Download or read book Measurement of the Q2 Dependence of the Hadronic Form Factor in D0 to K E Nu e Decays written by B. Aubert and published by . This book was released on 2006 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: A preliminary measurement of the q{sup 2} dependence of the D{sup 0} {yields} K{sup -}e{sup +}{nu}{sub e} decay rate is presented. This rate is proportional to the hadronic form factor squared, specified by a single parameter. This is either the mass in the simple pole ansatz m{sub pole} = (1.854 {+-} 0.016 {+-} 0.020) GeV/c{sup 2} or the scale in the modified pole ansatz {alpha}{sub pole} = 0.43 {+-} 0.03 {+-} 0.04. The first error refers to the statistical, the second to the systematic uncertainty.

Download or read book Measurement of the Hadronic Form Factor in D0 to K E Nu e Decays written by and published by . This book was released on 2007 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The shape of the hadronic form factor f+ (q2) in the decay D° → K− e?{sub e} has been measured in a model independent analysis and compared with theoretical calculations. They use 75 fb−1 of data recorded by the BABAR detector at the PEPII electron-positron collider. The corresponding decay branching fraction, relative to the decay D° → K−?+, has also been measured to be R{sub D} = BR(D° → K−e+?{sub e})/BR(D° → K−?+) = 0.927 ± 0.007 ± 0.012. From these results, and using the present world average value for BR(D° → K−?+), the normalization of the form factor at q2 = 0 is determined to be f+(0) = 0.727 ± 0.007 ± 0.005 ± 0.007 where the uncertainties are statistical, systematic, and from external inputs, respectively.

Download or read book Measurement of the Hadronic Form Factors in Ds to Phi E Nu Decays written by J. Serrano and published by . This book was released on 2006 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the measured four-dimensional rate for D{sub s}{sup +} {yields} {phi}e{sup +}{nu}{sub e} decays, they have determined the ratios of the three hadronic form factors, {tau}{sub V} = V(0)/A{sub 1}(0) = 1.636 {+-} 0.067 {+-} 0.038 and {tau}{sub 2} = A{sub 2}(0)/A{sub 1}(0) = 0.705 {+-} 0.056 {+-} 0.029, using a simple pole ansatz for the q{sup 2} dependence, with fixed values of the pole masses for both the vector and axial form factors. By a separate fit to the same data, they have also extracted the pole mass for the axial form factors, m{sub A}: {tau}{sub V} = V(0)/A{sub 1}(0) = 1.633 {+-} 0.081 {+-} 0.068, {tau}{sub 2} = A{sub 2}(0)/A{sub 1}(0) = 0.711 {+-} 0.111 {+-} 0.096 and m{sub A} = (2.53{sub -0.35}{sup +0.54} {+-} 0.54)GeV/c{sup 2}.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 964 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1990 with total page 1010 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics Briefs written by and published by . This book was released on 1989 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reconstruction of B D E Nu Decays and Determination of Vcb written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this analysis the decay B- --> D*° e- nu is measured. The underlying data sample consists of about 226 million B-meson pairs accumulated on the Y(4S) resonance by the BABAR detector at the asymmetric e+e- collider PEP II. The reconstruction of the decay uses the channels D*° --> D° pi°, D° --> K- pi+ and pi° --> gamma gamma. The neutrino is not reconstructed. Since the rest frame of the B meson is unknown, the boost w of the D*° meson in the B meson rest frame is estimated by w'. The w' spectrum of the data is described in terms of the partial decay width dGamma/dw given by theory and the detector simulation translating each spectrum dGamma/dw into an expectation of the measured w' spectrum. dGamma/dw depends on a form factor F(w) parameterizing the strong interaction in the decay process. To find the best descriptive dGamma/dw a fit to the data determines the following two parameters of dGamma/dw: (i) F(1)|Vcb|, the product between F at zero D*°-recoil and the Quark mixing parameter |Vcb|; (ii) rho^2, a parameter of the form factor F(w). The former parameter scales the height of dGamma/dw and rho^2 varies the shape of it. The determined values of F(1)|Vcb|, rho^2 and the branching fraction BF(B- --> D*° e- nu) are F(1)|Vcb| = (35.8 +- 0.5 +- 1.5) x 10e-03, rho^2 = (1.08 +- 0.05 +- 0.09) and BF(B- --> D*° e- nu) = (5.60 +- 0.08 +- 0.42)%, where the uncertainties are statistical and systematic, respectively. The value of BF(B- --> D*° e- nu) has been determined by an integration of dGamma/dw over the allowed w range using the fitted values of F(1)|Vcb| and rho^2.

Download or read book INIS Atomindeks written by and published by . This book was released on 1984 with total page 1116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of the Ds to K K e Nu Decay Channel with the BaBar Experiment written by and published by . This book was released on 2008 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Charm semileptonic decays allow a validation of lattice QCD calculations through the measurement of the hadronic form factors, which characterize the effect of strong interaction in these reactions. The accuracy of such calculations is crucial for the improvement of the test of the standard model in flavor physics. This thesis presents a study of the Ds+ → K+K-e+ve channel using 214 fb-1 recorded by de BAbar experiment. For events with a K+K- mass in the range between 1.01 GeV/c2 and 1.03 Gev/c2, the [Phi] → K+K- is the dominant component. Using the simple pole model to parameterize the q2 dependence of the form factors -V(q2), A1(q2) and A2(q2)- the following ratios are measured at q2 = 0; [tau]V = V(0)/A1(0) = 1.868 ± 0.061 ± 0.079, r2 = A2(0)/A1(0) = 0.763 ± 0.072 ± 0.062. The mass pole of the axial-vector form factor is also obtained: mA = (2.30-0.18+0.42 ± 0.21) GeV/c2. In the same mass range, the semileptonic branching fraction, relative to the Ds+ → [Phi][pi]+ channel, is measured, and the absolute normalization of the axial-vector form factor is extracted: A1(q2 = 0) and = 0.605 ± 0.012 ± 0.018 ± 0.018. The stated errors refer to the statistical, systematic and errors from external inputs, respectively. An S wave component in the K+K- system, possibly originating from a f0, is also studied through its interference with the [Phi]. An S wave component is observed for the first time in this decay channel with a 5[sigma] significance.

Download or read book Measurement of Ga Us in Hadronic Z Decays Using All orders Resummed Predic written by Et al and published by . This book was released on 1992 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Factorization and Heavy Quark Symmetry in Hadronic B meson Decays written by and published by . This book was released on 1992 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: We discuss within the context of heavy-quark symmetry a program for performing model 226 independent tests of the factorization scenario proposed by Dugan and Grinstein for hadronic B-meson decays. Preliminary, model 226 dependent results for decays to a D or D* and one, two, or three pions are presented which indicate that the predictions of factorization are consistent with the present experimental situation. Our results suggest that such decays may not only provide a precision testing ground for factorization, but also an opportunity to study the properties of excited D mesons and to measure many of the universal form factors of heavy-quark symmetry (including ones not otherwise readily accessible).

Download or read book Measurement of Relative Branching Fractions for D0 Meson Cabibbo Suppressed Hadronic Decays from the CDF Secondary Vertex Trigger Sample at the Tevatron Collider written by Sandro De Cecco and published by . This book was released on 2002 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Determination of ga us in Second Order QCD from Hadronic Z Decays written by P. Abreu and published by . This book was released on 1992 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Model independent Approaches to QCD and B Decays written by Christian Arnesen and published by . This book was released on 2007 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate theoretical expectations for B-meson decay rates in the Standard Model. Strong-interaction effects described by quantum chromodynamics (QCD) make this a challenging endeavor. Exact solutions to QCD are not known, but an arsenal of approximation techniques have been developed. We apply effective field theory methods, in particular the sophisticated machinery of the soft-collinear effective theory (SCET), to B decays with energetic hadrons in the final state. SCET separates perturbative interactions at the scales mb and ... from hadronic physics at AQCD by expanding in ratios of these scales. After a review of SCET, we construct a complete reparametrization-invariant basis for heavy-to-light currents in SCET at next-to-next-to-leading order in the power-counting expansion. Next we classify AQCD/mb corrections to non-leptonic B - M1 M2 decays, where M1,2 are charmless mesons (flavor singlets excluded). The leading contributions to annihilation amplitudes as well as the leading "chirally enhanced" contributions are calculated and depend on twist-2 two-parton and twist-3 three-parton distributions. We demonstrate that non-perturbative strong phases in annihilation are suppressed. Using simple models, we find that the three-parton and two-parton terms have comparable magnitude, both consistent with the expected size of power corrections. Finally, we present a method for determining Vub from B --> [pi] data that is competitive with inclusive methods. At large q2, the form factor is taken from unquenched lattice QCD. At q2 = 0, we impose a model-independent constraint obtained from B --> [pi][pi] using SCET, and the form factor shape is constrained using QCD dispersion relations. Theory error is dominated by the input points, with negligible uncertainty from the dispersion relations.

Download or read book Hadronic Form Factors written by and published by . This book was released on 1990 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The challenging problem of applicability of the perturbative QCD to exclusive processes is revealed. The basic ingredients both of the asymptotic large Q2 analysis and of the QCD sum rule approach are analyzed for the simplest and most well-studied example of the pion electromagnetic form factor. The main conclusion is that for accessible energies and momentum transfers the soft (nonperturbative) contributions dominate over those due to the hard quark rescattering subprocesses.

Download or read book Preasymptotic Versus Asymptotic QCD Relations for the Hadronic Form Factor and the Anomalous J psi and psi Decays written by M. Chaichian and published by . This book was released on 1988 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of gL ub Production and Lifetime in Z o0 Hadronic Decays written by DELPHI and published by . This book was released on 1993 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: