Branching fraction measurement of the B⁰→ K⁺π^-μ⁺μ^- decay at high dihadron mass

@misc{collaboration2026branching,
  title = {{Branching fraction measurement of the $B^0\to K^+π^-μ^+μ^-$ decay at high dihadron mass}},
  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 = oct,
  doi = {10.48550/arxiv.2610.14156},
  eprint = {2610.14156},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.14156},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Branching fraction measurement of the B^0→ K^+π^-μ^+μ^- decay at high dihadron mass
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  - 2026/10/09
PB  - arXiv
DO  - 10.48550/arxiv.2610.14156
UR  - https://arxiv.org/abs/2610.14156
AB  - This Letter presents the first measurement of the B^0 → K^+π^−μ^+μ^− differential branching fraction in the region of the dihadron K^+π^- mass, m_Kπ, 1000< m_Kπ < 1835 MeV/c^2. This decay mode is mediated by the quark-level transition b → sℓ^+ℓ^−, for which the measured effective couplings show tensions with Standard Model predictions. The analysis is performed using proton-proton collision data collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 8.4 fb^−1. The differential branching fraction is determined across different regions of dimuon mass squared, q^2, in the interval 0.1 < q^2 < 18.0 GeV^2/c^4, as well as in different regions of $ m_{Kπ}$ in the interval 1.1 < q^2 < 6.0 GeV^2/c^4. The results represent the first differential measurement of the branching fraction across m_Kπ within the selected dihadron-mass region, and the first observation of the decay within this region above the J/ψ resonance.
ER  -