First observation of $γγ\to p \bar{p} K^+ K^-$ and search for exotic baryons in $pK$ systems
Creators: name: Belle Collaboration
name: Shen, C. P.
name: Yuan, C. Z.
name: Adachi, I.
name: Aihara, H.
name: Asner, D. M.
name: Aulchenko, V.
name: Aushev, T.
name: Ayad, R.
name: Babu, V.
name: Badhrees, I.
name: Bakich, A. M.
name: Barberio, E.
name: Behera, P.
name: Bhardwaj, V.
name: Bhuyan, B.
name: Biswal, J.
name: Bobrov, A.
name: Bonvicini, G.
name: Bozek, A.
name: Bračko, M.
name: Browder, T. E.
name: Červenkov, D.
name: Chang, P.
name: Chekelian, V.
name: Chen, A.
name: Cheon, B. G.
name: Chilikin, K.
name: Chistov, R.
name: Cho, K.
name: Chobanova, V.
name: Choi, S. -K.
name: Choi, Y.
name: Cinabro, D.
name: Dalseno, J.
name: Danilov, M.
name: Dash, N.
name: Doležal, Z.
name: Drásal, Z.
name: Dutta, D.
name: Eidelman, S.
name: Fang, W. X.
name: Fast, J. E.
name: Ferber, T.
name: Fulsom, B. G.
name: Gaur, V.
name: Gabyshev, N.
name: Garmash, A.
name: Gillard, R.
name: Glattauer, R.
name: Goldenzweig, P.
name: Grzymkowska, O.
name: Haba, J.
name: Hayasaka, K.
name: Hayashii, H.
name: Hou, W. -S.
name: Iijima, T.
name: Inami, K.
name: Inguglia, G.
name: Ishikawa, A.
name: Itoh, R.
name: Iwasaki, Y.
name: Jaegle, I.
name: Jeon, H. B.
name: Joo, K. K.
name: Julius, T.
name: Kang, K. H.
name: Kato, E.
name: Kiesling, C.
name: Kim, D. Y.
name: Kim, J. B.
name: Kim, K. T.
name: Kim, S. H.
name: Kim, Y. J.
name: Kodyš, P.
name: Korpar, S.
name: Kotchetkov, D.
name: Križan, P.
name: Krokovny, P.
name: Kuzmin, A.
name: Kwon, Y. -J.
name: Lange, J. S.
name: Li, C. H.
name: Li, H.
name: Li, L.
name: Li, Y.
name: Gioi, L. Li
name: Libby, J.
name: Liventsev, D.
name: Lubej, M.
name: Luo, T.
name: Masuda, M.
name: Matsuda, T.
name: Matvienko, D.
name: Miyabayashi, K.
name: Miyata, H.
name: Mizuk, R.
name: Mohanty, G. B.
name: Mohanty, S.
name: Moll, A.
name: Moon, H. K.
name: Mussa, R.
name: Nakano, E.
name: Nakao, M.
name: Nanut, T.
name: Nath, K. J.
name: Natkaniec, Z.
name: Nishida, S.
name: Ogawa, S.
name: Olsen, S. L.
name: Ostrowicz, W.
name: Pakhlov, P.
name: Pakhlova, G.
name: Pal, B.
name: Park, C. -S.
name: Park, H.
name: Pesántez, L.
name: Pestotnik, R.
name: Petrič, M.
name: Piilonen, L. E.
name: Pulvermacher, C.
name: Rauch, J.
name: Ritter, M.
name: Sakai, Y.
name: Sandilya, S.
name: Santelj, L.
name: Sanuki, T.
name: Savinov, V.
name: Schlüter, T.
name: Schneider, O.
name: Schnell, G.
name: Schwanda, C.
name: Seino, Y.
name: Semmler, D.
name: Senyo, K.
name: Seong, I. S.
name: Sevior, M. E.
name: Shibata, T. -A.
name: Shiu, J. -G.
name: Shwartz, B.
name: Simon, F.
name: Sokolov, A.
name: Solovieva, E.
name: Stanič, S.
name: Starič, M.
name: Strube, J. F.
name: Stypula, J.
name: Sumihama, M.
name: Sumiyoshi, T.
name: Takizawa, M.
name: Tamponi, U.
name: Tanida, K.
name: Tenchini, F.
name: Trabelsi, K.
name: Uchida, M.
name: Uehara, S.
name: Uglov, T.
name: Unno, Y.
name: Uno, S.
name: Urquijo, P.
name: Usov, Y.
name: Van Hulse, C.
name: Varner, G.
name: Wang, C. H.
name: Wang, M. -Z.
name: Wang, P.
name: Watanabe, M.
name: Watanabe, Y.
name: Williams, K. M.
name: Won, E.
name: Yamaoka, J.
name: Yelton, J.
name: Yook, Y.
name: Yusa, Y.
name: Zhang, C. C.
name: Zhang, Z. P.
name: Zhilich, V.
name: Zhukova, V.
name: Zhulanov, V.
name: Zupanc, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The process $γγ\to p \bar{p} K^+ K^-$ and its intermediate processes are measured for the first time using a 980~fb$^{-1}$ data sample collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The production of $p \bar{p} K^+ K^-$ and a $Λ(1520)^0~(\barΛ(1520)^0)$ signal in the $pK^-$~($\bar{p} K^+$) invariant mass spectrum are clearly observed. However, no evidence for an exotic baryon near 1540~MeV/$c^2$, denoted as $Θ(1540)^0$~($\barΘ~(1540)^0$) or $Θ(1540)^{++}$~($Θ(1540)^{--}$), is seen in the $p K^-$~($\bar{p}K^+$) or $pK^+$~($\bar{p} K^-$) invariant mass spectra. Cross sections for $γγ\to p \bar{p} K^+ K^-$, $Λ(1520)^0 \bar{p} K^+ +c.c.$ and the products $σ(γγ\to Θ(1540)^0 \bar{p} K^+ +c.c.)\BR(Θ(1540)^0 \to p K^{-})$ and $σ(γγ\to Θ(1540)^{++} \bar{p} K^- +c.c.)\BR(Θ(1540)^{++}\to p K^{+})$ are measured. We also determine upper limits on the products of the $χ_{c0}$ and $χ_{c2}$ two-photon decay widths and their branching fractions to $p \bar{p} K^+ K^-$ at the 90\% credibility level.
description: 9 pages, 9 figures