Drell-Yan lepton pairs are produced in the process p (p) over bar -> mu(+)mu(-) + X through an intermediate gamma*/Zboson. The forward-backward asymmetry in the polar-angle distribution of the mu(-) as a function of the invariant mass of the mu(+)mu(-) pair is used to obtain the effective leptonic determination sin(2)theta(lept)(eff) of the electroweakmixing parameter sin(2)theta w, from which the value of sin(2)theta w is derived assuming the standard model. The measurement sample, recorded by the Collider Detector at Fermilab (CDF), corresponds to 9.2 fb(-1) of integrated luminosity from p (p) over bar collisions at a center-of-momentum energy of 1.96 TeV, and is the full CDF Run II data set. The value of sin(2)theta(lept)(eff) is found to be 0.2315 +/- 0.0010, where statistical and systematic uncertainties are combined in quadrature. When interpreted within the context of the standard model using the on-shell renormalization scheme, where sin(2)theta w = 1 - M-W(2)/M-Z(2), the measurement yields sin(2)theta w = 0.2233 +/- 0.0009, or equivalently a W-boson mass of 80.365 +/- 0.047 GeV/c(2). The value of the W-boson mass is in agreement with previous determinations in electron- positron collisions and at the Tevatron collider.
Indirect measurement of sin(2)theta(W) (or M-W) using mu(+)mu(-) pairs from gamma*/Z bosons produced in p(p)over-bar collisions at a center-of-momentum energy of 1.96 TeV
AMERIO, SILVIA;BUSETTO, GIOVANNI;LUCCHESI, DONATELLA;
2014
Abstract
Drell-Yan lepton pairs are produced in the process p (p) over bar -> mu(+)mu(-) + X through an intermediate gamma*/Zboson. The forward-backward asymmetry in the polar-angle distribution of the mu(-) as a function of the invariant mass of the mu(+)mu(-) pair is used to obtain the effective leptonic determination sin(2)theta(lept)(eff) of the electroweakmixing parameter sin(2)theta w, from which the value of sin(2)theta w is derived assuming the standard model. The measurement sample, recorded by the Collider Detector at Fermilab (CDF), corresponds to 9.2 fb(-1) of integrated luminosity from p (p) over bar collisions at a center-of-momentum energy of 1.96 TeV, and is the full CDF Run II data set. The value of sin(2)theta(lept)(eff) is found to be 0.2315 +/- 0.0010, where statistical and systematic uncertainties are combined in quadrature. When interpreted within the context of the standard model using the on-shell renormalization scheme, where sin(2)theta w = 1 - M-W(2)/M-Z(2), the measurement yields sin(2)theta w = 0.2233 +/- 0.0009, or equivalently a W-boson mass of 80.365 +/- 0.047 GeV/c(2). The value of the W-boson mass is in agreement with previous determinations in electron- positron collisions and at the Tevatron collider.Pubblicazioni consigliate
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