Simultaneous measurement of the photodisintegration of {sup 4}He in the giant dipole resonance region

Journal Article · Sat Oct 01 04:00:00 EDT 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.72.044004· OSTI ID:20699043

Shima, T; Naito, S; Nagai, Y; Baba, T; Tamura, K; Takahashi, T; Kii, T; Ohgaki, H; Toyokawa, H ^[1]

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1. Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan)

We have performed for the first time the simultaneous measurement of the two-body and three-body photodisintegration cross sections of {sup 4}He in the energy range from 21.8 to 29.8 MeV using monoenergetic pulsed photons and a 4{pi} time projection chamber containing {sup 4}He gas as an active target in an event-by-event mode. The photon beam was produced via the Compton backscattering of laser photons with high-energy electrons. The {sup 4}He({gamma},p){sup 3}H and {sup 4}He({gamma},n){sup 3}He cross sections were found to increase monotonically with energy up to 29.8 MeV, in contrast to the result of a recent theoretical calculation based on the Lorentz integral transform method that predicted a pronounced peak at around 26-27 MeV. The energy dependence of the obtained {sup 4}He({gamma},n){sup 3}He cross section up to 26.5 MeV is marginally consistent with a Faddeev-type calculation predicting a flat pattern of the excitation function. The cross section ratio of {sup 4}He({gamma},p){sup 3}H to {sup 4}He({gamma},n){sup 3}He is found to be consistent with the expected value for charge symmetry of the strong interaction within the experimental uncertainty in the measured energy range. The present results for the total and two-body cross sections of the photodisintegration of {sup 4}He are compared to previous experimental data and recent theoretical calculations.

• OSTI ID: 20699043
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 4 Vol. 72; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ATOMIC NUMBER
BACKSCATTERING
DIPOLES
ELECTRONS
ENERGY DEPENDENCE
ENERGY-LEVEL TRANSITIONS
EXCITATION FUNCTIONS
GIANT RESONANCE
HELIUM 3
HELIUM 4 TARGET
MEV RANGE
NEUTRONS
PHOTONS
PHOTONUCLEAR REACTIONS
PROTONS
STRONG INTERACTIONS
THREE-BODY PROBLEM
TIME PROJECTION CHAMBERS
TRITIUM
TWO-BODY PROBLEM