Tue·May 14, 2019Tuesday·May 14, 2019

1. 01*

   Investigation of neutron-induced reaction at the Goethe University Frankfurt

   Rene Reifarth🇩🇪 · Lukas Bott🇩🇪 · Benjamin Brückner🇩🇪 · Ozan Dogan · Markus Dworac · Anne Endres · Philipp Erbacher🇩🇪 · Stefan Fiebiger · Roman Gernhäuser🇩🇪 · Kathrin Göbel🇩🇪 · Fabian Hebermehl · Tanja Heftrich🇩🇪 and 18 other authors

   We present first results and plans for future neutron activation measurements at the Goethe University Frankfurt. The measurements were performed at the Van-de-Graaff accelerator employing the 7Li(p,n) reaction.

   nucl-exastro-ph.IMSpringer Proc.Phys.(2019)·0 citations
2. 02*

   A diquark model for the d*(2380) dibaryon resonance?

   Avraham Gal🇮🇱 · Marek Karliner🇮🇱

   Diquark models have been applied with varying degree of success to tetraquark and pentaquark states involving both light and heavy quark degrees of freedom. We discuss the applicability of such models to light quark dibaryons, viewed as three-diquark objects. Highlighting the case of the d*(2380) dibaryon resonance, we demonstrate the inapplicability of diquark models in the light quark sector.

   ↳ hep-phnucl-exnucl-thEPJC(2019)·7 citations
3. 03*

   Flow in AA and pA as an interplay of fluid-like and non-fluid like excitations

   Aleksi Kurkela🇨🇭 · Urs Achim Wiedemann🇨🇭 · Bin Wu🇨🇭

   To study the microscopic structure of quark-gluon plasma, data from hadronic collisions must be confronted with models that go beyond fluid dynamics. Here, we study a simple kinetic theory model that encompasses fluid dynamics but contains also particle-like excitations in a boost invariant setting with no symmetries in the transverse plane and with large initial momentum asymmetries. We determine the relative weight of fluid dynamical and particle like excitations as a function of system size and energy density by comparing kinetic transport to results from the 0th, 1st and 2nd order gradient expansion of viscous fluid dynamics. We then confront this kinetic theory with data on azimuthal flow coefficients over a wide centrality range in PbPb collisions at the LHC, in AuAu collisions at RHIC, and in pPb collisions at the LHC. Evidence is presented that non-hydrodynamic excitations make the dominant contribution to collective flow signals in pPb collisions at the LHC and contribute significantly to flow in peripheral nucleus-nucleus collisions, while fluid-like excitations dominate collectivity in central nucleus-nucleus collisions at collider energies.

   ↳ hep-phhep-exnucl-exnucl-thEPJC(2019)·112 citations
4. 04*

   Symmetry, symmetry breaking, and pion parton distributions

   Minghui Ding🇨🇳 · Khepani Raya🇲🇽 · Daniele Binosi🇮🇹 · Lei Chang🇨🇳 · C. D. Roberts🇺🇸 · S. M. Schmidt🇩🇪

   Pion valence, glue and sea distributions are calculated using a continuum approach to the two valence-body bound-state problem. Since the framework is symmetry preserving, physical features of the distributions are properly expressed. The analysis reveals that the emergent phenomenon of dynamical chiral symmetry breaking causes a hardening of the valence-quark distribution function, $q^{\pi }(x)$. Nevertheless, this distribution exhibits the $x\simeq 1$ behaviour predicted by quantum chromodynamics (QCD). At the scale ${\zeta }_2:=2$GeV, the following momentum fractions are predicted: $⟨x_{\mathrm{valence}}⟩=0.48(3)$, $⟨x_{\mathrm{glue}}⟩=0.41(2)$, $⟨x_{\mathrm{sea}}⟩=0.11(2)$. Evolving to $\zeta =5.2$GeV, the result for $q^{\pi }(x)$ agrees with that computed using lattice QCD. These outcomes should both spur improved analyses of existing experiments and stimulate efforts to obtain new data on the pion distribution functions using available and envisioned facilities.

   ↳ nucl-thhep-exhep-lathep-ph+1PRD(2020)·129 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.