Measurement of the W mass in e +e − collisions at 183 GeV

• Published in: Physics letters. B Vol. 453; no. 1; pp. 121 - 137
• Main Authors: Decamp, D., Lees, J.-P., Martin, F., Merle, E., Fernandez-Bosman, M., Grauges, E., Juste, A., Morawitz, P., Iaselli, G., Maggi, G., Ranieri, A., Selvaggi, G., Tricomi, A., Huang, X., Ouyang, Q., Wang, T., Zhao, W., Boix, G., Cattaneo, M., Dissertori, G., Forty, R.W., Gianotti, F., Hansen, J.B., Harvey, J., Janot, P., Mato, P., Rolandi, L., Rousseau, D., Schneider, O., Wright, A.E., Falvard, A., Ferdi, C., Pallin, D., Waananen, A., Markou, C., Swynghedauw, M., Parrini, G., Laurelli, P., Murtas, F., Pepe-Altarelli, M., Curtis, L., O'Shea, V., Teixeira-Dias, P., Geweniger, C., Hanke, P., Hansper, G., Kluge, E.E., Sommer, J., Werner, S., Wunsch, M., Binnie, D.M., Cameron, W., Girone, M., Goodsir, S., Girtler, P., Kuhn, D., Colrain, P., van Gemmeren, P., Hoffmann, C., Jakobs, K., Nurnberger, H.-A., Rohne, E., Benchouk, C., Bonissent, A., Coyle, P., Buscher, V., Mannert, C., Moser, H.-G., Settles, R., Seywerd, H., Azzurri, P., Callot, O., Grivaz, J.-F., Heusse, Ph, de Vivie de Regie, J.-B., Bozzi, C., Gregorio, A., Vannini, C., Blair, G.A., Hutchcroft, D.E., Jones, L.T., Medcalf, T., von Wimmersperg-Toeller, J.H., Botterill, D.R., Clifft, R.W., Thompson, J.C., Colas, P., Black, S.N., Kim, H.Y., Cartwright, S., Combley, F., Brandt, S., Grupen, C., Misiejuk, A., Ferguson, D.P.S., Greening, T.C., Hu, H., Orejudos, W., Saadi, Y., Scott, I.J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1999; Elsevier
• Subjects: High Energy Physics - Experiment; Physics
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/S0370-2693(99)00305-6

The mass of the W boson is obtained from reconstructed invariant mass distributions in W-pair events. The sample of W pairs is selected from 57 pb
−1 collected with the ALEPH detector in 1997 at a centre-of-mass energy of 183 GeV. The invariant mass distributions of reweighted Monte Carlo events are fitted separately to the experimental distributions in the
q
q
̄
q
q
̄
and all
ℓν
q
q
̄
channels to give the following W masses:
m
W
hadronic
=80.461±0.177
(stat.)±0.045
(syst.)±0.056
(theory)
GeV/c
2,
m
W
semileptonic
=80.326±0.184
(stat.)±0.040
(syst.)
GeV/c
2,
where the theory error represents the possible effects of final state interactions. The combination of these two measurements, including the LEP energy calibration uncertainty, gives
m
W
=80.393±0.128
(stat.)±0.041
(syst.)±0.028
(theory)±0.021
(LEP)
GeV/c
2.