cern.ch

Measurements of indirect CP asymmetries in $D^0\to K^-K^+$ and $D^0\to\pi^-\pi^+$ decays

[to restricted-access page]

Abstract

A study of indirect CP violation in $D^0$ mesons through the determination of the parameter $A_\Gamma$ is presented using a data sample of $pp$ collisions, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected with the LHCb detector and recorded at the centre-of-mass energy of 7 TeV at the LHC. The parameter $A_\Gamma$ is the asymmetry of the effective lifetimes measured in decays of $D^0$ and $\bar{D}^0$ mesons to the CP eigenstates $K^-K^+$ and $\pi^-\pi^+$. Fits to the data sample yield $A_\Gamma(KK)=(-0.35\pm0.62\pm0.12)\times 10^{-3}$ and $A_\Gamma(\pi\pi)=(0.33\pm1.06\pm0.14)\times 10^{-3}$, where the first uncertainties are statistical and the second systematic. The results represent the world's best measurements of these quantities. They show no difference in $A_\Gamma$ between the two final states and no indication of CP violation.

Figures and captions

Fit of $\Delta m$ for one of the eight subsets, containing the $\overline{ D }{} ^0 \!\rightarrow K ^- K ^+ $ candidates with magnet polarity down for the earlier run period.

Deltam[..].pdf [72 KiB]
HiDef png [366 KiB]
Thumbnail [69 KiB]
*.C file
Deltamfit_D0bar_KK_log.pdf

(Top) Fit of decay time to $\overline{ D }{} ^0 \!\rightarrow K ^- K ^+ $ and corresponding pull plot for candidates with magnet polarity down for the earlier run period, where pull is defined as $({\rm data}-{\rm model})/{\rm uncertainty}$, and (middle and bottom) ratio of $\overline{ D }{} ^0$ to $ D ^0$ data and fit model for decays to $ K ^- K ^+ $ and $\pi ^- \pi ^+ $ for all data, respectively.

Timefi[..].pdf [59 KiB]
HiDef png [626 KiB]
Thumbnail [111 KiB]
*.C file
Timefit_KK_log.pdf
ratio-[..].pdf [43 KiB]
HiDef png [170 KiB]
Thumbnail [37 KiB] *.C file
ratio-KK-noPull.pdf
ratio-[..].pdf [44 KiB]
HiDef png [190 KiB]
Thumbnail [42 KiB] *.C file
ratio-pipi-noPull.pdf

Fits of $\ln(\chi^2_{\rm IP} )$ for $\overline{ D }{} ^0 \!\rightarrow K ^- K ^+ $ candidates for decay-time bins (left to right) $0.25-0.37 {\rm \,ps} $, $0.74-0.78 {\rm \,ps} $, and $1.55-1.80 {\rm \,ps} $.

KK_Dow[..].pdf [29 KiB]
HiDef png [384 KiB]
Thumbnail [71 KiB]
*.C file
KK_Down_D0_D0bar_40000_FirstHalf_D0_lnIPChi2_bin0_nopull.pdf
KK_Dow[..].pdf [29 KiB]
HiDef png [398 KiB]
Thumbnail [73 KiB] *.C file
KK_Down_D0_D0bar_40000_FirstHalf_D0_lnIPChi2_bin10_nopull.pdf
KK_Dow[..].pdf [30 KiB]
HiDef png [455 KiB]
Thumbnail [84 KiB] *.C file
KK_Down_D0_D0bar_40000_FirstHalf_D0_lnIPChi2_bin20_nopull.pdf

Animated gif made out of all figures.

PAPER-2013-054.gif
Thumbnail
thumbnail_PAPER-2013-054.gif

Tables and captions

Systematic uncertainties, given as multiples of $10^{-3}$. The first column for each final state refers to the unbinned fit method and the second column to the binned fit method.

Table_1.pdf [41 KiB]
HiDef png [54 KiB]
Thumbnail [8 KiB]
tex code
Table_1.pdf

Supplementary Material [file]

Supplementary material full pdf

Supple[..].pdf [1 MiB]
Supplementary.pdf

This ZIP file contains supplemetary material for the publication LHCb-PAPER-2013-054. The files are: Supplementary.pdf : An overview of the extra figures *.pdf, *.png, *.eps : The figures in variuous formats

Figure10a.pdf [32 KiB]
HiDef png [412 KiB]
Thumbnail [80 KiB]
*C file
Figure10a.pdf
Figure10b.pdf [31 KiB]
HiDef png [345 KiB]
Thumbnail [74 KiB]
*C file
Figure10b.pdf
Figure10c.pdf [32 KiB]
HiDef png [416 KiB]
Thumbnail [79 KiB]
*C file
Figure10c.pdf
Figure10d.pdf [30 KiB]
HiDef png [355 KiB]
Thumbnail [73 KiB]
*C file
Figure10d.pdf
Figure11a.pdf [43 KiB]
HiDef png [264 KiB]
Thumbnail [63 KiB]
*C file
Figure11a.pdf
Figure11b.pdf [44 KiB]
HiDef png [283 KiB]
Thumbnail [68 KiB]
*C file
Figure11b.pdf
Figure12a.pdf [31 KiB]
HiDef png [518 KiB]
Thumbnail [108 KiB]
*C file
Figure12a.pdf
Figure12b.pdf [31 KiB]
HiDef png [519 KiB]
Thumbnail [108 KiB]
*C file
Figure12b.pdf
Figure12c.pdf [31 KiB]
HiDef png [527 KiB]
Thumbnail [108 KiB]
*C file
Figure12c.pdf
Figure13a.pdf [30 KiB]
HiDef png [486 KiB]
Thumbnail [105 KiB]
*C file
Figure13a.pdf
Figure13b.pdf [31 KiB]
HiDef png [527 KiB]
Thumbnail [114 KiB]
*C file
Figure13b.pdf
Figure13c.pdf [31 KiB]
HiDef png [528 KiB]
Thumbnail [114 KiB]
*C file
Figure13c.pdf
Figure14a.pdf [31 KiB]
HiDef png [435 KiB]
Thumbnail [96 KiB]
*C file
Figure14a.pdf
Figure14b.pdf [32 KiB]
HiDef png [443 KiB]
Thumbnail [97 KiB]
*C file
Figure14b.pdf
Figure14c.pdf [33 KiB]
HiDef png [512 KiB]
Thumbnail [110 KiB]
*C file
Figure14c.pdf
Figure15a.pdf [30 KiB]
HiDef png [378 KiB]
Thumbnail [89 KiB]
*C file
Figure15a.pdf
Figure15b.pdf [31 KiB]
HiDef png [456 KiB]
Thumbnail [103 KiB]
*C file
Figure15b.pdf
Figure15c.pdf [31 KiB]
HiDef png [438 KiB]
Thumbnail [100 KiB]
*C file
Figure15c.pdf
Figure16a.pdf [30 KiB]
HiDef png [441 KiB]
Thumbnail [91 KiB]
*C file
Figure16a.pdf
Figure16b.pdf [30 KiB]
HiDef png [457 KiB]
Thumbnail [94 KiB]
*C file
Figure16b.pdf
Figure16c.pdf [32 KiB]
HiDef png [517 KiB]
Thumbnail [107 KiB]
*C file
Figure16c.pdf
Figure17a.pdf [29 KiB]
HiDef png [395 KiB]
Thumbnail [87 KiB]
*C file
Figure17a.pdf
Figure17b.pdf [29 KiB]
HiDef png [413 KiB]
Thumbnail [89 KiB]
*C file
Figure17b.pdf
Figure17c.pdf [30 KiB]
HiDef png [478 KiB]
Thumbnail [103 KiB]
*C file
Figure17c.pdf
Figure18a.pdf [68 KiB]
HiDef png [397 KiB]
Thumbnail [65 KiB]
*C file
Figure18a.pdf
Figure18b.pdf [21 KiB]
HiDef png [342 KiB]
Thumbnail [88 KiB]
*C file
Figure18b.pdf
Figure18c.pdf [17 KiB]
HiDef png [255 KiB]
Thumbnail [69 KiB]
*C file
Figure18c.pdf
Figure4a.pdf [63 KiB]
HiDef png [489 KiB]
Thumbnail [99 KiB]
*C file
Figure4a.pdf
Figure4b.pdf [56 KiB]
HiDef png [475 KiB]
Thumbnail [100 KiB]
*C file
Figure4b.pdf
Figure4c.pdf [70 KiB]
HiDef png [579 KiB]
Thumbnail [113 KiB]
*C file
Figure4c.pdf
Figure4d.pdf [57 KiB]
HiDef png [482 KiB]
Thumbnail [98 KiB]
*C file
Figure4d.pdf
Figure5a.pdf [74 KiB]
HiDef png [427 KiB]
Thumbnail [91 KiB]
*C file
Figure5a.pdf
Figure5b.pdf [57 KiB]
HiDef png [381 KiB]
Thumbnail [86 KiB]
*C file
Figure5b.pdf
Figure5c.pdf [78 KiB]
HiDef png [472 KiB]
Thumbnail [98 KiB]
*C file
Figure5c.pdf
Figure5d.pdf [61 KiB]
HiDef png [403 KiB]
Thumbnail [86 KiB]
*C file
Figure5d.pdf
Figure6a.pdf [45 KiB]
HiDef png [469 KiB]
Thumbnail [96 KiB]
*C file
Figure6a.pdf
Figure6b.pdf [46 KiB]
HiDef png [454 KiB]
Thumbnail [95 KiB]
*C file
Figure6b.pdf
Figure6c.pdf [54 KiB]
HiDef png [649 KiB]
Thumbnail [123 KiB]
*C file
Figure6c.pdf
Figure6d.pdf [51 KiB]
HiDef png [553 KiB]
Thumbnail [109 KiB]
*C file
Figure6d.pdf
Figure7a.pdf [48 KiB]
HiDef png [467 KiB]
Thumbnail [96 KiB]
*C file
Figure7a.pdf
Figure7b.pdf [47 KiB]
HiDef png [452 KiB]
Thumbnail [95 KiB]
*C file
Figure7b.pdf
Figure7c.pdf [58 KiB]
HiDef png [662 KiB]
Thumbnail [127 KiB]
*C file
Figure7c.pdf
Figure7d.pdf [52 KiB]
HiDef png [549 KiB]
Thumbnail [110 KiB]
*C file
Figure7d.pdf
Figure8a.pdf [46 KiB]
HiDef png [423 KiB]
Thumbnail [83 KiB]
*C file
Figure8a.pdf
Figure8b.pdf [45 KiB]
HiDef png [404 KiB]
Thumbnail [83 KiB]
*C file
Figure8b.pdf
Figure8c.pdf [59 KiB]
HiDef png [609 KiB]
Thumbnail [110 KiB]
*C file
Figure8c.pdf
Figure8d.pdf [51 KiB]
HiDef png [521 KiB]
Thumbnail [98 KiB]
*C file
Figure8d.pdf
Figure9a.pdf [47 KiB]
HiDef png [442 KiB]
Thumbnail [83 KiB]
*C file
Figure9a.pdf
Figure9b.pdf [45 KiB]
HiDef png [408 KiB]
Thumbnail [82 KiB]
*C file
Figure9b.pdf
Figure9c.pdf [59 KiB]
HiDef png [626 KiB]
Thumbnail [111 KiB]
*C file
Figure9c.pdf
Figure9d.pdf [51 KiB]
HiDef png [521 KiB]
Thumbnail [98 KiB]
*C file
Figure9d.pdf

Created on 17 December 2018.Citation count from INSPIRE on 18 December 2018.