@article{526e3f2902b54c84913a6b1c05b62fdb,
title = "Measurement of the mass difference between neutral charm-meson eigenstates",
abstract = "We report a measurement of the mass difference between neutral charm-meson eigenstates using a novel approach that enhances sensitivity to this parameter. We use 2.3×106 D0→KS0π+π- decays reconstructed in proton-proton collisions collected by the LHCb experiment in 2011 and 2012. Allowing for CP violation in mixing and in the interference between mixing and decay, we measure the CP-averaged normalized mass difference xCP=[2.7±1.6(stat)±0.4(syst)]×10-3 and the CP-violating parameter Δx=[-0.53±0.70(stat)±0.22(syst)]×10-3. The results are consistent with CP symmetry. These determinations are the most precise from a single experiment and, combined with current world-average results, yield the first evidence that the masses of the neutral charm-meson eigenstates differ.",
author = "{LHCb Collaboration} and R. Aaij and {Abell{\'a}n Beteta}, C. and B. Adeva and M. Adinolfi and Aidala, {C. A.} and Z. Ajaltouni and S. Akar and P. Albicocco and J. Albrecht and F. Alessio and M. Alexander and {Alfonso Albero}, A. and G. Alkhazov and {Alvarez Cartelle}, P. and Alves, {A. A.} and S. Amato and Y. Amhis and L. An and L. Anderlini and G. Andreassi and M. Andreotti and Andrews, {J. E.} and F. Archilli and {Arnau Romeu}, J. and A. Artamonov and M. Artuso and K. Arzymatov and E. Aslanides and M. Atzeni and B. Audurier and S. Bachmann and Back, {J. J.} and S. Baker and V. Balagura and W. Baldini and A. Baranov and S. Bifani and R. Calladine and G. Chatzikonstantinidis and N. Farley and P. Griffith and P. Ilten and C. Lazzeroni and L. Pescatore and J. Plews and D. Popov and A. Sergi and Slater, {M. W.} and Watson, {N. K.} and Zarebski, {K. A.}",
year = "2019",
month = jun,
day = "14",
doi = "10.1103/PhysRevLett.122.231802",
language = "English",
volume = "122",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society (APS)",
number = "23",
}