Wed·Oct 7, 2020Wednesday·October 7, 2020

1. 01*

   Light (anti)nuclei production in high-energy nuclear collisions at the LHC with ALICE

   Chiara Pinto (for the ALICE Collaboration)🇮🇹

   The measurement of (anti)nuclei production in pp, p-A and A-A collisions at ultrarelativistic energies is important to understand hadronization. The excellent tracking and particle identification capabilities of ALICE make it the most suited detector at the LHC to study light (anti)nuclei produced in high-energy hadronic collisions. (Anti)nuclei with mass numbers up to 4, such as (anti)deuterons, (anti)tritons, (anti)${}^3$He and (anti)${}^4$He have been successfully identified in ALICE at midrapidity ($|\eta |<$0.9). In this contribution, multiplicity dependent results on the yields, nuclei-to-protons ratios as well as the coalescence parameter $B_{\mathrm{A}}$ as a function of the charged-particle multiplicity are presented and compared with the expectations of coalescence and statistical hadronization models (SHM) to provide insight into their production mechanism in heavy-ion collisions.

   nucl-exhep-exPoS(2021)·0 citations
2. 02*

   Cosmogenic activation in double beta decay experiments

   Susana Cebrian🇪🇸

   Double beta decay is a very rare nuclear process and, therefore, experiments intended to detect it must be operated deep underground and in ultra-low background conditions. Long-lived radioisotopes produced by the previous exposure of materials to cosmic rays on the Earth's surface or even underground can become problematic for the required sensitivity. Here, the studies developed to quantify and reduce the activation yields in detectors and materials used in the set-up of these experiments will be reviewed, considering target materials like germanium, tellurium and xenon together with other ones commonly used like copper, lead, stainless steel or argon. Calculations following very different approaches and measurements from irradiation experiments using beams or directly cosmic rays will be considered for relevant radioisotopes. The effect of cosmogenic activation in present and future double beta decay projects based on different types of detectors will be analyzed too.

   ↳ physics.ins-detastro-ph.IMhep-exnucl-exUniverse(2020)·18 citations
3. 03*

   Measurement of Differential Cross Sections for ${\nu }_{\mu }$-Ar Charged-Current Interactions with Protons and no Pions in the Final State with the MicroBooNE Detector

   MicroBooNE collaboration: P. Abratenko🇺🇸 · M. Alrashed🇺🇸 · R. An🇺🇸 · J. Anthony🇬🇧 · J. Asaadi🇺🇸 · A. Ashkenazi🇺🇸 · S. Balasubramanian🇺🇸 · B. Baller🇺🇸 · C. Barnes🇺🇸 · G. Barr🇬🇧 · V. Basque🇬🇧 · L. Bathe-Peters🇺🇸 and 172 other authors

   We present an analysis of MicroBooNE data with a signature of one muon, no pions, and at least one proton above a momentum threshold of 300 MeV/c (CC0$\pi$Np). This is the first differential cross section measurement of this topology in neutrino-argon interactions. We achieve a significantly lower proton momentum threshold than previous carbon and scintillator-based experiments. Using data collected from a total of approximately $1.6\times 10^{20}$ protons-on-target, we measure the muon neutrino cross section for the CC0$\pi$Np interaction channel in argon at MicroBooNE in the Booster Neutrino Beam which has a mean energy of around 800 MeV. We present the results from a data sample with estimated efficiency of 29\% and purity of 76\% as differential cross sections in five reconstructed variables: the muon momentum and polar angle, the leading proton momentum and polar angle, and the muon-proton opening angle. We include smearing matrices that can be used to "forward-fold" theoretical predictions for comparison with these data. We compare the measured differential cross sections to a number of recent theory predictions demonstrating largely good agreement with this first-ever data set on argon.

   ↳ hep-exhep-phnucl-exnucl-th+1PRD(2020)·91 citations
4. 04*

   Neutron skin thickness of ${}^{208}$Pb determined from reaction cross section for proton scattering

   Shingo Tagami🇯🇵 · Tomotsugu Wakasa🇯🇵 · Jun Matsui · Maya Takechi🇩🇪 · Masanobu Yahiro🇯🇵

   The reaction cross section ${\sigma }_R$ is useful to determine the neutron radius $R_n$ as well as the matter radius $R_m$. The chiral (Kyushu) $g$-matrix folding model for ${}^{12}$C scattering on ${}^9$Be, ${}^{12}$C, ${}^{27}$Al targets was tested in the incident energy range of $30\text{lsim}{E}_{\mathrm{in}}\text{lsim}400$ MeV, and it is found that the model reliably reproduces the ${\sigma }_R$ in $30\text{lsim}{E}_{\mathrm{in}}\text{lsim}100$ MeV and $250\text{lsim}{E}_{\mathrm{in}}\text{lsim}400$ MeV. \item[Aim] We determine $R_n$ and the neutron skin thickness $R_{\mathrm{skin}}$ of ${}^{208}\mathrm{Pb}$ by using high-quality ${\sigma }_R$ data for the $p+{}^{208}\mathrm{Pb}$ scattering in $30\le E_{\mathrm{in}}\le 100$ MeV. The theoretical model is the Kyushu $g$-matrix folding model with the densities calculated with Gongny-D1S HFB (GHFB) with the angular momentum projection (AMP). \item[Results] The Kyushu $g$-matrix folding model with the GHFB+AMP densities underestimates ${\sigma }_{\mathrm{R}}$ in $30\le E_{\mathrm{in}}\le 100$~MeV only by a factor of 0.97. Since the proton radius $R_p$ calculated with GHFB+AMP agrees with the precise experimental data of 5.444 fm, the small deviation of the theoretical result from the data on ${\sigma }_R$ allows us to scale the GHFB+AMP neutron density so as to reproduce the ${\sigma }_R$ data. In $E_{\mathrm{in}}$ = 30--100 MeV, the experimental ${\sigma }_R$ data can be reproduced by assuming the neutron radius of ${}^{208}\mathrm{Pb}$ as $R_n$ = $5.722\pm 0.035$ fm. \item[Conclusion] The present result $R_{\mathrm{skin}}$ = $0.278\pm 0.035$ fm is in good agreement with the recent PREX-II result of $r_{\mathrm{skin}}$ = $0.283\pm 0.071$ fm.

   ↳ nucl-thnucl-exPRC(2021)·32 citations
5. 05*

   Picosecond Timing Resolution Measurements of Low Gain Avalanche Detectors with a 120 GeV Proton Beam for the TOPSiDE Detector Concept

   M. Jadhav (1)🇺🇸 · W. Armstrong (1)🇺🇸 · I. Cloet (1)🇺🇸 · S. Joosten (1)🇺🇸 · S. M. Mazza (2)🇺🇸 · J. Metcalfe (1)🇺🇸 · Z.-E. Meziani (1)🇺🇸 · H.F.-W. Sadrozinski (2)🇺🇸 · B. Schumm (2)🇺🇸 · A. Seiden (2) ((1) Argonne National Laboratory, (2) Santa Cruz Institute for Particle Physics UC Santa Cruz)🇺🇸

   This paper presents results that take a critical step toward proving 10 ps timing resolution's feasibility for particle identification in the TOPSiDE detector concept for the Electron-Ion Collider. Measurements of LGADs with a thickness of 35 micro-m and 50 micro-m are evaluated with a 120 GeV proton beam. The performance of the gain and timing response is assessed, including the dependence on the reverse bias voltage and operating temperature. The best timing resolution of UFSDs in a test beam to date is achieved using three combined planes of 35 micro-m thick LGADs at -30 degree celsius with a precision of 14.3 ps (uncertainty 1.5 ps).

   ↳ physics.ins-dethep-exnucl-exJINST(2021)·6 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.