Thu·Apr 4, 2019Thursday·April 4, 2019

1. 01*

   Nuclear correlations and modifications of the nucleon-nucleon potential due to the QCD critical mode

   Juan M. Torres-Rincon🇺🇸 · Edward Shuryak🇺🇸

   The scalar-isoscalar mode of QCD becomes lighter/nearly massless close to the chiral transition/second-order critical point. From nuclear physics we know that this mode is the main responsible for the attractive part of the nucleon-nucleon potential at inter-particle distances of 1-2 fm. Therefore one expects that close to the critical point there is a long-range strong attraction among nucleons. Using a Walecka-Serot model for the NN potential we study the effects of the critical point in a finite system of nucleons and mesons by solving classical Molecular Dynamics+Langevin equations for the freeze-out conditions of heavy-ion collisions. Going beyond the mean-field approximation allows us to account for strong nucleon correlations in the time evolution, leading to baryon clustering. We observe that light cluster formation, together with an enhancement of higher-order cumulants of the proton distribution can signal the presence of the critical point.

   hep-phnucl-thPoS(2019)·1 citation
2. 02*

   On the convergence of chiral expansions for charmed meson masses in the up, down and strange quark masses

   Matthias F.M. Lutz🇩🇪 · Xiao-Yu Guo🇩🇪 · Yonggoo Heo🇹🇭

   We discuss the convergence properties of chiral expansions for the pseudoscalar and vector charmed meson masses based on the chiral SU(3) Lagrangian. Conventional expansion strategies as formulated in terms of bare meson masses are shown to suffer from poor convergence properties. This changes once the expansion is set up in terms of on-shell masses. We find a rapid convergence of the chiral expansion from vanishing quark masses up to physical values of the strange quark mass in this case. Detailed results are presented at the one-loop level for the D-meson and D^*-meson masses. It is emphasized that our results do not depend on the renormalization scale. An approximation hierarchy for the chiral Ward identities of QCD is obtained that keeps the proper form of low-energy branch points and cuts as they are implied by the use of on-shell masses. Given such a scheme we analyzed the charmed meson masses as available on various QCD lattice ensembles. In terms of the determined low-energy constants we consider the coupled-channel interactions of the Goldstone bosons with open-charm mesons. For the isospin violating hadronic decay width of the D_{s0}^*(2317) we predict the range (104-116) keV.

   hep-phnucl-thPoS(2019)·0 citations
3. 03*

   Anomalous magnetohydrodynamics with longitudinal boost invariance and chiral magnetic effect

   Irfan Siddique🇨🇳 · Ren-jie Wang🇨🇳 · Shi Pu🇨🇳 · Qun Wang🇨🇳

   We study relativistic magnetohydrodynamics with longitudinal boost invariance in the presence of chiral magnetic effects and finite electric conductivity. With initial magnetic fields parallel or anti-parallel to electric fields, we derive the analytic solutions of electromagnetic fields and the chiral number and energy density in an expansion of several parameters determined by initial conditions. The numerical solutions show that such analytic solutions work well in weak fields or large chiral fluctuations. We also discuss the properties of electromagnetic fields in the laboratory frame.

   hep-phnucl-thPRD(2019)·40 citations
4. 04*

   Event-by-Event Fluctuations Clusterization and Entropy Production in AA Collisions at AGS and SPS Energies

   Bushra Ali · Shaista Khan🇮🇳 · Anuj Chandra · Shakeel Ahmad🇮🇳

   Event-by-event (ebe) fluctuations in mean pseudorapidity values of relativistic charged particles in full phase space is studied by analysing experimental data on ${}^{16}O-AgBr$ collisions at 14.5A, 60A, and 200A GeV/c and ${}^{32}S-AgBr$ collisions at 200A GeV/c. The findings are compared with the prediction of A Multi-Phase Transport(\amm) model and those obtained from the analysis of correlation free Monte-Carlo events. Fluctuations in mean pseudorapidity distributions are noticed to be in excess to that expected from the statistically independent particle emission. The observed dependence of the fluctuation strength measure parameter,$\varphi$ on the beam energy and number of participating target nucleons indicate that nucleus-nucleus collisions can not be treated as simple superposition of multiple nucleon-nucleon interactions. Presence of clusters or jet-like phenomena in multihadron final states are searched for on ebe basis by using the concept of Jaynes Shannon entropy. The findings indicate the presence of cluster like objects in the experimental data with their size and frequency increasing with increasing beam energy. These observations, in turn suggest that the clustering or jet-like algorithm adopted in the present study may be used as a tool for triggering different classes of events.

   hep-phnucl-thIJMPE(2019)·6 citations
5. 05*

   Chiral-spin symmetry emergence in baryons and eigenmodes of the Dirac operator

   Marco Catillo🇦🇹 · Leonid Ya. Glozman🇦🇹 · Christian B. Lang🇦🇹

   Truncating the low-lying modes of the lattice Dirac operator results in an emergence of the chiral-spin symmetry $SU(2{)}_{CS}$ and its flavor extension $SU(2N_F)$ in hadrons. These are symmetries of the quark - chromo-electric interaction and include chiral symmetries as subgroups. Hence the quark - chromo-magnetic interaction, which breaks both symmetries, is located at least predominantly in the near - zero modes. Using as a tool the expansion of propagators into eigenmodes of the Dirac operator we here analytically study effects of a gap in the eigenmode spectrum on baryon correlators. We find that both $U(1{)}_A$ and $SU(2{)}_L\times SU(2{)}_R$ emerge automatically if there is a gap around zero. Emergence of larger $SU(2{)}_{CS}$ and $SU(4)$ symmetries requires in addition a microscopical dynamical input about the higher-lying modes and their symmetry structure.

   hep-phhep-latPRD(2019)·2 citations
6. 06*

   CP-Violation phase analysis via non-trivial correlation of quarks and leptons in 3+1 scenario

   Gazal Sharma🇮🇳 · B. C. Chauhan🇮🇳

   The existence and mysterious nature of sterile neutrinos are revolutionizing physics from the particle level to the cosmological scales. The recent results from the MiniBooNE experiment at Fermi-lab observed far more ${\nu }_e$ appearance than expected, which have provided a hint about the possible existence of \textit{sterile neutrinos}. The results, if confirmed in future experiments, will have significant implications for cosmology and astroparticle physics. This will require new neutrino mass models to accommodate these additional degrees of freedom. In respect to that, the present work is just an extension of our recent work towards the CP phase analysis of Quark-lepton complementarity(QLC) model in a 3+1 scenario. The parametrization of $CK{M}_4$ and $PMN{S}_4$ using Monte Carlo Simulation is used to estimate the texture of non-trivial correlation matrix ($V_{c_4}$). As such, we have successfully investigated the constrained values for sterile neutrino parameters, and also predicted the values for Dirac CP-Violation phase and the CP re-phasing invariant (J). The results obtained are consistent with the data available from various experiments, like No$\nu$A, MINOS, SuperK and IceCube-DeepCore. Furthermore, this analysis would be very important in view of growing sterile neutrino experiments.

   hep-phMod.Phys.Lett.A(2019)·1 citation
7. 07*

   Gluon-pair-Creation Production Model of Strong Interaction Vertices

   Bing-Dong Wan🇨🇳 · Cong-Feng Qiao🇨🇳

   By studying the ${\eta }_c$ exclusive decay to double glueballs, we introduce a model to mimic phenomenologically the gluon-pair-vacuum interaction vertices, namely the $0^{++}$ model. Based on this model, we study glueball production in pseudoscalar quarkonium decays, explicitly ${\eta }_c\to f_0(1500)\eta (1405)$, ${\eta }_b\to f_0(1500)\eta (1405)$ and ${\eta }_b\to f_0(1710)\eta (1405)$ processes. Among them $f_0(1500)$ and $f_0(1710)$ are well-known scalars possessing large glue components and $\eta (1405)$ is a potential candidate for pseudoscalar glueball. The preliminary calculation results indicate that these processes are marginally accessible in the presently running experiments BES III, BELLE II, and LHCb.

   hep-phCPC(2020)·10 citations
8. 08*

   Light in the beam dump -- ALP production from decay photons in proton beam-dumps

   Babette Döbrich🇨🇭 · Joerg Jaeckel🇩🇪 · Tommaso Spadaro🇮🇹

   The exploration of long-lived particles in the MeV-GeV region is a formidable task but it may provide us a unique access to dark sectors. Fixed-target facilities with sufficiently energetic and intense proton beams are an ideal tool for this challenge. In this work we show that the production rate of Axion-Like-Particles (ALPs) coupled pre-dominantly to photons receives a significant contribution from daughter-photons of secondary ${\pi }^0$ and $\eta$ mesons created in the proton shower. We carefully compare the PYTHIA simulated spectra of such secondaries to experimental literature, compute the ALP flux from the Primakoff conversion of these photons, and finally revisit existing limits on ALPs and update the prospects for a set of existing and future searches. Our results show that taking this production mechanism into account significantly enhances the sensitivity compared to previous studies based on coherent ALP production in primary proton-nucleus interactions.

   hep-phhep-exJHEP(2019)·164 citations
9. 09*

   Interpretable Deep Learning for Two-Prong Jet Classification with Jet Spectra

   Amit Chakraborty🇯🇵 · Sung Hak Lim🇯🇵 · Mihoko M. Nojiri🇯🇵

   Classification of jets with deep learning has gained significant attention in recent times. However, the performance of deep neural networks is often achieved at the cost of interpretability. Here we propose an interpretable network trained on the jet spectrum $S_2(R)$ which is a two-point correlation function of the jet constituents. The spectrum can be derived from a functional Taylor series of an arbitrary jet classifier function of energy flows. An interpretable network can be obtained by truncating the series. The intermediate feature of the network is an infrared and collinear safe C-correlator which allows us to estimate the importance of a $S_2(R)$ deposit at an angular scale R in the classification. The performance of the architecture is comparable to that of a convolutional neural network (CNN) trained on jet images, although the number of inputs and complexity of architecture is significantly simpler than the CNN classifier. We consider two examples: one is the classification of two-prong jets which differ in color charge of the mother particle, and the other is a comparison between Pythia 8 and Herwig 7 generated jets.

   hep-phhep-exstat.MLJHEP(2019)·58 citations
10. 10*

    Short-baseline neutrino oscillations with 3+1 non-unitary mixing

    C. Giunti🇮🇹

    We consider a scenario with unitary mixing of the three light standard neutrinos and a non-unitary mixing contribution of a heavier massive neutrino that can generate short-baseline neutrino oscillations. We show that this scenario predicts constant flavor-changing probabilities at short-baseline distances. Therefore, it cannot explain the spectral distortions observed in the LSND and MiniBooNE appearance experiments. On the other hand, the survival probabilities oscillate as functions of $L/E$ and could explain oscillations in short-baseline disappearance experiments. We also derive the bounds on the mixing parameters from the existing short-baseline neutrino oscillation data.

    hep-phhep-exPLB(2019)·4 citations
11. 11*

    ewN2HDECAY - A program for the Calculation of Electroweak One-Loop Corrections to Higgs Decays in the Next-to-Minimal Two-Higgs-Doublet Model Including State-of-the-Art QCD Corrections

    M. Krause🇩🇪 · M. Mühlleitner🇩🇪

    We present in this paper our new program package ewN2HDECAY for the calculation of the partial decay widths and branching ratios of the Higgs bosons of the Next-to-Minimal 2-Higgs Doublet Model (N2HDM). The N2HDM is based on a general CP-conserving 2HDM which is extended by a real scalar singlet field. The program computes the complete electroweak one-loop corrections to all non-loop-induced two-body on-shell Higgs boson decays in the N2HDM and combines them with the state-of-the-art QCD corrections that are already implemented in the existing program N2HDECAY. Most of the independent input parameters of the electroweak sector of the N2HDM are renormalized in an on-shell scheme. The soft-${\mathbb{Z}}_2$-breaking squared mass scale $m_{12}^2$ and the vacuum expectation value $v_S$ of the $SU(2{)}_L$ singlet field, however, are renormalized with $\overline{\text{MS}}$ conditions, while for the four scalar mixing angles ${\alpha }_i$ ($i=1,2,3$) and $\beta$ of the N2HDM, several different renormalization schemes are applied. By giving out the leading-order and the loop-corrected partial decay widths separately from the branching ratios, the program ewN2HDECAY not only allows for phenomenological analyses of the N2HDM at highest precision, it can also be used for a study of the impact of the electroweak corrections and the remaining theoretical uncertainty due to missing higher-order corrections based on a change of the renormalization scheme. The input parameters are then consistently calculated with a parameter conversion routine when switching from one renormalization scheme to the other. The latest version of the program ewN2HDECAY can be downloaded from the URL \href{https://github.com/marcel-krause/ewN2HDECAY}{https://github.com/marcel-krause/ewN2HDECAY}.

    hep-phComput.Phys.Commun.(2020)·21 citations
12. 12*

    Forecasting Cosmological Bias due to Local Gravitational Redshift

    Haoting Xu🇨🇳 · Zhiqi Huang🇨🇳 · Na Zhang🇨🇳 · Yundong Jiang🇨🇳

    When photons from distant galaxies and stars pass through our neighboring environment, the wavelengths of the photons would be shifted by our local gravitational potential. This local gravitational redshift effect can potentially have an impact on the measurement of cosmological distance-redshift relation. Using available supernovae data, Wojtak et al [1] found seemingly large biases of cosmological parameters for some extended models (non-flat $\Lambda$CDM, $w$CDM, etc.). Huang [2] pointed out that, however, the biases can be reduced to a negligible level if cosmic microwave background (CMB) data are added to break the strong degeneracy between parameters in the extended models. In this article we forecast the cosmological bias due to local gravitational redshifts for a future WFIRST-like supernovae survey. We find that the local gravitational redshift effect remains negligible, provided that CMB data or some future redshift survey data are added to break the degeneracy between parameters.

    ↳ astro-ph.COgr-qchep-phhep-thInt.J.Mod.Phys.D(2019)·1 citation
13. 13*

    Simulating chiral anomalies with spin dynamics

    Wen-Hao Zhou🇨🇳 · Jun Xu🇨🇳

    Considering that the chiral kinetic equations of motion (CEOM) can be derived from the spin kinetic equations of motion (SEOM) for massless particles with approximations, we simulate the chiral anomalies by using the latter in a box system with the periodic boundary condition under a uniform external magnetic field. We found that the chiral magnetic effect is weaker while the damping of the chiral magnetic wave is stronger from the SEOM compared with that from the CEOM. In addition, effects induced by chiral anomalies from the SEOM are less sensitive to the decay of the magnetic field than from the CEOM due to the spin relaxation process.

    ↳ nucl-thhep-phPLB(2019)·15 citations
14. 14*

    Hydrodynamics with spin --- recent developments

    Wojciech Florkowski🇵🇱

    Recent theoretical developments in hydrodynamics of particles with spin 1/2 are briefly reviewed.

    ↳ nucl-thhep-phActa Phys.Polon.B(2019)·2 citations
15. 15*

    Reliable estimation of the radius of convergence in finite density QCD

    Matteo Giordano🇭🇺 · Attila Pásztor🇭🇺

    We study different estimators of the radius of convergence of the Taylor series of the pressure in finite density QCD. We adopt the approach in which the radius of convergence is estimated first in a finite volume, and the infinite-volume limit is taken later. This requires an estimator for the radius of convergence that is reliable in a finite volume. Based on general arguments about the analytic structure of the partition function in a finite volume, we demonstrate that the ratio estimator cannot work in this approach, and propose three new estimators, capable of extracting reliably the radius of convergence, which coincides with the distance from the origin of the closest Lee-Yang zero. We also provide an estimator for the phase of the closest Lee-Yang zero, necessary to assess whether the leading singularity is a true critical point. We demonstrate the usage of these estimators on a toy model, namely 4 flavors of unimproved staggered fermions on a small $6^3\times 4$ lattice, where both the radius of convergence and the Taylor coefficients to any order can be obtained by a direct determination of the Lee-Yang zeros. Interestingly, while the relative statistical error of the Taylor expansion coefficients steadily grows with order, that of our estimators stabilizes, allowing for an accurate estimate of the radius of convergence. In particular, we show that despite the more than 100\% error bars on high-order Taylor coefficients, the given ensemble contains enough information about the radius of convergence.

    ↳ hep-latcond-mat.stat-mechhep-phnucl-thPRD(2019)·48 citations
16. 16*

    Implications from GW170817 for $\Delta$-isobar admixed hypernuclear compact stars

    Jia Jie Li (ITP, Frankfurt)🇩🇪 · Armen Sedrakian (FIAS)🇩🇪

    The effects of $\Delta$ isobars on the equation of state of dense matter and structure of compact stars (CSs) are explored within the covariant density functional theory and confronted with the data on tidal deformability (TD) extracted from the GW170817 event. We show that the presence of $\Delta$ isobars substantially softens the tension between the predictions of the hypernuclear density functionals and the inference from the observations of relatively small radius and small TD of canonical mass CSs. The TDs deduced from GW170817 are compatible with the existence of hypernuclear CSs containing an admixture of $\Delta$ isobars. We thus argue that the GW170817 event is consistent with a merger of a binary CS system having both strangeness (hyperons) and $\Delta$ isobars in the stellar core.

    ↳ nucl-thastro-ph.HEhep-phApJL(2019)·89 citations
17. 17*

    Lattice QCD form factor for $B_s\to D_s^{\ast }l\nu$ at zero recoil with non-perturbative current renormalisation

    E. McLean🇬🇧 · C. T. H. Davies🇬🇧 · A. T. Lytle🇮🇹 · J. Koponen🇯🇵

    We present details of a lattice QCD calculation of the $B_s\to D_s^{\ast }$ axial form factor at zero recoil using the Highly Improved Staggered Quark (HISQ) formalism on the second generation MILC gluon ensembles that include up, down, strange and charm quarks in the sea. Using the HISQ action for all valence quarks means that the lattice axial vector current that couples to the $W$ can be renormalized fully non-perturbatively, giving a result free of the perturbative matching errors that previous lattice QCD calculations have had. We calculate correlation functions at three values of the lattice spacing, and multiple `$b$'-quark masses, for physical $c$ and $s$. The functional dependence on the $b$-quark mass can be determined and compared to Heavy Quark Effective Theory expectations, and a result for the form factor obtained at the physical value of the $b$-quark mass. We find ${\mathcal{F}}^{B_s\to D_s^{\ast }}(1)=h_{A_1}^s(1)=0.9020(96{)}_{\text{stat}}(90{)}_{\text{sys}}$. This is in agreement with earlier lattice QCD results, which use NRQCD $b$ quarks, with a total uncertainty reduced by more than a factor of two. We discuss implications of this result for the $B\to D^{\ast }$ axial form factor at zero recoil and for determinations of $V_{cb}$.

    ↳ hep-lathep-phPRD(2019)·63 citations
18. 18*

    Mechanism of heating the Solar Corona in the splitting of Massive Photon Pairs

    I.K.Mirzoeva🇷🇺 · S.G.Chefranov🇷🇺

    Data obtained in the framework of the INTERBALL-Tail Probe (1995-2000) and RHESSI (from 2002 to the present) projects have revealed variations in the X-ray intensity of the solar corona in the photon energy range of 2-15 keV during the period of the quiet Sun. Previously, a hypothesis was proposed that this phenomenon could be associated with the effect of coronal heating. In the present study, a new mechanism of coronal plasma heating is proposed on the basis of the experimental data and the quantum theory of photon pairs that are produced from vacuum in the course of the Universe's expansion. A similar mechanism based on the splitting of photon pairs in the interplanetary and intergalactic space is also proposed to explain the observed microwave background radiation.

    ↳ astro-ph.HEastro-ph.SRhep-ph0 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.