Thu·Jun 1, 2023Thursday·June 1, 2023

1. 01*

   First direct measurement constraining the ${}^{34}$Ar($\alpha$,p)${}^{37}$K reaction cross section for mixed hydrogen and helium burning in accreting neutron stars

   J.Browne🇺🇸 · K.A.Chipps🇺🇸 · K. Schmidt🇩🇪 · H.Schatz🇺🇸 · S.Ahn🇰🇷 · S.D.Pain🇺🇸 · F. Montes🇺🇸 · W.J. Ong🇺🇸 · U. Greife🇺🇸 · J. Allen · D.W. Bardayan🇺🇸 · J.C. Blackmon🇺🇸 and 16 other authors

   The rate of the final step in the astrophysical $\alpha$p-process, the ${}^{34}$Ar($\alpha$,\textit{p})${}^{37}$K reaction, suffers from large uncertainties due to lack of experimental data, despite having a considerable impact on the observable light curves of x-ray bursts and the composition of the ashes of hydrogen and helium burning on accreting neutron stars. We present the first direct measurement constraining the ${}^{34}$Ar($\alpha$,p)${}^{37}$K reaction cross section, using the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target. The combined cross section for the ${}^{34}$Ar,Cl($\alpha$,p)${}^{37}$K,Ar reaction is found to agree well with Hauser-Feshbach predictions. The ${}^{34}$Ar($\alpha$,2p)${}^{36}$Ar cross section, which can be exclusively attributed to the ${}^{34}$Ar beam component, also agrees to within the typical uncertainties quoted for statistical models. This indicates the applicability of the statistical model for predicting astrophysical ($\alpha$,p) reaction rates in this part of the $\alpha$p process, in contrast to earlier findings from indirect reaction studies indicating orders-of-magnitude discrepancies. This removes a significant uncertainty in models of hydrogen and helium burning on accreting neutron stars.

   nucl-exPRL(2023)·7 citations
2. 02*

   Measurement of the Electron-Neutrino Charged-Current Cross Sections on ${}^{127}$I with the COHERENT NaI$\nu$E detector

   P. An🇺🇸 · C. Awe🇺🇸 · P.S. Barbeau🇺🇸 · B. Becker🇺🇸 · V. Belov🇷🇺 · I. Bernardi🇺🇸 · C. Bock🇺🇸 · A. Bolozdynya🇷🇺 · R. Bouabid🇺🇸 · A. Brown🇺🇸 · J. Browning🇺🇸 · B. Cabrera-Palmer🇺🇸 and 77 other authors

   Using an 185-kg NaI[Tl] array, COHERENT has measured the inclusive electron-neutrino charged-current cross section on ${}^{127}$I with pion decay-at-rest neutrinos produced by the Spallation Neutron Source at Oak Ridge National Laboratory. Iodine is one the heaviest targets for which low-energy ($\le$ 50 MeV) inelastic neutrino-nucleus processes have been measured, and this is the first measurement of its inclusive cross section. After a five-year detector exposure, COHERENT reports a flux-averaged cross section for electron neutrinos of $9.2_{-1.8}^{+2.1}\times 10^{-40}$ cm${}^2$. This corresponds to a value that is $\sim$41% lower than predicted using the MARLEY event generator with a measured Gamow-Teller strength distribution. In addition, the observed visible spectrum from charged-current scattering on ${}^{127}$I has been measured between 10 and 55 MeV, and the exclusive zero-neutron and one-or-more-neutron emission cross sections are measured to be $5.2_{-3.1}^{+3.4}\times 10^{-40}$ and $2.2_{-2.2}^{+3.5}\times 10^{-40}$ cm${}^2$, respectively.

   nucl-exhep-exPRL(2023)·32 citations
3. 03*

   Many-body correlations for nuclear physics across scales: from nuclei to quark-gluon plasmas to hadron distributions

   Giuliano Giacalone🇩🇪

   It is an experimental fact that multi-particle correlations in the final states of high-energy nucleus-nucleus collisions are sensitive to collective correlations of nucleons in the wave functions of the colliding nuclei. Here, I show that this connection is more direct than it intuitively seems. With an energy deposition scheme inspired by high-energy quantum chromodynamics, and within a linearized description of initial-state fluctuations in the quark-gluon plasma, I exhibit relations between $N$-particle correlations in the final states of nuclear collisions and $N$-nucleon density distributions in the colliding nuclei. This result formally justifies the sensitivity of the outcome of high-energy collisions to features such as nuclear deformations. It paves the way, thus, to systematic studies of the impact of state-of-the-art nuclear interactions in such processes.

   ↳ nucl-thhep-exhep-phnucl-exEPJA(2023)·43 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.