Mon·Feb 18, 2019Monday·February 18, 2019

1. 01*

   Measurement of $B^{+}$, $B^0$ and ${\Lambda }_b^0$ production in $p\mathrm{Pb}$ collisions at $\sqrt{s_{\mathrm{NN}}}=8.16\mathrm{TeV}$

   LHCb Collaboration: R. Aaij🇳🇱 · C. Abellán Beteta🇨🇭 · B. Adeva🇪🇸 · M. Adinolfi🇬🇧 · C.A. Aidala🇺🇸 · Z. Ajaltouni🇫🇷 · S. Akar🇺🇸 · P. Albicocco🇮🇹 · J. Albrecht🇩🇪 · F. Alessio🇨🇭 · M. Alexander🇬🇧 · A. Alfonso Albero🇪🇸 and 834 other authors

   The production of $B^{+}$, $B^0$ and ${\Lambda }_b^0$ hadrons is studied in proton-lead collisions at a centre-of-mass energy per nucleon pair of $\sqrt{s_{\mathrm{NN}}}=8.16\mathrm{TeV}$ recorded with the LHCb detector at the LHC. The measurement uses a dataset corresponding to an integrated luminosity of $12.2\pm 0.3{\mathrm{nb}}^{-1}$ for the case where the proton beam is projected into the LHCb detector (corresponding to measuring hadron production at positive rapidity) and $18.6\pm 0.5{\mathrm{nb}}^{-1}$ for the lead beam projected into the LHCb detector (corresponding to measuring hadron production at negative rapidity). Nuclear effects are probed through double-differential cross-sections, forward-to-backward cross-section ratios and nuclear modification factors of the beauty hadrons. The double-differential cross-sections are measured as a function of the beauty-hadron transverse momentum and rapidity in the nucleon-nucleon centre-of-mass frame. Forward-to-backward cross-section ratios and nuclear modification factors indicate a significant nuclear suppression at positive rapidity. The ratio of ${\Lambda }_b^0$ over $B^0$ production cross-sections is reported and is consistent with the corresponding measurement in $pp$~collisions.

   ↳ hep-exnucl-exPRD(2019)·79 citations
2. 02*

   Fock contributions to nuclear symmetry energy and its slope parameter based on Lorentz-covariant decomposition of nucleon self-energies

   Tsuyoshi Miyatsu🇯🇵 · Myung-Ki Cheoun🇰🇷 · Chikako Ishizuka🇯🇵 · K. S. Kim🇰🇷 · Tomoyuki Maruyama🇯🇵 · Koichi Saito🇯🇵

   Using relativistic Hartree-Fock (RHF) approximation, we study the effect of Fock terms on the nuclear properties not only around the saturation density, ${\rho }_0$, but also at higher densities. In particular, we investigate how the momentum dependence due to the exchange contribution affects the nuclear symmetry energy and its slope parameter, using the Lorentz-covariant decomposition of nucleon self-energies in an extended version of the RHF model, in which the exchange terms are adjusted so as to reproduce the single-nucleon potential at ${\rho }_0$. We find that the Fock contribution suppresses the kinetic term of nuclear symmetry energy at the densities around and beyond ${\rho }_0$. It is noticeable that not only the isovector-vector ($\rho$) meson but also the isoscalar mesons ($\sigma ,\omega$) and pion make significant influence on the potential term of nuclear symmetry energy through the exchange diagrams. Furthermore, the exchange contribution prevents the slope parameter from increasing monotonically at high densities.

   ↳ nucl-thnucl-ex4 citations
3. 03*

   Multi-stage jet evolution through QGP using the JETSCAPE framework: inclusive jets, correlations and leading hadrons

   C. Park · A. Angerami · S. A. Bass · S. Cao · J. Coleman · L. Cunqueiro · T. Dai · L. Du · H. Elfner · D. Everett · W. Fan · R. Fries and 32 other authors

   The JETSCAPE Collaboration has recently announced the first release of the JETSCAPE package that provides a modular, flexible, and extensible Monte Carlo event generator. This innovative framework makes it possible to perform a comprehensive study of multi-stage high-energy jet evolution in the Quark-Gluon Plasma. In this work, we illustrate the performance of the event generator for different algorithmic approaches to jet energy loss, and reproduce the measurements of several jet and hadron observables as well as correlations between the hard and soft sector. We also carry out direct comparisons between different approaches to energy loss to study their sensitivity to those observables.

   ↳ nucl-thhep-phnucl-exPoS(2019)·13 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.