1. The \pi^+\pi^- Coulomb interaction study and its use in the data processing
- Author
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Adeva, B., Afanasyev, L., Anania, A., Aogaki, S., Benelli, A., Brekhovskikh, V., Cechak, T., Chiba, M., Chliapnikov, P., Drijard, D., Dudarev, A., Dumitriu, D., Federicova, P., Gorin, A., Gritsay, K., Guaraldo, C., Gugiu, M., Hansroul, M., Hons, Z., Horikawa, S., Iwashita, Y., Kluson, J., Kobayashi, M., Kruglova, L., Kulikov, A., Kulish, E., Lamberto, A., Lanaro, A., Lednicky, R., Marinas, C., Martincik, J., Nemenov, L., Nikitin, M., Okada, K., Olchevskii, V., Pentia, M., Penzo, A., Plo, M., Prusa, P., Rappazzo, G., Vidal, A. Romero, Ryazantsev, A., Rykalin, V., Saborido, J., Schacher, J., Sidorov, A., Smolik, J., Takeutchi, F., Trojek, T., Trusov, S., Urban, T., Vrba, T., Yazkov, V., Yoshimura, Y., and Zrelov, P.
- Subjects
High Energy Physics - Phenomenology ,High Energy Physics - Experiment - Abstract
In this work the Coulomb effects (Coulomb correlations) in $\pi^+\pi^-$ pairs produced in p + Ni collisions at 24 GeV/$c$, are studied using experimental $\pi^+\pi^-$ pair distributions in $Q$, the relative momentum in the pair center of mass system (c.m.s), and its projections $Q_L$ (longitudinal component) and $Q_t$ (transverse component) relative to the pair direction in the laboratory system (l.s.). The $Q$, $Q_L$, and $Q_t$ distributions of the {\sl Coulomb pairs} in the c.m.s. have been simulated assuming they are described by the phase space modified by the known point-like Coulomb correlation function $A_C(Q)$, corrected for small effects due to the nonpoint-like pair production and the strong two-pion interaction. The same distributions of {\sl non-Coulomb pairs} have been simulated according to the phase space, but without $A_C(Q)$. It is shown that the number of {\sl Coulomb pairs} in all $Q_t$ intervals, including the small $Q_t$ (small opening angles $\theta$ in the l.s.) is calculated with the theoretical precision better than 2\%. The comparison of the simulated and experimental numbers of {\sl Coulomb pairs} at small $Q_t$ allows us to check and correct the detection efficiency for the pairs with small $\theta$ (0.06 mrad and smaller). It is shown that {\sl Coulomb pairs} can be used as a new physical tool to check and correct the quality of the simulated events. The special property of the {\sl Coulomb pairs} is the possibility of checking and correcting the detection efficiency, especially for the pairs with small opening angles.
- Published
- 2024