Thermal Evolution of Structure of Ultrafine Grained Copper, Processed by Severe Plastic Deformation

score: 0collation: 21-2

Identification of the e+e−→ nn̅ events in CMD-3 detector

A large amount of data collected with the CMD-3 detector above the threshold of the nn̅pair allows to measure the cross section of the process e+e−→ nn̅and the neutron form factor with good accuracy. This task is complicated by a large number of background events and necessity of finding ways to suppress them. A technique of identification for e+e−→ nn̅events is described

Identification of the

A large amount of data collected with the CMD-3 detector above the threshold of the nn̅pair allows to measure the cross section of the process e+e−→ nn̅and the neutron form factor with good accuracy. This task is complicated by a large number of background events and necessity of finding ways to suppress them. A technique of identification for e+e−→ nn̅events is described

Study of the processes

The data sample collected in 2011-2013 at the c.m.s. energies between 0.32-2 GeV with the CMD-3 detector operating at the VEPP-2000 e+e− collider is analzed. The collected data corresponds to an integrated luminosity about ∼ 60pb−1. The techniques for determination of the integrated luminosity for each energy setting is described. Some preliminary results of the study of the processes e+e−→ K+ K− + nπ (n = 1,2,3) with two charged kaons in the final state are presented. These processes have several intermediate states, which are important to correctly descript the angular distributions of final particles and the cross sections dependence on the energy

Study of the process e+e−→K+K− in the center-of-mass energy range 1010–1060 MeV with the CMD-3 detector

The process e+e−→K+K− has been studied using 1.7×106 events from a data sample corresponding to an integrated luminosity of 5.7 pb−1 collected with the CMD-3 detector in the center-of-mass energy range 1010–1060 MeV. The cross section is measured with about 2% systematic uncertainty and is used to calculate the contribution to the anomalous magnetic moment of the muon aμK+K−=(19.33±0.40)×10−10, and to obtain the ϕ(1020) meson parameters. We consider the relationship between the e+e−→K+K− and e+e−→KS0KL0 cross sections and compare it to the theoretical prediction

Study of the process e+e−→π+π−π+π− in the c.m. energy range 920–1060 MeV with the CMD-3 detector

A cross section of the process e+e−→π+π−π+π− has been measured using 6798±93 signal events from a data sample corresponding to an integrated luminosity of 9.8 pb−1 collected with the CMD-3 detector in the center-of-mass energy range 920–1060 MeV. The measured cross section exhibits a pattern of interference of the ϕ(1020)→π+π−π+π− decay with a non-resonant process e+e−→π+π−π+π−, from which we obtain the branching fraction of the doubly suppressed decays (by G-parity and OZI rule): B(ϕ→π+π−π+π−)=(6.5±2.7±1.6)×10−6