Measurement of R uds and R between 3.12 and 3.72 GeV at the KEDR detector

• DOI: 10.1016/j.physletb.2015.12.059
• Publication Date: 2015-12-23T19:01:50Z
• Authors: 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.A. Borodenko; 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.A. Kuper; 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; V.V. Petrov; S.G. Pivovarov; P.A. Piminov; 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
• Keywords: Nuclear and High Energy Physics; High Energy Physics - Experiment (hep-ex); Physics; QC1-999; 0103 physical sciences; FOS: Physical sciences; 7. Clean energy; 01 natural sciences; High Energy Physics - Experiment

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have measured the values of $R_{\text{uds}}$ and $R$ at seven points of the center-of-mass energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or better than $3.3\%$ at most of energy points with a systematic uncertainty of about $2.1\%$. At the moment it is the most accurate measurement of $R(s)$ in this energy range.