IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Measurement of the polarisation of $W$ bosons produced with large transverse momentum in $pp$ collisions at $\sqrt{s}=7$ TeV with the ATLAS experiment
Autor/es:
ANDUAGA, XABIER SEBASTIAN; THE ATLAS COLLABORATION
Revista:
EUROPEAN PHYSICAL JOURNAL C - PARTICLES AND FIELDS
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2012 p. 2001 - 2035
ISSN:
1434-6044
Resumen:
This paper describes an analysis of the angular
distribution of W->enu and W->munu decays, using data from pp
collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the
LHC in 2010, corresponding to an integrated luminosity of about 35
pb^-1. Using the decay lepton transverse momentum and the missing
transverse energy, the W decay angular distribution projected onto the
transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 <
ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with
theoretical predictions. For ptw > 50 GeV, the values of f0 and
fL-fR, averaged over charge and lepton flavour, are measured to be : f0 =
0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where
the first uncertainties are statistical, and the second include all
systematic effects.