Model-independent search for CP violation in D 0 → K − K + π − π + and D 0 →

A search for CP violation in the phase-space structures of D0 and D0 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. Submitted to Phys. Lett. B c © CERN on behalf of the LHCb collaboration, license CC-BY-3.0. †Authors are listed on the following pages. ar X iv :1 30 8. 31 89 v2 [ he pex ] 2 S ep 2 01 3