Diabatic-state treatment of negative-meson moderation and capture. II. Mixtures of hydrogen and helium

Journal Article · Fri Apr 01 04:00:00 EST 1983 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.27.1821· OSTI ID:6078859

Cohen, J S; Martin, R L; Wadt, W R

Slowing-down and capture cross sections have been consistently calculated for ..mu../sup -/, ..pi../sup -/, K/sup -/, and p-bar in collisions with hydrogen and helium atoms and isotopic variants. Capture-energy distributions are determined using the differential-energy-loss cross sections in the laboratory frame. Capture is found to occur predominantly at energies near or below the ionization potential of the target. Ratios of capture on different species are given as a function of the mole fraction of each species present in mixtures. For ..pi../sup -/ in a He-H mixture the reduced capture ratio obtained is approx.0.73, slightly less than the experimental value of 0.92 for the He-H/sub 2/ mixture. In contrast with another recent theoretical calculation and in agreement with experimental analysis, it is found that atomic capture of pions in the helium-hydrogen mixture is only slightly nonlinear. It is pointed out that some prior theoretical treatments are in error because of inconsistent calculation of the slowing-down and capture processes and/or subsequent approximate treatment of the energy transport. Use of capture and transfer rates in muon kinetics, e.g., muon-catalyzed fusion, is discussed.

• Research Organization: Theoretical Division, Los Alamos National Laboratory, University of California, Los Alamos, New Mexico 87545
• OSTI ID: 6078859
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 27:4; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640303* -- Atomic
Molecular & Chemical Physics-- Positronium
Muonium
& Muonic & Mesic Atoms & Molecules
654001 -- Radiation & Shielding Physics-- Radiation Physics
Shielding Calculations & Experiments
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
BINARY MIXTURES
BORN APPROXIMATION
BOSONS
CAPTURE
CATALYTIC EFFECTS
CHARGED-PARTICLE TRANSPORT
CONCENTRATION RATIO
CROSS SECTIONS
DISPERSIONS
DWBA
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
FLUIDS
FUSION REACTIONS
GASES
HADRONS
HELIUM
HYDROGEN
LEPTONS
MESONS
MIXTURES
MUONS
MUONS MINUS
NONMETALS
NUCLEAR REACTIONS
PIONS
PIONS MINUS
PSEUDOSCALAR MESONS
RADIATION TRANSPORT
RARE GASES
SLOWING-DOWN