H. Yuta, University of Rochester Report No. UR-875-271, 1969 (unpublished). 9~ similar calculation performed by F. Bomse and R. Moses, Phys. Rev. 3, 2163 (1968), also predicts a low-mass Kfa enhancement. Also see the analogous work pertaining to the Ai in F. Winkelmann, R. Mickens, and H. J. Lubatti, Nucl. Phys. m, 535 (1971), and in Ref. 3. "'The quantities da/dt jeXp were calculated in the manner described in Ref. 3. "~h e s e values of m a s s and width a r e similar to those which were found to describe the Q + signal produced in 12.7-GeV/c K'p interactions, s e e M. Farber et al., Phys. Rev. D 1, 78 (1970). We have widened the rcE to account for the different widths observed in Fig. 4. When fitting m a s s spectra we use a distorted Breit-Wigner: The simple Breit-Wigner form i s multiplied by the polynomial employed to describe the background.We present results of an energy-dependent phase-shift analysis for aa energies between 550 and 1150 MeV from reactions a+p -n+rr-A++ and a+p -K+K-A++ a t 7.1 GeV/c. The

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We report the first measurements of inclusive W and Z boson cross sections times the corresponding leptonic branching ratios for pp collisions at √ s = 1.96 TeV based on the decays of the W and Z bosons into electrons and muons. The data were recorded with the CDF II detector at the Fermilab 4Tevatron and correspond to an integrated luminosity of 72.0 ± 4.3 pb −1 . We test e-µ lepton universality in W decays by measuring the ratio of the W → µν to W → eν cross sections and determine a value of 0.991 ± 0.004(stat.) ± 0.011(syst.) for the ratio of W −ℓ−ν couplings (gµ/ge). Since there is no sign of non-universality, we combine our cross section measurements in the different lepton decay modes and obtain σW ×Br(pp → W → ℓν) = 2.749 ± 0.010(stat.) ± 0.053(syst.) ± 0.165(lum.) nb and σ γ * /Z × Br(pp → γ * /Z → ℓℓ) = 254.9 ± 3.3(stat.) ± 4.6(syst.) ± 15.2(lum.) pb for dilepton pairs in the mass range between 66 GeV/c 2 and 116 GeV/c 2 . We compute the ratio R of the W → ℓν to Z → ℓℓ cross sections taking all correlations among channels into account and obtain R = 10.84 ± 0.15(stat.) ± 0.14(syst.) including a correction for the virtual photon exchange component in our measured γ * /Z → ℓℓ cross section. Based on the measured value of R, we extract values for the W leptonic branching ratio, Br(W → ℓν) = 0.1082 ± 0.0022; the total width of the W boson, Γ(W ) = 2092 ± 42 MeV; and the ratio of W and Z boson total widths, Γ(W )/Γ(Z) = 0.838 ± 0.017. In addition, we use our extracted value of Γ(W ) whose value depends on various electroweak parameters and certain CKM matrix elements to constrain the Vcs CKM matrix element, |Vcs| = 0.976± 0.030.

We summarize and combine direct measurements of the mass of the W boson in √ s = 1.96 TeV proton-antiproton collision data collected by CDF and D0 experiments at the Fermilab Tevatron Collider. Earlier measurements from CDF and D0 are combined with the two latest, more precise measurements: a CDF measurement in the electron and muon channels using data corresponding to 2.2 fb −1 of integrated luminosity, and a D0 measurement in the electron channel using data corresponding to 4.3 fb −1 of integrated luminosity. The resulting Tevatron average for the mass of the W boson is MW = 80 387 ± 16 MeV. Including measurements obtained in electron-positron collisions at LEP yields the most precise value of MW = 80 385 ± 15 MeV.