Search for direct production of the f1(1285) resonance in e+e− collisions
/ Authors
M. Achasov, A. Barnyakov, K. Beloborodov, A. Berdyugin, D. Berkaev, A. Bogdanchikov, A. Botov, T. Dimova, V. Druzhinin, V. Golubev
and 28 more authors
L. Kardapoltsev, A. Kasaev, A. Kharlamov, I. Koop, A. A. Korol’, D. Kovrizhin, S. Koshuba, A. Kupich, R. Litvinov, A. Lysenko, K. Martin, N. Melnikova, N. Muchnoi, A. Obrazovsky, E. Pakhtusova, E. Perevedentsev, K. Pugachev, S. Serednyakov, Z. Silagadze, P. Shatunov, Y. Shatunov, D. Shtol, D. Shwartz, I. Surin, Y. Usov, I. Zemlyansky, V. Zhabin, V. Zhulanov
/ Abstract
The results of a search for direct production of the $f_1(1285)$ resonance in $e^+e^-$ annihilation are presented. The analysis is based on data with an integrated luminosity of 15.1 pb$^{-1}$ accumulated in the experiment with the SND detector at the VEPP-2000 $e^+e^-$ collider in the center-of-mass energy range $1.2-1.4$ GeV. Two $e^+e^-\to f_1(1285)$ candidate events are found at the peak of the resonance and zero events beyond the resonance. The significance of the $e^+e^-\to f_1(1285)$ signal is $2.7\sigma$. The cross section at the maximum of the resonance is found to be $\sigma(e^+e^-\to f_1)=54^{+32}_{-23}$ pb. The corresponding branching fraction $B(f_1(1285)\to e^+e^-)=(6.1^{+3.6}_{-2.6})\times 10^{-9}$. We consider this result as a first indication of the process $e^+e^-\to f_1(1285)$. The measured branching fraction is consistent with the theoretical prediction.
Journal: Physics Letters B