ISSN - 03702693, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 1998, vol. 427, p. 248-253
Upper limits for a narrow dibaryon in pp collisions at 200 and 310 MeV
Dibaryons, forbidden by mass to decay into NNπ channel and by quantum numbers into NN channel, may still have escaped detection. In fact, recently an observation of a narrow dibaryon (D) with the mass close to 1920 MeV was reported in the process pp → γγ + X. This dibaryon should also appear in the proton-proton bremsstrahlung data from measurements at 200 and 310 MeV, which have been carried out at the CELSIUS storage ring in Uppsala. From these data upper limits of 10 and 3 nb are obtained for the dibaryon production cross section (at 95% confidence level) for the two energies, respectively. © 1998 Elsevier Science B.V. All rights reserved.