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

• Main Authors: Alver, Burak Han (Contributor), Bauer, Gerry P. (Contributor), Bendavid, Joshua L. (Contributor), Busza, Wit (Contributor), Butz, Erik M. (Contributor), Cali, Ivan Amos (Contributor), Chan, M. (Contributor), Dutta, Valentina (Contributor), Everaerts, Pieter Bruno Bart (Contributor), Gomez-Ceballos, Guillelmo (Contributor), Goncharov, Maxim (Contributor), Hahn, Kristian Allan (Contributor), Harris, P. (Contributor), Kim, Y. (Contributor), Klute, Markus (Contributor), Lee, Y. J. (Contributor), Li, W. (Contributor), Loizides, Constantin (Contributor), Luckey, P. David, Jr (Contributor), Ma, Teng (Contributor), Nahn, Steven (Contributor), Paus, Christoph M. E. (Contributor), Ralph, Duncan Kelley (Contributor), Roland, Christof E. (Contributor), Roland, Gunther M. (Contributor), Rudolph, M. (Contributor), Stephans, George S. F. (Contributor), Stockli, F. (Contributor), Sumorok, Konstanty C. (Contributor), Sung, Kevin Kai Hong (Contributor), Wenger, Edward Allen (Contributor), Xie, Si (Contributor), Yang, M. (Contributor), Yilmaz, Yetkin (Contributor), Yoon, Andrew (Contributor), Zanetti, Marco (Contributor), Wyslouch, Boleslaw (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2011-11-18T19:18:00Z.
• Subjects: Article
• Online Access: Get fulltext

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[superscript -1] of data recorded at √s=7  TeV by the CMS detector at the LHC. The left-handed, right-handed, and longitudinal polarization fractions (f[subscript L], f[subscript R], and f[subscript 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[subscript L]-f[subscript R])-=0.240±0.036(stat)±0.031(syst) and f[subscript 0][superscript -]=0.183±0.087(stat)±0.123(syst) for negatively charged W bosons and (f[subscript L]-f[subscript R])[superscript +]=0.310±0.036(stat)±0.017(syst) and f[subscript 0][superscript +]=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.
National Science Foundation (U.S.)
United States. Dept. of Energy