Mon·Oct 7, 2019Monday·October 7, 2019

1. 01*

   First inverse kinematics study of the ${}^{22}$Ne$(p,\gamma {)}^{23}$Na reaction and its role in AGB star and classical nova nucleosynthesis

   M. Williams · A. Lennarz · A. M. Laird · U. Battino · J. José D. Connolly · C. Ruiz · A. Chen · B. Davids · N. Esker · B. R. Fulton · R. Garg · x M. Gay and 8 other authors

   The abundances of sodium and oxygen are observed to be anti-correlated in all well-studied globular clusters. Asymptotic giant branch (AGB) stars undergoing hot bottom burning (HBB) are thought to be prime candidates for producing sodium-rich oxygen-poor material and expelling it into the cluster ISM. The 22Ne(p,gamma)23Na reaction has been shown to strongly influence the amount of 23Na produced during HBB. This reaction is also important for classical novae nucleosynthesis, with sensitivity studies showing that the abundances of several isotopes in the Ne-Al region are significantly altered when varying the reaction rate between available compilations. Here we present the first inverse kinematics measurements of key resonances strengths as well as the direct capture S-factor. Together, this study represents the largest centre of mass energy range (149-1222 keV) over which this reaction has been measured in a single experiment. Our results for low-energy resonances at Ecm=149, 181 and 248 keV are in good agreement with recent forward kinematics results; we also find a direct capture S-factor consistent with the literature value of 62 keV.b. However, in the case of the important reference resonance at Ecm = 458 keV we find a strength value of wg=0.44 +/- 0.02 eV, which is significantly lower than recent results. Using our new recommended rate we explore the impact of these results on both AGB star and classical novae nucleosynthesis. In the case of AGB stars we see very little abundance changes with respect to the rate included in the STARLIB-2013. However, we observe changes of up to a factor of 2 in isotopes produced in both the carbon-oxygen (CO) and oxygen-neon (ONe) classical novae models considered here. The 22Ne(p,gamma)23Na reaction rate is now sufficiently well constrained to not significantly contribute toward abundance uncertainties from classical novae nucleosynthesis models.

   nucl-exPRC(2020)·22 citations
2. 02*

   Overview of Recent ALICE Results

   Robert Vertesi (for the ALICE Collaboration)🇭🇺

   A selection of recent ALICE results from pp, p--Pb, Pb--Pb and Xe--Xe collisions taken during the Run 1 and Run 2 phases are summarized in this contribution, and the prospects for the upcoming Run 3 phase are outlined.

   nucl-exhep-ex1 citation
3. 03*

   Design of a Multiple-Reflection Time-of-Flight Mass-Spectrometer for Barium-tagging

   K. Murray🇨🇦 · J. Dilling🇨🇦 · R. Gornea🇨🇦 · Y. Ito🇨🇦 · T. Koffas🇨🇦 · A.A. Kwiatkowski🇨🇦 · Y. Lan🇨🇦 · M.P. Reiter🇨🇦 · V. Varentsov🇩🇪 · T. Brunner🇨🇦

   The search for neutrinoless double beta decay requires increasingly advanced methods of background reduction. A bold approach to solving this problem, in experiments using Xe-136, is to extract and identify the daughter Ba-136 ion produced by double beta decay. Tagging events in this manner allows for a virtually background-free verification of double beta decay signals. Various approaches are being pursued by the nEXO collaboration to achieve Ba-tagging. A Multi-Reflection Time-of-Flight Mass Spectrometer (MR TOF) has been designed and optimized as one of the ion-identification methods, where it will investigate the ion-extraction efficiency, as well as provide further identification of the Ba isotope. The envisioned mode of operation allows the MR TOF to achieve a quickly adjustable mass-range and resolution, with simulations suggesting that a mass-resolving power of 140,000 is within reach. This work will discuss the MR TOF design and the methods employed to simulate and optimize it.

   ↳ physics.ins-detnucl-exHyperfine Interact.(2019)·6 citations
4. 04*

   Transition Distribution Amplitudes : from JLab to EIC

   L. Szymanowski🇵🇱 · B. Pire🇫🇷 · K. Semenov-Tian-Shansky🇷🇺

   Baryon-to-meson Transition Distribution Amplitudes extend both the concepts of generalized parton distributions and baryon distribution amplitudes encoding valuable complementary information on the 3-dimensional hadronic structure. The recent analysis of backward meson electroproduction at JLab supports the hope to perform femto-photography of hadrons from a brand new perspective.and in particular opens a new domain for EIC experiments.

   ↳ hep-phhep-exnucl-exnucl-th2 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.