First measurement of direct photoproduction of the a2(1320)0 meson on the proton
Physical Review C
We present the first measurement of the reaction γp→a2(1320)0p in the photon energy range 3.5-5.5GeV and four-momentum transfer squared 0.2<-t<2.0GeV2. Data were collected with the CEBAF Large Acceptance Spectrometer detector at the Thomas Jefferson National Accelerator Facility. The a2 resonance was detected by measuring the reaction γp→π0ηp and reconstructing the π0η invariant mass. The most prominent feature of the differential cross section is a dip at-t≈0.55GeV2. This can be described in the framework of Regge phenomenology, where the exchange degeneracy hypothesis predicts a zero in the reaction amplitude for this value of the four-momentum transfer.
Celentano, A., Battaglieri, M., De Vita, R., Marsicano, L., Mathieu, V., Pilloni, A., Szczepaniak, A., Adhikari, K., Adhikari, S., Amaryan, M., Angelini, G., Atac, H., Barion, L., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., & Biselli, A. (2020). First measurement of direct photoproduction of the a2(1320)0 meson on the proton. Physical Review C, 102 (3). https://doi.org/10.1103/PhysRevC.102.032201