Using the data collected by the L3 experiment at LEP from 1991 to 1995 at energies around the Z mass, a measurement of the weak anomalous magnetic dipole moment, at, and of the weak electric dipole moment, df, of the t lepton is performed. These quantities are obtained from angular distributions in e ' e TM t't TM h + vTh tg where h is a p or a p. The results are: Re( af) = (0.0 " 1.6 " 2.3) X 10-3, Im( af = (-1.0 " 3.6 " 4.3) X 10-3 and Re( df = (-0.44 " 0.88 " 1.33) X 10-17e • cm. This is the first direct measurement of af. © 1998 Elsevier Science B.V. All rights reserved.

A study of resonance formation is presented in the π+π−π0 final state in two-photon collisions at LEP. The a2(1320) radiative width is measured to be Γγγ = 0.98 ± 0.05 ± 0.09 keV. The helicity 2 production is dominant. Exclusive π+π−π0 production has also been studied in the mass region above the a2 in the ρπ and f2π channels. This region is dominated by a JP = 2+

The inclusive semileptonic branching ratios b —► e u X , uX , r vX and vX have been measured at LEP with a Supported by the German Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie b Supported by the Hungarian OTKA fund under contract number T 14459 c Supported also by the Comisión Interministerial de Ciencia y Technologia d Also supported by CONICET and Universidad Nacional de La Plata, CC 67, 1900 La Plata, Argentina e Also supported by Panjab University, Chandigarh-160014, India the L3 detector. The analysis is based on 2-jet hadronic Z decays obtained in the data collected between 1991 and 1992. Three separate event samples are analysed, contain­ ing electrons, muons and large missing energy (neutrinos), respectively. From the electron sample, we measure Br(b —> ez/X) (10.89±0.20=b0.51)% and, from the muon sam­ ple, Br(b —► ¡jl vX ) = (10.82±0.15±0.59)%, where the first error is statistical and the second is systematic. From

The BaBar detector operated successfully at the PEP-II asymmetric e+e− collider at the SLAC National Accelerator Laboratory from 1999 to 2008. This report covers upgrades, operation, and performance of the collider and the detector systems, as well as the trigger, online and offline computing, and aspects of event reconstruction since the beginning of data taking.

We present a study of the decay B- -> D*0 K*- based on a sample of 86 million Upsilon(4S) -> BBbar decays collected between 1999 and 2002 with the BaBar detector at the PEP-II asymmetric-energy B-Factory at SLAC. We measure the branching fraction B(B- -> D*0 K*-) = 8.3 +/- 1.1 (stat) +/- 1.0 (syst) x 10e-4, and the fraction of longitudinal polarization in this decay to be GammaL/Gamma = 0.86 +/- 0.06 +/- (stat) +/- 0.03 (syst).

We study the decays B{sup +} {yields} {eta}{sub c}K{sup +} and B{sup 0} {yields} {eta}{sub c}K{sup 0}, where the {eta}{sub c} is reconstructed in the K{sub S}{sup 0} K{sup {+-}} {pi}{sup {-+}} and K{sup +}K{sup -} {pi}{sup 0} decay modes. Results are based on a sample of 86 million B{bar B} pairs collected with the BABAR detector at the SLAC e{sup +}e{sup -} B Factory. We measure the branching fractions {Beta}(B{sup +} {yields} {eta}{sub c}K{sup +}) = (1.34 {+-} 0.09 {+-} 0.13 {+-} 0.41) x 10{sup -3} and {Beta}(B{sup 0} {yields} {eta}{sub c}K{sup 0}) = (1.18 {+-} 0.16 {+-} 0.13 {+-} 0.37) x 10{sup -3}, where the first error is statistical, the second is systematic, and the third reflects the {eta}{sub c} branching fraction uncertainty. In addition, we search for B {yields} {eta}{sub c}K events with {eta}{sub c} {yields} 2(K{sup +}K{sup -}) and {eta}{sub c} {yields} {phi}{phi} and determine the {eta}{sub c} decay branching fraction ratios {Beta}({eta}{sub c} {yields} 2(K{sup +}K{sup -}))/{Beta}({eta}{sub c} {yields} K{bar K}{pi}) = (2.3 {+-} 0.7 {+-} 0.6) x 10{sup -2} and {Beta}({eta}{sub c} {yields} {phi}{phi})/{Beta}({eta}{sub c} {yields} K{bar K}{pi}) = (5.5 {+-} 1.4 {+-} 0.5) x 10{sup -2}.

A narrow state, which we label DsJ(2458)+, with a mass 2458.0±1.0(stat)±1.0(syst)MeV/c2, is observed in the inclusive D+sπ0γ mass distribution in 91fb−1 of e+e− annihilation data recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy e+e− storage ring. The observed width is consistent with the experimental resolution. The data favor decay through D*s(2112)+π0 rather than through D*sJ(2317)+γ. An analysis of D+sπ0 data accounting for the influence of the DsJ(2458)+ produces a D*sJ(2317)+ mass of 2317.3±0.4(stat)±0.8(syst)MeV/c2. Received 24 October 2003DOI:https://doi.org/10.1103/PhysRevD.69.031101©2004 American Physical Society

A search for the lepton-flavor-violating decay of the tau into three charged leptons has been performed using 91.5 fb(-1) of data collected at an e(+)e(-)center-of-mass energy around 10.58 GeV with the BABAR detector at the SLAC storage ring PEP-II. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (1-3)x10(-7) at 90% confidence level.

We measure the branching fraction for the charmless semi-inclusive process B --> eta'Xs, where the eta' meson has a momentum in the range 2.0 to 2.7 GeV/c in the upsilon4S center-of-mass frame and Xs represents a system comprising a kaon and zero to four pions. We find B(B --> eta'Xs) = [3.9 +/- 0.8(stat) +/- 0.5(syst) +/- 0.8(model)] x 10(-4). We also obtain the Xs mass spectrum and find that it fits models predicting high masses.

We present measurements of the branching fractions and charge asymmetries (where appropriate) of two-body B decays to η(′) K*, η(′) ρ, η(′) π0, ωπ0, and φπ0. The data were recorded with the BABAR detector at PEP-II and correspond to 89×106 BB pairs produced in e +e- annihilation through the Υ (4S) resonance. We find significant signals for two decay modes and measure the branching fractions B(B+→ηK*+)=(25.6 ±4.0±2.4) ×10-6 and B(B0→ηK*0) = (18.6±23±1.2)×10-6, where the first error is statistical and the second systematic. We also find evidence with significance 3,5σ for a third decay mode and measure B(B+ →ηρ+)=(9.2±3.4±1.0)×10 -6. For other channels, we set 90% C.L. upper limits of B(B 0→ηρ0)<1.5 ×10-6, B(B+→η′K*+)<14×10 -6, B(B0→η′K*0)<7. 6×10-6, B(B0→η′K*0) <22×10-6, B(B0 →η′ρ 0)<4.3×10-6, B(B0→ηπ 0)<2.5×10-6, B(B0→η′ π0)<3.7×10-6, B(B0→ωπ 0)<1.2×10-6, and B(B0→φπ 0)<1.0×10-6. For self-flavor-tagging modes with significant signals, the time-integrated charge asymmetries are A ch(ηK*+)=+0.13±0.14±0.02 and Ach(ηK*0)=+0.02±0.11±0.02.

Using a sample of 88.8x10(6) B (B) over bar events collected with the BABAR detector at the PEP-II storage rings at the Stanford Linear Accelerator Center, we measure the branching fractions of seven color-suppressed B-meson decays: B((b) over bar (0)-->D(0)pi(0))=[2.9+/-0.2(stat)+/-0.3(syst)]x10(-4), B((B) over bar (0)-->D(*0)pi(0))=[2.9+/-0.4(stat)+/-0.5(syst)]x10(-4), B((B) over bar (0)-->D(0)eta)=[2.5+/-0.2(stat)+/-0.3(syst)]x10(-4), (0)-->D(*0)eta)=[2.6+/-0.4(stat)+/-0.4(syst)]x10(-4), B((B) over bar (0)-->D(0)omega)=[3.0+/-0.3(stat)+/-0.4(syst)]x10(-4), B((B) over bar (0)-->D(*0)omega)=[4.2+/-0.7(stat)+/-0.9(syst)]x10(-4), and B((B) over bar (0)-->D(0)eta('))=[1.7+/-0.4(stat)+/-0.2(syst)]x10(-4). We set the 90% confidence-level upper limit: B((B) over bar (0)-->D(*0)eta('))<2.6x10(-4). The channels (B) over bar (0)-->D(*0)eta, D(*0)omega, and D(0)eta(') are seen with more than five-sigma statistical significance. All of these branching fractions are significantly larger than theoretical expectations based on the "naive" factorization model.

The authors present a measurement of the average multiplicity of {phi} mesons in B{sup 0}, {bar B}{sup 0} and B{sup {+-}} meson decays. Using 17.6 fb{sup -1} of data taken at the {Upsilon}(4S) resonance by the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring at the Stanford Linear Accelerator Center, they reconstruct {phi} mesons in the K{sup +}K{sup -} decay mode and measure {Beta}(B {yields} {phi}X) = (3.41 {+-} 0.06 {+-} 0.12)%. This is significantly more precise than any previous measurement.

Received 14 October 2004DOI:https://doi.org/10.1103/PhysRevLett.93.189902©2004 American Physical Society