Wed·Jan 7, 2015Wednesday·January 7, 2015

1. 01*

   Nuclear structure studies of ${}^{24}$F

   L. Caceres (GANIL)🇫🇷 · A. Lepailleur (GANIL)🇫🇷 · O. Sorlin (GANIL)🇫🇷 · M. Stanoiu (GANIL)🇷🇴 · D. Sohler🇭🇺 · Zs. Dombradi🇭🇺 · S. K. Bogner🇺🇸 · B.A. Brown🇺🇸 · H. Hergert🇺🇸 · J.D. Holt🇨🇦 · A. Schwenk🇩🇪 · F. Azaiez (IPNO)🇫🇷 and 30 other authors

   The structure of the ${}^{24}$F nucleus has been studied at GANIL using the $\beta$ decay of ${}^{24}$O and the in-beam $\gamma$-ray spectroscopy from the fragmentation of projectile nuclei. Combining these complementary experimental techniques, the level scheme of ${}^{24}$F has been constructed up to 3.6 Mev by means of particle-$\gamma$ and particle-$\gamma \gamma$ coincidence relations. Experimental results are compared to shell-model calculations using the standard USDA and USDB interactions as well as ab-initio valence-space Hamiltonians calculated from the in-medium similarity renormalization group based on chiral two- and three-nucleon forces. Both methods reproduce the measured level spacings well, and this close agreement allows unidentified spins and parities to be consistently assigned.

   nucl-exnucl-thPRC(2015)·21 citations
2. 02*

   The RHIC SPIN Program: Achievements and Future Opportunities

   Elke-Caroline Aschenauer (BNL)🇺🇸 · Alexander Bazilevsky (BNL)🇺🇸 · Markus Diehl (DESY)🇩🇪 · James Drachenberg (Valparaiso U.)🇺🇸 · Kjeld Oleg Eyser (BNL)🇺🇸 · Renee Fatemi (Kentucky U.)🇺🇸 · Carl Gagliardi (Texas A&M)🇺🇸 · Zhongbo Kang (Los Alamos)🇺🇸 · Yuri V. Kovchegov (Ohio State U.)🇺🇸 · John Lajoie (Iowa State U.)🇺🇸 · Jeong-Hun Lee (BNL)🇺🇸 · Emanuele-R. Nocera (Milano U. & INFN)🇮🇹 and 12 other authors

   Time and again, spin has been a key element in the exploration of fundamental physics. Spin-dependent observables have often revealed deficits in the assumed theoretical framework and have led to novel developments and concepts. Spin is exploited in many parity-violating experiments searching for physics beyond the Standard Model or studying the nature of nucleon-nucleon forces. The RHIC spin program plays a special role in this grand scheme: it uses spin to study how a complex many-body system such as the proton arises from the dynamics of QCD. Many exciting results from RHIC spin have emerged to date, most of them from RHIC running after the 2007 Long Range Plan. In this document we present highlights from the RHIC program to date and lay out the roadmap for the significant advances that are possible with future RHIC running.

   nucl-exhep-phnucl-th144 citations
3. 03*

   Non-Perturbative Lepton Sea Fermions in the Nucleon and the Proton Radius Puzzle

   Gerald A. Miller🇺🇸

   A potential explanation [U.~D.~Jentschura, Phys.\ Rev.\ A {\bf 88}, 062514 (2013)] of the proton radius puzzle originating from the non-perturbative lepton-pair content of the proton is studied. Well-defined quantities that depend on this lepton-pair content are evaluated. Each is found to be of the order of $10(\frac{\alpha }{\pi }{)}^2$, so that we find such a lepton-pair content exists in the proton. However, we argue that this relatively large result and general features of loop diagrams rule out the possibility of lepton-pair content as an explanation of the proton radius puzzle. In addition, the contributions of a class of explanations of the proton radius puzzle (for which the dependence on the $\mu p$ relative distance is as a contact interaction) is determined.

   ↳ nucl-thhep-phnucl-exphysics.atom-phPRC(2015)·12 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.