8,569 research outputs found
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 form factors are studied in perturbative QCD approach
( denote a vector meson and two kinds of p-wave axial-vector mesons:
and 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 form factors have the same sign. The two strange mesons
and mix with each other via the SU(3) symmetry breaking effect. In
order to reduce the ambiguities in the mixing angle between and
, we propose a model-independent way that utilizes the B decay data.
Most of the branching fractions of the semilteptonic decays
are of the order , 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+eΒ‘ 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 Γ2 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 and decays in perturbative QCD approach
In perturbative QCD approach, we investigate the and 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 to for those
CKM-favored decays (governed by ) and in the range of to
for those CKM-suppressed decays (governed by ). We also
predict large transverse polarization contributions in many of the decay channels.Comment: 30 pages, 3 figures, typos correctet in Figs. 1 and
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 selected sample trees had different age and biometric parameters. The age of sample trees ranged from 9 to 90 years; diameter at breast height β from 4.0 to 41.7 cm; height β from 4.2 to 30.0 m, trunk volume β 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 β age and diameter at breast height
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
ΠΠ²Π°ΠΊΡΠ°ΡΠΈΡ Π°ΠΊΡΡΠ΅ΡΡΠΊΠΎ-Π³ΠΈΠ½Π΅ΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ Π±ΠΎΠ»ΡΠ½ΡΡ , Π½Π°Ρ ΠΎΠ΄ΡΡΠΈΡ ΡΡ Π² ΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠΌ ΡΠΎΡΡΠΎΡΠ½ΠΈΠΈ
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.Π¦Π΅Π»Ρ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ β ΠΎΡΠ΅Π½ΠΊΠ° ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΎΠ² ΡΠ²Π°ΠΊΡΠ°ΡΠΈΠΈ Π±ΠΎΠ»ΡΠ½ΡΡ
Π² ΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠΌ ΡΠΎΡΡΠΎΡΠ½ΠΈΠΈ Ρ Π°ΠΊΡΡΠ΅ΡΡΠΊΠΎ-Π³ΠΈΠ½Π΅ΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅Ρ-ΠΊΠΎΠΉ ΠΏΠ°ΡΠΎΠ»ΠΎΠ³ΠΈΠ΅ΠΉ Π½Π°Π·Π΅ΠΌΠ½ΡΠΌ ΠΈ Π²ΠΎΠ·Π΄ΡΡΠ½ΡΠΌ ΡΡΠ°Π½ΡΠΏΠΎΡΡΠΎΠΌ Π΄Π»Ρ ΡΠ»ΡΡΡΠ΅Π½ΠΈΡ ΠΊΠ°ΡΠ΅ΡΡΠ²Π° ΠΎΠΊΠ°Π·Π°Π½ΠΈΡ ΡΠΏΠ΅ΡΠΈΠ°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΠΌΠ΅Π΄ΠΈΡΠΈΠ½ΡΠΊΠΎΠΉ ΠΏΠΎΠΌΠΎΡΠΈ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ ΠΠ ΠΠ¦. ΠΠ°ΡΠ΅ΡΠΈΠ°Π» ΠΈ ΠΌΠ΅ΡΠΎΠ΄Ρ. Π Π°Π±ΠΎΡΠ° ΠΎΡΠ½ΠΎΠ²Π°Π½Π° Π½Π° ΡΠ΅ΡΡΠΎΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΠΎΠΌ ΠΈ ΠΏΡΠΎΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΠΎΠΌ Π°Π½Π°Π»ΠΈΠ·Π΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΎΠ² ΡΠ²Π°ΠΊΡΠ°ΡΠΈΠΈ 358 ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΎΠΊ Ρ Π°ΠΊΡΡΠ΅ΡΡΠΊΠΎ-Π³ΠΈΠ½Π΅ΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠ°ΡΠΎΠ»ΠΎΠ³ΠΈΠ΅ΠΉ Π² ΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠΌ ΡΠΎΡΡΠΎΡΠ½ΠΈΠΈ Π½Π° ΡΠΎΠ½Π΅ ΡΡΠΆΠ΅Π»ΡΡ
ΡΠΎΡΠΌ Π³Π΅ΡΡΠΎΠ·Π° (162 ΡΠ»ΡΡΠ°Ρ), Π°ΠΊΡΡΠ΅ΡΡΠΊΠΈΡ
ΠΊΡΠΎΠ²ΠΎΡΠ΅ΡΠ΅Π½ΠΈΠΉ (74), Π°Π±Π΄ΠΎΠΌΠΈΠ½Π°Π»ΡΠ½ΠΎΠ³ΠΎ (Π°ΠΊΡΡΠ΅ΡΡΠΊΠΎΠ³ΠΎ) ΡΠ΅ΠΏΡΠΈΡΠ° (68), Π° ΡΠ°ΠΊΠΆΠ΅ Ρ Π±Π΅ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
ΠΈ ΡΠΎΠ΄ΠΈΠ»ΡΠ½ΠΈΡ Ρ ΡΠΊΡΡΡΠ°Π³Π΅Π½ΠΈΡΠ°Π»ΡΠ½ΠΎΠΉ ΠΏΠ°ΡΠΎΠ»ΠΎΠ³ΠΈΠ΅ΠΉ (54) Π½Π°Π·Π΅ΠΌΠ½ΡΠΌ (26,5%) ΠΈ Π²ΠΎΠ·Π΄ΡΡΠ½ΡΠΌ (75,3%) ΡΡΠ°Π½ΡΠΏΠΎΡΡΠΎΠΌ ΡΠΈΠ»Π°ΠΌΠΈ Π°ΠΊΡΡΠ΅ΡΡΠΊΠΎΠ³ΠΎ ΡΠ΅Π°Π½ΠΈΠΌΠ°ΡΠΈΠΎΠ½Π½ΠΎ-ΠΊΠΎΠ½ΡΡΠ»ΡΡΠ°ΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠ΅Π½ΡΡΠ° Π·Π° ΠΏΠ΅ΡΠΈΠΎΠ΄ 1998β2006 Π³ΠΎΠ΄Ρ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ. ΠΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ½Π°Ρ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½Π°Ρ ΡΠ΅ΡΠ°ΠΏΠΈΡ, Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½Π½Π°Ρ Π½Π° ΠΊΠΎΡΡΠ΅ΠΊΡΠΈΡ ΠΎΡΠ½ΠΎΠ²Π½ΡΡ
ΡΠΈΠ½Π΄ΡΠΎΠΌΠΎΠ² ΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ, ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠΌΠ°Ρ Π² ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΡΠ²Π°ΠΊΡΠ°ΡΠΈΠΈ ΡΠ΅Π°Π½ΠΈΠΌΠ°ΡΠΈΠΎΠ½Π½ΠΎ-ΠΊΠΎΠ½ΡΡΠ»ΡΡΠ°ΡΠΈΠ²Π½ΠΎΠΉ Π±ΡΠΈΠ³Π°Π΄ΠΎΠΉ, ΠΏΠΎΠ·Π²ΠΎΠ»ΠΈΠ»Π° ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΡΡ ΡΡΠ°Π±ΠΈΠ»ΡΠ½ΡΠ΅ ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π»ΠΈ ΠΆΠΈΠ·Π½Π΅Π½Π½ΠΎ-Π²Π°ΠΆΠ½ΡΡ
ΡΡΠ½ΠΊΡΠΈΠΉ ΠΎΡΠ³Π°Π½ΠΈΠ·ΠΌΠ° Π² ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΡΡΠ°Π½ΡΠΏΠΎΡΡΠΈΡΠΎΠ²ΠΊΠΈ Π±ΠΎΠ»ΡΠ½ΡΡ
Ρ Π°ΠΊΡΡΠ΅ΡΡΠΊΠΎ-Π³ΠΈΠ½Π΅ΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠ°ΡΠΎΠ»ΠΎΠ³ΠΈΠ΅ΠΉ. ΠΠ°ΠΊΠ»ΡΡΠ΅Π½ΠΈΠ΅. Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π° ΡΡ
Π΅ΠΌΠ° Π±Π΅Π·ΠΎΠΏΠ°ΡΠ½ΠΎΠΉ ΡΠ²Π°ΠΊΡΠ°ΡΠΈΠΈ ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΎΠ² Ρ Π°ΠΊΡΡΠ΅ΡΡΠΊΠΎ-Π³ΠΈΠ½Π΅ΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠ°ΡΠΎΠ»ΠΎΠ³ΠΈΠ΅ΠΉ Π² ΠΊΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠΌ ΡΠΎΡΡΠΎΡΠ½ΠΈΠΈ Π½Π°Π·Π΅ΠΌΠ½ΡΠΌ ΠΈ Π²ΠΎΠ·Π΄ΡΡΠ½ΡΠΌ ΡΡΠ°Π½ΡΠΏΠΎΡΡΠΎΠΌ ΡΠΈΠ»Π°ΠΌΠΈ Π°ΠΊΡΡΠ΅ΡΡΠΊΠΎΠ³ΠΎ ΡΠ΅Π°Π½ΠΈΠΌΠ°ΡΠΈΠΎΠ½Π½ΠΎ-ΠΊΠΎΠ½ΡΡΠ»ΡΡΠ°ΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΡΠ΅Π½ΡΡΠ°. ΠΠ»ΡΡΠ΅Π²ΡΠ΅ ΡΠ»ΠΎΠ²Π°: ΡΠ²Π°ΠΊΡΠ°ΡΠΈΡ Π±ΠΎΠ»ΡΠ½ΡΡ
, Π³Π΅ΡΡΠΎΠ·, ΠΊΡΠΎΠ²ΠΎΡΠ΅ΡΠ΅Π½ΠΈΠ΅, ΡΠ΅ΠΏΡΠΈΡ, Π°ΠΊΡΡΠ΅ΡΡΡΠ²ΠΎ ΠΈ Π³ΠΈΠ½Π΅ΠΊΠΎΠ»ΠΎΠ³ΠΈΡ
- β¦