Study of the process e+e−→3(π+π−) in the c.m. energy range 1.5–2.0 GeV with the CMD-3 detector

AbstractThe cross section of the process e+e−→3(π+π−) has been measured using a data sample of 22 pb−1 collected with the CMD-3 detector at the VEPP-2000 e+e− collider. 7956 signal events are selected in the center-of-mass energy range 1.5–2.0 GeV. The measured cross section exhibits a sharp drop near the pp¯ threshold. A first study of dynamics of six-pion production has been performed

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

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

Study of the process e+e− → 2(π+π−π0) with the CMD-3 detector at VEPP-2000 collider

Since 2010 the CMD-3 detector has been collecting data at the VEPP-2000 e+e− collider. CMD-3 is a general purpose detector designed to study e+e− annihilation into hadrons in the center-of-mass (c.m.) energy range from 0.3 up to 2 GeV. Preliminary results for the e+e− → 2(π+π−π0) cross section were obtained in the c.m. energy range from 1.5 up to 2 GeV. The analysis is based on a data sample of 22 pb−1

CMD-3 Overview

The CMD-3 detector is installed at the VEPP-2000 e+e− collider at BINP (Novosibirsk, Russia). It is a general-purpose detector, equipped with a tracking system, two crystal (CSI and BGO) calorimeters, liquid Xe calorimeter, TOF and muon systems. The main goal of experiments at CMD-3 is a study of exclusive modes of e+e−→ hadrons at energies $\sqrt s \le$ GeV. In particular, these results provide an important input for calculation of the hadronic contribution to the muon anomalous magnetic moment. The first round of data taking was performed in 2011–2013, when about 60 1/pb were taken in the center-of-mass (c.m.) energy range from 0.32 to 2.0 GeV. Here we present a survey of results of data analysis. Between 2013 and 2016 the collider and the detector were upgraded. The data taking resumed by the end of 2016. In the first run after the upgrade about 50 1/pb were collected at the energy range between 1.28 and 2.007 GeV. We discuss the upgrade and the first preliminary results from the new data

Study of the process e+e−→KS0KL0 in the center-of-mass energy range 1004–1060 MeV with the CMD-3 detector at the VEPP-2000 e+e− collider

The e+e−→KS0KL0 cross section has been measured in the center-of-mass energy range 1004–1060 MeV at 25 energy points using 6.1×105 events with KS0→π+π− decay. The analysis is based on 5.9 pb−1 of an integrated luminosity collected with the CMD-3 detector at the VEPP-2000 e+e− collider. To obtain ϕ(1020) meson parameters the measured cross section is approximated according to the Vector Meson Dominance model as a sum of the ρ,ω,ϕ-like amplitudes and their excitations. This is the most precise measurement of the e+e−→KS0KL0 cross section with a 1.8% systematic uncertainty

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

CMD-3 Overview

The CMD-3 detector is installed at the VEPP-2000 e+e− collider at BINP (Novosibirsk, Russia). It is a general-purpose detector, equipped with a tracking system, two crystal (CSI and BGO) calorimeters, liquid Xe calorimeter, TOF and muon systems. The main goal of experiments at CMD-3 is a study of exclusive modes of e+e−→ hadrons at energies s≤2$\sqrt s \le$ GeV. In particular, these results provide an important input for calculation of the hadronic contribution to the muon anomalous magnetic moment. The first round of data taking was performed in 2011–2013, when about 60 1/pb were taken in the center-of-mass (c.m.) energy range from 0.32 to 2.0 GeV. Here we present a survey of results of data analysis. Between 2013 and 2016 the collider and the detector were upgraded. The data taking resumed by the end of 2016. In the first run after the upgrade about 50 1/pb were collected at the energy range between 1.28 and 2.007 GeV. We discuss the upgrade and the first preliminary results from the new data