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| CMS-EWK-10-014 ; CERN-PH-EP-2011-043 | ||
| Measurement of the Polarization of W Bosons with Large Transverse Momenta in W+Jets Events at the LHC | ||
| CMS Collaboration | ||
| 20 April 2011 | ||
| Phys. Rev. Lett. 107 (2011) 021802 | ||
| Abstract: 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 $\pm$ 0.036 (stat.) $\pm$ 0.031 (syst.) and $f_0 =$ 0.183 $\pm$ 0.087 (stat.) $\pm$ 0.123 (syst.) for negatively charged W bosons, and $(f_L - f_R) =$ 0.310 $\pm$ 0.036 (stat.) $\pm$ 0.017 (syst.) and $f_0 =$ 0.171 $\pm$ 0.085 (stat.) $\pm$ 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. | ||
| Links: e-print arXiv:1104.3829 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; Public twiki page ; CADI line (restricted) ; | ||
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Compact Muon Solenoid LHC, CERN |
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