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Measurement of the $\bar{B}_s^0\to D_s^-D_s^+$ and $\bar{B}_s^0\to D^-D_s^+$ effective lifetimes

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Abstract

The first measurement of the effective lifetime of the $\bar{B}_s^0$ meson in the decay $\bar{B}_s^0\to D_s^-D_s^+$ is reported using a proton-proton collision dataset, corresponding to an integrated luminosity of 3 fb$^{-1}$, collected by the LHCb experiment. The measured value of the $\bar{B}_s^0\to D_s^-D_s^+$ effective lifetime is $1.379\pm0.026\pm0.017$ ps, where the uncertainties are statistical and systematic, respectively. This lifetime translates into a measurement of the decay width of the light $\bar{B}_s^0$ mass eigenstate of \Gamma_L$=0.725\pm0.014\pm0.009$ ps$^{-1}$. The $\bar{B}_s^0$ lifetime is also measured using the flavor-specific $\bar{B}_s^0\to D^-D_s^+$ decay to be $1.52\pm0.15\pm0.01 {\rm ps}$.

Figures and captions

Ratio of selection efficiencies for $ B ^- \rightarrow D ^0 D ^-_ s $ relative to $\overline{ B }{} ^0_ s \rightarrow D ^-_ s D ^+_ s $ decays as a function of decay time. The uncertainties shown are due to finite simulated sample sizes.

EffRat[..].pdf [13 KiB]
HiDef png [47 KiB]
Thumbnail [9 KiB]
*.C file
EffRatioPlot1_dataPID.pdf

Mass distributions and fits to the full data sample for (left) $\overline{ B }{} ^0_ s \rightarrow D ^-_ s D ^+_ s $ and (right) $ B ^- \rightarrow D ^0 D ^-_ s $ candidates. The points are the data and the curves and shaded regions show the fit components.

Bs2DsD[..].pdf [26 KiB]
HiDef png [224 KiB]
Thumbnail [65 KiB]
*.C file
Bs2DsDsFit_nominal_TimeBin_0_9_ps.pdf
B2D0Ds[..].pdf [25 KiB]
HiDef png [185 KiB]
Thumbnail [57 KiB] *.C file
B2D0DsFit_nominal_TimeBin_0_9_ps.pdf

Efficiency corrected yield ratio of $\overline{ B }{} ^0_ s \rightarrow D ^-_ s D ^+_ s $ relative to $ B ^- \rightarrow D ^0 D ^-_ s $ as a function of decay time, along with the exponential fit. The uncertainties are statistical only.

CorrYi[..].pdf [14 KiB]
HiDef png [96 KiB]
Thumbnail [29 KiB]
*.C file
CorrYieldRatio_BsOverBu_dataPIDforPaper.pdf

Mass distribution and fits to the full data sample for $\overline{ B }{} ^0_ s $ and $ B ^0 $ decays into the $ D ^- D ^+_ s $ final state. The points are the data and the curves and shaded regions show the fit components.

B2DsDF[..].pdf [30 KiB]
HiDef png [305 KiB]
Thumbnail [88 KiB]
*.C file
B2DsDFit_forBs2DsD_TimeBin_0_9_ps.pdf

Animated gif made out of all figures.

PAPER-2013-060.gif
Thumbnail
thumbnail_PAPER-2013-060.gif

Supplementary Material [file]

This ZIP file contains supplemetary material for the publication LHCb-PAPER-2013-060. The files are: DeltaGamma_Phis_Lifetimes.pdf :

DeltaG[..].pdf [328 KiB]
HiDef png [464 KiB]
Thumbnail [94 KiB]
*C file
DeltaGamma_Phis_Lifetimes.pdf

Created on 09 December 2018.Citation count from INSPIRE on 18 December 2018.