The W± → l±ν charge asymmetry at hadron colliders

The W± → l±ν charge asymmetry A(yl) as measured at the pp Tevatron is analyzed in detail in the perturbative LO and NLO with particular emphasis on treating the dominant heavy quark (charm) contribution according to the massive (mc ≠ 0) subprocessing gq′ → W− c → l−νc with q′ = d, s etc., instead of considering massless “heavy” flavor constituents of the nucleon (cq′ → W−, etc.). It is furthermore demonstrated that most of the more recently suggested LO and NLO parton distributions are in very good agreement with present measurement of A(yl).