Measurement of the cross section for the production of a W boson in association with b-jets in pp collisions at root s=7 TeV with the ATLAS detector by Aad, G, Abbott, B, Abdallah, J, Abdelalim, A, Abdesselam, A, Abdinovl, O, Abi, B, Abolins, M, Abramowicz, H, Abreu, H, Acerbi, E, Acharya, B, Adams, D, Addy, T, Adelman, J, Aderholz, M, Adomeit, S, Adragna, P, Adye, T, Aefsky, S, Aguilar-Saavedra, J, Aharrouche, M, Ahlen, S, Ahles, F, Ahmad, A