Search for C P violation in D⁺ → ϕπ⁺ decays

@misc{collaboration2026search,
  title = {{Search for $C\!P$ violation in $D^+ \to ϕπ^+$ decays}},
  author = {LHCb collaboration and R. Aaij and M. Abdelfatah and A. S. W. Abdelmotteleb and C. Abellan Beteta and F. Abudinén and T. Ackernley and A. A. Adefisoye and B. Adeva and M. Adinolfi and P. Adlarson and C. Agapopoulou and C. A. Aidala and S. Akar and K. Akiba and P. Albicocco and J. Albrecht and R. Aleksiejunas and F. Alessio and P. Alvarez Cartelle and S. Amato and J. L. Amey and Y. Amhis and L. An and L. Anderlini and M. Andersson and P. Andreola and M. Andreotti and S. Andres Estrada and A. Anelli and D. Ao and C. Arata and F. Archilli and Z. Areg and M. Argenton and S. Arguedas Cuendis and L. Arnone and M. Artuso and E. Aslanides and R. Ataíde Da Silva and M. Atzeni and B. Audurier and J. A. Authier and D. Bacher and I. Bachiller Perea and S. Bachmann and M. Bachmayer and J. J. Back and Z. B. Bai and V. Balagura and A. Balboni and W. Baldini and Z. Baldwin and L. Balzani and H. Bao and J. Baptista de Souza Leite and C. Barbero Pretel and M. Barbetti and I. R. Barbosa and R. J. Barlow},
  howpublished = {arXiv},
  year = {2026},
  month = jul,
  doi = {10.48550/arxiv.2607.20276},
  eprint = {2607.20276},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2607.20276},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Search for C P violation in D^+ → ϕπ^+ decays
AU  - LHCb collaboration
AU  - R. Aaij
AU  - M. Abdelfatah
AU  - A. S. W. Abdelmotteleb
AU  - C. Abellan Beteta
AU  - F. Abudinén
AU  - T. Ackernley
AU  - A. A. Adefisoye
AU  - B. Adeva
AU  - M. Adinolfi
AU  - P. Adlarson
AU  - C. Agapopoulou
AU  - C. A. Aidala
AU  - S. Akar
AU  - K. Akiba
AU  - P. Albicocco
AU  - J. Albrecht
AU  - R. Aleksiejunas
AU  - F. Alessio
AU  - P. Alvarez Cartelle
AU  - S. Amato
AU  - J. L. Amey
AU  - Y. Amhis
AU  - L. An
AU  - L. Anderlini
AU  - M. Andersson
AU  - P. Andreola
AU  - M. Andreotti
AU  - S. Andres Estrada
AU  - A. Anelli
AU  - D. Ao
AU  - C. Arata
AU  - F. Archilli
AU  - Z. Areg
AU  - M. Argenton
AU  - S. Arguedas Cuendis
AU  - L. Arnone
AU  - M. Artuso
AU  - E. Aslanides
AU  - R. Ataíde Da Silva
AU  - M. Atzeni
AU  - B. Audurier
AU  - J. A. Authier
AU  - D. Bacher
AU  - I. Bachiller Perea
AU  - S. Bachmann
AU  - M. Bachmayer
AU  - J. J. Back
AU  - Z. B. Bai
AU  - V. Balagura
AU  - A. Balboni
AU  - W. Baldini
AU  - Z. Baldwin
AU  - L. Balzani
AU  - H. Bao
AU  - J. Baptista de Souza Leite
AU  - C. Barbero Pretel
AU  - M. Barbetti
AU  - I. R. Barbosa
AU  - R. J. Barlow
PY  - 2026
DA  - 2026/07/22
PB  - arXiv
DO  - 10.48550/arxiv.2607.20276
UR  - https://arxiv.org/abs/2607.20276
AB  - A search for charge-parity (C P) violation in the Cabibbo-suppressed D^+ → ϕπ^+ decay is presented, using proton-proton collision data corresponding to an integrated luminosity of 6 fb^−1, collected at a centre-of-mass energy of 13 TeV with the LHCb detector during Run 2. An abundant sample of D^+ → K_S^0 π^+ decays is employed to correct for asymmetries arising from the production of the charmed meson and from detection effects associated with the charged pion accompanying the ϕ meson. Asymmetries induced by interference of multiple processes, such as neutral kaon mixing, regeneration of neutral kaons, and interference between the Cabibbo-favoured D^+ → K̅^0 π^+ and the doubly Cabibbo-suppressed D^+ → K^0 π^+ decay, are subtracted. The direct C P asymmetry in the D^+ → ϕπ^+ decay is measured to be a_C P(D^+ → ϕπ^+) = (0.1 ± 4.9 (stat) ± 2.4 (syst) )× 10^−4. For the first time at a hadron collider, the modulus of the ratio and the relative strong phase of the D^+ → K^0 π^+ to D^+ → K̅^0 π^+ decay amplitudes are also investigated. Two-dimensional confidence intervals are reported for these parameters.
ER  -