Wed·Aug 7, 2019Wednesday·August 7, 2019

1. 01*

   Coupling constants calculation of charmed meson with kaon from QCD sum rules

   M.R. Seyedhabashy (1)🇮🇷 · E. Kazemi (2)🇮🇷 · M. Janbazi (1)🇮🇷 · N. Ghahramany (3) ((1) Nuclear Science and Technology Research Institute, Tehran, Iran, (2) Department of Physics, Faculty of Sciences, Salman Farsi University of Kazerun, Kazerun, Iran, (3) Department of Physics, and Biruni Observatory, College of Science, Shiraz University, Shiraz, 71946-84795, Iran)🇮🇷

   In this research, the strong coupling constants of the $D^{\ast }{D}_s^{\ast }K$, $D_1{D}_{s1}K$, $D^{\ast }{D}_{s}K$ and $D_1{D}_{s0}^{\ast }K$ vertices are evaluated, using the three-point QCD sum rules. In order to calculate the coupling constant of each vertex, either the kaon or the charmed meson is considered as the off-shell particle. The basic $g$ parameter, in the heavy quark effective theory, is related to the coupling constants of $D^{\ast }{D}_s^{\ast }K$ and $D^{\ast }{D}_{s}K$. Our obtained value for $g$ parameter is $0.24\pm 0.09$, which is in good agreement with the lower limits of the other existing predictions.

   hep-phNPA(2020)·4 citations
2. 02*

   Study of kaon structure using the light-cone quark model

   Satvir Kaur🇮🇳 · Harleen Dahiya🇮🇳

   We investigate the various distributions explaining multi-dimensional structure of kaon at the level of its constituents ($u$ and $\bar{s}$) using the light-cone quark model. The overlap form of wavefunctions associated with the light-cone quark model is adopted for the calculations. The generalized parton distributions(GPDs)of $u$ and $\bar{s}$ quarks are presented for the case when the momentum transfer in the longitudinal direction is non-zero. The dependence of kaon GPDs is studied in terms of variation of quark longitudinal momentum fraction, momentum transfer in longitudinal direction and total momentum transfer to the final state of hadron. The transverse impact-parameter dependent GPDs are also studied by taking the Fourier transformation of general GPDs. Further, the quantum phase-space distributions; Wigner distributions are studied for the case of unpolarized, longitudinally-polarized and transversely-polarized parton in an unpolarized kaon. The Wigner distributions are analysed in the transverse impact-parameter plane, the transverse momentum plane and the mixed plane. Further, to get a complete picture of kaon in terms of its valence quarks, the variation of longitudinal momentum fraction carried by quark and antiquark in the generalized transverse momentum-dependent parton distributions (GTMDs) is studied for different values of transverse quark and antiquark momentum $({\mathbf{k}}_{\perp })$ as well as for different values of momentum transferred to the kaon in transverse direction $({\mathbf{\Delta }}_{\perp })$. This has been done for zero as well as non-zero skewedness representing respectively the absence and presence of momentum transfer to the final state of kaon in longitudinal direction. Furthermore, the possible spin-orbit correlation for $u$ and $\bar{s}$ in kaon is elaborated in context of Wigner distributions and GTMDs.

   hep-phPRD(2019)·24 citations
3. 03*

   Quarkyonic phase from quenched dynamical holographic QCD model

   Xun Chen🇨🇳 · Danning Li🇨🇳 · Defu Hou🇨🇳 · Mei Huang🇨🇳

   Chiral and deconfinement phase transitions at finite temperature $T$ and quark number chemical potential $\mu$ are simultaneously studied in the quenched dynamical holographic QCD model within the Einstein-Dilaton-Maxwell framework. By calculating the corresponding order parameters, i.e., the chiral condensate and Polyakov loop, it is shown that the transition lines of these two phase transitions are separated in the $T-\mu$ plane. The deconfinement phase transition is shown to be always of crossover type and the transition line depends weakly on the baryon number density. Differently, the chiral transition is of crossover at small baryon number density and it turns to be of first order at sufficient large baryon number density. A critical endpoint (CEP), at which the transition becomes second order type, appears in the chiral transition line. This is the first time to realize the CEP of chiral phase transition in the $(T,\mu )$ plane using the holographic EMD(Einstein-Maxwell-Dilaton) model for two flavour case. It is observed that between these two phase transition lines, there is a region with chiral symmetry restored and color degrees still confined, which could be considered as the quarkyonic phase. Qualitatively, this behavior is in consistent with the result in the Polyakov-loop improved Nambu-Jona-Lasinio (PNJL) model.

   hep-phJHEP(2020)·73 citations
4. 04*

   Meson condensation

   Massimo Mannarelli🇮🇹

   We give a pedagogical review of the properties of the various meson condensation phases triggered by a large isospin or strangeness imbalance. We argue that these phases are extremely interesting and powerful playground for exploring the properties of hadronic matter. The reason is that they are realized in a regime in which various theoretical methods overlap with increasingly precise numerical lattice QCD simulations, providing insight on the properties of color confinement and of chiral symmetry breaking.

   hep-phhep-latnucl-thParticles(2019)·90 citations
5. 05*

   Invariant-mass distribution of top-quark pairs and top-quark mass determination

   Wan-Li Ju🇨🇳 · Guoxing Wang🇨🇳 · Xing Wang🇨🇳 · Xiaofeng Xu🇨🇳 · Yongqi Xu🇨🇳 · Li Lin Yang🇨🇳

   We investigate the invariant-mass distribution of top-quark pairs near the $2m_t$ threshold, which has strong impact on the determination of the top-quark mass $m_t$. We show that higher-order non-relativistic corrections lead to large contributions which are not included in the state-of-the-art theoretical predictions. We derive a factorization formula to resum such corrections to all orders in the strong-coupling, and calculate necessary ingredients to perform the resummation at next-to-leading power. We combine the resummation with fixed-order results and present phenomenologically relevant numeric results. We find that the resummation effect significantly enhances the differential cross section in the threshold region, and makes the theoretical prediction more compatible with experimental data. We estimate that using our prediction in the determination of $m_t$ will lead to a value closer to the result of direct measurement.

   hep-phCPC(2020)·11 citations
6. 06*

   Higher-order and mixed QCD-QED corrections for Drell-Yan

   German F. R. Sborlini🇪🇸

   In this article, we discuss about the Drell-Yan process focusing on the computation of radiative corrections for vector boson production. First, we describe the $q_T$-resummation formalism and its application to obtain higher-order QCD corrections. We briefly summarize the state-of-the-art in these calculations, and motivate the need of more refined theoretical predictions. After that, we center into the inclusion of mixed QCD-QED higher-order contributions, both for fixed order and resummed calculations. In particular, we present a framework based on the $q_T$-resummation formalism to simultaneously handle soft gluon and photon radiation. Finally, we discuss future extensions of this approach and its phenomenological relevance.

   hep-phPoS(2019)·0 citations
7. 07*

   Light-Cone Sum Rules for $B\to K\pi$ Form Factors and Applications to Rare Decays

   Sébastien Descotes-Genon🇫🇷 · Alexander Khodjamirian🇩🇪 · Javier Virto🇩🇪

   We derive a set of light-cone sum rules relating the hadronic form factors relevant for $B\to K\pi {\ell }^{+}{\ell }^{-}$ decays to the $B$-meson light-cone distribution amplitudes (LCDAs). We obtain the sum rule relations for all $B\to K\pi$ form factors of (axial)vector and (pseudo)tensor $b\to s$ currents with a $P$-wave $K\pi$ system. Our results reduce to the known light-cone sum rules for $B\to K^{\ast }$ form factors in the limit of a single narrow-width resonance. We update the operator-product expansion for the underlying correlation function by including a more complete set of $B$-meson LCDAs with higher twists, and produce numerical results for all $B\to K^{\ast }$ form factors in the narrow-width limit. We then use the new sum rules to estimate the effect of a non-vanishing $K^{\ast }$ width in $B\to K^{\ast }$ transitions, and find that this effect is universal and increases the factorizable part of the rate of $B\to K^{\ast }X$ decays by a factor of $20\%$. This effect, by itself, goes in the direction of increasing the current tension in the differential $B\to K^{\ast }\mu \mu$ branching fractions. We also discuss $B\to K\pi$ transitions outside the $K^{\ast }$ window, and explain how measurements of $B\to K\pi \ell \ell$ observables above the $K^{\ast }$ region can be used to further constrain the $B\to K^{\ast }$ form factors.

   hep-phJHEP(2019)·73 citations
8. 08*

   Viable secret neutrino interactions with ultralight dark matter

   James M. Cline🇨🇦

   Several anomalies in neutrino oscillation experiments point to the existence of a $\sim 1$eV sterile neutrino ${\nu }_s$ mixing with ${\nu }_e$ at the level of $U_{e4}\cong 0.1$, but such a neutrino is strongly disfavored by constraints on additional light degrees of freedom ($\delta N_{\mathrm{eff}}$) and total neutrino mass (${\sum }_{\nu }{m}_{\nu }$) from cosmology. "Secret neutrino interactions" that have been invoked to suppress the cosmological production of ${\nu }_s$ typically falter, but recently it was pointed out that ${\nu }_s$ could get a large mass in the early universe by coupling to ultralight dark matter $\varphi$, which can robustly suppress its production. The model has essentially two free parameters: $m_{\varphi }$, and $m_{s,0}$, the mass of the sterile neutrino at early times, enhanced by its coupling to $\varphi$. I determine the parameter regions allowed by limits on $\delta N_{\mathrm{eff}}$ and ${\sum }_{\nu }{m}_{\nu }$ from the cosmic microwave background and big bang nucleosynthesis, using a simplified yet accurate treatment of neutrino oscillations in the early universe. This mechanism could have an important impact on laboratory experiments that suggest oscillations with sterile neutrinos.

   hep-phastro-ph.COPLB(2020)·39 citations
9. 09*

   Measurement of the cross sections for inclusive electron scattering in the E12-14-012 experiment at Jefferson Lab

   M. Murphy🇺🇸 · H. Dai🇺🇸 · L. Gu🇺🇸 · D. Abrams🇺🇸 · A. M. Ankowski🇺🇸 · B. Aljawrneh🇺🇸 · S. Alsalmi🇺🇸 · J. Bane🇺🇸 · S. Barcus🇺🇸 · O. Benhar🇮🇹 · V. Bellini🇮🇹 · J. Bericic🇺🇸 and 47 other authors

   The E12-14-012 experiment performed at Jefferson Lab Hall A has collected inclusive electron-scattering data for different targets at the kinematics corresponding to beam energy 2.222 GeV and scattering angle 15.54 deg. Here we present a comprehensive analysis of the collected data and compare the double-differential cross sections for inclusive scattering of electrons, extracted using solid targets (aluminum, carbon, and titanium) and a closed argon-gas cell. The data extend over broad range of energy transfer, where quasielastic interaction, Delta-resonance excitation, and inelastic scattering yield contributions to the cross section. The double-differential cross sections are reported with high precision (~3%) for all targets over the covered kinematic range.

   ↳ hep-exhep-phnucl-exPRC(2019)·30 citations
10. 10*

    Overview of Gluon Helicity Measurements at STAR

    Christopher Dilks🇺🇸

    The contribution to the spin of the proton from the gluon helicity is starting to come into focus: for gluons carrying a large fraction $x$ of the proton momentum, evidence of positive gluon polarization has been observed, via measurements of the longitudinal double-spin asymmetry $A_{LL}$ for inclusive jet and dijet production. $A_{LL}$ is sensitive to the polarized gluon distribution function, $\Delta g(x)$, and while it is positive at high $x$, it is not well constrained for $x<0.05$. Recent measurements at STAR of observables originating dominantly from quark-gluon and gluon-gluon subprocesses aim to improve the precision of $\Delta g(x)$ at high $x$, as well as for the first time provide insight into the low-$x$ contribution. $A_{LL}$ measurements of inclusive jets and dijets at midrapidity $(|\eta |<1)$ and intermediate rapidity $(0.8<\eta <2)$ at STAR at $\sqrt{s}=200$ and $510$ GeV will be shown, along with the statuses of ongoing analyses; these measurements will help improve the $\Delta g(x)$ precision for $x\gtrsim 0.01$. Recent ${\pi }^0$ $A_{LL}$ measurements in the forward region $(2.65<\eta <3.9)$ at $\sqrt{s}=510$ GeV will also be presented, which probe $\Delta g(x)$ down to $x\sim 10^{-3}$. Comparisons of these results to recent global analyses and extrapolations will be discussed.

    ↳ hep-exhep-phPoS(2019)·0 citations
11. 11*

    Properties of strange quark stars with isovector interactions

    He Liu🇨🇳 · Jun Xu🇨🇳 · Che Ming Ko🇺🇸

    We study the properties of strange quark stars by employing a 3-flavor Nambu-Jona-Lasinio model with both scalar-isovector and vector-isovector interactions. Using the constraint on the vector-isoscalar interaction strength obtained from the elliptic flow splitting between particles and their antiparticles in relativistic heavy-ion collisions, we investigate the dependence of the properties of strange quark stars on the vector-isovector and the scalar-isovector interactions, and compare the results with the state-of-art astrophysical constraints on the compact star radius and mass as well as its tidal deformability from the GW170817 event. Results from our study reinforce the prospect of using both heavy-ion collisions and astrophysical observations to provide constraints on the isovector coupling strength in quark matter and thus the quark matter equation of state as well as the QCD phase structure at finite isospin chemical potentials.

    ↳ nucl-thastro-ph.HEastro-ph.SRhep-phPLB(2020)·14 citations
12. 12*

    On instabilities of stationary scalar field configurations supported by reflecting compact stars

    Yan Peng🇨🇳

    We study instabilities of the system composed of stationary scalar fields and asymptotically flat horizonless reflecting compact stars. In the probe limit, we obtain bounds on the scalar field frequency. Below this bound, stationary hairy stars are expected to suffer from nonlinear instabilities under massless field perturbations. In other words, we prove that stationary scalar hairy stars are unstable for scalar fields with small frequency.

    ↳ gr-qchep-phhep-thPLB(2019)·0 citations
13. 13*

    The First fm/c of Heavy-Ion Collisions

    Soeren Schlichting🇩🇪 · Derek Teaney🇺🇸

    We present an introductory review of the early time dynamics of high-energy heavy-ion collisions and the kinetics of high temperature QCD. The equilibration mechanisms in the quark-gluon plasma uniquely reflect the non-abelian and ultra-relativistic character of the many body system. Starting with a brief expose of the key theoretical and experimental questions, we provide an overview of the theoretical tools employed in weak coupling studies of the early time non-equilibrium dynamics. We highlight theoretical progress in understanding different thermalization mechanisms in weakly coupled non-abelian plasmas, and discuss their relevance in describing the approach to local thermal equilibrium during the first $\mathrm{fm}/c$ of a heavy-ion collision. Some important connections to the phenomenology of heavy-ion collisions are also briefly discussed.

    ↳ nucl-thhep-phhep-thAnn.Rev.Nucl.Part.Sci.(2019)·162 citations
14. 14*

    The Fröhlich-Morchio-Strocchi mechanism and quantum gravity

    Axel Maas🇦🇹

    Taking manifest invariance under both gauge symmetry and diffeomorphisms as a guiding principle physical objects are constructed for Yang-Mills-Higgs theory coupled to quantum gravity. These objects are entirely classified by quantum numbers defined in the tangent space. Applying the Fröhlich-Morchio-Strocchi mechanism to these objects reveals that they coincide with ordinary correlation functions in quantum-field theory, if quantum fluctuations of gravity and curvature become small. Taking these descriptions literally exhibits how quantum gravity fields need to dress quantum fields to create physical objects, i.e. giving a graviton component to ordinary observed particles. The same mechanism provides access to the physical spectrum of pure gravitational degrees of freedom.

    ↳ hep-thgr-qchep-phSciPost Phys.(2020)·17 citations
15. 15*

    Neutron valence structure from nuclear deep inelastic scattering

    E.P. Segarra🇺🇸 · A. Schmidt🇺🇸 · T. Kutz🇺🇸 · D.W. Higinbotham🇺🇸 · E. Piasetzky🇮🇱 · M. Strikman🇺🇸 · L.B. Weinstein🇺🇸 · O. Hen🇺🇸

    Mechanisms of spin-flavor SU(6) symmetry breaking in Quantum Chromodynamics (QCD) are studied via an extraction of the free neutron structure function from a global analysis of deep inelastic scattering (DIS) data on the proton and on nuclei from $A=2$ (deuterium) to 208 (lead). Modification of the structure function of nucleons bound in atomic nuclei (known as the EMC effect) are consistently accounted for within the framework of a universal modification of nucleons in short-range correlated (SRC) pairs. Our extracted neutron-to-proton structure function ratio $F_2^n/F_2^p$ becomes constant for $x_B\ge 0.6$, equalling $0.47\pm 0.04$ as $x_B\to 1$, in agreement with theoretical predictions of perturbative QCD and the Dyson Schwinger equation, and in disagreement with predictions of the Scalar Diquark dominance model. We also predict $F_2^{{}^3\mathrm{He}}/F_2^{{}^3\mathrm{H}}$, recently measured, yet unpublished, by the MARATHON collaboration, the nuclear correction function that is needed to extract $F_2^n/F_2^p$ from $F_2^{{}^3\mathrm{He}}/F_2^{{}^3\mathrm{H}}$, and the theoretical uncertainty associated with this extraction.

    ↳ nucl-thhep-exhep-phnucl-exPRL(2020)·43 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.