sup 4 He(. pi. ,. pi. prime p ) sup 3 He reaction near the P sub 33. pi. -nucleon resonance

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.46.52· OSTI ID:7113782

Jones, M K; Dehnhard, D; Nanda, S K; Sterbenz, S M ^[1]; Morris, C L; Plum, M ^[2]; Zumbro, J D ^[3]; Hussein, A H ^[4]; Oakley, D S; Smithson, M J; Williams, A L; McDonald, J; Bryan, M A; Fuentes, A H; Lynker, M; Crockett, D; Machuca, M A; Mordechai, S; Moore, C F ^[5]

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1. University of Minnesota,, Minneapolis, Minnesota 55455 (United States)
2. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
3. University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States) Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
4. King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)
5. University of Texas at Austin, Austin, Texas 78712-1081 (United States)

Inclusive and exclusive spectra of the {sup 4}He({pi},{pi}{prime},{ital p}) reaction were measured with {pi}{sup +} and {pi}{sup {minus}} at {ital T}{sub {pi}}=140 MeV and {theta}{sub {pi}}=40{degree}, and at 180 MeV and 30{degree}, 40{degree}, 60{degree}, and 80{degree} using the EPICS system at LAMPF in coincidence with elastic plastic scintillators. The inclusive spectra yield cross section ratios {ital R}{sub {pi}}={sigma}({pi}{sup +})/{sigma}({pi}{sup {minus}})=1.1{plus minus}0.1 at both {ital T}{sub {pi}} and all {theta}{sub {pi}}. Exclusive spectra were obtained between {sup 4}He{sup *} excitation energies {ital E}{sub {ital x}}=21.5 and 45.0 MeV. Angular correlation functions for ({pi},{pi}{prime},{ital p}) were extracted at {ital T}{sub {pi}}=180 MeV at the four pion angles for selected regions of {ital E}{sub {ital x}}. The ({pi}{sup +},{pi}{sup +{prime}}{ital p}) angular correlations show a distinct peak near the free proton knockout angle; however, the ({pi}{sup {minus}},{pi}{sup {minus}{prime}}{ital p}) data show either a flat distribution or a mininum near that angle. Calculations, using a distorted wave impulse approximation (DWIA) code which models the ({pi},{pi}{prime}{ital p}) reaction as a pion-induced proton knockout, predict peaks in the angular correlation functions in the quasifree knockout direction and reproduce quite well the ({pi}{sup +},{pi}{sup +{prime}}{ital p}) data above {ital E}{sub {ital x}}=30 MeV. However, these calculations do not resemble the ({pi}{sup {minus}},{pi}{sup {minus}{prime}}{ital p}) data at any excitation energy.

• OSTI ID: 7113782
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 46:1; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

663460* -- Meson- & Hyperon-induced Reactions & Scattering-- (1992-)
663510 -- Nuclear Mass Ranges-- A=1-5-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR CORRELATION
BARYONS
CHARGED-PARTICLE REACTIONS
CORRELATIONS
DIRECT REACTIONS
DISTORTED WAVE THEORY
ELEMENTARY PARTICLES
ENERGY RANGE
ENERGY SPECTRA
FERMIONS
GIANT RESONANCE
HADRON REACTIONS
HADRONS
HELIUM 4 TARGET
IMPULSE APPROXIMATION
KNOCK-OUT REACTIONS
MESON REACTIONS
MEV RANGE
MEV RANGE 100-1000
NUCLEAR REACTIONS
NUCLEONS
PION MINUS REACTIONS
PION PLUS REACTIONS
PION REACTIONS
PROTONS
QUASI-FREE REACTIONS
RESONANCE
SPECTRA
TARGETS