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0903.3596
Stefan Liebler
A. Bartl, M. Hirsch, S. Liebler, W. Porod, A. Vicente
LHC phenomenology of the $\mu\nu$SSM
35 pages, 23 figures; minor corrections, final version published in JHEP
JHEP 0905:120,2009
10.1088/1126-6708/2009/05/120
IFIC/09-09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $\mu\nu$SSM has been proposed to solve simultaneously the $\mu$-problem of the MSSM and explain current neutrino data. The model breaks lepton number as well as R-parity. In this paper we study the phenomenology of this proposal concentrating on neutrino masses and the decay of the lightest supersymmetric particle (LSP). At first we investigate in detail the $\mu\nu$SSM with one generation of singlets, which can explain all neutrino data, once 1-loop corrections are taken into account. Then we study variations of the model with more singlets, which can generate all neutrino masses and mixings at tree-level. We calculate the decay properties of the lightest supersymmetric particle, assumed to be the lightest neutralino, taking into account all possible final states. The parameter regions where the LSP decays within the LHC detectors but with a length large enough to show a displaced vertex are identified. Decay branching ratios of certain final states show characteristic correlations with the measured neutrino angles, allowing to test the model at the LHC. Finally we briefly discuss possible signatures, which allow to distinguish between different R-parity breaking models.
[ { "created": "Fri, 20 Mar 2009 19:50:01 GMT", "version": "v1" }, { "created": "Wed, 8 Apr 2009 15:20:15 GMT", "version": "v2" }, { "created": "Mon, 8 Jun 2009 19:15:09 GMT", "version": "v3" } ]
2009-06-08
[ [ "Bartl", "A.", "" ], [ "Hirsch", "M.", "" ], [ "Liebler", "S.", "" ], [ "Porod", "W.", "" ], [ "Vicente", "A.", "" ] ]
The $\mu\nu$SSM has been proposed to solve simultaneously the $\mu$-problem of the MSSM and explain current neutrino data. The model breaks lepton number as well as R-parity. In this paper we study the phenomenology of this proposal concentrating on neutrino masses and the decay of the lightest supersymmetric particle (LSP). At first we investigate in detail the $\mu\nu$SSM with one generation of singlets, which can explain all neutrino data, once 1-loop corrections are taken into account. Then we study variations of the model with more singlets, which can generate all neutrino masses and mixings at tree-level. We calculate the decay properties of the lightest supersymmetric particle, assumed to be the lightest neutralino, taking into account all possible final states. The parameter regions where the LSP decays within the LHC detectors but with a length large enough to show a displaced vertex are identified. Decay branching ratios of certain final states show characteristic correlations with the measured neutrino angles, allowing to test the model at the LHC. Finally we briefly discuss possible signatures, which allow to distinguish between different R-parity breaking models.
hep-ph/9908216
Christophe Royon
Christophe Royon (for the H1 Collaboration) (Service de Physique des Particules, DAPNIA, CEA-Saclay)
Measurement of the diffractive structure function $F_2^{D(3)}$
4 pages, talk given at the DIS99 Workshop, Zeuthen (Germany), 19-23 April 1999
Nucl.Phys.Proc.Suppl. 79 (1999) 256-259
10.1016/S0920-5632(99)00691-X
null
hep-ph
null
Measurements of the diffractive structure function $F_2^{D(3)}(x_{\PO}, \beta, Q^2)$, describing the process $ep \to eXY$, are presented in the two kinematic regions $0.4 \leq Q^2 \leq 5$, ${\rm GeV}^2$, $0.001 \leq \beta \leq 0.65$, and $200 \leq \beta \leq 800 {\rm GeV^2}$, $0.4 \leq \beta \leq 0.9$, both with $\xpom < 0.05$, $M_{_Y} < 1.6 {\rm GeV}$ and $|t| < 1.0 {\rm GeV^2}$. Together with published measurements at intermediate $Q^2$, the data are compared with models based on QCD and Regge phenomenology. The diffractive trajectory is found to have an intercept larger than that describing soft hadronic data and consistent with that determined using previously published H1 measurements at intermediate $Q^2$ alone. The data are also parameterised using a QCD motivated model based on the exchange of two gluons from the proton. In this model, the higher twist contribution to $F_2^{D(3)}$ at large $\beta$ is found to be important at low $Q^2$. The data are also compared with models based on BFKL dynamics.
[ { "created": "Mon, 2 Aug 1999 12:43:09 GMT", "version": "v1" } ]
2009-10-31
[ [ "Royon", "Christophe", "", "for the H1 Collaboration" ] ]
Measurements of the diffractive structure function $F_2^{D(3)}(x_{\PO}, \beta, Q^2)$, describing the process $ep \to eXY$, are presented in the two kinematic regions $0.4 \leq Q^2 \leq 5$, ${\rm GeV}^2$, $0.001 \leq \beta \leq 0.65$, and $200 \leq \beta \leq 800 {\rm GeV^2}$, $0.4 \leq \beta \leq 0.9$, both with $\xpom < 0.05$, $M_{_Y} < 1.6 {\rm GeV}$ and $|t| < 1.0 {\rm GeV^2}$. Together with published measurements at intermediate $Q^2$, the data are compared with models based on QCD and Regge phenomenology. The diffractive trajectory is found to have an intercept larger than that describing soft hadronic data and consistent with that determined using previously published H1 measurements at intermediate $Q^2$ alone. The data are also parameterised using a QCD motivated model based on the exchange of two gluons from the proton. In this model, the higher twist contribution to $F_2^{D(3)}$ at large $\beta$ is found to be important at low $Q^2$. The data are also compared with models based on BFKL dynamics.
hep-ph/0307256
Andrei Belitsky
A.V. Belitsky
Renormalons in exclusive meson electroproduction
5 pages, Aipproc, 2 figures
null
10.1063/1.1664310
null
hep-ph
null
We discuss the possibility of measuring generalized parton distributions in exclusive electroproduction of mesons off the nucleon and estimate the uncertainty from perturbatively induced higher-twist corrections. We find that, while the magnitude of the cross section changes significantly taking into account twist-four contributions modeled via renormalons, the transverse spin asymmetry is weakly sensitive to them and displays the precocious scaling.
[ { "created": "Mon, 21 Jul 2003 00:24:23 GMT", "version": "v1" } ]
2009-11-10
[ [ "Belitsky", "A. V.", "" ] ]
We discuss the possibility of measuring generalized parton distributions in exclusive electroproduction of mesons off the nucleon and estimate the uncertainty from perturbatively induced higher-twist corrections. We find that, while the magnitude of the cross section changes significantly taking into account twist-four contributions modeled via renormalons, the transverse spin asymmetry is weakly sensitive to them and displays the precocious scaling.
2110.12045
Vladyslav Shtabovenko
Vladyslav Shtabovenko
Towards two- and three-loop QCD corrections to the width difference in $B_s-\bar{B}_s$ mixing
7 pages, 2 figures. Contribution to the 15th International Symposium on Radiative Corrections (RADCOR) and the XIX Workshop on Radiative Corrections for the LHC and Future Colliders (LoopFest)
null
null
TTP21-041, P3H-21-079
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we address the issue of large perturbative uncertainties in the theory prediction for $\Delta \Gamma_s$, the width difference in the $B^0_s - \bar{B}^0_s$ mixing process. To this aim we complete important steps towards the full analytic result for the previously unknown Wilson coefficients from the matching between $|\Delta B|=1$ and $|\Delta B|=2$ effective Hamiltonians at next-to-next-leading order (NNLO) in the strong coupling constant. We provide a thorough discussion of technical and conceptual difficulties behind this computation and give an outlook regarding the availability of the new NNLO theory prediction for $\Delta \Gamma_s$.
[ { "created": "Fri, 22 Oct 2021 20:18:32 GMT", "version": "v1" } ]
2021-10-26
[ [ "Shtabovenko", "Vladyslav", "" ] ]
In this work we address the issue of large perturbative uncertainties in the theory prediction for $\Delta \Gamma_s$, the width difference in the $B^0_s - \bar{B}^0_s$ mixing process. To this aim we complete important steps towards the full analytic result for the previously unknown Wilson coefficients from the matching between $|\Delta B|=1$ and $|\Delta B|=2$ effective Hamiltonians at next-to-next-leading order (NNLO) in the strong coupling constant. We provide a thorough discussion of technical and conceptual difficulties behind this computation and give an outlook regarding the availability of the new NNLO theory prediction for $\Delta \Gamma_s$.
1405.4489
Zhaoxia Heng
Junjie Cao, Zhaoxia Heng, Dongwei Li, Liangliang Shang, Peiwen Wu
Higgs-strahlung production process e^+ e^- \to Z h at the future Higgs factory in the Minimal Dilaton Model
18pages, 8 fiugres, References added
null
10.1007/JHEP08(2014)138
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the Higgs-strahlung production process e^+ e^- \to Z h at the future Higgs factory such as TLEP by including radiative corrections in the Minimal Dilaton Model (MDM), which extends the SM by one singlet scalar called dilaton. We consider various theoretical and experimental constraints on the model, and perform fits to the Higgs data taken from ATLAS, CMS and CDF+D0. Then for the 1\sigma surviving samples, we calculate the MDM predictions on the inclusive production rate \sigma(e^+e^-\to Zh) at the 240-GeV Higgs factory, and also the signal rates of e^+e^-\to Zh with the Higgs boson decaying to b\bar b and \gamma\gamma. We have following observations: (1) In the heavy dilaton scenario, the deviation of \sigma(e^+e^-\to Zh) from its SM prediction can vary from -15\% to 85\%, which mainly arises from the modification of the tree-level hZZ coupling and also the radiative correction induced by possibly large Higgs self-couplings. (2) The processes e^+e^-\to Zh at the Higgs factory and pp\to hh at 14-TeV LHC are complementary in limiting the MDM parameter space. Requiring the deviation of \sigma(e^+e^-\to Zh) from its SM prediction to be less than 1\% and that of \sigma(p p \to h h) to be less than 50\%, \tan \theta_S in the MDM will be limited to be -0.1<\tan\theta_S<0.3, and the deviations of the signal rates are constrained to be |R_{b\bar b}|<2\% and |R_{\gamma\gamma}|<7\%. Especially, the Higgs self-coupling normalized to its SM prediction is now upper bounded by about 4. (3) In the light dilaton scenario, the deviation of \sigma(e^+e^-\to Zh) may reach -7\%, and requiring its size to be less than 1\% will result in 0<\tan\theta_S<0.1, and -10\% < R_{b\bar b}, R_{\gamma\gamma} < 1\%.
[ { "created": "Sun, 18 May 2014 10:52:52 GMT", "version": "v1" }, { "created": "Tue, 20 May 2014 14:00:37 GMT", "version": "v2" }, { "created": "Wed, 28 May 2014 08:40:22 GMT", "version": "v3" } ]
2015-06-19
[ [ "Cao", "Junjie", "" ], [ "Heng", "Zhaoxia", "" ], [ "Li", "Dongwei", "" ], [ "Shang", "Liangliang", "" ], [ "Wu", "Peiwen", "" ] ]
We investigate the Higgs-strahlung production process e^+ e^- \to Z h at the future Higgs factory such as TLEP by including radiative corrections in the Minimal Dilaton Model (MDM), which extends the SM by one singlet scalar called dilaton. We consider various theoretical and experimental constraints on the model, and perform fits to the Higgs data taken from ATLAS, CMS and CDF+D0. Then for the 1\sigma surviving samples, we calculate the MDM predictions on the inclusive production rate \sigma(e^+e^-\to Zh) at the 240-GeV Higgs factory, and also the signal rates of e^+e^-\to Zh with the Higgs boson decaying to b\bar b and \gamma\gamma. We have following observations: (1) In the heavy dilaton scenario, the deviation of \sigma(e^+e^-\to Zh) from its SM prediction can vary from -15\% to 85\%, which mainly arises from the modification of the tree-level hZZ coupling and also the radiative correction induced by possibly large Higgs self-couplings. (2) The processes e^+e^-\to Zh at the Higgs factory and pp\to hh at 14-TeV LHC are complementary in limiting the MDM parameter space. Requiring the deviation of \sigma(e^+e^-\to Zh) from its SM prediction to be less than 1\% and that of \sigma(p p \to h h) to be less than 50\%, \tan \theta_S in the MDM will be limited to be -0.1<\tan\theta_S<0.3, and the deviations of the signal rates are constrained to be |R_{b\bar b}|<2\% and |R_{\gamma\gamma}|<7\%. Especially, the Higgs self-coupling normalized to its SM prediction is now upper bounded by about 4. (3) In the light dilaton scenario, the deviation of \sigma(e^+e^-\to Zh) may reach -7\%, and requiring its size to be less than 1\% will result in 0<\tan\theta_S<0.1, and -10\% < R_{b\bar b}, R_{\gamma\gamma} < 1\%.
hep-ph/0504231
Adam Ritz
Maxim Pospelov, Adam Ritz
Electric dipole moments as probes of new physics
62 pages, 10 figures, invited review to appear in Annals of Physics; v2: references added
Annals Phys.318:119-169,2005
10.1016/j.aop.2005.04.002
null
hep-ph
null
We review several aspects of flavour-diagonal CP violation, focussing on the role played by the electric dipole moments (EDMs) of leptons, nucleons, atoms and molecules, which consitute the source of several stringent constraints on new CP-violating physics. We dwell specifically on the calculational aspects of applying the hadronic EDM constraints, reviewing in detail the application of QCD sum-rules to the calculation of nucleon EDMs and CP-odd pion-nucleon couplings. We also consider the current status of EDMs in the Standard Model, and on the ensuing constraints on the underlying sources of CP-violation in physics beyond the Standard Model, focussing on weak-scale supersymmetry.
[ { "created": "Tue, 26 Apr 2005 08:11:57 GMT", "version": "v1" }, { "created": "Fri, 16 Sep 2005 10:06:23 GMT", "version": "v2" } ]
2009-07-09
[ [ "Pospelov", "Maxim", "" ], [ "Ritz", "Adam", "" ] ]
We review several aspects of flavour-diagonal CP violation, focussing on the role played by the electric dipole moments (EDMs) of leptons, nucleons, atoms and molecules, which consitute the source of several stringent constraints on new CP-violating physics. We dwell specifically on the calculational aspects of applying the hadronic EDM constraints, reviewing in detail the application of QCD sum-rules to the calculation of nucleon EDMs and CP-odd pion-nucleon couplings. We also consider the current status of EDMs in the Standard Model, and on the ensuing constraints on the underlying sources of CP-violation in physics beyond the Standard Model, focussing on weak-scale supersymmetry.
2303.11363
Adil Jueid
Adil Jueid, Jochem Kip, Roberto Ruiz de Austri, Peter Skands
The Strong Force meets the Dark Sector: a robust estimate of QCD uncertainties for anti-matter dark matter searches
v1: 52 pages, 21 figures, and 9 tables
null
null
CTPU-PTC-23-08
hep-ph astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
In dark-matter annihilation channels to hadronic final states, stable particles -- such as positrons, photons, antiprotons, and antineutrinos -- are produced via complex sequences of phenomena including QED/QCD radiation, hadronisation, and hadron decays. These processes are normally modelled by Monte Carlo event generators whose limited accuracy imply intrinsic QCD uncertainties on the predictions for indirect-detection experiments like Fermi-LAT, Pamela, IceCube or AMS-02. In this article, we perform a complete analysis of QCD uncertainties in antimatter spectra from dark-matter annihilation, based on parametric variations of the Pythia 8 event generator. After performing several retunings of light-quark fragmentation functions, we define a set of variations that span a conservative estimate of the QCD uncertainties. We estimate the effects on antimatter spectra for various annihilation channels and final-state particle species, and discuss their impact on fitted values for the dark-matter mass and thermally-averaged annihilation cross section. We find dramatic impacts which can go up to $\mathcal{O}(40)$ GeV for uncertainties on the dark-matter mass and up to $\mathcal{O}(10\%)$ for the annihilation cross section. We provide the spectra in tabulated form including QCD uncertainties and code snippets to perform fast dark-matter fits, in this https://github.com/ajueid/qcd-dm.github.io.git repository.
[ { "created": "Mon, 20 Mar 2023 18:02:23 GMT", "version": "v1" } ]
2023-03-22
[ [ "Jueid", "Adil", "" ], [ "Kip", "Jochem", "" ], [ "de Austri", "Roberto Ruiz", "" ], [ "Skands", "Peter", "" ] ]
In dark-matter annihilation channels to hadronic final states, stable particles -- such as positrons, photons, antiprotons, and antineutrinos -- are produced via complex sequences of phenomena including QED/QCD radiation, hadronisation, and hadron decays. These processes are normally modelled by Monte Carlo event generators whose limited accuracy imply intrinsic QCD uncertainties on the predictions for indirect-detection experiments like Fermi-LAT, Pamela, IceCube or AMS-02. In this article, we perform a complete analysis of QCD uncertainties in antimatter spectra from dark-matter annihilation, based on parametric variations of the Pythia 8 event generator. After performing several retunings of light-quark fragmentation functions, we define a set of variations that span a conservative estimate of the QCD uncertainties. We estimate the effects on antimatter spectra for various annihilation channels and final-state particle species, and discuss their impact on fitted values for the dark-matter mass and thermally-averaged annihilation cross section. We find dramatic impacts which can go up to $\mathcal{O}(40)$ GeV for uncertainties on the dark-matter mass and up to $\mathcal{O}(10\%)$ for the annihilation cross section. We provide the spectra in tabulated form including QCD uncertainties and code snippets to perform fast dark-matter fits, in this https://github.com/ajueid/qcd-dm.github.io.git repository.
hep-ph/0301227
Hungchong Kim
Hungchong Kim (1,2), Makoto Oka (1) ((1) Tokyo Institute of Technology, (2) Yonsei University)
Update on pion weak decay constants in nuclear matter
18 pages including 5 postscript figures
Nucl.Phys. A720 (2003) 368-381
10.1016/S0375-9474(03)01004-2
null
hep-ph nucl-th
null
The QCD sum rule calculation of the in-medium pion decay constants using pseudoscalar-axial vector correlation function, $i \int d^4x e^{ip\cdot x} < \rho| T[{\bar d}(x) i \gamma_5 u (x) {\bar u}(0) \gamma_\mu \gamma_5 d (0)] | \rho>$ is revisited. In particular, we argue that the dimension 5 condensate, $<{\bar q} (i D_0)^2 q >_N + {1\over 8} < {\bar q} g_s \sigma \cdot {\cal G} q >_N$, which is crucial for splitting the time ($f_t$) and space ($f_s$) components of the decay constant, is not necessarily restricted to be positive. Its positive value is found to yield a tachyonic pion mass. Using the in-medium pion mass as an input, we fix the dimension 5 condensate to be around $-0.025 {\rm GeV}^2 \sim -0.019$ GeV$^2$. The role of the $N$ and $\Delta$ intermediate states in the correlation function is also investigated. The $N$ intermediate state is found not to contribute to the sum rules. For the $\Delta$ intermediate state, we either treat it as a part of the continuum or propose a way to subtract explicitly from the sum rules. With (and without) explicit $\Delta$ subtraction while allowing the in-medium pion mass to vary within 139 MeV $ \le m_\pi^* \le$ 159 MeV, we obtain $f_s/f_\pi = 0.37 \sim 0.78$ and $f_t / f_\pi = 0.63 \sim 0.79$.
[ { "created": "Mon, 27 Jan 2003 02:54:14 GMT", "version": "v1" } ]
2009-11-10
[ [ "Kim", "Hungchong", "" ], [ "Oka", "Makoto", "" ] ]
The QCD sum rule calculation of the in-medium pion decay constants using pseudoscalar-axial vector correlation function, $i \int d^4x e^{ip\cdot x} < \rho| T[{\bar d}(x) i \gamma_5 u (x) {\bar u}(0) \gamma_\mu \gamma_5 d (0)] | \rho>$ is revisited. In particular, we argue that the dimension 5 condensate, $<{\bar q} (i D_0)^2 q >_N + {1\over 8} < {\bar q} g_s \sigma \cdot {\cal G} q >_N$, which is crucial for splitting the time ($f_t$) and space ($f_s$) components of the decay constant, is not necessarily restricted to be positive. Its positive value is found to yield a tachyonic pion mass. Using the in-medium pion mass as an input, we fix the dimension 5 condensate to be around $-0.025 {\rm GeV}^2 \sim -0.019$ GeV$^2$. The role of the $N$ and $\Delta$ intermediate states in the correlation function is also investigated. The $N$ intermediate state is found not to contribute to the sum rules. For the $\Delta$ intermediate state, we either treat it as a part of the continuum or propose a way to subtract explicitly from the sum rules. With (and without) explicit $\Delta$ subtraction while allowing the in-medium pion mass to vary within 139 MeV $ \le m_\pi^* \le$ 159 MeV, we obtain $f_s/f_\pi = 0.37 \sim 0.78$ and $f_t / f_\pi = 0.63 \sim 0.79$.
1712.02359
Xiaochuan Lu
Xiaochuan Lu and Satoshi Shirai
Low-scale Gauge Mediation after LHC Run 2
19 pages, 5 figures
null
10.1016/j.physletb.2018.07.057
IPMU17-0171
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study low-scale gauge mediated supersymmetry breaking models with a very light gravitino of mass $\mathcal{O}(1)$ eV. The cosmological upper bound on the gravitino mass and the collider constraints on the sparticle masses give a significant impact on such models. We apply the latest results of the LHC to these models and obtain the current constraints. We find that perturbatively calculable classes of low-scale gauge mediation models can be largely excluded.
[ { "created": "Wed, 6 Dec 2017 19:00:02 GMT", "version": "v1" } ]
2018-08-08
[ [ "Lu", "Xiaochuan", "" ], [ "Shirai", "Satoshi", "" ] ]
We study low-scale gauge mediated supersymmetry breaking models with a very light gravitino of mass $\mathcal{O}(1)$ eV. The cosmological upper bound on the gravitino mass and the collider constraints on the sparticle masses give a significant impact on such models. We apply the latest results of the LHC to these models and obtain the current constraints. We find that perturbatively calculable classes of low-scale gauge mediation models can be largely excluded.
hep-ph/9511357
Debajyoti Choudhury
Debajyoti Choudhury and Subir Sarkar
A Supersymmetric Resolution of the KARMEN Anomaly
LaTeX; 8 pages, 2 figures (uuencoded compressed postscript files included); Physics Letters B (in press); (Changes: References updated ; One expression corrected without any changes in conclusions)
Phys.Lett.B374:87-92,1996
10.1016/0370-2693(96)00170-0
CERN-TH/95--299, OUTP-95-45P
hep-ph
null
We consider the hypothesis that the recently reported anomaly in the time structure of signals in the KARMEN experiment is due to the production of a light photino (or Zino) which decays radiatively due to violation of $R$-parity. Such a particle is shown to be consistent with all experimental data and with cosmological nucleosynthesis. There are difficulties with constraints from SN~1987A but these may be evaded if squarks are non-degenerate in mass.
[ { "created": "Fri, 17 Nov 1995 17:43:42 GMT", "version": "v1" }, { "created": "Wed, 20 Mar 1996 18:41:18 GMT", "version": "v2" } ]
2011-02-16
[ [ "Choudhury", "Debajyoti", "" ], [ "Sarkar", "Subir", "" ] ]
We consider the hypothesis that the recently reported anomaly in the time structure of signals in the KARMEN experiment is due to the production of a light photino (or Zino) which decays radiatively due to violation of $R$-parity. Such a particle is shown to be consistent with all experimental data and with cosmological nucleosynthesis. There are difficulties with constraints from SN~1987A but these may be evaded if squarks are non-degenerate in mass.
hep-ph/0011167
Angeles Faus-Golfe
J.Perez-Peraza, J. Velasco, A. Gallegos-Cruz, M. Alvarez-Madrigal, A. Faus-Golfe, A. Sanchez-Hertz
Parametrization of proton-proton total cross section from 10 GeV to 100 TeV
9 pages, 2 figures
null
null
null
hep-ph
null
Present estimations of proton-proton total cross section at very high energies are obtained from cosmic rays (>10^17 eV) by means of some approximations and the knowledge of the measured proton-air cross section at these energies. Besides, total cross section are measured with present day high energy colliders up to nearly 2 TeV in the center of mass (~ 10^15 eV in the laboratory). Here we use a phenomenological model based on the Multiple-Diffraction approach to succesfully describe data at accelerator energies. Then we estimate with it proton-proton total cross sections at cosmic ray energies. On the basis of a forecasting regression analysis we determine confident errors bands, analyzing the sensitivity of our predictions to the employed data for extrapolation.
[ { "created": "Mon, 13 Nov 2000 11:33:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Perez-Peraza", "J.", "" ], [ "Velasco", "J.", "" ], [ "Gallegos-Cruz", "A.", "" ], [ "Alvarez-Madrigal", "M.", "" ], [ "Faus-Golfe", "A.", "" ], [ "Sanchez-Hertz", "A.", "" ] ]
Present estimations of proton-proton total cross section at very high energies are obtained from cosmic rays (>10^17 eV) by means of some approximations and the knowledge of the measured proton-air cross section at these energies. Besides, total cross section are measured with present day high energy colliders up to nearly 2 TeV in the center of mass (~ 10^15 eV in the laboratory). Here we use a phenomenological model based on the Multiple-Diffraction approach to succesfully describe data at accelerator energies. Then we estimate with it proton-proton total cross sections at cosmic ray energies. On the basis of a forecasting regression analysis we determine confident errors bands, analyzing the sensitivity of our predictions to the employed data for extrapolation.
hep-ph/9901329
Xing Zhi-Zhong
Harry J. Lipkin and Zhi-zhong Xing
Flavor Symmetry, K^0-\bar{K}^0 Mixing and New Physics Effects on CP Violation in D^{\pm} and D^{\pm}_s Decays
Latex 12 pages (3 figs). Phys. Lett. B (in printing)
Phys.Lett. B450 (1999) 405-411
10.1016/S0370-2693(99)00170-7
LMU-99-02, WIS-99/01/Jan.DPP, TAU-2547-99
hep-ph hep-ex
null
Flavor symmetry and symmetry breaking, K^0-\bar{K}^0 mixing and possible effects of new physics on CP violation in weak decay modes D^{\pm} \to K_{S,L} + X^{\pm}, (K_{S,L} + \pi^0)_{K^*} + X^{\pm} (for X =\pi, \rho, a_1) and D^{\pm}_s \to K_{S,L} + X^{\pm}_s, (K_{S,L} +\pi^0)_{K^*} + X^{\pm}_s (for X_s = K, K^*) are analyzed. Relations between D^{\pm} and D^{\pm}_s decay branching ratios are obtained from the d \Leftrightarrow s subgroup of SU(3) and dominant symmetry-breaking mechanisms are investigated. A CP asymmetry of magnitude 3.3\times 10^{-3} is shown to result in the standard model from K^0-\bar{K}^0 mixing in the final-state. New physics affecting the doubly Cabibbo-suppressed channels might either cancel this asymmetry or enhance it up to the percent level. A comparison between the CP asymmetries in D^{\pm}_{(s)} \to K_{S} X^{\pm}_{(s)} and D^{\pm}_{(s)} \to K_L X^{\pm}_{(s)} can pin down effects of new physics.
[ { "created": "Sat, 16 Jan 1999 17:33:28 GMT", "version": "v1" }, { "created": "Tue, 2 Feb 1999 13:24:44 GMT", "version": "v2" } ]
2009-10-31
[ [ "Lipkin", "Harry J.", "" ], [ "Xing", "Zhi-zhong", "" ] ]
Flavor symmetry and symmetry breaking, K^0-\bar{K}^0 mixing and possible effects of new physics on CP violation in weak decay modes D^{\pm} \to K_{S,L} + X^{\pm}, (K_{S,L} + \pi^0)_{K^*} + X^{\pm} (for X =\pi, \rho, a_1) and D^{\pm}_s \to K_{S,L} + X^{\pm}_s, (K_{S,L} +\pi^0)_{K^*} + X^{\pm}_s (for X_s = K, K^*) are analyzed. Relations between D^{\pm} and D^{\pm}_s decay branching ratios are obtained from the d \Leftrightarrow s subgroup of SU(3) and dominant symmetry-breaking mechanisms are investigated. A CP asymmetry of magnitude 3.3\times 10^{-3} is shown to result in the standard model from K^0-\bar{K}^0 mixing in the final-state. New physics affecting the doubly Cabibbo-suppressed channels might either cancel this asymmetry or enhance it up to the percent level. A comparison between the CP asymmetries in D^{\pm}_{(s)} \to K_{S} X^{\pm}_{(s)} and D^{\pm}_{(s)} \to K_L X^{\pm}_{(s)} can pin down effects of new physics.
hep-ph/0501268
Wolfgang Lucha
Z.-F. Li, J. J. Liu, Wolfgang Lucha, W. G. Ma, F. F. Schoberl
Relativistic Harmonic Oscillator
14 pages, extended discussion of results
J.Math.Phys. 46 (2005) 103514
10.1063/1.2054648
HEPHY-PUB 800/05
hep-ph math-ph math.MP quant-ph
null
We study the semirelativistic Hamiltonian operator composed of the relativistic kinetic energy and a static harmonic-oscillator potential in three spatial dimensions and construct, for bound states with vanishing orbital angular momentum, its eigenfunctions in compact form, i. e., as power series, with expansion coefficients determined by an explicitly given recurrence relation. The corresponding eigenvalues are fixed by the requirement of normalizability of the solutions.
[ { "created": "Fri, 28 Jan 2005 10:14:02 GMT", "version": "v1" }, { "created": "Tue, 20 Sep 2005 11:53:36 GMT", "version": "v2" } ]
2009-11-11
[ [ "Li", "Z. -F.", "" ], [ "Liu", "J. J.", "" ], [ "Lucha", "Wolfgang", "" ], [ "Ma", "W. G.", "" ], [ "Schoberl", "F. F.", "" ] ]
We study the semirelativistic Hamiltonian operator composed of the relativistic kinetic energy and a static harmonic-oscillator potential in three spatial dimensions and construct, for bound states with vanishing orbital angular momentum, its eigenfunctions in compact form, i. e., as power series, with expansion coefficients determined by an explicitly given recurrence relation. The corresponding eigenvalues are fixed by the requirement of normalizability of the solutions.
hep-ph/9412263
Haret Rosu
Haret C. Rosu
On mean free path statistics of relativistic heavy ions in nuclear emulsion
13 pages, LaTex 11pt, no figures
Acta Phys. Polon. B25 (1994) 1459-1466
null
IFUG-94/10
hep-ph
null
We survey at the general level, and in a rather wide and historical context, some less known mathematical details of various mean free path statistics in nuclear emulsion as applied to relativistic projectile fragmentations. A number of comments are provided on Feller's paradox, ordered, censored, and truncated statistics, Erlang and Poisson observers of nuclear emulsion. All these issues are related to the statistical approaches used about a decade ago at Berkeley Bevalac for anomalons, some of which should be considered as standard methods for mean free paths' estimators of relativistic heavy ions.
[ { "created": "Fri, 9 Dec 1994 01:15:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rosu", "Haret C.", "" ] ]
We survey at the general level, and in a rather wide and historical context, some less known mathematical details of various mean free path statistics in nuclear emulsion as applied to relativistic projectile fragmentations. A number of comments are provided on Feller's paradox, ordered, censored, and truncated statistics, Erlang and Poisson observers of nuclear emulsion. All these issues are related to the statistical approaches used about a decade ago at Berkeley Bevalac for anomalons, some of which should be considered as standard methods for mean free paths' estimators of relativistic heavy ions.
hep-ph/0212171
Andrianov Alexander
A.A.Andrianov (1,2), V.A.Andrianov (2) and S.S.Afonin (2) ((1) INFN, Sezione di Bologna, (2) St.Petersburg State University)
Meson mass spectrum and OPE: matching to the large-N_c QCD
4 pages, more refs added, Talk at V Int. Conference "Quark Confinement and the Hadron Spectrum", 10-14 Sept. 2002, Garda Lake, Italy
null
10.1142/9789812704269_0062
null
hep-ph hep-th
null
The relations between masses and decay constants of variety of meson resonances in the energy range 0--3 GeV are verified from the string-like, linear mass spectrum for vector, axial-vector, scalar and pseudoscalar mesons with a universal slope. The way to match the universality with the Operator Product Expansion (OPE) is proposed. The necessity of small deviations from linearity in parameterization of the meson mass spectrum and their decay constants is proven from matching to OPE.
[ { "created": "Thu, 12 Dec 2002 12:27:09 GMT", "version": "v1" }, { "created": "Fri, 13 Dec 2002 16:13:22 GMT", "version": "v2" }, { "created": "Sun, 15 Dec 2002 19:05:40 GMT", "version": "v3" } ]
2017-08-23
[ [ "Andrianov", "A. A.", "" ], [ "Andrianov", "V. A.", "" ], [ "Afonin", "S. S.", "" ] ]
The relations between masses and decay constants of variety of meson resonances in the energy range 0--3 GeV are verified from the string-like, linear mass spectrum for vector, axial-vector, scalar and pseudoscalar mesons with a universal slope. The way to match the universality with the Operator Product Expansion (OPE) is proposed. The necessity of small deviations from linearity in parameterization of the meson mass spectrum and their decay constants is proven from matching to OPE.
1405.4300
Ernesto Arganda
E. Arganda, M.J. Herrero, X. Marcano, C. Weiland
Imprints of massive inverse seesaw model neutrinos in lepton flavor violating Higgs boson decays
29 pages, 13 figures, 1 table, 1 appendix: v4 matches the manuscript published in PRD
Phys. Rev. D 91 (2015) 1, 015001
10.1103/PhysRevD.91.015001
IFT-UAM/CSIC-14-018, FTUAM-14-016
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we consider a Higgs boson with mass and other properties compatible with those of the recently discovered Higgs particle at the LHC, and explore the possibility of new Higgs leptonic decays, beyond the standard model, with the singular feature of being lepton flavor violating (LFV). We study these LFV Higgs decays, $H \to l_k\bar l_m$, within the context of the inverse seesaw model (ISS) and consider the most generic case where three additional pairs of massive right-handed singlet neutrinos are added to the standard model particle content. We require in addition that the input parameters of this ISS model are compatible with the present neutrino data and other constraints, like perturbativity of the neutrino Yukawa couplings. We present a full one-loop computation of the BR($H \to l_k\bar l_m$) rates for the three possible channels, $l_k\bar l_m=\mu \bar \tau,\, e \bar \tau,\, e \bar \mu$, and analyze in full detail the predictions as functions of the various relevant ISS parameters. We study in parallel the correlated one-loop predictions for the radiative decays, $l_m \to l_k \gamma$, within this same ISS context, and require full compatibility of our predictions with the present experimental bounds for the three radiative decays, $\mu \to e \gamma$, $\tau \to \mu \gamma$, and $\tau \to e \gamma$. After exploring the ISS parameter space we conclude on the maximum allowed LFV Higgs decay rates within the ISS.
[ { "created": "Fri, 16 May 2014 20:25:15 GMT", "version": "v1" }, { "created": "Fri, 30 May 2014 16:54:34 GMT", "version": "v2" }, { "created": "Fri, 17 Oct 2014 18:37:56 GMT", "version": "v3" }, { "created": "Wed, 25 Feb 2015 10:53:54 GMT", "version": "v4" } ]
2015-02-26
[ [ "Arganda", "E.", "" ], [ "Herrero", "M. J.", "" ], [ "Marcano", "X.", "" ], [ "Weiland", "C.", "" ] ]
In this paper we consider a Higgs boson with mass and other properties compatible with those of the recently discovered Higgs particle at the LHC, and explore the possibility of new Higgs leptonic decays, beyond the standard model, with the singular feature of being lepton flavor violating (LFV). We study these LFV Higgs decays, $H \to l_k\bar l_m$, within the context of the inverse seesaw model (ISS) and consider the most generic case where three additional pairs of massive right-handed singlet neutrinos are added to the standard model particle content. We require in addition that the input parameters of this ISS model are compatible with the present neutrino data and other constraints, like perturbativity of the neutrino Yukawa couplings. We present a full one-loop computation of the BR($H \to l_k\bar l_m$) rates for the three possible channels, $l_k\bar l_m=\mu \bar \tau,\, e \bar \tau,\, e \bar \mu$, and analyze in full detail the predictions as functions of the various relevant ISS parameters. We study in parallel the correlated one-loop predictions for the radiative decays, $l_m \to l_k \gamma$, within this same ISS context, and require full compatibility of our predictions with the present experimental bounds for the three radiative decays, $\mu \to e \gamma$, $\tau \to \mu \gamma$, and $\tau \to e \gamma$. After exploring the ISS parameter space we conclude on the maximum allowed LFV Higgs decay rates within the ISS.
1401.2402
Jonathan Rosner
Jonathan L. Rosner
Sterile neutrinos in the grand unified group E6
One page (for Snowmass proceedings)
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This White Paper for the Snowmass proceedings recalls the motivation, based on the grand unified group E6, for expecting sterile neutrinos (if they exist) to come in threes.
[ { "created": "Thu, 27 Jun 2013 17:41:21 GMT", "version": "v1" } ]
2014-01-13
[ [ "Rosner", "Jonathan L.", "" ] ]
This White Paper for the Snowmass proceedings recalls the motivation, based on the grand unified group E6, for expecting sterile neutrinos (if they exist) to come in threes.
1911.07856
Thomas Rauh
Daniel King, Matthew Kirk, Alexander Lenz, Thomas Rauh
$|V_{cb}|$ and $\gamma$ from $B$-mixing -- Addendum to "$B_s$ mixing observables and $|V_{td}/V_{ts}|$ from sum rules"
7 pages, 4 figures; Journal version: added description of fit procedure
JHEP03(2020)112
10.1007/JHEP03(2020)112
IPPP/19/83
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this addendum to "$B_s$ mixing observables and $|V_{td}/V_{ts}|$ from sum rules" \cite{King:2019lal} we study the impact of the recent improvements in the theoretical precision of $B$ meson mixing onto CKM unitarity fits. Our key results are the most precise determination of the angle $\gamma = \left(63.4\pm0.9\right)^\circ$ in the unitarity triangle and a new value for the CKM element $|V_{cb}|=(41.6\pm0.7)\cdot10^{-3}$.
[ { "created": "Mon, 18 Nov 2019 19:00:02 GMT", "version": "v1" }, { "created": "Thu, 19 Mar 2020 14:47:09 GMT", "version": "v2" } ]
2020-03-20
[ [ "King", "Daniel", "" ], [ "Kirk", "Matthew", "" ], [ "Lenz", "Alexander", "" ], [ "Rauh", "Thomas", "" ] ]
In this addendum to "$B_s$ mixing observables and $|V_{td}/V_{ts}|$ from sum rules" \cite{King:2019lal} we study the impact of the recent improvements in the theoretical precision of $B$ meson mixing onto CKM unitarity fits. Our key results are the most precise determination of the angle $\gamma = \left(63.4\pm0.9\right)^\circ$ in the unitarity triangle and a new value for the CKM element $|V_{cb}|=(41.6\pm0.7)\cdot10^{-3}$.
hep-ph/0608127
Masahiro Ibe
M. Ibe, Y. Shinbara and T. T. Yanagida
A New Inflation Model with Anomaly-mediated Supersymmetry Breaking
14 pages, 4 figures, the title is corrected
Phys.Lett.B642:165-170,2006
10.1016/j.physletb.2006.09.022
UT-06-20
hep-ph
null
If there are a large number of vacua, multi-inflation may be a more mediocre phenomenon rather than a single inflation. In the multi-inflation scenario, new inflation is most likely the last inflation, since its energy scale is naturally low. Furthermore, it may explain the observed spectral index of the cosmic microwave background radiations. We show, in this letter, that a new inflation model proposed in supergravity accounts for all the present observations assuming anomaly mediation of supersymmetry breaking. As a result, we find that the relic density of the winos is consistent with the observed dark matter density in a wide range of the wino mass, 100 GeV lsim m_{tilde{w}} lsim 2 TeV, albeit for a low reheating temperature T_{R} simeq 10^{6-7},GeV.
[ { "created": "Fri, 11 Aug 2006 09:48:23 GMT", "version": "v1" }, { "created": "Tue, 22 Aug 2006 07:05:59 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ibe", "M.", "" ], [ "Shinbara", "Y.", "" ], [ "Yanagida", "T. T.", "" ] ]
If there are a large number of vacua, multi-inflation may be a more mediocre phenomenon rather than a single inflation. In the multi-inflation scenario, new inflation is most likely the last inflation, since its energy scale is naturally low. Furthermore, it may explain the observed spectral index of the cosmic microwave background radiations. We show, in this letter, that a new inflation model proposed in supergravity accounts for all the present observations assuming anomaly mediation of supersymmetry breaking. As a result, we find that the relic density of the winos is consistent with the observed dark matter density in a wide range of the wino mass, 100 GeV lsim m_{tilde{w}} lsim 2 TeV, albeit for a low reheating temperature T_{R} simeq 10^{6-7},GeV.
1109.6684
Zack Sullivan
Arjun Menon and Zack Sullivan
Higgs exclusion and the H -> WW^* -> l nu c j semi-leptonic channel at the Tevatron
6 pgs., revtex, 6 figs
null
null
IIT-CAPP-11-09
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Higgs boson decay to W+W-, where one boson decays to leptons, and the other decays to c+jet at Tevatron. Given the current charm tagging acceptances, this channel can help improve and confirm the current combined Tevatron exclusion limit on a standard model-like Higgs boson. If charm acceptance can be improved to at least 24%, this channel could provide the second tightest limits on a Higgs boson mass between 140-190 GeV from a single channel measurement.
[ { "created": "Thu, 29 Sep 2011 22:13:29 GMT", "version": "v1" } ]
2011-10-03
[ [ "Menon", "Arjun", "" ], [ "Sullivan", "Zack", "" ] ]
We study the Higgs boson decay to W+W-, where one boson decays to leptons, and the other decays to c+jet at Tevatron. Given the current charm tagging acceptances, this channel can help improve and confirm the current combined Tevatron exclusion limit on a standard model-like Higgs boson. If charm acceptance can be improved to at least 24%, this channel could provide the second tightest limits on a Higgs boson mass between 140-190 GeV from a single channel measurement.
1511.08832
Mateusz Iskrzy\'nski
Mateusz Iskrzy\'nski
Yukawa matrix unification in the Minimal Supersymmetric Standard Model
PhD thesis, based on arXiv: 1408.2165 and 1412.8651, 100 pages, 39 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this dissertation, the Minimal Supersymmetric Standard Model (MSSM) is studied as a low-energy theory stemming from the $SU(5)$ Grand Unified Theory (GUT). We investigate the possibility of satisfying the minimal $SU(5)$ boundary condition $\mathbf{Y}^d=\mathbf{Y}^{e\,T}$ for the full $3\!\times\!3$ down-quark and lepton Yukawa matrices at the GUT scale within the $R$-parity conserving MSSM. We give numerical evidence in favour of the statement: There exist regions in the parameter space of the R-parity conserving MSSM for which the unification of the down-quark and lepton Yukawa matrices takes place, while the predicted values of flavour, electroweak and other collider observables are consistent with experimental constraints. Furthermore, we find evidence that the bottom-tau and strange-muon Yukawa unification is possible with a stable MSSM vacuum in the standard form. We investigate two separate scenarios of the soft supersymmetry breaking terms at the GUT scale. In the first one, it is assumed that the soft terms are flavour-diagonal in the super-CKM basis. In such a case, the trilinear Higgs-squark-squark $A$-terms can generate large threshold corrections to $\mathbf{Y}^d$ at the superpartner decoupling scale. In effect, the condition $\mathbf{Y}^d=\mathbf{Y}^{e\,T}$ imposed at the GUT scale can be satisfied. However, the large trilinear terms make the usual Higgs vacuum metastable (though sufficiently long-lived). In the second scenario, we consider non-vanishing flavour off-diagonal entries in the soft SUSY-breaking mass matrices. We show that a non-trivial flavour structure of the soft SUSY-breaking sector can allow a precise bottom-tau and strange-muon Yukawa coupling unification, while satisfying all phenomenological constraints.
[ { "created": "Fri, 27 Nov 2015 21:49:19 GMT", "version": "v1" } ]
2015-12-01
[ [ "Iskrzyński", "Mateusz", "" ] ]
In this dissertation, the Minimal Supersymmetric Standard Model (MSSM) is studied as a low-energy theory stemming from the $SU(5)$ Grand Unified Theory (GUT). We investigate the possibility of satisfying the minimal $SU(5)$ boundary condition $\mathbf{Y}^d=\mathbf{Y}^{e\,T}$ for the full $3\!\times\!3$ down-quark and lepton Yukawa matrices at the GUT scale within the $R$-parity conserving MSSM. We give numerical evidence in favour of the statement: There exist regions in the parameter space of the R-parity conserving MSSM for which the unification of the down-quark and lepton Yukawa matrices takes place, while the predicted values of flavour, electroweak and other collider observables are consistent with experimental constraints. Furthermore, we find evidence that the bottom-tau and strange-muon Yukawa unification is possible with a stable MSSM vacuum in the standard form. We investigate two separate scenarios of the soft supersymmetry breaking terms at the GUT scale. In the first one, it is assumed that the soft terms are flavour-diagonal in the super-CKM basis. In such a case, the trilinear Higgs-squark-squark $A$-terms can generate large threshold corrections to $\mathbf{Y}^d$ at the superpartner decoupling scale. In effect, the condition $\mathbf{Y}^d=\mathbf{Y}^{e\,T}$ imposed at the GUT scale can be satisfied. However, the large trilinear terms make the usual Higgs vacuum metastable (though sufficiently long-lived). In the second scenario, we consider non-vanishing flavour off-diagonal entries in the soft SUSY-breaking mass matrices. We show that a non-trivial flavour structure of the soft SUSY-breaking sector can allow a precise bottom-tau and strange-muon Yukawa coupling unification, while satisfying all phenomenological constraints.
hep-ph/0410201
Tatsu Takeuchi
Tatsu Takeuchi (Virginia Tech) and Will Loinaz (Amherst College)
Phenomenology of Not-so-heavy Neutral Leptons: The NuTeV Anomaly, Lepton Universality, and Non-Universal Neutrino-Gauge Couplings
REVTeX4, 2 pages, 2 postscript figures
null
null
VPI-IPPAP-04-07
hep-ph
null
Talk presented by Takeuchi at the YITP workshop "Progress in Particle Physics" 2004.
[ { "created": "Thu, 14 Oct 2004 05:20:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Takeuchi", "Tatsu", "", "Virginia Tech" ], [ "Loinaz", "Will", "", "Amherst College" ] ]
Talk presented by Takeuchi at the YITP workshop "Progress in Particle Physics" 2004.
2004.14515
Adam Ritz
Saeid Foroughi-Abari, Adam Ritz
LSND Constraints on the Higgs Portal
8 pages, 6 figures; v2: references and KOTO contour added
Phys. Rev. D 102, 035015 (2020)
10.1103/PhysRevD.102.035015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High-luminosity fixed target experiments provide impressive sensitivity to new light weakly coupled degrees of freedom. We revisit the minimal case of a scalar singlet $S$ coupled to the Standard Model through the Higgs portal, that decays visibly to leptons for scalar masses below the di-pion threshold. The dataset from the LSND experiment is found to impose the leading constraints within two mass windows between $m_S \sim 100$ and 350 MeV. In the process, we analyze a number of scalar production channels in the target, finding that proton bremsstrahlung provides the dominant channel at LSND beam energies.
[ { "created": "Wed, 29 Apr 2020 23:34:34 GMT", "version": "v1" }, { "created": "Fri, 12 Jun 2020 02:43:00 GMT", "version": "v2" } ]
2020-08-19
[ [ "Foroughi-Abari", "Saeid", "" ], [ "Ritz", "Adam", "" ] ]
High-luminosity fixed target experiments provide impressive sensitivity to new light weakly coupled degrees of freedom. We revisit the minimal case of a scalar singlet $S$ coupled to the Standard Model through the Higgs portal, that decays visibly to leptons for scalar masses below the di-pion threshold. The dataset from the LSND experiment is found to impose the leading constraints within two mass windows between $m_S \sim 100$ and 350 MeV. In the process, we analyze a number of scalar production channels in the target, finding that proton bremsstrahlung provides the dominant channel at LSND beam energies.
1302.4743
Piotr Pietrulewicz
Simon Gritschacher, Andre H. Hoang, Ilaria Jemos and Piotr Pietrulewicz
Secondary Heavy Quark Production in Jets through Mass Modes
Mass mode presentation refined, treatment of rapidity divergences added, a number of typos eliminated, 27 pages, 12 figures
null
10.1103/PhysRevD.88.034021
UWTHPH 2012-20
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an effective field theory method to determine secondary massive quark effects in jet production taking the thrust distribution for e+ e- collisions in the dijet limit as a concrete example. The method is based on the field theoretic treatment of collinear and soft mass modes which have to be separated coherently from the collinear and ultrasoft modes related to massless quarks and gluons. For thrust the structure of the conceptual setup is closely related to the production of massive gauge bosons and involves four different effective field theories to describe all possible kinematic situations. The effective field theories merge into each other continuously and thus allow for a continuous description from infinitely heavy to arbitrarily small masses keeping the exact mass dependence of the most singular terms treated through factorization. The mass mode field theory method we present here is in the spirit of the variable fermion number scheme originally proposed by Aivazis, Collins, Olness and Tung and can also be applied in hadron collisions.
[ { "created": "Tue, 19 Feb 2013 21:00:06 GMT", "version": "v1" }, { "created": "Fri, 19 Jul 2013 09:55:38 GMT", "version": "v2" } ]
2013-08-21
[ [ "Gritschacher", "Simon", "" ], [ "Hoang", "Andre H.", "" ], [ "Jemos", "Ilaria", "" ], [ "Pietrulewicz", "Piotr", "" ] ]
We present an effective field theory method to determine secondary massive quark effects in jet production taking the thrust distribution for e+ e- collisions in the dijet limit as a concrete example. The method is based on the field theoretic treatment of collinear and soft mass modes which have to be separated coherently from the collinear and ultrasoft modes related to massless quarks and gluons. For thrust the structure of the conceptual setup is closely related to the production of massive gauge bosons and involves four different effective field theories to describe all possible kinematic situations. The effective field theories merge into each other continuously and thus allow for a continuous description from infinitely heavy to arbitrarily small masses keeping the exact mass dependence of the most singular terms treated through factorization. The mass mode field theory method we present here is in the spirit of the variable fermion number scheme originally proposed by Aivazis, Collins, Olness and Tung and can also be applied in hadron collisions.
hep-ph/0608064
Stefano Profumo
Stefano Profumo, Michael J. Ramsey-Musolf and Sean Tulin
Supersymmetric Contributions to Weak Decay Correlation Coefficients
Revised version - to appear in Phys.Rev.D
Phys.Rev.D75:075017,2007
10.1103/PhysRevD.75.075017
Caltech MAP-323
hep-ph
null
We study supersymmetric contributions to correlation coefficients that characterize the spectral shape and angular distribution for polarized muon- and beta-decays. In the minimal supersymmetric Standard Model (MSSM), one-loop box graphs containing superpartners can give rise to non-(V-A)x(V-A) four fermion operators in the presence of left-right or flavor mixing between sfermions. We analyze the present phenomenological constraints on such mixing and determine the range of allowed contributions to the weak decay correlation coefficients. We discuss the prospective implications for future muon- and beta-decay experiments, and argue that they may provide unique probes of left-right mixing in the first generation scalar fermion sector.
[ { "created": "Fri, 4 Aug 2006 18:25:20 GMT", "version": "v1" }, { "created": "Thu, 5 Apr 2007 18:49:11 GMT", "version": "v2" } ]
2008-11-26
[ [ "Profumo", "Stefano", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Tulin", "Sean", "" ] ]
We study supersymmetric contributions to correlation coefficients that characterize the spectral shape and angular distribution for polarized muon- and beta-decays. In the minimal supersymmetric Standard Model (MSSM), one-loop box graphs containing superpartners can give rise to non-(V-A)x(V-A) four fermion operators in the presence of left-right or flavor mixing between sfermions. We analyze the present phenomenological constraints on such mixing and determine the range of allowed contributions to the weak decay correlation coefficients. We discuss the prospective implications for future muon- and beta-decay experiments, and argue that they may provide unique probes of left-right mixing in the first generation scalar fermion sector.
hep-ph/0201206
William Kilgore
Robert V. Harlander, William B. Kilgore
Next-to-Next-to-Leading Order Higgs Production at Hadron Colliders
5 pages, 4 figures, minor changes
Phys.Rev.Lett. 88 (2002) 201801
10.1103/PhysRevLett.88.201801
BNL-HET-02/3, CERN-TH/2002-006
hep-ph
null
The Higgs boson production cross section at pp and p\bar{p} colliders is calculated in QCD at next-to-next-to-leading order (NNLO). We find that the perturbative expansion of the production cross section is well behaved and that scale dependence is reduced relative to the NLO result. These findings give us confidence in the reliability of the prediction. We also report an error in the NNLO correction to Drell-Yan production.
[ { "created": "Tue, 22 Jan 2002 19:02:52 GMT", "version": "v1" }, { "created": "Thu, 9 May 2002 01:59:29 GMT", "version": "v2" } ]
2009-11-07
[ [ "Harlander", "Robert V.", "" ], [ "Kilgore", "William B.", "" ] ]
The Higgs boson production cross section at pp and p\bar{p} colliders is calculated in QCD at next-to-next-to-leading order (NNLO). We find that the perturbative expansion of the production cross section is well behaved and that scale dependence is reduced relative to the NLO result. These findings give us confidence in the reliability of the prediction. We also report an error in the NNLO correction to Drell-Yan production.
2006.09062
Xun Chen Mr
Jing Zhou, Xun Chen, Yan-Qing Zhao, Jialun Ping
Thermodynamics of heavy quarkonium in magnetic field background
21 pages, 13 figures
Phys. Rev. D 102, 086020 (2020)
10.1103/PhysRevD.102.086020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effect of magnetic field on heavy quark-antiquark pair in both Einstein-Maxwell(EM) and Einstein-Maxwell-Dilaton(EMD) model. The interquark distance, free energy, entropy, binding energy and internal energy of the heavy quarkonium are calculated. It is found that the free energy suppresses and the entropy increases quickly with the increase of the magnetic field $B$. The binding energy vanishes at smaller distance when increasing the magnetic field, which indicates the quark-antiquark pair dissociates at smaller distance. The internal energy which consists of free energy and entropy will increase at large separating distance for non-vanishing magnetic field. These conclusions are consistent both in the EM and EMD model. Moreover, we also find that the quarkonium will dissociate easier in the parallel direction than that in the transverse direction for EMD model, but the conclusion is opposite in EM model. Lattice results are in favor of EMD model. Besides, a Coulomb-plus-linear potential(Cornell potential) can be realized only in EMD model. Thus, a dilaton field is proved to be important in holographic model. Finally, we also show that the free energy, entropy and internal energy of a single quark in EMD model with the presence of magnetic field.
[ { "created": "Tue, 16 Jun 2020 10:45:47 GMT", "version": "v1" }, { "created": "Wed, 17 Jun 2020 13:07:18 GMT", "version": "v2" }, { "created": "Sun, 4 Oct 2020 15:37:58 GMT", "version": "v3" } ]
2020-10-28
[ [ "Zhou", "Jing", "" ], [ "Chen", "Xun", "" ], [ "Zhao", "Yan-Qing", "" ], [ "Ping", "Jialun", "" ] ]
We study the effect of magnetic field on heavy quark-antiquark pair in both Einstein-Maxwell(EM) and Einstein-Maxwell-Dilaton(EMD) model. The interquark distance, free energy, entropy, binding energy and internal energy of the heavy quarkonium are calculated. It is found that the free energy suppresses and the entropy increases quickly with the increase of the magnetic field $B$. The binding energy vanishes at smaller distance when increasing the magnetic field, which indicates the quark-antiquark pair dissociates at smaller distance. The internal energy which consists of free energy and entropy will increase at large separating distance for non-vanishing magnetic field. These conclusions are consistent both in the EM and EMD model. Moreover, we also find that the quarkonium will dissociate easier in the parallel direction than that in the transverse direction for EMD model, but the conclusion is opposite in EM model. Lattice results are in favor of EMD model. Besides, a Coulomb-plus-linear potential(Cornell potential) can be realized only in EMD model. Thus, a dilaton field is proved to be important in holographic model. Finally, we also show that the free energy, entropy and internal energy of a single quark in EMD model with the presence of magnetic field.
hep-ph/0004231
Allan Widom
A. Widom, Y.N. Srivastava
Higgs Decay into Gravitons: Trees and Loops
3 Pages, RevTeX 3.1 format, 3 pages, 2 figures *.eps
null
null
null
hep-ph
null
The decay of the Higgs particle into two gravitons was previously calculated by us using a Born term from the Einstein field equations. Subsequently, others computed the same decay via one loop diagrams but omitting the Born terms. Here all of the diagrams up to one loop are discussed, and it is shown that the Born term is overwhelmingly dominant in agreement with our original results.
[ { "created": "Tue, 25 Apr 2000 17:43:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Widom", "A.", "" ], [ "Srivastava", "Y. N.", "" ] ]
The decay of the Higgs particle into two gravitons was previously calculated by us using a Born term from the Einstein field equations. Subsequently, others computed the same decay via one loop diagrams but omitting the Born terms. Here all of the diagrams up to one loop are discussed, and it is shown that the Born term is overwhelmingly dominant in agreement with our original results.
hep-ph/9408388
Sergey Goloskokov
S.V.Goloskokov and O.A.Listopadov
Spin Effects in High Energy Photon-Hadron Scattering in QCD
9 pages, LaTex, 4 Figures (not encluded, avalable from the authors), JINR Preprint E2-94-348, Dubna,1994
Phys.Atom.Nucl.58:1597-1601,1995; Yad.Fiz.58N9:1695-1700,1995
null
null
hep-ph
null
The spin effects at high energies and momenta transferred $|t|>1 GeV^2$ are analysed for quark-photon scattering. The energy independence of the ratio of spin-flip and spin-non-flip amplitudes in the same $\alpha_s$ order of QCD is obtained. It is shown that the contribution of the spin-dependent quark-pomeron vertex to the spin-flip amplitude is intensified by off-mass-shell effects in the quark loop. As a result, the magnitude of this amplitude can reach 20-30\% from a spin-non-flip one. The dependence of the cross-section on the form-factor and $\alpha_s^3$ spin-non-flip contributions are observed.
[ { "created": "Tue, 30 Aug 1994 11:20:40 GMT", "version": "v1" } ]
2011-08-17
[ [ "Goloskokov", "S. V.", "" ], [ "Listopadov", "O. A.", "" ] ]
The spin effects at high energies and momenta transferred $|t|>1 GeV^2$ are analysed for quark-photon scattering. The energy independence of the ratio of spin-flip and spin-non-flip amplitudes in the same $\alpha_s$ order of QCD is obtained. It is shown that the contribution of the spin-dependent quark-pomeron vertex to the spin-flip amplitude is intensified by off-mass-shell effects in the quark loop. As a result, the magnitude of this amplitude can reach 20-30\% from a spin-non-flip one. The dependence of the cross-section on the form-factor and $\alpha_s^3$ spin-non-flip contributions are observed.
1808.07460
Heinrich P\"as
Dominik D\"oring, Heinrich P\"as, Philipp Sicking, Thomas J. Weiler
Sterile Neutrinos with Altered Dispersion Relations as an Explanation for Neutrino Anomalies
40 pages, 27 figures, version to be published in European Physical Journal C
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently the MiniBooNE Collaboration has confirmed its anomalous excess in (anti)muon- to (anti)electron-neutrino oscillation data. Combined with long-standing results from the LSND experiment this amounts to a 6.1 sigma evidence for new physics beyond the Standard Model. In this paper we develop a framework with 3 active and 3 sterile neutrinos with altered dispersion relations that provides a mechanism to explain these anomalies without being in conflict with the absence of anomalous neutrino disappearance in other neutrino oscillation experiments.
[ { "created": "Wed, 22 Aug 2018 17:55:09 GMT", "version": "v1" }, { "created": "Fri, 29 Jan 2021 16:44:50 GMT", "version": "v2" } ]
2021-02-01
[ [ "Döring", "Dominik", "" ], [ "Päs", "Heinrich", "" ], [ "Sicking", "Philipp", "" ], [ "Weiler", "Thomas J.", "" ] ]
Recently the MiniBooNE Collaboration has confirmed its anomalous excess in (anti)muon- to (anti)electron-neutrino oscillation data. Combined with long-standing results from the LSND experiment this amounts to a 6.1 sigma evidence for new physics beyond the Standard Model. In this paper we develop a framework with 3 active and 3 sterile neutrinos with altered dispersion relations that provides a mechanism to explain these anomalies without being in conflict with the absence of anomalous neutrino disappearance in other neutrino oscillation experiments.
hep-ph/0504281
Hongshi Zong
Feng-yao Hou, Lei Chang, Wei-min Sun, Hong-shi Zong, Yu-xin Liu
New Method for Numerically Solving the Chemical Potential Dependence of the Dressed Quark Propagator
Revtex, 14 pages, 5 figures
Phys.Rev. C72 (2005) 034901
10.1103/PhysRevC.72.034901
null
hep-ph
null
Based on the rainbow approximation of Dyson-Schwinger equation and the assumption that the inverse dressed quark propagator at finite chemical potential is analytic in the neighborhood of $\mu=0$, a new method for obtaining the dressed quark propagator at finite chemical potential $\mu$ from the one at zero chemical potential is developed. Using this method the dressed quark propagator at finite chemical potential can be obtained directly from the one at zero chemical potential without the necessity of numerically solving the corresponding coupled integral equations by iteration methods. A comparison with previous results is given.
[ { "created": "Fri, 29 Apr 2005 03:32:07 GMT", "version": "v1" } ]
2009-11-11
[ [ "Hou", "Feng-yao", "" ], [ "Chang", "Lei", "" ], [ "Sun", "Wei-min", "" ], [ "Zong", "Hong-shi", "" ], [ "Liu", "Yu-xin", "" ] ]
Based on the rainbow approximation of Dyson-Schwinger equation and the assumption that the inverse dressed quark propagator at finite chemical potential is analytic in the neighborhood of $\mu=0$, a new method for obtaining the dressed quark propagator at finite chemical potential $\mu$ from the one at zero chemical potential is developed. Using this method the dressed quark propagator at finite chemical potential can be obtained directly from the one at zero chemical potential without the necessity of numerically solving the corresponding coupled integral equations by iteration methods. A comparison with previous results is given.
hep-ph/0406341
Servant
Geraldine Servant
Proton Stability and Dark Matter: Are They Related?
Talk given at the XXXIXth Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Italy, 21-28 Mar 2004. 6 pages, 3 figures
null
null
null
hep-ph
null
We address the problem of baryon number violation in Randall-Sundrum backgrounds and provide a solution leading to a stable light Kaluza--Klein fermion in warped GUT. This adds to the list of dark matter candidates which stability can follow from ensuring proton stability in weak scale extensions of the Standard Model
[ { "created": "Wed, 30 Jun 2004 16:32:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Servant", "Geraldine", "" ] ]
We address the problem of baryon number violation in Randall-Sundrum backgrounds and provide a solution leading to a stable light Kaluza--Klein fermion in warped GUT. This adds to the list of dark matter candidates which stability can follow from ensuring proton stability in weak scale extensions of the Standard Model
hep-ph/0209259
Sushan Konar
Sushan Konar (IIT, Kharagpur), Subinoy Das (Columbia University, New York)
Neutrino Propagation in a Weakly Magnetized Medium
14 pages, uses pramana.sty, accepted in Pramana
Pramana62:1241-1254,2004
10.1007/BF02704437
IUCAA-41/2002
hep-ph
null
Neutrino-photon processes, forbidden in vacuum, can take place in the presence of a thermal medium and/or an external electro-magnetic field, mediated by the corresponding charged leptons (real or virtual). Such interactions affect the propagation of neutrinos through a magnetized plasma. We investigate the neutrino-photon absorptive processes, at the one-loop level, for massless neutrinos in a weakly magnetized plasma. We find that there is no correction to the absorptive part of the axial-vector--vector amplitude due to the presence of a magnetic field to the linear order in the field strength.
[ { "created": "Mon, 23 Sep 2002 15:02:42 GMT", "version": "v1" }, { "created": "Mon, 29 Mar 2004 07:40:13 GMT", "version": "v2" } ]
2008-11-26
[ [ "Konar", "Sushan", "", "IIT, Kharagpur" ], [ "Das", "Subinoy", "", "Columbia University, New\n York" ] ]
Neutrino-photon processes, forbidden in vacuum, can take place in the presence of a thermal medium and/or an external electro-magnetic field, mediated by the corresponding charged leptons (real or virtual). Such interactions affect the propagation of neutrinos through a magnetized plasma. We investigate the neutrino-photon absorptive processes, at the one-loop level, for massless neutrinos in a weakly magnetized plasma. We find that there is no correction to the absorptive part of the axial-vector--vector amplitude due to the presence of a magnetic field to the linear order in the field strength.
0811.1646
Seungwon Baek
Seungwon Baek, Pyungwon Ko
Phenomenology of $U(1)_{L_\mu - L_\tau}$ charged dark matter at PAMELA/FERMI and colliders
18 pages, 5 figures; minor changes
JCAP 0910:011,2009
10.1088/1475-7516/2009/10/011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent data on $e^+/e^-$ and $\bar{p}$ cosmic rays suggest that dark matter annihilate into the standard model (SM) particles through new leptophilic interaction. In this paper, we consider a standard model extension with the gauged $U(1)_{L_\mu - L_\tau}$ group, with a new Dirac fermion charged under this U(1) as a dark matter. We study the muon $(g-2)_\mu$, thermal relic density of the cold dark matter, and the collider signatures of this model. $Z^{'}$ productions at the Tevatron or the LHC could be easily order of $O(1)-O(10^3)$ fb.
[ { "created": "Tue, 11 Nov 2008 08:11:32 GMT", "version": "v1" }, { "created": "Tue, 18 Nov 2008 04:13:49 GMT", "version": "v2" }, { "created": "Sat, 22 Aug 2009 05:25:30 GMT", "version": "v3" }, { "created": "Wed, 16 Sep 2009 10:35:50 GMT", "version": "v4" } ]
2011-01-05
[ [ "Baek", "Seungwon", "" ], [ "Ko", "Pyungwon", "" ] ]
Recent data on $e^+/e^-$ and $\bar{p}$ cosmic rays suggest that dark matter annihilate into the standard model (SM) particles through new leptophilic interaction. In this paper, we consider a standard model extension with the gauged $U(1)_{L_\mu - L_\tau}$ group, with a new Dirac fermion charged under this U(1) as a dark matter. We study the muon $(g-2)_\mu$, thermal relic density of the cold dark matter, and the collider signatures of this model. $Z^{'}$ productions at the Tevatron or the LHC could be easily order of $O(1)-O(10^3)$ fb.
hep-ph/0006352
Werner Vogelsang
Eric Laenen (NIKHEF), George Sterman (YITP, SUNY Stony Brook), Werner Vogelsang (RIKEN-BNL Research Center)
Current Issues in Prompt Photon Production
Contribution to the proceedings of the ``8th International Workshop on Deep-Inelastic Scattering'' (DIS2000), April 2000, Liverpool, UK; 7 Pages, LaTeX, three figures as eps files
null
null
NIKHEF/00-14, YITP-00-33
hep-ph
null
We give a brief account of recent theoretical developments in prompt photon production.
[ { "created": "Fri, 30 Jun 2000 15:40:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Laenen", "Eric", "", "NIKHEF" ], [ "Sterman", "George", "", "YITP, SUNY Stony Brook" ], [ "Vogelsang", "Werner", "", "RIKEN-BNL Research Center" ] ]
We give a brief account of recent theoretical developments in prompt photon production.
2106.07518
Julio Leite
Alex G. Dias, Julio Leite and Diego S. V. Gon\c{c}alves
Axion-Neutrino Interplay in a Gauged Two-Higgs-Doublet Model
30 pages, 2 figures, 3 tables; few refs added and typos corrected. To appear in PRD
null
10.1103/PhysRevD.104.075014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a gauged two-Higgs-doublet model (2HDM) featuring an anomalous Peccei-Quinn symmetry, $U(1)_{PQ}$. Dangerous tree-level flavour-changing neutral currents, common in 2HDMs, are forbidden by the extra gauge symmetry, $U(1)_X$. In our construction, the solutions to the important issues of neutrino masses, dark matter and the strong CP problem are interrelated. Neutrino masses are generated via a Dirac seesaw mechanism and are suppressed by the ratio of the $U(1)_X$ and the $U(1)_{PQ}$ breaking scales. Naturally small neutrino masses suggest that the breaking of $U(1)_X$ occurs at a relatively low scale, which may lead to observable signals in near-future experiments. Interestingly, spontaneous symmetry breaking does not lead to mixing between the $U(1)_X$ gauge boson, $Z^\prime$, and the standard $Z$. For the expected large values of the $U(1)_{PQ}$ scale, the associated axion becomes "invisible", with DFSZ-like couplings, and may account for the observed abundance of cold dark matter. Moreover, a viable parameter space region, which falls within the expected sensitivities of forthcoming axion searches, is identified. We also observe that the flavour-violating process of kaon decaying into pion plus axion, $K^+ \to \pi^+ a$, is further suppressed by the $U(1)_X$ scale, providing a rather weak lower bound for the axion decay constant $f_a$.
[ { "created": "Mon, 14 Jun 2021 15:44:55 GMT", "version": "v1" }, { "created": "Tue, 28 Sep 2021 07:03:22 GMT", "version": "v2" } ]
2021-10-27
[ [ "Dias", "Alex G.", "" ], [ "Leite", "Julio", "" ], [ "Gonçalves", "Diego S. V.", "" ] ]
We propose a gauged two-Higgs-doublet model (2HDM) featuring an anomalous Peccei-Quinn symmetry, $U(1)_{PQ}$. Dangerous tree-level flavour-changing neutral currents, common in 2HDMs, are forbidden by the extra gauge symmetry, $U(1)_X$. In our construction, the solutions to the important issues of neutrino masses, dark matter and the strong CP problem are interrelated. Neutrino masses are generated via a Dirac seesaw mechanism and are suppressed by the ratio of the $U(1)_X$ and the $U(1)_{PQ}$ breaking scales. Naturally small neutrino masses suggest that the breaking of $U(1)_X$ occurs at a relatively low scale, which may lead to observable signals in near-future experiments. Interestingly, spontaneous symmetry breaking does not lead to mixing between the $U(1)_X$ gauge boson, $Z^\prime$, and the standard $Z$. For the expected large values of the $U(1)_{PQ}$ scale, the associated axion becomes "invisible", with DFSZ-like couplings, and may account for the observed abundance of cold dark matter. Moreover, a viable parameter space region, which falls within the expected sensitivities of forthcoming axion searches, is identified. We also observe that the flavour-violating process of kaon decaying into pion plus axion, $K^+ \to \pi^+ a$, is further suppressed by the $U(1)_X$ scale, providing a rather weak lower bound for the axion decay constant $f_a$.
1306.3501
David Nolde
Stefan Antusch, David Nolde
Matter inflation with A_4 flavour symmetry breaking
26 pages, 4 figures, v2 matches publication in JCAP
JCAP10(2013)028
10.1088/1475-7516/2013/10/028
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss model building in tribrid inflation, which is a framework for realising inflation in the matter sector of supersymmetric particle physics models. The inflaton is a D-flat combination of matter fields, and inflation ends by a phase transition in which some Higgs field obtains a vacuum expectation value. We first describe the general procedure for implementing tribrid inflation in realistic models of particle physics that can be applied to a wide variety of BSM particle physics models around the GUT scale. We then demonstrate how the procedure works for an explicit lepton flavour model based on an A_4 family symmetry. The model is both predictive and phenomenologically viable, and illustrates how tribrid inflation connects cosmological and particle physics parameters. In particular, it predicts a relation between the neutrino Yukawa coupling and the running of the spectral index alpha_s. We also show how topological defects from the flavour symmetry breaking can be avoided automatically.
[ { "created": "Fri, 14 Jun 2013 20:00:02 GMT", "version": "v1" }, { "created": "Tue, 15 Oct 2013 15:10:49 GMT", "version": "v2" } ]
2013-10-16
[ [ "Antusch", "Stefan", "" ], [ "Nolde", "David", "" ] ]
We discuss model building in tribrid inflation, which is a framework for realising inflation in the matter sector of supersymmetric particle physics models. The inflaton is a D-flat combination of matter fields, and inflation ends by a phase transition in which some Higgs field obtains a vacuum expectation value. We first describe the general procedure for implementing tribrid inflation in realistic models of particle physics that can be applied to a wide variety of BSM particle physics models around the GUT scale. We then demonstrate how the procedure works for an explicit lepton flavour model based on an A_4 family symmetry. The model is both predictive and phenomenologically viable, and illustrates how tribrid inflation connects cosmological and particle physics parameters. In particular, it predicts a relation between the neutrino Yukawa coupling and the running of the spectral index alpha_s. We also show how topological defects from the flavour symmetry breaking can be avoided automatically.
1603.05602
C. Q. Geng
C.Q. Geng, Y.K. Hsiao and Eduardo Rodrigues
Exploring the simplest purely baryonic decay processes
10 pages, 3 figures, typos corrected
Phys. Rev. D 94, 014027 (2016)
10.1103/PhysRevD.94.014027
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Though not considered in general, purely baryonic decays could shed light on the puzzle of the baryon number asymmetry in the universe by means of a better understanding of the baryonic nature of our matter world. As such, they constitute a yet unexplored class of decay processes worth investigating. We propose to search for purely baryonic decay processes at the LHCb experiment. No such type of decay has ever been observed. In particular, we concentrate on the decay $\Lambda_b^0\to p\bar pn$, which is the simplest purely baryonic decay mode, with solely spin-1/2 baryons involved. We predict its decay branching ratio to be ${\cal B}(\Lambda_b^0\to p\bar pn)=(2.0^{+0.3}_{-0.2})\times 10^{-6}$, which is sufficiently large to make the decay mode accessible to LHCb. Our study can be extended to other purely baryonic decays such as $\Lambda_b^0\to p\bar p \Lambda$ and $\Lambda_b^0\to \Lambda\bar \Lambda\Lambda$, as well as to similar decays of anti-triplet $b$-baryons such as $\Xi_b^{0,-}$.
[ { "created": "Thu, 17 Mar 2016 18:18:21 GMT", "version": "v1" }, { "created": "Thu, 7 Jul 2016 13:23:16 GMT", "version": "v2" }, { "created": "Thu, 6 Oct 2016 06:42:51 GMT", "version": "v3" } ]
2016-10-07
[ [ "Geng", "C. Q.", "" ], [ "Hsiao", "Y. K.", "" ], [ "Rodrigues", "Eduardo", "" ] ]
Though not considered in general, purely baryonic decays could shed light on the puzzle of the baryon number asymmetry in the universe by means of a better understanding of the baryonic nature of our matter world. As such, they constitute a yet unexplored class of decay processes worth investigating. We propose to search for purely baryonic decay processes at the LHCb experiment. No such type of decay has ever been observed. In particular, we concentrate on the decay $\Lambda_b^0\to p\bar pn$, which is the simplest purely baryonic decay mode, with solely spin-1/2 baryons involved. We predict its decay branching ratio to be ${\cal B}(\Lambda_b^0\to p\bar pn)=(2.0^{+0.3}_{-0.2})\times 10^{-6}$, which is sufficiently large to make the decay mode accessible to LHCb. Our study can be extended to other purely baryonic decays such as $\Lambda_b^0\to p\bar p \Lambda$ and $\Lambda_b^0\to \Lambda\bar \Lambda\Lambda$, as well as to similar decays of anti-triplet $b$-baryons such as $\Xi_b^{0,-}$.
1909.13529
Jarah Evslin
Emilio Ciuffoli, Jarah Evslin and Hosam Mohammed
Measuring Entangled Neutrino States in a Toy Model QFT
25 pages, 5 PDF figures
Nucl Phys B958 (2020) 115113
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Localized wave packet treatments of neutrino oscillations by various groups lead to mutually inconsistent predictions. The neutrino wave packet description arises as an approximate substitute for the evolution of an entangled state which is not localized. The disagreements arise from qualitative differences in the framework which are not specific to electroweak interactions, and so have analogues in simpler models. Therefore in this note we introduce a toy model which allows one to explicitly test these predictions while consistently keeping track of the entanglement of the neutrinos and the source particles. Our study is robust as we use only the Schrodinger picture evolution equations on the entangled state, which are solved explicitly without recourse to the wave packet approximation.
[ { "created": "Mon, 30 Sep 2019 08:56:56 GMT", "version": "v1" }, { "created": "Thu, 16 Jul 2020 09:25:05 GMT", "version": "v2" } ]
2020-07-17
[ [ "Ciuffoli", "Emilio", "" ], [ "Evslin", "Jarah", "" ], [ "Mohammed", "Hosam", "" ] ]
Localized wave packet treatments of neutrino oscillations by various groups lead to mutually inconsistent predictions. The neutrino wave packet description arises as an approximate substitute for the evolution of an entangled state which is not localized. The disagreements arise from qualitative differences in the framework which are not specific to electroweak interactions, and so have analogues in simpler models. Therefore in this note we introduce a toy model which allows one to explicitly test these predictions while consistently keeping track of the entanglement of the neutrinos and the source particles. Our study is robust as we use only the Schrodinger picture evolution equations on the entangled state, which are solved explicitly without recourse to the wave packet approximation.
hep-ph/9802288
Vladimir Pascalutsa
V. Pascalutsa (U. of Utrecht)
Quantization of an interacting spin-3/2 field and the Delta isobar
20 pages, published version
Phys.Rev. D58 (1998) 096002
10.1103/PhysRevD.58.096002
THU-98/07
hep-ph
null
Quantization of the free and interacting Rarita-Schwinger field is considered using the Hamiltonian path-integral formulation. The particular interaction we study in detail is the $\pi N \De$ coupling used in the phenomenology of the pion-nucleon and nucleon-nucleon systems. Within the Dirac constraint analysis, we show that there is an excess of degrees of freedom in the model, as well as the inconsistency related to the Johnson-Sudarshan-Velo-Zwanzinger problem. It is further suggested that couplings invariant under the gauge transformation of the Rarita-Schwinger field are generally free from these inconsistencies. We then construct and briefly analyse some lowest in derivatives gauge-invariant $\pi N \De$ couplings.
[ { "created": "Tue, 10 Feb 1998 12:02:05 GMT", "version": "v1" }, { "created": "Fri, 18 Sep 1998 16:56:31 GMT", "version": "v2" } ]
2009-10-31
[ [ "Pascalutsa", "V.", "", "U. of Utrecht" ] ]
Quantization of the free and interacting Rarita-Schwinger field is considered using the Hamiltonian path-integral formulation. The particular interaction we study in detail is the $\pi N \De$ coupling used in the phenomenology of the pion-nucleon and nucleon-nucleon systems. Within the Dirac constraint analysis, we show that there is an excess of degrees of freedom in the model, as well as the inconsistency related to the Johnson-Sudarshan-Velo-Zwanzinger problem. It is further suggested that couplings invariant under the gauge transformation of the Rarita-Schwinger field are generally free from these inconsistencies. We then construct and briefly analyse some lowest in derivatives gauge-invariant $\pi N \De$ couplings.
1402.5977
Lorenzo Ubaldi
Herbi K. Dreiner, Florian Staub and Lorenzo Ubaldi
From the unification scale to the weak scale: A self consistent supersymmetric Dine-Fischler-Srednicki-Zhitnitsky axion model
v3: 11 pages, double-column format; added sections on RGEs and on couplings of axion/axino to gauge fields; expanded the discussion on the axino mass. This version matches the one to appear in PRD
Phys. Rev. D 90, 055016 (2014)
10.1103/PhysRevD.90.055016
BONN-TH-2014-04
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The distinguishing feature of the Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) axion is that it couples to the electroweak Higgs fields. There is thus an immediate connection between the Peccei-Quinn (PQ) scale and the weak scale. We wish to incorporate the DFSZ axion in a complete supersymmetric model, valid at all scales, and then to implement it in a numerical code connecting the high scale and the low scale physics on a quantitative level. We find that the simplest supersymmetric DFSZ model, as proposed by Rajagopal et al. in 1990, is inconsistent when we consider the minimization of the scalar potential. The problem is that we obtain a negative squared mass for the saxion, the scalar partner of the axion, at the minimum. We then consider the minimal extension in order to get a consistent model for all scales: one has to include an additional explicit sector to spontaneously break the PQ symmetry. In the complete model we can determine the mass of the axino, the fermionic partner of the axion. It is useful to distinguish two cases: (1) the supersymmetry (SUSY) breaking scale is lower than the PQ breaking scale, and (2) the scales are comparable. We find that the axino is very light in (1), while its mass is generically of the order of the other soft SUSY breaking masses in (2). We have implemented SUSY breaking via generic soft breaking terms, and thus make no explicit statement about the form and mediation of SUSY breaking. This complete model can then be incorporated in a numerical code connecting the two scales. We briefly discuss the renormalization group equations and the couplings of the axion to gluons and photons.
[ { "created": "Mon, 24 Feb 2014 21:02:54 GMT", "version": "v1" }, { "created": "Wed, 14 May 2014 17:27:58 GMT", "version": "v2" }, { "created": "Wed, 10 Sep 2014 16:14:25 GMT", "version": "v3" } ]
2014-09-17
[ [ "Dreiner", "Herbi K.", "" ], [ "Staub", "Florian", "" ], [ "Ubaldi", "Lorenzo", "" ] ]
The distinguishing feature of the Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) axion is that it couples to the electroweak Higgs fields. There is thus an immediate connection between the Peccei-Quinn (PQ) scale and the weak scale. We wish to incorporate the DFSZ axion in a complete supersymmetric model, valid at all scales, and then to implement it in a numerical code connecting the high scale and the low scale physics on a quantitative level. We find that the simplest supersymmetric DFSZ model, as proposed by Rajagopal et al. in 1990, is inconsistent when we consider the minimization of the scalar potential. The problem is that we obtain a negative squared mass for the saxion, the scalar partner of the axion, at the minimum. We then consider the minimal extension in order to get a consistent model for all scales: one has to include an additional explicit sector to spontaneously break the PQ symmetry. In the complete model we can determine the mass of the axino, the fermionic partner of the axion. It is useful to distinguish two cases: (1) the supersymmetry (SUSY) breaking scale is lower than the PQ breaking scale, and (2) the scales are comparable. We find that the axino is very light in (1), while its mass is generically of the order of the other soft SUSY breaking masses in (2). We have implemented SUSY breaking via generic soft breaking terms, and thus make no explicit statement about the form and mediation of SUSY breaking. This complete model can then be incorporated in a numerical code connecting the two scales. We briefly discuss the renormalization group equations and the couplings of the axion to gluons and photons.
hep-ph/9904321
Matthias Neubert
Matthias Neubert (SLAC)
Exploring the Weak Phase gamma in B^+- -> pi K Decays
6 pages, 1 figure, contains new results (!); invited talk at the 17th International Conference on Weak Interactions and Neutrinos, Cape Town, South Africa, 24-30 January 1999
null
null
SLAC-PUB-8122
hep-ph
null
Measurements of the rates for the hadronic decays B^+- -> pi K along with the CP-averaged B^+- -> pi^+- pi^0 branching ratio can be used to bound and extract the weak phase gamma=-arg(V_ub). Using preliminary CLEO data, we obtain the bounds |gamma|>93 degrees at 1 sigma, and |gamma|>71 degrees at 90 % confidence level.
[ { "created": "Tue, 13 Apr 1999 21:16:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Neubert", "Matthias", "", "SLAC" ] ]
Measurements of the rates for the hadronic decays B^+- -> pi K along with the CP-averaged B^+- -> pi^+- pi^0 branching ratio can be used to bound and extract the weak phase gamma=-arg(V_ub). Using preliminary CLEO data, we obtain the bounds |gamma|>93 degrees at 1 sigma, and |gamma|>71 degrees at 90 % confidence level.
2301.09273
Kuldeep Deka
Mathew Thomas Arun, Kuldeep Deka, Tripurari Srivastava
Constraining SMEFT BSM scenarios with EWPO and $\Delta_{CKM}$
31 pages, 6 figures, 19 tables
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Precision observables are well known for constraining most of the Beyond Standard Model (BSM) scenarios tightly. We present here a simple and comprehensive fitting framework for various BSM scenarios to these observables. We start with the fit of $S$, $T$ and $V$ parameter and their correlations using the Electroweak Precision Observables (EWPO) including the recent $m_W$ measurement from CDF-II. Utilizing these observables, we also fit various New Physics (NP) scenarios consisting of different subsets of dimension-6 Standard Model Effective Field Theory (SMEFT) operators in the Warsaw basis out of a total of 10 appearing at tree level in EWPO. To further constrain these scenarios, we augment these observables with $\Delta_{CKM}$ measurement using 1-loop matching of the Low Energy Effective Field Theory (LEFT) to SMEFT operators at the Z-pole. We show that the inclusion of $\Delta_{CKM}$ constraint indeed results in stronger bounds on the SMEFT Wilson Coefficients. We also constrain the UV parameters of BSM extensions like Vectorlike leptons (VLL) and find out that such a minimal extension is in tension with the forward-backward asymmetry in $b$-sector ($A_b^{FB}$) and the recent measurement of $M_W$. In order to lift the two blind directions, which one encounters while fitting all the 10 SMEFT WCs at tree-level, we also include the LEP-II observables pertaining to the $WW$ production and present the results for the fits with and without $\Delta_{CKM}$ constraint.
[ { "created": "Mon, 23 Jan 2023 05:05:26 GMT", "version": "v1" }, { "created": "Tue, 23 May 2023 11:44:13 GMT", "version": "v2" } ]
2023-05-24
[ [ "Arun", "Mathew Thomas", "" ], [ "Deka", "Kuldeep", "" ], [ "Srivastava", "Tripurari", "" ] ]
Precision observables are well known for constraining most of the Beyond Standard Model (BSM) scenarios tightly. We present here a simple and comprehensive fitting framework for various BSM scenarios to these observables. We start with the fit of $S$, $T$ and $V$ parameter and their correlations using the Electroweak Precision Observables (EWPO) including the recent $m_W$ measurement from CDF-II. Utilizing these observables, we also fit various New Physics (NP) scenarios consisting of different subsets of dimension-6 Standard Model Effective Field Theory (SMEFT) operators in the Warsaw basis out of a total of 10 appearing at tree level in EWPO. To further constrain these scenarios, we augment these observables with $\Delta_{CKM}$ measurement using 1-loop matching of the Low Energy Effective Field Theory (LEFT) to SMEFT operators at the Z-pole. We show that the inclusion of $\Delta_{CKM}$ constraint indeed results in stronger bounds on the SMEFT Wilson Coefficients. We also constrain the UV parameters of BSM extensions like Vectorlike leptons (VLL) and find out that such a minimal extension is in tension with the forward-backward asymmetry in $b$-sector ($A_b^{FB}$) and the recent measurement of $M_W$. In order to lift the two blind directions, which one encounters while fitting all the 10 SMEFT WCs at tree-level, we also include the LEP-II observables pertaining to the $WW$ production and present the results for the fits with and without $\Delta_{CKM}$ constraint.
2002.11696
Angel Gomez Nicola
Dom\`enec Espriu, Angel G\'omez Nicola, Andrea Vioque-Rodr\'iguez
Chiral perturbation theory for nonzero chiral imbalance
28 pages, 9 figures. Version accepted in JHEP. References, comments, section 5F and Figs.8,9 added
null
10.1007/JHEP06(2020)062
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct the most general low-energy effective lagrangian including local parity violating terms parametrized by an axial chemical potential or chiral imbalance $\mu_5$, up to ${\cal O}(p^4)$ order in the chiral expansion for two light flavours. For that purpose, we work within the Chiral Perturbation Theory framework where only pseudo-NGB fields are included, following the external source method. The $\cal{O}(p^2)$ lagrangian is only modified by constant terms, while the $\cal{O}(p^4)$ one includes new terms proportional to $\mu_5^2$ and new low-energy constants (LEC), which are renormalized and related to particular observables. In particular, we analyze the corrections to the pion dispersion relation and observables related to the vacuum energy density, namely the light quark condensate, the chiral and topological susceptibilities and the chiral charge density, providing numerical determinations of the new LEC when possible. In particular, we explore the dependence of the chiral restoration temperature $T_c$ with $\mu_5$. An increasing $T_c(\mu_5)$ is consistent with our fits to lattice data of the ChPT-based expressions. Although lattice uncertainties are still large and translate into the new LEC determination, a consistent physical description of those observables emerges from our present work, providing a theoretically robust model-independent framework for further study of physical systems where parity-breaking effects may be relevant, such as heavy-ion collisions.
[ { "created": "Wed, 26 Feb 2020 18:39:22 GMT", "version": "v1" }, { "created": "Mon, 9 Mar 2020 10:04:46 GMT", "version": "v2" }, { "created": "Tue, 9 Jun 2020 16:03:26 GMT", "version": "v3" } ]
2020-07-15
[ [ "Espriu", "Domènec", "" ], [ "Nicola", "Angel Gómez", "" ], [ "Vioque-Rodríguez", "Andrea", "" ] ]
We construct the most general low-energy effective lagrangian including local parity violating terms parametrized by an axial chemical potential or chiral imbalance $\mu_5$, up to ${\cal O}(p^4)$ order in the chiral expansion for two light flavours. For that purpose, we work within the Chiral Perturbation Theory framework where only pseudo-NGB fields are included, following the external source method. The $\cal{O}(p^2)$ lagrangian is only modified by constant terms, while the $\cal{O}(p^4)$ one includes new terms proportional to $\mu_5^2$ and new low-energy constants (LEC), which are renormalized and related to particular observables. In particular, we analyze the corrections to the pion dispersion relation and observables related to the vacuum energy density, namely the light quark condensate, the chiral and topological susceptibilities and the chiral charge density, providing numerical determinations of the new LEC when possible. In particular, we explore the dependence of the chiral restoration temperature $T_c$ with $\mu_5$. An increasing $T_c(\mu_5)$ is consistent with our fits to lattice data of the ChPT-based expressions. Although lattice uncertainties are still large and translate into the new LEC determination, a consistent physical description of those observables emerges from our present work, providing a theoretically robust model-independent framework for further study of physical systems where parity-breaking effects may be relevant, such as heavy-ion collisions.
1506.04808
Jayanti Prasad
Suratna Das, Gaurav Goswami, Jayanti Prasad and Raghavan Rangarajan
Constraints on just enough inflation preceded by a thermal era
Clearer presentation, agrees with published version
Phys. Rev. D 93, 023516 (2016)
10.1103/PhysRevD.93.023516
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If the inflationary era is preceded by a radiation dominated era in which the inflaton too was in thermal equilibrium at some very early time then the CMB data places an upper bound on the comoving temperature of the (decoupled) inflaton quanta. In addition, if one considers models of "just enough" inflation, where the number of e-foldings of inflation is just enough to solve the horizon and flatness problems, then we get a lower bound on the Hubble parameter during inflation, $H_{\rm inf}$, which is in severe conflict with the upper bound from tensor perturbations. Alternatively, imposing the upper bound on $H_{\rm inf}$ implies that such scenarios are compatible with the data only if the number of relativistic degrees of freedom in the thermal bath in the pre-inflationary Universe is extremely large (greater than $10^9$ or $10^{11})$. We are not aware of scenarios in which this can be satisfied.
[ { "created": "Tue, 16 Jun 2015 00:58:39 GMT", "version": "v1" }, { "created": "Sun, 24 Jan 2016 16:54:17 GMT", "version": "v2" } ]
2016-01-26
[ [ "Das", "Suratna", "" ], [ "Goswami", "Gaurav", "" ], [ "Prasad", "Jayanti", "" ], [ "Rangarajan", "Raghavan", "" ] ]
If the inflationary era is preceded by a radiation dominated era in which the inflaton too was in thermal equilibrium at some very early time then the CMB data places an upper bound on the comoving temperature of the (decoupled) inflaton quanta. In addition, if one considers models of "just enough" inflation, where the number of e-foldings of inflation is just enough to solve the horizon and flatness problems, then we get a lower bound on the Hubble parameter during inflation, $H_{\rm inf}$, which is in severe conflict with the upper bound from tensor perturbations. Alternatively, imposing the upper bound on $H_{\rm inf}$ implies that such scenarios are compatible with the data only if the number of relativistic degrees of freedom in the thermal bath in the pre-inflationary Universe is extremely large (greater than $10^9$ or $10^{11})$. We are not aware of scenarios in which this can be satisfied.
hep-ph/9806283
Boris Kopeliovich
B.Z. Kopeliovich (MPI-K, Heidelberg and JINR, Dubna)
Diffractive Production of Drell-Yan pairs and Heavy Flavors
Replaced by an extended version for Phys.Lett.B. Based on invited talks at the International Workshop on Diffraction Physics, Rio de Janeiro, February 16-20, 1998, and at DIS'98, Brussels, April 4-8, 1998
Phys.Lett. B447 (1999) 308-312
10.1016/S0370-2693(99)00011-8
MPIH-V24-1998
hep-ph nucl-th
null
Partonic interpretation of high-energy reactions is known to depend on a reference frame. Particularly, in the rest frame of the target Drell-Yan process looks like freeing of the projectile lepton-antilepton fluctuation, rather than q+qbar -> l+lbar annihilation. The light-cone representation for Drell-Yan reaction is very similar to that in DIS and exposes a substantial contamination of soft interactions, which turn out to be dominant in diffractive production of lepton pairs and in nuclear shadowing. We estimate the fraction of diffractive events in the total Drell-Yan cross section, which scales in M^2, and find a substantial deviation from factorization. An analogous approach is developed for diffractive production of heavy flavors.
[ { "created": "Fri, 5 Jun 1998 16:38:03 GMT", "version": "v1" }, { "created": "Tue, 30 Jun 1998 17:09:51 GMT", "version": "v2" }, { "created": "Thu, 19 Nov 1998 08:34:52 GMT", "version": "v3" } ]
2009-10-31
[ [ "Kopeliovich", "B. Z.", "", "MPI-K, Heidelberg and JINR, Dubna" ] ]
Partonic interpretation of high-energy reactions is known to depend on a reference frame. Particularly, in the rest frame of the target Drell-Yan process looks like freeing of the projectile lepton-antilepton fluctuation, rather than q+qbar -> l+lbar annihilation. The light-cone representation for Drell-Yan reaction is very similar to that in DIS and exposes a substantial contamination of soft interactions, which turn out to be dominant in diffractive production of lepton pairs and in nuclear shadowing. We estimate the fraction of diffractive events in the total Drell-Yan cross section, which scales in M^2, and find a substantial deviation from factorization. An analogous approach is developed for diffractive production of heavy flavors.
hep-ph/9207274
null
James M. Olness
The Nucleon ``Tensor Charges'' and the Skyrme Model
9 single-spaced pages, no figures, MIT-CTP-2122
Phys.Rev. D47 (1993) 2136-2139
10.1103/PhysRevD.47.2136
null
hep-ph
null
The lowest moment of the twist-two, chiral-odd parton distribution $h_1(x)$ of the nucleon can be related to the so-called ``tensor charges'' of the nucleon. We consider the tensor charges in the Skyrme model, and find that in the large-$N_c$, SU(3)-symmetric limit, the model predicts that the octet isosinglet tensor charge, $g^8_T$, is of order $1/N_c$ with respect to the octet isovector tensor charge, $g^3_T$. The predicted $F/D$ ratio is then 1/3, in the large-$N_c$ limit. These predictions coincide with the Skyrme model predictions for the octet ${\it axial}$ charges, $g^8_A$ and $g^3_A$. (The prediction $F/D=1/3$ for the axial charges differs from the commonly quoted prediction of 5/9, which is based on an inconsistent treatment of the large-$N_c$ limit.) The model also predicts that the singlet tensor charge, $g^0_T$, is of order $1/N_c$ with respect to $g^3_T$.
[ { "created": "Thu, 30 Jul 1992 21:56:15 GMT", "version": "v1" } ]
2009-10-22
[ [ "Olness", "James M.", "" ] ]
The lowest moment of the twist-two, chiral-odd parton distribution $h_1(x)$ of the nucleon can be related to the so-called ``tensor charges'' of the nucleon. We consider the tensor charges in the Skyrme model, and find that in the large-$N_c$, SU(3)-symmetric limit, the model predicts that the octet isosinglet tensor charge, $g^8_T$, is of order $1/N_c$ with respect to the octet isovector tensor charge, $g^3_T$. The predicted $F/D$ ratio is then 1/3, in the large-$N_c$ limit. These predictions coincide with the Skyrme model predictions for the octet ${\it axial}$ charges, $g^8_A$ and $g^3_A$. (The prediction $F/D=1/3$ for the axial charges differs from the commonly quoted prediction of 5/9, which is based on an inconsistent treatment of the large-$N_c$ limit.) The model also predicts that the singlet tensor charge, $g^0_T$, is of order $1/N_c$ with respect to $g^3_T$.
0704.3299
Kunihiko Terasaki
Kunihiko Terasaki
D_{s0}^+(2317) as an Iso-triplet Four-quark Meson and Production of Its Neutral and Doubly Charged Partners
6 pages, 3 figures, RevTeX
Prog.Theor.Phys.Suppl.168:211-218,2007
10.1143/PTPS.168.211
YITP-07-22, KANAZAWA-07-02
hep-ph hep-ex nucl-th
null
By studying the decays D_{s0}^+(2317) --> D_s^+ pi^0 and D_s^{*+} gamma, It is shown that its assignment to the I_3=0 component of iso-triplet scalar four-quark mesons is favored. Productions of its neutral and doubly charged partners are also studied. As the result, it is concluded that they could be observed in B decays. Their iso-singlet partner might have been observed in the radiative channels of B decays by the BELLE Collaboration.
[ { "created": "Wed, 25 Apr 2007 03:01:02 GMT", "version": "v1" } ]
2008-11-26
[ [ "Terasaki", "Kunihiko", "" ] ]
By studying the decays D_{s0}^+(2317) --> D_s^+ pi^0 and D_s^{*+} gamma, It is shown that its assignment to the I_3=0 component of iso-triplet scalar four-quark mesons is favored. Productions of its neutral and doubly charged partners are also studied. As the result, it is concluded that they could be observed in B decays. Their iso-singlet partner might have been observed in the radiative channels of B decays by the BELLE Collaboration.
1301.0829
Masha Baryakhtar
Masha Baryakhtar, Edward Hardy, John March-Russell
Axion Mediation
32 pages, 3 figures, references added, minor changes
null
null
SITP-12/43
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the possibility that supersymmetry breaking is mediated to the Standard Model sector through the interactions of a generalized axion multiplet that gains a F-term expectation value. Using an effective field theory framework we enumerate the most general possible set of axion couplings and compute the Standard Model sector soft-supersymmetry-breaking terms. Unusual, non-minimal spectra, such as those of both natural and split supersymmetry are easily implemented. We discuss example models and low-energy spectra, as well as implications of the particularly minimal case of mediation via the QCD axion multiplet. We argue that if the Peccei-Quinn solution to the strong-CP problem is realized in string theory then such axion-mediation is generic, while in a field theory model it is a natural possibility in both DFSZ- and KSVZ-like regimes. Axion mediation can parametrically dominate gravity-mediation and is also cosmologically beneficial as the constraints arising from axino and gravitino overproduction are reduced. Finally, in the string context, axion mediation provides a motivated mechanism where the UV completion naturally ameliorates the supersymmetric flavor problem.
[ { "created": "Fri, 4 Jan 2013 21:00:05 GMT", "version": "v1" }, { "created": "Tue, 26 Feb 2013 01:27:44 GMT", "version": "v2" } ]
2013-02-27
[ [ "Baryakhtar", "Masha", "" ], [ "Hardy", "Edward", "" ], [ "March-Russell", "John", "" ] ]
We explore the possibility that supersymmetry breaking is mediated to the Standard Model sector through the interactions of a generalized axion multiplet that gains a F-term expectation value. Using an effective field theory framework we enumerate the most general possible set of axion couplings and compute the Standard Model sector soft-supersymmetry-breaking terms. Unusual, non-minimal spectra, such as those of both natural and split supersymmetry are easily implemented. We discuss example models and low-energy spectra, as well as implications of the particularly minimal case of mediation via the QCD axion multiplet. We argue that if the Peccei-Quinn solution to the strong-CP problem is realized in string theory then such axion-mediation is generic, while in a field theory model it is a natural possibility in both DFSZ- and KSVZ-like regimes. Axion mediation can parametrically dominate gravity-mediation and is also cosmologically beneficial as the constraints arising from axino and gravitino overproduction are reduced. Finally, in the string context, axion mediation provides a motivated mechanism where the UV completion naturally ameliorates the supersymmetric flavor problem.
hep-ph/9908212
Igor Shovkovy
V. A. Miransky, I. A. Shovkovy and L. C. R. Wijewardhana
The effective potential of composite diquark fields and the spectrum of resonances in dense QCD
8 pages, 1 figure (new), REVTeX. The latest version to appear in Phys. Lett. B. References added, discussion improved
Phys.Lett. B468 (1999) 270-278
10.1016/S0370-2693(99)01267-8
UCTP-113-99
hep-ph hep-th nucl-th
null
The effective potential of composite diquark fields responsible for color symmetry breaking in cold very dense QCD, in which long-range interactions dominate, is derived. The spectrum of excitations and the universality class of this dynamics are described.
[ { "created": "Mon, 2 Aug 1999 14:31:50 GMT", "version": "v1" }, { "created": "Wed, 11 Aug 1999 20:11:31 GMT", "version": "v2" }, { "created": "Tue, 26 Oct 1999 14:31:21 GMT", "version": "v3" } ]
2009-10-31
[ [ "Miransky", "V. A.", "" ], [ "Shovkovy", "I. A.", "" ], [ "Wijewardhana", "L. C. R.", "" ] ]
The effective potential of composite diquark fields responsible for color symmetry breaking in cold very dense QCD, in which long-range interactions dominate, is derived. The spectrum of excitations and the universality class of this dynamics are described.
1305.6938
Christopher W. Murphy
Benjam\'in Grinstein, Christopher W. Murphy, David Pirtskhalava
Searching for New Physics in the Three-Body Decays of the Higgs-like Particle
20 pages, 5 figures, matches version published in JHEP
null
10.1007/JHEP10(2013)077
UCSD/PTH 13-06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the three-body decays of the resonance recently discovered at the LHC are potentially sensitive to effects of new physics. Even if the fully integrated partial decay widths are consistent with the minimal Standard Model there is information that is lost upon integration, which can be uncovered in the differential decay widths. Concentrating on the decay $h \to Z \ell \bar{\ell}$, we identify the regions in the three-body phase space in which these effects become especially pronounced and could be detected in future experiments.
[ { "created": "Wed, 29 May 2013 20:02:18 GMT", "version": "v1" }, { "created": "Thu, 14 Nov 2013 01:57:41 GMT", "version": "v2" } ]
2015-06-16
[ [ "Grinstein", "Benjamín", "" ], [ "Murphy", "Christopher W.", "" ], [ "Pirtskhalava", "David", "" ] ]
We show that the three-body decays of the resonance recently discovered at the LHC are potentially sensitive to effects of new physics. Even if the fully integrated partial decay widths are consistent with the minimal Standard Model there is information that is lost upon integration, which can be uncovered in the differential decay widths. Concentrating on the decay $h \to Z \ell \bar{\ell}$, we identify the regions in the three-body phase space in which these effects become especially pronounced and could be detected in future experiments.
1911.09699
Manuel Szewc
Ezequiel Alvarez, Federico Lamagna, Manuel Szewc
Topic Model for four-top at the LHC
26 pages, 10 figures, appendix included. Minor corrections to match JHEP version. As suggested by Referee, all the code needed to reproduce the results in the paper is uploaded to https://github.com/ManuelSzewc/Topic-Model-for-four-top-at-the-LHC/. Comments welcome
J. High Energ. Phys. 2020, 49 (2020)
10.1007/JHEP01(2020)049
ICAS 045/19
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the implementation of a Topic Model algorithm in four-top searches at the LHC as a test-probe of a not ideal system for applying this technique. We study this Topic Model behavior as its different hypotheses such as mutual reducibility and equal distribution in all samples shift from true. The four-top final state at the LHC is not only relevant because it does not fulfill these conditions, but also because it is a difficult and inefficient system to reconstruct and current Monte Carlo modeling of signal and backgrounds suffers from non-negligible uncertainties. We implement this Topic Model algorithm in the Same-Sign lepton channel where S/B is of order one and all backgrounds cannot have more than two b-jets at parton level. We define different mixtures according to the number of b-jets and we use the total number of jets to demix. Since only the background has an anchor bin, we find that we can reconstruct the background in the signal region independently of Monte Carlo. We propose to use this information to tune the Monte Carlo in the signal region and then compare signal prediction with data. We also explore Machine Learning techniques applied to this Topic Model algorithm and find slight improvements as well as potential roads to investigate. Although our findings indicate that still with the full LHC run 3 data the implementation would be challenging, we pursue through this work to find ways to reduce the impact of Monte Carlo simulations in four-top searches at the LHC.
[ { "created": "Thu, 21 Nov 2019 19:02:25 GMT", "version": "v1" }, { "created": "Thu, 12 Mar 2020 23:52:41 GMT", "version": "v2" } ]
2020-03-16
[ [ "Alvarez", "Ezequiel", "" ], [ "Lamagna", "Federico", "" ], [ "Szewc", "Manuel", "" ] ]
We study the implementation of a Topic Model algorithm in four-top searches at the LHC as a test-probe of a not ideal system for applying this technique. We study this Topic Model behavior as its different hypotheses such as mutual reducibility and equal distribution in all samples shift from true. The four-top final state at the LHC is not only relevant because it does not fulfill these conditions, but also because it is a difficult and inefficient system to reconstruct and current Monte Carlo modeling of signal and backgrounds suffers from non-negligible uncertainties. We implement this Topic Model algorithm in the Same-Sign lepton channel where S/B is of order one and all backgrounds cannot have more than two b-jets at parton level. We define different mixtures according to the number of b-jets and we use the total number of jets to demix. Since only the background has an anchor bin, we find that we can reconstruct the background in the signal region independently of Monte Carlo. We propose to use this information to tune the Monte Carlo in the signal region and then compare signal prediction with data. We also explore Machine Learning techniques applied to this Topic Model algorithm and find slight improvements as well as potential roads to investigate. Although our findings indicate that still with the full LHC run 3 data the implementation would be challenging, we pursue through this work to find ways to reduce the impact of Monte Carlo simulations in four-top searches at the LHC.
hep-ph/9306322
Wai-Yee Keung
Bohdan Grzadkowski and Wai-Yee Keung
SUSY-Induced CP Violation in $t$ Decays at $e^-e^+$ Colliders
17 pages, corrected former postscript output mistakes
Phys.Lett.B316:137-147,1993
10.1016/0370-2693(93)90669-9
CERN-TH.6917/93
hep-ph
null
CP violation in the decays $t \to \ell^+\nu b$ and $\bar t \to \ell^-\bar\nu \bar b$ from the production process $e^-e^+ \to \ttbar$ is discussed. Since the asymmetry proposed as a measure of CP violation vanishes even at the one-loop level in the Standard Model (SM), it may be a useful tool to search for sources of CP violation outside of the SM. As an illustration the asymmetry has been computed within supersymmetric extensions of the SM. Prospects for its measurement at future high-energy linear colliders are discussed.
[ { "created": "Mon, 28 Jun 1993 13:12:09 GMT", "version": "v1" }, { "created": "Thu, 4 Jun 1998 12:28:09 GMT", "version": "v2" } ]
2009-09-01
[ [ "Grzadkowski", "Bohdan", "" ], [ "Keung", "Wai-Yee", "" ] ]
CP violation in the decays $t \to \ell^+\nu b$ and $\bar t \to \ell^-\bar\nu \bar b$ from the production process $e^-e^+ \to \ttbar$ is discussed. Since the asymmetry proposed as a measure of CP violation vanishes even at the one-loop level in the Standard Model (SM), it may be a useful tool to search for sources of CP violation outside of the SM. As an illustration the asymmetry has been computed within supersymmetric extensions of the SM. Prospects for its measurement at future high-energy linear colliders are discussed.
hep-ph/9702423
Mihir P. Worah
Mihir P. Worah
Supersymmetric Baryogenesis at the Electroweak Phase Transition
Final PRD version. 2 typos (Eqs. 24 and 47) corrected
Phys. Rev. D 56, 2010 (1997)
10.1103/PhysRevD.56.2010
SLAC-PUB-7417
hep-ph
null
We study the possibility of baryogenesis in the case of supersymmetry breaking with large mixing between the right-handed scalar charm and right-handed scalar top or right-handed scalar up and right-handed scalar top squarks resulting in one light right-handed up-type squark mass eigenstate. We argue that in this case the electroweak phase transition will be first order, and that large phases already present in the quark mass matrices can generate a baryon asymmetry of the correct magnitude without introducing any new phases specifically for this purpose. We study in detail a particular ansatz for supersymmetry breaking and CP violation where there is only one CP violating phase in the theory: in the up-type quark mass matrix. We study the constraints placed on this model by baryogenesis and flavor physics. This scenario has robust implications for low energy flavor phsyics including D-Dbar mixing and an electric dipole moment for the neutron that are close to the experimental bounds, and CP violation in the B-Bbar system that is different from that in the Standard Model.
[ { "created": "Wed, 26 Feb 1997 02:31:45 GMT", "version": "v1" }, { "created": "Sun, 2 Mar 1997 22:18:18 GMT", "version": "v2" }, { "created": "Tue, 8 Jul 1997 20:46:05 GMT", "version": "v3" } ]
2016-08-24
[ [ "Worah", "Mihir P.", "" ] ]
We study the possibility of baryogenesis in the case of supersymmetry breaking with large mixing between the right-handed scalar charm and right-handed scalar top or right-handed scalar up and right-handed scalar top squarks resulting in one light right-handed up-type squark mass eigenstate. We argue that in this case the electroweak phase transition will be first order, and that large phases already present in the quark mass matrices can generate a baryon asymmetry of the correct magnitude without introducing any new phases specifically for this purpose. We study in detail a particular ansatz for supersymmetry breaking and CP violation where there is only one CP violating phase in the theory: in the up-type quark mass matrix. We study the constraints placed on this model by baryogenesis and flavor physics. This scenario has robust implications for low energy flavor phsyics including D-Dbar mixing and an electric dipole moment for the neutron that are close to the experimental bounds, and CP violation in the B-Bbar system that is different from that in the Standard Model.
2103.14673
Christian Fischer
Nico Santowsky, Gernot Eichmann, Christian S. Fischer, Paul C. Wallbott and Richard Williams
Reply to comment on "The $\sigma$-meson: four-quark vs. two-quark components and decay width in a Bethe-Salpeter approach"
3 pages, 1 figure
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
In a recent comment [1] Blankleider and Kvinikhidze claim that our work [2] is based on a set of inconsistent Bethe-Salpeter equations for the coupling of four-quark to two-quark states. Here we demonstrate that their argument is insubstantial.
[ { "created": "Fri, 26 Mar 2021 18:21:46 GMT", "version": "v1" } ]
2021-03-30
[ [ "Santowsky", "Nico", "" ], [ "Eichmann", "Gernot", "" ], [ "Fischer", "Christian S.", "" ], [ "Wallbott", "Paul C.", "" ], [ "Williams", "Richard", "" ] ]
In a recent comment [1] Blankleider and Kvinikhidze claim that our work [2] is based on a set of inconsistent Bethe-Salpeter equations for the coupling of four-quark to two-quark states. Here we demonstrate that their argument is insubstantial.
hep-ph/0409054
Noriko Shiiki
Noriko Shiiki, Nobuyuki Sawado, and Shinsho Oryu
Collective Quantisation of a Gravitating Skyrmion
10 pages, 9 figures, minor corrections, published version
Phys.Rev. D70 (2004) 114023
10.1103/PhysRevD.70.114023
null
hep-ph
null
Collective quantisation of a B=1 gravitating skyrmion is described. The rotational and isorotational modes are quantised in the same manner as the skyrmion without gravity. It is shown in this paper how the static properties of nucleons such as masses, charge densities, magnetic moments are modified by the gravitational interaction.
[ { "created": "Mon, 6 Sep 2004 11:03:12 GMT", "version": "v1" }, { "created": "Wed, 24 Nov 2004 07:48:32 GMT", "version": "v2" }, { "created": "Sun, 9 Jan 2005 07:59:00 GMT", "version": "v3" } ]
2009-11-10
[ [ "Shiiki", "Noriko", "" ], [ "Sawado", "Nobuyuki", "" ], [ "Oryu", "Shinsho", "" ] ]
Collective quantisation of a B=1 gravitating skyrmion is described. The rotational and isorotational modes are quantised in the same manner as the skyrmion without gravity. It is shown in this paper how the static properties of nucleons such as masses, charge densities, magnetic moments are modified by the gravitational interaction.
hep-ph/0002281
Alexei P. Martynenko
R.N.Faustov, A.P.Martynenko
Self-energy O(alpha^2) correction to the positronium decay rate
8 pages, LaTEX, 2 figures, uses linedraw.sty
null
null
SSU-HEP-00/01
hep-ph
null
Self-energy corrections of order O(alpha^2) to the parapositronium and orthopositronium decay rates are calculated. Numerical values of the corresponding coefficients are B_p=-3.74, B_o=2.02.
[ { "created": "Sat, 26 Feb 2000 13:29:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Faustov", "R. N.", "" ], [ "Martynenko", "A. P.", "" ] ]
Self-energy corrections of order O(alpha^2) to the parapositronium and orthopositronium decay rates are calculated. Numerical values of the corresponding coefficients are B_p=-3.74, B_o=2.02.
1706.09895
Aaron C. Vincent
Aaron C. Vincent, Carlos A. Arg\"uelles, Ali Kheirandish
High-energy neutrino attenuation in the Earth and its associated uncertainties
Matches published version. 11 pages, code available at https://github.com/aaronvincent/nuFATE. Stay tuned for nuFATE v2!
JCAP 1711 (2017) 012
10.1088/1475-7516/2017/11/012
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe nuFATE Neutrino Fast Attenuation Through Earth, a very rapid method of accurately computing the attenuation of high-energy neutrinos during their passage through Earth to detectors such as IceCube, ANTARES or KM3Net, including production of secondary neutrinos from $\tau^\pm$ lepton decay. We then use this method to quantify the error on attenuation due to uncertainties in the isotropic neutrino spectrum, the composition of the Earth, and the parton distribution functions. We show that these can be as large as 20%, which can significantly impact reconstructed astrophysical neutrino parameters, as well as searches for new physics. An implementation of this algorithm is provided as a public code.
[ { "created": "Thu, 29 Jun 2017 18:00:00 GMT", "version": "v1" }, { "created": "Wed, 16 Jan 2019 15:17:12 GMT", "version": "v2" } ]
2019-01-17
[ [ "Vincent", "Aaron C.", "" ], [ "Argüelles", "Carlos A.", "" ], [ "Kheirandish", "Ali", "" ] ]
We describe nuFATE Neutrino Fast Attenuation Through Earth, a very rapid method of accurately computing the attenuation of high-energy neutrinos during their passage through Earth to detectors such as IceCube, ANTARES or KM3Net, including production of secondary neutrinos from $\tau^\pm$ lepton decay. We then use this method to quantify the error on attenuation due to uncertainties in the isotropic neutrino spectrum, the composition of the Earth, and the parton distribution functions. We show that these can be as large as 20%, which can significantly impact reconstructed astrophysical neutrino parameters, as well as searches for new physics. An implementation of this algorithm is provided as a public code.
hep-ph/9708265
Sinisa Veseli
F.E. Close, I. Dunietz, P.R. Page, S. Veseli, and H. Yamamoto
Gluonic Hadrons and Charmless B Decays
12 pages, latex
Phys.Rev.D57:5653-5657,1998
10.1103/PhysRevD.57.5653
RAL-97-036, FERMILAB-PUB-97/232-T, HUTP97/A-040
hep-ph
null
Hybrid charmonium with mass ~4 GeV could be produced via a c c.bar color-octet component in b->c c.bar s. These states could be narrow and could have a significant branching ratio to light hadrons, perhaps enhanced by glueballs. Decays to gluonic hadrons could make a sizable contribution to B->no charm decays. Experimental signatures and search strategies are discussed.
[ { "created": "Wed, 6 Aug 1997 22:44:47 GMT", "version": "v1" } ]
2011-01-25
[ [ "Close", "F. E.", "" ], [ "Dunietz", "I.", "" ], [ "Page", "P. R.", "" ], [ "Veseli", "S.", "" ], [ "Yamamoto", "H.", "" ] ]
Hybrid charmonium with mass ~4 GeV could be produced via a c c.bar color-octet component in b->c c.bar s. These states could be narrow and could have a significant branching ratio to light hadrons, perhaps enhanced by glueballs. Decays to gluonic hadrons could make a sizable contribution to B->no charm decays. Experimental signatures and search strategies are discussed.
hep-ph/0609014
Tetsuo Hyodo
Tetsuo Hyodo (1), Daisuke Jido (1), Atsushi Hosaka (2) ((1) YITP, Kyoto Univ., (2) RCNP, Osaka Univ.)
Exotic hadrons in s-wave chiral dynamics
RevTeX4, 4 pages, 1 figure, 2 tables, typos corrected
Phys.Rev.Lett. 97 (2006) 192002
10.1103/PhysRevLett.97.192002
YITP-06-45, RCNP-Th06025
hep-ph nucl-th
null
We study s-wave scattering of a hadron and a Nambu-Goldstone boson induced by the model-independent low energy interaction in the flavor SU(3) symmetric limit. Establishing the general structure of the low energy interaction based on group theoretical arguments, we find that the interaction in the exotic channels are in most cases repulsive, and that for possible attractive channels the interaction strengths are weak and uniquely given independent of channel. Solving the scattering problem with this interaction, we show that the attraction in the exotic channels is not strong enough to generate a bound state from the physically known target hadrons. We also find that there are no attractive interaction in the exotic channels in large Nc limit.
[ { "created": "Sat, 2 Sep 2006 03:22:06 GMT", "version": "v1" }, { "created": "Wed, 13 Sep 2006 06:43:33 GMT", "version": "v2" } ]
2007-05-23
[ [ "Hyodo", "Tetsuo", "" ], [ "Jido", "Daisuke", "" ], [ "Hosaka", "Atsushi", "" ] ]
We study s-wave scattering of a hadron and a Nambu-Goldstone boson induced by the model-independent low energy interaction in the flavor SU(3) symmetric limit. Establishing the general structure of the low energy interaction based on group theoretical arguments, we find that the interaction in the exotic channels are in most cases repulsive, and that for possible attractive channels the interaction strengths are weak and uniquely given independent of channel. Solving the scattering problem with this interaction, we show that the attraction in the exotic channels is not strong enough to generate a bound state from the physically known target hadrons. We also find that there are no attractive interaction in the exotic channels in large Nc limit.
hep-ph/0106239
null
S.M. Barr and D. Seckel (Bartol Research Institute)
The Cosmological Constant, False Vacua, and Axions
17 pages, LaTex
Phys.Rev.D64:123513,2001
10.1103/PhysRevD.64.123513
BA-01-26
hep-ph
null
It is suggested that the true ground state of the world has exactly vanishing vacuum energy and that the cosmological constant that seems to have been observed is due to our region of the universe being stuck in a false vacuum, whose energy is split from the true vacuum by non-renormalizable operators that are suppressed by powers of the Planck scale. It is shown that conventional invisible axion models typically have the features needed to realize this possibility. In invisible axion models the same field and the same potential can explain both the cosmological constant (or dark energy) and the dark matter. It is also shown that the idea can be realized in non-axion models, an example of which is given having $\Lambda = M_W^7/M_{Pl}^3$, which accords well with the observed value.
[ { "created": "Thu, 21 Jun 2001 15:09:25 GMT", "version": "v1" } ]
2011-05-12
[ [ "Barr", "S. M.", "", "Bartol Research Institute" ], [ "Seckel", "D.", "", "Bartol Research Institute" ] ]
It is suggested that the true ground state of the world has exactly vanishing vacuum energy and that the cosmological constant that seems to have been observed is due to our region of the universe being stuck in a false vacuum, whose energy is split from the true vacuum by non-renormalizable operators that are suppressed by powers of the Planck scale. It is shown that conventional invisible axion models typically have the features needed to realize this possibility. In invisible axion models the same field and the same potential can explain both the cosmological constant (or dark energy) and the dark matter. It is also shown that the idea can be realized in non-axion models, an example of which is given having $\Lambda = M_W^7/M_{Pl}^3$, which accords well with the observed value.
hep-ph/9509364
Fernando Marroquim Leao de Almeida Jr.
F. M. L. Almeida Jr., J. H. Lopes, J. A. Martins Sim\~oes and A. J. Ramalho
Production and decay of single heavy spin-3/2 leptons in high energy electron-positron collisions
Plain Latex, 9 pages, 6 figures
Phys.Rev.D53:3555-3558,1996
10.1103/PhysRevD.53.3555
UFRJ-IF-FPC-022/95
hep-ph
null
We discuss the possibility of detecting heavy spin-3/2 leptons at LEP2 and NLC energies. The angular distributions of primary ordinary leptons are shown to be a good measure to discriminate between a heavy spin-3/2 lepton and a similar nonstandard spin-1/2 signal.
[ { "created": "Fri, 22 Sep 1995 09:52:12 GMT", "version": "v1" } ]
2008-11-26
[ [ "Almeida", "F. M. L.", "Jr." ], [ "Lopes", "J. H.", "" ], [ "Simões", "J. A. Martins", "" ], [ "Ramalho", "A. J.", "" ] ]
We discuss the possibility of detecting heavy spin-3/2 leptons at LEP2 and NLC energies. The angular distributions of primary ordinary leptons are shown to be a good measure to discriminate between a heavy spin-3/2 lepton and a similar nonstandard spin-1/2 signal.
2309.16919
Yu-Kuo Hsiao
Yu-Kuo Hsiao
Study of two-body doubly charmful baryonic $B$ decays with $SU(3)$ flavor symmetry
11 pages, 1 figure, 2 tables
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Within the framework of $SU(3)$ flavor symmetry, we investigate two-body doubly charmful baryonic $B\to{\bf B}_c\bar{\bf B}'_c$ decays, where ${\bf B}_c\bar{\bf B}'_c$ represents the anti-triplet charmed dibaryon. We determine the $SU(3)_f$ amplitudes and calculate ${\cal B}(B^-\to \Xi_c^0\bar \Xi_c^-)=(3.4^{+1.0}_{-0.9})\times 10^{-5}$ and ${\cal B}(\bar B^0_s\to \Lambda_c^+\bar \Xi_c^-)=(3.9^{+1.2}_{-1.0})\times 10^{-5}$ induced by the single $W$-emission configuration. We find that the $W$-exchange amplitude, previously neglected in studies, needs to be taken into account. It can cause a destructive interfering effect with the $W$-emission amplitude, alleviating the significant discrepancy between the theoretical estimation and experimental data for ${\cal B}(\bar B^0\to\Lambda_c^+\bar\Lambda_c^-)$. To test other interfering decay channels, we calculate ${\cal B}(\bar B^0_s\to \Xi_c^{0(+)}\bar \Xi_c^{0(+)})=(3.0^{+1.4}_{-1.1})\times 10^{-4}$ and ${\cal B}(\bar B^0\to \Xi_c^0\bar \Xi_c^0)=(1.5^{+0.7}_{-0.6})\times 10^{-5}$. We estimate non-zero branching fractions for the pure $W$-exchange decay channels, specifically ${\cal B}(\bar B^0_s\to \Lambda_c^+\bar \Lambda_c^-)=(8.1^{+1.7}_{-1.5})\times 10^{-5}$ and ${\cal B}(\bar B^0\to \Xi_c^+\bar \Xi_c^-)=(3.0\pm 0.6)\times 10^{-6}$. Additionally, we predict ${\cal B}(B^+_c\to \Xi_c^+\bar \Xi_c^0)=(2.8^{+0.9}_{-0.7})\times 10^{-4}$ and ${\cal B}(B^+_c\to \Lambda_c^+\bar \Xi_c^0)=(1.6^{+0.5}_{-0.4})\times 10^{-5}$, which are accessible to experimental facilities such as LHCb.
[ { "created": "Fri, 29 Sep 2023 01:24:27 GMT", "version": "v1" } ]
2023-10-02
[ [ "Hsiao", "Yu-Kuo", "" ] ]
Within the framework of $SU(3)$ flavor symmetry, we investigate two-body doubly charmful baryonic $B\to{\bf B}_c\bar{\bf B}'_c$ decays, where ${\bf B}_c\bar{\bf B}'_c$ represents the anti-triplet charmed dibaryon. We determine the $SU(3)_f$ amplitudes and calculate ${\cal B}(B^-\to \Xi_c^0\bar \Xi_c^-)=(3.4^{+1.0}_{-0.9})\times 10^{-5}$ and ${\cal B}(\bar B^0_s\to \Lambda_c^+\bar \Xi_c^-)=(3.9^{+1.2}_{-1.0})\times 10^{-5}$ induced by the single $W$-emission configuration. We find that the $W$-exchange amplitude, previously neglected in studies, needs to be taken into account. It can cause a destructive interfering effect with the $W$-emission amplitude, alleviating the significant discrepancy between the theoretical estimation and experimental data for ${\cal B}(\bar B^0\to\Lambda_c^+\bar\Lambda_c^-)$. To test other interfering decay channels, we calculate ${\cal B}(\bar B^0_s\to \Xi_c^{0(+)}\bar \Xi_c^{0(+)})=(3.0^{+1.4}_{-1.1})\times 10^{-4}$ and ${\cal B}(\bar B^0\to \Xi_c^0\bar \Xi_c^0)=(1.5^{+0.7}_{-0.6})\times 10^{-5}$. We estimate non-zero branching fractions for the pure $W$-exchange decay channels, specifically ${\cal B}(\bar B^0_s\to \Lambda_c^+\bar \Lambda_c^-)=(8.1^{+1.7}_{-1.5})\times 10^{-5}$ and ${\cal B}(\bar B^0\to \Xi_c^+\bar \Xi_c^-)=(3.0\pm 0.6)\times 10^{-6}$. Additionally, we predict ${\cal B}(B^+_c\to \Xi_c^+\bar \Xi_c^0)=(2.8^{+0.9}_{-0.7})\times 10^{-4}$ and ${\cal B}(B^+_c\to \Lambda_c^+\bar \Xi_c^0)=(1.6^{+0.5}_{-0.4})\times 10^{-5}$, which are accessible to experimental facilities such as LHCb.
1110.3904
Kohei Kamada
Kohei Kamada, Kazunori Nakayama, Jun'ichi Yokoyama
Phase transition and monopole production in supergravity inflation
26 pages, 4 figures; references added, typos corrected, published version; v3, references added
null
10.1103/PhysRevD.85.043503
DESY 11-182; UT-11-34; RESCEU-31/11
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In F-term supergravity inflation models, scalar fields other than the inflaton generically receive a Hubble induced mass, which may restore gauge symmetries during inflation and phase transitions may occur during or after inflation as the Hubble parameter decreases. We study monopole (and domain wall) production associated with such a phase transition in chaotic inflation in supergravity and obtain a severe constraint on the symmetry breaking scale which is related with the tensor-to-scalar ratio. Depending on model parameters, it is possible that monopoles are sufficiently diluted to be free from current constraints but still observable by planned experiments.
[ { "created": "Tue, 18 Oct 2011 08:12:56 GMT", "version": "v1" }, { "created": "Tue, 7 Feb 2012 19:03:26 GMT", "version": "v2" }, { "created": "Fri, 10 Feb 2012 15:47:52 GMT", "version": "v3" } ]
2013-05-30
[ [ "Kamada", "Kohei", "" ], [ "Nakayama", "Kazunori", "" ], [ "Yokoyama", "Jun'ichi", "" ] ]
In F-term supergravity inflation models, scalar fields other than the inflaton generically receive a Hubble induced mass, which may restore gauge symmetries during inflation and phase transitions may occur during or after inflation as the Hubble parameter decreases. We study monopole (and domain wall) production associated with such a phase transition in chaotic inflation in supergravity and obtain a severe constraint on the symmetry breaking scale which is related with the tensor-to-scalar ratio. Depending on model parameters, it is possible that monopoles are sufficiently diluted to be free from current constraints but still observable by planned experiments.
hep-ph/9903379
Wieslaw Placzek
M. Skrzypek, S. Jadach, W. Placzek, B. F. L. Ward, Z. Was
Precision Calculations of Heavy Boson Production - YFS Monte Carlo Approach
10 pages, uses sprocl.sty
null
null
CERN-TH/99-06, UTHEP-98-1001
hep-ph
null
In this talk I present the current status of the family of Monte Carlo programs for four-fermion physics based on the Yennie-Frautschie-Suura resummation of soft real and virtual photons. I focus on their applications to LEP2.
[ { "created": "Wed, 17 Mar 1999 12:05:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Skrzypek", "M.", "" ], [ "Jadach", "S.", "" ], [ "Placzek", "W.", "" ], [ "Ward", "B. F. L.", "" ], [ "Was", "Z.", "" ] ]
In this talk I present the current status of the family of Monte Carlo programs for four-fermion physics based on the Yennie-Frautschie-Suura resummation of soft real and virtual photons. I focus on their applications to LEP2.
hep-ph/0206222
Alekhin
Alekhin Sergey (IHEP, Protvino)
Perturbative stability of the QCD analysis of DIS data
4 pages, LATEX, 3 figures (EPS). Talk presented at the 37th Rencontres de Moriond, QCD and Hadronic Interactions, Les Arcs 1800 (France), March 16-23 2002
null
10.1103/PhysRevD.66.124021
null
hep-ph
null
We perform pQCD analysis of the existing DIS data for charged leptons with account of corrections up to the NNLO. The parton distributions, value of strong coupling constant, and high-twist terms are extracted and their stability with respect to account of the NNLO corrections is analyzed. All the quantities are generally stable within their experimental errors. Obtained value of the strong coupling constant is $\alpha_s^{\rm NNLO}(M_{\rm Z})=0.1143\pm 0.0014 ({\rm exp})$ with a guess $\alpha_s^{\rm NNNLO}(M_{\rm Z})\sim 0.113$.
[ { "created": "Sun, 23 Jun 2002 09:22:38 GMT", "version": "v1" } ]
2013-05-29
[ [ "Sergey", "Alekhin", "", "IHEP, Protvino" ] ]
We perform pQCD analysis of the existing DIS data for charged leptons with account of corrections up to the NNLO. The parton distributions, value of strong coupling constant, and high-twist terms are extracted and their stability with respect to account of the NNLO corrections is analyzed. All the quantities are generally stable within their experimental errors. Obtained value of the strong coupling constant is $\alpha_s^{\rm NNLO}(M_{\rm Z})=0.1143\pm 0.0014 ({\rm exp})$ with a guess $\alpha_s^{\rm NNNLO}(M_{\rm Z})\sim 0.113$.
2208.12436
Sarben Sarkar
N. E. Mavromatos, Sarben Sarkar and A. Soto
Schwinger-Dyson equations and mass generation for an axion theory with a PT symmetric Yukawa fermion interaction
null
null
10.1016/j.nuclphysb.2022.116048
KCL-PH-TH/2022-05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A nonperturbative Schwinger-Dyson analysis of mass generation is presented for a non-Hermitian PT-symmetric field theory in four dimensions of an axion coupled to a Dirac fermion.The model is motivated by phenomenological considerations.The axion has a quartic self-coupling $\lambda$ and a Yukawa coupling $g$ to the fermion. The Schwinger-Dyson equations are derived for the model with generic couplings. In the non-Hermitian case there is an additional nonperturbative contribution to the scalar mass. In a simplified rainbow analysis the solutions for the SD equations, are given for different regimes of the couplings $g$ and $\lambda$.
[ { "created": "Fri, 26 Aug 2022 04:53:27 GMT", "version": "v1" } ]
2023-01-04
[ [ "Mavromatos", "N. E.", "" ], [ "Sarkar", "Sarben", "" ], [ "Soto", "A.", "" ] ]
A nonperturbative Schwinger-Dyson analysis of mass generation is presented for a non-Hermitian PT-symmetric field theory in four dimensions of an axion coupled to a Dirac fermion.The model is motivated by phenomenological considerations.The axion has a quartic self-coupling $\lambda$ and a Yukawa coupling $g$ to the fermion. The Schwinger-Dyson equations are derived for the model with generic couplings. In the non-Hermitian case there is an additional nonperturbative contribution to the scalar mass. In a simplified rainbow analysis the solutions for the SD equations, are given for different regimes of the couplings $g$ and $\lambda$.
hep-ph/0103202
Ken Sasaki
Eiichi Mitsuda and Ken Sasaki
Zee model and phenomenology of lepton sector
13pages, 2figures, Latex; Notes added, two references added
null
10.1016/S0370-2693(01)00842-5
YNU-HEPTh-01-102
hep-ph
null
The virtual effects of the Zee charged scalar boson on the lepton-family-number (LFN) violating processes are studied. We obtain the constraints on the individual Yukawa coupling constants of the Zee boson to leptons. Using these constraints, we predict the upper bounds on the muonium-antimuonium conversion probability, the branching fractions of the LFN violating decays such as $\tau \to e\gamma$, $\tau \to \mu\gamma$, $\tau^- \to \mu^+e^-e^-$ and $\tau \to e^+\mu^-\mu^-$. The contribution of the Zee boson to the muon anomalous magnetic moment is also considered
[ { "created": "Mon, 19 Mar 2001 13:03:08 GMT", "version": "v1" }, { "created": "Fri, 23 Mar 2001 07:06:57 GMT", "version": "v2" }, { "created": "Wed, 30 May 2001 10:02:09 GMT", "version": "v3" } ]
2009-11-07
[ [ "Mitsuda", "Eiichi", "" ], [ "Sasaki", "Ken", "" ] ]
The virtual effects of the Zee charged scalar boson on the lepton-family-number (LFN) violating processes are studied. We obtain the constraints on the individual Yukawa coupling constants of the Zee boson to leptons. Using these constraints, we predict the upper bounds on the muonium-antimuonium conversion probability, the branching fractions of the LFN violating decays such as $\tau \to e\gamma$, $\tau \to \mu\gamma$, $\tau^- \to \mu^+e^-e^-$ and $\tau \to e^+\mu^-\mu^-$. The contribution of the Zee boson to the muon anomalous magnetic moment is also considered
1711.05063
Paolo Castorina
Paolo Castorina
Test of Space-Time Non-Commutativity at the Future Circular Collider
null
IJMP A 32 (2017) 1750179
10.1142/S0217751X17501792
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Future Circular Collider (FCC) is a crucial step forward to study new Physics beyond the standard model and to test fundamental aspects as space-time minimal length and Lorentz violations. As an example, a possible enhancement of $e^+e^-$ pair production due to non-commutative effects, catalyzed by the huge magnetic field produced at the beginning of a heavy ion collision at FCC, is discussed. In noncommutative electrodynamics a free photon in the magnetic background can produce a $e^+e^-$ pair. In particular for hard photons with transverse energy $100-600$ GeV at the beginning of the collision and for a particular kinematical setting of the pair , i.e. large total transverse momentum in the reaction plane and invariant mass in the range $200-400$ MeV, the non-commutative contribution, evaluated with the present bound of the non-commuativity fundamental area , can be significant. Other, more exotic, possible signatures of space-time non-commutativity are also considered.
[ { "created": "Tue, 14 Nov 2017 11:41:11 GMT", "version": "v1" } ]
2017-11-15
[ [ "Castorina", "Paolo", "" ] ]
The Future Circular Collider (FCC) is a crucial step forward to study new Physics beyond the standard model and to test fundamental aspects as space-time minimal length and Lorentz violations. As an example, a possible enhancement of $e^+e^-$ pair production due to non-commutative effects, catalyzed by the huge magnetic field produced at the beginning of a heavy ion collision at FCC, is discussed. In noncommutative electrodynamics a free photon in the magnetic background can produce a $e^+e^-$ pair. In particular for hard photons with transverse energy $100-600$ GeV at the beginning of the collision and for a particular kinematical setting of the pair , i.e. large total transverse momentum in the reaction plane and invariant mass in the range $200-400$ MeV, the non-commutative contribution, evaluated with the present bound of the non-commuativity fundamental area , can be significant. Other, more exotic, possible signatures of space-time non-commutativity are also considered.
hep-ph/9511453
Per Osland
Arild Skjold, Per Osland (Bergen)
CP Investigations in the Higgs Sector
12 pages, LaTex2e, plus 7 uuencoded figures. Invited paper, Third Tallinn Symposium on Neutrino Physics, Lohusalu, Estonia, October 7-11, 1995
null
null
Bergen Scientific/Technical Report No. 1995-17
hep-ph
null
In a more general electroweak theory, there could be Higgs particles that are odd under $CP$. When such particles decay via vector bosons to two fermion-antifermion pairs, the momenta of those will be correlated in a way which is determined by the $CP$ of the particle. Similarly, in the Bjorken process correlations among momenta of the initial electron and final-state fermions are sensitive to the $CP$ quantum number. Monte Carlo data on the expected efficiency demonstrate that it should be possible to verify the scalar character of an intermediate-mass Standard Model Higgs boson after three years of data taking at a future linear collider. This is most likely not possible at LEP2. Signals of possible presence of $CP$ violation in the Higgs sector are briefly discussed.
[ { "created": "Wed, 29 Nov 1995 14:13:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Skjold", "Arild", "", "Bergen" ], [ "Osland", "Per", "", "Bergen" ] ]
In a more general electroweak theory, there could be Higgs particles that are odd under $CP$. When such particles decay via vector bosons to two fermion-antifermion pairs, the momenta of those will be correlated in a way which is determined by the $CP$ of the particle. Similarly, in the Bjorken process correlations among momenta of the initial electron and final-state fermions are sensitive to the $CP$ quantum number. Monte Carlo data on the expected efficiency demonstrate that it should be possible to verify the scalar character of an intermediate-mass Standard Model Higgs boson after three years of data taking at a future linear collider. This is most likely not possible at LEP2. Signals of possible presence of $CP$ violation in the Higgs sector are briefly discussed.
hep-ph/0604181
Ken Sasaki
T. Ueda, T. Uematsu, K. Sasaki
Sum rules of polarized photon structure functions revisited-- NNLO corrections to the first moment of $g_1^\gamma (x,Q^2,P^2)$ --
5 pages, 1 eps figure, espcrc2.sty file included, Talk given at RADCOR2005, Shonan Village, Japan, October 2-7, 2005, to appear in the Proceedings
null
null
YNU-HEPTh-06-103, KUNS-2017
hep-ph
null
We present the next-to-next-to-leading order ($\alpha \alpha_s^2$) corrections to the first moment of the polarized virtual photon structure function $g_1^\gamma(x,Q^2,P^2)$ in the kinematical region $Q^2\gg P^2 \gg \Lambda^2$ in QCD. We find that the $\alpha \alpha_s^2$ corrections are about 3% of the sum of the leading ($\alpha$) and the next-to-leading ($\alpha\alpha_s$) contributions, when $Q^2=30\sim 100 {\rm GeV}^2$ and $P^2=3 {\rm GeV}^2$.
[ { "created": "Fri, 21 Apr 2006 08:22:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ueda", "T.", "" ], [ "Uematsu", "T.", "" ], [ "Sasaki", "K.", "" ] ]
We present the next-to-next-to-leading order ($\alpha \alpha_s^2$) corrections to the first moment of the polarized virtual photon structure function $g_1^\gamma(x,Q^2,P^2)$ in the kinematical region $Q^2\gg P^2 \gg \Lambda^2$ in QCD. We find that the $\alpha \alpha_s^2$ corrections are about 3% of the sum of the leading ($\alpha$) and the next-to-leading ($\alpha\alpha_s$) contributions, when $Q^2=30\sim 100 {\rm GeV}^2$ and $P^2=3 {\rm GeV}^2$.
1509.04432
Luca Rottoli
Patrick Groth Merrild, Luca Rottoli
Towards parton distributions with fitted charm
4 pages, 1 figure, to appear in the proceedings of the 18th High-Energy Physics International Conference in Quantum Chromodynamics (QCD 15), 29 Jun-03 Jul 2015, Montpellier
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modern parton distribution function fits require an accurate treatment of heavy quark mass effects. In this contribution, we discuss how the FONLL general-mass variable flavour number scheme can be extended to allow for the possibility of a fitted charm PDF. We present a first estimate of the impact of a fitted charm contribution in the FONLL structure functions, and we discuss the development towards including a fitted charm PDF in the NNPDF framework.
[ { "created": "Tue, 15 Sep 2015 08:00:43 GMT", "version": "v1" } ]
2015-09-16
[ [ "Merrild", "Patrick Groth", "" ], [ "Rottoli", "Luca", "" ] ]
Modern parton distribution function fits require an accurate treatment of heavy quark mass effects. In this contribution, we discuss how the FONLL general-mass variable flavour number scheme can be extended to allow for the possibility of a fitted charm PDF. We present a first estimate of the impact of a fitted charm contribution in the FONLL structure functions, and we discuss the development towards including a fitted charm PDF in the NNPDF framework.
1304.3815
Yuri Sinyukov
V.M. Shapoval, P. Braun-Munzinger, Iu.A. Karpenko, Yu.M. Sinyukov
Femtoscopic scales in $p+p$ and $p+$Pb collisions in view of the uncertainty principle
22 pages, 7 figures
Phys. Lett. B 725 (2013) 139-147
10.1016/j.physletb.2013.07.002
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A method for quantum corrections of Hanbury-Brown/Twiss (HBT) interferometric radii produced by semi-classical event generators is proposed. These corrections account for the basic indistinguishability and mutual coherence of closely located emitters caused by the uncertainty principle. A detailed analysis is presented for pion interferometry in $p+p$ collisions at LHC energy ($\sqrt{s}=7$ TeV). A prediction is also presented of pion interferometric radii for $p+$Pb collisions at $\sqrt{s}=5.02$ TeV. The hydrodynamic/hydrokinetic model with UrQMD cascade as 'afterburner' is utilized for this aim. It is found that quantum corrections to the interferometry radii improve significantly the event generator results which typically overestimate the experimental radii of small systems. A successful description of the interferometry structure of $p+p$ collisions within the corrected hydrodynamic model requires the study of the problem of thermalization mechanism, still a fundamental issue for ultrarelativistic $A+A$ collisions, also for high multiplicity $p+p$ and $p+$Pb events.
[ { "created": "Sat, 13 Apr 2013 15:15:28 GMT", "version": "v1" }, { "created": "Thu, 25 Apr 2013 07:03:02 GMT", "version": "v2" }, { "created": "Fri, 26 Jul 2013 18:42:25 GMT", "version": "v3" } ]
2013-07-29
[ [ "Shapoval", "V. M.", "" ], [ "Braun-Munzinger", "P.", "" ], [ "Karpenko", "Iu. A.", "" ], [ "Sinyukov", "Yu. M.", "" ] ]
A method for quantum corrections of Hanbury-Brown/Twiss (HBT) interferometric radii produced by semi-classical event generators is proposed. These corrections account for the basic indistinguishability and mutual coherence of closely located emitters caused by the uncertainty principle. A detailed analysis is presented for pion interferometry in $p+p$ collisions at LHC energy ($\sqrt{s}=7$ TeV). A prediction is also presented of pion interferometric radii for $p+$Pb collisions at $\sqrt{s}=5.02$ TeV. The hydrodynamic/hydrokinetic model with UrQMD cascade as 'afterburner' is utilized for this aim. It is found that quantum corrections to the interferometry radii improve significantly the event generator results which typically overestimate the experimental radii of small systems. A successful description of the interferometry structure of $p+p$ collisions within the corrected hydrodynamic model requires the study of the problem of thermalization mechanism, still a fundamental issue for ultrarelativistic $A+A$ collisions, also for high multiplicity $p+p$ and $p+$Pb events.
1907.04151
Roman Zhokhov
T. G. Khunjua, K. G. Klimenko, R. N. Zhokhov
Charged pion condensation and duality in dense and hot chirally and isospin asymmetric quark matter in the framework of NJL$_2$ model
19 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1608.07688, arXiv:1704.01477, arXiv:1710.09706
Phys. Rev. D 100, 034009 (2019)
10.1103/PhysRevD.100.034009
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we investigate in the large-$N_c$ limit ($N_c$ is the number of colored quarks) the phase structure of a massless (1+1)-dimensional quark model with four-quark interaction and in the presence of baryon ($\mu_B$), isospin ($\mu_I$) and chiral isospin ($\mu_{I5}$) chemical potentials as well as at nonzero temperature. It is established that chiral isospin chemical potential leads to the generation of charged pion condensation (PC) in dense (nonzero baryon density) and chiral asymmetric quark matter for a wide range of isospin densities. It is shown that there exists a duality correspondence between the chiral symmetry breaking and the charged PC phenomena at any values of temperature even for very hot quark gluon plasma. Moreover, it is shown that charged PC phase with nonzero baryon density can be induced in the model at comparatively high temperatures. This opens up new possible physical systems, where it can be of importance, such as heavy ion collisions, just born neutron stars (proto-neutron stars), supernovas as well as neutron star mergers.
[ { "created": "Mon, 8 Jul 2019 11:23:00 GMT", "version": "v1" } ]
2019-08-14
[ [ "Khunjua", "T. G.", "" ], [ "Klimenko", "K. G.", "" ], [ "Zhokhov", "R. N.", "" ] ]
In this paper we investigate in the large-$N_c$ limit ($N_c$ is the number of colored quarks) the phase structure of a massless (1+1)-dimensional quark model with four-quark interaction and in the presence of baryon ($\mu_B$), isospin ($\mu_I$) and chiral isospin ($\mu_{I5}$) chemical potentials as well as at nonzero temperature. It is established that chiral isospin chemical potential leads to the generation of charged pion condensation (PC) in dense (nonzero baryon density) and chiral asymmetric quark matter for a wide range of isospin densities. It is shown that there exists a duality correspondence between the chiral symmetry breaking and the charged PC phenomena at any values of temperature even for very hot quark gluon plasma. Moreover, it is shown that charged PC phase with nonzero baryon density can be induced in the model at comparatively high temperatures. This opens up new possible physical systems, where it can be of importance, such as heavy ion collisions, just born neutron stars (proto-neutron stars), supernovas as well as neutron star mergers.
1709.09090
Oleksii Matsedonskyi
Oleksii Matsedonskyi, Marc Montull
Light Higgs Boson from a Pole Attractor
version published in PRD
Phys. Rev. D 98, 015026 (2018)
10.1103/PhysRevD.98.015026
DESY 17-145
hep-ph
http://creativecommons.org/licenses/by/4.0/
We propose a new way of explaining the observed Higgs mass, within the cosmological relaxation framework. The key feature distinguishing it from other scanning scenarios is that the scanning field has a non-canonical kinetic term, whose role is to terminate the scan around the desired Higgs mass value. We propose a concrete realisation of this idea with two new singlet fields, one that scans the Higgs mass, and another that limits the time window in which the scan is possible. Within the provided time period, the scanning field does not significantly evolve after the Higgs field gets close to the Standard Model value, due to particle production friction.
[ { "created": "Tue, 26 Sep 2017 15:29:19 GMT", "version": "v1" }, { "created": "Thu, 19 Jul 2018 14:50:33 GMT", "version": "v2" } ]
2018-07-25
[ [ "Matsedonskyi", "Oleksii", "" ], [ "Montull", "Marc", "" ] ]
We propose a new way of explaining the observed Higgs mass, within the cosmological relaxation framework. The key feature distinguishing it from other scanning scenarios is that the scanning field has a non-canonical kinetic term, whose role is to terminate the scan around the desired Higgs mass value. We propose a concrete realisation of this idea with two new singlet fields, one that scans the Higgs mass, and another that limits the time window in which the scan is possible. Within the provided time period, the scanning field does not significantly evolve after the Higgs field gets close to the Standard Model value, due to particle production friction.
hep-ph/9410229
Georg Raffelt
Wolfgang Keil, H.-Thomas Janka, and Georg Raffelt
Reduced Neutrino Opacities and the SN 1987A Signal
22 pages (including figures) + 1 separate table, uuencoded and compressed postscript files
Phys.Rev. D51 (1995) 6635-6646
10.1103/PhysRevD.51.6635
null
hep-ph astro-ph
null
Axial-vector interactions of neutrinos and axions with a medium are based on structure functions which cannot be calculated in simple perturbative terms for nuclear densities. We use the SN~1987A neutrino signal duration to estimate the range of allowed neutrino opacities of a supernova (SN) core. We perform numerical simulations of the evolution from the hot, lepton-rich post-collapse stage to the cold, deleptonized neutron star and compare the predicted neutrino signal characteristics with the SN~1987A data. Besides the neutrino opacities we vary the mass, temperature profile, and equation of state of the initial model. Within plausible limits of these quantities the neutrino opacity cannot be much smaller than its ``standard'' value. This limits the width of the spin-density structure function to much smaller values than indicated by a perturbative calculation, implying that bremsstrahlung processes such as axion emission probably saturate at around 10\% nuclear density. A substantial suppression at yet larger densities that might have been expected does not seem to occur.
[ { "created": "Wed, 5 Oct 1994 19:18:25 GMT", "version": "v1" } ]
2009-10-28
[ [ "Keil", "Wolfgang", "" ], [ "Janka", "H. -Thomas", "" ], [ "Raffelt", "Georg", "" ] ]
Axial-vector interactions of neutrinos and axions with a medium are based on structure functions which cannot be calculated in simple perturbative terms for nuclear densities. We use the SN~1987A neutrino signal duration to estimate the range of allowed neutrino opacities of a supernova (SN) core. We perform numerical simulations of the evolution from the hot, lepton-rich post-collapse stage to the cold, deleptonized neutron star and compare the predicted neutrino signal characteristics with the SN~1987A data. Besides the neutrino opacities we vary the mass, temperature profile, and equation of state of the initial model. Within plausible limits of these quantities the neutrino opacity cannot be much smaller than its ``standard'' value. This limits the width of the spin-density structure function to much smaller values than indicated by a perturbative calculation, implying that bremsstrahlung processes such as axion emission probably saturate at around 10\% nuclear density. A substantial suppression at yet larger densities that might have been expected does not seem to occur.
hep-ph/9510299
Frank Cuypers
Frank Cuypers (MPI Munich)
Manifestations of Strong Electroweak Symmetry Breaking in $e^-e^-$ Scattering
9 pages, talk presented at the Santa Cruz e-e- Workshop, UCSC, 4-5 September 1995
Int.J.Mod.Phys.A11:1533-1540,1996
10.1142/S0217751X96000717
MPI-PhT/95-98
hep-ph
null
We analyze the incidence on polarized $e^-e^-$ scattering of the trilinear and quartic anomalous gauge couplings which arise in the realm of a non-linear realization of electroweak symmetry breaking.
[ { "created": "Mon, 16 Oct 1995 09:15:42 GMT", "version": "v1" } ]
2011-04-15
[ [ "Cuypers", "Frank", "", "MPI Munich" ] ]
We analyze the incidence on polarized $e^-e^-$ scattering of the trilinear and quartic anomalous gauge couplings which arise in the realm of a non-linear realization of electroweak symmetry breaking.
1411.5148
Maciej Rybczynski
Maciej Rybczynski, Grzegorz Wilk, and Zbigniew Wlodarczyk
System size dependence of the log-periodic oscillations of transverse momentum spectra
6 pages, 8 figures. Contibution to the XLIV International Symposium on Multiparticle Dynamics proceedings
EPJ Web Conf. 90 (2015) 01002
10.1051/epjconf/20159001002
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently the inclusive transverse momentum distributions of primary charged particles were measured for different centralities in $Pb+Pb$ collisions. A strong suppression of the nuclear modification factor in central collisions around $p_T \sim 6-7$ GeV/c was seen. As a possible explanation, the hydrodynamic description of the collision process was tentatively proposed. However, such effect, (albeit much weaker) also exists in the ratio of data/fits, both in nuclear $Pb+Pb$ collisions, and in the elementary $p+p$ data in the same range of transverse momenta for which such an explanation is doubtful. As shown recently, in this case, assuming that this effect is genuine, it can be attributed to a specific modification of a quasi-power like formula usually used to describe such $p_T$ data, namely the Tsallis distribution. Following examples from other branches of physics, one simply has to allow for the power index becoming a complex number. This results in specific log-periodic oscillations dressing the usual power-like distribution, which can fit the $p+p$ data. In this presentation we demonstrate that this method can also describe $Pb+Pb$ data for different centralities. We compare it also with a two component statistical model with two Tsallis distributions recently proposed showing that data at still larger $p_T$ will be sufficient to discriminate between these two approaches.
[ { "created": "Wed, 19 Nov 2014 09:01:25 GMT", "version": "v1" } ]
2015-04-03
[ [ "Rybczynski", "Maciej", "" ], [ "Wilk", "Grzegorz", "" ], [ "Wlodarczyk", "Zbigniew", "" ] ]
Recently the inclusive transverse momentum distributions of primary charged particles were measured for different centralities in $Pb+Pb$ collisions. A strong suppression of the nuclear modification factor in central collisions around $p_T \sim 6-7$ GeV/c was seen. As a possible explanation, the hydrodynamic description of the collision process was tentatively proposed. However, such effect, (albeit much weaker) also exists in the ratio of data/fits, both in nuclear $Pb+Pb$ collisions, and in the elementary $p+p$ data in the same range of transverse momenta for which such an explanation is doubtful. As shown recently, in this case, assuming that this effect is genuine, it can be attributed to a specific modification of a quasi-power like formula usually used to describe such $p_T$ data, namely the Tsallis distribution. Following examples from other branches of physics, one simply has to allow for the power index becoming a complex number. This results in specific log-periodic oscillations dressing the usual power-like distribution, which can fit the $p+p$ data. In this presentation we demonstrate that this method can also describe $Pb+Pb$ data for different centralities. We compare it also with a two component statistical model with two Tsallis distributions recently proposed showing that data at still larger $p_T$ will be sufficient to discriminate between these two approaches.
0707.1919
Makoto Sakaguchi
Holger B. Nielsen and Masao Ninomiya
Search for Effect of Influence from Future in Large Hadron Collider
18pp, comments added, change of title and corrections of main text; v4:minor typos corrected
Int.J.Mod.Phys.A23:919-932,2008
10.1142/S0217751X08039682
null
hep-ph hep-th physics.gen-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an experiment which consists of drawing a card and using it to decide restrictions on the running of Large Hadron Collider (LHC for short) at CERN, such as luminosity, and beam energy. There may potentially occur total shut down. The purpose of such an experiment is to search for influence from the future, that is, backward causation. Since LHC will produce particles of a mathematically new type of fundamental scalars, i.e., the Higgs particles, there is potentially a chance to find unseen effects, such as on influence going from future to past, which we suggest in the present paper.
[ { "created": "Fri, 13 Jul 2007 03:56:39 GMT", "version": "v1" }, { "created": "Mon, 16 Jul 2007 06:58:18 GMT", "version": "v2" }, { "created": "Thu, 13 Dec 2007 14:50:14 GMT", "version": "v3" }, { "created": "Wed, 4 Nov 2009 09:26:58 GMT", "version": "v4" } ]
2009-11-04
[ [ "Nielsen", "Holger B.", "" ], [ "Ninomiya", "Masao", "" ] ]
We propose an experiment which consists of drawing a card and using it to decide restrictions on the running of Large Hadron Collider (LHC for short) at CERN, such as luminosity, and beam energy. There may potentially occur total shut down. The purpose of such an experiment is to search for influence from the future, that is, backward causation. Since LHC will produce particles of a mathematically new type of fundamental scalars, i.e., the Higgs particles, there is potentially a chance to find unseen effects, such as on influence going from future to past, which we suggest in the present paper.
2009.14538
Cheng-Jian Xiao
Cheng-Jian Xiao, Dian-Yong Chen, Yu-Bing Dong, Guang-Wei Meng
A study of the decays of $S-$wave $\bar D^\ast K^\ast$ hadronic molecules: the scalar $X_0(2900)$ and its spin partners $X_{J(J=1,2)}$
null
Phys. Rev. D 103, 034004 (2021)
10.1103/PhysRevD.103.034004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we investigated the decays of the fully open-flavor tetraquark state $X_0(2900)$ which was observed by the LHCb Collaboration very recently. Here, the $X_0(2900)$ was assigned as a $S-$wave $\bar D^\ast K^\ast$ hadronic molecule with $I=0$, and the effective lagrangian approach was applied to estimate the partial decay widths. Moreover, we also predicted the decay behaviors of the other unobserved $X_{J(J=1,2)}$, which were the spin partners of the $X_0(2900)$ in the $S-$wave $\bar D^\ast K^\ast$ picture. It was pointed out that the $X_1$ state with $I=0$ was a broad state with the width more than one hundred MeV, while another $X_2$ state with $I=0$ was a narrow state with the width approaching half of that for the $X_0(2900)$. In addition, our results also showed that the $\bar D^\ast K$ mode was expected to be the dominant decay mode for both $X_1$ and $X_2$. Searching for those unobserved $X_{J(J=1,2)}$ in the future experiments might be helpful to understand the nature of $X_0(2900)$.
[ { "created": "Wed, 30 Sep 2020 09:44:32 GMT", "version": "v1" } ]
2021-02-17
[ [ "Xiao", "Cheng-Jian", "" ], [ "Chen", "Dian-Yong", "" ], [ "Dong", "Yu-Bing", "" ], [ "Meng", "Guang-Wei", "" ] ]
In this work, we investigated the decays of the fully open-flavor tetraquark state $X_0(2900)$ which was observed by the LHCb Collaboration very recently. Here, the $X_0(2900)$ was assigned as a $S-$wave $\bar D^\ast K^\ast$ hadronic molecule with $I=0$, and the effective lagrangian approach was applied to estimate the partial decay widths. Moreover, we also predicted the decay behaviors of the other unobserved $X_{J(J=1,2)}$, which were the spin partners of the $X_0(2900)$ in the $S-$wave $\bar D^\ast K^\ast$ picture. It was pointed out that the $X_1$ state with $I=0$ was a broad state with the width more than one hundred MeV, while another $X_2$ state with $I=0$ was a narrow state with the width approaching half of that for the $X_0(2900)$. In addition, our results also showed that the $\bar D^\ast K$ mode was expected to be the dominant decay mode for both $X_1$ and $X_2$. Searching for those unobserved $X_{J(J=1,2)}$ in the future experiments might be helpful to understand the nature of $X_0(2900)$.
1302.6344
Renata Jora
Renata Jora, Salah Nasri and Joseph Schechter
Naturalness in a simple two Higgs doublet model
typos corrected
null
10.1142/S0217751X1350036X
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the implications of a criterion of naturalness for a simple two Higgs doublet model in the context of the discovery of a Higgs like particle with a mass at 125 GeV. This condition which measures the amount of fine tuning further limits the parameter space of this particular model and together with other phenomenological constraints leads to an allowed range of masses for the other neutral or charged Higgs bosons: H, a^{\pm}, a^0.
[ { "created": "Tue, 26 Feb 2013 07:16:51 GMT", "version": "v1" }, { "created": "Mon, 4 Mar 2013 12:41:31 GMT", "version": "v2" }, { "created": "Fri, 19 Apr 2013 09:02:56 GMT", "version": "v3" } ]
2015-06-15
[ [ "Jora", "Renata", "" ], [ "Nasri", "Salah", "" ], [ "Schechter", "Joseph", "" ] ]
We study the implications of a criterion of naturalness for a simple two Higgs doublet model in the context of the discovery of a Higgs like particle with a mass at 125 GeV. This condition which measures the amount of fine tuning further limits the parameter space of this particular model and together with other phenomenological constraints leads to an allowed range of masses for the other neutral or charged Higgs bosons: H, a^{\pm}, a^0.
0903.4297
Balasubramanian Ananthanarayan
Gauhar Abbas, B. Ananthanarayan, S. Ramanan
New constraints on the Pion EM form factor using Pi'(-Q^2)
8 pages latex, uses EPJA style files, contains 12 figures; replaced with version accepted for publication in EPJA, minor typos corrected, discussion improved, reference added
Eur.Phys.J.A41:93-100,2009
10.1140/epja/i2009-10802-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the constraints arising on the expansion parameters c and d of the Pion electromagnetic form factor from the inclusion of pure space-like data and the phase of time-like data along with one space-like datum, using as input the first derivative of the QCD polarization amplitude Pi'(-Q^2). These constraints when combined with other analyses, provide a valuable check on a determination of c due to Guo et al. and on our previous work where pionic contribution to the (g-2) of the muon was used as the input. This work further illustrates the power of analyticity techniques in form factor analysis.
[ { "created": "Wed, 25 Mar 2009 11:09:53 GMT", "version": "v1" }, { "created": "Wed, 15 Apr 2009 03:35:01 GMT", "version": "v2" } ]
2009-07-22
[ [ "Abbas", "Gauhar", "" ], [ "Ananthanarayan", "B.", "" ], [ "Ramanan", "S.", "" ] ]
We study the constraints arising on the expansion parameters c and d of the Pion electromagnetic form factor from the inclusion of pure space-like data and the phase of time-like data along with one space-like datum, using as input the first derivative of the QCD polarization amplitude Pi'(-Q^2). These constraints when combined with other analyses, provide a valuable check on a determination of c due to Guo et al. and on our previous work where pionic contribution to the (g-2) of the muon was used as the input. This work further illustrates the power of analyticity techniques in form factor analysis.
hep-ph/0606263
Vittorio del Duca
Vittorio Del Duca
QCD challenges at the LHC
4 pages. To appear in the proceedings of 41st Rencontres de Moriond: QCD and Hadronic Interactions, La Thuile, Italy, 18-25 Mar 2006
null
null
null
hep-ph
null
In this talk I review some challenges which await perturbative QCD at the Large Hadron Collider. In particular, I consider the underlying event, Monte Carlo methods and next-to-leading order (NLO) calculations.
[ { "created": "Sun, 25 Jun 2006 10:49:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Del Duca", "Vittorio", "" ] ]
In this talk I review some challenges which await perturbative QCD at the Large Hadron Collider. In particular, I consider the underlying event, Monte Carlo methods and next-to-leading order (NLO) calculations.
1211.0197
David d'Enterria
David d'Enterria, and Alexander M. Snigirev
Same-sign WW production in proton-nucleus collisions at the LHC as a signal for double parton scattering
10 pages, 1 figure, 1 table. Tiny mods. Matches PLB published version
null
10.1016/j.physletb.2012.12.032
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of same-sign W-boson pairs from double parton scatterings (DPS) in proton-lead (p-Pb) collisions at the CERN Large Hadron Collider is studied. The signal and background cross sections are estimated with next-to-leading-order perturbative QCD calculations using nuclear parton distribution functions for the Pb ion. At sqrt(sNN) = 8.8 TeV the cross section for the DPS process is about 150 pb, i.e. 600 times larger than that in proton-proton collisions at the same centre-of-mass energy and 1.5 times higher than the pPb --> WW+2-jets single-parton background. The measurement of such a process, where 10 events with fully leptonic W's decays are expected after cuts in 2 pb^{-1}, would constitute an unambiguous DPS signal and would help determine the effective sigma_eff parameter characterising the transverse distribution of partons in the proton.
[ { "created": "Thu, 1 Nov 2012 15:03:35 GMT", "version": "v1" }, { "created": "Mon, 5 Nov 2012 00:04:22 GMT", "version": "v2" }, { "created": "Sat, 22 Dec 2012 13:44:44 GMT", "version": "v3" } ]
2012-12-27
[ [ "d'Enterria", "David", "" ], [ "Snigirev", "Alexander M.", "" ] ]
The production of same-sign W-boson pairs from double parton scatterings (DPS) in proton-lead (p-Pb) collisions at the CERN Large Hadron Collider is studied. The signal and background cross sections are estimated with next-to-leading-order perturbative QCD calculations using nuclear parton distribution functions for the Pb ion. At sqrt(sNN) = 8.8 TeV the cross section for the DPS process is about 150 pb, i.e. 600 times larger than that in proton-proton collisions at the same centre-of-mass energy and 1.5 times higher than the pPb --> WW+2-jets single-parton background. The measurement of such a process, where 10 events with fully leptonic W's decays are expected after cuts in 2 pb^{-1}, would constitute an unambiguous DPS signal and would help determine the effective sigma_eff parameter characterising the transverse distribution of partons in the proton.
2103.15769
Amin Aboubrahim
Amin Aboubrahim, Wan-Zhe Feng, Pran Nath, and Zhu-Yao Wang
A multi-temperature universe can allow a sub-MeV dark photon dark matter
33 pages, 7 figures, 3 tables -- Accepted in JHEP
null
10.1007/JHEP06(2021)086
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
An analysis of sub-MeV dark photon as dark matter is given which is achieved with two hidden sectors, one of which interacts directly with the visible sector while the second has only indirect coupling with the visible sector. The formalism for the evolution of three bath temperatures for the visible sector and the two hidden sectors is developed and utilized in solution of Boltzmann equations coupling the three sectors. We present exclusion plots where the sub-MeV dark photon can be dark matter. The analysis can be extended to a multi-temperature universe with multiple hidden sectors and multiple heat baths.
[ { "created": "Mon, 29 Mar 2021 17:03:03 GMT", "version": "v1" }, { "created": "Sun, 11 Apr 2021 17:25:29 GMT", "version": "v2" }, { "created": "Fri, 4 Jun 2021 07:50:19 GMT", "version": "v3" } ]
2021-06-30
[ [ "Aboubrahim", "Amin", "" ], [ "Feng", "Wan-Zhe", "" ], [ "Nath", "Pran", "" ], [ "Wang", "Zhu-Yao", "" ] ]
An analysis of sub-MeV dark photon as dark matter is given which is achieved with two hidden sectors, one of which interacts directly with the visible sector while the second has only indirect coupling with the visible sector. The formalism for the evolution of three bath temperatures for the visible sector and the two hidden sectors is developed and utilized in solution of Boltzmann equations coupling the three sectors. We present exclusion plots where the sub-MeV dark photon can be dark matter. The analysis can be extended to a multi-temperature universe with multiple hidden sectors and multiple heat baths.
hep-ph/0403248
Dejan Stojkovic
Dejan Stojkovic and Katherine Freese
A black hole solution to the cosmological monopole problem
accepted for publication in Phys. Lett. B
Phys.Lett. B606 (2005) 251-257
10.1016/j.physletb.2004.12.019
null
hep-ph astro-ph gr-qc
null
We propose a solution to the cosmological monopole problem: Primordial black holes, produced in the early universe, can accrete magnetic monopoles before the relics dominate the energy density of the universe. These small black holes quickly evaporate and thereby convert most of the monopole energy density into radiation. We estimate the range of parameters for which this solution is possible: under very conservative assumptions we find that the black hole mass must be less than 10^9 gm.
[ { "created": "Tue, 23 Mar 2004 18:11:30 GMT", "version": "v1" }, { "created": "Fri, 2 Apr 2004 18:27:52 GMT", "version": "v2" }, { "created": "Wed, 17 Nov 2004 19:38:14 GMT", "version": "v3" }, { "created": "Tue, 7 Dec 2004 19:28:00 GMT", "version": "v4" } ]
2009-11-10
[ [ "Stojkovic", "Dejan", "" ], [ "Freese", "Katherine", "" ] ]
We propose a solution to the cosmological monopole problem: Primordial black holes, produced in the early universe, can accrete magnetic monopoles before the relics dominate the energy density of the universe. These small black holes quickly evaporate and thereby convert most of the monopole energy density into radiation. We estimate the range of parameters for which this solution is possible: under very conservative assumptions we find that the black hole mass must be less than 10^9 gm.
0901.2756
Yuji Koike
Yuji Koike and Tetsuya Tomita (Niigata Univ.)
Soft-Fermion-Pole Mechanism to Single Spin Asymmetry in Hadronic Pion Production
4 pages, 1 figure; to appear in the proceedings of the 18th International Symposium on Spin Physics (SPIN2008), October 6 - 11, 2008, Charlottesville, Virginia, USA
AIP Conf.Proc.1149:672-675,2009
10.1063/1.3215735
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Single spin asymmetry (SSA) is a twist-3 observable in the collinear factorization approach. We present a twist-3 single-spin-dependent cross section formula for the pion production in pp-collision, p^\uparrow p\to\pi X, relevant to RHIC experiment. In particular, we calculate the soft-fermion-pole (SFP) contribution to the cross section from the quark-gluon correlation functions. We show that its effect can be as large as the soft-gluon-pole (SGP) contribution owing to the large SFP partonic hard cross section, even though the derivative of the SFP function does not participate in the cross section.
[ { "created": "Mon, 19 Jan 2009 01:36:01 GMT", "version": "v1" } ]
2009-08-24
[ [ "Koike", "Yuji", "", "Niigata Univ." ], [ "Tomita", "Tetsuya", "", "Niigata Univ." ] ]
Single spin asymmetry (SSA) is a twist-3 observable in the collinear factorization approach. We present a twist-3 single-spin-dependent cross section formula for the pion production in pp-collision, p^\uparrow p\to\pi X, relevant to RHIC experiment. In particular, we calculate the soft-fermion-pole (SFP) contribution to the cross section from the quark-gluon correlation functions. We show that its effect can be as large as the soft-gluon-pole (SGP) contribution owing to the large SFP partonic hard cross section, even though the derivative of the SFP function does not participate in the cross section.
2312.14145
Piotr Bargiela DPhil
Piotr Bargiela, Fabrizio Caola, Herschel Chawdhry, Xiao Liu
Two-loop mixed QCD-electroweak amplitudes for $Z+$jet production at the LHC: bosonic corrections
26 pages, 2 figures, 3 tables, partial overlap with DPhil thesis 2311.06977
null
null
OUTP-23-10P, ZU-TH 65/23
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a calculation of the bosonic contribution to the two-loop mixed QCD-electroweak scattering amplitudes for $Z$-boson production in association with one hard jet at hadron colliders. We employ a method to calculate amplitudes in the 't Hooft-Veltman scheme that reduces the amount of spurious non-physical information needed at intermediate stages of the computation, to keep the complexity of the calculation under control. We compute all the relevant Feynman integrals numerically using the Auxiliary Mass Flow method. We evaluate the two-loop scattering amplitudes on a two-dimensional grid in the rapidity and transverse momentum of the $Z$ boson, which has been designed to yield a reliable numerical sampling of the boosted-$Z$ region. This result provides an important building block for improving the theoretical modelling of a key background for monojet searches at the LHC.
[ { "created": "Thu, 21 Dec 2023 18:58:29 GMT", "version": "v1" } ]
2023-12-22
[ [ "Bargiela", "Piotr", "" ], [ "Caola", "Fabrizio", "" ], [ "Chawdhry", "Herschel", "" ], [ "Liu", "Xiao", "" ] ]
We present a calculation of the bosonic contribution to the two-loop mixed QCD-electroweak scattering amplitudes for $Z$-boson production in association with one hard jet at hadron colliders. We employ a method to calculate amplitudes in the 't Hooft-Veltman scheme that reduces the amount of spurious non-physical information needed at intermediate stages of the computation, to keep the complexity of the calculation under control. We compute all the relevant Feynman integrals numerically using the Auxiliary Mass Flow method. We evaluate the two-loop scattering amplitudes on a two-dimensional grid in the rapidity and transverse momentum of the $Z$ boson, which has been designed to yield a reliable numerical sampling of the boosted-$Z$ region. This result provides an important building block for improving the theoretical modelling of a key background for monojet searches at the LHC.
1809.08902
Menglin Du Dr.
Meng-Lin Du
Implication of chiral symmetry for the heavy-light meson spectroscopy
Talk presented CIPANP2018. 9 pages, LaTeX, 3 pdf figures
null
null
CIPANP2018-Du
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many hadronic states observed since 2003, especially for the positive-parity charm-strange states $D_{s0}^\ast (2317)$ and $D_{s1}(2460)$, do not conform with the conventional quark model expectations and raise various puzzles in charm meson spectroscopy. We demonstrate that those puzzles find a natural solution thanks to the recent development of chiral effective theory and Lattice simulations. The existence of the $D_{s0}^\ast (2317)$ and $D_{s1}(2460)$ are attributed to the nonperturbative dynamics of Goldstone bosons scattering off $D$ and $D^\ast$ mesons. It indicates that the lowest positive parity nonstrange scalar charm mesons, the $D_0^\ast(2400)$ in the Review of Particel Physics, should be replaced by two states. The well constructed amplitudes are fully in line with the high quality data on the decays $B^-\to D^+\pi^-\pi^-$ and $D_s^0\to \bar{D}^0K^-\pi^+$. This implies that the lowest positve-parity states are dynamically generated rather than conventional quark-antiquark states. This pattern has also been established for the scalar and axial-vector mesons made from light quarks ($u$, $d$ and $s$ quarks).
[ { "created": "Mon, 24 Sep 2018 13:27:14 GMT", "version": "v1" } ]
2018-09-25
[ [ "Du", "Meng-Lin", "" ] ]
Many hadronic states observed since 2003, especially for the positive-parity charm-strange states $D_{s0}^\ast (2317)$ and $D_{s1}(2460)$, do not conform with the conventional quark model expectations and raise various puzzles in charm meson spectroscopy. We demonstrate that those puzzles find a natural solution thanks to the recent development of chiral effective theory and Lattice simulations. The existence of the $D_{s0}^\ast (2317)$ and $D_{s1}(2460)$ are attributed to the nonperturbative dynamics of Goldstone bosons scattering off $D$ and $D^\ast$ mesons. It indicates that the lowest positive parity nonstrange scalar charm mesons, the $D_0^\ast(2400)$ in the Review of Particel Physics, should be replaced by two states. The well constructed amplitudes are fully in line with the high quality data on the decays $B^-\to D^+\pi^-\pi^-$ and $D_s^0\to \bar{D}^0K^-\pi^+$. This implies that the lowest positve-parity states are dynamically generated rather than conventional quark-antiquark states. This pattern has also been established for the scalar and axial-vector mesons made from light quarks ($u$, $d$ and $s$ quarks).
0905.3193
Ignazio Scimemi
Andre H. Hoang (MPI), Ambar Jain (MIT), Ignazio Scimemi (UCM), Iain W. Stewart (MIT)
The R-evolution of QCD matrix elements
International Workshop on Effective Field Theories: from the Pion to the Upsilon 1-6 February 2009,Valencia, Spain
null
null
MIT CTP-4040, MPP-2009-59
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Perturbation series in QCD are generally asymptotic and suffer from so-called infrared renormalon ambiguities. In the context of the standard operator product expansion in MS-bar these ambiguities are compensated by matrix elements of higher dimension operators, but the procedure can be difficult to control due to large numerical cancellations. Explicit subtractions for matrix elements and coefficients, depending on a subtraction scale R, can avoid this problem. The appropriate choice for R in the Wilson coefficients can widely vary for different processes. In this talk we discuss renormalization group evolution with the scale R, and show that it sums large logarithms in the difference of processes with widely different R's. We also show that the solution of the R-evolution equations can be used to recover the all order asymptotic form of the singularities in the Borel transform of the perturbative series. For the normalization of these singularities we obtain a quickly converging sum rule that only needs the known perturbative coefficients as an input. This sum rule can be used as a novel test for renormalon ambiguities without replying on the large-beta_0 approximation.
[ { "created": "Wed, 20 May 2009 18:45:22 GMT", "version": "v1" } ]
2009-05-21
[ [ "Hoang", "Andre H.", "", "MPI" ], [ "Jain", "Ambar", "", "MIT" ], [ "Scimemi", "Ignazio", "", "UCM" ], [ "Stewart", "Iain W.", "", "MIT" ] ]
Perturbation series in QCD are generally asymptotic and suffer from so-called infrared renormalon ambiguities. In the context of the standard operator product expansion in MS-bar these ambiguities are compensated by matrix elements of higher dimension operators, but the procedure can be difficult to control due to large numerical cancellations. Explicit subtractions for matrix elements and coefficients, depending on a subtraction scale R, can avoid this problem. The appropriate choice for R in the Wilson coefficients can widely vary for different processes. In this talk we discuss renormalization group evolution with the scale R, and show that it sums large logarithms in the difference of processes with widely different R's. We also show that the solution of the R-evolution equations can be used to recover the all order asymptotic form of the singularities in the Borel transform of the perturbative series. For the normalization of these singularities we obtain a quickly converging sum rule that only needs the known perturbative coefficients as an input. This sum rule can be used as a novel test for renormalon ambiguities without replying on the large-beta_0 approximation.
hep-ph/0505047
Comelli Denis
Paolo Ciafaloni and Denis Comelli
Electroweak Evolution Equations
15 pages, 3 figures
JHEP 0511 (2005) 022
10.1088/1126-6708/2005/11/022
null
hep-ph
null
Enlarging a previous analysis, where only fermions and transverse gauge bosons were taken into account, we write down infrared-collinear evolution equations for the Standard Model of electroweak interactions computing the full set of splitting functions. Due to the presence of double logs which are characteristic of electroweak interactions (Bloch-Nordsieck violation), new infrared singular splitting functions have to be introduced. We also include corrections related to the third generation Yukawa couplings.
[ { "created": "Fri, 6 May 2005 16:02:35 GMT", "version": "v1" } ]
2009-11-11
[ [ "Ciafaloni", "Paolo", "" ], [ "Comelli", "Denis", "" ] ]
Enlarging a previous analysis, where only fermions and transverse gauge bosons were taken into account, we write down infrared-collinear evolution equations for the Standard Model of electroweak interactions computing the full set of splitting functions. Due to the presence of double logs which are characteristic of electroweak interactions (Bloch-Nordsieck violation), new infrared singular splitting functions have to be introduced. We also include corrections related to the third generation Yukawa couplings.
1105.4560
Pier Francesco Monni
Pier Francesco Monni, Thomas Gehrmann, Gionata Luisoni
Two-Loop Soft Corrections and Resummation of the Thrust Distribution in the Dijet Region
50 pages, 12 figures, 1 table. Few minor changes. Version accepted for publication in JHEP
JHEP 1108:010,2011
10.1007/JHEP08(2011)010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The thrust distribution in electron-positron annihilation is a classical precision QCD observable. Using renormalization group (RG) evolution in Laplace space, we perform the resummation of logarithmically enhanced corrections in the dijet limit, $T\to 1$ to next-to-next-to-leading logarithmic (NNLL) accuracy. We independently derive the two-loop soft function for the thrust distribution and extract an analytical expression for the NNLL resummation coefficient $g_3$. To combine the resummed expressions with the fixed-order results, we derive the $\log(R)$-matching and $R$-matching of the NNLL approximation to the fixed-order NNLO distribution.
[ { "created": "Mon, 23 May 2011 16:57:52 GMT", "version": "v1" }, { "created": "Tue, 2 Aug 2011 17:51:44 GMT", "version": "v2" } ]
2015-03-19
[ [ "Monni", "Pier Francesco", "" ], [ "Gehrmann", "Thomas", "" ], [ "Luisoni", "Gionata", "" ] ]
The thrust distribution in electron-positron annihilation is a classical precision QCD observable. Using renormalization group (RG) evolution in Laplace space, we perform the resummation of logarithmically enhanced corrections in the dijet limit, $T\to 1$ to next-to-next-to-leading logarithmic (NNLL) accuracy. We independently derive the two-loop soft function for the thrust distribution and extract an analytical expression for the NNLL resummation coefficient $g_3$. To combine the resummed expressions with the fixed-order results, we derive the $\log(R)$-matching and $R$-matching of the NNLL approximation to the fixed-order NNLO distribution.
2305.07129
Adriano Lana Cherchiglia
Ricardo J. C. Rosado, Adriano Cherchiglia, Marcos Sampaio, Brigitte Hiller
Infrared Subtleties and Chiral Vertices at NLO: An Implicit Regularization Analysis
Appendix and references added. Complies with the version accepted at EPJC
null
10.1140/epjc/s10052-023-12052-2
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We employ implicit regularization (IReg) in quark-antiquark decays of the Z, or of a scalar (CP-even or odd) boson at NLO, and compare with dimensional schemes to reveal subtleties involving infrared divergence cancellation and $\gamma_5$-matrix issues. Besides the absence of evanescent fields in IReg, such as $\epsilon$-scalars required in certain schemes that operate partially in the physical dimension, we verify that our procedure preserves gauge invariance in the presence of the $\gamma_5$ matrix without requiring symmetry preserving counterterms while the amplitude is infrared finite as required by the KLN theorem.
[ { "created": "Thu, 11 May 2023 20:33:41 GMT", "version": "v1" }, { "created": "Fri, 29 Sep 2023 02:05:21 GMT", "version": "v2" } ]
2023-10-02
[ [ "Rosado", "Ricardo J. C.", "" ], [ "Cherchiglia", "Adriano", "" ], [ "Sampaio", "Marcos", "" ], [ "Hiller", "Brigitte", "" ] ]
We employ implicit regularization (IReg) in quark-antiquark decays of the Z, or of a scalar (CP-even or odd) boson at NLO, and compare with dimensional schemes to reveal subtleties involving infrared divergence cancellation and $\gamma_5$-matrix issues. Besides the absence of evanescent fields in IReg, such as $\epsilon$-scalars required in certain schemes that operate partially in the physical dimension, we verify that our procedure preserves gauge invariance in the presence of the $\gamma_5$ matrix without requiring symmetry preserving counterterms while the amplitude is infrared finite as required by the KLN theorem.
1805.03615
Sandra Robles
Steven Abel, David G. Cerdeno, Sandra Robles
The Power of Genetic Algorithms: what remains of the pMSSM?
40 pages, 27 figures, 13 tables, 1 appendix
null
null
IPPP/18/32
hep-ph astro-ph.CO cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Genetic Algorithms (GAs) are explored as a tool for probing new physics with high dimensionality. We study the 19-dimensional pMSSM, including experimental constraints from all sources and assessing the consistency of potential signals of new physics. We show that GAs excel at making a fast and accurate diagnosis of the cross-compatibility of a set of experimental constraints in such high dimensional models. In the case of the pMSSM, it is found that only ${\cal O}(10^4)$ model evaluations are required to obtain a best fit point in agreement with much more costly MCMC scans. This efficiency allows higher dimensional models to be falsified, and patterns in the spectrum identified, orders of magnitude more quickly. As examples of falsification, we consider the muon anomalous magnetic moment, and the Galactic Centre gamma-ray excess observed by Fermi-LAT, which could in principle be explained in terms of neutralino dark matter. We show that both observables cannot be explained within the pMSSM, and that they provide the leading contribution to the total goodness of the fit, with $\chi^2_{\delta a_\mu^{\mathrm{SUSY}}}\approx12$ and $\chi^2_{\rm GCE}\approx 155$, respectively.
[ { "created": "Wed, 9 May 2018 16:54:26 GMT", "version": "v1" } ]
2018-05-14
[ [ "Abel", "Steven", "" ], [ "Cerdeno", "David G.", "" ], [ "Robles", "Sandra", "" ] ]
Genetic Algorithms (GAs) are explored as a tool for probing new physics with high dimensionality. We study the 19-dimensional pMSSM, including experimental constraints from all sources and assessing the consistency of potential signals of new physics. We show that GAs excel at making a fast and accurate diagnosis of the cross-compatibility of a set of experimental constraints in such high dimensional models. In the case of the pMSSM, it is found that only ${\cal O}(10^4)$ model evaluations are required to obtain a best fit point in agreement with much more costly MCMC scans. This efficiency allows higher dimensional models to be falsified, and patterns in the spectrum identified, orders of magnitude more quickly. As examples of falsification, we consider the muon anomalous magnetic moment, and the Galactic Centre gamma-ray excess observed by Fermi-LAT, which could in principle be explained in terms of neutralino dark matter. We show that both observables cannot be explained within the pMSSM, and that they provide the leading contribution to the total goodness of the fit, with $\chi^2_{\delta a_\mu^{\mathrm{SUSY}}}\approx12$ and $\chi^2_{\rm GCE}\approx 155$, respectively.
2105.02163
Muslem Rahimi
Thomas Mannel, Muslem Rahimi, K. Keri Vos
Impact of background effects on the inclusive $V_{cb}$ determination
7 figures
null
10.1007/JHEP09(2021)051
P3H-21-027, SI-HEP-2021-13, Nikhef-2021-011
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The determination of the CKM element $V_{cb}$ from inclusive semileptonic $b\to c \ell \bar\nu$ decays has reached a high precision thanks to a combination of theoretical and experimental efforts. Aiming towards even higher precision, we discuss two processes that contaminate the inclusive $V_{cb}$ determination; the $b\to u$ background and the contribution of the tauonic mode: $b\to c(\tau \to \mu\nu\bar{\nu})\bar{\nu}$. Both of these contributions are dealt with at the experimental side, using Monte-Carlo methods and momentum cuts. However, these contributions can be calculated with high precision within the Heavy-Quark Expansion. In this note, we calculate the theoretical predictions for these two processes. The $b\to u$ results are compared with generator-level Monte-Carlo results used at Belle and Belle II. We have good agreement between theory and Monte-Carlo for lepton energy moments, but less for hadronic mass moments. Based on our results the uncertainties due to these backgrounds processes can basically be eliminated by properly including them into the analyses.
[ { "created": "Wed, 5 May 2021 16:19:02 GMT", "version": "v1" } ]
2021-09-29
[ [ "Mannel", "Thomas", "" ], [ "Rahimi", "Muslem", "" ], [ "Vos", "K. Keri", "" ] ]
The determination of the CKM element $V_{cb}$ from inclusive semileptonic $b\to c \ell \bar\nu$ decays has reached a high precision thanks to a combination of theoretical and experimental efforts. Aiming towards even higher precision, we discuss two processes that contaminate the inclusive $V_{cb}$ determination; the $b\to u$ background and the contribution of the tauonic mode: $b\to c(\tau \to \mu\nu\bar{\nu})\bar{\nu}$. Both of these contributions are dealt with at the experimental side, using Monte-Carlo methods and momentum cuts. However, these contributions can be calculated with high precision within the Heavy-Quark Expansion. In this note, we calculate the theoretical predictions for these two processes. The $b\to u$ results are compared with generator-level Monte-Carlo results used at Belle and Belle II. We have good agreement between theory and Monte-Carlo for lepton energy moments, but less for hadronic mass moments. Based on our results the uncertainties due to these backgrounds processes can basically be eliminated by properly including them into the analyses.
hep-ph/9811508
Yong Liu
Yong Liu
Cabibbo-Kobayashi-Maskawa Matrix, Unitarity Triangle and Geometry Origin of the Weak CP Phase
9 pages, Latex file, third revised version
null
null
null
hep-ph
null
In this work, the postulation that weak CP phase originates in a certain geometry, is further discussed. According to this postulation, the weak CP phase is determined by three mixing angles. So, if we can determine experimentally three elements of the Cabibbo-Kobayashi-Maskawa matrix, we can then determine the whole CKM matrix and correspondingly, the unitarity triangle. We find that the angle gamma is about pi/2 and the weak CP phase delta (delta_{13}) only can exist in the first or fourth quadrant. The conclusions coincide with the relevant analysis. Some other predictions are given in this paper, the comparison of the predictions based on the postulation to the relevant experimental and theoretical results is listed. All the predictions are consistent with the present experimental results.
[ { "created": "Mon, 30 Nov 1998 13:38:07 GMT", "version": "v1" }, { "created": "Tue, 1 Dec 1998 14:54:02 GMT", "version": "v2" }, { "created": "Wed, 2 Dec 1998 04:31:30 GMT", "version": "v3" }, { "created": "Thu, 10 Dec 1998 04:06:16 GMT", "version": "v4" }, { "cre...
2007-05-23
[ [ "Liu", "Yong", "" ] ]
In this work, the postulation that weak CP phase originates in a certain geometry, is further discussed. According to this postulation, the weak CP phase is determined by three mixing angles. So, if we can determine experimentally three elements of the Cabibbo-Kobayashi-Maskawa matrix, we can then determine the whole CKM matrix and correspondingly, the unitarity triangle. We find that the angle gamma is about pi/2 and the weak CP phase delta (delta_{13}) only can exist in the first or fourth quadrant. The conclusions coincide with the relevant analysis. Some other predictions are given in this paper, the comparison of the predictions based on the postulation to the relevant experimental and theoretical results is listed. All the predictions are consistent with the present experimental results.
1909.12771
Oleg Andreev
Oleg Andreev
Baryon modes in string breaking from gauge/string duality
6 pages, 3 figures; v2: typos corrected; v3: modification in title, comments and references added, journal version
Phys. Rev. D 101, 106003 (2020)
10.1103/PhysRevD.101.106003
LMU-ASC 30/19
hep-ph hep-lat hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the string breaking phenomenon within effective string models which purport to mimic QCD with two light flavors, with a special attention to baryon modes. We make some estimates of the string breaking distances at zero and non-zero baryon chemical potentials. Our estimates point towards the enhancement of baryon production in strong decays of heavy mesons in dense baryonic matter. We also suggest that the enhanced production of $\Lambda_c^+$ baryons in PbPb collisions is mainly due to larger values of chemical potential.
[ { "created": "Fri, 27 Sep 2019 16:15:24 GMT", "version": "v1" }, { "created": "Mon, 7 Oct 2019 13:46:07 GMT", "version": "v2" }, { "created": "Sat, 4 Apr 2020 15:44:37 GMT", "version": "v3" } ]
2020-05-13
[ [ "Andreev", "Oleg", "" ] ]
We consider the string breaking phenomenon within effective string models which purport to mimic QCD with two light flavors, with a special attention to baryon modes. We make some estimates of the string breaking distances at zero and non-zero baryon chemical potentials. Our estimates point towards the enhancement of baryon production in strong decays of heavy mesons in dense baryonic matter. We also suggest that the enhanced production of $\Lambda_c^+$ baryons in PbPb collisions is mainly due to larger values of chemical potential.
1508.07204
Yuri Sinyukov
V.Yu. Naboka, Iu.A. Karpenko, Yu.M. Sinyukov
Thermalization, evolution and LHC observables in an integrated hydrokinetic model of A+A collisions
22 pages, 11 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A further development of the evolutionary picture of A+A collisions, which we call the integrated HydroKinetic Model (iHKM), is proposed. The model comprises a generator of the initial state GLISSANDO, pre-thermal dynamics of A+A collisions leading to thermalization, subsequent relativistic viscous hydrodynamic expansion of quark-gluon and hadron medium (vHLLE), its particlization, and finally hadronic cascade ultrarelativistic QMD. We calculate mid-rapidity charged-particle multiplicities, pion, kaon, and antiproton spectra, charged-particle elliptic flows, and pion interferometry radii for Pb+Pb collisions at the energies available at the CERN Large Hadron Collider, $\sqrt{s} = 2.76$ TeV, at different centralities. We find that the best description of the experimental data is reached when the initial states are attributed to the very small initial time 0.1 fm/c, the pre-thermal stage (thermalization process) lasts at least until 1 fm/c, and the shear viscosity at the hydrodynamic stage of the matter evolution has its minimal value, $\eta/s = \frac{1}{4\pi}$. At the same time it is observed that the various momentum anisotropies of the initial states, different initial and relaxation times, as well as even a treatment of the pre-thermal stage within just viscous or ideal hydrodynamic approach, leads sometimes to worse but nevertheless similar results, if the normalization of maximal initial energy density in most central events is adjusted to reproduce the final hadron multiplicity in each scenario. This can explain a good enough data description in numerous variants of hybrid models without a prethermal stage when the initial energy densities are defined up to a common factor.
[ { "created": "Fri, 28 Aug 2015 13:34:19 GMT", "version": "v1" }, { "created": "Fri, 5 Feb 2016 12:54:50 GMT", "version": "v2" } ]
2016-02-08
[ [ "Naboka", "V. Yu.", "" ], [ "Karpenko", "Iu. A.", "" ], [ "Sinyukov", "Yu. M.", "" ] ]
A further development of the evolutionary picture of A+A collisions, which we call the integrated HydroKinetic Model (iHKM), is proposed. The model comprises a generator of the initial state GLISSANDO, pre-thermal dynamics of A+A collisions leading to thermalization, subsequent relativistic viscous hydrodynamic expansion of quark-gluon and hadron medium (vHLLE), its particlization, and finally hadronic cascade ultrarelativistic QMD. We calculate mid-rapidity charged-particle multiplicities, pion, kaon, and antiproton spectra, charged-particle elliptic flows, and pion interferometry radii for Pb+Pb collisions at the energies available at the CERN Large Hadron Collider, $\sqrt{s} = 2.76$ TeV, at different centralities. We find that the best description of the experimental data is reached when the initial states are attributed to the very small initial time 0.1 fm/c, the pre-thermal stage (thermalization process) lasts at least until 1 fm/c, and the shear viscosity at the hydrodynamic stage of the matter evolution has its minimal value, $\eta/s = \frac{1}{4\pi}$. At the same time it is observed that the various momentum anisotropies of the initial states, different initial and relaxation times, as well as even a treatment of the pre-thermal stage within just viscous or ideal hydrodynamic approach, leads sometimes to worse but nevertheless similar results, if the normalization of maximal initial energy density in most central events is adjusted to reproduce the final hadron multiplicity in each scenario. This can explain a good enough data description in numerous variants of hybrid models without a prethermal stage when the initial energy densities are defined up to a common factor.
hep-ph/0404061
John Bahcall
John N. Bahcall and Carlos Pe\~na-Garay
Solar models and solar neutrino oscillations
Submitted to the Neutrino Focus Issue of New Journal of Physics at http://www.njp.org
New J.Phys.6:63,2004
10.1088/1367-2630/6/1/063
null
hep-ph astro-ph hep-ex nucl-ex nucl-th
null
We provide a summary of the current knowledge, theoretical and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for doing new solar neutrino experiments and what we think may be learned from the future measurements.
[ { "created": "Tue, 6 Apr 2004 20:00:56 GMT", "version": "v1" } ]
2014-11-17
[ [ "Bahcall", "John N.", "" ], [ "Peña-Garay", "Carlos", "" ] ]
We provide a summary of the current knowledge, theoretical and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for doing new solar neutrino experiments and what we think may be learned from the future measurements.
hep-ph/0403139
Enrique Ruiz Arriola
E. Megias, E. Ruiz Arriola, L. L. Salcedo (Granada U.), W. Broniowski (Cracow INP)
Low Energy Chiral Lagrangian in Curved Space-Time from the Spectral Quark Model
18 pages, no figures
Phys.Rev. D70 (2004) 034031
10.1103/PhysRevD.70.034031
null
hep-ph
null
We analyze the recently proposed Spectral Quark Model in the light of Chiral Perturbation Theory in curved space-time. In particular, we calculate the chiral coefficients $L_1, ..., L_{10}$, as well as the coefficients $L_{11}$, $L_{12}$, and $L_{13}$, appearing when the model is coupled to gravity. The analysis is carried for the SU(3) case. We analyze the pattern of chiral symmetry breaking as well as elaborate on the fulfillment of anomalies. Matching the model results to resonance meson exchange yields the relation between the masses of the scalar, tensor and vector mesons, $M_{f_0}=M_{f_2}=\sqrt{2} M_V= 4 \sqrt{3 /N_c} \pi f_\pi$. Finally, the large-$N_c$ limit suggests the dual relations in the vector and scalar channels, $M_V=M_S= 2 \sqrt{6 /N_c} \pi f_\pi $ and $<r^2 >^{1/2}_S = < r^2 >^{1/2}_V = 2 \sqrt{N_c} / f_\pi = 0.59 {\rm fm} $.
[ { "created": "Fri, 12 Mar 2004 16:02:30 GMT", "version": "v1" }, { "created": "Sun, 14 Mar 2004 18:39:16 GMT", "version": "v2" } ]
2009-11-10
[ [ "Megias", "E.", "", "Granada U." ], [ "Arriola", "E. Ruiz", "", "Granada U." ], [ "Salcedo", "L. L.", "", "Granada U." ], [ "Broniowski", "W.", "", "Cracow INP" ] ]
We analyze the recently proposed Spectral Quark Model in the light of Chiral Perturbation Theory in curved space-time. In particular, we calculate the chiral coefficients $L_1, ..., L_{10}$, as well as the coefficients $L_{11}$, $L_{12}$, and $L_{13}$, appearing when the model is coupled to gravity. The analysis is carried for the SU(3) case. We analyze the pattern of chiral symmetry breaking as well as elaborate on the fulfillment of anomalies. Matching the model results to resonance meson exchange yields the relation between the masses of the scalar, tensor and vector mesons, $M_{f_0}=M_{f_2}=\sqrt{2} M_V= 4 \sqrt{3 /N_c} \pi f_\pi$. Finally, the large-$N_c$ limit suggests the dual relations in the vector and scalar channels, $M_V=M_S= 2 \sqrt{6 /N_c} \pi f_\pi $ and $<r^2 >^{1/2}_S = < r^2 >^{1/2}_V = 2 \sqrt{N_c} / f_\pi = 0.59 {\rm fm} $.