The time-integrated CP asymmetry in the Cabibbo-suppressed decay D0 → K− K+ is measured using proton-proton collision data, corresponding to an integrated luminosity of 5.7 fb^−1 collected at a center-of-mass energy of 13 TeV with the LHCb detector. The D0 mesons are required to originate from promptly produced D*+ → D0 π+ decays, and the charge of the companion pion is used to determine the flavor of the charm meson at production. The time-integrated CP asymmetry is measured to be A_CP(K− K+) = [6.8 ± 5.4 ± 1.6] × 10^−4 where the first uncertainty is statistical and the second systematic. The direct CP asymmetries in D0 → K− K+ and D0 → π− π+ decays, a_{K−K+}^d and a_{π−π+}^d, are derived by combining A_CP(K− K+) with the time-integrated CP asymmetry difference, ΔA_CP = A_CP(K− K+) − A_CP(π− π+), and other inputs, giving a_{K−K+}^d = (7.7 ± 5.7) × 10^−4, a_{π−π+}^d = (23.2 ± 6.1) × 10^−4, with a correlation coefficient corresponding to ρ = 0.88. The compatibility of these results with CP symmetry is 1.4 and 3.8 standard deviations for D0 → K− K+ and D0 → π− π+ decays, respectively. This is the first evidence for direct CP violation in a specific D0 decay.

Aaij, R., Abdelmotteleb, A.S.W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adeva, B., et al. (2023). Measurement of the Time-Integrated CP Asymmetry in D0 → K− K+ Decays. PHYSICAL REVIEW LETTERS, 131(9), 1-13 [10.1103/PhysRevLett.131.091802].

Measurement of the Time-Integrated CP Asymmetry in D0 → K− K+ Decays

Carbone, A;Ferrari, F;Galli, D;Manuzzi, D;Patrignani, C;Spedicato, E;Villa, A;Zucchelli, S;
2023

Abstract

The time-integrated CP asymmetry in the Cabibbo-suppressed decay D0 → K− K+ is measured using proton-proton collision data, corresponding to an integrated luminosity of 5.7 fb^−1 collected at a center-of-mass energy of 13 TeV with the LHCb detector. The D0 mesons are required to originate from promptly produced D*+ → D0 π+ decays, and the charge of the companion pion is used to determine the flavor of the charm meson at production. The time-integrated CP asymmetry is measured to be A_CP(K− K+) = [6.8 ± 5.4 ± 1.6] × 10^−4 where the first uncertainty is statistical and the second systematic. The direct CP asymmetries in D0 → K− K+ and D0 → π− π+ decays, a_{K−K+}^d and a_{π−π+}^d, are derived by combining A_CP(K− K+) with the time-integrated CP asymmetry difference, ΔA_CP = A_CP(K− K+) − A_CP(π− π+), and other inputs, giving a_{K−K+}^d = (7.7 ± 5.7) × 10^−4, a_{π−π+}^d = (23.2 ± 6.1) × 10^−4, with a correlation coefficient corresponding to ρ = 0.88. The compatibility of these results with CP symmetry is 1.4 and 3.8 standard deviations for D0 → K− K+ and D0 → π− π+ decays, respectively. This is the first evidence for direct CP violation in a specific D0 decay.
2023
Aaij, R., Abdelmotteleb, A.S.W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adeva, B., et al. (2023). Measurement of the Time-Integrated CP Asymmetry in D0 → K− K+ Decays. PHYSICAL REVIEW LETTERS, 131(9), 1-13 [10.1103/PhysRevLett.131.091802].
Aaij, R; Abdelmotteleb, A S W; Abellan Beteta, C; Abudinén, F; Ackernley, T; Adeva, B; Adinolfi, M; Adlarson, P; Afsharnia, H; Agapopoulou, C; Aidala,...espandi
File in questo prodotto:
File Dimensione Formato  
2023-AR-52-Meas_Time_Integrated_CP_Asymm_in_D0_to_Km_Kp-PRL-min.pdf

accesso aperto

Tipo: Versione (PDF) editoriale
Licenza: Licenza per Accesso Aperto. Creative Commons Attribuzione (CCBY)
Dimensione 618.34 kB
Formato Adobe PDF
618.34 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/953259
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 8
  • ???jsp.display-item.citation.isi??? 3
social impact