Observation of e(+) e(-) -> gamma chi(c1) and search for e(+) e(-) -> gamma chi(c0), gamma chi(c2), and gamma eta(c) at root s near 10.6 GeV at Belle

Jia, S.; Wang, X. L.; Shen, C. P.; Yuan, C. Z.; Adachi, I.; Aihara, H.; Al Said, S.; Asner, D. M.; Atmacan, H.; Aulchenko, V.; Aushev, T.; Ayad, R.; Babu, V.; Bansal, V.; Behera, P.; Beleno, C.; Berger, M.; Bhuyan, B.; Bilka, T.; Biswal, J.; Bobrov, A.; Bozek, A.; Bracko, M.; Browder, T. E.; Cao, L.; Cervenkov, D.; Chang, P.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Cho, K.; Choi, S. -K.; Choi, Y.; Choudhury, S.; Cinabro, D.; Cunliffe, S.; Dash, N.; Di Carlo, S.; Dolezal, Z.; Dong, T. V.; Eidelman, S.; Epifanov, D.; Fast, J. E.; Ferber, T.; Frey, A.; Fulsom, B. G.; Garg, R.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gelb, M.; Giri, A.; Goldenzweig, P.; Greenwald, D.; Haba, J.; Hayasaka, K.; Hayashii, H.; Hou, W. -S.; Hsu, C. -L.; Iijima, T.; Inami, K.; Inguglia, G.; Ishikawa, A.; Itoh, R.; Iwasaki, M.; Iwasaki, Y.; Jacobs, W. W.; Jin, Y.; Joffe, D.; Kahn, J.; Kaliyar, A. B.; Karyan, G.; Kawasaki, T.; Kichimi, H.; Kiesling, C.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, S. H.; Kinoshita, K.; Kodys, P.; Korpar, S.; Kotchetkov, D.; Krizan, P.; Kroeger, R.; Krokovny, P.; Kuhr, T.; Kulasiri, R.; Kumar, R.; Kuzmin, A.; Kwon, Y. -J.; Lalwani, K.; Lange, J. S.; Lee, I. S.; Lee, J. Y.; Lee, S. C.; Li, C. H.; Li, L. K.; Li, Y. B.; et al.

doi:10.1103/PhysRevD.98.092015

research article

Observation of e(+) e(-) -> gamma chi(c1) and search for e(+) e(-) -> gamma chi(c0), gamma chi(c2), and gamma eta(c) at root s near 10.6 GeV at Belle

Jia, S.

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Wang, X. L.

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Shen, C. P.

November 30, 2018

Physical Review D

Using data samples of 89.5 fb(-1), 711.0 fb(-1), and 121.4 fb(-1) collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider at center-of-mass energies 10.52, 10.58, and 10.867 GeV, respectively, we study the exclusive reactions e(+)e(-) -> gamma chi(cJ) (J = 0, 1, 2) and e(+)e(-) -> gamma chi(c). A significant gamma chi(c1) signal is observed for the first time at root s = 10.58 GeV with a significance of 5.1 sigma including systematic uncertainties. No significant excesses for gamma chi(c0), gamma chi(c2), and gamma chi(c) final states are found, and we set 90% credibility level upper limits on the Born cross sections (sigma(B)) at 10.52 GeV, 10.58 GeV, and 10.867 GeV. Together with cross sections measured by BESIII at lower center-of-mass energies, the energy dependency of sigma(B) (e(+)e(-) -> gamma chi(c1)) thorn is obtained.