Journal Article

High-statistics study ofK⁰_(S)pair production in two-photon collisions

Choi, S. -. K., Wagner, M. N., Nakazawa, H., Giordano, F., Nitoh, O., Nakao, M., Hayashii, H., Li, Y., Ko, B. R., Sanuki, T., Frey, A., Gaur, V., Kiesling, C., Hayasaka, K., Kim, J. H., Petric, M., Shapkin, M., Kim, H. O., Kwon, Y. -. J., Kawasaki, T., Van Hulse, C., Zhang, C. C., Chistov, R., Chekelian, V., Sumiyoshi, T., Cinabro, D., Chilikin, K., Sokolov, A., Seidl, R., Hou, W. -. S., Kim, Y. J., Uchida, M., Itoh, R., Unno, Y., Mori, T., Li, J., Yuan, C. Z., Shibata, T. -. A., Ferber, T., Miyata, H., Liu, C., Miyabayashi, K., Zhang, Z. P., Bozek, A., Kawai, H., Epifanov, D., Uehara, S., Zhulanov, V., Kodys, P., Ogawa, S., Dalseno, J., Krizan, P., Schneider, O., Steder, M., Farhat, H., Gabyshev, N., Schwanda, C., Saito, T., Zupanc, A., Shwartz, B., Ganguly, S., Ritter, M., Staric, M., Aushev, T., Nishida, S., Bonvicini, G., Park, H. K., Schnell, G., Julius, T., Savinov, V., Shiu, J. -. G., Fast, J. E., Watanabe, Y., Krokovny, P., Eidelman, S., Muramatsu, N., Bhardwaj, V., Okuno, S., Asner, D. M., Iwasaki, Y., Bhuyan, B., Pestotnik, R., Dingfelder, J., Park, H., Rostomyan, A., Sohn, Y. -. S., Yook, Y., Chobanova, V., Haba, J., Bakich, A. M., Tamponi, U., Sakai, Y

2013

Overview

We report a high-statistics measurement of the differential cross section of the process γγ → K⁰_(S) K⁰_(S) in the range 1.05 GeV ≤ W ≤ 4.00 GeV, where W is the center-of-mass energy of the colliding photons, using 972 fb-1 of data collected with the Belle detector at the KEKB asymmetric-energy e⁺ e⁻ collider operated at and near the Υ-resonance region. The differential cross section is fitted by parameterized S-, D0-, D2-, G0- and G2-wave amplitudes. In the D2 wave, the f₂(1270), a₂(1320) and f^(′)₂(1525) are dominant and a resonance, the f₂(2200), is also present. The f₀(1710) and possibly the f₀(2500) are seen in the S wave. The mass, total width and product of the two-photon partial decay width and decay branching fraction to the KK̅ state Γᵧᵧ(ΒKK̅) are extracted for the f^(′)₂(1525), f₀(1710), f₂(2200) and f₀(2500). The destructive interference between the f₂(1270) and a₂(1320) is confirmed by measuring their relative phase. The parameters of the charmonium states Χ_(c0) and Χ_(c2) are updated. Possible contributions from the Χ_(c0)(2P) and Χ_(c2)(2P) states are discussed. A new upper limit for the branching fraction of the P- and CP-violating decay channel η_(c) → K⁰_(S) K⁰_(S) is reported. The detailed behavior of the cross section is updated and compared with QCD-based calculations.

• Publisher: Physical Society of Japan
• Subject: C00 Quantum chromodynamics / C05 Quark model / C07 Particle properties / C21 Lepton collider experiments