Fri·Nov 3, 2017Friday·November 3, 2017

1. 01*

   "The school of Athens" or "Bridge between MEP and HEP"

   I.I. Bigi🇺🇸

   This century the situation has changed: neutrino oscillations have shown that the SM is incomplete. On the other hand, we have not found signs of SUSY, which is seen as the best candidate for New Dynamics (ND). We should search for ND indirectly with accuracy in regions that are above what LHC can find it directly. General comments: (a) QCD is the only local quantum field theory to describe strong forces. We have to apply non-perturbative QCD on different levels to flavor dynamics in strange, charm \& beauty hadrons and even for top quarks. We need consistent parameterization of the CKM matrix and apply to weak decays of beauty hadrons with many-body final states. (b) It is crucial to use the Wilsonian OPE as much as possible and discuss "duality" in the worlds of quarks and hadrons. The pole mass of heavy quarks is {\em not} well-defined on the non-perturbative level -- i.e., it is {\em not} Borel summable in total QCD. (c) We need a novel team to combine the strengths of our tools from MEP and HEP.

   hep-phPoS(2017)·0 citations
2. 02*

   Electromagnetic interactions of neutrinos in processes of low-energy elastic neutrino-electron scattering

   Konstantin A. Kouzakov🇷🇺 · Alexander I. Studenikin🇷🇺

   Electron energy and angular distributions in the process of low-energy elastic neutrino-electron scattering are treated in the free-electron approximation. The effects of the millicharges, magnetic, electric, and anapole moments of massive neutrinos along with the flavor change of neutrinos traveling from the source to the detector are taken into account under the assumption of three-neutrino mixing. The footprints of neutrino electromagnetic interactions in the electron energy and angle distributions are discussed.

   hep-phhep-exJ.Phys.Conf.Ser.(2020)·1 citation
3. 03*

   The correction of hadronic nucleus polarizability to hyperfine structure of light muonic atoms

   A.V. Eskin🇷🇺 · A.P. Martynenko🇷🇺 · E.N. Elekina🇷🇺

   The calculation of hadronic polarizability contribution of the nucleus to hyperfine structure of muonic hydrogen and helium is carried out within the unitary isobar model and experimental data on the polarized structure functions of deep inelastic lepton-proton and lepton-deuteron scattering. The calculation of virtual absorption cross sections of transversely and longitudinally polarized photons by nucleons in the resonance region is performed in the framework of the program MAID.

   hep-phphysics.atom-phEPJ Web Conf.(2017)·1 citation
4. 04*

   Top-quark loops and the muon anomalous magnetic moment

   Andrzej Czarnecki🇨🇦 · William J. Marciano🇺🇸

   The current status of electroweak radiative corrections to the muon anomalous magnetic moment is discussed. Asymptotic expansions for some important electroweak two loop top quark triangle diagrams are illustrated and extended to higher order. Results are compared with the more general integral representation solution for generic fermion triangle loops coupled to pseudoscalar and scalar bosons of arbitrary mass. Excellent agreement is found for a broader than expected range of mass parameters.

   hep-phPRD(2017)·8 citations
5. 05*

   Explaining the 3.5 keV X-ray Line in a $L_{\mu }-L_{\tau }$ Extension of the Inert Doublet Model

   Anirban Biswas🇮🇳 · Sandhya Choubey🇮🇳 · Laura Covi🇩🇪 · Sarif Khan🇮🇳

   We explain the existence of neutrino masses and their flavor structure, dark matter relic abundance and the observed 3.5 keV X-ray line within the framework of a gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ extension of the "scotogenic" model. In the $U(1{)}_{L_{\mu }-L_{\tau }}$ symmetric limit, two of the the RH neutrinos are degenerate in mass, while the third is heavier. The $U(1{)}_{L_{\mu }-L_{\tau }}$ symmetry is broken spontaneously. Firstly, this breaks the $\mu -\tau$ symmetry in the light neutrino sector. Secondly, this results in mild splitting of the two degenerate RH neutrinos, with their mass difference given in terms of the $U(1{)}_{L_{\mu }-L_{\tau }}$ breaking parameter. Finally, we get a massive $Z_{\mu \tau }$ gauge boson. Due to the added $Z_2$ symmetry under which the RH neutrinos and the inert doublet are odd, the canonical Type-I seesaw is forbidden and the tiny neutrino masses are generated radiatively at one loop. The same $Z_2$ symmetry also ensures that the lightest RH neutrino is stable and the other two can only decay into the lightest one. This makes the two nearly-degenerate lighter neutrinos a two-component dark matter, which in our model are produced by the freeze-in mechanism via the decay of the $Z_{\mu \tau }$ gauge boson in the early universe. We show that the next-to-lightest RH neutrino has a very long lifetime and decays into the lightest one at the present epoch explaining the observed 3.5 keV line.

   hep-phJCAP(2018)·28 citations
6. 06*

   A Lepton-specific Universal Seesaw Model with Left-Right Symmetry

   Ayon Patra🇮🇳 · Santosh Kumar Rai🇮🇳

   We propose a left-right symmetric framework with universal seesaw mechanism for the generation of masses of the Standard Model quarks and leptons. Heavy vector-like singlet quarks and leptons are required for generation of Standard Model-like quark and lepton masses through seesaw mechanism. A softly broken $Z_2$ symmetry distinguishes the lepton sector and the quark sector of the model. This leads to the presence of some lepton-specific interactions that can produce unique collider signatures which can be explored at the current Large Hadron Collider run and also future colliders.

   hep-phPRD(2018)·15 citations
7. 07*

   In-medium properties of pseudoscalar $D_s$ and $B_s$ mesons

   Rahul Chhabra🇮🇳 · Arvind Kumar🇮🇳

   We calculate the shift in masses and decay constants of $D_s(1968)$ and $B_s(5370)$ mesons in hot and dense asymmetric strange hadronic matter using QCD sum rules and chiral SU(3) model. In-medium strange quark condensates ${⟨\bar{s}s⟩}_{{\rho }_B}$, and gluon condensates ${⟨\frac{{\alpha }_s}{\pi }{G^a}_{\mu \nu }{G^a}^{\mu \nu }⟩}_{{\rho }_B}$ to be used in the QCD sum rules for pseudoscalar $D_s$ and $B_s$ mesons are calculated using chiral SU(3) model. As an application of our present work, we calculate the in-medium decay widths of the excited (c$\bar{s}$) states $D_s^{\ast }(2715)$ and $D_s^{\ast }(2860)$ decaying to ($D_s(1968)$,$\eta$) mesons. The medium effects in their decay widths are incorporated through the mass modification of the $D_s(1968)$ and $\eta$ mesons. Results of the present investigation may be helpful to understand the possible outcomes of the future experiments like CBM and PANDA under the FAIR facility.

   hep-phnucl-thEPJC(2017)·24 citations
8. 08*

   QCD-inequality analyses on pion condensate at real and imaginary isospin chemical potentials under finite imaginary quark chemical potential

   Junpei Sugano🇯🇵 · Hiroaki Kouno🇯🇵 · Masanobu Yahiro🇯🇵

   By employing QCD inequalities, we discuss appearance of the pion condensate for both real and imaginary isospin chemical potentials, taking also into account imaginary quark chemical potential. We show that the charged pion can condense for real isospin chemical potential, but not for imaginary one. Furthermore, we evaluate the expectation value of the neutral-pion field for imaginary isospin chemical potential by using framework of the twisted mass. As a result, it is found that the expectation value becomes zero for the finite current-quark mass, whereas the Banks-Casher relation is obtained in the massless limit.

   hep-ph0 citations
9. 09*

   Electroweak and non-resonant corrections to top-pair production near threshold at NNLO

   Martin Beneke🇩🇪 · Andreas Maier🇬🇧 · Thomas Rauh🇬🇧 · Pedro Ruiz-Femenía🇪🇸

   The top-quark mass can be determined with very high precision from a scan of the total $e^{+}{e}^{-}\to b\bar{b}{W}^{+}{W}^{-}X$ cross section near the top-pair production threshold. We present the full calculation of electroweak and non-resonant corrections to this process at NNLO. We discuss the size of the new contributions and estimate the theory uncertainty on the top-quark mass in the PS mass scheme.

   hep-phPoS(2017)·0 citations
10. 10*

    Non-SUSY WIMPS: simplified models and Dark Matter at the LHC

    Enrico Morgante🇩🇪

    I discuss the construction of Simplified Models for Dark Matter searches at the LHC. After reviewing the phylosophy and some simple example, I turn the attention to the aspect of the theoretical consistency of these models.

    hep-ph1 citation
11. 11*

    Absence of even-integer $\zeta$-function values in Euclidean physical quantities in QCD

    Matthias Jamin🇪🇸 · Ramon Miravitllas🇪🇸

    At order ${\alpha }_s^4$ in perturbative quantum chromodynamics, even-integer $\zeta$-function values are present in Euclidean physical correlation functions like the scalar quark correlation function or the scalar gluonium correlator. We demonstrate that these contributions cancel when the perturbative expansion is expressed in terms of the so-called $C$-scheme coupling ${\hat{\alpha }}_s$ which has recently been introduced in Ref. [1]. It is furthermore conjectured that a ${\zeta }_4$ term should arise in the Adler function at order ${\alpha }_s^5$ in the $\overline{\mathrm{MS}}$-scheme, and that this term is expected to disappear in the $C$-scheme as well.

    hep-phPLB(2018)·30 citations
12. 12*

    Modeling interactions of photons with pseudoscalar and vector mesons

    Henryk Czyż🇵🇱 · Patrycja Kisza🇵🇱 · Szymon Tracz🇵🇱

    We model interaction of photons, pseudoscalars and vector mesons within the resonance chiral symmetric theory with the SU(3) breaking. The couplings of the model are fitted to the experimental data. Within the developed model we predict the light-by-light contributions to the muon anomalous magnetic moment $a_{\mu }^P=(82.8\pm 3.4)\times 10^{-11}$. The error covers also the model dependence within the class of models considered in this paper. The model was implemented into the Monte Carlo event generator Ekhara to simulate the reactions $e^{+}{e}^{-}\to e^{+}{e}^{-}P$, $P={\pi }^0,\eta ,{\eta }^{\prime }$ and into the Monte Carlo event generator Phokhara to simulate the reactions $e^{+}{e}^{-}\to P\gamma (\gamma )$.

    hep-phhep-exPRD(2018)·48 citations
13. 13*

    ISR corrections to associated $HZ$ production at future Higgs factories

    Mario Greco🇮🇹 · Guido Montagna🇮🇹 · Oreste Nicrosini🇮🇹 · Fulvio Piccinini🇮🇹 · Gabriele Volpi🇮🇹

    We evaluate the QED corrections due to initial state radiation (ISR) to associated Higgs boson production in electron-positron ($e^{+}{e}^{-}$) annihilation at typical energies of interest for the measurement of the Higgs properties at future $e^{+}{e}^{-}$ colliders, such as CEPC and FCC-ee. We apply the QED Structure Function approach to the four-fermion production process $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}b\bar{b}$, including both signal and background contributions. We emphasize the relevance of the ISR corrections particularly near threshold and show that finite third order collinear contributions are mandatory to meet the expected experimental accuracy. We analyze in turn the rôle played by a full four-fermion calculation and beam energy spread in precision calculations for Higgs physics at future $e^{+}{e}^{-}$ colliders.

    hep-phPLB(2018)·14 citations
14. 14*

    Valence Quark and Gluon Distributions of Kaon from J/Psi Production

    Jen-Chieh Peng🇺🇸 · Wen-Chen Chang🇹🇼 · Stephane Platchkov🇫🇷 · Takahiro Sawada🇺🇸

    The only experimental information on the parton distribution of kaons was obtained from the scarce kaon-induced Drell-Yan cross section data. From these data, evidence for a valence $u$ quark distribution of kaon softer than that of pion was found. We study the feasibility to extract kaon's valence quark distribution via the existing kaon-induced J/psi production data. We compare the NA3 data on the K- / pi- and K+ / pi+ ratios for J/psi production on a platinum target with theoretical calculations based on the color-evaporation model. We show that the NA3 data on J/psi production provide an independent evidence for a valence $u$ quark distribution softer in kaon than in pion. The data also suggest different gluon distributions for kaon and pion.

    hep-phnucl-th13 citations
15. 15*

    Is Self-Interacting Dark Matter Undergoing Dark Fusion?

    Samuel D. McDermott🇺🇸

    We suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cross section to scale correctly across many decades of astrophysical masses from dwarf galaxies to galaxy clusters, we require the fractional binding energy released to be greater than v^n ~ [10^{-(2-3)}]^n, where n=1,2 depends on local dark sector chemistry. The size of the dark-sector interaction cross sections must be sigma ~ 0.1-1 barn, moderately larger than for Standard Model deuteron fusion, indicating a dark nuclear scale Lambda ~ O(100 MeV). Dark fusion firmly predicts constant sigma v below the characteristic velocities of galaxy clusters. Observations of the inner structure of galaxy groups with velocity dispersion of several hundred kilometer per second, of which a handful have been identified, could differentiate dark fusion from a dark photon model.

    hep-phastro-ph.COastro-ph.GAastro-ph.HEPRL(2018)·25 citations
16. 16*

    The Nelson-Barr Relaxion

    Oz Davidi🇮🇱 · Rick S. Gupta🇬🇧 · Gilad Perez🇮🇱 · Diego Redigolo🇮🇱 · Aviv Shalit🇮🇱

    Cosmological relaxation models in which the relaxion is identified with the QCD axion, generically fail to account for the smallness of the strong CP phase. We present a simple alternative solution to this "relaxion CP problem" based on the Nelson-Barr mechanism. We take CP to be a symmetry of the UV theory, and the relaxion to have no anomalous coupling with QCD. The non-zero vacuum expectation value of the relaxion breaks CP spontaneously, and the resulting phase is mapped to the Cabibbo-Kobayashi-Maskawa phase of the Standard Model. The extended Nelson-Barr quark sector generates the relaxion "rolling" potential radiatively, relating the new physics scale with the relaxion decay constant. With no new states within the reach of the LHC, our relaxion can still be probed in a variety of astrophysical and cosmological processes, as well as in flavor experiments.

    hep-phPRD(2019)·41 citations
17. 17*

    Investigating the quark flavor dependence of the chiral magnetic effect with a multiphase transport model

    Ling Huang🇨🇳 · Chun-Wang Ma🇨🇳 · Guo-Liang Ma🇨🇳

    Because the properties of the QCD phase transition and the chiral magnetic effect (CME) depend on the number of quark flavors ($N_f$) and quark mass, relativistic heavy-ion collisions provide a natural environment to investigate the flavor features if quark deconfinement occurs. We introduce an initial two-flavor or three-flavor dipole charge separation into a multiphase transport (AMPT) model to investigate the flavor dependence of the CME. By taking advantage of the recent ALICE data of charge azimuthal correlations with identified hadrons, we attempt to disentangle two-flavor and three-flavor CME scenarios in Pb+Pb collisions at 2.76 TeV. We find that the experimental data show a certain potential to distinguish the two scenarios, therefore we further suggest to collect more data to clarify the possible flavor dependence in future experiments.

    ↳ nucl-thhep-phnucl-exPRC(2018)·9 citations
18. 18*

    Relaxing the ${\sigma }_8$-tension through running vacuum in the Universe

    Adria Gomez-Valent🇪🇸 · Joan Sola🇪🇸

    It has recently been shown that the class of running vacuum models (RVMs) has the capacity to fit the overall cosmological observations better than the concordance $\Lambda$CDM model, therefore supporting the possibility of dynamical dark energy (DE). Apart from the cosmic microwave background (CMB) anisotropies, the most crucial datasets involved are: i) baryonic acoustic oscillations (BAO), and ii) direct large scale structure (LSS) formation data. Analyses mainly focusing on CMB and with insufficient BAO+LSS input generally fail to capture the dynamical DE signature, whereas the few existing studies accounting for the wealth of known CMB+BAO+LSS data (see in particular Solà, Gómez-Valent \& de Cruz Pérez 2015, 2017; and Zhao et al. 2017) do converge to the remarkable conclusion that dynamical DE might well be encoded in the current cosmological observations at a $3-4\sigma$ c.l. A decisive factor is the persistent ${\sigma }_8$-tension between the $\Lambda$CDM and the data. Because the issue is obviously pressing, we devote this work to explain how and why running vacuum in the expanding universe successfully relaxes the existing ${\sigma }_8$-tension and describes the LSS formation data significantly better than the $\Lambda$CDM.

    ↳ astro-ph.COgr-qchep-phhep-thEPL(2017)·94 citations
19. 19*

    Glueball relevant study on isoscalars from $N_f=2$ lattice QCD

    Wei Sun🇨🇳 · Long-cheng Gui🇨🇳 · Ying Chen🇨🇳 · Ming Gong🇨🇳 · Zhaofeng Liu🇨🇳

    We perform a glueball-relevant study on isoscalars based on anisotropic $N_f=2$ lattice QCD gauge configurations. In the scalar channel, we identify the ground state obtained through gluonic operators to be a single-particle state through its dispersion relation. When $q\bar{q}$ operator is included, we find the mass of this state does not change, and the $q\bar{q}$ operator couples very weakly to this state. So this state is most likely a glueball state. For pseudoscalars, along with the exiting lattice results, our study implies that both the conventional $q\bar{q}$ state ${\eta }_2$ (or ${\eta }^{\prime }$ in flavor $SU(3)$) and a heavier glueball-like state with a mass of roughly 2.6 GeV exist in the spectrum of lattice QCD with dynamical quarks.

    ↳ hep-lathep-phEPJ Web Conf.(2018)·3 citations
20. 20*

    Constraints on the Sommerfeld-enhanced dark matter annihilation from the gamma rays of subhalos and dwarf galaxies

    Bo-Qiang Lu🇨🇳 · Yue-Liang Wu🇨🇳 · Wei-Hong Zhang🇨🇳 · Yu-Feng Zhou🇨🇳

    The substructures of the Galactic dark matter halo such as dark matter subhalos and dwarf galaxies have very low velocity dispersions, which makes them useful in constraining the scenario of Sommerfeld-enhanced dark matter annihilation. We calculate the velocity distribution of dark matter particles in dark matter halo substructures using the Eddington's formula with NFW density profile. We parametrize the effect of Sommerfeld enhancement of s-wave dark matter annihilation on the gamma-ray flux as the Sommerfeld-enhanced J-factors, and explicitly calculate their values for 15 known dwarf spheroidal galaxies. Using the Fermi-LAT 3FGL data on the unassociated point-sources and the N-body simulation results on the dark matter subhalo distribution, we derive upper limits on the dark matter annihilation cross sections with Sommerfeld enhacement. Similar upper limits are derived from the Ferm-LAT gamma-ray data on the dwarf spheroidal galaxies. We find that in a wide region of parameter space, the constraints can be a few orders of magnitude more stringent than that in the case without the Sommerfeld enhancement. For dark matter annihilation dominantly into $e^{+}{e}^{-}$, ${\mu }^{+}{\mu }^{-}$, ${\tau }^{+}{\tau }^{-}$ and $b\bar{b}$, those constraints can exclude thermal relic dark matter for the dark matter mass below about 1 TeV.

    ↳ astro-ph.HEhep-phJCAP(2018)·18 citations
21. 21*

    Neutrino-Oxygen CC0$\pi$ scattering in the SuSAv2-MEC model

    G.D. Megias🇪🇸 · M.B. Barbaro🇮🇹 · J.A. Caballero🇪🇸 · J.E. Amaro🇪🇸 · T.W. Donnelly🇺🇸 · I. Ruiz Simo🇪🇸 · J. W. Van Orden🇺🇸

    We present the predictions of the SuSAv2-MEC model for the double differential charged-current muonic neutrino (antineutrino) cross section on water for the T2K neutrino (antineutrino) beam. We validate our model by comparing with the available inclusive electron scattering data on oxygen and compare our predictions with the recent T2K ${\nu }_{\mu }$-${}^{16}$O data, finding good agreement at all kinematics. We show that the results are very similar to those obtained for ${\nu }_{\mu }{-}^{12}$C scattering, except at low energies, and we comment on the origin of this difference. A factorized spectral function model of ${}^{16}$O is also included for purposes of comparison.

    ↳ nucl-thhep-phJ.Phys.G(2019)·51 citations
22. 22*

    Correlation between heavy flavour production and multiplicity in pp and p-Pb collisions at high energy in the multi-pomeron exchange model

    Grigory Feofilov🇷🇺 · Vladimir Kovalenko🇷🇺 · Andrei Puchkov (Saint Petersburg State University)🇷🇺

    The multiplicity dependence of heavy flavour production in pp-collisions at LHC energies is studied in the framework of the multi-pomeron exchange model. The model is introducing the string-string interaction collectivity effects in pp collisions, which modifies multiplicity and transverse momenta, leading to the non-trivial mean pt vs. multiplicity (<pt>_Nch - Nch) correlation. The string collectivity strength parameter is fixed by experimental data on multiplicity and transverse momentum correlation in a wide energy range (from ISR to LHC). The particles discrimination is implemented according to Schwinger mechanism taking into account the strong decays of hadron resonances. We demonstrate, that the faster-than-linear growth of the open charm production with the event charged particle multiplicity, observed in experimental pp high energy collisions, can be explained by the modification of the string tension due to the increasing overlap and interaction of quark-gluon strings. The model is extended for p-A interactions and the calculations for p-Pb collisions are performed.

    ↳ nucl-thhep-phEPJ Web Conf.(2018)·15 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.