A first measurement of the polarization of W bosons with large transverse momenta in pp collisions is presented. The measurement is based on 36  pb-1 of data recorded at √s=7  TeV by the CMS detector at the LHC. The left-handed, right-handed, and longitudinal polarization fractions (fL, fR, and f0, respectively) of W bosons with transverse momenta larger than 50 GeV are determined by using decays to both electrons and muons. The muon final state yields the most precise measurement: (fL-fR)-=0.240±0.036(stat)±0.031(syst) and f0-=0.183±0.087(stat)±0.123(syst) for negatively charged W bosons and (fL-fR)+=0.310±0.036(stat)±0.017(syst) and f0+=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.

Measurement of the Polarization of W Bosons with Large Transverse Momenta in W+jets Events at the LHC

TOSI, SILVANO;
2011-01-01

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  pb-1 of data recorded at √s=7  TeV by the CMS detector at the LHC. The left-handed, right-handed, and longitudinal polarization fractions (fL, fR, and f0, respectively) of W bosons with transverse momenta larger than 50 GeV are determined by using decays to both electrons and muons. The muon final state yields the most precise measurement: (fL-fR)-=0.240±0.036(stat)±0.031(syst) and f0-=0.183±0.087(stat)±0.123(syst) for negatively charged W bosons and (fL-fR)+=0.310±0.036(stat)±0.017(syst) and f0+=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.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/388109
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 76
  • ???jsp.display-item.citation.isi??? 66
social impact