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

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 root s = 7 TeV by the CMS detector at the LHC. The left-handed, right-handed, and longitudinal polarization fractions (f(L), f(R), and f(0), 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: (f(L) - f(R))(-) = 0.240 +/- 0.036(syst) +/- 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(syst) +/- 0.017(syst) and f(0)(+) = 0.171 +/- 0.085(syst) +/- 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.


Tutti gli autori

  • POMPILI A.;MARANGELLI B.;CALABRIA C.;SELVAGGI G.;LUSITO L.;BARBONE L.;ABBRESCIA M.;DE PALMA M.;PACIFICO N.;MY S.;NUZZO S.V.

Titolo volume/Rivista

Non Disponibile


Anno di pubblicazione

2011

ISSN

0031-9007

ISBN

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Numero di citazioni Wos

34

Ultimo Aggiornamento Citazioni

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Numero di citazioni Scopus

38

Ultimo Aggiornamento Citazioni

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Settori ERC

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Codici ASJC

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