This Letter describes the current most precise measurement of the W boson pair production cross section and most sensitive test of anomalous WW gamma and WWZ couplings in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV. The WW candidates are reconstructed from decays containing two charged leptons and two neutrinos. Using data collected by the CDF II detector from 3: 6 fb(-1) of integrated luminosity, a total of 654 candidate events are observed with an expected background of 320 +/- 47 events. The measured cross section is sigma(p (p) over bar -> W+W- +X) = 12.1 +/- 0.9(stat)(-1.4)(+1.6)(syst) pb, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous WW gamma and WWZ couplings.

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 muons, as well as the combined result, d(mu) = (0.0 +/- 0.9) x 10(-19)e cm, are all consistent with zero, we set a new muon EDM limit, vertical bar d(mu)vertical bar < 1.8 x 10(-19)e cm (95% C.L.). This represents a factor of 5 improvement over the previous best limit on the muon EDM.

The spin precession frequency of muons stored in the (g-2) storage ring has been analyzed for evidence of Lorentz and CPT violation. Two Lorentz and CPT violation signatures were searched for a nonzero delta omega a(=omega a mu+ - omega a mu-) and a sidereal variation of omega a mu+/-). No significant effect is found, and the following limits on the standard-model extension parameters are obtained: bZ = -(1.0+/-1.1) x 10(-23) GeV; (m mu dZ0 + HXY)=(1.8+/-6.0) x 10(-23) GeV; and the 95% confidence level limits b perpendicular mu+ <1.4 x 10(-24) GeV and b perpendicular mu- <2.6 x 10(-24) GeV.

We present the final report from a series of precision measurements of the muon anomalous magnetic moment, a(mu)=(g-2)/2. The details of the experimental method, apparatus, data taking, and analysis are summarized. Data obtained at Brookhaven National Laboratory, using nearly equal samples of positive and negative muons, were used to deduce a(mu)(Expt)=11659208.0(5.4)(3.3)x10(-10), where the statistical and systematic uncertainties are given, respectively. The combined uncertainty of 0.54 ppm represents a 14-fold improvement compared to previous measurements at CERN. The standard model value for a(mu) includes contributions from virtual QED, weak, and hadronic processes. While the QED processes account for most of the anomaly, the largest theoretical uncertainty, approximate to 0.55 ppm, is associated with first-order hadronic vacuum polarization. Present standard model evaluations, based on e(+)e(-) hadronic cross sections, lie 2.2-2.7 standard deviations below the experimental result.

We present the final report from a series of precision measurements of the muon anomalous magnetic moment, aμ = (g − 2)/2. The details of the experimental method, apparatus, data taking, and analysis are summarized. Data obtained at Brookhaven National Laboratory, using nearly equal samples of positive and negative muons, were used to deduce aμ(Expt) = 11 659 208.0(5.4)(3.3) × 10−10, where the statistical and systematic uncertainties are given, respectively. The combined uncertainty of 0.54 ppm represents a 14-fold improvement compared to previous measurements at CERN. The standard model value for aμ includes contributions from virtual QED, weak, and hadronic processes. While the QED processes account for most of the anomaly, the largest theoretical uncertainty, ≈ 0.55 ppm, is associated with first-order hadronic vacuum polarization. Present standard model evaluations, based on e+e− hadronic cross sections, lie 2.2 2.7 standard deviations below the experimental result.

P.Shagin and B. Bousquet, P. Cushman, L. Duong, I. Kronkvist, R. McNabb, T. Qian University of Minnesota, Minneapolis, MN 55455, USA G.W. Bennett, H.N. Brown, G. Bunce, G.T. Danby, R. Larsen, Y.Y. Lee, W. Meng, W.M. Morse, D. Nikas, R. Prigl, Y.K. Semertzidis BNL, Upton, NY 11973, USA R.M. Carey, M.F. Hare, X. Huang, F. Krienen, A. Lam, J.P. Miller, J.M. Paley, Q. Peng, O. Rind, B.L. Roberts, L.R. Sulak, A. Trofimov Boston University, Boston, MA 02215, USA V.P. Druzhinin, G.V. Fedotovich, D. Grigoriev, B.I. Khazin, I. Logashenko, S.I. Redin, N. Ryskulov, Yu.M. Shatunov, E. Solodov Budker Institute of Nuclear Physics, Novosibirsk, Russia Y. Orlov Cornell University, Ithaca, NY 14853, USA K. Jungmann KVI, NL 9747 AA Groningen, The Netherlands A. Grossmann, G. zu Putlitz, P. von Walter Heidelberg University, 69120 Heidelberg, Germany P.T. Debevec, F.E. Gray, D.W. Hertzog, C.J.G. Onderwater, C.S. Ozben, C.C. Polly, M. Sossong University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA A. Yamamoto KEK, Tsukuba, Ibaraki 305-0801, Japan M. Iwasaki Tokyo Institute of Technology, Tokyo, Japan M. Deile, H. Deng, S.K. Dhawan, F.J.M. Farley, M. Grosse-Perdekamp, V.M. Hughes∗, D. Kawall, J. Pretz, E.P. Sichtermann Yale University, New Haven, CT 06520, USA

The anomalous magnetic moment of the negative muon has been measured to a precision of 0.7 ppm (ppm) at the Brookhaven Alternating Gradient Synchrotron. This result is based on data collected in 2001, and is over an order of magnitude more precise than the previous measurement for the negative muon. The result a(mu(-))=11 659 214(8)(3) x 10(-10) (0.7 ppm), where the first uncertainty is statistical and the second is systematic, is consistent with previous measurements of the anomaly for the positive and the negative muon. The average of the measurements of the muon anomaly is a(mu)(exp)=11 659 208(6) x 10(-10) (0.5 ppm).

The muon (g-2) experiment is described, and the recent results are presented. These results represent the final measurement for the positive muon.

The Muon g - 2 collaboration has measured the anomalous magnetic g value, a = (g - 2)/2, of the positive muon with an unprecedented uncertainty of 0.7 parts per million. The result a(mu)(+)(expt) = 11659204(7)(5) x 10(-10), based on data collected in the year 2000 at Brookhaven National Laboratory, is in good agreement with the preceeding data on a(mu)(+) and a(mu)(-). The measurement tests standard model theory, which at the level of the current experimental uncertainty involves quantum electrodynamics, quantum chromodynamics, and electroweak interaction in a significant way.

The Muon g - 2 collaboration has measured the anomalous magnetic g value, a = (g - 2)/2, of the positive muon with an unprecedented uncertainty of 0.7 parts per million. The result a(mu)(+)(expt) = 11659204(7)(5) x 10(-10), based on data collected in the year 2000 at Brookhaven National Laboratory, is in good agreement with the preceeding data on a(mu)(+) and a(mu)(-). The measurement tests standard model theory, which at the level of the current experimental uncertainty involves quantum electrodynamics, quantum chromodynamics, and electroweak interaction in a significant way.

The measurement of the (g-2) value of leptons provides a unique test of theory since it is the only quantity (unlike charge and mass) calculable in the framework of the Standard Model of elementary particles. The muon (g-2) experiment E821 is currently in progress at Brookhaven National Laboratory. Four data taking runs for positive muons and one run for negative unions were successfully accomplished in 1997-2000 and 2001, respectively. Results of the 1997-2000 runs have been published, thus completing our experiment for mu(+). Data analysis for the 2001 run for mu(-) is currently in progress. To provide measurement of a(mu)- = 1/2(g-2)(mu)- at the same level of accuracy as for a(mu)+ = 1/2(g-2)(mu)+, we need to have one more data taking run.

Received 22 August 2002DOI:https://doi.org/10.1103/PhysRevLett.89.129903©2002 American Physical Society

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 × 109 events and had an accuracy of 1.3ppm. 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 0.5ppm is anticipated.

The muon (g – 2) experiment E821 is currently in progress at Brookhaven National Laboratory. Four data-taking runs for positive muons and one run for negative muons were successfully accomplished in 1997–2000 and 2001, respectively. Results of the 1997–2000 runs have been published, thus completing our experiment for µ + . Data analysis for the 2001 run for µ – is currently in progress. To provide measurement of a µ – = ½(g – 2) µ – at the same level of accuracy as for a µ + = ½(g – 2) µ +, we would need one more data-taking run. PACS Nos.: 31.15Pf, 31.30Jv, 32.10Hq

A higher precision measurement of the anomalous g value, a(mu)=(g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron, based on data collected in the year 2000. The result a(mu(+))=11 659 204(7)(5)x10(-10) (0.7 ppm) is in good agreement with previous measurements and has an error about one-half that of the combined previous data. The present world average experimental value is a(mu)(expt)=11 659 203(8)x10(-10) (0.7 ppm).

The Muon (g − 2) Experiment (E821) at Brookhaven National Laboratory (BNL) has measured the anomalous magnetic moment of the positive muon to an unprecedented precision of 1.3 parts per million. The result, a µ + = g−2 2 = 11 659 202(14)(6) × 10 −10 , is based on data recorded in 1999 and is in good agreement with previous measurements. Upcoming analysis of data recorded in 2000 and 2001 will substantially reduce the uncertainty on this measurement. Comparison of the new world average experimental value with the most comprehensive Standard Model calculation, a µ (SM) = 11 659 159.6(6.7)×10 −10 , yields a difference of a µ (exp) − a µ (SM) = 43(16) × 10 −10 .