Hot Topics from the BABAR Experiment

With a sample of about 384 million BBbar pairs recorded with the BABAR detector, we search for the flavor-changing charged current transition B+ -> \tau\nu and perform an amplitude analysis of the effective flavor-changing neutral current transition B+ -> \phi(1020)K*(892)+. We also extend our search for other K* final states in the decay B0 -> phi(1020)K*0 with a large K*0 -> K+pi- invariant mass. Two samples of events with one reconstructed hadronic B decay or one reconstructed semileptonic B decay are selected, and in the recoil a search for B+ -> \tau\nu is performed. We find a 2.6 sigma (3.2 sigma not including expected background uncertainty) excess in data which can be converted to a preliminary branching fraction central value of BR(B+ -> \tau\nu ) = (1.20 +0.40-0.38 +0.29-0.30 +-0.22) 10^-4. With the decay B+- -> \phi(1020)K*(892)+-, twelve parameters are measured, where our measurements of f_L=0.49+-0.05+-0.03, f_perp=0.21+-0.05+-0.02, and the strong phases point to the presence of a substantial helicity-plus amplitude from a presently unknown source.Comment: 14 pages, 33 postscript figures, proceedings of the 5th Flavor Physics And CP Violation Conference (FPCP 2007) C07/05/1

Transition form factors of B decays into p-wave axial-vector mesons in the perturbative QCD approach

The $B_{u,d,s}\to V,A$ form factors are studied in perturbative QCD approach ($V,A$ denote a vector meson and two kinds of p-wave axial-vector mesons: $^3P_1$ and $^1P_1$ states, respectively.). The form factors are directly studied in the large recoiling region and extrapolated to the whole kinematic region within the dipole parametrization. Adopting decay constants with different signs for the two kinds of axial-vectors, we find that the two kinds of $B\to A$ form factors have the same sign. The two strange mesons $K_{1A}$ and $K_{1B}$ mix with each other via the SU(3) symmetry breaking effect. In order to reduce the ambiguities in the mixing angle between $K_{1A}$ and $K_{1B}$, we propose a model-independent way that utilizes the B decay data. Most of the branching fractions of the semilteptonic $B\to Al\bar \nu_l$ decays are of the order $10^{-4}$, which still need experimental tests in the on-going and forthcoming experiments.Comment: 22 pages, 7 figure

Study of Polarization in B -> VT Decays

In this paper, we examine B -> VT decays (V is a vector and T is a tensor meson), whose final-state particles can have transverse or longitudinal polarization. Measurements have been made of B -> \phi K_2^*, and it is found that fT/fL is small, where fT (fL) is the fraction of transverse (longitudinal) decays. We find that the standard model (SM) naively predicts that fT/fL << 1. The two extensions of the naive SM which have been proposed to explain the large fT/fL in B -> \phi K^* -- penguin annihilation and rescattering -- make no firm predictions for the polarization in B -> \phi K_2^*. The two new-physics scenarios, which explain the data in B -> \pi K and the \phi (\rho) K^* polarization measurements, can reproduce the fT/fL data in B -> \phi K_2^* only if the B -> T form factors obey a certain hierarchy. Finally, we present the general angular analysis which can be used to get helicity information using two- and three-body decays.Comment: 15 pages, latex, 3 figures (enclosed), several changes made, conclusions unchanged, publication info adde

Internal alignement of the BABAR silicon vertex tracking detector

The BABAR Silicon Vertex Tracker (SVT ) is a five-layer double-sided silicon detector designed to provide precise measurements of the position and direction of primary tracks, and to fully reconstruct low-momentum tracks produced in e+e¡ collisions at the PEP-II asymmetric collider at Stanford Linear Accelerator Center. This paper describes the design, implementation, performance and validation of the local alignment procedure used to determine the relative positions and orientations of the 340 Silicon Vertex Trackerwafers. This procedure uses a tuned mix of lab-bench measurements and complementary in-situ experimental data to control systematic distortions. Wafer positions and orientations are determined by minimizing a Â2 computed using these data for each wafer individually, iterating to account for between-wafer correlations. A correction for aplanar distortions of the silicon wafers is measured and applied. The net effect of residual mis-alignments on relevant physical variables evaluated in special control samples is presented

The B(Bs)→D(s)(Dˉ(s))TB(B_{s})\rightarrow D_{(s)}(\bar{D}_{(s)}) T and D(s)∗(Dˉ(s)∗)TD_{(s)}^{*}(\bar{D}_{(s)}^{*})T decays in perturbative QCD approach

In perturbative QCD approach, we investigate the $B(B_{s})\rightarrow D_{(s)}(\bar{D}_{(s)})\,T$ and $D_{(s)}^{*}(\bar{D}_{(s)}^{*})\,T$ decays, which include the Cabibbo-Kobayashi-Maskawa (CKM) favored decays and the Cabibbo-Kobayashi-Maskawa-suppressed decays, where T denotes a light tensor meson. From our calculation, we find that the nonfactorizable emission diagrams and the annihilation type diagrams are important, especially for those color suppressed channels. For those decays with a tensor meson emitted, the factorizable emission diagrams vanish owing to the fact that a tensor meson can not be produced through the local (V-A) or tensor current. The numerical results show that the predictions for the branching ratios of considered charmed B decays are in the range of $10^{-4}$ to $10^{-6}$ for those CKM-favored decays (governed by $|V_{cb}|$) and in the range of $10^{-5}$ to $10^{-8}$ for those CKM-suppressed decays (governed by $|V_{ub}|$). We also predict large transverse polarization contributions in many of the $B(B_{s}) \rightarrow D_{(s)}^{\ast}(\bar{D}_{(s)}^{*})T$ decay channels.Comment: 30 pages, 3 figures, typos correctet in Figs. 1 and

The Discovery Potential of a Super B Factory

The Proceedings of the 2003 SLAC Workshops on flavor physics with a high luminosity asymmetric e+e- collider. The sensitivity of flavor physics to physics beyond the Standard Model is addressed in detail, in the context of the improvement of experimental measurements and theoretical calculations.Comment: 476 pages. Printed copies may be obtained by request to [email protected] . arXiv admin note: v2 appears to be identical to v

Radial increment dynamics in Pinus sylvestris stands within the Northern Steppe of Ukraine

The parameters of periodic increment (5-years) and peculiarities of its change depending on age, diameter, height and volume of trunk of Scots pine are determined. The influence of climate conditions (air temperature and precipitation) on the dynamics of radial increment change of Scots pine trees are established. The results of experimental studies, obtained from 20 temporary sample plots of pine stands within the Northern Steppe of Ukraine are presented. We conducted an estimate of radial increment of Scots pine trunks as a basis for development of normative and information support for assessment of biotic productivity of this category of forest. All&nbsp;selected sample trees had different age and biometric parameters. The age of sample trees ranged from 9 to 90 years; diameter at breast height – from 4.0 to 41.7 cm; height – from 4.2 to 30.0 m, trunk volume – from 0.002 to 1.748 m3. It is found that the radial increment of pine stem was significantly dependent on tree age. The highest values of radial increment of Scots pine trees were observed for trees aged up to 20 years. With increasing age, radial increment had a decreasing trend, including 90-year old trees. Regression models of the dependence of radial increment of pine trees on the age and diameter are presented. In the article, the dependence of the values of radial increment of sample trees from types of forest are demonstrated. The highest values of Scots pine radial increment was observed in sugruds and gruds, which were presented in tree samples of 20 years. Comparative analysis of radial increment change in the trees of one age category, which grew in different conditions, was conducted. The older trees had the maximum increment in the conditions of dry sugrud, and the minimum increment in conditions of fresh subor. Also in this article we used generalized chronology of Scots pine radial increment reflecting regional variability of growth in pine trees. The results supplemented the research obtained earlier with new data on the dependence of the pine radial growth rate on forest-biometric parameters. These experimental data, their graph-analytical evaluation yielded an information basis for modeling the radial increment of pine trees, created on the basis of dependence of this parameter on biometric indexes – age and diameter at breast height

Эвакуация акушерско-гинекологических больных, находящихся в критическом состоянии

Objective: to assess the results of evacuation of critically ill obstetric and gynecological patients by ground and air transports to improve the quality of a specialized medical aid on the basis of the technology developed by the Obstetric Resuscitative Advisory Center (ORAC). Subjects and methods. The study was based on the prospective and retrospective analysis of the results of evacuation of 358 critically ill obstetric and gynecological patients in the presence of severe gestosis (n=162), obstetric hemorrhages (n=74), abdominal (obstetric) sepsis (n=68), as well as pregnant women and puerparas with extragenital pathology (n=54) via ground (26.5%) and air (75.3%) transports by the workers of the ORAC in the period of 1998-2006. Results. Complex intensive care aimed at correcting major critical states, performed during evacuation by a resuscitative-advisory team, could provide the steady-state values of vital functions during transportation of obstetric and gynecological patients. Conclusion. A scheme has been developed for safe evacuation of critically ill obstetric and gynecological patients via ground and air transports by the ORAC workers. Key words: patient evacuation, gestosis, hemorrhage, sepsis, obstetrics, gynecology.Цель исследования — оценка результатов эвакуации больных в критическом состоянии с акушерско-гинекологичес-кой патологией наземным и воздушным транспортом для улучшения качества оказания специализированной медицинской помощи на основе технологии АРКЦ. Материал и методы. Работа основана на ретроспективном и проспективном анализе результатов эвакуации 358 пациенток с акушерско-гинекологической патологией в критическом состоянии на фоне тяжелых форм гестоза (162 случая), акушерских кровотечений (74), абдоминального (акушерского) сепсиса (68), а также у беременных и родильниц с экстрагенитальной патологией (54) наземным (26,5%) и воздушным (75,3%) транспортом силами акушерского реанимационно-консультативного центра за период 1998—2006 годы. Результаты исследования. Комплексная интенсивная терапия, направленная на коррекцию основных синдромов критического состояния, проводимая в процессе эвакуации реанимационно-консультативной бригадой, позволила обеспечить стабильные показатели жизненно-важных функций организма в процессе транспортировки больных с акушерско-гинекологической патологией. Заключение. Разработана схема безопасной эвакуации пациентов с акушерско-гинекологической патологией в критическом состоянии наземным и воздушным транспортом силами акушерского реанимационно-консультативного центра. Ключевые слова: эвакуация больных, гестоз, кровотечение, сепсис, акушерство и гинекология