Mon·Jul 29, 2019Monday·July 29, 2019

1. 01*

   Single-particle shell strengths near the doubly magic nucleus ${}^{56}$Ni and the ${}^{56}$Ni(p,$\gamma$)${}^{57}$Cu reaction rate in explosive astrophysical burning

   D. Kahl🇬🇧 · P. J. Woods🇬🇧 · T. Poxon-Pearson · F. M. Nunes🇺🇸 · B. A. Brown🇺🇸 · H. Schatz🇺🇸 · T. Baumann🇺🇸 · D. Bazin🇺🇸 · J. A. Belarge · P. C. Bender🇨🇦 · B. Elman · A. Estrade🇺🇸 and 15 other authors

   Angle-integrated cross-section measurements of the ${}^{56}$Ni(d,n) and (d,p) stripping reactions have been performed to determine the single-particle strengths of low-lying excited states in the mirror nuclei pair ${}^{57}$Cu-${}^{57}$Ni situated adjacent to the doubly magic nucleus ${}^{56}$Ni. The reactions were studied in inverse kinematics utilizing a beam of radioactive ${}^{56}$Ni ions in conjunction with the GRETINA $\gamma$-array. Spectroscopic factors are compared with new shell-model calculations using a full $pf$ model space with the GPFX1A Hamiltonian for the isospin-conserving strong interaction plus Coulomb and charge-dependent Hamiltonians. These results were used to set new constraints on the ${}^{56}$Ni(p,$\gamma$)${}^{57}$Cu reaction rate for explosive burning conditions in x-ray bursts, where ${}^{56}$Ni represents a key waiting point in the astrophysical rp-process.

   nucl-exastro-ph.SRnucl-thPLB(2019)·19 citations
2. 02*

   Lepton angular distributions of Drell-Yan process in pQCD and a geometric approach

   Wen-Chen Chang🇹🇼 · Randall Evan McClellan🇺🇸 · Jen-Chieh Peng🇺🇸 · Oleg Teryaev🇷🇺

   The lepton angular distributions of the Drell-Yan process in the fixed-target experiments are investigated by NLO and NNLO perturbative QCD. We present the calculated angular parameters $\lambda$, $\mu$, $\nu$ and the degree of violation of the Lam-Tung relation, $1-\lambda -2\nu$, for the E615 experiment as well as predictions for the COMPASS experiment. Many salient features of transverse momentum and rapidity dependence could be qualitatively understood by a geometric approach.

   ↳ hep-phnucl-exnucl-thPoS(2019)·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.