Model-independent search for CP violation in D0→K-K+π-π+ and D0→π-π+π+π- decays

Abstract A search for CP violation in the phase-space structures of D 0 and D ¯ 0 decays to the final states K − K + π − π + and π − π + π + π − is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb − 1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV . For the K − K + π − π + final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p -value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π − π + π + π − final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p -value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity.