Neutrino mean free paths in cold symmetric nuclear matter

Journal Article · Wed Sep 01 00:00:00 EDT 2004 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.70.035801· OSTI ID:20695550

Cowell, S; Pandharipande, V R ^[1]

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1. Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green St., Urbana, Illinois 61801 (United States)

The neutrino mean free paths (NMFP) for scattering and absorption in cold symmetric nuclear matter (SNM) are calculated using two-body effective interactions and one-body effective weak operators obtained from realistic models of nuclear forces using correlated basis theory. The infinite system is modeled in a box with periodic boundary conditions and the one particle-hole (p-h) response functions are calculated using the Tamm-Dancoff approximation (TDA). For the densities {rho}=(1/2), 1 (3/2){rho}{sub 0}, where {rho}{sub 0} is the equilibrium density of SNM, the strength of the response is shifted to higher energy transfers when compared to a noninteracting Fermi gas (FG). This and the weakness of effective operators compared to the bare operators, significantly reduces the cross sections, enhancing the NMFP by factors of {approx}2.5-3.5 at the densities considered. The NMFP at the equilibrium density {rho}{sub 0} are also calculated using the TDA and random phase approximation (RPA) using zero range Skyrme-like effective interactions with parameters chosen to reproduce the equation of state and spin-isospin susceptibilities of matter. Their results indicate that RPA corrections to correlated TDA may further increase the NMFP by {approx}25% to 3-4 times those in a noninteracting FG. Finally, the sums and the energy weighted sums of the Fermi and Gamow-Teller responses obtained from the correlated ground state are compared with those of the 1 p-h response functions to extract the sum and mean energies of multi p-h contributions to the weak response. The relatively large mean energy of the multi p-h excitations suggests that they may not contribute significantly to low energy NMFP.

• OSTI ID: 20695550
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 70, Issue 3; Other Information: DOI: 10.1103/PhysRevC.70.035801; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ABSORPTION
BOUNDARY CONDITIONS
COSMIC NEUTRINOS
CROSS SECTIONS
DENSITY
ENERGY TRANSFER
EQUATIONS OF STATE
EXCITATION
FERMI GAS
GAMOW-TELLER RULES
GROUND STATES
ISOSPIN
MEAN FREE PATH
NEUTRINO-NEUTRON INTERACTIONS
NUCLEAR FORCES
NUCLEAR MATTER
PARTICLE-HOLE MODEL
PERIODICITY
RANDOM PHASE APPROXIMATION
RESPONSE FUNCTIONS
SCATTERING
SKYRME POTENTIAL
SPIN
TWO-BODY PROBLEM