Determination of the CKM Matrix Element |V_cb| from Semileptonic B Decays

We report studies of semileptonic decays, B --> X_c l nu, based on a sample of 88 million BB events recorded with the BABAR detector. We have measured four moments of the electron energy distribution and four moments of the hadronic mass distribution, each as a function of the minimum electron energy. From these moments we determine the inclusive branching fraction, the CKM matrix element |V_cb|, and other heavy quark parameters, using Heavy Quark Expansions (HQE) to order 1/m_b^3 in the kinetic mass scheme. In addition, we have studied a large sample of exclusive B^0 --> D^*- l^+ nu decays. This sample is used to extract the vector and axial form factors, the normalization and slope of the HQET form factor to determine |V_cb|.Comment: 7 pages, 3 postscript figues, Talk presented at ICHEP04 in Beijin

Heavy flavor resonances and QED radiative corrections

An application of high precision QED against experimental data is presented. When the corrections to ψ and Υ families are improved according to the method described below, the masses and widths of the resonances below open flavor threshold change by up to three standard deviations from presently accepted experimental values.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87625/2/326_1.pd

Extraction of |V_ub| with Reduced Dependence on Shape Functions

Using BABAR measurements of the inclusive electron spectrum in B {yields} X{sub u}e{nu} decays and the inclusive photon spectrum in B {yields} X{sub s}{gamma} decays, we extract the magnitude of the CKM matrix element V{sub ub}. The extraction is based on several theoretical calculations designed to reduce the theoretical uncertainties by exploiting the assumption that the leading shape functions are the same for all b {yields} q transitions (q is a light quark). The current results agree well with the previous analysis, have indeed smaller theoretical errors, but are presently limited by the knowledge of the photon spectrum and the experimental errors on the lepton spectrum

Heavy flavor resonances and QED radiative corrections

We discuss QED radiative corrections applied to narrow resonances in e+e- annihilation. We establish a simple and precise prescription for extracting radiative corrections from experimental data. This prescription differs from those used in measurements of charm and bottom resonances and leads to resonance parameters which are significantly different. Using a simulation method, we calculate these differences, and conclude that the masses and widths of [psi] and [upsi] resonances change by up to three standard deviations from presently accepted values.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27876/1/0000290.pd

Semileptonic Decays

The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model

Annual review of nuclear and particle science

+501hlm.;23c

Age- and stage-dependent accumulation of advanced glycation end products in intracellular deposits in normal and Alzheimer's disease brains

In this immunohistochemical study, the age- and stage-dependent accumulation of advanced glycation end-products (AGEs) in Alzheimer's disease (AD) and their relation to the formation of neurofibrillary tangles and neuronal cell death was investigated. For this purpose, the distribution of AGEs in neurons and glia was analyzed in the auditory association area of superior temporal gyrus (Brodmann area 22) of young and old non-demented controls and compared with early- and late-stage AD. A possible co-localization of AGEs with typical hallmarks of AD, such as hyperphosphorylated tau (as a marker for disturbed kinase/phosphatase activity), nNOS (as a marker for nitroxidative stress) and caspase-3 (as a marker of apoptotic cell death), was also investigated. Our results show that the percentage of AGE-positive neurons (and astroglia) increase both with age and, in AD patients, with the progression of the disease (Braak stages). Interestingly, nearly all if those neurons which show diffuse cytosolic AGE immunoreactivity also contain hyperphosphoryated tau, suggesting a link between AGE accumulation and the formation of early neurofibrillary tangles. Many, but not all, neurons show a co-localization of AGEs with other markers of neurodegeneration, such as nNOS and caspase-3