Fri·Dec 15, 2023Friday·December 15, 2023

1. 01*

   Chasing the onset of QCD thermalization with ALICE

   Mario Ciacco (for the ALICE Collaboration)🇮🇹

   In heavy-ion and hadronic collisions, indications of thermalization are detected in the yields of produced hadrons: these observations call for a detailed study of the hadronization processes. Novel observables are required to discriminate between the different hadronization models that successfully describe the average yields of hadrons. The ALICE Collaboration reports on the studies of event-by-event fluctuations of the net-${\Xi }^{\pm }$ number, and Pearson correlations of both the net-${\Xi }^{\pm }$-net-kaon numbers and the antideuteron-antiproton numbers, in pp, p-Pb, and Pb-Pb collisions. The measured fluctuations are compared with different hadronization models to explore the compatibility with a charge-equilibration scenario. In all cases, the experimental data agree with Thermal-FIST canonical-statistical calculations, allowing for the extraction of the correlation length for strange and baryon quantum number conservation.

   nucl-exEPJ Web Conf.(2024)·0 citations
2. 02*

   A Vision for the Science of Rare Isotopes

   H. L. Crawford🇺🇸 · K. Fossez🇺🇸 · S. König🇺🇸 · A. Spyrou🇺🇸

   The field of nuclear science has considerably advanced since its beginning just over a century ago. Today, the science of rare isotopes is on the cusp of a new era with theoretical and computing advances complementing experimental capabilities at new facilities internationally. In this article we present a vision for the science of rare isotope beams (RIBs). We do not attempt to cover the full breadth of the field, but rather provide a perspective and address a selection of topics that reflect our own interests and expertise. We focus in particular on systems near the drip lines, where one often finds nuclei that are referred to as "exotic," and where the role of the "nuclear continuum" is only just starting to be explored. An important aspect of this article is the attempt to highlight the crucial connections between nuclear structure and nuclear reactions required to fully interpret and leverage the rich data to be collected in the next years at RIB facilities. Further, we connect the efforts in structure and reactions to key questions of nuclear astrophysics.

   nucl-exnucl-thAnn.Rev.Nucl.Part.Sci.(2024)·11 citations
3. 03*

   Radioisotopes production using lasers: from basic science to applications

   M. R. D. Rodrigues🇫🇷 · A. Bonasera🇺🇸 · M. Scisciò🇮🇹 · J. A. Pérez-Hernández🇪🇸 · M. Ehret🇪🇸 · F. Filippi🇮🇹 · P. L. Andreoli🇮🇹 · M. Huault🇪🇸 · H. Larreur🇪🇸 · D. Singappuli🇫🇷 · D. Molloy🇬🇧 · D. Raffestin🇫🇷 and 28 other authors

   Laser technologies improved after the understanding of the Chirped Pulse Amplification (CPA) which allows energetic laser beams to be compressed to tens of femtosecond (fs) pulse durations and focused to few $\mu$m. Protons of tens of MeV can be accelerated using for instance the Target Normal Sheath Acceleration (TNSA) method and focused on secondary targets. In such conditions, nuclear reactions can occur and radioisotopes relevant for medical purposes be produced. High repetition lasers can be used to produce enough isotopes for medical applications. This route is competitive to conventional methods mostly based on accelerators. In this paper we study the production of ${}^{67}$Cu, ${}^{63}$Zn, ${}^{18}$F and ${}^{11}$C currently used in positron emission tomography (PET) and other applications. At the same time, we study the reaction ${}^{10}$B(p,$\alpha$)${}^7$Be and ${}^{70}$Zn(p,4n)${}^{67}$Ga to put further constraints to the proton distributions at different angles and to the reaction ${}^{11}$B(p,$\alpha$)${}^8$Be relevant for energy production. The experiment was performed at the 1 petawatt (PW) laser facility at Vega III located in Salamanca-Spain. Angular distributions of radioisotopes in the forward (with respect to the laser direction) and backward directions were measured using a High Purity Germanium Detector (HPGE). Our results are reasonably reproduced by the numerical estimates following the approach of Kimura et al. (NIMA637(2011)167)

   nucl-exphysics.app-phphysics.plasm-phMatter Radiat.Extremes(2024)·3 citations
4. 04*

   Identified charged-hadron production in $p$$+$Al, ${}^3$He$+$Au, and Cu$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV and in U$+$U collisions at $\sqrt{s_{{}_{NN}}}=193$ GeV

   PHENIX Collaboration: N.J. Abdulameer🇭🇺 · U. Acharya🇺🇸 · A. Adare🇺🇸 · C. Aidala🇺🇸 · N.N. Ajitanand🇺🇸 · Y. Akiba🇯🇵 · R. Akimoto🇯🇵 · J. Alexander🇺🇸 · M. Alfred🇺🇸 · V. Andrieux🇺🇸 · K. Aoki🇯🇵 · N. Apadula🇺🇸 and 469 other authors

   The PHENIX experiment has performed a systematic study of identified charged-hadron (${\pi }^{\pm }$, $K^{\pm }$, $p$, $\bar{p}$) production at midrapidity in $p$$+$Al, ${}^3$He$+$Au, Cu$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV and U$+$U collisions at $\sqrt{s_{{}_{NN}}}=193$ GeV. Identified charged-hadron invariant transverse-momentum ($p_T$) and transverse-mass ($m_T$) spectra are presented and interpreted in terms of radially expanding thermalized systems. The particle ratios of $K/\pi$ and $p/\pi$ have been measured in different centrality ranges of large (Cu$+$Au, U$+$U) and small ($p$$+$Al, ${}^3$He$+$Au) collision systems. The values of $K/\pi$ ratios measured in all considered collision systems were found to be consistent with those measured in $p$$+$$p$ collisions. However the values of $p/\pi$ ratios measured in large collision systems reach the values of $\approx 0.6$, which is $\approx 2$ times larger than in $p$$+$$p$ collisions. These results can be qualitatively understood in terms of the baryon enhancement expected from hadronization by recombination. Identified charged-hadron nuclear-modification factors ($R_{AB}$) are also presented. Enhancement of proton $R_{AB}$ values over meson $R_{AB}$ values was observed in central ${}^3$He$+$Au, Cu$+$Au, and U$+$U collisions. The proton $R_{AB}$ values measured in $p$$+$Al collision system were found to be consistent with $R_{AB}$ values of $\varphi$, ${\pi }^{\pm }$, $K^{\pm }$, and ${\pi }^0$ mesons, which may indicate that the size of the system produced in $p$$+$Al collisions is too small for recombination to cause a noticeable increase in proton production.

   nucl-exPRC(2024)·11 citations
5. 05*

   Pseudo-neutrino versus recoil formalism for 4-body phase space and applications to nuclear decay

   Chien-Yeah Seng🇺🇸

   It is well-known that the traditional treatment of radiative corrections that utilizes the "true" neutrino momentum ${\vec{p}}_{\nu }$ in the differential decay rate formula could lead to a $\sim \alpha /\pi$ systematic error in certain observables due to the mistreatment of 4-body kinematics. We investigate the theory structure of one of the proposed solutions, the "${\nu }^{\prime }$-formalism", in the non-recoil limit appropriate for neutron and nuclear beta decays. We derive an elegant master formula for the 4-body phase space and use it to re-analyze the spectrum-dependent "outer" radiative corrections to the beta decay of a polarized spin-half nucleus; a complete set of analytic expressions is provided for readers to straightforwardly obtain the final numerical results. We compare it to the "recoil formalism" where the energy of the recoil nucleus is fixed.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2024)·8 citations
6. 06*

   The proton magnetic radius: a new puzzle?

   Yong-Hui Lin🇩🇪 · Hans-Werner Hammer🇩🇪 · Ulf-G. Meißner🇩🇪

   We comment on the puzzling status of the proton magnetic radius determinations.

   ↳ hep-phhep-exhep-latnucl-ex+1Sci.Bull.(2024)·8 citations
7. 07*

   Fate of the $\rho$-$a_1$ mixing in dilepton production

   Azumi Sakai🇯🇵 · Masayasu Harada🇯🇵 · Chiho Nonaka🇯🇵 · Chihiro Sasaki🇵🇱 · Kenta Shigaki🇯🇵 · Satoshi Yano🇯🇵

   We investigate the effect of chiral mixing on dilepton production by combining the in-medium spectral function in the chiral effective field theory with the state-of-the-art fluid dynamical simulations. We compare the spectral functions with different chiral symmetry restoration scenarios. We find that the scenario with proper chiral symmetry restoration that takes into account the degenerate $\rho$ and $a_1$ mesons leads to an increase of the yield in the window of $1.1<M<1.4$ GeV. Whereas, the low-temperature theorem of chiral mixing extrapolated toward a chiral crossover, often used in the literature, leads to a substantial overestimate at $M=1.2$ GeV.

   ↳ nucl-thhep-phnucl-exEPJ Web Conf.(2024)·3 citations
8. 08*

   Baryon electric charge correlation as a magnetometer of QCD

   Heng-Tong Ding🇨🇳 · Jin-Biao Gu🇨🇳 · Arpith Kumar🇨🇳 · Sheng-Tai Li🇨🇳 · Jun-Hong Liu🇨🇳

   The correlation between net baryon number and electric charge, ${\chi }_{11}^{\mathrm{BQ}}$, can serve as a magnetometer of QCD. This is demonstrated by lattice QCD computations using the highly improved staggered quarks with physical pion mass of $M_{\pi }=135$MeV on $N_{\tau }=8$ and 12 lattices. We find that ${\chi }_{11}^{\mathrm{BQ}}$ along the transition line starts to increase rapidly with magnetic field strength $eB\gtrsim 2M_{\pi }^2$ and by a factor 2 at $eB\simeq 8M_{\pi }^2$. Furthermore, the ratio of electric charge chemical potential to baryon chemical potential, ${\mu }_{\mathrm{Q}}/{\mu }_{\mathrm{B}}$, shows significant dependence on the magnetic field strength and varies from the ratio of electric charge to baryon number in the colliding nuclei in heavy ion collisions. These results can provide baselines for effective theory and model studies, and both ${\chi }_{11}^{\mathrm{BQ}}$ and ${\mu }_{\mathrm{Q}}/{\mu }_{\mathrm{B}}$ could be useful probes for the detection of magnetic fields in relativistic heavy ion collision experiments as compared with corresponding results from the hadron resonance gas model.

   ↳ hep-lathep-phnucl-exnucl-thPRL(2024)·39 citations
9. 09*

   Global and local polarization of $\Lambda$ hyperons across RHIC-BES energies

   Xiang-Yu Wu🇨🇳 · Cong Yi🇨🇳 · Guang-You Qin🇨🇳 · Shi Pu🇨🇳

   We report our recent study on the global and local polarization of $\Lambda$ hyperons in Au+Au collisions at RHIC-BES energies within the (3+1)-dimensional CLVisc hydrodynamics framework. We present our numerical results for the global polarization as the function of collision energies and the local polarization along the beam direction as functions of azimuthal angle in $20-50$% centrality at $\sqrt{s_{NN}}$=7.7 GeV Au+Au collision energy. We have discussed the effects of initial conditions, Spin Hall effect and baryon diffusion.

   ↳ nucl-thhep-exhep-phnucl-exEPJ Web Conf.(2024)·3 citations
10. 10*

    Exploring the freeze-out hypersurface of relativistic nuclear collisions with a rapidity-dependent thermal model

    Han Gao🇨🇦 · Lipei Du🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦

    Considering applications to relativistic heavy-ion collisions, we develop a rapidity-dependent thermal model that includes thermal smearing effect and longitudinal boost. We calibrate the model with thermal yields obtained from a multistage hydrodynamic simulation. Through Bayesian analysis, we find that our model extracts freeze-out thermodynamics with better precision than rapidity-independent models. The potential of such a model to constrain longitudinal flow from data is also demonstrated.

    ↳ nucl-thhep-phnucl-exEPJ Web Conf.(2024)·1 citation
11. 11*

    Nuclear modified transverse momentum dependent parton distribution and fragmentation functions

    Mishary Alrashed🇺🇸 · Zhong-Bo Kang🇺🇸 · John Terry🇺🇸 · Hongxi Xing🇨🇳 · Congyue Zhang🇺🇸

    In this study, we extend our previous global analysis of nuclear-modified transverse momentum distribution functions (nTMDs) to also consider the nuclear-modified collinear fragmentation function. Our methodology incorporates the global set of experimental data from both Drell-Yan production and Semi-Inclusive Deep Inelastic Scattering. Through a comprehensive global extraction of these distributions, we demonstrate the effectiveness of this extension by strongly describing the entire global dataset. A focal point of this paper is the impact of recent Jefferson Lab measurements. Most notably, to simultaneously describe experimental data at Jefferson Lab and HERMES we find that it is necessary to introduce a parameter which accounts for the non-perturbative scale evolution of the nTMDs. Additionally, we assess the kinematic coverage of the experimental data and provide insights into experimental opportunities at Jefferson Lab, future Electron-Ion Colliders, RHIC, and the LHC. These opportunities have the potential to significantly enhance and refine global analyses of nuclear-modified TMDs, contributing to a deeper understanding of the structure of cold nuclear matter.

    ↳ hep-phhep-exnucl-exnucl-th10 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.