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1004.3054
Pedro Bicudo
Pedro Bicudo
Confinement and chiral symmetry breaking, one or two critical points?
5 pages, 4 figures, contribution submitted to the XLVIII International Winter Meeting on Nuclear Physics, BORMIO2010 January 25-29, 2010 Bormio, Italy
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the QCD phase diagram, in particular we study the critical points of the two main QCD phase transitions, confinement and chiral symmetry breaking. Confinement drives chiral symmetry breaking, and, due to the finite quark mass, at small density both transitions are a crossover, while they are a first or second order phase transition in large density. We study the QCD phase diagram with a quark potential model including both confinement and chiral symmetry. This formalism, in the Coulomb gauge hamiltonian formalism of QCD, is presently the only one able to microscopically include both a quark-antiquark confining potential and a vacuum condensate of quark-antiquark pairs. Our order parameters are the Polyakov loop and the quark mass gap. The confining potential is extracted from the Lattice QCD data of the Bielefeld group. We scan the QCD phase diagram for different quark masses, in order to address how the quark masses affect the critical point location in the phase diagram.
[ { "created": "Sun, 18 Apr 2010 19:40:55 GMT", "version": "v1" } ]
2010-04-20
[ [ "Bicudo", "Pedro", "" ] ]
We study the QCD phase diagram, in particular we study the critical points of the two main QCD phase transitions, confinement and chiral symmetry breaking. Confinement drives chiral symmetry breaking, and, due to the finite quark mass, at small density both transitions are a crossover, while they are a first or second order phase transition in large density. We study the QCD phase diagram with a quark potential model including both confinement and chiral symmetry. This formalism, in the Coulomb gauge hamiltonian formalism of QCD, is presently the only one able to microscopically include both a quark-antiquark confining potential and a vacuum condensate of quark-antiquark pairs. Our order parameters are the Polyakov loop and the quark mass gap. The confining potential is extracted from the Lattice QCD data of the Bielefeld group. We scan the QCD phase diagram for different quark masses, in order to address how the quark masses affect the critical point location in the phase diagram.
1411.6222
Konstantin Astapov
K. O. Astapov, S. V. Demidov
Sgoldstino-Higgs mixing in models with low-scale supersymmetry breaking
34 pages, 14 figures. Reference has been added, misprints eliminated
null
10.1007/JHEP01(2015)136
INR-TH/2014-028
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a supersymmetric extension of the Standard Model with low-scale supersymmetry breaking. Besides usual superpartners it contains additional chiral goldstino supermultiplet whose scalar components - sgoldstinos can mix with scalars from the Higgs sector of the model. We show that this mixing can have considerable impact on phenomenology of the lightest Higgs boson and scalar sgoldstino. In particular, the latter can be a good candidate for explanation of 2-sigma LEP excess with mass around 98 GeV.
[ { "created": "Sun, 23 Nov 2014 10:39:36 GMT", "version": "v1" }, { "created": "Sun, 1 Feb 2015 11:09:57 GMT", "version": "v2" } ]
2015-02-03
[ [ "Astapov", "K. O.", "" ], [ "Demidov", "S. V.", "" ] ]
We consider a supersymmetric extension of the Standard Model with low-scale supersymmetry breaking. Besides usual superpartners it contains additional chiral goldstino supermultiplet whose scalar components - sgoldstinos can mix with scalars from the Higgs sector of the model. We show that this mixing can have considerable impact on phenomenology of the lightest Higgs boson and scalar sgoldstino. In particular, the latter can be a good candidate for explanation of 2-sigma LEP excess with mass around 98 GeV.
2312.13345
Da Liu
Hannah Day, Da Liu, Markus A. Luty, Yue Zhao
Blowing in the Dark Matter Wind
26 pages, 3 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Interactions between dark matter and ordinary matter will transfer momentum, and therefore give rise to a force on ordinary matter due to the dark matter `wind.' We present a realistic model of dark matter where this force can be maximal, meaning that an order-1 fraction of the dark matter momentum incident on a target of ordinary matter is reflected. The model consists of light m_\phi \sim eV scalar dark matter with an effective interaction \phi^2 \bar{\psi}\psi, where \psi is an electron or nucleon field. If the coupling is repulsive and sufficiently strong, the field \phi is excluded from ordinary matter, analogous to the Meissner effect for photons in a superconductor. We show that there is a large region of parameter space that is compatible with existing constraints, and which can be probed by sensitive force experiments, such as satellite tests of the equivalence principle and torsion balance experiments.
[ { "created": "Wed, 20 Dec 2023 19:00:01 GMT", "version": "v1" } ]
2023-12-22
[ [ "Day", "Hannah", "" ], [ "Liu", "Da", "" ], [ "Luty", "Markus A.", "" ], [ "Zhao", "Yue", "" ] ]
Interactions between dark matter and ordinary matter will transfer momentum, and therefore give rise to a force on ordinary matter due to the dark matter `wind.' We present a realistic model of dark matter where this force can be maximal, meaning that an order-1 fraction of the dark matter momentum incident on a target of ordinary matter is reflected. The model consists of light m_\phi \sim eV scalar dark matter with an effective interaction \phi^2 \bar{\psi}\psi, where \psi is an electron or nucleon field. If the coupling is repulsive and sufficiently strong, the field \phi is excluded from ordinary matter, analogous to the Meissner effect for photons in a superconductor. We show that there is a large region of parameter space that is compatible with existing constraints, and which can be probed by sensitive force experiments, such as satellite tests of the equivalence principle and torsion balance experiments.
hep-ph/9401250
PostDoc Its
R. Foot, X.-G. He, H. Lew and R. R. Volkas
Model for a Light Z' Boson
20 pages + 5 pages of figures (appended as postscipt files), LaTeX, OITS-532
Phys.Rev. D50 (1994) 4571-4580
10.1103/PhysRevD.50.4571
null
hep-ph
null
A model of a light $Z'$ boson is constructed and phenomenological bounds are derived. This $Z'$ boson arises from a very simple extension to the Standard Model, and it is constrained to be light because the vacuum expectation values which generate its mass also break the electroweak gauge group. It is difficult to detect experimentally because it couples exclusively or primarily (depending on symmetry breaking details) to second and third generation leptons. However, if the $Z'$ boson is sufficiently light, then there exists the possibility of the two-body decay $\tau \rightarrow \mu Z'$ occuring. This will provide a striking signature to test the model.
[ { "created": "Thu, 13 Jan 1994 23:55:02 GMT", "version": "v1" } ]
2009-10-28
[ [ "Foot", "R.", "" ], [ "He", "X. -G.", "" ], [ "Lew", "H.", "" ], [ "Volkas", "R. R.", "" ] ]
A model of a light $Z'$ boson is constructed and phenomenological bounds are derived. This $Z'$ boson arises from a very simple extension to the Standard Model, and it is constrained to be light because the vacuum expectation values which generate its mass also break the electroweak gauge group. It is difficult to detect experimentally because it couples exclusively or primarily (depending on symmetry breaking details) to second and third generation leptons. However, if the $Z'$ boson is sufficiently light, then there exists the possibility of the two-body decay $\tau \rightarrow \mu Z'$ occuring. This will provide a striking signature to test the model.
2009.03909
Renato Fonseca
Andreas Ekstedt, Renato M. Fonseca and Michal Malinsk\'y
Flavorgenesis
9 pages
null
10.1016/j.physletb.2021.136212
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model where all fermions are contained in a single irreducible representation of an SU(19) gauge symmetry group. If there is only one scalar field, Yukawa interactions are controlled by a single number rather than by one or more $3\times3$ matrices of couplings. The low-energy concept of flavor emerges entirely from the scalar-sector parameters; more specifically, entries of the Standard Model Yukawa matrices are controlled by several vacuum expectation values.
[ { "created": "Tue, 8 Sep 2020 18:00:02 GMT", "version": "v1" } ]
2021-03-17
[ [ "Ekstedt", "Andreas", "" ], [ "Fonseca", "Renato M.", "" ], [ "Malinský", "Michal", "" ] ]
We present a model where all fermions are contained in a single irreducible representation of an SU(19) gauge symmetry group. If there is only one scalar field, Yukawa interactions are controlled by a single number rather than by one or more $3\times3$ matrices of couplings. The low-energy concept of flavor emerges entirely from the scalar-sector parameters; more specifically, entries of the Standard Model Yukawa matrices are controlled by several vacuum expectation values.
1408.3545
Evangelos Matsinos
Evangelos Matsinos and G\"unther Rasche
The propagation of a massive spin-$\frac{3}{2}$ field, with application to $\pi N$ scattering
36 pages, 1 table, 3 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present paper, we investigate the propagation of a massive spin-$\frac{3}{2}$ field, aiming at a direct application in hadronic models of the pion-nucleon ($\pi N$) interaction. Suitable expressions for the contributions to the standard invariant amplitudes $A$ and $B$ are derived, applicable in the general case of isospin decomposition. We first deal with the details of the lengthy calculation involving the Rarita-Schwinger propagator and confirm the validity of the expressions which had appeared in the literature in the early 1970s. We subsequently derive the corresponding contributions when following two other approaches, one featuring the Williams propagator, the other being known as Pascalutsa's method.
[ { "created": "Fri, 15 Aug 2014 14:42:25 GMT", "version": "v1" } ]
2014-08-18
[ [ "Matsinos", "Evangelos", "" ], [ "Rasche", "Günther", "" ] ]
In the present paper, we investigate the propagation of a massive spin-$\frac{3}{2}$ field, aiming at a direct application in hadronic models of the pion-nucleon ($\pi N$) interaction. Suitable expressions for the contributions to the standard invariant amplitudes $A$ and $B$ are derived, applicable in the general case of isospin decomposition. We first deal with the details of the lengthy calculation involving the Rarita-Schwinger propagator and confirm the validity of the expressions which had appeared in the literature in the early 1970s. We subsequently derive the corresponding contributions when following two other approaches, one featuring the Williams propagator, the other being known as Pascalutsa's method.
hep-ph/9305227
null
Tanguy Altherr and David Seibert
Thermal quark production in pure glue and quark gluon plasmas
7 pages, 5 figures (available upon request), CERN preprint CERN-TH-6882/93
Phys.Lett. B313 (1993) 149-154; Erratum-ibid. B316 (1993) 633
10.1016/0370-2693(93)91204-Z
null
hep-ph nucl-th
null
We calculate production rates for massless $(u,d)$ and massive $(s,c,b)$ quarks in pure glue and quark gluon plasmas to leading order in the strong coupling constant $g$. The leading contribution comes from gluon decay into $q\bar q$ pairs, using a thermal gluon propagator with finite thermal mass and damping rate. The rate behaves as $\alpha_S^2(\ln 1/\alpha_S)^2 T^4$ when $m, \alpha_S \rightarrow 0$ and depends linearly on the transverse gluon damping rate for all values of the quark mass $m$. The light quark ($u$, $d$, $s$) chemical equilibration time is approximately 10-100 $T^{-1}$ for $g=$2-3, so that quarks are likely to remain far from chemical equilibrium in ultrarelativistic nuclear collisions.
[ { "created": "Fri, 7 May 1993 17:24:23 GMT", "version": "v1" } ]
2009-10-22
[ [ "Altherr", "Tanguy", "" ], [ "Seibert", "David", "" ] ]
We calculate production rates for massless $(u,d)$ and massive $(s,c,b)$ quarks in pure glue and quark gluon plasmas to leading order in the strong coupling constant $g$. The leading contribution comes from gluon decay into $q\bar q$ pairs, using a thermal gluon propagator with finite thermal mass and damping rate. The rate behaves as $\alpha_S^2(\ln 1/\alpha_S)^2 T^4$ when $m, \alpha_S \rightarrow 0$ and depends linearly on the transverse gluon damping rate for all values of the quark mass $m$. The light quark ($u$, $d$, $s$) chemical equilibration time is approximately 10-100 $T^{-1}$ for $g=$2-3, so that quarks are likely to remain far from chemical equilibrium in ultrarelativistic nuclear collisions.
1509.08125
Maarten F. L. Golterman
Diogo Boito, Anthony Francis, Maarten Golterman, Renwick Hudspith, Randy Lewis, Kim Maltman, Santiago Peris
Low-energy constants from ALEPH hadronic tau decay data
6 pages, contribution to the proceedings of Chiral Dynamics 2015; reference corrected
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determined the NLO chiral low-energy constant $L_{10}$, and various combinations of NNLO chiral low-energy constants employing recently revised ALEPH results for the non-strange vector (V) and axial-vector (A) hadronic tau decay distributions and recently updated RBC/UKQCD lattice data for the non-strange V-A two-point function. In this talk, we explain the ingredients of this determination. Our errors are at or below the level expected for contributions of yet higher order in the chiral expansion, suggesting that our results exhaust the possibilities of what can be meaningfully achieved in an NNLO analysis.
[ { "created": "Sun, 27 Sep 2015 19:12:35 GMT", "version": "v1" }, { "created": "Wed, 30 Sep 2015 16:47:52 GMT", "version": "v2" } ]
2015-10-01
[ [ "Boito", "Diogo", "" ], [ "Francis", "Anthony", "" ], [ "Golterman", "Maarten", "" ], [ "Hudspith", "Renwick", "" ], [ "Lewis", "Randy", "" ], [ "Maltman", "Kim", "" ], [ "Peris", "Santiago", "" ] ]
We determined the NLO chiral low-energy constant $L_{10}$, and various combinations of NNLO chiral low-energy constants employing recently revised ALEPH results for the non-strange vector (V) and axial-vector (A) hadronic tau decay distributions and recently updated RBC/UKQCD lattice data for the non-strange V-A two-point function. In this talk, we explain the ingredients of this determination. Our errors are at or below the level expected for contributions of yet higher order in the chiral expansion, suggesting that our results exhaust the possibilities of what can be meaningfully achieved in an NNLO analysis.
1411.1054
JiJi Fan
JiJi Fan, Matthew Reece and Lian-Tao Wang
Possible Futures of Electroweak Precision: ILC, FCC-ee, and CEPC
26 pages, 6 figures, minor modifications, references added and to appear in JHEP
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The future of high-precision electroweak physics lies in e+e- collider measurements of properties of the Z boson, the W boson, the Higgs boson, and the top quark. We estimate the expected performance of three possible future colliders: the ILC, FCC-ee (formerly known as TLEP), and CEPC. In particular, we present the first estimates of the possible reach of CEPC, China's proposed Circular Electron-Positron Collider, for the oblique parameters S and T and for seven-parameter fits of Higgs couplings. These results allow the physics potential for CEPC to be compared with that of the ILC and FCC-ee. We also show how the constraints on S and T would evolve as the uncertainties on each of the most important input measurements change separately. This clarifies the basic physics goals for future colliders. To improve on the current precision, the highest priorities are improving the uncertainties on the W mass and effective weak mixing angle. At the same time, improved measurements of the top mass, the Z mass, the running of alpha, and the Z width will offer further improvement which will determine the ultimate reach. Each of the possible future colliders we consider has strong prospects for probing TeV-scale electroweak physics.
[ { "created": "Tue, 4 Nov 2014 21:00:00 GMT", "version": "v1" }, { "created": "Tue, 8 Sep 2015 18:37:03 GMT", "version": "v2" } ]
2015-09-09
[ [ "Fan", "JiJi", "" ], [ "Reece", "Matthew", "" ], [ "Wang", "Lian-Tao", "" ] ]
The future of high-precision electroweak physics lies in e+e- collider measurements of properties of the Z boson, the W boson, the Higgs boson, and the top quark. We estimate the expected performance of three possible future colliders: the ILC, FCC-ee (formerly known as TLEP), and CEPC. In particular, we present the first estimates of the possible reach of CEPC, China's proposed Circular Electron-Positron Collider, for the oblique parameters S and T and for seven-parameter fits of Higgs couplings. These results allow the physics potential for CEPC to be compared with that of the ILC and FCC-ee. We also show how the constraints on S and T would evolve as the uncertainties on each of the most important input measurements change separately. This clarifies the basic physics goals for future colliders. To improve on the current precision, the highest priorities are improving the uncertainties on the W mass and effective weak mixing angle. At the same time, improved measurements of the top mass, the Z mass, the running of alpha, and the Z width will offer further improvement which will determine the ultimate reach. Each of the possible future colliders we consider has strong prospects for probing TeV-scale electroweak physics.
hep-ph/0209052
Michael Kuchiev
M. Yu. Kuchiev, V. V. Flambaum
Comment on ``Radiative corrections and parity nonconservation in heavy atoms''
2 pages, revtex4
null
null
null
hep-ph nucl-th physics.atom-ph
null
Very brief summary of the most recent developments in an area of QED corrections to the parity nonconservation in atoms is presented. Main conclusion - experimental results of Wood et al do not contradict the standard model
[ { "created": "Thu, 5 Sep 2002 02:00:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kuchiev", "M. Yu.", "" ], [ "Flambaum", "V. V.", "" ] ]
Very brief summary of the most recent developments in an area of QED corrections to the parity nonconservation in atoms is presented. Main conclusion - experimental results of Wood et al do not contradict the standard model
1902.11138
Ricardo Heras
Ricardo Heras
Comment on "Monopole production via photon fusion and Drell-Yan processes: MadGraph implementation and perturbativity via velocity-dependent coupling and magnetic moment as novel features"
null
null
null
null
hep-ph hep-th physics.class-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent study on monopole production [Eur. Phys. J. C (2018) 78: 966], Baines et al added the potential of a magnetic dipole to the Wu-Yang potentials for the Dirac monopole and claimed that this modified Wu-Yang configuration does not affect the Dirac quantisation condition. In this comment, we argue that their claim is incorrect by showing that their modified Wu-Yang configuration leads to an infinite number of quantisation conditions. In their study, they also incorrectly identified the magnetic field of the monopole with the magnetic field of the Dirac string and its attached magnetic monopole.
[ { "created": "Wed, 27 Feb 2019 18:55:13 GMT", "version": "v1" } ]
2019-03-01
[ [ "Heras", "Ricardo", "" ] ]
In a recent study on monopole production [Eur. Phys. J. C (2018) 78: 966], Baines et al added the potential of a magnetic dipole to the Wu-Yang potentials for the Dirac monopole and claimed that this modified Wu-Yang configuration does not affect the Dirac quantisation condition. In this comment, we argue that their claim is incorrect by showing that their modified Wu-Yang configuration leads to an infinite number of quantisation conditions. In their study, they also incorrectly identified the magnetic field of the monopole with the magnetic field of the Dirac string and its attached magnetic monopole.
hep-ph/0210340
Ian Hinchliffe
Ian Hinchliffe
Use of Taus in ATLAS
Invited talk at the Seventh International Workshop on Tau Lepton Physics (TAU02), Santa Cruz, Ca, USA, Sept 2002, 6 pages, LaTeX, 4 eps figures
eConf C0209101 (2002) WE13
10.1016/S0920-5632(03)02182-0
null
hep-ph
null
At the LHC, new particles can be expected that decay to final states involving taus. Examples are given from simulations by the ATLAS experiment showing how such final states can be exploited.
[ { "created": "Thu, 24 Oct 2002 20:18:18 GMT", "version": "v1" } ]
2009-11-07
[ [ "Hinchliffe", "Ian", "" ] ]
At the LHC, new particles can be expected that decay to final states involving taus. Examples are given from simulations by the ATLAS experiment showing how such final states can be exploited.
hep-ph/0410167
Vladimir Sauli
Vladimir Sauli
Some Analytical Aspects in Field Theories with Dynamical Mass Generation
published in Czech. J. Phys
null
10.1007/s10582-005-0129-4
null
hep-ph
null
The consequence of dynamical mass generation on the singularity structure of propagators is discussed. First the phenomena of dynamical mass generation is discussed in the framework of Euclidean gap equations, then a possible Minkowski solution is looking for. The examples are reviewed and studied for several models: Yukawa, QED, QCD and Wess-Zumino. It is argued that the absence of propagator pole goes hand by hand with the nontrivial solution for mass function. The consequences are discussed.
[ { "created": "Tue, 12 Oct 2004 14:04:11 GMT", "version": "v1" }, { "created": "Thu, 10 Nov 2005 16:51:09 GMT", "version": "v2" } ]
2009-11-10
[ [ "Sauli", "Vladimir", "" ] ]
The consequence of dynamical mass generation on the singularity structure of propagators is discussed. First the phenomena of dynamical mass generation is discussed in the framework of Euclidean gap equations, then a possible Minkowski solution is looking for. The examples are reviewed and studied for several models: Yukawa, QED, QCD and Wess-Zumino. It is argued that the absence of propagator pole goes hand by hand with the nontrivial solution for mass function. The consequences are discussed.
1304.1414
Vasiliki Mitsou
Vasiliki A. Mitsou (U. Valencia, IFIC)
Experimental status of particle and astroparticle searches for supersymmetry
17 pages, 18 figures; invited plenary talk in 3rd Symposium on Prospects in the Physics of Discrete Symmetries (DISCRETE 2012), 3-7 Dec 2012, Lisbon, Portugal; submitted to Journal of Physics: Conference Series
J.Phys.Conf.Ser. 447 (2013) 012019
10.1088/1742-6596/447/1/012019
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An overview of supersymmetry searches is presented, covering collider experiments, direct and indirect searches for supersymmetric dark matter. Recent LHC experimental results are reviewed, and the constraints from B-meson decays are reported. Implications for supersymmetry of the latest direct and indirect searches are thoroughly discussed. The focus is on the complementarity of the various probes -- particle and astrophysical -- for constraining Supersymmetry.
[ { "created": "Thu, 4 Apr 2013 16:05:15 GMT", "version": "v1" } ]
2015-11-11
[ [ "Mitsou", "Vasiliki A.", "", "U. Valencia, IFIC" ] ]
An overview of supersymmetry searches is presented, covering collider experiments, direct and indirect searches for supersymmetric dark matter. Recent LHC experimental results are reviewed, and the constraints from B-meson decays are reported. Implications for supersymmetry of the latest direct and indirect searches are thoroughly discussed. The focus is on the complementarity of the various probes -- particle and astrophysical -- for constraining Supersymmetry.
1402.4143
Viacheslav Bunichev
E. Boos (1), V. Bunichev (1), M. Dubinin (1), Y. Kurihara (2) ((1) Skobeltsyn Institute of Nuclear Physics, Moscow State University, (2) High Energy Accelerators Research Organization (KEK))
Expectations for the Higgs boson identification at the ILC
11 pages, 3 figures; corrected fig.2
null
null
SINP MSU 2014-2/885
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deviations from the standard Higgs sector generated by some new physics at an energy scale $\Lambda$ could be described by an effective $SU(3)_c \times SU(2)_L \times U(1)$ invariant non-renormalizable Lagrangian terms of dimension six. A systematic study of various Higgs boson production channels ($\gamma \gamma$, $ZZ$, $WW$, $b \bar b$, $\tau \bar \tau$) at the International Linear Collider (ILC) in the SM extension by effective operators is carried out. Statistical methods are used to establish a degree of consistency for the standard Higgs sector with the forthcoming data, using the expected ILC accuracies of the Higgs boson production channels. Global fits in the two-parametric anomalous coupling space indicating to possible deviations from the standard Higgs-fermion and Higgs-gauge boson couplings are performed.
[ { "created": "Mon, 17 Feb 2014 21:06:56 GMT", "version": "v1" }, { "created": "Wed, 12 Mar 2014 07:24:43 GMT", "version": "v2" } ]
2014-03-13
[ [ "Boos", "E.", "" ], [ "Bunichev", "V.", "" ], [ "Dubinin", "M.", "" ], [ "Kurihara", "Y.", "" ] ]
Deviations from the standard Higgs sector generated by some new physics at an energy scale $\Lambda$ could be described by an effective $SU(3)_c \times SU(2)_L \times U(1)$ invariant non-renormalizable Lagrangian terms of dimension six. A systematic study of various Higgs boson production channels ($\gamma \gamma$, $ZZ$, $WW$, $b \bar b$, $\tau \bar \tau$) at the International Linear Collider (ILC) in the SM extension by effective operators is carried out. Statistical methods are used to establish a degree of consistency for the standard Higgs sector with the forthcoming data, using the expected ILC accuracies of the Higgs boson production channels. Global fits in the two-parametric anomalous coupling space indicating to possible deviations from the standard Higgs-fermion and Higgs-gauge boson couplings are performed.
hep-ph/9805473
Daniel J. H. Chung
Daniel J. H. Chung, Edward W. Kolb, Antonio Riotto
Nonthermal Supermassive Dark Matter
11 page LaTeX file. No major changes. Version accepted by PRL
Phys.Rev.Lett. 81 (1998) 4048-4051
10.1103/PhysRevLett.81.4048
Fermilab FERMILAB-Pub-98/154-A, CERN CERN-TH/98-160, Oxford U. OUTP-98-40P
hep-ph astro-ph
null
We discuss several cosmological production mechanisms for nonthermal supermassive dark matter and argue that dark matter may be elementary particles of mass much greater than the weak scale. Searches for dark matter should not be limited to weakly interacting particles with mass of the order of the weak scale, but should extend into the supermassive range as well.
[ { "created": "Wed, 27 May 1998 20:44:24 GMT", "version": "v1" }, { "created": "Fri, 25 Sep 1998 05:48:21 GMT", "version": "v2" } ]
2009-10-31
[ [ "Chung", "Daniel J. H.", "" ], [ "Kolb", "Edward W.", "" ], [ "Riotto", "Antonio", "" ] ]
We discuss several cosmological production mechanisms for nonthermal supermassive dark matter and argue that dark matter may be elementary particles of mass much greater than the weak scale. Searches for dark matter should not be limited to weakly interacting particles with mass of the order of the weak scale, but should extend into the supermassive range as well.
0910.4855
Vincent Mathieu
Vincent Mathieu
How Many Degrees of Freedom Has the Gluon ?
Invited talk at International Workshop on QCD Green's Functions, Confinement, and Phenomenology (QCD-TNT09), Trento, Italy, 7-11 September 2009
PoS QCD-TNT09:024,2009
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In constituent models, glueballs are described as bound states of effective gluons. The dynamical mass generation lead to a gluon mass without violating gauge invariance. One can then consider three degrees of freedom for those effective massive gluons. However, models with only two degrees of freedom are shown to be in better agreement with the lattice glueball spectrum. I review both models for two- and three-gluon models and explain why even though the gluon gains a mass, it behaves as a massless particle with only two degrees of freedom.
[ { "created": "Mon, 26 Oct 2009 10:59:23 GMT", "version": "v1" } ]
2011-07-14
[ [ "Mathieu", "Vincent", "" ] ]
In constituent models, glueballs are described as bound states of effective gluons. The dynamical mass generation lead to a gluon mass without violating gauge invariance. One can then consider three degrees of freedom for those effective massive gluons. However, models with only two degrees of freedom are shown to be in better agreement with the lattice glueball spectrum. I review both models for two- and three-gluon models and explain why even though the gluon gains a mass, it behaves as a massless particle with only two degrees of freedom.
0911.0468
Olivier Pene
O. P\`ene, Ph. Boucaud, J.P. Leroy, A. Le Yaouanc, J. Micheli, J. Rodr\'iguez-Quintero
A Ghost Story: Ghosts and Gluons in the IR regime of QCD
12 pages 6 figures
PoS QCD-TNT09:035,2009
null
LPT-Orsay/09-88
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the different methods to obtain reliable informations about the deep infra-red behaviour of the gluon and ghost Green functions in QCD. We argue that a clever combination of analytical inputs and numerical ones is necessary. We illustrate this statement about the distinction between two classes of solutions of the ghost propagator Dyson-Schwinger equation (GPDSE). We conclude that the solution II ("decoupling") with a finite renormalised ghost dressing function at zero momentum is strongly favored by lattice QCD, We derive a method to solve numerically the GPDSE using lattice inputs concerning the gluon propagator. We derive an analytical small momentum expansion of the Ghost dressing function. We prove from the large cut-off behaviour of the ghost propagator renormalisation constant, $\widetilde Z_3$, that the bare ghost dressing function is infinite at the infinite cut-off limit.
[ { "created": "Tue, 3 Nov 2009 16:20:46 GMT", "version": "v1" } ]
2011-07-14
[ [ "Pène", "O.", "" ], [ "Boucaud", "Ph.", "" ], [ "Leroy", "J. P.", "" ], [ "Yaouanc", "A. Le", "" ], [ "Micheli", "J.", "" ], [ "Rodríguez-Quintero", "J.", "" ] ]
We discuss the different methods to obtain reliable informations about the deep infra-red behaviour of the gluon and ghost Green functions in QCD. We argue that a clever combination of analytical inputs and numerical ones is necessary. We illustrate this statement about the distinction between two classes of solutions of the ghost propagator Dyson-Schwinger equation (GPDSE). We conclude that the solution II ("decoupling") with a finite renormalised ghost dressing function at zero momentum is strongly favored by lattice QCD, We derive a method to solve numerically the GPDSE using lattice inputs concerning the gluon propagator. We derive an analytical small momentum expansion of the Ghost dressing function. We prove from the large cut-off behaviour of the ghost propagator renormalisation constant, $\widetilde Z_3$, that the bare ghost dressing function is infinite at the infinite cut-off limit.
hep-ph/0703074
Herbert Karl Dreiner
Herbi K. Dreiner (Bonn), Jong Soo Kim (Bonn), Oleg Lebedev (CERN), Marc Thormeier (Saclay)
Supersymmetric Jarlskog Invariants: the Neutrino Sector
10 pages, no figures
Phys.Rev.D76:015006,2007
10.1103/PhysRevD.76.015006
CERN-PH-TH/2007-042
hep-ph
null
We generalize the notion of the Jarlskog invariant to supersymmetric models with right--handed neutrinos. This allows us to formulate basis--independent necessary and sufficient conditions for CP conservation in such models.
[ { "created": "Wed, 7 Mar 2007 11:56:11 GMT", "version": "v1" } ]
2008-11-26
[ [ "Dreiner", "Herbi K.", "", "Bonn" ], [ "Kim", "Jong Soo", "", "Bonn" ], [ "Lebedev", "Oleg", "", "CERN" ], [ "Thormeier", "Marc", "", "Saclay" ] ]
We generalize the notion of the Jarlskog invariant to supersymmetric models with right--handed neutrinos. This allows us to formulate basis--independent necessary and sufficient conditions for CP conservation in such models.
2010.12971
Jose De Jesus Aguilera Verdugo
J. Jesus Aguilera-Verdugo, Roger J. Hernandez-Pinto, German Rodrigo, German F. R. Sborlini, William J. Torres Bobadilla
Mathematical properties of nested residues and their application to multi-loop scattering amplitudes
29 pages + appendices, 11 figures
null
10.1007/JHEP02(2021)112
IFIC/20-30; DESY 20-172; MPP-2020-184
hep-ph hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The computation of multi-loop multi-leg scattering amplitudes plays a key role to improve the precision of theoretical predictions for particle physics at high-energy colliders. In this work, we focus on the mathematical properties of the novel integrand-level representation of Feynman integrals, which is based on the Loop-Tree Duality (LTD). We explore the behaviour of the multi-loop iterated residues and explicitly show, by developing a general formal proof for the first time, that contributions associated to displaced poles are cancelled out. The remaining residues, called nested residues as originally introduced in Ref. \cite{Verdugo:2020kzh}, encode the relevant physical information and are naturally mapped onto physical configurations associated to nondisjoint on-shell states. By going further on the mathematical structure of the nested residues, we prove that unphysical singularities vanish, and show how the final expressions can be written by using only causal denominators. In this way, we provide a mathematical proof for the all-loop formulae presented in Ref. \cite{Aguilera-Verdugo:2020kzc}.
[ { "created": "Sat, 24 Oct 2020 20:09:58 GMT", "version": "v1" } ]
2021-03-17
[ [ "Aguilera-Verdugo", "J. Jesus", "" ], [ "Hernandez-Pinto", "Roger J.", "" ], [ "Rodrigo", "German", "" ], [ "Sborlini", "German F. R.", "" ], [ "Bobadilla", "William J. Torres", "" ] ]
The computation of multi-loop multi-leg scattering amplitudes plays a key role to improve the precision of theoretical predictions for particle physics at high-energy colliders. In this work, we focus on the mathematical properties of the novel integrand-level representation of Feynman integrals, which is based on the Loop-Tree Duality (LTD). We explore the behaviour of the multi-loop iterated residues and explicitly show, by developing a general formal proof for the first time, that contributions associated to displaced poles are cancelled out. The remaining residues, called nested residues as originally introduced in Ref. \cite{Verdugo:2020kzh}, encode the relevant physical information and are naturally mapped onto physical configurations associated to nondisjoint on-shell states. By going further on the mathematical structure of the nested residues, we prove that unphysical singularities vanish, and show how the final expressions can be written by using only causal denominators. In this way, we provide a mathematical proof for the all-loop formulae presented in Ref. \cite{Aguilera-Verdugo:2020kzc}.
2003.00112
Alfredo Iorio
Paolo Castorina, Alfredo Iorio, Daniele Lanteri, and Petr Lukes
Gluon Shadowing and Nuclear Entanglement
7 pages, 5 figures
null
10.1142/S0218301321500105
null
hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Relying on previous results that link entanglement entropy and parton distribution functions in deep inelastic scattering and focusing on the small Bjorken scaling region we present here indications that gluon shadowing might indeed be explained as due to a depletion of the entanglement entropy between observed and unobserved degrees of freedom per nucleon within a nucleus with respect to the free nucleon case. We apply to gluon shadowing the general Page approach to the calculation of the entanglement entropy in bipartite systems, giving physical motivations of the results.
[ { "created": "Fri, 28 Feb 2020 23:16:39 GMT", "version": "v1" } ]
2021-04-07
[ [ "Castorina", "Paolo", "" ], [ "Iorio", "Alfredo", "" ], [ "Lanteri", "Daniele", "" ], [ "Lukes", "Petr", "" ] ]
Relying on previous results that link entanglement entropy and parton distribution functions in deep inelastic scattering and focusing on the small Bjorken scaling region we present here indications that gluon shadowing might indeed be explained as due to a depletion of the entanglement entropy between observed and unobserved degrees of freedom per nucleon within a nucleus with respect to the free nucleon case. We apply to gluon shadowing the general Page approach to the calculation of the entanglement entropy in bipartite systems, giving physical motivations of the results.
1510.00389
Farinaldo Queiroz
Matthew G. Baring, Tathagata Ghosh, Farinaldo S. Queiroz, Kuver Sinha
New Limits on the Dark Matter Lifetime from Dwarf Spheroidal Galaxies using Fermi-LAT
4 figures, 7 pages. Inclusion of PASS 8 event-class, maximum likelihood analysis and a new figure concerning Reticulum-II. Accepted in Physical Review D
Phys. Rev. D 93, 103009 (2016)
10.1103/PhysRevD.93.103009
CETUP2015-025
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dwarf spheroidal galaxies (dSphs) are promising targets for the indirect detection of dark matter through gamma-ray emission due to their proximity, lack of astrophysical backgrounds and high dark matter density. They are often used to place restrictive bounds on the dark matter annihilation cross section. In this paper, we analyze six years of {\it Fermi}-LAT gamma-ray data from 19 dSphs that are satellites of the Milky Way, and derive from a stacked analysis of 15 dSphs, robust 95\% confidence level lower limits on the dark matter lifetime for several decay channels and dark matter masses between $\sim 1$GeV and $10$TeV. Our findings are based on a bin-by-bin maximum likelihood analysis treating the J-factor as a nuisance parameter using PASS 8 event-class. Our constraints from this ensemble are among the most stringent and solid in the literature, and competitive with existing ones coming from the extragalactic gamma-ray background, galaxy clusters, AMS-02 cosmic ray data, Super-K and ICECUBE neutrino data, while rather insensitive to systematic uncertainties. In particular, among gamma-ray searches, we improve existing limits for dark matter decaying into $\bar{b}b$, ($\mu^+\mu^-$) for DM masses below $\sim 30\, (200)$~GeV, demonstrating that dSphs are compelling targets for constraining dark matter decay lifetimes.
[ { "created": "Thu, 1 Oct 2015 20:03:33 GMT", "version": "v1" }, { "created": "Tue, 17 Nov 2015 10:44:18 GMT", "version": "v2" }, { "created": "Tue, 26 Apr 2016 22:53:12 GMT", "version": "v3" } ]
2016-06-01
[ [ "Baring", "Matthew G.", "" ], [ "Ghosh", "Tathagata", "" ], [ "Queiroz", "Farinaldo S.", "" ], [ "Sinha", "Kuver", "" ] ]
Dwarf spheroidal galaxies (dSphs) are promising targets for the indirect detection of dark matter through gamma-ray emission due to their proximity, lack of astrophysical backgrounds and high dark matter density. They are often used to place restrictive bounds on the dark matter annihilation cross section. In this paper, we analyze six years of {\it Fermi}-LAT gamma-ray data from 19 dSphs that are satellites of the Milky Way, and derive from a stacked analysis of 15 dSphs, robust 95\% confidence level lower limits on the dark matter lifetime for several decay channels and dark matter masses between $\sim 1$GeV and $10$TeV. Our findings are based on a bin-by-bin maximum likelihood analysis treating the J-factor as a nuisance parameter using PASS 8 event-class. Our constraints from this ensemble are among the most stringent and solid in the literature, and competitive with existing ones coming from the extragalactic gamma-ray background, galaxy clusters, AMS-02 cosmic ray data, Super-K and ICECUBE neutrino data, while rather insensitive to systematic uncertainties. In particular, among gamma-ray searches, we improve existing limits for dark matter decaying into $\bar{b}b$, ($\mu^+\mu^-$) for DM masses below $\sim 30\, (200)$~GeV, demonstrating that dSphs are compelling targets for constraining dark matter decay lifetimes.
hep-ph/0408322
Krishna Rajagopal
Kenji Fukushima (MIT, University of Tokyo), Chris Kouvaris (MIT), Krishna Rajagopal (MIT)
Heating (Gapless) Color-Flavor Locked Quark Matter
24 pages; 22 figures; typos in labelling of Figs. 7, 20 corrected
Phys.Rev.D71:034002,2005
10.1103/PhysRevD.71.034002
MIT-CTP-3525
hep-ph cond-mat.supr-con nucl-th
null
We explore the phase diagram of neutral quark matter at high baryon density as a function of the temperature T and the strange quark mass Ms. At T=0, there is a sharp distinction between the insulating color-flavor locked (CFL) phase, which occurs where Ms^2/mu < 2 Delta, and the metallic gapless CFL phase, which occurs at larger Ms^2/mu. Here, mu is the chemical potential for quark number and Delta is the gap in the CFL phase. We find this distinction blurred at nonzero T, as the CFL phase undergoes an insulator-to-metal crossover when it is heated. We present an analytic treatment of this crossover. At higher temperatures, we map out the phase transition lines at which the gap parameters Delta_1, Delta_2 and Delta_3 describing ds-pairing, us-pairing and ud-pairing respectively, go to zero in an NJL model. For small values of Ms^2/mu, we find that Delta_2 vanishes first, then Delta_1, then Delta_3. We find agreement with a previous Ginzburg-Landau analysis of the form of these transitions and find quantitative agreement with results obtained in full QCD at asymptotic density for ratios of coefficients in the Ginzburg-Landau potential. At larger Ms^2/mu, we find that Delta_1 vanishes first, then Delta_2, then Delta_3. Hence, we find a "doubly critical'' point in the (Ms^2/mu,T)-plane at which two lines of second order phase transitions (Delta_1->0 and Delta_2->0) cross. Because we do not make any small-Ms approximation, if we choose a relatively strong coupling leading to large gap parameters, we are able to pursue the analysis of the phase diagram all the way up to such large values of Ms that there are no strange quarks present.
[ { "created": "Sat, 28 Aug 2004 03:03:27 GMT", "version": "v1" }, { "created": "Tue, 31 Aug 2004 21:51:09 GMT", "version": "v2" } ]
2014-11-18
[ [ "Fukushima", "Kenji", "", "MIT, University of Tokyo" ], [ "Kouvaris", "Chris", "", "MIT" ], [ "Rajagopal", "Krishna", "", "MIT" ] ]
We explore the phase diagram of neutral quark matter at high baryon density as a function of the temperature T and the strange quark mass Ms. At T=0, there is a sharp distinction between the insulating color-flavor locked (CFL) phase, which occurs where Ms^2/mu < 2 Delta, and the metallic gapless CFL phase, which occurs at larger Ms^2/mu. Here, mu is the chemical potential for quark number and Delta is the gap in the CFL phase. We find this distinction blurred at nonzero T, as the CFL phase undergoes an insulator-to-metal crossover when it is heated. We present an analytic treatment of this crossover. At higher temperatures, we map out the phase transition lines at which the gap parameters Delta_1, Delta_2 and Delta_3 describing ds-pairing, us-pairing and ud-pairing respectively, go to zero in an NJL model. For small values of Ms^2/mu, we find that Delta_2 vanishes first, then Delta_1, then Delta_3. We find agreement with a previous Ginzburg-Landau analysis of the form of these transitions and find quantitative agreement with results obtained in full QCD at asymptotic density for ratios of coefficients in the Ginzburg-Landau potential. At larger Ms^2/mu, we find that Delta_1 vanishes first, then Delta_2, then Delta_3. Hence, we find a "doubly critical'' point in the (Ms^2/mu,T)-plane at which two lines of second order phase transitions (Delta_1->0 and Delta_2->0) cross. Because we do not make any small-Ms approximation, if we choose a relatively strong coupling leading to large gap parameters, we are able to pursue the analysis of the phase diagram all the way up to such large values of Ms that there are no strange quarks present.
1401.1364
Jan Uphoff
Jan Uphoff, Oliver Fochler, Florian Senzel, Christian Wesp, Zhe Xu, Carsten Greiner
Elliptic flow and nuclear modification factor in ultra-relativistic heavy-ion collisions within a partonic transport model
5 pages, 5 figures
Phys. Rev. Lett. 114, 112301 (2015)
10.1103/PhysRevLett.114.112301
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quark gluon plasma produced in ultra-relativistic heavy-ion collisions exhibits remarkable features. It behaves like a nearly perfect liquid with a small shear viscosity to entropy density ratio and leads to the quenching of highly energetic particles. We show that both effects can be understood for the first time within one common framework. Employing the parton cascade Boltzmann Approach to Multi-Parton Scatterings (BAMPS), the microscopic interactions and the space-time evolution of the quark gluon plasma are calculated by solving the relativistic Boltzmann equation. Based on cross sections obtained from perturbative QCD with explicitly taking the running coupling into account, we calculate the nuclear modification factor and elliptic flow in ultra-relativistic heavy-ion collisions. With only one single parameter associated with coherence effects of medium-induced gluon radiation, the experimental data of both observables can be understood on a microscopic level. Furthermore, we show that perturbative QCD interactions with a running coupling lead to a sufficiently small shear viscosity to entropy density ratio of the quark gluon plasma, which provides a microscopic explanation for the observations stated by hydrodynamic calculations.
[ { "created": "Tue, 7 Jan 2014 13:18:28 GMT", "version": "v1" } ]
2015-03-25
[ [ "Uphoff", "Jan", "" ], [ "Fochler", "Oliver", "" ], [ "Senzel", "Florian", "" ], [ "Wesp", "Christian", "" ], [ "Xu", "Zhe", "" ], [ "Greiner", "Carsten", "" ] ]
The quark gluon plasma produced in ultra-relativistic heavy-ion collisions exhibits remarkable features. It behaves like a nearly perfect liquid with a small shear viscosity to entropy density ratio and leads to the quenching of highly energetic particles. We show that both effects can be understood for the first time within one common framework. Employing the parton cascade Boltzmann Approach to Multi-Parton Scatterings (BAMPS), the microscopic interactions and the space-time evolution of the quark gluon plasma are calculated by solving the relativistic Boltzmann equation. Based on cross sections obtained from perturbative QCD with explicitly taking the running coupling into account, we calculate the nuclear modification factor and elliptic flow in ultra-relativistic heavy-ion collisions. With only one single parameter associated with coherence effects of medium-induced gluon radiation, the experimental data of both observables can be understood on a microscopic level. Furthermore, we show that perturbative QCD interactions with a running coupling lead to a sufficiently small shear viscosity to entropy density ratio of the quark gluon plasma, which provides a microscopic explanation for the observations stated by hydrodynamic calculations.
0706.1781
Marco Ruggieri
R. Anglani, R. Gatto, N. D. Ippolito, G. Nardulli and M. Ruggieri
Superfluid and Pseudo-Goldstone Modes in Three Flavor Crystalline Color Superconductivity
10 pages, RevTeX4 class. Section IIIA enlarged, to appear on Phys. Rev. D
Phys.Rev.D76:054007,2007
10.1103/PhysRevD.76.054007
BARI-TH 567/07
hep-ph
null
We study the bosonic excitations in the favorite cubic three flavor crystalline LOFF phases of QCD. We calculate in the Ginzburg-Landau approximation the masses of the eight pseudo Nambu-Goldstone Bosons (NGB) present in the low energy theory. We also compute the decay constants of the massless NGB Goldstones associated to superfluidity as well as those of the eight pseudo NGB. Differently from the corresponding situation in the Color-Flavor-Locking phase, we find that meson condensation phases are not expected in the present scenario.
[ { "created": "Wed, 13 Jun 2007 14:42:47 GMT", "version": "v1" }, { "created": "Thu, 16 Aug 2007 07:20:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Anglani", "R.", "" ], [ "Gatto", "R.", "" ], [ "Ippolito", "N. D.", "" ], [ "Nardulli", "G.", "" ], [ "Ruggieri", "M.", "" ] ]
We study the bosonic excitations in the favorite cubic three flavor crystalline LOFF phases of QCD. We calculate in the Ginzburg-Landau approximation the masses of the eight pseudo Nambu-Goldstone Bosons (NGB) present in the low energy theory. We also compute the decay constants of the massless NGB Goldstones associated to superfluidity as well as those of the eight pseudo NGB. Differently from the corresponding situation in the Color-Flavor-Locking phase, we find that meson condensation phases are not expected in the present scenario.
1505.04067
Antoni Szczurek
Antoni Szczurek
A short review of some double-parton scattering processes
10 pages, 9 figures, invited talk at the Excited QCD 2015, Tatranska Lomnica, Slovakia, 8-14 March 2015. arXiv admin note: text overlap with arXiv:1504.06491, order of figures changed, references added
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A few examples of quickly developing field of double parton scattering are discussed. We present arguments that the production of two pairs of charm quark-antiquark is the golden reaction to study the double parton scattering effects. We discuss briefly also mechanism of single parton scattering and show that it gives much smaller contribution to the $c \bar c c \bar c$ final state. In this context we discuss also the contribution of perturbative parton-splitting mechanism which should also be added to the conventional DPS mechanism. The presence of the letter leads to collision energy and other kinematical variables dependence of so-called $\sigma_{eff}$. We briefly discuss production of four jets. We concentrate on estimation of the contribution of DPS for jets widely separated in rapidity. Finally we briefly mention about DPS effects in production of $W^+ W^-$.
[ { "created": "Fri, 15 May 2015 13:56:19 GMT", "version": "v1" }, { "created": "Tue, 19 May 2015 07:35:53 GMT", "version": "v2" } ]
2015-05-20
[ [ "Szczurek", "Antoni", "" ] ]
A few examples of quickly developing field of double parton scattering are discussed. We present arguments that the production of two pairs of charm quark-antiquark is the golden reaction to study the double parton scattering effects. We discuss briefly also mechanism of single parton scattering and show that it gives much smaller contribution to the $c \bar c c \bar c$ final state. In this context we discuss also the contribution of perturbative parton-splitting mechanism which should also be added to the conventional DPS mechanism. The presence of the letter leads to collision energy and other kinematical variables dependence of so-called $\sigma_{eff}$. We briefly discuss production of four jets. We concentrate on estimation of the contribution of DPS for jets widely separated in rapidity. Finally we briefly mention about DPS effects in production of $W^+ W^-$.
1605.01630
Qin Chang
Qin Chang, Pan-Pan Li, Xiao-Hui Hu and Lin Han
Study of Nonleptonic $B^{\ast}_{(s)}\to M_1 M_2$ $(M=D$, $D_s$, $\pi$, $K)$ Weak Decays with Factorization Approach
17 pages, 5 tables, the version published in International Journal of Modern Physics A
Int.J.Mod.Phys. A30 (2015) no.27, 1550162
10.1142/S0217751X15501626
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the experiments of heavy flavor physics at running LHC and upgrading SuperKEKB/Belle-II in the future, the nonleptonic $B^{\ast}_{(s)}\to M_1 M_2$ $(M=D$, $D_s$, $\pi$, $K)$ weak decays are studied in this paper. The amplitudes are calculated with factorization approach, and the transition form factors $A_0^{B^{\ast}_{(s)}\to M_1}(0)$ are evaluated within BSW model. With the reasonable approximation $\Gamma_{tot}(B^*_{(s)})\simeq \Gamma(B^*_{(s)}\to B_{(s)}\gamma)$, our predictions of branching fractions are presented. Numerically, the CKM-favored tree-dominated $\bar{B}^{*0} \to D^+D^-_s$ and $\bar{B}^{*0}_s \to D^+_sD^-_s$ decays have the largest branching fractions of the order $\sim{\cal O}(10^{-8})$, and hence will be firstly observed by forthcoming Belle-II experiment. However, most of the other decay modes have the branching fractions~$<{\cal O}(10^{-9})$ and thus are hardly to be observed soon. Besides, for the possible detectable $B^{\ast}_{(s)}$ decays with branching fractions $\gtrsim{\cal O}(10^{-9})$, some useful ratios, such as $R_D$ {\it et al.,} are presented and discussed in detail.
[ { "created": "Thu, 5 May 2016 15:49:26 GMT", "version": "v1" } ]
2016-05-06
[ [ "Chang", "Qin", "" ], [ "Li", "Pan-Pan", "" ], [ "Hu", "Xiao-Hui", "" ], [ "Han", "Lin", "" ] ]
Motivated by the experiments of heavy flavor physics at running LHC and upgrading SuperKEKB/Belle-II in the future, the nonleptonic $B^{\ast}_{(s)}\to M_1 M_2$ $(M=D$, $D_s$, $\pi$, $K)$ weak decays are studied in this paper. The amplitudes are calculated with factorization approach, and the transition form factors $A_0^{B^{\ast}_{(s)}\to M_1}(0)$ are evaluated within BSW model. With the reasonable approximation $\Gamma_{tot}(B^*_{(s)})\simeq \Gamma(B^*_{(s)}\to B_{(s)}\gamma)$, our predictions of branching fractions are presented. Numerically, the CKM-favored tree-dominated $\bar{B}^{*0} \to D^+D^-_s$ and $\bar{B}^{*0}_s \to D^+_sD^-_s$ decays have the largest branching fractions of the order $\sim{\cal O}(10^{-8})$, and hence will be firstly observed by forthcoming Belle-II experiment. However, most of the other decay modes have the branching fractions~$<{\cal O}(10^{-9})$ and thus are hardly to be observed soon. Besides, for the possible detectable $B^{\ast}_{(s)}$ decays with branching fractions $\gtrsim{\cal O}(10^{-9})$, some useful ratios, such as $R_D$ {\it et al.,} are presented and discussed in detail.
hep-ph/0512028
Dirk Zerwas
R. Lafaye, T.Plehn, D. Zerwas
SUSY parameter determination
Invited talk at 2005 International Linear Collider Physics and Detector Workshop and Second ILC Accelerator Workshop, Snowmass, CO(Snowmass05) 3 pages, LaTeX
null
null
LAL 05-173
hep-ph
null
The impact of the LHC, SLHC and the ILC on the precision of the determination of supersymmetric parameters is investigated. In particular, in the point SPS1a the measurements performed at the ILC will improve by an order of magnitude the precision obtained by the LHC alone. The SLHC with respect to the LHC has the potential to reduce the errors by a factor two.
[ { "created": "Fri, 2 Dec 2005 10:51:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lafaye", "R.", "" ], [ "Plehn", "T.", "" ], [ "Zerwas", "D.", "" ] ]
The impact of the LHC, SLHC and the ILC on the precision of the determination of supersymmetric parameters is investigated. In particular, in the point SPS1a the measurements performed at the ILC will improve by an order of magnitude the precision obtained by the LHC alone. The SLHC with respect to the LHC has the potential to reduce the errors by a factor two.
hep-ph/9910393
Motohiko Yoshimura
Sh. Matsumoto and M. Yoshimura
Temperature Power Law of Equilibrium Heavy Particle Density
12 pages, LATEX file with 6 PS figures
Phys.Rev. D61 (2000) 123508
10.1103/PhysRevD.61.123508
TU/99/577 and RCNS-99-05
hep-ph
null
A standard calculation of the energy density of heavy stable particles that may pair-annihilate into light particles making up thermal medium is performed to second order of coupling, using the technique of thermal field theory. At very low temperatures a power law of temperature is derived for the energy density of the heavy particle. This is in sharp contrast to the exponentially suppressed contribution estimated from the ideal gas distribution function. The result supports a previous dynamical calculation based on the Hartree approximation, and implies that the relic abundance of dark matter particles is enhanced compared to that based on the Boltzmann equation.
[ { "created": "Tue, 19 Oct 1999 05:06:04 GMT", "version": "v1" } ]
2009-10-31
[ [ "Matsumoto", "Sh.", "" ], [ "Yoshimura", "M.", "" ] ]
A standard calculation of the energy density of heavy stable particles that may pair-annihilate into light particles making up thermal medium is performed to second order of coupling, using the technique of thermal field theory. At very low temperatures a power law of temperature is derived for the energy density of the heavy particle. This is in sharp contrast to the exponentially suppressed contribution estimated from the ideal gas distribution function. The result supports a previous dynamical calculation based on the Hartree approximation, and implies that the relic abundance of dark matter particles is enhanced compared to that based on the Boltzmann equation.
1902.04470
Michal Malinsk\'y
Mat\v{e}j Hudec, Michal Malinsk\'y
Hierarchy and decoupling
17 pages
null
10.1088/1361-6471/ab5138
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A large hierarchy between the electroweak scale and virtually any new scale of beyond-Standard-Model physics is often claimed to be unnatural. Sometimes, the apparent disparity between the measured Higgs mass and the size of the typical loop corrections encountered within such schemes is even interpretted as a profound indication that one should expect a remedy just behind the corner, probably in form of a new physics such as low-scale supersymmetry, new strong dynamics etc. In reality, all such potentially large corrections in the one- and two-point Green's functions cancel with each other in the physical Higgs mass $m_{H}$ which eventually turns out to be driven only by the electroweak VEV $v$. This, naively, may look like a miracle, the more that the standard perturbative approach often makes it irresistible to discuss the magnitudes of those corrections as if, individually, they were physically relevant. To shed some more light on this conundrum we advocate a method based on the symmetry properties of the Coleman-Weinberg effective potential which not only makes it very clear why $m_H\propto v$ to all orders in the perturbative expansion but, at the same time, it does not require any inspection of the explicit form of the tadpole equations whatsoever. Besides simplifying the calculations considerably it makes the "internal composition" of the VEV in terms of the high-scale parameters essentially irrelevant. We exemplify these findings on an extended series of specific simplified models in which the role of the heavy dynamics is played by all "reasonable" types of fields (barring gravity), i.e., by a heavy scalar, a heavy (Majorana) fermion and a heavy vector, respectively. We show that the dependence of $m_{H}$ on the heavy scale follows the expectation based on dynamical arguments such as the decoupling theorem.
[ { "created": "Tue, 12 Feb 2019 16:17:46 GMT", "version": "v1" } ]
2020-01-08
[ [ "Hudec", "Matěj", "" ], [ "Malinský", "Michal", "" ] ]
A large hierarchy between the electroweak scale and virtually any new scale of beyond-Standard-Model physics is often claimed to be unnatural. Sometimes, the apparent disparity between the measured Higgs mass and the size of the typical loop corrections encountered within such schemes is even interpretted as a profound indication that one should expect a remedy just behind the corner, probably in form of a new physics such as low-scale supersymmetry, new strong dynamics etc. In reality, all such potentially large corrections in the one- and two-point Green's functions cancel with each other in the physical Higgs mass $m_{H}$ which eventually turns out to be driven only by the electroweak VEV $v$. This, naively, may look like a miracle, the more that the standard perturbative approach often makes it irresistible to discuss the magnitudes of those corrections as if, individually, they were physically relevant. To shed some more light on this conundrum we advocate a method based on the symmetry properties of the Coleman-Weinberg effective potential which not only makes it very clear why $m_H\propto v$ to all orders in the perturbative expansion but, at the same time, it does not require any inspection of the explicit form of the tadpole equations whatsoever. Besides simplifying the calculations considerably it makes the "internal composition" of the VEV in terms of the high-scale parameters essentially irrelevant. We exemplify these findings on an extended series of specific simplified models in which the role of the heavy dynamics is played by all "reasonable" types of fields (barring gravity), i.e., by a heavy scalar, a heavy (Majorana) fermion and a heavy vector, respectively. We show that the dependence of $m_{H}$ on the heavy scale follows the expectation based on dynamical arguments such as the decoupling theorem.
2102.11151
Yen-Hsun Lin
Guey-Lin Lin and Yen-Hsun Lin
Exploring dark sector parameters in light of neutron star temperatures
27 pages, 10 figures, 1 table, accepted by PRD, matched the published version
Phys. Rev. D 104, 063021 (2021)
10.1103/PhysRevD.104.063021
null
hep-ph astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
Using neutron stars (NS) as a dark matter (DM) probe has gained broad attention recently, either from heating due to DM annihilation or its stability under the presence of DM. In this work, we investigate spin-$1/2$ fermionic DM $\chi$ charged under the $U(1)_{X}$ in the dark sector. The massive gauge boson $V$ of $U(1)_{X}$ gauge group can be produced in NS via DM annihilation. The produced gauge boson can decay into Standard Model (SM) particles before it exits the NS, despite its tiny couplings to SM particles. Thus, we perform a systematic study on $\chi\bar{\chi}\to2V\to4{\rm SM}$ as a new heating mechanism for NS in addition to $\chi\bar{\chi}\to2{\rm SM}$ and kinetic heating from DM-baryon scattering. The self-trapping due to $\chi V$ scattering is also considered. We assume the general framework that both kinetic and mass mixing terms between $V$ and SM gauge bosons are present. This allows both vector and axial-vector couplings between $V$ and SM fermions even for $m_V\ll m_Z$. Notably, the contribution from axial-vector coupling is not negligible when particles scatter relativistically. We point out that the above approaches to DM-induced NS heating are not yet adopted in recent analyses. Detectabilities of the aforementioned effects to the NS surface temperature by the future telescopes are discussed as well.
[ { "created": "Mon, 22 Feb 2021 16:19:06 GMT", "version": "v1" }, { "created": "Mon, 30 Aug 2021 16:15:01 GMT", "version": "v2" } ]
2021-09-22
[ [ "Lin", "Guey-Lin", "" ], [ "Lin", "Yen-Hsun", "" ] ]
Using neutron stars (NS) as a dark matter (DM) probe has gained broad attention recently, either from heating due to DM annihilation or its stability under the presence of DM. In this work, we investigate spin-$1/2$ fermionic DM $\chi$ charged under the $U(1)_{X}$ in the dark sector. The massive gauge boson $V$ of $U(1)_{X}$ gauge group can be produced in NS via DM annihilation. The produced gauge boson can decay into Standard Model (SM) particles before it exits the NS, despite its tiny couplings to SM particles. Thus, we perform a systematic study on $\chi\bar{\chi}\to2V\to4{\rm SM}$ as a new heating mechanism for NS in addition to $\chi\bar{\chi}\to2{\rm SM}$ and kinetic heating from DM-baryon scattering. The self-trapping due to $\chi V$ scattering is also considered. We assume the general framework that both kinetic and mass mixing terms between $V$ and SM gauge bosons are present. This allows both vector and axial-vector couplings between $V$ and SM fermions even for $m_V\ll m_Z$. Notably, the contribution from axial-vector coupling is not negligible when particles scatter relativistically. We point out that the above approaches to DM-induced NS heating are not yet adopted in recent analyses. Detectabilities of the aforementioned effects to the NS surface temperature by the future telescopes are discussed as well.
2207.07943
Johannes Bl\"umlein
J. Bl\"umlein, P. Marquard, C. Schneider, and K. Sch\"onwald
The 3-loop anomalous dimensions from off-shell operator matrix elements
12 pages Latex, Contributeion to the Proceedings of LL2022
PoS (LL2022) 048
null
DESY 19--061, DO-TH 20/09, TTP22--048, RISC Report Series 22--09, SAGEX 20--20
hep-ph hep-ex hep-th
http://creativecommons.org/licenses/by/4.0/
We report on the calculation of the three-loop polarized and unpolarized flavor non-singlet and the polarized singlet anomalous dimensions using massless off-shell operator matrix elements in a gauge-variant framework. We also reconsider the unpolarized two-loop singlet anomalous dimensions and correct errors in the foregoing literature.
[ { "created": "Sat, 16 Jul 2022 13:33:20 GMT", "version": "v1" } ]
2022-07-19
[ [ "Blümlein", "J.", "" ], [ "Marquard", "P.", "" ], [ "Schneider", "C.", "" ], [ "Schönwald", "K.", "" ] ]
We report on the calculation of the three-loop polarized and unpolarized flavor non-singlet and the polarized singlet anomalous dimensions using massless off-shell operator matrix elements in a gauge-variant framework. We also reconsider the unpolarized two-loop singlet anomalous dimensions and correct errors in the foregoing literature.
1103.6252
Korinna Zapp
Korinna Christine Zapp, Johanna Stachel, Urs Achim Wiedemann
A local Monte Carlo framework for coherent QCD parton energy loss
49 pages, 13 figures, v2: typos corrected
null
10.1007/JHEP07(2011)118
IPPP/11/16, DCPT/11/32, MCnet-11-11, CERN-PH-TH/2011-043
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Monte Carlo (MC) simulations are the standard tool for describing jet-like multi-particle final states. To apply them to the simulation of medium-modified jets in heavy ion collisions, a probabilistic implementation of medium-induced quantum interference effects is needed. Here, we analyze in detail how the quantum interference effects included in the BDMPS-Z formalism of medium-induced gluon radiation can be implemented in a quantitatively controlled, local probabilistic parton cascade. The resulting MC algorithm is formulated in terms of elastic and inelastic mean free paths, and it is by construction insensitive to the IR and UV divergences of the total elastic and inelastic cross sections that serve as its basic building blocks in the incoherent limit. Interference effects are implemented by reweighting gluon production histories as a function of the number of scattering centers that act within the gluon formation time. Unlike existing implementations based on gluon formation time, we find generic arguments for why a quantitative implementation of quantum interference cannot amount to a mere dead-time requirement for subsequent gluon production. We validate the proposed MC algorithm by comparing MC simulations with parametric dependencies and analytical results of the BDMPS-Z formalism. In particular, we show that the MC algorithm interpolates correctly between analytically known limiting cases for totally coherent and incoherent gluon production, and that it accounts quantitatively for the medium-induced gluon energy distribution and the resulting average parton energy loss. We also verify that the MC algorithm implements the transverse momentum broadening of the BDMPS-Z formalism. We finally discuss why the proposed MC algorithm provides a suitable starting point for going beyond the approximations of the BDMPS-Z formalism.
[ { "created": "Thu, 31 Mar 2011 17:46:17 GMT", "version": "v1" }, { "created": "Tue, 2 Aug 2011 14:45:40 GMT", "version": "v2" } ]
2011-08-03
[ [ "Zapp", "Korinna Christine", "" ], [ "Stachel", "Johanna", "" ], [ "Wiedemann", "Urs Achim", "" ] ]
Monte Carlo (MC) simulations are the standard tool for describing jet-like multi-particle final states. To apply them to the simulation of medium-modified jets in heavy ion collisions, a probabilistic implementation of medium-induced quantum interference effects is needed. Here, we analyze in detail how the quantum interference effects included in the BDMPS-Z formalism of medium-induced gluon radiation can be implemented in a quantitatively controlled, local probabilistic parton cascade. The resulting MC algorithm is formulated in terms of elastic and inelastic mean free paths, and it is by construction insensitive to the IR and UV divergences of the total elastic and inelastic cross sections that serve as its basic building blocks in the incoherent limit. Interference effects are implemented by reweighting gluon production histories as a function of the number of scattering centers that act within the gluon formation time. Unlike existing implementations based on gluon formation time, we find generic arguments for why a quantitative implementation of quantum interference cannot amount to a mere dead-time requirement for subsequent gluon production. We validate the proposed MC algorithm by comparing MC simulations with parametric dependencies and analytical results of the BDMPS-Z formalism. In particular, we show that the MC algorithm interpolates correctly between analytically known limiting cases for totally coherent and incoherent gluon production, and that it accounts quantitatively for the medium-induced gluon energy distribution and the resulting average parton energy loss. We also verify that the MC algorithm implements the transverse momentum broadening of the BDMPS-Z formalism. We finally discuss why the proposed MC algorithm provides a suitable starting point for going beyond the approximations of the BDMPS-Z formalism.
1309.7085
Simonetta Liuti
Evan Askanazi, Katherine Holcomb and Simonetta Liuti
Self-Organizing Maps Parametrization of Deep Inelastic Structure Functions with Error Determination
16 pages, 12 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present and discuss a new method to extract parton distribution functions from hard scattering processes based on an alternative type of neural network, the Self-Organizing Map. Quantitative results including a detailed treatment of uncertainties are presented within a Next to Leading Order analysis of inclusive electron proton deep inelastic scattering data.
[ { "created": "Thu, 26 Sep 2013 22:54:08 GMT", "version": "v1" } ]
2013-09-30
[ [ "Askanazi", "Evan", "" ], [ "Holcomb", "Katherine", "" ], [ "Liuti", "Simonetta", "" ] ]
We present and discuss a new method to extract parton distribution functions from hard scattering processes based on an alternative type of neural network, the Self-Organizing Map. Quantitative results including a detailed treatment of uncertainties are presented within a Next to Leading Order analysis of inclusive electron proton deep inelastic scattering data.
hep-ph/0407295
Wojciech Broniowski
Wojciech Broniowski, Enrique Ruiz Arriola
Kwiecinski evolution of unintegrated parton distributions
4 pages, 4 figures, talk presented by WB at DIS'2004, Strbske Pleso, Slovakia
null
null
null
hep-ph
null
The Kwiecinski evolution of unintegrated parton distributions (UPDs) in the transverse-coordinate space is analyzed with the help of the Mellin transform. Numerical results are presented for the unintegrated pion distributions with a simple valence-like initial condition at the low scale, which follows from chiral large-Nc quark models. The effect of spreading of UPDs in the transverse momentum with the increasing scale is confirmed, with <kT^2> growing asymptotically as Q^2 alpha(Q^2). Formal aspects of the equations, such as the limits of UPDs at x -> 0, x -> 1, and at low and large b, are straightforward to obtain with our method.
[ { "created": "Mon, 26 Jul 2004 13:44:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Broniowski", "Wojciech", "" ], [ "Arriola", "Enrique Ruiz", "" ] ]
The Kwiecinski evolution of unintegrated parton distributions (UPDs) in the transverse-coordinate space is analyzed with the help of the Mellin transform. Numerical results are presented for the unintegrated pion distributions with a simple valence-like initial condition at the low scale, which follows from chiral large-Nc quark models. The effect of spreading of UPDs in the transverse momentum with the increasing scale is confirmed, with <kT^2> growing asymptotically as Q^2 alpha(Q^2). Formal aspects of the equations, such as the limits of UPDs at x -> 0, x -> 1, and at low and large b, are straightforward to obtain with our method.
hep-ph/9807561
Bob Holdom
B. Holdom and T. Torma
New Axial Interactions at a TeV
14 pages, 1 figure, PRD version
Phys. Rev. D 59, 075005 (1999)
10.1103/PhysRevD.59.075005
UTPT-98-12
hep-ph
null
We consider a heavy fourth family with masses lying in the symmetry breaking channel of a new strong gauge interaction. This interaction generates a heavy quark axial-type operator, whose effects can be enhanced through multiple insertions. In terms of the strength of this operator we can express new negative contributions to the S and T parameters and the shifts of the Z couplings to the third family. In particular we find that the new contribution to T is strongly constrained by the experimental constraints on the Z coupling to the tau.
[ { "created": "Thu, 30 Jul 1998 20:10:37 GMT", "version": "v1" }, { "created": "Thu, 28 Jan 1999 15:21:21 GMT", "version": "v2" } ]
2016-08-25
[ [ "Holdom", "B.", "" ], [ "Torma", "T.", "" ] ]
We consider a heavy fourth family with masses lying in the symmetry breaking channel of a new strong gauge interaction. This interaction generates a heavy quark axial-type operator, whose effects can be enhanced through multiple insertions. In terms of the strength of this operator we can express new negative contributions to the S and T parameters and the shifts of the Z couplings to the third family. In particular we find that the new contribution to T is strongly constrained by the experimental constraints on the Z coupling to the tau.
1309.7287
Philipp Kant
Philipp Kant
Finding Linear Dependencies in Integration-By-Parts Equations: A Monte Carlo Approach
8 pages, 1 figure. Added references. Some minor additions
null
10.1016/j.cpc.2014.01.017
HU-EP-13/49, SFB/CPP-13-68
hep-ph cs.SC physics.comp-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The reduction of a large number of scalar integrals to a small set of master integrals via Laporta's algorithm is common practice in multi-loop calculations. It is also a major bottleneck in terms of running time and memory consumption. It involves solving a large set of linear equations where many of the equations are linearly dependent. We propose a simple algorithm that eliminates all linearly dependent equations from a given system, reducing the time and space requirements of a subsequent run of Laporta's algorithm.
[ { "created": "Fri, 27 Sep 2013 16:23:42 GMT", "version": "v1" }, { "created": "Tue, 11 Feb 2014 14:59:01 GMT", "version": "v2" } ]
2015-06-17
[ [ "Kant", "Philipp", "" ] ]
The reduction of a large number of scalar integrals to a small set of master integrals via Laporta's algorithm is common practice in multi-loop calculations. It is also a major bottleneck in terms of running time and memory consumption. It involves solving a large set of linear equations where many of the equations are linearly dependent. We propose a simple algorithm that eliminates all linearly dependent equations from a given system, reducing the time and space requirements of a subsequent run of Laporta's algorithm.
1005.3359
Xing-Gang Wu
Xing-Gang Wu and Tao Huang
An Implication on the Pion Distribution Amplitude from the Pion-Photon Transition Form Factor with the New BABAR Data
19 pages, 6 figures, 2 tables. Slightly changed, references updated. To be published in Phys.Rev. D
Phys.Rev.D82:034024,2010
10.1103/PhysRevD.82.034024
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The new BABAR data on the pion-photon transition form factor arouses people's new interests on the determination of pion distribution amplitude. To explain the data, we take both the leading valence quark state's and the non-valence quark states' contributions into consideration, where the valence quark part up to next-to-leading order is presented and the non-valence quark part is estimated by a phenomenological model based on its limiting behavior at both $Q^2\to 0$ and $Q^2\to\infty$. Our results show that to be consistent with the new BABAR data at large $Q^2$ region, a broader other than the asymptotic-like pion distribution amplitude should be adopted. The broadness of the pion distribution amplitude is controlled by a parameter $B$. It has been found that the new BABAR data at low and high energy regions can be explained simultaneously by setting $B$ to be around 0.60, in which the pion distribution amplitude is closed to the Chernyak-Zhitnitsky form.
[ { "created": "Wed, 19 May 2010 04:33:09 GMT", "version": "v1" }, { "created": "Thu, 29 Jul 2010 00:07:39 GMT", "version": "v2" } ]
2015-03-17
[ [ "Wu", "Xing-Gang", "" ], [ "Huang", "Tao", "" ] ]
The new BABAR data on the pion-photon transition form factor arouses people's new interests on the determination of pion distribution amplitude. To explain the data, we take both the leading valence quark state's and the non-valence quark states' contributions into consideration, where the valence quark part up to next-to-leading order is presented and the non-valence quark part is estimated by a phenomenological model based on its limiting behavior at both $Q^2\to 0$ and $Q^2\to\infty$. Our results show that to be consistent with the new BABAR data at large $Q^2$ region, a broader other than the asymptotic-like pion distribution amplitude should be adopted. The broadness of the pion distribution amplitude is controlled by a parameter $B$. It has been found that the new BABAR data at low and high energy regions can be explained simultaneously by setting $B$ to be around 0.60, in which the pion distribution amplitude is closed to the Chernyak-Zhitnitsky form.
0910.4947
Shu Lin
Shu Lin and Edward Shuryak
The Rise and Fall of Baryons
13 pages, 13 figures, minor changes to the text
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the baryonic contribution to QCD thermodynamics near the QCD phase transition, which we split into "stringy excitations" and the "chiral" lowest states. Our finite-$T$ string model for the former component is inspired by the lattice data on static potentials and ideas of string survival even $above$ $T_c$: it is used to explain two sets of baryonic susceptibilities calculated on the lattice by the Bielefeld-BNL group. Two new ingredients of the model are (i) the near-$T_c$ tightening of the strings, and (ii) physical upper limit of the string length. Then we proceed to more subtle effects related to chiral restoration dynamics near $T_c$: we suggest that "melting" of the sigma terms of the lowest nucleon/$\Delta$ masses can explain these susceptibilities. In a discussion, we consider bound monopole-quark states, as a possible explanation to some deficits of contribution at $T=(1-1.4)T_c$.
[ { "created": "Mon, 26 Oct 2009 18:21:15 GMT", "version": "v1" }, { "created": "Thu, 14 Jan 2010 20:15:45 GMT", "version": "v2" } ]
2010-01-14
[ [ "Lin", "Shu", "" ], [ "Shuryak", "Edward", "" ] ]
We discuss the baryonic contribution to QCD thermodynamics near the QCD phase transition, which we split into "stringy excitations" and the "chiral" lowest states. Our finite-$T$ string model for the former component is inspired by the lattice data on static potentials and ideas of string survival even $above$ $T_c$: it is used to explain two sets of baryonic susceptibilities calculated on the lattice by the Bielefeld-BNL group. Two new ingredients of the model are (i) the near-$T_c$ tightening of the strings, and (ii) physical upper limit of the string length. Then we proceed to more subtle effects related to chiral restoration dynamics near $T_c$: we suggest that "melting" of the sigma terms of the lowest nucleon/$\Delta$ masses can explain these susceptibilities. In a discussion, we consider bound monopole-quark states, as a possible explanation to some deficits of contribution at $T=(1-1.4)T_c$.
hep-ph/9705327
Svjetlana Fajfer, Ijs
S. Fajfer, P. Singer
Long distance $c \to u \gamma$ effects in weak radiative decays of D-mesons
28 pages, Latex, 2 Figures
Phys.Rev.D56:4302-4310,1997
10.1103/PhysRevD.56.4302
TECHNION-PH-97-05; IJS-TP-97/07
hep-ph
null
We present a detailed analysis of the $D \to V \gamma $ transitions, using a model which combines heavy quark effective theory and the chiral Lagrangian approach and includes symmetry breaking. We notice that in addition to the previously considered s - channel annihilation and t - channel W - exchange, there is a long distance penguin - like $ c \to u \gamma$ contribution in the t - channel of Cabibbo - suppressed modes. Its magnitude is determined by the size of symmetry breaking which we calculate with a vector dominance approach. Although smaller in magnitude, the penguin - like contribution would lead to sizeable effects in case of cancellations among the other contributions to the amplitude. Thus, it may invalidate suggested tests for beyond the standard model effects in these decays. We also indicate the range of expectations for the branching ratios of various $D \to V \gamma$ modes.
[ { "created": "Thu, 15 May 1997 17:23:46 GMT", "version": "v1" } ]
2011-02-01
[ [ "Fajfer", "S.", "" ], [ "Singer", "P.", "" ] ]
We present a detailed analysis of the $D \to V \gamma $ transitions, using a model which combines heavy quark effective theory and the chiral Lagrangian approach and includes symmetry breaking. We notice that in addition to the previously considered s - channel annihilation and t - channel W - exchange, there is a long distance penguin - like $ c \to u \gamma$ contribution in the t - channel of Cabibbo - suppressed modes. Its magnitude is determined by the size of symmetry breaking which we calculate with a vector dominance approach. Although smaller in magnitude, the penguin - like contribution would lead to sizeable effects in case of cancellations among the other contributions to the amplitude. Thus, it may invalidate suggested tests for beyond the standard model effects in these decays. We also indicate the range of expectations for the branching ratios of various $D \to V \gamma$ modes.
hep-ph/9305322
Steven Bass
S.D. Bass (Cavendish Lab., Cambridge, U.K.) and A. W. Thomas (Univ. Adelaide, Australia)
Mapping the x dependence of the axial anomaly in polarised deep inelastic scattering
11pages Latex, 6 Figs. appended as .ps files after main text, Cavendish preprint HEP-93/1
Phys.Lett.B312:345-350,1993
10.1016/0370-2693(93)91091-Z
null
hep-ph
null
We discuss the role of the U(1) axial anomaly in the spin structure functions of the nucleon, with particular emphasis on how one might determine its x dependence in present and future deep inelastic scattering experiments. We focus on the C-odd spin structure function g3 and also the deuteron structure function g1^d.
[ { "created": "Wed, 26 May 1993 14:59:10 GMT", "version": "v1" } ]
2010-02-17
[ [ "Bass", "S. D.", "", "Cavendish Lab., Cambridge, U.K." ], [ "Thomas", "A. W.", "", "Univ.\n Adelaide, Australia" ] ]
We discuss the role of the U(1) axial anomaly in the spin structure functions of the nucleon, with particular emphasis on how one might determine its x dependence in present and future deep inelastic scattering experiments. We focus on the C-odd spin structure function g3 and also the deuteron structure function g1^d.
hep-ph/0401166
Alexander Silenko
Alexander J. Silenko
Equation of spin motion in storage rings in a cylindrical coordinate system
14 pages
Published in Phys.Rev. ST Accel. Beams 9:034003,2006
10.1103/PhysRevSTAB.9.034003
null
hep-ph
null
The exact equation of spin motion in a cylindrical coordinate system with allowance for electric dipole moments of particles has been derived. This equation is convenient for analytical calculations of spin dynamics in circular storage rings when the configuration of main fields is simple enough. The generalized formula for the influence of a vertical betatron oscillation on the angular velocity of spin rotation has been found. This formula agrees with the previously obtained result and contains an additional oscillatory term that can be used for fitting. The relative importance of terms in the equation of spin motion is discussed.
[ { "created": "Thu, 22 Jan 2004 16:25:47 GMT", "version": "v1" }, { "created": "Thu, 30 Mar 2006 10:48:05 GMT", "version": "v2" } ]
2007-05-23
[ [ "Silenko", "Alexander J.", "" ] ]
The exact equation of spin motion in a cylindrical coordinate system with allowance for electric dipole moments of particles has been derived. This equation is convenient for analytical calculations of spin dynamics in circular storage rings when the configuration of main fields is simple enough. The generalized formula for the influence of a vertical betatron oscillation on the angular velocity of spin rotation has been found. This formula agrees with the previously obtained result and contains an additional oscillatory term that can be used for fitting. The relative importance of terms in the equation of spin motion is discussed.
1103.4320
Christoffer Flensburg
Christoffer Flensburg, G\"osta Gustafson, Leif L\"onnblad and Andras Ster
Correlations in double parton distributions at small x
19 pages v2: minor clarifications added. v3: citation added; JHEP 2011, Number 6, 66
null
10.1007/JHEP06(2011)066
LU-TP 11-12, CERN-PH-TH-2011-059, MCnet-11-09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a dynamical study of the double parton distribution in impact parameter space, which enters into the double scattering cross section in hadronic collisions. This distribution is analogous to the generalized parton densities in momentum space. We use the Lund Dipole Cascade model, presented in earlier articles, which is based on BFKL evolution including essential higher order corrections and saturation effects. As result we find large correlation effects, which break the factorization of the double scattering process. At small transverse separation we see the development of "hot spots", which become stronger with increasing Q^2. At smaller x-values the distribution widens, consistent with the shrinking of the diffractive peak in elastic scattering. The dependence on Q^2 is, however, significantly stronger than the dependence on x, which has implications for extrapolations to LHC, e.g. for results for underlying events associated with the production of new heavy particles.
[ { "created": "Tue, 22 Mar 2011 17:31:18 GMT", "version": "v1" }, { "created": "Tue, 21 Jun 2011 11:33:34 GMT", "version": "v2" }, { "created": "Mon, 27 Jun 2011 10:08:40 GMT", "version": "v3" } ]
2011-06-28
[ [ "Flensburg", "Christoffer", "" ], [ "Gustafson", "Gösta", "" ], [ "Lönnblad", "Leif", "" ], [ "Ster", "Andras", "" ] ]
We present a dynamical study of the double parton distribution in impact parameter space, which enters into the double scattering cross section in hadronic collisions. This distribution is analogous to the generalized parton densities in momentum space. We use the Lund Dipole Cascade model, presented in earlier articles, which is based on BFKL evolution including essential higher order corrections and saturation effects. As result we find large correlation effects, which break the factorization of the double scattering process. At small transverse separation we see the development of "hot spots", which become stronger with increasing Q^2. At smaller x-values the distribution widens, consistent with the shrinking of the diffractive peak in elastic scattering. The dependence on Q^2 is, however, significantly stronger than the dependence on x, which has implications for extrapolations to LHC, e.g. for results for underlying events associated with the production of new heavy particles.
1401.4801
Stefan Groote Dr.
S. Groote, J.G. K\"orner and D. Niinepuu
Perturbative $O(\alpha_s)$ corrections to the correlation functions of light tetraquark currents
31 pages, 2 figures and 2 tables
Phys. Rev. D 90, 054028 (2014)
10.1103/PhysRevD.90.054028
MITP/14-003
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the next-to-leading order QCD corrections to the perturbative term in the operator product expansion of the spectral functions of light tetraquark currents. By using also configuration space methods we keep the momentum space four-loop calculation to a manageable level. We find that the next-to-leading order corrections to the perturbative term are large and can amount to $O(100\%)$. The corrections to the corresponding Borel sum rules, however, are small since the nonperturbative condensate contributions dominate the Borel sum rules.
[ { "created": "Mon, 20 Jan 2014 06:38:30 GMT", "version": "v1" }, { "created": "Tue, 30 Sep 2014 06:06:58 GMT", "version": "v2" } ]
2014-10-01
[ [ "Groote", "S.", "" ], [ "Körner", "J. G.", "" ], [ "Niinepuu", "D.", "" ] ]
We calculate the next-to-leading order QCD corrections to the perturbative term in the operator product expansion of the spectral functions of light tetraquark currents. By using also configuration space methods we keep the momentum space four-loop calculation to a manageable level. We find that the next-to-leading order corrections to the perturbative term are large and can amount to $O(100\%)$. The corrections to the corresponding Borel sum rules, however, are small since the nonperturbative condensate contributions dominate the Borel sum rules.
0807.4380
Stefano Nicotri
Stefano Nicotri
$D_{sJ}(2700)$ and other puzzling states in charm spectroscopy
LaTeX, 3 pages. Talk given at IFAE 2008, Bologna, Italy, 26-28 March 2008
null
10.1393/ncb/i2008-10579-5
BA-TH/595-08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I briefly introduce the status of charm physics and I discuss the case of the meson with open charm $D_{sJ}(2700)$.
[ { "created": "Mon, 28 Jul 2008 08:48:23 GMT", "version": "v1" } ]
2009-11-13
[ [ "Nicotri", "Stefano", "" ] ]
I briefly introduce the status of charm physics and I discuss the case of the meson with open charm $D_{sJ}(2700)$.
hep-ph/9603449
null
Elizabeth Jenkins
Heavy Baryon Masses in the $1/m_Q$ and $1/N_c$ Expansions
21 pages, REVtex, version to appear Phys. Rev. D
Phys.Rev.D54:4515-4531,1996
10.1103/PhysRevD.54.4515
UCSD/PTH 96-08
hep-ph
null
The masses of baryons containing a single heavy quark are studied in a combined expansion in $1/m_Q$, $1/N_c$ and $SU(3)$ flavor symmetry breaking. Heavy quark baryon mass splittings are related to mass splittings of the octet and decuplet baryons. The $\Sigma_c^*$, $\Xi_c^\prime$ and $\Omega_c^*$ are predicted to the level of a few MeV. A number of bottom baryon mass splittings are predicted very accurately.
[ { "created": "Mon, 1 Apr 1996 01:31:14 GMT", "version": "v1" }, { "created": "Mon, 2 Sep 1996 23:04:06 GMT", "version": "v2" } ]
2008-11-26
[ [ "Jenkins", "Elizabeth", "" ] ]
The masses of baryons containing a single heavy quark are studied in a combined expansion in $1/m_Q$, $1/N_c$ and $SU(3)$ flavor symmetry breaking. Heavy quark baryon mass splittings are related to mass splittings of the octet and decuplet baryons. The $\Sigma_c^*$, $\Xi_c^\prime$ and $\Omega_c^*$ are predicted to the level of a few MeV. A number of bottom baryon mass splittings are predicted very accurately.
1211.4573
Miguel Pato
Mathias Garny, Alejandro Ibarra, Miguel Pato, Stefan Vogl
On the spin-dependent sensitivity of XENON100
7 pages, 3 figures
Phys. Rev. D 87, 056002 (2013)
10.1103/PhysRevD.87.056002
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The latest XENON100 data severely constrains dark matter elastic scattering off nuclei, leading to impressive upper limits on the spin-independent cross-section. The main goal of this paper is to stress that the same data set has also an excellent \emph{spin-dependent} sensitivity, which is of utmost importance in probing dark matter models. We show in particular that the constraints set by XENON100 on the spin-dependent neutron cross-section are by far the best at present, whereas the corresponding spin-dependent proton limits lag behind other direct detection results. The effect of nuclear uncertainties on the structure functions of xenon isotopes is analysed in detail and found to lessen the robustness of the constraints, especially for spin-dependent proton couplings. Notwithstanding, the spin-dependent neutron prospects for XENON1T and DARWIN are very encouraging. We apply our constraints to well-motivated dark matter models and demonstrate that in both mass-degenerate scenarios and the minimal supersymmetric standard model the spin-dependent neutron limits can actually override the spin-independent limits. This opens the possibility of probing additional unexplored regions of the dark matter parameter space with the next generation of ton-scale direct detection experiments.
[ { "created": "Mon, 19 Nov 2012 21:00:01 GMT", "version": "v1" }, { "created": "Tue, 12 Mar 2013 11:56:45 GMT", "version": "v2" } ]
2013-03-13
[ [ "Garny", "Mathias", "" ], [ "Ibarra", "Alejandro", "" ], [ "Pato", "Miguel", "" ], [ "Vogl", "Stefan", "" ] ]
The latest XENON100 data severely constrains dark matter elastic scattering off nuclei, leading to impressive upper limits on the spin-independent cross-section. The main goal of this paper is to stress that the same data set has also an excellent \emph{spin-dependent} sensitivity, which is of utmost importance in probing dark matter models. We show in particular that the constraints set by XENON100 on the spin-dependent neutron cross-section are by far the best at present, whereas the corresponding spin-dependent proton limits lag behind other direct detection results. The effect of nuclear uncertainties on the structure functions of xenon isotopes is analysed in detail and found to lessen the robustness of the constraints, especially for spin-dependent proton couplings. Notwithstanding, the spin-dependent neutron prospects for XENON1T and DARWIN are very encouraging. We apply our constraints to well-motivated dark matter models and demonstrate that in both mass-degenerate scenarios and the minimal supersymmetric standard model the spin-dependent neutron limits can actually override the spin-independent limits. This opens the possibility of probing additional unexplored regions of the dark matter parameter space with the next generation of ton-scale direct detection experiments.
hep-ph/0608276
Christoph Schuck
M. Gl\"uck, E. Reya
Parton evolution in the fixed flavor factorization scheme
5 pages
Mod.Phys.Lett.A22:351-354,2007
10.1142/S021773230702275X
null
hep-ph
null
It is argued that while the scale dependence of the parton distributions in the fixed flavor factorization scheme is governed by three active flavors, the scale dependence of the running coupling should nevertheless be better governed by a variable number of active flavors.
[ { "created": "Thu, 24 Aug 2006 14:15:13 GMT", "version": "v1" } ]
2008-11-26
[ [ "Glück", "M.", "" ], [ "Reya", "E.", "" ] ]
It is argued that while the scale dependence of the parton distributions in the fixed flavor factorization scheme is governed by three active flavors, the scale dependence of the running coupling should nevertheless be better governed by a variable number of active flavors.
hep-ph/9811432
Alexander S. Sakharov
M. Yu. Khlopov, A. S. Sakharov and A. L. Sudarikov
CosmoParticle Physics: Basic Principles and Prospects for Future Development
12 pages
Grav.Cosmol.4:S1,1998
null
null
hep-ph
null
COSMOPARTICLE PHYSICS is the specific crossdisciplinary field of science, studying foundations of particle physics and cosmology in the combination of indirect cosmological, astrophysical and physical signatures of their fundamental relationship. The possibilities to elaborate unique theoretical grounds for cosmology and particle physics and to study quantitative relationships between cosmological and laboratory effects follow from the basic principles of cosmoparticle physics and open new interesting fields of scientific research in its future development.
[ { "created": "Sat, 21 Nov 1998 22:38:58 GMT", "version": "v1" } ]
2008-11-26
[ [ "Khlopov", "M. Yu.", "" ], [ "Sakharov", "A. S.", "" ], [ "Sudarikov", "A. L.", "" ] ]
COSMOPARTICLE PHYSICS is the specific crossdisciplinary field of science, studying foundations of particle physics and cosmology in the combination of indirect cosmological, astrophysical and physical signatures of their fundamental relationship. The possibilities to elaborate unique theoretical grounds for cosmology and particle physics and to study quantitative relationships between cosmological and laboratory effects follow from the basic principles of cosmoparticle physics and open new interesting fields of scientific research in its future development.
hep-ph/0209123
Naotoshi Okamura
N. Okamura (Virginia Tech)
Measuring the CP-Violating Phase by a Long Baseline Neutrino Experiment with Hyper-Kamiokande
1 page, proccdings of Neutrino 2002, Munich, Germany, May 25-30, 2002, and YITP workshop, Kyoto, Japan, July 8-11. 2002
null
10.1016/S0920-5632(03)01365-3
VPI-IPPAP-02-10
hep-ph
null
This is a contribution paper of the XXth International Conference on Neutrino Physics and Astrophysics (Neutrino2002) and YITP workshop.
[ { "created": "Wed, 11 Sep 2002 19:48:25 GMT", "version": "v1" } ]
2009-11-07
[ [ "Okamura", "N.", "", "Virginia Tech" ] ]
This is a contribution paper of the XXth International Conference on Neutrino Physics and Astrophysics (Neutrino2002) and YITP workshop.
1101.0867
Fuminobu Takahashi
Fuminobu Takahashi and Tsutomu T. Yanagida
Why have supersymmetric particles not been observed?
9 pages. v2: Note added to clarify how the lower bound on the SUSY mass scale is obtained
Physics Letters B 698 (2011) 408-410
10.1016/j.physletb.2011.03.032
IPMU-11-0001
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If low-energy supersymmetry is the solution to the hierarchy problem, it is a puzzle why supersymmetric particles have not been observed experimentally to date. We show that supersymmetric particles in the TeV region can be explained if the fundamental cut-off scale of the theory is smaller than the 4-dimensional Planck scale and if thermal leptogenesis is the source of the observed baryon asymmetry. The supersymmetric particles such as sfermions and gauginos are predicted to be in the TeV region, while the gravitino is the LSP with mass of O(100)GeV and is a good candidate for dark matter. Interestingly, the cosmological moduli problem can be solved in the theory with the low cut-off scale.
[ { "created": "Wed, 5 Jan 2011 02:07:29 GMT", "version": "v1" }, { "created": "Wed, 23 Feb 2011 09:05:41 GMT", "version": "v2" } ]
2011-04-18
[ [ "Takahashi", "Fuminobu", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
If low-energy supersymmetry is the solution to the hierarchy problem, it is a puzzle why supersymmetric particles have not been observed experimentally to date. We show that supersymmetric particles in the TeV region can be explained if the fundamental cut-off scale of the theory is smaller than the 4-dimensional Planck scale and if thermal leptogenesis is the source of the observed baryon asymmetry. The supersymmetric particles such as sfermions and gauginos are predicted to be in the TeV region, while the gravitino is the LSP with mass of O(100)GeV and is a good candidate for dark matter. Interestingly, the cosmological moduli problem can be solved in the theory with the low cut-off scale.
2307.07844
Mayank Singh
Charles Gale, Sangyong Jeon, Daniel Pablos, Mayank Singh
Studying QGP transport properties in a concurrent minijet+hydro framework
6 pages, 4 figures, Proceedings for Hard Probes 2023
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Minijets are ubiquitous in heavy-ion collision experiments. However, they are often excluded from the hydrodynamic simulations of QGP as they do not thermalize at short time scales and are not treated as part of the collective medium. Using a concurrent jet+hydro framework, we show that the minijets could account for a significant portion of particle multiplicity. Therefore, the energy deposition from minijet-medium interactions can substantially modify the QGP transport properties inferred from model-to-data comparisons.
[ { "created": "Sat, 15 Jul 2023 16:33:36 GMT", "version": "v1" } ]
2023-07-18
[ [ "Gale", "Charles", "" ], [ "Jeon", "Sangyong", "" ], [ "Pablos", "Daniel", "" ], [ "Singh", "Mayank", "" ] ]
Minijets are ubiquitous in heavy-ion collision experiments. However, they are often excluded from the hydrodynamic simulations of QGP as they do not thermalize at short time scales and are not treated as part of the collective medium. Using a concurrent jet+hydro framework, we show that the minijets could account for a significant portion of particle multiplicity. Therefore, the energy deposition from minijet-medium interactions can substantially modify the QGP transport properties inferred from model-to-data comparisons.
hep-ph/0012288
Dmitri Kazakov
D. I. Kazakov (JINR, Dubna and ITEP, Moscow)
Beyond the Standard Model (In Search of Supersymmetry)
LaTeX2e, 80 pages, 60 eps figures, v2 references corrected Lectures given at the European School for High Energy Physics, Caramulo, Portugal, Aug.-Sept. 2000
null
null
null
hep-ph
null
The present lectures contain an introduction to low energy supersymmetry, a new symmetry that relates bosons and fermions, in particle physics. The Standard Model of fundamental interactions is briefly reviewed, and the motivation to introduce supersymmetry is discussed. The main notions of supersymmetry are introduced. The supersymmetric extension of the Standard Model - the Minimal Supersymmetric Standard Model - is considered in more detail. Phenomenological features of the MSSM as well as possible experimental signatures of SUSY are described. An intriguing situation with the supersymmetric Higgs boson is discussed.
[ { "created": "Thu, 21 Dec 2000 14:15:15 GMT", "version": "v1" }, { "created": "Thu, 11 Jan 2001 16:11:08 GMT", "version": "v2" } ]
2009-09-25
[ [ "Kazakov", "D. I.", "", "JINR, Dubna and ITEP, Moscow" ] ]
The present lectures contain an introduction to low energy supersymmetry, a new symmetry that relates bosons and fermions, in particle physics. The Standard Model of fundamental interactions is briefly reviewed, and the motivation to introduce supersymmetry is discussed. The main notions of supersymmetry are introduced. The supersymmetric extension of the Standard Model - the Minimal Supersymmetric Standard Model - is considered in more detail. Phenomenological features of the MSSM as well as possible experimental signatures of SUSY are described. An intriguing situation with the supersymmetric Higgs boson is discussed.
0901.2609
Seodong Shin
Yeong Gyun Kim and Seodong Shin
Singlet Fermionic Dark Matter explains DAMA signal
9 pages, 3 figures
JHEP 0905:036,2009
10.1088/1126-6708/2009/05/036
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been suggested that, considering channeling effect, the order of a few GeV dark matters which are elastically scattered from detector nuclei might be plausible candidates reconciling the DAMA annual modulation signal with the results of other null experiments. We show that Singlet Fermionic Dark Matter can be such a dark matter candidate, simultaneously providing the correct thermal relic density which is consistent with the WMAP data.
[ { "created": "Sat, 17 Jan 2009 03:59:12 GMT", "version": "v1" } ]
2010-01-15
[ [ "Kim", "Yeong Gyun", "" ], [ "Shin", "Seodong", "" ] ]
It has been suggested that, considering channeling effect, the order of a few GeV dark matters which are elastically scattered from detector nuclei might be plausible candidates reconciling the DAMA annual modulation signal with the results of other null experiments. We show that Singlet Fermionic Dark Matter can be such a dark matter candidate, simultaneously providing the correct thermal relic density which is consistent with the WMAP data.
hep-ph/9607459
Thomas Waas
N. Kaiser, T. Waas and W. Weise
SU(3) Chiral Dynamics with Coupled Channels: Eta and Kaon Photoproduction
27 pages, TeX type, 21 figures in ps, submitted to Nucl. Phys. A
Nucl.Phys. A612 (1997) 297-320
10.1016/S0375-9474(96)00321-1
null
hep-ph
null
We identify the leading s-wave amplitudes of the SU(3) chiral meson-baryon Lagrangian with an effective coupled-channel potential which is iterated in a Lippmann-Schwinger equation. The strangeness $S=-1$ resonance $\Lambda(1405)$ and the $S_{11}(1535)$ nucleon resonance emerge as quasi-bound states of anti-kaon/nucleon and kaon/$\Sigma$-hyperon. Our approach to meson photoproduction introduces no new parameters. By adjusting a few finite range parameters we are able to simultaneously describe a large amount of low energy data. These include the cross sections of $K^-p$ elastic and inelastic scattering, the cross sections of eta meson and kaon photoproduction from nucleons as well as those of pion induced production of etas and kaons (16 different reaction channels altogether).
[ { "created": "Mon, 29 Jul 1996 13:11:42 GMT", "version": "v1" } ]
2016-09-06
[ [ "Kaiser", "N.", "" ], [ "Waas", "T.", "" ], [ "Weise", "W.", "" ] ]
We identify the leading s-wave amplitudes of the SU(3) chiral meson-baryon Lagrangian with an effective coupled-channel potential which is iterated in a Lippmann-Schwinger equation. The strangeness $S=-1$ resonance $\Lambda(1405)$ and the $S_{11}(1535)$ nucleon resonance emerge as quasi-bound states of anti-kaon/nucleon and kaon/$\Sigma$-hyperon. Our approach to meson photoproduction introduces no new parameters. By adjusting a few finite range parameters we are able to simultaneously describe a large amount of low energy data. These include the cross sections of $K^-p$ elastic and inelastic scattering, the cross sections of eta meson and kaon photoproduction from nucleons as well as those of pion induced production of etas and kaons (16 different reaction channels altogether).
1611.09856
Krzysztof Rolbiecki
Daniel Dercks, Nishita Desai, Jong Soo Kim, Krzysztof Rolbiecki, Jamie Tattersall, Torsten Weber
CheckMATE 2: From the model to the limit
53 pages, 6 figures; references updated, instructions slightly changed
null
10.1016/j.cpc.2017.08.021
CTPU-16-36, CSIC-16-116, TTK-16-47
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the latest developments to the CheckMATE program that allows models of new physics to be easily tested against the recent LHC data. To achieve this goal, the core of CheckMATE now contains over 60 LHC analyses of which 12 are from the 13 TeV run. The main new feature is that CheckMATE 2 now integrates the Monte Carlo event generation via Madgraph and Pythia 8. This allows users to go directly from a SLHA file or UFO model to the result of whether a model is allowed or not. In addition, the integration of the event generation leads to a significant increase in the speed of the program. Many other improvements have also been made, including the possibility to now combine signal regions to give a total likelihood for a model.
[ { "created": "Tue, 29 Nov 2016 21:00:01 GMT", "version": "v1" }, { "created": "Tue, 28 Feb 2017 18:53:21 GMT", "version": "v2" } ]
2017-10-25
[ [ "Dercks", "Daniel", "" ], [ "Desai", "Nishita", "" ], [ "Kim", "Jong Soo", "" ], [ "Rolbiecki", "Krzysztof", "" ], [ "Tattersall", "Jamie", "" ], [ "Weber", "Torsten", "" ] ]
We present the latest developments to the CheckMATE program that allows models of new physics to be easily tested against the recent LHC data. To achieve this goal, the core of CheckMATE now contains over 60 LHC analyses of which 12 are from the 13 TeV run. The main new feature is that CheckMATE 2 now integrates the Monte Carlo event generation via Madgraph and Pythia 8. This allows users to go directly from a SLHA file or UFO model to the result of whether a model is allowed or not. In addition, the integration of the event generation leads to a significant increase in the speed of the program. Many other improvements have also been made, including the possibility to now combine signal regions to give a total likelihood for a model.
2310.19883
Julie Pag\`es
Elizabeth E. Jenkins, Aneesh V. Manohar, Luca Naterop, Julie Pag\`es
Two Loop Renormalization of Scalar Theories using a Geometric Approach
ChPT results to O($p^6$) now agree with Bijnens, Colangelo, and Ecker, hep-ph/9907333
null
null
ZU-TH 69/23, PSI-PR-23-39
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive a general formula for two-loop counterterms in Effective Field Theories (EFTs) using a geometric approach. This formula allows the two-loop results of our previous paper to be applied to a wide range of theories. The two-loop results hold for loop graphs in EFTs where the interaction vertices contain operators of arbitrarily high dimension, but at most two derivatives. We also extend our previous one-loop result to include operators with an arbitrary number of derivatives, as long as there is at most one derivative acting on each field. The final result for the two-loop counterterms is written in terms of geometric quantities such as the Riemann curvature tensor of the scalar manifold and its covariant derivatives. As applications of our results, we give the two-loop counterterms and renormalization group equations for the O(n) EFT to dimension six, the scalar sector of the Standard Model Effective Field Theory (SMEFT) to dimension six, and chiral perturbation theory to order $p^6$.
[ { "created": "Mon, 30 Oct 2023 18:00:04 GMT", "version": "v1" }, { "created": "Thu, 9 Nov 2023 19:25:02 GMT", "version": "v2" } ]
2023-11-13
[ [ "Jenkins", "Elizabeth E.", "" ], [ "Manohar", "Aneesh V.", "" ], [ "Naterop", "Luca", "" ], [ "Pagès", "Julie", "" ] ]
We derive a general formula for two-loop counterterms in Effective Field Theories (EFTs) using a geometric approach. This formula allows the two-loop results of our previous paper to be applied to a wide range of theories. The two-loop results hold for loop graphs in EFTs where the interaction vertices contain operators of arbitrarily high dimension, but at most two derivatives. We also extend our previous one-loop result to include operators with an arbitrary number of derivatives, as long as there is at most one derivative acting on each field. The final result for the two-loop counterterms is written in terms of geometric quantities such as the Riemann curvature tensor of the scalar manifold and its covariant derivatives. As applications of our results, we give the two-loop counterterms and renormalization group equations for the O(n) EFT to dimension six, the scalar sector of the Standard Model Effective Field Theory (SMEFT) to dimension six, and chiral perturbation theory to order $p^6$.
1904.07915
Tongyan Lin
Tongyan Lin
TASI lectures on dark matter models and direct detection
90 pages
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
These lectures provide an introduction to models and direct detection of dark matter. We summarize the general features and motivations for candidates in the full dark matter mass range, and then restrict to the keV-TeV mass window. Candidates in this window can be produced by thermal mechanisms in the standard cosmology, and are an important target for experimental searches. We then turn to sub-GeV dark matter (light dark matter) and dark sectors, an area where many new models and experiments are currently being proposed. We discuss the cosmology of dark sectors, specific portal realizations, and some of the prospects for detection. The final parts of these lectures focus on the theory for direct detection, both reviewing the fundamentals for nuclear recoils of WIMPs and describing new directions for sub-GeV candidates. A version of these lectures was originally presented at the TASI 2018 summer school on "Theory in an Era of Data".
[ { "created": "Tue, 16 Apr 2019 18:44:58 GMT", "version": "v1" } ]
2019-04-18
[ [ "Lin", "Tongyan", "" ] ]
These lectures provide an introduction to models and direct detection of dark matter. We summarize the general features and motivations for candidates in the full dark matter mass range, and then restrict to the keV-TeV mass window. Candidates in this window can be produced by thermal mechanisms in the standard cosmology, and are an important target for experimental searches. We then turn to sub-GeV dark matter (light dark matter) and dark sectors, an area where many new models and experiments are currently being proposed. We discuss the cosmology of dark sectors, specific portal realizations, and some of the prospects for detection. The final parts of these lectures focus on the theory for direct detection, both reviewing the fundamentals for nuclear recoils of WIMPs and describing new directions for sub-GeV candidates. A version of these lectures was originally presented at the TASI 2018 summer school on "Theory in an Era of Data".
0709.3816
Jurgen Reuter
Jurgen Reuter
Little Higgs Model Discrimination at the LHC and ILC
Submitted for the SUSY07 proceedings, 4 pages, 6 eps figures
null
null
FR-THEP-07-08
hep-ph
null
We propose a means to discriminate between the two basic variants of Little Higgs models, the Product Group and Simple Group models, at the next generation of colliders. It relies on a special coupling of light pseudoscalar particles present in Little Higgs models, the pseudoaxions, to the Z and the Higgs boson, which is present only in Simple Group models. We discuss the collider phenomenology of the pseudoaxion in the presence of such a coupling at the LHC, where resonant production and decay of either the Higgs or the pseudoaxion induced by that coupling can be observed for much of parameter space. The full allowed range of parameters, including regions where the observability is limited at the LHC, is covered by a future ILC, where double scalar production would be a golden channel to look for.
[ { "created": "Mon, 24 Sep 2007 16:56:20 GMT", "version": "v1" } ]
2007-09-25
[ [ "Reuter", "Jurgen", "" ] ]
We propose a means to discriminate between the two basic variants of Little Higgs models, the Product Group and Simple Group models, at the next generation of colliders. It relies on a special coupling of light pseudoscalar particles present in Little Higgs models, the pseudoaxions, to the Z and the Higgs boson, which is present only in Simple Group models. We discuss the collider phenomenology of the pseudoaxion in the presence of such a coupling at the LHC, where resonant production and decay of either the Higgs or the pseudoaxion induced by that coupling can be observed for much of parameter space. The full allowed range of parameters, including regions where the observability is limited at the LHC, is covered by a future ILC, where double scalar production would be a golden channel to look for.
hep-ph/0210086
Hassib Amini
Hassib Amini
Radiative Corrections to Higgs Masses in $Z^{\prime}$ Models
14 pages, 4 figures
New J.Phys. 5 (2003) 49
10.1088/1367-2630/5/1/349
null
hep-ph
null
We calculate radiative corrections to the masses of the Higgs bosons in a minimal supersymmetric model that contains an additional non-anomalous (U(1)') gauge symmetry. With some fine-tuning of the (U(1)') charges of the Higgs fields, it is possible to suppress the (Z)--(Z^{\prime}) mixing. We use this fact, along with the lower bound on the lightest Higgs mass after LEPII era, as a criterion to restrict the set of parameters in our analysis. We calculate the mass of the lightest Higgs and its mixing with the other Higgs bosons, in a large region of the parameter space.
[ { "created": "Fri, 4 Oct 2002 21:29:12 GMT", "version": "v1" }, { "created": "Wed, 16 Oct 2002 21:42:24 GMT", "version": "v2" }, { "created": "Wed, 25 Jun 2003 13:18:21 GMT", "version": "v3" } ]
2009-11-07
[ [ "Amini", "Hassib", "" ] ]
We calculate radiative corrections to the masses of the Higgs bosons in a minimal supersymmetric model that contains an additional non-anomalous (U(1)') gauge symmetry. With some fine-tuning of the (U(1)') charges of the Higgs fields, it is possible to suppress the (Z)--(Z^{\prime}) mixing. We use this fact, along with the lower bound on the lightest Higgs mass after LEPII era, as a criterion to restrict the set of parameters in our analysis. We calculate the mass of the lightest Higgs and its mixing with the other Higgs bosons, in a large region of the parameter space.
hep-ph/9301278
Patrick O'Donnell
Patrick J. O'Donnell and Humphrey K.K. Tung
The Rare Decay $B\to K^{\ast}\gamma$: A More Precise Calculation
15 pages, UTPT-93-02, in REVTEX with one figure in eps
Phys.Rev. D48 (1993) 2145-2151
10.1103/PhysRevD.48.2145
null
hep-ph
null
Efforts to predict the rare exclusive decay $B\to K^{\ast}\gamma$ from the well known inclusive decay $b\to s\gamma$ are frustrated by the effect of the large recoil momentum. We show how to reduce the large uncertainty in calculating this decay by relating $B\to K^{\ast}\gamma$ to the semileptonic process $B\to\rho e\bar{\nu}$ using the heavy-quark symmetry in B decays and SU(3) flavor symmetry. A direct measurement of the $q^{2}$-spectrum for the semileptonic decay can provide accurate information for the exclusive rare decay.
[ { "created": "Tue, 26 Jan 1993 19:44:54 GMT", "version": "v1" } ]
2009-10-22
[ [ "O'Donnell", "Patrick J.", "" ], [ "Tung", "Humphrey K. K.", "" ] ]
Efforts to predict the rare exclusive decay $B\to K^{\ast}\gamma$ from the well known inclusive decay $b\to s\gamma$ are frustrated by the effect of the large recoil momentum. We show how to reduce the large uncertainty in calculating this decay by relating $B\to K^{\ast}\gamma$ to the semileptonic process $B\to\rho e\bar{\nu}$ using the heavy-quark symmetry in B decays and SU(3) flavor symmetry. A direct measurement of the $q^{2}$-spectrum for the semileptonic decay can provide accurate information for the exclusive rare decay.
0809.0094
Shinya Kanemura
Eri Asakawa, Daisuke Harada, Shinya Kanemura, Yasuhiro Okada, Koji Tsumura
Higgs boson pair production at a photon-photon collision in the two Higgs doublet model
16 pages, 8 figures; added Appendix with a figure
null
10.1016/j.physletb.2009.01.050
KEK-TH-1271, UT-HET 014, IC/2008/59
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the cross section of Higgs boson pair production at a photon collider in the two Higgs doublet model. We focus on the scenario in which the lightest CP even Higgs boson ($h$) has the standard model like couplings to the gauge bosons. We take into account the one-loop correction to the $hhh$ coupling as well as additional one-loop diagrams due to charged Higgs bosons to the $\gamma\gamma\to hh$ helicity amplitudes. It is found that the full cross section can be enhanced by both these effects to a considerable level. We discuss the impact of these corrections on the $hhh$ coupling measurement at the photon collider.
[ { "created": "Sun, 31 Aug 2008 02:25:36 GMT", "version": "v1" }, { "created": "Wed, 7 Jan 2009 14:54:11 GMT", "version": "v2" } ]
2009-11-13
[ [ "Asakawa", "Eri", "" ], [ "Harada", "Daisuke", "" ], [ "Kanemura", "Shinya", "" ], [ "Okada", "Yasuhiro", "" ], [ "Tsumura", "Koji", "" ] ]
We calculate the cross section of Higgs boson pair production at a photon collider in the two Higgs doublet model. We focus on the scenario in which the lightest CP even Higgs boson ($h$) has the standard model like couplings to the gauge bosons. We take into account the one-loop correction to the $hhh$ coupling as well as additional one-loop diagrams due to charged Higgs bosons to the $\gamma\gamma\to hh$ helicity amplitudes. It is found that the full cross section can be enhanced by both these effects to a considerable level. We discuss the impact of these corrections on the $hhh$ coupling measurement at the photon collider.
hep-ph/0204048
Ed Stoeffhaas
M. M. Block
Forward Compton Scattering, using Real Analytic Amplitudes
Latex2e, 6 pages, 2 postscript figures placed with epsfig.sty. Fixed problem with Fig.1 placement. Version to be published in Phys. Rev. D
Phys.Rev. D65 (2002) 116005
10.1103/PhysRevD.65.116005
NUHEP 1000
hep-ph
null
We analyze forward Compton scattering, using real analytic amplitudes. By fitting the total \gamma p scattering cross section data in the high energy region 5 GeV < \sqrt s < 20 GeV, using a cross section rising as \ln^2 s, we calculate \rho_{\gamma p}, the ratio of the real to the imaginary portion of the the forward Compton scattering amplitude, and compare this to \rho_{nn}, the ratio of the even portions of the pp and p-bar p forward scattering amplitudes. We find that the two \rho-values are, within errors, the same in the c.m.s. energy region 5 GeV < \sqrt s < 200 GeV, as predicted by a factorization theorem of Block and Kadailov.
[ { "created": "Thu, 4 Apr 2002 03:38:53 GMT", "version": "v1" }, { "created": "Tue, 16 Apr 2002 19:59:22 GMT", "version": "v2" }, { "created": "Tue, 16 Apr 2002 20:08:41 GMT", "version": "v3" }, { "created": "Mon, 22 Apr 2002 18:12:44 GMT", "version": "v4" } ]
2009-11-07
[ [ "Block", "M. M.", "" ] ]
We analyze forward Compton scattering, using real analytic amplitudes. By fitting the total \gamma p scattering cross section data in the high energy region 5 GeV < \sqrt s < 20 GeV, using a cross section rising as \ln^2 s, we calculate \rho_{\gamma p}, the ratio of the real to the imaginary portion of the the forward Compton scattering amplitude, and compare this to \rho_{nn}, the ratio of the even portions of the pp and p-bar p forward scattering amplitudes. We find that the two \rho-values are, within errors, the same in the c.m.s. energy region 5 GeV < \sqrt s < 200 GeV, as predicted by a factorization theorem of Block and Kadailov.
2207.05578
Goutam Das
Guido Bell, Kevin Brune, Goutam Das and Marcel Wald
The NNLO quark beam function for jet-veto resummation
18 pages, 2 figures, 1 table, 8 ancillary files, Journal version
null
10.1007/JHEP01(2023)083
SI-HEP-2022-13, P3H-22-064
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider the quark beam function that describes collinear initial-state radiation that is constrained by a veto on reconstructed jets. As the veto is imposed on the transverse momenta of the jets, the beam function is subject to rapidity divergences, and we use the collinear-anomaly framework to extract the perturbative matching kernels to next-to-next-to-leading order (NNLO) in the strong-coupling expansion. Our calculation is based on a novel framework that automates the computation of beam functions in Mellin space and it provides the ingredients to extend jet-veto resummations for quark-initiated processes to NNLL$'$ accuracy.
[ { "created": "Tue, 12 Jul 2022 15:01:20 GMT", "version": "v1" }, { "created": "Wed, 18 Jan 2023 15:48:00 GMT", "version": "v2" } ]
2023-02-01
[ [ "Bell", "Guido", "" ], [ "Brune", "Kevin", "" ], [ "Das", "Goutam", "" ], [ "Wald", "Marcel", "" ] ]
We consider the quark beam function that describes collinear initial-state radiation that is constrained by a veto on reconstructed jets. As the veto is imposed on the transverse momenta of the jets, the beam function is subject to rapidity divergences, and we use the collinear-anomaly framework to extract the perturbative matching kernels to next-to-next-to-leading order (NNLO) in the strong-coupling expansion. Our calculation is based on a novel framework that automates the computation of beam functions in Mellin space and it provides the ingredients to extend jet-veto resummations for quark-initiated processes to NNLL$'$ accuracy.
1407.1694
Scientific Information Service CERN
K. Kawagoe and M. Mulders (CERN)(eds)
Proceedings of the 1st Asia-Europe-Pacific School of High-Energy Physics (AEPSHEP 12), Fukuoka, Japan, 14 - 27 Oct 2012
8 lectures, 285 pages, published as CERN Yellow Report https://cds.cern.ch/record/1443909
null
10.5170/CERN-2014-001
CERN-2014-001 ; KEK-Proceedings-2013-8
hep-ph hep-th
http://creativecommons.org/licenses/by/3.0/
The Asia-Europe-Pacific School of High-Energy Physics is intended to give young physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lectures on quantum field theory, quantum chromodynamics, flavour physics and CP-violation, physics beyond the Standard Model, neutrino physics, particle cosmology, heavy-ion physics, as well as a presentation of recent results from the Large Hadron Collider (LHC), practical statistics for particle physicists and a short introduction to the principles of particle physics instrumentation.
[ { "created": "Mon, 7 Jul 2014 12:53:46 GMT", "version": "v1" } ]
2014-07-08
[ [ "Kawagoe", "K.", "", "CERN" ], [ "Mulders", "M.", "", "CERN" ] ]
The Asia-Europe-Pacific School of High-Energy Physics is intended to give young physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lectures on quantum field theory, quantum chromodynamics, flavour physics and CP-violation, physics beyond the Standard Model, neutrino physics, particle cosmology, heavy-ion physics, as well as a presentation of recent results from the Large Hadron Collider (LHC), practical statistics for particle physicists and a short introduction to the principles of particle physics instrumentation.
hep-ph/0012207
Jose Luis Lucio M.
J. L. Lucio M. and J. Pestieau
Resonance Propagation and Threshold Singularities
5 pages, no figures, revtex
Mod.Phys.Lett. A16 (2001) 1315-1320
10.1142/S0217732301004534
null
hep-ph
null
We consider the problem of propagation of an unstable particle in the framework of Quantum Field Theory. Using unitarity, we show that a real renormalization constant free of threshold singularities naturally arises.
[ { "created": "Sat, 16 Dec 2000 19:29:31 GMT", "version": "v1" } ]
2009-10-31
[ [ "M.", "J. L. Lucio", "" ], [ "Pestieau", "J.", "" ] ]
We consider the problem of propagation of an unstable particle in the framework of Quantum Field Theory. Using unitarity, we show that a real renormalization constant free of threshold singularities naturally arises.
hep-ph/9611444
FJ Yndurain
J. Vermaseren, F. Barreiro, L. Labarga and F. J. Yndur\'ain
Pomerons and Jet Events at HERA
Latex file
Phys.Lett. B418 (1998) 363-370
10.1016/S0370-2693(97)01229-X
FTUAM 96-7
hep-ph
null
We study two and three jet events with a large rapidity gap at HERA. Unlike in the Ingelman-Schlein approach we do not adscribe a structure to the Pomeron. Instead, the coupling of the Pomeron to quarks or gluons is taken pointlike, which makes the model easy to test: the only degrees of freedom are the coupling constants of the Pomeron to the quarks or the gluons and a cutoff procedure to keep the Pomeron-gluon coupling well behaved.
[ { "created": "Wed, 27 Nov 1996 12:03:34 GMT", "version": "v1" } ]
2009-10-30
[ [ "Vermaseren", "J.", "" ], [ "Barreiro", "F.", "" ], [ "Labarga", "L.", "" ], [ "Ynduráin", "F. J.", "" ] ]
We study two and three jet events with a large rapidity gap at HERA. Unlike in the Ingelman-Schlein approach we do not adscribe a structure to the Pomeron. Instead, the coupling of the Pomeron to quarks or gluons is taken pointlike, which makes the model easy to test: the only degrees of freedom are the coupling constants of the Pomeron to the quarks or the gluons and a cutoff procedure to keep the Pomeron-gluon coupling well behaved.
hep-ph/9409371
null
K.G.Chetyrkin, C.A.Dominguez, D.Pirjol and K.Schilcher
Mass singularities in light quark correlators: the strange quark case
19 pages, Latex + 5 figures as uuencoded PS files, MZ-TH/94-21, UCT-TP 214/94
Phys.Rev. D51 (1995) 5090-5100
10.1103/PhysRevD.51.5090
null
hep-ph
null
The correlators of light-quark currents contain mass-singularities of the form log(m^2/Q^2). It has been known for quite some time that these mass- logarithms can be absorbed into the vacuum expectation values of other operators of appropriate dimension, provided that schemes without normal- ordering are used. We discuss in detail this procedure for the case of the mass logarithms m^4 log(m^2/Q^2), including also the mixing with the other dimension-4 operators to two-loop order. As an application we present an improved QCD sum rule determination of the strange-quark mass. We obtain m_s(1 GeV)=171 \pm 15 MeV.
[ { "created": "Wed, 21 Sep 1994 14:08:57 GMT", "version": "v1" } ]
2009-10-28
[ [ "Chetyrkin", "K. G.", "" ], [ "Dominguez", "C. A.", "" ], [ "Pirjol", "D.", "" ], [ "Schilcher", "K.", "" ] ]
The correlators of light-quark currents contain mass-singularities of the form log(m^2/Q^2). It has been known for quite some time that these mass- logarithms can be absorbed into the vacuum expectation values of other operators of appropriate dimension, provided that schemes without normal- ordering are used. We discuss in detail this procedure for the case of the mass logarithms m^4 log(m^2/Q^2), including also the mixing with the other dimension-4 operators to two-loop order. As an application we present an improved QCD sum rule determination of the strange-quark mass. We obtain m_s(1 GeV)=171 \pm 15 MeV.
hep-ph/0412180
Chuan Hung Chen
C.H. Chen and C.Q. Geng
T violation in $B\to K \phi \phi $ decays
11 pages, 2 figures, to appear in Phys. Lett. B
Phys.Lett.B607:115-122,2005
10.1016/j.physletb.2004.12.042
null
hep-ph
null
We present the general form of the decay width angular distributions with T-odd terms in $B\to K \phi \phi$ decays. We concentrate on the T violating effects by considering various possible T-odd momentum correlations. In a generic class of CP violating new physics interactions, we illustrate that the T violating effect could be more than 10%.
[ { "created": "Tue, 14 Dec 2004 13:44:40 GMT", "version": "v1" } ]
2014-11-18
[ [ "Chen", "C. H.", "" ], [ "Geng", "C. Q.", "" ] ]
We present the general form of the decay width angular distributions with T-odd terms in $B\to K \phi \phi$ decays. We concentrate on the T violating effects by considering various possible T-odd momentum correlations. In a generic class of CP violating new physics interactions, we illustrate that the T violating effect could be more than 10%.
hep-ph/9908481
Fu-Guang Cao
Fu-Guang Cao and A. I. Signal (Institute of Fundamental Sciences, Massey University, New Zealand)
Two analytical constraints on the $\eta$-$\eta^\prime$ mixing
8 pages, RevTex, no figures
Phys.Rev. D60 (1999) 114012
10.1103/PhysRevD.60.114012
null
hep-ph
null
We obtained two analytical constraints on the $\eta$-$\eta^\prime$ mixing parameters by considering two-photon decays of $\eta$ and $\eta^\prime$ [$\eta (\eta^\prime) \ra \gamma \gamma$], and productions of $\eta$ and $\eta^\prime$ in the $e^+ e^-$ scattering at large momentum transfer ($Q^2 \ra \infty$). Using the data given in the PDG98 for the decay processes and recent CLEO measurements on the meson-photon transition form factors, we estimate for the $\eta_8$-$\eta_1$ mixing scheme the mixing angle to be $\theta=-14.5^\circ \pm 2.0^\circ$ and the ratio of the decay constants of singlet to octet to be $f_1/f_8=1.17 \pm 0.08$. Applying our approach to the recently proposed $q \qbar$-$s \sbar$ mixing scheme, we obtain the mixing angle to be $\phi=39.8^\circ \pm 1.8^\circ$ and the ratio of the decay constants of $s\sbar$ state to $q\qbar$ state to be $f_s/f_q=1.20 \pm 0.10$.
[ { "created": "Thu, 26 Aug 1999 22:26:06 GMT", "version": "v1" }, { "created": "Wed, 5 Jan 2000 00:17:35 GMT", "version": "v2" } ]
2009-10-31
[ [ "Cao", "Fu-Guang", "", "Institute of Fundamental Sciences,\n Massey University, New Zealand" ], [ "Signal", "A. I.", "", "Institute of Fundamental Sciences,\n Massey University, New Zealand" ] ]
We obtained two analytical constraints on the $\eta$-$\eta^\prime$ mixing parameters by considering two-photon decays of $\eta$ and $\eta^\prime$ [$\eta (\eta^\prime) \ra \gamma \gamma$], and productions of $\eta$ and $\eta^\prime$ in the $e^+ e^-$ scattering at large momentum transfer ($Q^2 \ra \infty$). Using the data given in the PDG98 for the decay processes and recent CLEO measurements on the meson-photon transition form factors, we estimate for the $\eta_8$-$\eta_1$ mixing scheme the mixing angle to be $\theta=-14.5^\circ \pm 2.0^\circ$ and the ratio of the decay constants of singlet to octet to be $f_1/f_8=1.17 \pm 0.08$. Applying our approach to the recently proposed $q \qbar$-$s \sbar$ mixing scheme, we obtain the mixing angle to be $\phi=39.8^\circ \pm 1.8^\circ$ and the ratio of the decay constants of $s\sbar$ state to $q\qbar$ state to be $f_s/f_q=1.20 \pm 0.10$.
1501.02787
Kenji Nishiwaki
Tomo-hiro Abe, Yukihiro Fujimoto, Tatsuo Kobayashi, Takashi Miura, Kenji Nishiwaki, Makoto Sakamoto, and Yoshiyuki Tatsuta
Classification of three-generation models on magnetized orbifolds
28 pages (main body and references) + 65 pages (full list of classification), 22 tables (v1); typos corrected, problem in sentence fixed (v2)
Nucl.Phys. B894 (2015) 374-406
10.1016/j.nuclphysb.2015.03.004
EPHOH-15-001, KIAS-P15002, KOBE-TH-15-01, KUNS-2535, OU-HET-848, WU-HEP-15-01
hep-ph hep-th
http://creativecommons.org/licenses/by/3.0/
We classify the combinations of parameters which lead three generations of quarks and leptons in the framework of magnetized twisted orbifolds on $T^2/Z_2$, $T^2/Z_3$, $T^2/Z_4$ and $T^2/Z_6$ with allowing nonzero discretized Wilson line phases and Scherk-Schwarz phases. We also analyze two actual examples with nonzero phases leading to one-pair Higgs and five-pair Higgses and discuss the difference from the results without nonzero phases studied previously.
[ { "created": "Mon, 12 Jan 2015 20:14:27 GMT", "version": "v1" }, { "created": "Thu, 30 Apr 2015 14:10:07 GMT", "version": "v2" } ]
2015-06-23
[ [ "Abe", "Tomo-hiro", "" ], [ "Fujimoto", "Yukihiro", "" ], [ "Kobayashi", "Tatsuo", "" ], [ "Miura", "Takashi", "" ], [ "Nishiwaki", "Kenji", "" ], [ "Sakamoto", "Makoto", "" ], [ "Tatsuta", "Yoshiyuki", "" ] ]
We classify the combinations of parameters which lead three generations of quarks and leptons in the framework of magnetized twisted orbifolds on $T^2/Z_2$, $T^2/Z_3$, $T^2/Z_4$ and $T^2/Z_6$ with allowing nonzero discretized Wilson line phases and Scherk-Schwarz phases. We also analyze two actual examples with nonzero phases leading to one-pair Higgs and five-pair Higgses and discuss the difference from the results without nonzero phases studied previously.
2307.15565
Mar\'ia Dias Astros
Maria Dias Astros and Stefan Vogl
Boosting the production of sterile neutrino dark matter with self-interactions
17 pages plus appendices. Matches journal version
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sterile neutrinos are well-motivated and simple dark matter (DM) candidates. However, sterile neutrino DM produced through oscillations by the Dodelson-Widrow mechanism is excluded by current $X$-ray observations and bounds from structure formation. One minimal extension, that preserves the attractive features of this scenario, is self-interactions among sterile neutrinos. In this work, we analyze how sterile neutrino self-interactions mediated by a scalar affect the production of keV sterile neutrinos for a wide range of mediator masses. We find four distinct regimes of production characterized by different phenomena, including partial thermalization for low and intermediate masses and resonant production for heavier mediators. We show that significant new regions of parameter space become available which provide a target for future observations.
[ { "created": "Fri, 28 Jul 2023 14:02:39 GMT", "version": "v1" }, { "created": "Thu, 28 Sep 2023 14:01:19 GMT", "version": "v2" }, { "created": "Thu, 15 Feb 2024 10:25:13 GMT", "version": "v3" } ]
2024-02-16
[ [ "Astros", "Maria Dias", "" ], [ "Vogl", "Stefan", "" ] ]
Sterile neutrinos are well-motivated and simple dark matter (DM) candidates. However, sterile neutrino DM produced through oscillations by the Dodelson-Widrow mechanism is excluded by current $X$-ray observations and bounds from structure formation. One minimal extension, that preserves the attractive features of this scenario, is self-interactions among sterile neutrinos. In this work, we analyze how sterile neutrino self-interactions mediated by a scalar affect the production of keV sterile neutrinos for a wide range of mediator masses. We find four distinct regimes of production characterized by different phenomena, including partial thermalization for low and intermediate masses and resonant production for heavier mediators. We show that significant new regions of parameter space become available which provide a target for future observations.
1805.00568
Anirban Biswas
Anirban Biswas, Sandhya Choubey, Sarif Khan
Inverse seesaw and dark matter in a gauged ${\rm B-L}$ extension with flavour symmetry
30 pages, 11 figures, 3 tables, minor changes in the text, conclusion remains unchanged, version published in JHEP
JHEP 1808(2018)062
10.1007/JHEP08(2018)062
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a model which generates neutrino masses by the inverse seesaw mechanism, provides a viable dark matter candidate and explains the muon ($g-2$) anomaly. The Standard Model (SM) gauge group is extended with a gauged U(1)$_{\rm B-L}$ as well as a gauged U(1)$_{\rm L_{\mu} - L_{\tau}}$. While U(1)$_{\rm L_{\mu} - L_{\tau}}$ is anomaly free, the anomaly introduced by U(1)$_{\rm B-L}$ is cancelled between the six SM singlet fermions introduced for the inverse seesaw mechanism and four additional chiral fermions introduced in this model. After spontaneous symmetry breaking the four chiral fermionic degrees of freedom combine to give two Dirac states. The lightest Dirac fermion becomes stable and hence the dark matter candidate. We focus on the region of the parameter space where the dark matter annihilates to the right-handed neutrinos, relating the dark matter sector with the neutrino sector. The U(1)$_{\rm L_{\mu} - L_{\tau}}$ gauge symmetry provides a flavour structure to the inverse seesaw framework, successfully explaining the observed neutrino masses and mixings. We study the model parameters in the light of neutrino oscillation data and find correlation between them. Values of some of the model parameters are shown to be mutually exclusive between normal and inverted ordering of the neutrino mass eigenstates. Moreover, the muon ($g-2$) anomaly can be explained by the additional contribution arising from U(1)$_{\rm L_{\mu} - L_{\tau}}$ gauge boson.
[ { "created": "Tue, 1 May 2018 22:08:01 GMT", "version": "v1" }, { "created": "Thu, 16 Aug 2018 20:00:53 GMT", "version": "v2" } ]
2018-08-20
[ [ "Biswas", "Anirban", "" ], [ "Choubey", "Sandhya", "" ], [ "Khan", "Sarif", "" ] ]
We propose a model which generates neutrino masses by the inverse seesaw mechanism, provides a viable dark matter candidate and explains the muon ($g-2$) anomaly. The Standard Model (SM) gauge group is extended with a gauged U(1)$_{\rm B-L}$ as well as a gauged U(1)$_{\rm L_{\mu} - L_{\tau}}$. While U(1)$_{\rm L_{\mu} - L_{\tau}}$ is anomaly free, the anomaly introduced by U(1)$_{\rm B-L}$ is cancelled between the six SM singlet fermions introduced for the inverse seesaw mechanism and four additional chiral fermions introduced in this model. After spontaneous symmetry breaking the four chiral fermionic degrees of freedom combine to give two Dirac states. The lightest Dirac fermion becomes stable and hence the dark matter candidate. We focus on the region of the parameter space where the dark matter annihilates to the right-handed neutrinos, relating the dark matter sector with the neutrino sector. The U(1)$_{\rm L_{\mu} - L_{\tau}}$ gauge symmetry provides a flavour structure to the inverse seesaw framework, successfully explaining the observed neutrino masses and mixings. We study the model parameters in the light of neutrino oscillation data and find correlation between them. Values of some of the model parameters are shown to be mutually exclusive between normal and inverted ordering of the neutrino mass eigenstates. Moreover, the muon ($g-2$) anomaly can be explained by the additional contribution arising from U(1)$_{\rm L_{\mu} - L_{\tau}}$ gauge boson.
1607.03374
Takayasu Sekihara
Takayasu Sekihara (JAEA, Ibaraki)
Dynamically Generated $\Xi (1690)$
4 pages, 4 EPS figures, talk given at the 12th International Conference on Hypernuclear and Strange Particle Physics (HYP2015), Tohoku, Japan, 7-12 Sep. 2015
null
10.7566/JPSCP.17.072007
null
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the $\Xi (1690)$ resonance can be dynamically generated in the $s$-wave $\bar{K} \Sigma$-$\bar{K} \Lambda$-$\pi \Xi$-$\eta \Xi$ coupled-channels chiral unitary approach. In our model, the $\Xi (1690)$ resonance appears near the $\bar{K} \Sigma$ threshold as a $\bar{K} \Sigma$ molecular state and the experimental data are reproduced well. We discuss properties of the dynamically generated $\Xi (1690)$.
[ { "created": "Tue, 12 Jul 2016 14:40:16 GMT", "version": "v1" } ]
2017-08-02
[ [ "Sekihara", "Takayasu", "", "JAEA, Ibaraki" ] ]
We show that the $\Xi (1690)$ resonance can be dynamically generated in the $s$-wave $\bar{K} \Sigma$-$\bar{K} \Lambda$-$\pi \Xi$-$\eta \Xi$ coupled-channels chiral unitary approach. In our model, the $\Xi (1690)$ resonance appears near the $\bar{K} \Sigma$ threshold as a $\bar{K} \Sigma$ molecular state and the experimental data are reproduced well. We discuss properties of the dynamically generated $\Xi (1690)$.
1603.04349
Heikki M\"antysaari
Heikki M\"antysaari and Bj\"orn Schenke
Evidence of strong proton shape fluctuations from incoherent diffraction
7 pages, 4 figures. v2: typos fixed and references added. To be published in PRL
Phys. Rev. Lett. 117, 052301 (2016)
10.1103/PhysRevLett.117.052301
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show within the saturation framework that measurements of exclusive vector meson production at high energy provide evidence for strong geometric fluctuations of the proton. In comparison, the effect of saturation scale and color charge fluctuations is weak. This knowledge will allow detailed future measurements of the incoherent cross section to tightly constrain the fluctuating geometry of the proton as a function of the parton momentum fraction $x$.
[ { "created": "Mon, 14 Mar 2016 17:11:33 GMT", "version": "v1" }, { "created": "Mon, 18 Jul 2016 14:27:32 GMT", "version": "v2" } ]
2016-07-26
[ [ "Mäntysaari", "Heikki", "" ], [ "Schenke", "Björn", "" ] ]
We show within the saturation framework that measurements of exclusive vector meson production at high energy provide evidence for strong geometric fluctuations of the proton. In comparison, the effect of saturation scale and color charge fluctuations is weak. This knowledge will allow detailed future measurements of the incoherent cross section to tightly constrain the fluctuating geometry of the proton as a function of the parton momentum fraction $x$.
hep-ph/9507265
Joannis Papavassiliou
Joannis Papavassiliou, Kostas Philippides, and Ken Sasaki
Two-loop electroweak corrections to the $\rho$ parameter beyond the leading approximation
40 pages, TeXsis, uu encoded ps files, 14 figures included
Phys.Rev.D53:3942-3961,1996
10.1103/PhysRevD.53.3942
NYU-TH-95/07/01
hep-ph
null
We show that in the framework of the pinch technique the universal part of the $\rho$ parameter can be meaningfully defined, beyond one loop. The universal part so obtained satisfies the crucial requirements of gauge-independence, finiteness, and process-independence, even when subleading contributions of the top quark are included. The mechanism which enforces the aforementioned properties is explained in detail, and several subtle field theoretical issues are discussed. Explicit calculations of the sub-leading two-loop corrections of order $O(G_{\mu}^{2}m^{2}_{t}M_{Z}^{2})$ are carried out in the context of an $SU(2)$ model, with $M_{W}=M_{Z}$, and various intermediate and final results are reported.
[ { "created": "Sat, 8 Jul 1995 17:59:31 GMT", "version": "v1" } ]
2011-01-13
[ [ "Papavassiliou", "Joannis", "" ], [ "Philippides", "Kostas", "" ], [ "Sasaki", "Ken", "" ] ]
We show that in the framework of the pinch technique the universal part of the $\rho$ parameter can be meaningfully defined, beyond one loop. The universal part so obtained satisfies the crucial requirements of gauge-independence, finiteness, and process-independence, even when subleading contributions of the top quark are included. The mechanism which enforces the aforementioned properties is explained in detail, and several subtle field theoretical issues are discussed. Explicit calculations of the sub-leading two-loop corrections of order $O(G_{\mu}^{2}m^{2}_{t}M_{Z}^{2})$ are carried out in the context of an $SU(2)$ model, with $M_{W}=M_{Z}$, and various intermediate and final results are reported.
2107.14548
Haiying Cai
Haiying Cai, Giacomo Cacciapaglia and Seung J. Lee
Massive Gravitons as Feebly Interacting Dark Matter Candidates
6 pages plus appendix, 2 figures; published version
null
10.1103/PhysRevLett.128.081806
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We detailed our discovery of a chiral enhancement in the production cross sections of massive spin-2 gravitons, below the electroweak symmetry breaking scale, that makes them ideal dark matter candidates for the freeze-in mechanism. The result is independent of the physics at high scales, and points toward masses in the keV- MeV range. The graviton is, therefore, a sub-MeV dark matter particle, as favored by the small scale galaxy structures. We apply the novel calculation to a Randall-Sundrum model with multiple branes, showing a significant parameter space where the first two massive gravitons saturate the dark matter relic density.
[ { "created": "Fri, 30 Jul 2021 10:56:29 GMT", "version": "v1" }, { "created": "Thu, 9 Mar 2023 10:10:06 GMT", "version": "v2" } ]
2023-03-10
[ [ "Cai", "Haiying", "" ], [ "Cacciapaglia", "Giacomo", "" ], [ "Lee", "Seung J.", "" ] ]
We detailed our discovery of a chiral enhancement in the production cross sections of massive spin-2 gravitons, below the electroweak symmetry breaking scale, that makes them ideal dark matter candidates for the freeze-in mechanism. The result is independent of the physics at high scales, and points toward masses in the keV- MeV range. The graviton is, therefore, a sub-MeV dark matter particle, as favored by the small scale galaxy structures. We apply the novel calculation to a Randall-Sundrum model with multiple branes, showing a significant parameter space where the first two massive gravitons saturate the dark matter relic density.
1605.09242
Mihailo Backovic
Chiara Arina, Mihailo Backovi\'c, Eric Conte, Benjamin Fuks, Jun Guo, Jan Heisig, Beno\^it Hespel, Michael Kr\"amer, Fabio Maltoni, Antony Martini, Kentarou Mawatari, Mathieu Pellen and Eleni Vryonidou
A comprehensive approach to dark matter studies: exploration of simplified top-philic models
52 pages, 23 figures
JHEP 1611 (2016) 111
10.1007/JHEP11(2016)111
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Studies of dark matter lie at the interface of collider physics, astrophysics and cosmology. Constraining models featuring dark matter candidates entails the capability to provide accurate predictions for large sets of observables and compare them to a wide spectrum of data. We present a framework which, starting from a model lagrangian, allows one to consistently and systematically make predictions, as well as to confront those predictions with a multitude of experimental results. As an application, we consider a class of simplified dark matter models where a scalar mediator couples only to the top quark and a fermionic dark sector (i.e. the simplified top-philic dark matter model). We study in detail the complementarity of relic density, direct/indirect detection and collider searches in constraining the multi-dimensional model parameter space, and efficiently identify regions where individual approaches to dark matter detection provide the most stringent bounds. In the context of collider studies of dark matter, we point out the complementarity of LHC searches in probing different regions of the model parameter space with final states involving top quarks, photons, jets and/or missing energy. Our study of dark matter production at the LHC goes beyond the tree-level approximation and we show examples of how higher-order corrections to dark matter production processes can affect the interpretation of the experimental results.
[ { "created": "Mon, 30 May 2016 14:13:48 GMT", "version": "v1" } ]
2017-01-24
[ [ "Arina", "Chiara", "" ], [ "Backović", "Mihailo", "" ], [ "Conte", "Eric", "" ], [ "Fuks", "Benjamin", "" ], [ "Guo", "Jun", "" ], [ "Heisig", "Jan", "" ], [ "Hespel", "Benoît", "" ], [ "Krämer", "Michael", "" ], [ "Maltoni", "Fabio", "" ], [ "Martini", "Antony", "" ], [ "Mawatari", "Kentarou", "" ], [ "Pellen", "Mathieu", "" ], [ "Vryonidou", "Eleni", "" ] ]
Studies of dark matter lie at the interface of collider physics, astrophysics and cosmology. Constraining models featuring dark matter candidates entails the capability to provide accurate predictions for large sets of observables and compare them to a wide spectrum of data. We present a framework which, starting from a model lagrangian, allows one to consistently and systematically make predictions, as well as to confront those predictions with a multitude of experimental results. As an application, we consider a class of simplified dark matter models where a scalar mediator couples only to the top quark and a fermionic dark sector (i.e. the simplified top-philic dark matter model). We study in detail the complementarity of relic density, direct/indirect detection and collider searches in constraining the multi-dimensional model parameter space, and efficiently identify regions where individual approaches to dark matter detection provide the most stringent bounds. In the context of collider studies of dark matter, we point out the complementarity of LHC searches in probing different regions of the model parameter space with final states involving top quarks, photons, jets and/or missing energy. Our study of dark matter production at the LHC goes beyond the tree-level approximation and we show examples of how higher-order corrections to dark matter production processes can affect the interpretation of the experimental results.
2308.04497
Ajay Kaladharan
Ajay Kaladharan and Shaikh Saad
Fermion mass, Axion dark matter, and Leptogenesis in SO(10) GUT
14 pages+references, 1 figure, 1 table: Matches with published version, Comments are welcome
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
SO(10) grand unified theory with minimum parameters in the Yukawa sector employs the Peccei-Quinn symmetry that solves the strong CP problem. Such an economical Yukawa sector is highly appealing and has been extensively studied in the literature. However, when the running of the renormalization group equations of the Yukawa couplings are considered, this scenario shows somewhat tension with the observed fermion masses and mixing. In this work, we propose an extension of the minimal framework that alleviates this tension by introducing only a few new parameters. The proposed model consists of a fermion in the fundamental and a scalar in the spinorial representations. While the latter is needed to implement the Peccei-Quinn symmetry successfully, the presence of both is essential in obtaining an excellent fit to the fermion mass spectrum. In our model, axions serve the role of dark matter, and the out-of-equilibrium decays of the right-handed neutrinos successfully generate the matter-antimatter symmetry of the Universe.
[ { "created": "Tue, 8 Aug 2023 18:02:38 GMT", "version": "v1" }, { "created": "Thu, 7 Mar 2024 18:40:52 GMT", "version": "v2" } ]
2024-03-08
[ [ "Kaladharan", "Ajay", "" ], [ "Saad", "Shaikh", "" ] ]
SO(10) grand unified theory with minimum parameters in the Yukawa sector employs the Peccei-Quinn symmetry that solves the strong CP problem. Such an economical Yukawa sector is highly appealing and has been extensively studied in the literature. However, when the running of the renormalization group equations of the Yukawa couplings are considered, this scenario shows somewhat tension with the observed fermion masses and mixing. In this work, we propose an extension of the minimal framework that alleviates this tension by introducing only a few new parameters. The proposed model consists of a fermion in the fundamental and a scalar in the spinorial representations. While the latter is needed to implement the Peccei-Quinn symmetry successfully, the presence of both is essential in obtaining an excellent fit to the fermion mass spectrum. In our model, axions serve the role of dark matter, and the out-of-equilibrium decays of the right-handed neutrinos successfully generate the matter-antimatter symmetry of the Universe.
hep-ph/0506095
Vladislav Pantuev S.
V.S. Pantuev
Jet absorption and corona effect at RHIC. Extracting collision geometry from experimental data
Version published in JETP Letters
JETPLett.85:104-108,2007
10.1134/S0021364007020026
null
hep-ph
null
We demonstrate a possible existence of a finite formation time of strongly interacting plasma in nuclear collisions at RHIC from recent experimental data. To show this, we use a simple model based on Monte Carlo simulation of nucleus-nucleus collisions with realistic nuclear density distribution. The most striking feature of the experimental data - an absence of absorption of high transverse momentum pions in the reaction plane direction for mid-peripheral collisions - points to the presence of a surface zone with no absorption and strong suppression in the inner core. A natural interpretation of such a zone could be the plasma formation time T~2-3 fm/c. The existence of a formation time could dramatically change our understanding of many experimentally observed features. With this assumption we describe the angular anisotropy of high transverse momentum pions with respect to the reaction plane and the centrality dependence of nuclear modification factor in Au+Au and Cu+Cu collisions.
[ { "created": "Thu, 9 Jun 2005 17:46:41 GMT", "version": "v1" }, { "created": "Tue, 22 Nov 2005 16:27:22 GMT", "version": "v2" }, { "created": "Mon, 14 May 2007 20:23:05 GMT", "version": "v3" } ]
2008-11-26
[ [ "Pantuev", "V. S.", "" ] ]
We demonstrate a possible existence of a finite formation time of strongly interacting plasma in nuclear collisions at RHIC from recent experimental data. To show this, we use a simple model based on Monte Carlo simulation of nucleus-nucleus collisions with realistic nuclear density distribution. The most striking feature of the experimental data - an absence of absorption of high transverse momentum pions in the reaction plane direction for mid-peripheral collisions - points to the presence of a surface zone with no absorption and strong suppression in the inner core. A natural interpretation of such a zone could be the plasma formation time T~2-3 fm/c. The existence of a formation time could dramatically change our understanding of many experimentally observed features. With this assumption we describe the angular anisotropy of high transverse momentum pions with respect to the reaction plane and the centrality dependence of nuclear modification factor in Au+Au and Cu+Cu collisions.
hep-ph/9302283
null
M.C. Gonzalez-Garcia, F. Halzen, R.A. Vazquez, and E Zas
Empirical Determination of the Very High Energy Heavy Quark Cross Section from Non-Accelerator Data
(8 pages, latex file, 3 figures available upon request) MAD/PH/740
Phys.Rev. D49 (1994) 2310-2315
10.1103/PhysRevD.49.2310
null
hep-ph
null
To cosmic rays incident near the horizon the Earth's atmosphere represents a beam dump with a slant depth reaching 36000~g~cm$^{-2}$ at $90^\circ$. The prompt decay of a heavy quark produced by very high energy cosmic ray showers will leave an unmistakable signature in this dump. We translate the failure of experiments to detect such a signal into an upper limit on the heavy quark hadroproduction cross section in the energy region beyond existing accelerators. Our results disfavor any rapid growth of the cross section or the gluon structure function beyond very conservative estimates based on perturbative QCD.
[ { "created": "Sat, 20 Feb 1993 20:59:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Gonzalez-Garcia", "M. C.", "" ], [ "Halzen", "F.", "" ], [ "Vazquez", "R. A.", "" ], [ "Zas", "E", "" ] ]
To cosmic rays incident near the horizon the Earth's atmosphere represents a beam dump with a slant depth reaching 36000~g~cm$^{-2}$ at $90^\circ$. The prompt decay of a heavy quark produced by very high energy cosmic ray showers will leave an unmistakable signature in this dump. We translate the failure of experiments to detect such a signal into an upper limit on the heavy quark hadroproduction cross section in the energy region beyond existing accelerators. Our results disfavor any rapid growth of the cross section or the gluon structure function beyond very conservative estimates based on perturbative QCD.
1301.1683
Ethan Neil
Joachim Kopp, Ethan T. Neil, Reinard Primulando and Jure Zupan
From gamma ray line signals of dark matter to the LHC
27 pages, 10 figures. v2: added references, fixed import-order issue with cleveref and hyperref. v3: updated to journal version. v4: erratum correction to figs. 7-8 for monojet/monophoton cross-sections
Phys.Dark.Univ. 2 (2013) 22-34
10.1016/j.dark.2013.02.001
FERMILAB-PUB-13-006-T
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the relationship between astrophysical gamma-ray signals and LHC signatures for a class of phenomenologically successful secluded dark matter models, motivated by recent evidence for a ~130 GeV gamma-ray line. We consider in detail scenarios in which interactions between the dark sector and the standard model are mediated by a vev-less scalar field \phi, transforming as an N-plet (N > 3) under SU(2)_L. Since some of the component fields of \phi carry large electric charges, loop induced dark matter annihilation to \gamma \gamma and \gamma Z can be enhanced without the need for non-perturbatively large couplings, and without overproduction of continuum gamma-rays from other final states. We discuss prospects for other experimental tests, including dark matter-nucleon scattering and production of \phi at the LHC, where future searches for anomalous charged tracks may be sensitive. The first LHC hints could come from the Higgs sector, where loop corrections involving \phi lead to significantly modified h to \gamma \gamma and h to \gamma Z branching ratios.
[ { "created": "Tue, 8 Jan 2013 21:00:03 GMT", "version": "v1" }, { "created": "Thu, 10 Jan 2013 20:29:08 GMT", "version": "v2" }, { "created": "Wed, 20 Mar 2013 16:45:42 GMT", "version": "v3" }, { "created": "Sun, 18 Aug 2013 15:00:56 GMT", "version": "v4" } ]
2013-08-20
[ [ "Kopp", "Joachim", "" ], [ "Neil", "Ethan T.", "" ], [ "Primulando", "Reinard", "" ], [ "Zupan", "Jure", "" ] ]
We explore the relationship between astrophysical gamma-ray signals and LHC signatures for a class of phenomenologically successful secluded dark matter models, motivated by recent evidence for a ~130 GeV gamma-ray line. We consider in detail scenarios in which interactions between the dark sector and the standard model are mediated by a vev-less scalar field \phi, transforming as an N-plet (N > 3) under SU(2)_L. Since some of the component fields of \phi carry large electric charges, loop induced dark matter annihilation to \gamma \gamma and \gamma Z can be enhanced without the need for non-perturbatively large couplings, and without overproduction of continuum gamma-rays from other final states. We discuss prospects for other experimental tests, including dark matter-nucleon scattering and production of \phi at the LHC, where future searches for anomalous charged tracks may be sensitive. The first LHC hints could come from the Higgs sector, where loop corrections involving \phi lead to significantly modified h to \gamma \gamma and h to \gamma Z branching ratios.
hep-ph/0007229
Fritz W. Bopp
Fritz W. Bopp
Baryon Transport in Dual Models and the Possibility of a Backward Peak in Diffraction
10 pages, 10 figures, presented at the conference Crimean Summer School-Seminar, Yalta, May 27 - June 4, 2000
null
null
SI-00-7
hep-ph
null
We begin to briefly survey the experimental and conceptual side of baryon transfers in particle scattering. A discussion of baryon transfers in heavy ion scattering follows. It shortly reviews existing string model concepts, which were found to be consistent with the data. With this motivation we turn to a more careful consideration of the relevant topological structures. The baryon transfer is associated with one of two possible cuts in baryonium exchange. From the color structure the baryonium can be identified with an Odderon exchange. We conjecture that the two Odderon cuts occur with an opposite sign and partially cancel. As the Odderon is predicted to have a rather high trajectory it has to involve small coupling constants. As this suppression is not anticipated for diffractive processes a tiny observable backward peak is argued to occur in the initial baryon distribution in massive diffractive systems.
[ { "created": "Thu, 20 Jul 2000 18:12:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bopp", "Fritz W.", "" ] ]
We begin to briefly survey the experimental and conceptual side of baryon transfers in particle scattering. A discussion of baryon transfers in heavy ion scattering follows. It shortly reviews existing string model concepts, which were found to be consistent with the data. With this motivation we turn to a more careful consideration of the relevant topological structures. The baryon transfer is associated with one of two possible cuts in baryonium exchange. From the color structure the baryonium can be identified with an Odderon exchange. We conjecture that the two Odderon cuts occur with an opposite sign and partially cancel. As the Odderon is predicted to have a rather high trajectory it has to involve small coupling constants. As this suppression is not anticipated for diffractive processes a tiny observable backward peak is argued to occur in the initial baryon distribution in massive diffractive systems.
2004.01206
Marcel Golz
Rigo Bause, Hector Gisbert, Marcel Golz, Gudrun Hiller
Exploiting CP-asymmetries in rare charm decays
13 pages, 5 figures
Phys. Rev. D 101, 115006 (2020)
10.1103/PhysRevD.101.115006
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze patterns from CP-violating new physics (NP) in hadronic and semileptonic rare charm $\vert \Delta c \vert=\vert \Delta u\vert=1$ transitions. Observation of direct CP-violation in hadronic decays, as in $\Delta A_{\text{CP}}$, provides opportunities for $c \to u \,\ell^+ \ell^-$, $\ell=e,\mu$ transitions, and vice versa. For the concrete case of flavorful, anomaly-free $Z^\prime$-models a NP-interpretation of $\Delta A_{\text{CP}}$ suggests measurable CP-asymmetries in semileptonic decays such as $D \to \pi\, \ell^+ \ell^-$ or $D \to \pi \pi\, \ell^+ \ell^-$. Conversely, an observation of CP-violation in $c \to u\, e^+ e^-$ or $c \to u\, \mu^+ \mu^-$ decays supports a NP--interpretation of $\Delta A_{\text{CP}}$. Flavorful $U(1)^\prime$-extensions provide explicit U--spin and isospin breaking which can be probed in patterns of hadronic decays of charm mesons. We work out signatures for CP-asymmetries in $D^0 \to \pi^+ \pi^-$, $D^0 \to K^+ K^-$ and $D^0 \to \pi^0 \pi^0$, $D^+ \to \pi^+ \pi^0$ decays, which can be probed in the future at LHCb and Belle II and provide further informative cross checks.
[ { "created": "Thu, 2 Apr 2020 18:06:07 GMT", "version": "v1" } ]
2020-07-01
[ [ "Bause", "Rigo", "" ], [ "Gisbert", "Hector", "" ], [ "Golz", "Marcel", "" ], [ "Hiller", "Gudrun", "" ] ]
We analyze patterns from CP-violating new physics (NP) in hadronic and semileptonic rare charm $\vert \Delta c \vert=\vert \Delta u\vert=1$ transitions. Observation of direct CP-violation in hadronic decays, as in $\Delta A_{\text{CP}}$, provides opportunities for $c \to u \,\ell^+ \ell^-$, $\ell=e,\mu$ transitions, and vice versa. For the concrete case of flavorful, anomaly-free $Z^\prime$-models a NP-interpretation of $\Delta A_{\text{CP}}$ suggests measurable CP-asymmetries in semileptonic decays such as $D \to \pi\, \ell^+ \ell^-$ or $D \to \pi \pi\, \ell^+ \ell^-$. Conversely, an observation of CP-violation in $c \to u\, e^+ e^-$ or $c \to u\, \mu^+ \mu^-$ decays supports a NP--interpretation of $\Delta A_{\text{CP}}$. Flavorful $U(1)^\prime$-extensions provide explicit U--spin and isospin breaking which can be probed in patterns of hadronic decays of charm mesons. We work out signatures for CP-asymmetries in $D^0 \to \pi^+ \pi^-$, $D^0 \to K^+ K^-$ and $D^0 \to \pi^0 \pi^0$, $D^+ \to \pi^+ \pi^0$ decays, which can be probed in the future at LHCb and Belle II and provide further informative cross checks.
hep-ph/9807426
Emilio Torrente Lujan
E. Torrente-Lujan
Solar Antineutrinos from Fluctuating Magnetic Fields at Kamiokande
10 pags. latex. 3 figures, 3 ps files. epsfig.sty neccesary. Version with minor typo errors corrected
Phys.Lett. B441 (1998) 305-312
10.1016/S0370-2693(98)01166-6
IFIC-9833, FTUV-9833, UQbar-TH/98345
hep-ph
null
We consider the effect of a strongly chaotic magnetic field at the narrow bottom of the convective zone of the Sun together with resonant matter oscillations on the production of electron Majorana antineutrinos. Even for moderate levels of noise, we show that it is possible to obtain a small but significant probability for $\nu_e\to \bar{\nu}_e$ conversions (1-3%) at the energy range 2-10 MeV for large regions of the mixing parameter space while still satisfying present (Super)-Kamiokande antineutrino bounds and observed total rates. In the other hand it would be possible to obtain information about the solar magnetic internal field if antineutrino bounds reach the 1% level and a particle physics solution to the SNP is assumed. The mechanism presented here has the advantage of being independent of the largely unknown magnetic profile of the Sun and the intrinsic neutrino magnetic moment.
[ { "created": "Mon, 20 Jul 1998 19:13:43 GMT", "version": "v1" }, { "created": "Fri, 31 Jul 1998 16:23:51 GMT", "version": "v2" } ]
2009-10-31
[ [ "Torrente-Lujan", "E.", "" ] ]
We consider the effect of a strongly chaotic magnetic field at the narrow bottom of the convective zone of the Sun together with resonant matter oscillations on the production of electron Majorana antineutrinos. Even for moderate levels of noise, we show that it is possible to obtain a small but significant probability for $\nu_e\to \bar{\nu}_e$ conversions (1-3%) at the energy range 2-10 MeV for large regions of the mixing parameter space while still satisfying present (Super)-Kamiokande antineutrino bounds and observed total rates. In the other hand it would be possible to obtain information about the solar magnetic internal field if antineutrino bounds reach the 1% level and a particle physics solution to the SNP is assumed. The mechanism presented here has the advantage of being independent of the largely unknown magnetic profile of the Sun and the intrinsic neutrino magnetic moment.
1309.7444
Volkan Ari
V. Ari, O. \c{C}akir, S. Kuday
Pair Production of New Heavy Leptons with $U(1)'$ Charge at Linear Colliders
13 pages, 9 figures
null
10.1142/S0217751X14500559
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the pair production of new heavy leptons within a new $U(1)'$ symmetry extension of the Standard Model. Because of the new symmetry, the production and decay modes of the new heavy leptons would be different from those of three families of the standard model. The pair production cross sections depending on the mixing parameter and the mass of heavy leptons have been calculated for the center of mass energies of $0.5$ TeV, $1$ TeV and $3$ TeV. The accessible ranges of the parameters have been obtained for different luminosity projections at linear colliders. We find the sensitivity to the range of mixing parameter $-1<x<1$ for the mass range $M_{l'}<800$ GeV at $\sqrt{s}=3$ TeV and $L_{int}=100$ fb$^{-1}$
[ { "created": "Sat, 28 Sep 2013 10:18:03 GMT", "version": "v1" }, { "created": "Tue, 24 Dec 2013 13:10:16 GMT", "version": "v2" } ]
2015-06-17
[ [ "Ari", "V.", "" ], [ "Çakir", "O.", "" ], [ "Kuday", "S.", "" ] ]
We study the pair production of new heavy leptons within a new $U(1)'$ symmetry extension of the Standard Model. Because of the new symmetry, the production and decay modes of the new heavy leptons would be different from those of three families of the standard model. The pair production cross sections depending on the mixing parameter and the mass of heavy leptons have been calculated for the center of mass energies of $0.5$ TeV, $1$ TeV and $3$ TeV. The accessible ranges of the parameters have been obtained for different luminosity projections at linear colliders. We find the sensitivity to the range of mixing parameter $-1<x<1$ for the mass range $M_{l'}<800$ GeV at $\sqrt{s}=3$ TeV and $L_{int}=100$ fb$^{-1}$
hep-ph/0612226
Qiang Zhao
Qiang Zhao
Charmonium hadronic decays and the OZI rule violation effects
Proceeding of the International Workshop on Tau-Charm Physics, Beijing, China, June 5-7, 2006
Int.J.Mod.Phys. A21 (2006) 5529-5534
10.1142/S0217751X06034707
null
hep-ph
null
We discuss the scalar meson mixing scenario and present an OZI rule violation mechanism for understanding the scalar productions in charmoium hadronic decays. We stress that the OZI violation could play a key role in disentangling the structure of the scalars: $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$.
[ { "created": "Tue, 19 Dec 2006 12:41:41 GMT", "version": "v1" } ]
2009-11-11
[ [ "Zhao", "Qiang", "" ] ]
We discuss the scalar meson mixing scenario and present an OZI rule violation mechanism for understanding the scalar productions in charmoium hadronic decays. We stress that the OZI violation could play a key role in disentangling the structure of the scalars: $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$.
1708.01259
David McKeen
Kyle Aitken, David McKeen, Ann E. Nelson, Thomas Neder
Baryogenesis from Oscillations of Charmed or Beautiful Baryons
15 pages, 6 figures
Phys. Rev. D 96, 075009 (2017)
10.1103/PhysRevD.96.075009
PITT-PACC-1709
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a model for CP violating oscillations of neutral, heavy-flavored baryons into antibaryons at rates which are within a few orders of magnitude of their lifetimes. The flavor structure of the baryon violation suppresses neutron oscillations and baryon number violating nuclear decays to experimentally allowed rates. We also propose a scenario for producing such baryons in the early Universe via the out-of-equilibrium decays of a neutral particle, after hadronization but before nucleosynthesis. We find parameters where CP violating baryon oscillations at a temperature of a few MeV could result in the observed asymmetry between baryons and antibaryons. Furthermore, part of the relevant parameter space for baryogenesis is potentially testable at Belle II via decays of heavy flavor baryons into an exotic neutral fermion. The model introduces four new particles: three light Majorana fermions and a colored scalar. The lightest of these fermions is typically long lived on collider timescales and may be produced in decays of bottom and possibly charmed hadrons.
[ { "created": "Thu, 3 Aug 2017 18:00:04 GMT", "version": "v1" } ]
2017-10-18
[ [ "Aitken", "Kyle", "" ], [ "McKeen", "David", "" ], [ "Nelson", "Ann E.", "" ], [ "Neder", "Thomas", "" ] ]
We propose a model for CP violating oscillations of neutral, heavy-flavored baryons into antibaryons at rates which are within a few orders of magnitude of their lifetimes. The flavor structure of the baryon violation suppresses neutron oscillations and baryon number violating nuclear decays to experimentally allowed rates. We also propose a scenario for producing such baryons in the early Universe via the out-of-equilibrium decays of a neutral particle, after hadronization but before nucleosynthesis. We find parameters where CP violating baryon oscillations at a temperature of a few MeV could result in the observed asymmetry between baryons and antibaryons. Furthermore, part of the relevant parameter space for baryogenesis is potentially testable at Belle II via decays of heavy flavor baryons into an exotic neutral fermion. The model introduces four new particles: three light Majorana fermions and a colored scalar. The lightest of these fermions is typically long lived on collider timescales and may be produced in decays of bottom and possibly charmed hadrons.
hep-ph/9601340
Takeshi Kurimoto
Ciprian Dariescu and Marina-Aura Dariescu
Perturbative QCD analyses of the nonleptonic $B$ meson decays
13 pages, LaTeX format, figures not included
Phys.Lett. B378 (1996) 323-328
10.1016/0370-2693(96)00349-8
TOYAMA-87
hep-ph
null
Based on Brodsky-Lepage approach, the nonleptonic $B$ meson decay branching ratio is derived in terms of three parameters and is geometrically analysed as the 3-surface embedded in the 4-dimensional (abstract) Euclidean space generated by the three parameters and $BR$. Investigating its 2-dimensional sections, we find ranges for these parameters imposed by a comparison with experimental data.
[ { "created": "Fri, 26 Jan 1996 07:06:39 GMT", "version": "v1" } ]
2009-10-28
[ [ "Dariescu", "Ciprian", "" ], [ "Dariescu", "Marina-Aura", "" ] ]
Based on Brodsky-Lepage approach, the nonleptonic $B$ meson decay branching ratio is derived in terms of three parameters and is geometrically analysed as the 3-surface embedded in the 4-dimensional (abstract) Euclidean space generated by the three parameters and $BR$. Investigating its 2-dimensional sections, we find ranges for these parameters imposed by a comparison with experimental data.
2103.04319
Rene Poncelet
Herschel A. Chawdhry, Michal Czakon, Alexander Mitov, Rene Poncelet
Two-loop leading-colour QCD helicity amplitudes for two-photon plus jet production at the LHC
13 pages, 1 figure, 3 tables, published version
null
10.1007/JHEP07(2021)164
OUTP-21-06P, Cavendish-HEP-21/05, P3H-21-014, TTK-21-09
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We calculate the complete set of two-loop leading-colour QCD helicity amplitudes for $\gamma \gamma j$-production at hadron colliders. Our results are presented in a compact, fully-analytical form.
[ { "created": "Sun, 7 Mar 2021 10:55:27 GMT", "version": "v1" }, { "created": "Tue, 24 Aug 2021 08:03:38 GMT", "version": "v2" } ]
2021-08-25
[ [ "Chawdhry", "Herschel A.", "" ], [ "Czakon", "Michal", "" ], [ "Mitov", "Alexander", "" ], [ "Poncelet", "Rene", "" ] ]
We calculate the complete set of two-loop leading-colour QCD helicity amplitudes for $\gamma \gamma j$-production at hadron colliders. Our results are presented in a compact, fully-analytical form.
hep-ph/9811427
Gerald Cleaver
G.B. Cleaver, A.E. Faraggi and D.V. Nanopoulos
String derived MSSM and M-theory Unification
18 pages. Standard Latex. Version to appear in PLB
Phys.Lett.B455:135-146,1999
10.1016/S0370-2693(99)00413-X
ACT-11/98, CTP-TAMU-45/98, TPI-MINN-98/24, UMN-TH-1729-98
hep-ph astro-ph hep-th
null
The recent conjecture of possible equivalence between the string scale $M_S$ and the minimal supersymmetric standard model unification scale M_U ~ 2.5 x 10^{16} GeV is considered in the context of string models. This conjecture suggests that the observable gauge group just below the string scale should be SU(3)_C x SU(2)_L x U(1)_Y and that the SU(3)_C x SU(2)_L x U(1)_Y-charged spectrum of the observable sector should consist solely of the MSSM spectrum. We demonstrate that string models can actually be constructed that possess these observable features. Two aspects generic to many classes of three family SU(3)_C x SU(2)_L x U(1)_Y string models are both an extra local anomalous U(1)_A and numerous (often fractionally charged) exotic particles beyond the MSSM. Thus, for these classes, the key to obtaining an M_S = M_U ~ 2.5 x 10^{16} GeV string model is the existence of F- and D-flat directions that near the string scale can simultaneously break the anomalous U(1) and give mass to all exotic SM-charged observable particles, decoupling them from the low energy spectrum. In this letter we show, in the context of free fermionic strings, that string models with flat directions possessing these features do exist. We present one such string derived model in which all such exotic observable states beyond the MSSM receive mass at the scale generated by the Fayet- Iliopoulos term. The associated F- and D-flat direction is proven flat to all orders of the superpotential.
[ { "created": "Sat, 21 Nov 1998 00:22:22 GMT", "version": "v1" }, { "created": "Mon, 23 Nov 1998 00:17:12 GMT", "version": "v2" }, { "created": "Mon, 5 Apr 1999 16:51:45 GMT", "version": "v3" } ]
2010-04-06
[ [ "Cleaver", "G. B.", "" ], [ "Faraggi", "A. E.", "" ], [ "Nanopoulos", "D. V.", "" ] ]
The recent conjecture of possible equivalence between the string scale $M_S$ and the minimal supersymmetric standard model unification scale M_U ~ 2.5 x 10^{16} GeV is considered in the context of string models. This conjecture suggests that the observable gauge group just below the string scale should be SU(3)_C x SU(2)_L x U(1)_Y and that the SU(3)_C x SU(2)_L x U(1)_Y-charged spectrum of the observable sector should consist solely of the MSSM spectrum. We demonstrate that string models can actually be constructed that possess these observable features. Two aspects generic to many classes of three family SU(3)_C x SU(2)_L x U(1)_Y string models are both an extra local anomalous U(1)_A and numerous (often fractionally charged) exotic particles beyond the MSSM. Thus, for these classes, the key to obtaining an M_S = M_U ~ 2.5 x 10^{16} GeV string model is the existence of F- and D-flat directions that near the string scale can simultaneously break the anomalous U(1) and give mass to all exotic SM-charged observable particles, decoupling them from the low energy spectrum. In this letter we show, in the context of free fermionic strings, that string models with flat directions possessing these features do exist. We present one such string derived model in which all such exotic observable states beyond the MSSM receive mass at the scale generated by the Fayet- Iliopoulos term. The associated F- and D-flat direction is proven flat to all orders of the superpotential.
0912.4917
Olexandr Novak
O. P. Novak, R. I. Kholodov
Spin-polarization effects in the processes of synchrotron radiation and electron-positron pair production by a photon in a magnetic field
RevTeX, 12 pages, 8 figures, published in Physical Review D
Phys.Rev.D80:025025,2009
10.1103/PhysRevD.80.025025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spin and polarization effects and correlations between them in the processes of pair production by a photon and synchrotron radiation in a magnetic field are considered. Expressions for the probabilities of the processes with arbitrary polarizations of the particles are obtained. These expressions are analyzed in detail in both the lowest Landau levels and ultrarelativistic approximations.
[ { "created": "Thu, 24 Dec 2009 21:14:14 GMT", "version": "v1" } ]
2010-04-23
[ [ "Novak", "O. P.", "" ], [ "Kholodov", "R. I.", "" ] ]
Spin and polarization effects and correlations between them in the processes of pair production by a photon and synchrotron radiation in a magnetic field are considered. Expressions for the probabilities of the processes with arbitrary polarizations of the particles are obtained. These expressions are analyzed in detail in both the lowest Landau levels and ultrarelativistic approximations.
hep-ph/0011084
Maarten F. L. Golterman
Maarten Golterman (Washington U.)
Chiral Perturbation Theory, Non-leptonic Kaon Decays, and the Lattice
13 pages, invited plenary talk at Chiral 2000, Jefferson Lab., July 17-22, 2000
null
10.1142/9789812810977_0003
null
hep-ph hep-lat
null
In this talk, I first motivate the use of Chiral Perturbation Theory in the context of Lattice QCD. In particular, I explain how partially quenched QCD, which has, in general, unequal valence- and sea-quark masses, can be used to obtain real-world (i.e. unquenched) results for low-energy constants. In the second part, I review how Chiral Perturbation Theory may be used to overcome theoretical difficulties which afflict the computation of non-leptonic kaon decay rates from Lattice QCD. I argue that it should be possible to determine at least the O(p^2) weak low-energy constants reliably from numerical computations of the K to pi and K to vacuum matrix elements of the corresponding weak operators.
[ { "created": "Mon, 6 Nov 2000 23:32:56 GMT", "version": "v1" } ]
2017-08-23
[ [ "Golterman", "Maarten", "", "Washington U." ] ]
In this talk, I first motivate the use of Chiral Perturbation Theory in the context of Lattice QCD. In particular, I explain how partially quenched QCD, which has, in general, unequal valence- and sea-quark masses, can be used to obtain real-world (i.e. unquenched) results for low-energy constants. In the second part, I review how Chiral Perturbation Theory may be used to overcome theoretical difficulties which afflict the computation of non-leptonic kaon decay rates from Lattice QCD. I argue that it should be possible to determine at least the O(p^2) weak low-energy constants reliably from numerical computations of the K to pi and K to vacuum matrix elements of the corresponding weak operators.
1708.02243
Hou Keong Lou
Simon Knapen, Hou Keong Lou, Michele Papucci, Jack Setford
Tracking down Quirks at the Large Hadron Collider
9 pages, 10 figures, submitted to PRD, minor changes
Phys. Rev. D 96, 115015 (2017)
10.1103/PhysRevD.96.115015
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-helical tracks are the smoking gun signature of charged and/or colored quirks, which are pairs of particles bound by a new, long-range confining force. We propose a method to efficiently search for these non-helical tracks at the LHC, without the need to fit their trajectories. We show that the hits corresponding to quirky trajectories can be selected efficiently by searching for co-planar hits in the inner layers of the ATLAS and CMS trackers, even in the presence of on average 50 pile-up vertices. We further argue that backgrounds from photon conversions and unassociated pile-up hits can be removed almost entirely, while maintaining a signal reconstruction efficiency as high as 70%. With the 300 fb$^{-1}$ dataset, this implies a discovery potential for string tension between 100 eV and 30 keV, and colored (electroweak charged) quirks as heavy as 1600 (650) GeV may be discovered.
[ { "created": "Mon, 7 Aug 2017 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 13 Nov 2017 19:30:49 GMT", "version": "v2" } ]
2017-12-27
[ [ "Knapen", "Simon", "" ], [ "Lou", "Hou Keong", "" ], [ "Papucci", "Michele", "" ], [ "Setford", "Jack", "" ] ]
Non-helical tracks are the smoking gun signature of charged and/or colored quirks, which are pairs of particles bound by a new, long-range confining force. We propose a method to efficiently search for these non-helical tracks at the LHC, without the need to fit their trajectories. We show that the hits corresponding to quirky trajectories can be selected efficiently by searching for co-planar hits in the inner layers of the ATLAS and CMS trackers, even in the presence of on average 50 pile-up vertices. We further argue that backgrounds from photon conversions and unassociated pile-up hits can be removed almost entirely, while maintaining a signal reconstruction efficiency as high as 70%. With the 300 fb$^{-1}$ dataset, this implies a discovery potential for string tension between 100 eV and 30 keV, and colored (electroweak charged) quirks as heavy as 1600 (650) GeV may be discovered.
1409.7816
Danny van Dyk
I. Sentitemsu Imsong, Alexander Khodjamirian, Thomas Mannel, Danny van Dyk (Siegen U.)
Extrapolation and unitarity bounds for the $B \to \pi$ form factor
26 pages, 4 figures; v2: as published (reference and zoomed plot added, conclusions and numerics unchanged)
JHEP02(2015)126
10.1007/JHEP02(2015)126
SI-HEP-2014-21, QFET-2014-14, EOS-2014-02
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the problem of extrapolating the vector form factor $f_{B\pi}^+$, which is relevant to $B\to \pi\ell \nu_\ell$ decays, from the region of small to the region of large momentum transfer. As input, we use the QCD light-cone sum rule at small momentum transfer. We carry out a comprehensive Bayesian uncertainty analysis and obtain correlated uncertainties for the normalization and shape parameters of the form factor. The $z$-series parametrization for $f_{B\pi}^+$ is employed to extrapolate our results to large momentum transfer, and to compare with the lattice QCD results. To test the validity of our extrapolation we use the upper and lower bounds from the unitarity and positivity of the two-point correlator of heavy-light quark currents. This correlator is updated by including the NNLO perturbative term and the NLO correction to the quark condensate contribution. We demonstrate that an additional input including the form factor, its first and second derivative calculated at one value of momentum transfer from the light-cone sum rules, considerably improves the bounds. This only holds when the correlations between the form factor parameters are taken into account. We further combine our results with the latest experimental measurements of $B\to \pi \ell \nu_\ell$ by the BaBar and Belle collaborations, and obtain $|V_{ub}|= (3.32^{+0.26}_{-0.22}) \cdot 10^{-3}$ from a Bayesian analysis.
[ { "created": "Sat, 27 Sep 2014 15:20:03 GMT", "version": "v1" }, { "created": "Thu, 5 Mar 2015 09:59:40 GMT", "version": "v2" } ]
2015-03-06
[ [ "Imsong", "I. Sentitemsu", "", "Siegen U." ], [ "Khodjamirian", "Alexander", "", "Siegen U." ], [ "Mannel", "Thomas", "", "Siegen U." ], [ "van Dyk", "Danny", "", "Siegen U." ] ]
We address the problem of extrapolating the vector form factor $f_{B\pi}^+$, which is relevant to $B\to \pi\ell \nu_\ell$ decays, from the region of small to the region of large momentum transfer. As input, we use the QCD light-cone sum rule at small momentum transfer. We carry out a comprehensive Bayesian uncertainty analysis and obtain correlated uncertainties for the normalization and shape parameters of the form factor. The $z$-series parametrization for $f_{B\pi}^+$ is employed to extrapolate our results to large momentum transfer, and to compare with the lattice QCD results. To test the validity of our extrapolation we use the upper and lower bounds from the unitarity and positivity of the two-point correlator of heavy-light quark currents. This correlator is updated by including the NNLO perturbative term and the NLO correction to the quark condensate contribution. We demonstrate that an additional input including the form factor, its first and second derivative calculated at one value of momentum transfer from the light-cone sum rules, considerably improves the bounds. This only holds when the correlations between the form factor parameters are taken into account. We further combine our results with the latest experimental measurements of $B\to \pi \ell \nu_\ell$ by the BaBar and Belle collaborations, and obtain $|V_{ub}|= (3.32^{+0.26}_{-0.22}) \cdot 10^{-3}$ from a Bayesian analysis.
hep-ph/0003229
Uma Mahanta
Uma Mahanta
Higgs induced light leptoquark-diquark mixing and proton decay
Plain Tex, 8 pages no figures
Eur.Phys.J.C16:367-369,2000
10.1007/s100520050029
null
hep-ph
null
In low energy phenomenology to avoid the strong constraints of proton decay it is usually assumed that light ($\approx $ 250 Gev) leptoquarks couple only to quark-lepton pairs and light diquarks couple only to quark pairs. In this paper we present two specific examples where the higgs induced mixing between leptoquarks and diquarks through trilinear interaction terms reintroduces the troublesome couplings and gives rise to proton decay. The bound on the unknown parameters of this scenario that arise from proton life time has been derived.
[ { "created": "Thu, 23 Mar 2000 11:57:16 GMT", "version": "v1" } ]
2011-09-13
[ [ "Mahanta", "Uma", "" ] ]
In low energy phenomenology to avoid the strong constraints of proton decay it is usually assumed that light ($\approx $ 250 Gev) leptoquarks couple only to quark-lepton pairs and light diquarks couple only to quark pairs. In this paper we present two specific examples where the higgs induced mixing between leptoquarks and diquarks through trilinear interaction terms reintroduces the troublesome couplings and gives rise to proton decay. The bound on the unknown parameters of this scenario that arise from proton life time has been derived.
1501.01296
Sandra Robles
D.G. Cerdeno, M. Peiro, and S. Robles
Fits to the Fermi-LAT GeV excess with RH sneutrino dark matter: implications for direct and indirect dark matter searches and the LHC
13 pages, 9 figures, 1 table. Discussion extended, matches Phys. Rev. D published version
Phys. Rev. D 91, 123530 (2015)
10.1103/PhysRevD.91.123530
IPPP/15/01, DCTP/15/02, IFT-UAM/CSIC-15-001, FTUAM-15-1
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the right-handed (RH) sneutrino in the NMSSM can account for the observed excess in the Fermi-LAT spectrum of gamma rays from the Galactic Centre, while fulfilling all the current experimental constraints from the LHC as well as from direct and indirect dark matter searches. We have explored the parameter space of this scenario, computed the gamma ray spectrum for each phenomenologically viable solution and then performed a chi^2 fit to the excess. Unlike previous studies based on model independent interpretations, we have taken into account the full annihilation spectrum, without assuming pure annihilation channels. Furthermore, we have incorporated limits from direct detection experiments, LHC bounds and also the constraints from Fermi-LAT on dwarf spheroidal galaxies (dSphs) and gamma ray spectral lines. In addition, we have estimated the effect of the most recent Fermi-LAT reprocessed data (Pass 8). In general, we obtain good fits to the GCE when the RH sneutrino annihilates mainly into pairs of light singlet-like scalar or pseudoscalar Higgs bosons that subsequently decay in flight, producing four-body final states and spectral features that improve the goodness of the fit at large energies. The best fit (chi^2=20.8) corresponds to a RH sneutrino with a mass of 64 GeV which annihilates preferentially into a pair of light singlet-like pseudoscalar Higgs bosons (with masses of order 60 GeV). Besides, we have analysed other channels that also provide good fits to the excess. Finally, we discuss the implications for direct and indirect detection searches paying special attention to the possible appearance of gamma ray spectral features in near future Fermi-LAT analyses, as well as deviations from the SM-like Higgs properties at the LHC. Remarkably, many of the scenarios that fit the GCE can also be probed by these other complementary techniques.
[ { "created": "Tue, 6 Jan 2015 20:52:52 GMT", "version": "v1" }, { "created": "Mon, 19 Jan 2015 16:11:08 GMT", "version": "v2" }, { "created": "Fri, 31 Jul 2015 19:07:34 GMT", "version": "v3" } ]
2015-08-03
[ [ "Cerdeno", "D. G.", "" ], [ "Peiro", "M.", "" ], [ "Robles", "S.", "" ] ]
We show that the right-handed (RH) sneutrino in the NMSSM can account for the observed excess in the Fermi-LAT spectrum of gamma rays from the Galactic Centre, while fulfilling all the current experimental constraints from the LHC as well as from direct and indirect dark matter searches. We have explored the parameter space of this scenario, computed the gamma ray spectrum for each phenomenologically viable solution and then performed a chi^2 fit to the excess. Unlike previous studies based on model independent interpretations, we have taken into account the full annihilation spectrum, without assuming pure annihilation channels. Furthermore, we have incorporated limits from direct detection experiments, LHC bounds and also the constraints from Fermi-LAT on dwarf spheroidal galaxies (dSphs) and gamma ray spectral lines. In addition, we have estimated the effect of the most recent Fermi-LAT reprocessed data (Pass 8). In general, we obtain good fits to the GCE when the RH sneutrino annihilates mainly into pairs of light singlet-like scalar or pseudoscalar Higgs bosons that subsequently decay in flight, producing four-body final states and spectral features that improve the goodness of the fit at large energies. The best fit (chi^2=20.8) corresponds to a RH sneutrino with a mass of 64 GeV which annihilates preferentially into a pair of light singlet-like pseudoscalar Higgs bosons (with masses of order 60 GeV). Besides, we have analysed other channels that also provide good fits to the excess. Finally, we discuss the implications for direct and indirect detection searches paying special attention to the possible appearance of gamma ray spectral features in near future Fermi-LAT analyses, as well as deviations from the SM-like Higgs properties at the LHC. Remarkably, many of the scenarios that fit the GCE can also be probed by these other complementary techniques.
hep-ph/0212097
David A. Kosower
David A. Kosower
Multiple Singular Emission in Gauge Theories
Corrections for final journal version (sign in eqn. (6.11), equation references, typos in indices) & removal of comment about FDH
Phys.Rev. D67 (2003) 116003
10.1103/PhysRevD.67.116003
Saclay/SPhT-T02/174
hep-ph
null
I derive a class of functions unifying all singular limits for the emission of a given number of soft or collinear gluons in tree-level gauge-theory amplitudes. Each function is a generalization of the single-emission antenna function of ref. [1]. The helicity-summed squares of these functions are thus also generalizations to multiple singular emission of the Catani--Seymour dipole factorization function.
[ { "created": "Fri, 6 Dec 2002 11:06:16 GMT", "version": "v1" }, { "created": "Fri, 19 Dec 2003 17:55:46 GMT", "version": "v2" } ]
2009-11-07
[ [ "Kosower", "David A.", "" ] ]
I derive a class of functions unifying all singular limits for the emission of a given number of soft or collinear gluons in tree-level gauge-theory amplitudes. Each function is a generalization of the single-emission antenna function of ref. [1]. The helicity-summed squares of these functions are thus also generalizations to multiple singular emission of the Catani--Seymour dipole factorization function.
hep-ph/0507046
Jae Sik Lee
John Ellis, Jae Sik Lee and Apostolos Pilaftsis
Resonant CP Violation in Higgs Radiation at e^+e^- Linear Collider
22 pages, 8 figures, to appear in Phys. Rev. D
Phys.Rev.D72:095006,2005
10.1103/PhysRevD.72.095006
CERN-PH-TH/2005-112
hep-ph
null
We study resonant CP violation in the Higgsstrahlung process e^+e^- -> H_{1,2,3} (Z -> e^+e^-, \mu^+\mu^-) and subsequent decays H_{1,2,3} -> b \bar{b}, \tau^-\tau^+, in the MSSM with Higgs-sector CP violation induced by radiative corrections. At a high-energy e^+e^- linear collider, the recoil-mass method enables one to determine the invariant mass of a fermion pair produced by Higgs decays with a precision as good as 1 GeV. Assuming an integrated luminosity of 100/fb, we show that the production lineshape of a coupled system of neutral Higgs bosons decaying into b\bar{b} quarks is sensitive to the CP-violating parameters. When the Higgs bosons decay into \tau^-\tau^+, two CP asymmetries can be defined using the longitudinal and transverse polarizations of the tau leptons. Taking into account the constraints from electric dipole moments, we find that these CP asymmetries can be as large as 80 %, in a tri-mixing scenario where all three neutral Higgs states of the MSSM are nearly degenerate and mix significantly.
[ { "created": "Mon, 4 Jul 2005 19:55:52 GMT", "version": "v1" }, { "created": "Wed, 5 Oct 2005 14:07:11 GMT", "version": "v2" } ]
2009-09-11
[ [ "Ellis", "John", "" ], [ "Lee", "Jae Sik", "" ], [ "Pilaftsis", "Apostolos", "" ] ]
We study resonant CP violation in the Higgsstrahlung process e^+e^- -> H_{1,2,3} (Z -> e^+e^-, \mu^+\mu^-) and subsequent decays H_{1,2,3} -> b \bar{b}, \tau^-\tau^+, in the MSSM with Higgs-sector CP violation induced by radiative corrections. At a high-energy e^+e^- linear collider, the recoil-mass method enables one to determine the invariant mass of a fermion pair produced by Higgs decays with a precision as good as 1 GeV. Assuming an integrated luminosity of 100/fb, we show that the production lineshape of a coupled system of neutral Higgs bosons decaying into b\bar{b} quarks is sensitive to the CP-violating parameters. When the Higgs bosons decay into \tau^-\tau^+, two CP asymmetries can be defined using the longitudinal and transverse polarizations of the tau leptons. Taking into account the constraints from electric dipole moments, we find that these CP asymmetries can be as large as 80 %, in a tri-mixing scenario where all three neutral Higgs states of the MSSM are nearly degenerate and mix significantly.
1406.2972
Felix Karbstein
Holger Gies, Felix Karbstein, Rashid Shaisultanov
Laser photon merging in an electromagnetic field inhomogeneity
28 pages, 6 figures; some clarifications added, matches journal version
Phys. Rev. D 90, 033007 (2014)
10.1103/PhysRevD.90.033007
null
hep-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effect of laser photon merging, or equivalently high harmonic generation, in the quantum vacuum subject to inhomogeneous electromagnetic fields. Such a process is facilitated by the effective nonlinear couplings arising from charged particle-antiparticle fluctuations in the quantum vacuum subject to strong electromagnetic fields. We derive explicit results for general kinematic and polarization configurations involving optical photons. Concentrating on merged photons in reflected channels which are preferable in experiments for reasons of noise suppression, we demonstrate that photon merging is typically dominated by the competing nonlinear process of quantum reflection, though appropriate polarization and signal filtering could specifically search for the merging process. As a byproduct, we devise a novel systematic expansion of the photon polarization tensor in plane wave fields.
[ { "created": "Wed, 11 Jun 2014 17:23:01 GMT", "version": "v1" }, { "created": "Wed, 13 Aug 2014 09:49:04 GMT", "version": "v2" } ]
2014-08-14
[ [ "Gies", "Holger", "" ], [ "Karbstein", "Felix", "" ], [ "Shaisultanov", "Rashid", "" ] ]
We study the effect of laser photon merging, or equivalently high harmonic generation, in the quantum vacuum subject to inhomogeneous electromagnetic fields. Such a process is facilitated by the effective nonlinear couplings arising from charged particle-antiparticle fluctuations in the quantum vacuum subject to strong electromagnetic fields. We derive explicit results for general kinematic and polarization configurations involving optical photons. Concentrating on merged photons in reflected channels which are preferable in experiments for reasons of noise suppression, we demonstrate that photon merging is typically dominated by the competing nonlinear process of quantum reflection, though appropriate polarization and signal filtering could specifically search for the merging process. As a byproduct, we devise a novel systematic expansion of the photon polarization tensor in plane wave fields.