Search for narrow states by detection of monochromatic gamma rays in p-barp annihilation at rest

Journal Article · Tue Dec 01 04:00:00 EST 1987 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.36.3321· OSTI ID:5584589

Chiba, M; Doi, K; Fujitani, T; Iwahori, J; Kawaguti, M; Kobayashi, M; Koike, M; Kozuki, T; Kurokawa, S; Kusumoto, H

We measured inclusive ..gamma..-ray spectra from p-barp annihilation at rest to search for narrow ..gamma.. lines associated with the production of baryonia. The measurement was done with statistics several times as high as those of earlier experiments by using modularized NaI(Tl) detectors. We have not observed any narrow states, i.e., baryonium candidates, with statistical significance higher than 4sigma. The 4sigma upper limits for the yield of p-barp..--> gamma..B times the decay branching ratio of B into N/sub ch/-prong states is (1.2--0.2) x 10/sup -3/ at ..gamma..-ray energy of 80--938 MeV for the sum over N/sub ch/, (0.3--0.1) x 10/sup -3/ for each of N/sub ch/ = 0 and greater than or equal to6, and (0.8--0.1) x 10/sup -3/ for each of N/sub ch/ = 2 and 4. At 2 to 3sigma levels, however, we have seen nine narrow ..gamma..-ray peaks with individual yields between 10/sup -4/ and 10/sup -3/ for various charge multiplicities.

• Research Organization: Faculty of Engineering, Fukui University, Fukui 910, Japan
• OSTI ID: 5584589
• Journal Information: Phys. Rev. D; (United States), Journal Name: Phys. Rev. D; (United States) Vol. 36:11; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645103* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Strong Interactions & Baryon & Meson Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
BARYON-BARYON INTERACTIONS
BARYONIUM
BASIC INTERACTIONS
BOSONS
BOUND STATE
BRANCHING RATIO
DECAY
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
FIELD THEORIES
GAMMA SPECTRA
HADRON-HADRON INTERACTIONS
HADRONS
INCLUSIVE INTERACTIONS
INTERACTIONS
MASS
MESONS
MULTIPLICITY
NUCLEON-ANTINUCLEON INTERACTIONS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
POSTULATED PARTICLES
PROTON-ANTIPROTON INTERACTIONS
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARKS
SPECTRA