The exclusive reaction gamma p -> pp(+)pi(-) was studied in the photon energy range 3.0-3.8 GeV and the momentum transfer range 0.4 < -t < 1.0 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. In this kinematic range, the integrated luminosity was about 20 pb(-1). The reaction was isolated by detecting the pi(+) and proton in CLAS, and reconstructing the pi(-) via the missing-mass technique. Moments of the di-pion decay angular distributions were derived from the experimental data. Differential cross sections for the S, P, and D-waves, in the M pi+pi- mass range 0.4-1.4 GeV, were derived performing a partial wave expansion of the extracted moments. Beside the dominant contribution of the rho(770) meson in the P-wave, evidence for the f(0)(980) and the f(2)(1270) mesons was found in the S and D-waves, respectively. The differential production cross sections d sigma/dt for individual waves in the mass range of the above-mentioned mesons were extracted. This is the first time the f(0)(980) has been measured in a photoproduction experiment.
Battaglieri, M., De Vita, R., Szczepaniak, A., Adhikari, K., Amaryan, M., Anghinolfi, M., et al. (2009). Photoproduction of pi(+)pi(-) meson pairs on the proton. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 80, 072005-072005--1--072005--19 [10.1103/PhysRevD.80.072005].
Photoproduction of pi(+)pi(-) meson pairs on the proton
D'ANGELO, ANNALISA;PISANO, SILVIA;
2009-01-01
Abstract
The exclusive reaction gamma p -> pp(+)pi(-) was studied in the photon energy range 3.0-3.8 GeV and the momentum transfer range 0.4 < -t < 1.0 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. In this kinematic range, the integrated luminosity was about 20 pb(-1). The reaction was isolated by detecting the pi(+) and proton in CLAS, and reconstructing the pi(-) via the missing-mass technique. Moments of the di-pion decay angular distributions were derived from the experimental data. Differential cross sections for the S, P, and D-waves, in the M pi+pi- mass range 0.4-1.4 GeV, were derived performing a partial wave expansion of the extracted moments. Beside the dominant contribution of the rho(770) meson in the P-wave, evidence for the f(0)(980) and the f(2)(1270) mesons was found in the S and D-waves, respectively. The differential production cross sections d sigma/dt for individual waves in the mass range of the above-mentioned mesons were extracted. This is the first time the f(0)(980) has been measured in a photoproduction experiment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
