Mon·Apr 29, 2024Monday·April 29, 2024

1. 01*

   Most general neutron decay correlations: Standard Model recoil and radiative corrections

   Chien-Yeah Seng🇺🇸

   To continue from our previous work Phys.Rev.D 109(2024),073007, we derive the full Standard Model prediction of the most general free neutron differential decay rate with all massive particles (neutron, proton and electron) polarized, including the $\mathcal{O}(1/m_N)$ recoil corrections and $\mathcal{O}(\alpha /\pi )$ radiative corrections. For the latter we adopt the newly-developed pseudo-neutrino formalism which is compatible to realistic experimental setups, in which neutrinos and photons are not detected. We also provide readily-executable Mathematica notebooks to evaluate these corrections.

   ↳ hep-phhep-exhep-latnucl-ex+1PRD(2024)·2 citations
2. 02*

   TALYS calculation and a short review of the experimental status of proton capture studies on p-nuclei: A guide to future investigation

   Indrani Ray🇮🇳 · Argha Deb🇮🇳

   TALYS calculations were performed to obtain the theoretical proton capture cross-sections on the p-nuclei. A short review on the status of related experimental studies was also conducted. Some basic properties such as Q-values, Coulomb barrier, Gamow peak, Gamow Window, and decay properties of the parent and daughter nuclei were studied. Various experimental parameters, e.g., beam energy, beam current, targets, and detectors, used in experimental investigations reported in the literature, were tabulated. The results of the TALYS calculations in the Gamow region were compared with the corresponding experimental values wherever available. This study is expected to facilitate the planning of future experiments.

   ↳ nucl-thnucl-exCPC(2024)·0 citations
3. 03*

   Measurement of ${\Omega }_{\mathrm{c}}^0$ baryon production and branching-fraction ratio $\mathrm{BR}({\mathrm{\Omega }}_{\mathrm{c}}^0\to {\mathrm{\Omega }}^{-}{\mathrm{e}}^{+}{\nu }_{\mathrm{e}})/\mathrm{BR}({\mathrm{\Omega }}_{\mathrm{c}}^0\to {\mathrm{\Omega }}^{-}{\pi }^{+})$ in pp collisions at $\sqrt{s}$ = 13 TeV

   ALICE Collaboration

   The inclusive production of the charm-strange baryon ${\Omega }_{\mathrm{c}}^0$ is measured for the first time via its semileptonic decay into ${\Omega }^{-}{\mathrm{e}}^{+}{\nu }_{\mathrm{e}}$ at midrapidity ($|y|<0.8$) in proton$-$proton (pp) collisions at the centre-of-mass energy $\sqrt{s}=13$ TeV with the ALICE detector at the LHC. The transverse momentum ($p_{\mathrm{T}}$) differential cross section multiplied by the branching ratio is presented in the interval $2<p_{\mathrm{T}}<12\mathrm{GeV}/c$. The branching-fraction ratio $\mathrm{BR}({\Omega }_{\mathrm{c}}^0\to {\Omega }^{-}{\mathrm{e}}^{+}{\nu }_{\mathrm{e}})/\mathrm{BR}({\Omega }_{\mathrm{c}}^0\to {\Omega }^{-}{\pi }^{+})$ is measured to be 1.12 $\pm$ 0.22 (stat.) $\pm$ 0.27 (syst.). Comparisons with other experimental measurements, as well as with theoretical calculations, are presented.

   ↳ hep-exnucl-exPRD(2024)·6 citations
4. 04*

   Performance of CMS muon reconstruction from proton-proton to heavy ion collisions

   CMS Collaboration

   The performance of muon tracking, identification, triggering, momentum resolution, and momentum scale has been studied with the CMS detector at the LHC using data collected at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV in proton-proton (pp) and lead-lead (PbPb) collisions in 2017 and 2018, respectively, and at $\sqrt{s_{\mathrm{NN}}}$ = 8.16 TeV in proton-lead (pPb) collisions in 2016. Muon efficiencies, momentum resolutions, and momentum scales are compared by focusing on how the muon reconstruction performance varies from relatively small occupancy pp collisions to the larger occupancies of pPb collisions and, finally, to the highest track multiplicity PbPb collisions. We find the efficiencies of muon tracking, identification, and triggering to be above 90% throughout most of the track multiplicity range. The momentum resolution and scale are unaffected by the detector occupancy. The excellent muon reconstruction of the CMS detector enables precision studies across all available collision systems.

   ↳ hep-exnucl-exphysics.ins-detJINST(2024)·19 citations
5. 05*

   Global Data-Driven Determination of Baryon Transition Form Factors

   Yu-Fei Wang🇩🇪 · Michael Döring🇺🇸 · Jackson Hergenrather🇺🇸 · Maxim Mai🇺🇸 · Terry Mart🇮🇩 · Ulf-G. Meißner🇩🇪 · Deborah Rönchen🇩🇪 · Ronald Workman (Jülich-Bonn-Washington Collaboration)🇺🇸

   Hadronic resonances emerge from strong interactions encoding the dynamics of quarks and gluons. The structure of these resonances can be probed by virtual photons parameterized in transition form factors. In this study, twelve $N^{\ast }$ and $\Delta$ transition form factors at the pole are extracted from data with the center-of-mass energy from $\pi N$ threshold to $1.8\mathrm{GeV}$, and the photon virtuality $0\le Q^2/{\mathrm{GeV}}^2\le 8$. For the first time, these results are determined from a simultaneous analysis of more than one state, i.e., $\sim 10^5$ $\pi N$, $\eta N$, and $K\Lambda$ electroproduction data. In addition, about $5\cdot 10^4$ data in the hadronic sector as well as photoproduction serve as boundary conditions. For the $\Delta (1232)$ and $N(1440)$ states our results are in qualitative agreement with previous studies, while the transition form factors at the poles of some higher excited states are estimated for the first time. Realistic uncertainties are determined by further exploring the parameter space.

   ↳ nucl-thhep-phnucl-exPRL(2024)·19 citations
6. 06*

   Nuclear suppression of coherent $J/\psi$ photoproduction in heavy-ion UPCs and leading twist nuclear shadowing

   V. Guzey (Jyvaskyla U. and Helsinki Inst. of Phys.)🇫🇮 · M. Strikman (Penn State U.)🇺🇸

   We determine the nuclear suppression factor $S_{Pb}(x)$, where $x=M_{J/\psi }^2/W_{\gamma p}^2$ with $M_{J/\psi }$ the $J/\psi$ mass and $W_{\gamma p}$ the photon-nucleon energy, for the cross section of coherent $J/\psi$ photoproduction in heavy-ion ultraperipheral collisions (UPCs) at the Large Hadron Collider (LHC) and Relativistic Heavy Ion Collider (RHIC) by performing the ${\chi }^2$ fit to all available data on the cross section $d{\sigma }^{AA\to J/\psi AA}/dy$ as a function of the $J/\psi$ rapidity $y$ and the photoproduction cross section ${\sigma }^{\gamma A\to J/\psi A}(W_{\gamma p})$ as a function of $W_{\gamma p}$. We find that while the $d{\sigma }^{AA\to J/\psi AA}/dy$ data alone constrain $S_{Pb}(x)$ for $x\ge 10^{-3}$, the combined $d{\sigma }^{AA\to J/\psi AA}/dy$ and ${\sigma }^{\gamma A\to J/\psi A}(W_{\gamma p})$ data allow us to determine $S_{Pb}(x)$ in the wide interval $10^{-5}<x<0.05$. In particular, the data favor $S_{Pb}(x)$, which decreases with a decrease of $x$ in the $10^{-4}<x<0.01$ interval, and can be both decreasing or constant for $x<10^{-4}$. Identifying $S_{Pb}(x)$ with the ratio of the gluon distributions in Pb and the proton $R_g(x,Q_0^2)=g_A(x,Q_0^2)/[A{g}_p(x,Q_0^2)]$, we demonstrate that the leading twist approximation (LTA) for nuclear shadowing provides a good description of all the data on $d{\sigma }^{AA\to J/\psi AA}/dy$ and ${\sigma }^{\gamma A\to J/\psi A}(W_{\gamma p})$ as well as on the experimental values for $S_{Pb}(x)$ derived from ${\sigma }^{\gamma A\to J/\psi A}(W_{\gamma p})$. We also show that modern nuclear PDFs reasonably reproduce $S_{Pb}(x)$ as well.

   ↳ hep-phhep-exnucl-exPRC(2024)·10 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.