Tue·Aug 2, 2022Tuesday·August 2, 2022

1. 01*

   Pion, kaon, and (anti-)proton production in U+U Collisions at $\sqrt{s_{NN}}$ = 193 GeV measured with the STAR detector

   STAR Collaboration: M. S. Abdallah🇪🇬 · B. E. Aboona🇺🇸 · J. Adam🇺🇸 · J. R. Adams🇺🇸 · J. K. Adkins🇺🇸 · G. Agakishiev🇷🇺 · I. Aggarwal🇮🇳 · M. M. Aggarwal🇮🇳 · Z. Ahammed🇮🇳 · A. Aitbaev🇷🇺 · I. Alekseev🇷🇺 · D. M. Anderson🇺🇸 and 342 other authors

   We present the first measurements of transverse momentum spectra of ${\pi }^{\pm }$, $K^{\pm }$, $p(\bar{p})$ at midrapidity ($|y|<0.1$) in U+U collisions at $\sqrt{s_{NN}}$ = 193 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The centrality dependence of particle yields, average transverse momenta, particle ratios and kinetic freeze-out parameters are discussed. The results are compared with the published results from Au+Au collisions at $\sqrt{s_{NN}}=$ 200 GeV in STAR. The results are also compared to those from A Multi Phase Transport (AMPT) model.

   nucl-exhep-exhep-phnucl-thPRC(2023)·18 citations
2. 02*

   GTMDs and the factorization of exclusive double Drell-Yan

   Miguel G. Echevarria🇪🇸 · Patricia A. Gutierrez Garcia🇪🇸 · Ignazio Scimemi🇪🇸

   Different exclusive processes have been proposed to access the generalized transverse momentum dependent distributions (GTMDs) with no proof of factorization, which allows to rigorously define the GTMDs. Using Soft Collinear Effective Theory we derive for the first time the factorization of the differential cross section for the exclusive double Drell-Yan process for the exclusive double Drell-Yan process pion N to N' gamma* gamma* to N' (l^+l^-)(l^+l^-), for small transverse momenta of the photons in terms of a perturbatively calculable hard factor, GTMDs and light-cone wave functions (LCWFs). We find that the hard factor of the process can be obtained from single inclusive Drell-Yan production so that one can resum logarithms at high orders in QCD. We also discuss the evolution of the GTMDs and the LCWFs.

   ↳ hep-phhep-exhep-latnucl-ex+1PLB(2023)·15 citations
3. 03*

   Light baryon resonances from a coupled-channel study including $\mathbf{K\Sigma }$ photoproduction

   Deborah Rönchen🇩🇪 · Michael Döring🇺🇸 · Ulf-G. Meißner🇩🇪 · Chao-Wei Shen🇩🇪

   The Jülich-Bonn dynamical coupled-channel approach is extended to include $K\Sigma$ photoproduction off the proton. Differential cross section and (double) polarization data for $K^{+}{\Sigma }^0$ and $K^0{\Sigma }^{+}$ are analysed simultaneously with the pion- and photon-induced production of $\pi N$, $\eta N$, $K\Lambda$, and $K\Sigma$ final states, totaling more than 67,000 data points for center-of-mass energies $W<2.4$ GeV. Based on the fit results the spectrum of $N^{\ast }$ and $\Delta$ resonances is extracted in terms of pole positions and residues. We discuss the impact of the $\gamma p\to K\Sigma$ channels in detail and investigate the influence of recent polarization data for $\eta p$ photoproduction.

   ↳ nucl-thhep-phnucl-exEPJA(2022)·55 citations
4. 04*

   Impact of Symmetry Energy on Sound Speed and Spinodal Decomposition in Dense Neutron-Rich Matter

   Nai-Bo Zhang🇨🇳 · Bao-An Li🇺🇸

   Using a meta model for nuclear Equation of State (EOS) with its parameters constrained by astrophysical observations and terrestrial nuclear experiments, we examine effects of nuclear EOS especially its symmetry energy \esym term on the speed of sound squared $C_s^2(\rho )$ and the critical density ${\rho }_t$ where $C_s^2({\rho }_t)$ vanishes (indicating the onset of spinodal decomposition) in both dense neutron-rich nucleonic matter relevant for relativistic heavy-ion collisions and the cold $n+p+e+\mu$ matter in neutron stars at $\beta$-equilibrium. Unlike in nucleonic matter with fixed values of the isospin asymmetry $\delta$, in neutron stars with a density dependent isospin profile $\delta (\rho )$ determined consistently by the $\beta$ equilibrium and charge neutrality conditions, the $C_s^2(\rho )$ almost always show a peak and then vanishes at ${\rho }_t$. The latter strongly depends on the high-density behavior of \esym if the skewness parameter $J_0$ characterizing the stiffness of high-density symmetric nuclear matter (SNM) EOS is not too far above its currently known most probable value of about $-190$ MeV inferred from recent Bayesian analyses of neutron star observables. Moreover, in the case of having a super-soft \esym that is decreasing with increasing density above about twice the saturation density of nuclear matter, the ${\rho }_t$ is significantly lower than the density where the \esym vanishes (indicating the onset of isospin-separation instability and pure neutron matter formation) in neutron star cores.

   ↳ nucl-thastro-ph.HEhep-phnucl-exEPJA(2023)·30 citations
5. 05*

   Effect of global momentum conservation on longitudinal flow decorrelation

   Pingal Dasgupta🇨🇳 · Han-Sheng Wang🇨🇳 · Guo-Liang Ma🇨🇳

   We calculate the longitudinal flow decorrelation coefficients, i.e., $r_n(\eta ,{\eta }_r)$ for $n=2,3$, in the presence of hydro-like flow and the global momentum conservation (GMC) constraint. The longitudinal flow decorrelation is weakened due to the GMC constraint. The GMC effect is sensitive to the total number of particles involved in GMC, the average longitudinal momentum, the transverse momentum, and the reference pseudorapidity. Our results of the $r_2(\eta ,{\eta }_{rA})/r_2(\eta ,{\eta }_{rB})$ ratio between two reference pseudorapidity bins are consistent with the experimental measurements. We predict that the modification effect of GMC on longitudinal flow decorrelation is more noticeable at BNL Relativistic Heavy Ion Collider energies than at CERN Large Hadron Collider energies. Our finding provides a new perspective for understanding the longitudinal flow decorrelation in relativistic heavy-ion collisions.

   ↳ nucl-thhep-phnucl-exPRC(2023)·4 citations
6. 06*

   A New Structure in the Deuteron

   Misak M. Sargsian🇺🇸 · Frank Vera🇺🇸

   We demonstrate that a paradigm shift from considering the deuteron as a system of bound proton and neutron to considering it as a pseudo-vector system in which we observe proton and neutron, results in a possibility of probing a new "incomplete" P-state like structure on the light-front (LF), at extremely large internal momenta, which can be achieved in high energy transfer electro-disintegration of the deuteron. Investigating the deuteron on the light-front, where the vacuum-fluctuations are suppressed, we found that this new structure, together with conventional S- and D- states, is a leading order in transferred energy of the reaction, thus it is not suppressed on the light-front.The incompleteness of the observed P-state results in a violation of angular condition which can happen only if deuteron contains non-nucleonic structures such as $\Delta$$\Delta$, $N^{\ast }N$ or hidden color components. We demonstrate that experimentally verifiable signatures of "incomplete" P-states are angular anisotropy of LF momentum distribution of the nucleon in the deuteron as well as an enhancement of the tensor polarization strength beyond the S- and D- wave predictions at large internal momenta in the deuteron.

   ↳ nucl-thhep-phnucl-exPRL(2023)·14 citations
7. 07*

   Electroweak production of ${\chi }_{Q1}$ states in $e^{+}{e}^{-}$ collisions: A brief review

   N.N. Achasov🇷🇺 · A.V. Kiselev🇷🇺 · G.N. Shestakov🇷🇺

   A brief review of the available experimental and theoretical results on the production of the ${\chi }_{Q1}$ states in $e^{+}{e}^{-}$ annihilation and photon-photon $\gamma {\gamma }^{\ast }$ interactions is presented. Future data on the production of the ${\chi }_{c1}(1P)$, ${\chi }_{c1}(3872)$, ${\chi }_{c1}(4140)$, ${\chi }_{c1}(4274)$, ${\chi }_{c1}(4685)$, ${\chi }_{b1}(1P)$, ${\chi }_{b1}(2P)$, and ${\chi }_{b1}(3P)$ resonances in $e^{+}{e}^{-}$ annihilation and $\gamma {\gamma }^{\ast }$ interactions will help the development and unification of theoretical predictions related to the electroweak decays of heavy quarkonia, the reduction of their spread and model uncertainties.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2022)·10 citations
8. 08*

   Ab-initio no-core shell model study of ${}^{18-24}$Ne isotopes

   Chandan Sarma🇮🇳 · Praveen C. Srivastava🇮🇳

   We report \textit{ab initio} no-core shell model (NCSM) study of ${}^{18-24}$Ne isotopes for energy spectra, electromagnetic properties, and point-proton radii using three realistic $NN$ interactions. We have used inside nonlocal outside Yukawa (INOY), charge-dependent Bonn 2000 (CDB2K) and the chiral next-to-next-to-next-to-leading order (N${}^3$LO) interactions. We are able to reach basis size up to $N_{max}$ = 6 for ${}^{18}$Ne and $N_{max}$ = 4 for the ${}^{19-24}$Ne isotopes with m-scheme dimensions up to 1.0 $\times$ $10^9$ in case of ${}^{24}$Ne. We observed better results for INOY interaction in terms of the binding energies of ground state (g.s.), and overall all three interactions provide good agreement with the experimental low-energy spectra. Our results for reduced $M1$ transition strengths and magnetic moments are close to the experimental values. We found that for long-range observables such as the $E2$ transition strengths, the electric quadrupole moments, and the point-proton radii ($r_p$), we need higher $N_{max}$ calculations to obtain results comparable to the experimental data. We have observed almost 6 \% increment in the converged $r_p$ as we increase the model space from $N_{max}$ = 4 to $N_{max}$ = 6.

   ↳ nucl-thnucl-exJ.Phys.G(2023)·14 citations
9. 09*

   Multi-hadron molecules: status and prospect

   Tian-Wei Wu🇨🇳 · Ya-Wen Pan🇨🇳 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳

   Starting from 2003, the discovery of a large amount of the so-called exotic hadronic states, i.e., the $XYZ$ states, the pentaquark states as well as the tetraquark states, have not only revived studies of hadron spectroscopy, but also hinted at the existence of new multi-hadron states made of hadrons other than nucleons and hyperons. We briefly comment on some of the latest studies on multi-hadron molecules in the light and heavy flavor sectors and highlight what should be done in the future.

   ↳ hep-phhep-exhep-latnucl-ex+1Sci.Bull.(2022)·30 citations
10. 10*

    Multi-scale evolution of charmed particles in a nuclear medium

    JETSCAPE collaboration: W. Fan🇺🇸 · G. Vujanovic🇺🇸 · S. A. Bass🇺🇸 · A. Majumder🇺🇸 · A. Angerami🇺🇸 · R. Arora🇺🇸 · S. Cao🇺🇸 · Y. Chen🇺🇸 · T. Dai🇺🇸 · L. Du🇨🇦 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 and 47 other authors

    Parton energy-momentum exchange with the quark gluon plasma (QGP) is a multi-scale problem. In this work, we calculate the interaction of charm quarks with the QGP within the higher twist formalism at high virtuality and high energy using the MATTER model, while the low virtuality and high energy portion is treated via a (linearized) Boltzmann Transport (LBT) formalism. Coherence effect that reduces the medium-induced emission rate in the MATTER model is also taken into account. The interplay between these two formalisms is studied in detail and used to produce a good description of the D-meson and charged hadron nuclear modification factor RAA across multiple centralities. All calculations were carried out utilizing the JETSCAPE framework.

    ↳ nucl-thhep-phnucl-exPRC(2023)·28 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.