Search for CP violation in the phase space of D0 → π+π−π+π− decays

Journal article

A search for time-integrated CP violation in the Cabibbo-suppressed decay D0 → π+π−π+π− is performed using an unbinned, model-independent technique known as the energy test. This is the first application of the energy test in four-body decays. The search is performed for P-even CP asymmetries and, for the first time, is extended to probe the P-odd case. Using proton–proton collision data corresponding to an integrated luminosity of 3.0 fb −1 collected by the LHCb detector at centre-of-mass energies of s=7 TeV and 8 TeV, the world's best sensitivity to CP violation in this decay is obtained. The data are found to be consistent with the hypothesis of CP symmetry with a p-value of (4.6±0.5)% in the P-even case, and marginally consistent with a p-value of (0.6±0.2)% in the P-odd case, corresponding to a significance for CP non-conservation of 2.7 standard deviations.

Authors: Aaij, R; Adeva, B; Adinolfi, M; Evans, T; Gandini, P

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Physics Letters B
• Volume: 769
• Pages: 345-356
• Publication date: 2017-04-01
• Acceptance date: 2017-03-27
• DOI: 10.1016/j.physletb.2017.03.062
• EISSN: 1873-2445
• ISSN: 0370-2693
• Keywords: hep-ex