MEASUREMENT OF THE PBARP ANNIHILATION CROSS-SECTIONS AT VERY LOW ENERGIES

被引:21
作者
AGNELLO, M
BALESTRA, F
BELLI, G
BENDISCIOLI, G
BERTIN, A
BOCCACCIO, P
BONAZZOLA, GC
BRESSANI, T
BRUSCHI, M
BUSSA, MP
BUSSO, L
CALVO, D
CAPPONI, M
CORRADINI, M
COSTA, S
DECASTRO, S
DISEP, D
FALOMKIN, IV
FAVA, L
FELICIELLO, A
FERRERO, L
FILIPPINI, V
GARFAGNINI, R
GASTALDI, U
GIANOTTI, P
GRASSO, A
GUARALDO, C
IAZZI, F
LANARO, A
RIZZINI, EL
LOMBARDI, M
MACCIOTTA, MP
MAGGIORA, A
MARCELLO, S
MARCONI, U
MARGAGLIOTTI, GV
MARON, G
MASALA, M
MASONI, A
MASSA, I
MINETTI, B
MORANDO, M
MORGANTI, M
PANZIERI, D
PAULI, G
PICCININI, M
PIRAGINO, R
POLI, M
PONTECORVO, GB
PUDDU, G
机构
[1] IST NAZL FIS NUCL, SEZ TORINO, TURIN, ITALY
[2] UNIV CAGLIARI, DIPARTIMENTO SCI FIS, I-09100 CAGLIARI, ITALY
[3] IST NAZL FIS NUCL, SEZ CAGLIARI, I-09100 CAGLIARI, ITALY
[4] UNIV BRESCIA, DIPARTIMENTO AUTOMAZ IND, BRESCIA, ITALY
[5] IST NAZL FIS NUCL, SEZ TORINO, I-25060 BRESCIA, ITALY
[6] UNIV PAVIA, DIPARTIMENTO FIS NUCL & TEOR, I-27100 PAVIA, ITALY
[7] IST NAZL FIS NUCL, I-27100 PAVIA, ITALY
[8] IST NAZL FIS NUCL, BOLOGNA, ITALY
[9] UNIV BOLOGNA, DIPARTIMENTO FIS, I-40100 BOLOGNA, ITALY
[10] INST NAZL FIS NUCL, LAB NAZL LEGNARO, I-35100 PADUA, ITALY
[11] UNIV TURIN, INST FIS, I-10125 TURIN, ITALY
[12] IST NAZL FIS NUCL, TURIN, ITALY
[13] CERN, EP, CH-1211 GENEVA 23, SWITZERLAND
[14] JOINT INST NUCL RES, DUBNA 101000, USSR
[15] IST NAZL FIS NUCL, LAB NATL FRASCATI, I-00044 FRASCATI, ITALY
[16] UNIV TRIESTE, INST FIS, I-34127 TRIESTE, ITALY
[17] IST NAZL FIS NUCL, TRIESTE, ITALY
[18] UNIV PADUA, DIPARTMENTO FIS, I-35100 PADUA, ITALY
[19] IST NAZL FIS NUCL, PADUA, ITALY
[20] UNIV FLORENCE, DIPARTIMENTO ENERGET, I-50121 FLORENCE, ITALY
[21] UNIV UDINE, INST FIS, I-33100 UDINE, ITALY
[22] IST NAZL FIS NUCL, SEZ TRIESTE, I-33100 UDINE, ITALY
关键词
D O I
10.1016/0370-2693(91)91774-P
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The pBARp annihilation cross-sections at 66.4-68.9-71.4 MeV/c have been measured using the presently instrumented part of the OBELIX spectrometer. The results have been obtained at pBAR energies (almost-equal-to 2.5 MeV) by one order of magnitude smaller than in any existing experiment concerning the in-flight antiproton-proton annihilation. The average value obtained over the total interval 65.1-72.5 MeV/c, beta-sigma-an(T) = 33.2 +/- 1.7 (stat.) +/- 1.8 (syst.) mb, in agreement with a specific calculation, would favour for the spin-averaged S-wave scattering length the value (-0.7 + i0.8) fm. The branching ratios for the annihilations in two, four and six charged mesons turn out to be quite similar to those for annihilation at rest in liquid hydrogen.
引用
收藏
页码:349 / 353
页数:5
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