Neutrons from multiplicity-selected Au-Au collisions at 150{ital A}, 250{ital A}, 400{ital A}, and 650{ital A} MeV
- Department of Physics and Center for Nuclear Research, Kent State University, Kent, Ohio 44242 (United States)
- Department of Physics and Astronomy, Michigan State University, E. Lansing, Michigan 44823 (United States)
- Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)
- Department of Physics, McGill University, Montreal, QC, Canada, H3A-2T8 (Canada)
We measured neutron triple-differential cross sections from multiplicity-selected Au-Au collisions at 150{ital A}, 250{ital A}, 400{ital A}, and 650{ital A} MeV. The reaction plane for each collision was estimated from the summed transverse velocity vector of the charged fragments emitted in the collision. We examined the azimuthal distribution of the triple-differential cross sections as a function of the polar angle and the neutron rapidity. We extracted the average in-plane transverse momentum {l_angle}{ital P}{sub {ital x}}{r_angle} and the normalized observable {l_angle}{ital P}{sub {ital x}}/{ital P}{sub {perpendicular}}{r_angle}, where {ital P}{sub {perpendicular}} is the neutron transverse momentum, as a function of the neutron center-of-mass rapidity, and we examined the dependence of these observables on beam energy. These collective flow observables for neutrons, which are consistent with those of protons plus bound nucleons from the Plastic Ball Group, agree with the Boltzmann-Uehling-Uhlenback (BUU) calculations with a momentum-dependent interaction. Also, we calculated the polar-angle-integrated maximum azimuthal anisotropy ratio {ital R} from the value of {l_angle}{ital P}{sub {ital x}}/{ital P}{sub {perpendicular}}{r_angle}.
- Research Organization:
- Lawrence Berkeley National Laboratory
- DOE Contract Number:
- AC03-76SF00098; FG02-89ER40531
- OSTI ID:
- 124774
- Journal Information:
- Physical Review, C, Journal Name: Physical Review, C Journal Issue: 5 Vol. 52; ISSN 0556-2813; ISSN PRVCAN
- Country of Publication:
- United States
- Language:
- English
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