Measurement of $R$ between 1.84 and 3.05 GeV at the KEDR detector

V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. Yu. Basok, A. M. Batrakov, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, D. N. Grigoriev, Yu. M. Glukhovchenko, S. E. Karnaev, G. V. Karpov, S. V. Karpov, P. V. Kasyanenko, T. A. Kharlamova, V. A. Kiselev, V. V. Kolmogorov, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. N. Kudryavtsev, V. F. Kulikov, G. Ya. Kurkin, I. A. Kuyanov, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, O. I. Meshkov, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, A. A. Osipov, I. V. Ovtin, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, V. G. Prisekin, O. L. Rezanova, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, A. N. Skrinsky, A. V. Sokolov, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev

Published 2016-10-10Version 1

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have determined the values of $R$ at thirteen points of the center-of-mass energy between 1.84 and 3.05 GeV. The achieved accuracy is about or better than $3.9\%$ at most of the energy points with a systematic uncertainty less than $2.4\%$.