PAPER / ARXIV:2609.11057
SND Collaboration , M. N. Achasov , A. E. Alizzi , A. Yu. Barnyakov , E. V. Bedarev , K. I. Beloborodov , A. V. Berdyugin , D. E. Berkaev , A. G. Bogdanchikov , A. A. Botov , D. E. Chistyakov , T. V. Dimova , V. P. Druzhinin , R. A. Efremov , L. V. Kardapoltsev , A. S. Kasaev , A. A. Kattsin , V. R. Khamidullin , A. G. Kharlamov , I. A. Koop , A. A. Korol , D. P. Kovrizhin , A. S. Kupich , A. P. Kryukov , A. R. Mamedov , N. A. Melnikova , N. Yu. Muchnoi , A. E. Obrazovsky , A. A. Oorzhak , I. V. Ovtin , E. V. Pakhtusova , I. A. Polomoshnov , K. V. Pugachev , S, A. Rastigeev , Yu. A. Rogovsky , V. A. Romanov , S. I. Serednyakov , D. A. Shtol , Z. K. Silagadze , K. D. Sungurov , I. K. Surin , Yu. V. Usov , V. N. Zhabin , V. V. Zhulanov
RESUMO
In the experiment with the SND detector at the VEPP-2000 $e^+e^-$ collider, a search is performed for the direct production of the $C$-even $f_1(1285)$ resonance in $e^+e^-$ collisions. The analysis is based on data with an integrated luminosity of about 200 pb$^{-1}$, accumulated in the center-of-mass energy range of 1.14--1.46 GeV, of which about 72 pb$^{-1}$ were recorded near the maximum of the $f_1(1285)$ resonance. The $f_1(1285)$ production cross section at the resonance maximum $\sigma(e^+e^-\to f_1)=(31\pm 13\pm 2)$ pb and the branching fraction $B(f_1(1285)\to e^+e^-)=(3.5\pm 1.4\pm 0.3)\times 10^{-9}$ have been measured. The significance of the observation of the $e^+e^-\to f_1(1285)$ process is $2.5\sigma$. Since the significance is low, we also present the upper limits at the 90% confidence level: $\sigma(e^+e^-\to f_1)<48\mbox{ pb}$ and $B(f_1(1285)\to e^+e^-)<5.4\times 10^{-9}$.
NO MESMO MAPA