Muon capture at large y-energetic nucleon emission

Conference · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5399644

Martoff, C. J.

Capture of a negative muon by a nucleus leads in some fraction of cases to emission of a nucleon carrying a substantial fraction of the entire available energy Q = {Delta}m + m{sub {mu}} {minus} B{sub {mu}}. Here {Delta}m is the difference of initial and final (excited) nuclear masses, m{sub {mu}} is the muon mass, and B{sub {mu}} is the atomic binding energy of the muon before capture. This corresponds to emission of nucleons with 350--420 MeV/c of momentum, while the momentum transfer at the leptonic vertex is small and generally timelike ({vert bar} Q{sup 2} {vert bar}<100MeV/c). Such high momentum emitted particles have very poor wave function overlap with bound nucleons in conventional nuclear models, making the observed rates much too large to account for in such models. In this report I will examine energetic nucleon data from muon capture in {sup 40}Ca, to see how this reaction can be understood. I will show that in addition to the usual IA mechanism, the data requires an additional capture interaction between the muon and a pair of nucleons. The resulting nucleon and neutrino energy/momentum distribution in the rest system of the (pair + muon) is essentially given by phase space. The strength of the pair capture relative to the IA is several per cent. 21 refs., 3 figs.

• Research Organization: Temple Univ., Philadelphia, PA (USA). Dept. of Physics
• Sponsoring Organization: DOE/ER
• DOE Contract Number: FG02-88ER40389
• OSTI ID: 5399644
• Report Number(s): DOE/ER/40389-56; CONF-8906160--7; ON: DE90002568
• Country of Publication: United States
• Language: English

Related Subjects

651520* -- Nuclear Properties &amp; Reactions
A=39-58
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BRANCHING RATIO
CALCIUM 40 TARGET
CHARGED-PARTICLE REACTIONS
GIANT RESONANCE
IMPULSE APPROXIMATION
LEPTON REACTIONS
MOMENTUM TRANSFER
MUON REACTIONS
NUCLEAR REACTIONS
NUCLEAR STRUCTURE
RESONANCE
TARGETS