Measurement of CP violation in B00→ D++D− and Bs0​→Ds+Ds−​ decays

The LHCb Collaboration; W. Barter; F. Betti; A. Bohare; E. Buchanan; P. E. L. Clarke; R. Currie; S. Eisenhardt; K. Farmer; S. Gambetta; M. Kane; Y. Liu; F. Muheim; M. Needham; F. Oliva; R.H. O'Neil; O. Ozcelik; M. Richardson-Slipper; G. Sarpis; L. Soares Lavra; C. Vrahas; M. R. J. Williams

doi:10.1007/JHEP01(2025)061

Measurement of CP violation in B00→ D++D− and Bs0→Ds+Ds− decays

The LHCb Collaboration
, W. Barter
, F. Betti
, A. Bohare
, E. Buchanan
, P. E. L. Clarke
, R. Currie
, S. Eisenhardt
, K. Farmer
, S. Gambetta
, M. Kane
, Y. Liu
, F. Muheim
, M. Needham
, F. Oliva
, R.H. O'Neil
, O. Ozcelik
, M. Richardson-Slipper
, G. Sarpis
, L. Soares Lavra

C. Vrahas, M. R. J. Williams

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract

A time-dependent, flavour-tagged measurement of CP violation is performed with B00→ D++D− and Bs0→Ds+Ds− decays, using data collected by the LHCb detector in proton-proton collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 6 fb−1−1. In B00→ D++D−− decays the CP-violation parameters are measured to be SD+D−=−0.552±0.100(stat)±0.010(syst),CD+D−=0.128±0.103(stat)±0.010(syst).SD+D−=−0.552±0.100(stat)±0.010(syst),CD+D−=0.128±0.103(stat)±0.010(syst).In Bs0Bs0→Ds+Ds−Ds+Ds− decays the CP-violating parameter formulation in terms of ϕss and |λ| results inϕs=−0.086±0.106(stat)±0.028(syst)rad,∣λDs+Ds−∣=1.145±0.126(stat)±0.031(syst).ϕs=−0.086±0.106(stat)±0.028(syst)rad,∣λDs+Ds−∣=1.145±0.126(stat)±0.031(syst).
These results represent the most precise single measurement of the CP-violation parameters in their respective channels. For the first time in a single measurement, CP symmetry is observed to be violated in B00→ D++D−− decays with a significance exceeding six standard deviations.

Original language	English
Article number	61
Pages (from-to)	1-25
Number of pages	25
Journal	Journal of High Energy Physics
Volume	2025
Issue number	01
DOIs	https://doi.org/10.1007/JHEP01(2025)061
Publication status	Published - 9 Jan 2025

Keywords / Materials (for Non-textual outputs)

CP Violation
Hadron-Hadron Scattering

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10.1007/JHEP01(2025)061Licence: Creative Commons: Attribution (CC-BY)

3 Active
4 Finished

Experimental Particle Physics at the University of Edinburgh
Leonidopoulos, C. (Principal Investigator)
Science and Technology Facilities Council
1/04/23 → 30/09/26
Project: Research
Experimental Particle Physics at the University of Edinburgh
Leonidopoulos, C. (Principal Investigator)
Science and Technology Facilities Council
1/10/22 → 30/09/26
Project: Research
Beautiful Flavours: Discovering New Physics with B-hadrons and Tau-leptons
Barter, W. (Principal Investigator)
UKRI (formerly RCUK)
1/07/22 → 11/08/27
Project: Research

Cite this

The LHCb Collaboration, Barter, W., Betti, F., Bohare, A., Buchanan, E., Clarke, P. E. L., Currie, R., Eisenhardt, S., Farmer, K., Gambetta, S., Kane, M., Liu, Y., Muheim, F., Needham, M., Oliva, F., O'Neil, R. H., Ozcelik, O., Richardson-Slipper, M., Sarpis, G., ... Williams, M. R. J. (2025). Measurement of CP violation in B00→ D++D− and Bs0→Ds+Ds− decays. Journal of High Energy Physics, 2025(01), 1-25. Article 61. https://doi.org/10.1007/JHEP01(2025)061

@article{dce719b8ccf94259aff1a4981f0a71e8,

title = "Measurement of CP violation in B00→ D++D− and Bs0→Ds+Ds− decays",

abstract = "A time-dependent, flavour-tagged measurement of CP violation is performed with B00→ D++D− and Bs0→Ds+Ds− decays, using data collected by the LHCb detector in proton-proton collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 6 fb−1−1. In B00→ D++D−− decays the CP-violation parameters are measured to be SD+D−=−0.552±0.100(stat)±0.010(syst),CD+D−=0.128±0.103(stat)±0.010(syst).SD+D−=−0.552±0.100(stat)±0.010(syst),CD+D−=0.128±0.103(stat)±0.010(syst).In Bs0Bs0→Ds+Ds−Ds+Ds− decays the CP-violating parameter formulation in terms of ϕss and |λ| results inϕs=−0.086±0.106(stat)±0.028(syst)rad,∣λDs+Ds−∣=1.145±0.126(stat)±0.031(syst).ϕs=−0.086±0.106(stat)±0.028(syst)rad,∣λDs+Ds−∣=1.145±0.126(stat)±0.031(syst). These results represent the most precise single measurement of the CP-violation parameters in their respective channels. For the first time in a single measurement, CP symmetry is observed to be violated in B00→ D++D−− decays with a significance exceeding six standard deviations.",

keywords = "CP Violation, Hadron-Hadron Scattering",

author = "\{The LHCb Collaboration\} and W. Barter and F. Betti and A. Bohare and E. Buchanan and Clarke, \{P. E. L.\} and R. Currie and S. Eisenhardt and K. Farmer and S. Gambetta and M. Kane and Y. Liu and F. Muheim and M. Needham and F. Oliva and R.H. O'Neil and O. Ozcelik and M. Richardson-Slipper and G. Sarpis and Lavra, \{L. Soares\} and C. Vrahas and Williams, \{M. R. J.\}",

year = "2025",

month = jan,

day = "9",

doi = "10.1007/JHEP01(2025)061",

language = "English",

volume = "2025",

pages = "1--25",

journal = "Journal of High Energy Physics",

issn = "1126-6708",

publisher = "Springer",

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The LHCb Collaboration, Barter, W, Betti, F, Bohare, A, Buchanan, E , Clarke, PEL , Currie, R , Eisenhardt, S, Farmer, K, Gambetta, S , Kane, M, Liu, Y, Muheim, F , Needham, M , Oliva, F, O'Neil, RH, Ozcelik, O, Richardson-Slipper, M, Sarpis, G, Lavra, LS, Vrahas, C & Williams, MRJ 2025, 'Measurement of CP violation in B00→ D++D− and Bs0→Ds+Ds− decays', Journal of High Energy Physics, vol. 2025, no. 01, 61, pp. 1-25. https://doi.org/10.1007/JHEP01(2025)061

TY - JOUR

T1 - Measurement of CP violation in B00→ D++D− and Bs0→Ds+Ds− decays

AU - The LHCb Collaboration

AU - Barter, W.

AU - Betti, F.

AU - Bohare, A.

AU - Buchanan, E.

AU - Clarke, P. E. L.

AU - Currie, R.

AU - Eisenhardt, S.

AU - Farmer, K.

AU - Gambetta, S.

AU - Kane, M.

AU - Liu, Y.

AU - Muheim, F.

AU - Needham, M.

AU - Oliva, F.

AU - O'Neil, R.H.

AU - Ozcelik, O.

AU - Richardson-Slipper, M.

AU - Sarpis, G.

AU - Lavra, L. Soares

AU - Vrahas, C.

AU - Williams, M. R. J.

PY - 2025/1/9

Y1 - 2025/1/9

N2 - A time-dependent, flavour-tagged measurement of CP violation is performed with B00→ D++D− and Bs0→Ds+Ds− decays, using data collected by the LHCb detector in proton-proton collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 6 fb−1−1. In B00→ D++D−− decays the CP-violation parameters are measured to be SD+D−=−0.552±0.100(stat)±0.010(syst),CD+D−=0.128±0.103(stat)±0.010(syst).SD+D−=−0.552±0.100(stat)±0.010(syst),CD+D−=0.128±0.103(stat)±0.010(syst).In Bs0Bs0→Ds+Ds−Ds+Ds− decays the CP-violating parameter formulation in terms of ϕss and |λ| results inϕs=−0.086±0.106(stat)±0.028(syst)rad,∣λDs+Ds−∣=1.145±0.126(stat)±0.031(syst).ϕs=−0.086±0.106(stat)±0.028(syst)rad,∣λDs+Ds−∣=1.145±0.126(stat)±0.031(syst). These results represent the most precise single measurement of the CP-violation parameters in their respective channels. For the first time in a single measurement, CP symmetry is observed to be violated in B00→ D++D−− decays with a significance exceeding six standard deviations.

AB - A time-dependent, flavour-tagged measurement of CP violation is performed with B00→ D++D− and Bs0→Ds+Ds− decays, using data collected by the LHCb detector in proton-proton collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 6 fb−1−1. In B00→ D++D−− decays the CP-violation parameters are measured to be SD+D−=−0.552±0.100(stat)±0.010(syst),CD+D−=0.128±0.103(stat)±0.010(syst).SD+D−=−0.552±0.100(stat)±0.010(syst),CD+D−=0.128±0.103(stat)±0.010(syst).In Bs0Bs0→Ds+Ds−Ds+Ds− decays the CP-violating parameter formulation in terms of ϕss and |λ| results inϕs=−0.086±0.106(stat)±0.028(syst)rad,∣λDs+Ds−∣=1.145±0.126(stat)±0.031(syst).ϕs=−0.086±0.106(stat)±0.028(syst)rad,∣λDs+Ds−∣=1.145±0.126(stat)±0.031(syst). These results represent the most precise single measurement of the CP-violation parameters in their respective channels. For the first time in a single measurement, CP symmetry is observed to be violated in B00→ D++D−− decays with a significance exceeding six standard deviations.

KW - CP Violation

KW - Hadron-Hadron Scattering

U2 - 10.1007/JHEP01(2025)061

DO - 10.1007/JHEP01(2025)061

M3 - Article

SN - 1126-6708

VL - 2025

SP - 1

EP - 25

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

IS - 01

M1 - 61

ER -

Measurement of CP violation in B00→ D++D− and Bs0​→Ds+Ds−​ decays

Abstract

Keywords / Materials (for Non-textual outputs)

Access to Document

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Projects

Experimental Particle Physics at the University of Edinburgh

Experimental Particle Physics at the University of Edinburgh

Beautiful Flavours: Discovering New Physics with B-hadrons and Tau-leptons

Cite this

Measurement of CP violation in B00→ D++D− and Bs0→Ds+Ds− decays