Tue·Jul 16, 2024Tuesday·July 16, 2024

1. 01*

   Coherent J/$\psi$ photoproduction and polarization in peripheral Pb-Pb collisions with ALICE

   L. Massacrier (for the ALICE Collaboration)🇫🇷

   Photonuclear reactions are induced by the strong electromagnetic field generated by ultrarelativistic heavy ions. These processes have been extensively studied in ultraperipheral collisions. In recent years, the observation of coherent J/$\psi$ photoproduction has been claimed in nucleus-nucleus (A-A) collisions with nuclear overlap, based on the measurement of an excess in the very low transverse momentum ($p_{\mathrm{T}}$) J/$\psi$ yield. Such quarkonium measurements can help constraining the nuclear gluon distribution at low Bjorken-$x$ and can shed light on the theory behind photon induced reactions in A-A collisions with nuclear overlap. In order to confirm the photoproduction origin of the very low-$p_{\mathrm{T}}$ J/$\psi$ yield excess, polarization measurement is a golden observable. It is indeed expected that the produced quarkonium would keep the polarization of the incoming photon due to $s$-channel helicity conservation. ALICE can measure inclusive and exclusive quarkonium production down to zero transverse momentum, at forward rapidity (2.5 $<y<$ 4) and midrapidity ($|y|<$ 0.9). In this contribution, we will report on the new preliminary measurement of the $y$-differential cross section and the first polarization analysis at LHC of coherently photoproduced J/$\psi$ in peripheral Pb-Pb collisions. Both measurements are conducted at forward rapidity in the dimuon decay channel.

   nucl-exhep-ex6 citations
2. 02*

   Decay study of ${}^{11}$Be with an Optical TPC detector

   N. Sokołowska🇵🇱 · V. Guadilla🇵🇱 · C. Mazzocchi🇵🇱 · R. Ahmed🇵🇰 · M. Borge🇪🇸 · G. Cardella🇮🇹 · A.A. Ciemny🇵🇱 · L.G. Cosentino🇮🇹 · E. De Filippo🇮🇹 · V. Fedosseev🇨🇭 · A. Fijałkowska🇵🇱 · L.M. Fraile🇪🇸 and 27 other authors

   The $\beta$ decay of one-neutron halo nucleus ${}^{11}$Be was investigated using the Warsaw Optical Time Projection Chamber (OTPC) detector to measure $\beta$-delayed charged particles. The results of two experiments are reported. In the first one, carried out in LNS Catania, the absolute branching ratio for $\beta$-delayed $\alpha$ emission was measured by counting incoming ${}^{11}$Be ions stopped in the detector and the observed decays with the emission of $\alpha$ particle. The result of 3.27(46)\% is in good agreement with the literature value. In the second experiment, performed at the HIE-ISOLDE facility at CERN, bunches containing several hundreds of ${}^{11}$Be ions were implanted into the OTPC detector followed by the detection of decays with the emission of charged particles. The energy spectrum of $\beta$-delayed $\alpha$ particles was determined in the full energy range. It was analysed in the R-matrix framework and was found to be consistent with the literature. The best description of the spectrum was obtained assuming that the two $3/2^{+}$ and one $1/2^{+}$ states in ${}^{11}$B are involved in the transition. The search for $\beta$-delayed emission of protons was undertaken. Only the upper limit for the branching ratio for this process of $(2.2\pm 0.6_{\mathrm{stat}}\pm 0.6_{\mathrm{sys}})\times 10^{-6}$ could be determined. This value is in conflict with the result published in [Ayyad et al. Phys. Rev. Lett. 123, 082501 (2019)] but does agree with the limit reported in [Riisager et al., Eur. Phys. J. A (2020) 56:100]

   nucl-exPRC(2024)·5 citations
3. 03*

   Strangeness Production in $\sqrt{s_{\mathrm{NN}}}=3$ GeV Au+Au Collisions at RHIC

   The STAR Collaboration

   We report multi-differential measurements of strange hadron production ranging from mid- to target-rapidity in Au+Au collisions at a center-of-momentum energy per nucleon pair of $\sqrt{s_{\mathrm{NN}}}=3$ GeV with the STAR experiment at RHIC. $K_S^0$ meson and $\Lambda$ hyperon yields are measured via their weak decay channels. Collision centrality and rapidity dependences of the transverse momentum spectra and particle ratios are presented. Particle mass and centrality dependence of the average transverse momenta of $\Lambda$ and $K_S^0$ are compared with other strange particles, providing evidence of the development of hadronic rescattering in such collisions. The 4$\pi$ yields of each of these strange hadrons show a consistent centrality dependence. Discussions on radial flow, the strange hadron production mechanism, and properties of the medium created in such collisions are presented together with results from hadronic transport and thermal model calculations.

   nucl-exnucl-thJHEP(2024)·33 citations
4. 04*

   Charge radii of ${}^{11-16}$C, ${}^{13-17}$N and ${}^{15-18}$O determined from their charge-changing cross-sections and the mirror-difference charge radii

   J.W. Zhao🇩🇪 · B.-H. Sun🇨🇳 · I. Tanihata🇯🇵 · J.Y. Xu🇨🇳 · K.Y. Zhang🇨🇳 · A. Prochazka · L.H. Zhu · S. Terashima · J. Meng🇨🇳 · L.C. He · C.Y. Liu · G.S. Li🇨🇳 and 15 other authors

   Charge-changing cross-sections of ${}^{11-16}$C, ${}^{13-17}$N and ${}^{15-18}$O on a carbon target have been determined at energies around 300 MeV/nucleon. A nucleon separation energy-dependent correction factor has been introduced to the Glauber model calculation for extracting the nuclear charge radii from the experimental CCCSs. The charge radii of ${}^{11}$C, ${}^{13,16}$N and ${}^{15}$O thus were determined for the first time. With the new radii, we studied the experimental mirror-difference charge radii ($\Delta R_{\text{ch}}^{\text{mirror}}$) of ${}^{11}$B-${}^{11}$C, ${}^{13}$C-${}^{13}$N, ${}^{15}$N-${}^{15}$O, ${}^{17}$N-${}^{17}$Ne pairs for the first time. We find that the $\Delta R_{\text{ch}}^{\text{mirror}}$ values of ${}^{13}$C-${}^{13}$N and ${}^{15}$N-${}^{15}$O pairs follow well the empirical relation to the isospin asymmetry predicted by the $ab$ $initio$ calculations, while $\Delta R_{\text{ch}}^{\text{mirror}}$ of ${}^{11}$B-${}^{11}$C and ${}^{17}$N-${}^{17}$Ne pairs deviate from such relation by more than two standard deviations.

   nucl-exnucl-thPLB(2024)·26 citations
5. 05*

   Rapidity dependence of antideuteron coalescence in pp collisions at $\sqrt{s}$ = 13 TeV with ALICE

   ALICE Collaboration

   The production yields of antideuterons and antiprotons are measured in pp collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV, as a function of transverse momentum ($p_{\mathrm{T}}$) and rapidity ($y$), for the first time rapidity-differentially up to $|y|=0.7$. The measured spectra are used to study the $p_{\mathrm{T}}$ and rapidity dependence of the coalescence parameter $B_2$, which quantifies the coalescence probability of antideuterons. The $p_{\mathrm{T}}$ and rapidity dependence of the obtained $B_2$ is extrapolated for $p_{\mathrm{T}}>1.7$ GeV/$c$ and $|y|>0.7$ using the phenomenological antideuteron production model implemented in PYTHIA 8.3 as well as a baryon coalescence afterburner model based on EPOS 3. Such measurements are of interest to the astrophysics community, since they can be used for the calculation of the flux of antinuclei from cosmic rays, in combination with coalescence models.

   nucl-exhep-exPLB(2025)·5 citations
6. 06*

   Measurement of beauty production via non-prompt charm hadrons in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

   ALICE Collaboration

   The production cross sections of ${\mathrm{D}}^0$, ${\mathrm{D}}^{+}$, and ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$ hadrons originating from beauty-hadron decays (i.e. non-prompt) were measured for the first time at midrapidity in proton$-$lead (p$-$Pb) collisions at the center-of-mass energy per nucleon pair of $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. Nuclear modification factors ($R_{\mathrm{pPb}}$) of non-prompt ${\mathrm{D}}^0$, ${\mathrm{D}}^{+}$, and ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}$ are calculated as a function of the transverse momentum ($p_{\mathrm{T}}$) to investigate the modification of the momentum spectra measured in p$-$Pb collisions with respect to those measured in proton$-$proton (pp) collisions at the same energy. The $R_{\mathrm{pPb}}$ measurements are compatible with unity and with the measurements in the prompt charm sector, and do not show a significant $p_{\mathrm{T}}$ dependence. The $p_{\mathrm{T}}$-integrated cross sections and $p_{\mathrm{T}}$-integrated $R_{\mathrm{pPb}}$ of non-prompt ${\mathrm{D}}^0$ and ${\mathrm{D}}^{+}$ mesons are also computed by extrapolating the visible cross sections down to $p_{\mathrm{T}}$ = 0. The non-prompt D-meson $R_{\mathrm{pPb}}$ integrated over $p_{\mathrm{T}}$ is compatible with unity and with model calculations implementing modification of the parton distribution functions of nucleons bound in nuclei with respect to free nucleons. The non-prompt ${\mathrm{\Lambda }}_{\mathrm{c}}^{+}/{\mathrm{D}}^0$ and ${\mathrm{D}}^{+}/{\mathrm{D}}^0$ production ratios are computed to investigate hadronisation mechanisms of beauty quarks into mesons and baryons. The measured ratios as a function of $p_{\mathrm{T}}$ display a similar trend to that measured for charm hadrons in the same collision system.

   nucl-exhep-exJHEP(2024)·8 citations
7. 07*

   Supernova Pointing Capabilities of DUNE

   DUNE Collaboration: A. Abed Abud · B. Abi · R. Acciarri · M. A. Acero · M. R. Adames · G. Adamov · M. Adamowski · D. Adams · M. Adinolfi · C. Adriano · A. Aduszkiewicz · J. Aguilar and 1352 other authors

   The determination of the direction of a stellar core collapse via its neutrino emission is crucial for the identification of the progenitor for a multimessenger follow-up. A highly effective method of reconstructing supernova directions within the Deep Underground Neutrino Experiment (DUNE) is introduced. The supernova neutrino pointing resolution is studied by simulating and reconstructing electron-neutrino charged-current absorption on 40Ar and elastic scattering of neutrinos on electrons. Procedures to reconstruct individual interactions, including a newly developed technique called ``brems flipping'', as well as the burst direction from an ensemble of interactions are described. Performance of the burst direction reconstruction is evaluated for supernovae happening at a distance of 10 kpc for a specific supernova burst flux model. The pointing resolution is found to be 3.4 degrees at 68% coverage for a perfect interaction-channel classification and a fiducial mass of 40 kton, and 6.6 degrees for a 10 kton fiducial mass respectively. Assuming a 4% rate of charged-current interactions being misidentified as elastic scattering, DUNE's burst pointing resolution is found to be 4.3 degrees (8.7 degrees) at 68% coverage.

   ↳ hep-exastro-ph.HEastro-ph.IMastro-ph.SR+2PRD(2025)·29 citations
8. 08*

   Solar neutrino capture by 128, 130Te isotopes and Baksan Large Neutrino Telescope Project

   A. N. Fazliakhmetov🇷🇺 · Yu. S. Lutostansky🇷🇺 · B. K. Lubsandorzhiev🇷🇺 · G. A. Koroteev🇷🇺 · V. N. Tikhonov🇷🇺

   This paper discusses the charge-exchange strength functions $S(E)$ of the isotopes ${}^{128,130}$Te. The experimental data of the $S(E)$ strength functions obtained from ${(}^3\mathrm{He},t)$ reactions, as well as the $S(E)$ strength functions calculated in the microscopic theory of finite fermi-systems, are analyzed. The resonance structure of the strength function $S(E)$ is examined, and the Gamow-Teller and Pygmy resonances are identified. The resonance structure of the strength function $S(E)$ is vital for the calculation and analysis of the process of neutrino capture by atomic nuclei.

   ↳ nucl-thnucl-ex0 citations
9. 09*

   Global analysis of nuclear parton distribution functions

   M. Klasen🇩🇪

   We review the theoretical foundations, methodological approaches and current status of the determination of nuclear parton distribution functions (PDFs). A large variety of measurements in fixed-target and collider experiments provide increasingly precise constraints on various aspects of nuclear PDFs, including shadowing, antishadowing, the EMC effect, Fermi motion, flavour separation, deuteron binding, target-mass and other higher-twist effects. We give particular emphasis to measurements carried out in proton-lead collisions at the Large Hadron Collider, which have revolutionised the global analysis during the past decade. These measurements include electroweak boson, isolated photon, single inclusive hadron, jet, and heavy-flavour observables.

   ↳ hep-phhep-exnucl-exnucl-thPoS(2025)·2 citations
10. 10*

    First Indication of Solar ${}^8$B Neutrino Flux through Coherent Elastic Neutrino-Nucleus Scattering in PandaX-4T

    PandaX Collaboration: Zihao Bo🇨🇳 · Wei Chen🇨🇳 · Xun Chen🇨🇳 · Yunhua Chen🇨🇳 · Zhaokan Cheng🇨🇳 · Xiangyi Cui🇨🇳 · Yingjie Fan🇨🇳 · Deqing Fang🇨🇳 · Zhixing Gao🇨🇳 · Lisheng Geng🇨🇳 · Karl Giboni🇨🇳 · Xunan Guo🇨🇳 and 89 other authors

    The PandaX-4T liquid xenon detector at the China Jinping Underground Laboratory is used to measure the solar ${}^8$B neutrino flux by detecting neutrinos through coherent scattering with xenon nuclei. Data samples requiring the coincidence of scintillation and ionization signals (paired), as well as unpaired ionization-only signals (US2), are selected with energy threshold of approximately 1.1 keV (0.33 keV) nuclear recoil energy. Combining the commissioning run and the first science run of PandaX-4T, a total exposure of 1.20 and 1.04 tonne$\cdot$year are collected for the paired and US2, respectively. After unblinding, 3 and 332 events are observed with an expectation of 2.8$\pm$0.5 and 251$\pm$32 background events, for the paired and US2 data, respectively. A combined analysis yields a best-fit ${}^8$B neutrino signal of 3.5 (75) events from the paired (US2) data sample, with $\sim$37\% uncertainty, and the background-only hypothesis is disfavored at 2.64$\sigma$ significance. This gives a solar ${}^8$B neutrino flux of ($8.4\pm 3.1$)$\times$10${}^6$ cm${}^{-2}$s${}^{-1}$, consistent with the standard solar model prediction. It is also the first indication of solar ${}^8$B neutrino ``fog'' in a dark matter direct detection experiment.

    ↳ hep-exastro-ph.SRnucl-exPRL(2024)·194 citations
11. 11*

    A Nuclear Interferometer for Ultra-Light Dark Matter Detection

    Hannah Banks🇬🇧 · Elina Fuchs🇩🇪 · Matthew McCullough🇨🇭

    We propose the nuclear interferometer - a single-photon interferometry experiment based upon the thorium-229 nuclear clock transition - as a novel detector for ultra-light dark matter. Thanks to the enhanced sensitivity of this transition to the variation of fundamental constants, we find that possible realisations of such an experiment deploying either single ions or clouds of atoms have the potential to complement advanced very-long-baseline terrestrial clock atom interferometers in the search for ultra-light dark matter with scalar couplings to photons in the future. Nuclear interferometry may also offer an unparalleled window to new physics coupling to the QCD sector via quarks or gluons, with a discovery reach that could enhance existing and proposed experiments over a range of frequencies in the direction of well-motivated parameter space.

    ↳ hep-phhep-exnucl-exphysics.atom-phPRD(2026)·6 citations
12. 12*

    Spin correlation in two-proton emission from ${}^6$Be

    Tomohiro Oishi🇯🇵

    This paper presents a theoretical evaluation of spin correlation in the two-proton ($2p$) radioactive emission. The three-body model of ${}^6$Be with the proton-proton interaction, which is adjusted to reproduce the experimental energy release, is utilized. Time-dependent calculation is performed to compute the coupled-spin state of the emitted two protons. The spin-correlation function $S$ as the Clauser-Horne-Shimony-Holt (CHSH) indicator is evaluated as $|S|\cong 2.65$. Namely, the $2p$-spin correlation beyond the limit of local-hidden-variable (LHV) theory is suggested. This correlation is sensitive to the proton-proton interaction. The short-lived (broad-width) $2p$~state has the weaker spin correlation. In parallel, the core-proton interactions do not harm this correlation during the time-dependent decaying process. The CHSH measurement can be a novel probe into the effective nuclear interaction inside finite systems. Two-proton emitters can provide a testing field for identical-particle entanglement.

    ↳ nucl-thnucl-exquant-phPLB(2025)·3 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.