ترغب بنشر مسار تعليمي؟ اضغط هنا

Analysis of $D^+tobar K^0e^+ u_e$ and $D^+topi^0e^+ u_e$ Semileptonic Decays

103   0   0.0 ( 0 )
 نشر من قبل Yi Fang
 تاريخ النشر 2017
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

Using 2.93~fb$^{-1}$ of data taken at 3.773 GeV with the BESIII detector operated at the BEPCII collider, we study the semileptonic decays $D^+ to bar K^0e^+ u_e$ and $D^+ to pi^0 e^+ u_e$. We measure the absolute decay branching fractions $mathcal B(D^+ to bar K^0e^+ u_e)=(8.60pm0.06pm 0.15)times10^{-2}$ and $mathcal B(D^+ to pi^0e^+ u_e)=(3.63pm0.08pm0.05)times10^{-3}$, where the first uncertainties are statistical and the second systematic. We also measure the differential decay rates and study the form factors of these two decays. With the values of $|V_{cs}|$ and $|V_{cd}|$ from Particle Data Group fits assuming CKM unitarity, we obtain the values of the form factors at $q^2=0$, $f^K_+(0) = 0.725pm0.004pm 0.012$ and $f^{pi}_+(0) = 0.622pm0.012pm 0.003$. Taking input from recent lattice QCD calculations of these form factors, we determine values of the CKM matrix elements $|V_{cs}|=0.944 pm 0.005 pm 0.015 pm 0.024$ and $|V_{cd}|=0.210 pm 0.004 pm 0.001 pm 0.009$, where the third uncertainties are theoretical.



قيم البحث

اقرأ أيضاً

Using 6.32 fb$^{-1}$ of electron-positron collision data recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, we present the first search for the decay $D_s^+to a_0(980)^0 e^+ u_e,,a_0(980)^0rightarrow pi^0eta$, whi ch could proceed via $a_0(980)$-$f_0(980)$ mixing. No significant signal is observed. An upper limit of $1.2 times 10^{-4}$ at the $90%$ confidence level is set on the product of the branching fractions of $D_{s}^{+}to a_0(980)^0 e^+ u_e$ and $a_0(980)^0rightarrow pi^0eta$ decays.
We report on new measurements of Cabibbo-suppressed semileptonic $D_s^+$ decays using $3.19~mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data sample collected at a center-of-mass energy of 4.178~GeV with the BESIII detector at the BEPCII collider. Our r esults include branching fractions $mathcal B({D^+_srightarrow K^0 e^+ u_{e}})=(3.25pm0.38({rm stat.})pm0.16({rm syst.}))times10^{-3}$ and $mathcal B({D^+_srightarrow K^{*0} e^+ u_{e}})=(2.37pm0.26({rm stat.})pm0.20({rm syst.}))times10^{-3}$ which are much improved relative to previous measurements, and the first measurements of the hadronic form-factor parameters for these decays. For $D^+_srightarrow K^0 e^+ u_{e}$, we obtain $f_+(0)=0.720pm0.084({rm stat.})pm0.013({rm syst.})$, and for $D^+_srightarrow K^{*0} e^+ u_{e}$, we find form-factor ratios $r_V=V(0)/A_1(0)=1.67pm0.34({rm stat.})pm0.16({rm syst.})$ and $r_2=A_2(0)/A_1(0)=0.77pm0.28({rm stat.})pm0.07({rm syst.})$.
Using 2.93 fb$^{-1}$ of $e^+e^-$ collision data collected with the BESIII detector at a center-of-mass energy of 3.773 GeV, we measure the absolute branching fractions of the decays $D^0to K^-e^+ u_e$ and $D^+to bar K^0 e^+ u_e$ to be $(3.567pm0.031_ {rm stat}pm 0.025_{rm syst})%$ and $(8.68pm0.14_{rm stat}pm 0.16_{rm syst})%$, respectively. Starting with the process $e^+e^-to Dbar{D}$, a new reconstruction method is employed to select events that contain candidates for both $Dto bar Ke^+ u_e$ and $bar Dto Ke^-bar u_e$ decays. The branching fractions reported in this work are consistent within uncertainties with previous BESIII measurements that selected events containing $Dto bar Ke^+ u_e$ and hadronic $bar D$ decays. Combining our results with the lifetimes of the $D^0$ and $D^+$ mesons and the previous BESIII measurements leads to a ratio of the two decay partial widths of $frac{bar Gamma_{D^0to K^{-}e^+ u_{e}}}{bar Gamma_{D^{+}to bar K^{0}e^+ u_{e}}}=1.039pm0.021$. This ratio supports isospin symmetry in the $D^0to K^-e^+ u_e$ and $D^+to bar K^0 e^+ u_e$ decays within $1.9sigma$.
We present an analysis of the decay $D^{+} to K^{-} pi^+ e^+ u_e$ based on data collected by the BESIII experiment at the $psi(3770)$ resonance. Using a nearly background-free sample of 18262 events, we measure the branching fraction $mathcal{B}(D^{ +} to K^{-} pi^+ e^+ u_e) = (3.71 pm 0.03 pm 0.08)%$. For $0.8<m_{Kpi}<1.0$ GeV/$c^{2}$ the partial branching fraction is $mathcal{B}(D^{+} to K^{-} pi^+ e^+ u_e)_{[0.8,1]} = (3.33 pm 0.03 pm 0.07)%$. A partial wave analysis shows that the dominant $bar K^{*}(892)^{0}$ component is accompanied by an emph{S}-wave contribution accounting for $(6.05pm0.22pm0.18)%$ of the total rate and that other components are negligible. The parameters of the $bar K^{*}(892)^{0}$ resonance and of the form factors based on the spectroscopic pole dominance predictions are also measured. We also present a measurement of the $bar K^{*}(892)^{0}$ helicity basis form factors in a model-independent way.
Using an $e^+e^-$ collision data sample of 2.93 fb$^{-1}$ collected at a center-of-mass energy of 3.773 GeV by the BESIII detector at BEPCII, we report the observation of $D^0 to a_0(980)^- e^+ u_e$ and evidence for $D^+ to a_0(980)^0 e^+ u_e~$ wit h significances of $6.4sigma$ and $2.9sigma$, respectively. The absolute branching fractions are determined to be $mathcal{B}(D^0 to a_0(980)^- e^+ u_e)timesmathcal{B}(a_0(980)^- to eta pi^-) = (1.33_{-0.29}^{+0.33}({rm stat})pm0.09({rm syst}))times10^{-4}~$ and $mathcal{B}(D^+ to a_0(980)^0 e^+ u_e)timesmathcal{B}(a_0(980)^0 to eta pi^0) = (1.66_{-0.66}^{+0.81}({rm stat})pm0.11({rm syst}))times10^{-4}~$. An upper limit of $mathcal{B}(D^+ to a_0(980)^0 e^+ u_e)timesmathcal{B}(a_0(980)^0 to eta pi^0)<3.0times10^{-4}~$ is also determined at the $90%~$ confidence level.
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