We present the first direct measurement of the W production charge asymmetry as a function of the W boson rapidity y_w in p anti-p collisions at s**(1/2) =1.96 TeV. We use a sample of W --> e nu events in data from 1 fb-1 of integrated luminosity collected using the CDF II detector. In the region |y_w| < 3.0, this measurement is capable of constraining the ratio of up and down quark momentum distributions in the proton more directly than in previous measurements of the asymmetry that are a function of the charged-lepton pseudorapidity.
A. Castro, M. Deninno, P. Mazzanti, N. Moggi, F. Rimondi, F. Semeria, et al. (2009). Direct Measurement of the W Production Charge Asymmetry in p anti-p Collisions at s**(1/2) =1.96 TeV. PHYSICAL REVIEW LETTERS, 102, 181801-1-181801-7 [10.1103/PhysRevLett.102.181801].
Direct Measurement of the W Production Charge Asymmetry in p anti-p Collisions at s**(1/2) =1.96 TeV
CASTRO, ANDREA;DENINNO, MARIA MADDALENA;MOGGI, NICCOLO';RIMONDI, FRANCO;ZUCCHELLI, STEFANO
2009
Abstract
We present the first direct measurement of the W production charge asymmetry as a function of the W boson rapidity y_w in p anti-p collisions at s**(1/2) =1.96 TeV. We use a sample of W --> e nu events in data from 1 fb-1 of integrated luminosity collected using the CDF II detector. In the region |y_w| < 3.0, this measurement is capable of constraining the ratio of up and down quark momentum distributions in the proton more directly than in previous measurements of the asymmetry that are a function of the charged-lepton pseudorapidity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.