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.
Recent results from the BNL g — 2 experiment Debevec, P.T.; Brown, H.N.; Bunce, G. ...
Nuclear physics. Section B, Proceedings supplement,
11/2002, Letnik:
111, Številka:
1
Journal Article
The status of the muon
g — 2 experiment at the AGS facility of Brookhaven National Laboratory is discussed. Data obtained in 1999 with positive muons has been analyzed and published. The final data ...set contained 0.95 × 10
9 events and had an accuracy of 1.3
ppm. Approximately four times more data with positive muons and three times more data with negative muons were obtained in 2000 and 2001, respectively. These data were obtained with a more uniform magnetic field and with different storage ring tunes. An accuracy of the order of 0.5
ppm is anticipated.
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: \(B(\phi\to K^+K^-) = 0.493\pm 0.003\pm 0.007\), \(B(\phi\to K_LK_S) = 0.336\pm 0.002\pm 0.006\), \(B(\phi\to\pi^+\pi^-\pi^0) = 0.155\pm 0.002\pm 0.005\), \(B(\phi\to\eta\gamma) = 0.0138\pm 0.0002\pm 0.0002\).
A precise measurement of the anomalous
g value,
a
+
μ = (
g − 2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron. The result
a
+
μ = 11 659 202(14)(6) × 10
...−10 (1.3 ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The current theoretical value from the standard model is
a
μ(SM)= 11 659 159.6(6.7) × 10
−10 (0.57 ppm) and
a
μ(exp)−
a
μ(SM) = 42(16) × 10
−10 in which
a
μ(exp) is the world average experimental value.
Phys.Lett.B648:28-38,2007 We present a measurement of the pion form factor based on e+e- annihilation
data from the CMD-2 detector in the energy range 0.6<sqrt(s)<1.0 GeV with a
systematic ...uncertainty of 0.8%. A data sample is five times larger than that
used in our previous measurement.
JETPLett.84:413-417,2006; PismaZh.Eksp.Teor.Fiz.84:491-495,2006 The cross section of the process e+e- -> pi+pi- has been measured at the
CMD-2 detector in the 370-520 MeV center-of-mass (c.m.) energy ...range. A
systematic uncertainty of the measurement is 0.7 %. Using all CMD-2 data on the
pion form factor, the pion electromagnetic radius was calculated. The cross
section of muon pair production was also determined.
Three independent searches for an electric dipole moment (EDM) of the positive and negative muons have been performed, using spin precession data from the muon g-2 storage ring at Brookhaven National ...Laboratory. Details on the experimental apparatus and the three analyses are presented. Since the individual results on the positive and negative muon, as well as the combined result, d=-0.1(0.9)E-19 e-cm, are all consistent with zero, we set a new muon EDM limit, |d| < 1.9E-19 e-cm (95% C.L.). This represents a factor of 5 improvement over the previous best limit on the muon EDM.
Status of the BNL muon (g-2) experiment Prigl, R.; Dhawan, S.K.; Druzhinin, V.P. ...
1998 Conference on Precision Electromagnetic Measurements Digest (Cat. No.98CH36254),
1998
Conference Proceeding
Odprti dostop
The muon (g-2) experiment at Brookhaven has completed a first run. 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. The analysis of data taken in June and July 1997 is in progress.
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