Measurement of the CKM angle γ in B± → DK± and B± → Dπ± decays with D → $$ {K}_{\mathrm{S}}^0 $$h+h−
R. Aaij, C. Abellán Beteta, T. Ackernley, B. Adeva, M. Adinolfi, H. Afsharnia, C. A. Aidala, S. Aiola, Z. Ajaltouni, S. Akar, J. Albrecht, F. Alessio, M. Alexander, A. Alfonso Albero, Z. Aliouche, G. Alkhazov, P. Alvarez Cartelle, S. Amato, Y. Amhis, L. An, L. Anderlini, A. Andreianov, M. Andreotti, F. Archilli, A. Artamonov, M. Artuso, K. Arzymatov, E. Aslanides, M. Atzeni, B. Audurier, S. Bachmann, M. Bachmayer, J. J. Back, S. Baker, P. Baladron Rodriguez, V. Balagura, W. Baldini, J. Baptista Leite, R. J. Barlow, S. Barsuk, W. Barter, M. Bartolini, F. Baryshnikov, J. M. Basels, G. Bassi, B. Batsukh, A. Battig, A. Bay, M. Becker, F. Bedeschi, I. Bediaga, A. Beiter, V. Belavin, S. Belin, V. Bellee, K. Belous, I. Belov, I. Belyaev, G. Bencivenni, E. Ben-Haim, A. Berezhnoy, R. Bernet, D. Berninghoff, H. C. Bernstein, C. Bertella, E. Bertholet, A. Bertolin, C. Betancourt, F. Betti, M. O. Bettler, Ia. Bezshyiko, S. Bhasin, J. Bhom, L. Bian, M. S. Bieker, S. Bifani, P. Billoir, M. Birch, F. C. R. Bishop, A. Bizzeti, M. Bjørn, M. P. Blago, T. Blake, F. Blanc, S. Blusk, D. Bobulska, V. Bocci, J. A. Boelhauve, O. Boente Garcia, T. Boettcher, A. Boldyrev, A. Bondar, N. Bondar, S. Borghi, M. Borisyak, M. Borsato, J. T. Borsuk, S. A. Bouchiba, T. J. V. Bowcock, A. Boyer
Abstract
A bstract A measurement of CP -violating observables is performed using the decays B ± → DK ± and B ± → Dπ ± , where the D meson is reconstructed in one of the self-conjugate three-body final states $$ {K}_{\mathrm{S}}^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> π + π − and $$ {K}_{\mathrm{S}}^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> K + K − (commonly denoted $$ {K}_{\mathrm{S}}^0 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>K</mml:mi> <mml:mi>S</mml:mi> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> h + h − ). The decays are analysed in bins of the D -decay phase space, leading to a measurement that is independent of the modelling of the D -decay amplitude. The observables are inter- preted in terms of the CKM angle γ . Using a data sample corresponding to an integrated luminosity of 9 fb − 1 collected in proton-proton collisions at centre-of mass energies of 7, 8, and 13 TeV with the LHCb experiment, γ is measured to be $$ \left({68.7}_{-5.1}^{+5.2}\right){}^{\circ} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mfenced> <mml:msubsup> <mml:mn>68.7</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>5.1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>5.2</mml:mn> </mml:mrow> </mml:msubsup> </mml:mfenced> <mml:mo>°</mml:mo> </mml:math> . The hadronic parameters $$ {r}_B^{D K},{r}_B^{D\pi},{\delta}_B^{D K},\kern0.5em \mathrm{and}\kern0.5em {\delta}_B^{D\pi} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>r</mml:mi> <mml:mi>B</mml:mi> <mml:mi>DK</mml:mi> </mml:msubsup> <mml:mo>,</mml:mo> <mml:msubsup> <mml:mi>r</mml:mi> <mml:mi>B</mml:mi> <mml:mi>Dπ</mml:mi> </mml:msubsup> <mml:mo>,</mml:mo> <mml:msubsup> <mml:mi>δ</mml:mi> <mml:mi>B</mml:mi> <mml:mi>DK</mml:mi> </mml:msubsup> <mml:mo>,</mml:mo> <mml:mspace/> <mml:mtext>and</mml:mtext> <mml:mspace/> <mml:msubsup> <mml:mi>δ</mml:mi> <mml:mi>B</mml:mi> <mml:mi>Dπ</mml:mi> </mml:msubsup> </mml:math> , which are the ratios and strong-phase differences of the suppressed and favoured B ± decays, are also reported.