Recent results from the CMD-2 detector at the VEPP-2M collider
- Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation)
The general-purpose detector CMD-2 is taking data at the Novosibirsk VEPP-2M e{sup -}e{sup -} collider in the energy range 360-1400 MeV, with luminosity of {approx} 5.0 x 10{sup 30} cm{sup -2} s{sup -1} for the {phi} resonance region. Data from {approx} 1500 nb{sup -1} of integrated luminosity around 1.02 GeV and {approx}500 nb{sup -1} in the 600-1000 MeV range have been collected and preliminary analyses performed. We present progress in studies of the {phi} meson and K{sub S}K{sub L} systems: (a) measurement of the {phi} meson parameters; (b) searches for {phi} rare decays. The new upper limits B({phi}{yields}{eta}{prime} {gamma}) < 2.4 x 10{sup -4}, B({phi} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}) < 1.0 x 10{sup -4}, and B({phi} {yields} f{sub 0}{gamma}) < 8 x 10{sup -4} have been obtained; (c) the study of the K{sub L} interactions in the CsI calorimeter; (d) with the help of 32,340 tagged K{sub S}, the semi-rare decay of K{sub S} {yields} {pi}{sup +}{pi}{sup -}{gamma} has been observed with a branching ratio of (1.82 {+-} 0.49)x10{sup -3}; and (e) selection of events with K{sub S}K{sub L} coupled decays and interactions. The regeneration cross section of the low moments K{sub L} was found to be {sigma}{sub reg}{sup Be} = 63 {+-} 19 mb. Data from the 600-1000 MeV energy range are used for high-accuracy measurement of the e{sup +}e{sup -} annihilation cross section, and the preliminary analysis is presented in this paper.
- Research Organization:
- Stanford Linear Accelerator Center, Menlo Park, CA (United States)
- OSTI ID:
- 542806
- Report Number(s):
- SLAC-R--494; CONF-9507258--; ON: DE97006538
- Country of Publication:
- United States
- Language:
- English
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