Tue·Sep 24, 2019Tuesday·September 24, 2019

1. 01*

   Measurements of inclusive jet spectra in pp and central Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

   ALICE Collaboration

   This article reports measurements of the $p_{\mathrm{T}}$-differential inclusive jet cross-section in pp collisions at $\sqrt{s}$ = 5.02 TeV and the $p_{\mathrm{T}}$-differential inclusive jet yield in Pb-Pb 0-10% central collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV. Jets were reconstructed at mid-rapidity with the ALICE tracking detectors and electromagnetic calorimeter using the anti-$k_{\mathrm{T}}$ algorithm. For pp collisions, we report jet cross-sections for jet resolution parameters $R=0.1-0.6$ over the range $20<p_{\mathrm{T},\mathrm{jet}}<140$ GeV/$c$, as well as the jet cross-section ratios of different $R$, and comparisons to two next-to-leading-order (NLO)-based theoretical predictions. For Pb-Pb collisions, we report the $R=0.2$ and $R=0.4$ jet spectra for $40<p_{\mathrm{T},\mathrm{jet}}<140$ GeV/$c$ and $60<p_{\mathrm{T},\mathrm{jet}}<140$ GeV/$c$, respectively. The scaled ratio of jet yields observed in Pb-Pb to pp collisions, $R_{\mathrm{AA}}$, is constructed, and exhibits strong jet quenching and a clear $p_{\mathrm{T}}$-dependence for $R=0.2$. No significant $R$-dependence of the jet $R_{\mathrm{AA}}$ is observed within the uncertainties of the measurement. These results are compared to several theoretical predictions.

   nucl-exhep-exPRC(2020)·184 citations
2. 02*

   Beam Asymmetries ($\Sigma$) for ${\pi }^0$, $\eta$ and ${\eta }^{\prime }$ in Photoproduction at GlueX

   William McGinley🇺🇸 · Tegan Beattie (on behalf of the GlueX Collaboration)🇨🇦

   The GlueX experiment is a photoproduction experiment located at Thomas Jefferson National Lab in Newport News, Virginia. GlueX is capable of making beam asymmetry ($\Sigma$) measurements using a tagged, linearly-polarized 9 GeV photon beam incident on a hydrogen target. Measurements of the beam asymmetry for the exclusive reactions $\gamma p\to {\pi }^{0}p$, $\gamma p\to \eta p$ and $\gamma p\to {\eta }^{\prime }p$ will provide insight into the meson production mechanisms. GlueX measurements are the first beam asymmetry results for the $\eta$ and ${\eta }^{\prime }$ in this energy range and are expected to further constrain Regge theory models for photoproduced pseudoscalar mesons. This talk will present preliminary results of the photon beam asymmetries as a function of the Mandelstam variable, t, for multiple $\eta$ decay modes and the ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\eta$ decay mode.

   nucl-exhep-exAIP Conf.Proc.(2020)·0 citations
3. 03*

   Performance of Large Area Picosecond Photo-Detectors (LAPPD)

   A. V. Lyashenko · B. W. Adams · M. Aviles · T. Cremer · C. D. Ertley · M. R. Foley · M. J. Minot · M. A. Popecki · M. E. Stochaj · W. A. Worstell · J. W. Elam · A. U. Mane and 5 other authors

   We report on performance results achieved for recently produced LAPPDs - largest comercially available planar geometry photodetectors based on microchannel plates. These results include electron gains of up to $10^7$, low dark noise rates ($\sim$100 Hz/cm${}^2$ at a gain of $6\cdot 10^6$), single photoelectron (PE) timing resolution of $\sim$50 picoseconds RMS (electronics limited), and single photoelectron spatial resolution along and across strips of 3.2mm (electronics limited) and 0.8 mm RMS respectively and high (about 25\% or higher in some units) QE uniform bi-alkali photocathodes. LAPPDs is a good candidate to be employed in neutrino experiments (e.g. ANNIE, WATCHMAN, DUNE), particle collider experiments (e.g. EIC), neutrinoless double-beta decay experiments (e.g. THEIA), medical and nuclear non-proliferation applications.

   ↳ physics.ins-detnucl-exphysics.med-phNucl.Instrum.Meth.A(2020)·70 citations
4. 04*

   Global fluid fits to identified particle transverse momentum spectra from heavy-ion collisions at the Large Hadron Collider

   D. Devetak🇩🇪 · A. Dubla🇩🇪 · S. Floerchinger🇩🇪 · E. Grossi🇩🇪 · S. Masciocchi🇩🇪 · A. Mazeliauskas🇨🇭 · I. Selyuzhenkov🇩🇪

   Transverse momentum spectra of identified particles produced in heavy-ion collisions at the Large Hadron Collider are described with relativistic fluid dynamics. We perform a systematic comparison of experimental data for pions, kaons and protons up to a transverse momentum of 3 GeV$/c$ with calculations using the FluiduM code package to solve the evolution equations of fluid dynamics, the TrENTo model to describe the initial state and the FastReso code to take resonance decays into account. Using data in five centrality classes at the center-of-mass collision energy per nucleon pair $\sqrt{s_{\text{NN}}}=2.76\text{TeV}$, we determine systematically the most likely parameters of our theoretical model including the shear and bulk viscosity to entropy ratios, the initialization time, initial density and freeze-out temperature through a global search and quantify their posterior probability. This is facilitated by the very efficient numerical implementation of FluiduM and FastReso. Based on the most likely model parameters we present predictions for the transverse momentum spectra of multi-strange hadrons as well as identified particle spectra from Pb-Pb collisions at $\sqrt{s_{\text{NN}}}=5.02\text{TeV}$.

   ↳ hep-phnucl-exnucl-thJHEP(2020)·50 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.