Nuclear Theory·nucl-th

Friday·February 28, 2020

11 papers—5 primary·6 cross-listed

06
Scalar spectrum in a graviton soft wall model
Matteo Rinaldi🇮🇹 · Vicente Vento🇪🇸
In this study we present a unified phenomenological analysis of the scalar glueball and scalar meson spectra within an AdS/QCD framework in the bottom up approach. For this purpose we generalize the recently developed graviton soft-wall (GSW) model, which has shown an excellent agreement with the lattice QCD glueball spectrum, to a description of glueballs and mesons with a unique energy scale. In this scheme, dilatonic effects, are incorporated in the metric as a deformation of the AdS space. We apply the model also to the heavy meson spectra with success. We obtain quadratic mass equations for all scalar mesons while the glueballs satisfy an almost linear mass equation. Besides their spectra, we also discuss the mixing of scalar glueball and light scalar meson states within a unified framework: the GSW model. To this aim, the light-front holographic approach, which connects the mode functions of AdS/QCD to the light-front wave functions, is applied. This relation provides the probabilistic interpretation required to properly investigate the mixing conditions.
↳ hep-phnucl-thJ.Phys.G(2020)·20 citations
07
Shear transport far from equilibrium via holography
Michael F. Wondrak🇩🇪 · Matthias Kaminski🇺🇸 · Marcus Bleicher🇩🇪
In heavy-ion collisions, the quark-gluon plasma is produced far from equilibrium. This regime is currently inaccessible by quantum chromodynamics (QCD) computations. We calculate shear transport and entropy far from equilibrium in a holographic model, defining a time-dependent ratio of shear viscosity to entropy density, $η / s$ . Large deviations of up to 60% from its near-equilibrium value, $1/4 π$ , are found for realistic situations at the Large Hadron Collider. We predict the far-from-equilibrium time-dependence of $η / s$ to substantially affect the evolution of the QCD plasma and to impact the extraction of QCD properties from flow coefficients in heavy-ion collision data.
↳ hep-phhep-thnucl-thPLB(2020)·20 citations
08
Long-range collectivity in small collision-systems with two- and four-particle correlations @ STAR
Roy A. Lacey (for the STAR Collaboration)🇺🇸
New STAR differential and integral v{2,3} measurements that explicitly account for non-flow contributions are reported for p/d/3He+Au, collisions at Roots=200 GeV. The measurements, which leverage the two-particle correlators for p/d/3He+Au and minimum-bias p+p collisions in tandem with three well-established methods of non-flow subtraction, are observed to be method-independent. For comparable multiplicities, they further indicate system-independent v2{2} and v3{2} values that are consistent with the critical role of both size (N{ch}) and the subnucleonic-fluctuations-driven eccentricities e{2,3} but are inconsistent with the notion of shape engineering in p/d/3He+Au collisions. The scaling function derived from the measurements, confirm the important role of final-state effects across a broad spectrum of collision-system sizes and energies and suggests an increase in eta/s(T,muB) for small collision-systems.
↳ nucl-exhep-exhep-phnucl-thNPA(2021)·14 citations
09
New developments in lattice QCD on equilibrium physics and phase diagram
Heng-Tong Ding🇨🇳
I review recent new lattice QCD results on a few selected topics which are relevant to the heavy ion physics community. Special emphasis is put on the QCD phase diagram towards the chiral limit and at nonzero baryon density as well as the fate of quarkonia and heavy quark drag coefficients.
↳ hep-lathep-phnucl-exnucl-thNPA(2021)·38 citations
10
Pole analysis on the hadron spectroscopy of $Λ_{b} \to J /Ψ p K^{-}$
Shi-Qing Kuang🇨🇳 · Ling-Yun Dai🇨🇳 · Xian-Wei Kang🇨🇳 · De-Liang Yao🇨🇳
In this paper we study the $J /Ψ p$ spectroscopy in the process of $Λ_{b} \to J /Ψ p K^{-}$ . The final state interactions of coupled channel $J /Ψ p$ ~-~ $D ˉ Σ_{c}$ ~-~ $D ˉ^{*} Σ_{c}$ are constructed based on K-matrix with the Chew-Mandelstam function. We build the $Λ_{b} \to J /Ψ p K^{-}$ amplitude according to the Au-Morgan-Pennington method. The event shape is fitted and the decay width of $Λ_{b} \to J /Ψ p K^{-}$ is used to constrain the parameters, too. With the amplitudes we extract out the poles and their residues. Our amplitude and pole analysis suggest that the $P_{c} (4312)$ should be $D ˉ Σ_{c}$ molecule, the $P_{c} (4440)$ could be an S-wave compact pentaquark state, and the structure around $P_{c} (4457)$ is caused by the cusp effect. The future experimental measurement of the decays of $Λ_{b} \to D ˉ Σ_{c} K^{-}$ and $Λ_{b} \to D ˉ^{*} Σ_{c} K^{-}$ would further help to study the nature of these resonances.
↳ hep-phnucl-thEPJC(2020)·42 citations
11
Probing Nucleons and Nuclei in High Energy Collisions
Christine A. Aidala · Elke Aschenauer · Fatma Aslan · Alessandro Bacchetta · Ian Balitsky · Sanjin Benic · Shohini Bhattacharya · Mariaelena Boglione · Matthias Burkardt · Justin Cammarota · Giovanni A. Chirilli · Christopher Cocuzza and 78 other authors
This volume is a collection of contributions for the 7-week program "Probing Nucleons and Nuclei in High Energy Collisions" that was held at the Institute for Nuclear Theory in Seattle, WA, USA, from October 1 until November 16, 2018. The program was dedicated to the physics of the Electron Ion Collider (EIC), the world's first polarized electron-nucleon (ep) and electron-nucleus (eA) collider to be constructed in the USA. These proceedings are organized by chapters, corresponding to the weeks of the program: Week I, Generalized parton distributions; Week II, Transverse spin and TMDs; Week III, Longitudinal spin; Week IV, Symposium week; Weeks V & VI, eA collisions; Week VII, pA and AA collisions. We hope these proceedings will be useful to readers as a compilation of EIC-related science at the end of the second decade of the XXI century.
↳ hep-phhep-exnucl-exnucl-th90 citations

Affiliations

first authorsco-authorsvia INSPIRE

Scalar spectrum in a graviton soft wall model

Shear transport far from equilibrium via holography

Long-range collectivity in small collision-systems with two- and four-particle correlations @ STAR

New developments in lattice QCD on equilibrium physics and phase diagram

Pole analysis on the hadron spectroscopy of Λb​→J/ΨpK−

Probing Nucleons and Nuclei in High Energy Collisions

Affiliations

Pole analysis on the hadron spectroscopy of $Λ_{b} \to J /Ψ p K^{-}$