Mon·Mar 2, 2020Monday·March 2, 2020

1. 01*

   Measurement of the Sixth-Order Cumulant of Net-Proton Distributions in Au+Au Collisions from the STAR Experiment

   Toshihiro Nonaka (for the STAR Collaboration)🇨🇳

   Higher-order cumulants of the net-baryon multiplicity distributions are predicted to be sensitive to the properties of the nuclear matter created in high-energy nuclear collisions. In this talk, we present the collision centrality and acceptance (rapidity and transverse momentum) dependence of the ratio of the 6${}^{\mathrm{th}}$- to the 2${}^{\mathrm{nd}}$-order cumulant ratio ($C_6/C_2$) of net-proton in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=54.4$ and 200 GeV measured by the STAR detector at RHIC. The new results are compared to hadron transport model and lattice QCD calculations.

   nucl-exhep-exNPA(2021)·16 citations
2. 02*

   Dalitz plots and lineshape of $a_1(1260)$ from a relativistic three-body unitary approach

   Daniel Sadasivan🇺🇸 · Maxim Mai🇺🇸 · Hakan Akdag🇩🇪 · Michael Döring🇺🇸

   We formulate the final state interaction of the $a_1(1260)$ resonance decay in a manifestly three-body unitary parameterization and fit it to the $a_1(1260)$ lineshape measured by the ALEPH experiment. Dalitz plots calculated from this fit are presented. The work demonstrates the feasibility to numerically solve a previously derived amplitude and its generalization to isobars with spin and coupled channels. The model can also be applied to other meson decays and modified for the finite-volume problem as it arises in lattice QCD due to its manifest unitarity.

   ↳ nucl-thhep-phnucl-exPRD(2020)·37 citations
3. 03*

   The dijet mass distribution in heavy ion collisions

   Jared Reiten🇺🇸

   In these proceedings, we review the production of both light and heavy flavor dijets in heavy ion collisions and highlight a promising observable to expose their distinct signatures. We propose the modification of dijet invariant mass distributions in heavy ion collisions as a novel observable that exhibits striking sensitivity to the quark-gluon plasma transport properties and heavy quark mass effects on in-medium parton showers. This observable has the advantage of amplifying the effects of jet quenching in contrast to conventional observables, such as the dijet momentum imbalance shift, which involve cancellations of such effects and, hence, result in less pronounced signals. Predictions are presented for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV to guide the future sPHENIX program at the Relativistic Heavy Ion Collider.

   ↳ hep-phhep-exnucl-exnucl-thEPJ Web Conf.(2020)·0 citations
4. 04*

   Effects of high-$j$ orbitals, pairing and deformed neutron shells on upbendings of ground-state bands in neutron-rich even-even isotopes ${}^{170-184}$Hf

   Xiao-Tao He🇨🇳 · Yang Cao · Xiao-Ling Gan

   The ground-state bands (GSBs) in the even-even hafnium isotopes ${}^{170-184}$Hf are investigated by using the cranked shell model (CSM) with pairing correlations treated by the particle-number conserving (PNC) method. The experimental kinematic moments of inertia are reproduced very well by theoretical calculations. The second upbending of the GSB at high frequency $\hslash \omega \approx 0.5$ MeV observed (predicted) in ${}^{172}$Hf (${}^{170,174-178}$Hf) attributes to the sudden alignments of the proton high-$j$ orbitals $\pi 1i_{13/2}$ $(1/2^{+}[660])$, $\pi 1h_{9/2}$ $(1/2^{-}[541])$ and orbital $\pi 1h_{11/2}$ $(7/2^{-}[523])$. The first upbendings of GSBs at low frequency $\hslash \omega =0.2-0.3$ MeV in ${}^{170-178}$Hf, which locate below the deformed neutron shell $N=108$, attribute to the alignment of the neutron orbital $\nu 1i_{13/2}$. For the heavier even-even isotopes ${}^{180-184}$Hf, compared to the lighter isotopes, the first band-crossing is delayed to the high frequency due to the existence of the deformed shells $N=108,116$. The upbendings of GSBs in ${}^{180-184}$Hf are predicted to occur at $\hslash \omega \approx 0.5$MeV, which come from the sharp raise of the simultaneous alignments of both proton $\pi 1i_{13/2}$, $\pi 1h_{9/2}$ and neutron $\nu 2g_{9/2}$ orbitals. The pairing correlation plays a very important role in the rotational properties of GSBs in even-even isotopes ${}^{180-184}$Hf. Its effects on upbendings and band-crossing frequencies are investigated.

   ↳ nucl-thnucl-exPRC(2020)·1 citation
5. 05*

   Charge-dependent flow induced by electromagnetic fields in heavy ion collisions

   U. Gürsoy🇳🇱 · D.E. Kharzeev🇺🇸 · E. Marcus🇳🇱 · K. Rajagopal🇺🇸 · C. Shen🇺🇸

   The colliding heavy ions create extremely strong magnetic and electric fields that significantly affect the evolution of the produced quark-gluon plasma (QGP). The knowledge of these fields is essential for establishing the role of topological fluctuations in the QGP through the chiral magnetic effect and related anomaly-induced phenomena. In this talk, we describe our work on the evolution of the QGP in electric and magnetic fields in the framework of hydrodynamics supplemented, in a perturbative fashion, by the dynamical electromagnetism. The evolution of the QGP fluid is described within the iEBE-VISHNU framework. We find that the electromagnetically induced currents result in a charge-odd directed flow $\Delta v_1$ and a charge-odd $\Delta v_3$ flow both of which are odd in rapidity. While the predicted magnitude of these charge-odd flows agrees with the data from RHIC and LHC, the sign of the predicted asymmetry between the flows of positive and negative hadrons is opposite to the data.

   ↳ hep-phnucl-exnucl-thNPA(2021)·5 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.