Tue·Aug 22, 2017Tuesday·August 22, 2017

1. 01*

   Effects of next-to-leading order DGLAP evolution on generalized parton distributions of the proton and deeply virtual Compton scattering at high energy

   Hamzeh Khanpour (Mazandaran U., Behshahr & IPM, Tehran)🇮🇷 · Muhammad Goharipour (IPM, Tehran)🇮🇷 · Vadim Guzey (St. Petersburg, INP)🇷🇺

   We studied the effects of NLO $Q^2$ evolution of generalized parton distributions (GPDs) using the aligned-jet model for the singlet quark and gluon GPDs at an initial evolution scale. We found that the skewness ratio for quarks is a slow logarithmic function of $Q^2$ reaching $r^S=1.5-2$ at $Q^2=100$ GeV${}^2$ and $r^g\approx 1$ for gluons in a wide range of $Q^2$. Using the resulting GPDs, we calculated the DVCS cross section on the proton in NLO pQCD and found that this model in conjunction with modern parameterizations of proton PDFs (CJ15 and CT14) provides a good description of the available H1 and ZEUS data in a wide kinematic range.

   hep-phhep-exEPJC(2018)·19 citations
2. 02*

   Axion-like Particles from Primakov production in beam-dumps

   Babette Döbrich🇨🇭

   We discuss searches for Axion-like Particles which are coupled predominantly to photons from proton- or electron beam-dumps. In particular, we scrutinize the present state of exclusions from SLAC 141 in the mass range of $\sim$ 10-30 MeV

   hep-phhep-exCERN Proc.(2018)·31 citations
3. 03*

   On the absorption and production cross sections of $K$ and $K^{\ast }$

   A. Martinez Torres🇧🇷 · K. P. Khemchandani🇧🇷 · L. M. Abreu🇧🇷 · F. S. Navarra🇧🇷 · M. Nielsen🇧🇷

   We have computed the isospin and spin averaged cross sections of the processes $\pi K^{\ast }\to \rho K$ and $\rho K^{\ast }\to \pi K$, which are crucial in the determination of the abundances of $K^{\ast }$ and $K$ in heavy ion collisions. Improving previous calculations, we have considered several mechanisms which were missing, such as the exchange of axial and vector resonances ($K_1(1270)$, $K_2^{\ast }(1430)$, $h_1(1170)$, etc...) and also other processes such as $\pi K^{\ast }\to \omega K,\varphi K$ and $\omega K^{\ast },\varphi K^{\ast }\to \pi K$. We find that some of these mechanisms give important contributions to the cross section. Our results also suggest that, in a hadron gas, $K^{\ast }$ production might be more important than its absorption.

   hep-phnucl-thPRD(2018)·10 citations
4. 04*

   Dependencies of Lepton Angular Distribution Coefficients on the Transverse Momentum and Rapidity of$Z$ Bosons Produced in $pp$ Collisions at LHC

   Wen-Chen Chang🇹🇼 · Randall Evan McClellan🇺🇸 · Jen-Chieh Peng🇺🇸 · Oleg Teryaev🇷🇺

   High precision data of lepton angular distributions for ${\gamma }^{\ast }/Z$ production in $pp$ collisions at the LHC, covering broad ranges of dilepton transverse momenta ($q_T$) and rapidity ($y$), were recently reported. Strong $q_T$ dependencies were observed for several angular distribution coefficients, $A_i$, including $A_0-A_4$. Significant $y$ dependencies were also found for the coefficients $A_1$, $A_3$ and $A_4$, while $A_0$ and $A_2$ exhibit very weak rapidity dependence. Using an intuitive geometric picture we show that the $q_T$ and $y$ dependencies of the angular distributions coefficients can be well described.

   hep-phhep-exnucl-exnucl-thPRD(2017)·18 citations
5. 05*

   Flattening the inflaton potential beyond minimal gravity

   Hyun Min Lee🇰🇷

   We review the status of the Starobinsky-like models for inflation beyond minimal gravity and discuss the unitarity problem due to the presence of a large non-minimal gravity coupling. We show that the induced gravity models allow for a self-consistent description of inflation and discuss the implications of the inflaton couplings to the Higgs field in the Standard Model.

   hep-phastro-ph.COEPJ Web Conf.(2018)·1 citation
6. 06*

   Constraining $qqtt$ operators from four-top production: a case for enhanced EFT sensitivity

   Cen Zhang🇨🇳

   Recently, experimental collaborations have reported $\mathcal{O}(10)$ upper limits on the signal strength of four-top production at the LHC. Surprisingly, we find that the constraining power of four-top production on the $qqtt$ type of operators is already competitive with the measurements of top-pair production, even though the precision level of the latter is more than two orders of magnitude better. This is explained by the enhanced sensitivity of the four-top cross section to $qqtt$ operators, due to multiple insertion of operators in the squared amplitude, and to the large threshold energy of four-top production. We point out that even though the dominant contribution beyond the standard model comes from the $\mathcal{O}(C^4/{\Lambda }^8)$ terms, the effective field theory expansion remains valid for a wide range of underlying theories. Considering the possible improvements of this measurement with higher integrated luminosity, we believe that this process will become even more crucial for probing and testing the standard model deviations in the top-quark sector, and will eventually provide valuable information about the top-quark properties, leading to significant improvements in precision top physics.

   hep-phhep-exCPC(2018)·73 citations
7. 07*

   SIMP dark matter and its cosmic abundances

   Soo-Min Choi🇰🇷 · Hyun Min Lee🇰🇷 · Min-Seok Seo🇰🇷

   We give a review on the thermal average of the annihilation cross-sections for $3\to 2$ and general higher-order processes. Thermal average of higher order annihilations highly depend on the velocity of dark matter, especially, for the case with resonance poles. We show such examples for scalar dark matter in gauged $Z_3$ models.

   hep-phEPJ Web Conf.(2018)·1 citation
8. 08*

   Forbidden Channels and SIMP Dark Matter

   Soo-Min Choi🇰🇷 · Yoo-Jin Kang🇰🇷 · Hyun Min Lee🇰🇷

   In this review, we focus on dark matter production from thermal freeze-out with forbidden channels and SIMP processes. We show that forbidden channels can be dominant to produce dark matter depending on the dark photon and / or dark Higgs mass compared to SIMP.

   hep-phEPJ Web Conf.(2018)·0 citations
9. 09*

   ${\eta }_Q$ meson photoproduction in ultrarelativistic heavy ion collisions

   Gong-Ming Yu🇨🇳 · Gao-Gao Zhao🇨🇳 · Zhen Bai🇨🇳 · Yan-Bing Cai🇨🇳 · Hai-Tao Yang🇨🇳 · Jian-Song Wang🇨🇳

   The transverse momentum distributions for inclusive ${\eta }_{c,b}$ meson described by gluon-gluon interactions from photoproduction processes in relativistic heavy ion collisions are calculated. We considered the color singlet (CS) and color octet (CO) components with the framework of non-relativistic Quantum Chromodynamics (NRQCD) into the production of heavy quarkonium. The phenomenological values of the matrix elements for the color-singlet and color-octet components give the main contribution to the production of heavy quarkonium from the gluon-gluon interaction caused by the emission of additional gluon in the initial state. The numerical results indicate that the contribution of photoproduction processes cannot be negligible for mid-rapidity in p-p and Pb-Pb collisions at the Large Hadron Collider (LHC) energies.

   hep-phAdv.High Energy Phys.(2017)·2 citations
10. 10*

    Fermi Liquid Model for Hadrons in Medium

    A. Bhattacharya🇮🇳 · S. Pal🇮🇳 · R. Ghosh🇮🇳 · B.Chakrabarti🇮🇳

    A Fermi liquid model for hadrons has been suggested for the hadrons in medium. The hadrons are supposed to behave like quasi particle as Fermi excitation while in the medium and the effective mass of the hadrons have been estimated using Fermi liquid model. Considering a momentum dependent potential inside the medium to describe the interaction, the effective masses of the hadrons are estimated. The temperature dependence of effective masses has also been studied. The possibility of describing masses of the quarks as Fermi excitation has been investigated. Compressibility, specific heats, density of states in medium has been studied. The potential depth for light and singly heavy baryons in medium has been extracted. The results are found to be very interesting and compared with the other studies available in literature.

    hep-phnucl-th0 citations
11. 11*

    Adiabatic suppression of the axion abundance and isocurvature due to coupling to hidden monopoles

    Masahiro Kawasaki🇯🇵 · Fuminobu Takahashi🇯🇵 · Masaki Yamada🇺🇸

    The string theory predicts many light fields called moduli and axions, which cause a cosmological problem due to the overproduction of their coherent oscillation after inflation. One of the prominent solutions is an adiabatic suppression mechanism, which, however, is non-trivial to achieve in the case of axions because it necessitates a large effective mass term which decreases as a function of time. The purpose of this paper is twofold. First, we provide an analytic method to calculate the cosmological abundance of coherent oscillation in a general situation under the adiabatic suppression mechanism. Secondly, we apply our method to some concrete examples, including the one where a string axion acquires a large effective mass due to the Witten effect in the presence of hidden monopoles.

    hep-phastro-ph.COhep-thJHEP(2018)·50 citations
12. 12*

    Tests of bottom quark CSM properties

    Fernand M. Renard🇫🇷

    We look for possible (partial) compositeness properties of the bottom quark according to the Composite Standard Model (CSM) concept in the same way this was previously done for Higgs boson and top quark. After looking at the direct form factor effects appearing in $e^{+}{e}^{-}\to b\bar{b}$ we analyze the more complex features of the $e^{+}{e}^{-},gg,\gamma \gamma \to b\bar{b}H,b\bar{b}Z,t\bar{b}{W}^{-}$ processes. We emphasize typical differences appearing between CSM concerving and CSM violating cases. We also mention the possible appearence of an effective bottom mass.

    hep-ph1 citation
13. 13*

    Transverse momentum fluctuation under the Tsallis distribution at high energies

    Masamichi Ishihara🇯🇵

    We studied the effects of the Tsallis distribution on the transverse momentum fluctuation in high energy collisions. The parton-hadron duality and the Bose-Einstein type correlation between partons were assumed. The fluctuation was calculated in the boost-invariant picture for the expectation value used in the Boltzmann-Gibbs statistics and for the expectation value used in the Tsallis nonextensive statistics. It was shown that the fluctuation is a function of $\eta$ which is the ratio of the inverse temperature to the correlation length. We found the following points: (1) the fluctuation depends on the form of the distribution and depends weakly on the definition of the expectation value used in the statistics,(2) the fluctuation increases as the entropic parameter value of the Tsallis distribution increases, and (3) the variation of the fluctuation as a function of the entropic parameter for the expectation value used in the Boltzmann-Gibbs statistics is larger than that for the expectation value used in the Tsallis nonextensive statistics in the wide range of $\eta$.

    hep-phIJMPE(2017)·7 citations
14. 14*

    A testable radiative neutrino mass model with multi-charged particles

    Kingman Cheung🇹🇼 · Hiroshi Okada🇹🇼

    We propose a radiatively-induced neutrino mass model at one-loop level by introducing a pair of doubly-charged fermions and a few multi-charged bosons. We investigate the contributions of the model to neutrino masses, lepton-flavor violations, muon $g-2$, oblique parameters, and collider signals, and find a substantial fraction of the parameter space that can satisfy all the constraints. Furthermore, we discuss the possibility of detecting the doubly-charged fermions at the LHC.

    hep-phPLB(2017)·8 citations
15. 15*

    Testing Minimal Flavor Violation in Leptoquark Models of the $R_{K^{(\ast )}}$ Anomaly

    Daniel Aloni🇮🇱 · Avital Dery🇮🇱 · Claudia Frugiuele🇮🇱 · Yosef Nir🇮🇱

    The $R_{K^{(\ast )}}$ anomaly can be explained by tree level exchange of leptoquarks. We study the consequences of subjecting these models to the principle of minimal flavor violation (MFV). We consider MFV in the linear regime, and take the charged lepton Yukawa matrix to be the only spurion that violates lepton flavor universality. We find that a combination of constraints from a variety of processes -- $b\to s\mu \mu$, $b\to s\tau \tau$, $b\to s\nu \nu$, $b\bar{b}\to \tau \tau$ and $b\to c\tau \nu$ -- excludes MFV in these models.

    hep-phJHEP(2017)·36 citations
16. 16*

    $R(D^{(\ast )})$ in a general two Higgs doublet model

    Syuhei Iguro🇯🇵 · Kazuhiro Tobe🇯🇵

    Motivated by an anomaly in $R(D^{(\ast )})=\mathrm{BR}(\bar{B}\to D^{(\ast )}{\tau }^{-}\bar{\nu })/\mathrm{BR}(\bar{B}\to D^{(\ast )}{l}^{-}\bar{\nu })$ reported by BaBar, Belle and LHCb, we study $R(D^{(\ast )})$ in a general two Higgs doublet model (2HDM). Although it has been suggested that it is difficult for the 2HDM to explain the current world average for $R(D^{(\ast )})$, it would be important to clarify how large deviations from the standard model predictions for $R(D^{(\ast )})$ are possible in the 2HDM. We investigate possible corrections to $R(D^{(\ast )})$ in the 2HDM by taking into account various flavor physics constraints (such as $B_c^{-}\to {\tau }^{-}\bar{\nu }$, $b\to s\gamma$, $b\to s{l}^{+}{l}^{-}$, $\Delta m_{B_{d,s}}$, $B_s\to {\mu }^{+}{\mu }^{-}$ and ${\tau }^{+}{\tau }^{-}$, and $B^{-}\to {\tau }^{-}\bar{\nu }$), and find that it would be possible (impossible) to accommodate the 1$\sigma$ region suggested by the Belle's result when we adopt a constraint $\mathrm{BR}(B_c^{-}\to {\tau }^{-}\bar{\nu })\le 30\%$ ($\mathrm{BR}(B_c^{-}\to {\tau }^{-}\bar{\nu })\le 10\%$). We also study productions and decays of heavy neutral and charged Higgs bosons at the Large Hadron Collider (LHC) experiment and discuss the constraints and implications at the LHC. We show that in addition to well-studied production modes $bg\to t{H}^{-}$ and $gg\to H/A$, exotic productions of heavy Higgs bosons such as $cg\to b{H}^{+},t+H/A$ and $c\bar{b}\to H^{+}$ would be significantly large, and the search for their exotic decay modes such as $H/A\to t\bar{c}+c\bar{t},{\mu }^{\pm }{\tau }^{\mp }$ and $H^{+}\to c\bar{b}$ as well as $H/A\to {\tau }^{+}{\tau }^{-}$ and $H^{+}\to {\tau }^{+}\nu$ would be important to probe the interesting parameter regions for $R(D^{(\ast )})$.

    hep-phNPB(2017)·139 citations
17. 17*

    Spectrum of Yang-Mills theory in 3 and 4 dimensions

    Marco Frasca🇮🇹

    We solve exactly the Dyson-Schwinger equations for Yang-Mills theory in 3 and 4 dimensions. This permits us to obtain the exact correlation functions till order 2. In this way, the spectrum of the theory is straightforwardly obtained and comparison with lattice data can be accomplished. The results are in exceedingly good agreement with an error well below 1\%. This extends both to 3 and 4 dimensions and varying the degree of the gauge group. These results provide a strong support to the value of the lattice computations and show once again how precise can be theoretical computations in quantum field theory.

    hep-phhep-lathep-thNucl.Part.Phys.Proc.(2018)·24 citations
18. 18*

    Probing sterile neutrinos in the framework of inverse seesaw mechanism through leptoquark productions

    Debottam Das🇮🇳 · Kirtiman Ghosh🇮🇳 · Manimala Mitra🇮🇳 · Subhadeep Mondal🇮🇳

    We consider an extension of the Standard Model (SM) augmented by two neutral singlet fermions per generation and a leptoquark. In order to generate the light neutrino masses and mixing, we incorporate inverse seesaw mechanism. The right handed neutrino production in this model is significantly larger than the conventional inverse seesaw scenario. We analyze the different collider signatures of this model and find that the final states associated with three or more leptons, multi jet and at least one b-tagged and (or) $\tau$-tagged jet can probe larger RH neutrino mass scale. We have also proposed a same-sign dilepton signal region associated with multiple jets and missing energy that can be used to distinguish the the present scenario from the usual inverse seesaw extended SM.

    hep-phPRD(2018)·21 citations
19. 19*

    NLO QCD predictions for $Z+\gamma$ + jets production with Sherpa

    Johannes Krause🇩🇪 · Frank Siegert🇩🇪

    We present precise predictions for prompt photon production in association with a $Z$ boson and jets. They are obtained within the Sherpa framework as a consistently merged inclusive sample. Leptonic decays of the $Z$ boson are fully included in the calculation with all offshell effects. Virtual matrix elements are provided by OpenLoops and parton shower effects are simulated with a dipole parton shower. Thanks to the NLO QCD corrections included not only for inclusive $Z\gamma$ production but also for the $Z\gamma$ + 1-jet process we find significantly reduced systematic uncertainties and very good agreement with experimental measurements at $\sqrt{s}=8$ TeV. Predictions at $\sqrt{s}=13$ TeV are displayed including a study of theoretical uncertainties. In view of an application of these simulations within LHC experiments, we discuss in detail the necessary combination with a simulation of the $Z$ + jets final state. In addition to a corresponding prescription we introduce recommended cross checks to avoid common pitfalls during the overlap removal between the two samples.

    hep-phEPJC(2018)·16 citations
20. 20*

    Bjorken sum rule in QCD frameworks with analytic (holomorphic) coupling

    Cesar Ayala🇨🇱 · Gorazd Cvetic🇨🇱 · Anatoly V. Kotikov🇷🇺 · Binur G. Shaikhatdenov🇷🇺

    We investigate the Bjorken polarized sum rule (BSR) in three approaches to QCD with analytic (holomorphic) coupling: Analytic Perturbation Theory (APT), Two-delta analytic QCD (2$\delta$anQCD), and Three-delta lattice-motivated analytic QCD in the three-loop and four-loop MOM scheme (3l3$\delta$anQCD, 4l3$\delta$anQCD). These couplings do not have unphysical (Landau) singularities, and have finite values when the transferred momentum goes to zero, which allows us to explore the infrared regime. With the exception of APT, these theories at high momenta practically coincide with the underlying perturbative QCD (pQCD) in the same scheme. We apply them in order to verify the Bjorken sum rule within the range of energies available in the data collected by the experimental JLAB collaboration, i.e., $0.05Ge{V}^2<Q^2<3Ge{V}^2$ and compare the results with those obtained by using the perturbative QCD coupling. The results of the new frameworks with respective couplings (2$\delta$ and 3$\delta$) are in good agreement with the experimental data for $0.5Ge{V}^2<Q^2<3Ge{V}^2$ already when only one higher-twist term is used. In the low-$Q^2$ regime ($Q^2\lesssim 1Ge{V}^2$) we use $\chi$PT-motivated expression or an expression motivated by the light-front holography (LFH) QCD used earlier in the literature.

    hep-phInt.J.Mod.Phys.A(2018)·28 citations
21. 21*

    Hadronic resonances with exotic electric charge

    G. De Conto🇧🇷 · V. Pleitez🇧🇷

    We classify the meson and baryon long lived resonances considering quarks with electric charge 5/3 and $-4/3$ (in units of $|e|$) predicted by some 3-3-1 models. Some of these exotic resonances have the usual electric charges $0,\pm 1$, others have $\pm (3,4,5)$, and the lightest ones decaying only into leptons plus known resonances. We propose another heavy $SU(3{)}_H$ global symmetry under which hadrons involving only exotic quarks can be constructed.

    hep-phPRD(2017)·4 citations
22. 22*

    Quo vadis flavour physics? - FPCP2017 theory summary and outlook

    Monika Blanke🇩🇪

    We review the recent highlights of theoretical flavour physics, based on the theory summary talk given at FPCP2017. Over the past years, a number of intriguing anomalies have emerged in flavour violating $K$ and $B$ meson decays, constituting some of the most promising hints for the presence of physics beyond the Standard Model. We discuss the theory status of these anomalies and outline possible future directions to test the underlying New Physics.

    hep-phPoS(2017)·4 citations
23. 23*

    Dark Photons from Nuclear Transitions

    Jonathan Kozaczuk🇺🇸

    Light new particles can be emitted in decays of excited nuclear states. Experiments analyzing such transitions and incorporating high-resolution detectors can be sensitive to new MeV-scale physics at a level competitive with upcoming collider and other fixed target experiments, provided sufficient luminosity. We demonstrate this in the case of the ${}^8\text{Be}$ system, showing that searches targeting the reported anomaly in ${}^8\text{Be}$ nuclear transitions can also be sensitive to currently unexplored regions of the canonical dark photon parameter space with 1 MeV $\lesssim m_{A^{\prime }}\lesssim 18$ MeV and ${\epsilon }^2\gtrsim 10^{-7}$. These experiments could be performed on a short timescale, at low cost, and directly probe both the hadronic and leptonic couplings of light hidden particles.

    hep-phnucl-exPRD(2018)·18 citations
24. 24*

    Baryon Number and Lepton Universality Violation in Leptoquark and Diquark Models

    Nima Assad🇺🇸 · Bartosz Fornal🇺🇸 · Benjamin Grinstein🇺🇸

    We perform a systematic study of models involving leptoquarks and diquarks with masses well below the grand unification scale and demonstrate that a large class of them is excluded due to rapid proton decay. After singling out the few phenomenologically viable color triplet and sextet scenarios, we show that there exist only two leptoquark models which do not suffer from tree-level proton decay and which have the potential for explaining the recently discovered anomalies in B meson decays. Both of those models, however, contain dimension five operators contributing to proton decay and require a new symmetry forbidding them to emerge at a higher scale. This has a particularly nice realization for the model with the vector leptoquark $(3,1{)}_{2/3}$, which points to a specific extension of the Standard Model, namely the Pati-Salam unification model, where this leptoquark naturally arises as the new gauge boson. We explore this possibility in light of recent B physics measurements. Finally, we analyze also a vector diquark model, discussing its LHC phenomenology and showing that it has nontrivial predictions for neutron-antineutron oscillation experiments.

    hep-phPLB(2018)·224 citations
25. 25*

    Higgs characterisation in the presence of theoretical uncertainties and invisible decays

    Christoph Englert🇬🇧 · Roman Kogler🇩🇪 · Holger Schulz🇬🇧 · Michael Spannowsky🇬🇧

    While the Higgs characterisation programme is well underway, direct signs for new physics beyond the Standard Model remain elusive. Performing a fit of fully differential Higgs production cross sections at the LHC to a subset of Higgs-relevant effective operators, we discuss the extent to which theoretical uncertainties can limit the sensitivity in such a new physics search programme. Extending the dimension-6 Higgs Effective Field Theory framework by introducing new light degrees of freedom that can contribute to an invisible (or undetectable) Higgs decay width $h\to \varphi \varphi$, we show how differential coupling fits can disentangle effects from non-Standard Model couplings and an invisible decay width, as present in many new physics scenarios, such as Higgs-portal dark matter. Including the so-called off-shell measurement that has been advocated as a sensitive determination of the Higgs width in the $\kappa$ framework, we show explicitly that this method does not provide complementary sensitivity for scale-separated new physics $\Lambda \gg m_h\gg m_{\varphi }$, which is favoured in beyond the Standard Model scenarios that relate astrophysics and collider phenomenology in light of non-observation of new physics during run 1 of the LHC.

    hep-phhep-exEPJC(2017)·37 citations
26. 26*

    Search for axion-like dark matter through nuclear spin precession in electric and magnetic fields

    C. Abel🇬🇧 · N.J. Ayres🇬🇧 · G. Ban🇫🇷 · G. Bison🇨🇭 · K. Bodek🇵🇱 · V. Bondar🇧🇪 · M. Daum🇨🇭 · M. Fairbairn🇬🇧 · V.V. Flambaum🇦🇺 · P. Geltenbort🇫🇷 · K. Green🇬🇧 · W.C. Griffith🇬🇧 and 36 other authors

    We report on a search for ultra-low-mass axion-like dark matter by analysing the ratio of the spin-precession frequencies of stored ultracold neutrons and ${}^{199}$Hg atoms for an axion-induced oscillating electric dipole moment of the neutron and an axion-wind spin-precession effect. No signal consistent with dark matter is observed for the axion mass range $10^{-24}\text{eV}\le m_a\le 10^{-17}\text{eV}$. Our null result sets the first laboratory constraints on the coupling of axion dark matter to gluons, which improve on astrophysical limits by up to 3 orders of magnitude, and also improves on previous laboratory constraints on the axion coupling to nucleons by up to a factor of 40.

    hep-phastro-ph.COnucl-exnucl-th+1PRX(2017)·331 citations
27. 27*

    Thermo-magnetic Effects in an External Magnetic Field in the Logarithmic-Quark Sigma Model

    M. Abu-Shady🇪🇬

    The phenomenon of magnetic catalysis of chiral symmetry breaking in the quantum chromodynamic theory in the framework of logarithmic quark sigma model is studied. Thermodynamic properties are calculated in the mean-field approximation such as the pressure, the entropy density, the energy density, and measure interaction. The pressure, the entropy density, and the energy density increase with increasing temperature and an external magnetic field. The critical temperature increases with increasing an external magnetic field. In addition, the chiral phase transition is crossover in the presence of an external magnetic field with absent of baryonic chemical potential when explicit symmetry breaking is included. A comparison is presented with the original sigma model and other works. A conclusion indicates that the logarithmic quark model enhances the magnetic catalysis phenomenon.

    hep-phInternational Journal of Modern Physics a…·0 citations
28. 28*

    Remarks on a $B\wedge F$ model with topological mass from gauging spin

    Patricio Gaete🇨🇱 · José A. Helayël-Neto🇧🇷

    Aspects of screening and confinement are reassessed for a $B\wedge F$ model with topological mass with the gauging of spin. Our discussion is carried out using the gauge-invariant, but path-dependent, variables formalism. We explicitly show that the static potential profile is the sum of a Yukawa and a linear potential, leading to the confinement of static external charges. Interestingly enough, similar results are obtained in a theory of antisymmetric tensor fields that results from the condensation of topological defects as a consequence of the Julia-Toulouse mechanism.

    ↳ hep-thhep-phEPL(2017)·1 citation
29. 29*

    Exploring the dark matter inelastic frontier with 79.6 days of PandaX-II data

    PandaX-II Collaboration: Xun Chen · Abdusalam Abdukerim🇨🇳 · Wei Chen · Yunhua Chen · Xiangyi Cui🇨🇳 · Deqing Fang🇨🇳 · Changbo Fu🇨🇳 · Karl Giboni🇨🇳 · Franco Giuliani🇨🇳 · Xuyuan Guo · Zhifan Guo · Ke Han🇨🇳 and 35 other authors

    We report here the results of searching for inelastic scattering of dark matter (initial and final state dark matter particles differ by a small mass splitting) with nucleon with the first 79.6-day of PandaX-II data (Run 9). We set the upper limits for the spin independent WIMP-nucleon scattering cross section up to a mass splitting of 300 keV/c${}^2$ at two benchmark dark matter masses of 1 and 10 TeV/c${}^2$.

    ↳ hep-exastro-ph.COhep-phPRD(2017)·28 citations
30. 30*

    Holographic vector mesons in a dilaton background

    Rico Zöllner🇩🇪 · Burkhard Kämpfer🇩🇪

    Within a holographic framework, we consider vector mesons riding on a gravity-dilaton background. The latter one is determined directly from a Schrödinger equivalent potential which delivers a proper $\rho$ meson Regge trajectory. The mapping on the dilaton potential yields a thermodynamic phase structure with a first-order transition.

    ↳ hep-thhep-phJ.Phys.Conf.Ser.(2018)·7 citations
31. 31*

    Fluctuations of electromagnetic fields in heavy ion collisions

    B.G. Zakharov🇷🇺

    We perform quantum calculations of fluctuations of the electromagnetic fields in $AA$ collisions at RHIC and LHC energies. We find that in the quantum picture the field fluctuations are much smaller than predictions of the classical Monte-Carlo simulation with the Woods-Saxon nuclear density.

    ↳ nucl-thhep-ph3 citations
32. 32*

    Isoscalar $\pi \pi ,K\overline{K},\eta \eta$ scattering and the $\sigma ,f_0,f_2$ mesons from QCD

    Raul A. Briceno🇺🇸 · Jozef J. Dudek🇺🇸 · Robert G. Edwards🇺🇸 · David J. Wilson🇮🇪

    We present the first lattice QCD study of coupled isoscalar $\pi \pi ,K\overline{K},\eta \eta$ $S$- and $D$-wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the quark mass corresponding to $m_{\pi }\sim 391$ MeV. In the $J^P=0^{+}$ sector we find analogues of the experimental $\sigma$ and $f_0(980)$ states, where the $\sigma$ appears as a stable bound-state below $\pi \pi$ threshold, and, similar to what is seen in experiment, the $f_0(980)$ manifests itself as a dip in the $\pi \pi$ cross section in the vicinity of the $K\overline{K}$ threshold. For $J^P=2^{+}$ we find two states resembling the $f_2(1270)$ and $f_2^{\prime }(1525)$, observed as narrow peaks, with the lighter state dominantly decaying to $\pi \pi$ and the heavier state to $K\overline{K}$. The presence of all these states is determined rigorously by finding the pole singularity content of scattering amplitudes, and their couplings to decay channels are established using the residues of the poles.

    ↳ hep-lathep-phPRD(2018)·181 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.