Nuclear Experiment·nucl-ex
3 papers—1 primary·2 cross-listed·reconstructed*
Andrea Festanti (for the ALICE Collaboration)🇮🇹
The measurement of heavy-flavour production and nuclear modification factor in heavy-ion collisions provides insights into the mechanisms of parton energy loss in the hot and dense medium formed in these collisions. ALICE results on heavy-flavour decay electrons and muons and on D mesons are presented.
Zack Wolff🇺🇸 · Denes Molnar🇺🇸
Comparing hydrodynamic simulations to heavy-ion data inevitably requires the conversion of the fluid to particles. This conversion, typically done in the Cooper-Frye formalism, is ambiguous for viscous fluids. We compute self-consistent phase space corrections by solving the linearized Boltzmann equation and contrast the solutions to those obtained using the ad-hoc "democratic Grad" ansatz typically employed in the literature where coefficients are independent of particle dynamics. Solutions are calculated analytically for a massless gas and numerically for both a pion-nucleon gas and for the general case of a hadron resonance gas. We find that the momentum dependence of the corrections in all systems investigated is best fit by a power close to 3/2 rather than the typically used quadratic ansatz. The effects on harmonic flow coefficients and are substantial, and should be taken into account when extracting medium properties from experimental data.
T. J. Langford🇺🇸 · C. D. Bass🇺🇸 · E. J. Beise🇺🇸 · H. Breuer🇺🇸 · D. K. Erwin🇺🇸 · C. R. Heimbach🇺🇸 · J. S. Nico🇺🇸
A fast neutron spectrometer consisting of segmented plastic scintillator and He-3 proportional counters was constructed for the measurement of neutrons in the energy range 1 MeV to 200 MeV. We discuss its design, principles of operation, and the method of analysis. The detector is capable of observing very low neutron fluxes in the presence of ambient gamma background and does not require scintillator pulseshape discrimination. The spectrometer was characterized for its energy response in fast neutron fields of 2.5 MeV and 14 MeV, and the results are compared with Monte Carlo simulations. Measurements of the fast neutron flux and energy response at 120 m above sea-level (39.130 deg. N, 77.218 deg. W) and at a depth of 560 m in a limestone mine are presented. Finally, the design of a spectrometer with improved sensitivity and energy resolution is discussed.
* 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.