Regular data taking started at the VEPP-2000 e+e− collider with the CMD-3 detector. An energy scan of a center-of-mass energy range from 1 GeV to 2 GeV has been performed with an integrated ...luminosity of about 20 pb−1. We present first preliminary results from the CMD-3 detector.
The process e+ e- -> phi -> K+ K- has been studied with the CMD-2 detector using about 542 000 events detected in the center-of-mass energy range from 1.01 to 1.034 GeV. The systematic error of the ...cross section is estimated to be 2.2%. The phi(1020) meson parameters in the phi -> K+K- decay channel have been measured: sigma_0(phi-> K+K-) = 2016 +- 8 +- 44 nb, m(phi) = 1019.441 +- 0.008 +- 0.080 MeV/c2, Gamma(phi) = 4.24 +- 0.02 +- 0.03 MeV, B(e+e-)B(K+K-) = (14.27 +- 0.05 +- 0.31)*10(-5).
The cross section of the process $e^+e^- \to 3(\pi^+\pi^-)$ has been measured
using 22 pb$^{-1}$ of integrated luminosity collected with the CMD-3 detector
at the VEPP-2000 $e^+e^-$ collider in the ...c.m. energy range 1.5 -- 2.0 GeV. The
measured cross section exhibits a sharp drop near the $p\bar p$ threshold. A
first study of dynamics of six-pion production has been performed.
Status of the BNL muon (g-2) experiment Prigl, R.; Brown, H.N.; Bunce, G. ...
IEEE transactions on instrumentation and measurement,
04/1999, Letnik:
48, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The muon (g-2) experiment at Brookhaven completed a first run in June and July 1997. The main components of the experiment, which include the superconducting inflector, the superferric storage ring, ...the electrostatic quadrupoles and the lead-scintillating fiber electron calorimeters, have been commissioned satisfactorily. Our first measurement of the ratio R of the spin precession frequency of the positive muon relative to that of a free proton, R=(3.707219/spl plusmn/0.000048)/spl times/10/sup -3/, is in good agreement with the previous CERN measurements for /spl mu//sup +/ and /spl mu//sup -/, and has approximately the same uncertainty as each of these measurements. In spring 1998 a muon kicker was installed and successfully tested in the storage ring magnet and a significant improvement in the knowledge of the muon g-factor is expected from upcoming runs in August 1998 and January 1999.
Phys.Lett.B695:412-418,2011 The $\phi$(1020) meson leptonic width has been determined from the combined
analysis of 4 major decay modes of the resonance ($\phi\to K^+
...K^-,K^0_LK^0_S,\pi^+\pi^-\pi^0,\eta\gamma$) studied with the CMD-2 detector at
the VEPP-2M $e^+e^-$ collider. The following value has been obtained:
$\Gamma(\phi\to e^+e^-) = 1.235\pm 0.006\pm 0.022$ keV.
The $\phi(1020)$ meson parameters in four main decay channels have been also
recalculated: $B(\phi\to K^+K^-) = 0.493\pm 0.003\pm 0.007$, $B(\phi\to K_LK_S)
= 0.336\pm 0.002\pm 0.006$, $B(\phi\to\pi^+\pi^-\pi^0) = 0.155\pm 0.002\pm
0.005$, $B(\phi\to\eta\gamma) = 0.0138\pm 0.0002\pm 0.0002$.
The current status of the updated results from the CMD-2 detector is presented. The cross sections of
e
+
e
−annihilation into hadrons were measured in the c.m. energy range from 0.37 to 1.39 GeV and ...are based on the total integrated luminosity of about 30 pb
−1. Results of refitting experimental data for the
ρ, ω and mesons are reviewed.
The Muon g - 2 collaboration has measured the anomalous magnetic g value of the positive muon with an uncertainty of 1.3 parts per million. The result alpha (+)mu (expt) = 11659202(14)(6) OE 10 exp ...-10, based on data collected in 1999 at Brookhaven National Laboratory, is in good agreement with the preceding data on alpha(+)mu and alpha(-)mu, and improves the combined uncertainty by a factor of about three. The analysis of data collected in 2000 and 2001 is well underway and, when combined with data from a requested final run in the fall of 2002 and winter of 2003, is expected to further improve the experimental uncertainty by a factor of about three to 0.4 ppm. The measurement tests standard theory and has the potential to discover new physics. (Author)
The cross section of the process \(e^+e^- \to 3(\pi^+\pi^-)\) has been measured using 22 pb\(^{-1}\) of integrated luminosity collected with the CMD-3 detector at the VEPP-2000 \(e^+e^-\) collider in ...the c.m. energy range 1.5 -- 2.0 GeV. The measured cross section exhibits a sharp drop near the \(p\bar p\) threshold. A first study of dynamics of six-pion production has been performed.
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