Measurement of the Polarization of W Bosons with Large Transverse Momenta in W+Jets Events at the LHC
Collaboration
24 pages
Published in:
- Phys.Rev.Lett. 107 (2011) 021802
e-Print:
- 1104.3829 [hep-ex]
Report number:
- CERN-PH-EP-2011-043,
- CMS-EWK-10-014
Experiments:
Citations per year
Abstract: (arXiv)
A first measurement of the polarization of W bosons with large transverse momenta in pp collisions is presented. The measurement is based on 36 inverse picobarns of data recorded at sqrt(s) = 7 TeV by the CMS detector at the LHC. The left-handed, right-handed and longitudinal polarization fractions (f_L, f_R, f_0) of W bosons with transverse momenta larger than 50 GeV are determined using decays to both electrons and muons. The muon final state yields the most precise measurement, (f_L - f_R) = 0.240 +/- 0.036 (stat.) +/- 0.031 (syst.) and f_0 = 0.183 +/- 0.087 (stat.) +/- 0.123 (syst.) for negatively charged W bosons, and (f_L - f_R) = 0.310 +/- 0.036 (stat.) +/- 0.017 (syst.) and f_0 = 0.171 +/- 0.085 (stat.) +/- 0.099 (syst.) for positively charged W bosons. This establishes, for the first time, that W bosons produced in pp collisions with large transverse momenta are predominantly left-handed, as expected in the standard model.- 12.15.Ji
- 13.88.+e
- 14.70.Fm
- W: polarization: measured
- polarization: longitudinal
- muon: final state
- electron: final state
- transverse momentum: high
- CMS
- p p: interaction
References(11)
Figures(6)