systematically with $\sqrt{s}$. For ultra-relativistic heavy ion reactions the calculation is augmented with the effects of initial multiple parton scattering and final state radiative energy loss. Baseline CERN-LHC predictions for hadron production in $p+p$ and suppression in central $Pb+Pb$ reactions at $\sqrt{s} = 5.5$ TeV are given in comparison to the corresponding results at BNL-RHIC and CERN-SPS energies.
[ { "created": "Sat, 7 Dec 2002 01:15:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Vitev", "Ivan", "" ] ]
Hadron production in leading order pQCD is reviewed. The shape of the single inclusive particle spectra is well described for $p_T \geq 2-3$ GeV at center of mass energies from 20 GeV to 2 TeV. The phenomenological K-factor is found to decrease systematically with $\sqrt{s}$. For ultra-relativistic heavy ion reactions the calculation is augmented with the effects of initial multiple parton scattering and final state radiative energy loss. Baseline CERN-LHC predictions for hadron production in $p+p$ and suppression in central $Pb+Pb$ reactions at $\sqrt{s} = 5.5$ TeV are given in comparison to the corresponding results at BNL-RHIC and CERN-SPS energies.
2006.04587
Arlene Cristina Aguilar
A. C. Aguilar, M. N. Ferreira, J. Papavassiliou
Novel sum rules for the three-point sector of QCD
34 pages, 7 figures, 1 table
null
10.1140/epjc/s10052-020-08453-2
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For special kinematic configurations involving a single momentum scale, certain standard relations, originating from the Slavnov-Taylor identities of the theory, may be interpreted as ordinary differential equations for the ``kinetic term'' of the gluon propagator. The exact solutions of these equations exhibit poles at the origin, which are incompatible with the physical answer, known to diverge only logarithmically; their elimination hinges on the validity of two integral conditions that we denominate ``asymmetric'' and ``symmetric'' sum rules, depending on the kinematics employed in their derivation. The corresponding integrands contain components of the three-gluon vertex and the ghost-gluon kernel, whose dynamics are constrained when the sum rules are imposed. For the numerical treatment we single out the asymmetric sum rule, given that its support stems predominantly from low and intermediate energy regimes of the defining integral, which are physically more interesting. Adopting a combined approach based on Schwinger-Dyson equations and lattice simulations, we demonstrate how the sum rule clearly favors the suppression of an effective form factor entering in the definition of its kernel. The results of the present work offer an additional vantage point into the rich and complex structure of the three-point sector of QCD.
[ { "created": "Mon, 8 Jun 2020 13:32:50 GMT", "version": "v1" } ]
2020-10-28
[ [ "Aguilar", "A. C.", "" ], [ "Ferreira", "M. N.", "" ], [ "Papavassiliou", "J.", "" ] ]
For special kinematic configurations involving a single momentum scale, certain standard relations, originating from the Slavnov-Taylor identities of the theory, may be interpreted as ordinary differential equations for the ``kinetic term'' of the gluon propagator. The exact solutions of these equations exhibit poles at the origin, which are incompatible with the physical answer, known to diverge only logarithmically; their elimination hinges on the validity of two integral conditions that we denominate ``asymmetric'' and ``symmetric'' sum rules, depending on the kinematics employed in their derivation. The corresponding integrands contain components of the three-gluon vertex and the ghost-gluon kernel, whose dynamics are constrained when the sum rules are imposed. For the numerical treatment we single out the asymmetric sum rule, given that its support stems predominantly from low and intermediate energy regimes of the defining integral, which are physically more interesting. Adopting a combined approach based on Schwinger-Dyson equations and lattice simulations, we demonstrate how the sum rule clearly favors the suppression of an effective form factor entering in the definition of its kernel. The results of the present work offer an additional vantage point into the rich and complex structure of the three-point sector of QCD.
2311.05898
Halil Gams{\i}zkan
Murat Alt{\i}nl{\i}, Halil Gams{\i}zkan
ERNIE: A Reactor Antineutrino Inverse Beta Decay Event Generator
19 pages, 7 figures
Computer Physics Communications 282 (2023) 108543
10.1016/j.cpc.2022.108543
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present ERNIE, a computer program which generates nuclear reactor electron antineutrinos and inverse beta decay events induced by these particles, using the Monte-Carlo method. The program allows the usage of different antineutrino energy spectra models and can simulate the time evolution of the overall antineutrino spectrum because of the burn-up effect. The output of the program can readily be used in detector simulations made with eg. GEANT 4.
[ { "created": "Fri, 10 Nov 2023 07:06:35 GMT", "version": "v1" } ]
2023-11-13
[ [ "Altınlı", "Murat", "" ], [ "Gamsızkan", "Halil", "" ] ]
We present ERNIE, a computer program which generates nuclear reactor electron antineutrinos and inverse beta decay events induced by these particles, using the Monte-Carlo method. The program allows the usage of different antineutrino energy spectra models and can simulate the time evolution of the overall antineutrino spectrum because of the burn-up effect. The output of the program can readily be used in detector simulations made with eg. GEANT 4.
hep-ph/9405225
Andreas Laser
J.Kripfganz, A.Laser and M.G.Schmidt
Critical Bubbles and Fluctuations at the Electroweak Phase Transition
HD-THEP-94-13 30 pages, 10 figures included at the end, LaTeX, epsf.sty
Nucl.Phys. B433 (1995) 467-497
10.1016/0550-3213(94)00452-K
null
hep-ph
null
We discuss the critical bubbles of the electroweak phase transition using an effective high-temperature 3-dimensional action for the Higgs field $\varphi$. The separate integration of gauge and Goldstone boson degrees of freedom is conveniently described in the 't Hooft-Feynman covariant background gauge. The effective dimensionless gauge coupling $g_3(T)^2$ in the broken phase is well behaved throughout the phase transition. However, the behavior of the one-loop $Z(\varphi)$ factors of the Higgs and gauge kinetic terms signalizes the breakdown of the derivative expansion and of the perturbative expansion for a range of small $\varphi$ values increasing with the Higgs mass $m_H$. Taking a functional $S_z[\varphi]$ with constant $Z(\varphi)=z$ instead of the full non-local effective action in some neighborhood of the saddlepoint we are calculating the critical bubbles for several temperatures. The fluctuation determinant is calculated to high accuracy using a variant of the heat kernel method. It gives a strong suppression of the transition rate compared to previous estimates.
[ { "created": "Wed, 4 May 1994 18:14:07 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kripfganz", "J.", "" ], [ "Laser", "A.", "" ], [ "Schmidt", "M. G.", "" ] ]
We discuss the critical bubbles of the electroweak phase transition using an effective high-temperature 3-dimensional action for the Higgs field $\varphi$. The separate integration of gauge and Goldstone boson degrees of freedom is conveniently described in the 't Hooft-Feynman covariant background gauge. The effective dimensionless gauge coupling $g_3(T)^2$ in the broken phase is well behaved throughout the phase transition. However, the behavior of the one-loop $Z(\varphi)$ factors of the Higgs and gauge kinetic terms signalizes the breakdown of the derivative expansion and of the perturbative expansion for a range of small $\varphi$ values increasing with the Higgs mass $m_H$. Taking a functional $S_z[\varphi]$ with constant $Z(\varphi)=z$ instead of the full non-local effective action in some neighborhood of the saddlepoint we are calculating the critical bubbles for several temperatures. The fluctuation determinant is calculated to high accuracy using a variant of the heat kernel method. It gives a strong suppression of the transition rate compared to previous estimates.
2105.10728
Shiladitya Porey
Arnab Chaudhuri, Maxim Yu. Khlopov and Shiladitya Porey
Effects of 2HDM in electroweak phase transition
8 pages, 5 figures
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
The entropy production scenarios due to electroweak phase transition (EWPT) in the framework of the minimal extension of standard model namely two Higgs doublet model(2HDM) is revisited. The possibility of first order phase transition is discussed. Intense parameter scanning is done with the help of BSMPT, a C++ package. Numerical calculations are performed in order to calculate the entropy production with numerous benchmark points.
[ { "created": "Sat, 22 May 2021 13:35:46 GMT", "version": "v1" } ]
2021-05-25
[ [ "Chaudhuri", "Arnab", "" ], [ "Khlopov", "Maxim Yu.", "" ], [ "Porey", "Shiladitya", "" ] ]
The entropy production scenarios due to electroweak phase transition (EWPT) in the framework of the minimal extension of standard model namely two Higgs doublet model(2HDM) is revisited. The possibility of first order phase transition is discussed. Intense parameter scanning is done with the help of BSMPT, a C++ package. Numerical calculations are performed in order to calculate the entropy production with numerous benchmark points.
1908.10900
Tim Stefaniak
Tim Stefaniak
Higgs physics beyond the Standard Model
9 pages, 4 figures, to appear in the Proceedings of ALPS2019 - An Alpine LHC Physics Summit
null
null
DESY 19-150
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give a brief review of beyond-the-Standard Model (BSM) extensions of the Standard Model (SM) Higgs sector. Going from very simple to more complicated models, our survey includes models with additional scalar singlet fields, the Two Higgs Doublet Model (2HDM) and the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM). We discuss the impact of current experimental results from LHC Higgs searches and measurements and the prospective reach of the LHC in the high-luminosity (HL) phase. We furthermore highlight possible new collider signatures within these models that have not been experimentally probed to date.
[ { "created": "Wed, 28 Aug 2019 18:36:09 GMT", "version": "v1" } ]
2019-08-30
[ [ "Stefaniak", "Tim", "" ] ]
We give a brief review of beyond-the-Standard Model (BSM) extensions of the Standard Model (SM) Higgs sector. Going from very simple to more complicated models, our survey includes models with additional scalar singlet fields, the Two Higgs Doublet Model (2HDM) and the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM). We discuss the impact of current experimental results from LHC Higgs searches and measurements and the prospective reach of the LHC in the high-luminosity (HL) phase. We furthermore highlight possible new collider signatures within these models that have not been experimentally probed to date.
2109.10195
Ignasi Rosell
Ignasi Rosell, Antonio Pich, Juan Jos\'e Sanz-Cillero
Heavy states and electroweak effective approaches
6 pages, 1 figure, 1 table. Talk given at The European Physical Society Conference on High Energy Physics - EPS-HEP2021 (26-30 July 2021, online conference, Hamburg, Germany)
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The existence of a mass gap between the Standard Model (SM) and possible new states encourages us to use effective field theories. Here we follow the non-linear realization of the electroweak symmetry breaking: the electroweak effective theory (EWET), also known as Higgs effective field theory (HEFT) or electroweak chiral Lagrangian (EWChL). At short distances an effective resonance Lagrangian which couples the SM states to bosonic and fermionic resonances is considered. After integrating out the resonances and assuming a well-behaved high-energy behavior, we estimate or bound purely bosonic low-energy constants in terms of only resonance masses. Current experimental information on these low-energy constants allows us to constrain the high-energy resonance masses.
[ { "created": "Tue, 21 Sep 2021 14:20:40 GMT", "version": "v1" } ]
2021-09-22
[ [ "Rosell", "Ignasi", "" ], [ "Pich", "Antonio", "" ], [ "Sanz-Cillero", "Juan José", "" ] ]
The existence of a mass gap between the Standard Model (SM) and possible new states encourages us to use effective field theories. Here we follow the non-linear realization of the electroweak symmetry breaking: the electroweak effective theory (EWET), also known as Higgs effective field theory (HEFT) or electroweak chiral Lagrangian (EWChL). At short distances an effective resonance Lagrangian which couples the SM states to bosonic and fermionic resonances is considered. After integrating out the resonances and assuming a well-behaved high-energy behavior, we estimate or bound purely bosonic low-energy constants in terms of only resonance masses. Current experimental information on these low-energy constants allows us to constrain the high-energy resonance masses.
1011.6412
Bo-Qiang Ma
Nan Qin, Bo-Qiang Ma
A new simple form of quark mixing matrix
10 pages, 1 figure, final version for journal publication
Phys.Lett.B695:194-198,2011
10.1016/j.physletb.2010.11.013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although different parametrizations of quark mixing matrix are mathematically equivalent, the consequences of experimental analysis may be distinct. Based on the triminimal expansion of Kobayashi-Maskawa matrix around the unit matrix, we propose a new simple parametrization. Compared with the Wolfenstein parametrization, we find that the new form is not only consistent with the original one in the hierarchical structure, but also more convenient for numerical analysis and measurement of the CP-violating phase. By discussing the relation between our new form and the unitarity boomerang, we point out that along with the unitarity boomerang, this new parametrization is useful in hunting for new physics.
[ { "created": "Mon, 29 Nov 2010 23:16:59 GMT", "version": "v1" } ]
2011-01-27
[ [ "Qin", "Nan", "" ], [ "Ma", "Bo-Qiang", "" ] ]
Although different parametrizations of quark mixing matrix are mathematically equivalent, the consequences of experimental analysis may be distinct. Based on the triminimal expansion of Kobayashi-Maskawa matrix around the unit matrix, we propose a new simple parametrization. Compared with the Wolfenstein parametrization, we find that the new form is not only consistent with the original one in the hierarchical structure, but also more convenient for numerical analysis and measurement of the CP-violating phase. By discussing the relation between our new form and the unitarity boomerang, we point out that along with the unitarity boomerang, this new parametrization is useful in hunting for new physics.
hep-ph/0602046
Hisakazu Minakata
Hisakazu Minakata, Shoichi Uchinami
Recoilless Resonant Absorption of Monochromatic Neutrino Beam for Measuring Delta m^2_{31} and theta_{13}
23 pages, 3 figures, version to appear in New Journal of Physics
New J.Phys. 8 (2006) 143
10.1088/1367-2630/8/8/143
null
hep-ph hep-ex
null
We discuss, in the context of precision measurement of Delta m^2_{31} and theta_{13}, physics capabilities enabled by the recoilless resonant absorption of monochromatic antineutrino beam enhanced by the M\"ossbauer effect recently proposed by Raghavan. Under the assumption of small relative systematic error of a few tenth of percent level between measurement at different detector locations, we give analytical and numerical estimates of the sensitivities to Delta m^2_{31} and sin^2 2theta_{13}. The accuracies of determination of them are enormous; The fractional uncertainty in Delta m^2_{31} achievable by 10 point measurement is 0.6% (2.4%) for sin^2 2theta_{13} = 0.05, and the uncertainty of sin^2 2theta_{13} is 0.002 (0.008) both at 1 sigma CL with the optimistic (pessimistic) assumption of systematic error of 0.2% (1%). The former opens a new possibility of determining the neutrino mass hierarchy by comparing the measured value of Delta m^2_{31} with the one by accelerator experiments, while the latter will help resolving the theta_{23} octant degeneracy.
[ { "created": "Mon, 6 Feb 2006 12:55:32 GMT", "version": "v1" }, { "created": "Tue, 21 Feb 2006 00:03:35 GMT", "version": "v2" }, { "created": "Sat, 5 Aug 2006 00:00:21 GMT", "version": "v3" } ]
2009-11-11
[ [ "Minakata", "Hisakazu", "" ], [ "Uchinami", "Shoichi", "" ] ]
We discuss, in the context of precision measurement of Delta m^2_{31} and theta_{13}, physics capabilities enabled by the recoilless resonant absorption of monochromatic antineutrino beam enhanced by the M\"ossbauer effect recently proposed by Raghavan. Under the assumption of small relative systematic error of a few tenth of percent level between measurement at different detector locations, we give analytical and numerical estimates of the sensitivities to Delta m^2_{31} and sin^2 2theta_{13}. The accuracies of determination of them are enormous; The fractional uncertainty in Delta m^2_{31} achievable by 10 point measurement is 0.6% (2.4%) for sin^2 2theta_{13} = 0.05, and the uncertainty of sin^2 2theta_{13} is 0.002 (0.008) both at 1 sigma CL with the optimistic (pessimistic) assumption of systematic error of 0.2% (1%). The former opens a new possibility of determining the neutrino mass hierarchy by comparing the measured value of Delta m^2_{31} with the one by accelerator experiments, while the latter will help resolving the theta_{23} octant degeneracy.
2201.13432
Felipe Gregoletto Ben
F. G. Ben, A. V. Giannini and M. V. T. Machado
Nuclear transverse momentum imbalance in the color dipole approach at the LHC regime
6 pages, 2 figure, 2 tables
null
10.1088/1361-6471/ac8b27
null
hep-ph hep-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Transverse momentum broadening of a parton propagating through a large nucleus is evaluated in the color dipole approach using different models for the dipole cross section or unintegrated gluon distribution, which lead to different values of the coefficient $C_{\mathcal{F}}(0,s)$. Numerical calculations are compared to data extracted from LHCb and ALICE experiments for nuclear broadening of $J/\psi$. We find that different models which describe the small-$x$ data predict values of $\Delta p_T^2$ that agree reasonably well with experiment, specially for forward rapidity. The centrality dependence was also analysed and the models are consistent with the ALICE measurements.
[ { "created": "Mon, 31 Jan 2022 18:44:56 GMT", "version": "v1" }, { "created": "Sun, 20 Mar 2022 23:36:55 GMT", "version": "v2" } ]
2022-09-21
[ [ "Ben", "F. G.", "" ], [ "Giannini", "A. V.", "" ], [ "Machado", "M. V. T.", "" ] ]
Transverse momentum broadening of a parton propagating through a large nucleus is evaluated in the color dipole approach using different models for the dipole cross section or unintegrated gluon distribution, which lead to different values of the coefficient $C_{\mathcal{F}}(0,s)$. Numerical calculations are compared to data extracted from LHCb and ALICE experiments for nuclear broadening of $J/\psi$. We find that different models which describe the small-$x$ data predict values of $\Delta p_T^2$ that agree reasonably well with experiment, specially for forward rapidity. The centrality dependence was also analysed and the models are consistent with the ALICE measurements.
hep-ph/9710272
null
M. Grazzini
Cut Vertices and Semi-Inclusive Deep Inelastic Processes
LaTex2e, 24 pages including 17 postscript figures
Phys.Rev. D57 (1998) 4352-4360
10.1103/PhysRevD.57.4352
UPRF-97-016
hep-ph
null
Cut vertices, a generalization of matrix elements of local operators, are revisited, and an expansion in terms of minimally subtracted cut vertices is formulated. An extension of the formalism to deal with semi-inclusive deep inelastic processes in the target fragmentation region is explicitly constructed. The problem of factorization is discussed in detail.
[ { "created": "Tue, 7 Oct 1997 16:27:32 GMT", "version": "v1" } ]
2009-10-30
[ [ "Grazzini", "M.", "" ] ]
Cut vertices, a generalization of matrix elements of local operators, are revisited, and an expansion in terms of minimally subtracted cut vertices is formulated. An extension of the formalism to deal with semi-inclusive deep inelastic processes in the target fragmentation region is explicitly constructed. The problem of factorization is discussed in detail.
1301.0507
Ruben Concei\c{c}\~ao
Ruben Concei\c{c}\~ao, Sofia Andringa, Lorenzo Cazon, M\'ario Pimenta
The interplay between the electromagnetic and the muonic longitudinal profile at production
5 pages, to appear in conference proceedings of International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2012), Berlin, Germany
null
10.1051/epjconf/20125203004
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The electromagnetic and the muonic longitudinal profile at production enclosure important information about the primary particle and the hadronic interactions that rule the shower development. In fact, these two profiles provide two different insights of the shower: the electromagnetic component gives a measurement of the energy and the strength of the neutral pion channel; while the muonic profile, being intimately related with the charged mesons decays, can be used as a direct probe for the high energy hadronic interactions. In this work we explore the interplay between the electromagnetic and muonic profiles, by analysing their phenomenologic behaviour for different primary masses and energies, zenith angles, and also different high energy hadronic interaction models. We have found that the muonic longitudinal profile at production displays universal features similar to what is known for the electromagnetic one. Moreover, we show that both profiles have new primary mass composition variables which are fairly independent of the high energy hadronic interaction model. Finally we discuss how the information in the electromagnetic and the muonic longitudinal profile can be combined to break the degeneracy between the primary mass composition and the high energy hadronic physics.
[ { "created": "Thu, 3 Jan 2013 17:07:15 GMT", "version": "v1" } ]
2015-06-12
[ [ "Conceição", "Ruben", "" ], [ "Andringa", "Sofia", "" ], [ "Cazon", "Lorenzo", "" ], [ "Pimenta", "Mário", "" ] ]
The electromagnetic and the muonic longitudinal profile at production enclosure important information about the primary particle and the hadronic interactions that rule the shower development. In fact, these two profiles provide two different insights of the shower: the electromagnetic component gives a measurement of the energy and the strength of the neutral pion channel; while the muonic profile, being intimately related with the charged mesons decays, can be used as a direct probe for the high energy hadronic interactions. In this work we explore the interplay between the electromagnetic and muonic profiles, by analysing their phenomenologic behaviour for different primary masses and energies, zenith angles, and also different high energy hadronic interaction models. We have found that the muonic longitudinal profile at production displays universal features similar to what is known for the electromagnetic one. Moreover, we show that both profiles have new primary mass composition variables which are fairly independent of the high energy hadronic interaction model. Finally we discuss how the information in the electromagnetic and the muonic longitudinal profile can be combined to break the degeneracy between the primary mass composition and the high energy hadronic physics.
2312.00424
Pengcheng Zhao
Pengcheng Zhao
Momentum space oscillation properties of vortex states collision
15 pages, 10 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
A qualitative calculation and discussion of two vortex states collisions are given in the scalar $\phi ^4$ model. Three kinds of vortex states -- Bessel, general monochromatic, and Laguerre-Gaussian vortex states -- are considered. It is found that the total final momentum distribution in collision of physical vortex states displays general topological structures, which depend on the initial vortex states' topological charges, which are proportional to the orbital angular momenta. This peculiar matching provides a novel observable, the topological number of momentum distribution, and it may represent a new fascinating research direction in particle physics. We also find that the situation when the angular momenta of the two colliding Laguerre-Gaussian states combine to zero can be recognized by the total final momentum distribution close to the collision axis. Both features can be used to measure the orbital angular momentum of vortex states.
[ { "created": "Fri, 1 Dec 2023 08:47:05 GMT", "version": "v1" } ]
2023-12-04
[ [ "Zhao", "Pengcheng", "" ] ]
A qualitative calculation and discussion of two vortex states collisions are given in the scalar $\phi ^4$ model. Three kinds of vortex states -- Bessel, general monochromatic, and Laguerre-Gaussian vortex states -- are considered. It is found that the total final momentum distribution in collision of physical vortex states displays general topological structures, which depend on the initial vortex states' topological charges, which are proportional to the orbital angular momenta. This peculiar matching provides a novel observable, the topological number of momentum distribution, and it may represent a new fascinating research direction in particle physics. We also find that the situation when the angular momenta of the two colliding Laguerre-Gaussian states combine to zero can be recognized by the total final momentum distribution close to the collision axis. Both features can be used to measure the orbital angular momentum of vortex states.
hep-ph/9501231
Stefano Forte
R. D. Ball and S. Forte
Summation of Leading Logarithms at Small x
21 pages, TeX with harvmac, 3 figures in compressed postscript. Final published version (several minor corrections)
Phys.Lett.B351:313-324,1995
10.1016/0370-2693(95)00395-2
CERN-TH/95-1
hep-ph
null
We show how perturbation theory may be reorganized to give splitting functions which include order by order convergent sums of all leading logarithms of $x$. This gives a leading twist evolution equation for parton distributions which sums all leading logarithms of $x$ and $Q^2$, allowing stable perturbative evolution down to arbitrarily small values of $x$. Perturbative evolution then generates the double scaling rise of $F_2$ observed at HERA, while in the formal limit $x\to 0$ at fixed $Q^2$ the Lipatov $x^{-\lambda}$ behaviour is eventually reproduced. We are thus able to explain why leading order perturbation theory works so well in the HERA region.
[ { "created": "Sun, 8 Jan 1995 00:35:47 GMT", "version": "v1" }, { "created": "Wed, 11 Jan 1995 20:37:59 GMT", "version": "v2" }, { "created": "Tue, 4 Apr 1995 13:10:04 GMT", "version": "v3" } ]
2014-11-17
[ [ "Ball", "R. D.", "" ], [ "Forte", "S.", "" ] ]
We show how perturbation theory may be reorganized to give splitting functions which include order by order convergent sums of all leading logarithms of $x$. This gives a leading twist evolution equation for parton distributions which sums all leading logarithms of $x$ and $Q^2$, allowing stable perturbative evolution down to arbitrarily small values of $x$. Perturbative evolution then generates the double scaling rise of $F_2$ observed at HERA, while in the formal limit $x\to 0$ at fixed $Q^2$ the Lipatov $x^{-\lambda}$ behaviour is eventually reproduced. We are thus able to explain why leading order perturbation theory works so well in the HERA region.
1906.11189
Jos\'e Carlos Jim\'enez Apaza
Jos\'e C. Jim\'enez, Eduardo S. Fraga
Radial oscillations of quark stars from perturbative QCD
10 pages, 5 figures; v2: figures added, references added, modifications to the text
Phys. Rev. D 100, 114041 (2019)
10.1103/PhysRevD.100.114041
null
hep-ph astro-ph.HE gr-qc nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform the general relativistic stability analysis against radial oscillations of unpaired quark stars obtained using the equation of state for cold quark matter from perturbative QCD, the only free parameter being the renormalization scale. This approach consistently incorporates the effects of interactions and includes a built-in estimate of the inherent systematic uncertainties in the evaluation of the equation of state. We also take into account the constraints imposed by the recent gravitational wave event GW 170817 to the compact star masses and radii, and restrict their vibrational spectrum.
[ { "created": "Wed, 26 Jun 2019 16:15:10 GMT", "version": "v1" }, { "created": "Mon, 30 Dec 2019 17:04:36 GMT", "version": "v2" } ]
2020-01-03
[ [ "Jiménez", "José C.", "" ], [ "Fraga", "Eduardo S.", "" ] ]
We perform the general relativistic stability analysis against radial oscillations of unpaired quark stars obtained using the equation of state for cold quark matter from perturbative QCD, the only free parameter being the renormalization scale. This approach consistently incorporates the effects of interactions and includes a built-in estimate of the inherent systematic uncertainties in the evaluation of the equation of state. We also take into account the constraints imposed by the recent gravitational wave event GW 170817 to the compact star masses and radii, and restrict their vibrational spectrum.
2303.12932
Yann Cado
Yann Cado, Mariano Quir\'os
Baryogenesis from Higgs Inflation
22 pages, 4 figures
null
10.1103/PhysRevD.108.023508
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
If the inflaton field is coupled to the hypercharge Chern-Simons density $F\tilde F$, an explosive production of helical gauge fields when inflation ends can trigger baryogenesis at the electroweak phase transition. Besides, Higgs inflation identifies the inflaton with the Higgs field $\mathcal H$, thus relating cosmological observables to properties of electroweak physics. In this paper we merge both approaches: the helical gauge fields are produced at the end of Higgs inflation from the coupling $|\mathcal H|^2 F\tilde F$. In the metric formulation of gravity we found a window in the parameter space for electroweak baryogenesis consistent with all experimental observations. Conversely, for the Palatini formalism the non-gaussianity bounds strongly constrain the helicity produced at the end of inflation, forbidding an efficient baryogenesis.
[ { "created": "Wed, 22 Mar 2023 22:10:53 GMT", "version": "v1" } ]
2023-07-26
[ [ "Cado", "Yann", "" ], [ "Quirós", "Mariano", "" ] ]
If the inflaton field is coupled to the hypercharge Chern-Simons density $F\tilde F$, an explosive production of helical gauge fields when inflation ends can trigger baryogenesis at the electroweak phase transition. Besides, Higgs inflation identifies the inflaton with the Higgs field $\mathcal H$, thus relating cosmological observables to properties of electroweak physics. In this paper we merge both approaches: the helical gauge fields are produced at the end of Higgs inflation from the coupling $|\mathcal H|^2 F\tilde F$. In the metric formulation of gravity we found a window in the parameter space for electroweak baryogenesis consistent with all experimental observations. Conversely, for the Palatini formalism the non-gaussianity bounds strongly constrain the helicity produced at the end of inflation, forbidding an efficient baryogenesis.
hep-ph/0111223
Kari J. Eskola
K.J. Eskola
Initial state of the QGP from perturbative QCD + saturation
10 pages, 8 figures. Invited talk at the International Conference on Statistical QCD, August 2001, Bielefeld
Nucl.Phys. A702 (2002) 249-258
10.1016/S0375-9474(02)00712-1
null
hep-ph
null
The production of the initial state of the QGP in very high-energy $AA$ collisions is discussed within the framework of perturbative QCD and saturation. The next-to-leading order computation of the transverse energy of minijets is reviewed. Saturation of parton production, conjectured to occur at a dynamically determinable perturbative scale, leads to estimates of the initial densities. The final state multiplicities are predicted by assuming an isentropic hydrodynamical further evolution. Comparison with RHIC data is shown.
[ { "created": "Mon, 19 Nov 2001 11:26:05 GMT", "version": "v1" } ]
2009-11-07
[ [ "Eskola", "K. J.", "" ] ]
The production of the initial state of the QGP in very high-energy $AA$ collisions is discussed within the framework of perturbative QCD and saturation. The next-to-leading order computation of the transverse energy of minijets is reviewed. Saturation of parton production, conjectured to occur at a dynamically determinable perturbative scale, leads to estimates of the initial densities. The final state multiplicities are predicted by assuming an isentropic hydrodynamical further evolution. Comparison with RHIC data is shown.
1512.08378
Haipeng An
Haipeng An, Clifford Cheung, Yue Zhang
Broad Diphotons from Narrow States
7 pages, 6 figures
null
null
CALT-TH-2015-065
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
ATLAS and CMS have each reported a modest diphoton excess consistent with the decay of a broad resonance at ~ 750 GeV. We show how this signal can arise in a weakly coupled theory comprised solely of narrow width particles. In particular, if the decaying particle is produced off-shell, then the associated diphoton resonance will have a broad, adjustable width. We present simplified models which explain the diphoton excess through the three-body decay of a scalar or fermion. Our minimal ultraviolet completion is a weakly coupled and renormalizable theory of a singlet scalar plus a heavy vector-like quark and lepton. The smoking gun of this mechanism is an asymmetric diphoton peak recoiling against missing transverse energy, jets, or leptons.
[ { "created": "Mon, 28 Dec 2015 11:22:07 GMT", "version": "v1" } ]
2015-12-29
[ [ "An", "Haipeng", "" ], [ "Cheung", "Clifford", "" ], [ "Zhang", "Yue", "" ] ]
ATLAS and CMS have each reported a modest diphoton excess consistent with the decay of a broad resonance at ~ 750 GeV. We show how this signal can arise in a weakly coupled theory comprised solely of narrow width particles. In particular, if the decaying particle is produced off-shell, then the associated diphoton resonance will have a broad, adjustable width. We present simplified models which explain the diphoton excess through the three-body decay of a scalar or fermion. Our minimal ultraviolet completion is a weakly coupled and renormalizable theory of a singlet scalar plus a heavy vector-like quark and lepton. The smoking gun of this mechanism is an asymmetric diphoton peak recoiling against missing transverse energy, jets, or leptons.
hep-ph/9901245
Yue-Liang Wu
Yue-Liang Wu (ITP)
Nearly Degenerate Mass and Bi-maximal Mixing of Neutrinos in the SO(3) Gauge Model of Leptons
14 pages, latex, no figures, references added, to appear in Eur. Phys. J. C
Eur.Phys.J.C10:491-497,1999
10.1007/s100520050773
AS-ITP-99-01
hep-ph
null
A realistic scheme for masses and mixing of leptons is investigated in the model with gauged SO(3) lepton flavor symmetry. Within this scheme, a nearly `bi-maximal' neutrino mixing pattern with maximal CP-violating phase is found to be the only possible solution for reconciling both solar and atmospheric neutrino flux anomalies. Three Majorana neutrino masses are nearly degenerate and allow to be large enough to play a significant cosmological role. Lepton flavor-violating effects via SO(3) gauge interactions can be as large as the present experimental limits. Masses of the SO(3) gauge bosons are bounded to be above 24 TeV when taking the SO(3) gauge boson mixing angle $\theta_{F}$ and coupling constant $g'_{3}$ to be the same as those ($\theta_{W}$ and $g$) in the electroweak theory.
[ { "created": "Fri, 8 Jan 1999 05:50:43 GMT", "version": "v1" }, { "created": "Thu, 10 Jun 1999 10:54:48 GMT", "version": "v2" } ]
2011-09-13
[ [ "Wu", "Yue-Liang", "", "ITP" ] ]
A realistic scheme for masses and mixing of leptons is investigated in the model with gauged SO(3) lepton flavor symmetry. Within this scheme, a nearly `bi-maximal' neutrino mixing pattern with maximal CP-violating phase is found to be the only possible solution for reconciling both solar and atmospheric neutrino flux anomalies. Three Majorana neutrino masses are nearly degenerate and allow to be large enough to play a significant cosmological role. Lepton flavor-violating effects via SO(3) gauge interactions can be as large as the present experimental limits. Masses of the SO(3) gauge bosons are bounded to be above 24 TeV when taking the SO(3) gauge boson mixing angle $\theta_{F}$ and coupling constant $g'_{3}$ to be the same as those ($\theta_{W}$ and $g$) in the electroweak theory.
1505.05523
Krzysztof Rolbiecki
Krzysztof Rolbiecki, Jamie Tattersall
Refining light stop exclusion limits with $W^+W^-$ cross sections
5 pages, 2 figures; references updated, minor changes; to appear in Phys. Lett. B
null
10.1016/j.physletb.2015.09.028
IFT-UAM/CSIC-15-052
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If light supersymmetric top (stop) quarks are produced at the LHC and decay via on- or off-shell $W$-bosons they can be expected to contribute to a precision $W^+W^-$ cross section measurement. Using the latest results of the CMS experiment, we revisit constraints on the stop quark production and find that this measurement can exclude portions of the parameter space not probed by dedicated searches. In particular we can exclude light top squarks up to 230~GeV along the line separating three- and four-body decays, $\tilde{t}_1 \to \tilde{\chi}_1^0 W^{(*)} b$. We also study the exclusion limits in the case when the branching ratio for these decays is reduced and we show significant improvement over previously existing limits.
[ { "created": "Wed, 20 May 2015 20:08:52 GMT", "version": "v1" }, { "created": "Tue, 26 May 2015 16:21:24 GMT", "version": "v2" }, { "created": "Wed, 16 Sep 2015 11:30:17 GMT", "version": "v3" } ]
2015-09-17
[ [ "Rolbiecki", "Krzysztof", "" ], [ "Tattersall", "Jamie", "" ] ]
If light supersymmetric top (stop) quarks are produced at the LHC and decay via on- or off-shell $W$-bosons they can be expected to contribute to a precision $W^+W^-$ cross section measurement. Using the latest results of the CMS experiment, we revisit constraints on the stop quark production and find that this measurement can exclude portions of the parameter space not probed by dedicated searches. In particular we can exclude light top squarks up to 230~GeV along the line separating three- and four-body decays, $\tilde{t}_1 \to \tilde{\chi}_1^0 W^{(*)} b$. We also study the exclusion limits in the case when the branching ratio for these decays is reduced and we show significant improvement over previously existing limits.
1009.1303
Andrzej Buras
Andrzej J. Buras
Flavour Theory and the LHC Era
17 Pages, 1 Figure, Plenary talk presented at the Symposium "Physics at the LHC 2010", DESY, June, 2010
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This decade should make a significant progress towards the Theory of Flavour and the main goal of this talk is to transfer this believe to my colleagues in the particle physics community. Indeed a significant part of this decade could turn out to be the Flavour Era with participation of the LHC, Belle II, Super-Flavour-Facility and dedicated Kaon and lepton flavour violation experiments. Selected superstars of flavour physics listed below will play a prominent role in these events. In this writeup the leading role is played by the prima donna of 2010: CP violation in B_s system.
[ { "created": "Tue, 7 Sep 2010 14:16:12 GMT", "version": "v1" } ]
2010-09-08
[ [ "Buras", "Andrzej J.", "" ] ]
This decade should make a significant progress towards the Theory of Flavour and the main goal of this talk is to transfer this believe to my colleagues in the particle physics community. Indeed a significant part of this decade could turn out to be the Flavour Era with participation of the LHC, Belle II, Super-Flavour-Facility and dedicated Kaon and lepton flavour violation experiments. Selected superstars of flavour physics listed below will play a prominent role in these events. In this writeup the leading role is played by the prima donna of 2010: CP violation in B_s system.
1711.09773
Dimitrios K. Papoulias
D. K. Papoulias and T. S. Kosmas
COHERENT constraints to conventional and exotic neutrino physics
10 pages, 9 figures, 1 table, authors order reversed, matches published version to PRD
Phys. Rev. D 97, 033003 (2018)
10.1103/PhysRevD.97.033003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The process of neutral-current coherent elastic neutrino-nucleus scattering, consistent with the Standard Model (SM) expectation, has been recently measured by the COHERENT experiment at the Spallation Neutron Source. On the basis of the observed signal and our nuclear calculations for the relevant Cs and I isotopes, the extracted constraints on both conventional and exotic neutrino physics are updated. The present study concentrates on various SM extensions involving vector and tensor nonstandard interactions as well as neutrino electromagnetic properties, with an emphasis on the neutrino magnetic moment and the neutrino charge radius. Furthermore, models addressing a light sterile neutrino state and scenarios with new propagator fields---such as vector $Z^\prime$ and scalar bosons---are examined, and the corresponding regions excluded by the COHERENT experiment are presented.
[ { "created": "Mon, 27 Nov 2017 15:42:29 GMT", "version": "v1" }, { "created": "Sun, 10 Dec 2017 17:37:16 GMT", "version": "v2" }, { "created": "Thu, 15 Feb 2018 20:32:52 GMT", "version": "v3" } ]
2018-02-21
[ [ "Papoulias", "D. K.", "" ], [ "Kosmas", "T. S.", "" ] ]
The process of neutral-current coherent elastic neutrino-nucleus scattering, consistent with the Standard Model (SM) expectation, has been recently measured by the COHERENT experiment at the Spallation Neutron Source. On the basis of the observed signal and our nuclear calculations for the relevant Cs and I isotopes, the extracted constraints on both conventional and exotic neutrino physics are updated. The present study concentrates on various SM extensions involving vector and tensor nonstandard interactions as well as neutrino electromagnetic properties, with an emphasis on the neutrino magnetic moment and the neutrino charge radius. Furthermore, models addressing a light sterile neutrino state and scenarios with new propagator fields---such as vector $Z^\prime$ and scalar bosons---are examined, and the corresponding regions excluded by the COHERENT experiment are presented.
2405.18697
Wei Kou
Wei Kou, Xurong Chen
Locating Quark-Antiquark String Breaking in QCD through Chiral Symmetry Restoration and Hawking-Unruh Effect
8 pages, 2 tables, 4 figures, accepted for publication in Physics Letters B
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
The relationship between QCD and the string model offers a valuable perspective for exploring the interaction potential between quarks. In this study, we investigate the restoration of chiral symmetry in connection with the Unruh effect experienced by accelerating observers. Utilizing the Schwinger model, we analyze the critical point at which the string or chromoelectric flux tube between quark-antiquarks breaks with increasing separation between quarks. In this study, the critical distance for quark-antiquark chromoelectric flux tube or string breaking is determined to be $r_c=1.294\pm0.040$ fm. The acceleration and Unruh temperature corresponding to this critical point signify the transition of the system's chiral symmetry from a broken to a restored state. Our estimates for the critical acceleration ($a_c=1.14\times 10^{34}$ cm/s$^{2}$) and Unruh temperature ($T_c=0.038$ GeV) align with previous studies. This analysis illuminates the interplay between chiral symmetry restoration, the Unruh effect, and the breaking of the string or chromoelectric flux tube within the context of quark interactions.
[ { "created": "Wed, 29 May 2024 02:17:24 GMT", "version": "v1" }, { "created": "Sat, 10 Aug 2024 08:40:46 GMT", "version": "v2" } ]
2024-08-13
[ [ "Kou", "Wei", "" ], [ "Chen", "Xurong", "" ] ]
The relationship between QCD and the string model offers a valuable perspective for exploring the interaction potential between quarks. In this study, we investigate the restoration of chiral symmetry in connection with the Unruh effect experienced by accelerating observers. Utilizing the Schwinger model, we analyze the critical point at which the string or chromoelectric flux tube between quark-antiquarks breaks with increasing separation between quarks. In this study, the critical distance for quark-antiquark chromoelectric flux tube or string breaking is determined to be $r_c=1.294\pm0.040$ fm. The acceleration and Unruh temperature corresponding to this critical point signify the transition of the system's chiral symmetry from a broken to a restored state. Our estimates for the critical acceleration ($a_c=1.14\times 10^{34}$ cm/s$^{2}$) and Unruh temperature ($T_c=0.038$ GeV) align with previous studies. This analysis illuminates the interplay between chiral symmetry restoration, the Unruh effect, and the breaking of the string or chromoelectric flux tube within the context of quark interactions.
2304.09195
Manuel Kunkel
Thomas Flacke, Jeong Han Kim, Manuel Kunkel, Pyungwon Ko, Jun Seung Pi, Werner Porod, Leonard Schwarze
Uncovering doubly charged scalars with dominant three-body decays using machine learning
16 pages, 14 figures, 2 technical appendices
null
null
KIAS-A23009
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We propose a deep learning-based search strategy for pair production of doubly charged scalars undergoing three-body decays to $W^+ t\bar b$ in the same-sign lepton plus multi-jet final state. This process is motivated by composite Higgs models with an underlying fermionic UV theory. We demonstrate that for such busy final states, jet image classification with convolutional neural networks outperforms standard fully connected networks acting on reconstructed kinematic variables. We derive the expected discovery reach and exclusion limit at the high-luminosity LHC.
[ { "created": "Tue, 18 Apr 2023 18:00:02 GMT", "version": "v1" } ]
2023-04-20
[ [ "Flacke", "Thomas", "" ], [ "Kim", "Jeong Han", "" ], [ "Kunkel", "Manuel", "" ], [ "Ko", "Pyungwon", "" ], [ "Pi", "Jun Seung", "" ], [ "Porod", "Werner", "" ], [ "Schwarze", "Leonard", "" ] ]
We propose a deep learning-based search strategy for pair production of doubly charged scalars undergoing three-body decays to $W^+ t\bar b$ in the same-sign lepton plus multi-jet final state. This process is motivated by composite Higgs models with an underlying fermionic UV theory. We demonstrate that for such busy final states, jet image classification with convolutional neural networks outperforms standard fully connected networks acting on reconstructed kinematic variables. We derive the expected discovery reach and exclusion limit at the high-luminosity LHC.
hep-ph/0009287
Steve King
S. F. King and M.Oliveira
Neutrino Masses and Mixing Angles in a Realistic String-Inspired Model
53 pages, Latex
Phys.Rev. D63 (2001) 095004
10.1103/PhysRevD.63.095004
null
hep-ph
null
We analyse a supersymmetric string-inspired model of all fermion masses and mixing angles based on the Pati-Salam $SU(4)\times SU(2)_L \times SU(2)_R$ gauge group supplemented by a $U(1)_X$ flavour symmetry. The model involves third family Yukawa unification and predicts the top mass and the ratio of the vacuum expectation values $\tan \beta$. The model also provides a successful description of the CKM matrix and predicts the masses of the down and strange quarks. However our main focus is on the neutrino masses and MNS mixing angles, and we show how the recent atmospheric neutrino mixing observed by Super-Kamiokande, and the MSW solution to the solar neutrino problem lead to important information about the flavour structure of the model near the string scale. We show how single right-handed neutrino dominance may be implemented by the use of ``Clebsch zeros'', leading to the LMA MSW solution, corresponding to bi-maximal mixing. The LOW MSW and SMA MSW solutions are also discussed.
[ { "created": "Mon, 25 Sep 2000 16:06:53 GMT", "version": "v1" }, { "created": "Thu, 28 Sep 2000 16:36:37 GMT", "version": "v2" } ]
2016-09-06
[ [ "King", "S. F.", "" ], [ "Oliveira", "M.", "" ] ]
We analyse a supersymmetric string-inspired model of all fermion masses and mixing angles based on the Pati-Salam $SU(4)\times SU(2)_L \times SU(2)_R$ gauge group supplemented by a $U(1)_X$ flavour symmetry. The model involves third family Yukawa unification and predicts the top mass and the ratio of the vacuum expectation values $\tan \beta$. The model also provides a successful description of the CKM matrix and predicts the masses of the down and strange quarks. However our main focus is on the neutrino masses and MNS mixing angles, and we show how the recent atmospheric neutrino mixing observed by Super-Kamiokande, and the MSW solution to the solar neutrino problem lead to important information about the flavour structure of the model near the string scale. We show how single right-handed neutrino dominance may be implemented by the use of ``Clebsch zeros'', leading to the LMA MSW solution, corresponding to bi-maximal mixing. The LOW MSW and SMA MSW solutions are also discussed.
1107.2084
Simone Marzani
Rosa Maria Duran Delgado, Jeffrey R. Forshaw, Simone Marzani and Michael H. Seymour
The dijet cross section with a jet veto
null
null
10.1007/JHEP08(2011)157
MAN/HEP/2011/10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study dijet production in proton-proton collisions with a veto on the emission of a third jet in the rapidity region in between the two leading ones. We resum the leading logarithms in the ratio of the transverse momentum of the leading jets and the veto scale and we match this result to leading-order QCD matrix elements. We find that, in order to obtain sensible results, we have to modify the resummation and take into account energy-momentum conservation effects. We compare our theoretical predictions for the gap fraction to experimental data measured by the ATLAS collaboration and find good agreement, although our results are affected by large theoretical uncertainties. We then discuss differences and similarities of our calculation to other theoretical approaches.
[ { "created": "Mon, 11 Jul 2011 18:36:53 GMT", "version": "v1" } ]
2015-05-28
[ [ "Delgado", "Rosa Maria Duran", "" ], [ "Forshaw", "Jeffrey R.", "" ], [ "Marzani", "Simone", "" ], [ "Seymour", "Michael H.", "" ] ]
We study dijet production in proton-proton collisions with a veto on the emission of a third jet in the rapidity region in between the two leading ones. We resum the leading logarithms in the ratio of the transverse momentum of the leading jets and the veto scale and we match this result to leading-order QCD matrix elements. We find that, in order to obtain sensible results, we have to modify the resummation and take into account energy-momentum conservation effects. We compare our theoretical predictions for the gap fraction to experimental data measured by the ATLAS collaboration and find good agreement, although our results are affected by large theoretical uncertainties. We then discuss differences and similarities of our calculation to other theoretical approaches.
2012.01574
Tobias Neumann
John Campbell, Tobias Neumann, Zack Sullivan
Single-top-quark production in the $t$-channel at NNLO
40 pages, 22 figures, JHEP published version
JHEP 02 (2021) 040
10.1007/JHEP02(2021)040
FERMILAB-PUB-20-608-T, IIT-CAPP-20-05
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a calculation of t-channel single-top-quark production and decay in the five-flavor scheme at NNLO. Our results resolve a disagreement between two previous calculations of this process that found a difference in the inclusive cross section at the level of the NNLO coefficient itself. We compare in detail with the previous calculations at the inclusive, differential and fiducial level including b-quark tagging at a fixed scale $\mu=m_t$. In addition, we advocate the use of double deep inelastic scattering (DDIS) scales ($\mu^2=Q^2$ for the light-quark line and $\mu^2=Q^2+m_t^2$ for the heavy-quark line) that maximize perturbative stability and allow for robust scale uncertainties. All NNLO and NLO$\,\otimes\,$NLO contributions for production and decay are included in the on-shell and vertex-function approximation. We present fiducial and differential results for a variety of observables used in Standard Model and Beyond Standard Model analyses, and find an important difference between the NLO and NNLO predictions of exclusive $t+n$-jet cross sections. Overall we find that NNLO corrections are crucial for a precise identification of the t-channel process.
[ { "created": "Wed, 2 Dec 2020 22:20:24 GMT", "version": "v1" }, { "created": "Thu, 18 Feb 2021 16:59:30 GMT", "version": "v2" } ]
2021-02-19
[ [ "Campbell", "John", "" ], [ "Neumann", "Tobias", "" ], [ "Sullivan", "Zack", "" ] ]
We present a calculation of t-channel single-top-quark production and decay in the five-flavor scheme at NNLO. Our results resolve a disagreement between two previous calculations of this process that found a difference in the inclusive cross section at the level of the NNLO coefficient itself. We compare in detail with the previous calculations at the inclusive, differential and fiducial level including b-quark tagging at a fixed scale $\mu=m_t$. In addition, we advocate the use of double deep inelastic scattering (DDIS) scales ($\mu^2=Q^2$ for the light-quark line and $\mu^2=Q^2+m_t^2$ for the heavy-quark line) that maximize perturbative stability and allow for robust scale uncertainties. All NNLO and NLO$\,\otimes\,$NLO contributions for production and decay are included in the on-shell and vertex-function approximation. We present fiducial and differential results for a variety of observables used in Standard Model and Beyond Standard Model analyses, and find an important difference between the NLO and NNLO predictions of exclusive $t+n$-jet cross sections. Overall we find that NNLO corrections are crucial for a precise identification of the t-channel process.
1410.5220
Michal Praszalowicz
Michal Praszalowicz
Why mean $p_{\rm T}$ is interesting
4 pages, 3 figures, talk presented at the International Workshop on Diffraction in High-Energy Physics Primosten (Croatia), September 10 - 16, 2014
AIP Conf.Proc. 1654 (2015) 080001
10.1063/1.4916004
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
We discuss energy dependence of mean $p_{\rm T}$ correlation with $N_{\rm ch}$ basing on general features of high energy collisions such as saturation and geometrical scaling. We use Color Glass Condensate calculation of an effective interaction radius that scales as a third root of multiplicity, and then saturates. With this model input we construct scaling variable for $< p_{\rm T} > (N_{\rm ch})$ at different energies both for pp and pPb collisions, and show that recent ALICE data indeed does exhibit this scaling property. We discuss energy dependence of the interaction radius and argue that since the radius cannot grow too large, a universal behavior of $< p_{\rm T} >$ for large multiplicities is expected.
[ { "created": "Mon, 20 Oct 2014 10:14:50 GMT", "version": "v1" }, { "created": "Tue, 21 Oct 2014 05:37:00 GMT", "version": "v2" } ]
2015-10-29
[ [ "Praszalowicz", "Michal", "" ] ]
We discuss energy dependence of mean $p_{\rm T}$ correlation with $N_{\rm ch}$ basing on general features of high energy collisions such as saturation and geometrical scaling. We use Color Glass Condensate calculation of an effective interaction radius that scales as a third root of multiplicity, and then saturates. With this model input we construct scaling variable for $< p_{\rm T} > (N_{\rm ch})$ at different energies both for pp and pPb collisions, and show that recent ALICE data indeed does exhibit this scaling property. We discuss energy dependence of the interaction radius and argue that since the radius cannot grow too large, a universal behavior of $< p_{\rm T} >$ for large multiplicities is expected.
2406.17016
Thomas Spieksma
Enrico Cannizzaro, Thomas F.M. Spieksma
Phenomenology of ultralight bosons around compact objects: in-medium suppression
12 pages, 4 figures
null
null
null
hep-ph astro-ph.HE gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mixing between ultralight bosons and the Standard Model photon may allow access to the hitherto invisible Universe. In the presence of plasma, photons are dressed with an effective mass which will influence the conversion between the two. We study this phenomenon, known as in-medium suppression, in the context of black hole physics. We consider both axion-photon mixing around charged black holes and dark photon-photon mixing around neutral black holes. We find that the presence of plasma indeed influences the conversion rate, possibly quenching it altogether for large plasma densities, and discuss implications for superradiance and observational signatures.
[ { "created": "Mon, 24 Jun 2024 18:00:02 GMT", "version": "v1" } ]
2024-06-26
[ [ "Cannizzaro", "Enrico", "" ], [ "Spieksma", "Thomas F. M.", "" ] ]
Mixing between ultralight bosons and the Standard Model photon may allow access to the hitherto invisible Universe. In the presence of plasma, photons are dressed with an effective mass which will influence the conversion between the two. We study this phenomenon, known as in-medium suppression, in the context of black hole physics. We consider both axion-photon mixing around charged black holes and dark photon-photon mixing around neutral black holes. We find that the presence of plasma indeed influences the conversion rate, possibly quenching it altogether for large plasma densities, and discuss implications for superradiance and observational signatures.
1211.6961
Olga Voskresenskaya
E. A. Kuraev, O. O. Voskresenskaya, and A. V. Tarasov
Coulomb Correction to the Screening Angle of the Moliere Multiple Scattering Theory
The results of this work are revised, supplemented and presented in the paper arXiv:1312.7809
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High-energy Coulomb correction to the screening angular parameter of the Moliere multiple scattering theory is found. Numerical calculations are presented in the range of nuclear charge from Z=4 to Z=82. The accuracy of the Moliere theory in determining the Coulomb correction to the screening angle is estimated.
[ { "created": "Thu, 29 Nov 2012 16:01:46 GMT", "version": "v1" }, { "created": "Fri, 7 Dec 2012 08:48:50 GMT", "version": "v2" }, { "created": "Mon, 8 Apr 2013 22:19:31 GMT", "version": "v3" }, { "created": "Wed, 15 Jan 2014 21:19:29 GMT", "version": "v4" } ]
2014-01-21
[ [ "Kuraev", "E. A.", "" ], [ "Voskresenskaya", "O. O.", "" ], [ "Tarasov", "A. V.", "" ] ]
High-energy Coulomb correction to the screening angular parameter of the Moliere multiple scattering theory is found. Numerical calculations are presented in the range of nuclear charge from Z=4 to Z=82. The accuracy of the Moliere theory in determining the Coulomb correction to the screening angle is estimated.
1402.7272
Samuel Wallon
A. Besse, L. Szymanowski, S. Wallon
Phenomenology of the polarized cross-sections of the rho meson leptoproduction at high energy
6 pages, 3 figures, proceedings of Photon 2013, May 20 - 24 2013, Paris, France
null
null
LPT-14-3, IRFU-13-171
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model for the polarized cross-sections of the hard diffractive leptoproduction of rho meson in the high energy limit. Our model is based on the light-cone collinear factorization of the virtual photon to rho meson impact factor when using the impact factor representation of the helicity amplitudes of the rho meson leptoproduction. This gauge invariant treatment when expressed in impact parameter space, leads to the factorization on one hand of the color dipole scattering amplitude and on the other hand of the distribution amplitudes of the rho meson up to twist 2 and 3. We show that the results of this approach are in good agreement with HERA data for virtualities above ~5 GeV^2.
[ { "created": "Fri, 28 Feb 2014 15:07:24 GMT", "version": "v1" } ]
2014-03-03
[ [ "Besse", "A.", "" ], [ "Szymanowski", "L.", "" ], [ "Wallon", "S.", "" ] ]
We present a model for the polarized cross-sections of the hard diffractive leptoproduction of rho meson in the high energy limit. Our model is based on the light-cone collinear factorization of the virtual photon to rho meson impact factor when using the impact factor representation of the helicity amplitudes of the rho meson leptoproduction. This gauge invariant treatment when expressed in impact parameter space, leads to the factorization on one hand of the color dipole scattering amplitude and on the other hand of the distribution amplitudes of the rho meson up to twist 2 and 3. We show that the results of this approach are in good agreement with HERA data for virtualities above ~5 GeV^2.
1710.07649
Patrick J. Fox
Patrick J. Fox and Neal Weiner
Light Signals from a Lighter Higgs
15 pages, 3 figures
null
10.1007/JHEP08(2018)025
Fermilab-Pub-17-468-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the Higgs search program already quite mature, there is the exciting possibility of discovering a new particle with rates near that of the SM Higgs. We consider models with a signal in $\gamma \gamma$ below the SM Higgs mass, taking the recent $2.9\, \sigma$ (local) CMS excess at 95 GeV as a target. We discuss singlet models with additional vectorlike matter, but argue that a Type-I two Higgs doublet model provides a more economical scenario. In such a setup, going into regions of moderate-to-strong fermiophobia, the enhanced $\gamma \gamma$ branching ratio allows signals from $VH$+VBF production to yield $\sigma \times BR_{\gamma\gamma} $ comparable to total SM rates. Light $H$ production can be dominated via rare top decays $t \rightarrow b H^+ \rightarrow b W^{*} H$, which provides an alternate explanation of the excess. We consider this in the context of other Higgs anomalies, namely the LEP Higgs excess near the same mass, and excesses in $t\bar{t}h$ searches at Tevatron and LHC. We find that with $140\, \mathrm{GeV} < m_{H^+} < 160\, \mathrm{GeV}$, $\tan \beta \sim 5$ and a coupling to gauge bosons of $\sin^2 \delta \sim 0.1$, such a scenario can produce all the excesses simultanously, where $tth$ arise from contamination from the rare top decays, as previously proposed. An implication of the Type-I scenario is that any $\gamma \gamma$ excess should be associated with additional elements that could reduce background, including $b$-jets, forward jets or signs of vector boson production.
[ { "created": "Fri, 20 Oct 2017 18:01:06 GMT", "version": "v1" } ]
2018-08-29
[ [ "Fox", "Patrick J.", "" ], [ "Weiner", "Neal", "" ] ]
With the Higgs search program already quite mature, there is the exciting possibility of discovering a new particle with rates near that of the SM Higgs. We consider models with a signal in $\gamma \gamma$ below the SM Higgs mass, taking the recent $2.9\, \sigma$ (local) CMS excess at 95 GeV as a target. We discuss singlet models with additional vectorlike matter, but argue that a Type-I two Higgs doublet model provides a more economical scenario. In such a setup, going into regions of moderate-to-strong fermiophobia, the enhanced $\gamma \gamma$ branching ratio allows signals from $VH$+VBF production to yield $\sigma \times BR_{\gamma\gamma} $ comparable to total SM rates. Light $H$ production can be dominated via rare top decays $t \rightarrow b H^+ \rightarrow b W^{*} H$, which provides an alternate explanation of the excess. We consider this in the context of other Higgs anomalies, namely the LEP Higgs excess near the same mass, and excesses in $t\bar{t}h$ searches at Tevatron and LHC. We find that with $140\, \mathrm{GeV} < m_{H^+} < 160\, \mathrm{GeV}$, $\tan \beta \sim 5$ and a coupling to gauge bosons of $\sin^2 \delta \sim 0.1$, such a scenario can produce all the excesses simultanously, where $tth$ arise from contamination from the rare top decays, as previously proposed. An implication of the Type-I scenario is that any $\gamma \gamma$ excess should be associated with additional elements that could reduce background, including $b$-jets, forward jets or signs of vector boson production.
hep-ph/9801346
Bodo Lampe
Bodo Lampe
Complete Description of Polarization Effects in Top Quark Decays Including Higher Order QCD Corrections
invited talk presented at the International Workshop on QCD and New Physics, Hiroshima, 1997
null
null
MPI-PhT/98-07
hep-ph
null
The complete set of matrix elements for all polarization configurations in top quark decays is presented including higher order QCD corrections. The analysis is done in the framework of the helicity formalism. The results can be used in a variety of circumstances, e.g. in the experimental analysis of top quark production and decay at Tevatron, LHC and NLC. Relations to LEP1 and LEP2 physics are pointed out.
[ { "created": "Mon, 19 Jan 1998 17:25:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lampe", "Bodo", "" ] ]
The complete set of matrix elements for all polarization configurations in top quark decays is presented including higher order QCD corrections. The analysis is done in the framework of the helicity formalism. The results can be used in a variety of circumstances, e.g. in the experimental analysis of top quark production and decay at Tevatron, LHC and NLC. Relations to LEP1 and LEP2 physics are pointed out.
0811.0645
Youngman Kim
Hyun-Chul Kim and Youngman Kim
Hybrid exotic meson with J^{PC}=1^{-+} in AdS/QCD
10 pages, 1 Table
JHEP 0901:034,2009
10.1088/1126-6708/2009/01/034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the hybrid exotic meson with $J^{PC}=1^{-+}$ within the framework of an AdS/QCD model. Introducing a holographic field dual to the operator for hybrid exotic meson, we obtain the eigen-value equation for its mass. Fixing all free parameters by QCD observables such as the $\rho$-meson mass, we predict the masses of the hybrid exotic meson. The results turn out to be $1476 \mathrm{MeV}$ for the ground state, and $2611 \mathrm{MeV}$ for the first excited one. Being compared with the existing experimental data for the $\pi_1(1400)$, which is known to be $m_{\pi_1} = 1351\pm30 \mathrm{MeV}$, the present result seems to be qualitative in agreement with it. We also predict the decay constant of $\pi_1$(1400): $F_{\pi_1}= 10.6$ MeV.
[ { "created": "Wed, 5 Nov 2008 04:16:50 GMT", "version": "v1" } ]
2010-04-21
[ [ "Kim", "Hyun-Chul", "" ], [ "Kim", "Youngman", "" ] ]
We investigate the hybrid exotic meson with $J^{PC}=1^{-+}$ within the framework of an AdS/QCD model. Introducing a holographic field dual to the operator for hybrid exotic meson, we obtain the eigen-value equation for its mass. Fixing all free parameters by QCD observables such as the $\rho$-meson mass, we predict the masses of the hybrid exotic meson. The results turn out to be $1476 \mathrm{MeV}$ for the ground state, and $2611 \mathrm{MeV}$ for the first excited one. Being compared with the existing experimental data for the $\pi_1(1400)$, which is known to be $m_{\pi_1} = 1351\pm30 \mathrm{MeV}$, the present result seems to be qualitative in agreement with it. We also predict the decay constant of $\pi_1$(1400): $F_{\pi_1}= 10.6$ MeV.
2002.12010
Kingman Cheung
C.J. Ouseph and Kingman Cheung
Higgs Inflation With Four-form Couplings
9 pages; references added
null
10.1088/1361-6471/abefa4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a new inflationary model in which an antisymmetric tensor field $A_{\nu\rho\sigma}$ and its four-form field strength $F_{\mu\nu\rho\sigma}=4\partial_{[\mu} A_{\nu\rho\sigma]}$ are coupled to the scalar sector of the standard model and to the Ricci scalar $\mathcal{R}$. The four-form field induces modifications to the Higgs self-coupling constant, the cosmological constant, and the non-minimal coupling constant, which results in the modification to the inflaton potential. We also show that there is no need for the Higgs-gravity coupling in the presence of four-form-gravity interaction, but still can produce the right amount of density perturbation for inflation.
[ { "created": "Thu, 27 Feb 2020 10:06:05 GMT", "version": "v1" }, { "created": "Fri, 6 Mar 2020 03:52:06 GMT", "version": "v2" } ]
2021-05-26
[ [ "Ouseph", "C. J.", "" ], [ "Cheung", "Kingman", "" ] ]
We consider a new inflationary model in which an antisymmetric tensor field $A_{\nu\rho\sigma}$ and its four-form field strength $F_{\mu\nu\rho\sigma}=4\partial_{[\mu} A_{\nu\rho\sigma]}$ are coupled to the scalar sector of the standard model and to the Ricci scalar $\mathcal{R}$. The four-form field induces modifications to the Higgs self-coupling constant, the cosmological constant, and the non-minimal coupling constant, which results in the modification to the inflaton potential. We also show that there is no need for the Higgs-gravity coupling in the presence of four-form-gravity interaction, but still can produce the right amount of density perturbation for inflation.
0712.2488
Peinado Eduardo
A. Mondrag\'on, M. Mondrag\'on and E. Peinado
Nearly tri-bimaximal mixing in the S_3 flavour symmetry
6 pages, Talk given at XI Mexican Workshop on Particles and Fields, Tuxtla Gutierrez, Chiapas, Mexico, 7-12 Nov 2007. To be published in AIP conference proceedings
AIP Conf.Proc.1026:164-169,2008
10.1063/1.2965040
null
hep-ph
null
We present an analysis of the theoretical neutrino mixing matrix, V_{PMNS}^{th}, previously derived in the framework of the minimal S_3-invariant extension of the Standard Model. All entries in the neutrino mixing matrix, V_{PMNS}^{th}, the mixing angles and the Majorana phases are given as exact, explicit analytical functions of the mass ratios of the charged leptons and neutrinos, and one Dirac phase, in excellent agreement with the the latest experimental data. Here, it will be shown that all entries in V_{PMNS}^{th} are numerically very close to the tri-bimaximal form of the neutrino mixing matrix, so that V_{PMNS}^{th} may be written as V^{tri}+\Delta V_{PMNS}^{tri}. The small correction \Delta V_{PMNS}^{tri} is expressed as a sum of two terms: first, a small correction term proportional to m_{e}/m_{\mu} depending only on the charged lepton mass ratios and, second, a Cabbibo-like, small term, \delta t_{12}, which is a function of both the charged lepton and the neutrino mass ratios.
[ { "created": "Sat, 15 Dec 2007 02:35:23 GMT", "version": "v1" } ]
2009-01-06
[ [ "Mondragón", "A.", "" ], [ "Mondragón", "M.", "" ], [ "Peinado", "E.", "" ] ]
We present an analysis of the theoretical neutrino mixing matrix, V_{PMNS}^{th}, previously derived in the framework of the minimal S_3-invariant extension of the Standard Model. All entries in the neutrino mixing matrix, V_{PMNS}^{th}, the mixing angles and the Majorana phases are given as exact, explicit analytical functions of the mass ratios of the charged leptons and neutrinos, and one Dirac phase, in excellent agreement with the the latest experimental data. Here, it will be shown that all entries in V_{PMNS}^{th} are numerically very close to the tri-bimaximal form of the neutrino mixing matrix, so that V_{PMNS}^{th} may be written as V^{tri}+\Delta V_{PMNS}^{tri}. The small correction \Delta V_{PMNS}^{tri} is expressed as a sum of two terms: first, a small correction term proportional to m_{e}/m_{\mu} depending only on the charged lepton mass ratios and, second, a Cabbibo-like, small term, \delta t_{12}, which is a function of both the charged lepton and the neutrino mass ratios.
1605.01733
Marco Bonvini
Marco Bonvini, Andrew S. Papanastasiou, Frank J. Tackmann
Matched predictions for the $b\bar{b}H$ cross section at the 13 TeV LHC
26 pages, 7 figures, 4 tables. Final version published in JHEP
JHEP10(2016)053
10.1007/JHEP10(2016)053
OUTP-16-08P, CAVENDISH-HEP-16-06, DESY 16-076
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present up-to-date matched predictions for the $b\bar{b}H$ inclusive cross section at the LHC at $\sqrt{s}=13$ TeV. Using a previously developed method, our predictions consistently combine the complete NLO contributions that are present in the 4-flavor scheme calculation, including finite b-quark mass effects as well as top-loop induced $Y_b Y_t$ interference contributions, with the resummation of collinear logarithms of $m_b/m_H$ as present in the 5-flavor scheme calculation up to NNLO. We provide a detailed estimate of the perturbative uncertainties of the matched result by examining its dependence on the factorization and renormalization scales, the scale of the Yukawa coupling, and also the low b-quark matching scale in the PDFs. We motivate the use of a central renormalization scale of $m_H$/2, which is halfway between the values typically chosen in the 4-flavor and 5-flavor scheme calculations. We evaluate the parametric uncertainties due to the PDFs and the b-quark mass, and in particular discuss how to systematically disentangle the parametric $m_b$ dependence and the unphysical b-quark matching scale dependence. Our best prediction for the $b\bar{b} H$ production cross section in the Standard Model at 13 TeV and for $m_H$ = 125 GeV is $\sigma(b\bar b H) = 0.52 \,{\rm pb}\, [1 \pm 9.6\% {\rm (perturbative)}\,{}^{+2.9\%}_{-3.6\%} {\rm (parametric)}]$. We also provide predictions for a range of Higgs masses $m_H\in [50, 750]$ GeV. Our method to compute the matched prediction and to evaluate its uncertainty can be readily applied to other heavy-quark-initiated processes at the LHC.
[ { "created": "Thu, 5 May 2016 20:00:04 GMT", "version": "v1" }, { "created": "Mon, 7 Nov 2016 15:39:33 GMT", "version": "v2" } ]
2016-11-08
[ [ "Bonvini", "Marco", "" ], [ "Papanastasiou", "Andrew S.", "" ], [ "Tackmann", "Frank J.", "" ] ]
We present up-to-date matched predictions for the $b\bar{b}H$ inclusive cross section at the LHC at $\sqrt{s}=13$ TeV. Using a previously developed method, our predictions consistently combine the complete NLO contributions that are present in the 4-flavor scheme calculation, including finite b-quark mass effects as well as top-loop induced $Y_b Y_t$ interference contributions, with the resummation of collinear logarithms of $m_b/m_H$ as present in the 5-flavor scheme calculation up to NNLO. We provide a detailed estimate of the perturbative uncertainties of the matched result by examining its dependence on the factorization and renormalization scales, the scale of the Yukawa coupling, and also the low b-quark matching scale in the PDFs. We motivate the use of a central renormalization scale of $m_H$/2, which is halfway between the values typically chosen in the 4-flavor and 5-flavor scheme calculations. We evaluate the parametric uncertainties due to the PDFs and the b-quark mass, and in particular discuss how to systematically disentangle the parametric $m_b$ dependence and the unphysical b-quark matching scale dependence. Our best prediction for the $b\bar{b} H$ production cross section in the Standard Model at 13 TeV and for $m_H$ = 125 GeV is $\sigma(b\bar b H) = 0.52 \,{\rm pb}\, [1 \pm 9.6\% {\rm (perturbative)}\,{}^{+2.9\%}_{-3.6\%} {\rm (parametric)}]$. We also provide predictions for a range of Higgs masses $m_H\in [50, 750]$ GeV. Our method to compute the matched prediction and to evaluate its uncertainty can be readily applied to other heavy-quark-initiated processes at the LHC.