Tue·Dec 27, 2022Tuesday·December 27, 2022

1. 01*

   Azimuthal anisotropy of jet particles in p-Pb and Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

   ALICE Collaboration

   The azimuthal anisotropy of particles associated with jets (jet particles) at midrapidity is measured for the first time in p-Pb and Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV down to transverse momentum ($p_{\mathrm{T}}$) of 0.5 GeV/$c$ and 2 GeV/$c$, respectively, with ALICE. The results obtained in p-Pb collisions are based on a novel three-particle correlation technique. The azimuthal anisotropy coefficient $v_2$ in high-multiplicity p-Pb collisions is positive, with a significance reaching 6.8$\sigma$ at low $p_{\mathrm{T}}$, and its magnitude is smaller than in semicentral Pb-Pb collisions. In contrast to the measurements in Pb-Pb collisions, the $v_2$ coefficient is also found independent of $p_{\mathrm{T}}$ within uncertainties. Comparisons with the inclusive charged-particle $v_2$ and with AMPT calculations are discussed. The predictions suggest that parton interactions play an important role in generating a non-zero jet-particle $v_2$ in p-Pb collisions, even though they overestimate the reported measurement. These observations shed new insights on the understanding of the origin of the collective behaviour of jet particles in small systems such as p-Pb collisions, and provide significant stringent new constraints to models.

   nucl-exhep-exJHEP(2024)·17 citations
2. 02*

   Collective flow of light nuclei and hyper-nuclei in Au+Au collisions at $\sqrt{s_{NN}}$ = 3, 14.6, 19.6, 27, and 54.4 GeV using the STAR detector

   Rishabh Sharma🇮🇳

   Light nuclei and hyper-nuclei are produced in abundance in heavy-ion collisions. The production mechanism of these species in heavy-ion collisions still remains to be understood. In these proceedings, we report the transverse momentum and centrality dependence of elliptic flow ($v_2$) of $d$, $t$, and ${}^3\text{He}$ in Au+Au collisions at $\sqrt{s_{NN}}$ = 14.6, 19.6, 27, and 54.4 GeV. Mass number scaling of $v_2(p_T)$ of light nuclei is shown. We also report the first observation of hyper-nuclei ${}_{\Lambda }^3$H and ${}_{\Lambda }^4$H directed flow ($v_1$) in $\sqrt{s_{NN}}$ = 3 GeV mid-central (5-40\%) Au+Au collisions in the fixed target mode.

   nucl-exhep-exhep-phnucl-thEPJ Web Conf.(2023)·2 citations
3. 03*

   Indication of a p-$\varphi$ bound state from a correlation function analysis

   Emma Chizzali🇨🇭 · Yuki Kamiya🇩🇪 · Raffaele Del Grande🇩🇪 · Takumi Doi🇯🇵 · Laura Fabbietti🇩🇪 · Tetsuo Hatsuda🇯🇵 · Yan Lyu🇨🇳

   The existence of a nucleon-$\varphi$ (N-$\varphi$) bound state has been subject of theoretical and experimental investigations for decades. In this letter, indication of a \pphi bound state is found, using for the first time two-particle correlation functions as alternative to invariant mass spectra. Newly available lattice calculations for the spin 3/2 \Nphi interaction by the HAL QCD collaboration are used to constrain the spin 1/2 counterpart from the fit of the experimental \pphi correlation function measured by ALICE. The corresponding scattering length and effective range are $f_0^{(1/2)}=\left(-1.54_{-0.53}^{+0.53}(stat.{)}_{-0.09}^{+0.16}(syst.)+i\cdot 0.00_{-0.00}^{+0.35}(stat.{)}_{-0.00}^{+0.16}(syst.)\right)$~fm and $d_0^{(1/2)}=\left(0.39_{-0.09}^{+0.09}(stat.{)}_{-0.03}^{+0.02}(syst.)+i\cdot 0.00_{-0.04}^{+0.00}(stat.{)}_{-0.02}^{+0.00}(syst.)\right)$~fm, respectively. The results imply the appearance of a \pphi bound state with an estimated binding energy in the range of $12.8-56.1$ MeV.

   nucl-exhep-latPLB(2024)·44 citations
4. 04*

   Unbound states in 17C and p-sd shell-model interactions

   Sunji Kim🇰🇷 · Jongwon Hwang🇰🇷 · Yoshiteru Satou🇰🇷 · Nigel A. Orr🇫🇷 · Takashi Nakamura🇯🇵 · Yosuke Kondo🇯🇵 · Julien Gibelin🇫🇷 · Nadia Lynda Achouri🇫🇷 · Thomas Aumann🇩🇪 · Hidetada Baba🇯🇵 · Franck Delaunay🇫🇷 · Pieter Doornenbal🇯🇵 and 33 other authors

   Unbound states in 17C were investigated via one-neutron removal from a 18C beam at an energy of 245 MeV/nucleon on a carbon target. The energy spectrum of 17C, above the single-neutron decay threshold, was reconstructed using invariant mass spectroscopy from the measured momenta of the 16C fragment and neutron, and was found to exhibit resonances at Er=0.52(2), 0.77(2), 1.36(1), 1.91(1), 2.22(3) and 3.20(1) MeV. The resonance at Er=0.77(2) MeV [Ex=1.51(3) MeV] was provisionally assigned as the second 5/2+ state. The two resonances at Er=1.91(1) and 3.20(1) MeV [Ex=2.65(2) and 3.94(2) MeV] were identified, through comparison of the energies, cross sections and momentum distributions with shell-model and eikonal reaction calculations, as p-shell hole states with spin-parities 1/2- and 3/2-, respectively. A detailed comparison was made with the results obtained using a range of shell-model interactions. The YSOX shell-model Hamiltonian, the cross-shell part of which is based on the monopole-based universal interaction, was found to provide a very good description of the present results and those for the neighbouring odd-A carbon isotopes - in particular for the negative parity cross-shell states.

   nucl-exnucl-thPLB(2023)·5 citations
5. 05*

   Elliptic flow of strange and multi-strange hadrons in isobar collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV at RHIC

   Priyanshi Sinha🇮🇳

   We report the elliptic flow ($v_2$) of $K_s^0$, $\Lambda$, $\bar{\Lambda }$, $\varphi$, ${\Xi }^{-}$, and ${\overline{\Xi }}^{+}$ at mid-rapidity for Ru+Ru and Zr+Zr collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV. The transverse momentum ($p_T$) and centrality dependence of $v_2$ have been studied. The number of constituent quark (NCQ) scaling for all the (multi-)strange hadrons has also been tested. The dependence in the ratio of average $v_2$ ($⟨$$v_2$$⟩$) on centrality shows a deviation from unity indicating a difference in nuclear structure and deformation between the isobars. The results show a systematic size dependence when compared to Cu+Cu, Au+Au, and U+U collisions at similar beam energies.

   nucl-exhep-exEPJ Web Conf.(2023)·2 citations
6. 06*

   Unpolarized proton PDF at NNLO from lattice QCD with physical quark masses

   Xiang Gao🇺🇸 · Andrew D. Hanlon🇺🇸 · Jack Holligan🇺🇸 · Nikhil Karthik🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Sergey Syritsyn🇺🇸 · Yong Zhao🇺🇸

   We present a lattice QCD calculation of the unpolarized isovector quark parton distribution function (PDF) of the proton utilizing a perturbative matching at next-to-next-to-leading-order (NNLO). The calculations are carried out using a single ensemble of gauge configurations generated with $N_f=2+1$ highly-improved staggered quarks with physical masses and a lattice spacing of $a=0.076$ fm. We use one iteration of hypercubic smearing on these gauge configurations, and the resulting smeared configurations are then used for all aspects of the subsequent calculation. For the valence quarks, we use the Wilson-clover action with physical quark masses. We consider several methods for extracting information on the PDF. We first extract the lowest four Mellin moments using the leading-twist operator product expansion approximation. Then, we determine the $x$ dependence of the PDF through a deep neural network within the pseudo-PDF approach and additionally through the framework of large-momentum effective theory utilizing a hybrid renormalization scheme. This is the first application of the NNLO matching coefficients for the nucleon directly at the physical point.

   ↳ hep-lathep-exhep-phnucl-ex+1PRD(2023)·57 citations
7. 07*

   Developing a single phase liquid argon detector with SiPM readout

   L. Wang · Y. Lei · T.A. Wang · C. Guo · K.K. Zhao · X.H. Liang · S.B. Wang · Y.D. Chen

   Liquid argon is used as a target material in several current and planned experiments related to dark matter direct searching and neutrino detection. SiPM is becoming the standard for scintillator detectors because of its advantages over traditional PMT. In this paper, we developed a single-phase liquid argon detector using eight 1 $\times$1 inch${}^2$ Hamamatsu S14161-6050HS 4$\times$4 SiPM arrays. The directly measured light yield is 25.7 $\pm$ 1.6 photo-electrons per keV, which corresponds to 12.8 $\pm$ 0.8 photo-electrons primarily generated by the argon scintillation. The rest is contributed by the cross-talk and after-pulse of SiPM. In addition, we provide an experimental method to estimate the effect of crosstalk and afterpulse on light yield using dark noise data. Finally, we quantitatively give the relationship between the light yield and the decay time of the slow component of a liquid argon detector.

   ↳ physics.ins-detnucl-exEur.Phys.J.Plus(2023)·4 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.