Fri·Sep 7, 2018Friday·September 7, 2018

1. 01*

   Open heavy-flavour production in heavy-ion collisions at the LHC

   Jeremy Wilkinson (for the ALICE, ATLAS, CMS and LHCb Collaborations)🇮🇹

   This work presents the latest results on open heavy-flavour production in proton-proton, proton-lead, lead-lead and xenon-xenon collisions from the ALICE, ATLAS, CMS and LHCb Collaborations at the LHC.

   nucl-exhep-exJ.Phys.Conf.Ser.(2019)·4 citations
2. 02*

   Search for the Chiral Magnetic Wave with Anisotropic Flow of Identified Particles at RHIC-STAR

   Qi-Ye Shou (for the STAR Collaboration)🇨🇳

   The chiral magnetic wave (CMW) has been theorized to propagate in the Quark-Gluon Plasma formed in high-energy heavy-ion collisions. It could cause a finite electric quadrupole moment of the collision system, and may be observed as a dependence of elliptic flow, $v_2$, on the asymmetry between positively and negatively charged hadrons, $A_{\mathrm{ch}}$. However, non-CMW mechanisms, such as local charge conservation (LCC) and hydrodynamics with isospin effect, could also contribute to the experimental observations. Here we present the STAR measurements of elliptic flow $v_2$ and triangular flow $v_3$ of charged pions, along with $v_2$ of charged kaons and protons, as functions of $A_{\mathrm{ch}}$ in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV. The slope parameters of $\Delta v_2$($A_{\mathrm{ch}}$) and $\Delta v_3$($A_{\mathrm{ch}}$) are reported and compared to investigate the LCC background. The similarity between pion and kaon slopes suggests that the hydrodynamics is not the dominant mechanism. The difference between the normalized $\Delta v_2$ and $\Delta v_3$ slopes, together with the small slopes in p+Au and d+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV, suggest that the CMW picture remains a viable interpretation at RHIC.

   nucl-exNPA(2019)·9 citations
3. 03*

   Mass-dependent cuts in longitudinal phase space

   P. Pauli🇬🇧 · D.I. Glazier🇬🇧 · M. Battaglieri🇮🇹 · A. Celentano🇮🇹 · R. De Vita🇮🇹 · S. Diehl🇺🇸 · A. Filippi🇮🇹 · J.T. Londergan🇺🇸 · V. Mathieu🇺🇸 · A. P. Szczepaniak🇺🇸

   Longitudinal phase space analyses as introduced by van Hove provided a simplified method of separating different reaction production mechanisms. Cuts in the longitudinal phase space can help to select specific reaction kinematics but also induce nonflat acceptance effects in angular distributions. We show that in photoproduction reactions dominated by t-channel exchanges, selection of meson or baryon production over a large mass range can be optimized through calculating mass-dependent cut limits compared to cuts on a van Hove plot sector alone. A cut is presented that improves this selection of one type of hadron production by rejecting another. In addition we demonstrate that using cuts in longitudinal phase space preserves sufficient information to reliably extract observables from the angular distribution of the final state particles.

   nucl-exhep-exPRC(2018)·3 citations
4. 04*

   Probing color reconnection with underlying event observables at the LHC energies

   Antonio Ortiz🇲🇽 · Lizardo Valencia Palomo🇲🇽

   In this work we study the underlying event (UE) activity as a function of the highest jet transverse momentum ($p_{\mathrm{T}}^{\mathrm{jet}}$) in terms of the number and summed $p_{\mathrm{T}}$ densities of charged particles in the azimuthal region transverse to the $p_{\mathrm{T}}^{\mathrm{jet}}$ direction. The UE observables normalised to the INEL multiplicity obey an approximate Koba-Nielsen-Olesen (KNO) scaling. Based on PYTHIA~8.2 simulations of $pp$ collisions at LHC energies, we show that the remaining imperfection of the KNO scaling is due to the increasing importance of multiple partonic interactions (MPI) at higher $\sqrt{s}$. Motivated by this, we studied the UE activity considering charged particles within different $p_{\mathrm{T}}$ intervals in $pp$ collisions at $\sqrt{s}=7$\,TeV. We demonstrate that the saturations of both number and summed $p_{\mathrm{T}}$ densities, which are commonly claimed, are only observed for low-\pt charged particles ($0.5<p_{\mathrm{T}}<2$\,GeV/$c$). Moreover, for the $p_{\mathrm{T}}$-integrated case ($p_{\mathrm{T}}>0.5$\,GeV/$c$) the summed $p_{\mathrm{T}}$ density is not sensitive to the variation of color reconnection (CR), however at low-p_{\rm T} it is reduced with increasing CR, whereas an opposite behaviour is found at intermediate-$p_{\mathrm{T}}$ ($2<p_{\mathrm{T}}<10$\,GeV/$c$). Finally, we show that CR produces flow-like behaviour only in the UE region and the effects are reduced with increasing $p_{\mathrm{T}}^{\mathrm{jet}}$ due to the hardering of UE. The outcomes encourage the measurement of inclusive and identified charged particle $p_{\mathrm{T}}$ spectra (over a wide range of $p_{\mathrm{T}}$) associated to UE aimed at better understanding the similarities between $pp$ and heavy-ion data discovered at the LHC.

   ↳ hep-exhep-phnucl-exPRD(2019)·25 citations
5. 05*

   Momentum distributions and short-range correlations in the deuteron and ${}^3$He with modern chiral potentials

   L.E. Marcucci🇮🇹 · F. Sammarruca🇺🇸 · M. Viviani🇮🇹 · R. Machleidt🇺🇸

   We study momentum distributions and short-range correlation probabilities in $A$=2 and $A$=3 systems. First, we show results with phenomenological and meson-theoretic two- and three-nucleon forces to verify consistency with previous similar studies. We then apply most recent high-quality chiral nucleon-nucleon potentials up to fifth order in the chiral expansion together with the leading chiral three-nucleon force. Predictions are examined in the context of a broader discussion of short-range correlation probabilities extracted from analyses of inclusive electron scattering data, addressing the question of whether modern interactions can be reconciled with the latter.

   ↳ nucl-thnucl-exPRC(2019)·32 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.