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hep-ph/0412410
Serguey Petcov
S. T. Petcov
Towards Complete Neutrino Mixing Matrix and CP-Violation
Somewhat extended version (including additional comments, references and figure) of the invited plenary talk given at the XXIst International Conference on Neutrino Physics and Astrophysics, June 14-19, 2004, Paris, France; 10 pages, 4 figures
null
10.1016/j.nuclphysbps.2005.01.101
Ref. SISSA 84/2004/EP
hep-ph
null
The compelling experimental evidences for oscillations of solar, atmospheric and reactor neutrinos imply the existence of 3-neutrino mixing in vacuum. We review the phenomenology of 3-neutrino mixing, and the current data on the 3-neutrino mixing parameters. The opened questions and the main goals of future research in the field of neutrino mixing and oscillations are outlined. A phenomenological approach for understanding the pattern of neutrino mixing as an interplay between the mixing, arising from the charged lepton sector, and bimaximal mixing, arising from a neutrino Majorana mass matrix, is considered with emphasis on the CP-violating case. We comment also on planned future steps in the experimental studies of neutrino mixing.
[ { "created": "Wed, 29 Dec 2004 17:34:29 GMT", "version": "v1" } ]
2009-11-10
[ [ "Petcov", "S. T.", "" ] ]
The compelling experimental evidences for oscillations of solar, atmospheric and reactor neutrinos imply the existence of 3-neutrino mixing in vacuum. We review the phenomenology of 3-neutrino mixing, and the current data on the 3-neutrino mixing parameters. The opened questions and the main goals of future research in the field of neutrino mixing and oscillations are outlined. A phenomenological approach for understanding the pattern of neutrino mixing as an interplay between the mixing, arising from the charged lepton sector, and bimaximal mixing, arising from a neutrino Majorana mass matrix, is considered with emphasis on the CP-violating case. We comment also on planned future steps in the experimental studies of neutrino mixing.
hep-ph/0007017
Pallante
Elisabetta Pallante
Final State Interactions in $\epsilon'/\epsilon$
Talk presented at the XXXVth Rencontres de Moriond on Electroweak Interactions and Unified Theories, March 2000; 8 pages, 1 eps figure
null
null
null
hep-ph
null
Strong final state interaction (FSI) effects can play a central role in the Standard Model prediction of weak $K\to 2\pi$ matrix elements. Here, I discuss how FSI's affect the direct CP violation parameter $\vepp / \vep$ by solving the Omn\`es problem for the necessary $K\to 2\pi$ amplitudes. The main results of this analysis have been reported in a previous paper [1] and are further discussed in Refs. [2,3]. The resulting Standard Model prediction ${Re} (\vepp / \vep) = (15\pm 5)\times 10^{-4}$ is in good agreement with the present experimental world average.
[ { "created": "Mon, 3 Jul 2000 16:58:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pallante", "Elisabetta", "" ] ]
Strong final state interaction (FSI) effects can play a central role in the Standard Model prediction of weak $K\to 2\pi$ matrix elements. Here, I discuss how FSI's affect the direct CP violation parameter $\vepp / \vep$ by solving the Omn\`es problem for the necessary $K\to 2\pi$ amplitudes. The main results of this analysis have been reported in a previous paper [1] and are further discussed in Refs. [2,3]. The resulting Standard Model prediction ${Re} (\vepp / \vep) = (15\pm 5)\times 10^{-4}$ is in good agreement with the present experimental world average.
2104.04373
Rojalin Padhan
Genevi\`eve B\'elanger, Sarif Khan, Rojalin Padhan, Manimala Mitra, Sujay Shil
Right Handed Neutrinos, TeV Scale BSM Neutral Higgs and FIMP Dark Matter in EFT Framework
39 pages, 15 figures
Phys. Rev. D 104, 055047 (2021)
10.1103/PhysRevD.104.055047
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider an effective field theory framework with three standard model (SM) gauge singlet right handed neutrinos, and an additional SM gauge singlet scalar field. The framework successfully generates eV masses of the light neutrinos via seesaw mechanism, and accommodates a feebly interacting massive particle (FIMP) as dark matter candidate. Two of the gauge singlet neutrinos participate in neutrino mass generation, while the third gauge singlet neutrino is a FIMP dark matter. We explore the correlation between the $\textit{vev}$ of the gauge singlet scalar field which translates as mass of the BSM Higgs, and the mass of dark matter, which arises due to relic density constraint. We furthermore explore the constraints from the light neutrino masses in this set-up. We chose the gauge singlet BSM Higgs in this framework in the TeV scale. We perform a detailed collider analysis to analyse the discovery prospect of the TeV scale BSM Higgs through its di-fatjet signature, at a future $pp$ collider which can operate with $\sqrt{s}=100$ TeV c.m.energy.
[ { "created": "Fri, 9 Apr 2021 14:05:36 GMT", "version": "v1" } ]
2021-10-04
[ [ "Bélanger", "Geneviève", "" ], [ "Khan", "Sarif", "" ], [ "Padhan", "Rojalin", "" ], [ "Mitra", "Manimala", "" ], [ "Shil", "Sujay", "" ] ]
We consider an effective field theory framework with three standard model (SM) gauge singlet right handed neutrinos, and an additional SM gauge singlet scalar field. The framework successfully generates eV masses of the light neutrinos via seesaw mechanism, and accommodates a feebly interacting massive particle (FIMP) as dark matter candidate. Two of the gauge singlet neutrinos participate in neutrino mass generation, while the third gauge singlet neutrino is a FIMP dark matter. We explore the correlation between the $\textit{vev}$ of the gauge singlet scalar field which translates as mass of the BSM Higgs, and the mass of dark matter, which arises due to relic density constraint. We furthermore explore the constraints from the light neutrino masses in this set-up. We chose the gauge singlet BSM Higgs in this framework in the TeV scale. We perform a detailed collider analysis to analyse the discovery prospect of the TeV scale BSM Higgs through its di-fatjet signature, at a future $pp$ collider which can operate with $\sqrt{s}=100$ TeV c.m.energy.
2212.12136
Raphael M. Albuquerque
R.M. Albuquerque, S. Narison and D. Rabetiarivony
1+ XTZ States within QCD Sum Rules
To appear in the proceedings of the 25th High-Energy Physics International Conference in Quantum Chromodynamics (QCD 22)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present improved estimates of the couplings, masses and mass ratios of the $X_Q, Z_Q$ and $T_{QQ\bar q\bar q'}$ states using (inverse) QCD Laplace sum rules (LSR), their ratios ${\cal R}$ and double ratios (DRSR), within stability criteria. We conclude that the observed $X_c(3872)$ and $Z_c(3900)$ are tetramoles states (superposition of quasi-degenerated molecule and tetraquark states having similar couplings to the currents) with the predicted masses: $M_{{\cal T}_{X_c}}=3876(44)$ MeV and $M_{{\cal T}_{Z_c}}=3900(42)$ MeV. We also do an extensive analysis of the four-quark nature of different $T_{QQ\bar q\bar q'}$ axial-vector states. Then, combining ${\cal R}$ and DRSR, we reanalyze the observed state $X_c(3872)$ and we obtain a precise prediction of $M_{T_{cc}^{1^+}}$=3886(6) MeV. Extending to the beauty sector, we find the results: $M_{{\cal T}_{Z_b}}=10579(99)$ MeV and $M_{X_b}=10545(131)$ MeV. Finally, we confront our combined LSR $\oplus$ DRSR results with the ones from some other approaches (lattices and quark models).
[ { "created": "Fri, 23 Dec 2022 04:10:51 GMT", "version": "v1" } ]
2022-12-26
[ [ "Albuquerque", "R. M.", "" ], [ "Narison", "S.", "" ], [ "Rabetiarivony", "D.", "" ] ]
We present improved estimates of the couplings, masses and mass ratios of the $X_Q, Z_Q$ and $T_{QQ\bar q\bar q'}$ states using (inverse) QCD Laplace sum rules (LSR), their ratios ${\cal R}$ and double ratios (DRSR), within stability criteria. We conclude that the observed $X_c(3872)$ and $Z_c(3900)$ are tetramoles states (superposition of quasi-degenerated molecule and tetraquark states having similar couplings to the currents) with the predicted masses: $M_{{\cal T}_{X_c}}=3876(44)$ MeV and $M_{{\cal T}_{Z_c}}=3900(42)$ MeV. We also do an extensive analysis of the four-quark nature of different $T_{QQ\bar q\bar q'}$ axial-vector states. Then, combining ${\cal R}$ and DRSR, we reanalyze the observed state $X_c(3872)$ and we obtain a precise prediction of $M_{T_{cc}^{1^+}}$=3886(6) MeV. Extending to the beauty sector, we find the results: $M_{{\cal T}_{Z_b}}=10579(99)$ MeV and $M_{X_b}=10545(131)$ MeV. Finally, we confront our combined LSR $\oplus$ DRSR results with the ones from some other approaches (lattices and quark models).
hep-ph/9903495
Hirotsugu Fujii
H.Fujii and D.Kharzeev
Long-Range Forces of QCD
16pages, 9 eps figures; discussion extended, 2 new references added, to appear in Phys.Rev.D
Phys.Rev. D60 (1999) 114039
10.1103/PhysRevD.60.114039
null
hep-ph nucl-th
null
We consider the scattering of two color dipoles (e.g., heavy quarkonium states) at low energy - a QCD analog of Van der Waals interaction. Even though the couplings of the dipoles to the gluon field can be described in perturbation theory, which leads to the potential proportional to (N_c^2-1)/R^{7}, at large distances R the interaction becomes totally non-perturbative. Low-energy QCD theorems are used to evaluate the leading long-distance contribution \sim (N_f^2-1)/(11N_c - 2N_f)^2 R^{-5/2} exp(-2 \mu R) (\mu is the Goldstone boson mass), which is shown to arise from the correlated two-boson exchange. The sum rule which relates the overall strength of the interaction to the energy density of QCD vacuum is derived. Surprisingly, we find that when the size of the dipoles shrinks to zero (the heavy quark limit in the case of quarkonia), the non-perturbative part of the interaction vanishes more slowly than the perturbative part as a consequence of scale anomaly. As an application, we evaluate elastic \pi J/\psi and \pi J/\psi \to \pi \psi' cross sections.
[ { "created": "Thu, 25 Mar 1999 23:44:11 GMT", "version": "v1" }, { "created": "Tue, 24 Aug 1999 01:59:33 GMT", "version": "v2" } ]
2009-10-31
[ [ "Fujii", "H.", "" ], [ "Kharzeev", "D.", "" ] ]
We consider the scattering of two color dipoles (e.g., heavy quarkonium states) at low energy - a QCD analog of Van der Waals interaction. Even though the couplings of the dipoles to the gluon field can be described in perturbation theory, which leads to the potential proportional to (N_c^2-1)/R^{7}, at large distances R the interaction becomes totally non-perturbative. Low-energy QCD theorems are used to evaluate the leading long-distance contribution \sim (N_f^2-1)/(11N_c - 2N_f)^2 R^{-5/2} exp(-2 \mu R) (\mu is the Goldstone boson mass), which is shown to arise from the correlated two-boson exchange. The sum rule which relates the overall strength of the interaction to the energy density of QCD vacuum is derived. Surprisingly, we find that when the size of the dipoles shrinks to zero (the heavy quark limit in the case of quarkonia), the non-perturbative part of the interaction vanishes more slowly than the perturbative part as a consequence of scale anomaly. As an application, we evaluate elastic \pi J/\psi and \pi J/\psi \to \pi \psi' cross sections.
1004.4853
Richard Neufeld Jr.
R. B. Neufeld
Jets associated with Z^0 boson production in heavy-ion collisions at the LHC
To appear in the proceedings of the 2010 Winter Workshop on Nuclear Dynamics, which was held in Ocho Rios, Jamaica, mon.
J.Phys.Conf.Ser.230:012035,2010
10.1088/1742-6596/230/1/012035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The heavy ion program at the LHC will present unprecedented opportunities to probe hot QCD matter, that is, the quark gluon plasma (QGP). Among these exciting new probes are high energy partons associated with the production of a Z^0 boson, or Z^0 tagged jets. Once produced, Z^0 bosons are essentially unaffected by the strongly interacting medium produced in heavy-ion collisions, and therefore provide a powerful signal of the initial partonic energy and subsequent medium induced partonic energy loss. When compared with theory, experimental measurements of Z^0 tagged jets will help quantify the jet quenching properties of the QGP and discriminate between different partonic energy loss formalisms. In what follows, I discuss the advantages of tagged jets over leading particles, and present preliminary results of the production and suppression of Z^0 tagged jets in relativistic heavy-ion collisions at LHC energies using the Guylassy-Levai-Vitev (GLV) partonic energy loss formalism.
[ { "created": "Tue, 27 Apr 2010 16:22:55 GMT", "version": "v1" } ]
2014-11-20
[ [ "Neufeld", "R. B.", "" ] ]
The heavy ion program at the LHC will present unprecedented opportunities to probe hot QCD matter, that is, the quark gluon plasma (QGP). Among these exciting new probes are high energy partons associated with the production of a Z^0 boson, or Z^0 tagged jets. Once produced, Z^0 bosons are essentially unaffected by the strongly interacting medium produced in heavy-ion collisions, and therefore provide a powerful signal of the initial partonic energy and subsequent medium induced partonic energy loss. When compared with theory, experimental measurements of Z^0 tagged jets will help quantify the jet quenching properties of the QGP and discriminate between different partonic energy loss formalisms. In what follows, I discuss the advantages of tagged jets over leading particles, and present preliminary results of the production and suppression of Z^0 tagged jets in relativistic heavy-ion collisions at LHC energies using the Guylassy-Levai-Vitev (GLV) partonic energy loss formalism.
1303.4639
Aleksi Kurkela
Aleksi Kurkela
Thermalization in collisions of large nuclei at high energies
8 pages, 4 figures; presentation at Xth Conference on Quark Confinement and the Hadron Spectrum, 8-12 October 2012, Munich, Germany
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hydrodynamical analysis of experimental data of ultrarelativistic heavy ion collisions seems to indicate that the hot QCD matter created in the collisions thermalizes very quickly. Theoretically, we have no idea why this should be true. In this proceeding, I will describe how the thermalization takes place in the most theoretically clean limit -- that of large nuclei at asymptotically high energy per nucleon, where the system is described by weak-coupling QCD. In this limit, plasma instabilities dominate the dynamics from immediately after the collision until well after the plasma becomes nearly in equilibrium at time t \alpha^(-5/2)Q^(-1).
[ { "created": "Tue, 19 Mar 2013 15:37:41 GMT", "version": "v1" } ]
2013-03-20
[ [ "Kurkela", "Aleksi", "" ] ]
Hydrodynamical analysis of experimental data of ultrarelativistic heavy ion collisions seems to indicate that the hot QCD matter created in the collisions thermalizes very quickly. Theoretically, we have no idea why this should be true. In this proceeding, I will describe how the thermalization takes place in the most theoretically clean limit -- that of large nuclei at asymptotically high energy per nucleon, where the system is described by weak-coupling QCD. In this limit, plasma instabilities dominate the dynamics from immediately after the collision until well after the plasma becomes nearly in equilibrium at time t \alpha^(-5/2)Q^(-1).
1402.1203
Evgeny Zhemchugov
E. V. Zhemchugov
On $Z \to \gamma \gamma$ decay and cancellation of axial anomaly in $Z \to \gamma \gamma$ transition amplitude for massive fermions
11 pages, 4 figures, 2 tables
Physics of Atomic Nuclei 77, 11 (2014) 1390
10.1134/S1063778814100147
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
$Z \to \gamma \gamma$ decay amplitude is considered and proven to be zero due to properties of polarization vectors and Bose statistics. Triangular diagrams for a pseudoscalar $\to \gamma \gamma$ and $Z \to \gamma \gamma$ processes with massive fermions in the loop are explicitely calculated. In the Standard Model axial anomaly vanishes in the sum of these diagrams as Z boson is mixed with one of the Goldstone bosons.
[ { "created": "Tue, 4 Feb 2014 20:07:11 GMT", "version": "v1" } ]
2015-03-17
[ [ "Zhemchugov", "E. V.", "" ] ]
$Z \to \gamma \gamma$ decay amplitude is considered and proven to be zero due to properties of polarization vectors and Bose statistics. Triangular diagrams for a pseudoscalar $\to \gamma \gamma$ and $Z \to \gamma \gamma$ processes with massive fermions in the loop are explicitely calculated. In the Standard Model axial anomaly vanishes in the sum of these diagrams as Z boson is mixed with one of the Goldstone bosons.
hep-ph/9804279
Yuichi Chikira
Yuichi Chikira, Naoyuki Haba and Yukihiro Mimura
The Sliding Singlet Mechanism with Gauge Mediated Supersymmetry Breaking
LaTeX 15 pages, no figures, mistakes in Eq.(3.27) crrected, a part of conclusion corrected
Phys. Rev. D 59, 055002 (1999)
10.1103/PhysRevD.59.055002
TIT-HEP-389, ICRR-Report-415-98-11
hep-ph
null
The sliding singlet mechanism is one of the most interesting solutions of the triplet-doublet splitting problem. We analyze this mechanism in the gauge mediated supersymmetry breaking scenario. We show that the sliding singlet mechanism does not work in the naive gauge mediation scenario because of the singlet linear terms derived from the gravity, although $F$ term is much smaller than the one in the gravity mediation scenario. We also consider the extension in order for the sliding singlet mechanism to work.
[ { "created": "Mon, 13 Apr 1998 11:10:49 GMT", "version": "v1" }, { "created": "Tue, 21 Apr 1998 07:39:48 GMT", "version": "v2" }, { "created": "Wed, 4 Nov 1998 10:08:11 GMT", "version": "v3" } ]
2016-08-25
[ [ "Chikira", "Yuichi", "" ], [ "Haba", "Naoyuki", "" ], [ "Mimura", "Yukihiro", "" ] ]
The sliding singlet mechanism is one of the most interesting solutions of the triplet-doublet splitting problem. We analyze this mechanism in the gauge mediated supersymmetry breaking scenario. We show that the sliding singlet mechanism does not work in the naive gauge mediation scenario because of the singlet linear terms derived from the gravity, although $F$ term is much smaller than the one in the gravity mediation scenario. We also consider the extension in order for the sliding singlet mechanism to work.
2407.11731
Yu Hamada
Minoru Eto, Yu Hamada and Muneto Nitta
Tying knots in particle physics
14 pages, 4 figures; v2: minor revisions
null
null
YGHP-24-06, DESY-24-104
hep-ph astro-ph.CO cond-mat.supr-con hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lord Kelvin's pioneering hypothesis that the identity of atoms is knots of vortices of the aether had a profound impact on the fields of mathematics and physics despite being subsequently refuted by experiments. While knot-like excitations emerge in various systems of condensed matter physics, the fundamental constituents of matter have been revealed to be elementary particles such as electrons and quarks, seemingly leaving no room for the appearance of knots in particle physics. Here, we show that knots indeed appear as meta-stable solitons in a realistic extension of the standard model of particle physics that provides the QCD axion and right-handed neutrinos. This result suggests that during the early Universe, a "knot dominated era" may have existed, where knots were a dominant component of the Universe, and this scenario can be tested through gravitational wave observations. Furthermore, we propose that the end of this era involves the collapse of the knots via quantum tunneling, leading to the generation of matter-antimatter asymmetry in the Universe. Our findings exhibit the significant role of knots in particle physics and represent a modern version of Kelvin's hypothesis.
[ { "created": "Tue, 16 Jul 2024 13:51:02 GMT", "version": "v1" }, { "created": "Mon, 5 Aug 2024 14:51:31 GMT", "version": "v2" } ]
2024-08-06
[ [ "Eto", "Minoru", "" ], [ "Hamada", "Yu", "" ], [ "Nitta", "Muneto", "" ] ]
Lord Kelvin's pioneering hypothesis that the identity of atoms is knots of vortices of the aether had a profound impact on the fields of mathematics and physics despite being subsequently refuted by experiments. While knot-like excitations emerge in various systems of condensed matter physics, the fundamental constituents of matter have been revealed to be elementary particles such as electrons and quarks, seemingly leaving no room for the appearance of knots in particle physics. Here, we show that knots indeed appear as meta-stable solitons in a realistic extension of the standard model of particle physics that provides the QCD axion and right-handed neutrinos. This result suggests that during the early Universe, a "knot dominated era" may have existed, where knots were a dominant component of the Universe, and this scenario can be tested through gravitational wave observations. Furthermore, we propose that the end of this era involves the collapse of the knots via quantum tunneling, leading to the generation of matter-antimatter asymmetry in the Universe. Our findings exhibit the significant role of knots in particle physics and represent a modern version of Kelvin's hypothesis.
1307.6900
Andrea Ferroglia
Andrea Ferroglia, Christoph Greub, Alberto Sirlin, and Zhibai Zhang
Contributions of the W-boson propagator to muon and tau leptonic decay rates
5 pages
null
10.1103/PhysRevD.88.033012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive closed expressions and useful expansions for the contributions of the tree-level W-boson propagator to the the muon and tau leptonic decay rates. Calling M and m the masses of the initial and final charged leptons, our results in the limit m=0 are valid to all orders in M^2/M_W^2. In the terms of O(m_j^2/M_W^2) (m_j=M,m), our leading corrections, of O(M^2/M_W^2), agree with the canonical value (3/5) M^2/M_W^2, while the coefficient of our subleading contributions, of O(m^2/M_W^2), differs from that reported in the recent literature. A possible explanation of the discrepancy is presented. The numerical effect of the O(m_j^2/M_W^2) corrections is briefly discussed. A general expression, valid for arbitrary values of M_W, M and m in the range M_W>M>m, is given in the Appendix. The paper also contains a review of the traditional definition and evaluation of the Fermi constant.
[ { "created": "Fri, 26 Jul 2013 00:44:48 GMT", "version": "v1" } ]
2013-08-28
[ [ "Ferroglia", "Andrea", "" ], [ "Greub", "Christoph", "" ], [ "Sirlin", "Alberto", "" ], [ "Zhang", "Zhibai", "" ] ]
We derive closed expressions and useful expansions for the contributions of the tree-level W-boson propagator to the the muon and tau leptonic decay rates. Calling M and m the masses of the initial and final charged leptons, our results in the limit m=0 are valid to all orders in M^2/M_W^2. In the terms of O(m_j^2/M_W^2) (m_j=M,m), our leading corrections, of O(M^2/M_W^2), agree with the canonical value (3/5) M^2/M_W^2, while the coefficient of our subleading contributions, of O(m^2/M_W^2), differs from that reported in the recent literature. A possible explanation of the discrepancy is presented. The numerical effect of the O(m_j^2/M_W^2) corrections is briefly discussed. A general expression, valid for arbitrary values of M_W, M and m in the range M_W>M>m, is given in the Appendix. The paper also contains a review of the traditional definition and evaluation of the Fermi constant.
0808.0523
Jonas Mureika
J. R. Mureika
Differentiating unparticles from extra dimensions via mini black hole thermodynamics
17 pp, LaTeX; 3 figures; Title slightly changed; added discussion of parton-parton cross sections and implications for unparticle-driven black holes; To appear in Phys Rev D
Phys.Rev.D79:056003,2009
10.1103/PhysRevD.79.056003
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A simple method for differentiating two similar accelerator-based black hole creation mechanisms -- compactified extra dimensions and unparticle-enhanced gravity -- is discussed, in light of several properties of black hole thermodynamics. The real-valued scaling dimension $\du$ will induce interactions that mimic those in a universe with $(2\du-2)$-extra spatial dimensions, and thus provides an alternative mechanism for black hole creation at the LHC within the confines of standard 4D general relativity. This results in mass-dependent Hawking temperature profiles that depend primarily on $\du$, yielding an evaporation signature unique to the framework. Specifically, a precision reconstruction of the Hawking temperature spectrum morphology for black holes of mass $\Mbh$ yields conclusive evidence of one mechanism over the other, due to the presence of additional adjustable parameters in the unparticle sector.
[ { "created": "Mon, 4 Aug 2008 22:36:48 GMT", "version": "v1" }, { "created": "Sun, 22 Feb 2009 22:17:11 GMT", "version": "v2" } ]
2009-11-06
[ [ "Mureika", "J. R.", "" ] ]
A simple method for differentiating two similar accelerator-based black hole creation mechanisms -- compactified extra dimensions and unparticle-enhanced gravity -- is discussed, in light of several properties of black hole thermodynamics. The real-valued scaling dimension $\du$ will induce interactions that mimic those in a universe with $(2\du-2)$-extra spatial dimensions, and thus provides an alternative mechanism for black hole creation at the LHC within the confines of standard 4D general relativity. This results in mass-dependent Hawking temperature profiles that depend primarily on $\du$, yielding an evaporation signature unique to the framework. Specifically, a precision reconstruction of the Hawking temperature spectrum morphology for black holes of mass $\Mbh$ yields conclusive evidence of one mechanism over the other, due to the presence of additional adjustable parameters in the unparticle sector.
1201.6368
Dmitry Levkov
D. G. Levkov, V. A. Rubakov, S. V. Troitsky, Y. A. Zenkevich
Constraining holographic technicolor
8 pages; journal version
Phys.Lett.B716:350-355,2012
10.1016/j.physletb.2012.08.038
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain a new bound on the value of Peskin-Takeuchi S parameter in a wide class of bottom-up holographic models for technicolor. Namely, we show that weakly coupled holographic description in these models implies S>>0.2. Our bound is in conflict with the results of electroweak precision measurements, so it strongly disfavors the models we consider.
[ { "created": "Mon, 30 Jan 2012 21:00:10 GMT", "version": "v1" }, { "created": "Wed, 22 Aug 2012 10:14:44 GMT", "version": "v2" } ]
2012-11-16
[ [ "Levkov", "D. G.", "" ], [ "Rubakov", "V. A.", "" ], [ "Troitsky", "S. V.", "" ], [ "Zenkevich", "Y. A.", "" ] ]
We obtain a new bound on the value of Peskin-Takeuchi S parameter in a wide class of bottom-up holographic models for technicolor. Namely, we show that weakly coupled holographic description in these models implies S>>0.2. Our bound is in conflict with the results of electroweak precision measurements, so it strongly disfavors the models we consider.
hep-ph/0108196
Borut Bajc
Borut Bajc, Ilia Gogoladze, Ramon Guevara and Goran Senjanovic
Flat directions, doublet-triplet splitting, the monopole problem, and all that
Latex, 11 pages, no figures. Improved version, more discussion on 1/M_Pl corrections and unwanted relics, new references
Phys.Lett. B525 (2002) 189-194
10.1016/S0370-2693(01)01434-4
null
hep-ph
null
We discuss a supersymmetric SU(6) grand unified theory with the GUT flat direction being lifted by soft supersymmetry breaking, and the doublet-triplet splitting being achieved with Higgs as a pseudo-Goldstone boson. The theory offers a simple solution to the false vacuum and monopole problems.
[ { "created": "Thu, 23 Aug 2001 16:46:51 GMT", "version": "v1" }, { "created": "Fri, 16 Nov 2001 12:57:59 GMT", "version": "v2" } ]
2009-11-07
[ [ "Bajc", "Borut", "" ], [ "Gogoladze", "Ilia", "" ], [ "Guevara", "Ramon", "" ], [ "Senjanovic", "Goran", "" ] ]
We discuss a supersymmetric SU(6) grand unified theory with the GUT flat direction being lifted by soft supersymmetry breaking, and the doublet-triplet splitting being achieved with Higgs as a pseudo-Goldstone boson. The theory offers a simple solution to the false vacuum and monopole problems.
hep-ph/9605351
Steve Mrenna
G.L. Kane (Univ. of Mich.) and S. Mrenna (Argonne)
Do About Half the Top Quarks at FNAL Come From Gluino Decays?
18 pages, including 4 Postscript figures, uses epsf.tex, also available at http://www.hep.anl.gov/theory/mrenna/
Phys.Rev.Lett.77:3502-3505,1996
10.1103/PhysRevLett.77.3502
ANL-HEP-PR-96-43, UM-TH-96-06
hep-ph
null
We argue that it is possible to make a consistent picture of FNAL data including the production and decay of gluinos and squarks. The additional cross section is several pb, about the size of that for Standard Model (SM) top quark pair production. If the stop squark mass is small enough, about half of the top quarks decay to stop squarks, and the loss of SM top quark pair production rate is compensated by the supersymmetric processes. This behavior is consistent with the reported top quark decay rates in various modes and other aspects of the data, and suggests several other possible decay signatures. This picture can be tested easily with more data, perhaps even with the data in hand, and demonstrates the potential power of a hadron collider to determine supersymmetric parameters. It also has implications for the top mass measurement and the interpretation of the LEP $R_b$ excess.
[ { "created": "Sun, 19 May 1996 21:08:32 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kane", "G. L.", "", "Univ. of Mich." ], [ "Mrenna", "S.", "", "Argonne" ] ]
We argue that it is possible to make a consistent picture of FNAL data including the production and decay of gluinos and squarks. The additional cross section is several pb, about the size of that for Standard Model (SM) top quark pair production. If the stop squark mass is small enough, about half of the top quarks decay to stop squarks, and the loss of SM top quark pair production rate is compensated by the supersymmetric processes. This behavior is consistent with the reported top quark decay rates in various modes and other aspects of the data, and suggests several other possible decay signatures. This picture can be tested easily with more data, perhaps even with the data in hand, and demonstrates the potential power of a hadron collider to determine supersymmetric parameters. It also has implications for the top mass measurement and the interpretation of the LEP $R_b$ excess.
hep-ph/9710536
V. V. Gubin
N.N.Achasov and V.V.Gubin (S.L.Sobolev Institute for Mathematics, Novosibirsk)
Search for the scalar a_0 and f_0 mesons in the \phi radiative decays
Talk given at HADRON-97
null
10.1063/1.55972
null
hep-ph hep-ex
null
The potentialities of the production of the $a_0$ and $f_0$ mesons in the $\phi$ radiative decays are considered based on a new two-channel analysis of the $\pi\pi$ scattering in a energy region near 1 GeV. We predict $BR(\phi\to\gamma f_0(980))\sim10^{-5}-10^{-4}$ that is a great value for the decay forbidden by the Okubo-Zweig-Iizuka rule. We discuss the four-quark, $K\bar K$-molecule and two-quark scenarios for the $a_0$ and $f_0$ mesons. It is presented arguments that the $e^+e^-$-colliders and especially the $\phi$ factories give the possibility to choose a single one out of them.
[ { "created": "Thu, 30 Oct 1997 04:32:11 GMT", "version": "v1" } ]
2009-10-30
[ [ "Achasov", "N. N.", "", "S.L.Sobolev Institute for Mathematics,\n Novosibirsk" ], [ "Gubin", "V. V.", "", "S.L.Sobolev Institute for Mathematics,\n Novosibirsk" ] ]
The potentialities of the production of the $a_0$ and $f_0$ mesons in the $\phi$ radiative decays are considered based on a new two-channel analysis of the $\pi\pi$ scattering in a energy region near 1 GeV. We predict $BR(\phi\to\gamma f_0(980))\sim10^{-5}-10^{-4}$ that is a great value for the decay forbidden by the Okubo-Zweig-Iizuka rule. We discuss the four-quark, $K\bar K$-molecule and two-quark scenarios for the $a_0$ and $f_0$ mesons. It is presented arguments that the $e^+e^-$-colliders and especially the $\phi$ factories give the possibility to choose a single one out of them.
hep-ph/0404032
Ming-Qiu Huang
Ming-Qiu Huang (NUDT, Hunan)
Exclusive semileptonic B_s decays to excited D_s mesons: Search of D_{sJ}(2317) and D_{sJ}(2460)
15 pages, 6 eps figures, RevTeX 4, accepted for publication in Phys. Rev. D
Phys.Rev. D69 (2004) 114015
10.1103/PhysRevD.69.114015
null
hep-ph
null
We study the exclusive semileptonic decays B_s->D_{s0}^*\ell\bar\nu and B_s->D_{s1}^*\ell\bar\nu, where p-wave excited D_{s0}^* and D_{s1}^* states are identified with the newly observed D_{sJ}(2317) and D_{sJ}(2460) states. Within the framework of HQET the Isgur-Wise functions up to the subleading order of the heavy quark expansion are calculated by QCD sum rules. The decay rates and branching ratios are computed with the inclusion of the order of 1/m_Q corrections. We point out that the investigation of the B_s semileptonic decays to excited D_s mesons may provide some information about the nature of the new D_{sJ}^* mesons.
[ { "created": "Sat, 3 Apr 2004 18:02:49 GMT", "version": "v1" } ]
2009-11-10
[ [ "Huang", "Ming-Qiu", "", "NUDT, Hunan" ] ]
We study the exclusive semileptonic decays B_s->D_{s0}^*\ell\bar\nu and B_s->D_{s1}^*\ell\bar\nu, where p-wave excited D_{s0}^* and D_{s1}^* states are identified with the newly observed D_{sJ}(2317) and D_{sJ}(2460) states. Within the framework of HQET the Isgur-Wise functions up to the subleading order of the heavy quark expansion are calculated by QCD sum rules. The decay rates and branching ratios are computed with the inclusion of the order of 1/m_Q corrections. We point out that the investigation of the B_s semileptonic decays to excited D_s mesons may provide some information about the nature of the new D_{sJ}^* mesons.
0801.0036
Adrian Palcu
Adrian Palcu
Charged and Neutral Currents in a 3-3-1 Model with Right-Handed Neutrinos
14 pages, 1 Table, no figures
Mod.Phys.Lett. A23 (2008) 387-399
10.1142/S0217732308026509
null
hep-ph
null
The charged and the neutral currents are obtained by using a formal algebraical approach (developed and applied by the author) within the exact solution of a 3-3-1 gauge model with right-handed neutrinos. The entire Standard Model phenomenology is recovered without imposing any supplemental condition, but only by choosing an adecquate set of parameters from the very beginning of the calculus. A new and rich phenomenology regarding the particles and their currents occurs as well. The appealing feature of our results resides in the exact expressions of the currents which need not the adjustment usually due to the small mixing angle $\phi$ between neutral bosons $Z$ and $Z^{\prime}$ (like in the most of the papers in the literature treating the same issue). The required mixing was considered and aleready performed as an intermediate step by the solving method itself, since the physical eigenstates of those bosons were determined and then identified in the neutral currents.
[ { "created": "Sat, 29 Dec 2007 08:26:32 GMT", "version": "v1" } ]
2009-02-24
[ [ "Palcu", "Adrian", "" ] ]
The charged and the neutral currents are obtained by using a formal algebraical approach (developed and applied by the author) within the exact solution of a 3-3-1 gauge model with right-handed neutrinos. The entire Standard Model phenomenology is recovered without imposing any supplemental condition, but only by choosing an adecquate set of parameters from the very beginning of the calculus. A new and rich phenomenology regarding the particles and their currents occurs as well. The appealing feature of our results resides in the exact expressions of the currents which need not the adjustment usually due to the small mixing angle $\phi$ between neutral bosons $Z$ and $Z^{\prime}$ (like in the most of the papers in the literature treating the same issue). The required mixing was considered and aleready performed as an intermediate step by the solving method itself, since the physical eigenstates of those bosons were determined and then identified in the neutral currents.
1711.10410
Tommi Alanne
Tommi Alanne, Diogo Buarque Franzosi, Mads T. Frandsen, Mette L.A. Kristensen, Aurora Meroni, Martin Rosenlyst
Partially composite Higgs models: Phenomenology and RG analysis
24 pages, 11 figures. v2 matches the published version
JHEP1801 (2018) 051
10.1007/JHEP01(2018)051
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the phenomenology of partially composite-Higgs models where electroweak symmetry breaking is dynamically induced, and the Higgs is a mixture of a composite and an elementary state. The models considered have explicit realizations in terms of gauge-Yukawa theories with new strongly interacting fermions coupled to elementary scalars and allow for a very SM-like Higgs state. We study constraints on their parameter spaces from vacuum stability and perturbativity as well as from LHC results and find that requiring vacuum stability up to the compositeness scale already imposes relevant constraints. A small part of parameter space around the classically conformal limit is stable up to the Planck scale. This is however already strongly disfavored by LHC results. In different limits, the models realize both (partially) composite-Higgs and (bosonic) technicolor models and a dynamical extension of the fundamental Goldstone-Higgs model. Therefore, they provide a general framework for exploring the phenomenology of composite dynamics.
[ { "created": "Tue, 28 Nov 2017 17:09:59 GMT", "version": "v1" }, { "created": "Wed, 24 Jan 2018 12:57:58 GMT", "version": "v2" } ]
2018-02-14
[ [ "Alanne", "Tommi", "" ], [ "Franzosi", "Diogo Buarque", "" ], [ "Frandsen", "Mads T.", "" ], [ "Kristensen", "Mette L. A.", "" ], [ "Meroni", "Aurora", "" ], [ "Rosenlyst", "Martin", "" ] ]
We study the phenomenology of partially composite-Higgs models where electroweak symmetry breaking is dynamically induced, and the Higgs is a mixture of a composite and an elementary state. The models considered have explicit realizations in terms of gauge-Yukawa theories with new strongly interacting fermions coupled to elementary scalars and allow for a very SM-like Higgs state. We study constraints on their parameter spaces from vacuum stability and perturbativity as well as from LHC results and find that requiring vacuum stability up to the compositeness scale already imposes relevant constraints. A small part of parameter space around the classically conformal limit is stable up to the Planck scale. This is however already strongly disfavored by LHC results. In different limits, the models realize both (partially) composite-Higgs and (bosonic) technicolor models and a dynamical extension of the fundamental Goldstone-Higgs model. Therefore, they provide a general framework for exploring the phenomenology of composite dynamics.
1806.02593
Stephen Jones
S. P. Jones, B. Ruijl
Numerical Methods and the 4-point 2-loop Higgs amplitudes
8 pages, 2 figures. To appear in the proceedings of `ACAT 2017', Seattle (USA), August 2017
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Some of the difficulties faced when calculating multi-loop amplitudes with several mass scales are reviewed. We then focus on one particular difficulty, the evaluation of the Feynman integrals, and introduce the program pySecDec which can be used to numerically compute such integrals. Some of the new features and in particular the sector symmetry finder, which can help to reduce the number of sectors to be numerically integrated after sector decomposition, are described.
[ { "created": "Thu, 7 Jun 2018 10:01:58 GMT", "version": "v1" } ]
2018-06-08
[ [ "Jones", "S. P.", "" ], [ "Ruijl", "B.", "" ] ]
Some of the difficulties faced when calculating multi-loop amplitudes with several mass scales are reviewed. We then focus on one particular difficulty, the evaluation of the Feynman integrals, and introduce the program pySecDec which can be used to numerically compute such integrals. Some of the new features and in particular the sector symmetry finder, which can help to reduce the number of sectors to be numerically integrated after sector decomposition, are described.
2306.17247
Roberto A. Morales
R. A. Morales
Exploring Bell inequalities and quantum entanglement in vector boson scattering
17 pages + 4 appendices with 11 captioned figures. Discussion and references added. Results are unchanged
null
null
null
hep-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
Quantum properties of vector boson scattering $V'_1V'_2\to V_1 V_2$, related to entanglement and violation of Bell inequalities, are explored in this paper. The analysis is based on the construction of the polarization density matrix associated to the final state $V_1V_2$ by means of the computation of the corresponding tree level amplitudes within the Standard Model. The aim of this work is to determine the regions of the phase space where the final vector bosons after the scattering result entangled and if is it possible to test the Bell inequalities in those regions. We found that in all cases the entanglement is present. The amount of it depends on the process and the Maximally Entangled state is reached in some particular channels. Concerning the Bell inequality, it could be also tested in certain kinematical regions for some of these processes. This work is a first step in the analysis of these quantum properties for this kind of processes and it is postponed for future studies the reconstruction of the polarization density matrix and the related quantum parameters from experimental data through Monte-Carlo simulations using quantum tomography techniques.
[ { "created": "Thu, 29 Jun 2023 18:29:31 GMT", "version": "v1" }, { "created": "Tue, 29 Aug 2023 20:57:01 GMT", "version": "v2" } ]
2023-08-31
[ [ "Morales", "R. A.", "" ] ]
Quantum properties of vector boson scattering $V'_1V'_2\to V_1 V_2$, related to entanglement and violation of Bell inequalities, are explored in this paper. The analysis is based on the construction of the polarization density matrix associated to the final state $V_1V_2$ by means of the computation of the corresponding tree level amplitudes within the Standard Model. The aim of this work is to determine the regions of the phase space where the final vector bosons after the scattering result entangled and if is it possible to test the Bell inequalities in those regions. We found that in all cases the entanglement is present. The amount of it depends on the process and the Maximally Entangled state is reached in some particular channels. Concerning the Bell inequality, it could be also tested in certain kinematical regions for some of these processes. This work is a first step in the analysis of these quantum properties for this kind of processes and it is postponed for future studies the reconstruction of the polarization density matrix and the related quantum parameters from experimental data through Monte-Carlo simulations using quantum tomography techniques.
1210.3826
Brett D. Altschul
Alejandro Ferrero, Brett Altschul
Quantum Effects of a Spacetime Varying alpha on the Propagation of Electrically Charged Fermions
12 pages
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A spacetime-varying fine structure constant alpha(x^mu) could generate quantum corrections in some of the coefficients of the Lorentz-violating standard model extension (SME) associated with electrically charged fermions. The quantum corrections depend on d_mu alpha, the spacetime gradient of the fine structure constant. Lorentz-violating operators involving fermions arise from the one-loop corrections to the quantum electrodynamics (QED) vertex function and fermion self-energy. Both g^(lambda mu nu) and c^(mu nu) terms are generated, at O(d_mu alpha) and O[(d_mu alpha)^2], respectively. The g^(lambda mu nu) terms so generated are different in the vertex and self-energy, which represents a radiatively induced violation of gauge invariance.
[ { "created": "Sun, 14 Oct 2012 19:27:26 GMT", "version": "v1" } ]
2012-10-16
[ [ "Ferrero", "Alejandro", "" ], [ "Altschul", "Brett", "" ] ]
A spacetime-varying fine structure constant alpha(x^mu) could generate quantum corrections in some of the coefficients of the Lorentz-violating standard model extension (SME) associated with electrically charged fermions. The quantum corrections depend on d_mu alpha, the spacetime gradient of the fine structure constant. Lorentz-violating operators involving fermions arise from the one-loop corrections to the quantum electrodynamics (QED) vertex function and fermion self-energy. Both g^(lambda mu nu) and c^(mu nu) terms are generated, at O(d_mu alpha) and O[(d_mu alpha)^2], respectively. The g^(lambda mu nu) terms so generated are different in the vertex and self-energy, which represents a radiatively induced violation of gauge invariance.
0810.1230
Tobias Huber
M. Beneke (RWTH Aachen University, University of Zurich), T. Huber (RWTH Aachen University), Xin-Qiang Li (RWTH Aachen University)
Two-loop QCD correction to differential semi-leptonic b --> u decays in the shape-function region
24 pages, 4 figures. Properly MSbar-renormalized coefficient functions introduced. Matches published version
Nucl.Phys.B811:77-97,2009
10.1016/j.nuclphysb.2008.11.019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the two-loop QCD correction to the form factors of on-shell b-quark decay to an energetic massless quark, which constitutes the last missing piece required for an O(alpha_s^2) determination of |V_ub| from inclusive semi-leptonic \bar B --> X_u l nu decays in the shape-function region.
[ { "created": "Tue, 7 Oct 2008 16:09:05 GMT", "version": "v1" }, { "created": "Mon, 24 Nov 2008 21:02:59 GMT", "version": "v2" } ]
2014-11-18
[ [ "Beneke", "M.", "", "RWTH Aachen University, University of Zurich" ], [ "Huber", "T.", "", "RWTH Aachen University" ], [ "Li", "Xin-Qiang", "", "RWTH Aachen University" ] ]
We calculate the two-loop QCD correction to the form factors of on-shell b-quark decay to an energetic massless quark, which constitutes the last missing piece required for an O(alpha_s^2) determination of |V_ub| from inclusive semi-leptonic \bar B --> X_u l nu decays in the shape-function region.
1712.06539
Felix Kling
Felix Kling, Arvind Rajaraman
On Profiles of Boson Stars with Self-Interactions
13 pages, Version 2: updated after accepted by journal, references updated, minor changes
Phys. Rev. D 97, 063012 (2018)
10.1103/PhysRevD.97.063012
UCI-HEP-TR-2017-17
hep-ph astro-ph.GA gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Under the influence of gravity, light scalar fields can form bound compact objects called boson stars. We use the technique of matching asymptotic expansions to obtain the profile for boson stars where the constituent particles have self-interactions. We obtain parametric representations of these profiles as a function of the self-interactions, including the case of very strong self-interactions. We show that our methods agree with solutions obtained by purely numerical methods. Significant distortions are found as compared to the noninteracting case.
[ { "created": "Mon, 18 Dec 2017 17:25:57 GMT", "version": "v1" }, { "created": "Fri, 15 Jun 2018 19:24:06 GMT", "version": "v2" } ]
2018-06-19
[ [ "Kling", "Felix", "" ], [ "Rajaraman", "Arvind", "" ] ]
Under the influence of gravity, light scalar fields can form bound compact objects called boson stars. We use the technique of matching asymptotic expansions to obtain the profile for boson stars where the constituent particles have self-interactions. We obtain parametric representations of these profiles as a function of the self-interactions, including the case of very strong self-interactions. We show that our methods agree with solutions obtained by purely numerical methods. Significant distortions are found as compared to the noninteracting case.
1512.09202
Manimala Mitra
Arnab Dasgupta, Manimala Mitra and Debasish Borah
Minimal Left-Right Symmetry Confronted with the 750 GeV Di-photon Excess at LHC
19 pages, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent results of 13 TeV ATLAS and CMS di-photon searches show an excess at di-photon invariant mass of 750 GeV. We look for possible explanation of this within minimal left right symmetric model (MLRSM). The possible candidate is a neutral Higgs of mass 750 GeV that can decay to di-photon via charged Higgs and right handed gauge boson loop. However, the cross-section is not consistent with the ATLAS and CMS results. We then discuss one possible variation of this model with universal seesaw for fermion masses that can explain this excess.
[ { "created": "Thu, 31 Dec 2015 02:55:20 GMT", "version": "v1" } ]
2016-01-01
[ [ "Dasgupta", "Arnab", "" ], [ "Mitra", "Manimala", "" ], [ "Borah", "Debasish", "" ] ]
The recent results of 13 TeV ATLAS and CMS di-photon searches show an excess at di-photon invariant mass of 750 GeV. We look for possible explanation of this within minimal left right symmetric model (MLRSM). The possible candidate is a neutral Higgs of mass 750 GeV that can decay to di-photon via charged Higgs and right handed gauge boson loop. However, the cross-section is not consistent with the ATLAS and CMS results. We then discuss one possible variation of this model with universal seesaw for fermion masses that can explain this excess.
2001.06042
Jui-Lin Kuo
Xiaoyong Chu, Jui-Lin Kuo, Josef Pradler
Dark sector-photon interactions in proton-beam experiments
17 pages, 7 figures, to match the published version
Phys. Rev. D 101, 075035 (2020)
10.1103/PhysRevD.101.075035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider electromagnetically neutral dark states that couple to the photon through higher dimensional effective operators, such as electric and magnetic dipole moment, anapole moment and charge radius operators. We investigate the possibility of probing the existence of such dark states, taking a Dirac fermion $\chi$ as an example, at several representative proton-beam experiments. As no positive signal has been reported, we obtain upper limits (or projected sensitivities) on the corresponding electromagnetic form factors for dark states lighter than several GeV. We demonstrate that while the current limits from proton-beam experiments are at most comparable with those from high-energy electron colliders, future experiments, such as DUNE and SHiP, will be able to improve the sensitivities to electric and magnetic dipole moment interactions, owing to their high intensity.
[ { "created": "Thu, 16 Jan 2020 19:26:40 GMT", "version": "v1" }, { "created": "Thu, 16 Apr 2020 19:42:49 GMT", "version": "v2" } ]
2020-04-20
[ [ "Chu", "Xiaoyong", "" ], [ "Kuo", "Jui-Lin", "" ], [ "Pradler", "Josef", "" ] ]
We consider electromagnetically neutral dark states that couple to the photon through higher dimensional effective operators, such as electric and magnetic dipole moment, anapole moment and charge radius operators. We investigate the possibility of probing the existence of such dark states, taking a Dirac fermion $\chi$ as an example, at several representative proton-beam experiments. As no positive signal has been reported, we obtain upper limits (or projected sensitivities) on the corresponding electromagnetic form factors for dark states lighter than several GeV. We demonstrate that while the current limits from proton-beam experiments are at most comparable with those from high-energy electron colliders, future experiments, such as DUNE and SHiP, will be able to improve the sensitivities to electric and magnetic dipole moment interactions, owing to their high intensity.
hep-ph/0611090
Reinhard Alkofer
Reinhard Alkofer
QCD Green Functions and their Application to Hadron Physics
21 pages, 32 figures; lectures presented at the conference ``Infrared QCD in Rio: Propagators, Condensates and Topological Effects (IRQCD 2006)'', Rio de Janeiro, Brazil, 5-9 Jun 2006; a few typos corrected (no other changes)
Braz.J.Phys.37:144-164,2007
null
null
hep-ph
null
In a functional approach to QCD the infrared behaviour of Landau gauge Green functions is investigated. It can be proven that the ghost Dyson-Schwinger equation implies the Gribov-Zwanziger horizon condition. Its relation to the Kugo-Ojima confinement scenario is elucidated. Positivity violation for gluons is demonstrated, and the analytic structure of the gluon propagator is studied. Quark confinement is related to an infrared divergence of the quark-gluon vertex. It is shown that in the latter various components are non-vanishing due to the dynamical breaking of chiral symmetry. As a result an infrared finite running coupling in the Yang-Mills sector is derived whereas the running coupling related to the quark-gluon vertex is infrared divergent. In Coulomb gauge QCD already the one-gluon-exchange (over-)confines. This leads to a vanishing quark propagator, and thus quarks are confined. Nevertheless colour singlet quantities derived from the quark propagator are well-defined. Especially the expression for the quark condensate proves that chiral symmetry is dynamically broken. As expected the properties of mesons can be directly calculated whereas the mass of coloured diquarks diverges, and thus diquarks are confined. The latter nevertheless possess a well-defined size. In the third part the results obtained so far will be used to formulate a covariant Faddeev approach to nucleons. The resulting amplitudes describe the quark core of the nucleon. Besides the mass of this state also the electromagnetic form factors are calculated. The results for charge radii and magnetic moments as a function of the quark current mass provide some indication what the missing pion cloud may contribute to the nucleons' properties.
[ { "created": "Tue, 7 Nov 2006 22:17:39 GMT", "version": "v1" }, { "created": "Fri, 20 Apr 2007 14:59:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Alkofer", "Reinhard", "" ] ]
In a functional approach to QCD the infrared behaviour of Landau gauge Green functions is investigated. It can be proven that the ghost Dyson-Schwinger equation implies the Gribov-Zwanziger horizon condition. Its relation to the Kugo-Ojima confinement scenario is elucidated. Positivity violation for gluons is demonstrated, and the analytic structure of the gluon propagator is studied. Quark confinement is related to an infrared divergence of the quark-gluon vertex. It is shown that in the latter various components are non-vanishing due to the dynamical breaking of chiral symmetry. As a result an infrared finite running coupling in the Yang-Mills sector is derived whereas the running coupling related to the quark-gluon vertex is infrared divergent. In Coulomb gauge QCD already the one-gluon-exchange (over-)confines. This leads to a vanishing quark propagator, and thus quarks are confined. Nevertheless colour singlet quantities derived from the quark propagator are well-defined. Especially the expression for the quark condensate proves that chiral symmetry is dynamically broken. As expected the properties of mesons can be directly calculated whereas the mass of coloured diquarks diverges, and thus diquarks are confined. The latter nevertheless possess a well-defined size. In the third part the results obtained so far will be used to formulate a covariant Faddeev approach to nucleons. The resulting amplitudes describe the quark core of the nucleon. Besides the mass of this state also the electromagnetic form factors are calculated. The results for charge radii and magnetic moments as a function of the quark current mass provide some indication what the missing pion cloud may contribute to the nucleons' properties.
2303.02071
CaiChang Li
Gui-Jun Ding, Stephen F. King, Cai-Chang Li, Xiang-Gan Liu, Jun-Nan Lu
Neutrino Mass and Mixing Models with Eclectic Flavor Symmetry $\Delta (27) \rtimes T'$
47 pages, 2 figures
null
10.1007/JHEP05(2023)144
UCI-TR-2022-29
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The K\"ahler potentials of modular symmetry models receive unsuppressed contributions which may be controlled by a flavor symmetry, where the combination of the two symmetry types is referred to as eclectic flavor symmetry. After briefly reviewing the consistency conditions of eclectic flavor symmetry models, including with generalised (g)CP, we perform a comprehensive bottom-up study of eclectic flavor symmetry models based on $\Omega(1)\cong \Delta(27)\rtimes T^\prime$, consisting of the flavor symmetry $\Delta(27)$ in a semi-direct product with the modular symmetry $T^\prime$. The modular transformations of different $\Delta(27)$ multiplets are given by solving the consistency condition. The eight nontrivial singlets of $\Delta(27)$ are related by $T'$ modular symmetry, and they have to be present or absent simultaneously in any $\Omega(1)$ model. The most general forms of the superpotential and K\"ahler potential invariant under $\Omega(1)$ are discussed, and the corresponding fermion mass matrices are presented. Based on the eclectic flavor group $\Omega(1)$, two concrete lepton models which can successfully describe the experimental data of lepton masses and mixing parameters are constructed. For the two models without gCP, all six mixing parameters vary in small regions. A nearly maximal atmospheric mixing angle $\theta_{23}$ and Dirac CP phase $\delta_{CP}$ are obtained in the first model. After considering the compatible gCP symmetry and the assumption of $\Re \tau=0$ in the first model, the $\mu-\tau$ reflection symmetry is preserved in the charged lepton diagonal basis. As a consequence, the atmospheric mixing angle and Dirac CP phase are predicted to be maximal, and two Majorana CP phases are predicted to be $\pi$.
[ { "created": "Fri, 3 Mar 2023 16:39:20 GMT", "version": "v1" } ]
2023-06-07
[ [ "Ding", "Gui-Jun", "" ], [ "King", "Stephen F.", "" ], [ "Li", "Cai-Chang", "" ], [ "Liu", "Xiang-Gan", "" ], [ "Lu", "Jun-Nan", "" ] ]
The K\"ahler potentials of modular symmetry models receive unsuppressed contributions which may be controlled by a flavor symmetry, where the combination of the two symmetry types is referred to as eclectic flavor symmetry. After briefly reviewing the consistency conditions of eclectic flavor symmetry models, including with generalised (g)CP, we perform a comprehensive bottom-up study of eclectic flavor symmetry models based on $\Omega(1)\cong \Delta(27)\rtimes T^\prime$, consisting of the flavor symmetry $\Delta(27)$ in a semi-direct product with the modular symmetry $T^\prime$. The modular transformations of different $\Delta(27)$ multiplets are given by solving the consistency condition. The eight nontrivial singlets of $\Delta(27)$ are related by $T'$ modular symmetry, and they have to be present or absent simultaneously in any $\Omega(1)$ model. The most general forms of the superpotential and K\"ahler potential invariant under $\Omega(1)$ are discussed, and the corresponding fermion mass matrices are presented. Based on the eclectic flavor group $\Omega(1)$, two concrete lepton models which can successfully describe the experimental data of lepton masses and mixing parameters are constructed. For the two models without gCP, all six mixing parameters vary in small regions. A nearly maximal atmospheric mixing angle $\theta_{23}$ and Dirac CP phase $\delta_{CP}$ are obtained in the first model. After considering the compatible gCP symmetry and the assumption of $\Re \tau=0$ in the first model, the $\mu-\tau$ reflection symmetry is preserved in the charged lepton diagonal basis. As a consequence, the atmospheric mixing angle and Dirac CP phase are predicted to be maximal, and two Majorana CP phases are predicted to be $\pi$.
2404.08049
Claudio Severi
Fabio Maltoni, Claudio Severi, Simone Tentori, Eleni Vryonidou
Quantum tops at circular lepton colliders
33 pages plus Appendix, 16 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
We study the quantum properties of top quark pairs in lepton colliders with unpolarised beams, including spin correlations, entanglement, and violation of Bell inequalities. We present analytical results in the SM and in the SMEFT and discuss several practical aspects, like the choice of quantization axes and $t \bar t$ threshold effects. We also note a correspondence between parity symmetry and entanglement. We find that quantum observables exhibit a rich phenomenology in the SM, and can also provide additional leverage in detecting new physics residing at higher scales.
[ { "created": "Thu, 11 Apr 2024 18:00:03 GMT", "version": "v1" } ]
2024-04-15
[ [ "Maltoni", "Fabio", "" ], [ "Severi", "Claudio", "" ], [ "Tentori", "Simone", "" ], [ "Vryonidou", "Eleni", "" ] ]
We study the quantum properties of top quark pairs in lepton colliders with unpolarised beams, including spin correlations, entanglement, and violation of Bell inequalities. We present analytical results in the SM and in the SMEFT and discuss several practical aspects, like the choice of quantization axes and $t \bar t$ threshold effects. We also note a correspondence between parity symmetry and entanglement. We find that quantum observables exhibit a rich phenomenology in the SM, and can also provide additional leverage in detecting new physics residing at higher scales.
hep-ph/9810369
Keum Yong-Yeon
Y.-Y. Keum
Decay Constants $f_{D_s^*}$ and $f_{D_s}$ from ${\bar{B}}^0\to D^+ l^- {\bar{\nu}}$ and ${\bar{B}}^0\to D^+ D_s^{-(*)}$ Decays
17 pages, no figure
null
null
APCTP/98-22, KEK-TH-594
hep-ph
null
We calculate the decay constant of $D_s$ and $D_s^{*}$ with $\bar{B}^0 \ra D^{+}\ell^{-}\nu$ and $\bar{B}^0 \ra D^{+}D_s^{-(*)}$ decays. In our analysis we assume that factorization ansatz works and used two different form factor behaviours (constant and monopole-type) for $F_0(q^2)$. We also consider the QCD-penguin contributions in hadronic decays within the NDR renormalization scheme at NLO calculation. We estimate the decay constant of the $D_s$ meson to be $219\pm46 MeV$ for (pole/pole)-type form factor and $239\pm50$ $MeV$ for (pole/constant)-type form factor. For $D_s^{*}$ meson, we predict $f_{D_s^{*}} = 336 \pm 79 MeV$, and $f_{D_s^{*}}/f_{D_s} = 1.41 \pm 0.41$ for (pole/constant)-type form factor.
[ { "created": "Thu, 15 Oct 1998 11:43:35 GMT", "version": "v1" }, { "created": "Thu, 22 Oct 1998 16:02:30 GMT", "version": "v2" } ]
2007-05-23
[ [ "Keum", "Y. -Y.", "" ] ]
We calculate the decay constant of $D_s$ and $D_s^{*}$ with $\bar{B}^0 \ra D^{+}\ell^{-}\nu$ and $\bar{B}^0 \ra D^{+}D_s^{-(*)}$ decays. In our analysis we assume that factorization ansatz works and used two different form factor behaviours (constant and monopole-type) for $F_0(q^2)$. We also consider the QCD-penguin contributions in hadronic decays within the NDR renormalization scheme at NLO calculation. We estimate the decay constant of the $D_s$ meson to be $219\pm46 MeV$ for (pole/pole)-type form factor and $239\pm50$ $MeV$ for (pole/constant)-type form factor. For $D_s^{*}$ meson, we predict $f_{D_s^{*}} = 336 \pm 79 MeV$, and $f_{D_s^{*}}/f_{D_s} = 1.41 \pm 0.41$ for (pole/constant)-type form factor.
0805.4245
Fuminobu Takahashi
Shinta Kasuya, Masahiro Kawasaki, Fuminobu Takahashi
Isocurvature fluctuations in Affleck-Dine mechanism and constraints on inflation models
18 pages, 1 figure
JCAP 0810:017,2008
10.1088/1475-7516/2008/10/017
IPMU 08-0032
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reconsider the Affleck-Dine mechanism for baryogenesis and show that the baryonic isocurvature fluctuations are generated in many inflation models in supergravity. The inflationary scale and the reheating temperature must satisfy certain constraints to avoid too large baryonic isocurvature fluctuations.
[ { "created": "Wed, 28 May 2008 01:42:19 GMT", "version": "v1" } ]
2014-11-18
[ [ "Kasuya", "Shinta", "" ], [ "Kawasaki", "Masahiro", "" ], [ "Takahashi", "Fuminobu", "" ] ]
We reconsider the Affleck-Dine mechanism for baryogenesis and show that the baryonic isocurvature fluctuations are generated in many inflation models in supergravity. The inflationary scale and the reheating temperature must satisfy certain constraints to avoid too large baryonic isocurvature fluctuations.
hep-ph/9503357
Mostafa Mostafa
M. G.-H. Mostafa, Cheuk-Yin Wong, Lali Chatterjee, and Zhong-Qi Wang
Effect of $q\bar q$ Initial-state Interaction on Dilepton Emission Rate from Quark-Gluon Plasma
14 pages(REVTeX),includes 3 uuencoded compressed postscript figures
null
null
ORNL-CTP-95-03/ASU-FSHEP-95-01
hep-ph
null
We calculate the dilepton production rate from a thermalized quark-gluon plasma in heavy-ion collisions at RHIC energies. Higher-order QCD corrections are included by using an analytical correction factor $K^{(i)}$, which takes into account the $q\bar q$ initial-state interactions. We show that the analytic correction factor gives very good agreement with experimental Drell-Yan data and leads to large enhancement of the thermal dilepton emission rates. We compare the thermal dilepton yields with the expected production from open-charm decays and Drell-Yan background and assess the prospects of observing thermal dileptons from the quark-gluon-plasma at invariant masses of a few GeV.
[ { "created": "Thu, 16 Mar 1995 21:59:02 GMT", "version": "v1" }, { "created": "Mon, 18 Dec 1995 16:06:08 GMT", "version": "v2" } ]
2009-09-25
[ [ "Mostafa", "M. G. -H.", "" ], [ "Wong", "Cheuk-Yin", "" ], [ "Chatterjee", "Lali", "" ], [ "Wang", "Zhong-Qi", "" ] ]
We calculate the dilepton production rate from a thermalized quark-gluon plasma in heavy-ion collisions at RHIC energies. Higher-order QCD corrections are included by using an analytical correction factor $K^{(i)}$, which takes into account the $q\bar q$ initial-state interactions. We show that the analytic correction factor gives very good agreement with experimental Drell-Yan data and leads to large enhancement of the thermal dilepton emission rates. We compare the thermal dilepton yields with the expected production from open-charm decays and Drell-Yan background and assess the prospects of observing thermal dileptons from the quark-gluon-plasma at invariant masses of a few GeV.
1211.4648
Eric S. Swanson
Joseph Meyers and Eric S. Swanson
Spin Zero Glueballs in the Bethe-Salpeter Formalism
13 pages, 11 pdf figures
null
10.1103/PhysRevD.87.036009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Schwinger-Dyson Bethe-Salpeter approach to the bound state problem is applied to the spin zero glueball spectrum. Although a moderately successful description of the two point functions and the glueball spectrum can be obtained, further work is required to reduce sensitivity to model truncations.
[ { "created": "Tue, 20 Nov 2012 01:39:51 GMT", "version": "v1" } ]
2013-03-14
[ [ "Meyers", "Joseph", "" ], [ "Swanson", "Eric S.", "" ] ]
The Schwinger-Dyson Bethe-Salpeter approach to the bound state problem is applied to the spin zero glueball spectrum. Although a moderately successful description of the two point functions and the glueball spectrum can be obtained, further work is required to reduce sensitivity to model truncations.
2103.04299
Rahul Ramachandran Nair
Rahul Ramachandran Nair
On the light front surfaces in the phase space of hadrons in heavy-ion collisions
6 pages, 4 figures, 1 table
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Surfaces corresponding to the constant values of the light front variable forms paraboloids in the phase space of the inclusively produced hadrons in heavy-ion collisions. In this paper, it is demonstrated with the simulated Au-Au collisions at $\sqrt{s} = 200$ GeV using the UrQMD event generator that the paraboloidal surface defined by a certain constant value of the light front variable divides the particles in the phase space into two groups such that the distributions of the square of the transverse momentum, the polar angle and the light front variable of particles belonging to one among them can be described with the Boltzmann distribution parameterised by the mass-dependent temperature.
[ { "created": "Sun, 7 Mar 2021 08:31:06 GMT", "version": "v1" } ]
2021-03-09
[ [ "Nair", "Rahul Ramachandran", "" ] ]
Surfaces corresponding to the constant values of the light front variable forms paraboloids in the phase space of the inclusively produced hadrons in heavy-ion collisions. In this paper, it is demonstrated with the simulated Au-Au collisions at $\sqrt{s} = 200$ GeV using the UrQMD event generator that the paraboloidal surface defined by a certain constant value of the light front variable divides the particles in the phase space into two groups such that the distributions of the square of the transverse momentum, the polar angle and the light front variable of particles belonging to one among them can be described with the Boltzmann distribution parameterised by the mass-dependent temperature.
hep-ph/9511452
Jan Bolz
P. Kroll (University of Wuppertal, Germany)
Spin effects in hard exclusive reactions
Invited talk presented at the SPIN95 Conference, Protvino (1995); 14 pages Latex (uses 'epsf' and 'psfig'), including 5 PS-figures in uu-encoded compressed file
null
null
WU-B 95-31
hep-ph
null
The present status of applications of perturbative QCD to large momentum transfer exclusive reactions is discussed. It is argued that in the region of momentum transfer accessible to present day experiments soft contributions dominate the exclusive processes.
[ { "created": "Wed, 29 Nov 1995 13:58:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kroll", "P.", "", "University of Wuppertal, Germany" ] ]
The present status of applications of perturbative QCD to large momentum transfer exclusive reactions is discussed. It is argued that in the region of momentum transfer accessible to present day experiments soft contributions dominate the exclusive processes.
0804.0648
Ying Li
Yu-ming Wang, Ying Li, Cai-Dian Lu
Rare Decays of \Lambda_b->\Lambda + \gamma and \Lambda_b ->\Lambda + l^{+} l^{-} in the Light-cone Sum Rules
38 pages, 15 figures, some typos are corrected and more references are added
Eur.Phys.J.C59:861-882,2009
10.1140/epjc/s10052-008-0846-5
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the Standard Model, we investigate the weak decays of $\Lambda_b \to \Lambda + \gamma$ and $\Lambda_b \to \Lambda + l^{+} l^{-}$ with the light-cone sum rules approach. The higher twist distribution amplitudes of $\Lambda$ baryon to the leading conformal spin are included in the sum rules for transition form factors. Our results indicate that the higher twist distribution amplitudes almost have no influences on the transition form factors retaining the heavy quark spin symmetry, while such corrections can result in significant impacts on the form factors breaking the heavy quark spin symmetry. Two phenomenological models (COZ and FZOZ) for the wave function of $\Lambda$ baryon are also employed in the sum rules for a comparison, which can give rise to the form factors approximately 5 times larger than that in terms of conformal expansion. Utilizing the form factors calculated in LCSR, we then perform a careful study on the decay rate, polarization asymmetry and forward-backward asymmetry, with respect to the decays of $\Lambda_b \to \Lambda \gamma$, $\Lambda l^{+}l^{-}$.
[ { "created": "Fri, 4 Apr 2008 03:39:31 GMT", "version": "v1" }, { "created": "Sun, 13 Apr 2008 12:11:52 GMT", "version": "v2" }, { "created": "Fri, 18 Apr 2008 14:00:18 GMT", "version": "v3" } ]
2014-11-18
[ [ "Wang", "Yu-ming", "" ], [ "Li", "Ying", "" ], [ "Lu", "Cai-Dian", "" ] ]
Within the Standard Model, we investigate the weak decays of $\Lambda_b \to \Lambda + \gamma$ and $\Lambda_b \to \Lambda + l^{+} l^{-}$ with the light-cone sum rules approach. The higher twist distribution amplitudes of $\Lambda$ baryon to the leading conformal spin are included in the sum rules for transition form factors. Our results indicate that the higher twist distribution amplitudes almost have no influences on the transition form factors retaining the heavy quark spin symmetry, while such corrections can result in significant impacts on the form factors breaking the heavy quark spin symmetry. Two phenomenological models (COZ and FZOZ) for the wave function of $\Lambda$ baryon are also employed in the sum rules for a comparison, which can give rise to the form factors approximately 5 times larger than that in terms of conformal expansion. Utilizing the form factors calculated in LCSR, we then perform a careful study on the decay rate, polarization asymmetry and forward-backward asymmetry, with respect to the decays of $\Lambda_b \to \Lambda \gamma$, $\Lambda l^{+}l^{-}$.
hep-ph/0106136
Erhan Iltan
E. O. Iltan (METU,Ankara), G. Turan (METU,Ankara), I. Turan (METU,Ankara)
B --> K^* \tau^+ \tau^- decay in the general two Higgs doublet model including the neutral Higgs boson effects
20 pages, 11 Figures
J.Phys.G28:307-320,2002
10.1088/0954-3899/28/2/309
null
hep-ph
null
We study the CP violating asymmetry, the forward-backward asymmetry of the lepton pair and the CP asymmetry in the forward backward asymmetry for the exclusive decay $B --> K^* \tau^+ \tau^- in the general two Higgs doublet model including the neutral Higgs boson effects. We analyse the dependencies of these quantities on the model III parameters. We found that the physical parameters studied above are at the order of the magnitude 1% and neutral Higgs boson effects are detectable for large values of the coupling \bar{\xi}_{N,\tau\tau}^D.
[ { "created": "Wed, 13 Jun 2001 14:13:11 GMT", "version": "v1" } ]
2010-05-28
[ [ "Iltan", "E. O.", "", "METU,Ankara" ], [ "Turan", "G.", "", "METU,Ankara" ], [ "Turan", "I.", "", "METU,Ankara" ] ]
We study the CP violating asymmetry, the forward-backward asymmetry of the lepton pair and the CP asymmetry in the forward backward asymmetry for the exclusive decay $B --> K^* \tau^+ \tau^- in the general two Higgs doublet model including the neutral Higgs boson effects. We analyse the dependencies of these quantities on the model III parameters. We found that the physical parameters studied above are at the order of the magnitude 1% and neutral Higgs boson effects are detectable for large values of the coupling \bar{\xi}_{N,\tau\tau}^D.
hep-ph/0109255
Jonathan Osborne
Jonathan Osborne
A Study of Nucleon Spin Struture from Quantum Chromodynamics
319 pages, 29 figures
null
null
null
hep-ph
null
I present an introduction to the field of Quantum Chromodynamics (QCD) with emphasis on nucleon spin structure and perturbative methods. After a somewhat comprehensive overview of perturbative QCD, including the systematics of renormalization, I introduce deeply-inelastic scattering and deeply-virtual Compton scattering along with the nonperturbative distribution functions appearing in these processes. I show how these processes can be used to extract the distribution of longitudinal spin of nucleons, and briefly discuss the complications associated with transverse spin components. There are five appendices which accompany this work, discussing topics ranging from canonical field quantization to dimensional regularization to the structure of several important Lie groups. These appendices are meant to give the reader a certain basic understanding of some of the mathematical details underlying the main text, as well as provide a useful reference. This work was submitted in a slightly different form to the University of Maryland at College Park in partial completion of the requirements for a doctor of philosophy in physics, received August 2000.
[ { "created": "Thu, 27 Sep 2001 00:04:10 GMT", "version": "v1" }, { "created": "Thu, 29 Nov 2001 21:53:51 GMT", "version": "v2" } ]
2007-05-23
[ [ "Osborne", "Jonathan", "" ] ]
I present an introduction to the field of Quantum Chromodynamics (QCD) with emphasis on nucleon spin structure and perturbative methods. After a somewhat comprehensive overview of perturbative QCD, including the systematics of renormalization, I introduce deeply-inelastic scattering and deeply-virtual Compton scattering along with the nonperturbative distribution functions appearing in these processes. I show how these processes can be used to extract the distribution of longitudinal spin of nucleons, and briefly discuss the complications associated with transverse spin components. There are five appendices which accompany this work, discussing topics ranging from canonical field quantization to dimensional regularization to the structure of several important Lie groups. These appendices are meant to give the reader a certain basic understanding of some of the mathematical details underlying the main text, as well as provide a useful reference. This work was submitted in a slightly different form to the University of Maryland at College Park in partial completion of the requirements for a doctor of philosophy in physics, received August 2000.
1710.04114
Aleksandra Lelek
Aleksandra Lelek (DESY)
Collinear and Transverse Momentum Dependent parton densities obtained with a Parton Branching Method
null
null
null
DESY 17-134
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a solution of the DGLAP evolution equations, written in terms of Sudakov form factors to describe the branching and no-branching probabilities, using a parton branching Monte Carlo method. We demonstrate numerically that this method reproduces the semi-analytical solutions. We show how this method can be used to determine Transverse Momentum Dependent (TMD) parton distribution functions, in addition to the usual integrated parton distributions functions. We discuss numerical effects of the boundary of soft gluon resolution scale parameter on the resulting parton distribution functions. We show that a very good fit of the integrated TMDs to high precision HERA data can be obtained over a large range in x and Q^2.
[ { "created": "Wed, 11 Oct 2017 15:24:25 GMT", "version": "v1" } ]
2017-10-12
[ [ "Lelek", "Aleksandra", "", "DESY" ] ]
We present a solution of the DGLAP evolution equations, written in terms of Sudakov form factors to describe the branching and no-branching probabilities, using a parton branching Monte Carlo method. We demonstrate numerically that this method reproduces the semi-analytical solutions. We show how this method can be used to determine Transverse Momentum Dependent (TMD) parton distribution functions, in addition to the usual integrated parton distributions functions. We discuss numerical effects of the boundary of soft gluon resolution scale parameter on the resulting parton distribution functions. We show that a very good fit of the integrated TMDs to high precision HERA data can be obtained over a large range in x and Q^2.
1204.5986
Arcadi Santamaria
Francisco del Aguila, Alberto Aparici, Subhaditya Bhattacharya, Arcadi Santamaria, Jose Wudka
Effective Lagrangian approach to neutrinoless double beta decay and neutrino masses
Accepted for publication. Few misprints corrected and new references added
null
10.1007/JHEP06(2012)146
CAFPE-166/11,UG-FT-296/11,FTUV-12-0426,IFIC/11-66,UCRHEP-T519
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrinoless double beta ($0\nu\beta\beta$) decay can in general produce electrons of either chirality, in contrast with the minimal Standard Model (SM) extension with only the addition of the Weinberg operator, which predicts two left-handed electrons in the final state. We classify the lepton number violating (LNV) effective operators with two leptons of either chirality but no quarks, ordered according to the magnitude of their contribution to \znbb decay. We point out that, for each of the three chirality assignments, $e_Le_L, e_Le_R$ and $e_Re_R$, there is only one LNV operator of the corresponding type to lowest order, and these have dimensions 5, 7 and 9, respectively. Neutrino masses are always induced by these extra operators but can be delayed to one or two loops, depending on the number of RH leptons entering in the operator. Then, the comparison of the $0\nu\beta\beta$ decay rate and neutrino masses should indicate the effective scenario at work, which confronted with the LHC searches should also eventually decide on the specific model elected by nature. We also list the SM additions generating these operators upon integration of the heavy modes, and discuss simple realistic examples of renormalizable theories for each case.
[ { "created": "Thu, 26 Apr 2012 17:13:35 GMT", "version": "v1" }, { "created": "Wed, 20 Jun 2012 18:38:07 GMT", "version": "v2" } ]
2015-06-04
[ [ "del Aguila", "Francisco", "" ], [ "Aparici", "Alberto", "" ], [ "Bhattacharya", "Subhaditya", "" ], [ "Santamaria", "Arcadi", "" ], [ "Wudka", "Jose", "" ] ]
Neutrinoless double beta ($0\nu\beta\beta$) decay can in general produce electrons of either chirality, in contrast with the minimal Standard Model (SM) extension with only the addition of the Weinberg operator, which predicts two left-handed electrons in the final state. We classify the lepton number violating (LNV) effective operators with two leptons of either chirality but no quarks, ordered according to the magnitude of their contribution to \znbb decay. We point out that, for each of the three chirality assignments, $e_Le_L, e_Le_R$ and $e_Re_R$, there is only one LNV operator of the corresponding type to lowest order, and these have dimensions 5, 7 and 9, respectively. Neutrino masses are always induced by these extra operators but can be delayed to one or two loops, depending on the number of RH leptons entering in the operator. Then, the comparison of the $0\nu\beta\beta$ decay rate and neutrino masses should indicate the effective scenario at work, which confronted with the LHC searches should also eventually decide on the specific model elected by nature. We also list the SM additions generating these operators upon integration of the heavy modes, and discuss simple realistic examples of renormalizable theories for each case.
hep-ph/9911533
A. A. Arkhipov
A.A. Arkhipov
On Global Structure of Hadronic Total Cross-Sections
RevTex, 13 pages, 6 figures, this version was sent for publication in the Physical Review D
null
null
Preprint IHEP 99-45, Protvino, 1999
hep-ph
null
Simple theoretical formula describing the global structure of pp and p\bar p total cross-secrions in the whole range of energies available up today has been derived. The fit to the experimental data with the formula has been made. It is shown that there is a very good correspondence of the theoretical formula to the existing experimental data.
[ { "created": "Tue, 30 Nov 1999 13:07:55 GMT", "version": "v1" }, { "created": "Fri, 14 Dec 2001 15:04:26 GMT", "version": "v2" } ]
2007-05-23
[ [ "Arkhipov", "A. A.", "" ] ]
Simple theoretical formula describing the global structure of pp and p\bar p total cross-secrions in the whole range of energies available up today has been derived. The fit to the experimental data with the formula has been made. It is shown that there is a very good correspondence of the theoretical formula to the existing experimental data.
hep-ph/0301126
Markus Buescher
M.Buescher, F.P.Sassen, N.N.Achasov, L.Kondratyuk
Investigation of light scalar resonances at COSY
Contribution to the workshop on the future physics program at COSY-Juelich, CSS2002 (8 pages, no figures)
null
null
null
hep-ph nucl-ex nucl-th
null
The $a_0$(980) and $f_0$(980) resonances are two well established states in the excited meson spectrum. We review the most prominent theoretical models which try to explain the structure of these states. It is discussed whether data from COSY on $a_0$ and $f_0$ production in $pp$, $pn$, $pd$ and $dd$ collisions allow to distinguish between the different approaches. Very promising in this respect seems to be the measurement of the reaction $dd \to (\mathrm{^4He} a_0^0 \to) \mathrm{^4He} \pi^0\eta$ which violates isospin conservation and can be related to $a_0$-$f_0$ mixing.
[ { "created": "Fri, 17 Jan 2003 08:10:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Buescher", "M.", "" ], [ "Sassen", "F. P.", "" ], [ "Achasov", "N. N.", "" ], [ "Kondratyuk", "L.", "" ] ]
The $a_0$(980) and $f_0$(980) resonances are two well established states in the excited meson spectrum. We review the most prominent theoretical models which try to explain the structure of these states. It is discussed whether data from COSY on $a_0$ and $f_0$ production in $pp$, $pn$, $pd$ and $dd$ collisions allow to distinguish between the different approaches. Very promising in this respect seems to be the measurement of the reaction $dd \to (\mathrm{^4He} a_0^0 \to) \mathrm{^4He} \pi^0\eta$ which violates isospin conservation and can be related to $a_0$-$f_0$ mixing.
hep-ph/0404142
Hisakazu Minakata
Martin Blom and Hisakazu Minakata
Unity of CP and T Violation in Neutrino Oscillations
20 references added, version to appear in "Focus Issue on Neutrino Physics" of New Journal of Physics
New J.Phys. 6 (2004) 130
10.1088/1367-2630/6/1/130
null
hep-ph
null
In a previous work a simultaneous P- CP[P] and P- T[P] bi-probability plot was proposed as a useful tool for unified graphical description of CP and T violation in neutrino oscillation. The ``baseball diamond'' structure of the plot is understood as a consequence of the approximate CP-CP and the T-CP relations obeyed by the oscillation probabilities. In this paper, we make a step forward toward deeper understanding of the unified graphical representation by showing that these two relations are identical in its content, suggesting a truly unifying view of CP and T violation in neutrino oscillations. We suspect that the unity reflects the underlying CPT theorem. We also present calculation of corrections to the CP-CP and the T-CP relations to leading order in Delta m^2_{21} / Delta m^2_{31} and s^2_{13}.
[ { "created": "Fri, 16 Apr 2004 22:52:19 GMT", "version": "v1" }, { "created": "Fri, 27 Aug 2004 17:50:30 GMT", "version": "v2" } ]
2009-11-10
[ [ "Blom", "Martin", "" ], [ "Minakata", "Hisakazu", "" ] ]
In a previous work a simultaneous P- CP[P] and P- T[P] bi-probability plot was proposed as a useful tool for unified graphical description of CP and T violation in neutrino oscillation. The ``baseball diamond'' structure of the plot is understood as a consequence of the approximate CP-CP and the T-CP relations obeyed by the oscillation probabilities. In this paper, we make a step forward toward deeper understanding of the unified graphical representation by showing that these two relations are identical in its content, suggesting a truly unifying view of CP and T violation in neutrino oscillations. We suspect that the unity reflects the underlying CPT theorem. We also present calculation of corrections to the CP-CP and the T-CP relations to leading order in Delta m^2_{21} / Delta m^2_{31} and s^2_{13}.
1911.12686
Igor Strakovsky
Igor Strakovsky (GWU), Denis Epifanov (Budker Ins), and Lubomir Pentchev (JLab)
J/$\psi$p Scattering Length from GlueX Threshold Measurements
5 pages, 2 figures, v1 had a typo
Phys. Rev. C 101, 042201 (2020)
10.1103/PhysRevC.101.042201
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quality of the recent GlueX $J/\psi $ photoproduction data from Hall~D at Jefferson Laboratory, and the proximity of the data to the energy threshold, gives access to a variety of interesting physics aspects. As an example, an estimation of the $J/\psi$-nucleon scattering length $\alpha_{J/\psi p}$ is provided within the vector meson dominance model. It results in $|\alpha_{J/\psi p}| = (3.08\pm 0.55 ({\rm stat.}) \pm 0.45 ({\rm syst.}))$~mfm.
[ { "created": "Thu, 28 Nov 2019 12:55:28 GMT", "version": "v1" }, { "created": "Tue, 17 Dec 2019 22:47:14 GMT", "version": "v2" } ]
2020-04-15
[ [ "Strakovsky", "Igor", "", "GWU" ], [ "Epifanov", "Denis", "", "Budker Ins" ], [ "Pentchev", "Lubomir", "", "JLab" ] ]
The quality of the recent GlueX $J/\psi $ photoproduction data from Hall~D at Jefferson Laboratory, and the proximity of the data to the energy threshold, gives access to a variety of interesting physics aspects. As an example, an estimation of the $J/\psi$-nucleon scattering length $\alpha_{J/\psi p}$ is provided within the vector meson dominance model. It results in $|\alpha_{J/\psi p}| = (3.08\pm 0.55 ({\rm stat.}) \pm 0.45 ({\rm syst.}))$~mfm.
1604.03255
Norihito Toyota
Kanji Fujii and Norihito Toyota
Remark on Structure of Expectation Values of Flavor-Lepton Numbers with respect to Neutrino-Source Hadron States: Deviation from Fermi's Golden Relatio
6pages, 4 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In our preceeding reports, we have pointed out that a unified description of weak decays accompanying neutrinos and the oscillation process is obtained on the basis of the expectation values of flavor-neutrino numbers with respect to the neutrino-source hadron state. In the present report, we investigate the effect on the expectation values due to the deviation from Fermi's golden relation, and give concrete features of these deviations in the case of $\pi^+$ and $K^+$-decays under the simple situation with the $3$-momentum $\vec{p_A}=0$ for $A=\pi^+$, $K^+$. %numerical results under simple situations.
[ { "created": "Tue, 12 Apr 2016 06:13:42 GMT", "version": "v1" }, { "created": "Tue, 19 Apr 2016 05:32:11 GMT", "version": "v2" } ]
2016-04-20
[ [ "Fujii", "Kanji", "" ], [ "Toyota", "Norihito", "" ] ]
In our preceeding reports, we have pointed out that a unified description of weak decays accompanying neutrinos and the oscillation process is obtained on the basis of the expectation values of flavor-neutrino numbers with respect to the neutrino-source hadron state. In the present report, we investigate the effect on the expectation values due to the deviation from Fermi's golden relation, and give concrete features of these deviations in the case of $\pi^+$ and $K^+$-decays under the simple situation with the $3$-momentum $\vec{p_A}=0$ for $A=\pi^+$, $K^+$. %numerical results under simple situations.
1208.4086
Martin Block
Martin M. Block and Francis Halzen
New experimental evidence that the proton develops asymptotically into a black disk
4 pages, 3 figures
null
10.1103/PhysRevD.86.051504
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, the Auger group has extracted the proton-air cross section from observations of air showers produced by cosmic ray protons (and nuclei) interacting in the atmosphere and converted it into measurements of the total and inelastic $pp$ cross sections $\sigma_{\rm tot}$ and $\sigma_{\rm inel}$ at the super-LHC energy of 57 TeV. Their results reinforce our earlier conclusions that the proton becomes a black disk at asymptotic energies, a prediction reached on the basis of sub-LHC $\pbar p$ and $pp$ measurements of $\sigma_{\rm tot}$ and $\rho$, the ratio of the real to the imaginary part of the forward scattering amplitude [M. M. Block and F. Halzen, Phys. Rev. Lett. {\bf 107}, 212002 (2011)]. The same black disk description of the proton anticipated the values of $\sigma_{\rm tot}$ and $\sigma_{\rm inel}$ measured by the TOTEM experiment at the LHC cms (center of mass) energy of $\sqrt s=7$ TeV, as well as those of $\sigma_{\rm inel}$ measured by ALICE, ATLAS and CMS, as well as the ALICE measurement at 2.76 TeV. All data are consistent with a proton that is asymptotically a black disk of gluons: (i) both $\sigma_{\rm tot}$ and $\sigma_{\rm inel}$ behave as $\ln^2s$, saturating the Froissart bound, (ii) the forward scattering amplitude becomes pure imaginary (iii) the ratio $\sigma_{\rm inel}/\sigma_{\rm tot}=0.509 \pm 0.021$, compatible with the black disk value of 1/2, and (iv) proton interactions become flavor blind.
[ { "created": "Mon, 20 Aug 2012 19:20:53 GMT", "version": "v1" } ]
2015-06-11
[ [ "Block", "Martin M.", "" ], [ "Halzen", "Francis", "" ] ]
Recently, the Auger group has extracted the proton-air cross section from observations of air showers produced by cosmic ray protons (and nuclei) interacting in the atmosphere and converted it into measurements of the total and inelastic $pp$ cross sections $\sigma_{\rm tot}$ and $\sigma_{\rm inel}$ at the super-LHC energy of 57 TeV. Their results reinforce our earlier conclusions that the proton becomes a black disk at asymptotic energies, a prediction reached on the basis of sub-LHC $\pbar p$ and $pp$ measurements of $\sigma_{\rm tot}$ and $\rho$, the ratio of the real to the imaginary part of the forward scattering amplitude [M. M. Block and F. Halzen, Phys. Rev. Lett. {\bf 107}, 212002 (2011)]. The same black disk description of the proton anticipated the values of $\sigma_{\rm tot}$ and $\sigma_{\rm inel}$ measured by the TOTEM experiment at the LHC cms (center of mass) energy of $\sqrt s=7$ TeV, as well as those of $\sigma_{\rm inel}$ measured by ALICE, ATLAS and CMS, as well as the ALICE measurement at 2.76 TeV. All data are consistent with a proton that is asymptotically a black disk of gluons: (i) both $\sigma_{\rm tot}$ and $\sigma_{\rm inel}$ behave as $\ln^2s$, saturating the Froissart bound, (ii) the forward scattering amplitude becomes pure imaginary (iii) the ratio $\sigma_{\rm inel}/\sigma_{\rm tot}=0.509 \pm 0.021$, compatible with the black disk value of 1/2, and (iv) proton interactions become flavor blind.
hep-ph/0503136
Joao Silva
F. J. Botella and J. P. Silva
Reparametrization invariance of B decay amplitudes and implications for new physics searches in B decays
16 pages, RevTex
Phys.Rev. D71 (2005) 094008
10.1103/PhysRevD.71.094008
null
hep-ph
null
When studying B decays within the Standard Model, it is customary to use the unitarity of the CKM matrix in order to write the decay amplitudes in terms of only two of the three weak phases which appear in the various diagrams. Occasionally, it is mentioned that those two weak phases can be used in order to describe any decay amplitude, even beyond the Standard Model. Here we point out that, when describing a generic decay amplitude, the two weak phases can be chosen completely at will, and we study the behavior of the decay amplitudes under changes in the two weak phases chosen as a basis. Of course, physical observables cannot depend on such reparametrizations. This has an impact in discussions of the SM and in attempts to parametrize new physics effects in the decay amplitudes. We illustrate these issues by looking at B --> psi K_S and the isospin analysis in B --> pi pi.
[ { "created": "Mon, 14 Mar 2005 21:07:13 GMT", "version": "v1" } ]
2009-11-11
[ [ "Botella", "F. J.", "" ], [ "Silva", "J. P.", "" ] ]
When studying B decays within the Standard Model, it is customary to use the unitarity of the CKM matrix in order to write the decay amplitudes in terms of only two of the three weak phases which appear in the various diagrams. Occasionally, it is mentioned that those two weak phases can be used in order to describe any decay amplitude, even beyond the Standard Model. Here we point out that, when describing a generic decay amplitude, the two weak phases can be chosen completely at will, and we study the behavior of the decay amplitudes under changes in the two weak phases chosen as a basis. Of course, physical observables cannot depend on such reparametrizations. This has an impact in discussions of the SM and in attempts to parametrize new physics effects in the decay amplitudes. We illustrate these issues by looking at B --> psi K_S and the isospin analysis in B --> pi pi.
hep-ph/9901436
Nobuyuki Sakai
Yoonbai Kim, Seung Joo Lee (Sungkyunkwan U.), Kei-ichi Maeda (Waseda U.), Nobuyuki Sakai (YITP, Kyoto U.)
Gauged Monopole-Bubble
13 pages, latex, including figures
Phys.Lett. B452 (1999) 214-220
10.1016/S0370-2693(99)00299-3
SNUTP-98-102, WU-AP/73/98, YITP-98-64
hep-ph hep-th
null
The decay of a metastable false vacuum by bubble nucleation is studied in the high temperature limit of the gauge theory in which an SO(3) gauge symmetry is spontaneously broken to an SO(2). The effects of internal symmetry are so drastic that, in addition to the known Euclidean bounce solution, there exists a new bubble solution involving a 't Hooft-Polyakov monopole at its center the moment it is nucleated. The decay rate and evolution are analyzed.
[ { "created": "Thu, 28 Jan 1999 05:54:48 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kim", "Yoonbai", "", "Sungkyunkwan U." ], [ "Lee", "Seung Joo", "", "Sungkyunkwan U." ], [ "Maeda", "Kei-ichi", "", "Waseda\n U." ], [ "Sakai", "Nobuyuki", "", "YITP, Kyoto U." ] ]
The decay of a metastable false vacuum by bubble nucleation is studied in the high temperature limit of the gauge theory in which an SO(3) gauge symmetry is spontaneously broken to an SO(2). The effects of internal symmetry are so drastic that, in addition to the known Euclidean bounce solution, there exists a new bubble solution involving a 't Hooft-Polyakov monopole at its center the moment it is nucleated. The decay rate and evolution are analyzed.
1112.5958
Badri Magradze
B.A. Magradze
Strong Coupling Constant from $\tau$ Decay within a Dispersive Approach to Perturbative QCD
17 pages,1 postscript fig. 6 Tables, Talk presented at the international conference "Continuum mechanics and related problems of Analysis" dedicated to the 120-th birthday of academician N. Muskhelishvili. Abstract corrected, Introduction corrected, Figure 1 added, in Sect.3 new material added, Eqs.(40),(41),(42),(43) added. References 17 and 51 added
Proceedings of A. Razmadze Mathematical Institute Vol. 160 (2012), 91-111
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new dispersive framework for the extraction of the strong coupling constant $\alpha_s$ from $\tau$-lepton decays. A new feature of our procedure is the use of the quark-hadron duality on the limited region $s_{\rm d}<s<m_{\tau}^{2}$. The duality point $s_{\rm d}$ and the $\bar{\rm MS}$ strong coupling constant $\alpha_{s}(m_{\tau}^{2})$ are self-consistently extracted from the $\tau$ data for the non-strange vector spectral function. We use 2005 ALEPH and 1998 OPAL experimental data on the vector spectral function. We compare the new framework with the contour improved perturbation theory up to order $\alpha_s^{5}$. The new procedure yields systematically lower values for $\alpha_s$. From the 2005 ALEPH data, we obtain $\alpha_{s}(m_{\tau}^{2})=0.308\pm 0.014_{\rm exp}\pm 0.005_{\rm th}$ which corresponds to $\alpha_{s}(M_{\rm_{z}}^{2})=0.1170\pm 0.0018_{\rm exp}\pm 0.0007_{\rm th}\pm 0.0005_{\rm ev}$. The extracted value for the duality point $s_{\rm d}$ is found surprisingly stable against perturbation theory corrections $s_{\rm d}= 1.71\pm 0.05_{\rm exp}\pm 0.00_{\rm th}\,\, {\rm GeV^{2}}$. From the 1998 OPAL data, we obtain $\alpha_{s}(m_{\tau}^{2})=0.290\pm 0.023_{\rm exp}$ and $s_{\rm d}=1.68\pm 0.10_{\rm exp}\,\, {\rm GeV^{2}}$.
[ { "created": "Tue, 27 Dec 2011 13:27:20 GMT", "version": "v1" }, { "created": "Thu, 15 Mar 2012 13:59:04 GMT", "version": "v2" } ]
2012-11-26
[ [ "Magradze", "B. A.", "" ] ]
We present a new dispersive framework for the extraction of the strong coupling constant $\alpha_s$ from $\tau$-lepton decays. A new feature of our procedure is the use of the quark-hadron duality on the limited region $s_{\rm d}<s<m_{\tau}^{2}$. The duality point $s_{\rm d}$ and the $\bar{\rm MS}$ strong coupling constant $\alpha_{s}(m_{\tau}^{2})$ are self-consistently extracted from the $\tau$ data for the non-strange vector spectral function. We use 2005 ALEPH and 1998 OPAL experimental data on the vector spectral function. We compare the new framework with the contour improved perturbation theory up to order $\alpha_s^{5}$. The new procedure yields systematically lower values for $\alpha_s$. From the 2005 ALEPH data, we obtain $\alpha_{s}(m_{\tau}^{2})=0.308\pm 0.014_{\rm exp}\pm 0.005_{\rm th}$ which corresponds to $\alpha_{s}(M_{\rm_{z}}^{2})=0.1170\pm 0.0018_{\rm exp}\pm 0.0007_{\rm th}\pm 0.0005_{\rm ev}$. The extracted value for the duality point $s_{\rm d}$ is found surprisingly stable against perturbation theory corrections $s_{\rm d}= 1.71\pm 0.05_{\rm exp}\pm 0.00_{\rm th}\,\, {\rm GeV^{2}}$. From the 1998 OPAL data, we obtain $\alpha_{s}(m_{\tau}^{2})=0.290\pm 0.023_{\rm exp}$ and $s_{\rm d}=1.68\pm 0.10_{\rm exp}\,\, {\rm GeV^{2}}$.
1703.07127
Giovanni Salm\`e
Giovanni Salme' (INFN-Rome), Wayne de Paula (ITA-S. Jose' dos Campos), Tobias Frederico (ITA-S. Jose' dos Campos) and Michele Viviani (INFN-Pisa)
Two-fermion Bethe-Salpeter Equation in Minkowski Space: the Nakanishi Way
8 pages and 4 figures. Accepted for publication in Light-Cone 2016, Topical Collection
Few-Body Systems (2017)
10.1007/s00601-017-1286-2
null
hep-ph cond-mat.str-el nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possibility of solving the Bethe-Salpeter Equation in Minkowski space, even for fermionic systems, is becoming actual, through the applications of well-known tools: i) the Nakanishi integral representation of the Bethe-Salpeter amplitude and ii) the light-front projection onto the null-plane. The theoretical background and some preliminary calculations are illustrated, in order to show the potentiality and the wide range of application of the method.
[ { "created": "Tue, 21 Mar 2017 10:25:19 GMT", "version": "v1" } ]
2017-03-22
[ [ "Salme'", "Giovanni", "", "INFN-Rome" ], [ "de Paula", "Wayne", "", "ITA-S. Jose' dos Campos" ], [ "Frederico", "Tobias", "", "ITA-S. Jose' dos Campos" ], [ "Viviani", "Michele", "", "INFN-Pisa" ] ]
The possibility of solving the Bethe-Salpeter Equation in Minkowski space, even for fermionic systems, is becoming actual, through the applications of well-known tools: i) the Nakanishi integral representation of the Bethe-Salpeter amplitude and ii) the light-front projection onto the null-plane. The theoretical background and some preliminary calculations are illustrated, in order to show the potentiality and the wide range of application of the method.
hep-ph/9702411
Conrad Burden
C. J. Burden (Australian National University)
The analytic structure of heavy quark propagators
21 pages Latex and 5 postscript figures. The original version of this paper has been considerably extended to include a formalism dealing with the renormalised heavy quark Dyson-Schwinger equation and uses a more realistic Ansatz for the gluon propagator.
Phys.Rev. D57 (1998) 276-286
10.1103/PhysRevD.57.276
null
hep-ph
null
The renormalised quark Dyson-Schwinger equation is studied in the limit of the renormalised current heavy quark mass m_R --> infinity. We are particularly interested in the analytic pole structure of the heavy quark propagator in the complex momentum plane. Approximations in which the quark-gluon vertex is modelled by either the bare vertex or the Ball-Chiu Ansatz, and the Landau gauge gluon propagator takes either a gaussian form or a gaussian form with an ultraviolet asymptotic tail are used.
[ { "created": "Tue, 25 Feb 1997 03:17:04 GMT", "version": "v1" }, { "created": "Mon, 29 Sep 1997 01:00:24 GMT", "version": "v2" } ]
2009-10-30
[ [ "Burden", "C. J.", "", "Australian National University" ] ]
The renormalised quark Dyson-Schwinger equation is studied in the limit of the renormalised current heavy quark mass m_R --> infinity. We are particularly interested in the analytic pole structure of the heavy quark propagator in the complex momentum plane. Approximations in which the quark-gluon vertex is modelled by either the bare vertex or the Ball-Chiu Ansatz, and the Landau gauge gluon propagator takes either a gaussian form or a gaussian form with an ultraviolet asymptotic tail are used.
1412.4357
Redamy P\'erez-Ramos
Redamy P\'erez-Ramos
Inclusive transverse momentum distribution of hadrons in jets produced in PbPb and pp collisions at the LHC: Data versus jet-quenching Monte Carlos
6 pages and 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The inclusive transverse momentum (pt) distribution of hadrons inside jets produced in PbPb and pp collisions are simulated with the YaJEM and Pythia 6 Monte Carlo (MC) event generators. The effects of jet quenching are studied via the ratios of PbPb over pp hadron pt spectra, either by accounting for the induced virtuality Delta Q^2 transferred from the strongly-interacting medium to the parton shower or by modifying the soft sector of the parton-to-hadron fragmentation functions. The MC results are compared to experimental jet data measured by the CMS experiment at a center-of-mass energy of 2.76 TeV in four jet p_T^{jet} ranges above 100 GeV, accounting or not for the experimental jet reconstruction biases. The level of data-MC (dis)agreement provides valuable information on the mechanism of parton energy loss.
[ { "created": "Sun, 14 Dec 2014 13:40:45 GMT", "version": "v1" } ]
2014-12-16
[ [ "Pérez-Ramos", "Redamy", "" ] ]
The inclusive transverse momentum (pt) distribution of hadrons inside jets produced in PbPb and pp collisions are simulated with the YaJEM and Pythia 6 Monte Carlo (MC) event generators. The effects of jet quenching are studied via the ratios of PbPb over pp hadron pt spectra, either by accounting for the induced virtuality Delta Q^2 transferred from the strongly-interacting medium to the parton shower or by modifying the soft sector of the parton-to-hadron fragmentation functions. The MC results are compared to experimental jet data measured by the CMS experiment at a center-of-mass energy of 2.76 TeV in four jet p_T^{jet} ranges above 100 GeV, accounting or not for the experimental jet reconstruction biases. The level of data-MC (dis)agreement provides valuable information on the mechanism of parton energy loss.
1709.08543
Mari\'an Koles\'ar
Marian Kolesar, Jiri Novotny
Constraints on low energy QCD parameters from $\eta \to 3\pi$ and $\pi\pi$ scattering
23 pages, 8 figures
null
10.1140/epjc/s10052-018-5668-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $\eta \to 3\pi$ decays are a valuable source of information on low energy QCD. Yet they were not used for an extraction of the three flavor chiral symmetry breaking order parameters until now. We use a Bayesian approach in the framework of resummed chiral perturbation theory to obtain constraints on the quark condensate and pseudoscalar decay constant in the chiral limit. We compare our results with recent CHPT and lattice QCD fits and find some tension, as the $\eta \to 3\pi$ data seem to prefer a larger ratio of the chiral order parameters. The results also disfavor a very large value of the pseudoscalar decay constant in the chiral limit, which was found by some recent works. In addition, we present results of a combined analysis including $\eta \to 3\pi$ decays and $\pi\pi$ scattering and though the picture does not changed appreciably, we find some tension between the data we use. We also try to extract information on the mass difference of the light quarks, but the uncertainties prove to be large.
[ { "created": "Mon, 25 Sep 2017 15:15:55 GMT", "version": "v1" } ]
2018-04-18
[ [ "Kolesar", "Marian", "" ], [ "Novotny", "Jiri", "" ] ]
The $\eta \to 3\pi$ decays are a valuable source of information on low energy QCD. Yet they were not used for an extraction of the three flavor chiral symmetry breaking order parameters until now. We use a Bayesian approach in the framework of resummed chiral perturbation theory to obtain constraints on the quark condensate and pseudoscalar decay constant in the chiral limit. We compare our results with recent CHPT and lattice QCD fits and find some tension, as the $\eta \to 3\pi$ data seem to prefer a larger ratio of the chiral order parameters. The results also disfavor a very large value of the pseudoscalar decay constant in the chiral limit, which was found by some recent works. In addition, we present results of a combined analysis including $\eta \to 3\pi$ decays and $\pi\pi$ scattering and though the picture does not changed appreciably, we find some tension between the data we use. We also try to extract information on the mass difference of the light quarks, but the uncertainties prove to be large.
2304.10299
Paul D. Grannis
J.A. Bagger, S. Belomestnykh, P.C. Bhat, J.E. Brau, M. Demarteau, D. Denisov, S. Gori, P.D. Grannis, T. Junginger, A.J. Lankford, M. Liepe, T.W. Markiewicz, H.E. Montgomery, M. Perelstein, M.E. Peskin, J. Strube, A.P. White, G.W. Wilson
Statement from the American Linear Collider Committee to the P5 subpanel
6 pages
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This statement from the American Linear Collider Committee to the P5 subpanel has three purposes. It presents a brief summary of the case for an $e^+e^-$ Higgs factory that has emerged from Snowmass 2021. It highlights the special virtues of the ILC that are shared with other linear colliders but not with circular colliders. Finally, it calls attention to the resources available in the ILC White Paper for Snowmass (arXiv:2203.07622). The ALCC urges P5 to move the Higgs factory forward as a global project by assigning the idea of an $e^+e^-$ Higgs factory high priority, initiating a global discussion of the technology choice and cost sharing, and offering the option of siting the Higgs factory in the U.S.
[ { "created": "Thu, 20 Apr 2023 13:28:20 GMT", "version": "v1" }, { "created": "Wed, 26 Apr 2023 14:07:45 GMT", "version": "v2" }, { "created": "Wed, 17 May 2023 15:03:21 GMT", "version": "v3" } ]
2023-05-18
[ [ "Bagger", "J. A.", "" ], [ "Belomestnykh", "S.", "" ], [ "Bhat", "P. C.", "" ], [ "Brau", "J. E.", "" ], [ "Demarteau", "M.", "" ], [ "Denisov", "D.", "" ], [ "Gori", "S.", "" ], [ "Grannis", "P. D.", "" ], [ "Junginger", "T.", "" ], [ "Lankford", "A. J.", "" ], [ "Liepe", "M.", "" ], [ "Markiewicz", "T. W.", "" ], [ "Montgomery", "H. E.", "" ], [ "Perelstein", "M.", "" ], [ "Peskin", "M. E.", "" ], [ "Strube", "J.", "" ], [ "White", "A. P.", "" ], [ "Wilson", "G. W.", "" ] ]
This statement from the American Linear Collider Committee to the P5 subpanel has three purposes. It presents a brief summary of the case for an $e^+e^-$ Higgs factory that has emerged from Snowmass 2021. It highlights the special virtues of the ILC that are shared with other linear colliders but not with circular colliders. Finally, it calls attention to the resources available in the ILC White Paper for Snowmass (arXiv:2203.07622). The ALCC urges P5 to move the Higgs factory forward as a global project by assigning the idea of an $e^+e^-$ Higgs factory high priority, initiating a global discussion of the technology choice and cost sharing, and offering the option of siting the Higgs factory in the U.S.
hep-ph/9501238
Schlei Bernd
R.M. Weiner
Correlations and strong interactions
13 pages
null
null
null
hep-ph
null
It is argued that correlations and multiplicity distributions constitute one of the most characteristic properties of strong interactions. The progress made in the last years in our understanding of correlations is reviewed.
[ { "created": "Mon, 9 Jan 1995 09:34:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Weiner", "R. M.", "" ] ]
It is argued that correlations and multiplicity distributions constitute one of the most characteristic properties of strong interactions. The progress made in the last years in our understanding of correlations is reviewed.
0909.2238
Jian Zhou Mr.
Jian Zhou, Feng Yuan, Zuo-Tang Liang
Transverse momentum dependent quark distributions and polarized Drell-Yan processes
25 pages, 2 figures
null
10.1103/PhysRevD.81.054008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the spin-dependent quark distributions at large transverse momentum. We derive their transverse momentum behaviors in the collinear factorization approach in this region. We further calculate the angular distribution of the Drell-Yan lepton pair production with polarized beams and present the results in terms of the collinear twist-three quark-gluon correlation functions. In the intermediate transverse momentum region, we find that the two pproaches: the collinear factorization and the transverse momentum dependent factorization approaches are consistent in the description of the lepton pair angular distributions.
[ { "created": "Fri, 11 Sep 2009 19:53:25 GMT", "version": "v1" } ]
2013-05-29
[ [ "Zhou", "Jian", "" ], [ "Yuan", "Feng", "" ], [ "Liang", "Zuo-Tang", "" ] ]
We study the spin-dependent quark distributions at large transverse momentum. We derive their transverse momentum behaviors in the collinear factorization approach in this region. We further calculate the angular distribution of the Drell-Yan lepton pair production with polarized beams and present the results in terms of the collinear twist-three quark-gluon correlation functions. In the intermediate transverse momentum region, we find that the two pproaches: the collinear factorization and the transverse momentum dependent factorization approaches are consistent in the description of the lepton pair angular distributions.
1112.3633
Omar Gustavo Miranda
E. A. Garces, O. G. Miranda, M. A. Tortola and J. W. F. Valle
Low-energy neutrino-electron scattering as a Standard Model probe: the potential of LENA as case study
8 pages, 4 figures, fig 4 changed, final version to be published in Phys. Rev. D
null
10.1103/PhysRevD.85.073006
IFIC/11-68
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several proposals for studying neutrinos with large detectors are currently under discussion. We suggest that they could provide a precise measurement of the electroweak mixing angle as well as a probe for new physics, such as non-standard neutrino interactions (NSI), and the electroweak gauge structure. We illustrate this explicitly for the case of the LENA proposal, either with an artificial radioactive source or by using the solar neutrino flux.
[ { "created": "Thu, 15 Dec 2011 20:15:10 GMT", "version": "v1" }, { "created": "Fri, 23 Mar 2012 23:28:13 GMT", "version": "v2" } ]
2013-05-30
[ [ "Garces", "E. A.", "" ], [ "Miranda", "O. G.", "" ], [ "Tortola", "M. A.", "" ], [ "Valle", "J. W. F.", "" ] ]
Several proposals for studying neutrinos with large detectors are currently under discussion. We suggest that they could provide a precise measurement of the electroweak mixing angle as well as a probe for new physics, such as non-standard neutrino interactions (NSI), and the electroweak gauge structure. We illustrate this explicitly for the case of the LENA proposal, either with an artificial radioactive source or by using the solar neutrino flux.
1904.03119
Vadim Bednyakov Dr.
Vadim A. Bednyakov and Dmitry V. Naumov
On coherent neutrino and antineutrino scattering off nuclei
9 pages, 4 figures, 83 references. arXiv admin note: substantial text overlap with arXiv:1806.08768
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino-nucleus $\nu A\to \nu A$ and antineutrino-nucleus $\bar\nu A\to \bar\nu A$ interactions, when the nucleus conserves its integrity, are discussed with coherent (elastic) and incoherent (inelastic) scattering regimes taken into account. In the first regime the nucleus remains in the same quantum state after the scattering and the cross-section depends on the quadratic number of nucleons. In the second regime the nucleus changes its quantum state and the cross-section has an essentially linear dependence on the number of nucleons. The coherent and incoherent cross-sections are driven by a nuclear nucleon form-factor squared $|F|^2$ term and a $(1-|F|^2)$ term, respectively. One has a smooth transition between the regimes of coherent and incoherent (anti)neutrino-nucleus scattering. Due to the neutral current nature these elastic and inelastic processes are indistinguishable if the nucleus recoil energy is only observed. One way to separate the coherent signal from the incoherent one is to register $\gamma$ quanta from deexcitation of the nucleus excited during the incoherent scattering. Another way is to use a very low-energy threshold detector and collect data at very low recoil energies, where the incoherent scattering is vanishingly small. In particular, for ${}^{133}\text{Cs}$ and neutrino energies of 30--50 MeV the incoherent cross-section is about 15-20\% of the coherent one. Therefore, the COHERENT experiment (with ${}^{133}\text{Cs}$) has measured the coherent elastic neutrino nucleus scattering (CE$\nu$NS) with the inelastic admixture at a level of 15-20\%, if the excitation $\gamma$ quantum escapes its detection.
[ { "created": "Fri, 5 Apr 2019 15:26:57 GMT", "version": "v1" } ]
2019-04-08
[ [ "Bednyakov", "Vadim A.", "" ], [ "Naumov", "Dmitry V.", "" ] ]
Neutrino-nucleus $\nu A\to \nu A$ and antineutrino-nucleus $\bar\nu A\to \bar\nu A$ interactions, when the nucleus conserves its integrity, are discussed with coherent (elastic) and incoherent (inelastic) scattering regimes taken into account. In the first regime the nucleus remains in the same quantum state after the scattering and the cross-section depends on the quadratic number of nucleons. In the second regime the nucleus changes its quantum state and the cross-section has an essentially linear dependence on the number of nucleons. The coherent and incoherent cross-sections are driven by a nuclear nucleon form-factor squared $|F|^2$ term and a $(1-|F|^2)$ term, respectively. One has a smooth transition between the regimes of coherent and incoherent (anti)neutrino-nucleus scattering. Due to the neutral current nature these elastic and inelastic processes are indistinguishable if the nucleus recoil energy is only observed. One way to separate the coherent signal from the incoherent one is to register $\gamma$ quanta from deexcitation of the nucleus excited during the incoherent scattering. Another way is to use a very low-energy threshold detector and collect data at very low recoil energies, where the incoherent scattering is vanishingly small. In particular, for ${}^{133}\text{Cs}$ and neutrino energies of 30--50 MeV the incoherent cross-section is about 15-20\% of the coherent one. Therefore, the COHERENT experiment (with ${}^{133}\text{Cs}$) has measured the coherent elastic neutrino nucleus scattering (CE$\nu$NS) with the inelastic admixture at a level of 15-20\%, if the excitation $\gamma$ quantum escapes its detection.
1101.0419
Romuald A. Janik
Romuald A. Janik
AdS/CFT and the dynamics of quark-gluon plasma
7 pages, talk presented at the New Frontiers in QCD 2010 program at YITP Kyoto
null
10.1143/PTPS.186.534
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we first discuss the motivation for using the AdS/CFT correspondence as a tool for the understanding of real-time dynamics of quark-gluon plasma. After describing the effective dual degrees of freedom for a strongly coupled gauge theory system, we review the subsequent theoretical `layers' in the physics of quark-gluon plasma: a uniform plasma at fixed temperature, linearized fluctuations, nonlinear hydrodynamic behaviour and finally some aspects of addressing non-equilibrium physics. The discussion is brief and aimed at nonspecialists.
[ { "created": "Sun, 2 Jan 2011 17:37:47 GMT", "version": "v1" } ]
2015-05-20
[ [ "Janik", "Romuald A.", "" ] ]
In this talk we first discuss the motivation for using the AdS/CFT correspondence as a tool for the understanding of real-time dynamics of quark-gluon plasma. After describing the effective dual degrees of freedom for a strongly coupled gauge theory system, we review the subsequent theoretical `layers' in the physics of quark-gluon plasma: a uniform plasma at fixed temperature, linearized fluctuations, nonlinear hydrodynamic behaviour and finally some aspects of addressing non-equilibrium physics. The discussion is brief and aimed at nonspecialists.
1010.5640
Monika Randhawa
Neelu Mahajan, Monika Randhawa, Manmohan Gupta, P.S. Gill
Investigating texture six zero lepton mass matrices
14 pages, 2 figures
Prog. Theor. Exp. Phys. 2013, 083B02 (2013)
10.1093/ptep/ptt060
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Texture six zero Fritzsch like as well as non Fritzsch like hermitian lepton mass matrices (144 combinations in all) have been investigated for both Majorana and Dirac neutrinos for their compatibility with the current neutrino oscillation data, keeping in mind the hierarchy of neutrino masses. All the combinations considered here for Majorana neutrino masses are ruled out by the existing data in the case of inverted hierarchy and degenerate scenario. For Majorana neutrinos with normal hierarchy, only 16 combinations can accommodate the experimental data. Assuming neutrinos to be Dirac particles, normal hierarchy, inverted hierarchy as well as degenerate neutrinos are ruled out for all combinations of texture 6 zero hermitian mass matrices.
[ { "created": "Wed, 27 Oct 2010 10:35:15 GMT", "version": "v1" }, { "created": "Fri, 21 Jun 2013 10:06:38 GMT", "version": "v2" } ]
2013-08-19
[ [ "Mahajan", "Neelu", "" ], [ "Randhawa", "Monika", "" ], [ "Gupta", "Manmohan", "" ], [ "Gill", "P. S.", "" ] ]
Texture six zero Fritzsch like as well as non Fritzsch like hermitian lepton mass matrices (144 combinations in all) have been investigated for both Majorana and Dirac neutrinos for their compatibility with the current neutrino oscillation data, keeping in mind the hierarchy of neutrino masses. All the combinations considered here for Majorana neutrino masses are ruled out by the existing data in the case of inverted hierarchy and degenerate scenario. For Majorana neutrinos with normal hierarchy, only 16 combinations can accommodate the experimental data. Assuming neutrinos to be Dirac particles, normal hierarchy, inverted hierarchy as well as degenerate neutrinos are ruled out for all combinations of texture 6 zero hermitian mass matrices.
hep-ph/0312368
Abdel-Nasser Tawfik
David E. Miller and Abdel-Nasser M. Tawfik
Entanglement in condensates involving strong interactions
17 pages, 2 eps figures
Appl. Math. Inf. Sci. 5:239-252,2011
null
BI-TP 2003/29
hep-ph nucl-th quant-ph
null
We look at two well known examples of interacting systems relating to condensed matter in which we put the strong interacting parameters. At high quark chemical potentials and low temperatures we study the entropy arising from the excitation in the BCS model of superconductivity and the Bose-Einstein condensation (BEC) of colored quark pairs. We compare it with the ground state entropy for a system consisting of two colored quarks. In the BCS model we found that the entropy strongly depends on the energy gap. Both for the very small values of the momenta as well as those much greater than the characterizing Fermi momentum $p_f$, the ground state entropy is dominant. For the BEC case we suggest a phenomenological model to build up colored bosonic quark pairs. Here the entropy entirely depends upon the short ranged repulsive interactions between the quark pairs and vanishes for large momenta.
[ { "created": "Mon, 29 Dec 2003 18:28:13 GMT", "version": "v1" }, { "created": "Tue, 30 Dec 2003 12:24:35 GMT", "version": "v2" }, { "created": "Fri, 9 Jan 2004 10:06:26 GMT", "version": "v3" } ]
2011-06-09
[ [ "Miller", "David E.", "" ], [ "Tawfik", "Abdel-Nasser M.", "" ] ]
We look at two well known examples of interacting systems relating to condensed matter in which we put the strong interacting parameters. At high quark chemical potentials and low temperatures we study the entropy arising from the excitation in the BCS model of superconductivity and the Bose-Einstein condensation (BEC) of colored quark pairs. We compare it with the ground state entropy for a system consisting of two colored quarks. In the BCS model we found that the entropy strongly depends on the energy gap. Both for the very small values of the momenta as well as those much greater than the characterizing Fermi momentum $p_f$, the ground state entropy is dominant. For the BEC case we suggest a phenomenological model to build up colored bosonic quark pairs. Here the entropy entirely depends upon the short ranged repulsive interactions between the quark pairs and vanishes for large momenta.
2212.11953
Benedict von Harling
Sebastian Bruggisser, Benedict von Harling, Oleksii Matsedonskyi, Geraldine Servant
Status of Electroweak Baryogenesis in Minimal Composite Higgs
43 pages, 10 figures; v2: one plot, comments and references added, JHEP version
null
null
DESY-22-209
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an update on the status of electroweak baryogenesis in minimal composite Higgs models. The particularity of this framework is that the electroweak phase transition can proceed simultaneously with the confinement phase transition of the new strong dynamics that produces the composite Higgs. The latter transition is controlled by the dilaton - the pseudo-Goldstone boson of an approximate scale invariance of the composite sector. Since it naturally is first-order, the electroweak phase transition becomes first-order too. Another appealing aspect is that the necessary additional source of CP violation can arise from the variation of the quark Yukawa couplings during the phase transition, which is built-in naturally in this scenario. These two features address the shortcomings of electroweak baryogenesis in the Standard Model. We confront this scenario with the latest experimental bounds derived from collider searches for new resonances and measurements of the Higgs couplings and electric dipole moments. All these constraints provide (or will be able to provide in the near future) important bounds on the considered scenario, with the most stringent ones coming from LHC searches for new resonances which constrain the dilaton mass and couplings. We identify the viable region of parameter space which satisfies all the constraints, and is characterized by a dilaton mass in the $300-500$ GeV range and a Higgs decay constant $f \lesssim 1.1$ TeV. We discuss its future tests.
[ { "created": "Thu, 22 Dec 2022 18:40:25 GMT", "version": "v1" }, { "created": "Sun, 10 Dec 2023 18:11:38 GMT", "version": "v2" } ]
2023-12-12
[ [ "Bruggisser", "Sebastian", "" ], [ "von Harling", "Benedict", "" ], [ "Matsedonskyi", "Oleksii", "" ], [ "Servant", "Geraldine", "" ] ]
We present an update on the status of electroweak baryogenesis in minimal composite Higgs models. The particularity of this framework is that the electroweak phase transition can proceed simultaneously with the confinement phase transition of the new strong dynamics that produces the composite Higgs. The latter transition is controlled by the dilaton - the pseudo-Goldstone boson of an approximate scale invariance of the composite sector. Since it naturally is first-order, the electroweak phase transition becomes first-order too. Another appealing aspect is that the necessary additional source of CP violation can arise from the variation of the quark Yukawa couplings during the phase transition, which is built-in naturally in this scenario. These two features address the shortcomings of electroweak baryogenesis in the Standard Model. We confront this scenario with the latest experimental bounds derived from collider searches for new resonances and measurements of the Higgs couplings and electric dipole moments. All these constraints provide (or will be able to provide in the near future) important bounds on the considered scenario, with the most stringent ones coming from LHC searches for new resonances which constrain the dilaton mass and couplings. We identify the viable region of parameter space which satisfies all the constraints, and is characterized by a dilaton mass in the $300-500$ GeV range and a Higgs decay constant $f \lesssim 1.1$ TeV. We discuss its future tests.
2203.12153
Zhilei Ma
Zhi-Lei Ma, Zhun Lu, and Li Zhang
Inelastic heavy quarkonium photoproduction in ultrarelativistic heavy-ion collisions
19 pages, 10 figures. arXiv admin note: text overlap with arXiv:2104.14120
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The inelastic charmonium ($J/\psi$, $\psi(2S)$, $\eta_{c}$, $h_{c}$ and $\chi_{cJ}$) and bottomonium ($\Upsilon(nS)$, $\eta_{b}$, $h_{b}$, and $\chi_{bJ}$) photoproductions in ultrarelativistic heavy-ion collisions at LHC energies are studied, where the fragmentation processes are included. Based on the factorization formalism of non-relativistic QCD, an exact treatment is developed, which can weight the contribution from different channels and recovers the Weizs\"{a}cker-Williams approximation (WWA) near the region $Q^{2}\sim0$. The relevant kinematical relations are also achieved. We present a comprehensive analysis for the properties of WWA in heavy-ion collisions, and discuss the contribution of inelastic photoproduction processes to the heavy quarkonium production. The $Q^{2}$-, $y$-, $\sqrt{s}$-, and $p_{T}$-dependent cross sections, and the total cross sections are estimated. It is shown that the inelastic photoproduction and fragmentation processes can provide the evident modification to the heavy quarkonium production in $p$-$p$ and $Pb$-$Pb$ collisions at LHC energies, where the ultra-incoherent photon emission plays a very important role. Moreover, the WWA is only effective in very restricted domains, and the exact treatment can naturally avoid double counting and WWA errors.
[ { "created": "Wed, 23 Mar 2022 02:59:23 GMT", "version": "v1" } ]
2022-03-24
[ [ "Ma", "Zhi-Lei", "" ], [ "Lu", "Zhun", "" ], [ "Zhang", "Li", "" ] ]
The inelastic charmonium ($J/\psi$, $\psi(2S)$, $\eta_{c}$, $h_{c}$ and $\chi_{cJ}$) and bottomonium ($\Upsilon(nS)$, $\eta_{b}$, $h_{b}$, and $\chi_{bJ}$) photoproductions in ultrarelativistic heavy-ion collisions at LHC energies are studied, where the fragmentation processes are included. Based on the factorization formalism of non-relativistic QCD, an exact treatment is developed, which can weight the contribution from different channels and recovers the Weizs\"{a}cker-Williams approximation (WWA) near the region $Q^{2}\sim0$. The relevant kinematical relations are also achieved. We present a comprehensive analysis for the properties of WWA in heavy-ion collisions, and discuss the contribution of inelastic photoproduction processes to the heavy quarkonium production. The $Q^{2}$-, $y$-, $\sqrt{s}$-, and $p_{T}$-dependent cross sections, and the total cross sections are estimated. It is shown that the inelastic photoproduction and fragmentation processes can provide the evident modification to the heavy quarkonium production in $p$-$p$ and $Pb$-$Pb$ collisions at LHC energies, where the ultra-incoherent photon emission plays a very important role. Moreover, the WWA is only effective in very restricted domains, and the exact treatment can naturally avoid double counting and WWA errors.
2008.06169
Ismail Zahed
Edward Shuryak and Ismail Zahed
Nonperturbative quark-antiquark interactions in mesonic form factors
82 pages, 17 figures
Phys. Rev. D 103, 054028 (2021)
10.1103/PhysRevD.103.054028
null
hep-ph hep-lat hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The existing theory of hard exclusive QCD processes is based on two assumptions: (i) $factorization$ into a $hard\,block$ times light front distribution amplitudes (DA's); (ii) use of perturbative gluon exchanges within the hard block. However, unlike DIS and jet physics, the characteristic momentum transfer $Q$ involved in the factorized block is not large enough for this theory to be phenomenologically successful. In this work, we revisit the latter assumption (ii), by explicitly calculating the $instanton-induced$ contributions to the hard block, and show that they contribute substantially to the vector, scalar and gravitational form factors of the pseudoscalar, scalar and vector mesons, over a wide range of momentum transfer.
[ { "created": "Fri, 14 Aug 2020 02:31:21 GMT", "version": "v1" }, { "created": "Tue, 24 Nov 2020 03:39:55 GMT", "version": "v2" } ]
2021-03-31
[ [ "Shuryak", "Edward", "" ], [ "Zahed", "Ismail", "" ] ]
The existing theory of hard exclusive QCD processes is based on two assumptions: (i) $factorization$ into a $hard\,block$ times light front distribution amplitudes (DA's); (ii) use of perturbative gluon exchanges within the hard block. However, unlike DIS and jet physics, the characteristic momentum transfer $Q$ involved in the factorized block is not large enough for this theory to be phenomenologically successful. In this work, we revisit the latter assumption (ii), by explicitly calculating the $instanton-induced$ contributions to the hard block, and show that they contribute substantially to the vector, scalar and gravitational form factors of the pseudoscalar, scalar and vector mesons, over a wide range of momentum transfer.
2005.10689
G\"oran F\"aldt
G\"oran F\"aldt
Remarks on the analysis of the reaction $e^+e^-\rightarrow\Sigma^0\bar{\Sigma}^0$
arXiv admin note: text overlap with arXiv:1908.04157
Phys. Rev. D 103, 033001 (2021)
10.1103/PhysRevD.103.033001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate roads for evaluating model-independent cross-section distributions for the sequential hyperon decay $\Sigma^0\rightarrow\Lambda \gamma;\Lambda\rightarrow p\pi^- $ and its corresponding antihyperon decay. The hyperons are produced in the reaction $e^+e^-\rightarrow J/{\psi}\rightarrow \Sigma^0\bar{\Sigma}^0$. Cross-section distributions are calculated using the folding technique.
[ { "created": "Tue, 19 May 2020 19:08:38 GMT", "version": "v1" } ]
2021-02-10
[ [ "Fäldt", "Göran", "" ] ]
We investigate roads for evaluating model-independent cross-section distributions for the sequential hyperon decay $\Sigma^0\rightarrow\Lambda \gamma;\Lambda\rightarrow p\pi^- $ and its corresponding antihyperon decay. The hyperons are produced in the reaction $e^+e^-\rightarrow J/{\psi}\rightarrow \Sigma^0\bar{\Sigma}^0$. Cross-section distributions are calculated using the folding technique.
1609.02572
Keh-Fei Liu
Keh-Fei Liu
Baryons and Chiral Symmetry
To appear in G.E. Brown Memorial Volume
null
10.1142/S021830131740016X
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The relevance of chiral symmetry in baryons is highlighted in three examples in the nucleon spectroscopy and structure. The first one is the importance of chiral dynamics in understanding the Roper resonance. The second one is the role of chiral symmetry in the lattice calculation of $\pi N \sigma$ term and strangeness. The third one is the role of chiral $U(1)$ anomaly in the anomalous Ward identity in evaluating the quark spin and the quark orbital angular momentum. Finally, the chiral effective theory for baryons is discussed.
[ { "created": "Thu, 8 Sep 2016 20:02:00 GMT", "version": "v1" } ]
2017-03-08
[ [ "Liu", "Keh-Fei", "" ] ]
The relevance of chiral symmetry in baryons is highlighted in three examples in the nucleon spectroscopy and structure. The first one is the importance of chiral dynamics in understanding the Roper resonance. The second one is the role of chiral symmetry in the lattice calculation of $\pi N \sigma$ term and strangeness. The third one is the role of chiral $U(1)$ anomaly in the anomalous Ward identity in evaluating the quark spin and the quark orbital angular momentum. Finally, the chiral effective theory for baryons is discussed.
1411.6417
Artem Lipatov
S.P. Baranov, A.V. Lipatov, N.P. Zotov
TMD PDFs in Drell-Yan lepton pair production at LHC
Talk presented at International Workshop on Diffraction in High-Energy Physics, Diffraction-2014
null
10.1063/1.4916001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the transverse momentum dependent (TMD) quark densities of the proton which are very important ingredients for unpolarized Drell-Yan (DY) lepton pair production. We calculate the TMD sea quark density as a convolution of the Catani-Ciafaloni-Fiorani-Marchesini (CCFM)-evolved gluon distribution and the TMD gluon-to-quark splitting function. Based on the ${\cal O}(\alpha^2)$ production amplitude $q^* + \bar q^* \to Z/\gamma^* \to l^+ + l^-$, calculated by taking into account the effective $q^*\bar q^* Z/\gamma^*$ - vertex, we analyze the distributions on the dilepton invariant mass, transverse momentum and rapidity and specific angular correlations between the produced leptons as measured by the CMS, ATLAS and LHCb collaborations. We briefly duscuss also the process of assiciated lepton pair and jet production in $pp$ collisions at the LHC.
[ { "created": "Mon, 24 Nov 2014 11:44:07 GMT", "version": "v1" } ]
2015-06-23
[ [ "Baranov", "S. P.", "" ], [ "Lipatov", "A. V.", "" ], [ "Zotov", "N. P.", "" ] ]
We consider the transverse momentum dependent (TMD) quark densities of the proton which are very important ingredients for unpolarized Drell-Yan (DY) lepton pair production. We calculate the TMD sea quark density as a convolution of the Catani-Ciafaloni-Fiorani-Marchesini (CCFM)-evolved gluon distribution and the TMD gluon-to-quark splitting function. Based on the ${\cal O}(\alpha^2)$ production amplitude $q^* + \bar q^* \to Z/\gamma^* \to l^+ + l^-$, calculated by taking into account the effective $q^*\bar q^* Z/\gamma^*$ - vertex, we analyze the distributions on the dilepton invariant mass, transverse momentum and rapidity and specific angular correlations between the produced leptons as measured by the CMS, ATLAS and LHCb collaborations. We briefly duscuss also the process of assiciated lepton pair and jet production in $pp$ collisions at the LHC.
hep-ph/0501282
Drago Alessandro
Alessandro Drago (Ferrara U. & INFN sez. Ferrara)
Time-reversal odd distribution functions in chiral models with vector mesons
4 pages
Phys.Rev. D71 (2005) 057501
10.1103/PhysRevD.71.057501
null
hep-ph
null
The so-called time-reversal odd distribution functions are known to be non-vanishing in QCD due to the presence of the link operator in the definition of these quantities. I show that T-odd distributions can be non-vanishing also in chiral models, if vector mesons are introduced as dynamical gauge bosons of a hidden local symmetry. Moreover, since the flavor dependence of these distributions is different in chiral models respect to non chiral ones, the phenomenological analysis of experimental data will be able to distinguish between these two classes of models.
[ { "created": "Sun, 30 Jan 2005 23:54:55 GMT", "version": "v1" } ]
2009-11-11
[ [ "Drago", "Alessandro", "", "Ferrara U. & INFN sez. Ferrara" ] ]
The so-called time-reversal odd distribution functions are known to be non-vanishing in QCD due to the presence of the link operator in the definition of these quantities. I show that T-odd distributions can be non-vanishing also in chiral models, if vector mesons are introduced as dynamical gauge bosons of a hidden local symmetry. Moreover, since the flavor dependence of these distributions is different in chiral models respect to non chiral ones, the phenomenological analysis of experimental data will be able to distinguish between these two classes of models.
hep-ph/9710276
Yuval Grossman
Yuval Grossman
Sneutrino Mixing
11 pages, latex, using iopconf1 and axodraw; one figure included. Talk presented at ``Beyond the Desert'' Workshop, Castle Ringberg, Tegernsee, Germany, 8-14 June 1997
null
null
SLAC-PUB-7671
hep-ph
null
In supersymmetric models with nonvanishing Majorana neutrino masses, the sneutrino and antisneutrino mix. The conditions under which this mixing is experimentally observable are studied, and mass-splitting of the sneutrino mass eigenstates and sneutrino oscillation phenomena are analyzed.
[ { "created": "Tue, 7 Oct 1997 20:58:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Grossman", "Yuval", "" ] ]
In supersymmetric models with nonvanishing Majorana neutrino masses, the sneutrino and antisneutrino mix. The conditions under which this mixing is experimentally observable are studied, and mass-splitting of the sneutrino mass eigenstates and sneutrino oscillation phenomena are analyzed.
2212.03272
Enrico Trotti
Enrico Trotti, Shahriyar Jafarzade and Francesco Giacosa
Thermodynamics of the Glueball Resonance Gas
18 pages, 6 figures
null
10.1140/epjc/s10052-023-11557-0
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the thermodynamic properties -- pressure, entropy and trace anomaly -- of a gas of glueballs that includes the glueball states obtained by various lattice simulations. We show that this model, called Glueball Resonance Gas (GRG) approach, describes well the thermal properties of the Yang-Mills sector of QCD below the critical temperature $T_c$, provided that $T_c$ is properly matched to the corresponding determination of the glueball masses, obtaining $T_c \sim 320 \pm 20$ MeV. The inclusion into the GRG of heavier glueballs not yet seen on the lattice, assuming that glueballs follow Regge trajectories as quark-antiquark states do, leads only to a small correction. We consider the contribution to the pressure of the interactions between scalar-scalar and tensor-tensor glueballs, which turn out to be also negligible.
[ { "created": "Tue, 6 Dec 2022 19:02:49 GMT", "version": "v1" }, { "created": "Mon, 26 Dec 2022 10:57:19 GMT", "version": "v2" } ]
2023-05-24
[ [ "Trotti", "Enrico", "" ], [ "Jafarzade", "Shahriyar", "" ], [ "Giacosa", "Francesco", "" ] ]
We study the thermodynamic properties -- pressure, entropy and trace anomaly -- of a gas of glueballs that includes the glueball states obtained by various lattice simulations. We show that this model, called Glueball Resonance Gas (GRG) approach, describes well the thermal properties of the Yang-Mills sector of QCD below the critical temperature $T_c$, provided that $T_c$ is properly matched to the corresponding determination of the glueball masses, obtaining $T_c \sim 320 \pm 20$ MeV. The inclusion into the GRG of heavier glueballs not yet seen on the lattice, assuming that glueballs follow Regge trajectories as quark-antiquark states do, leads only to a small correction. We consider the contribution to the pressure of the interactions between scalar-scalar and tensor-tensor glueballs, which turn out to be also negligible.
1101.2584
Egle Tomasi-Gustafsson
G. I. Gakh, N. P. Merenkov and E. Tomasi-Gustafsson
Analysis of polarization observables and radiative effects for the reaction $\bar p+p\rightarrow e^++e^-$
18 pages, 8 figures
Phys.Rev.C83:045202,2011
10.1103/PhysRevC.83.045202
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The expressions for the differential cross section and of the polarization observables for the reaction $\bar p+p\rightarrow e^++e^-$ are given in terms of the nucleon electromagnetic form factors in the laboratory system. Radiative corrections due to the emission of virtual and real soft photons from the leptons are also calculated. Unlike the center-of- mass system case, they depend on the scattering angle. Polarization effects are derived in the case when the antiproton beam, the target and the electron in the final state are polarized. Numerical estimations have been done for all observables for the PANDA experimental conditions using models for the nucleon electromagnetic form factors in the time-like region. The radiative corrections to the differential cross section are calculated as function of the beam energy and of the electron angle.
[ { "created": "Thu, 13 Jan 2011 15:34:56 GMT", "version": "v1" } ]
2015-03-17
[ [ "Gakh", "G. I.", "" ], [ "Merenkov", "N. P.", "" ], [ "Tomasi-Gustafsson", "E.", "" ] ]
The expressions for the differential cross section and of the polarization observables for the reaction $\bar p+p\rightarrow e^++e^-$ are given in terms of the nucleon electromagnetic form factors in the laboratory system. Radiative corrections due to the emission of virtual and real soft photons from the leptons are also calculated. Unlike the center-of- mass system case, they depend on the scattering angle. Polarization effects are derived in the case when the antiproton beam, the target and the electron in the final state are polarized. Numerical estimations have been done for all observables for the PANDA experimental conditions using models for the nucleon electromagnetic form factors in the time-like region. The radiative corrections to the differential cross section are calculated as function of the beam energy and of the electron angle.
1308.0320
Diptimoy Ghosh
Diptimoy Ghosh (INFN, Rome and Fermilab)
Boosted di-boson from a mixed heavy stop
One reference added. To appear in Physical Review D
Phys.Rev. D88 (2013) 115013
10.1103/PhysRevD.88.115013
FERMILAB-PUB-13-306-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The lighter mass eigenstate ($\widetilde{t}_1$) of the two top squarks, the scalar superpartners of the top quark, is extremely difficult to discover if it is almost degenerate with the lightest neutralino ($\widetilde{\chi}_1^0$), the lightest and stable supersymmetric particle in the R-parity conserving supersymmetry. The current experimental bound on $\widetilde{t}_1$ mass in this scenario stands only around 200 GeV. For such a light $\widetilde{t}_1$, the heavier top squark ($\widetilde{t}_2$) can also be around the TeV scale. Moreover, the high value of the higgs ($h$) mass prefers the left and right handed top squarks to be highly mixed allowing the possibility of a considerable branching ratio for $\widetilde{t}_2 \to \widetilde{t}_1 h$ and $\widetilde{t}_2 \to \widetilde{t}_1 Z$. In this paper, we explore the above possibility together with the pair production of $\widetilde{t}_2$ $\widetilde{t}_2^*$ giving rise to the spectacular di-boson + missing transverse energy final state. For an approximately 1 TeV $\widetilde{t}_2$ and a few hundred GeV $\widetilde{t}_1$ the final state particles can be moderately boosted which encourages us to propose a novel search strategy employing the jet substructure technique to tag the boosted $h$ and $Z$. The reconstruction of the $h$ and $Z$ momenta also allows us to construct the stransverse mass $M_{T2}$ providing an additional efficient handle to fight the backgrounds. We show that a 4--5$\sigma$ signal can be observed at the 14 TeV LHC for $\sim$ 1 TeV $\widetilde{t}_2$ with 100 fb$^{-1}$ integrated luminosity.
[ { "created": "Thu, 1 Aug 2013 19:51:16 GMT", "version": "v1" }, { "created": "Mon, 25 Nov 2013 19:51:17 GMT", "version": "v2" } ]
2013-12-30
[ [ "Ghosh", "Diptimoy", "", "INFN, Rome and Fermilab" ] ]
The lighter mass eigenstate ($\widetilde{t}_1$) of the two top squarks, the scalar superpartners of the top quark, is extremely difficult to discover if it is almost degenerate with the lightest neutralino ($\widetilde{\chi}_1^0$), the lightest and stable supersymmetric particle in the R-parity conserving supersymmetry. The current experimental bound on $\widetilde{t}_1$ mass in this scenario stands only around 200 GeV. For such a light $\widetilde{t}_1$, the heavier top squark ($\widetilde{t}_2$) can also be around the TeV scale. Moreover, the high value of the higgs ($h$) mass prefers the left and right handed top squarks to be highly mixed allowing the possibility of a considerable branching ratio for $\widetilde{t}_2 \to \widetilde{t}_1 h$ and $\widetilde{t}_2 \to \widetilde{t}_1 Z$. In this paper, we explore the above possibility together with the pair production of $\widetilde{t}_2$ $\widetilde{t}_2^*$ giving rise to the spectacular di-boson + missing transverse energy final state. For an approximately 1 TeV $\widetilde{t}_2$ and a few hundred GeV $\widetilde{t}_1$ the final state particles can be moderately boosted which encourages us to propose a novel search strategy employing the jet substructure technique to tag the boosted $h$ and $Z$. The reconstruction of the $h$ and $Z$ momenta also allows us to construct the stransverse mass $M_{T2}$ providing an additional efficient handle to fight the backgrounds. We show that a 4--5$\sigma$ signal can be observed at the 14 TeV LHC for $\sim$ 1 TeV $\widetilde{t}_2$ with 100 fb$^{-1}$ integrated luminosity.
hep-ph/0604036
Eduardo Souza Fraga
Bruno G. Taketani and Eduardo S. Fraga
Effects from inhomogeneities in the chiral transition
11 pages, 5 figures. v2: appendix and references added, published version
Phys.Rev. D74 (2006) 085013
10.1103/PhysRevD.74.085013
null
hep-ph hep-th nucl-th
null
We consider an approximation procedure to evaluate the finite-temperature one-loop fermionic density in the presence of a chiral background field which systematically incorporates effects from inhomogeneities in the chiral field through a derivative expansion. We apply the method to the case of a simple low-energy effective chiral model which is commonly used in the study of the chiral phase transition, the linear sigma-model coupled to quarks. The modifications in the effective potential and their consequences for the bubble nucleation process are discussed.
[ { "created": "Tue, 4 Apr 2006 20:40:59 GMT", "version": "v1" }, { "created": "Tue, 17 Oct 2006 18:05:37 GMT", "version": "v2" } ]
2009-11-11
[ [ "Taketani", "Bruno G.", "" ], [ "Fraga", "Eduardo S.", "" ] ]
We consider an approximation procedure to evaluate the finite-temperature one-loop fermionic density in the presence of a chiral background field which systematically incorporates effects from inhomogeneities in the chiral field through a derivative expansion. We apply the method to the case of a simple low-energy effective chiral model which is commonly used in the study of the chiral phase transition, the linear sigma-model coupled to quarks. The modifications in the effective potential and their consequences for the bubble nucleation process are discussed.
hep-ph/9801437
Rmt
M. Masip, R. Munoz-Tapia and A. Pomarol
Limits on the mass of the lightest Higgs in supersymmetric models
11pages, LaTex, uses epsfig, 3 figures
Phys.Rev.D57:R5340,1998
10.1103/PhysRevD.57.5340
UG-FT-84/97, UAB-FT-436
hep-ph
null
In supersymmetric models extended with a gauge singlet the mass of the lightest Higgs boson has contributions proportional to the adimensional coupling $\lambda$. In minimal scenarios, the requirement that this coupling remains perturbative up to the unification scale constrains $\lambda$ to be smaller than $\approx 0.7$. We study the maximum value of $\lambda$ consistent with a perturbative unification of the gauge couplings in models containing nonstandard fields at intermediate scales. These fields appear in scenarios with gauge mediation of supersymmetry breaking. We find that the presence of extra fields can raise the maximum value of $\lambda$ up to a 19%, increasing the limits on the mass of the lightest Higgs from 135 GeV to 155 GeV.
[ { "created": "Thu, 29 Jan 1998 20:09:00 GMT", "version": "v1" } ]
2009-12-30
[ [ "Masip", "M.", "" ], [ "Munoz-Tapia", "R.", "" ], [ "Pomarol", "A.", "" ] ]
In supersymmetric models extended with a gauge singlet the mass of the lightest Higgs boson has contributions proportional to the adimensional coupling $\lambda$. In minimal scenarios, the requirement that this coupling remains perturbative up to the unification scale constrains $\lambda$ to be smaller than $\approx 0.7$. We study the maximum value of $\lambda$ consistent with a perturbative unification of the gauge couplings in models containing nonstandard fields at intermediate scales. These fields appear in scenarios with gauge mediation of supersymmetry breaking. We find that the presence of extra fields can raise the maximum value of $\lambda$ up to a 19%, increasing the limits on the mass of the lightest Higgs from 135 GeV to 155 GeV.
hep-ph/0105344
Matej Pavsic
Matej Pavsic
External Inversion, Internal Inversion, and Reflection Invariance
15 pages. An early proposal of "mirror matter", published in 1974. This is an exact copy of the published paper. I am posting it here because of the increasing interest in the "exact parity models" and its experimental consequences
Int.J.Theor.Phys.9:229-244,1974
10.1007/BF01810695
null
hep-ph hep-th
null
Having in mind that physical systems have different levels of structure we develop the concept of external, internal and total improper Lorentz transformation (space inversion and time reversal). A particle obtained from the ordinary one by the application of internal space inversion or time reversal is generally a different particle. From this point of view the intrinsic parity of a nuclear particle (`elementary particle') is in fact the external intrinsic parity, if we take into account the internal structure of a particle. We show that non-conservation of the external parity does not necessarily imply non-invariance of nature under space inversion. The conventional theory of beta-decay can be corrected by including the internal degrees of freedom to become invariant under total space inversion, though not under the external one.
[ { "created": "Thu, 31 May 2001 17:21:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Pavsic", "Matej", "" ] ]
Having in mind that physical systems have different levels of structure we develop the concept of external, internal and total improper Lorentz transformation (space inversion and time reversal). A particle obtained from the ordinary one by the application of internal space inversion or time reversal is generally a different particle. From this point of view the intrinsic parity of a nuclear particle (`elementary particle') is in fact the external intrinsic parity, if we take into account the internal structure of a particle. We show that non-conservation of the external parity does not necessarily imply non-invariance of nature under space inversion. The conventional theory of beta-decay can be corrected by including the internal degrees of freedom to become invariant under total space inversion, though not under the external one.
hep-ph/0407208
Elvio Di Salvo
E. Di Salvo
Q^2 Dependence of the azimuthal Asymmetry in Unpolarized Drell-Yan
15 pages, 4 figures. Presented at "HiX2004", Marseille, July 26-28, 2004
null
10.1063/1.1871665
null
hep-ph
null
We study the azimuthal asymmetry of the unpolarized Drell-Yan in the framework of the T-odd functions. We find, on the basis of quite general arguments, that for |{\bf q}_{\perp}| << Q such an asymmetry decreases as Q^{-2}, where {\bf q}_{\perp} and Q are respectively the transverse momentum and the center-of-mass energy of the muon pair. The experimental results support this conclusion.
[ { "created": "Mon, 19 Jul 2004 10:32:58 GMT", "version": "v1" } ]
2009-11-10
[ [ "Di Salvo", "E.", "" ] ]
We study the azimuthal asymmetry of the unpolarized Drell-Yan in the framework of the T-odd functions. We find, on the basis of quite general arguments, that for |{\bf q}_{\perp}| << Q such an asymmetry decreases as Q^{-2}, where {\bf q}_{\perp} and Q are respectively the transverse momentum and the center-of-mass energy of the muon pair. The experimental results support this conclusion.
1706.06728
Kazuhiro Watanabe
Hirotsugu Fujii, Kazuhiro Watanabe
Nuclear modification of forward $D$ production in pPb collisions at the LHC
12 pages, 3 figures; v2: typo in (3) corrected
null
null
JLAB-THY-17-2506
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study nuclear modification factors for single $D$ meson and semileptonic decay lepton $l$ ($=e,\mu$) production in minimum bias proton-nucleus (p$A$) collisions at the LHC in the color-glass-condensate (CGC) framework at leading order in strong coupling. In our numerical computations, transverse momentum ($k_\perp$) dependent multi-point Wilson line correlators are employed for describing target nucleus for p$A$ and proton for pp. The projectile proton is treated with unintegrated gluon distribution function, which is also $k_\perp$-dependent. The rapidity evolutions of these functions in the small Bjorken $x$ region are taken into account by solving running coupling Balitsky-Kovchegov (BK) equation at leading logarithmic accuracy. For simplicity, we employ Kartvelishvili's type fragmentation function and a simple model for lepton energy distribution from seileptonic decay, respectively, to compute differential cross sections for $D$ and $l$ production. The gluon saturation scale inside the heavy nucleus is enhanced and dependent on $x$, which we take into account by replacing the initial saturation scale in the BK equation with a larger value for the heavy nucleus. We show that the saturation effect leads to perceptible nuclear suppression of $D$ production at forward rapidity. Our numerical results predict similar nuclear suppressions in p$A$ collisions for forward $l$ production at lower transverse momentum $p_\perp<2\;{\rm GeV}$. Numerical tables on the nuclear modifications of $D$ and $l$ are listed in this note.
[ { "created": "Wed, 21 Jun 2017 03:17:13 GMT", "version": "v1" }, { "created": "Mon, 5 Feb 2018 04:51:03 GMT", "version": "v2" } ]
2018-02-06
[ [ "Fujii", "Hirotsugu", "" ], [ "Watanabe", "Kazuhiro", "" ] ]
We study nuclear modification factors for single $D$ meson and semileptonic decay lepton $l$ ($=e,\mu$) production in minimum bias proton-nucleus (p$A$) collisions at the LHC in the color-glass-condensate (CGC) framework at leading order in strong coupling. In our numerical computations, transverse momentum ($k_\perp$) dependent multi-point Wilson line correlators are employed for describing target nucleus for p$A$ and proton for pp. The projectile proton is treated with unintegrated gluon distribution function, which is also $k_\perp$-dependent. The rapidity evolutions of these functions in the small Bjorken $x$ region are taken into account by solving running coupling Balitsky-Kovchegov (BK) equation at leading logarithmic accuracy. For simplicity, we employ Kartvelishvili's type fragmentation function and a simple model for lepton energy distribution from seileptonic decay, respectively, to compute differential cross sections for $D$ and $l$ production. The gluon saturation scale inside the heavy nucleus is enhanced and dependent on $x$, which we take into account by replacing the initial saturation scale in the BK equation with a larger value for the heavy nucleus. We show that the saturation effect leads to perceptible nuclear suppression of $D$ production at forward rapidity. Our numerical results predict similar nuclear suppressions in p$A$ collisions for forward $l$ production at lower transverse momentum $p_\perp<2\;{\rm GeV}$. Numerical tables on the nuclear modifications of $D$ and $l$ are listed in this note.
hep-ph/9906511
Ivan Schmidt
Hung-Jung Lu (Knowledge Adventure Inc., Glendale, CA), Rodrigo Rivera and Ivan Schmidt (Univ. Federico Santa Maria, Valparaiso, Chile)
Peripheral Meson Model of Deep Inelastic Rapidity Gap Events
12 pages, 2 figures
Phys.Lett. B484 (2000) 35-42
10.1016/S0370-2693(00)00627-4
USM-TH-76
hep-ph
null
We show that a peripheral meson model can explain the large deep inelastic electron-proton scattering rapidity gap events observed at HERA.
[ { "created": "Fri, 25 Jun 1999 22:28:15 GMT", "version": "v1" } ]
2009-10-31
[ [ "Lu", "Hung-Jung", "", "Knowledge Adventure Inc., Glendale, CA" ], [ "Rivera", "Rodrigo", "", "Univ. Federico Santa Maria, Valparaiso, Chile" ], [ "Schmidt", "Ivan", "", "Univ. Federico Santa Maria, Valparaiso, Chile" ] ]
We show that a peripheral meson model can explain the large deep inelastic electron-proton scattering rapidity gap events observed at HERA.
1604.02157
R. Sekhar Chivukula
R. Sekhar Chivukula, Arsham Farzinnia, Kirtimaan Mohan and Elizabeth H. Simmons
Diphoton Resonances in the Renormalizable Coloron Model
18 pages, 5 figures. (Modified to respond to referee comments, discussion of Landau poles in scalar couplings added.)
Phys. Rev. D 94, 035018 (2016)
10.1103/PhysRevD.94.035018
MSUHEP-160407
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The renormalizable coloron model, which has previously been shown in the literature to be consistent with a wide array of theoretical and precision electroweak constraints, includes a pair of spinless bosons (one scalar, one pseudoscalar). We show that either of them, or both together if they are degenerate, could be responsible for the diphoton resonance signal for which both CMS and ATLAS have seen evidence. Because either of these bosons would be produced and decay through loops of spectator fermions, the absence of signals in dijet, $t\bar{t}$, and electroweak boson pair channels is not a surprise.
[ { "created": "Thu, 7 Apr 2016 20:02:29 GMT", "version": "v1" }, { "created": "Thu, 14 Apr 2016 19:45:46 GMT", "version": "v2" }, { "created": "Mon, 25 Apr 2016 22:29:12 GMT", "version": "v3" }, { "created": "Fri, 15 Jul 2016 16:26:23 GMT", "version": "v4" } ]
2016-08-31
[ [ "Chivukula", "R. Sekhar", "" ], [ "Farzinnia", "Arsham", "" ], [ "Mohan", "Kirtimaan", "" ], [ "Simmons", "Elizabeth H.", "" ] ]
The renormalizable coloron model, which has previously been shown in the literature to be consistent with a wide array of theoretical and precision electroweak constraints, includes a pair of spinless bosons (one scalar, one pseudoscalar). We show that either of them, or both together if they are degenerate, could be responsible for the diphoton resonance signal for which both CMS and ATLAS have seen evidence. Because either of these bosons would be produced and decay through loops of spectator fermions, the absence of signals in dijet, $t\bar{t}$, and electroweak boson pair channels is not a surprise.
hep-ph/0101155
Havard B. Sandvik
J. Magueijo, H. Sandvik and T.W.B. Kibble
Nielsen-Olesen vortex in varying-alpha theories
7 pages, 1 figure
Phys.Rev. D64 (2001) 023521
10.1103/PhysRevD.64.023521
null
hep-ph astro-ph
null
We consider soliton solutions to Bekenstein's theory, for which the fine structure constant $\alpha=e^2/(4\pi\hbar c)$ is allowed to vary due to the presence of a dielectric field pervading the vacuum. More specifically we investigate the effects of a varying $\alpha$ upon a complex scalar field with a U(1) electromagnetic gauge symmetry subject to spontaneous symmetry breaking. We find vortex solutions to this theory, similar to the Nielsen-Olesen vortex. Near the vortex core the electric charge is typically much larger than far away from the string, lending these strings a superconducting flavour. In general the dielectric field coats the usual local string with a global string envelope. We discuss the cosmological implications of networks of such strings, with particular emphasis on their ability to generate inhomogeneous recombination scenarios. We also consider the possibility of the dielectric being a charged free field. Even though the vacuum of such a field is trivial, we find that the dielectric arranges itself in the shape of a local string, with a quantized magnetic flux at the core -- presumably borrowing these topological features from the underlying Nielsen-Olesen vortex.
[ { "created": "Mon, 15 Jan 2001 12:21:15 GMT", "version": "v1" }, { "created": "Fri, 30 Mar 2001 18:58:10 GMT", "version": "v2" } ]
2009-11-07
[ [ "Magueijo", "J.", "" ], [ "Sandvik", "H.", "" ], [ "Kibble", "T. W. B.", "" ] ]
We consider soliton solutions to Bekenstein's theory, for which the fine structure constant $\alpha=e^2/(4\pi\hbar c)$ is allowed to vary due to the presence of a dielectric field pervading the vacuum. More specifically we investigate the effects of a varying $\alpha$ upon a complex scalar field with a U(1) electromagnetic gauge symmetry subject to spontaneous symmetry breaking. We find vortex solutions to this theory, similar to the Nielsen-Olesen vortex. Near the vortex core the electric charge is typically much larger than far away from the string, lending these strings a superconducting flavour. In general the dielectric field coats the usual local string with a global string envelope. We discuss the cosmological implications of networks of such strings, with particular emphasis on their ability to generate inhomogeneous recombination scenarios. We also consider the possibility of the dielectric being a charged free field. Even though the vacuum of such a field is trivial, we find that the dielectric arranges itself in the shape of a local string, with a quantized magnetic flux at the core -- presumably borrowing these topological features from the underlying Nielsen-Olesen vortex.
1611.02846
Jenny List
Howard Baer, Mikael Berggren, Keisuke Fujii, Suvi-Leena Lehtinen, Jenny List, Tomohiko Tanabe, Jacqueline Yan
Naturalness and light higgsinos: A powerful reason to build the ILC
5pages plus title page, proceedings ICHEP 2016
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A core prediction of natural Supersymmetry is the existence of four light higgsinos not too far above the mass of the $Z$ boson. The small mass splittings amongst the higgsinos -- typically 5-20\,GeV -- imply very little visible energy release from decays of heavier higgsinos. In particular, if other SUSY particles are quite heavy, as can be the case in SUSY with radiatively-driven naturalness, the higgsinos are extremely hard to detect at hadron colliders. The clean environment of electron-positron colliders with $\sqrt{s} > 2m_{\mathrm{higgsino}}$, however, would allow for a decisive search for the required light higgsinos. Thus, $e^+e^-$ colliders should either discover or exclude natural SUSY. We present a detailed study of higgsino pair production at the proposed International Linear $e^+e^-$ Collider which is under consideration for construction in Japan. A variety of precision measurements should allow for extraction of underlying parameters and provide a window onto physics at the grand unified scale.
[ { "created": "Wed, 9 Nov 2016 08:29:12 GMT", "version": "v1" } ]
2016-11-10
[ [ "Baer", "Howard", "" ], [ "Berggren", "Mikael", "" ], [ "Fujii", "Keisuke", "" ], [ "Lehtinen", "Suvi-Leena", "" ], [ "List", "Jenny", "" ], [ "Tanabe", "Tomohiko", "" ], [ "Yan", "Jacqueline", "" ] ]
A core prediction of natural Supersymmetry is the existence of four light higgsinos not too far above the mass of the $Z$ boson. The small mass splittings amongst the higgsinos -- typically 5-20\,GeV -- imply very little visible energy release from decays of heavier higgsinos. In particular, if other SUSY particles are quite heavy, as can be the case in SUSY with radiatively-driven naturalness, the higgsinos are extremely hard to detect at hadron colliders. The clean environment of electron-positron colliders with $\sqrt{s} > 2m_{\mathrm{higgsino}}$, however, would allow for a decisive search for the required light higgsinos. Thus, $e^+e^-$ colliders should either discover or exclude natural SUSY. We present a detailed study of higgsino pair production at the proposed International Linear $e^+e^-$ Collider which is under consideration for construction in Japan. A variety of precision measurements should allow for extraction of underlying parameters and provide a window onto physics at the grand unified scale.
hep-ph/9712484
W. Porod
A. Bartl, F. de Campos, M. A. Garcia-Jareno, M. B. Magro, W. Majerotto, W. Porod, J. W. F. Valle
Gluino Cascade Decays With Broken R--Parity
5 pages LaTeX including 2 figures, uses sprocl.sty. Talk presented by W. Porod at the "International Workshop on Physics Beyond The Standard Model: from Theory to Experiment", October 13 - 17, 1997, Valencia, Spain
null
null
UWThPh-1997-50, HEPHY-PUB 683/97
hep-ph
null
We study the pattern of gluino cascade decays in a class of supersymmetric models where R-parity is spontaneously broken. The multi-lepton and same-sign dilepton rates in these models are compared with those of the Minimal Supersymmetric Standard Model. We show that these rates can be substantially enhanced in models with broken R-parity.
[ { "created": "Mon, 22 Dec 1997 15:21:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bartl", "A.", "" ], [ "de Campos", "F.", "" ], [ "Garcia-Jareno", "M. A.", "" ], [ "Magro", "M. B.", "" ], [ "Majerotto", "W.", "" ], [ "Porod", "W.", "" ], [ "Valle", "J. W. F.", "" ] ]
We study the pattern of gluino cascade decays in a class of supersymmetric models where R-parity is spontaneously broken. The multi-lepton and same-sign dilepton rates in these models are compared with those of the Minimal Supersymmetric Standard Model. We show that these rates can be substantially enhanced in models with broken R-parity.
2311.12934
Yan Luo
Qing-Hong Cao, Jinhui Guo, Jia Liu, Yan Luo, Xiao-Ping Wang
Long-lived Searches of Vector-like Lepton and Its Accompanying Scalar at Colliders
33 pages, 9 figures; v2: matched to journal version
Phys. Rev. D 110, 015029 (2024)
10.1103/PhysRevD.110.015029
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, the vector-like leptons (VLLs) as a simple extension to the standard model (SM) have attracted widespread attention both in theory and experiments. The present collider searches mainly focus on the studies of their prompt decays, which prefer a relatively large coupling. In this paper, we concentrate on searches for long-lived signatures of the singlet VLLs $F$ or their accompanying scalar particles $\phi$ both in the hadronic and electronic colliders. The long-lived signatures are naturally induced from small chiral mass mixing between VLLs and SM leptons. Two specific models distinguished by whether the VLLs couple to scalar particles are introduced to realize the aforementioned features. For long-lived VLLs case, we find that with the kink track method the sensitivities at future HL-LHC with $\sqrt{s}=14~\text{TeV}$ can reach the regions for VLL mass $m_F \in [200,1100]~\text{GeV}$ and the mass mixing parameter $\theta_L \in [10^{-10},3\times 10^{-8}]$. For the long-lived accompanying scalar particle case, by fixing VLLs or scalar mass, or the mass ratio between VLL and the accompanying scalar, we explore the projected sensitivities through the time delay and displaced vertex strategies, which can probe the regions for $m_F \in [200,1200]~\text{GeV}$ and coupling $y\theta_L\in [10^{-11},10^{-6}]$. Furthermore, we also explore the long-lived accompanying scalars at the future CEPC provided that the VLLs can couple to the SM first-generation leptons. We find that CEPC has good performances for $m_\phi < 120~\text{GeV}$ and $m_F<1200~\text{GeV}$. These long-lived searches are complementary to previous studies, which opens the door towards the smaller coupling regions.
[ { "created": "Tue, 21 Nov 2023 19:00:13 GMT", "version": "v1" }, { "created": "Mon, 29 Jul 2024 08:43:31 GMT", "version": "v2" } ]
2024-07-31
[ [ "Cao", "Qing-Hong", "" ], [ "Guo", "Jinhui", "" ], [ "Liu", "Jia", "" ], [ "Luo", "Yan", "" ], [ "Wang", "Xiao-Ping", "" ] ]
Recently, the vector-like leptons (VLLs) as a simple extension to the standard model (SM) have attracted widespread attention both in theory and experiments. The present collider searches mainly focus on the studies of their prompt decays, which prefer a relatively large coupling. In this paper, we concentrate on searches for long-lived signatures of the singlet VLLs $F$ or their accompanying scalar particles $\phi$ both in the hadronic and electronic colliders. The long-lived signatures are naturally induced from small chiral mass mixing between VLLs and SM leptons. Two specific models distinguished by whether the VLLs couple to scalar particles are introduced to realize the aforementioned features. For long-lived VLLs case, we find that with the kink track method the sensitivities at future HL-LHC with $\sqrt{s}=14~\text{TeV}$ can reach the regions for VLL mass $m_F \in [200,1100]~\text{GeV}$ and the mass mixing parameter $\theta_L \in [10^{-10},3\times 10^{-8}]$. For the long-lived accompanying scalar particle case, by fixing VLLs or scalar mass, or the mass ratio between VLL and the accompanying scalar, we explore the projected sensitivities through the time delay and displaced vertex strategies, which can probe the regions for $m_F \in [200,1200]~\text{GeV}$ and coupling $y\theta_L\in [10^{-11},10^{-6}]$. Furthermore, we also explore the long-lived accompanying scalars at the future CEPC provided that the VLLs can couple to the SM first-generation leptons. We find that CEPC has good performances for $m_\phi < 120~\text{GeV}$ and $m_F<1200~\text{GeV}$. These long-lived searches are complementary to previous studies, which opens the door towards the smaller coupling regions.
1708.03580
Debashis Saha
Pankaj Agrawal, Debashis Saha, Ambresh Shivaji
Production of $HHH$ and $HHV(V=\gamma,Z)$ at the hadron colliders
Version to be appeared in PRD
Phys. Rev. D 97, 036006 (2018)
10.1103/PhysRevD.97.036006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the production of two Higgs bosons in association with a gauge boson or another Higgs boson at the hadron colliders. We compute the cross sections and distributions for the processes $ p p \to H H H $ and $H H Z$ within the standard model. In particular, we compute the gluon-gluon fusion one-loop contributions mediated via heavy quarks in the loop. It is the leading order contribution to $ p p \to H H H $ process. To the process $ p p \to H H Z $, it is next-to-next-to-leading-order (NNLO) contribution in QCD coupling. We also compare this contribution to the next-to-leading-order (NLO) QCD contribution to this process. The NNLO contribution can be similar to NLO contribution at the Large Hadron Collider (LHC), and significantly more at higher center-of-mass energy machines. We also study new physics effects in these processes by considering $ttH, HHH, HHHH, HZZ$, and $HHZZ$ interactions as anomalous. The anomalous couplings can enhance the cross sections significantly. The $gg \to HHH$ process is specially sensitive to anomalous trilinear Higgs boson self-coupling. For the $gg \to HHZ$ process, there is some modest dependence on anomalous $HZZ$ couplings.
[ { "created": "Fri, 11 Aug 2017 15:50:06 GMT", "version": "v1" }, { "created": "Sat, 20 Jan 2018 09:24:33 GMT", "version": "v2" } ]
2018-02-21
[ [ "Agrawal", "Pankaj", "" ], [ "Saha", "Debashis", "" ], [ "Shivaji", "Ambresh", "" ] ]
We consider the production of two Higgs bosons in association with a gauge boson or another Higgs boson at the hadron colliders. We compute the cross sections and distributions for the processes $ p p \to H H H $ and $H H Z$ within the standard model. In particular, we compute the gluon-gluon fusion one-loop contributions mediated via heavy quarks in the loop. It is the leading order contribution to $ p p \to H H H $ process. To the process $ p p \to H H Z $, it is next-to-next-to-leading-order (NNLO) contribution in QCD coupling. We also compare this contribution to the next-to-leading-order (NLO) QCD contribution to this process. The NNLO contribution can be similar to NLO contribution at the Large Hadron Collider (LHC), and significantly more at higher center-of-mass energy machines. We also study new physics effects in these processes by considering $ttH, HHH, HHHH, HZZ$, and $HHZZ$ interactions as anomalous. The anomalous couplings can enhance the cross sections significantly. The $gg \to HHH$ process is specially sensitive to anomalous trilinear Higgs boson self-coupling. For the $gg \to HHZ$ process, there is some modest dependence on anomalous $HZZ$ couplings.
2102.02770
Matthew Feickert
Matthew Feickert and Benjamin Nachman
A Living Review of Machine Learning for Particle Physics
3 pages, 3 figures, GitHub repository of Living Review https://github.com/iml-wg/HEPML-LivingReview
null
null
null
hep-ph cs.LG hep-ex physics.data-an stat.ML
http://creativecommons.org/licenses/by/4.0/
Modern machine learning techniques, including deep learning, are rapidly being applied, adapted, and developed for high energy physics. Given the fast pace of this research, we have created a living review with the goal of providing a nearly comprehensive list of citations for those developing and applying these approaches to experimental, phenomenological, or theoretical analyses. As a living document, it will be updated as often as possible to incorporate the latest developments. A list of proper (unchanging) reviews can be found within. Papers are grouped into a small set of topics to be as useful as possible. Suggestions and contributions are most welcome, and we provide instructions for participating.
[ { "created": "Tue, 2 Feb 2021 04:39:40 GMT", "version": "v1" } ]
2021-02-05
[ [ "Feickert", "Matthew", "" ], [ "Nachman", "Benjamin", "" ] ]
Modern machine learning techniques, including deep learning, are rapidly being applied, adapted, and developed for high energy physics. Given the fast pace of this research, we have created a living review with the goal of providing a nearly comprehensive list of citations for those developing and applying these approaches to experimental, phenomenological, or theoretical analyses. As a living document, it will be updated as often as possible to incorporate the latest developments. A list of proper (unchanging) reviews can be found within. Papers are grouped into a small set of topics to be as useful as possible. Suggestions and contributions are most welcome, and we provide instructions for participating.
1307.1819
Thomas A. Trainor
Thomas A. Trainor and Duncan J. Prindle
Two-component model of 2D trigger-associated hadron correlations on rapidity space $\bf y_{ta} \times y_{tt}$ derived from 1D $\bf p_t$ spectra for p-p collisions at $\bf \sqrt{s} = 200$ GeV
16 pages, 11 figures
null
10.1103/PhysRevD.88.094018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A two-component model (TCM) for single-particle $p_t$ spectra describes 200 GeV p-p data accurately. Based on that TCM a spectrum hard component was isolated that is related quantitatively to pQCD predictions for jet fragmentation down to low jet energies ($\approx 3$ GeV). We here address jet-related structure in 2D trigger-associated (TA) correlations as a more-detailed method to explore the kinematic limits of low-energy jet production and low-momentum jet fragment structure in p-p collisions. We derive a TCM for p-p TA correlations that can be used to isolate 2D jet-related structure. Inferred minimum-bias (mainly low-energy) jet-related TA correlations may challenge several major assumptions about jet production in p-p (and A-A) collisions. These results should be relevant to p-p underlying-event studies and Monte Carlo predictions of multiple parton interactions.
[ { "created": "Sat, 6 Jul 2013 22:53:40 GMT", "version": "v1" } ]
2015-06-16
[ [ "Trainor", "Thomas A.", "" ], [ "Prindle", "Duncan J.", "" ] ]
A two-component model (TCM) for single-particle $p_t$ spectra describes 200 GeV p-p data accurately. Based on that TCM a spectrum hard component was isolated that is related quantitatively to pQCD predictions for jet fragmentation down to low jet energies ($\approx 3$ GeV). We here address jet-related structure in 2D trigger-associated (TA) correlations as a more-detailed method to explore the kinematic limits of low-energy jet production and low-momentum jet fragment structure in p-p collisions. We derive a TCM for p-p TA correlations that can be used to isolate 2D jet-related structure. Inferred minimum-bias (mainly low-energy) jet-related TA correlations may challenge several major assumptions about jet production in p-p (and A-A) collisions. These results should be relevant to p-p underlying-event studies and Monte Carlo predictions of multiple parton interactions.
1511.04371
Samuel Wallon
R. Boussarie, B. Pire, L. Szymanowski and S. Wallon
On $\gamma N \to \gamma \rho N'$ at large $\gamma \rho$ invariant mass
5 pages, 3 figures; proceedings of PHOTON 2015: International Conference on the Structure and the Interactions of the Photon, Novosibirsk, Russia, 15 - 19 June, 2015
null
null
CPHT-PC053.1115, LPT-Orsay-15-84
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Photoproduction of a pair of particles with large invariant mass is a natural extension of collinear QCD factorization theorems which have been much studied for deeply virtual Compton scattering and deeply virtual meson production. We consider the case where the wide angle Compton scattering subprocess $\gamma (q\bar q) \to \gamma \rho $ factorizes from generalized parton distribution. At dominant twist, separating the transverse (respectively longitudinal) polarization of the $\rho$ meson allows one to get access to chiral-odd (respectively chiral-even) GPDs. This opens a new way to the extraction of these elusive transversity GPDs.
[ { "created": "Fri, 13 Nov 2015 17:19:55 GMT", "version": "v1" } ]
2015-11-16
[ [ "Boussarie", "R.", "" ], [ "Pire", "B.", "" ], [ "Szymanowski", "L.", "" ], [ "Wallon", "S.", "" ] ]
Photoproduction of a pair of particles with large invariant mass is a natural extension of collinear QCD factorization theorems which have been much studied for deeply virtual Compton scattering and deeply virtual meson production. We consider the case where the wide angle Compton scattering subprocess $\gamma (q\bar q) \to \gamma \rho $ factorizes from generalized parton distribution. At dominant twist, separating the transverse (respectively longitudinal) polarization of the $\rho$ meson allows one to get access to chiral-odd (respectively chiral-even) GPDs. This opens a new way to the extraction of these elusive transversity GPDs.
2306.14599
N\'estor G. Gracia
Nestor G. Gracia
Asymptoticity of QCD and massive, oriented event-shapes
307 pages, 100 figures
null
null
null
hep-ph hep-th
http://creativecommons.org/publicdomain/zero/1.0/
This is a doctoral thesis dissertation developed in the frame of theoretical QCD predictions, with focus on two main topics. On the one hand, the large-order bahavior of perturbative QCD series is discussed. By reviewing the main literature, a cohesive discussion is made that includes the topics of large-order divergencies in QCD, renormalons, summation methods for asymptotic series and non-perturbative power corrections. A formalism for perturbative QCD series in the large-$\beta_0$ is presented, which allows for (1) the computation of the series, its renormalization factor and anomalous dimension, (2) the sum of all these quantities, (3) the study of the renormalon structure of the series and (4), the ambiguity in the sum due to IR renormalons, which is associated with the size of non-power corrections. Original and published work has been made to develop this formalism for both series without and with cusp-anomalous dimension. A large number of applications of our formalism are also presented, covering the short-distance mass schemes $\bar{\rm MS}$ and MSR, the QCD-to-SCET and SCET-to-bHQET matching coeficients and the SCET and bHQET jet functions. On the other hand, original and also published work in fixed-order perturbation theory is also carried out in the field of event shapes. The event-shape distribution for $e^+e^-$ to hadrons is computed to NLO differential with respect to the angle between the initial beam and the thrust axis of the event. The relevant finding is the presence of the quark mass already at $\cal{O}(\alpha_s^0)$ for the vector current. Finally, the dissertation also contains a brief study on the FOPT-CIPT difference in the context of tau decays.
[ { "created": "Mon, 26 Jun 2023 11:22:37 GMT", "version": "v1" } ]
2023-06-27
[ [ "Gracia", "Nestor G.", "" ] ]
This is a doctoral thesis dissertation developed in the frame of theoretical QCD predictions, with focus on two main topics. On the one hand, the large-order bahavior of perturbative QCD series is discussed. By reviewing the main literature, a cohesive discussion is made that includes the topics of large-order divergencies in QCD, renormalons, summation methods for asymptotic series and non-perturbative power corrections. A formalism for perturbative QCD series in the large-$\beta_0$ is presented, which allows for (1) the computation of the series, its renormalization factor and anomalous dimension, (2) the sum of all these quantities, (3) the study of the renormalon structure of the series and (4), the ambiguity in the sum due to IR renormalons, which is associated with the size of non-power corrections. Original and published work has been made to develop this formalism for both series without and with cusp-anomalous dimension. A large number of applications of our formalism are also presented, covering the short-distance mass schemes $\bar{\rm MS}$ and MSR, the QCD-to-SCET and SCET-to-bHQET matching coeficients and the SCET and bHQET jet functions. On the other hand, original and also published work in fixed-order perturbation theory is also carried out in the field of event shapes. The event-shape distribution for $e^+e^-$ to hadrons is computed to NLO differential with respect to the angle between the initial beam and the thrust axis of the event. The relevant finding is the presence of the quark mass already at $\cal{O}(\alpha_s^0)$ for the vector current. Finally, the dissertation also contains a brief study on the FOPT-CIPT difference in the context of tau decays.
hep-ph/9311256
Pietro
Pietro Santorelli (Univ. of Napoli)
Rare $B$-Decays and Heavy to Light Semileptonic Transitions in the Isgur and Wise Limit
9 pages, 1 Figure avalaible on request from SANTORELLI@NA.INFN.IT
Z.Phys.C61:449-452,1994
10.1007/BF01413184
null
hep-ph
null
From the experimental branching ratios for $B^- --> \rho^0 l^-\bar\nu_l$ and $D^+ --> {\overl K}^{*0}({\overl K}^0) e^+ \nu_e$ one finds, in the Heavy Quark Limit of $HQET$, $ |V_{bu}|=(8.1\pm 1.7) x 10^{-3}$, larger but consistent with the actual quoted range $(2 - 7) x 10^{-3}$. In the same framework one predicts for $R(B --> K^*\gamma)=( 2 \pm 2 ) 10^{-2}$.
[ { "created": "Wed, 10 Nov 1993 10:02:44 GMT", "version": "v1" } ]
2010-11-01
[ [ "Santorelli", "Pietro", "", "Univ. of Napoli" ] ]
From the experimental branching ratios for $B^- --> \rho^0 l^-\bar\nu_l$ and $D^+ --> {\overl K}^{*0}({\overl K}^0) e^+ \nu_e$ one finds, in the Heavy Quark Limit of $HQET$, $ |V_{bu}|=(8.1\pm 1.7) x 10^{-3}$, larger but consistent with the actual quoted range $(2 - 7) x 10^{-3}$. In the same framework one predicts for $R(B --> K^*\gamma)=( 2 \pm 2 ) 10^{-2}$.
2306.17146
Wen Yin
Naoya Kitajima, Junseok Lee, Kai Murai, Fuminobu Takahashi, Wen Yin
Gravitational Waves from Domain Wall Collapse, and Application to Nanohertz Signals with QCD-coupled Axions
v2: 9 pages, 6figures, 1 table, Lattice resolution significantly improved. Conclusions unchanged
null
null
TU-1198
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study for the first time the gravitational waves generated during the collapse of domain walls, incorporating the potential bias in the lattice simulations. The final stages of domain wall collapse are crucial for the production of gravitational waves, but have remained unexplored due to computational difficulties. As a significant application of this new result, we show that the observed NANOGrav, EPTA, PPTA, and CPTA data, which indicate stochastic gravitational waves in the nanohertz regime, can be attributed to axion domain walls coupled to QCD. In our model, non-perturbative effects of QCD induce a temperature-dependent bias around the QCD crossover, inducing the rapid collapse of the domain walls. We use sophisticated lattice simulations that account for the temperature-dependent bias to measure the gravitational waves resulting from the domain wall annihilation. We also discuss the future prospects for accelerator-based searches for the axion and the potential for the formation and detection of primordial black holes.
[ { "created": "Thu, 29 Jun 2023 17:49:30 GMT", "version": "v1" }, { "created": "Wed, 4 Oct 2023 15:20:04 GMT", "version": "v2" } ]
2023-10-05
[ [ "Kitajima", "Naoya", "" ], [ "Lee", "Junseok", "" ], [ "Murai", "Kai", "" ], [ "Takahashi", "Fuminobu", "" ], [ "Yin", "Wen", "" ] ]
We study for the first time the gravitational waves generated during the collapse of domain walls, incorporating the potential bias in the lattice simulations. The final stages of domain wall collapse are crucial for the production of gravitational waves, but have remained unexplored due to computational difficulties. As a significant application of this new result, we show that the observed NANOGrav, EPTA, PPTA, and CPTA data, which indicate stochastic gravitational waves in the nanohertz regime, can be attributed to axion domain walls coupled to QCD. In our model, non-perturbative effects of QCD induce a temperature-dependent bias around the QCD crossover, inducing the rapid collapse of the domain walls. We use sophisticated lattice simulations that account for the temperature-dependent bias to measure the gravitational waves resulting from the domain wall annihilation. We also discuss the future prospects for accelerator-based searches for the axion and the potential for the formation and detection of primordial black holes.
1803.07605
Alexandre Deur
Alexandre Deur
The QCD running coupling at all scales and the connection between hadron masses and \Lambda_s
Contribution to the proceedings of the 11th International Workshop on the Physics of Excited Nucleons (NSTAR 2017) 11 pages, 2 figures
Few-Body Syst (2018) 59: 146
10.1007/s00601-018-1463-y
JLAB-PHY-18-2672. DOE/OR/23177-4401
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on recent experimental and theoretical developments in our understanding of the QCD running coupling \alpha_s in QCD's nonperturbative regime. They allow us to analytically compute the hadron mass spectrum, with \Lambda_s the only input necessary to this determination. The computed spectra agrees well with experimental data.
[ { "created": "Tue, 20 Mar 2018 18:59:53 GMT", "version": "v1" } ]
2018-11-15
[ [ "Deur", "Alexandre", "" ] ]
We report on recent experimental and theoretical developments in our understanding of the QCD running coupling \alpha_s in QCD's nonperturbative regime. They allow us to analytically compute the hadron mass spectrum, with \Lambda_s the only input necessary to this determination. The computed spectra agrees well with experimental data.
hep-ph/9807464
Silvano Simula
D. Melikhov, N. Nikitin and S. Simula
Probing right-handed currents in B -> K* l+ l- transitions
latex, 10 pp., 3 figures, submitted to Phys. Lett. B
Phys.Lett. B442 (1998) 381-389
10.1016/S0370-2693(98)01271-4
preprint INFN-RM3 98/1, July 1998
hep-ph
null
We discuss a possibility to probe right-handed weak hadronic currents in rare semileptonic b -> s transitions. It is shown that within models involving right-handed as well as left-handed quark currents (LR models) one can expect a strong enhancement of the right-handed K* production in B -> K* l+ l- decays compared with models including only left-handed quark currents (SM, MSSM). Hence an experimental study of the transverse asymmetry of the produced K* mesons provides a clear test of the presence of the right-handed quark currents and a possibiltity to discriminate between the MSSM and LR extentions of the SM. At the same time, MSSM and LR models are found to yield qualitatively the same type of deviations from the SM in the forward-backward and the longitudinal lepton polarization asymmetries.
[ { "created": "Wed, 22 Jul 1998 14:15:49 GMT", "version": "v1" } ]
2009-10-31
[ [ "Melikhov", "D.", "" ], [ "Nikitin", "N.", "" ], [ "Simula", "S.", "" ] ]
We discuss a possibility to probe right-handed weak hadronic currents in rare semileptonic b -> s transitions. It is shown that within models involving right-handed as well as left-handed quark currents (LR models) one can expect a strong enhancement of the right-handed K* production in B -> K* l+ l- decays compared with models including only left-handed quark currents (SM, MSSM). Hence an experimental study of the transverse asymmetry of the produced K* mesons provides a clear test of the presence of the right-handed quark currents and a possibiltity to discriminate between the MSSM and LR extentions of the SM. At the same time, MSSM and LR models are found to yield qualitatively the same type of deviations from the SM in the forward-backward and the longitudinal lepton polarization asymmetries.
hep-ph/0306213
Weizhen Deng
Weizhen Deng, Yanrui Liu, Xiaolin Chen, Dahai Lu, Shilin Zhu
Chiral Symmetry in an Extended Constituent Quark Potential Model
null
Phys.Lett. B575 (2003) 55-65
10.1016/j.physletb.2003.09.035
null
hep-ph
null
The chiral symmetry is applied to an extended constituent quark potential model. With random phase approximation (RPA), the model comprises sea quark excitations. To obtain the pseudoscalar $\pi$ meson as a Goldstone boson, the quark effective potentials are modified in the model to account for the dynamical breaking of chiral symmetry. Also the vector $\rho$ meson is calculated and the KSRF relation about $\pi$ and $\rho$ meson decay constants is derived in the model.
[ { "created": "Mon, 23 Jun 2003 14:02:27 GMT", "version": "v1" }, { "created": "Tue, 5 Aug 2003 03:38:54 GMT", "version": "v2" }, { "created": "Mon, 8 Sep 2003 07:29:57 GMT", "version": "v3" } ]
2015-06-25
[ [ "Deng", "Weizhen", "" ], [ "Liu", "Yanrui", "" ], [ "Chen", "Xiaolin", "" ], [ "Lu", "Dahai", "" ], [ "Zhu", "Shilin", "" ] ]
The chiral symmetry is applied to an extended constituent quark potential model. With random phase approximation (RPA), the model comprises sea quark excitations. To obtain the pseudoscalar $\pi$ meson as a Goldstone boson, the quark effective potentials are modified in the model to account for the dynamical breaking of chiral symmetry. Also the vector $\rho$ meson is calculated and the KSRF relation about $\pi$ and $\rho$ meson decay constants is derived in the model.
1405.1355
Michael Strickland
Mohammad Nopoush, Radoslaw Ryblewski, Michael Strickland
Bulk viscous evolution within anisotropic hydrodynamics
34 pages, 5 figures; v2 - PRC version
Phys. Rev. C 90, 014908 (2014)
10.1103/PhysRevC.90.014908
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive a system of moment-based dynamical equations that describe the 1+1d space-time evolution of a cylindrically symmetric massive gas undergoing boost-invariant longitudinal expansion. Extending previous work, we introduce an explicit degree of freedom associated with the bulk pressure of the system. The resulting form generalizes the ellipsoidal one-particle distribution function appropriate for massless particles to massive particles. Using this generalized form, we obtain a system of partial differential equations that can be solved numerically. In order to assess the performance of this scheme, we compare the resulting anisotropic hydrodynamics solutions with the exact solution of the 0+1d Boltzmann equation in the relaxation time approximation. We find that the inclusion of the bulk degree of freedom improves agreement between anisotropic hydrodynamics and the exact solution for a massive gas.
[ { "created": "Tue, 6 May 2014 16:37:33 GMT", "version": "v1" }, { "created": "Tue, 29 Jul 2014 19:57:28 GMT", "version": "v2" } ]
2014-07-30
[ [ "Nopoush", "Mohammad", "" ], [ "Ryblewski", "Radoslaw", "" ], [ "Strickland", "Michael", "" ] ]
We derive a system of moment-based dynamical equations that describe the 1+1d space-time evolution of a cylindrically symmetric massive gas undergoing boost-invariant longitudinal expansion. Extending previous work, we introduce an explicit degree of freedom associated with the bulk pressure of the system. The resulting form generalizes the ellipsoidal one-particle distribution function appropriate for massless particles to massive particles. Using this generalized form, we obtain a system of partial differential equations that can be solved numerically. In order to assess the performance of this scheme, we compare the resulting anisotropic hydrodynamics solutions with the exact solution of the 0+1d Boltzmann equation in the relaxation time approximation. We find that the inclusion of the bulk degree of freedom improves agreement between anisotropic hydrodynamics and the exact solution for a massive gas.
2305.03746
Ivan Esteban
Toni Bert\'olez-Mart\'inez, Carlos A. Arg\"uelles, Ivan Esteban, Jacobo Lopez-Pavon, Ivan Martinez-Soler, Jordi Salvado
IceCube and the origin of ANITA-IV events
11 pages, 7 figures + Appendices. Comments welcome! v2: Added references and expanded the discussion on particle physics models. Matches version accepted by JHEP
null
10.1007/JHEP07(2023)005
FTUV-23-0426.7835, IFIC/23-14
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, the ANITA collaboration announced the detection of new, unsettling upgoing Ultra-High-Energy (UHE) events. Understanding their origin is pressing to ensure success of the incoming UHE neutrino program. In this work, we study their internal consistency and the implications of the lack of similar events in IceCube. We introduce a generic, simple parametrization to study the compatibility between these two observatories in Standard Model-like and Beyond Standard Model scenarios: an incoming flux of particles that interact with Earth nucleons with cross section $\sigma$, producing particle showers along with long-lived particles that decay with lifetime $\tau$ and generate a shower that explains ANITA observations. We find that the ANITA angular distribution imposes significant constraints, and when including null observations from IceCube only $\tau \sim 10^{-3}$ - $10^{-2} \,\mathrm{s}$ and $\sigma \sim 10^{-33}$ - $10^{-32}\,\mathrm{cm^2}$ can explain the data. This hypothesis is testable with future IceCube data. Finally, we discuss a specific model that can realize this scenario. Our analysis highlights the importance of simultaneous observations by high-energy optical neutrino telescopes and new UHE radio detectors to uncover cosmogenic neutrinos or discover new physics.
[ { "created": "Fri, 5 May 2023 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 26 Jun 2023 14:31:38 GMT", "version": "v2" } ]
2023-08-07
[ [ "Bertólez-Martínez", "Toni", "" ], [ "Argüelles", "Carlos A.", "" ], [ "Esteban", "Ivan", "" ], [ "Lopez-Pavon", "Jacobo", "" ], [ "Martinez-Soler", "Ivan", "" ], [ "Salvado", "Jordi", "" ] ]
Recently, the ANITA collaboration announced the detection of new, unsettling upgoing Ultra-High-Energy (UHE) events. Understanding their origin is pressing to ensure success of the incoming UHE neutrino program. In this work, we study their internal consistency and the implications of the lack of similar events in IceCube. We introduce a generic, simple parametrization to study the compatibility between these two observatories in Standard Model-like and Beyond Standard Model scenarios: an incoming flux of particles that interact with Earth nucleons with cross section $\sigma$, producing particle showers along with long-lived particles that decay with lifetime $\tau$ and generate a shower that explains ANITA observations. We find that the ANITA angular distribution imposes significant constraints, and when including null observations from IceCube only $\tau \sim 10^{-3}$ - $10^{-2} \,\mathrm{s}$ and $\sigma \sim 10^{-33}$ - $10^{-32}\,\mathrm{cm^2}$ can explain the data. This hypothesis is testable with future IceCube data. Finally, we discuss a specific model that can realize this scenario. Our analysis highlights the importance of simultaneous observations by high-energy optical neutrino telescopes and new UHE radio detectors to uncover cosmogenic neutrinos or discover new physics.
hep-ph/0201174
Matthias Jamin
Matthias Jamin
Flavour-symmetry breaking of the quark condensate and chiral corrections to the Gell-Mann-Oakes-Renner relation
12 pages, discussion of Psi(0) determinations corrected, refs. added
Phys.Lett. B538 (2002) 71-76
10.1016/S0370-2693(02)01951-2
HD-THEP-0201
hep-ph hep-lat nucl-th
null
The relation between the chiral quark condensate in QCD sum rules and chiral perturbation theory is clarified with the help of a low-energy theorem for the scalar and pseudoscalar correlation functions. It is found that the quark condensate should be identified with the non-normal-ordered vacuum expectation value of quark-antiquark fields. Utilising results on flavour SU(3) breaking of the quark condensate from QCD sum rules, the unphysical low-energy constant H_2^r in the chiral Lagrangian, as well as next-to-leading order corrections to the Gell-Mann-Oakes-Renner relation are estimated.
[ { "created": "Fri, 18 Jan 2002 16:16:55 GMT", "version": "v1" }, { "created": "Fri, 8 Feb 2002 17:12:43 GMT", "version": "v2" } ]
2015-06-25
[ [ "Jamin", "Matthias", "" ] ]
The relation between the chiral quark condensate in QCD sum rules and chiral perturbation theory is clarified with the help of a low-energy theorem for the scalar and pseudoscalar correlation functions. It is found that the quark condensate should be identified with the non-normal-ordered vacuum expectation value of quark-antiquark fields. Utilising results on flavour SU(3) breaking of the quark condensate from QCD sum rules, the unphysical low-energy constant H_2^r in the chiral Lagrangian, as well as next-to-leading order corrections to the Gell-Mann-Oakes-Renner relation are estimated.
2008.01736
Lorenzo Zoppi
E. Laenen, J. Sinninghe Damst\'e, L. Vernazza, W. Waalewijn, L. Zoppi
Towards all-order factorization of QED amplitudes at next-to-leading power
31 pages, 18 figures. v2: as in journal version
Phys. Rev. D 103, 034022 (2021)
10.1103/PhysRevD.103.034022
NIKHEF 2020-019
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We generalise the factorization of abelian gauge theory amplitudes to next-to-leading power (NLP) in a soft scale expansion, following a recent generalisation for Yukawa theory. From an all-order power counting analysis of leading and next-to-leading regions, we infer the factorized structure for both a parametrically small and zero fermion mass. This requires the introduction of new universal jet functions, for non-radiative and single-radiative QED amplitudes, which we compute at one-loop order. We show that our factorization formula reproduces the relevant regions in one- and two-loop scattering amplitudes, appropriately addressing endpoint divergences. It provides a description of virtual collinear modes and accounts for non-trivial hard-collinear interplay present beyond the one-loop level, making this a first step towards a complete all-order factorization framework for gauge-theory amplitudes at NLP.
[ { "created": "Tue, 4 Aug 2020 18:00:02 GMT", "version": "v1" }, { "created": "Mon, 15 Feb 2021 13:17:30 GMT", "version": "v2" } ]
2021-03-01
[ [ "Laenen", "E.", "" ], [ "Damsté", "J. Sinninghe", "" ], [ "Vernazza", "L.", "" ], [ "Waalewijn", "W.", "" ], [ "Zoppi", "L.", "" ] ]
We generalise the factorization of abelian gauge theory amplitudes to next-to-leading power (NLP) in a soft scale expansion, following a recent generalisation for Yukawa theory. From an all-order power counting analysis of leading and next-to-leading regions, we infer the factorized structure for both a parametrically small and zero fermion mass. This requires the introduction of new universal jet functions, for non-radiative and single-radiative QED amplitudes, which we compute at one-loop order. We show that our factorization formula reproduces the relevant regions in one- and two-loop scattering amplitudes, appropriately addressing endpoint divergences. It provides a description of virtual collinear modes and accounts for non-trivial hard-collinear interplay present beyond the one-loop level, making this a first step towards a complete all-order factorization framework for gauge-theory amplitudes at NLP.
hep-ph/0105087
Osamu Yasuda
John Pinney and Osamu Yasuda
Correlations of errors in measurements of CP violation at neutrino factories
35 pages, 12 sets of figures, uses epsfig
Phys.Rev.D64:093008,2001
10.1103/PhysRevD.64.093008
null
hep-ph
null
Using $\Delta\chi^2$ which is defined by the difference of the number of events with the CP phase $\delta$ and the hypothetical one with $\delta=0$, we discuss correlations of errors of the CP phase and other oscillation parameters as well as the matter effect in measurements at neutrino factories. By varying the oscillation parameters and the normalization of the matter effect, we evaluated the data size required to reject a hypothesis with $\delta=0$ at 3$\sigma$CL. The optimum muon energy and the baseline depends on the magnitude of $\theta_{13}$, the background fraction, the uncertainty of the normalization of the matter effect, but in general lie in the ranges 20GeV $\lesssim E_\mu\lesssim$ 50GeV, 1000km$\lesssim L\lesssim$3000km. If we assume that the uncertainty of the matter effect is as large as 20% then the optimum values may be modified to $E_\mu\lesssim$ 10GeV, $L\lesssim$1000km due to the strong correlation of $\delta$ and the matter effect. We show analytically that sensitivity to CP violation is lost for $E_\mu\ll$ 10GeV or for $E_\mu\gg$ 50GeV. We also discuss the possibility of measuring CP violation at the upgraded JHF experiment by taking all the error correlations into account, and show that it is possible to demonstrate $\delta\ne0$ at 3$\sigma$CL for $\theta_{13}\gtrsim 3^\circ$.
[ { "created": "Thu, 10 May 2001 07:47:25 GMT", "version": "v1" } ]
2014-11-17
[ [ "Pinney", "John", "" ], [ "Yasuda", "Osamu", "" ] ]
Using $\Delta\chi^2$ which is defined by the difference of the number of events with the CP phase $\delta$ and the hypothetical one with $\delta=0$, we discuss correlations of errors of the CP phase and other oscillation parameters as well as the matter effect in measurements at neutrino factories. By varying the oscillation parameters and the normalization of the matter effect, we evaluated the data size required to reject a hypothesis with $\delta=0$ at 3$\sigma$CL. The optimum muon energy and the baseline depends on the magnitude of $\theta_{13}$, the background fraction, the uncertainty of the normalization of the matter effect, but in general lie in the ranges 20GeV $\lesssim E_\mu\lesssim$ 50GeV, 1000km$\lesssim L\lesssim$3000km. If we assume that the uncertainty of the matter effect is as large as 20% then the optimum values may be modified to $E_\mu\lesssim$ 10GeV, $L\lesssim$1000km due to the strong correlation of $\delta$ and the matter effect. We show analytically that sensitivity to CP violation is lost for $E_\mu\ll$ 10GeV or for $E_\mu\gg$ 50GeV. We also discuss the possibility of measuring CP violation at the upgraded JHF experiment by taking all the error correlations into account, and show that it is possible to demonstrate $\delta\ne0$ at 3$\sigma$CL for $\theta_{13}\gtrsim 3^\circ$.
hep-ph/9405354
Park Gye Tai
Gye T. Park and T. K. Kuo
Inclusion of Z->b b-bar vertex corrections in Precision Electroweak Tests on the Sp(6)_L X U(1)_Y Model
Latex, 16 pages+4 figures(not included but available as uuencoded or PS files from gtpark@phya.snu.ac.kr), PURD-TH-94-08, SNUTP-94-46
Int.J.Mod.Phys. A10 (1995) 4387-4398
10.1142/S0217751X95002035
null
hep-ph
null
We extend our previous work on the precision electroweak tests in the Sp(6)_L X U(1)_Y family model to include for the first time the important Z->b b-bar vertex corrections encoded in a new variable epsilon_b, utilizing all the latest LEP data. We include in our analysis the one loop EW radiative corrections due to the new bosons in terms of epsilon_1, epsilon_b and $\Delta\Gamma_Z$. We find that the correlation between epsilon_1 and epsilon_b makes the combined constraint much stronger than the individual ones. The model is consistent with the recent CDF result of $m_t=174\pm 10^{+13}_{-12}\GeV$, but it can not accomodate $m_t\gsim 195\GeV$.
[ { "created": "Mon, 23 May 1994 10:59:46 GMT", "version": "v1" } ]
2015-06-25
[ [ "Park", "Gye T.", "" ], [ "Kuo", "T. K.", "" ] ]
We extend our previous work on the precision electroweak tests in the Sp(6)_L X U(1)_Y family model to include for the first time the important Z->b b-bar vertex corrections encoded in a new variable epsilon_b, utilizing all the latest LEP data. We include in our analysis the one loop EW radiative corrections due to the new bosons in terms of epsilon_1, epsilon_b and $\Delta\Gamma_Z$. We find that the correlation between epsilon_1 and epsilon_b makes the combined constraint much stronger than the individual ones. The model is consistent with the recent CDF result of $m_t=174\pm 10^{+13}_{-12}\GeV$, but it can not accomodate $m_t\gsim 195\GeV$.
1704.08377
Edward K. G. Sarkisyan
Ranjit K. Nayak, Sadhana Dash (Indian Inst. Tech., Mumbai), Edward K. Sarkisyan-Grinbaum (CERN & Texas U., Arlington), Marek Tasevsky (Prague, Inst. Phys.)
Describing dynamical fluctuations and genuine correlations by Weibull regularity
10 pages, 2 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Weibull parametrization of the multiplicity distribution is used to describe the multidimensional local fluctuations and genuine multiparticle correlations measured by OPAL in the large statistics $e^{+}e^{-} \to Z^{0} \to hadrons$ sample. The data are found to be well reproduced by the Weibull model up to higher orders. The Weibull predictions are compared to the predictions by the two other models, namely by the negative binomial and modified negative binomial distributions which mostly failed to fit the data. The Weibull regularity, which is found to reproduce the multiplicity distributions along with the genuine correlations, looks to be the optimal model to describe the multiparticle production process.
[ { "created": "Wed, 26 Apr 2017 23:10:29 GMT", "version": "v1" }, { "created": "Sun, 30 Apr 2017 06:29:40 GMT", "version": "v2" } ]
2018-03-08
[ [ "Nayak", "Ranjit K.", "", "Indian Inst. Tech., Mumbai" ], [ "Dash", "Sadhana", "", "Indian Inst. Tech., Mumbai" ], [ "Sarkisyan-Grinbaum", "Edward K.", "", "CERN & Texas U., Arlington" ], [ "Tasevsky", "Marek", "", "Prague,\n Inst. Phys." ] ]
The Weibull parametrization of the multiplicity distribution is used to describe the multidimensional local fluctuations and genuine multiparticle correlations measured by OPAL in the large statistics $e^{+}e^{-} \to Z^{0} \to hadrons$ sample. The data are found to be well reproduced by the Weibull model up to higher orders. The Weibull predictions are compared to the predictions by the two other models, namely by the negative binomial and modified negative binomial distributions which mostly failed to fit the data. The Weibull regularity, which is found to reproduce the multiplicity distributions along with the genuine correlations, looks to be the optimal model to describe the multiparticle production process.