Test of the independence hypothesis and isospin conservation in compound-statistical reactions

Journal Article · Sat Sep 01 00:00:00 EDT 1973 · Nuclear Physics. A

DOI:https://doi.org/10.1016/0375-9474(73)90034-1· OSTI ID:4431103

Wiley, J.; Pacer, J. C.; Lux, C. R.; Porile, N. T.

Energy spectra and angular distributions of protons and alpha particles emitted in the decay of ⁵⁶Fe, ⁶⁰Ni, ⁶³Cu, ⁶⁴Zn, a nd ⁶⁶Zn were measured. These compound nuclei were produced with a given excitation energy by irradiation of appropriate targets with 14.0-MeV protons and 15- to 19-MeV alpha particles. The proton spectra featured a low-energy peak ascribable to the (p, np) or ( sigma , np) reaction, as well as a higher energy peak due to the (p p') or ( alpha , p) reaction. These peaks were sufficiently well resolved that differential cross sections could be obtained for the p, np, as well as alpha exit channels. The alpha and np exit channels were found to be free of precompound effects and are not affected by isospin conservation. Comparison of these particular cross sections for both entrance channels permits a test of the independence hypothesis provided a correction is made for the different angular momentum distributions in the entrance channels. When this correction is applied on the basis of the spin-dependent statistical theory, it is found that the independence hypothesis is confirmed in all cases. Comparison of the p and alpha exit channels leads to values of the isospin mixing fraction, mu , between the T> and T< states of the compound nucleus. The values of mu are 0.4 plus or minus 0.2 for all five compounds nuclei, and correspond to Coulomb mixing widths whose value is approximately 20 keV. (8 figures, 4 tables) (auth)

• Research Organization: Purdue Univ., Lafayette, IN
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-001661
• OSTI ID: 4431103
• Journal Information: Nuclear Physics. A, Journal Name: Nuclear Physics. A Journal Issue: 1 Vol. 212; ISSN 0375-9474
• Publisher: Elsevier
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA PARTICLES
ALPHA REACTIONS-- CHROMIUM 52-- IRON 56-- NICKEL 60
ANGULAR DISTRIBUTION
CONSERVATION LAWS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ENERGY SPECTRA
ISOSPIN
MEV RANGE 10-100
NEUTRONS
PROTONS COPPER 63-- COPPER 65-- MANGANESE 55-- PROTON REACTIONS