Fri·Jul 28, 2023Friday·July 28, 2023

1. 01*

   Possible formation of Quark-Gluon Plasma in small collision systems at the Large Hadron Collider: Observations and Challenges

   Raghunath Sahoo🇮🇳

   With the advent of unprecedented collision energy at the Large Hadron Collider, CERN, Geneva, a new domain of particle production and possible formation of Quark-Gluon Plasma (QGP) in high-multiplicity proton-proton collisions and the collisions of light nuclei has been a much-discussed topic recently. In this review, I discuss some of the recent observations leading to such a possibility, associated challenges, and some predictions for the upcoming light-nuclei collisions at the LHC.

   ↳ hep-phhep-exnucl-exnucl-thSpringer Proc.Phys.(2024)·2 citations
2. 02*

   Reexamining charm versus bottom quark energy loss inside a color-deconfined medium

   Yichao Dang🇨🇳 · Wen-Jing Xing🇨🇳 · Shanshan Cao🇨🇳 · Guang-You Qin🇨🇳

   The general intuition that heavier partons suffer weaker energy loss inside a quark-gluon plasma (QGP) medium is critically re-examined. Within a linear Boltzmann transport model that includes both Yukawa and string types of interactions between heavy quarks and the QGP, we find that while the radiative energy loss is suppressed by the parton mass, heavier partons can experience stronger string potential scatterings with the medium. Their competition may result in less energy loss of bottom quarks than charm quarks at low transverse momentum ($p_{\mathrm{T}}$) but an inverse order at high $p_{\mathrm{T}}$. Our model calculation shows a weaker nuclear modification on bottom particles than charm particles at low $p_{\mathrm{T}}$, as observed by both RHIC and LHC experiments, but predicts an opposite hierarchy at high $p_{\mathrm{T}}$. A larger momentum space transport coefficient ($\hat{q}$) and a smaller spatial diffusion coefficient ($D_{\mathrm{s}}$) are found for bottom quarks than for charm quarks.

   ↳ nucl-thhep-phnucl-exPRC(2024)·9 citations
3. 03*

   Triaxial projected shell model approach for negative parity states in even-even nuclei

   Nazira Nazir · S. Jehangir🇮🇳 · S.P. Rouoof · G.H. Bhat🇮🇳 · J.A. Sheikh🇮🇳 · N. Rather · Manzoor A. Malik

   The triaxial projected shell model (TPSM) approach is generalized to investigate the negative parity band structures in even-even systems. In the earlier version of the TPSM approach, the quasiparticle excitations were restricted to one major oscillator shell and it was possible to study only positive parity states in even-even systems. In the present extension, the excited quasiparticles are allowed to occupy two major oscillator shells, which makes it possible to generate the negative parity states. As a major application of this development, the extended approach is applied to elucidate the negative parity high-spin band structures in ${}^{102-112}$Ru and it is shown that energies obtained with neutron excitation are slightly lower than the energies calculated with proton excitation. However, the calculated aligned angular momentum ($i_x$) clearly separates the two spectra with neutron $i_x$ in reasonable agreement with the empirically evaluated $i_x$ from the experimental data, whereas proton $i_x$ shows large deviations. Furthermore, we have also deduced the transition quadrupole moments from the TPSM wavefunctions along the negative-parity yrast- and yrare- bands and it is shown that these quantities exhibit rapid changes in the bandcrossing region.

   ↳ nucl-thnucl-exPRC(2023)·9 citations
4. 04*

   Test of ${}^{116}$CdWO${}_4$ and Li${}_2$MoO${}_4$ scintillating bolometers in the CROSS underground facility with upgraded detector suspension

   A. Ahmine🇫🇷 · I.C. Bandac🇪🇸 · A.S. Barabash🇷🇺 · V. Berest🇫🇷 · L. Bergé🇫🇷 · J.M. Calvo-Mozota🇪🇸 · P. Carniti🇮🇹 · M. Chapellier🇫🇷 · I. Dafinei🇮🇹 · F.A. Danevich🇺🇦 · T. Dixon🇫🇷 · L. Dumoulin🇫🇷 and 29 other authors

   In preparation to the CROSS $2\beta$ decay experiment, we installed a new detector suspension with magnetic dumping inside a pulse-tube cryostat of a dedicated low-background facility at the LSC (Spain). The suspension was tested with two scintillating bolometers based on large-volume 116CdWO4 (CWO-enr) and Li2MoO4 (LMO) crystals. The former, a reference device, was used for testing new noise conditions and for comparing bolometric performance of an advanced Li2MoO4 crystal developed in the framework of the CLYMENE project, in view of next-generation double-beta decay experiments like CUPID. We cooled down detectors to 15 mK and achieved high performance for all tested devices. In particular both CWO-enr and LMO bolometers demonstrated the energy resolution of 6 keV FWHM for the 2.6 MeV gamma quanta, among the best for thermal detectors based on such compounds. The baseline noise resolution (FWHM) of the CWO-enr detector was improved by 2 keV, compared to the best previous measurement of this detector in the CROSS facility, while the noise of the Ge-based optical bolometer was improved by a factor 2, to 100 eV FWHM. Despite of the evident progress in the improving of noise conditions of the set-up, we see high-frequency harmonics of a pulse-tube induced noise, suggesting a noise pick-up by cabling. Another Ge light detector was assisted with the signal amplification exploiting the Neganov-Trofimov-Luke effect, which allowed to reach 20 eV FWHM noise resolution by applying 60 V electrode bias. Highly-efficient particle identification was achieved with both detectors, despite a low scintillation efficiency of the LMO material. The radiopurity level of the LMO crystal is rather high; only traces of 210Po and 226Ra were detected (0.1 mBq/kg each), while the 228Th activity is expected to be at least an order of magnitude lower, as well as a 40K activity is found to be < 6 mBq/kg.

   ↳ physics.ins-detnucl-exJINST(2023)·9 citations
5. 05*

   Confronting axial-vector form factor from lattice QCD with MINERvA antineutrino-proton data

   Oleksandr Tomalak🇺🇸 · Rajan Gupta🇺🇸 · Tanmoy Bhattacharya🇺🇸

   We compare recent MINERvA antineutrino-hydrogen charged-current measurements to phenomenological predictions of the axial-vector form factor based on fits to all available electron scattering and deuterium bubble-chamber data and to representative lattice-QCD (LQCD) determination by the PNDME Collaboration. While there is $1$--$2\sigma$ agreement in the cross section with MINERvA data for each bin in $Q^2$, we identify three regions with different relevance and opportunity for LQCD predictions. For $Q^2\lesssim 0.2{\mathrm{GeV}}^2$, the phenomenological extractions have large number of data points and LQCD is competitive, while MINERvA data have large errors. For $0.2{\mathrm{GeV}}^2\lesssim Q^2\lesssim 1{\mathrm{GeV}}^2$, LQCD is competitive with the MINERvA determination, and both give values larger than from phenomenological extraction. For $Q^2>1{\mathrm{GeV}}^2$, the MINERvA data are the most precise. Our analysis indicates that with improving precision of MINERvA-like experiments and LQCD data, the uncertainty in the nucleon axial-vector form factor will be steadily reduced.

   ↳ hep-lathep-exhep-phnucl-ex+1PRD(2023)·27 citations
6. 06*

   Seeing Beauty in the Quark-Gluon Plasma with Energy Correlators

   Carlota Andres🇫🇷 · Fabio Dominguez🇪🇸 · Jack Holguin🇫🇷 · Cyrille Marquet🇫🇷 · Ian Moult🇺🇸

   Heavy quarks created in heavy-ion collisions serve as an excellent probe of the produced quark-gluon plasma (QGP). The radiation pattern of jets formed from heavy quarks as they traverse the QGP exhibits a particularly interesting structure due to the interplay of two competing effects: the suppression of small-angle radiation, also known as the ``dead-cone'' effect, and the enhancement of emitted gluons by medium-induced radiation. In this Letter, we propose a new observable, based on the energy correlator approach to jet substructure, which will allow us to disentangle the two scales associated to these two phenomena and to determine under which conditions the dead-cone is filled by medium-induced radiation. Combined with the forthcoming high-statistics measurements of heavy-flavor jets, this work provides a novel tool to unravel the dynamics of the QGP.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2024)·60 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.