Mon·May 30, 2022Monday·May 30, 2022

1. 01*

   First measurement of ${\mathrm{\Omega }}_{\mathrm{c}}^0$ production in pp collisions at $\sqrt{s}=13$ TeV

   ALICE Collaboration

   The inclusive production of the charm-strange baryon ${\mathrm{\Omega }}_{\mathrm{c}}^0$ is measured for the first time via its hadronic decay into ${\mathrm{\Omega }}^{-}{\pi }^{+}$ at midrapidity ($|y|<0.5$) 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 $p_{\mathrm{T}}$ dependence of the ${\mathrm{\Omega }}_{\mathrm{c}}^0$-baryon production relative to the prompt ${\mathrm{D}}^0$-meson and to the prompt ${\mathrm{\Xi }}_{\mathrm{c}}^0$-baryon production is compared to various models that take different hadronisation mechanisms into consideration. In the measured $p_{\mathrm{T}}$ interval, the ratio of the $p_{\mathrm{T}}$-integrated cross sections of ${\mathrm{\Omega }}_{\mathrm{c}}^0$ and prompt ${\Lambda }_{\mathrm{c}}^{+}$ baryons multiplied by the ${\mathrm{\Omega }}^{-}{\pi }^{+}$ branching ratio is found to be larger by a factor of about 20 with a significance of about 4$\sigma$ when compared to ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ collisions.

   nucl-exhep-exPLB(2023)·51 citations
2. 02*

   $\Sigma (1385{)}^{\pm }$ resonance production in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

   ALICE Collaboration

   Hadronic resonances are used to probe the hadron gas produced in the late stage of heavy-ion collisions since they decay on the same timescale, of the order of 1 to 10 fm/$c$, as the decoupling time of the system. In the hadron gas, (pseudo)elastic scatterings among the products of resonances that decayed before the kinetic freeze-out and regeneration processes counteract each other, the net effect depending on the resonance lifetime, the duration of the hadronic phase, and the hadronic cross sections at play. In this context, the $\Sigma (1385{)}^{\pm }$ particle is of particular interest as models predict that regeneration dominates over rescattering despite its relatively short lifetime of about 5.5 fm/$c$. The first measurement of the $\Sigma (1385{)}^{\pm }$ resonance production at midrapidity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with the ALICE detector is presented in this Letter. The resonances are reconstructed via their hadronic decay channel, $\Lambda \pi$, as a function of the transverse momentum ($p_{\mathrm{T}}$) and the collision centrality. The results are discussed in comparison with the measured yield of pions and with expectations from the statistical hadronization model as well as commonly employed event generators, including PYTHIA8/Angantyr and EPOS3 coupled to the UrQMD hadronic cascade afterburner. None of the models can describe the data. For $\Sigma (1385{)}^{\pm }$, a similar behaviour as ${\mathrm{K}}^{\ast }(892{)}^0$ is observed in data unlike the predictions of EPOS3 with afterburner.

   nucl-exhep-exEPJC(2023)·26 citations
3. 03*

   Production of light antinuclei in $pp$ collisions by dynamical coalescence and their fluxes in cosmic rays near earth

   Tianhao Shao🇨🇳 · Jinhui Chen🇨🇳 · Yu-Gang Ma🇨🇳 · Zhangbu Xu🇺🇸

   Light antinucleus yields are calculated in a multiphase transport model (AMPT) coupled with a dynamical coalescence model. The model is tuned to reproduce the transverse momentum and rapidity distributions of antiproton in $pp$ collisions at $\sqrt{\mathrm{s}}$ = 7.7 GeV to 7 TeV. By applying a widely used cosmic ray propagation model, the antinucleus fluxes near the earth are estimated over a broad range of kinetic energies. Our result on the antideuteron flux is consistent with the calculations in the literature, while our upper limit on the antihelium-3 flux sits in-between calculations in the field that span an order of magnitude in its value. This study suggests that further accurate estimation of secondary antihelium-3 flux could be improved with more ground-based experiments and model simulations. Most importantly, our value of antinucleus background from hadronic source is far below the projected sensitivity of AMS-02 with 5 years of integration time, which supports the idea of searching for new physics by measurements of light antinuclei in upcoming decade.

   ↳ hep-phnucl-exPRC(2022)·10 citations
4. 04*

   Heavy + heavy and heavy + light pseudoscalar to vector semileptonic transitions

   Hui-Yu Xing🇨🇳 · Zhen-Ni Xu🇨🇳 · Zhu-Fang Cui🇨🇳 · Craig D. Roberts🇨🇳 · Chang Xu🇨🇳

   Using a symmetry-preserving regularisation of a vector$\times$vector contact interaction (SCI), we complete a systematic treatment of twelve semileptonic transitions with vector meson final states: $D\to \rho$, $D_{(s)}\to K^{\ast }$, $D_s\to \varphi$, $B\to \rho$, $B_s\to K^{\ast }$, $B_{(s)}\to D_{(s)}^{\ast }$, $B_c\to B_{(s)}^{\ast },J/\psi ,D^{\ast }$; and thereby finalise a unified analysis of semileptonic decays of heavy+heavy and heavy+light pseudoscalar mesons to both pseudoscalar and vector meson final states. The analysis is marked by algebraic simplicity, few parameters, and the ability to consistently describe systems from Nambu-Goldstone modes to heavy+heavy mesons. Regarding the behaviour of the transition form factors, the SCI results compare well wherever sound experimental or independent theory analyses are available; hence, the SCI branching fraction predictions should be a reasonable guide. Considering the ratios $R(D_{(s)}^{(\ast )})$, $R(J/\psi )$, $R({\eta }_c)$, whose values are key tests of lepton universality in weak interactions, the SCI values agree with Standard Model predictions. The $B_{(s)}\to D_{(s)}^{\ast }$ transitions are used to predict the precursor functions that evolve into the universal Isgur-Wise function in the heavy-quark limit, with results that conform with those from other sources where such are available. The study also exposes effects on the transition form factors that flow from interference between emergent hadron mass from the strong interaction and Higgs boson couplings via current-quark masses, including flavour symmetry violation.

   ↳ hep-phhep-exhep-latnucl-ex+1EPJC(2022)·24 citations
5. 05*

   ${}^{10}$Be-nucleus optical potentials developed from chiral effective field theory $NN$ interactions

   V. Durant🇩🇪 · P. Capel🇧🇪

   We present a determination of optical potentials for ${}^{10}$Be-nucleus collisions using the double-folding method to compute the real part and Kramers-Kronig dispersion relations to derive the imaginary part. As microscopic inputs we use chiral effective field theory nucleon-nucleon interactions at next-to-next-to-leading order combined with state-of-the-art nucleonic densities. With these potentials, we compute elastic scattering cross sections for the exotic nucleus 10 Be off various targets, and compare them to experiment. Without any fitting parameter, we obtain good agreement with data. For collisions on light targets, we observe significant uncertainty related to the short-range physics, whereas for heavy targets that uncertainty remains small.

   ↳ nucl-thnucl-exPRC(2022)·5 citations
6. 06*

   Monte-Carlo Simulations of Superconducting Tunnel Junction Quantum Sensors for the BeEST Experiment

   Connor E. Bray🇺🇸 · Larry J. Hiller🇺🇸 · Kyle G. Leach🇺🇸 · Stephan Friedrich🇺🇸

   Superconducting Tunnel Junctions (STJs) are used as high-resolution quantum sensors to search for evidence of sterile neutrinos in the electron capture decay of ${}^7$Be. We are developing spatially-resolved Monte-Carlo simulations of the energy relaxation in superconductors to understand electron escape after the ${}^7$Be decay and distinguish details in the STJ response function from a possible sterile neutrino signal. Simulations of the charge generation and the Fano factor for different materials agree with the literature values. Initial simulations of the escape tail are consistent with observations, and contain fine structure in the line shape. The line shape will be refined as better experimental data become available.

   ↳ physics.comp-phcond-mat.supr-connucl-exphysics.ins-detJ.Low Temp.Phys.(2022)·1 citation

* 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.