اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدFirst Measurement of the Form Factors in the Decays D0 to rho- e+ nu_e and D+ to rho0 e+ nu_e
216
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Using the entire CLEO-c psi(3770) to DDbar event sample, corresponding to an integrated luminosity of 818 pb^-1 and approximately 5.4 x 10^6 DDbar events, we measure the form factors for the decays D0 to rho- e+ nu_e and D+ to rho0 e+ nu_e for the first time and the branching fractions with improved precision. A four-dimensional unbinned maximum likelihood fit determines the form factor ratios to be: V(0)/A_1(0) = 1.48 +- 0.15 +- 0.05 and A_2(0)/A_1(0)= 0.83 +- 0.11 +- 0.04. Assuming CKM unitarity, the known D meson lifetimes and our measured branching fractions we obtain the form factor normalizations A_1(0), A_2(0), and V(0). We also present a measurement of the branching fraction for D^+ to omega e^+ nu_e with improved precision.
قيم البحث
اقرأ أيضاً
Using 1.8 million DDbar pairs and a neutrino reconstruction technique, we have studied the decays D^0 -> K^- e^+ nu_e, D^0 -> pi^- e^+ nu_e, D^+ -> Kbar^0 e^+ nu_e, and D^+ -> pi^0 e^+ nu_e. We find B(D^0 -> pi^- e^+ nu_e) = 0.299(11)(9)%, B(D^+ -> p
i^0 e^+ nu_e) = 0.373(22)(13)%, B(D^0 -> K^- e^+ nu_e) = 3.56(3)(9)%, and B(D^+ -> Kbar^0 e^+ nu_e) = 8.53(13)(23)%. In addition, form factors are studied through fits to the partial branching fractions obtained in five q^2 ranges. By combining our results with recent unquenched lattice calculations, we obtain |Vcd| = 0.217(9)(4)(23) and |Vcs| = 1.015(10)(11)(106).
Using a sample of 1.8 million DDbar meson pairs collected at the psi(3770) with the CLEO-c detector, we study the semileptonic decays D^0 -> pi^- e^+ nu_e, D^+ -> pi^0 e^+ u_e, D^0 -> K^- e^+ u_e, and D^+ -> Kbar^0 e^+ nu_e. For the total branching
fractions we find B(D^0 -> pi^- e^+ u_e) = 0.299(11)(9)%, B(D^+ -> pi^0 e^+ u_e) = 0.373(22)(13)%, B(D^0 -> K^- e^+ nu_e) = 3.56(3)(9)%, and B(D^+ -> Kbar^0 e^+ nu_e) = 8.53(13)(23)%, where the first error is statistical and the second systematic. In addition, form factors are studied through fits to the partial branching fractions obtained in five q^2 ranges. By combining our results with recent unquenched lattice calculations, we obtain |Vcd| = 0.217(9)(4)(23) and |Vcs| = 1.015(10)(11)(106), where the final error is theoretical.
Using the CLEO detector at the Cornell Electron Storage Ring we have studied the angular distributions in the decay Lambda_c^+ to Lambda e+ nu_e. By performing a four-dimensional maximum likelihood fit, we extract the form factor ratio, R = f_2/f_1,
and the pole mass, which determines the shape of the form factors, M_{pole}. They are found to be -0.31 +/- 0.05_{stat} +/- 0.04_{syst}$ and (2.13 +/- 0.07_{stat} +/- 0.10_{syst}) GeV/c^2, respectively. These results correspond to the following value of the decay asymmetry parameter: alpha_{Lambda_c} = -0.85 +/- {0.03}_{stat} +/- 0.02_{sys}, for <q^2> = 0.67 (GeV/c^2)^2. We search for CP violation in the angular distributions of the decay and find no evidence for CP violation, obtaining anasymmetry ratio; A_{Lambda_{c}} = (alpha_{Lambda_c} + alpha_{bar{Lambda}_c}) / (alpha_{Lambda_c} - alpha_{bar{Lambda}_c}) = 0.01 +/- 0.03_{stat} +/- 0.01_{sys} +/- 0.02_{A_{Lambda}}, where the third error is from the uncertainty in the world average of the CP violating parameter, A_{Lambda}, for Lambda decay to p pi^-. All results presented in this paper are preliminary.
We report the first observation of the decay D^+ -> eta e^+ nu_e in two analyses, which combined provide a branching fraction of B(D+ -> eta e nu) = (2.16 +/- 0.53 +/- 0.07) x 10^{-4}. We also provide an improved measurement of B(D+ -> eta e nu) = (1
1.4 +/- 0.9 +/- 0.4) x 10^{-4}, provide the first form factor measurement, and set the improved upper limit B(D+ -> phi e nu) < 0.9 x 10^{-4} (90% C.L.).
Using 2.92 fb$^{-1}$ of electron-positron annihilation data collected at a center-of-mass energy of $sqrt{s}= 3.773$ GeV with the BESIII detector, we present an improved measurement of the branching fraction $mathcal{B}(D^+ to omega e^+ u_{e}) = (1.
63pm0.11pm0.08)times 10^{-3}$. The parameters defining the corresponding hadronic form factor ratios at zero momentum transfer are determined for the first time, we measure them to be $r_V = 1.24pm0.09pm0.06$ and $r_2 = 1.06pm0.15 pm 0.05$. The first and second uncertainties are statistical and systematic, respectively. We also search for the decay $D^+ to phi e^+ u_{e}$. An improved upper limit $mathcal{B}(D^+ to phi e^+ u_{e}) < 1.3 times 10^{-5}$ is set at 90% confidence level.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
