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arXiv · 1712.03220

Updated determination of $D^0$-$\overline{D}{}^0$ mixing and CP violation parameters with $D^0\to K^+\pi^-$ decays

LHCb collaboration·R. Aaij·B. Adeva·M. Adinolfi·Z. Ajaltouni·S. Akar·J. Albrecht·F. Alessio·M. Alexander·A. Alfonso Albero·S. Ali·G. Alkhazov·P. Alvarez Cartelle·A. A. Alves Jr·S. Amato·S. Amerio·Y. Amhis·L. An·L. Anderlini·G. Andreassi·M. Andreotti·J. E. Andrews·R. B. Appleby·F. Archilli·P. d'Argent·J. Arnau Romeu·A. Artamonov·M. Artuso·E. Aslanides·M. Atzeni·G. Auriemma·M. Baalouch·I. Babuschkin·S. Bachmann·J. J. Back·A. Badalov·C. Baesso·S. Baker·V. Balagura·W. Baldini·A. Baranov·R. J. Barlow·C. Barschel·S. Barsuk·W. Barter·F. Baryshnikov·V. Batozskaya·V. Battista·A. Bay·L. Beaucourt·J. Beddow·F. Bedeschi·I. Bediaga·A. Beiter·L. J. Bel·N. Beliy·V. Bellee·N. Belloli·K. Belous·I. Belyaev·E. Ben-Haim·G. Bencivenni·S. Benson·S. Beranek·A. Berezhnoy·R. Bernet·D. Berninghoff·E. Bertholet·A. Bertolin·C. Betancourt·F. Betti·M. O. Bettler·M. van Beuzekom·Ia. Bezshyiko·S. Bifani·P. Billoir·A. Birnkraut·A. Bizzeti·M. Bjørn·T. Blake·F. Blanc·S. Blusk·V. Bocci·T. Boettcher·A. Bondar·N. Bondar·I. Bordyuzhin·S. Borghi·M. Borisyak·M. Borsato·F. Bossu·M. Boubdir·T. J. V. Bowcock·E. Bowen·C. Bozzi·S. Braun·J. Brodzicka·D. Brundu·E. Buchanan·C. Burr
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Abstract

We report measurements of charm-mixing parameters based on the decay-time-dependent ratio of $D^0\to K^+\pi^-$ to $D^0\to K^-\pi^+$ rates. The analysis uses a data sample of proton-proton collisions corresponding to an integrated luminosity of $5.0$ fb$^{-1}$ recorded by the LHCb experiment from 2011 through 2016. Assuming charge-parity (CP) symmetry, the mixing parameters are determined to be $x'^2=(3.9 \pm 2.7) \times10^{-5}$, $y'=(5.28 \pm 0.52) \times 10^{-3}$, and $R_D=(3.454 \pm 0.031)\times10^{-3}$. Without this assumption, the measurement is performed separately for $D^0$ and $\overline{D}{}^0$ mesons, yielding a direct CP-violating asymmetry $A_D =(-0.1\pm9.1)\times10^{-3}$, and magnitude of the ratio of mixing parameters $1.00< |q/p| <1.35$ at the $68.3\%$ confidence level. All results include statistical and systematic uncertainties and improve significantly upon previous single-measurement determinations. No evidence for CP violation in charm mixing is observed.

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LHCb collaboration, R. Aaij, B. Adeva, M. Adinolfi, Z. Ajaltouni, S. Akar, J. Albrecht, F. Alessio, M. Alexander, A. Alfonso Albero, S. Ali, G. Alkhazov, P. Alvarez Cartelle, A. A. Alves Jr, S. Amato, S. Amerio, Y. Amhis, L. An, L. Anderlini, G. Andreassi, M. Andreotti, J. E. Andrews, R. B. Appleby, F. Archilli, P. d'Argent, J. Arnau Romeu, A. Artamonov, M. Artuso, E. Aslanides, M. Atzeni, G. Auriemma, M. Baalouch, I. Babuschkin, S. Bachmann, J. J. Back, A. Badalov, C. Baesso, S. Baker, V. Balagura, W. Baldini, A. Baranov, R. J. Barlow, C. Barschel, S. Barsuk, W. Barter, F. Baryshnikov, V. Batozskaya, V. Battista, A. Bay, L. Beaucourt, J. Beddow, F. Bedeschi, I. Bediaga, A. Beiter, L. J. Bel, N. Beliy, V. Bellee, N. Belloli, K. Belous, I. Belyaev, E. Ben-Haim, G. Bencivenni, S. Benson, S. Beranek, A. Berezhnoy, R. Bernet, D. Berninghoff, E. Bertholet, A. Bertolin, C. Betancourt, F. Betti, M. O. Bettler, M. van Beuzekom, Ia. Bezshyiko, S. Bifani, P. Billoir, A. Birnkraut, A. Bizzeti, M. Bjørn, T. Blake, F. Blanc, S. Blusk, V. Bocci, T. Boettcher, A. Bondar, N. Bondar, I. Bordyuzhin, S. Borghi, M. Borisyak, M. Borsato, F. Bossu, M. Boubdir, T. J. V. Bowcock, E. Bowen, C. Bozzi, S. Braun, J. Brodzicka, D. Brundu, E. Buchanan, C. Burr. 2017-12-08. Updated determination of $D^0$-$\overline{D}{}^0$ mixing and CP violation parameters with $D^0\to K^+\pi^-$ decays. https://doi.org/10.1103/physrevd.97.031101

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