Nuclear Theory·nucl-th

Wednesday·December 18, 2019

6 papers—3 primary·3 cross-listed

04
Shell evolution of $N = 40$ isotones towards $^{60}$ Ca: First spectroscopy of $^{62}$ Ti
M. L. Cortés🇯🇵 · W. Rodriguez🇨🇴 · P. Doornenbal🇯🇵 · A. Obertelli🇫🇷 · J. D. Holt🇨🇦 · S. M. Lenzi🇮🇹 · J. Menéndez🇯🇵 · F. Nowacki🇫🇷 · K. Ogata🇯🇵 · A. Poves🇪🇸 · T. R. Rodríguez🇪🇸 · A. Schwenk🇩🇪 and 72 other authors
Excited states in the $N = 40$ isotone $^{62}$ Ti were populated via the $^{63}$ V $(p, 2 p)$ $^{62}$ Ti reaction at $\sim$ 200~MeV/u at the Radioactive Isotope Beam Factory and studied using $γ$ -ray spectroscopy. The energies of the $2_{1}^{+} \to 0_{gs}^{+}$ and $4_{1}^{+} \to 2_{1}^{+}$ transitions, observed here for the first time, indicate a deformed $^{62}$ Ti ground state. These energies are increased compared to the neighboring $^{64}$ Cr and $^{66}$ Fe isotones, suggesting a small decrease of quadrupole collectivity. The present measurement is well reproduced by large-scale shell-model calculations based on effective interactions, while ab initio and beyond mean-field calculations do not yet reproduce our findings. The shell-model calculations for $^{62}$ Ti show a dominant configuration with four neutrons excited across the $N = 40$ gap. Likewise, they indicate that the $N = 40$ island of inversion extends down to $Z = 20$ , disfavoring a possible doubly magic character of the elusive $^{60}$ Ca.
↳ nucl-exnucl-thPLB(2020)·48 citations
05
An Effective Theory of Quarkonia in QCD Matter
Yiannis Makris🇮🇹 · Ivan Vitev🇺🇸
The problem of quarkonium production in heavy ion collisions presents a set of unique theoretical challenges -- from the relevant production mechanism of $J / ψ$ and $Υ$ to the relative significance of distinct cold and hot nuclear matter effects in the observed attenuation of quarkonia. Inthese proceedings we summarize recent work on the generalization of non-relativistic Quantum Chromodynamics (NRQCD) to include off-shell gluon (Glauber/Coulomb) interactions in strongly interacting matter. This new effective theory provides for the first time a universal microscopic description of the in-medium interaction of heavy quarkonia, consistently applicable to a range of phases such as cold nuclear matter, dense hadron gas, and quark-gluon plasma. It is an important step forward in understanding the common trends in proton-nucleus and nucleus-nucleus data on quarkonium suppression. We derive explicitly the leading and sub-leading interaction terms in the Lagrangian and show the connection of the leading result to existing phenomenology.
↳ hep-phnucl-thNPA(2021)·6 citations
06
Probing the Sivers function with an unpolarized target: GTMD distributions and the Odderons
Renaud Boussarie🇺🇸 · Yoshitaka Hatta🇺🇸 · Lech Szymanowski🇵🇱 · Samuel Wallon🇫🇷
It is commonly believed that the Sivers function has uniquely to do with processes involving a transversely polarized nucleon. In this paper we show that it is not necessarily the case. We demonstrate that exclusive pion production in $u n$ polarized electron-proton scattering in the forward region is a direct probe of the gluon Sivers function due to its connection to the QCD Odderon.
↳ hep-phhep-exnucl-exnucl-thPRL(2020)·48 citations

Affiliations

first authorsco-authorsvia INSPIRE

Shell evolution of N=40 isotones towards 60Ca: First spectroscopy of 62Ti

An Effective Theory of Quarkonia in QCD Matter

Probing the Sivers function with an unpolarized target: GTMD distributions and the Odderons

Affiliations

Shell evolution of $N = 40$ isotones towards $^{60}$ Ca: First spectroscopy of $^{62}$ Ti