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تسجيل مستخدم جديدCP asymmetries in three-body B+- decays to charged pions and kaons
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CP asymmetries have been measured recently by the LHCb collaboration in three-body $B^+$ decays to final states involving charged pions and kaons. Large asymmetries with opposite signs at a level of about 60% have been observed in $B^pmto pi^pm({rm or} K^pm)pi^+pi^-$ and $B^pm to pi^pm K^+K^-$ for restricted regions in the Dalitz plots involving $pi^+pi^-$ and $K^+K^-$ with low invariant mass. U-spin is shown to predict corresponding $Delta S=0$ and $Delta S=1$ asymmetries with opposite signs and inversely proportional to their branching ratios, in analogy with a successful relation predicted thirteen years ago between asymmetries in $B_sto K^-pi^+$ and $B^0 to K^+ pi^-$. We compare these predictions with the measured integrated asymmetries. Effects of specific resonant or non-resonant partial waves on enhanced asymmetries for low-pair-mass regions of the Dalitz plot are studied in $B^pm to pi^pm pi^+pi^-$. The closure of low-mass $pi^+pi^-$ and $K^+K^-$ channels involving only $pipi leftrightarrow Kbar K$ rescattering may explain by CPT approximately equal magnitudes and opposite signs measured in $B^pmto pi^pmpi^+pi^-$ and $B^pm to pi^pm K^+K^-$.
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of-mass energy of 13 TeV. The results are begin{eqnarray*} C_{pipi} & = & -0.311 pm 0.045 pm 0.015, S_{pipi} & = & -0.706 pm 0.042 pm 0.013, C_{KK} & = & phantom{-}0.164 pm 0.034 pm 0.014, S_{KK} & = & phantom{-}0.123 pm 0.034 pm 0.015, cal {A}^{mathrm{DeltaGamma}}_{mathit{KK}} & = & -0.83phantom{0} pm 0.05phantom{0} pm 0.09, end{eqnarray*} where the first uncertainties are statistical and the second systematic. The same data sample is used to measure the time-integrated $CP$ asymmetries of $B^0to K^+pi^-$ and $B^0_mathrm{s}to K^-pi^+$ decays and the results are begin{eqnarray*} A_{CP}^{B^0} & = & -0.0824 pm 0.0033 pm 0.0033, A_{CP}^{B^0_mathrm{s}} & = & phantom{-}0.236phantom{0} pm 0.013phantom{0} pm 0.011. end{eqnarray*} All results are consistent with earlier measurements. A combination of LHCb measurements provides the first observation of time-dependent $CP$ violation in $B^0_mathrm{s}$ decays.
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