Search results for "W bosons"
showing 7 items of 7 documents
Measurement of parity-violating spin asymmetries in W± production at midrapidity in longitudinally polarized p+p collisions
2016
We present midrapidity measurements from the PHENIX experiment of large parity-violating singlespin asymmetries of high transverse momentum electrons and positrons from W =Z decays, produced in longitudinally polarized p þ p collisions at center of mass energies of ffiffi s p ¼ 500 and 510 GeV. These asymmetries allow direct access to the antiquark polarized parton distribution functions due to the parityviolating nature of the W-boson coupling to quarks and antiquarks. The results presented are based on data collected in 2011, 2012, and 2013 with an integrated luminosity of 240 pb−1, which exceeds previous PHENIX published results by a factor of more than 27. These high Q2 data probe the p…
Combination of CDF and D0 W-Boson mass measurements
2013
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 M W=80387±16 MeV. Including measurements obtained in electron-positron collisions at LEP yields the most precise value of M W…
Features of W production in p-p, p-Pb and Pb-Pb collisions
2017
We consider the production of inclusive W bosons in variety of high-energy hadronic collisions: p--p, p--$\overline{\rm p}$, p--Pb, and Pb--Pb. In particular, we focus on the resulting distributions of charged leptons from W decay that can be measured with relatively low backgrounds. The leading-order expressions within the collinearly factorized QCD indicate that the center-of-mass energy dependence at forward/backward rapidities should be well approximated by a simple power law. The scaling exponent is related to the small-$x$ behaviour of the quark distributions, which is largely driven by the parton evolution. An interesting consequence is the simple scaling law for the lepton charge as…
Combination of CDF and D0 measurements of the W boson helicity in top quark decays
2012
Aaltonen, T. et al.
Search for anomalous heavy-flavor quark production in association with W bosons.
2004
We present a search for anomalous production of heavy-flavor quark jets in association with a W boson at the Fermilab Tevatron ppbar Collider. This search is conducted through an examination of the exclusive jet spectrum of W+jets final states in which the heavy-flavor quark content has been enhanced by requiring at least one tagged jet in an event. Jets are tagged by the combined use of two algorithms, one based on semileptonic decays of b/c hadrons, and the other on their lifetimes. We compare data in e+jets (164 pb-1) and mu+jets (145 pb-1) channels, collected with the D0 detector at sqrt{s}=1.96 TeV, to expectations from the standard model, and set upper limits on anomalous production o…
Cross section and longitudinal single-spin asymmetry AL for forward W±→μ±ν production in polarized p+p collisions at √s = 510 GeV
2018
We have measured the cross section and single-spin asymmetries from forward W ± → μ ± ν production in longitudinally polarized p + p collisions at √ s = 510 GeV using the PHENIX detector at the Relativistic Heavy Ion Collider. The cross sections are consistent with previous measurements at this collision energy, while the most forward and backward longitudinal single spin asymmetries provide new insights into the sea quark helicities in the proton. The charge of the W bosons provides a natural flavor separation of the participating partons. peerReviewed
First measurement of the W-boson mass in run II of the Tevatron.
2007
7 pages, 4 figures.-- PACS nrs.: 14.70.Fm; 13.38.Be; 13.85.Qk.-- ISI Article Identifier: 000250140600014.-- ArXiv pre-print available at: http://arxiv.org/abs/0707.0085.-- et al.