
Accession Number : AD0637734
Title : STUDY OF PI(+) 2 PI() FINAL STATES COHERENTLY PRODUCED ON NUCLEI BY 16 GEV/C PI().
Descriptive Note : Final technical rept.
Corporate Author : CALIFORNIA UNIV BERKELEY COSMIC RAY GROUP
Personal Author(s) : Allard,J. F. ; Drijard,D. ; Hennessy,J. ; Huson,R. ; Lloret,A.
Report Date : AUG 1966
Pagination or Media Count : 25
Abstract : Coherent production of pi(+) 2pi() occurs in approx. 1% of 15 and 16 GeV/c pi() C2F5C1 interactions (studied in the Ecole Polytechnique HLBC exposed at the CERN P.S.). For nearly every coherent event, one or both pi(+) pi() combinations lies in the rho(o) or f(o). The ratio of pi() f(o) to pi() rho o coherent production is 0.05 plus or minus 0.02. No N(*) peaks are seen in the coherent events. Swave pi() rho(o) (J(P) = 1(+)) dominates up to at least 1.2 GeV in M pi() rho(o) but small admixture of waves of opposite parity is necessary to explain some angular distribution asymmetries. The Dalitz plot excludes dominance of triangle singularity effects. The pi() rho(o) mass distribution is dominated by a peak in the A sub 1 region, nearly 250 MeV wide, but too narrow to be explained by the momentum transfer limitation imposed by the nuclear form factor. The calculated OPE (Deck model) and rho exchange M sub pi rho distributions are also too broad to fit out data, but uncertainties in the model preclude its firm rejection. If M sub pi rho distribution is assumed due entirely to resonances, there must be one dominant J(P) = 1(+) resonance near 1.05 GeV. To preserve the A sub 1 with width <150 MeV one must assume two other resonances (approx 940 and approx 1180 MeV) in addition to the A sub 2 (1315). (Author)
Descriptors : (*MESONS, NUCLEAR REACTIONS), COHERENT SCATTERING, INELASTIC SCATTERING, BUBBLE CHAMBERS, PIONS, NUCLEAR PHYSICS, FRANCE
Subject Categories : Nuclear Physics & Elementary Particle Physics
Distribution Statement : APPROVED FOR PUBLIC RELEASE