Wed·Jul 14, 2021Wednesday·July 14, 2021

1. 01*

   The EXO-200 detector, part II: Auxiliary Systems

   N. Ackerman · J. Albert · M. Auger · D. J. Auty · I. Badhrees · P. S. Barbeau · L. Bartoszek · E. Baussan · V. Belov · C. Benitez-Medina · T. Bhatta · M. Breidenbach and 148 other authors

   The EXO-200 experiment searched for neutrinoless double-beta decay of ${}^{136}$Xe with a single-phase liquid xenon detector. It used an active mass of 110 kg of 80.6%-enriched liquid xenon in an ultra-low background time projection chamber with ionization and scintillation detection and readout. This paper describes the design and performance of the various support systems necessary for detector operation, including cryogenics, xenon handling, and controls. Novel features of the system were driven by the need to protect the thin-walled detector chamber containing the liquid xenon, to achieve high chemical purity of the Xe, and to maintain thermal uniformity across the detector.

   ↳ physics.ins-dethep-exnucl-exJINST(2022)·17 citations
2. 02*

   Bottomonium production in heavy-ion collisions using quantum trajectories: Differential observables and momentum anisotropy

   Nora Brambilla🇩🇪 · Miguel Ángel Escobedo🇪🇸 · Michael Strickland🇺🇸 · Antonio Vairo🇩🇪 · Peter Vander Griend🇩🇪 · Johannes Heinrich Weber🇩🇪

   We report predictions for the suppression and elliptic flow of the ${\rm Y}(1S)$, ${\rm Y}(2S)$, and ${\rm Y}(3S)$ as a function of centrality and transverse momentum in ultra-relativistic heavy-ion collisions. We obtain our predictions by numerically solving a Lindblad equation for the evolution of the heavy-quarkonium reduced density matrix derived using potential nonrelativistic QCD and the formalism of open quantum systems. To numerically solve the Lindblad equation, we make use of a stochastic unraveling called the quantum trajectories algorithm. This unraveling allows us to solve the Lindblad evolution equation efficiently on large lattices with no angular momentum cutoff. The resulting evolution describes the full 3D quantum and non-abelian evolution of the reduced density matrix for bottomonium states. We expand upon our previous work by treating differential observables and elliptic flow; this is made possible by a newly implemented Monte-Carlo sampling of physical trajectories. Our final results are compared to experimental data collected in $\sqrt{s_{NN}}=5.02$ TeV Pb-Pb collisions by the ALICE, ATLAS, and CMS collaborations.

   ↳ hep-phnucl-exnucl-thphysics.comp-phPRD(2021)·71 citations
3. 03*

   Constraining Neutron-Star Matter with Microscopic and Macroscopic Collisions

   S. Huth🇩🇪 · P. T. H. Pang🇳🇱 · I. Tews🇺🇸 · T. Dietrich🇩🇪 · A. Le Fèvre🇩🇪 · A. Schwenk🇩🇪 · W. Trautmann🇩🇪 · K. Agarwal🇩🇪 · M. Bulla🇸🇪 · M. W. Coughlin🇺🇸 · C. Van Den Broeck🇳🇱

   Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores of neutron stars remains limited. Fortunately, dense matter is not only probed in astrophysical observations, but also in terrestrial heavy-ion collision experiments. In this work, we use Bayesian inference to combine data from astrophysical multi-messenger observations of neutron stars and from heavy-ion collisions of gold nuclei at relativistic energies with microscopic nuclear theory calculations to improve our understanding of dense matter. We find that the inclusion of heavy-ion collision data indicates an increase in the pressure in dense matter relative to previous analyses, shifting neutron-star radii towards larger values, consistent with recent NICER observations. Our findings show that constraints from heavy-ion collision experiments show a remarkable consistency with multi-messenger observations and provide complementary information on nuclear matter at intermediate densities. This work combines nuclear theory, nuclear experiment, and astrophysical observations, and shows how joint analyses can shed light on the properties of neutron-rich supranuclear matter over the density range probed in neutron stars.

   ↳ nucl-thastro-ph.HEastro-ph.SRgr-qc+1Nature(2022)·388 citations
4. 04*

   MuSIC@Indiana: an effective tool for accurate measurement of fusion with low-intensity radioactive beams

   J. E. Johnstone🇺🇸 · Rohit Kumar · S. Hudan🇺🇸 · Varinderjit Singh🇺🇸 · R. T. deSouza🇺🇸 · J. Allen🇺🇸 · D.W. Bardayan🇺🇸 · D. Blankstein · C. Boomershine🇺🇸 · S. Carmichael · A.M. Clark🇺🇸 · S. Coil · S.L. Henderson · P.D. O'Malley

   The design, construction, and characterization of the Multi-Sampling Ionization Chamber, MuSIC@Indiana, are described. This detector provides efficient and accurate measurement of the fusion cross-section at near-barrier energies. The response of the detector to low-intensity beams of ${}^{17,18}$O, ${}^{19}$F, ${}^{23}$Na, ${}^{24,26}$Mg, ${}^{27}$Al, and ${}^{28}$Si at E${}_{lab}$ = 50-60 MeV was examined. MuSIC@Indiana was commissioned by measuring the ${}^{18}$O+${}^{12}$C fusion excitation function for 11 $<$ E${}_{cm}$ $<$ 20 MeV using CH${}_4$ gas. A simple, effective analysis cleanly distinguishes proton capture and two-body scattering events from fusion on carbon. With MuSIC@Indiana, measurement of 15 points on the excitation function for a single incident beam energy is achieved. The resulting excitation function is shown to be in good agreement with literature data

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2021)·10 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.