Mon·Oct 2, 2023Monday·October 2, 2023

1. 01*

   Extraction of the neutron F2 structure function from inclusive proton and deuteron deep-inelastic scattering data

   Shujie Li🇺🇸 · Alberto Accardi🇺🇸 · Matteo Cerutti🇺🇸 · Ishara. P. Fernando🇺🇸 · Cynthia E. Keppel🇺🇸 · Wally Melnitchouk🇺🇸 · Peter Monaghan🇺🇸 · Gabriel Niculescu🇺🇸 · Maria I. Niculescu🇺🇸 · Jeff. F. Owens🇺🇸

   The available world deep-inelastic scattering data on proton and deuteron structure functions F2p, F2d, and their ratios, are leveraged to extract the free neutron F2n structure function, the F2n/F2p ratio, and associated uncertainties using the latest nuclear effect calculations in the deuteron. Special attention is devoted to the normalization of the proton and deuteron experimental datasets and to the treatment of correlated systematic errors, as well as the quantification of procedural and theoretical uncertainties. The extracted F2n dataset is utilized to evaluate the Q2 dependence of the Gottfried sum rule and the nonsinglet F2p - F2n moments. To facilitate replication of our study, as well as for general applications, a comprehensive DIS database including all recent JLab 6 GeV measurements, the extracted F2n, a modified CTEQ-JLab global PDF fit named CJ15nlo_mod, and grids with calculated proton, neutron and deuteron DIS structure functions at next-to-leading order, are discussed and made publicly available.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2024)·16 citations
2. 02*

   Nucleonic Shells and Nuclear Masses

   Landon Buskirk · Kyle Godbey🇺🇸 · Witold Nazarewicz🇺🇸 · Wojciech Satula🇵🇱

   The binding energy of an isotope is a sensitive indicator of the underlying shell structure as it reflects the net energy content of a nucleus. Since magic nuclei are significantly lighter, or more bound, compared to their neighbors, the presence of nucleonic shell structure makes an imprint on nuclear masses. In this work, using a carefully designed binding-energy indicator, we catalog the appearance of spherical and deformed shell and subshell closures throughout the nuclear landscape. After presenting experimental evidence for shell and subshell closures as seen through the lens of nuclear masses, we study the ability of global nuclear mass models to predict local binding-energy variations related to shell effects.

   ↳ nucl-thnucl-exPRC(2024)·15 citations
3. 03*

   Achieving ultra-low and -uniform residual magnetic fields in a very large magnetically shielded room for fundamental physics experiments

   N. J. Ayres🇨🇭 · G. Ban🇫🇷 · G. Bison🇨🇭 · K. Bodek🇵🇱 · V. Bondar🇨🇭 · T. Bouillaud🇫🇷 · D. Bowles🇺🇸 · E. Chanel🇨🇭 · W. Chen🇨🇭 · P.-J. Chiu🇨🇭 · C. B. Crawford🇺🇸 · O. Naviliat-Cuncic🇫🇷 and 38 other authors

   High-precision searches for an electric dipole moment of the neutron (nEDM) require stable and uniform magnetic field environments. We present the recent achievements of degaussing and equilibrating the magnetically shielded room (MSR) for the n2EDM experiment at the Paul Scherrer Institute. We present the final degaussing configuration that will be used for n2EDM after numerous studies. The optimized procedure results in a residual magnetic field that has been reduced by a factor of two. The ultra-low field is achieved with the full magnetic-field-coil system, and a large vacuum vessel installed, both in the MSR. In the inner volume of ~1.4 m^3, the field is now more uniform and below 300 pT. In addition, the procedure is faster and dissipates less heat into the magnetic environment, which in turn, reduces its thermal relaxation time from 12 h down to ~1.5 h.

   ↳ physics.ins-dethep-exnucl-exEPJC(2024)·7 citations
4. 04*

   Data-driven reevaluation of $ft$-values in superallowed $\beta$ decays

   Chien-Yeah Seng🇺🇸 · Mikhail Gorchtein🇩🇪

   We present a comprehensive re-evaluation of the $ft$ values in superallowed nuclear $\beta$ decays crucial for the precise determination of $V_{ud}$ and low-energy tests of the electroweak Standard Model. It consists of the first, fully data-driven analysis of the nuclear $\beta$ decay form factor, that utilizes isospin relations to connect the nuclear charged weak distribution to the measurable charge distributions. This prescription supersedes previous shell-model estimations, and allows for a rigorous quantification of theory uncertainties in $f$ which is absent in the existing literature. Our new evaluation shows an overall downward shift of the central values of $f$ at the level of 0.01\%.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2024)·25 citations
5. 05*

   Possible inconsistency between phenomenological and theoretical determinations of charge symmetry breaking in nuclear energy density functionals

   Tomoya Naito🇯🇵 · Gianluca Colò🇮🇹 · Tetsuo Hatsuda🇯🇵 · Haozhao Liang🇯🇵 · Xavier Roca-Maza🇮🇹 · Hiroyuki Sagawa🇯🇵

   We summarize the recent progress on the determination of the charge symmetry breaking term of nuclear energy density functionals. We point out that the strength of the term determined theoretically is remarkably smaller than that determined phenomenologically, which is still an open question.

   ↳ nucl-thnucl-exNuovo Cim.C(2024)·3 citations
6. 06*

   Nuclear Modification Factor in Pb-Pb and p-Pb collisions at $\sqrt{s_{NN}}$=5.02 TeV at LHC energies using Boltzmann Transport Equation with Tsallis Blast Wave Description

   Aditya Kumar Singh🇮🇳 · Aviral Akhil🇮🇳 · Swatantra Kumar Tiwari🇮🇳 · Pooja Pareek🇮🇳

   In this article, we have studied the nuclear modification factor measured in Pb-Pb collisions ($R_{PbPb}$) for ${\pi }^{\pm }$, $K^{\pm }$, $p+\bar{p}$, $K^{\ast 0}+\overline{K^{\ast 0}}$, $\varphi$ and in p-Pb collisions ($R_{pPb}$) for ${\pi }^{\pm }$, $K^{\pm }$, $p+\bar{p}$ at Large hadron collider (LHC) energy of $\sqrt{s_{NN}}$ = 5.02 TeV for the most central and peripheral collisions. We have also analysed the experimental data of transverse momentum ($p_T$) spectra for these identified hadrons at LHC for Pb-Pb as well as for p-Pb collisions. We have used Boltzmann transport equation (BTE) in relaxation time approximation (RTA) for this analysis. The Tsallis statistics is used as an initial distribution function and The Tsallis blast wave (TBW) model is employed as an equilibrium distribution in BTE. The present model fits the measured transverse momentum spectra, $R_{PbPb}$, and $R_{pPb}$ successfully upto $p_T$ = 8 GeV with a reasonable ${\chi }^2/ndf$ for all the considered hadrons at various centralities. The experimental data for $R_{pPb}$ are generated using the particle yields at pPb and pp collisions where number of binary collisions are taken from Glauber model calculations. We find that the average transverse flow velocity ($<{\beta }_r>$) follows the mass and centrality ordering and decreases with the mass as well as when one move from the central collisions to peripheral collisions. These findings are inline with the results of the hydrodynamical calculations.

   ↳ nucl-thhep-exhep-phnucl-exEur.Phys.J.Plus(2024)·5 citations
7. 07*

   An algebraic model to study the internal structure of pseudo-scalar mesons with heavy-light quark content

   B. Almeida-Zamora🇲🇽 · J.J. Cobos-Martínez🇲🇽 · A. Bashir🇲🇽 · K. Raya🇪🇸 · J. Rodríguez-Quintero🇪🇸 · J. Segovia🇪🇸

   The internal structure of all lowest-lying pseudo-scalar mesons with heavy-light quark content is studied in detail using an algebraic model that has been applied recently, and successfully, to the same physical observables of pseudo-scalar and vector mesons with hidden-flavor quark content, from light to heavy quark sectors. The algebraic model consists on constructing simple and evidence-based \emph{ansätze} of the meson's Bethe-Salpeter amplitude (BSA) and quark's propagator in such a way that the Bethe-Salpeter wave function (BSWF) can then be readily computed algebraically. Its subsequent projection onto the light front yields the light front wave function (LFWF) whose form allows us a simple access to the valence-quark Parton Distribution Amplitude (PDA) by integrating over the transverse momentum squared. We exploit our current knowledge of the PDAs of lowest-lying pseudo-scalar heavy-light mesons to compute their Generalized Parton Distributions (GPDs) through the overlap representation of LFWFs. From these three dimensional knowledge, different limits/projections lead us to deduce the related Parton Distribution functions (PDFs), Electromagnetic Form Factors (EFFs), and Impact parameter space GPDs (IPS-GPDs). When possible, we make explicit comparisons with available experimental results and earlier theoretical predictions.

   ↳ hep-phhep-exhep-latnucl-ex+1PRD(2024)·20 citations
8. 08*

   Contrasting Features of Parton Energy Loss in Heavy-ion Collisions at RHIC and the LHC

   Thomas Marshall🇺🇸 · Philip Suh🇺🇸 · Gang Wang🇺🇸 · Huan Zhong Huang🇺🇸

   Energetic quarks and gluons lose energy as they traverse the hot and dense medium created in high-energy heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). The nuclear modification factor ($R_{AA}$) of leading particles quantifies parton energy loss in such collisions, with the particle spectrum in $p+p$ collisions as a reference. Previous $R_{AA}$ measurements at RHIC energies have revealed an approximately constant trend at high transverse momenta ($p_T$), implying a scenario where parton energy loss, $\Delta p_T$, scales proportionally with $p_T$, a feature naively expected from energy loss dynamics in elastic collisions. In this study, we investigate the LHC $R_{AA}$ measurements which exhibit a pronounced $p_T$ dependence of $R_{AA}$ for various particle species, and our analysis attributes this behavior to $\Delta p_T$ being approximately proportional to $\sqrt{p_T}$. These distinct features are consistent with model calculations of dominant radiative energy loss dynamics at the LHC, in contrast to the dominance of collisional energy loss at RHIC. Additionally, the linear increase of fractional energy loss with medium density at different $p_T$ magnitudes affirms the previous empirical observation that the magnitude of the energy loss depends mostly on the initial entropy density, with no significant path-length dependence. Implications on the dynamical scenarios of parton energy loss and future experimental investigations will also be discussed.

   ↳ nucl-thhep-exhep-phnucl-exCPC(2025)·2 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.