
Accession Number : AD0614740
Title : THE BINDING ENERGY DIFFERENCE BETWEEN THE HYPERNUCLIDES 4HE SUB LAMBDA AND 4H SUB LAMBDA.
Descriptive Note : Doctoral thesis,
Corporate Author : CHICAGO UNIV ILL ENRICO FERMI INST FOR NUCLEAR STUDIES
Personal Author(s) : Raymund,M.
Report Date : 03 OCT 1963
Pagination or Media Count : 33
Abstract : Experimental and theoretical studies indicate a departure from charge symmetry for the mirror hypernuclides 4He sub lambda and 4He sub lambda amounting to a few tenths of a MeV in the binding energies. A nuclear emulsion experiment utilizing 45 newly measured pion() mesic decays of 4He sub lambda and 4H sub lambda is reported to give delta B sub lambda = B sub lambda (4He sub lambda) B sub lambda (4H sub lambda) = (0.55=0.26) MeV. Contamination by other hypernuclides (probably 5He sub lambda) was eliminated from the 4He sub lambda sample by a strict recoilrange requirement (R> or = 10 micro. m), while, on the other hand, no contaminants were found among the 4H sub lambda decays. The binding energy discrepancy between the pionr and pionpr decays of 4H sub lambda was found to be due to pion range measurement losses which are important mainly for the pionr events (R sub pi = 4 cm). The final value of delta B sub lambda for the latter sample is (0.30=0.14) MeV. Because a negative term in the theoretical calculation of delta B sub lambda is expected from a Coulomb energy increase in the 3He core of 4He sub lambda, this positive experimental result is a strong indication of chargesymmetry violation in the lambda hyperon N interaction compatible with estimates of the virtual electromagnetic effects in (lambda hyperon to lambda hyperon + pion) suggested by theoretical workers.
Descriptors : (*NUCLEAR BINDING ENERGY, HYPERONS), (*HELIUM, NUCLEAR BINDING ENERGY), (*HYDROGEN, NUCLEAR BINDING ENERGY), DECAY SCHEMES, PIONS, SIGMA HYPERONS
Distribution Statement : APPROVED FOR PUBLIC RELEASE