Measurements of R and A search for heavy-Quark production in e+e- annihilation at s=50 and 52 GeV

H. Sagawa, T. Mori, K. Abe, S. Chakrabarti, Y. Fujii, Y. Higashi, S. Ishimoto, Y. Kurihara, A. Maki, P. Mani, T. Nozaki, T. Omori, P. Perez, Y. Sakai, Y. Sugimoto, Y. Takaiwa, S. Terada, K. Tsuchiya, A. Bacala, R. ImlayP. Kirk, W. Marterer, R. R. McNeil, W. Metcalf, C. P. Cheng, Z. P. Mao, Y. Yan, Y. T. Xu, H. S. Zhou, Y. C. Zhu, A. Abashian, K. Gotow, F. Kajino, F. Naito, F. Avignone, R. Childers, C. Darden, J. Edwards, S. Lusin, C. Rosenfeld, S. Wilson, D. Johnson, M. Frautschi, H. Kagan, R. Kass, C. G. Trahern, H. Y. Lee, Winston Ko, R. L. Lander, K. Maeshima, R. L. Malchow, D. Saroff, K. Sparks, M. C.S. Williams, A. Aldritch, J. Green, I. H. Park, S. Sakamoto, F. Sannes, S. Schnetzer, R. Stone, S. Trentalange, D. Zimmerman, K. Miyano, H. Miyata, M. Ogawa, Y. Yamashita, D. Blanis, A. Bodek, H. Budd, R. Coombes, S. Eno, C. A. Fry, H. Harada, Y. H. Ho, Y. K. Kim, T. Kumita, S. L. Olsen, R. Poling, N. M. Shaw, A. Sill, E. H. Thorndike, K. Ueno, H. W. Zheng, H. Asakura, K. Eguchi, H. Itoh, S. Kobayashi, A. Murakami, K. Toyoshima, J. S. Kang, H. J. Kim, S. K. Kim, S. S. Myung, E. J. Kim, G. N. Kim, D. Son, H. Kozuka, S. Matsumoto, H. Otsuki, T. Sasaki, T. Takeda, R. Tanaka, R. Chiba, K. Hanaoka, S. Igarashi, M. Miyashita, H. Murata, H. Yokota, Y. Ishi, T. Ishizuka, T. Maruta, K. Ohta

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The ratio R of the cross section for e+e- annihilation into hadronic final states to the QED cross section for muon-pair production is measured to be 4.340.450.30 and at c.m. energies of 50 and 52 GeV, respectively. From these values of R and an analysis of the event shapes we deduce a 95%-confidence-level upper limit for the production rate of new heavy charge +23e or -13e quarks to be 0.19 units of R.

Original languageEnglish (US)
Pages (from-to)93-96
Number of pages4
JournalPhysical review letters
Issue number2
StatePublished - 1988


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