Photon pair production at flavour factories with per mille accuracy

We present a high-precision QED calculation, with 0.1% theoretical accuracy, of two photon production in $e^+ e^-$ annihilation, as required by more and more accurate luminosity monitoring at flavour factories. The accuracy of the approach, which is based on the matching of exact next-to-leading order corrections with a QED Parton Shower algorithm, is demonstrated through a detailed analysis of the impact of the various sources of radiative corrections to the experimentally relevant observables. The calculation is implemented in the latest version of the event generator BabaYaga, available for precision simulations of photon pair production at $e^+ e^-$ colliders of moderately high energies.Comment: 11 pages, 5 figures, 1 tabl

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

Study of the process

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

Study of the processes

We report preliminary results on the measurement of the cross sections of the processes e+e− → K+K−π+π− and e+e− → ϕη in the c.m.energy range from 1.5 GeV to 2 GeV with the CMD-3 detector. The cross sections of these processes agree with BaBar results and have better accuracy