학술논문
First observations of Pontecorvo reactions with a recoiling neutron
Document Type
Original Paper
Author
Amsler, C.; Armstrong, D. S.; Augustin, I.; Baker, C. A.; Barnett, B. M.; Batty, C. J.; Beuchert, K.; Birien, P.; Blüm, P.; Bossingham, R.; Braune, K.; Brose, J.; Bugg, D. V.; Burchell, M.; Case, T.; Cooper, A.; Cramer, O.; Crowe, K. M.; Degener, T.; Dietz, H. P.; Dombrowski, S. v.; Doser, M.; Dünnweber, W.; Engelhardt, D.; Englert, M.; Faessler, M. A.; Felix, C.; Hackmann, R.; Haddock, R. P.; Heinsius, F. H.; Herz, M.; Hessey, N. P.; Hidas, P.; Illinger, P.; Jamnik, D.; Kalinowsky, H.; Kämmle, B.; Kiel, T.; Kisiel, J.; Klempt, E.; Kobel, M.; Koch, H.; Kolo, C.; Königsmann, K.; Kuhn, J.; Kunze, M.; Lakata, M.; Landua, R.; Lüdemann, J.; Matthäy, H.; Merkel, M.; Merlo, J. P.; Meyer, C. A.; Montanet, L.; Noble, A.; Ould-Saada, F.; Peters, K.; Pinder, C. N.; Pinter, G.; Ravndal, S.; Schäfer, E.; Schmidt, P.; Spanier, S.; Stöck, H.; Straßburger, C.; Strohbusch, U.; Suffert, M.; Thoma, U.; Urner, D.; Völcker, C.; Walter, F.; Walther, D.; Wiedner, U.; Winter, N.; Zoll, J.; Zou, B. S.; Zupančič, Č; The Crystal Barrel Collaboration
Source
Zeitschrift für Physik A Hadrons and Nuclei. September 1995 351(3):325-331
Subject
Language
English
ISSN
0939-7922
Abstract
We report the first observations of Pontecorvo reactions of the type ¯pd →Xn. We fully reconstruct the outgoing meson and, for antiprotons stopped in liquid deuterium, we measure: BR(¯pd→π0 )=(7.03±0.72)×10−6 , BR(¯pd→ηn)=(3.19+0.48)×10−6 , BR(¯pd→ωn)=(22.8+4.1)×10−6 , BR(¯pd→η′n)14×10−6 (at 95% confidence level). Assuming charge independence, our result for¯ pd→π0 n is compatible with measurements of the only other observed Pontecorvo reaction ¯pd → π− p. The experimental ratios between the above branching ratios are in fair agreement with both the statistical model and dynamical two-step models (assumingN¯ N annihilation into two mesons, with subsequent absorption of one meson on the remaining nucleon). This agreement suggests that there may be appreciable rates for Pontecorvo reactions producing final state mesons with masses above 1 GeV.