Wed·May 24, 2023Wednesday·May 24, 2023

1. 01*

   Systematics of yields of strange hadrons from heavy-ion collisions around threshold energies

   K. Piasecki🇵🇱 · P. Piotrowski🇵🇱

   The parametrizations of experimental yields of K${}^{\pm ,0}$, $\varphi$ and $\Lambda +{\Sigma }^0$ are proposed as function of available energy, $\sqrt{s_{\mathrm{NN}}}$, and number of participants, $⟨A_{\mathrm{part}}{⟩}_{\mathrm{b}}$, for $\sqrt{s_{\mathrm{NN}}}$ from 2.15 to 3 GeV. For all the dataset the $⟨A_{\mathrm{part}}{⟩}_{\mathrm{b}}$ was extracted using the Glauber Monte Carlo method. The $\alpha$ exponent of yield dependency on $⟨A_{\mathrm{part}}{⟩}_{\mathrm{b}}$ appears not to change with beam energy and is found to be 1.30 $\pm$ 0.02. Our parametrization and the predictions of public versions of RQMD.RMF, SMASH and UrQMD transport models are compared to the HADES experimental data for Ar+KCl at $\sqrt{s_{\mathrm{NN}}}$ of 2.61 GeV. The phenomenological parametrization currently offers the best overall description of these yields. Predictions are given for yields from Ag+Ag collisions at available energies of 2.41 and 2.55 GeV, analysed by HADES, Au+Au experiment at 2.16 and 2.24 GeV planned by this collaboration, some unpublished yields for STAR's Au+Au collisions at 3 GeV, and for Au+Au collisions planned by CBM, up to 3.85 GeV.

   nucl-exEPJA(2023)·6 citations
2. 02*

   Electromagnetic form factors for nucleons in short-range correlations

   Wanli Xing🇦🇺 · Xuan-Gong Wang🇦🇺 · Anthony W. Thomas🇦🇺

   Recent experimental studies have led to the suggestion that short-range correlations may be a major contributor to the nuclear EMC effect. This hypothesis requires that the structure function for nucleons involved in short-range correlations should be heavily suppressed compared to that of a free nucleon. Based on calculations performed within an AdS/QCD motivated, light-front quark-diquark model, we find that this large suppression of the nucleon structure function leads to a strong suppression of the nucleon elastic form factors.

   ↳ hep-phhep-exnucl-exnucl-thPLB(2023)·8 citations
3. 03*

   First measurements with a new $\beta$-electron detector for spectral shape studies

   V. Guadilla🇫🇷 · A. Algora🇪🇸 · M. Estienne🇫🇷 · M. Fallot🇫🇷 · W. Gelletly🇬🇧 · A. Porta🇫🇷 · L.-M. Rigalleau🇫🇷 · J.-S. Stutzmann🇫🇷

   The shape of the electron spectrum emitted in $\beta$ decay carries a wealth of information about nuclear structure and fundamental physics. In spite of that, few dedicated measurements have been made of $\beta$-spectrum shapes. In this work we present a newly developed detector for $\beta$ electrons based on a telescope concept. A thick plastic scintillator is employed in coincidence with a thin silicon detector. The first measurements employing this detector have been carried out with mono-energetic electrons from the high-energy resolution electron-beam spectrometer at Bordeaux. Here we report on the good reproduction of the experimental spectra of mono-energetic electrons using Monte Carlo simulations. This is a crucial step for future experiments, where a detailed Monte Carlo characterization of the detector is needed to determine the shape of the $\beta$-electron spectra by deconvolution of the measured spectra with the response function of the detector. A chamber to contain two telescope assemblies has been designed for future $\beta$-decay experiments at the Ion Guide Isotope Separator On-Line facility in Jyväskylä, aimed at improving our understanding of reactor antineutrino spectra.

   ↳ physics.ins-detnucl-exJINST(2024)·8 citations
4. 04*

   Nonlocal optical potential in the inelastic deuteron scattering off ${}^{24}$Mg

   A. Deltuva🇱🇹 · D. Jurčiukonis🇱🇹

   Nonlocal nucleon-nucleus optical potential with rotational quadrupole deformation enabling the excitation of the ${}^{24}\mathrm{Mg}(2^{+})$ state is developed; it fits well the proton-${}^{24}\mathrm{Mg}$ elastic and inelastic differential cross section in the beam energy range from 30 to 45 MeV per nucleon. The inelastic deuteron-${}^{24}\mathrm{Mg}$ scattering leading to the excited ${}^{24}\mathrm{Mg}(2^{+})$ state is studied in the same energy regime by solving the three-body Faddeev-type equations for transition operators. Effects of the optical potential nonlocality are evaluated by comparison with local models. Significant effects on the inelastic differential cross section are found at forward angles up to the first peak and at larger angles beyond the second peak. Nonlocal optical potential provides a simultaneous reasonable reproduction of the experimental data for the elastic and inelastic proton-${}^{24}\mathrm{Mg}$ and deuteron-${}^{24}\mathrm{Mg}$ scattering, not achieved using local potentials.

   ↳ nucl-thnucl-exPRC(2023)·5 citations
5. 05*

   Effect of nuclear structure on particle production in relativistic heavy-ion collisions using the AMPT model

   P. Sinha🇮🇳 · V. Bairathi🇨🇱 · K. Gopal🇮🇳 · C. Jena🇮🇳 · S. Kabana🇨🇱

   We report first study of transverse momentum ($p_{\mathrm{T}}$) spectra for ${\pi }^{\pm }$, $K^{\pm }$, $p$, and $\bar{p}$ in isobar, ${}_{44}^{96}$Ru+${}_{44}^{96}$Ru and ${}_{40}^{96}$Zr+${}_{40}^{96}$Zr, collisions at $\sqrt{s_{\mathrm{NN}}}=200$ GeV using a multi-phase transport (AMPT) model. Particle yields ($dN/dy$), average transverse momenta ($⟨p_{\mathrm{T}}⟩$), and particle ratios are reported in various collision systems with different parameterizations of the Woods-Saxon (WS) distribution. We observed a maximum difference of 5% in the particle yields in peripheral collisions when we included a quadrupole and octupole deformation and a nuclear size difference between the isobars. The ${\pi }^{-}$/${\pi }^{+}$ ratio is smaller in Ru+Ru collisions compared to Zr+Zr collisions indicating an effect of isospin due to difference in number of protons and neutrons between the two nuclei. The $K^{-}$/$K^{+}$ ratio is same in both the systems indicating the dominance of the pair production mechanism in the kaon production. The $\bar{p}/p$ ratio is further smaller in Ru+Ru collisions than Zr+Zr collisions, indicating the effect of baryon stopping in addition to the isospin effect. A system size dependence is observed in $dN/dy$ and $⟨p_{\mathrm{T}}⟩$ when we compare the results from isobar collisions with Au+Au and U+U collisions.

   ↳ hep-phhep-exnucl-exPRC(2023)·13 citations
6. 06*

   Advancing the IAV Model with CDCC Wave Functions for Realistic Descriptions of Two-Body Projectile Breakup

   Jin Lei🇨🇳 · Antonio M. Moro🇪🇸

   Inclusive breakup is an important reaction mechanism of reactions induced by weakly bound nuclei. The Ichimura, Austern, and Vincent (IAV) model is widely used to analyze inclusive breakup processes and is based on a Distorted Wave Born Approximation (DWBA). However, the validity of the DWBA form for inclusive breakup requires further exploration. In this study, we present a derivation of the IAV model, using the continuum-discretized coupled-channels (CDCC) wave function, and apply it to the $d{+}^{93}$Nb reaction. We examine the differences between the CDCC-IAV and DWBA-IAV models by artificially modifying the binding energy of the deuteron using two distinct types of optical potential. Our findings indicate that the CDCC method potentially provides a more fundamental description of the $d$+$A$ interaction and may provide a more realistic description of the interior part of the wave function. This study offers significant potential in increasing the precision and dependability of weakly bound nuclei inclusive breakup process estimation within a fully quantum mechanical model.

   ↳ nucl-thnucl-exPRC(2023)·14 citations
7. 07*

   Vector quarkonia at the LHC with JETHAD: A high-energy viewpoint

   Francesco Giovanni Celiberto🇪🇸

   In this review we discuss and extend the study of the inclusive production of vector quarkonia, $J/\psi$ and ${\rm Y}$, emitted with large transverse momenta and rapidities at the LHC. We adopt the novel ZCW19${}^{+}$ determination to depict the quarkonium production mechanism at the next-to-leading level of perturbative QCD. This approach is based on the nonrelativistic QCD formalism well adapted to describe the production of a quarkonium state from the collinear fragmentation of a gluon or a constituent heavy quark at the lowest energy scale. We rely upon the NLL/NLO${}^{+}$ hybrid high-energy and collinear factorization for differential cross sections, where the standard collinear formalism is enhanced by the BFKL resummation of next-to-leading energy logarithms arising in the $t$-channel. We employ the JETHAD method to analyze the behavior of rapidity distributions for double inclusive vector-quarkonium and inclusive vector-quarkonium plus jet emissions. We discovered that the natural stability of the high-energy series, previously observed in observables sensitive to the emission of hadrons with heavy flavor detected in the rapidity acceptance of LHC barrel calorimeters, becomes even more manifest when these particles are tagged in forward regions covered by endcaps. Our findings brace the important message that vector quarkonia at the LHC via the hybrid factorization offer a unique chance to perform precision studies of high-energy QCD, as well as an intriguing opportunity to shed light on the quarkonium production puzzle.

   ↳ hep-phhep-exnucl-exnucl-thUniverse(2023)·35 citations
8. 08*

   Unraveling the nature of the novel ${\mathbf{T}}_{\mathbf{cs}}$ and ${\mathbf{T}}_{\mathbf{c}\bar{\mathbf{s}}}$ tetraquark candidates

   P.G. Ortega🇪🇸 · D.R. Entem🇪🇸 · F. Fernandez🇪🇸 · J. Segovia🇪🇸

   Using proton-proton collisions at centre-of-mass energies $7$, $8$, and $13$ TeV, with a total integrated luminosity of $9{\text{fb}}^{-1}$, the LHCb collaboration has performed amplitude analyses of the $B^{+}\to D^{+}{D}^{-}{K}^{+}$, $B^{+}\to D^{-}{D}_s^{+}{\pi }^{+}$ and $B^0\to {\bar{D}}^0{D}_s^{+}{\pi }^{-}$ decays, observing that new $T_{cs}$ and $T_{c\bar{s}}$ resonances are required in order to explain the experimental data. These signals could be the first observation of tetraquark candidates that do not contain a heavy quark-antiquark pair; in fact, they consist of four different flavours of quarks, one of which is a doubly charged open-charm state. We present herein an analysis of the $T_{cs}$ and $T_{c\bar{s}}$ states, which is an extension of our recently published study of similar $T_{cc}^{+}$ exotic candidates. Our theoretical framework is a constituent-quark-model-based coupled-channels calculation of $q{q}^{\prime }\bar{s}\bar{c}$ and $cq\bar{s}{\bar{q}}^{\prime }$ tetraquark sectors for $T_{cs}$ and $T_{c\bar{s}}$ structures, respectively. We explore the nature, and pole position, of the singularities that appear in the scattering matrix with spin-parity quantum numbers: $J^P=0^{\pm }$, $1^{\mp }$, and $2^{\pm }$. The constituent quark model has been widely used in the heavy quark sector, and thus all model parameters are already constrained from previous works. This makes our predictions robust and parameter-free. We find many singularities in the solution of various scattering-matrix problems which are either virtual states or resonances, but not bound states. Some of them fit well with the experimental observations of the spin-parity, mass and width of $T_{cs}$ and $T_{c\bar{s}}$ candidates, and thus tentative assignments are made; however, with caution, because the experimental Breit-Wigner parameters are related to the pole characteristics.

   ↳ hep-phhep-exhep-latnucl-ex+1PRD(2023)·30 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.