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Measurement ofγrays from antiproton-deuterium annihilation at rest

Authors :
Masami Chiba
Minoru Takasaki
T. Fujitani
T. Omori
J. Iwahori
Y. Nagashima
Y. Yamaguchi
Shigeki Sugimoto
M. Kawaguti
Makoto Kobayashi
Hajime Yoshida
Shin-ichi Kurokawa
Fujio Takeutchi
Source :
Physical Review D. 44:1933-1944
Publication Year :
1991
Publisher :
American Physical Society (APS), 1991.

Abstract

Using modularized NaI(Tl) detectors, we have carried out a high-statistics measurement of inclusive {gamma}-ray spectra from {ital {bar p}d} annihilation at rest separately for each charge multiplicity of the final state. We have not seen, at statistical significance above 4{sigma}, any monochromatic {gamma}-ray peaks, which may be assigned to baryonium production {ital {bar p}p} or {ital {bar p}n}{r arrow}{gamma}{ital B} or to {ital {bar N}NN} bound-state production {ital {bar p}d}{r arrow}{gamma}({ital {bar N}NN}). The 4{sigma} upper limit for baryonium production per annihilation varied between 10{sup {minus}2} and 10{sup {minus}4} depending on baryonium mass of 1700 to 600 MeV/{ital c}{sup 2} and on the charge multiplicity. At (2--3){sigma} levels, however, five peaks were observed and three of them are located at the same position with the similar (2--3){sigma} peaks observed in {ital {bar p}p}{r arrow}{gamma}{ital B} and {ital {bar p}p}{r arrow}{pi}{sup 0}{ital B}.

Details

ISSN :
05562821
Volume :
44
Database :
OpenAIRE
Journal :
Physical Review D
Accession number :
edsair.doi.dedup.....25fddba9bf71a387032072be540e4d42
Full Text :
https://doi.org/10.1103/physrevd.44.1933