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arXiv · 2608.12614

Observation of several sources of $C\!P$ violation in $B^+ \!\to K^+ \pi^+ \pi^-$ decays

LHCb collaboration·R. Aaij·M. Abdelfatah·A. S. W. Abdelmotteleb·C. Abellan Beteta·F. Abudinén·T. Ackernley·A. A. Adefisoye·B. Adeva·M. Adinolfi·P. Adlarson·C. Agapopoulou·C. A. Aidala·Z. Ajaltouni·S. Akar·K. Akiba·P. Albicocco·J. Albrecht·R. Aleksiejunas·F. Alessio·P. Alvarez Cartelle·R. Amalric·S. Amato·J. L. Amey·Y. Amhis·L. An·L. Anderlini·M. Andersson·P. Andreola·M. Andreotti·S. Andres Estrada·A. Anelli·D. Ao·C. Arata·F. Archilli·Z. Areg·M. Argenton·S. Arguedas Cuendis·L. Arnone·M. Artuso·E. Aslanides·R. Ataíde Da Silva·M. Atzeni·B. Audurier·J. A. Authier·D. Bacher·I. Bachiller Perea·S. Bachmann·M. Bachmayer·J. J. Back·Z. B. Bai·P. Baladron Rodriguez·V. Balagura·A. Balboni·W. Baldini·Z. Baldwin·L. Balzani·H. Bao·J. Baptista de Souza Leite·C. Barbero Pretel·M. Barbetti·I. R. Barbosa·R. J. Barlow·M. Barnyakov·S. Barsuk·W. Barter·J. Bartz·S. Bashir·B. Batsukh·P. B. Battista·A. Bavarchee·A. Bay·A. Beck·M. Becker·F. Bedeschi·I. B. Bediaga·N. A. Behling·S. Belin·A. Bellavista·I. Belov·I. Belyaev·G. Benane·G. Bencivenni·E. Ben-Haim·R. Bernet·A. Bertolin·F. Betti·J. Bex·O. Bezshyyko·S. Bhattacharya·M. S. Bieker·N. V. Biesuz·A. Biolchini·M. Birch·F. C. R. Bishop·A. Bitadze·A. Bizzeti·T. Blake·F. Blanc·J. E. Blank
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Abstract

An amplitude analysis of $B^+ \!\to K^+ \pi^+ \pi^-$ decays is presented in which six $C\!P$-violating phenomena are judged to be of significance for the first time. This analysis is based on $pp$ collision data recorded with the LHCb detector in 2011-2012, corresponding to an integrated luminosity of $3\,\text{fb}^{-1}$. Quasi-two-body $C\!P$ violation in $B^+ \!\to \rho(770)^0 K^+$ decays is discovered, while $C\!P$ violation at amplitude level is established in $B^+ \!\to f_2(1270) K^+$ decays. First evidence for $C\!P$ violation is reported in both the fully elastic S-wave $\pi\pi$-$\pi\pi$ rescattering region and also for any decay involving a spin-3 resonance. Additionally, significant $C\!P$-violation effects are identified in the interference between different $\pi\pi$ partial waves, with observation in S-P wave interference and evidence in S-D wave interference, both of which must be driven by long-distance interactions.

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LHCb collaboration, R. Aaij, M. Abdelfatah, A. S. W. Abdelmotteleb, C. Abellan Beteta, F. Abudinén, T. Ackernley, A. A. Adefisoye, B. Adeva, M. Adinolfi, P. Adlarson, C. Agapopoulou, C. A. Aidala, Z. Ajaltouni, S. Akar, K. Akiba, P. Albicocco, J. Albrecht, R. Aleksiejunas, F. Alessio, P. Alvarez Cartelle, R. Amalric, S. Amato, J. L. Amey, Y. Amhis, L. An, L. Anderlini, M. Andersson, P. Andreola, M. Andreotti, S. Andres Estrada, A. Anelli, D. Ao, C. Arata, F. Archilli, Z. Areg, M. Argenton, S. Arguedas Cuendis, L. Arnone, M. Artuso, E. Aslanides, R. Ataíde Da Silva, M. Atzeni, B. Audurier, J. A. Authier, D. Bacher, I. Bachiller Perea, S. Bachmann, M. Bachmayer, J. J. Back, Z. B. Bai, P. Baladron Rodriguez, V. Balagura, A. Balboni, W. Baldini, Z. Baldwin, L. Balzani, H. Bao, J. Baptista de Souza Leite, C. Barbero Pretel, M. Barbetti, I. R. Barbosa, R. J. Barlow, M. Barnyakov, S. Barsuk, W. Barter, J. Bartz, S. Bashir, B. Batsukh, P. B. Battista, A. Bavarchee, A. Bay, A. Beck, M. Becker, F. Bedeschi, I. B. Bediaga, N. A. Behling, S. Belin, A. Bellavista, I. Belov, I. Belyaev, G. Benane, G. Bencivenni, E. Ben-Haim, R. Bernet, A. Bertolin, F. Betti, J. Bex, O. Bezshyyko, S. Bhattacharya, M. S. Bieker, N. V. Biesuz, A. Biolchini, M. Birch, F. C. R. Bishop, A. Bitadze, A. Bizzeti, T. Blake, F. Blanc, J. E. Blank. 2026-08-12. Observation of several sources of $C\!P$ violation in $B^+ \!\to K^+ \pi^+ \pi^-$ decays. https://arxiv.org/abs/2608.12614

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