With experimental data of pbar p annihilation at rest on nuclei of 4He, collected by the Obelix spectrometer (LEAR, CERN), we have studied a number of reactions with 4 and 5 charged particles in the final state, distinguishing the annihilations on more than one nucleon, and with strangeness production. The main results of our observations are: (a) a higher (up to 20 times) strangeness production in 4He than in H; (b) the evidence of a possible signature of a Kpp (Kppn) bound state; (c) a measurement of a double strangeness production (2Kþ) and a hint for some production yields of double-strange bound systems like 2K-2n; (d) a signal compatible with the baryonic Theta+(1530) resonance, interpreted as a pentaquark system.
Recent results on antiproton annihilation in 4He
MONTAGNA, PAOLO MARIA;BENDISCIOLI, GIORGIO;FONTANA, ANDREA;LAVEZZI, LIA;ROTONDI, ALBERTO;
2008-01-01
Abstract
With experimental data of pbar p annihilation at rest on nuclei of 4He, collected by the Obelix spectrometer (LEAR, CERN), we have studied a number of reactions with 4 and 5 charged particles in the final state, distinguishing the annihilations on more than one nucleon, and with strangeness production. The main results of our observations are: (a) a higher (up to 20 times) strangeness production in 4He than in H; (b) the evidence of a possible signature of a Kpp (Kppn) bound state; (c) a measurement of a double strangeness production (2Kþ) and a hint for some production yields of double-strange bound systems like 2K-2n; (d) a signal compatible with the baryonic Theta+(1530) resonance, interpreted as a pentaquark system.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
