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arXiv · 1103.5445

Left-Handed W Bosons at the LHC

Z. Bern·G. Diana·L. J. Dixon·F. Febres Cordero·D. Forde·T. Gleisberg·S. Hoeche·H. Ita·D. A. Kosower·D. Maitre·K. Ozeren
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Abstract

The production of W bosons in association with jets is an important background to new physics at the LHC. Events in which the W carries large transverse momentum and decays leptonically lead to large missing energy and are of particular importance. We show that the left-handed nature of the W coupling, combined with valence quark domination at a pp machine, leads to a large left-handed polarization for both W^+ and W^- bosons at large transverse momenta. The polarization fractions are very stable with respect to QCD corrections. The leptonic decay of the W bosons translates the common left-handed polarization into a strong asymmetry in transverse momentum distributions between positrons and electrons, and between neutrinos and anti-neutrinos (missing transverse energy). Such asymmetries may provide an effective experimental handle on separating W + jets from top quark production, which exhibits very little asymmetry due to C invariance, and from various types of new physics.

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Z. Bern, G. Diana, L. J. Dixon, F. Febres Cordero, D. Forde, T. Gleisberg, S. Hoeche, H. Ita, D. A. Kosower, D. Maitre, K. Ozeren. 2011-04-25. Left-Handed W Bosons at the LHC. https://doi.org/10.1103/physrevd.84.034008

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