Fri·Jun 19, 2020Friday·June 19, 2020

1. 01*

   Deconfinement and degrees of freedom in $pp$ and $A-A$ collisions at LHC energies

   Aditya N Mishra🇲🇽 · Guy Paić🇲🇽 · C. Pajares🇪🇸 · R. P. Scharenberg🇺🇸 · B. K. Srivastava🇺🇸

   We present the extraction of the temperature by analyzing the charged particle transverse momentum spectra in lead-lead (Pb-Pb) and proton-proton ($\mathbf{pp}$) collisions at LHC energies from the ALICE Collaboration using the Color String Percolation Model (CSPM). From the measured energy density $\mathbf{\epsilon }$ and the temperature T the dimensionless quantity $\mathbf{\epsilon }/T^4$ is obtained to get the degrees of freedom (DOF), $\mathbf{\epsilon }/T^4$ = DOF ${\pi }^2$/30. We observe for the first time a two-step behavior in the increase of DOF, characteristic of deconfinement, above the hadronization temperature at temperature $\sim$ 210 MeV for both Pb-Pb and $\mathbf{pp}$ collisions and a sudden increase to the ideal gas value of $\sim$ 47 corresponding to three quark flavors in the case of Pb-Pb collisions.

   ↳ hep-phhep-exhep-thnucl-exEPJA(2021)·18 citations
2. 02*

   Short-Range Correlations and the Nuclear EMC Effect in Deuterium and Helium-3

   E.P. Segarra🇺🇸 · J.R. Pybus🇺🇸 · F. Hauenstein🇺🇸 · D.W. Higinbotham🇺🇸 · G.A. Miller🇺🇸 · E. Piasetzky🇮🇱 · A. Schmidt🇺🇸 · M. Strikman🇺🇸 · L.B. Weinstein🇺🇸 · O. Hen🇺🇸

   The EMC effect in deuterium and helium-3 is studied using a convolution formalism that allows isolating the impact of high-momentum nucleons in short-ranged correlated (SRC) pairs. We assume that the modification of the structure function of bound nucleons is given by a universal (i.e. nucleus independent) function of their virtuality, and find that the effect of such modifications is dominated by nucleons in SRC pairs. This SRC-dominance of nucleon modifications is observed despite the fact that the bulk of the nuclear inelastic scattering cross-section comes from interacting with low-momentum nucleons. These findings are found to be robust to model details including nucleon modification function parametrization, free nucleon structure function and treatment of nucleon motion effects. While existing data cannot discriminate between such model details, we present predictions for measured, but not yet published, tritium EMC effect and tagged nucleon structure functions in deuterium that are sensitive to the neutron structure functions and bound nucleon modification functions.

   ↳ hep-phhep-exnucl-exnucl-thPRResearch(2021)·15 citations
3. 03*

   Elimination of the effect of internal activity in LaCl3:Ce scintillator

   D. Chattopadhyay🇮🇳 · Sathi Sharma · M. Saha Sarkar🇮🇳

   The Lanthanum Halide scintillator detectors have been widely used for nuclear spectroscopy experiments because of their excellent energy and time resolutions. Despite having these advantages, the intrinsic alpha and beta contaminations in these scintillators pose a severe limitation in their usage in rare-event detections. In the present work, pulse shape discrimination (PSD) with a fast digitizer has been shown to be an efficient method to separate the effect of alpha contamination from the spectrum. The shape of the beta spectrum has been generated with the help of Monte Carlo based simulation code, and its contribution has been eliminated from the spectrum. The reduction in the background events generated by both intrinsic beta and alpha activities has been demonstrated. The present study will encourage the application of these detectors in low cross-section measurement experiments relevant to nuclear astrophysics.

   ↳ physics.ins-detnucl-exnucl-thJINST(2021)·0 citations
4. 04*

   Asymmetric jet clustering in deep-inelastic scattering

   Miguel Arratia🇺🇸 · Yiannis Makris🇮🇹 · Duff Neill🇺🇸 · Felix Ringer🇺🇸 · Nobuo Sato🇺🇸

   We propose a new jet algorithm for deep-inelastic scattering (DIS) that accounts for the forward-backward asymmetry in the Breit frame. The Centauro algorithm is longitudinally invariant and can cluster jets with Born kinematics, which enables novel studies of transverse-momentum-dependent observables. Furthermore, we show that spherically-invariant algorithms in the Breit frame give access to low-energy jets from current fragmentation. We propose novel studies in unpolarized, polarized, and nuclear DIS at the future Electron-Ion Collider.

   ↳ hep-phnucl-exnucl-thPRD(2021)·51 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.