Tue·Apr 1, 2025Tuesday·April 1, 2025

1. 01*

   Bayesian and Monte Carlo approaches to estimating uncertainty for the measurement of the bound-state $\beta$ decay of ${}^{205}{\mathrm{Tl}}^{81+}$

   G. Leckenby🇨🇦 · M. Trassinelli🇫🇷 · R. J. Chen🇩🇪 · R. S. Sidhu🇩🇪 · J. Glorius🇩🇪 · M. S. Sanjari🇩🇪 · Yu. A. Litvinov🇩🇪 · M. Bai🇩🇪 · F. Bosch🇩🇪 · C. Brandau🇩🇪 · T. Dickel🇩🇪 · I. Dillmann🇨🇦 and 38 other authors

   The measurement of the bound-state $\beta$ decay of ${}^{205}{\mathrm{Tl}}^{81+}$ at the Experimental Storage Ring at GSI, Darmstadt, has recently been reported with substantial impact on the use of ${}^{205}\mathrm{Pb}$ as an early Solar System chronometer and the low-energy measurement of the solar neutrino spectrum via the LOREX project. Due to the technical challenges in producing a high-purity ${}^{205}{\mathrm{Tl}}^{81+}$ secondary beam, a robust statistical method needed to be developed to estimate the variation in the contaminant ${}^{205}{\mathrm{Pb}}^{81+}$ produced in the fragmentation reaction, which was subsequently transmitted and stored in the ESR. Here we show that Bayesian and Monte Carlo methods produced comparable estimates for the contaminant variation, each with unique advantages and challenges given the complex statistical problems for this experiment. We recommend the adoption of such methods in future experiments that exhibit unknown statistical fluctuations.

   nucl-exCPC(2025)·1 citation
2. 02*

   To examine the variation in dissipation near the shell closure using neutron multiplicity as a probe

   Punit Dubey · Mahima Upadhyay · Mahesh Choudhary · Namrata Singh · Shweta Singh🇩🇪 · N. Saneesh🇮🇳 · Mohit Kumar · Rishabh Prajapati · K. S. Golda🇮🇳 · Akhil Jhingan🇮🇳 · P. Sugathan🇮🇳 · Jhilam Sadhukhan and 3 other authors

   The pre and post-scission neutron multiplicities have been determined for the fission of the compound nucleus (CN) 206Rn, induced by the reaction 28Si+178Hf within the excitation energy interval of 61.0-90.0 MeV. We intentionally formed CN 206 Rn, which is below the shell closure CN, to examine the variation in N/Z with total neutron multiplicity, as data for other CNs of 208,210,212,214,216Rn have already been published in the literature. We identified a new trend in the N/Z ratio, where the total neutron multiplicity initially decreases as we approach the shell closure of the compound nucleus and then starts to increase as we move away from the shell closure. Furthermore, we have observed that below the neutron shell closure, the dissipation in compound nuclei (CN) escalates with rising excitation energy, remains stable at the shell closure CN, and thereafter diminishes with increasing excitation energy above the shell closure CN.

   nucl-ex0 citations
3. 03*

   Measurement of Kaon Directed Flow in Au+Au Collisions in the High Baryon Density Region

   STAR Collaboration: B. E. Aboona · J. Adam · G. Agakishiev · I. Aggarwal · M. M. Aggarwal · Z. Ahammed · A. Aitbayev · I. Alekseev · E. Alpatov · A. K. Alshammri · A. Aparin · S. Aslam and 375 other authors

   Rapidity-odd directed flow $v_1$ measurements are presented for $K^{\pm }$ and $K_S^0$ in Au$+$Au collisions at $\sqrt{s_{\text{NN}}}$ = 3.0, 3.2, 3.5, and 3.9 GeV with the STAR experiment. For comparison, $v_1$ of ${\pi }^{\pm }$, protons, and $\Lambda$ from the same collisions are also discussed. The mid-rapidity $v_1$ slope $\text{d}{v}_1/\text{d}y{|}_{y=0}$ for protons and $\Lambda$ is positive in these collisions. On the other hand, $v_1$ slope of kaons exhibits a strong $p_{\text{T}}$ dependence: negative at $p_{\text{T}}<$ 0.6 GeV/$c$ and positive at higher $p_{\text{T}}$. A similar $p_{\text{T}}$ dependence is also evident for the $v_1$ slope of charged pions. Compared to the spectator-removed calculations in Au$+$Au collisions at $\sqrt{s_{\text{NN}}}=$ 3.0-3.9 GeV, the JAM model demonstrates a pronounced shift of the $v_1$ slopes of mesons towards the negative direction. It suggests that the shadowing effect of the spectators plays an important role in the observed kaon anti-flow at low $p_{\text{T}}$ in the high baryon density region of non-central collisions.

   nucl-exPLB(2026)·9 citations
4. 04*

   Universality of Shell Effects in Fusion-Fission Mass Distributions

   J. Buete · B. M. A. Swinton-Bland · D. J. Hinde · K. J. Cook🇺🇸 · M. Dasgupta · A. C. Berriman · D. Y. Jeung · K. Banerjee🇮🇳 · L. T. Bezzina · I. P. Carter · C. Sengupta🇨🇳 · C. Simenel🇦🇺 · E. C. Simpson

   We present the results of a broad, systematic study of heavy-ion induced fission mass distributions for every even-Z compound nucleus ($Z_{\mathrm{CN}}$) from ${}^{144}$Gd to ${}^{212}$Th. We find systematic evidence of shell-driven structure in every fission mass distribution. The change in shape of the mass distributions with $Z_{\mathrm{CN}}$ is consistent with the results of quantitative simultaneous fitting in mass and total kinetic energy, demonstrating that fragment proton shell gaps at $Z_{\mathrm{FF}}=34,36$ and $Z_{\mathrm{FF}}=44,46$ are \textit{both} major drivers of fission mass distributions below the actinide region. The mass distributions show enhanced yields at mass symmetry for values of $Z_{\mathrm{CN}}$ equal to two times these favoured $Z_{\mathrm{FF}}$ values. Thus, the same shell gaps that are drivers of mass-asymmetric fission also affect mass distributions at and near mass-symmetry. For all systems a second, more mass-asymmetric, fission mode is required to fit the fission mass distributions. If driven by a single shell gap, it appears to be in the light fragment around $Z_{\mathrm{FF}}=28,30$.

   nucl-exPLB(2025)·5 citations
5. 05*

   Event-activity dependence of heavy-flavor production at the ALICE experiment

   Robert Vertesi (for the ALICE Collaboration)🇭🇺

   Heavy-flavor production at the LHC offers valuable tests of quantum-chromodynamics calculations, owing to the large masses of heavy quarks. Measurements of charm production as a function of event activity reveal new features of charm production and fragmentation, providing insights to the interplay between soft and hard processes. In addition, charm production in heavy-ion collisions addresses flavor-dependent quark transport properties in both hot and cold nuclear matter, helping to clarify the roles of coalescence and fragmentation in heavy-flavor hadron formation. This contribution summarizes recent measurements from the ALICE experiment on charm production as a function of charged-particle multiplicity in pp collisions at various energies, including the measurements of charm baryon-to-meson production yield ratios in pp, p--Pb and Pb--Pb collisions. New results on ${\mathrm{D}}^0$ production in pp collisions as a function of the transverse spherocity of the event, as well as of the transverse event-activity classifier $R_{\mathrm{T}}$, are also presented.

   nucl-exActa Phys.Polon.Supp.(2025)·0 citations
6. 06*

   European Strategy for Particle Physics 2026: the NA60+/DiCE experiment at the SPS

   NA60+/DiCE Collaboration

   The exploration of the phase diagram of Quantum ChromoDynamics (QCD) is carried out by studying ultrarelativistic heavy-ion collisions. The energy range covered by the CERN SPS ($\sqrt{s_{\mathrm{NN}}}\sim 6-17$ GeV) is ideal for the investigation of the region corresponding to finite baryochemical potential (${\mu }_{\mathrm{B}}$), and was little explored up to now. We propose in this document a new experiment, NA60+/DiCE (Dilepton and Charm Experiment), that will address several observables which are fundamental for the understanding of the phase transition from hadronic matter towards a Quark-Gluon Plasma (QGP) at finite ${\mu }_B$. In particular, we propose to study, in Pb-Pb collisions, as a function of the collision energy, the production of thermal dimuons, from which one can obtain a caloric curve of the QCD phase diagram that may be sensitive to the order of the phase transition. In addition, the measurement of a $\rho -{\mathrm{a}}_1$ mixing contribution will provide conclusive insights into the restoration of the chiral symmetry of QCD. Studies of open charm and charmonium production will also be carried out, addressing the measurement of transport properties of the QGP and the investigation of the onset of the deconfinement transition. Reference measurements with proton-nucleus collisions are an essential part of this program. The experimental set-up couples a vertex telescope based on monolithic active pixel sensors (MAPS) to a muon spectrometer with MWPC detectors. Two existing CERN dipole magnets, MEP48 and MNP33, will be used for the vertex and muon spectrometers, respectively. The continuing availability of Pb ion beams in the CERN SPS is a crucial requirement for the experimental program. After the submission of a LoI, the experiment proposal is currently in preparation and is due by mid 2025. The start of the data taking is foreseen by 2029/2030, and should last about 7 years.

   nucl-exhep-ex3 citations
7. 07*

   Experimental and theoretical research of photoneutron reactions in the 181Ta nucleus

   J.H. Khushvaktov · M.A. Demichev · D.L. Demin · S.A. Evseev · M.I. Gostkin · V.V. Kobets · D.V. Ponomarev · F.A. Rasulova · S.V. Rozov🇷🇺 · E.T. Ruziev · A.A. Solnyshkin · T.N. Tran🇺🇸 · E.A. Yakushev

   Bremsstrahlung fluxes for irradiating tantalum samples were formed by irradiating a tungsten converter with an electron beam with energy up to 130 MeV. The relative yields and flux-averaged cross-sections of multinucleon photonuclear reactions with the emission of up to 9 neutrons in 181Ta nuclei were determined. Monte Carlo simulations to study the yields of photonuclear reactions were performed using Geant4 and TALYS-2.0 codes. The obtained experimental results were compared with the available literature data and calculated results. The comparison showed that the values of the relative reaction yield and the flux-averaged cross-section coincide with the literature data, taking into account the different geometry of the experiments. The calculated results coincide with the experimental ones only for reactions with the emission of up to 5 neutrons from the nucleus.

   nucl-exCPC(2025)·0 citations
8. 08*

   Evidence for the collective nature of radial flow in Pb+Pb collisions with the ATLAS detector

   ATLAS Collaboration

   Anisotropic flow and radial flow are two key probes of the expansion dynamics and properties of the quark-gluon plasma (QGP). While anisotropic flow has been extensively studied, radial flow, which governs the system's radial expansion, has received less attention. Notably, experimental evidence for the global and collective nature of radial flow has been lacking. This Letter presents the first measurement of transverse momentum ($p_{\mathrm{T}}$) dependence of radial flow fluctuations ($v_0(p_{\mathrm{T}})$) over $0.5<p_{\mathrm{T}}<10$ GeV, using a two-particle correlation method in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. The data reveal three key features supporting the collective nature of radial flow: long-range correlation in pseudorapidity, factorization in $p_{\mathrm{T}}$, and centrality-independent shape in $p_{\mathrm{T}}$. The comparison with a hydrodynamic model demonstrates the sensitivity of $v_0(p_{\mathrm{T}})$ to bulk viscosity, a crucial transport property of the QGP. These findings establish a new, powerful tool for probing collective dynamics and properties of the QGP.

   nucl-exhep-exPRL(2026)·37 citations
9. 09*

   Half-life and precision shape measurement of 2{\nu}{\beta}{\beta} decay of ${}^{130}$Te

   D. Q. Adams · C. Alduino · K. Alfonso · F. T. Avignone III · O. Azzolini · G. Bari · F. Bellini · G. Benato · M. Beretta · M. Biassoni · A. Branca · C. Brofferio and 110 other authors

   We present a new measurement of the 2nbb half-life of 130Te (T1/2) using the first complete model of the CUORE data, based on 1038 kg yr of collected exposure. Thanks to optimized data selection, we achieve a factor of two improvement in precision, obtaining T1/2 = (9.32 +0.05 -0.04 (stat.) +0.07 -0.07 (syst.)) x10^20 yr. The signal-to-background ratio is increased by 70% compared to our previous results, enabling the first application of the improved 2nbb formalism to 130Te. Within this framework, we determine a credibility interval for the effective axial coupling in the nuclear medium as a function of nuclear matrix elements. We also extract values for the higher-order nuclear matrix element ratios: second-to-first and third-to-first. The second-to-first ratio agrees with nuclear model predictions, while the third-to-first ratio deviates from theoretical expectations. These findings provide essential tests of nuclear models and key inputs for future 0nbb searches.

   nucl-exPRL(2025)·6 citations
10. 10*

    Heavy ion physics with LHCb Upgrade II

    LHCb collaboration

    A second major LHCb detector upgrade will be installed during long shutdown 4 (LS4) of the CERN Large Hadron Collider. The new detector will provide excellent performance for studies of Quantum Chromodynamics at high temperature and density, as achieved in collisions of heavy nuclei. The high granularity of the tracking system will allow lead-lead collisions to be reconstructed across the full range of centrality at far forward rapidity for the first time. Moreover, the forward acceptance of the detector, covering the pseudorapidity region close to the beamline, and the capability to reconstruct a wide range of hadrons containing strange, charm, and beauty quarks result in unique potential to probe the medium produced in the collisions. In this document, the heavy ion physics programme that will be pursued in LHCb Upgrade II is summarised, including precision studies of the partonic structure of nuclei, probes of the conditions allowing deconfinement, and measurements of plasma properties.

    ↳ hep-exnucl-ex6 citations
11. 11*

    Bayesian method for quantifying the non-Gaussian fluctuations in low-intermediate energy heavy ion collisions

    Xinyu Wang🇨🇳 · Xiang Chen🇨🇳 · Junping Yang🇨🇳 · Ying Cui🇨🇳 · Zhuxia Li🇨🇳 · Kai Zhao🇨🇳 · Yingxun Zhang🇨🇳

    In this work, we present a model-independent method to quantify the non-Gaussian fluctuations in the observable distributions, which are assessed by the difference between the measured observable distributions and reconstructed observable distributions via the Bayesian method. Our results indicate that the strength of non-Gaussian fluctuation increases with the beam energy, and is primarily driven by non-central collision mechanisms. The experimental measurement of the strength of non-Gaussian fluctuation of the observable distributions will provide valuable insights into understanding the nonequilibrium effects in heavy ion collisions and the liquid-gas phase transition in finite nuclei.

    ↳ nucl-thhep-exhep-phnucl-exPLB(2025)·0 citations
12. 12*

    Neutrino Scattering: Connections Across Theory and Experiment

    L. Alvarez-Ruso🇪🇸 · A.M. Ankowski🇵🇱 · A. Ashkenazi🇮🇱 · J. Barrow🇺🇸 · M. Betancourt🇺🇸 · K. Borah🇺🇸 · M. Sajjad Athar🇮🇳 · E. Catano-Mur🇺🇸 · P. Coloma🇪🇸 · P. Dunne🇬🇧 · L. Doria🇩🇪 · A. Fedynitch🇹🇼 and 22 other authors

    In this document drafted by the Neutrino Scattering Theory Experiment Collaboration (NuSTEC), we provide input on the synergies between theoretical and experimental efforts that can provide critical input to the prediction accuracy needed for the forthcoming high-precision neutrino measurements. These efforts involve a wide range of energies and interaction processes, as well as target nuclei and interaction probes. The challenges discussed will be overcome only through the active support of integrated collaboration across strong and electroweak physics from both the nuclear and high energy physics communities.

    ↳ hep-exhep-thnucl-exnucl-th7 citations
13. 13*

    The effect of recoils on soft-drop-groomed observables in $\gamma$-tagged jets in a multistage approach

    Y. Tachibana🇯🇵 · C. Sirimanna🇺🇸 · A. Majumder🇺🇸 · A. Angerami🇺🇸 · R. Arora🇺🇸 · S. A. Bass🇺🇸 · Y. Chen🇺🇸 · R. Datta🇺🇸 · L. Du🇨🇦 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 · R. J. Fries🇺🇸 and 40 other authors

    We investigate medium-induced modifications to jet substructure observables that characterize hard components in central Pb-Pb collisions at $\sqrt{s_{NN}}=5.02$~TeV. Using a multistage Monte Carlo simulation of in-medium jet shower evolution, we explore flavor-dependent medium effects through simulations of inclusive and $\gamma$-tagged jets. The results show that quark jets undergo a nonmonotonic modification compared with gluon jets in observables such as the Pb-Pb to $p$-$p$ ratio of the soft drop prong angle $r_g$, the relative prong transverse momentum $k_{T,g}$, and the groomed mass $m_g$ distributions. Due to this nonmonotonic modification, $\gamma$-tagged jets, enriched in quark jets, provide surprisingly clear signals of medium-induced structural modifications, distinct from effects dominated by selection bias. Further systematic studies demonstrate that these effects are dominated by recoil medium response. This work highlights the potential of hard substructures in $\gamma$-tagged jets as powerful tools for probing the jet-medium interactions in high-energy heavy-ion collisions, in particular by enabling detailed investigations of jet-medium parton scatterings via their associated medium response. All simulations for $\gamma$-tagged jet analyses carried out in this paper used triggered events containing at least one hard photon, which highlights the utility of these observables for future Bayesian analysis.

    ↳ hep-phnucl-exnucl-thPRC(2026)·9 citations
14. 14*

    Nuclear clustering process in heavy-ion collisions : experimental constraints on the low-temperature region of the QCD phase diagram

    E. Bonnet🇫🇷 · B. Borderie🇫🇷 · R. Bougault🇫🇷 · A. Chbihi🇫🇷 · Q. Fable🇫🇷 · J.D. Frankland🇫🇷 · D. Gruyer🇫🇷 · M. La Commara🇮🇹 · A. Le Fèvre🇩🇪 · N. Le Neindre🇫🇷 · I. Lombardo🇮🇹 · J. Łukasik🇵🇱 and 3 other authors

    In this article, we study the production of Hydrogen and Helium isotopes in heavy-ion collisions in the incident energy range between 80 and 150 MeV/nucleon. We compare their inclusive multiplicities emitted in the transverse plane of the reaction with the predictions given by the thermal model. As a first step, we validate the choice of this approach to describe the experimental measurements. We also show that the transient states have to be explicitly taken into account for a good statistical description of the experimental multiplicities. From the thermodynamical parameter values obtained we complete the existing database built with the use of thermal-statistical models to reproduce particle production in the (ultra-)relativistic-energy measurements. We then proposed a new constraint on the so-called freeze-out region in the temperature (T) versus baryonic chemical potential (muB) phase diagram of the quantum chromodynamics. These new results indicate that there is a common framework to describe the hadron production and nuclear clustering processes in heavy-ion collisions.

    ↳ nucl-thhep-phnucl-exPRC(2025)·4 citations
15. 15*

    NUMEXO2: a versatile digitizer for nuclear physics

    C.Houarner🇫🇷 · A.Boujrad🇫🇷 · M.Tripon🇫🇷 · M.Bezard🇫🇷 · M.Blaizot🇫🇷 · P.Bourgault🇫🇷 · S.Coudert🇫🇷 · B.Duclos🇫🇷 · F.J.Egea🇪🇸 · G de France🇫🇷 · A.Gadea🇪🇸 · A.Lemasson🇫🇷 and 7 other authors

    NUMEXO2 is a 16 channels 14bit/200MHz digitizer and processing board initially developed for gamma-ray spectroscopy (for EXOGAM: EXOtic nuclei GAMma ray). Numexo2 has been gradually extended and improved as a general purpose digitizer to fulfill various needs in nuclear physics detection at GANIL. This was possible thanks to reprogrammable components like FPGAs and the optimization of different algorithms. The originality of this work compared to similar systems is that all numerical operations follow the digital data flow from ADCs, without any storage step of samples. Some details are given on digital processing of the signals, delivered by a large variety of detectors: HPGe, silicon strip detector, ionisation chamber, liquid and plastic scintillators read-out with photomultipliers, Multi Wire Proportional Counter and drift chamber.

    ↳ physics.ins-detnucl-exJINST(2025)·2 citations
16. 16*

    Leading qT/Q correction for Drell-Yan in TMD factorization

    Arturo Arroyo-Castro🇪🇸 · Ignazio Scimemi🇪🇸 · Alexey Vladimirov🇪🇸

    The transverse momentum dependent (TMD) factorization theorem accommodates various types of power corrections. Among them, the least studied are qT/Q corrections, which become significant at large values of transverse momentum. These corrections partially originate from higher-twist TMD distributions, which exhibit singularity at small transverse distances. We propose a decomposition that reveals this singularity explicitly, and makes the qT/Q correction manifest. As a concrete application, we consider the next-to-leading power correction for the angular distributions in Drell-Yan, and determine the leading qT/Q corrections. These corrections are significant for the angular distributions A1 and A3, in complete agreement with the data.

    ↳ hep-phhep-exhep-latnucl-ex+1JHEP(2025)·7 citations
17. 17*

    Transverse Energy--Energy Correlators at Small $x$ for Photon--Hadron Production

    Zhong-Bo Kang🇺🇸 · Robert Kao🇺🇸 · Meijian Li🇪🇸 · Jani Penttala🇺🇸

    We study the transverse energy--energy correlator (TEEC) observable in photon--hadron and photon--jet production in p+p and p+A collisions at small $x$. We derive the relevant expressions in the high-energy limit of the scattering where the dipole picture is applicable and show how the dependence on the fragmentation function of the hadron cancels due to the momentum-sum rule. The nonperturbative scattering with the target nucleus is expressed in terms of the dipole amplitude, which also describes nonlinear gluon saturation effects. The TEEC observable is computed in the RHIC and LHC kinematics, and we show that it can be sensitive to the dipole amplitude, making it a potentially good observable for studying saturation effects.

    ↳ hep-phhep-exnucl-exnucl-thPRD(2025)·9 citations
18. 18*

    Open quantum system approach to inclusive jet production in heavy-ion collisions

    Yacine Mehtar-Tani🇺🇸 · Felix Ringer🇺🇸 · Balbeer Singh🇺🇸 · Varun Vaidya🇺🇸

    We derive a factorization formula for inclusive jet production in heavy-ion collisions using the tools of Effective Field Theory (EFT). We show how physics at widely separated scales in this process can be systematically separated by matching to EFTs at successively lower virtualities. Owing to a strong scale separation, we recover a vacuum-like DGLAP evolution above the jet scale, while the additional low-energy scales induced by the medium effectively probe the internal structure of the jet. As a result, the cross section can be written as a series with an increasing number of subjets characterized by perturbative matching coefficients each of which is convolved with a {\it distinct} function. These functions encode broadening, medium-induced radiations as well as quantum interference such as the Landau-Pomeranchuk-Migdal effect and color coherence dynamics to all orders in perturbation theory. As a first application of this EFT framework, we investigate the case of an unresolved jet and show how the cross section can be factorized and fully separate the jet dynamics from the universal physics of the medium. To compare to the existing literature, we explicitly compute the medium jet function at next-to-leading order in the coupling and leading order in medium opacity.

    ↳ hep-phnucl-exnucl-thJHEP(2026)·11 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.