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1506.04285
Alexander Bylinkin
A. A. Bylinkin, N. S. Chernyavskaya, A. A. Rostovtsev
Two components in charged particle production in heavy-ion collisions
a version as to appear in NPB after editorial comments
null
10.1016/j.nuclphysb.2015.12.009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transverse momentum spectra of charged particle production in heavy-ion collisions are considered in terms of a recently introduced Two Component parameterization combining exponential ("soft") and power-law ("hard") functional forms. The charged hadron densities calculated separately for them are plotted versus number of participating nucleons, $N_{part}$. The obtained dependences are discussed and the possible link between the two component parameterization introduced by the authors and the two component model historically used for the case of heavy-ion collisions is established. Next, the variations of the parameters of the introduced approach with the center of mass energy and centrality are studied using the available data from RHIC and LHC experiments. The spectra shapes are found to show universal dependences on $N_{part}$ for all investigated collision energies.
[ { "created": "Sat, 13 Jun 2015 16:10:12 GMT", "version": "v1" }, { "created": "Mon, 23 Nov 2015 20:56:14 GMT", "version": "v2" } ]
2016-02-17
[ [ "Bylinkin", "A. A.", "" ], [ "Chernyavskaya", "N. S.", "" ], [ "Rostovtsev", "A. A.", "" ] ]
Transverse momentum spectra of charged particle production in heavy-ion collisions are considered in terms of a recently introduced Two Component parameterization combining exponential ("soft") and power-law ("hard") functional forms. The charged hadron densities calculated separately for them are plotted versus number of participating nucleons, $N_{part}$. The obtained dependences are discussed and the possible link between the two component parameterization introduced by the authors and the two component model historically used for the case of heavy-ion collisions is established. Next, the variations of the parameters of the introduced approach with the center of mass energy and centrality are studied using the available data from RHIC and LHC experiments. The spectra shapes are found to show universal dependences on $N_{part}$ for all investigated collision energies.
hep-ph/9903536
Larry McLerran
Larry McLerran
Three Lectures on the Physics of Small x and High Gluon Density
23 figures, Lectures presented at the VIII'th Mexican School of Particles and Fields
AIP Conf.Proc.490:42-79,1999
10.1063/1.1301382
null
hep-ph
null
In these lectures, I shall discuss small x physics and the consequences of high gluon density which arises as x decreases. I argue that an understanding of this problem would lead to knowledge of the high energy asymptotics of hadronic processes. The high gluon density should allow a first principles computation of these asymptotics from QCD.
[ { "created": "Tue, 30 Mar 1999 21:45:29 GMT", "version": "v1" } ]
2010-12-13
[ [ "McLerran", "Larry", "" ] ]
In these lectures, I shall discuss small x physics and the consequences of high gluon density which arises as x decreases. I argue that an understanding of this problem would lead to knowledge of the high energy asymptotics of hadronic processes. The high gluon density should allow a first principles computation of these asymptotics from QCD.
1409.8620
Eduardo Rojas
E. Rojas, B. El-Bennich, J.P.B.C. De Melo, M.Ali Paracha
Insights into the quark-gluon vertex from lattice QCD and meson spectroscopy
null
null
10.1007/s00601-015-1020-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By comparing successful quark-gluon vertex interaction models with the corresponding interaction extracted from lattice-QCD data on the quark's propagator, we identify common qualitative features which could be important to tune future interaction models beyond the rainbow ladder approximation. Clearly, a quantitative comparison is conceptually not simple, but qualitatively the results suggest that a realistic interaction should be relatively broad with a strong support at about $0.4-0.6$~GeV and infrared-finite.
[ { "created": "Tue, 30 Sep 2014 16:31:05 GMT", "version": "v1" }, { "created": "Tue, 7 Oct 2014 17:35:33 GMT", "version": "v2" }, { "created": "Tue, 8 Sep 2015 16:30:51 GMT", "version": "v3" } ]
2015-09-30
[ [ "Rojas", "E.", "" ], [ "El-Bennich", "B.", "" ], [ "De Melo", "J. P. B. C.", "" ], [ "Paracha", "M. Ali", "" ] ]
By comparing successful quark-gluon vertex interaction models with the corresponding interaction extracted from lattice-QCD data on the quark's propagator, we identify common qualitative features which could be important to tune future interaction models beyond the rainbow ladder approximation. Clearly, a quantitative comparison is conceptually not simple, but qualitatively the results suggest that a realistic interaction should be relatively broad with a strong support at about $0.4-0.6$~GeV and infrared-finite.
2203.01708
Nicolo de Groot
Nicolo de Groot
Plutonium-241 as a possible isotope for neutrino mass measurement and capture
6 pages, 1 figure
null
10.1088/1361-6471/acc5fc
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Tritium has been the isotope of choice for measurements of the neutrino mass and planned detection of the relic neutrino background. The low mass of $^{3}$H leads to large recoil energy of the nucleus. This has emerged as a limiting factor for both measurements. We investigate $^{241}$Pu as an alternative. The recoil is 80x smaller and it has similar decay energy and lifetime as $^{3}$H. We evaluate for the first time its soft-neutrino capture cross-section and find $(\sigma v)_{\nu} = 1.52 \times 10^{-45}$. This is 40% of the capture cross-section for tritium and makes $^{241}$Pu an interesting alternative for $^{3}$H.
[ { "created": "Thu, 3 Mar 2022 13:31:20 GMT", "version": "v1" }, { "created": "Fri, 4 Mar 2022 08:50:15 GMT", "version": "v2" }, { "created": "Tue, 11 Oct 2022 12:42:27 GMT", "version": "v3" } ]
2023-04-26
[ [ "de Groot", "Nicolo", "" ] ]
Tritium has been the isotope of choice for measurements of the neutrino mass and planned detection of the relic neutrino background. The low mass of $^{3}$H leads to large recoil energy of the nucleus. This has emerged as a limiting factor for both measurements. We investigate $^{241}$Pu as an alternative. The recoil is 80x smaller and it has similar decay energy and lifetime as $^{3}$H. We evaluate for the first time its soft-neutrino capture cross-section and find $(\sigma v)_{\nu} = 1.52 \times 10^{-45}$. This is 40% of the capture cross-section for tritium and makes $^{241}$Pu an interesting alternative for $^{3}$H.
1606.06238
Pasquale Di Bari
Pasquale Di Bari, Patrick Otto Ludl and Sergio Palomares-Ruiz
Unifying leptogenesis, dark matter and high-energy neutrinos with right-handed neutrino mixing via Higgs portal
48 pages, 10 figures, version for publication in JCAP: v3: corrected calculation of the abundance of the source right-handed neutrino for initial vanishing abundance (Eq. (75)): the upper bound on the DM mass gets more stringent but conclusion almost unchanged; see footnote on the cover page for more details
null
10.1088/1475-7516/2016/11/044
IFIC/16-42
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit a model in which neutrino masses and mixing are described by a two right-handed (RH) neutrino seesaw scenario, implying a strictly hierarchical light neutrino spectrum. A third decoupled RH neutrino, $N_{\rm DM}$ with mass $M_{\rm DM}$, plays the role of cold dark matter (DM) and is produced by the mixing with a source RH neutrino, $N_{\rm S}$ with mass $M_{\rm S}$, induced by Higgs portal interactions. The same interactions are also responsible for $N_{\rm DM}$ decays. We discuss in detail the constraints coming from DM abundance and stability conditions, showing that in the hierarchical case ($M_{\rm DM} \gg M_{\rm S}$) there is an allowed window on $M_{\rm DM}$, which necessarily implies a contribution from DM decays to the high-energy neutrino flux recently detected by IceCube. We also show how the model can explain the matter-antimatter asymmetry of the Universe via leptogenesis in the quasi-degenerate limit. In this case, the DM mass should be within the range 300 GeV $\lesssim M_{\rm S} < M_{\rm DM} \lesssim$ 10 PeV. We discuss the specific properties of this high-energy neutrino flux and show the predicted event spectrum for two exemplary cases. Although DM decays, with a relatively hard spectrum, cannot account for all the IceCube high-energy data, we illustrate how this extra source of high-energy neutrinos could reasonably explain some potential features in the observed spectrum. In this way, this represents a unified scenario for leptogenesis and DM that could be tested during the next years with more high-energy neutrino events.
[ { "created": "Mon, 20 Jun 2016 18:34:25 GMT", "version": "v1" }, { "created": "Thu, 10 Nov 2016 15:47:14 GMT", "version": "v2" }, { "created": "Mon, 19 Nov 2018 16:18:05 GMT", "version": "v3" } ]
2018-11-20
[ [ "Di Bari", "Pasquale", "" ], [ "Ludl", "Patrick Otto", "" ], [ "Palomares-Ruiz", "Sergio", "" ] ]
We revisit a model in which neutrino masses and mixing are described by a two right-handed (RH) neutrino seesaw scenario, implying a strictly hierarchical light neutrino spectrum. A third decoupled RH neutrino, $N_{\rm DM}$ with mass $M_{\rm DM}$, plays the role of cold dark matter (DM) and is produced by the mixing with a source RH neutrino, $N_{\rm S}$ with mass $M_{\rm S}$, induced by Higgs portal interactions. The same interactions are also responsible for $N_{\rm DM}$ decays. We discuss in detail the constraints coming from DM abundance and stability conditions, showing that in the hierarchical case ($M_{\rm DM} \gg M_{\rm S}$) there is an allowed window on $M_{\rm DM}$, which necessarily implies a contribution from DM decays to the high-energy neutrino flux recently detected by IceCube. We also show how the model can explain the matter-antimatter asymmetry of the Universe via leptogenesis in the quasi-degenerate limit. In this case, the DM mass should be within the range 300 GeV $\lesssim M_{\rm S} < M_{\rm DM} \lesssim$ 10 PeV. We discuss the specific properties of this high-energy neutrino flux and show the predicted event spectrum for two exemplary cases. Although DM decays, with a relatively hard spectrum, cannot account for all the IceCube high-energy data, we illustrate how this extra source of high-energy neutrinos could reasonably explain some potential features in the observed spectrum. In this way, this represents a unified scenario for leptogenesis and DM that could be tested during the next years with more high-energy neutrino events.
1808.10518
A. B. Balantekin
A. Baha Balantekin, Andr\'e de Gouv\^ea, and Boris Kayser
Addressing the Majorana vs. Dirac Question with Neutrino Decays
11 pages, 3 figures
null
10.1016/j.physletb.2018.11.068
FERMILAB-PUB-18-418-T, NUHEP-TH/18-09
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Majorana versus Dirac nature of neutrinos remains an open question. This is due, in part, to the fact that virtually all the experimentally accessible neutrinos are ultra-relativistic. Noting that Majorana neutrinos can behave quite differently from Dirac ones when they are non-relativistic, we show that, at leading order, the angular distribution of the daughters in the decay of a heavy neutrino into a lighter one and a self-conjugate boson is isotropic in the parent's rest frame if the neutrinos are Majorana, independent of the parent's polarization. If the neutrinos are Dirac fermions, this is, in general, not the case. This result follows from CPT invariance and is independent of the details of the physics responsible for the decay. We explore the feasibility of using these angular distributions -- or, equivalently, the energy distributions of the daughters in the laboratory frame -- in order to address the Majorana versus Dirac nature of neutrinos if a fourth, heavier neutrino mass eigenstate reveals itself in the current or next-generation of high-energy colliders, intense meson facilities, or neutrino beam experiments.
[ { "created": "Thu, 30 Aug 2018 21:01:43 GMT", "version": "v1" }, { "created": "Fri, 30 Nov 2018 20:32:44 GMT", "version": "v2" } ]
2019-01-09
[ [ "Balantekin", "A. Baha", "" ], [ "de Gouvêa", "André", "" ], [ "Kayser", "Boris", "" ] ]
The Majorana versus Dirac nature of neutrinos remains an open question. This is due, in part, to the fact that virtually all the experimentally accessible neutrinos are ultra-relativistic. Noting that Majorana neutrinos can behave quite differently from Dirac ones when they are non-relativistic, we show that, at leading order, the angular distribution of the daughters in the decay of a heavy neutrino into a lighter one and a self-conjugate boson is isotropic in the parent's rest frame if the neutrinos are Majorana, independent of the parent's polarization. If the neutrinos are Dirac fermions, this is, in general, not the case. This result follows from CPT invariance and is independent of the details of the physics responsible for the decay. We explore the feasibility of using these angular distributions -- or, equivalently, the energy distributions of the daughters in the laboratory frame -- in order to address the Majorana versus Dirac nature of neutrinos if a fourth, heavier neutrino mass eigenstate reveals itself in the current or next-generation of high-energy colliders, intense meson facilities, or neutrino beam experiments.
1911.01675
Abdel Nasser Tawfik
Abdel Nasser Tawfik (Nile U., ECTP), Mahmoud Hanafy (Benha U. and WLCAPP, Cairo), Werner Scheinast (LHEP JINR, Dubna)
Multiplicity per rapidity in Carruthers and hadron resonance gas approaches
16 pages, 2 figures, 2 tables submitted to UJP
null
10.1007/s12648-021-02228-5
ECTP-2019-15, WLCAPP-2019-15
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The multiplicity per rapidity of the well-identified particles $\pi^{-}$, $\pi^{+}$, $k^{-}$, $k^{+}$, $\bar{p}$, $p$, and $p-\bar{p}$ measured in different high-energy experiments, at energies ranging from $6.3$ to $5500~$GeV, are successfully compared with the Cosmic Ray Monte Carlo (CRMC) event generator. For these rapidity distributions, we introduce a theoretical approach based on fluctuations and correlations (Carruthers) and another one based on statistical thermal assumptions (hadron resonance gas model). Both approaches are fitted to the two sets of results deduced from experiments and simulations. We found that the Carruthers approach reproduces well the full range of multiplicity per rapidity for all produced particles, at the various energies, while the HRG approach fairly describes the results within a narrower rapidity-range. While the Carruthers approach seems to match well with the Gaussian normal distribution, ingredients such as flow and interactions should be first incorporated in the HRG approach.
[ { "created": "Tue, 5 Nov 2019 09:11:18 GMT", "version": "v1" } ]
2022-03-08
[ [ "Tawfik", "Abdel Nasser", "", "Nile U., ECTP" ], [ "Hanafy", "Mahmoud", "", "Benha U. and\n WLCAPP, Cairo" ], [ "Scheinast", "Werner", "", "LHEP JINR, Dubna" ] ]
The multiplicity per rapidity of the well-identified particles $\pi^{-}$, $\pi^{+}$, $k^{-}$, $k^{+}$, $\bar{p}$, $p$, and $p-\bar{p}$ measured in different high-energy experiments, at energies ranging from $6.3$ to $5500~$GeV, are successfully compared with the Cosmic Ray Monte Carlo (CRMC) event generator. For these rapidity distributions, we introduce a theoretical approach based on fluctuations and correlations (Carruthers) and another one based on statistical thermal assumptions (hadron resonance gas model). Both approaches are fitted to the two sets of results deduced from experiments and simulations. We found that the Carruthers approach reproduces well the full range of multiplicity per rapidity for all produced particles, at the various energies, while the HRG approach fairly describes the results within a narrower rapidity-range. While the Carruthers approach seems to match well with the Gaussian normal distribution, ingredients such as flow and interactions should be first incorporated in the HRG approach.
2304.03305
Oscar J. P. \'Eboli
Tyler Corbett, Jay Desai, O. J. P. Eboli, M. C. Gonzalez-Garcia, Matheus Martines, and Peter Reimitz
Impact of dimension-eight SMEFT operators in the EWPO and Triple Gauge Couplings analysis in Universal SMEFT
17 pages and 3 figures
null
10.1103/PhysRevD.107.115013
YITP-SB-2023-04, FERMILAB-PUB-23-134-V, UWThPh 2023-13
hep-ph
http://creativecommons.org/licenses/by/4.0/
We perform a complete study of the electroweak precision observables and electroweak gauge boson pair production in terms of the SMEFT up to ${\cal O}(1/\Lambda^4)$ under the assumption of universal, C and P conserving new physics. We show that the analysis of data from those two sectors allows us to obtain closed constraints in the relevant parameter space in this scenario. In particular we find that the Large Hadron Collider data can independently constrain the Wilson coefficients of the dimension-six and -eight operators directly contributing to the triple gauge boson vertices. Our results show that the impact of dimension-eight operators in the study of triple gauge couplings is small.
[ { "created": "Thu, 6 Apr 2023 18:00:02 GMT", "version": "v1" } ]
2023-06-21
[ [ "Corbett", "Tyler", "" ], [ "Desai", "Jay", "" ], [ "Eboli", "O. J. P.", "" ], [ "Gonzalez-Garcia", "M. C.", "" ], [ "Martines", "Matheus", "" ], [ "Reimitz", "Peter", "" ] ]
We perform a complete study of the electroweak precision observables and electroweak gauge boson pair production in terms of the SMEFT up to ${\cal O}(1/\Lambda^4)$ under the assumption of universal, C and P conserving new physics. We show that the analysis of data from those two sectors allows us to obtain closed constraints in the relevant parameter space in this scenario. In particular we find that the Large Hadron Collider data can independently constrain the Wilson coefficients of the dimension-six and -eight operators directly contributing to the triple gauge boson vertices. Our results show that the impact of dimension-eight operators in the study of triple gauge couplings is small.
hep-ph/0507141
Miroslav Pardy
Miroslav Pardy
Volkov solution for two laser beams and ITER
13 pages
Int.J.Theor.Phys. 45 (2006) 647-659
10.1007/s10773-006-9056-9
MUNI-2005-27
hep-ph
null
We find the solution of the Dirac equation for two plane waves (laser beams) and we determine the modified Compton formula for the scattering of two photons on an alectron. The practical meaning of the two laser beams is, that two laser beams impinging on a targed which is constituted from material in the form of a foam, can replace 100-200 laser beams impinging on a normal targed. It means that the nuclear fusion with two laser beams is realistic in combination with the nuclear reactor such as ITER.
[ { "created": "Tue, 12 Jul 2005 08:32:49 GMT", "version": "v1" } ]
2009-11-11
[ [ "Pardy", "Miroslav", "" ] ]
We find the solution of the Dirac equation for two plane waves (laser beams) and we determine the modified Compton formula for the scattering of two photons on an alectron. The practical meaning of the two laser beams is, that two laser beams impinging on a targed which is constituted from material in the form of a foam, can replace 100-200 laser beams impinging on a normal targed. It means that the nuclear fusion with two laser beams is realistic in combination with the nuclear reactor such as ITER.
1801.08037
Daniel Dercks
Daniel Dercks and Gudrid Moortgat-Pick
Automatised ILC-Bounds on Dark Matter Models with CheckMATE
10 pages, 7 figures; Talk presented at the International Workshop on Future Linear Colliders (LCWS2017), Strasbourg, France, 23-27 October 2017. C17-10-23.2
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The public collider phenomenology computing tool CheckMATE (Check Models at Terascale Energies) was originally designed to allow theorists to quickly test their favourite BSM models against various existing LHC analyses performed by ATLAS and CMS. It offers an automatised chain of Monte Carlo event generation, detector simulation, event analysis and statistical evaluation so that it can automatically determine whether a given parameter point of a BSM model is excluded or not. Currently, it contains more than 50 individual ATLAS or CMS analyses whose several hundred signal regions target various final states as they typically appear in theories beyond the Standard Model. In this study, we extend this functionality to allow sensitivity studies for the International Linear Collider. As an example, we implemente a dark matter monophoton search and use it to analyse three benchmark scenarios with different assumptions about the interaction between dark matter and Standard Model particles. We determine the ILC sensitivity expected for a $\sqrt{s} =$ 500 GeV, $L = 500$ fb$^{-1}$and compare the results for the cases of completely unpolarised beams and for individual lepton polarisation settings.
[ { "created": "Wed, 24 Jan 2018 15:47:20 GMT", "version": "v1" } ]
2018-01-25
[ [ "Dercks", "Daniel", "" ], [ "Moortgat-Pick", "Gudrid", "" ] ]
The public collider phenomenology computing tool CheckMATE (Check Models at Terascale Energies) was originally designed to allow theorists to quickly test their favourite BSM models against various existing LHC analyses performed by ATLAS and CMS. It offers an automatised chain of Monte Carlo event generation, detector simulation, event analysis and statistical evaluation so that it can automatically determine whether a given parameter point of a BSM model is excluded or not. Currently, it contains more than 50 individual ATLAS or CMS analyses whose several hundred signal regions target various final states as they typically appear in theories beyond the Standard Model. In this study, we extend this functionality to allow sensitivity studies for the International Linear Collider. As an example, we implemente a dark matter monophoton search and use it to analyse three benchmark scenarios with different assumptions about the interaction between dark matter and Standard Model particles. We determine the ILC sensitivity expected for a $\sqrt{s} =$ 500 GeV, $L = 500$ fb$^{-1}$and compare the results for the cases of completely unpolarised beams and for individual lepton polarisation settings.
hep-ph/0011115
Sang Pyo Kim
Sang Pyo Kim (Univ. of Alberta, Kunsan Nat'l Univ.) and F. C. Khanna (Univ. of Alberta)
Non-Gaussian Effects on Domain Growth
RevTex 9 pages, no figure; main part is rewritten to control the global behavior of perturbation; format changed
null
null
null
hep-ph cond-mat.stat-mech hep-th nucl-th
null
The vacuum two-point function is calculated beyond the Gaussian approximation during the second order phase transition. It is found that the correlation function is dominated by the Gaussian term immediately after the phase transition but later is taken over by non-Gaussian terms as the spinodal instability continues. The non-Gaussian effects lead to larger size of domains and may imply a smaller density of topological defects than that predicted by the Hartree-Fock approximation.
[ { "created": "Wed, 8 Nov 2000 23:22:38 GMT", "version": "v1" }, { "created": "Thu, 12 Jul 2001 21:06:39 GMT", "version": "v2" }, { "created": "Fri, 11 Jan 2002 18:31:52 GMT", "version": "v3" } ]
2007-05-23
[ [ "Kim", "Sang Pyo", "", "Univ. of Alberta, Kunsan Nat'l Univ." ], [ "Khanna", "F. C.", "", "Univ. of Alberta" ] ]
The vacuum two-point function is calculated beyond the Gaussian approximation during the second order phase transition. It is found that the correlation function is dominated by the Gaussian term immediately after the phase transition but later is taken over by non-Gaussian terms as the spinodal instability continues. The non-Gaussian effects lead to larger size of domains and may imply a smaller density of topological defects than that predicted by the Hartree-Fock approximation.
hep-ph/9504343
null
David Saltzberg (CERN-PPE Division)
COMMENT ON THE KAMIOKANDE ATMOSPHERIC NEUTRINO DEFICIT
2pp. LATEX format. No figures. Postscript available at ftp://fnald.fnal.gov/usr$root39/saltzberg/nu.ps
Phys.Lett.B355:499-500,1995
10.1016/0370-2693(95)00766-E
null
hep-ph
null
I describe an attempt to understand the significance of the atmospheric neutrino deficit observed by the Kamiokande neutrino detector. In particular, I am concerned with the statistical significance quoted for the zenith-angle dependence of the deficit, which has been cited as evidence for neutrino flavor oscillations free of systematic uncertainties.
[ { "created": "Wed, 19 Apr 1995 16:34:36 GMT", "version": "v1" } ]
2010-11-01
[ [ "Saltzberg", "David", "", "CERN-PPE Division" ] ]
I describe an attempt to understand the significance of the atmospheric neutrino deficit observed by the Kamiokande neutrino detector. In particular, I am concerned with the statistical significance quoted for the zenith-angle dependence of the deficit, which has been cited as evidence for neutrino flavor oscillations free of systematic uncertainties.
1505.02763
A. F. W. van Hameren
A. van Hameren, P. Kotko, K. Kutak
Resummation effects in forward production of Z0+jet at LHC
16 pages
Phys. Rev. D 92, 054007 (2015)
10.1103/PhysRevD.92.054007
IFJPAN-IV-2015-8
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate several differential cross sections for Z0 and high-pT jet production in the forward rapidity region at the LHC using the hybrid High Energy Factorization. We test various unintegrated gluon distributions involving subleading BFKL effects (such as kinematic constraint, running strong coupling and DGLAP correction) and compare the results with experimental data obtained by the LHCb experiment. We find that the hard scale dependence of unintegrated gluon distributions, which effectively resums the Sudakov-type logarithms on the top of the resummation of the small x logarithms, is essential to describe the normalized azimuthal decorrelations between the Z0-boson and the jet.
[ { "created": "Mon, 11 May 2015 19:56:22 GMT", "version": "v1" }, { "created": "Wed, 20 May 2015 19:22:10 GMT", "version": "v2" } ]
2015-09-16
[ [ "van Hameren", "A.", "" ], [ "Kotko", "P.", "" ], [ "Kutak", "K.", "" ] ]
We calculate several differential cross sections for Z0 and high-pT jet production in the forward rapidity region at the LHC using the hybrid High Energy Factorization. We test various unintegrated gluon distributions involving subleading BFKL effects (such as kinematic constraint, running strong coupling and DGLAP correction) and compare the results with experimental data obtained by the LHCb experiment. We find that the hard scale dependence of unintegrated gluon distributions, which effectively resums the Sudakov-type logarithms on the top of the resummation of the small x logarithms, is essential to describe the normalized azimuthal decorrelations between the Z0-boson and the jet.
2208.02276
Francesco Hautmann
A. Bermudez Martinez, F. Hautmann and M.L. Mangano
Multi-jet Merging with TMD Parton Branching
Latex, 43 pages; version v2: typos corrected, additional comments and references inserted
null
10.1007/JHEP09(2022)060
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the main theoretical systematics in studies of final states with large jet multiplicities at high-energy hadron colliders is associated with the merging of QCD parton showers and hard-scattering matrix elements. We present a method to incorporate the physics of transverse momentum recoils due to initial-state shower evolution into multi-jet merging algorithms by using the concept of transverse momentum dependent (TMD) distributions and the associated parton branching. We investigate the dependence on the merging scale and illustrate the impact of the new method at the level of both exclusive and inclusive final-state observables by studying differential jet rates, transverse momentum spectra and multiplicity distributions, using vector boson + jets events at the LHC as a case study.
[ { "created": "Wed, 3 Aug 2022 18:01:02 GMT", "version": "v1" }, { "created": "Wed, 14 Sep 2022 17:48:30 GMT", "version": "v2" } ]
2022-09-28
[ [ "Martinez", "A. Bermudez", "" ], [ "Hautmann", "F.", "" ], [ "Mangano", "M. L.", "" ] ]
One of the main theoretical systematics in studies of final states with large jet multiplicities at high-energy hadron colliders is associated with the merging of QCD parton showers and hard-scattering matrix elements. We present a method to incorporate the physics of transverse momentum recoils due to initial-state shower evolution into multi-jet merging algorithms by using the concept of transverse momentum dependent (TMD) distributions and the associated parton branching. We investigate the dependence on the merging scale and illustrate the impact of the new method at the level of both exclusive and inclusive final-state observables by studying differential jet rates, transverse momentum spectra and multiplicity distributions, using vector boson + jets events at the LHC as a case study.
hep-ph/0111048
Jiunn-Wei Chen
Jiunn-Wei Chen and Xiangdong Ji
Leading Chiral Contributions to the Spin Structure of the Proton
8 pages, 2 figures; a typo in Ref. 7 corrected
Phys.Rev.Lett. 88 (2002) 052003
10.1103/PhysRevLett.88.052003
UMD-PP-02-020
hep-ph hep-lat nucl-th
null
The leading chiral contributions to the quark and gluon components of the proton spin are calculated using heavy-baryon chiral perturbation theory. Similar calculations are done for the moments of the generalized parton distributions relevant to the quark and gluon angular momentum densities. These results provide useful insight about the role of pions in the spin structure of the nucleon, and can serve as a guidance for extrapolating lattice QCD calculations at large quark masses to the chiral limit.
[ { "created": "Tue, 6 Nov 2001 19:50:59 GMT", "version": "v1" }, { "created": "Mon, 10 Dec 2001 19:57:52 GMT", "version": "v2" } ]
2009-11-07
[ [ "Chen", "Jiunn-Wei", "" ], [ "Ji", "Xiangdong", "" ] ]
The leading chiral contributions to the quark and gluon components of the proton spin are calculated using heavy-baryon chiral perturbation theory. Similar calculations are done for the moments of the generalized parton distributions relevant to the quark and gluon angular momentum densities. These results provide useful insight about the role of pions in the spin structure of the nucleon, and can serve as a guidance for extrapolating lattice QCD calculations at large quark masses to the chiral limit.
2106.09474
Joseph Aylett-Bullock
Joseph Aylett-Bullock, Simon Badger, Ryan Moodie
Optimising simulations for diphoton production at hadron colliders using amplitude neural networks
31 pages, 12 figures, 2 tables
null
10.1007/JHEP08(2021)066
null
hep-ph cs.AI cs.LG
http://creativecommons.org/licenses/by/4.0/
Machine learning technology has the potential to dramatically optimise event generation and simulations. We continue to investigate the use of neural networks to approximate matrix elements for high-multiplicity scattering processes. We focus on the case of loop-induced diphoton production through gluon fusion and develop a realistic simulation method that can be applied to hadron collider observables. Neural networks are trained using the one-loop amplitudes implemented in the NJet C++ library and interfaced to the Sherpa Monte Carlo event generator where we perform a detailed study for $2\to3$ and $2\to4$ scattering problems. We also consider how the trained networks perform when varying the kinematic cuts effecting the phase space and the reliability of the neural network simulations.
[ { "created": "Thu, 17 Jun 2021 13:24:36 GMT", "version": "v1" }, { "created": "Fri, 25 Jun 2021 10:25:05 GMT", "version": "v2" } ]
2021-09-01
[ [ "Aylett-Bullock", "Joseph", "" ], [ "Badger", "Simon", "" ], [ "Moodie", "Ryan", "" ] ]
Machine learning technology has the potential to dramatically optimise event generation and simulations. We continue to investigate the use of neural networks to approximate matrix elements for high-multiplicity scattering processes. We focus on the case of loop-induced diphoton production through gluon fusion and develop a realistic simulation method that can be applied to hadron collider observables. Neural networks are trained using the one-loop amplitudes implemented in the NJet C++ library and interfaced to the Sherpa Monte Carlo event generator where we perform a detailed study for $2\to3$ and $2\to4$ scattering problems. We also consider how the trained networks perform when varying the kinematic cuts effecting the phase space and the reliability of the neural network simulations.
1212.0789
Marc Sher
Marc Sher
Review of prospects for H^+ in non-SUSY multi-Higgs models in view of LHC results
8 pages. Talk given at "Prospects for Charged Higgs Discovery at Colliders", October 2012, Uppsala, Sweden
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, prospects for the charged Higgs in non-SUSY models are reviewed, in view of LHC results (as of October, 2012). The four models (Type I, Type II, lepton-specific and flipped) without tree level flavor-changing neutral currents are discussed. Updates for the case in which the charged Higgs is lighter than the top, leading to production in top decays, are presented along with expectations for the future. If the charged Higgs is heavier than the top quark, detection may be possible through the tau-nu decay mode. In addition, it is pointed out that the decay of the charged Higgs into W h, where h is the 125 GeV state, may be dominant. Charged Higgs phenomenology in models which do contain tree level flavor-changing neutral currents, as well as the inert doublet model and others, are also briefly reviewed.
[ { "created": "Tue, 4 Dec 2012 17:07:38 GMT", "version": "v1" } ]
2012-12-05
[ [ "Sher", "Marc", "" ] ]
In this talk, prospects for the charged Higgs in non-SUSY models are reviewed, in view of LHC results (as of October, 2012). The four models (Type I, Type II, lepton-specific and flipped) without tree level flavor-changing neutral currents are discussed. Updates for the case in which the charged Higgs is lighter than the top, leading to production in top decays, are presented along with expectations for the future. If the charged Higgs is heavier than the top quark, detection may be possible through the tau-nu decay mode. In addition, it is pointed out that the decay of the charged Higgs into W h, where h is the 125 GeV state, may be dominant. Charged Higgs phenomenology in models which do contain tree level flavor-changing neutral currents, as well as the inert doublet model and others, are also briefly reviewed.
2104.14626
Simone Biondini
Simone Biondini
Revisiting freeze-in dark matter from renormalizable operators
Proceedings of the (online) BSM-2021 Conference to appear in LHEP
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this conference paper we summarise the findings of a recent study, where the impact of the ultra-relativistic regime on the production of a feebly interacting dark matter particle is considered. As its population accumulates over the thermal history, we inspected thoroughly the temperature window $T \gg M$, which has been previously neglected in the context of dark matter models with renormalizable operators. At high temperatures, and for the model considered in our work, the production rate of the feebly interacting particle is driven by multiple soft scatterings, as well as $2 \to 2$ processes, that can give a large contribution to the dark matter energy density.
[ { "created": "Thu, 29 Apr 2021 19:26:30 GMT", "version": "v1" } ]
2021-05-03
[ [ "Biondini", "Simone", "" ] ]
In this conference paper we summarise the findings of a recent study, where the impact of the ultra-relativistic regime on the production of a feebly interacting dark matter particle is considered. As its population accumulates over the thermal history, we inspected thoroughly the temperature window $T \gg M$, which has been previously neglected in the context of dark matter models with renormalizable operators. At high temperatures, and for the model considered in our work, the production rate of the feebly interacting particle is driven by multiple soft scatterings, as well as $2 \to 2$ processes, that can give a large contribution to the dark matter energy density.
2401.01358
Patricio Gaete
Patricio Gaete and Jos\'e Abdalla Helay\"el-Neto
QED-vacuum response and Cherenkov radiated energy in non-linear and Lorentz-symmetry violating scenarios
22 pages
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate physical consequences of non-linear electrodynamic coupled to parameters that signal violation Lorentz-symmetry breaking (LSV). Our undertaking is done by considering a general non-linear photonic Lagrangian which coupled to the Carroll-Field-Jackiw's model (CFJ). Our endeavor reveals how the (meta) material constitutive properties of the vacuum and wave propagation are affected by the interference of the LSV parameters LSV with the specific non-linear electrodynamic model under consideration. We also discuss the refractive indices for this new medium characterized by the coupling between non-linearities and the operators that carry the LSV message. Our results show that the QED-vacuum responds with birefringence and a dispersive propagation of waves. Subsequently, we consider the electromagnetic radiation produced by a moving charged particle interacting with this new medium. Our inspection illustrates that the emitted radiation reproduces the features of the Cherenkov effect for certain intensities of background magnetic fields . Finally, we compute the static potential profile within the framework of the gauge-invariant, but path-dependent, variables formalism. A logarithmic correction to the usual static Coulomb potential emerges driven by the LSV parameter and there also appear corrections due to the non-linearity; nevertheless, the logarithm behavior drops out whenever the LSV parameter is switched off.
[ { "created": "Tue, 12 Dec 2023 17:55:52 GMT", "version": "v1" } ]
2024-01-04
[ [ "Gaete", "Patricio", "" ], [ "Helayël-Neto", "José Abdalla", "" ] ]
We investigate physical consequences of non-linear electrodynamic coupled to parameters that signal violation Lorentz-symmetry breaking (LSV). Our undertaking is done by considering a general non-linear photonic Lagrangian which coupled to the Carroll-Field-Jackiw's model (CFJ). Our endeavor reveals how the (meta) material constitutive properties of the vacuum and wave propagation are affected by the interference of the LSV parameters LSV with the specific non-linear electrodynamic model under consideration. We also discuss the refractive indices for this new medium characterized by the coupling between non-linearities and the operators that carry the LSV message. Our results show that the QED-vacuum responds with birefringence and a dispersive propagation of waves. Subsequently, we consider the electromagnetic radiation produced by a moving charged particle interacting with this new medium. Our inspection illustrates that the emitted radiation reproduces the features of the Cherenkov effect for certain intensities of background magnetic fields . Finally, we compute the static potential profile within the framework of the gauge-invariant, but path-dependent, variables formalism. A logarithmic correction to the usual static Coulomb potential emerges driven by the LSV parameter and there also appear corrections due to the non-linearity; nevertheless, the logarithm behavior drops out whenever the LSV parameter is switched off.
hep-ph/0106154
John F. Gunion
John F. Gunion
Hunting the Higgs Boson(s)
26 pages, 9 figures; based on presentations at RADCOR--2000 and PASCOS--2001
null
null
null
hep-ph
null
I give a brief review of some of the opportunities and challenges that could arise in our quest to unravel the Higgs sector that very probably underlies electroweak symmetry breaking. In particular, I review scenarios with an extended Higgs sector that allow for a heavy SM-like Higgs boson and/or make discovery more difficult while at the same time maintaining consistency with current limits and precision electroweak constraints.
[ { "created": "Thu, 14 Jun 2001 17:42:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gunion", "John F.", "" ] ]
I give a brief review of some of the opportunities and challenges that could arise in our quest to unravel the Higgs sector that very probably underlies electroweak symmetry breaking. In particular, I review scenarios with an extended Higgs sector that allow for a heavy SM-like Higgs boson and/or make discovery more difficult while at the same time maintaining consistency with current limits and precision electroweak constraints.
1006.5614
Gijs Oord van den
Ronald Kleiss and Gijs van den Oord
CAMORRA: a C++ library for recursive computation of particle scattering amplitudes
22 pages
Comput.Phys.Commun.182:435-447,2011
10.1016/j.cpc.2010.09.020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new Monte Carlo tool that computes full tree-level matrix elements in high-energy physics. The program accepts user-defined models and has no restrictions on the process multiplicity. To achieve acceptable performance, CAMORRA evaluates the matrix elements in a recursive way by combining off-shell currents. Furthermore, CAMORRA can be used to compute amplitudes involving continuous color and helicity final states.
[ { "created": "Tue, 29 Jun 2010 13:43:38 GMT", "version": "v1" } ]
2010-11-23
[ [ "Kleiss", "Ronald", "" ], [ "Oord", "Gijs van den", "" ] ]
We present a new Monte Carlo tool that computes full tree-level matrix elements in high-energy physics. The program accepts user-defined models and has no restrictions on the process multiplicity. To achieve acceptable performance, CAMORRA evaluates the matrix elements in a recursive way by combining off-shell currents. Furthermore, CAMORRA can be used to compute amplitudes involving continuous color and helicity final states.
0804.2428
Michael Rauch
Michael Rauch
Quantum Effects in Higgs-Boson Production Processes at Hadron Colliders
167 pages, 124 figures; PhD thesis
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The search for Higgs bosons and extensions of the Standard Model of Elementary Particle Physics are main tasks of the Large Hadron Collider (LHC) at CERN which will start operation mid-2008. In this thesis processes which can be used to detect supersymmetric Higgs bosons at the LHC were considered. First a computer program was written which completes the toolbox for automatic calculations of hadronic cross sections. Using this program, the supersymmetric QCD corrections to associated H-W+-production and h0-production via vector-boson fusion and in association with heavy quarks were calculated. The corrections partly give significant contributions to the total cross section. Additionally, the possibility to measure the quartic Higgs self-coupling via triple-Higgs production was investigated and found to be challenging.
[ { "created": "Tue, 15 Apr 2008 15:23:24 GMT", "version": "v1" } ]
2008-04-16
[ [ "Rauch", "Michael", "" ] ]
The search for Higgs bosons and extensions of the Standard Model of Elementary Particle Physics are main tasks of the Large Hadron Collider (LHC) at CERN which will start operation mid-2008. In this thesis processes which can be used to detect supersymmetric Higgs bosons at the LHC were considered. First a computer program was written which completes the toolbox for automatic calculations of hadronic cross sections. Using this program, the supersymmetric QCD corrections to associated H-W+-production and h0-production via vector-boson fusion and in association with heavy quarks were calculated. The corrections partly give significant contributions to the total cross section. Additionally, the possibility to measure the quartic Higgs self-coupling via triple-Higgs production was investigated and found to be challenging.
1602.02776
Franco D. Albareti
Franco D. Albareti, Antonio L. Maroto, Francisco Prada
Gravitational perturbations of the Higgs field
15 pages. Version accepted for publication in PRD. Error corrected in the angular integration in Appendix B. Conclusions changed. New section included
Phys. Rev. D 95, 044030 (2017)
10.1103/PhysRevD.95.044030
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the possible effects of classical gravitational backgrounds on the Higgs field through the modifications induced in the one-loop effective potential and the vacuum expectation value of the energy-momentum tensor. We concentrate our study on the Higgs self-interaction contribution in a perturbed FRW metric. For weak and slowly varying gravitational fields, a complete set of mode solutions for the Klein-Gordon equation is obtained to leading order in the adiabatic approximation. Dimensional regularization has been used in the integral evaluation and a detailed study of the integration of nonrational functions in this formalism has been presented. As expected, the regularized effective potential contains the same divergences as in flat spacetime, which can be renormalized without the need of additional counterterms. We find that, in contrast with other regularization methods, even though metric perturbations affect the mode solutions, they do not contribute to the leading adiabatic order of the potential. We also obtain explicit expressions of the complete energy-momentum tensor for general nonminimal coupling in terms of the perturbed modes. The corresponding leading adiabatic contributions are also obtained.
[ { "created": "Mon, 8 Feb 2016 21:01:07 GMT", "version": "v1" }, { "created": "Wed, 15 Feb 2017 20:18:45 GMT", "version": "v2" } ]
2017-03-01
[ [ "Albareti", "Franco D.", "" ], [ "Maroto", "Antonio L.", "" ], [ "Prada", "Francisco", "" ] ]
We study the possible effects of classical gravitational backgrounds on the Higgs field through the modifications induced in the one-loop effective potential and the vacuum expectation value of the energy-momentum tensor. We concentrate our study on the Higgs self-interaction contribution in a perturbed FRW metric. For weak and slowly varying gravitational fields, a complete set of mode solutions for the Klein-Gordon equation is obtained to leading order in the adiabatic approximation. Dimensional regularization has been used in the integral evaluation and a detailed study of the integration of nonrational functions in this formalism has been presented. As expected, the regularized effective potential contains the same divergences as in flat spacetime, which can be renormalized without the need of additional counterterms. We find that, in contrast with other regularization methods, even though metric perturbations affect the mode solutions, they do not contribute to the leading adiabatic order of the potential. We also obtain explicit expressions of the complete energy-momentum tensor for general nonminimal coupling in terms of the perturbed modes. The corresponding leading adiabatic contributions are also obtained.
2105.07928
Yufeng Li
Ziyi Yuan, Yu-Feng Li, Xiang Zhou
Spin Flavor Spectral Splits of Supernova Neutrino Flavor Conversions
10 pages, 4 figures
null
null
null
hep-ph astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
The supernova neutrino flavor evolution in the presence of the non-trivial neutrino magnetic moment and strong magnetic field is numerically derived using the two-flavor and single-angle approximation. The novel properties of collective neutrino oscillations are studied and distinct patterns of flavor and spin-flavor spectral splits are presented. Finally we also discuss how the neutrino magnetic moment affects the observable supernova neutrino energy spectra.
[ { "created": "Mon, 17 May 2021 15:06:04 GMT", "version": "v1" } ]
2021-05-18
[ [ "Yuan", "Ziyi", "" ], [ "Li", "Yu-Feng", "" ], [ "Zhou", "Xiang", "" ] ]
The supernova neutrino flavor evolution in the presence of the non-trivial neutrino magnetic moment and strong magnetic field is numerically derived using the two-flavor and single-angle approximation. The novel properties of collective neutrino oscillations are studied and distinct patterns of flavor and spin-flavor spectral splits are presented. Finally we also discuss how the neutrino magnetic moment affects the observable supernova neutrino energy spectra.
1808.00833
Mikhail Braun
M.A. Braun and C. Pajares
$p_t$- dependence of the flow coefficients for pp collisions in the color string scenario. Monte-Carlo simulations
10 pages, 6 figures. arXiv admin note: text overlap with arXiv:1407.4590
null
10.1140/epja/i2018-12616-1
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the color string picture with fusion and percolation the dependence of the flow coefficients $v_n$ on the transverse momentum is studied for pp collisions the LHC energy respectively. Monte-Carlo simulations are used to locate simple strings and their fused clusters. The results favorably agree with the CMS data in the region $0.2 \le p_t\le 3.$ GeV/c appropriate for the string scenario.
[ { "created": "Wed, 1 Aug 2018 08:56:08 GMT", "version": "v1" } ]
2018-11-14
[ [ "Braun", "M. A.", "" ], [ "Pajares", "C.", "" ] ]
In the color string picture with fusion and percolation the dependence of the flow coefficients $v_n$ on the transverse momentum is studied for pp collisions the LHC energy respectively. Monte-Carlo simulations are used to locate simple strings and their fused clusters. The results favorably agree with the CMS data in the region $0.2 \le p_t\le 3.$ GeV/c appropriate for the string scenario.
1304.3773
Alan Jamison
Alan O. Jamison
Effects of gravitational confinement on bosonic asymmetric dark matter in stars
2 pages, typos fixed to match published version
Phys. Rev. D 88, 035004 (2013)
10.1103/PhysRevD.88.035004
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Considering the existence of old neutron stars puts strong limits on the dark matter/nucleon cross section for bosonic asymmetric dark matter. Key to these bounds is formation of a Bose-Einstein condensate (BEC) of the asymmetric dark matter particles. We consider the effects of the host neutron star's gravitational field on the BEC transition. We find this substantially shifts the transition temperature and so strengthens the bounds on cross section. In particular, for the well-motivated mass range of ~5-15 GeV, we improve previous bounds by an order of magnitude.
[ { "created": "Sat, 13 Apr 2013 04:22:29 GMT", "version": "v1" }, { "created": "Wed, 8 Jan 2014 06:28:27 GMT", "version": "v2" } ]
2014-01-09
[ [ "Jamison", "Alan O.", "" ] ]
Considering the existence of old neutron stars puts strong limits on the dark matter/nucleon cross section for bosonic asymmetric dark matter. Key to these bounds is formation of a Bose-Einstein condensate (BEC) of the asymmetric dark matter particles. We consider the effects of the host neutron star's gravitational field on the BEC transition. We find this substantially shifts the transition temperature and so strengthens the bounds on cross section. In particular, for the well-motivated mass range of ~5-15 GeV, we improve previous bounds by an order of magnitude.
hep-ph/0408161
Christian Bauer
Christian W. Bauer and Dan Pirjol
Graphical amplitudes from SCET
7 pages; one additional relation included, minor corrections. version published in Physics Letters B
Phys.Lett. B604 (2004) 183-191
10.1016/j.physletb.2004.10.047
null
hep-ph
null
We discuss the relationship between the graphical amplitudes T, C, P, ... used to parameterize nonleptonic B decay amplitudes, and matrix elements of operators in the soft-collinear effective theory (SCET) at leading order in \Lambda/m_b. Using the SU(3) flavor symmetry of the weak Hamiltonian we derive all-order constraints on the electroweak penguin contributions to the Wilson coefficients of SCET operators.
[ { "created": "Fri, 13 Aug 2004 22:27:49 GMT", "version": "v1" }, { "created": "Wed, 12 Jan 2005 02:17:10 GMT", "version": "v2" } ]
2009-11-10
[ [ "Bauer", "Christian W.", "" ], [ "Pirjol", "Dan", "" ] ]
We discuss the relationship between the graphical amplitudes T, C, P, ... used to parameterize nonleptonic B decay amplitudes, and matrix elements of operators in the soft-collinear effective theory (SCET) at leading order in \Lambda/m_b. Using the SU(3) flavor symmetry of the weak Hamiltonian we derive all-order constraints on the electroweak penguin contributions to the Wilson coefficients of SCET operators.
1905.06601
Rafiqul Rahaman
Satendra Kumar, Poulose Poulose, Rafiqul Rahaman and Ritesh K. Singh
Measuring Higgs self couplings in the presence of VVH and VVHH at the ILC
18 pages, 13 figures and 1 table. This version supersedes arXiv:1408.3563
null
10.1142/S0217751X19500945
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent discovery of a Higgs boson at the LHC, while establishing the Higgs mechanism as the way of electroweak symmetry breaking, started an era of precision measurements involving the Higgs boson. In an effective Lagrangian framework, we consider the $e^+e^-\rightarrow ZHH$ process at the ILC running at a centre of mass energy of 500 GeV to investigate the effect of the $ZZH$ and $ZZHH$ couplings on the sensitivity of $HHH$ coupling in this process. Our results show that the sensitivity of the trilinear Higgs self couplings on this process has somewhat strong dependence on the Higgs-gauge boson couplings. Single and two parameter reach of the ILC with an integrated luminosity of 1000 fb$^{-1}$ are obtained on all the effective couplings indicating how these limits are affected by the presence of anomalous $ZZH$ and $ZZHH$ couplings. The kinematic distributions studied to understand the effect of the anomalous couplings, again, show a strong influence of $Z$-$H$ couplings on the dependence of these distributions on $HHH$ coupling. Similar results are indicated in the case of the process, $e^+e^-\rightarrow \nu\bar \nu HH$, considered at a centre of mass energy of 2 TeV, where the cross section is large enough. The effect of $WWH$ and $WWHH$ couplings on the sensitivity of $HHH$ coupling is clearly established through our analyses in this process.
[ { "created": "Thu, 16 May 2019 08:48:53 GMT", "version": "v1" } ]
2019-07-24
[ [ "Kumar", "Satendra", "" ], [ "Poulose", "Poulose", "" ], [ "Rahaman", "Rafiqul", "" ], [ "Singh", "Ritesh K.", "" ] ]
The recent discovery of a Higgs boson at the LHC, while establishing the Higgs mechanism as the way of electroweak symmetry breaking, started an era of precision measurements involving the Higgs boson. In an effective Lagrangian framework, we consider the $e^+e^-\rightarrow ZHH$ process at the ILC running at a centre of mass energy of 500 GeV to investigate the effect of the $ZZH$ and $ZZHH$ couplings on the sensitivity of $HHH$ coupling in this process. Our results show that the sensitivity of the trilinear Higgs self couplings on this process has somewhat strong dependence on the Higgs-gauge boson couplings. Single and two parameter reach of the ILC with an integrated luminosity of 1000 fb$^{-1}$ are obtained on all the effective couplings indicating how these limits are affected by the presence of anomalous $ZZH$ and $ZZHH$ couplings. The kinematic distributions studied to understand the effect of the anomalous couplings, again, show a strong influence of $Z$-$H$ couplings on the dependence of these distributions on $HHH$ coupling. Similar results are indicated in the case of the process, $e^+e^-\rightarrow \nu\bar \nu HH$, considered at a centre of mass energy of 2 TeV, where the cross section is large enough. The effect of $WWH$ and $WWHH$ couplings on the sensitivity of $HHH$ coupling is clearly established through our analyses in this process.
hep-ph/9412370
null
D.A.Dicus, B.Dutta and S.Nandi
Top Quark Signature in Extended Color Theories
21 pages, Latex, Figures available on request
Phys.Rev. D51 (1995) 6085-6091
10.1103/PhysRevD.51.6085
OSU-292, DOE-ER 40757, CPP-94-36-059
hep-ph
null
We consider the implications of an extended color group, $SU\left( 3\right) _I\times SU\left( 3\right) _{II}$, spontaneously broken to $SU\left( 3\right) _c$ at a TeV or lower scale, for the hadronic colliders. The associated massive color octet gauge bosons (the colorons) can enhance the $t \overline{t}$ pair production at the Tevatron collider. At the LHC, the colorons can be pair produced, each decaying to a $t\overline{t}$ pair. This gives rise to anomalous multi W production: a clear signature of physics beyond the Standard Model. We calculate the associated multijet and multilepton final states at the Tevatron and the LHC energies, and compare these with the expectations from the Standard Model.
[ { "created": "Mon, 26 Dec 1994 07:05:51 GMT", "version": "v1" } ]
2009-10-28
[ [ "Dicus", "D. A.", "" ], [ "Dutta", "B.", "" ], [ "Nandi", "S.", "" ] ]
We consider the implications of an extended color group, $SU\left( 3\right) _I\times SU\left( 3\right) _{II}$, spontaneously broken to $SU\left( 3\right) _c$ at a TeV or lower scale, for the hadronic colliders. The associated massive color octet gauge bosons (the colorons) can enhance the $t \overline{t}$ pair production at the Tevatron collider. At the LHC, the colorons can be pair produced, each decaying to a $t\overline{t}$ pair. This gives rise to anomalous multi W production: a clear signature of physics beyond the Standard Model. We calculate the associated multijet and multilepton final states at the Tevatron and the LHC energies, and compare these with the expectations from the Standard Model.
hep-ph/9811487
Katsuji Yamamoto
K. Yamamoto and S. Matsuki
Quantum Analysis of Rydberg Atom Cavity Detector for Dark Matter Axion Search
6 pages, 4 figures, Invited talk presented at the IDM'98, Buxton, UK, 7-11 September, 1998, latex, sprocl.sty
null
null
NEAP-55
hep-ph
null
Quantum analysis is made on the dynamical system consisting of the cosmic axions, photons and Rydberg atoms which are interacting in the resonant cavity. The atomic motion in a continuous incident beam is taken into account properly in order to make a precise estimate of the efficiency of the Rydberg atom cavity detector for dark matter axion search.
[ { "created": "Fri, 27 Nov 1998 02:38:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Yamamoto", "K.", "" ], [ "Matsuki", "S.", "" ] ]
Quantum analysis is made on the dynamical system consisting of the cosmic axions, photons and Rydberg atoms which are interacting in the resonant cavity. The atomic motion in a continuous incident beam is taken into account properly in order to make a precise estimate of the efficiency of the Rydberg atom cavity detector for dark matter axion search.
hep-ph/0408092
Umberto D'Alesio
Umberto D'Alesio and Francesco Murgia (University and INFN, Cagliari, Italy)
Parton intrinsic motion in inclusive particle production: unpolarized cross sections, single spin asymmetries and the Sivers effect
RevTeX, 29 pages, 20 ps figures
Phys.Rev.D70:074009,2004
10.1103/PhysRevD.70.074009
null
hep-ph
null
The relevance of intrinsic (or primordial) transverse momentum of partons in the inclusive production of particles at high energy and moderately large p_T has been known for a long time, beginning with Drell-Yan and diphoton processes, and continuing with photon and meson production in hadronic collisions. In view of its renewed interest in the context of polarized processes and single spin asymmetries we perform, in the framework of perturbative QCD with the inclusion of spin and transverse momentum effects, a detailed analysis of several such processes in different kinematical situations. We show that the inclusion of these effects leads, at the level of accuracy reachable in this approach, to an overall satisfactory agreement between theoretical predictions and experimental unpolarized data, thus giving support to the study of spin effects and single spin asymmetries within the same scheme. We present results for transverse single spin asymmetries, generated by the so-called Sivers effect, in inclusive pion and photon production in proton-proton collisions. We compare our results with the available experimental data and with previous results obtained using simplified versions of this approach.
[ { "created": "Fri, 6 Aug 2004 18:21:04 GMT", "version": "v1" } ]
2010-04-06
[ [ "D'Alesio", "Umberto", "", "University and INFN, Cagliari,\n Italy" ], [ "Murgia", "Francesco", "", "University and INFN, Cagliari,\n Italy" ] ]
The relevance of intrinsic (or primordial) transverse momentum of partons in the inclusive production of particles at high energy and moderately large p_T has been known for a long time, beginning with Drell-Yan and diphoton processes, and continuing with photon and meson production in hadronic collisions. In view of its renewed interest in the context of polarized processes and single spin asymmetries we perform, in the framework of perturbative QCD with the inclusion of spin and transverse momentum effects, a detailed analysis of several such processes in different kinematical situations. We show that the inclusion of these effects leads, at the level of accuracy reachable in this approach, to an overall satisfactory agreement between theoretical predictions and experimental unpolarized data, thus giving support to the study of spin effects and single spin asymmetries within the same scheme. We present results for transverse single spin asymmetries, generated by the so-called Sivers effect, in inclusive pion and photon production in proton-proton collisions. We compare our results with the available experimental data and with previous results obtained using simplified versions of this approach.
hep-ph/0101061
Gregory W. Carter
G.W. Carter and E.V. Shuryak
Do Instantons and Strings Cluster when the Number of Colors is Large?
10 pages, 1 figure, uses epsf.sty
Phys.Lett. B524 (2002) 297-302
10.1016/S0370-2693(01)01399-5
null
hep-ph
null
We consider the $N_c\to\infty$ limit of QCD using a toy model in which instantons exchange color-singlet scalar fields which do not self-interact. Our main observation is that collective attraction leads the formation of large clusters containing $O(N_c)$ nonperturbative objects. We further show that this clustering of instantons is limited due to a non-trivial repulsion inherent in the ADHM multi-instanton solution. As a result the vacuum is very different from that at low $N_c$, notably being more inhomogeneous, in ways which will affect chiral symmetry breaking of light quarks. We also briefly discuss a similar phenomenon for color strings in baryons made of medium-mass (charm-like) quarks.
[ { "created": "Mon, 8 Jan 2001 15:20:00 GMT", "version": "v1" }, { "created": "Mon, 8 Oct 2001 23:08:24 GMT", "version": "v2" } ]
2009-11-07
[ [ "Carter", "G. W.", "" ], [ "Shuryak", "E. V.", "" ] ]
We consider the $N_c\to\infty$ limit of QCD using a toy model in which instantons exchange color-singlet scalar fields which do not self-interact. Our main observation is that collective attraction leads the formation of large clusters containing $O(N_c)$ nonperturbative objects. We further show that this clustering of instantons is limited due to a non-trivial repulsion inherent in the ADHM multi-instanton solution. As a result the vacuum is very different from that at low $N_c$, notably being more inhomogeneous, in ways which will affect chiral symmetry breaking of light quarks. We also briefly discuss a similar phenomenon for color strings in baryons made of medium-mass (charm-like) quarks.
1203.1705
Tom\'a\v{s} Brauner
Hiroaki Abuki and Tom\'a\v{s} Brauner
How does color neutrality affect collective modes in color superconductors?
14 pages, REVTeX 4.1, 1 eps figure
Phys.Rev.D85:116004,2012
10.1103/PhysRevD.85.116004
BI-TP 2012/07
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the issue of color neutrality in effective model descriptions of dense quark matter based on global color symmetry. While the equilibrium thermodynamics of such models is now well understood, we examine the collective modes, focusing on the fluctuations of the order parameter. We point out that the constraint of color neutrality must be carefully generalized in order to obtain physically consistent and well-defined results. Particularly important is that the collective modes associated with order parameter fluctuations couple to charge density fluctuations in the neutral medium. We start by proving explicitly that, in contrast to claims made previously in literature, Nambu-Goldstone bosons of spontaneously broken global color symmetry remain exactly massless even after imposing the color neutrality constraint. As the next step, we make the argument general by using effective field theory. We then employ the high-density approximation to calculate the couplings in the effective Lagrangian and thus the Nambu-Goldstone boson dispersion relations.
[ { "created": "Thu, 8 Mar 2012 08:21:04 GMT", "version": "v1" } ]
2012-06-18
[ [ "Abuki", "Hiroaki", "" ], [ "Brauner", "Tomáš", "" ] ]
We revisit the issue of color neutrality in effective model descriptions of dense quark matter based on global color symmetry. While the equilibrium thermodynamics of such models is now well understood, we examine the collective modes, focusing on the fluctuations of the order parameter. We point out that the constraint of color neutrality must be carefully generalized in order to obtain physically consistent and well-defined results. Particularly important is that the collective modes associated with order parameter fluctuations couple to charge density fluctuations in the neutral medium. We start by proving explicitly that, in contrast to claims made previously in literature, Nambu-Goldstone bosons of spontaneously broken global color symmetry remain exactly massless even after imposing the color neutrality constraint. As the next step, we make the argument general by using effective field theory. We then employ the high-density approximation to calculate the couplings in the effective Lagrangian and thus the Nambu-Goldstone boson dispersion relations.
hep-ph/0206062
Thomas Schaefer
Thomas Schaefer (Duke U, SUNY Stony Brook, Riken-BNL)
Instantons in QCD with Many Colors
40 pages, 16 figures, minor revisions, to appear in PRD
Phys.Rev. D66 (2002) 076009
10.1103/PhysRevD.66.076009
null
hep-ph
null
We study instantons in QCD with many colors. We first discuss a number of qualitative arguments concerning the large N_c scaling behavior of a random instanton ensemble. We show that most hadronic observables are compatible with standard large N_c counting rules provided the average instanton size is O(1) and the instanton density is O(N_c) in the large N_c limit. This is not the case for the topological susceptibility and the mass of the eta'. For these observables consistency with conventional large N_c counting requires that fluctuations in the instanton liquid are suppressed compared to Poissonian fluctuations. Using mean field estimates and numerical simulations we show that the required scaling behavior of the instanton density is natural in models in which the instanton density is regularized in terms of a classical repulsive core. We also show that in these models fluctuations of the topological charge are suppressed and that m^2_eta'=O(1/N_c). We conclude that the instanton liquid model is not necessarily in conflict with the 1/N_c expansion.
[ { "created": "Thu, 6 Jun 2002 06:54:40 GMT", "version": "v1" }, { "created": "Tue, 1 Oct 2002 16:45:45 GMT", "version": "v2" } ]
2009-11-07
[ [ "Schaefer", "Thomas", "", "Duke U, SUNY Stony Brook, Riken-BNL" ] ]
We study instantons in QCD with many colors. We first discuss a number of qualitative arguments concerning the large N_c scaling behavior of a random instanton ensemble. We show that most hadronic observables are compatible with standard large N_c counting rules provided the average instanton size is O(1) and the instanton density is O(N_c) in the large N_c limit. This is not the case for the topological susceptibility and the mass of the eta'. For these observables consistency with conventional large N_c counting requires that fluctuations in the instanton liquid are suppressed compared to Poissonian fluctuations. Using mean field estimates and numerical simulations we show that the required scaling behavior of the instanton density is natural in models in which the instanton density is regularized in terms of a classical repulsive core. We also show that in these models fluctuations of the topological charge are suppressed and that m^2_eta'=O(1/N_c). We conclude that the instanton liquid model is not necessarily in conflict with the 1/N_c expansion.
hep-ph/0703218
Dario Zappala
Paolo Castorina, Dario Zappala'
Inhomogeneous phase of a Gluon Plasma at finite temperature and density
5 pages, 2 figures
Europhys.Lett.80:22001,2007
10.1209/0295-5075/80/22001
null
hep-ph
null
By considering the non-perturbative effects associated with the fundamental modular region, a new phase of a Gluon Plasma at finite density is proposed. It corresponds to the transition from glueballs to non-perturbative gluons which condense at a non vanishing momentum. In this respect the proposed phase is analogous to the color superconducting LOFF phase for fermionic systems.
[ { "created": "Tue, 20 Mar 2007 15:28:49 GMT", "version": "v1" } ]
2008-11-26
[ [ "Castorina", "Paolo", "" ], [ "Zappala'", "Dario", "" ] ]
By considering the non-perturbative effects associated with the fundamental modular region, a new phase of a Gluon Plasma at finite density is proposed. It corresponds to the transition from glueballs to non-perturbative gluons which condense at a non vanishing momentum. In this respect the proposed phase is analogous to the color superconducting LOFF phase for fermionic systems.
1111.1424
Ruben Concei\c{c}\~ao
S. Andringa, L. Cazon, R. Concei\c{c}\~ao, M. Pimenta
The muonic longitudinal shower profiles at production
null
null
10.1016/j.astropartphys.2012.03.010
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper the longitudinal profile of muon production along the shower axis is studied. The characteristics of this distribution is investigated for different primary masses, zenith angles, primary energies, and different high energy hadronic models. It is found that the shape of this distribution displays universal features similarly to what is known for the electromagnetic profile. The relation between the muon production distribution and the longitudinal electromagnetic evolution is also discussed.
[ { "created": "Sun, 6 Nov 2011 15:02:45 GMT", "version": "v1" }, { "created": "Thu, 8 Mar 2012 13:03:04 GMT", "version": "v2" } ]
2015-06-03
[ [ "Andringa", "S.", "" ], [ "Cazon", "L.", "" ], [ "Conceição", "R.", "" ], [ "Pimenta", "M.", "" ] ]
In this paper the longitudinal profile of muon production along the shower axis is studied. The characteristics of this distribution is investigated for different primary masses, zenith angles, primary energies, and different high energy hadronic models. It is found that the shape of this distribution displays universal features similarly to what is known for the electromagnetic profile. The relation between the muon production distribution and the longitudinal electromagnetic evolution is also discussed.
2004.05200
Saul Ramos-Sanchez
Hans Peter Nilles, Saul Ramos-Sanchez, Patrick K.S. Vaudrevange
Lessons from eclectic flavor symmetries
30 pages, 2 tables, 1 figure; v2: assumptions clarified, references added and updated, matches version published in NPB
null
10.1016/j.nuclphysb.2020.115098
TUM-HEP 1256/20
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A top-down approach to the flavor problem motivated from string theory leads to the concept of eclectic flavor groups that combine traditional and modular flavor symmetries. To make contact with models constructed in the bottom-up approach, we analyze a specific example based on the eclectic flavor group Omega(1) (a nontrivial combination of the traditional flavor group Delta(54) and the finite modular group T') in order to extract general lessons from the eclectic scheme. We observe that this scheme is highly predictive since it severely restricts the possible group representations and modular weights of matter fields. Thereby, it controls the structure of the Kaehler potential and the superpotential, which we discuss explicitly. In particular, both Kaehler potential and superpotential are shown to transform nontrivially, but combine to an invariant action. Finally, we find that discrete R-symmetries are intrinsic to eclectic flavor groups.
[ { "created": "Fri, 10 Apr 2020 18:49:30 GMT", "version": "v1" }, { "created": "Wed, 8 Jul 2020 12:11:27 GMT", "version": "v2" } ]
2020-08-26
[ [ "Nilles", "Hans Peter", "" ], [ "Ramos-Sanchez", "Saul", "" ], [ "Vaudrevange", "Patrick K. S.", "" ] ]
A top-down approach to the flavor problem motivated from string theory leads to the concept of eclectic flavor groups that combine traditional and modular flavor symmetries. To make contact with models constructed in the bottom-up approach, we analyze a specific example based on the eclectic flavor group Omega(1) (a nontrivial combination of the traditional flavor group Delta(54) and the finite modular group T') in order to extract general lessons from the eclectic scheme. We observe that this scheme is highly predictive since it severely restricts the possible group representations and modular weights of matter fields. Thereby, it controls the structure of the Kaehler potential and the superpotential, which we discuss explicitly. In particular, both Kaehler potential and superpotential are shown to transform nontrivially, but combine to an invariant action. Finally, we find that discrete R-symmetries are intrinsic to eclectic flavor groups.
hep-ph/0310030
Joao Magueijo
Dagny Kimberly and Joao Magueijo
Varying Alpha and the Electroweak Model
null
Phys.Lett. B584 (2004) 8-15
10.1016/j.physletb.2004.01.050
null
hep-ph astro-ph gr-qc
null
Inspired by recent claims for a varying fine structure constant, alpha, we investigate the effect of ``promoting coupling constants to variables'' upon various parameters of the standard model. We first consider a toy model: Proca's theory of the massive photon. We then explore the electroweak theory with one and two dilaton fields. We find that a varying alpha unavoidably implies varying W and Z masses. This follows from gauge invariance, and is to be contrasted with Proca' theory. For the two dilaton theory the Weinberg angle is also variable, but Fermi's constant and the tree level fermion masses remain constant unless the Higgs' potential becomes dynamical. We outline some cosmological implications.
[ { "created": "Thu, 2 Oct 2003 13:51:15 GMT", "version": "v1" } ]
2009-11-10
[ [ "Kimberly", "Dagny", "" ], [ "Magueijo", "Joao", "" ] ]
Inspired by recent claims for a varying fine structure constant, alpha, we investigate the effect of ``promoting coupling constants to variables'' upon various parameters of the standard model. We first consider a toy model: Proca's theory of the massive photon. We then explore the electroweak theory with one and two dilaton fields. We find that a varying alpha unavoidably implies varying W and Z masses. This follows from gauge invariance, and is to be contrasted with Proca' theory. For the two dilaton theory the Weinberg angle is also variable, but Fermi's constant and the tree level fermion masses remain constant unless the Higgs' potential becomes dynamical. We outline some cosmological implications.
hep-ph/0309249
Werner Rodejohann
W. Rodejohann
A Parametrization for the Neutrino Mixing Matrix
26 pages. Subsection about possible origin of deviations and some references added. To appear in PRD
Phys.Rev.D69:033005,2004
10.1103/PhysRevD.69.033005
SISSA 83/2003/EP
hep-ph hep-ex nucl-ex
null
We propose a flexible and model independent parametrization of the neutrino mixing matrix, which takes advantage of the fact that there are up to three small quantities in neutrino mixing phenomenology: (i) the deviation from maximal mixing of solar neutrinos, (ii) the mixing matrix element U_{e3} and (iii) the deviation from maximal mixing of atmospheric neutrinos. It is possible to quantify those three observations with a parameter \lambda \sim 0.2, which appears at least linearly in all elements of the mixing matrix. The limit \lambda -> 0 corresponds to exact bimaximal mixing. Present and future experiments can be used to pin down the power of \lambda required to usefully describe the observed phenomenology. Observing that the ratio of the two measured mass squared differences is roughly \lambda^2 allows to further study the structure of the Majorana mass matrix. We comment on the implications of this parametrization for neutrinoless double beta decay and on the oscillation probabilities in long-baseline experiments.
[ { "created": "Mon, 22 Sep 2003 14:24:01 GMT", "version": "v1" }, { "created": "Sat, 6 Dec 2003 14:34:57 GMT", "version": "v2" } ]
2008-11-26
[ [ "Rodejohann", "W.", "" ] ]
We propose a flexible and model independent parametrization of the neutrino mixing matrix, which takes advantage of the fact that there are up to three small quantities in neutrino mixing phenomenology: (i) the deviation from maximal mixing of solar neutrinos, (ii) the mixing matrix element U_{e3} and (iii) the deviation from maximal mixing of atmospheric neutrinos. It is possible to quantify those three observations with a parameter \lambda \sim 0.2, which appears at least linearly in all elements of the mixing matrix. The limit \lambda -> 0 corresponds to exact bimaximal mixing. Present and future experiments can be used to pin down the power of \lambda required to usefully describe the observed phenomenology. Observing that the ratio of the two measured mass squared differences is roughly \lambda^2 allows to further study the structure of the Majorana mass matrix. We comment on the implications of this parametrization for neutrinoless double beta decay and on the oscillation probabilities in long-baseline experiments.
1806.09112
Ye-Ling Zhou
S. T. Petcov and Ye-Ling Zhou
On Neutrino Mixing in Matter and CP and T Violation Effects in Neutrino Oscillations
17 pages, 6 figures, refs added, published in PLB
Phys.Lett. B785 (2018) 95
10.1016/j.physletb.2018.08.025
SISSA 23/2018/FISI, IPMU18--0112, IPPP/18/47
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Aspects of 3-neutrino mixing and oscillations in vacuum and in matter with constant density are investigated working with a real form of the neutrino Hamiltonian. We find the (approximate) equalities $\theta^m_{23} = \theta_{23}$ and $\delta^m = \delta$, $\theta_{23}$ ($\theta^m_{23}$) and $\delta$ ($\delta^m$) being respectively the atmospheric neutrino mixing angle and the Dirac CP violation phase in vacuum (in matter) of the neutrino mixing matrix, which are shown to represent excellent approximations for the conditions of the T2K (T2HK), T2HKK, NO$\nu$A and DUNE neutrino oscillation experiments. A new derivation of the known relation $\sin2\theta^m_{23} \sin\delta^m = \sin2\theta_{23} \sin\delta$ is presented and it is used to obtain a correlation between the shifts of $\theta_{23}$ and $\delta$ due to the matter effect. A derivation of the relation between the rephasing invariants which determine the magnitude of CP and T violating effects in 3-flavour neutrino oscillations in vacuum, $J_{\rm CP}$, and of the T violating effects in matter with constant density, $J^{m}_{\rm T} \equiv J^{m}$, reported in \cite{Krastev:1988yu} without a proof, is presented. It is shown that the function $F$ which appears in this relation, $J^{m} = J_{\rm CP}\,F$, and whose explicit form was given in \cite{Krastev:1988yu}, coincides with the function $\tilde{F}$ in the similar relation $J^{m} = J_{\rm CP}\tilde{F}$ derived in \cite{Naumov:1991ju}, although $F$ and $\tilde{F}$ are expressed in terms of different sets of neutrino mass and mixing parameters and have completely different forms.
[ { "created": "Sun, 24 Jun 2018 09:19:59 GMT", "version": "v1" }, { "created": "Fri, 14 Sep 2018 10:58:49 GMT", "version": "v2" } ]
2018-09-17
[ [ "Petcov", "S. T.", "" ], [ "Zhou", "Ye-Ling", "" ] ]
Aspects of 3-neutrino mixing and oscillations in vacuum and in matter with constant density are investigated working with a real form of the neutrino Hamiltonian. We find the (approximate) equalities $\theta^m_{23} = \theta_{23}$ and $\delta^m = \delta$, $\theta_{23}$ ($\theta^m_{23}$) and $\delta$ ($\delta^m$) being respectively the atmospheric neutrino mixing angle and the Dirac CP violation phase in vacuum (in matter) of the neutrino mixing matrix, which are shown to represent excellent approximations for the conditions of the T2K (T2HK), T2HKK, NO$\nu$A and DUNE neutrino oscillation experiments. A new derivation of the known relation $\sin2\theta^m_{23} \sin\delta^m = \sin2\theta_{23} \sin\delta$ is presented and it is used to obtain a correlation between the shifts of $\theta_{23}$ and $\delta$ due to the matter effect. A derivation of the relation between the rephasing invariants which determine the magnitude of CP and T violating effects in 3-flavour neutrino oscillations in vacuum, $J_{\rm CP}$, and of the T violating effects in matter with constant density, $J^{m}_{\rm T} \equiv J^{m}$, reported in \cite{Krastev:1988yu} without a proof, is presented. It is shown that the function $F$ which appears in this relation, $J^{m} = J_{\rm CP}\,F$, and whose explicit form was given in \cite{Krastev:1988yu}, coincides with the function $\tilde{F}$ in the similar relation $J^{m} = J_{\rm CP}\tilde{F}$ derived in \cite{Naumov:1991ju}, although $F$ and $\tilde{F}$ are expressed in terms of different sets of neutrino mass and mixing parameters and have completely different forms.
0810.5082
Christophe Royon
G. Beuf, C. Royon, D. Salek
Geometric Scaling of $F_2$ and $F_2^c$ in data and QCD Parametrisations
11 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The scaling properties at low $x$ of the proton DIS cross section and its charm component are analyzed with the help of the quality factor method. Scaling properties are tested both in the deep inelastic scattering data and in the structure functions reconstructed from CTEQ, MRST and GRV parametrisations of parton density functions. The results for DIS cross sections are fully compatible between data and parametrisations. Even with larger error bars, the charm component data favors the same geometric scaling properties as the ones of inclusive DIS. This is not the case for all parametrisations of the charm component.
[ { "created": "Tue, 28 Oct 2008 16:56:10 GMT", "version": "v1" } ]
2008-10-29
[ [ "Beuf", "G.", "" ], [ "Royon", "C.", "" ], [ "Salek", "D.", "" ] ]
The scaling properties at low $x$ of the proton DIS cross section and its charm component are analyzed with the help of the quality factor method. Scaling properties are tested both in the deep inelastic scattering data and in the structure functions reconstructed from CTEQ, MRST and GRV parametrisations of parton density functions. The results for DIS cross sections are fully compatible between data and parametrisations. Even with larger error bars, the charm component data favors the same geometric scaling properties as the ones of inclusive DIS. This is not the case for all parametrisations of the charm component.
2007.06269
Vladimir Skalozub
V. Skalozub and M. Dmytriiev
On direct search for dark matter in scattering processes within Yukawa model
14 pages, 9 figures, 13 references
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
\begin{abstract} Nowadays, no dark matter candidates have been discovered. We consider two possible reasons for that, both related to the approach of on-peak resonance searching for. As is believed usually, a new particle suits the conditions that the ratio of the width to the mass is less than $1-3 \%$ and a narrow width approximation (NWA) is applicable to identify the such type resonant peak in the invariant mass spectrum of collision products. In the present paper, in the framework of generalized Yukawa model, we find out the properties of the searched particle when its width is larger than a maximal one expected during experiments and so this state could be missed as a noise. We also ascertain the values of particle's parameters when the NWA is not applicable and estimate the width value when it happens. These estimations are relevant to interactions between the Standard model and dark matter particles. Such approach is focused on the role of couplings and mass values introduced in the model describing interaction of visible and dark matter. Key words: dark matter; resonance; narrow width approximation; mixing of fields.
[ { "created": "Mon, 13 Jul 2020 09:46:52 GMT", "version": "v1" }, { "created": "Wed, 13 Oct 2021 11:08:43 GMT", "version": "v2" } ]
2021-10-14
[ [ "Skalozub", "V.", "" ], [ "Dmytriiev", "M.", "" ] ]
\begin{abstract} Nowadays, no dark matter candidates have been discovered. We consider two possible reasons for that, both related to the approach of on-peak resonance searching for. As is believed usually, a new particle suits the conditions that the ratio of the width to the mass is less than $1-3 \%$ and a narrow width approximation (NWA) is applicable to identify the such type resonant peak in the invariant mass spectrum of collision products. In the present paper, in the framework of generalized Yukawa model, we find out the properties of the searched particle when its width is larger than a maximal one expected during experiments and so this state could be missed as a noise. We also ascertain the values of particle's parameters when the NWA is not applicable and estimate the width value when it happens. These estimations are relevant to interactions between the Standard model and dark matter particles. Such approach is focused on the role of couplings and mass values introduced in the model describing interaction of visible and dark matter. Key words: dark matter; resonance; narrow width approximation; mixing of fields.
2202.10315
Giorgio Galanti
Giorgio Galanti
Photon-ALP interaction as a measure of initial photon polarization
9 pages, 3 figures. This version matches the published paper: Phys. Rev. D 105, 083022 (2022)
Phys. Rev. D 105, 083022 (2022)
10.1103/PhysRevD.105.083022
null
hep-ph astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Axion-like particles (ALPs) are very light, neutral, spin zero bosons predicted by superstring theory. ALPs interact primarily with two photons and in the presence of an external magnetic field they generate photon-ALP oscillations and the change of the polarization state of photons. While well motivated from a theoretical point of view, hints on ALP existence come from astrophysics. In this paper, we state and demonstrate some theorems about a strict relationship between initial photon polarization and photon-ALP conversion probability - which can be extrapolated by observed astrophysical spectra - so that, in the presence of ALPs, flux-measuring observatories become also porarimeters.
[ { "created": "Mon, 21 Feb 2022 15:40:03 GMT", "version": "v1" }, { "created": "Thu, 28 Apr 2022 16:08:16 GMT", "version": "v2" } ]
2022-04-29
[ [ "Galanti", "Giorgio", "" ] ]
Axion-like particles (ALPs) are very light, neutral, spin zero bosons predicted by superstring theory. ALPs interact primarily with two photons and in the presence of an external magnetic field they generate photon-ALP oscillations and the change of the polarization state of photons. While well motivated from a theoretical point of view, hints on ALP existence come from astrophysics. In this paper, we state and demonstrate some theorems about a strict relationship between initial photon polarization and photon-ALP conversion probability - which can be extrapolated by observed astrophysical spectra - so that, in the presence of ALPs, flux-measuring observatories become also porarimeters.
0710.0680
T. Becher
Thomas Becher, Matthias Neubert and Gang Xu
Dynamical Threshold Enhancement and Resummation in Drell-Yan Production
43 pages; references added; small numerical changes at NNLO due to improved fixed-order code
JHEP 0807:030,2008
10.1088/1126-6708/2008/07/030
CLNS 07/2009, FERMILAB-PUB-07-507-T, MZ-TH/07-16
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Partonic cross sections for the production of massive objects in hadronic collisions receive large corrections when the invariant mass of the initial-state partons is just above the production threshold. Since typically the center-of-mass energy of the hadronic collision is much higher than the mass of the heavy objects, it is not obvious that these contributions translate into large corrections to the hadronic cross section. Using a recent approach to threshold resummation based on effective field theory, we quantify to which extent the fall-off of the parton densities at high x leads to a dynamical enhancement of the partonic threshold region. With the example of Drell-Yan production, we study the emergence of an effective physical scale characterizing the soft emissions in the process. We derive compact analytical expressions for the resummed Drell-Yan cross section and rapidity distribution directly in momentum space. They are free of Landau-pole singularities and are trivially matched onto fixed-order perturbative calculations. Evaluating the resummed cross sections at NNNLL order and matching onto NNLO fixed-order calculations, we perform a detailed numerical analysis of the cross section and rapidity distribution in proton-proton collisions.
[ { "created": "Wed, 3 Oct 2007 00:17:13 GMT", "version": "v1" }, { "created": "Thu, 26 Jun 2008 02:30:33 GMT", "version": "v2" } ]
2009-04-17
[ [ "Becher", "Thomas", "" ], [ "Neubert", "Matthias", "" ], [ "Xu", "Gang", "" ] ]
Partonic cross sections for the production of massive objects in hadronic collisions receive large corrections when the invariant mass of the initial-state partons is just above the production threshold. Since typically the center-of-mass energy of the hadronic collision is much higher than the mass of the heavy objects, it is not obvious that these contributions translate into large corrections to the hadronic cross section. Using a recent approach to threshold resummation based on effective field theory, we quantify to which extent the fall-off of the parton densities at high x leads to a dynamical enhancement of the partonic threshold region. With the example of Drell-Yan production, we study the emergence of an effective physical scale characterizing the soft emissions in the process. We derive compact analytical expressions for the resummed Drell-Yan cross section and rapidity distribution directly in momentum space. They are free of Landau-pole singularities and are trivially matched onto fixed-order perturbative calculations. Evaluating the resummed cross sections at NNNLL order and matching onto NNLO fixed-order calculations, we perform a detailed numerical analysis of the cross section and rapidity distribution in proton-proton collisions.
1609.09612
Paolo Cea
Paolo Cea
On the new LHC resonance
27 pages, 7 figures, final version
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an alternative interpretation within the Standard Model of the new LHC resonance at $125 \; GeV$. We further elaborate on our previous proposal that the resonance at 125 GeV could be interpreted as a pseudoscalar meson with quantum number $J^{PC} = 0^{- +}$. We develop a phenomenological approach where this pseudoscalar mimics the decays of the Standard Model Higgs boson in the vector boson decay channels. We propose that the true Higgs boson should be a heavy resonance with mass of $750 \, GeV$ as argued in Ref.~\cite{Cea:2012}. We determine the most relevant decay modes and estimate the partial decay widths and branching ratios. We also discuss briefly the experimental signatures of this heavy Higgs boson. Finally, we attempt a comparison of our theoretical expectations with recent data at $\sqrt{s} =13 \,TeV$ from ATLAS and CMS experiments in the so-called golden channel. We find that the available experimental data could be consistent with the heavy Higgs scenario.
[ { "created": "Fri, 30 Sep 2016 06:34:14 GMT", "version": "v1" }, { "created": "Mon, 13 Mar 2017 14:09:14 GMT", "version": "v2" } ]
2017-03-14
[ [ "Cea", "Paolo", "" ] ]
We present an alternative interpretation within the Standard Model of the new LHC resonance at $125 \; GeV$. We further elaborate on our previous proposal that the resonance at 125 GeV could be interpreted as a pseudoscalar meson with quantum number $J^{PC} = 0^{- +}$. We develop a phenomenological approach where this pseudoscalar mimics the decays of the Standard Model Higgs boson in the vector boson decay channels. We propose that the true Higgs boson should be a heavy resonance with mass of $750 \, GeV$ as argued in Ref.~\cite{Cea:2012}. We determine the most relevant decay modes and estimate the partial decay widths and branching ratios. We also discuss briefly the experimental signatures of this heavy Higgs boson. Finally, we attempt a comparison of our theoretical expectations with recent data at $\sqrt{s} =13 \,TeV$ from ATLAS and CMS experiments in the so-called golden channel. We find that the available experimental data could be consistent with the heavy Higgs scenario.
1411.4612
Hendrik van Hees
Ralf Rapp and Hendrik van Hees
Thermal Dileptons as Fireball Thermometer and Chronometer
4 pages 3 figures
Phys.Lett. B 753, 586 (2016)
10.1016/j.physletb.2015.12.065
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Thermal dilepton radiation from the hot fireballs created in high-energy heavy-ion collisions provides unique insights into the properties of the produced medium. We first show how the predictions of hadronic many-body theory for a melting $\rho$ meson, coupled with QGP emission utilizing a modern lattice-QCD based equation of state, yield a quantitative description of dilepton spectra in heavy-ion collisions at the SPS and the RHIC beam energy scan program. We utilize these results to systematically extract the excess yields and their invariant-mass spectral slopes to predict the excitation function of fireball lifetimes and (early) temperatures, respectively. We thereby demonstrate that future measurements of these quantities can yield unprecedented information on basic fireball properties. Specifically, our predictions quantify the relation between the measured and maximal fireball temperatures, and the proportionality of excess yields and total lifetime. This information can serve as a "caloric" curve to search for a first-order QCD phase transition, and to detect non-monotonous lifetime variations possibly related to critical phenomena.
[ { "created": "Mon, 17 Nov 2014 20:01:43 GMT", "version": "v1" } ]
2016-02-24
[ [ "Rapp", "Ralf", "" ], [ "van Hees", "Hendrik", "" ] ]
Thermal dilepton radiation from the hot fireballs created in high-energy heavy-ion collisions provides unique insights into the properties of the produced medium. We first show how the predictions of hadronic many-body theory for a melting $\rho$ meson, coupled with QGP emission utilizing a modern lattice-QCD based equation of state, yield a quantitative description of dilepton spectra in heavy-ion collisions at the SPS and the RHIC beam energy scan program. We utilize these results to systematically extract the excess yields and their invariant-mass spectral slopes to predict the excitation function of fireball lifetimes and (early) temperatures, respectively. We thereby demonstrate that future measurements of these quantities can yield unprecedented information on basic fireball properties. Specifically, our predictions quantify the relation between the measured and maximal fireball temperatures, and the proportionality of excess yields and total lifetime. This information can serve as a "caloric" curve to search for a first-order QCD phase transition, and to detect non-monotonous lifetime variations possibly related to critical phenomena.
2405.07025
Min He
Shouxing Zhao and Min He
Second-Order Dissociation and Transition of Heavy Quarkonia in the Quark-Gluon Plasma
17 pages, 13 figures
null
null
null
hep-ph nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
We revisit the dissociation of heavy quarkonia by thermal partons at the next-to-leading order (NLO, also known as inelastic parton scattering dissociation) in the Quark-Gluon Plasma (QGP). Utilizing the chromo-electric dipole coupling from QCD multipole expansion as an effective Hamiltonian, this has been conducted in the approach of second-order quantum mechanical perturbation theory, which allows us to systematically incorporate the bound state wave functions. Employing the quarkonium wave functions and binding energies obtained from an in-medium potential model, we then numerically evaluate the dissociation cross sections and rates for various charmonia and bottomonia, where the infrared and collinear divergences are regularized by the thermal masses of medium partons. We demonstrate that distinct from the leading order (LO, also known as gluo-dissociation) counterparts peaking at relatively low gluon energy and falling off thereafter, the NLO cross sections first grow and then nearly saturate as the incident parton energy increases, as a result of the outgoing parton carrying away the excess energy. The resulting NLO dissociation rates increase with temperature and take over from the LO counterparts toward high temperatures, similar to pertinent findings from previous studies. We also evaluate the in-medium second-order transition between different bound states, which may contribute to the total thermal decay widths of heavy quarkonia in the QGP.
[ { "created": "Sat, 11 May 2024 14:51:47 GMT", "version": "v1" } ]
2024-05-14
[ [ "Zhao", "Shouxing", "" ], [ "He", "Min", "" ] ]
We revisit the dissociation of heavy quarkonia by thermal partons at the next-to-leading order (NLO, also known as inelastic parton scattering dissociation) in the Quark-Gluon Plasma (QGP). Utilizing the chromo-electric dipole coupling from QCD multipole expansion as an effective Hamiltonian, this has been conducted in the approach of second-order quantum mechanical perturbation theory, which allows us to systematically incorporate the bound state wave functions. Employing the quarkonium wave functions and binding energies obtained from an in-medium potential model, we then numerically evaluate the dissociation cross sections and rates for various charmonia and bottomonia, where the infrared and collinear divergences are regularized by the thermal masses of medium partons. We demonstrate that distinct from the leading order (LO, also known as gluo-dissociation) counterparts peaking at relatively low gluon energy and falling off thereafter, the NLO cross sections first grow and then nearly saturate as the incident parton energy increases, as a result of the outgoing parton carrying away the excess energy. The resulting NLO dissociation rates increase with temperature and take over from the LO counterparts toward high temperatures, similar to pertinent findings from previous studies. We also evaluate the in-medium second-order transition between different bound states, which may contribute to the total thermal decay widths of heavy quarkonia in the QGP.
hep-ph/0204323
Zuo-tang Liang
Zuo-tang Liang (Shandong U.) and Chun-xiu Liu (Shandong U. & IHEP Bejing)
Hyperon polarization in \nu_\mu charged current interaction at the NOMAD energies
11 pages, 3 figures
Phys. Rev. D66, 057302 (2002)
10.1103/PhysRevD.66.057302
null
hep-ph
null
We show that, in $\nu_\mu N\to \mu^-\Lambda X$ at the NOMAD energies, it is impossible to separate the products of the fragmentation of the struck quark from those of the nucleon remnant. The latter has a large contribution even in the current fragmentation region and has to be taken into account in calculating $\Lambda$ polarization using different pictures. Based on this, we make a rough estimation for the longitudinal $\Lambda$ polarization in $\nu_{\mu} N \to \mu^- \Lambda X$ at the NOMAD energies. A comparison with the data is given and predictions for $\nu_\mu N\to\mu^-\Sigma^+X$ are presented.
[ { "created": "Sun, 28 Apr 2002 08:17:02 GMT", "version": "v1" }, { "created": "Mon, 15 Jul 2002 19:35:25 GMT", "version": "v2" } ]
2009-11-07
[ [ "Liang", "Zuo-tang", "", "Shandong U." ], [ "Liu", "Chun-xiu", "", "Shandong U. & IHEP\n Bejing" ] ]
We show that, in $\nu_\mu N\to \mu^-\Lambda X$ at the NOMAD energies, it is impossible to separate the products of the fragmentation of the struck quark from those of the nucleon remnant. The latter has a large contribution even in the current fragmentation region and has to be taken into account in calculating $\Lambda$ polarization using different pictures. Based on this, we make a rough estimation for the longitudinal $\Lambda$ polarization in $\nu_{\mu} N \to \mu^- \Lambda X$ at the NOMAD energies. A comparison with the data is given and predictions for $\nu_\mu N\to\mu^-\Sigma^+X$ are presented.
1412.5174
Felix Kahlhoefer
Matthew J. Dolan, Felix Kahlhoefer, Christopher McCabe, Kai Schmidt-Hoberg
A taste of dark matter: Flavour constraints on pseudoscalar mediators
35 pages + appendices, 12 figures; v2: minor changes, references added, matches published version; v3: equation (2.8) corrected, discussion updated, conclusions unchanged
JHEP 1503 (2015) 171
10.1007/JHEP03(2015)171
DESY 14-238, SLAC-PUB-16179
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter interacting via the exchange of a light pseudoscalar can induce observable signals in indirect detection experiments and experience large self-interactions while evading the strong bounds from direct dark matter searches. The pseudoscalar mediator will however induce flavour-changing interactions in the Standard Model, providing a promising alternative way to test these models. We investigate in detail the constraints arising from rare meson decays and fixed target experiments for different coupling structures between the pseudoscalar and Standard Model fermions. The resulting bounds are highly complementary to the information inferred from the dark matter relic density and the constraints from primordial nucleosynthesis. We discuss the implications of our findings for the dark matter self-interaction cross section and the prospects of probing dark matter coupled to a light pseudoscalar with direct or indirect detection experiments. In particular, we find that a pseudoscalar mediator can only explain the Galactic Centre excess if its mass is above that of the B mesons, and that it is impossible to obtain a sufficiently large direct detection cross section to account for the DAMA modulation
[ { "created": "Tue, 16 Dec 2014 21:00:05 GMT", "version": "v1" }, { "created": "Wed, 18 Feb 2015 21:51:45 GMT", "version": "v2" }, { "created": "Fri, 3 Jul 2015 13:27:05 GMT", "version": "v3" } ]
2015-07-06
[ [ "Dolan", "Matthew J.", "" ], [ "Kahlhoefer", "Felix", "" ], [ "McCabe", "Christopher", "" ], [ "Schmidt-Hoberg", "Kai", "" ] ]
Dark matter interacting via the exchange of a light pseudoscalar can induce observable signals in indirect detection experiments and experience large self-interactions while evading the strong bounds from direct dark matter searches. The pseudoscalar mediator will however induce flavour-changing interactions in the Standard Model, providing a promising alternative way to test these models. We investigate in detail the constraints arising from rare meson decays and fixed target experiments for different coupling structures between the pseudoscalar and Standard Model fermions. The resulting bounds are highly complementary to the information inferred from the dark matter relic density and the constraints from primordial nucleosynthesis. We discuss the implications of our findings for the dark matter self-interaction cross section and the prospects of probing dark matter coupled to a light pseudoscalar with direct or indirect detection experiments. In particular, we find that a pseudoscalar mediator can only explain the Galactic Centre excess if its mass is above that of the B mesons, and that it is impossible to obtain a sufficiently large direct detection cross section to account for the DAMA modulation
hep-ph/9208233
Ajit Srivastava
M.J. Bowick, L. Chandar, E.A. Schiff, and A.M. Srivastava
The Cosmological Kibble Mechanism in the Laboratory: String Formation in Liquid Crystals
17 pages, in TEX, 2 figures (not included, available on request)
Science 263:943-945,1994
10.1126/science.263.5149.943
SU-HEP-4241-512, TPI-MINN-92/35-T
hep-ph cond-mat hep-th
null
We have observed the production of strings (disclination lines and loops) via the Kibble mechanism of domain (bubble) formation in the isotropic to nematic phase transition of a sample of uniaxial nematic liquid crystal. The probablity of string formation per bubble is measured to be $0.33 \pm 0.01$. This is in good agreement with the theoretical value $1/ \pi$ expected in two dimensions for the order parameter space $S^2/{\bf Z}_2$ of a simple uniaxial nematic liquid crystal.
[ { "created": "Wed, 19 Aug 1992 15:17:02 GMT", "version": "v1" } ]
2011-07-19
[ [ "Bowick", "M. J.", "" ], [ "Chandar", "L.", "" ], [ "Schiff", "E. A.", "" ], [ "Srivastava", "A. M.", "" ] ]
We have observed the production of strings (disclination lines and loops) via the Kibble mechanism of domain (bubble) formation in the isotropic to nematic phase transition of a sample of uniaxial nematic liquid crystal. The probablity of string formation per bubble is measured to be $0.33 \pm 0.01$. This is in good agreement with the theoretical value $1/ \pi$ expected in two dimensions for the order parameter space $S^2/{\bf Z}_2$ of a simple uniaxial nematic liquid crystal.
1612.04086
Margarete Muhlleitner
P. Basler, M. Krause, M. Muhlleitner, J. Wittbrodt, A. Wlotzka
Strong First Order Electroweak Phase Transition in the CP-Conserving 2HDM Revisited
34 pages, 12 figures, 3 tables. Matches journal version accepted for publication
null
10.1007/JHEP02(2017)121
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discovery of the Higgs boson by the LHC experiments ATLAS and CMS has marked a milestone for particle physics. Yet, there are still many open questions that cannot be answered within the Standard Model (SM). For example, the generation of the observed matter-antimatter asymmetry in the universe through baryogenesis can only be explained qualitatively in the SM. A simple extension of the SM compatible with the current theoretical and experimental constraints is given by the 2-Higgs-Doublet Model (2HDM) where a second Higgs doublet is added to the Higgs sector. We investigate the possibility of a strong first order electroweak phase transition in the CP-conserving 2HDM type I and type II where either of the CP-even Higgs bosons is identified with the SM-like Higgs boson. The renormalisation that we apply on the loop-corrected Higgs potential allows us to efficiently scan the 2HDM parameter space and simultaneously take into account all relevant theoretical and up-to-date experimental constraints. The 2HDM parameter regions found to be compatible with the applied constraints and a strong electroweak phase transition are analysed systematically. Our results show that there is a strong interplay between the requirement of a strong phase transition and collider phenomenology with testable implications for searches at the LHC.
[ { "created": "Tue, 13 Dec 2016 10:23:03 GMT", "version": "v1" }, { "created": "Sat, 25 Mar 2017 05:09:38 GMT", "version": "v2" } ]
2017-03-28
[ [ "Basler", "P.", "" ], [ "Krause", "M.", "" ], [ "Muhlleitner", "M.", "" ], [ "Wittbrodt", "J.", "" ], [ "Wlotzka", "A.", "" ] ]
The discovery of the Higgs boson by the LHC experiments ATLAS and CMS has marked a milestone for particle physics. Yet, there are still many open questions that cannot be answered within the Standard Model (SM). For example, the generation of the observed matter-antimatter asymmetry in the universe through baryogenesis can only be explained qualitatively in the SM. A simple extension of the SM compatible with the current theoretical and experimental constraints is given by the 2-Higgs-Doublet Model (2HDM) where a second Higgs doublet is added to the Higgs sector. We investigate the possibility of a strong first order electroweak phase transition in the CP-conserving 2HDM type I and type II where either of the CP-even Higgs bosons is identified with the SM-like Higgs boson. The renormalisation that we apply on the loop-corrected Higgs potential allows us to efficiently scan the 2HDM parameter space and simultaneously take into account all relevant theoretical and up-to-date experimental constraints. The 2HDM parameter regions found to be compatible with the applied constraints and a strong electroweak phase transition are analysed systematically. Our results show that there is a strong interplay between the requirement of a strong phase transition and collider phenomenology with testable implications for searches at the LHC.
hep-ph/0703050
Robert Shrock
Robert Shrock
Some Recent Results on Models of Dynamical Electroweak Symmetry Breaking
15 pages 3 figures, review talk given at SCGT06, International Workshop on Strongly Coupled Gauge Theories, Nagoya, Nov. 2006, to appear in the Proceedings of SCGT06, eds. M. Tanabashi, M. Harada, and K. Yamawaki
null
10.1142/9789812790750_0023
YITP-SB-07-06
hep-ph
null
We review some recent results on models of dynamical electroweak symmetry breaking involving extended technicolor.
[ { "created": "Mon, 5 Mar 2007 14:20:26 GMT", "version": "v1" } ]
2017-08-23
[ [ "Shrock", "Robert", "" ] ]
We review some recent results on models of dynamical electroweak symmetry breaking involving extended technicolor.
1305.3768
Ruben Sandapen
Jeff Forshaw and Ruben Sandapen
Diffractive vector meson production at HERA using holographic AdS/QCD wavefunctions
Proceedings Contribution to the XXI International Workshop on Deep-Inelastic Scattering and Related Subjects, 22-26 April, 2013, Marseilles, France. 5 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate another success of the AdS/QCD correspondence by showing that an AdS/QCD holographic light-front wavefunction for the $\rho$ meson generates predictions for the cross-sections of diffractive $\rho$ production that are in agreement with data collected at the HERA electron-proton collider.
[ { "created": "Thu, 16 May 2013 11:53:09 GMT", "version": "v1" } ]
2013-05-17
[ [ "Forshaw", "Jeff", "" ], [ "Sandapen", "Ruben", "" ] ]
We demonstrate another success of the AdS/QCD correspondence by showing that an AdS/QCD holographic light-front wavefunction for the $\rho$ meson generates predictions for the cross-sections of diffractive $\rho$ production that are in agreement with data collected at the HERA electron-proton collider.
hep-ph/9708376
Hajime Aoki
H. Aoki
Baryogenesis at the Electroweak Scale and Above
35 pages, Latex, uses epsf, 5 figures. To be published in the proceedings of 5th KEK Meeting on CP Violation and Its Origin, Tsukuba, Japan, 6-7 Mar 1997. References added
null
null
KEK-TH-534
hep-ph
null
We consider origins of the baryon asymmetry which we observe today. We review the progress of electroweak-scale baryogenesis, and show a new mechanism, string-scale baryogenesis.
[ { "created": "Sat, 16 Aug 1997 19:33:43 GMT", "version": "v1" }, { "created": "Mon, 29 Sep 1997 11:25:42 GMT", "version": "v2" } ]
2008-02-03
[ [ "Aoki", "H.", "" ] ]
We consider origins of the baryon asymmetry which we observe today. We review the progress of electroweak-scale baryogenesis, and show a new mechanism, string-scale baryogenesis.
2106.04585
Aleksas Mazeliauskas
Claude Duhr, Alexander Huss, Aleksas Mazeliauskas, Robert Szafron
An analysis of Bayesian estimates for missing higher orders in perturbative calculations
63 pages, 27 figures, for MiHO code see https://github.com/aykhuss/miho v2: updated references, other small changes, published version
JHEP 09 (2021) 122
10.1007/JHEP09(2021)122
CERN-TH-2021-058
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
With current high precision collider data, the reliable estimation of theoretical uncertainties due to missing higher orders (MHOs) in perturbation theory has become a pressing issue for collider phenomenology. Traditionally, the size of the MHOs is estimated through scale variation, a simple but ad hoc method without probabilistic interpretation. Bayesian approaches provide a compelling alternative to estimate the size of the MHOs, but it is not clear how to interpret the perturbative scales, like the factorisation and renormalisation scales, in a Bayesian framework. Recently, it was proposed that the scales can be incorporated as hidden parameters into a Bayesian model. In this paper, we thoroughly scrutinise Bayesian approaches to MHO estimation and systematically study the performance of different models on an extensive set of high-order calculations. We extend the framework in two significant ways. First, we define a new model that allows for asymmetric probability distributions. Second, we introduce a prescription to incorporate information on perturbative scales without interpreting them as hidden model parameters. We clarify how the two scale prescriptions bias the result towards specific scale choice, and we discuss and compare different Bayesian MHO estimates among themselves and to the traditional scale variation approach. Finally, we provide a practical prescription of how existing perturbative results at the standard scale variation points can be converted to 68%/95% credibility intervals in the Bayesian approach using the new public code MiHO.
[ { "created": "Tue, 8 Jun 2021 18:00:00 GMT", "version": "v1" }, { "created": "Wed, 29 Sep 2021 06:58:38 GMT", "version": "v2" } ]
2021-09-30
[ [ "Duhr", "Claude", "" ], [ "Huss", "Alexander", "" ], [ "Mazeliauskas", "Aleksas", "" ], [ "Szafron", "Robert", "" ] ]
With current high precision collider data, the reliable estimation of theoretical uncertainties due to missing higher orders (MHOs) in perturbation theory has become a pressing issue for collider phenomenology. Traditionally, the size of the MHOs is estimated through scale variation, a simple but ad hoc method without probabilistic interpretation. Bayesian approaches provide a compelling alternative to estimate the size of the MHOs, but it is not clear how to interpret the perturbative scales, like the factorisation and renormalisation scales, in a Bayesian framework. Recently, it was proposed that the scales can be incorporated as hidden parameters into a Bayesian model. In this paper, we thoroughly scrutinise Bayesian approaches to MHO estimation and systematically study the performance of different models on an extensive set of high-order calculations. We extend the framework in two significant ways. First, we define a new model that allows for asymmetric probability distributions. Second, we introduce a prescription to incorporate information on perturbative scales without interpreting them as hidden model parameters. We clarify how the two scale prescriptions bias the result towards specific scale choice, and we discuss and compare different Bayesian MHO estimates among themselves and to the traditional scale variation approach. Finally, we provide a practical prescription of how existing perturbative results at the standard scale variation points can be converted to 68%/95% credibility intervals in the Bayesian approach using the new public code MiHO.
1911.07286
Paul Hoyer
Paul Hoyer
Bound states and perturbation theory
4 pages. Talk at Light Cone 2019, 16-20 September 2019, Ecole Polytechnique, Palaiseau, France
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A perturbative expansion for QED and QCD bound states is formulated in $A^0=0$ gauge. The constituents of each Fock state are bound by their instantaneous interaction. In QCD an O($\alpha_s^0$) confining potential arises from a homogeneous solution of Gauss' constraint. The potential is uniquely determined by the QCD action, up to a universal scale. The Cornell potential is reproduced for quarkonia, and corresponding ones found for higher Fock states, baryons and glueballs.
[ { "created": "Sun, 17 Nov 2019 17:10:13 GMT", "version": "v1" } ]
2019-11-19
[ [ "Hoyer", "Paul", "" ] ]
A perturbative expansion for QED and QCD bound states is formulated in $A^0=0$ gauge. The constituents of each Fock state are bound by their instantaneous interaction. In QCD an O($\alpha_s^0$) confining potential arises from a homogeneous solution of Gauss' constraint. The potential is uniquely determined by the QCD action, up to a universal scale. The Cornell potential is reproduced for quarkonia, and corresponding ones found for higher Fock states, baryons and glueballs.
0901.3545
Hyun Min Lee
Ki-Young Choi and Hyun Min Lee
U(1)_R-mediated supersymmetry breaking from a six-dimensional flux compactification
33 pages, 9 figures, published version in JHEP
JHEP 0903:132,2009
10.1088/1126-6708/2009/03/132
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the U(1)_R-mediated supersymmetry breaking in a flux compactification of 6D chiral gauged supergravity with codimension-two branes. We consider a concrete model with manifest U(1)_R invariance for moduli stabilization and visible sector in the context of 4D effective supergravity with gauged U(1)_R and determine soft scalar masses in the visible sector mainly by a nonzero U(1)_R D-term. We obtain a low energy superparticle spectrum and discuss on the implications of the obtained non-universal scalar soft masses on the SUSY phenomenology such as dark matter relic abundances.
[ { "created": "Thu, 22 Jan 2009 19:56:32 GMT", "version": "v1" }, { "created": "Mon, 23 Mar 2009 14:07:35 GMT", "version": "v2" } ]
2010-04-21
[ [ "Choi", "Ki-Young", "" ], [ "Lee", "Hyun Min", "" ] ]
We study the U(1)_R-mediated supersymmetry breaking in a flux compactification of 6D chiral gauged supergravity with codimension-two branes. We consider a concrete model with manifest U(1)_R invariance for moduli stabilization and visible sector in the context of 4D effective supergravity with gauged U(1)_R and determine soft scalar masses in the visible sector mainly by a nonzero U(1)_R D-term. We obtain a low energy superparticle spectrum and discuss on the implications of the obtained non-universal scalar soft masses on the SUSY phenomenology such as dark matter relic abundances.
1307.0965
Pouya Bakhti
Pouya Bakhti, Yasaman Farzan
Measuring Dirac CP-violating phase with intermediate energy beta beam facility
14 pages, 7 figures
null
10.1140/epjc/s10052-014-2777-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Taking the established nonzero value of $\theta_{13}$, we study the possibility of extracting the Dirac CP-violating phase by a beta beam facility with a boost factor $100<\gamma<450$. We compare the performance of different setups with different baselines, boost factors and detector technologies. We find that an antineutrino beam from $^6$He decay with a baseline of $L=1300$ km has a very promising CP discovery potential using a 500 kton Water Cherenkov (WC) detector. Fortunately this baseline corresponds to the distance between FermiLAB to Sanford underground research facility in South Dakota.
[ { "created": "Wed, 3 Jul 2013 10:54:05 GMT", "version": "v1" }, { "created": "Thu, 19 Dec 2013 05:40:23 GMT", "version": "v2" } ]
2015-06-16
[ [ "Bakhti", "Pouya", "" ], [ "Farzan", "Yasaman", "" ] ]
Taking the established nonzero value of $\theta_{13}$, we study the possibility of extracting the Dirac CP-violating phase by a beta beam facility with a boost factor $100<\gamma<450$. We compare the performance of different setups with different baselines, boost factors and detector technologies. We find that an antineutrino beam from $^6$He decay with a baseline of $L=1300$ km has a very promising CP discovery potential using a 500 kton Water Cherenkov (WC) detector. Fortunately this baseline corresponds to the distance between FermiLAB to Sanford underground research facility in South Dakota.
hep-ph/9905284
Mustafa Savci
T. M. Aliev, M. Savci (Middle East Technical University, Ankara, Turkey)
The "radiative Delta -> N gamma" decay in light cone QCD
9 pages, 1figures, LaTeX formatted
Phys.Rev. D60 (1999) 114031
10.1103/PhysRevD.60.114031
metu-phys-hep-99-25
hep-ph
null
The "g_{Delta N gamma}" coupling for the "Delta -> N gamma" decay is calculated in framework of the light cone QCD sum rules and is found to be g_{Delta N gamma} = (1.6 pm 0.2) GeV^(-1). Using this value of g_{Delta N gamma} we estimate the branching ratio of the Delta^+ -> N gamma decay, which is in a very good agreement with the experimental result.
[ { "created": "Mon, 10 May 1999 12:09:33 GMT", "version": "v1" } ]
2009-10-31
[ [ "Aliev", "T. M.", "", "Middle East Technical University, Ankara,\n Turkey" ], [ "Savci", "M.", "", "Middle East Technical University, Ankara,\n Turkey" ] ]
The "g_{Delta N gamma}" coupling for the "Delta -> N gamma" decay is calculated in framework of the light cone QCD sum rules and is found to be g_{Delta N gamma} = (1.6 pm 0.2) GeV^(-1). Using this value of g_{Delta N gamma} we estimate the branching ratio of the Delta^+ -> N gamma decay, which is in a very good agreement with the experimental result.
1008.4555
Doug McKay
Martin M. Block, Phuoc Ha and Douglas W. McKay
Ultrahigh energy neutrino scattering: an update
8 pages, 1 figure, 3 tables
Phys.Rev.D82:077302,2010
10.1103/PhysRevD.82.077302
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We update our estimates of charged and neutral current neutrino total cross sections on isoscalar nucleons at ultrahigh energies using a global (x, Q^2) fit, motivated by the Froissart bound, to the F_2 (electron-proton) structure function utilizing the most recent analysis of the complete ZEUS and H1 data sets from HERA I. Using the large Q^2, small Bjorken-x limits of the "wee" parton model, we connect the ultrahigh energy neutrino cross sections directly to the large Q^2, small-x extrapolation of our new fit, which we assume saturates the Froissart bound. We compare both to our previous work, which utilized only the smaller ZEUS data set, as well as to recent results of a calculation using the ZEUS-S based global perturbative QCD parton distributions using the combined HERA I results as input. Our new results substantiate our previous conclusions, again predicting significantly smaller cross sections than those predicted by extrapolating pQCD calculations to neutrino energies above 10^9 GeV.
[ { "created": "Thu, 26 Aug 2010 17:51:57 GMT", "version": "v1" } ]
2014-11-21
[ [ "Block", "Martin M.", "" ], [ "Ha", "Phuoc", "" ], [ "McKay", "Douglas W.", "" ] ]
We update our estimates of charged and neutral current neutrino total cross sections on isoscalar nucleons at ultrahigh energies using a global (x, Q^2) fit, motivated by the Froissart bound, to the F_2 (electron-proton) structure function utilizing the most recent analysis of the complete ZEUS and H1 data sets from HERA I. Using the large Q^2, small Bjorken-x limits of the "wee" parton model, we connect the ultrahigh energy neutrino cross sections directly to the large Q^2, small-x extrapolation of our new fit, which we assume saturates the Froissart bound. We compare both to our previous work, which utilized only the smaller ZEUS data set, as well as to recent results of a calculation using the ZEUS-S based global perturbative QCD parton distributions using the combined HERA I results as input. Our new results substantiate our previous conclusions, again predicting significantly smaller cross sections than those predicted by extrapolating pQCD calculations to neutrino energies above 10^9 GeV.
1507.01693
Giulia Zanderighi
Giulia Zanderighi
QCD and High Energy Interactions: Moriond 2015 Theory Summary
15 pages, 8 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I will summarise the new theory developments that emerged during the 2015 QCD Moriond conference. I will give my perspective on some of the topics and emphasise what I consider most relevant.
[ { "created": "Tue, 7 Jul 2015 07:42:38 GMT", "version": "v1" } ]
2015-07-08
[ [ "Zanderighi", "Giulia", "" ] ]
I will summarise the new theory developments that emerged during the 2015 QCD Moriond conference. I will give my perspective on some of the topics and emphasise what I consider most relevant.
1503.07661
Asgeir Osland
Matti Herranen, Asgeir Osland, Anders Tranberg
Quantum corrections to inflaton dynamics, the semi-classical approach and the semi-classical limit
Some revision and rewordings, added references. 16 pages
Phys. Rev. D 92, 083530 (2015)
10.1103/PhysRevD.92.083530
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Computations of quantum corrections to the CMB spectrum and to scalar field dynamics during inflation very often take advantage of the "semi-classical" approach, where the metric fluctuations are simply omitted. On the other hand, a complete computation ought to take into account that the matter field perturbation and scalar metric perturbation together constitute a single physical degree of freedom. The question then naturally arises, in which sense the semi-classical approach is an approximation to the complete calculation, and whether there are specific limits where this is also a good approximation. We consider the quantum corrected dynamics of interacting scalar fields in an expanding inflationary background. We demonstrate this by explicitly computing the leading quantum radiative corrections to the evolution equation of the mean field ("condensate") and the Friedmann equations taking into account scalar perturbations of both the matter field and the metric, and when omitting the latter. We find that the two agree in the limit H << M_pl , but one is not a limit of the other. We also find that in simple models of inflation, H/M_pl is not small enough that the two approaches can be said to agree. By direct comparison, we demonstrate how to interpret the "semi-classical" approach often employed in more complex computations as a well-defined approximation, and quantify its validity.
[ { "created": "Thu, 26 Mar 2015 09:47:00 GMT", "version": "v1" }, { "created": "Wed, 19 Aug 2015 09:45:36 GMT", "version": "v2" }, { "created": "Mon, 24 Aug 2015 08:06:50 GMT", "version": "v3" } ]
2015-11-04
[ [ "Herranen", "Matti", "" ], [ "Osland", "Asgeir", "" ], [ "Tranberg", "Anders", "" ] ]
Computations of quantum corrections to the CMB spectrum and to scalar field dynamics during inflation very often take advantage of the "semi-classical" approach, where the metric fluctuations are simply omitted. On the other hand, a complete computation ought to take into account that the matter field perturbation and scalar metric perturbation together constitute a single physical degree of freedom. The question then naturally arises, in which sense the semi-classical approach is an approximation to the complete calculation, and whether there are specific limits where this is also a good approximation. We consider the quantum corrected dynamics of interacting scalar fields in an expanding inflationary background. We demonstrate this by explicitly computing the leading quantum radiative corrections to the evolution equation of the mean field ("condensate") and the Friedmann equations taking into account scalar perturbations of both the matter field and the metric, and when omitting the latter. We find that the two agree in the limit H << M_pl , but one is not a limit of the other. We also find that in simple models of inflation, H/M_pl is not small enough that the two approaches can be said to agree. By direct comparison, we demonstrate how to interpret the "semi-classical" approach often employed in more complex computations as a well-defined approximation, and quantify its validity.
1111.3294
Tao Wang
Miao Li, Da Liu, Jun Meng, Tower Wang, Lanjun Zhou
Replaying neutrino bremsstrahlung with general dispersion relations
16 pages, 3 figures; sect 5.5 added, squared amplitude corrected and decay width adjusted accordingly
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is generally held that neutrinos with superluminal velocity will lose their energy spontaneously by radiating electron-positron pairs, similar to bremsstrahlung process. Recently, this process was closely studied for neutrinos whose energy is roughly proportional to their momentum. Confronted with an increasing amount of superluminal neutrino models, it is urgent to calculate the same process for general dispersion relations. The calculation is performed in this paper, without resorting to any nontrivial frame such as the effective "rest frame".
[ { "created": "Mon, 14 Nov 2011 17:29:06 GMT", "version": "v1" }, { "created": "Tue, 21 Feb 2012 09:42:31 GMT", "version": "v2" } ]
2012-02-22
[ [ "Li", "Miao", "" ], [ "Liu", "Da", "" ], [ "Meng", "Jun", "" ], [ "Wang", "Tower", "" ], [ "Zhou", "Lanjun", "" ] ]
It is generally held that neutrinos with superluminal velocity will lose their energy spontaneously by radiating electron-positron pairs, similar to bremsstrahlung process. Recently, this process was closely studied for neutrinos whose energy is roughly proportional to their momentum. Confronted with an increasing amount of superluminal neutrino models, it is urgent to calculate the same process for general dispersion relations. The calculation is performed in this paper, without resorting to any nontrivial frame such as the effective "rest frame".
1704.06222
Amir N. Khan
Amir N. Khan, Douglas W. McKay
$\sin^2(\theta)w$ estimate and bounds on nonstandard interactions at source and detector in the solar neutrino low-energy regime
20 pages, 09 figures, lowest-energy value of sin^2(theta)w to date has been reported. Some text added. New sub-section(7.5) added. Published in JHEP
J. High Energ. Phys. (2017) 2017: 143
10.1007/JHEP07(2017)143
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the implications of the Borexino experiment's real time measurements of the lowest energy part of the neutrino spectrum from the primary pp fusion process up to 0.420 MeV through the 7^Be decay at 0.862 MeV to the pep reaction at 1.44 MeV. We exploit the fact that at such low energies, the large mixing angle solution to the Mikheyev-Smirnov-Wolfenstein matter effects in the sun are small for 7^Be and pep and negligible for pp. Consequently, the neutrinos produced in the sun change their flavor almost entirely through vacuum oscillations during propagation from the sun's surface and through possible nonstandard interactions acting at the solar source and Borexino detector. We combine the different NSI effects at source and detector in a single framework and use the current Borexino data to bound NSI non-universal and flavor- changing parameters at energies below the reach of reactor neutrino experiments. We also study the implication of the current data for the weak- mixing angle at this "low-energy frontier" data from the Borexino experiment, where it is expected to be slightly larger than its value at the Z mass. We find $\sin^2(\theta)w=0.224+-0.016$, the lowest energy-scale estimate to date. Looking to the future, we use projected sensitivities to solar neutrinos in next generation dedicated solar experiments and direct dark matter detection experiments and find a potential factor five improvement in determination of the weak-mixing angle and up to an order of magnitude improvement in probing the NSI parameters space.
[ { "created": "Thu, 20 Apr 2017 16:48:12 GMT", "version": "v1" }, { "created": "Tue, 1 Aug 2017 16:28:11 GMT", "version": "v2" } ]
2017-08-02
[ [ "Khan", "Amir N.", "" ], [ "McKay", "Douglas W.", "" ] ]
We explore the implications of the Borexino experiment's real time measurements of the lowest energy part of the neutrino spectrum from the primary pp fusion process up to 0.420 MeV through the 7^Be decay at 0.862 MeV to the pep reaction at 1.44 MeV. We exploit the fact that at such low energies, the large mixing angle solution to the Mikheyev-Smirnov-Wolfenstein matter effects in the sun are small for 7^Be and pep and negligible for pp. Consequently, the neutrinos produced in the sun change their flavor almost entirely through vacuum oscillations during propagation from the sun's surface and through possible nonstandard interactions acting at the solar source and Borexino detector. We combine the different NSI effects at source and detector in a single framework and use the current Borexino data to bound NSI non-universal and flavor- changing parameters at energies below the reach of reactor neutrino experiments. We also study the implication of the current data for the weak- mixing angle at this "low-energy frontier" data from the Borexino experiment, where it is expected to be slightly larger than its value at the Z mass. We find $\sin^2(\theta)w=0.224+-0.016$, the lowest energy-scale estimate to date. Looking to the future, we use projected sensitivities to solar neutrinos in next generation dedicated solar experiments and direct dark matter detection experiments and find a potential factor five improvement in determination of the weak-mixing angle and up to an order of magnitude improvement in probing the NSI parameters space.
2108.02871
Igor Strakovsky
Igor I. Strakovsky (GW), William J. Briscoe (GW), Lubomir Pentchev (JLab), and Axel Schmidt (GW)
Threshold Upsilon-meson Photoproduction at EIC and EicC
6 pages, 6 figures, 3 tables
null
10.1103/PhysRevD.104.074028
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
High-accuracy $\Upsilon$-meson photoproduction data from EIC and EicC experiments will allow the measurement of the near-threshold total cross section of the reaction $\gamma p\to\Upsilon p$, from which the absolute value of the $\Upsilon p$ scattering length, $|\alpha_{\Upsilon p}|$, can be extracted using a Vector-Meson Dominance model. For this evaluation, we used $\Upsilon$-meson photoproduction quasi-data from the QCD approach (the production amplitude can be factorized in terms of gluonic generalized parton distributions and the quarkonium distribution amplitude). A comparative analysis of $|\alpha_{\Upsilon p}|$ with the recently determined scattering lengths for $\omega p$, $\phi p$, and $J/\psi p$ using the A2, CLAS, and GlueX experimental data are performed. The role of the "young" vector-meson effect is evaluated.
[ { "created": "Thu, 5 Aug 2021 22:23:58 GMT", "version": "v1" } ]
2021-11-10
[ [ "Strakovsky", "Igor I.", "", "GW" ], [ "Briscoe", "William J.", "", "GW" ], [ "Pentchev", "Lubomir", "", "JLab" ], [ "Schmidt", "Axel", "", "GW" ] ]
High-accuracy $\Upsilon$-meson photoproduction data from EIC and EicC experiments will allow the measurement of the near-threshold total cross section of the reaction $\gamma p\to\Upsilon p$, from which the absolute value of the $\Upsilon p$ scattering length, $|\alpha_{\Upsilon p}|$, can be extracted using a Vector-Meson Dominance model. For this evaluation, we used $\Upsilon$-meson photoproduction quasi-data from the QCD approach (the production amplitude can be factorized in terms of gluonic generalized parton distributions and the quarkonium distribution amplitude). A comparative analysis of $|\alpha_{\Upsilon p}|$ with the recently determined scattering lengths for $\omega p$, $\phi p$, and $J/\psi p$ using the A2, CLAS, and GlueX experimental data are performed. The role of the "young" vector-meson effect is evaluated.
hep-ph/0306283
Thomas G. Rizzo
Thomas G. Rizzo
More Transverse Polarization Signatures of Extra Dimensions at Linear Colliders
20 pages, 5 figs, LaTex
JHEP 0308 (2003) 051
10.1088/1126-6708/2003/08/051
SLAC-PUB-10001
hep-ph
null
Polarization of both electron and positron beams at a future linear collider (LC) allows for the measurement of transverse polarization asymmetries. These asymmetries have been shown to be particularly sensitive to graviton or other spin-2, $s-$channel exchanges in the process $e^+e^- \to f\bar f (f\neq e)$ which allows for a doubling of the usual search reach. A question then arises as to whether other $e^+e^-$ processes also show comparable sensitivity. Here we extend our previous analysis to the set of final states $e^+e^-, W^+W^-,~2\gamma$ and $~2Z$ as well as to the M{\o}ller scattering process $e^-e^-\to e^-e^-$. We demonstrate that these reactions yield transverse polarization asymmetries which are somewhat less sensitive to graviton exchange than are those obtained in our earlier analysis for $e^+e^-\to f\bar f$.
[ { "created": "Fri, 27 Jun 2003 21:24:56 GMT", "version": "v1" } ]
2009-11-10
[ [ "Rizzo", "Thomas G.", "" ] ]
Polarization of both electron and positron beams at a future linear collider (LC) allows for the measurement of transverse polarization asymmetries. These asymmetries have been shown to be particularly sensitive to graviton or other spin-2, $s-$channel exchanges in the process $e^+e^- \to f\bar f (f\neq e)$ which allows for a doubling of the usual search reach. A question then arises as to whether other $e^+e^-$ processes also show comparable sensitivity. Here we extend our previous analysis to the set of final states $e^+e^-, W^+W^-,~2\gamma$ and $~2Z$ as well as to the M{\o}ller scattering process $e^-e^-\to e^-e^-$. We demonstrate that these reactions yield transverse polarization asymmetries which are somewhat less sensitive to graviton exchange than are those obtained in our earlier analysis for $e^+e^-\to f\bar f$.
1804.06389
Kourosh Nozari
M. Khodadi, K. Nozari, A. Bhat and S. Mohsenian
Probing Planck Scale Spacetime By Cavity Opto-Atomic $^{87}$Rb Interferometry
12 pages, 2 figures, Revised Version, Accepted for publication in Progress of Theoretical and Experimental Physics
Prog Theor Exp Phys (2019)
10.1093/ptep/ptz039
null
hep-ph gr-qc hep-th physics.ins-det
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The project of \emph{"quantum spacetime phenomenology"} focuses on searching pragmatically for the Planck scale quantum features of spacetime. Among these features is the existence of a characteristic length scale addressed commonly by effective approaches to quantum gravity (QG). This characteristic length scale could be realized, for instance and simply, by generalizing the standard Heisenberg uncertainty principle (HUP) to a \emph{"generalized uncertainty principle"} (GUP). While usually it is expected that phenomena belonging to the realm of QG are essentially probable solely at the so-called Planck energy, here we show how a GUP proposal containing the most general modification of coordinate representation of the momentum operator could be probed by a \emph{"cold atomic ensemble recoil experiment"} (CARE) as a low energy quantum system. This proposed atomic interferometer setup has advantages over the conventional architectures owing to the enclosure in a high finesse optical cavity which is supported by a new class of low power consumption integrated devices known as \emph{"micro-electro-opto-mechanical systems"} (MEOMS). The proposed system comprises of a micro mechanical oscillator instead of spherical confocal mirrors as one of the components of high finesse optical cavity. In the framework of a bottom-up QG phenomenological viewpoint and by taking into account the measurement accuracy realized for the fine structure constant (FSC) from the Rubidium ($^{87}$Rb) CARE, we set some constraints as upper bounds on the characteristic parameters of the underlying GUP. In the case of superposition of the possible GUP modification terms, we managed to set a tight constraint as $0.999978<\lambda_0<1.00002$ for the dimensionless characteristic parameter.
[ { "created": "Thu, 12 Apr 2018 08:01:49 GMT", "version": "v1" }, { "created": "Tue, 12 Mar 2019 04:55:21 GMT", "version": "v2" } ]
2019-12-06
[ [ "Khodadi", "M.", "" ], [ "Nozari", "K.", "" ], [ "Bhat", "A.", "" ], [ "Mohsenian", "S.", "" ] ]
The project of \emph{"quantum spacetime phenomenology"} focuses on searching pragmatically for the Planck scale quantum features of spacetime. Among these features is the existence of a characteristic length scale addressed commonly by effective approaches to quantum gravity (QG). This characteristic length scale could be realized, for instance and simply, by generalizing the standard Heisenberg uncertainty principle (HUP) to a \emph{"generalized uncertainty principle"} (GUP). While usually it is expected that phenomena belonging to the realm of QG are essentially probable solely at the so-called Planck energy, here we show how a GUP proposal containing the most general modification of coordinate representation of the momentum operator could be probed by a \emph{"cold atomic ensemble recoil experiment"} (CARE) as a low energy quantum system. This proposed atomic interferometer setup has advantages over the conventional architectures owing to the enclosure in a high finesse optical cavity which is supported by a new class of low power consumption integrated devices known as \emph{"micro-electro-opto-mechanical systems"} (MEOMS). The proposed system comprises of a micro mechanical oscillator instead of spherical confocal mirrors as one of the components of high finesse optical cavity. In the framework of a bottom-up QG phenomenological viewpoint and by taking into account the measurement accuracy realized for the fine structure constant (FSC) from the Rubidium ($^{87}$Rb) CARE, we set some constraints as upper bounds on the characteristic parameters of the underlying GUP. In the case of superposition of the possible GUP modification terms, we managed to set a tight constraint as $0.999978<\lambda_0<1.00002$ for the dimensionless characteristic parameter.
hep-ph/9806437
Bjoern Poetter
B. P\"otter
JetViP 1.1: Calculating One- and Two-Jet Cross Sections with Virtual Photons in NLO QCD
31 pages, LaTeX, 3 eps figures
Comput.Phys.Commun. 119 (1999) 45-66
10.1016/S0010-4655(99)00190-3
DESY 98-071
hep-ph
null
JetViP is a computer program for the calculation of inclusive single- and dijet cross sections in eP- and e-gamma-scattering in NLO QCD. The virtuality of the photon, radiated by the incoming electron, can be chosen in a continuous range, reaching from photoproduction into deep inelastic scattering. The various contributions to the full jet cross section, including the resolved photon contributions, are implemented. The calculation is based on the phase-space-slicing method.
[ { "created": "Mon, 22 Jun 1998 12:38:34 GMT", "version": "v1" } ]
2009-10-31
[ [ "Pötter", "B.", "" ] ]
JetViP is a computer program for the calculation of inclusive single- and dijet cross sections in eP- and e-gamma-scattering in NLO QCD. The virtuality of the photon, radiated by the incoming electron, can be chosen in a continuous range, reaching from photoproduction into deep inelastic scattering. The various contributions to the full jet cross section, including the resolved photon contributions, are implemented. The calculation is based on the phase-space-slicing method.
1407.7436
Barbara Betz
Barbara Betz and Miklos Gyulassy
Azimuthal Jet Tomography at RHIC and LHC
4 pages, 4 figures, proceedings of the Quark Matter 2014 conference
null
10.1016/j.nuclphysa.2014.08.109
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Results based on a generic jet-energy loss model that interpolates between running coupling pQCD-based and AdS/CFT-inspired holographic prescriptions are compared to recent data on the high-p_T pion nuclear modification factor and the high-p_T elliptic flow in nuclear collisions at RHIC and LHC. The jet-energy loss model is coupled to various (2+1)d (viscous hydrodynamic) fields. The impact of energy-loss fluctuations is discussed. While a previously proposed AdS/CFT jet-energy loss model with a temperature-independent jet-medium coupling is shown to be inconsistent with the LHC data, we find a rather broad class of jet-energy independent energy-loss models $dE/dx= \kappa(T) x^z T^{2+z}$ that can account for the current data with different temperature-dependent jet-medium couplings $\kappa(T)$ and path-length dependence exponents of $0\le z \le 2$.
[ { "created": "Mon, 28 Jul 2014 14:56:52 GMT", "version": "v1" } ]
2015-06-22
[ [ "Betz", "Barbara", "" ], [ "Gyulassy", "Miklos", "" ] ]
Results based on a generic jet-energy loss model that interpolates between running coupling pQCD-based and AdS/CFT-inspired holographic prescriptions are compared to recent data on the high-p_T pion nuclear modification factor and the high-p_T elliptic flow in nuclear collisions at RHIC and LHC. The jet-energy loss model is coupled to various (2+1)d (viscous hydrodynamic) fields. The impact of energy-loss fluctuations is discussed. While a previously proposed AdS/CFT jet-energy loss model with a temperature-independent jet-medium coupling is shown to be inconsistent with the LHC data, we find a rather broad class of jet-energy independent energy-loss models $dE/dx= \kappa(T) x^z T^{2+z}$ that can account for the current data with different temperature-dependent jet-medium couplings $\kappa(T)$ and path-length dependence exponents of $0\le z \le 2$.
hep-ph/0606091
Kochelev Nikolai Innokentevich
N.Kochelev
Soft Contribution to Quark-Quark Scattering Induced by an Anomalous Chromomagnetic Interaction
4 pages, 2 figures
JETP Lett. 83 (2006) 527-529
null
null
hep-ph
null
We calculate the soft contribution to high energy quark-quark scattering that arises from an instanton-induced quark anomalous chromomagnetic moment. We demonstrate that this is a large contribution, which cannot be neglected for transverse momenta of a few GeV. We discuss the influence of this effect on inclusive particle production.
[ { "created": "Thu, 8 Jun 2006 01:04:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kochelev", "N.", "" ] ]
We calculate the soft contribution to high energy quark-quark scattering that arises from an instanton-induced quark anomalous chromomagnetic moment. We demonstrate that this is a large contribution, which cannot be neglected for transverse momenta of a few GeV. We discuss the influence of this effect on inclusive particle production.
1909.03063
Hai-Yang Cheng
Hai-Yang Cheng, Cheng-Wei Chiang
Revisiting CP violation in $D\to P\!P$ and $V\!P$ decays
31 pages, references updated, to appear in Phys. Rev. D. arXiv admin note: text overlap with arXiv:1205.0580
Phys. Rev. D 100, 093002 (2019)
10.1103/PhysRevD.100.093002
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Direct CP violation in the hadronic charm decays provides a good testing ground for the Kobayashi-Maskawa mechanism in the Standard Model. Any significant deviations from the expectation would be indirect evidence of physics beyond the Standard Model. In view of improved measurements from LHCb and BESIII experiments, we re-analyze the Cabibbo-favored $D \to P\!P$ and $V\!P$ decays in the topological diagram approach. By assuming certain SU(3)-breaking effects in the tree-type amplitudes, we make predictions for both branching fractions and CP asymmetries of the singly Cabibbo-suppressed decay modes. While the color-allowed and -suppressed amplitudes are preferred to scale by the factor dictated by factorization in the $P\!P$ modes, no such scaling is required in the $V\!P$ modes. The $W$-exchange amplitudes are found to change by 10\% to 50\% and depend on whether $d\overline{d}$ or $s\overline{s}$ pair directly emerges from $W$-exchange. The predictions of branching fractions are generally improved after these SU(3) symmetry breaking effects are taken into account. We show in detail how the tree-type, QCD-penguin, and weak penguin-annihilation diagrams contribute and modify CP asymmetry predictions. Future measurements of sufficiently many direct CP asymmetries will be very useful in removing a discrete ambiguity in the strong phases as well as discriminating among different theory approaches. In particular, we predict $a_{CP}(K^+K^-)-a_{CP}(\pi^+\pi^-) = (-1.14 \pm 0.26) \times 10^{-3}$ or $(-1.25 \pm 0.25) \times 10^{-3}$, consistent with the latest data, and $a_{CP}(K^+K^{*-})-a_{CP}(\pi^+\rho^-) = (-1.52 \pm 0.43) \times 10^{-3}$, an attractive and measurable observable in the near future. Moreover, we observe that such CP asymmetry differences are dominated by long-distance penguin-exchange through final-state rescattering.
[ { "created": "Fri, 6 Sep 2019 13:26:18 GMT", "version": "v1" }, { "created": "Tue, 22 Oct 2019 14:18:54 GMT", "version": "v2" } ]
2019-11-20
[ [ "Cheng", "Hai-Yang", "" ], [ "Chiang", "Cheng-Wei", "" ] ]
Direct CP violation in the hadronic charm decays provides a good testing ground for the Kobayashi-Maskawa mechanism in the Standard Model. Any significant deviations from the expectation would be indirect evidence of physics beyond the Standard Model. In view of improved measurements from LHCb and BESIII experiments, we re-analyze the Cabibbo-favored $D \to P\!P$ and $V\!P$ decays in the topological diagram approach. By assuming certain SU(3)-breaking effects in the tree-type amplitudes, we make predictions for both branching fractions and CP asymmetries of the singly Cabibbo-suppressed decay modes. While the color-allowed and -suppressed amplitudes are preferred to scale by the factor dictated by factorization in the $P\!P$ modes, no such scaling is required in the $V\!P$ modes. The $W$-exchange amplitudes are found to change by 10\% to 50\% and depend on whether $d\overline{d}$ or $s\overline{s}$ pair directly emerges from $W$-exchange. The predictions of branching fractions are generally improved after these SU(3) symmetry breaking effects are taken into account. We show in detail how the tree-type, QCD-penguin, and weak penguin-annihilation diagrams contribute and modify CP asymmetry predictions. Future measurements of sufficiently many direct CP asymmetries will be very useful in removing a discrete ambiguity in the strong phases as well as discriminating among different theory approaches. In particular, we predict $a_{CP}(K^+K^-)-a_{CP}(\pi^+\pi^-) = (-1.14 \pm 0.26) \times 10^{-3}$ or $(-1.25 \pm 0.25) \times 10^{-3}$, consistent with the latest data, and $a_{CP}(K^+K^{*-})-a_{CP}(\pi^+\rho^-) = (-1.52 \pm 0.43) \times 10^{-3}$, an attractive and measurable observable in the near future. Moreover, we observe that such CP asymmetry differences are dominated by long-distance penguin-exchange through final-state rescattering.
1701.08730
Bertrand Duclou\'e
B. Duclou\'e
Nuclear modification of forward Drell-Yan production at the LHC
6 pages, 7 figures. v2: published version
Phys. Rev. D 96, 094014 (2017)
10.1103/PhysRevD.96.094014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Forward Drell-Yan production at high energy can provide important constraints on gluon densities at small $x$, in the saturation regime. In this work we focus on the nuclear modification of this process, which could be measured at the LHC in the near future. For this we employ the color dipole approach, using the optical Glauber model to relate the dipole cross section of a nucleus to the one of a proton. Combining these results with our earlier results for forward $J/\psi$ production, we compute the ratio of the nuclear modification factors of these two processes. This observable was recently suggested as a way to distinguish between initial and final state effects in forward particle production.
[ { "created": "Mon, 30 Jan 2017 17:56:07 GMT", "version": "v1" }, { "created": "Mon, 20 Nov 2017 13:09:26 GMT", "version": "v2" } ]
2017-11-21
[ [ "Ducloué", "B.", "" ] ]
Forward Drell-Yan production at high energy can provide important constraints on gluon densities at small $x$, in the saturation regime. In this work we focus on the nuclear modification of this process, which could be measured at the LHC in the near future. For this we employ the color dipole approach, using the optical Glauber model to relate the dipole cross section of a nucleus to the one of a proton. Combining these results with our earlier results for forward $J/\psi$ production, we compute the ratio of the nuclear modification factors of these two processes. This observable was recently suggested as a way to distinguish between initial and final state effects in forward particle production.
2110.15319
Joshua Isaacson
Joshua Isaacson, Stefan H\"oche, Diego Lopez Gutierrez, Noemi Rocco
A novel event generator for the automated simulation of neutrino scattering
13 pages, 8 figures
null
10.1103/PhysRevD.105.096006
FERMILAB-PUB-21-537-T, MCNET-21-31
hep-ph hep-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
An event generation framework is presented that enables the automatic simulation of events for next-generation neutrino experiments in the Standard Model or extensions thereof. The new generator combines the calculation of the leptonic current based on an automated matrix element generator, and the computation of the hadronic current based on a state-of-the-art nuclear physics model. The approach is validated in Standard-Model simulations for electron scattering and neutrino scattering. Furthermore, the first fully-differential neutrino trident production results are shown in the quasielastic region.
[ { "created": "Thu, 28 Oct 2021 17:33:54 GMT", "version": "v1" }, { "created": "Fri, 18 Feb 2022 15:37:34 GMT", "version": "v2" } ]
2022-05-18
[ [ "Isaacson", "Joshua", "" ], [ "Höche", "Stefan", "" ], [ "Gutierrez", "Diego Lopez", "" ], [ "Rocco", "Noemi", "" ] ]
An event generation framework is presented that enables the automatic simulation of events for next-generation neutrino experiments in the Standard Model or extensions thereof. The new generator combines the calculation of the leptonic current based on an automated matrix element generator, and the computation of the hadronic current based on a state-of-the-art nuclear physics model. The approach is validated in Standard-Model simulations for electron scattering and neutrino scattering. Furthermore, the first fully-differential neutrino trident production results are shown in the quasielastic region.
1512.04901
Robert Harlander
Robert V. Harlander
Higgs production in heavy quark annihilation through next-to-next-to-leading order QCD
21 pages, 7 figures, 1 table. Matches published version
null
10.1140/epjc/s10052-016-4093-x
TTH-15-38
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The total inclusive cross section for charged and neutral Higgs production in heavy-quark annihilation is presented through NNLO QCD. It is shown that, aside from an overall factor, the partonic cross section is independent of the initial-state quark flavors, and that any interference terms involving two different Yukawa couplings vanish. A simple criterion for defining the central renormalization and factorization scale is proposed. Its application to the $b\bar bH$ process yields results which are compatible with the values usually adopted for this process. Remarkably, we find little variation in these values for the other initial-state quark flavors. Finally, we disentangle the impact of the different parton luminosities from genuine hard NNLO effects and find that, for the central scales, a naive rescaling by the parton luminosities approximates the full result remarkably well.
[ { "created": "Tue, 15 Dec 2015 19:07:48 GMT", "version": "v1" }, { "created": "Mon, 9 May 2016 08:59:23 GMT", "version": "v2" } ]
2016-05-25
[ [ "Harlander", "Robert V.", "" ] ]
The total inclusive cross section for charged and neutral Higgs production in heavy-quark annihilation is presented through NNLO QCD. It is shown that, aside from an overall factor, the partonic cross section is independent of the initial-state quark flavors, and that any interference terms involving two different Yukawa couplings vanish. A simple criterion for defining the central renormalization and factorization scale is proposed. Its application to the $b\bar bH$ process yields results which are compatible with the values usually adopted for this process. Remarkably, we find little variation in these values for the other initial-state quark flavors. Finally, we disentangle the impact of the different parton luminosities from genuine hard NNLO effects and find that, for the central scales, a naive rescaling by the parton luminosities approximates the full result remarkably well.
2205.15061
Julia Panteleeva
J.Yu. Panteleeva, E. Epelbaum, J. Gegelia, U.-G. Mei{\ss}ner
On the definition of electromagnetic local spatial densities for composite spin-$1/2$ systems
null
null
10.1103/PhysRevD.106.056019
null
hep-ph hep-th nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
An unambiguous definition of the electromagnetic spatial densities for a spin-1/2 system is proposed and worked out in the zero average momentum frame and in moving frames. The obtained results are compared with the traditional definition of the densities in terms of the three-dimensional Fourier transforms of the electromagnetic form factors in the Breit frame.
[ { "created": "Mon, 30 May 2022 12:41:29 GMT", "version": "v1" } ]
2022-10-05
[ [ "Panteleeva", "J. Yu.", "" ], [ "Epelbaum", "E.", "" ], [ "Gegelia", "J.", "" ], [ "Meißner", "U. -G.", "" ] ]
An unambiguous definition of the electromagnetic spatial densities for a spin-1/2 system is proposed and worked out in the zero average momentum frame and in moving frames. The obtained results are compared with the traditional definition of the densities in terms of the three-dimensional Fourier transforms of the electromagnetic form factors in the Breit frame.
2111.08732
Guo-Yuan Huang
Guo-yuan Huang and Newton Nath
Neutrino meets ultralight dark matter: $\boldsymbol{0\nu\beta\beta}$ decay and cosmology
10 pages, 5 figures, v2: matching the published version
JCAP05(2022)034
10.1088/1475-7516/2022/05/034
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We explore the neutrinoless double beta ($0\nu \beta\beta$) decay induced by an ultralight dark matter field coupled to neutrinos. The effect on $0\nu\beta\beta$ decay is significant if the coupling violates the lepton number, for which the $\Delta L=2$ transition is directly driven by the dark matter field without further suppression of small neutrino masses. As the ultralight dark matter can be well described by a classical field, the effect features a periodic modulation pattern in decay events. However, we find that in the early Universe such coupling will be very likely to alter the standard cosmological results. In particular, the requirement of neutrino free-streaming before the matter-radiation equality severely constrains the parameter space, such that the future $0\nu \beta\beta$ decay experiments can hardly see any signal even with a meV sensitivity to the effective neutrino mass.
[ { "created": "Tue, 16 Nov 2021 19:09:18 GMT", "version": "v1" }, { "created": "Thu, 16 Jun 2022 16:54:40 GMT", "version": "v2" } ]
2022-06-17
[ [ "Huang", "Guo-yuan", "" ], [ "Nath", "Newton", "" ] ]
We explore the neutrinoless double beta ($0\nu \beta\beta$) decay induced by an ultralight dark matter field coupled to neutrinos. The effect on $0\nu\beta\beta$ decay is significant if the coupling violates the lepton number, for which the $\Delta L=2$ transition is directly driven by the dark matter field without further suppression of small neutrino masses. As the ultralight dark matter can be well described by a classical field, the effect features a periodic modulation pattern in decay events. However, we find that in the early Universe such coupling will be very likely to alter the standard cosmological results. In particular, the requirement of neutrino free-streaming before the matter-radiation equality severely constrains the parameter space, such that the future $0\nu \beta\beta$ decay experiments can hardly see any signal even with a meV sensitivity to the effective neutrino mass.
hep-ph/0307004
Hiroyuki Abe
Hiroyuki Abe
Spontaneous and dynamical symmetry breaking in higher-dimensional space-time with boundary terms
Doctoral thesis, submitted to Department of Physics, Hiroshima University (February 2003), 110 pages, 38 figures
null
null
null
hep-ph hep-th
null
In this thesis we study physics beyond the standard model focusing on the quantum field theory in higher-dimensional space-time with some boundary terms. The boundary term causes nontrivial consequences about the vacuum structure of the higher-dimensional theory. We take particular note of two independent solutions to the weak and Planck hierarchy problem: ``low scale supersymmetry'' and ``dynamical electroweak symmetry breaking.'' From a viewpoint of the low scale supersymmetry, we study $F$ and $D$ term supersymmetry breaking effects on sparticle spectra from a boundary. While we also investigate a nonperturbative effect caused by a bulk (nonsupersymmetric) gauge dynamics on a fermion bilinear condensation on a boundary, and analyze the dynamical symmetry breaking on the brane. From these analyses we conclude that the field localization in higher-dimensional space-time involves in a nontrivial vacuum structure of the theory, and the resultant low energy four-dimensional effective theory has phenomenologically interesting structure. In a framework of purely four-dimensional theory, we also construct the above nontrivial effect of localization in the extra dimension.
[ { "created": "Tue, 1 Jul 2003 04:27:52 GMT", "version": "v1" } ]
2007-05-23
[ [ "Abe", "Hiroyuki", "" ] ]
In this thesis we study physics beyond the standard model focusing on the quantum field theory in higher-dimensional space-time with some boundary terms. The boundary term causes nontrivial consequences about the vacuum structure of the higher-dimensional theory. We take particular note of two independent solutions to the weak and Planck hierarchy problem: ``low scale supersymmetry'' and ``dynamical electroweak symmetry breaking.'' From a viewpoint of the low scale supersymmetry, we study $F$ and $D$ term supersymmetry breaking effects on sparticle spectra from a boundary. While we also investigate a nonperturbative effect caused by a bulk (nonsupersymmetric) gauge dynamics on a fermion bilinear condensation on a boundary, and analyze the dynamical symmetry breaking on the brane. From these analyses we conclude that the field localization in higher-dimensional space-time involves in a nontrivial vacuum structure of the theory, and the resultant low energy four-dimensional effective theory has phenomenologically interesting structure. In a framework of purely four-dimensional theory, we also construct the above nontrivial effect of localization in the extra dimension.
0803.0796
Yuji Omura
Hajime Ishimori, Tatsuo Kobayashi, Hiroshi Ohki, Yuji Omura, Ryo Takahashi and Morimitsu Tanimoto
Soft supersymmetry breaking terms from D4 x Z2 lepton flavor symmetry
17 pages, no figure, comments and refs added
Phys.Rev.D77:115005,2008
10.1103/PhysRevD.77.115005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the supersymmetric model with $D_4 \times Z_2$ lepton flavor symmetry. We evaluate soft supersymmetry breaking terms, i.e. soft slepton masses and A-terms, which are predicted in the $D_4$ flavor model. We consider constraints due to experiments of flavor changing neutral current processes.
[ { "created": "Thu, 6 Mar 2008 06:24:33 GMT", "version": "v1" }, { "created": "Mon, 21 Apr 2008 04:53:20 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ishimori", "Hajime", "" ], [ "Kobayashi", "Tatsuo", "" ], [ "Ohki", "Hiroshi", "" ], [ "Omura", "Yuji", "" ], [ "Takahashi", "Ryo", "" ], [ "Tanimoto", "Morimitsu", "" ] ]
We study the supersymmetric model with $D_4 \times Z_2$ lepton flavor symmetry. We evaluate soft supersymmetry breaking terms, i.e. soft slepton masses and A-terms, which are predicted in the $D_4$ flavor model. We consider constraints due to experiments of flavor changing neutral current processes.
1109.2117
David Wilson
M. R. Pennington and D. J. Wilson
Are the Dressed Gluon and Ghost Propagators in the Landau Gauge presently determined in the confinement regime of QCD?
15 pages, 12 figures. v2: references added and updated, minor corrections to text, Fig. 12 updated, matches journal version
Phys.Rev.D84:094028,2011; Publisher's Note: Phys.Rev.D84:119901(E),2011
10.1103/PhysRevD.84.094028
JLAB-THY-11-1426
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Gluon and Ghost propagators in Landau gauge QCD are investigated using the Schwinger-Dyson equation approach. Working in Euclidean spacetime, we solve for these propagators using a selection of vertex inputs, initially for the ghost equation alone and then for both propagators simultaneously. The results are shown to be highly sensitive to the choices of vertices. We favor the infrared finite ghost solution from studying the ghost equation alone where we argue for a specific unique solution. In order to solve this simultaneously with the gluon using a dressed-one-loop truncation, we find that a non-trivial full ghost-gluon vertex is required in the vanishing gluon momentum limit. The self-consistent solutions we obtain correspond to having a mass-like term in the gluon propagator dressing, in agreement with similar studies supporting the long held proposal of Cornwall.
[ { "created": "Fri, 9 Sep 2011 20:00:04 GMT", "version": "v1" }, { "created": "Thu, 22 Dec 2011 13:38:26 GMT", "version": "v2" } ]
2012-01-12
[ [ "Pennington", "M. R.", "" ], [ "Wilson", "D. J.", "" ] ]
The Gluon and Ghost propagators in Landau gauge QCD are investigated using the Schwinger-Dyson equation approach. Working in Euclidean spacetime, we solve for these propagators using a selection of vertex inputs, initially for the ghost equation alone and then for both propagators simultaneously. The results are shown to be highly sensitive to the choices of vertices. We favor the infrared finite ghost solution from studying the ghost equation alone where we argue for a specific unique solution. In order to solve this simultaneously with the gluon using a dressed-one-loop truncation, we find that a non-trivial full ghost-gluon vertex is required in the vanishing gluon momentum limit. The self-consistent solutions we obtain correspond to having a mass-like term in the gluon propagator dressing, in agreement with similar studies supporting the long held proposal of Cornwall.
1609.03030
Ajay Kumar Rai
Zalak Shah, Kaushal Thakkar and Ajay Kumar Rai
Excited State Mass spectra of doubly heavy baryons $\Omega_{cc}$, $\Omega_{bb}$ and $\Omega_{bc}$
10 pages, 5 figures
Eur. Phys. J. C (2016) 76:530
10.1140/epjc/s10052-016-4379-z
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the mass spectrum of $\Omega$ baryon with two heavy quarks and one light quark (\textit{ccs, bbs and bcs}). The main goal of the paper is to calculate the ground state masses and after that, the positive and negative parity excited states masses are also obtained within a Hypercentral Constituent quark model, using coulomb plus linear potential framework. We also added first order correction to the potential. The mass spectra upto 5S for radial excited states and 1P-5P, 1D-4D and 1F-2F states for orbital excited states are computed for $\Omega_{cc}$, $\Omega_{bb}$ and $\Omega_{bc}$ baryons. Our obtained results are compared with other theoretical predictions which could be a useful complementary tool for the interpretation of experimentaly unknown heavy baryon spectra. The Regge trajectory is constructed in both ($n_r$, $M^{2}$) and ($J$, $M^{2}$) planes for $\Omega_{cc}$,$\Omega_{bb}$ and $\Omega_{bc}$ baryons and their slopes and intercepts are also determined. Magnetic moments of doubly heavy $\Omega'$s are also calculated.
[ { "created": "Sat, 10 Sep 2016 11:34:34 GMT", "version": "v1" } ]
2016-09-30
[ [ "Shah", "Zalak", "" ], [ "Thakkar", "Kaushal", "" ], [ "Rai", "Ajay Kumar", "" ] ]
We discuss the mass spectrum of $\Omega$ baryon with two heavy quarks and one light quark (\textit{ccs, bbs and bcs}). The main goal of the paper is to calculate the ground state masses and after that, the positive and negative parity excited states masses are also obtained within a Hypercentral Constituent quark model, using coulomb plus linear potential framework. We also added first order correction to the potential. The mass spectra upto 5S for radial excited states and 1P-5P, 1D-4D and 1F-2F states for orbital excited states are computed for $\Omega_{cc}$, $\Omega_{bb}$ and $\Omega_{bc}$ baryons. Our obtained results are compared with other theoretical predictions which could be a useful complementary tool for the interpretation of experimentaly unknown heavy baryon spectra. The Regge trajectory is constructed in both ($n_r$, $M^{2}$) and ($J$, $M^{2}$) planes for $\Omega_{cc}$,$\Omega_{bb}$ and $\Omega_{bc}$ baryons and their slopes and intercepts are also determined. Magnetic moments of doubly heavy $\Omega'$s are also calculated.
hep-ph/0212320
Alejandro Ayala
Alejandro Ayala (ICN-UNAM)
Density effects on the pion dispersion relation at finite temperature
8 pages 4 eps figures. Invited talk given at the X Mexican School of Particles and Fields, Playa del Carmen, Mexico 2002
AIP Conf.Proc. 670 (2003) 11-18
10.1063/1.1594313
null
hep-ph
null
We study the behavior of the pion dispersion relation in a pion medium at finite density and temperature, introducing a chemical potential to describe the finite pion number density. Such description is particularly important during the hadronic phase of a relativistic heavy-ion collision, between chemical and thermal freeze-out, where the pion number changing processes, driven by the strong interaction, can be considered to be frozen. We make use of an effective Lagrangian that explicitly respects chiral symmetry through the enforcement of the chiral Ward identities. The pion dispersion relation is computed through the computation of the pion self-energy in a non-perturbative fashion by giving an approximate solution to the Schwinger-Dyson equation for this self-energy. The dispersion relation is described in terms of a density and temperature dependent mass and an index of refraction which is also temperature, density as well as momentum dependent. The index of refraction is larger than unity for all values of the momentum for finite \mu and T. Given the strong coupling between \rho vectors and pions, we argue that the modification of the pion mass due to finite pion density effects has to be taken into account self-consistently for the description of the in-medium modifications of \rho's.
[ { "created": "Fri, 20 Dec 2002 19:59:26 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ayala", "Alejandro", "", "ICN-UNAM" ] ]
We study the behavior of the pion dispersion relation in a pion medium at finite density and temperature, introducing a chemical potential to describe the finite pion number density. Such description is particularly important during the hadronic phase of a relativistic heavy-ion collision, between chemical and thermal freeze-out, where the pion number changing processes, driven by the strong interaction, can be considered to be frozen. We make use of an effective Lagrangian that explicitly respects chiral symmetry through the enforcement of the chiral Ward identities. The pion dispersion relation is computed through the computation of the pion self-energy in a non-perturbative fashion by giving an approximate solution to the Schwinger-Dyson equation for this self-energy. The dispersion relation is described in terms of a density and temperature dependent mass and an index of refraction which is also temperature, density as well as momentum dependent. The index of refraction is larger than unity for all values of the momentum for finite \mu and T. Given the strong coupling between \rho vectors and pions, we argue that the modification of the pion mass due to finite pion density effects has to be taken into account self-consistently for the description of the in-medium modifications of \rho's.
hep-ph/0110163
Kingman Cheung
Kingman Cheung (National Center for Theoretical Sciences, Taiwan)
Black hole production and Large Extra Dimensions
4 pages, constraint of entropy is included and cross sections changed, some new references are added
Phys.Rev.Lett.88:221602,2002
10.1103/PhysRevLett.88.221602
NSC-NCTS-011012
hep-ph hep-th
null
Black hole (BH) production at colliders is possible when the colliding energy is above the Planck scale, which can effectively be at TeV scale in models of large extra dimensions. In this work, we study the production of black holes at colliders and discuss the possible signatures. We point out the ``$ij\to {\rm BH}+ $ others'' subprocesses, in which the BH and other SM particles are produced with a large transverse momentum. When the BH decays, it gives a signature that consists of particles of high multiplicity in a boosted spherical shape on one side of the event and a few number of high $p_T$ partons on the other side, which provide very useful tags for the event.
[ { "created": "Fri, 12 Oct 2001 03:30:12 GMT", "version": "v1" }, { "created": "Mon, 14 Jan 2002 16:16:25 GMT", "version": "v2" } ]
2008-11-26
[ [ "Cheung", "Kingman", "", "National Center for Theoretical Sciences, Taiwan" ] ]
Black hole (BH) production at colliders is possible when the colliding energy is above the Planck scale, which can effectively be at TeV scale in models of large extra dimensions. In this work, we study the production of black holes at colliders and discuss the possible signatures. We point out the ``$ij\to {\rm BH}+ $ others'' subprocesses, in which the BH and other SM particles are produced with a large transverse momentum. When the BH decays, it gives a signature that consists of particles of high multiplicity in a boosted spherical shape on one side of the event and a few number of high $p_T$ partons on the other side, which provide very useful tags for the event.
2003.13219
Hiroshi Okada
Hiroshi Okada, Yutaro Shoji
A radiative seesaw model with three Higgs doublets in modular $A_4$ symmetry
19 pages, 2 tables, 6 figures; version accepted for publication in Nuclear Physics B, discussions on LFVs and fixed point at tau=i are added
null
10.1016/j.nuclphysb.2020.115216
APCTP Pre2020 - 005
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a radiative seesaw model based on a modular $A_4$ symmetry, which has good predictability in the lepton sector. We execute a numerical analysis to search for parameters that satisfy the experimental constraints such as those from neutrino oscillation data and lepton flavor violations. Then, we present several predictions in our model that originate from the modular symmetry at a fixed point as well as fundamental region of $\tau$.
[ { "created": "Mon, 30 Mar 2020 04:54:07 GMT", "version": "v1" }, { "created": "Tue, 13 Oct 2020 06:22:02 GMT", "version": "v2" } ]
2020-12-02
[ [ "Okada", "Hiroshi", "" ], [ "Shoji", "Yutaro", "" ] ]
We propose a radiative seesaw model based on a modular $A_4$ symmetry, which has good predictability in the lepton sector. We execute a numerical analysis to search for parameters that satisfy the experimental constraints such as those from neutrino oscillation data and lepton flavor violations. Then, we present several predictions in our model that originate from the modular symmetry at a fixed point as well as fundamental region of $\tau$.
1003.2132
Joao Pacheco B. C. de Melo Dr.
J. P. B. C. de Melo, and T. Frederico (Laborat\'orio de F\'isica Teorica e Computa\c{c}\~ao Cientifica, LFTC, Universidade Cruzeiro do Sul, S\~ao Paulo, Brazil and Instituto de F\'isica Te\'orica, Universidade Estadual Paulista, IFT-UNESP, S\~ao Paulo, Brazil, Dep. de F\'isica, Instituto Tecnol\'ogico de Aeron\'autica, S\~ao Jos\'e dos Campos, Brazil.)
Light-Front Model of Transition Form-Factors in Heavy Meson Decay
Paper with 5 pages and 2 eps figures. To appear to Nuclear Physics B. Talk at Light Cone 2009: Relativistic Hadronic and Particle Physics (LC 2009), Sao Jose dos Campos, S.P, Brazil, 8-13 Jul 2009.
Nucl.Phys.Proc.Suppl.199:276-280,2010
10.1016/j.nuclphysbps.2010.02.043
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electroweak transition form factors of heavy meson decays are important ingredients in the extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements from experimental data. In this work, within a light-front framework, we calculate electroweak transition form factor for the semileptonic decay of $D$ mesons into a pion or a kaon. The model results underestimate in both cases the new data of CLEO for the larger momentum transfers accessible in the experiment. We discuss possible reasons for that in order to improve the model.
[ { "created": "Wed, 10 Mar 2010 15:47:29 GMT", "version": "v1" } ]
2014-11-20
[ [ "de Melo", "J. P. B. C.", "", "Laboratório de Física\n Teorica e Computação Cientifica, LFTC, Universidade Cruzeiro do Sul,\n São Paulo, Brazil and Instituto de Física Teórica, Universidade\n Estadual Paulista, IFT-UNESP, São Paulo, Brazil, Dep. de Física,\n Instituto Tecnológico de Aeronáutica, São José dos Campos, Brazil." ], [ "Frederico", "T.", "", "Laboratório de Física\n Teorica e Computação Cientifica, LFTC, Universidade Cruzeiro do Sul,\n São Paulo, Brazil and Instituto de Física Teórica, Universidade\n Estadual Paulista, IFT-UNESP, São Paulo, Brazil, Dep. de Física,\n Instituto Tecnológico de Aeronáutica, São José dos Campos, Brazil." ] ]
Electroweak transition form factors of heavy meson decays are important ingredients in the extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements from experimental data. In this work, within a light-front framework, we calculate electroweak transition form factor for the semileptonic decay of $D$ mesons into a pion or a kaon. The model results underestimate in both cases the new data of CLEO for the larger momentum transfers accessible in the experiment. We discuss possible reasons for that in order to improve the model.
2201.04991
V. E. Troitsky
A.F. Krutov, V.E. Troitsky
Relativistic composite-particle theory of the gravitational form factors of pion: quantitative results
13 pages, 3 figures (5 panels), RevTex 4-2. V3: considerable changes in presentaton, results unchanged. Version accepted by PRD
Phys. Rev. D 106 (2022) 054013
10.1103/PhysRevD.106.054013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use a version of the instant-form relativistic quantum mechanics of composite systems to obtain the gravitational form factors of the pion in a common approach to its electroweak and gravitational properties. In the preceding work [arXiv:2010.11640] we formulated the mathematical background, presented the principal scheme of calculation and testified the obtained qualitative results to satisfy the general constraints given by the principles of the theory of hadron structure. In the present work we give the detailed calculation of the gravitational form factors in large range of momentum transfer, their static limits and the slopes at zero value, the mean-square mass and mechanical radii of the pion. Now we take into account the qravitational structure of the constituent quarks. We show that the results are almost insensitive to the type of the model two-quark wave function in a close analogy to the case of the pion electromagnetic form factor. We present a correct calculation of the form factor $D$ and corresponding matrix element of the energy-momentum tensor, going beyond the scope of the modified impulse approximation. Most of the parameters that we use for the calculation had been fixed even earlier in our works on the pion electromagnetic form factors. The only free parameter is the $D$-term of the constituent quark, which we fix by fitting the result for the slope at zero of the normalized to pion $D$-term form factor $D$ of pion, to a choosen experimental value.
[ { "created": "Thu, 13 Jan 2022 14:03:46 GMT", "version": "v1" }, { "created": "Sun, 16 Jan 2022 11:33:25 GMT", "version": "v2" }, { "created": "Thu, 15 Sep 2022 13:30:38 GMT", "version": "v3" } ]
2022-09-16
[ [ "Krutov", "A. F.", "" ], [ "Troitsky", "V. E.", "" ] ]
We use a version of the instant-form relativistic quantum mechanics of composite systems to obtain the gravitational form factors of the pion in a common approach to its electroweak and gravitational properties. In the preceding work [arXiv:2010.11640] we formulated the mathematical background, presented the principal scheme of calculation and testified the obtained qualitative results to satisfy the general constraints given by the principles of the theory of hadron structure. In the present work we give the detailed calculation of the gravitational form factors in large range of momentum transfer, their static limits and the slopes at zero value, the mean-square mass and mechanical radii of the pion. Now we take into account the qravitational structure of the constituent quarks. We show that the results are almost insensitive to the type of the model two-quark wave function in a close analogy to the case of the pion electromagnetic form factor. We present a correct calculation of the form factor $D$ and corresponding matrix element of the energy-momentum tensor, going beyond the scope of the modified impulse approximation. Most of the parameters that we use for the calculation had been fixed even earlier in our works on the pion electromagnetic form factors. The only free parameter is the $D$-term of the constituent quark, which we fix by fitting the result for the slope at zero of the normalized to pion $D$-term form factor $D$ of pion, to a choosen experimental value.
0810.3961
Navneet Kumar Pruthi
Neetika Sharma, Avinash C. Sharma
Weak Hadronic decays of Charmed Baryons and Current-Algebra Scheme
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The weak decay of charmed baryons multiplets into ground state and mesons are investigated using current algebra technique. Some of the interesting results on the partial decays rates and the asymmetry parameters for $\Delta$C=$\Delta$S=-1 the mode are calculated and consequences discussed
[ { "created": "Wed, 22 Oct 2008 03:07:24 GMT", "version": "v1" } ]
2008-10-23
[ [ "Sharma", "Neetika", "" ], [ "Sharma", "Avinash C.", "" ] ]
The weak decay of charmed baryons multiplets into ground state and mesons are investigated using current algebra technique. Some of the interesting results on the partial decays rates and the asymmetry parameters for $\Delta$C=$\Delta$S=-1 the mode are calculated and consequences discussed
2311.00029
Di Liu
Yann Gouttenoire, Eric Kuflik, Di Liu
Heavy Baryon Dark Matter from $SU(N)$ Confinement: Bubble Wall Velocity and Boundary Effects
35 pages, 10 figures, comments are welcomed
null
null
LAPTH-055/23
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Confinement in $SU(N_{\rm DC})$ Yang-Mills theories is known to proceed through first-order phase transition. The wall velocity is bounded by $v_w \lesssim 10^{-6}$ due to the needed time for the substantial latent heat released during the phase transition to dissipate through Hubble expansion. Quarks much heavier than the confinement scale can be introduced without changing the confinement dynamics. After they freeze-out, heavy quarks are squeezed into pockets of the deconfined phase until they completely annihilate with anti-quarks. We calculate the dark baryon abundance surviving annihilation, due to bound-state formation occurring both in the bulk and - for the first time - at the boundary. We find that dark baryons can be dark matter with a mass up to $10^3~\rm TeV$. We study indirect and direct detection, CMB and BBN probes, assuming portals to Higgs and neutrinos.
[ { "created": "Tue, 31 Oct 2023 18:00:01 GMT", "version": "v1" } ]
2023-11-02
[ [ "Gouttenoire", "Yann", "" ], [ "Kuflik", "Eric", "" ], [ "Liu", "Di", "" ] ]
Confinement in $SU(N_{\rm DC})$ Yang-Mills theories is known to proceed through first-order phase transition. The wall velocity is bounded by $v_w \lesssim 10^{-6}$ due to the needed time for the substantial latent heat released during the phase transition to dissipate through Hubble expansion. Quarks much heavier than the confinement scale can be introduced without changing the confinement dynamics. After they freeze-out, heavy quarks are squeezed into pockets of the deconfined phase until they completely annihilate with anti-quarks. We calculate the dark baryon abundance surviving annihilation, due to bound-state formation occurring both in the bulk and - for the first time - at the boundary. We find that dark baryons can be dark matter with a mass up to $10^3~\rm TeV$. We study indirect and direct detection, CMB and BBN probes, assuming portals to Higgs and neutrinos.
1207.3699
Alexandre Alves
Alexandre Alves, A. G. Dias, E. Ramirez Barreto, C. A. de S. Pires, Farinaldo S. Queiroz, and P. S. Rodrigues da Silva
Explaining the Higgs Decays at the LHC with an Extended Electroweak Model
16 pages, 5 figures
null
10.1140/epjc/s10052-013-2288-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the recent discovery of a new boson at the LHC, which we assume to be a Higgs boson, and the observed enhancement in its diphoton decays compared to the SM prediction, can be explained by a new doublet of charged vector bosons from an extended electroweak gauge sector model with SU(3)$_C\otimesSU(3)_L\otimesU(1)_X$ symmetry. Our results show a good agreement between our theoretical expected sensitivity to a 126--125 GeV Higgs boson and the experimental significance observed in the diphoton channel at the 8 TeV LHC. Effects of an invisible decay channel for the Higgs boson are also taken into account, in order to anticipate a possible confirmation of deficits in the branching ratios into $ZZ^*$, $WW^*$, bottom quarks, and tau leptons.
[ { "created": "Mon, 16 Jul 2012 14:55:54 GMT", "version": "v1" }, { "created": "Mon, 23 Jul 2012 14:37:10 GMT", "version": "v2" } ]
2015-06-05
[ [ "Alves", "Alexandre", "" ], [ "Dias", "A. G.", "" ], [ "Barreto", "E. Ramirez", "" ], [ "Pires", "C. A. de S.", "" ], [ "Queiroz", "Farinaldo S.", "" ], [ "da Silva", "P. S. Rodrigues", "" ] ]
We show that the recent discovery of a new boson at the LHC, which we assume to be a Higgs boson, and the observed enhancement in its diphoton decays compared to the SM prediction, can be explained by a new doublet of charged vector bosons from an extended electroweak gauge sector model with SU(3)$_C\otimesSU(3)_L\otimesU(1)_X$ symmetry. Our results show a good agreement between our theoretical expected sensitivity to a 126--125 GeV Higgs boson and the experimental significance observed in the diphoton channel at the 8 TeV LHC. Effects of an invisible decay channel for the Higgs boson are also taken into account, in order to anticipate a possible confirmation of deficits in the branching ratios into $ZZ^*$, $WW^*$, bottom quarks, and tau leptons.
1204.4820
Igor Lokhtin P.
I. P. Lokhtin, A. V. Belyaev, L. V. Malinina, S. V. Petrushanko, E. P. Rogochaya, A. M. Snigirev
Hadron spectra, flow and correlations in PbPb collisions at the LHC: interplay between soft and hard physics
10 pages including 7 figures as EPS-files; prepared using LaTeX package for publication in the European Physical Journal C
Eur.Phys.J.C72:2045,2012
10.1140/epjc/s10052-012-2045-7
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The started LHC heavy ion program makes it possible to probe new frontiers of the high temperature Quantum Chromodynamics. It is expected that the role of hard and semi-hard particle production processes may be significant at ultra-high energies even for bulk properties of the created matter. In this paper, the LHC data on multiplicity, hadron spectra, elliptic flow and femtoscopic correlations from PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed in the framework of the HYDJET++ model. The influence of the jet production mechanism on these observables is discussed.
[ { "created": "Sat, 21 Apr 2012 15:36:49 GMT", "version": "v1" }, { "created": "Thu, 7 Jun 2012 07:47:48 GMT", "version": "v2" } ]
2012-09-20
[ [ "Lokhtin", "I. P.", "" ], [ "Belyaev", "A. V.", "" ], [ "Malinina", "L. V.", "" ], [ "Petrushanko", "S. V.", "" ], [ "Rogochaya", "E. P.", "" ], [ "Snigirev", "A. M.", "" ] ]
The started LHC heavy ion program makes it possible to probe new frontiers of the high temperature Quantum Chromodynamics. It is expected that the role of hard and semi-hard particle production processes may be significant at ultra-high energies even for bulk properties of the created matter. In this paper, the LHC data on multiplicity, hadron spectra, elliptic flow and femtoscopic correlations from PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed in the framework of the HYDJET++ model. The influence of the jet production mechanism on these observables is discussed.
hep-ph/9707262
Leonard Haakman
L.P.A. Haakman (NIKHEF), O.K. Kancheli (ITEP), J.H. Koch (NIKHEF)
The BFKL Pomeron with running coupling constant: how much of its hard nature survives?
23 pages REVTEX and 4 figures included
Nucl.Phys. B518 (1998) 275-302
10.1016/S0550-3213(98)00034-0
NIKHEF 97-020
hep-ph
null
We discuss the BFKL equation with a running gauge coupling and identify in its solutions the contributions originating from different transverse momentum scales. We show that for a running coupling constant the distribution of the gluons making up the BFKL Pomeron shifts to smaller transverse momenta so that the dominant part of Pomeron can have a nonperturbative origin. It is demonstrated how this soft physics enters into the BFKL solution through the boundary condition. We consider two kinematical regimes leading to different behaviour of the rapidity and transverse momentum dependence of the gluon distribution. In the diffusion approximation to the BFKL kernel with running $\alpha_s$, we find a sequence of poles which replaces the cut for fixed $\alpha_s$. The second regime corresponds to the singular part of the kernel, which gives the dominant contribution in the limit of very large transverse momenta. Finally, a simple more general picture is obtained for the QCD Pomeron in hard processes: it is of soft, nonperturbative nature, but has hard ends of DGLAP-type.
[ { "created": "Mon, 7 Jul 1997 12:26:12 GMT", "version": "v1" } ]
2009-10-30
[ [ "Haakman", "L. P. A.", "", "NIKHEF" ], [ "Kancheli", "O. K.", "", "ITEP" ], [ "Koch", "J. H.", "", "NIKHEF" ] ]
We discuss the BFKL equation with a running gauge coupling and identify in its solutions the contributions originating from different transverse momentum scales. We show that for a running coupling constant the distribution of the gluons making up the BFKL Pomeron shifts to smaller transverse momenta so that the dominant part of Pomeron can have a nonperturbative origin. It is demonstrated how this soft physics enters into the BFKL solution through the boundary condition. We consider two kinematical regimes leading to different behaviour of the rapidity and transverse momentum dependence of the gluon distribution. In the diffusion approximation to the BFKL kernel with running $\alpha_s$, we find a sequence of poles which replaces the cut for fixed $\alpha_s$. The second regime corresponds to the singular part of the kernel, which gives the dominant contribution in the limit of very large transverse momenta. Finally, a simple more general picture is obtained for the QCD Pomeron in hard processes: it is of soft, nonperturbative nature, but has hard ends of DGLAP-type.
hep-ph/0305062
Hiroyuki Hagura
Hirotaka Sugawara (Univ. of Hawaii), Hiroyuki Hagura (KEK) and Toshiya Sanami (KEK)
Destruction of Nuclear Bombs Using Ultra-High Energy Neutrino Beam
18 pages, 8 figures, LaTeX2e; Typos corrected, some Figs. modified and Refs. added
null
null
KEK-TH-882
hep-ph hep-ex
null
We discuss the possibility of utilizing the ultra-high energy neutrino beam (about 1000 TeV) to detect and destroy the nuclear bombs wherever they are and whoever possess them.
[ { "created": "Wed, 7 May 2003 05:03:19 GMT", "version": "v1" }, { "created": "Sun, 29 Jun 2003 15:41:33 GMT", "version": "v2" } ]
2007-05-23
[ [ "Sugawara", "Hirotaka", "", "Univ. of Hawaii" ], [ "Hagura", "Hiroyuki", "", "KEK" ], [ "Sanami", "Toshiya", "", "KEK" ] ]
We discuss the possibility of utilizing the ultra-high energy neutrino beam (about 1000 TeV) to detect and destroy the nuclear bombs wherever they are and whoever possess them.
hep-ph/0012186
Tatsu Takeuchi
Tatsu Takeuchi, Lay Nam Chang, Oleg Lebedev, and Will Loinaz
Universal Torsion Induced Interaction from Large Extra Dimensions
4 pages LaTeX, style files included. Talk presented by Takeuchi at LCWS2000
null
10.1063/1.1394388
VPI-IPPAP-00-06
hep-ph
null
We consider a model with extra compact dimensions in which only gravity exists in the 4+n dimensional bulk. If the gravitational connection is not assumed to be symmetric, that is, unless torsion is artificially set to zero, then a universal contact interaction among the fermions on the 4-dimensional wall is induced. Using a global fit to Z-pole observables, we find the 3 sigma bound on the scale of quantum gravity to be M_S = 28 TeV for n=2. If Dirac or light sterile neutrinos are present, the data from SN1987A increase the bound to \sqrt{n} M_S >= 210 TeV.
[ { "created": "Fri, 15 Dec 2000 08:49:12 GMT", "version": "v1" } ]
2009-10-31
[ [ "Takeuchi", "Tatsu", "" ], [ "Chang", "Lay Nam", "" ], [ "Lebedev", "Oleg", "" ], [ "Loinaz", "Will", "" ] ]
We consider a model with extra compact dimensions in which only gravity exists in the 4+n dimensional bulk. If the gravitational connection is not assumed to be symmetric, that is, unless torsion is artificially set to zero, then a universal contact interaction among the fermions on the 4-dimensional wall is induced. Using a global fit to Z-pole observables, we find the 3 sigma bound on the scale of quantum gravity to be M_S = 28 TeV for n=2. If Dirac or light sterile neutrinos are present, the data from SN1987A increase the bound to \sqrt{n} M_S >= 210 TeV.
hep-ph/0406334
Giovanni Ossola
A.Ferroglia, G.Ossola, and A.Sirlin
Bounds on the Higgs Boson Mass from M_W
12 pages, 4 figures, talk given at the Incontri sulla Fisica delle Alte Energie, XVI Ciclo di Incontri, Torino, Italy, April 14-16, 2004
null
null
null
hep-ph
null
Recent experimental and theoretical progress in the M_H estimates from M_W and Sin^2_eff_lept is reviewed, with particular emphasis on the role played by M_t. Assuming that the SM is correct and taking into account the lower bound on M_H from direct searches, we derive restrictive bounds on M_W and M_t. We also discuss a representative ``benchmark'' scenario for the possible future evolution of these parameters. Amusingly, this benchmark scenario suggested some time ago a value for M_t that turned out to be in very close agreement with its most recent experimental determination.
[ { "created": "Wed, 30 Jun 2004 13:29:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ferroglia", "A.", "" ], [ "Ossola", "G.", "" ], [ "Sirlin", "A.", "" ] ]
Recent experimental and theoretical progress in the M_H estimates from M_W and Sin^2_eff_lept is reviewed, with particular emphasis on the role played by M_t. Assuming that the SM is correct and taking into account the lower bound on M_H from direct searches, we derive restrictive bounds on M_W and M_t. We also discuss a representative ``benchmark'' scenario for the possible future evolution of these parameters. Amusingly, this benchmark scenario suggested some time ago a value for M_t that turned out to be in very close agreement with its most recent experimental determination.
hep-ph/0501143
Alexander Vereshagin
Kirill Semenov-Tian-Shansky (St.-Petersburg State University and Universit'e de Li`ege au Sart Tilman)
Bootstrap Equations for String-Like Amplitude
7 pages, talk given at QFTHEP 2004, Russia, June 2004, to be published in Proceedings
null
null
null
hep-ph
null
One of the ways to check the consistency of our effective field theory (EFT) approach (explained by A.Vereshagin and V.Vereshagin at this conference) is to perform the numerical testing of those sum rules for hadron resonance parameters which follow from the system of bootstrap constrains. In this talk we discuss the peculiar features of this procedure for the case of exactly solvable bootstrap model based on Veneziano string amplitude. This allows us to simulate different situations that may encounter in realistic EFT models. We also make a short review of the technique that may be useful for further analysis of various bootstrap systems.
[ { "created": "Sat, 15 Jan 2005 17:07:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Semenov-Tian-Shansky", "Kirill", "", "St.-Petersburg State University and\n Universit'e de Li`ege au Sart Tilman" ] ]
One of the ways to check the consistency of our effective field theory (EFT) approach (explained by A.Vereshagin and V.Vereshagin at this conference) is to perform the numerical testing of those sum rules for hadron resonance parameters which follow from the system of bootstrap constrains. In this talk we discuss the peculiar features of this procedure for the case of exactly solvable bootstrap model based on Veneziano string amplitude. This allows us to simulate different situations that may encounter in realistic EFT models. We also make a short review of the technique that may be useful for further analysis of various bootstrap systems.
hep-ph/0112286
Timothy L. Barklow
Timothy L. Barklow (SLAC)
Strong Symmetry Breaking at e+e- Linear Colliders
7 pages, 2 figures, presented at Snowmass 2001
eConf C010630 (2001) E3067
null
SLAC-PUB-9067
hep-ph
null
The study of strong symmetry breaking at an e+e linear collider with sqrt(s)=0.5-1.5 TeV is reviewed. It is shown that processes such as e+e- --> nu nubar W+ W-, e+e- --> nu nubar t tbar, and and e+e- --> W+ W- can be used to measure chiral Lagrangian and strong resonance parameters. The linear collider results are compared with those expected from the LHC.
[ { "created": "Fri, 21 Dec 2001 00:21:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Barklow", "Timothy L.", "", "SLAC" ] ]
The study of strong symmetry breaking at an e+e linear collider with sqrt(s)=0.5-1.5 TeV is reviewed. It is shown that processes such as e+e- --> nu nubar W+ W-, e+e- --> nu nubar t tbar, and and e+e- --> W+ W- can be used to measure chiral Lagrangian and strong resonance parameters. The linear collider results are compared with those expected from the LHC.
2111.09328
Maksim Nekrasov L
M. L. Nekrasov
Resonant mode of elastic scattering of protons at ultra-high energies
11 pages. The lower bound for the energy of the onset of the resonant scattering mode is specified
Phys. Rev. D 106, 014028 (2022)
10.1103/PhysRevD.106.014028
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
An interpretation is given for elastic proton scattering at ultra-high energies with impact-parameter amplitude exceeding the black disk limit. It is shown that this scattering mode can arise due to the contribution of an exceptional intermediate state that unites correlated partons of colliding protons at ultra-high energies into a single coherent system. The behavior of the real part of the amplitude in this mode is discussed.
[ { "created": "Wed, 17 Nov 2021 19:00:02 GMT", "version": "v1" }, { "created": "Thu, 3 Feb 2022 17:48:34 GMT", "version": "v2" }, { "created": "Wed, 20 Jul 2022 11:28:20 GMT", "version": "v3" } ]
2022-08-04
[ [ "Nekrasov", "M. L.", "" ] ]
An interpretation is given for elastic proton scattering at ultra-high energies with impact-parameter amplitude exceeding the black disk limit. It is shown that this scattering mode can arise due to the contribution of an exceptional intermediate state that unites correlated partons of colliding protons at ultra-high energies into a single coherent system. The behavior of the real part of the amplitude in this mode is discussed.
hep-ph/0202222
Mahiko Suzuki
M. Suzuki
Helicity conservation and factorization-suppressed charmless B decays
The version to appear in Phys. Rev. D after minor alterations
Phys.Rev.D65:097501,2002
10.1103/PhysRevD.65.097501
LBNL-49672/UCB-PTH-02/09
hep-ph
null
Toward the goal of extracting the weak angle alpha, the decay B^0/B^0-bar to a_0^{+/-}pi^{-/+} was recently measured. The decay B^0 to a_0^+pi^- is not only forbidden in the factorization limit of the tree interaction, but also strongly suppressed for the penguin interaction if short-distance QCD dominates. This makes extraction of alpha very difficult from a^{+/-}\pi^{-/+}. We examine the simlar factorization-suppressed decays, in particular, B^0\to b_1^+pi^-. The prospect of obtaining alpha is even less promising with b_1^{+/-}pi^{-/+}. To probe how well the short-distance dominance works, we emphasize importance of testing helicity conservation in the charmless B decays with spins.
[ { "created": "Sat, 23 Feb 2002 19:03:33 GMT", "version": "v1" }, { "created": "Tue, 26 Mar 2002 20:17:45 GMT", "version": "v2" } ]
2014-11-17
[ [ "Suzuki", "M.", "" ] ]
Toward the goal of extracting the weak angle alpha, the decay B^0/B^0-bar to a_0^{+/-}pi^{-/+} was recently measured. The decay B^0 to a_0^+pi^- is not only forbidden in the factorization limit of the tree interaction, but also strongly suppressed for the penguin interaction if short-distance QCD dominates. This makes extraction of alpha very difficult from a^{+/-}\pi^{-/+}. We examine the simlar factorization-suppressed decays, in particular, B^0\to b_1^+pi^-. The prospect of obtaining alpha is even less promising with b_1^{+/-}pi^{-/+}. To probe how well the short-distance dominance works, we emphasize importance of testing helicity conservation in the charmless B decays with spins.
hep-ph/0309141
Abel Miranda Dr
A. Miranda
The quark vacuum
20 pages, 10 figures
null
null
null
hep-ph
null
We conjecture on the structure of the quark vacuum from a viewpoint somewhat different from, but perhaps supplementary to, standard philosophies. Using a rather simple dynamical Hamiltonian model, vacuum excitations carrying helicities 0 and +/-1 are discussed in connection with the dynamical stability of solutions. We speculate on how the rest masses of the light mesons pi^0, eta^0 and eta'^0 could be related to these excitations.
[ { "created": "Fri, 12 Sep 2003 11:50:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Miranda", "A.", "" ] ]
We conjecture on the structure of the quark vacuum from a viewpoint somewhat different from, but perhaps supplementary to, standard philosophies. Using a rather simple dynamical Hamiltonian model, vacuum excitations carrying helicities 0 and +/-1 are discussed in connection with the dynamical stability of solutions. We speculate on how the rest masses of the light mesons pi^0, eta^0 and eta'^0 could be related to these excitations.
2107.05495
Francisco J. de Anda
Alfredo Aranda, Francisco J. de Anda, Ant\'onio P. Morais, Roman Pasechnik
Sculpting the Standard Model from low-scale Gauge-Higgs-Matter $E_8$ Grand Unification in ten dimensions
56 pages, 6 figures. v2: changed the orbifold
Nucl.Phys.B 993 (2023) 116266
10.1016/j.nuclphysb.2023.116266
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The construction and general implications of a model with complete supersymmetric unification of the Standard Model matter content, interactions and families' replication into a single $E_{8}$ gauge superfield in ten dimensions is presented. The gauge and extended Poincar\'e symmetries are broken through compactification of the $\mathbb{T}^6/(\mathbb{Z}_3\times \mathbb{Z}_3)$ orbifold with Wilson lines, which reduces the original symmetry and matter content into those of the Standard Model plus additional heavier states. Proton decay can be suppressed automatically while the compactification scale may be as low as $10^9~\rm{GeV}$, so that the corresponding GUT-scale physics may be potentially accessible and testable by future collider measurements.
[ { "created": "Mon, 12 Jul 2021 15:27:59 GMT", "version": "v1" }, { "created": "Tue, 9 Aug 2022 22:57:03 GMT", "version": "v2" } ]
2023-06-28
[ [ "Aranda", "Alfredo", "" ], [ "de Anda", "Francisco J.", "" ], [ "Morais", "António P.", "" ], [ "Pasechnik", "Roman", "" ] ]
The construction and general implications of a model with complete supersymmetric unification of the Standard Model matter content, interactions and families' replication into a single $E_{8}$ gauge superfield in ten dimensions is presented. The gauge and extended Poincar\'e symmetries are broken through compactification of the $\mathbb{T}^6/(\mathbb{Z}_3\times \mathbb{Z}_3)$ orbifold with Wilson lines, which reduces the original symmetry and matter content into those of the Standard Model plus additional heavier states. Proton decay can be suppressed automatically while the compactification scale may be as low as $10^9~\rm{GeV}$, so that the corresponding GUT-scale physics may be potentially accessible and testable by future collider measurements.
hep-ph/0007297
Burkert
Volker D. Burkert (Jefferson Lab) (for the CLAS collaboration)
Probing the Structure of Nucleons in the Resonance Region with CLAS at Jefferson Lab
Talk presented at Few Body Problems in Physics, Taipei, March 6-10, 2000, 10 pages, 8 figures
Nucl.Phys.A684:16-25,2001
10.1016/S0375-9474(01)00482-1
JLAB-PHY-00-10
hep-ph
null
The physics of electromagnetic excitation of nucleon resonances and of their relevance in nucleon structure studies are discussed. Preliminary data from the CLAS detector on the N-Delta(1232) transition multipoles, the helicity amplitudes of the N*(1535), and the search for so-called "missing resonances" at Jefferson Lab are presented.
[ { "created": "Wed, 26 Jul 2000 16:33:19 GMT", "version": "v1" } ]
2019-08-14
[ [ "Burkert", "Volker D.", "", "Jefferson Lab" ] ]
The physics of electromagnetic excitation of nucleon resonances and of their relevance in nucleon structure studies are discussed. Preliminary data from the CLAS detector on the N-Delta(1232) transition multipoles, the helicity amplitudes of the N*(1535), and the search for so-called "missing resonances" at Jefferson Lab are presented.