Observation of the mass difference between neutral charm-meson eigenstates
A measurement of mixing and CP violation in neutral charm mesons is performed using data reconstructed in proton-proton collisions collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of 5.4 fb−1. A total of 30.6 million D0→K0Sπ+π− decays are analyzed using a...
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| Main Authors: | , , , , , , , , , , , , , , , , , , , , , |
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| Corporate Author: | |
| Format: | Article (Journal) |
| Language: | English |
| Published: |
7 September 2021
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| In: |
Physical review letters
Year: 2021, Volume: 127, Issue: 11, Pages: 1-12 |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/PhysRevLett.127.111801 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/PhysRevLett.127.111801 Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/PhysRevLett.127.111801 |
| Author Notes: | R. Aaij et al.* (LHCb Collaboration) |
| Summary: | A measurement of mixing and CP violation in neutral charm mesons is performed using data reconstructed in proton-proton collisions collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of 5.4 fb−1. A total of 30.6 million D0→K0Sπ+π− decays are analyzed using a method optimized for the measurement of the mass difference between neutral charm-meson eigenstates. Allowing for CP violation in mixing and in the interference between mixing and decay, the mass and decay-width differences are measured to be xCP=[3.97±0.46(stat)±0.29(syst)]×10−3 and yCP=[4.59±1.20(stat)±0.85(syst)]×10−3, respectively. The CP-violating parameters are measured as Δx=[−0.27±0.18(stat)±0.01(syst)]×10−3 and Δy=[0.20±0.36(stat)±0.13(syst)]×10−3. This is the first observation of a nonzero mass difference in the D0 meson system, with a significance exceeding seven standard deviations. The data are consistent with CP symmetry and improve existing constraints on the associated parameters. |
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| Item Description: | *LHCb Collaboration: R. Aaij, F. Archilli, S. Bachmann, D. Berninghoff, M. Borsato, G. Frau, D. Gerick, J.P. Grabowski, P.A. Günter, X. Han, S. Hansmann-Menzemer, J. Hu, R. Kopecná, B. Leverington, P. Li, H. Malygina, J. Marks, D.J. Unverzagt, U. Uwer, C. Wang, L. Witola, A. Zhelezov [und 947 weitere Personen] Gesehen am 11.11.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/PhysRevLett.127.111801 |