The measurement of different reactions of (p) over bar d annihilation at rest in a gaseous target has been performed using the OBELIX spectrometer at LEAR (CERN). A strong deviation from the OZI-rule prediction was found from the measurement of the ratio R = phi pi/omega pi in two regions of proton momenta, P < 200 MeV/c and P > 400 MeV/c: R(phi pi(-)/omega pi(-)) = (133 +/- 26) x 10(-3) and (113 +/- 30)x 10(-3), respectively. These values are about 30 times greater than the theoretical prediction. For the first time the excitation of the Delta-resonance was observed among the final-state products of (p) over bar d annihilation. The existence of a broad enhancement in the 4 pi invariant mass at m approximate to 1480 MeV, seen in previous experiments, was confirmed. A approximate to 100 MeV downward shift of the bump position, when the proton momentum increased up to P > 400 MeV/c, was also observed, while the positions of omega, rho and f(2)(1270) did not change with the proton momentum.
Titolo: | Measurements of the (anti)p-D annihilation at rest |
Autori: | |
Data di pubblicazione: | 1995 |
Rivista: | |
Abstract: | The measurement of different reactions of (p) over bar d annihilation at rest in a gaseous target has been performed using the OBELIX spectrometer at LEAR (CERN). A strong deviation from the OZI-rule prediction was found from the measurement of the ratio R = phi pi/omega pi in two regions of proton momenta, P < 200 MeV/c and P > 400 MeV/c: R(phi pi(-)/omega pi(-)) = (133 +/- 26) x 10(-3) and (113 +/- 30)x 10(-3), respectively. These values are about 30 times greater than the theoretical prediction. For the first time the excitation of the Delta-resonance was observed among the final-state products of (p) over bar d annihilation. The existence of a broad enhancement in the 4 pi invariant mass at m approximate to 1480 MeV, seen in previous experiments, was confirmed. A approximate to 100 MeV downward shift of the bump position, when the proton momentum increased up to P > 400 MeV/c, was also observed, while the positions of omega, rho and f(2)(1270) did not change with the proton momentum. |
Handle: | http://hdl.handle.net/11368/2634813 |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/0375-9474(94)00523-P |
Appare nelle tipologie: | 1.1 Articolo in Rivista |