%0 Journal Article %T Measurement of the CP-violating phase beta in B-0 -> J/psi pi(+)pi(-) decays and limits on penguin effects %A LHCb Collaboration (Aaij, R. et al %A Martinez-Vidal, F. %A Oyanguren, A. %A Ruiz Valls, P. %A Sanchez Mayordomo, C. %J Physics Letters B %D 2015 %V 742 %I Elsevier Science Bv %@ 0370-2693 %G English %F LHCbCollaborationAaij_etal2015 %O WOS:000350555900007 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=2154), last updated on Thu, 09 Apr 2015 15:58:08 +0000 %X Time-dependent CP violation is measured in the (B-0) over bar -> J/psi pi(+)pi(-) p-channel for each pi(+)pi(-) resonant final state using data collected with an integrated luminosity of 3.0 fb(-1) in pp collisions using the LHCb detector. The final state with the largest rate, J/psi rho(0)(770), is used to measure the CP-violating angle 2 beta(eff) to be (41.7 +/- 9.6(-6.3)(+2.8)).. This result can be used to limit the size of penguin amplitude contributions to CPviolation measurements in, for example, (B-0) over bar -> J/psi pi(+)pi(-) decays. Assuming approximate SU(3) flavour symmetry and neglecting higher order diagrams, the shift in the CP-violating phase phi(s) limited to be within the interval [-1.05 degrees, + 1.18 degrees] at 95% confidence level. Changes to the limit due to SU(3) symmetry breaking effects are also discussed. %R 10.1016/j.physletb.2015.01.008 %U http://arxiv.org/abs/1411.1634 %U https://doi.org/10.1016/j.physletb.2015.01.008 %P 38-49