ترغب بنشر مسار تعليمي؟ اضغط هنا

Observation of the decay $B_c^+ to psi(2S)pi^+$

133   0   0.0 ( 0 )
 نشر من قبل Yiming Li
 تاريخ النشر 2013
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

The decay $B_c^+ to psi(2S)pi^+$ with $psi(2S) to mu^+mu^-$ is observed with a significance of $5.2,sigma$ using $pp$ collision data corresponding to an integrated luminosity of $1.0,invfb$ collected by the LHCb experiment. The branching fraction of $B_c^+ to psi(2S)pi^+$ decays relative to that of the $B_c^+ to J/psipi^+$ mode is measured to be begin{equation*} frac{mathcal{B}(B_c^+ to psi(2S)pi^+)}{mathcal{B}(B_c^+ to J/psipi^+)} = 0.250 pm 0.068 ,text{stat} pm 0.014 ,text{syst} pm 0.006 ,(mathcal{B}). end{equation*} The last term is the uncertainty on the ratio $mathcal{B}(psi(2S) to mu^+mu^-)/mathcal{B}(J/psi to mu^+mu^-)$.



قيم البحث

اقرأ أيضاً

The decay $B_crightarrow J/psi K^+ K^- pi^+$ is observed for the first time, using proton-proton collisions collected with the LHCb detector corresponding to an integrated luminosity of 3fb$^{-1}$. A signal yield of $78pm14$ decays is reported with a significance of 6.2 standard deviations. The ratio of the branching fraction of $B_c rightarrow J/psi K^+ K^- pi^+$ decays to that of $B_c rightarrow J/psi pi^+$ decays is measured to be $0.53pm 0.10pm0.05$, where the first uncertainty is statistical and the second is systematic.
Using $pp$ collision data collected by LHCb at center-of-mass energies $sqrt{s}$ = 7 TeV and 8 TeV, corresponding to an integrated luminosity of 3 fb$^{-1}$, the ratio of the branching fraction of the $B_c^+ rightarrow psi(2S)pi^+$ decay relative to that of the $B_c^+ rightarrow J/psipi^+$ decay is measured to be 0.268 $pm$ 0.032 (stat) $pm$ 0.007 (syst) $pm$ 0.006 (BF). The first uncertainty is statistical, the second is systematic, and the third is due to the uncertainties on the branching fractions of the $J/psi rightarrow mu^+mu^-$ and $psi(2S) rightarrow mu^+mu^-$ decays. This measurement is consistent with the previous LHCb result, and the statistical uncertainty is halved.
Measurements of $B_c^+$ production and mass are performed with the decay mode $B_c^+ to J/psi pi^+$ using 0.37 fb$^{-1}$ of data collected in $pp$ collisions at $sqrt{s}=7$ TeV by the LHCb experiment. The ratio of the production cross-section times b ranching fraction between the $B_c^+ to J/psi pi^+$ and the $B^+ to J/psi K^+$ decays is measured to be $(0.68 pm 0.10,({rm stat.}) pm 0.03,({rm syst.}) pm 0.05,({rm lifetime}))$% for $B_c^+$ and $B^+$ mesons with transverse momenta $p_{rm T}>4 $GeV/$c$ and pseudorapidities $2.5<eta<4.5$. The $B_c^+$ mass is directly measured to be $6273.7 pm 1.3,({rm stat.}) pm 1.6 ,({rm syst.})$ MeV/$c^2$, and the measured mass difference with respect to the $B^+$ meson is $M(B_c^+)-M(B^+) = 994.6 pm 1.3,({rm stat.}) pm 0.6,({rm syst.})$ MeV/$c^2$.
The decay $overline{B}_s^0 rightarrow psi(2S) K^+ pi^-$ is observed using a data set corresponding to an integrated luminosity of $3.0fb^{-1}$ collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies of 7 and 8 TeV. The branchin g fraction relative to the $B^0rightarrow psi(2S) K^+ pi^-$ decay mode is measured to be begin{equation} frac{{cal B}(overline{B}^0_s rightarrow psi(2S) K^+ pi^-)}{{cal B}(B^0 rightarrow psi(2S) K^+ pi^-)} = 5.38 pm 0.36 (stat) pm 0.22 (syst) pm 0.31 , (f_s/f_d) , %, onumber end{equation} where $f_s/f_d$ indicates the uncertainty due to the ratio of probabilities for a $b$ quark to hadronise into a $B_s^0$ or $B^0$ meson. Using an amplitude analysis, the fraction of decays proceeding via an intermediate $K^*(892)^0$ meson is measured to be $0.645 pm 0.049 (stat) pm 0.049 (syst)$ and its longitudinal polarisation fraction is $0.524 pm 0.056 (stat) pm 0.029 (syst)$. The relative branching fraction for this component is determined to be begin{equation} frac{{cal B}(overline{B}^0_s rightarrow psi(2S) K^*(892)^0)}{{cal B}(B^0 rightarrow psi(2S) K^*(892)^0)} = 5.58 pm 0.57 (stat) pm 0.40 (syst) pm 0.32 , (f_s/f_d) , %. onumber end{equation} In addition, the mass splitting between the $B_s^0$ and $B^0$ mesons is measured as begin{equation} M(B^0_s) - M(B^0) = 87.45 pm 0.44 (stat) pm 0.07 (syst) MeV/c^2. onumber end{equation}
The decay Bc+ --> J/psi pi+pi-pi+ is observed for the first time, using 0.8 fb-1 of pp collisions at sqrt{s}=7 TeV collected by the LHCb experiment. The ratio of branching fractions BR(Bc+ --> J/psi pi+pi-pi+)/BR(B_c+ --> J/psi pi+) is measured to be 2.41+-0.30+-0.33, where the first uncertainty is statistical and the second systematic. The result is in agreement with theoretical predictions.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا