اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدMeasurement of the semileptonic $CP$ asymmetry in $B^0-overline{B}{}^0$ mixing
137
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The semileptonic $CP$ asymmetry in $B^0-overline{B}{}^0$ mixing, $a_{rm sl}^d$, is measured in proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb$^{-1}$, recorded by the LHCb experiment. Semileptonic $B^0$ decays are reconstructed in the inclusive final states $D^-mu^+$ and $D^{*-}mu^+$, where the $D^-$ meson decays into the $K^+pi^-pi^-$ final state, and the $D^{*-}$ meson into the $overline{D}{}^0(rightarrow K^+pi^-)pi^-$ final state. The asymmetry between the numbers of $D^{(*)-}mu^+$ and $D^{(*)+}mu^-$ decays is measured as a function of the decay time of the $B^0$ mesons. The $CP$ asymmetry is measured to be $a_{rm sl}^d = (-0.02 pm 0.19 pm 0.30)%$, where the first uncertainty is statistical and the second systematic. This is the most precise measurement of $a_{rm sl}^d$ to date and is consistent with the prediction from the Standard Model.
قيم البحث
اقرأ أيضاً
The $CP$ asymmetry in the mixing of $B_s^0$ and $overline{B}{}_s^0$ mesons is measured in proton-proton collision data corresponding to an integrated luminosity of 3.0 fb$^{-1}$, recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 T
eV. Semileptonic $B_s^0$ and $overline{B}{}_s^0$ decays are studied in the inclusive mode $D_s^{mp} mu^{pm} u_{mu} X$ with the $D_s^{mp}$ mesons reconstructed in the $K^+ K^- pi^{mp}$ final state. Correcting the observed charge asymmetry for detection and background effects, the $CP$ asymmetry is found to be $a_{text{sl}}^s = (0.39 pm 0.26 pm 0.20) % $, where the first uncertainty is statistical and the second systematic. This is the most precise measurement of $a_{text{sl}}^s$ to date. It is consistent with the prediction from the Standard Model and will constrain new models of particle physics.
We study the decays B- --> D*0 pi- and B- --> D*0 K-, where the D*0 decays into D0 pi0, with the D0 reconstructed in the CP-even (CP+) eigenstates K- K+ and pi- pi+ and in the (non-CP) channels K- pi+, K- pi+ pi+ pi-, and K- pi+ pi0. Using a sample o
f about 123 million BBbar pairs, we measure the ratios of decay rates R*(non-CP)=BR(B- --> D*0(non-CP) K-)/BR(B- --> D*0(non-CP) pi-) = 0.0813+-0.0040(stat)+0.0042-0.0031}(syst), and provide the first measurements of R*(CP+)= BR(B- --> D*0(CP+) K-)/BR(B- --> D*0(CP+) pi-) = 0.086+-0.021(stat)+-0. 007(syst), and of the CP asymmetry A*(CP+) = (BR(B- --> D*0(CP+) K-) - BR(B+ --> D*0(CP+) K+))/(BR(B- --> D*0(CP+) K-) + BR(B+ --> D*0(CP+) K+)) = -0.10+-0.23(stat)+0.03-0.04(syst).
The $CP$ asymmetry in $B^-to D_s^-D^0$ and $B^-to D^-D^0$ decays is measured using LHCb data corresponding to an integrated luminosity of 3.0 fb$^{-1}$, collected in $pp$ collisions at centre-of-mass energies of 7 and 8 TeV. The results are $A^{CP}(B
^-to D_s^-D^0)=(-0.4pm 0.5pm 0.5)%$ and $A^{CP}(B^-to D^-D^0)=( 2.3pm 2.7pm 0.4)%$, where the first uncertainties are statistical and the second systematic. This is the first measurement of $A^{CP}(B^-to D_s^-D^0)$ and the most precise determination of $A^{CP}(B^-to D^-D^0)$. Neither result shows evidence of $CP$ violation.
The time-integrated Dalitz plot of the three-body hadronic charmless decay ${{overline{B}}^0 to K_{mathrm{scriptscriptstyle S}}^0 pi^+ pi^-}$ is studied using a $pp$ collision data sample recorded with the LHCb detector, corresponding to an integrate
d luminosity of $3.0;mathrm{fb}^{-1}$. The decay amplitude is described with an isobar model. Relative contributions of the isobar amplitudes to the ${overline{B}^0 to K_{mathrm{scriptscriptstyle S}}^0 pi^+ pi^-}$ decay branching fraction and CP asymmetries of the flavour-specific amplitudes are measured. The CP asymmetry between the conjugate ${overline{B}^0 to K^{*}(892)^{-}pi^+}$ and ${overline{B}^0 to K^{*}(892)^{+}pi^-}$ decay rates is determined to be $-0.308 pm 0.062$.
The decay of the narrow resonance $overline{B}{}_{s2}^{*0}!rightarrow B^- K^+$ can be used to determine the $B^-$ momentum in partially reconstructed decays without any assumptions on the decay products of the $B^-$ meson. This technique is employed
for the first time to distinguish contributions from $D^0$, $D^{*0}$, and higher-mass charmed states ($D^{**0}$) in semileptonic $B^-$ decays by using the missing-mass distribution. The measurement is performed using a data sample corresponding to an integrated luminosity of 3.0 fb${}^{-1}$ collected with the LHCb detector in $pp$ collisions at center-of-mass energies of 7 and 8 TeV. The resulting branching fractions relative to the inclusive $B^- !rightarrow D^0 X mu^- overline{ u}_mu$ are $f_{D^0} = mathcal{B}( B^- rightarrow D^0mu^-overline{ u}_mu )/mathcal{B}( B^- rightarrow D^0 X mu^- overline{ u}_mu ) = 0.25 pm 0.06$, $f_{D^{**0}} = mathcal{B}( B^- rightarrow ( D^{**0} rightarrow D^0 X)mu^-overline{ u}_mu )/mathcal{B}( B^- rightarrow D^0 X mu^- overline{ u}_mu ) = 0.21 pm 0.07$, with $f_{D^{*0}} = 1 - f_{D^0} - f_{D^{**0}}$ making up the remainder.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
