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→KS0π+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.

Observation of the Mass Difference between Neutral Charm-Meson Eigenstates / Aaij, R., Beteta, C.A., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., Aidala, C.A., Aiola, S., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Albero, A.A., Aliouche, Z., Alkhazov, G., Cartelle, P.A., Amato, S., Amhis, Y., An, L., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 127:11(2021), pp. 0-0. [10.1103/PhysRevLett.127.111801]

Observation of the Mass Difference between Neutral Charm-Meson Eigenstates

Bizzeti A.;
2021

Abstract

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→KS0π+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.
2021
127
11
0
0
Observation of the Mass Difference between Neutral Charm-Meson Eigenstates / Aaij, R., Beteta, C.A., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., Aidala, C.A., Aiola, S., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Albero, A.A., Aliouche, Z., Alkhazov, G., Cartelle, P.A., Amato, S., Amhis, Y., An, L., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 127:11(2021), pp. 0-0. [10.1103/PhysRevLett.127.111801]
Aaij, R.; Beteta, C. A.; Ackernley, T.; Adeva, B.; Adinolfi, M.; Afsharnia, H.; Aidala, C. A.; Aiola, S.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Aless...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1353372
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