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0808.2215
Leszek Motyka
L. Motyka
Proton elastic impact factors for two, three, and four gluons
4 pages, 2 figures. To be published in the Proceedings of the 16th International Workshop on Deep Inelastic Scattering, DIS2008, London, April 7-11th 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we report on recent calculation of high energy baryon scattering amplitudes in QCD. Elastic baryon impact factors for two, three and four gluons are presented and their energy evolution is described that incorporates unitarity corrections. We find that the baryon couples directly to the BFKL Pomeron, to the BKP odderon and to a new state, a three-gluon BKP Pomeron. The new state may decay into four gluons with a new 3 -> 4 transition vertex. This vertex defines the transition amplitude of the three-gluon BKP Pomeron state into two BFKL Pomerons.
[ { "created": "Fri, 15 Aug 2008 22:28:59 GMT", "version": "v1" } ]
2008-08-19
[ [ "Motyka", "L.", "" ] ]
In this talk we report on recent calculation of high energy baryon scattering amplitudes in QCD. Elastic baryon impact factors for two, three and four gluons are presented and their energy evolution is described that incorporates unitarity corrections. We find that the baryon couples directly to the BFKL Pomeron, to the BKP odderon and to a new state, a three-gluon BKP Pomeron. The new state may decay into four gluons with a new 3 -> 4 transition vertex. This vertex defines the transition amplitude of the three-gluon BKP Pomeron state into two BFKL Pomerons.
2008.11686
Inar Timiryasov
Mikhail Shaposhnikov, Andrey Shkerin, Inar Timiryasov, and Sebastian Zell
Einstein-Cartan Portal to Dark Matter
9 pages, 2 figures; v2: updated references, corrections to appendix A and sign in Eq. (2), added appendix D; matches published version (including erratum)
Phys. Rev. Lett. 126, 161301 (2021)
10.1103/PhysRevLett.126.161301
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well-known since the works of Utiyama and Kibble that the gravitational force can be obtained by gauging the Poincar\'e group, which puts gravity on the same footing as the Standard Model fields. The resulting theory -- Einstein-Cartan gravity -- inevitably contains four-fermion and scalar-fermion interactions that originate from torsion associated with spin degrees of freedom. We show that these interactions lead to a novel mechanism for producing singlet fermions in the Early Universe. These fermions can play the role of dark matter particles. The mechanism is operative in a large range of dark matter particle masses: from a few keV up to $\sim 10^8~$GeV. We discuss potential observational consequences of keV-scale dark matter produced this way, in particular for right-handed neutrinos. We conclude that a determination of the primordial dark matter momentum distribution might be able to shed light on the gravity-induced fermionic interactions.
[ { "created": "Wed, 26 Aug 2020 17:22:05 GMT", "version": "v1" }, { "created": "Fri, 22 Oct 2021 08:36:01 GMT", "version": "v2" } ]
2021-10-25
[ [ "Shaposhnikov", "Mikhail", "" ], [ "Shkerin", "Andrey", "" ], [ "Timiryasov", "Inar", "" ], [ "Zell", "Sebastian", "" ] ]
It is well-known since the works of Utiyama and Kibble that the gravitational force can be obtained by gauging the Poincar\'e group, which puts gravity on the same footing as the Standard Model fields. The resulting theory -- Einstein-Cartan gravity -- inevitably contains four-fermion and scalar-fermion interactions that originate from torsion associated with spin degrees of freedom. We show that these interactions lead to a novel mechanism for producing singlet fermions in the Early Universe. These fermions can play the role of dark matter particles. The mechanism is operative in a large range of dark matter particle masses: from a few keV up to $\sim 10^8~$GeV. We discuss potential observational consequences of keV-scale dark matter produced this way, in particular for right-handed neutrinos. We conclude that a determination of the primordial dark matter momentum distribution might be able to shed light on the gravity-induced fermionic interactions.
2012.09565
Matthias Heller
Matthias Heller, Niklas Keil and Marc Vanderhaeghen
Leading-order QED radiative corrections to timelike Compton scattering on the proton
16 pages, 13 figures
Phys. Rev. D 103, 036009 (2021)
10.1103/PhysRevD.103.036009
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We evaluate the leading-order QED radiative corrections to the timelike Compton scattering (TCS) process $\gamma p \to l^- l^+ p$. We study these corrections in two energy regimes using different models for the TCS amplitude. In the low-energy regime we calculate the contribution due to the proton and its lowest-energy excitation, the $\Delta(1232)$ resonance. In the high-energy near-forward kinematical regime we calculate the TCS amplitude in a handbag approach in terms of Generalized Parton Distributions (GPDs). On the level of cross sections we find the QED radiative corrections to be in the $5 -10\%$ range in the low-energy regime and around $20\%$ in the high-energy regime. We show that in both the di-lepton forward-backward asymmetry as well as in the photon beam helicity asymmetry these corrections nearly cancel out, making them gold-plated observables to extract the real and imaginary parts of the TCS amplitude. We demonstrate in particular the sensitivity of these asymmetries on GPD parameterizations for a recent CLAS12@JLab TCS experiment.
[ { "created": "Thu, 17 Dec 2020 13:25:23 GMT", "version": "v1" } ]
2021-02-17
[ [ "Heller", "Matthias", "" ], [ "Keil", "Niklas", "" ], [ "Vanderhaeghen", "Marc", "" ] ]
We evaluate the leading-order QED radiative corrections to the timelike Compton scattering (TCS) process $\gamma p \to l^- l^+ p$. We study these corrections in two energy regimes using different models for the TCS amplitude. In the low-energy regime we calculate the contribution due to the proton and its lowest-energy excitation, the $\Delta(1232)$ resonance. In the high-energy near-forward kinematical regime we calculate the TCS amplitude in a handbag approach in terms of Generalized Parton Distributions (GPDs). On the level of cross sections we find the QED radiative corrections to be in the $5 -10\%$ range in the low-energy regime and around $20\%$ in the high-energy regime. We show that in both the di-lepton forward-backward asymmetry as well as in the photon beam helicity asymmetry these corrections nearly cancel out, making them gold-plated observables to extract the real and imaginary parts of the TCS amplitude. We demonstrate in particular the sensitivity of these asymmetries on GPD parameterizations for a recent CLAS12@JLab TCS experiment.
1110.5403
Hiroshi Takano
Mayumi Aoki, Jisuke Kubo, Taishi Okawa, and Hiroshi Takano
Impact of Inert Higgsino Dark Matter
15 pages, 5 figures
null
10.1016/j.physletb.2011.12.012
KANAZAWA-11-18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a recently proposed supersymmetric radiative seesaw model which is coupled with the minimal supergravity. The conventional R parity and $Z_2$ invariance are imposed, which ensures the existence of a multi-component dark matter system. We assume that the pair of the lightest neutralino $\tilde{\chi}$ and the fermionic component $\tilde{\xi}$ of the inert Higgs supermultiplet is dark matter. If $\tilde{\xi}$ is lighter than $\tilde{\chi}$, and the lightest neutral inert Higgs boson is kinematically forbidden to decay (third dark matter), the allowed region in the $m_0{\rm \mathchar`-}M_{1/2}$ plane increases considerably, where $m_0$ and $M_{1/2}$ are the universal soft-supersymmetry-breaking scalar and gaugino mass, respectively, although the dominant component of the multi-component dark matter system is $\tilde{\chi}$. There is a wide allowed region above the recent LHC limit.
[ { "created": "Tue, 25 Oct 2011 03:43:17 GMT", "version": "v1" }, { "created": "Mon, 19 Dec 2011 04:11:06 GMT", "version": "v2" } ]
2011-12-21
[ [ "Aoki", "Mayumi", "" ], [ "Kubo", "Jisuke", "" ], [ "Okawa", "Taishi", "" ], [ "Takano", "Hiroshi", "" ] ]
We consider a recently proposed supersymmetric radiative seesaw model which is coupled with the minimal supergravity. The conventional R parity and $Z_2$ invariance are imposed, which ensures the existence of a multi-component dark matter system. We assume that the pair of the lightest neutralino $\tilde{\chi}$ and the fermionic component $\tilde{\xi}$ of the inert Higgs supermultiplet is dark matter. If $\tilde{\xi}$ is lighter than $\tilde{\chi}$, and the lightest neutral inert Higgs boson is kinematically forbidden to decay (third dark matter), the allowed region in the $m_0{\rm \mathchar`-}M_{1/2}$ plane increases considerably, where $m_0$ and $M_{1/2}$ are the universal soft-supersymmetry-breaking scalar and gaugino mass, respectively, although the dominant component of the multi-component dark matter system is $\tilde{\chi}$. There is a wide allowed region above the recent LHC limit.
1507.04051
Michele Della Morte Prof.
Michele Della Morte
Lattice inputs to Flavor Physics
Invited talk at the 50th Rencontres de Moriond EW 2015. 8 pages, 5 figures
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review recent lattice results for quark masses and low-energy hadronic parameters relevant for flavor physics. We do that by describing the FLAG initiative, with emphasis on its scope and rating criteria. The emerging picture is that while for light quantities a large number of computations using different approaches exist, and this increases the overall confidence on the final averages/estimates, in the heavy-light case the field is less advanced and, with the exception of decay constants, only a few computations are available. The precision reached for the light quantities is such that electromagnetic (EM) corrections, beyond the point-like approximation, are becoming relevant. We discuss recent computations of the spectrum based on direct simulations of QED+QCD. We also present theoretical developments for including EM effects in leptonic decays. We conclude describing recent results for the $K \to \pi \pi$ transition amplitudes and prospects for tackling hadronic decays on the lattice.
[ { "created": "Tue, 14 Jul 2015 23:49:33 GMT", "version": "v1" } ]
2015-07-16
[ [ "Della Morte", "Michele", "" ] ]
We review recent lattice results for quark masses and low-energy hadronic parameters relevant for flavor physics. We do that by describing the FLAG initiative, with emphasis on its scope and rating criteria. The emerging picture is that while for light quantities a large number of computations using different approaches exist, and this increases the overall confidence on the final averages/estimates, in the heavy-light case the field is less advanced and, with the exception of decay constants, only a few computations are available. The precision reached for the light quantities is such that electromagnetic (EM) corrections, beyond the point-like approximation, are becoming relevant. We discuss recent computations of the spectrum based on direct simulations of QED+QCD. We also present theoretical developments for including EM effects in leptonic decays. We conclude describing recent results for the $K \to \pi \pi$ transition amplitudes and prospects for tackling hadronic decays on the lattice.
1611.07261
Maria Gomez-Rocha
Mar\'ia G\'omez-Rocha
Asymptotic freedom in the Hamiltonian approach to binding of color
Presented at XII Quark Confinement and the Hadron Spectrum, Thessaloniki (Greece) August 29th - September 3rd 2016. 8pages, 4 figures
null
10.1051/epjconf/201713703020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive asymptotic freedom and the $SU(3)$ Yang-Mills $\beta$-function using the renormalization group procedure for effective particles. In this procedure, the concept of effective particles of size $s$ is introduced. Effective particles in the Fock space build eigenstates of the effective Hamiltonian $H_s$, which is a matrix written in a basis that depend on the scale (or size) parameter $s$. The effective Hamiltonians $H_s$ and the (regularized) canonical Hamiltonian $H_{0}$ are related by a similarity transformation. We calculate the effective Hamiltonian by solving its renormalization-group equation perturbatively up to third order and calculate the running coupling from the three-gluon-vertex function in the effective Hamiltonian operator.
[ { "created": "Tue, 22 Nov 2016 11:46:07 GMT", "version": "v1" } ]
2017-04-05
[ [ "Gómez-Rocha", "María", "" ] ]
We derive asymptotic freedom and the $SU(3)$ Yang-Mills $\beta$-function using the renormalization group procedure for effective particles. In this procedure, the concept of effective particles of size $s$ is introduced. Effective particles in the Fock space build eigenstates of the effective Hamiltonian $H_s$, which is a matrix written in a basis that depend on the scale (or size) parameter $s$. The effective Hamiltonians $H_s$ and the (regularized) canonical Hamiltonian $H_{0}$ are related by a similarity transformation. We calculate the effective Hamiltonian by solving its renormalization-group equation perturbatively up to third order and calculate the running coupling from the three-gluon-vertex function in the effective Hamiltonian operator.
hep-ph/0211171
Michele Caffo
M. Caffo (1 and 2), H. Czyz (3) and E. Remiddi (2 and 1) ((1) INFN-Bologna, (2) Univ. of Bologna, (3) Univ. of Silesia)
Numerical evaluation of the general massive 2-loop self-mass master integrals from differential equations
Latex, 2 pages, 1ps-figure, uses included espcrc2.sty, presented at ACAT'2002, VIII International Workshop on Advanced Computing and Analysis Techniques in Physics Research, Moscow, 24-28 June 2002
Nucl.Instrum.Meth. A502 (2003) 613-614
10.1016/S0168-9002(03)00520-5
null
hep-ph
null
The system of 4 differential equations in the external invariant satisfied by the 4 master integrals of the general massive 2-loop sunrise self-mass diagram is solved by the Runge-Kutta method in the complex plane. The method offers a reliable and robust approach to the direct and precise numerical evaluation of Feynman graph integrals.
[ { "created": "Tue, 12 Nov 2002 13:25:30 GMT", "version": "v1" } ]
2009-11-07
[ [ "Caffo", "M.", "", "1 and 2" ], [ "Czyz", "H.", "", "2 and 1" ], [ "Remiddi", "E.", "", "2 and 1" ] ]
The system of 4 differential equations in the external invariant satisfied by the 4 master integrals of the general massive 2-loop sunrise self-mass diagram is solved by the Runge-Kutta method in the complex plane. The method offers a reliable and robust approach to the direct and precise numerical evaluation of Feynman graph integrals.
hep-ph/0308065
Alexander Samsonov
A. Samsonov
Magnetic moment of the rho-meson in QCD sum rules: perturbative corrections
10 pages, 5 figures
JHEP 0312 (2003) 061
10.1088/1126-6708/2003/12/061
null
hep-ph
null
The magnetic moment of the rho-meson is calculated in the framework of QCD sum rules in external fields. Perturbative corrections are taken into account. Bare loop calculations (parton model) give the value 2.0. The nonperturbative effects (operators of dimension 6) result in negative contribution, whereas perturbative corrections -- positive one. The final answer is 1.8.
[ { "created": "Wed, 6 Aug 2003 09:10:48 GMT", "version": "v1" } ]
2009-11-10
[ [ "Samsonov", "A.", "" ] ]
The magnetic moment of the rho-meson is calculated in the framework of QCD sum rules in external fields. Perturbative corrections are taken into account. Bare loop calculations (parton model) give the value 2.0. The nonperturbative effects (operators of dimension 6) result in negative contribution, whereas perturbative corrections -- positive one. The final answer is 1.8.
1110.1598
Jin-Hee Yoon
Jin-Hee Yoon, Byeong-Noh Kim, Horace W. Crater, Cheuk-Yin Wong
On the Mass Difference between pion and rho meson using a Relativistic Two-Body Model
Talk presented at the Fifth Asia-Pacific Conference on Few-Body Problems in Physics, August 22-26, 2011, Seoul, Republic of Korea, to be published in Few-Body Systems
null
10.1007/s00601-012-0415-1
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The big mass difference between the pion and rho meson possibly originates from the spin-dependent nature of the interactions in the two states since these two states are similar except for spin. Both pi and rho are quark-antiquark systems which can be treated using the two-body Dirac equations (TBDE) of constraint dynamics. This relativistic approach for two-body system has the advantage over the non-relativistic treatment in the sense that the spin-dependent nature is automatically coming out from the formalism. We employed Dirac's relativistic constraint dynamics to describe quark-antiquark systems. Within this formalism, the 16-component Dirac equation is reduced to the 4-component 2nd-order differential equation and the radial part of this equation is simply a Schroedinger-type equation with various terms calculated from the basic radial potential. We used a modified Richardson potential for quark-antiquark systems which satisfies the conditions of confinement and asymptotic freedom. We obtained the wave functions for these two mesons which are not singular at short distances. We also found that the cancellation between the Darwin and spin-spin interaction terms occurs in the pi mass but not in the rho mass and this is the main source of the big difference in the two meson masses.
[ { "created": "Fri, 7 Oct 2011 18:14:10 GMT", "version": "v1" } ]
2015-05-30
[ [ "Yoon", "Jin-Hee", "" ], [ "Kim", "Byeong-Noh", "" ], [ "Crater", "Horace W.", "" ], [ "Wong", "Cheuk-Yin", "" ] ]
The big mass difference between the pion and rho meson possibly originates from the spin-dependent nature of the interactions in the two states since these two states are similar except for spin. Both pi and rho are quark-antiquark systems which can be treated using the two-body Dirac equations (TBDE) of constraint dynamics. This relativistic approach for two-body system has the advantage over the non-relativistic treatment in the sense that the spin-dependent nature is automatically coming out from the formalism. We employed Dirac's relativistic constraint dynamics to describe quark-antiquark systems. Within this formalism, the 16-component Dirac equation is reduced to the 4-component 2nd-order differential equation and the radial part of this equation is simply a Schroedinger-type equation with various terms calculated from the basic radial potential. We used a modified Richardson potential for quark-antiquark systems which satisfies the conditions of confinement and asymptotic freedom. We obtained the wave functions for these two mesons which are not singular at short distances. We also found that the cancellation between the Darwin and spin-spin interaction terms occurs in the pi mass but not in the rho mass and this is the main source of the big difference in the two meson masses.
hep-ph/0506193
Keitaro Nagata
Keitaro Nagata, Atsushi Hosaka
Two Nucleon-States in a Chiral Quark-Diquark Model
11 pages, 5 figures. Errors are corrected. Conclusions are not affected
J.Phys. G32 (2006) 777-786
10.1088/0954-3899/32/6/003
null
hep-ph
null
We study the ground and first excited states of nucleons in a chiral quark-diquark model. We include two quark-diquark channels of the scalar-isoscalar and axial-vector-isovector types for the nucleon states. The diquark correlation violating the spin-flavor SU(4)$_{SF}$ symmetry allows to treat the two quark-diquark channels independently. Hence the two states appear as the superpositions of the two quark-diquark channels; one is the nucleon and the other is a state which does not appear in the SU(4)$_{SF}$ quark models. With a reasonable choice of model parameters, the mass of the excited state appears at around 1.5 GeV, which we identify with the Roper resonance N(1440).
[ { "created": "Mon, 20 Jun 2005 08:11:02 GMT", "version": "v1" }, { "created": "Thu, 5 Jan 2006 08:52:56 GMT", "version": "v2" } ]
2009-11-11
[ [ "Nagata", "Keitaro", "" ], [ "Hosaka", "Atsushi", "" ] ]
We study the ground and first excited states of nucleons in a chiral quark-diquark model. We include two quark-diquark channels of the scalar-isoscalar and axial-vector-isovector types for the nucleon states. The diquark correlation violating the spin-flavor SU(4)$_{SF}$ symmetry allows to treat the two quark-diquark channels independently. Hence the two states appear as the superpositions of the two quark-diquark channels; one is the nucleon and the other is a state which does not appear in the SU(4)$_{SF}$ quark models. With a reasonable choice of model parameters, the mass of the excited state appears at around 1.5 GeV, which we identify with the Roper resonance N(1440).
1302.6127
Phuoc Ha
Martin M. Block, Loyal Durand, Phuoc Ha, and Douglas W. McKay
Implications of a Froissart bound saturation of $\gamma^*$-$p$ deep inelastic scattering. Part II. Ultra-high energy neutrino interactions
15 pages, 6 figures. The paper is now shorter with the new results clearly emphasized
Phys. Rev. D88 (2013) 013003
10.1103/PhysRevD.88.013003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In Part I (in this journal) we argued that the structure function $F_2^{\gamma p}(x,Q^2)$ in deep inelastic $ep$ scattering, regarded as a cross section for virtual $\gamma^*p$ scattering, has a saturated Froissart-bounded form behaving as $\ln^2 (1/x)$ at small $x$. This form provides an excellent fit to the low $x$ HERA data, including the very low $Q^2$ regions, and can be extrapolated reliably to small $x$ using the natural variable $\ln(1/x)$. We used our fit to derive quark distributions for values of $x$ down to $x=10^{-14}$. We use those distributions here to evaluate ultra-high energy (UHE) cross sections for neutrino scattering on an isoscalar nucleon, $N=(n+p)/2$, up to laboratory neutrino energies $E_\nu \sim 10^{16}$-$10^{17}$ GeV where there are now limits on neutrino fluxes. We estimate that these cross sections are accurate to $\sim$2% at the highest energies considered, with the major uncertainty coming from the errors in the parameters that were needed to fit $F_2^{\gamma p}(x,Q^2)$. We compare our results to recently published neutrino cross sections derived from NLO parton distribution functions, which become much larger at high energies because of the use of power-law extrapolations of quark distributions to small $x$. We argue that our calculation of the UHE $\nu N$ cross sections is the best one can make based the existing experimental deep inelastic scattering data. Further, we show that the strong interaction Froissart bound of $\ln^2 (1/x)$ on $F_2^{\gamma p}$ translates to an exact bound of $\ln^3E_\nu$ for leading-order-weak $\nu N$ scattering. The energy dependence of $\nu N$ total cross section measurements consequently has important implications for hadronic interactions at enormous cms (center-of-mass) energies not otherwise accessible.
[ { "created": "Mon, 25 Feb 2013 15:37:46 GMT", "version": "v1" }, { "created": "Sat, 18 May 2013 17:40:14 GMT", "version": "v2" } ]
2014-02-10
[ [ "Block", "Martin M.", "" ], [ "Durand", "Loyal", "" ], [ "Ha", "Phuoc", "" ], [ "McKay", "Douglas W.", "" ] ]
In Part I (in this journal) we argued that the structure function $F_2^{\gamma p}(x,Q^2)$ in deep inelastic $ep$ scattering, regarded as a cross section for virtual $\gamma^*p$ scattering, has a saturated Froissart-bounded form behaving as $\ln^2 (1/x)$ at small $x$. This form provides an excellent fit to the low $x$ HERA data, including the very low $Q^2$ regions, and can be extrapolated reliably to small $x$ using the natural variable $\ln(1/x)$. We used our fit to derive quark distributions for values of $x$ down to $x=10^{-14}$. We use those distributions here to evaluate ultra-high energy (UHE) cross sections for neutrino scattering on an isoscalar nucleon, $N=(n+p)/2$, up to laboratory neutrino energies $E_\nu \sim 10^{16}$-$10^{17}$ GeV where there are now limits on neutrino fluxes. We estimate that these cross sections are accurate to $\sim$2% at the highest energies considered, with the major uncertainty coming from the errors in the parameters that were needed to fit $F_2^{\gamma p}(x,Q^2)$. We compare our results to recently published neutrino cross sections derived from NLO parton distribution functions, which become much larger at high energies because of the use of power-law extrapolations of quark distributions to small $x$. We argue that our calculation of the UHE $\nu N$ cross sections is the best one can make based the existing experimental deep inelastic scattering data. Further, we show that the strong interaction Froissart bound of $\ln^2 (1/x)$ on $F_2^{\gamma p}$ translates to an exact bound of $\ln^3E_\nu$ for leading-order-weak $\nu N$ scattering. The energy dependence of $\nu N$ total cross section measurements consequently has important implications for hadronic interactions at enormous cms (center-of-mass) energies not otherwise accessible.
hep-ph/9211284
Rick Watkins
Tanmay Vachaspati and Richard Watkins
Bound States Can Stabilize Electroweak Strings
11 pages (1 figure available on request), Tufts preprint# TU-92-10
Phys.Lett. B318 (1993) 163-168
10.1016/0370-2693(93)91800-3
null
hep-ph
null
We show that the electroweak $Z-$string can be stabilized by the presence of bound states of a complex scalar field. We argue that fermions coupled to the scalar field of the string can also make the string stable and discuss the physical case where the string is coupled to quarks and leptons. This stabilization mechanism is expected to work for other embedded defects and also for unstable solutions such as the sphaleron.
[ { "created": "Fri, 20 Nov 1992 16:17:39 GMT", "version": "v1" }, { "created": "Mon, 23 Nov 1992 20:09:38 GMT", "version": "v2" } ]
2009-10-22
[ [ "Vachaspati", "Tanmay", "" ], [ "Watkins", "Richard", "" ] ]
We show that the electroweak $Z-$string can be stabilized by the presence of bound states of a complex scalar field. We argue that fermions coupled to the scalar field of the string can also make the string stable and discuss the physical case where the string is coupled to quarks and leptons. This stabilization mechanism is expected to work for other embedded defects and also for unstable solutions such as the sphaleron.
hep-ph/9801370
Takashi Nasuno
Michihiro Hori (Hiroshima Univ.), Yuichiro Kiyo (Hiroshima Univ.), Jiro Kodaira (Hiroshima Univ.), Takashi Nasuno (Hiroshima Univ.), Stephen Parke (Fermi National Accelerator Laboratory)
Top Pair Production in e^+ e^- and gamma gamma Processes
10 pages, 5 Postscript figures, sprocl.sty, psfig.sty and here.sty are required. Invited talk presented at the International Symposium on ``QCD Corrections and New Physics'' October 27-29, 1997 held at Hiroshima, Japan
null
null
null
hep-ph
null
We analyze spin correlations between top quark and anti-top quark produced at polarized e^+ e^- and gamma gamma colliders. We consider a generic spin basis to find a strong spin correlation. Optimal spin decompositions for top quark pair are presented for e^+ e^- and gamma gamma colliders. We show the cross-section in these bases and discuss the characteristics of results.
[ { "created": "Wed, 21 Jan 1998 09:49:42 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hori", "Michihiro", "", "Hiroshima Univ." ], [ "Kiyo", "Yuichiro", "", "Hiroshima Univ." ], [ "Kodaira", "Jiro", "", "Hiroshima Univ." ], [ "Nasuno", "Takashi", "", "Hiroshima Univ." ], [ "Parke", "Stephen", "", "Fermi National Accelerator Laboratory" ] ]
We analyze spin correlations between top quark and anti-top quark produced at polarized e^+ e^- and gamma gamma colliders. We consider a generic spin basis to find a strong spin correlation. Optimal spin decompositions for top quark pair are presented for e^+ e^- and gamma gamma colliders. We show the cross-section in these bases and discuss the characteristics of results.
1803.08119
Keisuke Harigaya
Lawrence J. Hall, Keisuke Harigaya
Implications of Higgs Discovery for the Strong CP Problem and Unification
36 pages, 5 figures
null
10.1007/JHEP10(2018)130
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A $Z_2$ symmetry that extends the weak interaction, $SU(2)_L \rightarrow SU(2)_L \times SU(2)'$, and the Higgs sector, $H(2) \rightarrow H(2,1) + H'(1,2)$, yields a Standard Model quartic coupling that vanishes at scale $v' = <H'>~\gg~<H>$. Near $v'$, theories either have a "prime" sector, or possess "Left-Right" (LR) symmetry with $SU(2)' = SU(2)_R$. If the $Z_2$ symmetry incorporates spacetime parity, these theories can solve the strong CP problem. The LR theories have all quark and lepton masses arising from operators of dimension 5 or more, requiring Froggatt-Nielsen structures. Two-loop contributions to $\bar{\theta}$ are estimated and typically lead to a neutron electric dipole moment of order $10^{-27}$e cm that can be observed in future experiments. Minimal models, with gauge group $SU(3) \times SU(2)_L \times SU(2)_L \times U(1)_{B-L}$, have precise gauge coupling unification for $v' = 10^{10\pm1}$ GeV, successfully correlating gauge unification with the observed Higgs mass of $125$ GeV. With $SU(3) \times U(1)_{B-L}$ embedded in $SU(4)$, the central value of the unification scale is reduced from $10^{16-17}$ GeV to below $10^{16}$ GeV, improving the likelihood of proton decay discovery. Unified theories based on $SO(10) \times CP$ are constructed that have $H+H'$ in a ${\bf 16}$ or ${\bf 144}$ and generate higher-dimensional flavor operators, while maintaining perturbative gauge couplings.
[ { "created": "Wed, 21 Mar 2018 20:30:36 GMT", "version": "v1" } ]
2018-11-14
[ [ "Hall", "Lawrence J.", "" ], [ "Harigaya", "Keisuke", "" ] ]
A $Z_2$ symmetry that extends the weak interaction, $SU(2)_L \rightarrow SU(2)_L \times SU(2)'$, and the Higgs sector, $H(2) \rightarrow H(2,1) + H'(1,2)$, yields a Standard Model quartic coupling that vanishes at scale $v' = <H'>~\gg~<H>$. Near $v'$, theories either have a "prime" sector, or possess "Left-Right" (LR) symmetry with $SU(2)' = SU(2)_R$. If the $Z_2$ symmetry incorporates spacetime parity, these theories can solve the strong CP problem. The LR theories have all quark and lepton masses arising from operators of dimension 5 or more, requiring Froggatt-Nielsen structures. Two-loop contributions to $\bar{\theta}$ are estimated and typically lead to a neutron electric dipole moment of order $10^{-27}$e cm that can be observed in future experiments. Minimal models, with gauge group $SU(3) \times SU(2)_L \times SU(2)_L \times U(1)_{B-L}$, have precise gauge coupling unification for $v' = 10^{10\pm1}$ GeV, successfully correlating gauge unification with the observed Higgs mass of $125$ GeV. With $SU(3) \times U(1)_{B-L}$ embedded in $SU(4)$, the central value of the unification scale is reduced from $10^{16-17}$ GeV to below $10^{16}$ GeV, improving the likelihood of proton decay discovery. Unified theories based on $SO(10) \times CP$ are constructed that have $H+H'$ in a ${\bf 16}$ or ${\bf 144}$ and generate higher-dimensional flavor operators, while maintaining perturbative gauge couplings.
hep-ph/9911502
Scimemi Ignazio
M.C. Banuls, A. Pich, I. Scimemi
Electromagnetic Decays of Heavy Baryons
17 pages, 3 figures, submitted to Phys. Rev. D
Phys.Rev. D61 (2000) 094009
10.1103/PhysRevD.61.094009
FTUV/99-75, IFIC/99-78
hep-ph
null
The electromagnetic decays of the ground state baryon multiplets with one heavy quark are calculated using Heavy Hadron Chiral Perturbation Theory. The M1 and E2 amplitudes for S^{*}--> S gamma, S^{*} --> T gamma and S --> T gamma are separately computed. All M1 transitions are calculated up to O(1/Lambda_chi^2). The E2 amplitudes contribute at the same order for S^{*}--> S gamma, while for S^{*} --> T gamma they first appear at O(1/(m_Q \Lambda_\chi^2)) and for S --> T gamma are completely negligible. The renormalization of the chiral loops is discussed and relations among different decay amplitudes are derived. We find that chiral loops involving electromagnetic interactions of the light pseudoscalar mesons provide a sizable enhancement of these decay widths. Furthermore, we obtain an absolute prediction for the widths of Xi^{0'(*)}_c--> Xi^{0}_c gamma and Xi^{-'(*)}_b--> Xi^{-}_b gamma. Our results are compared to other estimates existing in the literature.
[ { "created": "Fri, 26 Nov 1999 15:39:48 GMT", "version": "v1" } ]
2009-10-31
[ [ "Banuls", "M. C.", "" ], [ "Pich", "A.", "" ], [ "Scimemi", "I.", "" ] ]
The electromagnetic decays of the ground state baryon multiplets with one heavy quark are calculated using Heavy Hadron Chiral Perturbation Theory. The M1 and E2 amplitudes for S^{*}--> S gamma, S^{*} --> T gamma and S --> T gamma are separately computed. All M1 transitions are calculated up to O(1/Lambda_chi^2). The E2 amplitudes contribute at the same order for S^{*}--> S gamma, while for S^{*} --> T gamma they first appear at O(1/(m_Q \Lambda_\chi^2)) and for S --> T gamma are completely negligible. The renormalization of the chiral loops is discussed and relations among different decay amplitudes are derived. We find that chiral loops involving electromagnetic interactions of the light pseudoscalar mesons provide a sizable enhancement of these decay widths. Furthermore, we obtain an absolute prediction for the widths of Xi^{0'(*)}_c--> Xi^{0}_c gamma and Xi^{-'(*)}_b--> Xi^{-}_b gamma. Our results are compared to other estimates existing in the literature.
hep-ph/0408303
Sergio Sciutto
R. Luna, A. Zepeda, C. A. Garcia Canal, S. J. Sciutto
Influence of diffractive interactions on cosmic ray air showers
null
Phys.Rev. D70 (2004) 114034
10.1103/PhysRevD.70.114034
null
hep-ph
null
A comparative study of commonly used hadronic collision simulation packages is presented. The characteristics of the products of hadron-nucleus collisions are analyzed from a general perspective, but focusing on their correlation with diffractive processes. One of the purposes of our work is to give quantitative estimations of the impact that different characteristics of the hadronic models have on air shower observables. Several sets of shower simulations using different settings for the parameters controlling the diffractive processes are used to analyze the correlations between diffractivity and shower observables. We find that the relative probability of diffractive processes during the shower development have a non negligible influence over the longitudinal profile as well as the distribution of muons at ground level. The implications on experimental data analysis are discussed.
[ { "created": "Thu, 26 Aug 2004 14:40:31 GMT", "version": "v1" }, { "created": "Wed, 3 Nov 2004 15:17:06 GMT", "version": "v2" }, { "created": "Mon, 27 Dec 2004 16:25:19 GMT", "version": "v3" } ]
2009-11-10
[ [ "Luna", "R.", "" ], [ "Zepeda", "A.", "" ], [ "Canal", "C. A. Garcia", "" ], [ "Sciutto", "S. J.", "" ] ]
A comparative study of commonly used hadronic collision simulation packages is presented. The characteristics of the products of hadron-nucleus collisions are analyzed from a general perspective, but focusing on their correlation with diffractive processes. One of the purposes of our work is to give quantitative estimations of the impact that different characteristics of the hadronic models have on air shower observables. Several sets of shower simulations using different settings for the parameters controlling the diffractive processes are used to analyze the correlations between diffractivity and shower observables. We find that the relative probability of diffractive processes during the shower development have a non negligible influence over the longitudinal profile as well as the distribution of muons at ground level. The implications on experimental data analysis are discussed.
1101.2967
Henryk Czyz
Henryk Czyz and Agnieszka Grzelinska
PHOKHARA 7.0 Monte Carlo generator: the narrow resonances implementation and new pion and kaon form factors
Presented at International workshop on Tau Lepton Physics, TAU10 Manchester GB, September, 2010
Nucl.Phys.Proc.Suppl.218:201-206,2011
10.1016/j.nuclphysbps.2011.06.032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Experiments at high luminosity electron-positron colliders allow to study the kaon and the pion form factors in the time-like region up to high energies. Also the kaon and the pion pair production at and around the narrow resonances J/psi and psi(2S) can be investigated, with the interference between electromagnetic and hadronic amplitudes as one of the most interesting phenomenas. Parameterisations of charged and neutral kaon as well as pion form factors, which lead to an improved description of the data in the region of large invariant masses of the meson pair, are presented. They are implemented into the Monte Carlo generator PHOKHARA, together with the hadronic couplings of charged and neutral kaons to J/psi and psi(2S). The physics case as well as details of the implementation are discussed.
[ { "created": "Sat, 15 Jan 2011 10:40:01 GMT", "version": "v1" } ]
2011-09-20
[ [ "Czyz", "Henryk", "" ], [ "Grzelinska", "Agnieszka", "" ] ]
Experiments at high luminosity electron-positron colliders allow to study the kaon and the pion form factors in the time-like region up to high energies. Also the kaon and the pion pair production at and around the narrow resonances J/psi and psi(2S) can be investigated, with the interference between electromagnetic and hadronic amplitudes as one of the most interesting phenomenas. Parameterisations of charged and neutral kaon as well as pion form factors, which lead to an improved description of the data in the region of large invariant masses of the meson pair, are presented. They are implemented into the Monte Carlo generator PHOKHARA, together with the hadronic couplings of charged and neutral kaons to J/psi and psi(2S). The physics case as well as details of the implementation are discussed.
hep-ph/0201171
Nils Tornqvist
Nils A. Tornqvist (Physics Department, University of Helsinki)
The lightest scalar nonet
Errata corrected, Published in the proceedings of the IPN Orsay workshop ``Chiral fluctuations in hadronic matter'', Orsay, September 16-20, 2001. p. 267, Edited by Z. Aouissat et al
null
null
null
hep-ph
null
First I review some previous work on the lightest scalars below 1.5 GeV, and how these scalars can be understood as unitarized nonet states. The bare scalars are strongly distorted by hadronic mass shifts, and the lightest I=0 state becomes a very broad resonance of mass and width of about 500 MeV. This is the sigma meson required by models based on linear realization of chiral symmetry. Recently the light sigma has clearly been observed in D decay to 3 pions by the E791 experiment at Fermilab and I discuss how this decay channel can be predicted in a Constituent Quark Meson Model, which incorporates heavy quark and chiral symmetries. At the end I discuss the likely possibility that there are in fact two light scalar nonets, such as one mainly meson-meson (or 4-quark) nonet and one qq bar nonet. I point out that an interesting approximate description of this could be modelled by starting with two coupled linear sigma models. After gauging the overall symmetry one of these could be looked upon as the "Higgs sector of strong interactions", and the lightest scalar nonet becomes the corresponding Higgs nonet.
[ { "created": "Fri, 18 Jan 2002 09:41:27 GMT", "version": "v1" }, { "created": "Wed, 12 Jun 2002 07:45:27 GMT", "version": "v2" } ]
2016-09-06
[ [ "Tornqvist", "Nils A.", "", "Physics Department, University of Helsinki" ] ]
First I review some previous work on the lightest scalars below 1.5 GeV, and how these scalars can be understood as unitarized nonet states. The bare scalars are strongly distorted by hadronic mass shifts, and the lightest I=0 state becomes a very broad resonance of mass and width of about 500 MeV. This is the sigma meson required by models based on linear realization of chiral symmetry. Recently the light sigma has clearly been observed in D decay to 3 pions by the E791 experiment at Fermilab and I discuss how this decay channel can be predicted in a Constituent Quark Meson Model, which incorporates heavy quark and chiral symmetries. At the end I discuss the likely possibility that there are in fact two light scalar nonets, such as one mainly meson-meson (or 4-quark) nonet and one qq bar nonet. I point out that an interesting approximate description of this could be modelled by starting with two coupled linear sigma models. After gauging the overall symmetry one of these could be looked upon as the "Higgs sector of strong interactions", and the lightest scalar nonet becomes the corresponding Higgs nonet.
0805.4792
Chihiro Sasaki
C. Sasaki (TU Munich), M. Harada (Nagoya Univ.), W. Weise (TU Munich)
Vector-axialvector mixing in hot matter and its hadronic effective field theory description
4 pages, 3 figures, based on presentations given in Quark Matter 2008, Jaipur, India, Feb 4-10, 2008 and the YITP International Symposium "Fundamental Problems in Hot and/or Dense QCD", Kyoto, Japan, March 3-6, 2008
Prog.Theor.Phys.Suppl.174:173-176,2008; Indian J.Phys.85:1203-1206,2011
10.1143/PTPS.174.173 10.1007/s12648-011-0123-6
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the importance of the axialvector meson in chiral phase transition at finite temperature. We show that there exists a significant contribution in the vector spectral function from the axialvector meson through the vector-axialvector mixing in hot matter.
[ { "created": "Fri, 30 May 2008 15:30:34 GMT", "version": "v1" } ]
2011-08-11
[ [ "Sasaki", "C.", "", "TU Munich" ], [ "Harada", "M.", "", "Nagoya Univ." ], [ "Weise", "W.", "", "TU Munich" ] ]
We discuss the importance of the axialvector meson in chiral phase transition at finite temperature. We show that there exists a significant contribution in the vector spectral function from the axialvector meson through the vector-axialvector mixing in hot matter.
hep-ph/0605160
Mark Strikman
L. Frankfurt, M.Strikman, M.Zhalov
Elastic and large t rapidity gap vector meson production in ultraperipheral proton-ion collisions
21 pages, 9 figures, a reference to experimental data is added
Phys.Lett. B640 (2006) 162-169
10.1016/j.physletb.2006.07.059
null
hep-ph
null
We evaluate the cross sections for the production of vector mesons in exclusive ultraperipheral proton-ion collisions at LHC. We find that the rates are high enough to study the energy and momentum transfer dependence of vector mesons - rho,phi, J/psi, Upsilon photoproduction in gamma p scattering in a wide energy range extending the measurements which were performed at HERA, providing new information about interplay of soft and hard physics in diffraction. Also, we calculate the contributions to the vector meson yield due to production of vector mesons off nuclear target by photons emitted by proton. We find, that least in the case of Upsilon production it is feasible to observe simultaneously both these processes. Such measurements would increase the precision with which the A-dependence of exclusive onium production can be determined. This would also enable one to estimate the amount of nuclear gluon shadowing of generalized gluon distributions at much smaller x than that is possible in AA collisions and to measure the cross sections for photoproduction processes in a significantly wider energy range than that achieved in experiments with fixed nuclear targets. We also present the cross section for vector meson production in pA collisions at RHIC. In addition, we consider production of vector mesons off protons with large rapidity gaps and large t. These processes probe small x dynamics of the elastic interaction of small dipoles at high energies and large but finite t, that is in the kinematics where DGLAP evolution is strongly suppressed. We estimate that this process could be studied at LHC up to W ~1 TeV with detectors which will be available at LHC.
[ { "created": "Sun, 14 May 2006 01:23:07 GMT", "version": "v1" }, { "created": "Tue, 23 May 2006 09:34:36 GMT", "version": "v2" } ]
2009-11-11
[ [ "Frankfurt", "L.", "" ], [ "Strikman", "M.", "" ], [ "Zhalov", "M.", "" ] ]
We evaluate the cross sections for the production of vector mesons in exclusive ultraperipheral proton-ion collisions at LHC. We find that the rates are high enough to study the energy and momentum transfer dependence of vector mesons - rho,phi, J/psi, Upsilon photoproduction in gamma p scattering in a wide energy range extending the measurements which were performed at HERA, providing new information about interplay of soft and hard physics in diffraction. Also, we calculate the contributions to the vector meson yield due to production of vector mesons off nuclear target by photons emitted by proton. We find, that least in the case of Upsilon production it is feasible to observe simultaneously both these processes. Such measurements would increase the precision with which the A-dependence of exclusive onium production can be determined. This would also enable one to estimate the amount of nuclear gluon shadowing of generalized gluon distributions at much smaller x than that is possible in AA collisions and to measure the cross sections for photoproduction processes in a significantly wider energy range than that achieved in experiments with fixed nuclear targets. We also present the cross section for vector meson production in pA collisions at RHIC. In addition, we consider production of vector mesons off protons with large rapidity gaps and large t. These processes probe small x dynamics of the elastic interaction of small dipoles at high energies and large but finite t, that is in the kinematics where DGLAP evolution is strongly suppressed. We estimate that this process could be studied at LHC up to W ~1 TeV with detectors which will be available at LHC.
2305.04663
Sebastian Trojanowski
Sebastian Trojanowski
Beyond the Standard Model physics in the far-forward region of the Large Hadron Collider
17 pages, 3 figures, proceeding of the XXIX Cracow Epiphany Conference, Cracow, Poland, January 16-19 2023; references added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new physics program has been initiated as part of the ongoing LHC physics run in the far-forward region, where dedicated FASER and SND@LHC experiments are currently taking data. We discuss the possible discovery prospects of this program in the search for signatures of beyond the Standard Model physics. We focus on both the present period and the proposed future Forward Physics Facility (FPF) that will operate in the high luminosity LHC era.
[ { "created": "Mon, 8 May 2023 12:35:14 GMT", "version": "v1" }, { "created": "Fri, 12 May 2023 22:45:14 GMT", "version": "v2" } ]
2023-05-16
[ [ "Trojanowski", "Sebastian", "" ] ]
A new physics program has been initiated as part of the ongoing LHC physics run in the far-forward region, where dedicated FASER and SND@LHC experiments are currently taking data. We discuss the possible discovery prospects of this program in the search for signatures of beyond the Standard Model physics. We focus on both the present period and the proposed future Forward Physics Facility (FPF) that will operate in the high luminosity LHC era.
hep-ph/0401176
Marco Sozzi
M. S. Sozzi
On the direct CP violation parameter epsilon prime
9 pages, 1 figure
Eur.Phys.J.C36:37-42,2004
10.1140/epjc/s2004-01895-0
null
hep-ph
null
We review different definitions of the $\epsilon'$ parameter describing direct CP violation in neutral kaon decays, which was precisely measured in recent experiments, and point out the inconsistency of some of them due to a CPT constraint. The proper comparison of the experimental results to the theoretical computations is discussed.
[ { "created": "Fri, 23 Jan 2004 11:47:43 GMT", "version": "v1" } ]
2008-11-26
[ [ "Sozzi", "M. S.", "" ] ]
We review different definitions of the $\epsilon'$ parameter describing direct CP violation in neutral kaon decays, which was precisely measured in recent experiments, and point out the inconsistency of some of them due to a CPT constraint. The proper comparison of the experimental results to the theoretical computations is discussed.
1602.05493
John Ellis
John Ellis
Time to move on?
12 pages, 4 figures, invited talk at Second LeCosPA Symposium, Taipei, Dec. 2015, contribution to the Proceedings
null
10.1142/S0218271816450140
KCL-PH-TH/2016-07, LCTS/2016-05, CERN-TH-2016-036
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cosmology and particle physics have long been dominated by theoretical paradigms: Einstein's general theory of relativity in cosmology and the Standard Model of particle physics. The time may have come for paradigm shifts. Does cosmological inflation require a modification of Einstein's gravity? Have experiments at the LHC discovered a new particle beyond the Standard Model? It is premature to answer these questions, but we theorists can dream about the possibilities.
[ { "created": "Wed, 17 Feb 2016 17:19:03 GMT", "version": "v1" } ]
2016-11-23
[ [ "Ellis", "John", "" ] ]
Cosmology and particle physics have long been dominated by theoretical paradigms: Einstein's general theory of relativity in cosmology and the Standard Model of particle physics. The time may have come for paradigm shifts. Does cosmological inflation require a modification of Einstein's gravity? Have experiments at the LHC discovered a new particle beyond the Standard Model? It is premature to answer these questions, but we theorists can dream about the possibilities.
hep-ph/0111144
Yang Jin-min
Junjie Cao, Zhaohua Xiong, Jin Min Yang
Can MSSM with light sbottom and light gluino survive Z-peak constraints ?
discussion on SUSY-EW effects added, to appear in PRL
Phys.Rev.Lett.88:111802,2002
10.1103/PhysRevLett.88.111802
null
hep-ph
null
In the framework of minimal supersymmetric model we examine the Z-peak constraints on the scenario of one light sbottom (2--5.5 GeV) and light gluino (12--16 GeV), which has been successfully used to explain the excess of bottom quark production in hadron collision. Such a scenario is found to be severely constrained by LEP Z-peak observables, especially by R_b, due to the large effect of gluino-sbottom loops. To account for the R_b data in this scenario, the other mass eigenstate of sbottom, i.e., the heavier one, must be lighter than 125 (195) GeV at 2-sigma (3-sigma) level, which should have been produced in association with the lighter one at LEP II and will probobaly be within the reach of Tevatron Run 2.
[ { "created": "Mon, 12 Nov 2001 15:31:18 GMT", "version": "v1" }, { "created": "Mon, 4 Mar 2002 11:40:23 GMT", "version": "v2" } ]
2011-01-27
[ [ "Cao", "Junjie", "" ], [ "Xiong", "Zhaohua", "" ], [ "Yang", "Jin Min", "" ] ]
In the framework of minimal supersymmetric model we examine the Z-peak constraints on the scenario of one light sbottom (2--5.5 GeV) and light gluino (12--16 GeV), which has been successfully used to explain the excess of bottom quark production in hadron collision. Such a scenario is found to be severely constrained by LEP Z-peak observables, especially by R_b, due to the large effect of gluino-sbottom loops. To account for the R_b data in this scenario, the other mass eigenstate of sbottom, i.e., the heavier one, must be lighter than 125 (195) GeV at 2-sigma (3-sigma) level, which should have been produced in association with the lighter one at LEP II and will probobaly be within the reach of Tevatron Run 2.
2212.06610
Aditya Srivastav
Neelima Agarwal, Sourav Pal, Aditya Srivastav, Anurag Tripathi
Deciphering Colour Building Blocks of Massive Multiparton Amplitudes at 4-loops and beyond
57 pages, 33 figures, Published Version. arXiv admin note: text overlap with arXiv:2204.05936
Journal of High Energy Physics 2023
10.1007/JHEP02(2023)258
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
The soft function in non-abelian gauge theories exponentiate, and their logarithms can be organised in terms of the collections of Feynman diagrams called Cwebs. The colour factors that appear in the logarithm are controlled by the web mixing matrices. Direct construction of the diagonal blocks of Cwebs using the new concepts of Normal ordering, basis Cweb and Fused-Web was recently carried out in~\cite{Agarwal:2022wyk}. In this article we establish correspondence between the boomerang webs introduced in ~\cite{Gardi:2021gzz} and non-boomerang Cwebs. We use this correspondence together with Uniqueness theorem and Fused web formalism introduced in ~\cite{Agarwal:2022wyk} to obtain the diagonal blocks of four general classes of Cwebs to all orders in perturbation theory which also cover all the four loop Boomerang Cwebs connecting four Wilson lines. We also fully construct the mixing matrix of a special Cweb to all orders in perturbation theory.
[ { "created": "Tue, 13 Dec 2022 14:33:27 GMT", "version": "v1" }, { "created": "Thu, 2 Mar 2023 06:27:24 GMT", "version": "v2" } ]
2023-03-03
[ [ "Agarwal", "Neelima", "" ], [ "Pal", "Sourav", "" ], [ "Srivastav", "Aditya", "" ], [ "Tripathi", "Anurag", "" ] ]
The soft function in non-abelian gauge theories exponentiate, and their logarithms can be organised in terms of the collections of Feynman diagrams called Cwebs. The colour factors that appear in the logarithm are controlled by the web mixing matrices. Direct construction of the diagonal blocks of Cwebs using the new concepts of Normal ordering, basis Cweb and Fused-Web was recently carried out in~\cite{Agarwal:2022wyk}. In this article we establish correspondence between the boomerang webs introduced in ~\cite{Gardi:2021gzz} and non-boomerang Cwebs. We use this correspondence together with Uniqueness theorem and Fused web formalism introduced in ~\cite{Agarwal:2022wyk} to obtain the diagonal blocks of four general classes of Cwebs to all orders in perturbation theory which also cover all the four loop Boomerang Cwebs connecting four Wilson lines. We also fully construct the mixing matrix of a special Cweb to all orders in perturbation theory.
hep-ph/0402092
Manuel Toharia
Manuel Toharia
Precision Electroweak Constraints on the mixed Radion-Higgs sector
Talk presented at SUSY 2003: Supersymmetry in the Desert, held at the University of Arizona, Tucson, AZ, June 5-10, 2003. To appear in the Proceedings
null
null
null
hep-ph
null
Adding radion perturbations (up to second order) to the static (RS) metric allows us to calculate the general first and second order interactions of the radion field with the electroweak vector bosons. We use these interactions to compute precision electroweak observables in the case of Higgs-radion mixing and compare with experiment.
[ { "created": "Mon, 9 Feb 2004 18:12:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Toharia", "Manuel", "" ] ]
Adding radion perturbations (up to second order) to the static (RS) metric allows us to calculate the general first and second order interactions of the radion field with the electroweak vector bosons. We use these interactions to compute precision electroweak observables in the case of Higgs-radion mixing and compare with experiment.
hep-ph/0411103
R. Ramachandran
R. Ramachandran
Chiral Soliton Model vs Pentaquark Structure for \Theta (1540)
11 pages, references added, final published version
Pramana 65:381-392,2005
10.1007/BF02704197
null
hep-ph nucl-th
null
The exotic baryon $\Theta^+$ (1540 MeV)$ is visualised as an expected (iso) rotational excitation in the Chiral Soliton Model. It is also argued as a Pentaquark baryon state in a constituent quark model with strong diquark correlations. I contrast the two points of view; the similarities and differences between the two pictures. Collective excitation, characteristic of Chiral Soliton Model points toward small mixing of representations in the wake of SU(3) breaking. In contrast, Constituent quark Models prefer near ``ideal'' mixing, similar to $\omega - \phi$ mixing.
[ { "created": "Mon, 8 Nov 2004 10:10:09 GMT", "version": "v1" }, { "created": "Wed, 17 Nov 2004 12:21:16 GMT", "version": "v2" }, { "created": "Tue, 24 May 2005 07:18:46 GMT", "version": "v3" } ]
2010-11-19
[ [ "Ramachandran", "R.", "" ] ]
The exotic baryon $\Theta^+$ (1540 MeV)$ is visualised as an expected (iso) rotational excitation in the Chiral Soliton Model. It is also argued as a Pentaquark baryon state in a constituent quark model with strong diquark correlations. I contrast the two points of view; the similarities and differences between the two pictures. Collective excitation, characteristic of Chiral Soliton Model points toward small mixing of representations in the wake of SU(3) breaking. In contrast, Constituent quark Models prefer near ``ideal'' mixing, similar to $\omega - \phi$ mixing.
2309.07850
Yong-Hui Lin
Yong-Hui Lin, Feng-Kun Guo, Ulf-G. Mei{\ss}ner
Method for measuring the charge radii of charged hyperons from the time-like region
10 pages, 6 figures; PLB accepted version
null
10.1016/j.physletb.2024.138887
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel method for measuring the charge radii of charged stable hadrons, with which the first measurement of the charge radii of the $\Sigma^+$ and the $\Xi^-$ is foreseen. The method explores the facts that the Dalitz decay $\psi(2S) \to Y\bar{Y}e^+e^-$ contains the hyperon form factors and the lowest measurable four-momentum transfer squared can be as low as $\sim 4m_e^2= 1.05\times10^{-6}\,{\rm GeV^2}$ in the time-like region. We identify a kinematic region where the hyperon form factors are essential and propose a method for subtracting the background from the data. It is estimated that the hyperon charge radii can be measured to a precision of about {0.2~fm} with the BES\Rom{3} experiment and one order of magnitude better at the future Super $\tau$-Charm Facility. Moreover, the same method can be used to measure the charge radius of the proton, which provides an independent cross-check on the extraction of proton radius from elastic $ep$ scattering or leptonic hydrogen spectroscopy.
[ { "created": "Thu, 14 Sep 2023 16:49:02 GMT", "version": "v1" }, { "created": "Fri, 15 Sep 2023 08:47:29 GMT", "version": "v2" }, { "created": "Mon, 15 Jul 2024 09:00:46 GMT", "version": "v3" } ]
2024-07-23
[ [ "Lin", "Yong-Hui", "" ], [ "Guo", "Feng-Kun", "" ], [ "Meißner", "Ulf-G.", "" ] ]
We propose a novel method for measuring the charge radii of charged stable hadrons, with which the first measurement of the charge radii of the $\Sigma^+$ and the $\Xi^-$ is foreseen. The method explores the facts that the Dalitz decay $\psi(2S) \to Y\bar{Y}e^+e^-$ contains the hyperon form factors and the lowest measurable four-momentum transfer squared can be as low as $\sim 4m_e^2= 1.05\times10^{-6}\,{\rm GeV^2}$ in the time-like region. We identify a kinematic region where the hyperon form factors are essential and propose a method for subtracting the background from the data. It is estimated that the hyperon charge radii can be measured to a precision of about {0.2~fm} with the BES\Rom{3} experiment and one order of magnitude better at the future Super $\tau$-Charm Facility. Moreover, the same method can be used to measure the charge radius of the proton, which provides an independent cross-check on the extraction of proton radius from elastic $ep$ scattering or leptonic hydrogen spectroscopy.
2106.03384
Motoko Fujiwara
Motoko Fujiwara, Junji Hisano, Takashi Toma
Vanishing or non-vanishing rainbow? Reduction formulas of electric dipole moment
23 pages, 7 figures, 2 tables, the version published in JHEP
JHEP 10 (2021) 237
10.1007/JHEP10(2021)237
IPMU21-0032, KANAZAWA-21-07
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we derive a simplified formula of electric dipole moments (EDMs) of a fermion. In the Standard Model, it is well-known that non-trivial cancellations between some rainbow-type diagrams induced by $W$ boson exchanges occur in the calculation of the neutron EDM at the two-loop level due to the gauge symmetry. The fermion self-energy and the vertex correction are related through the Ward-Takahashi identity, and this relation causes the exact cancellation of the EDM. We derive EDM formulas for a more general setup by introducing the form factors for the fermion self-energy and the vertex correction so that the derived formulas can be applicable to a larger class of models. We conclude that the non-zero EDM contributions are induced from rainbow-type diagrams with the chirality flipping effects for internal fermions. We also discuss the other possible generalization of the EDM calculation which is applicable to the other classes of models.
[ { "created": "Mon, 7 Jun 2021 07:25:28 GMT", "version": "v1" }, { "created": "Tue, 2 Nov 2021 14:26:55 GMT", "version": "v2" } ]
2021-11-03
[ [ "Fujiwara", "Motoko", "" ], [ "Hisano", "Junji", "" ], [ "Toma", "Takashi", "" ] ]
In this paper, we derive a simplified formula of electric dipole moments (EDMs) of a fermion. In the Standard Model, it is well-known that non-trivial cancellations between some rainbow-type diagrams induced by $W$ boson exchanges occur in the calculation of the neutron EDM at the two-loop level due to the gauge symmetry. The fermion self-energy and the vertex correction are related through the Ward-Takahashi identity, and this relation causes the exact cancellation of the EDM. We derive EDM formulas for a more general setup by introducing the form factors for the fermion self-energy and the vertex correction so that the derived formulas can be applicable to a larger class of models. We conclude that the non-zero EDM contributions are induced from rainbow-type diagrams with the chirality flipping effects for internal fermions. We also discuss the other possible generalization of the EDM calculation which is applicable to the other classes of models.
hep-ph/9609214
Martin Beneke
M. Beneke (SLAC)
Lifetime Difference of Neutral $B_s$ Mesons and its Implications
8 pages, LaTeX, sprocl.sty provided (To appear in the Proceedings of the 28th International Conference on High Energy Physics, Warsaw, Poland, 25-31 July 1996)
null
null
SLAC-PUB-96-7258
hep-ph
null
We discuss the calculation of the width difference $\Delta\Gamma_{B_s}$ between the $B_s$ mass eigenstates to next-to-leading order in the heavy quark expansion. $1/m_b$-corrections are estimated to reduce the leading order result by typically $30\%$. The error of the present estimate $(\Delta\Gamma/\Gamma)_{B_s} = 0.16^{+0.11}_{-0.09}$ could be substantially improved by pinning down the value of $\langle \bar{B}_s |(\bar b_is_i)_{S-P}(\bar b_js_j)_{S-P}| B_s\rangle$ and an accuracy of $10\%$ in $(\Delta\Gamma/\Gamma)_{B_s}$ should eventually be reached. We briefly mention strategies to measure $(\Delta\Gamma/\Gamma)_{B_s}$, and its implications for constraints on $\Delta M_{B_s}$, CKM parameters and the observation of CP violation in untagged $B_s$ samples.
[ { "created": "Sun, 1 Sep 1996 01:43:50 GMT", "version": "v1" } ]
2016-09-06
[ [ "Beneke", "M.", "", "SLAC" ] ]
We discuss the calculation of the width difference $\Delta\Gamma_{B_s}$ between the $B_s$ mass eigenstates to next-to-leading order in the heavy quark expansion. $1/m_b$-corrections are estimated to reduce the leading order result by typically $30\%$. The error of the present estimate $(\Delta\Gamma/\Gamma)_{B_s} = 0.16^{+0.11}_{-0.09}$ could be substantially improved by pinning down the value of $\langle \bar{B}_s |(\bar b_is_i)_{S-P}(\bar b_js_j)_{S-P}| B_s\rangle$ and an accuracy of $10\%$ in $(\Delta\Gamma/\Gamma)_{B_s}$ should eventually be reached. We briefly mention strategies to measure $(\Delta\Gamma/\Gamma)_{B_s}$, and its implications for constraints on $\Delta M_{B_s}$, CKM parameters and the observation of CP violation in untagged $B_s$ samples.
hep-ph/9710503
Nicolas Pott
N. Pott (Technical University Munich)
Anomalous dimensions of four-quark operators in the large N_f limit
17 pages, LaTex, two figures
null
null
TUM-HEP-298/97
hep-ph
null
The anomalous dimensions of four-quark operators $(\bar q_i q_j)_{V-A} (\bar q_k q_l)_{V-A}$ are calculated in the large $N_f$ limit. As expected, the result is a convergent series without renormalon ambiguities. Using the approximation of "Naive Nonabelianization", an additional all-order contribution to the anomalous dimension matrix is obtained which is somewhat larger than the exact NLO correction itself. Possible phenomenological applications in nonleptonic B decays and $B^0 - \bar B^0$ mixing are briefly considered.
[ { "created": "Tue, 28 Oct 1997 14:03:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pott", "N.", "", "Technical University Munich" ] ]
The anomalous dimensions of four-quark operators $(\bar q_i q_j)_{V-A} (\bar q_k q_l)_{V-A}$ are calculated in the large $N_f$ limit. As expected, the result is a convergent series without renormalon ambiguities. Using the approximation of "Naive Nonabelianization", an additional all-order contribution to the anomalous dimension matrix is obtained which is somewhat larger than the exact NLO correction itself. Possible phenomenological applications in nonleptonic B decays and $B^0 - \bar B^0$ mixing are briefly considered.
hep-ph/9603245
null
M. Kacir and I. Zahed
Two-Dimensional Solitons at Finite Temperature
13 pages in LaTex format, 3 figures (submitted to Phys. Lett. B)
null
null
SUNY-NTG-95-53
hep-ph
null
The partition function of two-dimensional solitons in a heat bath of mesons is worked out to one-loop. For temperatures large compared to the meson mass, the free energy is dominated by the meson-soliton bound states and the zero modes, a consequence of Levinson's theorem. Using the Bethe-Uhlenbeck formula we compare the soliton energy-shift to the shift expected in the pole mass using a virial expansion. We construct the partition function associated to a fast moving soliton at finite temperature, and found that the soliton thermal inertial mass is no longer constrained by Poincare's symmetry. At finite temperature, the concept of quasiparticles is process dependent.
[ { "created": "Thu, 7 Mar 1996 13:49:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kacir", "M.", "" ], [ "Zahed", "I.", "" ] ]
The partition function of two-dimensional solitons in a heat bath of mesons is worked out to one-loop. For temperatures large compared to the meson mass, the free energy is dominated by the meson-soliton bound states and the zero modes, a consequence of Levinson's theorem. Using the Bethe-Uhlenbeck formula we compare the soliton energy-shift to the shift expected in the pole mass using a virial expansion. We construct the partition function associated to a fast moving soliton at finite temperature, and found that the soliton thermal inertial mass is no longer constrained by Poincare's symmetry. At finite temperature, the concept of quasiparticles is process dependent.
hep-ph/9610441
null
Zurab Tavartkiladze (INFN Ferrara)
SUSY SU(6) GUT without Gauge Hierarchy Problem
8 pages, LATEX, some misprints are corrected, as appeared in Phys.Lett. B
Phys.Lett. B392 (1997) 360-364
10.1016/S0370-2693(96)01567-5
INFN-FE 12-96
hep-ph
null
A solution of the doublet-triplet splitting problem in the supersymmetric $SU(6)$ gauge theory is suggested. The `missing doublet' multiplet -- 175-plet of the $SU(6)$ group as well as the custodial $SU(2)_{cus}$ global symmetry play crucial role for achieving the doublet-triplet hierarchy. Two examples in which the doublet-triplet splitting occurs naturally are presented.
[ { "created": "Tue, 22 Oct 1996 14:23:32 GMT", "version": "v1" }, { "created": "Wed, 26 Feb 1997 23:55:45 GMT", "version": "v2" } ]
2009-10-30
[ [ "Tavartkiladze", "Zurab", "", "INFN Ferrara" ] ]
A solution of the doublet-triplet splitting problem in the supersymmetric $SU(6)$ gauge theory is suggested. The `missing doublet' multiplet -- 175-plet of the $SU(6)$ group as well as the custodial $SU(2)_{cus}$ global symmetry play crucial role for achieving the doublet-triplet hierarchy. Two examples in which the doublet-triplet splitting occurs naturally are presented.
hep-ph/0607092
Tomohiro Matsuda
Tomohiro Matsuda
Vacuum energy reduction through destabilization: a unification of quintessence and a dynamical approach?
18 pages
null
null
null
hep-ph astro-ph gr-qc hep-th
null
Although quintessence cosmologies seem to explain the amount of cosmological constant today, the required conditions are severe. For example, an extremely slowly varying and light scalar field that rolls toward the vanishing vacuum energy state is needed, which must satisfy the required initial conditions so that the energy density in matter is comparable to the energy density stored in quintessence today. Our first question is whether it is possible to explain why quintessence ``knows'' that the Universe is going toward the vanishing energy state. We show from a new perspective that the conventional $O(H)$ corrections may reproduce the required potential. Our second question is whether it is possible to obtain plausible amount of the potential energy density today without tuning initial conditions. Since our resultant potentials mimic quintessence, one may solve the coincidence problem using the conventional techniques for solving the coincidence problem in quintessence cosmology. However, in our scenario we have another option, which is qualitatively different from the one that have been discussed in quintessence cosmology. Besides quintessence cosmology, we show that there is a relation between a dynamical approach, which suggests that we can solve the coincidence problem in a dynamical approach. As far as we know, this is the first attempt to discuss about the unified picture and the important relations between these distinctive scenarios.
[ { "created": "Sun, 9 Jul 2006 06:03:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Matsuda", "Tomohiro", "" ] ]
Although quintessence cosmologies seem to explain the amount of cosmological constant today, the required conditions are severe. For example, an extremely slowly varying and light scalar field that rolls toward the vanishing vacuum energy state is needed, which must satisfy the required initial conditions so that the energy density in matter is comparable to the energy density stored in quintessence today. Our first question is whether it is possible to explain why quintessence ``knows'' that the Universe is going toward the vanishing energy state. We show from a new perspective that the conventional $O(H)$ corrections may reproduce the required potential. Our second question is whether it is possible to obtain plausible amount of the potential energy density today without tuning initial conditions. Since our resultant potentials mimic quintessence, one may solve the coincidence problem using the conventional techniques for solving the coincidence problem in quintessence cosmology. However, in our scenario we have another option, which is qualitatively different from the one that have been discussed in quintessence cosmology. Besides quintessence cosmology, we show that there is a relation between a dynamical approach, which suggests that we can solve the coincidence problem in a dynamical approach. As far as we know, this is the first attempt to discuss about the unified picture and the important relations between these distinctive scenarios.
hep-ph/9604361
Andrea Romanino
Andrea Romanino
Electric dipole moments in supersymmetric theories
5 pages, LaTex2e using amstex.sty, amssymb.sty, apalike.sty, no figs., to appear in Proceedings of the XXIV ITEP Winter School of Physics
Surveys High Energ.Phys.10:383-387,1997
10.1080/01422419708219642
IFUP-TH 22/96
hep-ph
null
Intrinsic EDMs in microscopic systems at a level of sensitivity achievable in experiments under way or foreseen are predicted in supersymmetric unified theories. I describe this and other sources of measurable EDMs and I show how these sources can be distinguished through experiments in different systems.
[ { "created": "Fri, 19 Apr 1996 14:02:22 GMT", "version": "v1" } ]
2015-06-25
[ [ "Romanino", "Andrea", "" ] ]
Intrinsic EDMs in microscopic systems at a level of sensitivity achievable in experiments under way or foreseen are predicted in supersymmetric unified theories. I describe this and other sources of measurable EDMs and I show how these sources can be distinguished through experiments in different systems.
1509.07090
Arunansu Sil
Biswajit Karmakar and Arunansu Sil
Spontaneous CP Violation in Lepton-sector: a common origin for $\theta_{13}$, Dirac CP phase and leptogenesis
31 pages, 17 figures
Phys. Rev. D 93, 013006 (2016)
10.1103/PhysRevD.93.013006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A possible interplay between the two terms of the general type-II seesaw formula is exercised which leads to the generation of nonzero $\theta_{13}$. The specific flavor structure of the model, guided by the $A_4 \times Z_4 \times Z_3$ symmetry and accompanied with the Standard Model singlet flavons, yields the conventional seesaw contribution to produce the tribimaximal lepton mixing which is further corrected by the presence of the $SU(2)_L$ triplet contribution to accommodate $\theta_{13}$. We consider the CP symmetry to be spontaneously broken by the complex vacuum expectation value (vev) of a singlet field $S$. While the magnitude of its complex vev is responsible for generating $\theta_{13}$, its phase part induces the low energy CP violating phase ($\delta$) and the CP violation required for leptogenesis. Hence the triplet contribution, although sub-dominant, plays crucial role in providing a common source for non-zero $\theta_{13}$, $\delta$ and CP-violation required for leptogenesis. We find that the recent hint for $\delta$ close to $3\pi/2$ is somewhat favored in this set-up though it excludes the exact equality with $3\pi/2$. We also discuss the generation of lepton asymmetry in this scenario.
[ { "created": "Wed, 23 Sep 2015 18:43:49 GMT", "version": "v1" } ]
2016-01-13
[ [ "Karmakar", "Biswajit", "" ], [ "Sil", "Arunansu", "" ] ]
A possible interplay between the two terms of the general type-II seesaw formula is exercised which leads to the generation of nonzero $\theta_{13}$. The specific flavor structure of the model, guided by the $A_4 \times Z_4 \times Z_3$ symmetry and accompanied with the Standard Model singlet flavons, yields the conventional seesaw contribution to produce the tribimaximal lepton mixing which is further corrected by the presence of the $SU(2)_L$ triplet contribution to accommodate $\theta_{13}$. We consider the CP symmetry to be spontaneously broken by the complex vacuum expectation value (vev) of a singlet field $S$. While the magnitude of its complex vev is responsible for generating $\theta_{13}$, its phase part induces the low energy CP violating phase ($\delta$) and the CP violation required for leptogenesis. Hence the triplet contribution, although sub-dominant, plays crucial role in providing a common source for non-zero $\theta_{13}$, $\delta$ and CP-violation required for leptogenesis. We find that the recent hint for $\delta$ close to $3\pi/2$ is somewhat favored in this set-up though it excludes the exact equality with $3\pi/2$. We also discuss the generation of lepton asymmetry in this scenario.
2203.16947
Jose Manuel Morgado Ch\'avez
Jose Manuel Morgado Ch\'avez, Valerio Bertone, Maxime Defurne, Feliciano de Soto, C\'edric Mezrag, Herv\'e Moutarde, Jos\'e Rodr\'iguez-Quintero, Jorge Segovia
Accessing pion GPDs through the Sullivan process: is it feasible?
Proceedings of the 19th International Conference on Hadron Spectroscopy and Structure in memoriam Simon Eidelman (HADRON2021), 26-31 July (2021), Mexico City (Mexico). To appear in Suplemento de la Revista Mexicana de F\'isica
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Describing hadronic structure is one of the most intriguing problems in physics. In this respect, generalized parton distributions (GPDs) constitute an outstanding tool, allowing to draw "three dimensional pictures" of hadron's inside. Starting from contemporary models for pion's GPDs fulfilling all constraints imposed by QCD, we compute Compton form factors (CFFs) of pions subjected to deeply virtual Compton scattering. We show the behaviour of CFFs to be gluon-dominated at EIC's kinematics. Finally we evaluate lepton-beam-spin asymmetries in the Sullivan process, demonstrating the existence of such and thus triggering optimism about the possibility of probing pion's 3D structure at electron-ion colliders.
[ { "created": "Thu, 31 Mar 2022 11:11:09 GMT", "version": "v1" } ]
2022-04-01
[ [ "Chávez", "Jose Manuel Morgado", "" ], [ "Bertone", "Valerio", "" ], [ "Defurne", "Maxime", "" ], [ "de Soto", "Feliciano", "" ], [ "Mezrag", "Cédric", "" ], [ "Moutarde", "Hervé", "" ], [ "Rodríguez-Quintero", "José", "" ], [ "Segovia", "Jorge", "" ] ]
Describing hadronic structure is one of the most intriguing problems in physics. In this respect, generalized parton distributions (GPDs) constitute an outstanding tool, allowing to draw "three dimensional pictures" of hadron's inside. Starting from contemporary models for pion's GPDs fulfilling all constraints imposed by QCD, we compute Compton form factors (CFFs) of pions subjected to deeply virtual Compton scattering. We show the behaviour of CFFs to be gluon-dominated at EIC's kinematics. Finally we evaluate lepton-beam-spin asymmetries in the Sullivan process, demonstrating the existence of such and thus triggering optimism about the possibility of probing pion's 3D structure at electron-ion colliders.
hep-ph/9811220
Markus Diehl
M. Diehl, T. Gousset and B. Pire
Exclusive electroproduction and off-diagonal parton distributions
7 pages, 3 figures, LaTeX2e. Talk given at the Fourth Workshop on Quantum Chromodynamics, Paris, France, 1-6 June 1998
null
null
DESY-98-168 and CPHT-PC669-1098
hep-ph
null
Off-diagonal parton distributions occur in several hard exclusive reactions. They extend the study of hadron structure beyond what can be learned from ordinary distributions and have a particularly rich spin structure. The hard scattering subprocesses in electroproduction of mesons and of real photons satisfy helicity selection rules, which provide powerful tools to test leading-twist dominance at a given value of the hard scale.
[ { "created": "Mon, 2 Nov 1998 17:23:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Diehl", "M.", "" ], [ "Gousset", "T.", "" ], [ "Pire", "B.", "" ] ]
Off-diagonal parton distributions occur in several hard exclusive reactions. They extend the study of hadron structure beyond what can be learned from ordinary distributions and have a particularly rich spin structure. The hard scattering subprocesses in electroproduction of mesons and of real photons satisfy helicity selection rules, which provide powerful tools to test leading-twist dominance at a given value of the hard scale.
hep-ph/0502007
Egle Tomasi-Gustafsson
Egle Tomasi-Gustafsson
Nucleon electromagnetic structure: past, present, and future
10 pages, 3 figures, to be included in a special issue of Nuovo Cimento C
Nuovo Cim. C27 (2004) 413-422
10.1393/ncc/i2005-10010-0
null
hep-ph
null
We present the experimental status of electromagnetic hadron form factors. New and surprising results, based on polarization measurements, have been recently obtained for the electric proton and neutron form factors. In particular, the electric and magnetic distributions inside the proton appear not to be the same, in disagreement with results extracted from the unpolarized cross section, using the Rosenbluth separation. The new findings have given rise to a large number of papers and different speculations, as they question directly the models of nucleon structure and the reaction mechanism itself (based on $1\gamma$-exchange), with a possible revision of the calculation of radiative corrections, two-photon contribution etc. New data in time-like region are also available, through annihilation reactions. A large interest in this field arises, due also to the possibility of new measurements in polarized electron nucleon elastic scattering at JLab, and also in the time-like region, at Frascati and at the future FAIR international facility.
[ { "created": "Tue, 1 Feb 2005 13:34:15 GMT", "version": "v1" } ]
2015-06-25
[ [ "Tomasi-Gustafsson", "Egle", "" ] ]
We present the experimental status of electromagnetic hadron form factors. New and surprising results, based on polarization measurements, have been recently obtained for the electric proton and neutron form factors. In particular, the electric and magnetic distributions inside the proton appear not to be the same, in disagreement with results extracted from the unpolarized cross section, using the Rosenbluth separation. The new findings have given rise to a large number of papers and different speculations, as they question directly the models of nucleon structure and the reaction mechanism itself (based on $1\gamma$-exchange), with a possible revision of the calculation of radiative corrections, two-photon contribution etc. New data in time-like region are also available, through annihilation reactions. A large interest in this field arises, due also to the possibility of new measurements in polarized electron nucleon elastic scattering at JLab, and also in the time-like region, at Frascati and at the future FAIR international facility.
1402.0417
Gilberto Ramalho
G. Ramalho and M.T. Pena
A covariant model for the $\gamma^\ast N \to N^\ast(1520)$ reaction
3 figure, 3 pages. Contribution to the 13th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2013), Rome, September-October 2013
EPJ Web Conf.73 (2014) 08006
10.1051/epjconf/20147304018
null
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply the covariant spectator quark model to the study of the electromagnetic structure of the $N^\ast(1520)$ state ($J^{P}= \frac{3}{2}^-$), an important resonance from the second resonance region in both spacelike and timelike regimes. The contributions from the valence quark effects are calculated for the $\gamma^\ast N \to N^\ast(1520)$ helicity amplitudes. The results are used to parametrize the meson cloud dominant at low $Q^2$.
[ { "created": "Mon, 3 Feb 2014 16:25:19 GMT", "version": "v1" } ]
2014-06-17
[ [ "Ramalho", "G.", "" ], [ "Pena", "M. T.", "" ] ]
We apply the covariant spectator quark model to the study of the electromagnetic structure of the $N^\ast(1520)$ state ($J^{P}= \frac{3}{2}^-$), an important resonance from the second resonance region in both spacelike and timelike regimes. The contributions from the valence quark effects are calculated for the $\gamma^\ast N \to N^\ast(1520)$ helicity amplitudes. The results are used to parametrize the meson cloud dominant at low $Q^2$.
hep-ph/0503240
Julien Serreau
Juergen Berges, Szabolcs Borsanyi, Urko Reinosa, Julien Serreau
Nonperturbative renormalization for 2PI effective action techniques
71 pages, 30 figures, published version
Annals Phys. 320 (2005) 344-398
10.1016/j.aop.2005.06.001
TUW-05-05 ; APC-05-07 ; LPT-ORSAY 05-21
hep-ph astro-ph hep-th nucl-th
null
Nonperturbative approximation schemes based on two-particle irreducible (2PI) effective actions provide an important means for our current understanding of (non-)equilibrium quantum field theory. A remarkable property is their renormalizability, since these approximations involve selective summations to infinite perturbative orders. In this paper we show how to renormalize all $n$-point functions of the theory, which are given by derivatives of the 2PI-resummed effective action $\Gamma[\phi]$ for scalar fields $\phi$. This provides a complete description in terms of the generating functional for renormalized proper vertices, which extends previous prescriptions in the literature on the renormalization for 2PI effective actions. The importance of the 2PI-resummed generating functional for proper vertices stems from the fact that the latter respect all symmetry properties of the theory and, in particular, Goldstone's theorem in the phase with spontaneous symmetry breaking. This is important in view of the application of these techniques to gauge theories, where Ward identities play a crucial role.
[ { "created": "Wed, 23 Mar 2005 16:26:51 GMT", "version": "v1" }, { "created": "Tue, 11 Oct 2005 13:46:04 GMT", "version": "v2" } ]
2009-11-11
[ [ "Berges", "Juergen", "" ], [ "Borsanyi", "Szabolcs", "" ], [ "Reinosa", "Urko", "" ], [ "Serreau", "Julien", "" ] ]
Nonperturbative approximation schemes based on two-particle irreducible (2PI) effective actions provide an important means for our current understanding of (non-)equilibrium quantum field theory. A remarkable property is their renormalizability, since these approximations involve selective summations to infinite perturbative orders. In this paper we show how to renormalize all $n$-point functions of the theory, which are given by derivatives of the 2PI-resummed effective action $\Gamma[\phi]$ for scalar fields $\phi$. This provides a complete description in terms of the generating functional for renormalized proper vertices, which extends previous prescriptions in the literature on the renormalization for 2PI effective actions. The importance of the 2PI-resummed generating functional for proper vertices stems from the fact that the latter respect all symmetry properties of the theory and, in particular, Goldstone's theorem in the phase with spontaneous symmetry breaking. This is important in view of the application of these techniques to gauge theories, where Ward identities play a crucial role.
2203.13753
Cyrin Neeraj
Akanksha Bhardwaj, Tanumoy Mandal, Subhadip Mitra, and Cyrin Neeraj
Roadmap to explore vectorlike quarks decaying to a new scalar or pseudoscalar
14 pages, 5 figures, 2 tables; Updated parametrisation, conclusions unchanged
Phys. Rev. D 106 (2022) 095014
10.1103/PhysRevD.106.095014
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The current experimental data allow for a sub-TeV colourless weak-singlet scalar or pseudoscalar. If such a singlet field is present together with TeV-range vectorlike top and bottom partners, there is a possibility that the heavy quarks decay dominantly to the singlet state and a third-generation quark, and the singlet state decays to quark and boson pairs. Such a possibility may arise in various models but it has not been explored experimentally, especially in the context of vectorlike-quark searches. We consider some minimal models, covering the possible weak representations of the top and bottom partners, that can be mapped to many well-motivated ultraviolet-complete theories. We chart out the possible interesting and unexplored signatures of the exotic decay of vectorlike quarks and identify benchmark points representing different signal topologies for the high luminosity LHC. We perform a general scan of the parameter space with the relevant direct search bounds and find that large regions, which do not require any fine-tuning, remain open for the unexplored channels. We also perform a simple projection study in the cleanest channel and indicate how other new but experimentally challenging channels can be used to probe more regions of the parameter space.
[ { "created": "Fri, 25 Mar 2022 16:34:45 GMT", "version": "v1" }, { "created": "Mon, 10 Oct 2022 13:01:59 GMT", "version": "v2" } ]
2022-11-14
[ [ "Bhardwaj", "Akanksha", "" ], [ "Mandal", "Tanumoy", "" ], [ "Mitra", "Subhadip", "" ], [ "Neeraj", "Cyrin", "" ] ]
The current experimental data allow for a sub-TeV colourless weak-singlet scalar or pseudoscalar. If such a singlet field is present together with TeV-range vectorlike top and bottom partners, there is a possibility that the heavy quarks decay dominantly to the singlet state and a third-generation quark, and the singlet state decays to quark and boson pairs. Such a possibility may arise in various models but it has not been explored experimentally, especially in the context of vectorlike-quark searches. We consider some minimal models, covering the possible weak representations of the top and bottom partners, that can be mapped to many well-motivated ultraviolet-complete theories. We chart out the possible interesting and unexplored signatures of the exotic decay of vectorlike quarks and identify benchmark points representing different signal topologies for the high luminosity LHC. We perform a general scan of the parameter space with the relevant direct search bounds and find that large regions, which do not require any fine-tuning, remain open for the unexplored channels. We also perform a simple projection study in the cleanest channel and indicate how other new but experimentally challenging channels can be used to probe more regions of the parameter space.
hep-ph/0306105
Mishra
Amruta Mishra and Hiranmaya Mishra
Chiral symmetry breaking, color superconductivity and color neutral quark matter: a variational approach
13 pages, 6 figures,to appear in Phys. Rev.D
Phys.Rev. D69 (2004) 014014
10.1103/PhysRevD.69.014014
null
hep-ph nucl-th
null
We investigate the vacuum realignment for chiral symmetry breaking and color superconductivity at finite density in Nambu-Jona-Lasinio model in a variational method. The treatment allows us to investigate simultaneous formation of condensates in quark antiquark as well as in diquark channels. The methodology involves an explicit construction of a variational ground state and minimisation of the thermodynamic potential. Color and electric charge neutrality conditions are imposed through introduction of appropriate chemical potentials. Color and flavor dependent condensate functions are determined through minimisation of the thermodynamic potential. The equation of state is calculated. Simultaneous existence of a mass gap and superconducting gap is seen in a small window of quark chemical potential within the model when charge neutrality conditions are not imposed. Enforcing color and electric charge neutrality conditions gives rise to existence of gapless superconducting modes depending upon the magnitude of the gap and the difference of the chemical potentials of the condensing quarks.
[ { "created": "Thu, 12 Jun 2003 16:11:14 GMT", "version": "v1" }, { "created": "Wed, 5 Nov 2003 17:47:39 GMT", "version": "v2" } ]
2009-11-10
[ [ "Mishra", "Amruta", "" ], [ "Mishra", "Hiranmaya", "" ] ]
We investigate the vacuum realignment for chiral symmetry breaking and color superconductivity at finite density in Nambu-Jona-Lasinio model in a variational method. The treatment allows us to investigate simultaneous formation of condensates in quark antiquark as well as in diquark channels. The methodology involves an explicit construction of a variational ground state and minimisation of the thermodynamic potential. Color and electric charge neutrality conditions are imposed through introduction of appropriate chemical potentials. Color and flavor dependent condensate functions are determined through minimisation of the thermodynamic potential. The equation of state is calculated. Simultaneous existence of a mass gap and superconducting gap is seen in a small window of quark chemical potential within the model when charge neutrality conditions are not imposed. Enforcing color and electric charge neutrality conditions gives rise to existence of gapless superconducting modes depending upon the magnitude of the gap and the difference of the chemical potentials of the condensing quarks.
hep-ph/0410273
Bennie F. L. Ward
B.F.L. Ward (Department of Physics, Baylor University, Waco, TX, USA)
Massive Elementary Particles and Black Holes in Resummed Quantum Gravity
4 pages, 1 figure; presented at ICHEP04
null
10.1142/9789812702227_0061
BU-HEPP-04-05
hep-ph
null
We use exact results in a new approach to quantum gravity to show that the classical conclusion that a massive elementary point particle is a black hole is obviated by quantum loop effects. Further phenomenological implications are discussed.
[ { "created": "Wed, 20 Oct 2004 13:47:43 GMT", "version": "v1" } ]
2017-08-23
[ [ "Ward", "B. F. L.", "", "Department of Physics, Baylor University, Waco, TX, USA" ] ]
We use exact results in a new approach to quantum gravity to show that the classical conclusion that a massive elementary point particle is a black hole is obviated by quantum loop effects. Further phenomenological implications are discussed.
1908.05320
Ramona Vogt
R. Vogt
$b \bar b$ Kinematic Correlations in Cold Nuclear Matter
18 pages, 17 figures
Phys. Rev. C 101, 024910 (2020)
10.1103/PhysRevC.101.024910
LLNL-JRNL-785319
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Background: The LHCb Collaboration has studied a number of kinematic correlations between $B$-hadron pairs through their subsequent decays to $J/\psi$ pairs at 7 and 8 TeV for four minimum values of the $J/\psi$ $p_T$. Purpose: In this work, these measurements are compared to calculations of $b \bar b$ pairs and their hadronization and inclusive decays to $J/\psi J/\psi$ are compared to the same observables. Potential cold matter effects on the $b \bar b$ pair observables are discussed to determine which are most likely to provide insights about the system and why. Methods: The calculations, employing the exclusive HVQMNR code, assume the same intrinsic $k_T$-broadening and fragmentation as in [R. Vogt, Phys. Rev. C {\bf 98} (2018) 034907]. The pair distributions presented by LHCb are calculated in this approach, both for the parent $b \bar b$ and the $J/\psi J/\psi$ pairs produced in their decay. The sensitivity of the results to the intrinsic $k_T$ broadening is shown. The theoretical uncertainties due to the $b$ quark mass and scale variations on both the initial $b \bar b$ pairs and the resulting $J/\psi$ pairs are also shown. Possible effects due to the presence of the nucleus are studied by increasing the size of the $k_T$ broadening and modification of the fragmentation parameter. Results: Good agreement with the LHCb data is found for all observables. The parent $b \bar b$ distributions are more sensitive to the $k_T$ broadening than are the final-state $J/\psi$ pairs. Conclusions: Next-to-leading order calculations with $k_T$ broadening, as in [R. Vogt, Phys. Rev. C {\bf 98} (2018) 034907], can describe all correlated observables. Multiple measurements of correlated observables are sensitive to different nuclear effects which can help distinguish between them.
[ { "created": "Wed, 14 Aug 2019 19:24:51 GMT", "version": "v1" }, { "created": "Thu, 30 Jan 2020 05:27:38 GMT", "version": "v2" } ]
2020-02-26
[ [ "Vogt", "R.", "" ] ]
Background: The LHCb Collaboration has studied a number of kinematic correlations between $B$-hadron pairs through their subsequent decays to $J/\psi$ pairs at 7 and 8 TeV for four minimum values of the $J/\psi$ $p_T$. Purpose: In this work, these measurements are compared to calculations of $b \bar b$ pairs and their hadronization and inclusive decays to $J/\psi J/\psi$ are compared to the same observables. Potential cold matter effects on the $b \bar b$ pair observables are discussed to determine which are most likely to provide insights about the system and why. Methods: The calculations, employing the exclusive HVQMNR code, assume the same intrinsic $k_T$-broadening and fragmentation as in [R. Vogt, Phys. Rev. C {\bf 98} (2018) 034907]. The pair distributions presented by LHCb are calculated in this approach, both for the parent $b \bar b$ and the $J/\psi J/\psi$ pairs produced in their decay. The sensitivity of the results to the intrinsic $k_T$ broadening is shown. The theoretical uncertainties due to the $b$ quark mass and scale variations on both the initial $b \bar b$ pairs and the resulting $J/\psi$ pairs are also shown. Possible effects due to the presence of the nucleus are studied by increasing the size of the $k_T$ broadening and modification of the fragmentation parameter. Results: Good agreement with the LHCb data is found for all observables. The parent $b \bar b$ distributions are more sensitive to the $k_T$ broadening than are the final-state $J/\psi$ pairs. Conclusions: Next-to-leading order calculations with $k_T$ broadening, as in [R. Vogt, Phys. Rev. C {\bf 98} (2018) 034907], can describe all correlated observables. Multiple measurements of correlated observables are sensitive to different nuclear effects which can help distinguish between them.
hep-ph/0402237
Nils Tornqvist
Nils A. Tornqvist
Isospin breaking of the narrow charmonium state of Belle at 3872 MeV as a deuson
7 latex pages 5 figures. This report supercedes the unpublished reminder hep-ph/0308277. Version 2 to appear in Physics Letters B, one reference added and minor improvements
Phys.Lett.B590:209-215,2004
10.1016/j.physletb.2004.03.077
null
hep-ph nucl-th
null
The narrow charmonium state near 3872 MeV reported by the Belle collaboration and confirmedby CDF lies almost exactly at the neutral D anti-D* threshold. As was predicted many years ago it can be a deuteronlike meson-meson state called a deuson. If so, it should be an axial, or possibily a pseudoscalar state with C=0, and isospin predominantly 0. Large isospin breaking is expected because of the isospin mass splitting between the neutral and charged D (D*) mesons. Because of this large isospin breaking the decay X(3872) to J/psi rho would be allowed, while J/psi sigma would be forbidden by C-parity, as indicated by the present data.
[ { "created": "Mon, 23 Feb 2004 15:51:12 GMT", "version": "v1" }, { "created": "Mon, 29 Mar 2004 10:01:45 GMT", "version": "v2" } ]
2008-11-26
[ [ "Tornqvist", "Nils A.", "" ] ]
The narrow charmonium state near 3872 MeV reported by the Belle collaboration and confirmedby CDF lies almost exactly at the neutral D anti-D* threshold. As was predicted many years ago it can be a deuteronlike meson-meson state called a deuson. If so, it should be an axial, or possibily a pseudoscalar state with C=0, and isospin predominantly 0. Large isospin breaking is expected because of the isospin mass splitting between the neutral and charged D (D*) mesons. Because of this large isospin breaking the decay X(3872) to J/psi rho would be allowed, while J/psi sigma would be forbidden by C-parity, as indicated by the present data.
hep-ph/0506132
Tamas Biro S
T. S. Biro and A. Peshier
Limiting temperature from a parton gas with power-law tailed distribution
4 pages, 2 figures, revtex4 style, v2 more references
Phys.Lett. B632 (2006) 247-251
10.1016/j.physletb.2005.10.064
null
hep-ph
null
We combine Tsallis distributed massless partons to an effective thermal prehadron spectrum by folding. A limiting temperature and a mass spectrum combined of three exponentials emerge from this procedure. Meson and baryon resonance spectra have different polynomial prefactors.
[ { "created": "Tue, 14 Jun 2005 10:03:38 GMT", "version": "v1" }, { "created": "Mon, 27 Jun 2005 13:38:28 GMT", "version": "v2" } ]
2016-09-06
[ [ "Biro", "T. S.", "" ], [ "Peshier", "A.", "" ] ]
We combine Tsallis distributed massless partons to an effective thermal prehadron spectrum by folding. A limiting temperature and a mass spectrum combined of three exponentials emerge from this procedure. Meson and baryon resonance spectra have different polynomial prefactors.
hep-ph/9710507
Dietmar Ebert
D.Ebert (Humboldt-University, Berlin)
Hadronization in Particle Physics
7 pages, LaTeX, uses lamuphys.sty, 2 LaTeX figures, talk given at the Workshop "Field Theoretical Tools in Polymer and Particle Physics", University Wuppertal, June 17-19, 1997
null
10.1007/BFb0106880
HUB-EP-97/80
hep-ph
null
The method of path integral hadronization is applied to a local quark-diquark toy model in order to derive an effective chiral meson-baryon Lagrangian. Further generalizations to models including both scalar and axial-vector diquarks as well as nonlocal interactions are discussed.
[ { "created": "Tue, 28 Oct 1997 15:07:44 GMT", "version": "v1" } ]
2009-10-30
[ [ "Ebert", "D.", "", "Humboldt-University, Berlin" ] ]
The method of path integral hadronization is applied to a local quark-diquark toy model in order to derive an effective chiral meson-baryon Lagrangian. Further generalizations to models including both scalar and axial-vector diquarks as well as nonlocal interactions are discussed.
hep-ph/9910529
Piotr Zenczykowski
P. Zenczykowski (Institute of Nuclear Physics, Krakow, Poland)
Weak Radiative Hyperon Decays: Questioning the Basics
8 LaTeX pages, uses hyperon99_paper.sty which is included; Talk given at Hyperon 99: Hyperon Physics Symposium, Batavia, IL, 27-29 Sep 1999
null
null
null
hep-ph
null
Main theoretical approaches to weak radiative hyperon decays are briefly reviewed. It is emphasized that only approaches with great predictive power should be seriously considered when seeking a resolution of the puzzle presented by observed large negative asymmetry alpha (Sigma ^+ --> p gamma). In such cases, asymmetry in the Xi ^0 --> Lambda gamma decay is always large while its sign is positive (negative) if Hara's theorem is violated (satisfied). Measuring this asymmetry is therefore crucial for determining whether the large value of alpha (Sigma ^+ --> p gamma) is due to large SU(3) breaking or to some deeper reason. Some arguments suggesting that violation of Hara's theorem might be a feature of Nature, and hints as to its possible origin are also given.
[ { "created": "Thu, 28 Oct 1999 12:44:47 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zenczykowski", "P.", "", "Institute of Nuclear Physics, Krakow, Poland" ] ]
Main theoretical approaches to weak radiative hyperon decays are briefly reviewed. It is emphasized that only approaches with great predictive power should be seriously considered when seeking a resolution of the puzzle presented by observed large negative asymmetry alpha (Sigma ^+ --> p gamma). In such cases, asymmetry in the Xi ^0 --> Lambda gamma decay is always large while its sign is positive (negative) if Hara's theorem is violated (satisfied). Measuring this asymmetry is therefore crucial for determining whether the large value of alpha (Sigma ^+ --> p gamma) is due to large SU(3) breaking or to some deeper reason. Some arguments suggesting that violation of Hara's theorem might be a feature of Nature, and hints as to its possible origin are also given.
hep-ph/9708279
Peter Stockinger
W. Grimus, P. Stockinger (Univ. of Vienna, Austria)
Effects of neutrino oscillations and neutrino magnetic moments on elastic neutrino-electron scattering
12 pages, REVTEX file, no figures, submitted to Phys.Rev. D
Phys.Rev. D57 (1998) 1762-1768
10.1103/PhysRevD.57.1762
UWThPh-1997-20
hep-ph
null
We consider elastic antineutrino-electron scattering taking into account possible effects of neutrino masses and mixing and of neutrino magnetic moments and electric dipole moments. Having in mind antineutrinos produced in a nuclear reactor we compute, in particular, the weak-electromagnetic interference terms which are linear in the magnetic (electric dipole) moments and also in the neutrino masses. We show that these terms are, however, suppressed compared to the pure weak and electromagnetic cross section. We also comment upon the possibility of using the electromagnetic cross section to investigate neutrino oscillations.
[ { "created": "Thu, 7 Aug 1997 12:51:04 GMT", "version": "v1" } ]
2009-10-30
[ [ "Grimus", "W.", "", "Univ. of Vienna, Austria" ], [ "Stockinger", "P.", "", "Univ. of Vienna, Austria" ] ]
We consider elastic antineutrino-electron scattering taking into account possible effects of neutrino masses and mixing and of neutrino magnetic moments and electric dipole moments. Having in mind antineutrinos produced in a nuclear reactor we compute, in particular, the weak-electromagnetic interference terms which are linear in the magnetic (electric dipole) moments and also in the neutrino masses. We show that these terms are, however, suppressed compared to the pure weak and electromagnetic cross section. We also comment upon the possibility of using the electromagnetic cross section to investigate neutrino oscillations.
hep-ph/0507064
Lance Dixon
Lance J. Dixon
Recent Developments in Perturbative QCD
13 pages, 7 figures. Talk presented at 13th International Workshop on Deep Inelastic Scattering (DIS 05), Madison, Wisconsin, April, 2005
AIP Conf.Proc.792:61-72,2005
10.1063/1.2122012
SLAC-PUB-11316
hep-ph
null
I review recent progress in perturbative QCD on two fronts: extending next-to-next-to-leading order QCD corrections to a broader range of collider processes, and applying twistor-space methods (and related spinoffs) to computations of multi-parton scattering amplitudes.
[ { "created": "Tue, 5 Jul 2005 23:59:28 GMT", "version": "v1" } ]
2010-11-15
[ [ "Dixon", "Lance J.", "" ] ]
I review recent progress in perturbative QCD on two fronts: extending next-to-next-to-leading order QCD corrections to a broader range of collider processes, and applying twistor-space methods (and related spinoffs) to computations of multi-parton scattering amplitudes.
hep-ph/0205078
Malcolm Fairbairn
Malcolm Fairbairn
Time varying gauge couplings and di-nucleon states
8 pages, 1 figure to appear in proceedings of Recontres de Moriond 'Electroweak interactions and unified theories 2002'
null
null
null
hep-ph
null
In this talk we discuss the effect upon the di-proton, di-neutron and deuteron of a time variation of the QCD gauge coupling. We describe how a time evolution of the size of extra dimensions can give rise to such a variation and show how this is related to the recent results on possible time variation of the electromagnetic fine structure constant. Based on work in collaboration with Tom Dent.
[ { "created": "Wed, 8 May 2002 12:54:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fairbairn", "Malcolm", "" ] ]
In this talk we discuss the effect upon the di-proton, di-neutron and deuteron of a time variation of the QCD gauge coupling. We describe how a time evolution of the size of extra dimensions can give rise to such a variation and show how this is related to the recent results on possible time variation of the electromagnetic fine structure constant. Based on work in collaboration with Tom Dent.
hep-ph/0106107
Sherif Moussa
Salah Nasri and Sherif Moussa
Model for Small neutrino masses at the TeV Scale
13 pages, 2 figures
Mod.Phys.Lett. A17 (2002) 771-778
10.1142/S0217732302007119
null
hep-ph
null
We propose a model for neutrino mass generation in wich no physics beyond a TeV is required. We extend the standard model by adding two charged singlet fields with lepton number two. Dirac neutrino masses $m_{\nu_D} \leq MeV$ are generated at the one loop level. Small left handed majorana neutrino masses can be generated via the seesaw mechanism with right handed neutrino masses $M_R$ are of order TeV scale.
[ { "created": "Mon, 11 Jun 2001 05:12:59 GMT", "version": "v1" } ]
2009-11-07
[ [ "Nasri", "Salah", "" ], [ "Moussa", "Sherif", "" ] ]
We propose a model for neutrino mass generation in wich no physics beyond a TeV is required. We extend the standard model by adding two charged singlet fields with lepton number two. Dirac neutrino masses $m_{\nu_D} \leq MeV$ are generated at the one loop level. Small left handed majorana neutrino masses can be generated via the seesaw mechanism with right handed neutrino masses $M_R$ are of order TeV scale.
hep-ph/0302109
Ramona Vogt
R. Vogt (UC Davis and LBNL) and T.D. Gutierrez (UC Davis)
$\Xi^-$ and $\Omega$ Distributions in Hadron-Nucleus Interactions
23 pages, 5 eps figures
Nucl.Phys.A726:134-156,2003
10.1016/j.nuclphysa.2003.07.003
LBNL-52160
hep-ph
null
Strange baryons have long been known to exhibit a leading particle effect. A recent comparison of $\Xi^-$ production in $\pi^-$, $n$, and $\Sigma^-$ interactions with nuclei show this effect clearly. These data are supplemented by earlier measurements of $\Xi^-$ and $\Omega$ production by a $\Xi^-$ beam. We calculate the $\Xi^-$ and $\Omega$ $x_F$ distributions and nuclear dependence in $hA$ interactions using the intrinsic model.
[ { "created": "Thu, 13 Feb 2003 21:13:18 GMT", "version": "v1" } ]
2014-11-17
[ [ "Vogt", "R.", "", "UC Davis and LBNL" ], [ "Gutierrez", "T. D.", "", "UC Davis" ] ]
Strange baryons have long been known to exhibit a leading particle effect. A recent comparison of $\Xi^-$ production in $\pi^-$, $n$, and $\Sigma^-$ interactions with nuclei show this effect clearly. These data are supplemented by earlier measurements of $\Xi^-$ and $\Omega$ production by a $\Xi^-$ beam. We calculate the $\Xi^-$ and $\Omega$ $x_F$ distributions and nuclear dependence in $hA$ interactions using the intrinsic model.
1507.01572
Karol Kolodziej
Karol Kolodziej and Aleksandra Slapik
Probing the top-Higgs coupling through the secondary lepton distributions in the associated production of the top-quark pair and Higgs boson at the LHC
12 pages, 11 figures, referee's suggestions taken into account
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We complement the analysis of the anomalous top-Higgs coupling effects on the secondary lepton distributions in the associated production of the top-quark pair and Higgs boson in proton-proton collisions at the LHC of the former work by one of the present authors by taking into account the quark-antiquark production mechanism. We also present simple arguments which explain why the effects of the scalar and pseudoscalar anomalous couplings on the unpolarized cross section of the process are completely insensitive to the sign of either of them.
[ { "created": "Mon, 6 Jul 2015 19:33:35 GMT", "version": "v1" }, { "created": "Fri, 4 Sep 2015 13:06:43 GMT", "version": "v2" } ]
2015-09-07
[ [ "Kolodziej", "Karol", "" ], [ "Slapik", "Aleksandra", "" ] ]
We complement the analysis of the anomalous top-Higgs coupling effects on the secondary lepton distributions in the associated production of the top-quark pair and Higgs boson in proton-proton collisions at the LHC of the former work by one of the present authors by taking into account the quark-antiquark production mechanism. We also present simple arguments which explain why the effects of the scalar and pseudoscalar anomalous couplings on the unpolarized cross section of the process are completely insensitive to the sign of either of them.
hep-ph/9401270
S. V. Mikhailov
D.V. Shirkov and S.V. Mikhailov
Mass Dependent $\alpha_S$ Evolution and the Light Gluino Existence
13, Latex
Z.Phys.C63:463-470,1994
10.1007/BF01580326
BI-TP 93/75
hep-ph
null
There is an intriguing discrepancy between \alpha_s(M_Z) values measured directly at the CERN $Z_0$-factory and low-energy (at few GeV) measurements transformed to $Q=M_{Z_0}$ by a massless QCD \alpha_s(Q) evolution relation. There exists an attempt to reconcile this discrepancy by introducing a light gluino $\gl$ in the MSSM. We study in detail the influence of heavy thresholds on \alpha_s(Q) evolution. First, we consruct the "exact" explicit solution to the mass-dependent two-loop RG equation for the running \alpha_s(Q). This solution describes heavy thresholds smoothly. Second, we use this solution to recalculate anew \alpha_s(M_Z) values corresponding to "low-energy" input data. Our analysis demonstrates that using {\it mass-dependent RG procedure} generally produces corrections of two types: Asymptotic correction due to effective shift of threshold position; Local threshold correction only for the case when input experiment lies in the close vicinity of heavy particle threshold: $Q_{expt} \simeq M_h $. Both effects result in the effective shift of the \asmz values of the order of $10^{-3}$. However, the second one could be enhanced when the gluino mass is close to a heavy quark mass. For such a case the sum effect could be important for the discussion of the light gluino existence as it further changes the $\gl$ mass.
[ { "created": "Mon, 17 Jan 1994 12:54:49 GMT", "version": "v1" }, { "created": "Wed, 23 Mar 1994 11:49:15 GMT", "version": "v2" } ]
2010-11-01
[ [ "Shirkov", "D. V.", "" ], [ "Mikhailov", "S. V.", "" ] ]
There is an intriguing discrepancy between \alpha_s(M_Z) values measured directly at the CERN $Z_0$-factory and low-energy (at few GeV) measurements transformed to $Q=M_{Z_0}$ by a massless QCD \alpha_s(Q) evolution relation. There exists an attempt to reconcile this discrepancy by introducing a light gluino $\gl$ in the MSSM. We study in detail the influence of heavy thresholds on \alpha_s(Q) evolution. First, we consruct the "exact" explicit solution to the mass-dependent two-loop RG equation for the running \alpha_s(Q). This solution describes heavy thresholds smoothly. Second, we use this solution to recalculate anew \alpha_s(M_Z) values corresponding to "low-energy" input data. Our analysis demonstrates that using {\it mass-dependent RG procedure} generally produces corrections of two types: Asymptotic correction due to effective shift of threshold position; Local threshold correction only for the case when input experiment lies in the close vicinity of heavy particle threshold: $Q_{expt} \simeq M_h $. Both effects result in the effective shift of the \asmz values of the order of $10^{-3}$. However, the second one could be enhanced when the gluino mass is close to a heavy quark mass. For such a case the sum effect could be important for the discussion of the light gluino existence as it further changes the $\gl$ mass.
hep-ph/9607356
Diego Alejandro Restrepo Quintero
D. A. Restrepo
From hierarchical radiative quark mass matrices and mixings to FCNC in $SU(3)_c\times SU(2)_L\times U(1)_Y\times U(1)_H$
17 pages, Latex
null
null
UDEA-96-52
hep-ph
null
We present the realization of a mechanism that generates all mases and mixing angles by using the top quark as seed in the context of an anomaly free abelian extension of the standard model.
[ { "created": "Wed, 17 Jul 1996 16:00:08 GMT", "version": "v1" }, { "created": "Fri, 19 Jul 1996 20:58:21 GMT", "version": "v2" }, { "created": "Sat, 15 Nov 1997 12:27:04 GMT", "version": "v3" } ]
2008-02-03
[ [ "Restrepo", "D. A.", "" ] ]
We present the realization of a mechanism that generates all mases and mixing angles by using the top quark as seed in the context of an anomaly free abelian extension of the standard model.
1910.07909
Yuji Shi
Xiao-Hui Hu and Yu-Ji Shi
Light-Cone Sum Rules Analysis of $\Xi_{QQ^{\prime}}\to\Sigma_{Q^{\prime}}$ Weak Decays
20 pages, 3 figures, 9 tables. arXiv admin note: substantial text overlap with arXiv:1903.03921
null
10.1140/epjc/s10052-020-7635-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As a continuation of our previous work, we investigate the weak decays of doubly-heavy baryons $\Xi_{QQ^{\prime}}$ into sextet $\Sigma_{Q^{\prime}}$ with light-cone sum rules. We calculate the form factors for these decays with the parallel light-cone distribution amplitudes of $\Sigma_{Q^{\prime}}$. Numerical results of these form factors are used to predict the decay widths and branching ratios of the corresponding semi-leptonic processes. Parametric uncertainties and theoretical analyses are also given in detail. We find that the decay widths of $\Xi_{cc}$ and $\Xi_{bc}$ decays are several orders of magnitude larger than those of $\Xi_{bb}$ decays.
[ { "created": "Wed, 16 Oct 2019 13:46:39 GMT", "version": "v1" }, { "created": "Thu, 9 Jan 2020 18:33:59 GMT", "version": "v2" } ]
2020-02-19
[ [ "Hu", "Xiao-Hui", "" ], [ "Shi", "Yu-Ji", "" ] ]
As a continuation of our previous work, we investigate the weak decays of doubly-heavy baryons $\Xi_{QQ^{\prime}}$ into sextet $\Sigma_{Q^{\prime}}$ with light-cone sum rules. We calculate the form factors for these decays with the parallel light-cone distribution amplitudes of $\Sigma_{Q^{\prime}}$. Numerical results of these form factors are used to predict the decay widths and branching ratios of the corresponding semi-leptonic processes. Parametric uncertainties and theoretical analyses are also given in detail. We find that the decay widths of $\Xi_{cc}$ and $\Xi_{bc}$ decays are several orders of magnitude larger than those of $\Xi_{bb}$ decays.
hep-ph/0005011
Ed Stoeffhaas
V. Barger
Overview of Neutrino Oscillation Physics
9 pages, Latex2e, no figures. Uses ws-p8-50x6-00.cls, included. Talk presented at the 7th International Symposium on Particles, Strings and Cosmology (PASCOS 99), Granlibakken, California, December 1999
null
10.1142/9789812792433_0062
MADPH-00-1168
hep-ph
null
Recent evidence for neutrino oscillations has revolutionized the study of neutrino masses and mixing. This report gives an overview of what we are learning from the neutrino oscillation experiments, the prospects for the near term, and the bright future of neutrino mass studies.
[ { "created": "Mon, 1 May 2000 16:40:32 GMT", "version": "v1" } ]
2016-11-03
[ [ "Barger", "V.", "" ] ]
Recent evidence for neutrino oscillations has revolutionized the study of neutrino masses and mixing. This report gives an overview of what we are learning from the neutrino oscillation experiments, the prospects for the near term, and the bright future of neutrino mass studies.
1908.09845
Grant Remmen
Grant N. Remmen and Nicholas L. Rodd
Consistency of the Standard Model Effective Field Theory
64 pages, 10 figures, updated Table 2
JHEP 1912:032,2019
10.1007/JHEP12(2019)032
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive bounds on couplings in the standard model effective field theory (SMEFT) as a consequence of causality and the analytic structure of scattering amplitudes. In the SMEFT, there are 64 independent operators at mass dimension eight that are quartic in bosons (either Higgs or gauge fields) and that contain four derivatives and/or field strengths, including both CP-conserving and CP-violating operators. Using analytic dispersion relation arguments for two-to-two bosonic scattering amplitudes, we derive 27 independent bounds on the sign or magnitude of the couplings. We show that these bounds also follow as a consequence of causality of signal propagation in nonvacuum SM backgrounds. These bounds come in two qualitative forms: i) positivity of (various linear combinations of) couplings of CP-even operators and ii) upper bounds on the magnitude of CP-odd operators in terms of (products of) CP-even couplings. We exhibit various classes of example completions, which all satisfy our EFT bounds. These bounds have consequences for current and future particle physics experiments, as part of the observable parameter space is inconsistent with causality and analyticity. To demonstrate the impact of our bounds, we consider applications both to SMEFT constraints derived at colliders and to limits on the neutron electric dipole moment, highlighting the connection between such searches suggested by infrared consistency.
[ { "created": "Mon, 26 Aug 2019 18:00:03 GMT", "version": "v1" }, { "created": "Tue, 10 Dec 2019 18:04:11 GMT", "version": "v2" }, { "created": "Mon, 14 Sep 2020 23:21:52 GMT", "version": "v3" } ]
2020-09-16
[ [ "Remmen", "Grant N.", "" ], [ "Rodd", "Nicholas L.", "" ] ]
We derive bounds on couplings in the standard model effective field theory (SMEFT) as a consequence of causality and the analytic structure of scattering amplitudes. In the SMEFT, there are 64 independent operators at mass dimension eight that are quartic in bosons (either Higgs or gauge fields) and that contain four derivatives and/or field strengths, including both CP-conserving and CP-violating operators. Using analytic dispersion relation arguments for two-to-two bosonic scattering amplitudes, we derive 27 independent bounds on the sign or magnitude of the couplings. We show that these bounds also follow as a consequence of causality of signal propagation in nonvacuum SM backgrounds. These bounds come in two qualitative forms: i) positivity of (various linear combinations of) couplings of CP-even operators and ii) upper bounds on the magnitude of CP-odd operators in terms of (products of) CP-even couplings. We exhibit various classes of example completions, which all satisfy our EFT bounds. These bounds have consequences for current and future particle physics experiments, as part of the observable parameter space is inconsistent with causality and analyticity. To demonstrate the impact of our bounds, we consider applications both to SMEFT constraints derived at colliders and to limits on the neutron electric dipole moment, highlighting the connection between such searches suggested by infrared consistency.
1207.7128
John R. Hiller
S. S. Chabysheva and J. R. Hiller
A dynamical model for longitudinal wave functions in light-front holographic QCD
12 pages, 2 figures, RevTeX 4.1; expanded discussion, with calculation details moved to appendices
null
10.1016/j.aop.2013.06.016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a Schrodinger-like equation for the longitudinal wave function of a meson in the valence qq-bar sector, based on the 't Hooft model for large-N two-dimensional QCD, and combine this with the usual transverse equation from light-front holographic QCD, to obtain a model for mesons with massive quarks. The computed wave functions are compared with the wave function ansatz of Brodsky and De Teramond and used to compute decay constants and parton distribution functions. The basis functions used to solve the longitudinal equation may be useful for more general calculations of meson states in QCD.
[ { "created": "Mon, 30 Jul 2012 23:02:12 GMT", "version": "v1" }, { "created": "Sun, 14 Jul 2013 14:40:07 GMT", "version": "v2" } ]
2015-06-05
[ [ "Chabysheva", "S. S.", "" ], [ "Hiller", "J. R.", "" ] ]
We construct a Schrodinger-like equation for the longitudinal wave function of a meson in the valence qq-bar sector, based on the 't Hooft model for large-N two-dimensional QCD, and combine this with the usual transverse equation from light-front holographic QCD, to obtain a model for mesons with massive quarks. The computed wave functions are compared with the wave function ansatz of Brodsky and De Teramond and used to compute decay constants and parton distribution functions. The basis functions used to solve the longitudinal equation may be useful for more general calculations of meson states in QCD.
2312.08858
Konstantin Gaul
Konstantin Gaul and Robert Berger
Global analysis of CP-violation in atoms, molecules and role of medium-heavy systems
27 pages, 5 figures, 14 tables, supplementary material; correction of Wdm DFT values for TlF, minor corrections in table VI, improved MQM values in table X, references and acknowledgements updated, minor corrections on the text
null
null
null
hep-ph physics.atom-ph physics.chem-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
Detection of parity (P) and time-reversal (T) symmetry-odd electric dipole moments (EDMs) within currently achievable resolution would evidence physics beyond the Standard Model of particle physics. Via the CPT-theorem, which includes charge conjugation (C), such low-energy searches complement high-energy physics experiments that probe CP-violation up to the TeV scale. Heavy-elemental atoms and molecules are considered to be among the most promising candidates for a first direct detection of P,T-violation due to enhancement effects that increase steeply with increasing nuclear charge number $Z$. However, different P,T-odd sources on the subatomic level can contribute to molecular or atomic EDMs, which are target of measurements, and this complicates obtaining rigorous bounds on P,T-violation on a fundamental level. Consequently, several experiments of complementary sensitivity to these individual P,T-odd sources are required for this purpose. Herein, a simply-applicable qualitative model is developed for global analysis of the P,T-odd parameter space from an electronic-structure theory perspective. Rules of thumb are derived for the choice of atoms and molecules in terms of their angular momenta and nuclear charge number. Contrary to naive expectations from $Z$-scaling laws, it is demonstrated that medium-heavy molecules with $Z\leq54$ can be of great value to tighten global bounds on P,T-violating parameters, in particular, if the number of complementary experiments increases. The model is confirmed by explicit density functional theory calculations of all relevant P,T-odd electronic structure parameters in systems that were used in past experiments or are of current interest for future experiments, respectively: the atoms Xe, Cs, Yb, Hg, Tl, Ra, Fr and the molecules CaOH, SrOH, YO, CdH, BaF, YbF, YbOH, HfF$^+$, WC, TlF, PbO, RaF, ThO, ThF$^+$ and PaF$^{3+}$.
[ { "created": "Thu, 14 Dec 2023 12:26:46 GMT", "version": "v1" }, { "created": "Sat, 2 Mar 2024 10:55:04 GMT", "version": "v2" }, { "created": "Mon, 6 May 2024 07:42:44 GMT", "version": "v3" } ]
2024-05-07
[ [ "Gaul", "Konstantin", "" ], [ "Berger", "Robert", "" ] ]
Detection of parity (P) and time-reversal (T) symmetry-odd electric dipole moments (EDMs) within currently achievable resolution would evidence physics beyond the Standard Model of particle physics. Via the CPT-theorem, which includes charge conjugation (C), such low-energy searches complement high-energy physics experiments that probe CP-violation up to the TeV scale. Heavy-elemental atoms and molecules are considered to be among the most promising candidates for a first direct detection of P,T-violation due to enhancement effects that increase steeply with increasing nuclear charge number $Z$. However, different P,T-odd sources on the subatomic level can contribute to molecular or atomic EDMs, which are target of measurements, and this complicates obtaining rigorous bounds on P,T-violation on a fundamental level. Consequently, several experiments of complementary sensitivity to these individual P,T-odd sources are required for this purpose. Herein, a simply-applicable qualitative model is developed for global analysis of the P,T-odd parameter space from an electronic-structure theory perspective. Rules of thumb are derived for the choice of atoms and molecules in terms of their angular momenta and nuclear charge number. Contrary to naive expectations from $Z$-scaling laws, it is demonstrated that medium-heavy molecules with $Z\leq54$ can be of great value to tighten global bounds on P,T-violating parameters, in particular, if the number of complementary experiments increases. The model is confirmed by explicit density functional theory calculations of all relevant P,T-odd electronic structure parameters in systems that were used in past experiments or are of current interest for future experiments, respectively: the atoms Xe, Cs, Yb, Hg, Tl, Ra, Fr and the molecules CaOH, SrOH, YO, CdH, BaF, YbF, YbOH, HfF$^+$, WC, TlF, PbO, RaF, ThO, ThF$^+$ and PaF$^{3+}$.
2008.01110
Julia Gehrlein
Peter B. Denton, Julia Gehrlein, Rebekah Pestes
CP-Violating Neutrino Non-Standard Interactions in Long-Baseline-Accelerator Data
9 pages, 4 figures
Phys. Rev. Lett. 126, 051801 (2021)
10.1103/PhysRevLett.126.051801
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino oscillations in matter provide a unique probe of new physics. Leveraging the advent of neutrino appearance data from NOvA and T2K in recent years, we investigate the presence of CP-violating neutrino non-standard interactions in the oscillation data. We first show how to very simply approximate the expected NSI parameters to resolve differences between two long-baseline appearance experiments analytically. Then, by combining recent NOvA and T2K data, we find a tantalizing hint of CP-violating NSI preferring a new complex phase that is close to maximal: $\phi_{e\mu}$ or $\phi_{e\tau}\approx3\pi/2$ with $|\epsilon_{e\mu}|$ or $|\epsilon_{e\tau}|\sim0.2$. We then compare the results from long-baseline data to constraints from IceCube and COHERENT.
[ { "created": "Mon, 3 Aug 2020 18:01:58 GMT", "version": "v1" }, { "created": "Thu, 4 Feb 2021 17:08:29 GMT", "version": "v2" } ]
2021-02-05
[ [ "Denton", "Peter B.", "" ], [ "Gehrlein", "Julia", "" ], [ "Pestes", "Rebekah", "" ] ]
Neutrino oscillations in matter provide a unique probe of new physics. Leveraging the advent of neutrino appearance data from NOvA and T2K in recent years, we investigate the presence of CP-violating neutrino non-standard interactions in the oscillation data. We first show how to very simply approximate the expected NSI parameters to resolve differences between two long-baseline appearance experiments analytically. Then, by combining recent NOvA and T2K data, we find a tantalizing hint of CP-violating NSI preferring a new complex phase that is close to maximal: $\phi_{e\mu}$ or $\phi_{e\tau}\approx3\pi/2$ with $|\epsilon_{e\mu}|$ or $|\epsilon_{e\tau}|\sim0.2$. We then compare the results from long-baseline data to constraints from IceCube and COHERENT.
2207.02230
Giulio Barni Mr
Aleksandr Azatov, Giulio Barni, Sabyasachi Chakraborty, Miguel Vanvlasselaer, Wen Yin
Ultra-relativistic bubbles from the simplest Higgs portal and their cosmological consequences
30 pages + appendix, 13 figures, 4 tables, comments and feedback welcome
null
10.1007/JHEP10(2022)017
SISSA 12/2022/FISI TU-1157
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We analyze the phase transitions in the minimal extension of the SM with a real singlet scalar field. The novelty of our study is that we identify and analyze in details the region of parameter space where the first order phase transition can occur and in particular when the bubbles with true vacuum can reach relativistic velocities. This region is interesting since it can lead to the new recently discussed baryogenesis and Dark Matter production mechanisms. We fully analyze different models for the production of Dark Matter and baryogenesis as well as the possibilities of discovery at the current and future experiments.
[ { "created": "Tue, 5 Jul 2022 18:00:06 GMT", "version": "v1" } ]
2022-10-26
[ [ "Azatov", "Aleksandr", "" ], [ "Barni", "Giulio", "" ], [ "Chakraborty", "Sabyasachi", "" ], [ "Vanvlasselaer", "Miguel", "" ], [ "Yin", "Wen", "" ] ]
We analyze the phase transitions in the minimal extension of the SM with a real singlet scalar field. The novelty of our study is that we identify and analyze in details the region of parameter space where the first order phase transition can occur and in particular when the bubbles with true vacuum can reach relativistic velocities. This region is interesting since it can lead to the new recently discussed baryogenesis and Dark Matter production mechanisms. We fully analyze different models for the production of Dark Matter and baryogenesis as well as the possibilities of discovery at the current and future experiments.
hep-ph/9702387
null
J. L. Goity and Longzhe Zhang
Complete Leading Order Analysis in Chiral Perturbation Theory of the Decays $K_L\to\gamma\gamma$ and $K_L\to\ell^+\el^-\gamma$
10 pages, one table, two figures. One reference has been added and one typo in reference to Enagonio et al. has been corrected
Phys.Lett.B398:387-392,1997
10.1016/S0370-2693(97)00246-3
JLAB-THY-97-06
hep-ph
null
The decays $K_L \to \gamma\gamma$ and $K_L \to \ell^+ \ell^- \gamma$ are studied at the leading order $p^6$ in Chiral Perturbation Theory. One-loop contributions stemming from the odd intrinsic parity $|\Delta S| = 1$ effective Lagrangian of order $p^4$ are included and shown to be of possible relevance. They affect the decay $K_L \to \gamma\gamma$ adding to the usual pole terms a piece free of counterterm uncertainties. In the case of the $K_L \to \ell^+ \ell^- \gamma$ decays the dependence of the form factor on the dilepton invariant mass requires a counterterm. The form factor may receive a sizeable contribution from chiral logarithms. Including considerations from the $K_L \to \pi^+ \pi^- \gamma$ direct emission amplitude, we obtain two consistent scenarios. In one scenario the long distance contributions from the one-loop terms are important, while in the other they are marginal. In both cases the counterterm is shown to be significant.
[ { "created": "Fri, 21 Feb 1997 15:24:50 GMT", "version": "v1" }, { "created": "Mon, 24 Feb 1997 15:54:56 GMT", "version": "v2" } ]
2014-11-17
[ [ "Goity", "J. L.", "" ], [ "Zhang", "Longzhe", "" ] ]
The decays $K_L \to \gamma\gamma$ and $K_L \to \ell^+ \ell^- \gamma$ are studied at the leading order $p^6$ in Chiral Perturbation Theory. One-loop contributions stemming from the odd intrinsic parity $|\Delta S| = 1$ effective Lagrangian of order $p^4$ are included and shown to be of possible relevance. They affect the decay $K_L \to \gamma\gamma$ adding to the usual pole terms a piece free of counterterm uncertainties. In the case of the $K_L \to \ell^+ \ell^- \gamma$ decays the dependence of the form factor on the dilepton invariant mass requires a counterterm. The form factor may receive a sizeable contribution from chiral logarithms. Including considerations from the $K_L \to \pi^+ \pi^- \gamma$ direct emission amplitude, we obtain two consistent scenarios. In one scenario the long distance contributions from the one-loop terms are important, while in the other they are marginal. In both cases the counterterm is shown to be significant.
2011.01398
Ernest Ma
Ernest Ma (UC Riverside)
Dark Matter from $SU(6) \to SU(5) \times U(1)_N$
14 pages, 2 figures, version to be published in PRD
Phys. Rev. D 103, 051704 (2021)
10.1103/PhysRevD.103.L051704
UCRHEP-T603
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Matter and dark matter are unified under the framework of $SU(6)\to SU(5) \times U(1)_N$. A dark-matter candidate is possible, not because it is stable, but because it has a very long lifetime, in analogy to that of the proton in theories of grand unification. A specific example is presented.
[ { "created": "Tue, 3 Nov 2020 00:35:12 GMT", "version": "v1" }, { "created": "Wed, 3 Mar 2021 03:45:43 GMT", "version": "v2" } ]
2021-03-31
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
Matter and dark matter are unified under the framework of $SU(6)\to SU(5) \times U(1)_N$. A dark-matter candidate is possible, not because it is stable, but because it has a very long lifetime, in analogy to that of the proton in theories of grand unification. A specific example is presented.
hep-ph/0404231
Jonathan Feng
Jonathan L. Feng, Shufang Su, Fumihiro Takayama
Supergravity with a Gravitino LSP
24 pages, updated figures and minor changes, version to appear in Phys.Rev.D
Phys.Rev.D70:075019,2004
10.1103/PhysRevD.70.075019
UCI-TR-2004-11
hep-ph astro-ph hep-ex
null
We investigate supergravity models in which the lightest supersymmetric particle (LSP) is a stable gravitino. We assume that the next-lightest supersymmetric particle (NLSP) freezes out with its thermal relic density before decaying to the gravitino at time t ~ 10^4 s - 10^8 s. In contrast to studies that assume a fixed gravitino relic density, the thermal relic density assumption implies upper, not lower, bounds on superpartner masses, with important implications for particle colliders. We consider slepton, sneutrino, and neutralino NLSPs, and determine what superpartner masses are viable in all of these cases, applying CMB and electromagnetic and hadronic BBN constraints to the leading two- and three-body NLSP decays. Hadronic constraints have been neglected previously, but we find that they provide the most stringent constraints in much of the natural parameter space. We then discuss the collider phenomenology of supergravity with a gravitino LSP. We find that colliders may provide important insights to clarify BBN and the thermal history of the Universe below temperatures around 10 GeV and may even provide precise measurements of the gravitino's mass and couplings.
[ { "created": "Tue, 27 Apr 2004 19:28:24 GMT", "version": "v1" }, { "created": "Fri, 4 Feb 2005 21:27:46 GMT", "version": "v2" } ]
2008-11-26
[ [ "Feng", "Jonathan L.", "" ], [ "Su", "Shufang", "" ], [ "Takayama", "Fumihiro", "" ] ]
We investigate supergravity models in which the lightest supersymmetric particle (LSP) is a stable gravitino. We assume that the next-lightest supersymmetric particle (NLSP) freezes out with its thermal relic density before decaying to the gravitino at time t ~ 10^4 s - 10^8 s. In contrast to studies that assume a fixed gravitino relic density, the thermal relic density assumption implies upper, not lower, bounds on superpartner masses, with important implications for particle colliders. We consider slepton, sneutrino, and neutralino NLSPs, and determine what superpartner masses are viable in all of these cases, applying CMB and electromagnetic and hadronic BBN constraints to the leading two- and three-body NLSP decays. Hadronic constraints have been neglected previously, but we find that they provide the most stringent constraints in much of the natural parameter space. We then discuss the collider phenomenology of supergravity with a gravitino LSP. We find that colliders may provide important insights to clarify BBN and the thermal history of the Universe below temperatures around 10 GeV and may even provide precise measurements of the gravitino's mass and couplings.
hep-ph/9912511
Yutaka Sakamura
Yutaka Sakamura
Spontaneous CP violation model with flavor symmetry in large extra dimensions
LaTeX file, 11 page, 2eps figures, some changes included
null
null
TIT/HEP-438
hep-ph
null
We construct the minimal SUSY model that causes spontaneous CP violation with an abelian flavor symmetry in the context of the large extra dimensions and show that various phenomenological problems can be solved by introducing only scales below the low fundamental scale. We also realize the realistic size of the CP violation and the small masses of the neutrinos. The strong CP problem can be solved by the axion scenario and the axion can be made invisible by introducing an additional large extra dimension.
[ { "created": "Mon, 27 Dec 1999 05:35:54 GMT", "version": "v1" }, { "created": "Wed, 19 Jan 2000 05:19:50 GMT", "version": "v2" }, { "created": "Mon, 24 Apr 2000 07:12:53 GMT", "version": "v3" } ]
2007-05-23
[ [ "Sakamura", "Yutaka", "" ] ]
We construct the minimal SUSY model that causes spontaneous CP violation with an abelian flavor symmetry in the context of the large extra dimensions and show that various phenomenological problems can be solved by introducing only scales below the low fundamental scale. We also realize the realistic size of the CP violation and the small masses of the neutrinos. The strong CP problem can be solved by the axion scenario and the axion can be made invisible by introducing an additional large extra dimension.
hep-ph/0204321
Ho-Meoyng Choi
Ho-Meoyng Choi (Carnegie Mellon U.), Chueng-Ryong Ji (North Carolina State U.), L.S. Kisslinger (Carnegie Mellon U.)
Continuity of generalized parton distributions for the pion virtual Compton scattering
14 pages, 9 figures, we (1) changed the title, (2) added references, (3) discussed the GPD value at the crossover in Sec. III, version to appear in Phys. Rev. D
Phys.Rev. D66 (2002) 053011
10.1103/PhysRevD.66.053011
null
hep-ph
null
We discuss a consistent treatment of the light-front gauge-boson and meson wave functions in the analyses of the generalized parton distributions(GPDs) and the scattering amplitudes in deeply virtual Compton scattering(DVCS) for the pion. The continuity of the GPDs at the crossover, where the longitudinal momentum fraction of the probed quark is same with the skewedness parameter, and the finiteness of the DVCS amplitude are ensured if the same light-front radial wave function as that of the meson bound state wave function is used for the gauge boson bound state arising from the pair-creation(or nonvalence) diagram. The frame-independence of our model calculation is also guaranteed by the constraint from the sum rule between the GPDs and the form factors.
[ { "created": "Sun, 28 Apr 2002 00:53:43 GMT", "version": "v1" }, { "created": "Mon, 29 Jul 2002 16:42:03 GMT", "version": "v2" } ]
2009-11-07
[ [ "Choi", "Ho-Meoyng", "", "Carnegie Mellon U." ], [ "Ji", "Chueng-Ryong", "", "North Carolina\n State U." ], [ "Kisslinger", "L. S.", "", "Carnegie Mellon U." ] ]
We discuss a consistent treatment of the light-front gauge-boson and meson wave functions in the analyses of the generalized parton distributions(GPDs) and the scattering amplitudes in deeply virtual Compton scattering(DVCS) for the pion. The continuity of the GPDs at the crossover, where the longitudinal momentum fraction of the probed quark is same with the skewedness parameter, and the finiteness of the DVCS amplitude are ensured if the same light-front radial wave function as that of the meson bound state wave function is used for the gauge boson bound state arising from the pair-creation(or nonvalence) diagram. The frame-independence of our model calculation is also guaranteed by the constraint from the sum rule between the GPDs and the form factors.
hep-ph/9308232
Anton K. Rebhan
A. K. Rebhan
The Nonabelian Debye Mass at Next-to-Leading Order
8 pages, REVTEX v3.0, BI-TP 93/42 (minor corrections in text and references)
Phys.Rev. D48 (1993) 3967-3970
10.1103/PhysRevD.48.R3967
null
hep-ph hep-th
null
It is shown that after a resummation of leading high-temperature contributions, a complete and gauge-independent result for the nonabelian Debye screening mass at next-to-leading order can be extracted from the static gluon propagator. In contrast to previous, incomplete results, the correction to the Debye mass is found to be logarithmically sensitive to the nonperturbative magnetic mass and positive, in accordance with recent high-statistics results from lattice calculations.
[ { "created": "Thu, 5 Aug 1993 15:46:47 GMT", "version": "v1" }, { "created": "Tue, 21 Sep 1993 14:47:03 GMT", "version": "v2" } ]
2009-10-22
[ [ "Rebhan", "A. K.", "" ] ]
It is shown that after a resummation of leading high-temperature contributions, a complete and gauge-independent result for the nonabelian Debye screening mass at next-to-leading order can be extracted from the static gluon propagator. In contrast to previous, incomplete results, the correction to the Debye mass is found to be logarithmically sensitive to the nonperturbative magnetic mass and positive, in accordance with recent high-statistics results from lattice calculations.
hep-ph/0205067
Yasunori Nomura
Lawrence J. Hall and Yasunori Nomura
A Complete Theory of Grand Unification in Five Dimensions
51 pages, latex
Phys.Rev.D66:075004,2002
10.1103/PhysRevD.66.075004
UCB-PTH-02/20, LBNL-50199
hep-ph
null
A fully realistic unified theory is constructed, with SU(5) gauge symmetry and supersymmetry both broken by boundary conditions in a fifth dimension. Despite the local explicit breaking of SU(5) at a boundary of the dimension, the large size of the extra dimension allows precise predictions for gauge coupling unification, alpha_s(M_Z) = 0.118 \pm 0.003, and for Yukawa coupling unification, m_b(M_Z) = 3.3 \pm 0.2 GeV. A complete understanding of the MSSM Higgs sector is given; with explanations for why the Higgs triplets are heavy, why the Higgs doublets are protected from a large tree-level mass, and why the mu and B parameters are naturally generated to be of order the SUSY breaking scale. All sources of d=4,5 proton decay are forbidden, while a new origin for d=6 proton decay is found to be important. Several aspects of flavor follow from an essentially unique choice of matter location in the fifth dimension: only the third generation has an SU(5) mass relation, and the lighter two generations have small mixings with the heaviest generation. The entire superpartner spectrum is predicted in terms of only two free parameters. The squark and slepton masses are determined by their location in the fifth dimension, allowing a significant experimental test of the detailed structure of the extra dimension. Lepton flavor violation is found to be generically large in higher dimensional unified theories with high mediation scales of SUSY breaking. In our theory this forces a common location for all three neutrinos, predicting large neutrino mixing angles. Rates for mu -> e gamma, mu -> e e e, mu -> e conversion and tau -> mu gamma are larger in our theory than in conventional 4D supersymmetric GUTs. Proposed experiments probing mu -> e transitions will probe the entire interesting parameter space of our theory.
[ { "created": "Wed, 8 May 2002 18:50:23 GMT", "version": "v1" } ]
2009-09-29
[ [ "Hall", "Lawrence J.", "" ], [ "Nomura", "Yasunori", "" ] ]
A fully realistic unified theory is constructed, with SU(5) gauge symmetry and supersymmetry both broken by boundary conditions in a fifth dimension. Despite the local explicit breaking of SU(5) at a boundary of the dimension, the large size of the extra dimension allows precise predictions for gauge coupling unification, alpha_s(M_Z) = 0.118 \pm 0.003, and for Yukawa coupling unification, m_b(M_Z) = 3.3 \pm 0.2 GeV. A complete understanding of the MSSM Higgs sector is given; with explanations for why the Higgs triplets are heavy, why the Higgs doublets are protected from a large tree-level mass, and why the mu and B parameters are naturally generated to be of order the SUSY breaking scale. All sources of d=4,5 proton decay are forbidden, while a new origin for d=6 proton decay is found to be important. Several aspects of flavor follow from an essentially unique choice of matter location in the fifth dimension: only the third generation has an SU(5) mass relation, and the lighter two generations have small mixings with the heaviest generation. The entire superpartner spectrum is predicted in terms of only two free parameters. The squark and slepton masses are determined by their location in the fifth dimension, allowing a significant experimental test of the detailed structure of the extra dimension. Lepton flavor violation is found to be generically large in higher dimensional unified theories with high mediation scales of SUSY breaking. In our theory this forces a common location for all three neutrinos, predicting large neutrino mixing angles. Rates for mu -> e gamma, mu -> e e e, mu -> e conversion and tau -> mu gamma are larger in our theory than in conventional 4D supersymmetric GUTs. Proposed experiments probing mu -> e transitions will probe the entire interesting parameter space of our theory.
1209.1275
Yoshio Koide
Yoshio Koide and Hiroyuki Nishiura
Large $\theta_{13}^\nu$ and Unified Description of Quark and Lepton Mixing Matrices
13 pages, 3 figures, version accepted by EPJC
null
10.1140/epjc/s10052-013-2277-1
MISC-2012-17
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a revised version of the so-called "yukawaon model", which was proposed for the purpose of a unified description of the lepton mixing matrix $U_{PMNS}$ and the quark mixing matrix $V_{CKM}$. It is assumed from a phenomenological point of view that the neutrino Dirac mass matrix $M_D$ is given with a somewhat different structure from the charged lepton mass matrix $M_e$, although $M_D=M_e$ was assumed in the previous model. As a result, the revised model predicts a reasonable value $\sin^2 2\theta_{13} \sim 0.07$ with keeping successful results for other parameters in $U_{PMNS}$ as well as $V_{CKM}$ and quark and lepton mass ratios.
[ { "created": "Thu, 6 Sep 2012 13:35:29 GMT", "version": "v1" }, { "created": "Sat, 27 Oct 2012 03:54:50 GMT", "version": "v2" }, { "created": "Thu, 3 Jan 2013 03:50:49 GMT", "version": "v3" } ]
2015-06-11
[ [ "Koide", "Yoshio", "" ], [ "Nishiura", "Hiroyuki", "" ] ]
We present a revised version of the so-called "yukawaon model", which was proposed for the purpose of a unified description of the lepton mixing matrix $U_{PMNS}$ and the quark mixing matrix $V_{CKM}$. It is assumed from a phenomenological point of view that the neutrino Dirac mass matrix $M_D$ is given with a somewhat different structure from the charged lepton mass matrix $M_e$, although $M_D=M_e$ was assumed in the previous model. As a result, the revised model predicts a reasonable value $\sin^2 2\theta_{13} \sim 0.07$ with keeping successful results for other parameters in $U_{PMNS}$ as well as $V_{CKM}$ and quark and lepton mass ratios.
1106.4070
Abdelhamid Albaid
Abdelhamid Albaid
Flavor Violation in a Minimal SO(10)\times A_4 SUSY GUT
31 pages, 2 figures; International Journal of Modern Physics A, Vol.27 (2012)
null
10.1142/S0217751X12500054
OSU-HEP-11-06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavor violating processes in the quark and lepton sectors are investigated within a realistic supersymmetric $SO(10)\times A_4$ grand unification model. By employing exotic heavy fermion fields, this model successfully describes various features of the fermion masses and mixings including large neutrino mixings accompanied by small quark mixings. In this model the flavor violation is induced at GUT scale, at which $A_4$ flavor symmetry is broken, as a consequence of the large mixings of the light fermion fields with these exotic heavy fields. The stringent experimental constraint from $\mu\rightarrow e\gamma$ decay rate necessitates a high degree of degeneracy of the supersymmetry breaking soft scalar masses of the exotic heavy fields and supersymmetric scalar partners of the light fermion fields. The choice of slepton masses of order 1 TeV is found to be consistent with the constraints from branching ratio of $\mu\rightarrow e\gamma$ and with all other flavor changing neutral current processes being sufficiently suppressed.
[ { "created": "Tue, 21 Jun 2011 02:04:15 GMT", "version": "v1" }, { "created": "Tue, 27 Dec 2011 18:11:39 GMT", "version": "v2" } ]
2011-12-30
[ [ "Albaid", "Abdelhamid", "" ] ]
Flavor violating processes in the quark and lepton sectors are investigated within a realistic supersymmetric $SO(10)\times A_4$ grand unification model. By employing exotic heavy fermion fields, this model successfully describes various features of the fermion masses and mixings including large neutrino mixings accompanied by small quark mixings. In this model the flavor violation is induced at GUT scale, at which $A_4$ flavor symmetry is broken, as a consequence of the large mixings of the light fermion fields with these exotic heavy fields. The stringent experimental constraint from $\mu\rightarrow e\gamma$ decay rate necessitates a high degree of degeneracy of the supersymmetry breaking soft scalar masses of the exotic heavy fields and supersymmetric scalar partners of the light fermion fields. The choice of slepton masses of order 1 TeV is found to be consistent with the constraints from branching ratio of $\mu\rightarrow e\gamma$ and with all other flavor changing neutral current processes being sufficiently suppressed.
hep-ph/9701253
Sergei Kovalenko
M. Hirsch, H.V. Klapdor-Kleingrothaus and S.G. Kovalenko
B-L-violating Masses in Softly Broken Supersymmetry
7 pages, Latex, 1 Postscript figure
Phys.Lett. B398 (1997) 311-314
10.1016/S0370-2693(97)00234-7
null
hep-ph
null
We prove a general low-energy theorem establishing a generic relation between the neutrino Majorana mass and the superpartner sneutrino B-L-violating "Majorana"-like mass term. The theorem states that, if one of these two quantities is non-zero the other one is also non-zero and, vice versa, if one of them vanishes the other vanishes, too. The theorem is a consequence of the underlying supersymmetry (SUSY) and valid for any realistic gauge model with weak scale softly broken SUSY.
[ { "created": "Thu, 9 Jan 1997 12:11:09 GMT", "version": "v1" } ]
2009-10-30
[ [ "Hirsch", "M.", "" ], [ "Klapdor-Kleingrothaus", "H. V.", "" ], [ "Kovalenko", "S. G.", "" ] ]
We prove a general low-energy theorem establishing a generic relation between the neutrino Majorana mass and the superpartner sneutrino B-L-violating "Majorana"-like mass term. The theorem states that, if one of these two quantities is non-zero the other one is also non-zero and, vice versa, if one of them vanishes the other vanishes, too. The theorem is a consequence of the underlying supersymmetry (SUSY) and valid for any realistic gauge model with weak scale softly broken SUSY.
hep-ph/0411092
Jose L. Goity
J.L.Goity, C.Schat and N.Scoccola
Decays of Non-strange Negative Parity Baryons in the 1/Nc Expansion
24 pages, 8 tables
Phys.Rev.D71:034016,2005
10.1103/PhysRevD.71.034016
JLAB-THY-04-37
hep-ph
null
The decays of non-strange negative parity baryons via the emission of single $\pi$ and $\eta$ mesons are analyzed in the framework of the $1/N_c$ expansion. A basis of spin-flavor operators for the partial wave amplitudes is established to order $1/N_c$ and the unknown effective coefficients are determined by fitting to the S- and D-wave partial widths as provided by the Particle Data Group. A set of relations between widths that result at the leading order, i.e. order $N_c^0$, is given and tested with the available data. Up to a few exceptions, a good description of the partial decays widths is already obtained at that order. Because of the rather large errors in the empirical input data the next to leading order fit fails to pin down with satisfactory accuracy the subleading effective coefficients. The hierarchy expected from the $1/N_c$ expansion is reflected in the results.
[ { "created": "Fri, 5 Nov 2004 19:03:01 GMT", "version": "v1" }, { "created": "Fri, 5 Nov 2004 21:06:27 GMT", "version": "v2" } ]
2014-11-18
[ [ "Goity", "J. L.", "" ], [ "Schat", "C.", "" ], [ "Scoccola", "N.", "" ] ]
The decays of non-strange negative parity baryons via the emission of single $\pi$ and $\eta$ mesons are analyzed in the framework of the $1/N_c$ expansion. A basis of spin-flavor operators for the partial wave amplitudes is established to order $1/N_c$ and the unknown effective coefficients are determined by fitting to the S- and D-wave partial widths as provided by the Particle Data Group. A set of relations between widths that result at the leading order, i.e. order $N_c^0$, is given and tested with the available data. Up to a few exceptions, a good description of the partial decays widths is already obtained at that order. Because of the rather large errors in the empirical input data the next to leading order fit fails to pin down with satisfactory accuracy the subleading effective coefficients. The hierarchy expected from the $1/N_c$ expansion is reflected in the results.
hep-ph/0011300
E. Reya
M. Gluck, A. Hartl and E. Reya
On the Determination of the Polarized Sea Distributions of the Nucleon
28 pages, LaTeX
Eur.Phys.J.C19:77-87,2001
10.1007/s100520100576
DO-TH 2000/15
hep-ph
null
The possibilities to determine the flavor structure of the polarized sea (antiquark) distributions of the nucleon via vector boson $(\gamma^*, W^{\pm}, Z^0)$ production at high energy polarized hadron--hadron colliders, such as the Relativistic Heavy--Ion Collider (RHIC), are studied in detail. In particular the perturbative stability of the expected asymmetries in two representative models for the (un)broken flavor structure are investigated by confronting perturbative QCD leading order predictions of the expected asymmetries with their next--to--leading order counterparts.
[ { "created": "Fri, 24 Nov 2000 13:15:14 GMT", "version": "v1" } ]
2009-01-07
[ [ "Gluck", "M.", "" ], [ "Hartl", "A.", "" ], [ "Reya", "E.", "" ] ]
The possibilities to determine the flavor structure of the polarized sea (antiquark) distributions of the nucleon via vector boson $(\gamma^*, W^{\pm}, Z^0)$ production at high energy polarized hadron--hadron colliders, such as the Relativistic Heavy--Ion Collider (RHIC), are studied in detail. In particular the perturbative stability of the expected asymmetries in two representative models for the (un)broken flavor structure are investigated by confronting perturbative QCD leading order predictions of the expected asymmetries with their next--to--leading order counterparts.
1005.5131
Seodong Shin
Kyu Jung Bae, Hyung Do Kim, Seodong Shin
Light neutralino dark matter with a very light Higgs for CoGeNT and DAMA/LIBRA data
21 pages, 5 figures
Phys.Rev.D82:115014,2010
10.1103/PhysRevD.82.115014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, the CoGeNT collaboration reported the WIMP candidate signal events exceeding the known backgrounds where the light WIMP with large cross section is supported. Motivated by this issue, we analyze a light neutralino dark matter scenario with a very light CP-even Higgs mediation in the elastic scattering process, which provides the mass and direct detection cross section to explain the CoGeNT result. To be compatible with the result of LEP experiments, the light CP-even Higgs is favored to be in 9 to 10 GeV. Such a scenario can be realized in the "Beyond the MSSM" context. The relic abundance consistent with the WMAP result can be obtained when twice of neutralino mass is close to the light Higgs mass via the resonance enhancement of the annihilation cross section. As a result, the neutralino mass is predicted to be at around 5 to 6 GeV.
[ { "created": "Thu, 27 May 2010 17:47:13 GMT", "version": "v1" }, { "created": "Wed, 29 Dec 2010 05:32:08 GMT", "version": "v2" } ]
2010-12-30
[ [ "Bae", "Kyu Jung", "" ], [ "Kim", "Hyung Do", "" ], [ "Shin", "Seodong", "" ] ]
Recently, the CoGeNT collaboration reported the WIMP candidate signal events exceeding the known backgrounds where the light WIMP with large cross section is supported. Motivated by this issue, we analyze a light neutralino dark matter scenario with a very light CP-even Higgs mediation in the elastic scattering process, which provides the mass and direct detection cross section to explain the CoGeNT result. To be compatible with the result of LEP experiments, the light CP-even Higgs is favored to be in 9 to 10 GeV. Such a scenario can be realized in the "Beyond the MSSM" context. The relic abundance consistent with the WMAP result can be obtained when twice of neutralino mass is close to the light Higgs mass via the resonance enhancement of the annihilation cross section. As a result, the neutralino mass is predicted to be at around 5 to 6 GeV.
hep-ph/9504412
Erwin Mirkes
E. Mirkes and C.S. Kim
J/Psi Decay Lepton Distribution in Hadronic Collisions
8 pages, RevTex, 2 figures;
Phys.Lett. B346 (1995) 124-128
10.1016/0370-2693(94)01689-A
MADPH-94-860
hep-ph
null
We propose the measurement of the decay angular distribution of leptons from J/Psi's produced at high transverse momentum balanced by a photon [or gluon] in hadronic collisions. The polar and azimuthal angular distribution are calculated in the color singlet model (CSM). It is shown that the general structure of the decay lepton distribution is controlled by four invariant structure functions, which are functions of the transverse momentum and the rapidity of the J/Psi. We found that two of these structure functions [the longitudinal and transverse interference structure functions] are identical in the CSM. We present analytical and numerical results in the Collins-Soper and in the Gottfried-Jackson frame.
[ { "created": "Thu, 27 Apr 1995 16:26:48 GMT", "version": "v1" } ]
2009-10-28
[ [ "Mirkes", "E.", "" ], [ "Kim", "C. S.", "" ] ]
We propose the measurement of the decay angular distribution of leptons from J/Psi's produced at high transverse momentum balanced by a photon [or gluon] in hadronic collisions. The polar and azimuthal angular distribution are calculated in the color singlet model (CSM). It is shown that the general structure of the decay lepton distribution is controlled by four invariant structure functions, which are functions of the transverse momentum and the rapidity of the J/Psi. We found that two of these structure functions [the longitudinal and transverse interference structure functions] are identical in the CSM. We present analytical and numerical results in the Collins-Soper and in the Gottfried-Jackson frame.
1601.07832
Hiroaki Kohyama
Hiroaki Kohyama
Possible interpretation on the origin of four-fermion interaction
4 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a possible interpretation on the origin of the four-fermion interaction used in effective field theories. Inspired by the sharp momentum peak seen in Bose-Einstein condensate state, we incorporate the special gluon condensate effect into the gluon propagator. We then find that, if one considers hypothetic situation with the condensed gluon, the four-fermion contact interaction can arise from the first principle theory of quantum chromodynamics.
[ { "created": "Thu, 28 Jan 2016 17:05:42 GMT", "version": "v1" } ]
2016-01-29
[ [ "Kohyama", "Hiroaki", "" ] ]
We present a possible interpretation on the origin of the four-fermion interaction used in effective field theories. Inspired by the sharp momentum peak seen in Bose-Einstein condensate state, we incorporate the special gluon condensate effect into the gluon propagator. We then find that, if one considers hypothetic situation with the condensed gluon, the four-fermion contact interaction can arise from the first principle theory of quantum chromodynamics.
0801.4256
Wambach
P. Braun-Munzinger, J. Wambach
The Phase Diagram of Strongly-Interacting Matter
20 pages, Rev. Mod. Phys. Vol 81, (2009) 1031-1050
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A fundamental question of physics is what ultimately happens to matter as it is heated or compressed. In the realm of very high temperature and density the fundamental degrees of freedom of the strong interaction, quarks and gluons, come into play and a transition from matter consisting of confined baryons and mesons to a state with 'liberated' quarks and gluons is expected. The study of the possible phases of strongly-interacting matter is at the focus of many research activities worldwide. In this article we discuss physical aspects of the phase diagram, its relation to the evolution of the early universe as well as the inner core of neutron stars. We also summarize recent progress in the experimental study of hadronic or quark-gluon matter under extreme conditions with ultrarelativistic nucleus-nucleus collisions.
[ { "created": "Mon, 28 Jan 2008 12:39:28 GMT", "version": "v1" }, { "created": "Tue, 28 Jul 2009 13:47:48 GMT", "version": "v2" } ]
2009-07-28
[ [ "Braun-Munzinger", "P.", "" ], [ "Wambach", "J.", "" ] ]
A fundamental question of physics is what ultimately happens to matter as it is heated or compressed. In the realm of very high temperature and density the fundamental degrees of freedom of the strong interaction, quarks and gluons, come into play and a transition from matter consisting of confined baryons and mesons to a state with 'liberated' quarks and gluons is expected. The study of the possible phases of strongly-interacting matter is at the focus of many research activities worldwide. In this article we discuss physical aspects of the phase diagram, its relation to the evolution of the early universe as well as the inner core of neutron stars. We also summarize recent progress in the experimental study of hadronic or quark-gluon matter under extreme conditions with ultrarelativistic nucleus-nucleus collisions.
1212.0487
Alessandro Papa
Francesco Caporale, Dmitry Yu. Ivanov, Beatrice Murdaca, Alessandro Papa, Amedeo Perri
NLO forward jet vertex
4 pages, presented at the International Workshop 'Diffraction 2012', Puerto del Carmen (Spain), September 10-15, 2012
null
10.1063/1.4802167
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate in the BFKL approach the jet vertex relevant for the production of Mueller-Navelet jets in proton-proton collisions. We consider both cases of incoming quark and gluon and show explicitly that all infrared divergences cancel when renormalized parton densities are considered. Finally we compare our expression for the vertex with a previous calculation [1].
[ { "created": "Mon, 3 Dec 2012 18:53:15 GMT", "version": "v1" } ]
2015-06-12
[ [ "Caporale", "Francesco", "" ], [ "Ivanov", "Dmitry Yu.", "" ], [ "Murdaca", "Beatrice", "" ], [ "Papa", "Alessandro", "" ], [ "Perri", "Amedeo", "" ] ]
We calculate in the BFKL approach the jet vertex relevant for the production of Mueller-Navelet jets in proton-proton collisions. We consider both cases of incoming quark and gluon and show explicitly that all infrared divergences cancel when renormalized parton densities are considered. Finally we compare our expression for the vertex with a previous calculation [1].
hep-ph/9505292
Brian Edward Hanlon
B. E. Hanlon, G. C. Joshi
BRS Symmetry in Connes' Non-commutative Geometry
28 pages, To appear in the Journal of Physics A
J.Phys. A28 (1995) 2889-2904
10.1088/0305-4470/28/10/018
UM-P-94/80, KEK-TH-406
hep-ph
null
We extend the BRS and anti-BRS symmetry to the two point space of Connes' non-commutative model building scheme. The constraint relations are derived and the quantum Lagrangian constructed. We find that the quantum Lagrangian can be written as a functional of the curvature for symmetric gauges with the BRS, anti-BRS auxiliary field finding a geometrical interepretation as the extension of the Higgs scalar.
[ { "created": "Fri, 12 May 1995 09:18:48 GMT", "version": "v1" } ]
2009-10-28
[ [ "Hanlon", "B. E.", "" ], [ "Joshi", "G. C.", "" ] ]
We extend the BRS and anti-BRS symmetry to the two point space of Connes' non-commutative model building scheme. The constraint relations are derived and the quantum Lagrangian constructed. We find that the quantum Lagrangian can be written as a functional of the curvature for symmetric gauges with the BRS, anti-BRS auxiliary field finding a geometrical interepretation as the extension of the Higgs scalar.
hep-ph/9503370
PostDoc Its
N.G. Deshpande and Xiao-Gang He
HADRONIC PENGUINS IN $B$ DECAYS AND EXTRACTION OF $\alpha$, $\beta$ AND $\gamma$
3 pages, Talk presented at the Beyond the Standard Model IV, Lake Tahoe, California, December 13 - 18, 1994
null
null
OITS-572
hep-ph
null
Electroweak penguin operators become important when $m_t \approx 174$ GeV. We discuss their implications for measuring CP violating phases $\alpha$, $\beta$ and $\gamma$.
[ { "created": "Fri, 17 Mar 1995 23:55:41 GMT", "version": "v1" } ]
2016-09-01
[ [ "Deshpande", "N. G.", "" ], [ "He", "Xiao-Gang", "" ] ]
Electroweak penguin operators become important when $m_t \approx 174$ GeV. We discuss their implications for measuring CP violating phases $\alpha$, $\beta$ and $\gamma$.
hep-ph/9904303
Kiichi Kurosawa
K.-I. Izawa, Kiichi Kurosawa, Yasunori Nomura, T. Yanagida
Grand-Unification Scale Generation through the Anomalous U(1) Breaking
14 pages, Latex, references added
Phys.Rev.D60:115016,1999
10.1103/PhysRevD.60.115016
UT-842, YITP-99-21
hep-ph
null
We discuss the anomalous U(1) gauge symmetry as a mechanism of generating the grand-unification scale. We conclude that unification to a simple group cannot be realized unless some parameters are ``tuned'', and that models with product gauge groups are preferred. We consider the ``R-invariant natural unification'' model with gauge groups SU(5)_{GUT} \times U(3)_H. In this model the doublet-triplet splitting problem is solved and the unwanted GUT relation m_s = m_\mu is avoided maintaining m_b = m_\tau. Moreover, R-invariance suppresses the dangerous proton decays induced by dimension four and five operators.
[ { "created": "Mon, 12 Apr 1999 15:05:41 GMT", "version": "v1" }, { "created": "Mon, 27 Sep 1999 08:46:35 GMT", "version": "v2" } ]
2009-09-29
[ [ "Izawa", "K. -I.", "" ], [ "Kurosawa", "Kiichi", "" ], [ "Nomura", "Yasunori", "" ], [ "Yanagida", "T.", "" ] ]
We discuss the anomalous U(1) gauge symmetry as a mechanism of generating the grand-unification scale. We conclude that unification to a simple group cannot be realized unless some parameters are ``tuned'', and that models with product gauge groups are preferred. We consider the ``R-invariant natural unification'' model with gauge groups SU(5)_{GUT} \times U(3)_H. In this model the doublet-triplet splitting problem is solved and the unwanted GUT relation m_s = m_\mu is avoided maintaining m_b = m_\tau. Moreover, R-invariance suppresses the dangerous proton decays induced by dimension four and five operators.
1805.07344
Luis Hernandez
Alejandro Ayala, Jorge David Casta\~no-Yepes, C. A. Dominguez, S. Hernandez-Ortiz, L. A. Hernandez, M. Loewe, D. Manreza Paret and R. Zamora
Thermal corrections to the gluon magnetic Debye mass
17 pages, 3 figures. Version published in Rev. Mex. Fis
null
10.31349/RevMexFis.66.446
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the gluon polarization tensor in a thermo-magnetic environment in the strong magnetic field limit at zero and high temperature. The magnetic field effects are introduced using Schwinger's proper time method. Thermal effects are computed in the HTL approximation. At zero temperature, we reproduce the well-known result whereby for a non-vanishing quark mass, the polarization tensor reduces to the parallel structure and its coefficient develops an imaginary part corresponding to the threshold for quark-antiquark pair production. This coefficient is infrared finite and simplifies considerably when the quark mass vanishes. Keeping always the field strength as the largest energy scale, in the high temperature regime we analyze two complementary hierarchies of scales: $q^2\ll m_f^2\ll T^2$ and $m_f^2\ll q^2\ll T^2$. In the latter, we show that the polarization tensor is infrared finite as $m_f$ goes to zero. In the former, we discuss the thermal corrections to the magnetic Debye mass.
[ { "created": "Fri, 18 May 2018 17:56:40 GMT", "version": "v1" }, { "created": "Fri, 25 May 2018 19:38:13 GMT", "version": "v2" }, { "created": "Mon, 13 Jan 2020 15:12:06 GMT", "version": "v3" }, { "created": "Sun, 10 May 2020 20:16:01 GMT", "version": "v4" }, { "created": "Fri, 24 Jul 2020 16:31:55 GMT", "version": "v5" } ]
2020-07-27
[ [ "Ayala", "Alejandro", "" ], [ "Castaño-Yepes", "Jorge David", "" ], [ "Dominguez", "C. A.", "" ], [ "Hernandez-Ortiz", "S.", "" ], [ "Hernandez", "L. A.", "" ], [ "Loewe", "M.", "" ], [ "Paret", "D. Manreza", "" ], [ "Zamora", "R.", "" ] ]
We compute the gluon polarization tensor in a thermo-magnetic environment in the strong magnetic field limit at zero and high temperature. The magnetic field effects are introduced using Schwinger's proper time method. Thermal effects are computed in the HTL approximation. At zero temperature, we reproduce the well-known result whereby for a non-vanishing quark mass, the polarization tensor reduces to the parallel structure and its coefficient develops an imaginary part corresponding to the threshold for quark-antiquark pair production. This coefficient is infrared finite and simplifies considerably when the quark mass vanishes. Keeping always the field strength as the largest energy scale, in the high temperature regime we analyze two complementary hierarchies of scales: $q^2\ll m_f^2\ll T^2$ and $m_f^2\ll q^2\ll T^2$. In the latter, we show that the polarization tensor is infrared finite as $m_f$ goes to zero. In the former, we discuss the thermal corrections to the magnetic Debye mass.
1901.06787
Premomoy Ghosh
Samrangy Sadhu and Premomoy Ghosh
Anomalous features of particle production in high-multiplicity events of pp collisions at the LHC energies
11 pages 12 figures
Phys. Rev. D 99, 034020 (2019)
10.1103/PhysRevD.99.034020
null
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Prevalent models of multi-particle production in relativistic pp collisions at pre-LHC energies, fail to provide convincing explanations to certain significant features of the final-state charged particles in high-multiplicity pp events at the LHC. This article presents a study, contrasting those features, usually interpreted as collective behaviour of particle production in relativistic heavy-ion collisions, in the framework of hydrodynamic EPOS3 model, emphasizing quantitative comparison between the data and the model-based simulation in the same kinematic ranges, for better cognizance of the data. The work reveals quantitative mismatch between the data and the model.
[ { "created": "Mon, 21 Jan 2019 04:09:16 GMT", "version": "v1" } ]
2019-02-27
[ [ "Sadhu", "Samrangy", "" ], [ "Ghosh", "Premomoy", "" ] ]
Prevalent models of multi-particle production in relativistic pp collisions at pre-LHC energies, fail to provide convincing explanations to certain significant features of the final-state charged particles in high-multiplicity pp events at the LHC. This article presents a study, contrasting those features, usually interpreted as collective behaviour of particle production in relativistic heavy-ion collisions, in the framework of hydrodynamic EPOS3 model, emphasizing quantitative comparison between the data and the model-based simulation in the same kinematic ranges, for better cognizance of the data. The work reveals quantitative mismatch between the data and the model.
1512.04853
Eric S. Swanson
Eric S. Swanson
XYZ States: Theory Overview
6 pages, Proceedings of Hadron2015
null
10.1063/1.4949381
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Various ideas associated with exotic hadrons, and hadronic structure in general, are briefly reviewed.
[ { "created": "Tue, 15 Dec 2015 16:58:42 GMT", "version": "v1" } ]
2016-06-22
[ [ "Swanson", "Eric S.", "" ] ]
Various ideas associated with exotic hadrons, and hadronic structure in general, are briefly reviewed.
1712.07635
Benedict von Harling
Nayara Fonseca, Benedict von Harling, Leonardo de Lima, Camila S. Machado
A warped relaxion
38 pages, 3 figures, 4 tables; v2: several clarifications, table 3 and appendix A added, matches published version
null
10.1007/JHEP07(2018)033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a UV completion of the relaxion in a warped extra dimension. We identify the relaxion with the zero mode of the fifth component of a bulk gauge field and show how hierarchically different decay constants for this field can be achieved by different localizations of anomalous terms in the warped space. This framework may also find applications for other axion-like fields. The cutoff of the relaxion model is identified as the scale of the IR brane where the Higgs lives, which can be as high as $10^6$ GeV, while above this scale warping takes over in protecting the Higgs mass.
[ { "created": "Wed, 20 Dec 2017 18:45:30 GMT", "version": "v1" }, { "created": "Fri, 7 Sep 2018 18:39:08 GMT", "version": "v2" } ]
2018-09-11
[ [ "Fonseca", "Nayara", "" ], [ "von Harling", "Benedict", "" ], [ "de Lima", "Leonardo", "" ], [ "Machado", "Camila S.", "" ] ]
We construct a UV completion of the relaxion in a warped extra dimension. We identify the relaxion with the zero mode of the fifth component of a bulk gauge field and show how hierarchically different decay constants for this field can be achieved by different localizations of anomalous terms in the warped space. This framework may also find applications for other axion-like fields. The cutoff of the relaxion model is identified as the scale of the IR brane where the Higgs lives, which can be as high as $10^6$ GeV, while above this scale warping takes over in protecting the Higgs mass.
1006.0390
Christoph Englert
F. Campanario, C. Englert, S. Kallweit, M. Spannowsky, D. Zeppenfeld
NLO QCD corrections to WZ+jet production with leptonic decays
14 pages, 7 figures
JHEP 1007:076,2010
10.1007/JHEP07(2010)076
KA-TP-11-2010, PSI-PR-10-09, SFB/CPP-10-41
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the next-to-leading order QCD corrections to WZ+jet production at the Tevatron and the LHC, including decays of the electroweak bosons to light leptons with all off-shell effects taken into account. The corrections are sizable and have significant impact on the differential distributions.
[ { "created": "Wed, 2 Jun 2010 14:24:06 GMT", "version": "v1" } ]
2014-11-21
[ [ "Campanario", "F.", "" ], [ "Englert", "C.", "" ], [ "Kallweit", "S.", "" ], [ "Spannowsky", "M.", "" ], [ "Zeppenfeld", "D.", "" ] ]
We compute the next-to-leading order QCD corrections to WZ+jet production at the Tevatron and the LHC, including decays of the electroweak bosons to light leptons with all off-shell effects taken into account. The corrections are sizable and have significant impact on the differential distributions.
hep-ph/0205347
Rabindra Nath Mohapatra
R. N. Mohapatra and A. Perez-Lorenzana
Left-right symmetry in 5D and neutrino mass in TeV scale gravity models
20 pages; some new materials and references added
Phys.Rev.D66:035005,2002
10.1103/PhysRevD.66.035005
null
hep-ph hep-th
null
We construct a left-right symmetric model based on the gauge group $SU(2)_L\times SU(2)_R\times U(1)_{B-L}$ in five dimensions where both the gauge bosons and fermions reside in all five dimensions. The orbifold boundary conditions are used not only to break the gauge symmetry down to $SU(2)_L\times U(1)_Y\times U(1)_{Y'}$ but also to ``project'' the right handed neutrino out of the zero mode part of the spectrum, providing a new way to understand the small neutrino masses without adding (singlet) bulk neutrinos. This formulation of the left-right model has also two new features: (i) it avoids most existing phenomenological bounds on the scale of the right handed $W_R$ boson allowing for the possibility that the right handed gauge bosons could have masses under a TeV, and (ii) it predicts a stable lepton with mass of order of the inverse radius of the fifth dimension.
[ { "created": "Fri, 31 May 2002 17:09:39 GMT", "version": "v1" }, { "created": "Fri, 14 Jun 2002 16:54:39 GMT", "version": "v2" } ]
2008-11-26
[ [ "Mohapatra", "R. N.", "" ], [ "Perez-Lorenzana", "A.", "" ] ]
We construct a left-right symmetric model based on the gauge group $SU(2)_L\times SU(2)_R\times U(1)_{B-L}$ in five dimensions where both the gauge bosons and fermions reside in all five dimensions. The orbifold boundary conditions are used not only to break the gauge symmetry down to $SU(2)_L\times U(1)_Y\times U(1)_{Y'}$ but also to ``project'' the right handed neutrino out of the zero mode part of the spectrum, providing a new way to understand the small neutrino masses without adding (singlet) bulk neutrinos. This formulation of the left-right model has also two new features: (i) it avoids most existing phenomenological bounds on the scale of the right handed $W_R$ boson allowing for the possibility that the right handed gauge bosons could have masses under a TeV, and (ii) it predicts a stable lepton with mass of order of the inverse radius of the fifth dimension.
1002.1011
Roberto Contino
Roberto Contino, Christophe Grojean, Mauro Moretti, Fulvio Piccinini, Riccardo Rattazzi
Strong Double Higgs Production at the LHC
54 pages, 26 figures. v2: typos corrected, a few comments and one table added. Version published in JHEP
JHEP 1005:089,2010
10.1007/JHEP05(2010)089
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hierarchy problem and the electroweak data, together, provide a plausible motivation for considering a light Higgs emerging as a pseudo-Goldstone boson from a strongly-coupled sector. In that scenario, the rates for Higgs production and decay differ significantly from those in the Standard Model. However, one genuine strong coupling signature is the growth with energy of the scattering amplitudes among the Goldstone bosons, the longitudinally polarized vector bosons as well as the Higgs boson itself. The rate for double Higgs production in vector boson fusion is thus enhanced with respect to its negligible rate in the SM. We study that reaction in pp collisions, where the production of two Higgs bosons at high pT is associated with the emission of two forward jets. We concentrate on the decay mode hh -> WW^(*)WW^(*) and study the semi-leptonic decay chains of the W's with 2, 3 or 4 leptons in the final states. While the 3 lepton final states are the most relevant and can lead to a 3 sigma signal significance with 300 fb^{-1} collected at a 14 TeV LHC, the two same-sign lepton final states provide complementary information. We also comment on the prospects for improving the detectability of double Higgs production at the foreseen LHC energy and luminosity upgrades.
[ { "created": "Thu, 4 Feb 2010 15:07:36 GMT", "version": "v1" }, { "created": "Mon, 24 May 2010 20:04:26 GMT", "version": "v2" } ]
2014-11-20
[ [ "Contino", "Roberto", "" ], [ "Grojean", "Christophe", "" ], [ "Moretti", "Mauro", "" ], [ "Piccinini", "Fulvio", "" ], [ "Rattazzi", "Riccardo", "" ] ]
The hierarchy problem and the electroweak data, together, provide a plausible motivation for considering a light Higgs emerging as a pseudo-Goldstone boson from a strongly-coupled sector. In that scenario, the rates for Higgs production and decay differ significantly from those in the Standard Model. However, one genuine strong coupling signature is the growth with energy of the scattering amplitudes among the Goldstone bosons, the longitudinally polarized vector bosons as well as the Higgs boson itself. The rate for double Higgs production in vector boson fusion is thus enhanced with respect to its negligible rate in the SM. We study that reaction in pp collisions, where the production of two Higgs bosons at high pT is associated with the emission of two forward jets. We concentrate on the decay mode hh -> WW^(*)WW^(*) and study the semi-leptonic decay chains of the W's with 2, 3 or 4 leptons in the final states. While the 3 lepton final states are the most relevant and can lead to a 3 sigma signal significance with 300 fb^{-1} collected at a 14 TeV LHC, the two same-sign lepton final states provide complementary information. We also comment on the prospects for improving the detectability of double Higgs production at the foreseen LHC energy and luminosity upgrades.
hep-ph/0305323
Eri Asakawa
Eri Asakawa, and Kaoru Hagiwara
Probing the CP nature of the Higgs bosons by top-pair production at photon linear colliders
34 pages, LATEX file with 6 PS figures, comments added
Eur.Phys.J.C31:351-364,2003
10.1140/epjc/s2003-01280-7
UT-ICEPP 03-04 and KEK-TH-888
hep-ph
null
We study effects of heavy Higgs bosons on the top-pair production process at photon linear colliders. The interference patterns between the resonant Higgs-production amplitudes and the continuum QED amplitudes are examined. The patterns tell us not only the CP nature of the Higgs bosons but also the phase of the $\gamma\gamma$--Higgs vertex which gives new information about the Higgs couplings to new charged particles. We point out that it is necessary to use circularly polarized photon beams to produce efficiently heavy Higgs bosons whose masses exceed the electron beam energy, and show that the above interference patterns of the production amplitudes can be studied by observing top decay angular distributions. Analytic expressions for the helicity amplitudes for the sequential process $\gamma\gamma \to t \bar{t} \to (bW^+) (\bar{b}W^-) \to (b f_1 \bar{f}_2) (\bar{b} f_3 \bar{f}_4)$ are presented in terms of the generic $\gamma\gamma \to t \bar{t}$ production amplitudes.
[ { "created": "Thu, 29 May 2003 15:32:14 GMT", "version": "v1" }, { "created": "Fri, 30 May 2003 12:52:30 GMT", "version": "v2" } ]
2011-07-19
[ [ "Asakawa", "Eri", "" ], [ "Hagiwara", "Kaoru", "" ] ]
We study effects of heavy Higgs bosons on the top-pair production process at photon linear colliders. The interference patterns between the resonant Higgs-production amplitudes and the continuum QED amplitudes are examined. The patterns tell us not only the CP nature of the Higgs bosons but also the phase of the $\gamma\gamma$--Higgs vertex which gives new information about the Higgs couplings to new charged particles. We point out that it is necessary to use circularly polarized photon beams to produce efficiently heavy Higgs bosons whose masses exceed the electron beam energy, and show that the above interference patterns of the production amplitudes can be studied by observing top decay angular distributions. Analytic expressions for the helicity amplitudes for the sequential process $\gamma\gamma \to t \bar{t} \to (bW^+) (\bar{b}W^-) \to (b f_1 \bar{f}_2) (\bar{b} f_3 \bar{f}_4)$ are presented in terms of the generic $\gamma\gamma \to t \bar{t}$ production amplitudes.
2305.16403
Sirshendu Samanta
Biswarup Mukhopadhyaya, Sirshendu Samanta, Tousik Samui, Ritesh K. Singh
Novel signals for the Type-X two Higgs doublet scenario at the Large Hadron Collider
16 pages, 3 figures, 4 tables
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider, in the context of the Large Hadron Collider, the signals of the Type-X two Higgs doublet model (2HDM) in the parameter region answering to the best possible solution to the muon $(g-2)$ data within this framework. The analysis takes into account all theoretical and observational constraints, and is based on the final state comprising a same-sign dilepton pair and a pair of same-sign $\tau$ jets. The crucial ingredient in making the signal clean is the same-sign feature of both the dilepton and the $\tau$-jet pair individually. After a detailed estimate of the signal and all noteworthy backgrounds, we show that this channel offers by far the best signal significance among those studied so far, predicting discovery with an integrated luminosity of 3000 fb$^{-1}$, and strong indications even with 1000 fb$^{-1}$ if systematic uncertainies do not exceed about 10%. We also demonstrate that the recently developed dynamic radius jet algorithm is effective in this connection.
[ { "created": "Thu, 25 May 2023 18:11:07 GMT", "version": "v1" } ]
2023-05-29
[ [ "Mukhopadhyaya", "Biswarup", "" ], [ "Samanta", "Sirshendu", "" ], [ "Samui", "Tousik", "" ], [ "Singh", "Ritesh K.", "" ] ]
We consider, in the context of the Large Hadron Collider, the signals of the Type-X two Higgs doublet model (2HDM) in the parameter region answering to the best possible solution to the muon $(g-2)$ data within this framework. The analysis takes into account all theoretical and observational constraints, and is based on the final state comprising a same-sign dilepton pair and a pair of same-sign $\tau$ jets. The crucial ingredient in making the signal clean is the same-sign feature of both the dilepton and the $\tau$-jet pair individually. After a detailed estimate of the signal and all noteworthy backgrounds, we show that this channel offers by far the best signal significance among those studied so far, predicting discovery with an integrated luminosity of 3000 fb$^{-1}$, and strong indications even with 1000 fb$^{-1}$ if systematic uncertainies do not exceed about 10%. We also demonstrate that the recently developed dynamic radius jet algorithm is effective in this connection.
hep-ph/9705225
Zhang Wei-Ming
Wei-Min Zhang (Institute of Physics, Academia Sinica, Taipei)
Light-Front QCD and Heavy Quark Systems
lecture notes, 45 pages. Based on lectures delivered at the First International School on Light-Front Quantization and Non-Perturbative QCD, May 6 - June 2, 1996, International Institute of Theoretical and Applied Physics, Iowa State University, Ames, IA, U.S.A
null
null
null
hep-ph
null
In this series of lectures, I shall begin with the current investigations on phenomenology of hadron dynamics to demonstrate the importance of solving hadronic bound states within the framework of light-front (LF) QCD. Then, I will describe the basic procedure how to formulate the canonical theory of LFQCD, including light-front quantization of QCD, light-front gauge singularity, and light-front two-component formalism. I will also present a complete one-loop QCD calculation in terms of the light-front time-ordering perturbation theory, in comparison with the usual covariant perturbative QCD calculation. Following thereby I will discuss the development of heavy-quark effective theory and the manifestation of heavy quark symmetry on the light-front. Finally, by applying recently developed similarity renormalization group approach to light-front heavy quark effective theory, I will show a rigorous derivation of quark confinement interaction from LFQCD and its application to solve heavy hadron bound states.
[ { "created": "Sun, 4 May 1997 15:46:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zhang", "Wei-Min", "", "Institute of Physics, Academia Sinica, Taipei" ] ]
In this series of lectures, I shall begin with the current investigations on phenomenology of hadron dynamics to demonstrate the importance of solving hadronic bound states within the framework of light-front (LF) QCD. Then, I will describe the basic procedure how to formulate the canonical theory of LFQCD, including light-front quantization of QCD, light-front gauge singularity, and light-front two-component formalism. I will also present a complete one-loop QCD calculation in terms of the light-front time-ordering perturbation theory, in comparison with the usual covariant perturbative QCD calculation. Following thereby I will discuss the development of heavy-quark effective theory and the manifestation of heavy quark symmetry on the light-front. Finally, by applying recently developed similarity renormalization group approach to light-front heavy quark effective theory, I will show a rigorous derivation of quark confinement interaction from LFQCD and its application to solve heavy hadron bound states.
1407.7082
Kazunori Nakayama
Kazunori Nakayama, Fuminobu Takahashi, Tsutomu T. Yanagida
Polynomial Chaotic Inflation in Supergravity Revisited
13 pages, 6 figures
null
10.1016/j.physletb.2014.08.043
UT-14-34, TU-977, IPMU14-0223
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit a polynomial chaotic inflation model in supergravity which we proposed soon after the Planck first data release. Recently some issues have been raised in Ref.[12], concerning the validity of our polynomial chaotic inflation model. We study the inflaton dynamics in detail, and confirm that the inflaton potential is very well approximated by a polynomial potential for the parameters of our interest in any practical sense, and in particular, the spectral index and the tensor-to-scalar ratio can be estimated by single-field approximation. This justifies our analysis of the polynomial chaotic inflation in supergravity.
[ { "created": "Sat, 26 Jul 2014 02:38:40 GMT", "version": "v1" } ]
2015-06-22
[ [ "Nakayama", "Kazunori", "" ], [ "Takahashi", "Fuminobu", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
We revisit a polynomial chaotic inflation model in supergravity which we proposed soon after the Planck first data release. Recently some issues have been raised in Ref.[12], concerning the validity of our polynomial chaotic inflation model. We study the inflaton dynamics in detail, and confirm that the inflaton potential is very well approximated by a polynomial potential for the parameters of our interest in any practical sense, and in particular, the spectral index and the tensor-to-scalar ratio can be estimated by single-field approximation. This justifies our analysis of the polynomial chaotic inflation in supergravity.
1206.0987
Asan Damanik
Asan Damanik
Nonzero $\theta_{13}$ and Neutrino Masses from the Modified Tribimaximal Neutrino Mixing Matrix
6 pages, no figure, typos corrected, talk given at 24th Rencontres de Blois 2012: Particle Physics and Cosmology, Chateau Royal de Blois, France, 27 May-1 June 2012, published in EJTP with permission from the 24th Rencontres de Blois 2012 Organizer
EJTP 11, No. 31 (2014) 125-130
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to accommodate nonzero and relatively large of mixing angle $\theta_{13}$, we modified the tribimaximal mixing(TBM) matrix by introducing a simple perturbation matrix to perturb TBM matrix. The modified TBM can reproduce nonzero mixing angle $\theta_{13}=7.9^{0}$ which is in agreement with the present experimental results. By imposing two zeros texture into the obtained neutrino mass matrix from modified TBM, we then have the neutrino mass spectrum in normal hierarchy. Some phenomenological implications are also discussed
[ { "created": "Tue, 5 Jun 2012 16:54:57 GMT", "version": "v1" }, { "created": "Sat, 9 Jun 2012 16:20:44 GMT", "version": "v2" }, { "created": "Tue, 26 Jun 2012 18:33:35 GMT", "version": "v3" }, { "created": "Fri, 26 Jul 2013 11:08:54 GMT", "version": "v4" }, { "created": "Thu, 30 Jan 2014 21:16:30 GMT", "version": "v5" }, { "created": "Wed, 23 Dec 2015 02:37:31 GMT", "version": "v6" } ]
2015-12-24
[ [ "Damanik", "Asan", "" ] ]
In order to accommodate nonzero and relatively large of mixing angle $\theta_{13}$, we modified the tribimaximal mixing(TBM) matrix by introducing a simple perturbation matrix to perturb TBM matrix. The modified TBM can reproduce nonzero mixing angle $\theta_{13}=7.9^{0}$ which is in agreement with the present experimental results. By imposing two zeros texture into the obtained neutrino mass matrix from modified TBM, we then have the neutrino mass spectrum in normal hierarchy. Some phenomenological implications are also discussed
1601.00293
Dimiter Hadjimichef
Dimiter Hadjimichef
Massive dark photons in a Higgs portal model
null
null
10.1063/1.4937205
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An extension of the Standard Model with a hidden sector which consists of gauge singlets (a Dirac fermion $\chi$ and a scalar $S$) plus a vector boson $V_\mu$ (dark massive photon) is studied. The singlet scalar interacts with the Standard Model sector through the triple and quartic scalar interactions, while the singlet fermion and vector boson field interact with the Standard Model only via the singlet scalar. The scalar field generates the vector boson's mass. Perspectives for future $e^{-}e^{+}$ colliders is considered.
[ { "created": "Sun, 3 Jan 2016 13:21:40 GMT", "version": "v1" } ]
2016-01-08
[ [ "Hadjimichef", "Dimiter", "" ] ]
An extension of the Standard Model with a hidden sector which consists of gauge singlets (a Dirac fermion $\chi$ and a scalar $S$) plus a vector boson $V_\mu$ (dark massive photon) is studied. The singlet scalar interacts with the Standard Model sector through the triple and quartic scalar interactions, while the singlet fermion and vector boson field interact with the Standard Model only via the singlet scalar. The scalar field generates the vector boson's mass. Perspectives for future $e^{-}e^{+}$ colliders is considered.
1712.01230
Patricia Magalh\~aes
Ignacio Bediaga, Tobias Frederico and Patricia C Magalh\~aes
Charm Penguin in $B^\pm \to K^\pm K^+ K^-$: partonic and hadronic loops
null
null
10.1016/j.physletb.2018.02.062
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charm penguin diagrams are known to be the main contribution to charmless B decay process with strangeness variation equal to minus one, which is the case of $B^\pm \to K^\pm K^+ K^-$ decay. The large phase space available in this and other B three-body decays allows non trivial final state interactions with all sort of rescattering processes and also access high momentum transfers in the central region of the Dalitz plane. In this work we investigate the charm Penguin contribution to $B^\pm \to K^\pm K^+ K^-$, described by a hadronic triangle loop in nonperturbative regions of the phase space, and by a partonic loop at the quasi perturbative region. These nonresonant amplitudes should have a particular structure in the Dalitz plane and their contributions to the final decay amplitude can be confirmed by a data amplitude analysis in this channel. In particular, the hadronic amplitude has a changing sign in the phase at $D\bar{D}$ threshold which can result in a change of sign for the CP asymmetry.
[ { "created": "Mon, 4 Dec 2017 18:10:46 GMT", "version": "v1" } ]
2018-04-18
[ [ "Bediaga", "Ignacio", "" ], [ "Frederico", "Tobias", "" ], [ "Magalhães", "Patricia C", "" ] ]
Charm penguin diagrams are known to be the main contribution to charmless B decay process with strangeness variation equal to minus one, which is the case of $B^\pm \to K^\pm K^+ K^-$ decay. The large phase space available in this and other B three-body decays allows non trivial final state interactions with all sort of rescattering processes and also access high momentum transfers in the central region of the Dalitz plane. In this work we investigate the charm Penguin contribution to $B^\pm \to K^\pm K^+ K^-$, described by a hadronic triangle loop in nonperturbative regions of the phase space, and by a partonic loop at the quasi perturbative region. These nonresonant amplitudes should have a particular structure in the Dalitz plane and their contributions to the final decay amplitude can be confirmed by a data amplitude analysis in this channel. In particular, the hadronic amplitude has a changing sign in the phase at $D\bar{D}$ threshold which can result in a change of sign for the CP asymmetry.
0710.3339
Gang Hao
Gang Hao, Cong-Feng Qiao, Peng Sun
Investigation of the bottomonium ground state \eta_b via its inclusive charm decays
Minor corrections and References added;to appear in PRD
Phys.Rev.D76:125013,2007
10.1103/PhysRevD.76.125013
GUCAS-CPS-07-007
hep-ph hep-ex
null
Based on the non-relativistic QCD factorization formalism, we calculate the bottomonium ground state, $\eta_b$, inclusive charm decays at the leading order in the strong coupling constant $\alpha_s$ and quarkonium internal relative velocity $v$. The inclusive charm pair production in $\eta_b$ decay is mainly realized through $\eta_b \to c \bar{c} g$ process, where the charm and anti-charm quarks then dominantly hadronize into charmed hadrons. The momentum distributions of the final states are presented. In this work, we also calculate the $J/\psi$ inclusive production rate in the $\eta_b$ decays, where the color-octet contribution is found to be very important. We expect this study may shed some light on finding $\eta_b$ or knowing more about its nature.
[ { "created": "Wed, 17 Oct 2007 16:09:09 GMT", "version": "v1" }, { "created": "Fri, 19 Oct 2007 07:40:58 GMT", "version": "v2" }, { "created": "Wed, 21 Nov 2007 14:09:21 GMT", "version": "v3" } ]
2008-11-26
[ [ "Hao", "Gang", "" ], [ "Qiao", "Cong-Feng", "" ], [ "Sun", "Peng", "" ] ]
Based on the non-relativistic QCD factorization formalism, we calculate the bottomonium ground state, $\eta_b$, inclusive charm decays at the leading order in the strong coupling constant $\alpha_s$ and quarkonium internal relative velocity $v$. The inclusive charm pair production in $\eta_b$ decay is mainly realized through $\eta_b \to c \bar{c} g$ process, where the charm and anti-charm quarks then dominantly hadronize into charmed hadrons. The momentum distributions of the final states are presented. In this work, we also calculate the $J/\psi$ inclusive production rate in the $\eta_b$ decays, where the color-octet contribution is found to be very important. We expect this study may shed some light on finding $\eta_b$ or knowing more about its nature.
hep-ph/0401195
Maxim Pospelov
Chris Bird, Paul Jackson, Robert Kowalewski, and Maxim Pospelov
Search for Dark Matter in b -> s Transitions with Missing Energy
4 pages, 2 figures. A minor misprint corrected
Phys.Rev.Lett.93:201803,2004
10.1103/PhysRevLett.93.201803
UVIC-TH/04-02
hep-ph astro-ph
null
Dedicated underground experiments searching for dark matter have little sensitivity to GeV and sub-GeV masses of dark matter particles. We show that the decay of B mesons to K(K^*) and missing energy in the final state can be an efficient probe of dark matter models in this mass range. We analyze the minimal scalar dark matter model to show that the width of the decay mode with two dark matter scalars B\to KSS may exceed the decay width in the Standard Model channel, B\to K\nu\bar\nu, by up to two orders of magnitude. Existing data from B physics experiments almost entirely exclude dark matter scalars with masses less than 1 GeV. Expected data from B factories will probe the range of dark matter masses up to 2 GeV.
[ { "created": "Sat, 24 Jan 2004 21:03:17 GMT", "version": "v1" }, { "created": "Sat, 12 Jun 2004 15:35:39 GMT", "version": "v2" }, { "created": "Mon, 13 Sep 2004 14:29:31 GMT", "version": "v3" }, { "created": "Fri, 8 Oct 2004 21:17:38 GMT", "version": "v4" } ]
2008-11-26
[ [ "Bird", "Chris", "" ], [ "Jackson", "Paul", "" ], [ "Kowalewski", "Robert", "" ], [ "Pospelov", "Maxim", "" ] ]
Dedicated underground experiments searching for dark matter have little sensitivity to GeV and sub-GeV masses of dark matter particles. We show that the decay of B mesons to K(K^*) and missing energy in the final state can be an efficient probe of dark matter models in this mass range. We analyze the minimal scalar dark matter model to show that the width of the decay mode with two dark matter scalars B\to KSS may exceed the decay width in the Standard Model channel, B\to K\nu\bar\nu, by up to two orders of magnitude. Existing data from B physics experiments almost entirely exclude dark matter scalars with masses less than 1 GeV. Expected data from B factories will probe the range of dark matter masses up to 2 GeV.