3,368 research outputs found
Measurement of the τ-lepton Lifetime at Belle
The lifetime of the τ lepton is measured using the process e+e−→τ+τ−, where both τ leptons decay to 3πντ. The result for the mean lifetime, based on 711 fb−1 of data collected with the Belle detector at the ϒ(4S) resonance and 60 MeV below, is τ=(290.17±0.53(stat)±0.33(syst))×10−15 s. The first measurement of the lifetime difference betweenτ+ and τ− is performed. The upper limit on the relative lifetime difference between positive and negative τ leptons is |Δτ|/τ\u3c7.0×10−3 at 90% C.L
Search for the h_c meson in B^+- ->h_c K^+-
We report a search for the meson via the decay chain , \etac \gamma with and
. No significant signals are observed. We obtain upper limits on the
branching fractions for in bins of the
invariant mass. The results are based on an analysis of 253
fb of data collected by the Belle detector at the KEKB
collider.Comment: 12 pages, 6 figures, submitted to Phys. Rev.
ИЗМЕРЕНИЕ ГЛУБИНЫ НАРУШЕННОГО СЛОЯ НА ПОВЕРХНОСТИ КРЕМНИЕВЫХ ПЛАСТИН МЕТОДОМ ОЖЕ-СПЕКТРОСКОПИИ
The paper proposes a method for depth measurement of a disrupted layer on silicon wafer surface which is based on application of Auger spectroscopy with the precision sputtering of surface silicon layers and registration of the Auger electron yield intensity. In order to measure the disrupted layer with the help of Auger spectroscopy it is necessary to determine dependence of the released Auger electron amount on sputtering time (profile) and then the dependence is analyzed. Silicon amount in the disrupted layer is less than in the volume. While going deeper the disruptive layer is decreasing that corresponds to an increase of atom density in a single layer. The essence of the method lies in the fact the disruptive layer is removed by ion beam sputtering and detection of interface region is carried out with the help of registration of the Auger electron yield intensity from the sputtered surface up to the moment when it reaches the value which is equal to the Auger electron yield intensity for single-crystal silicon. While removing surface silicon layers the registration of the Auger electron yield intensity from silicon surface makes it possible to control efficiently a presence of the disrupted layer on the silicon wafer surface. In this case depth control locality is about 1.0 nm due to some peculiarities of Auger spectroscopy method. The Auger electron yield intensity is determined automatically while using Auger spectrometer and while removing the disrupted layer the intensity is gradually increasing. Depth of the disrupted layer is determined by measuring height of the step which has been formed as a result of removal of the disrupted layer from the silicon wafer surface. Auger spectroscopy methods ensures an efficient depth control surface disruptions at the manufacturing stages of silicon wafers and integrated circuits. The depth measurement range of disruptions constitutes 0.001–1.000 um.Предложен метод измерения глубины нарушенного слоя на поверхности кремниевых пластин, основанный на использовании оже-спектрометра с прецизионным распылением поверхностных слоев кремния и регистрацией интенсивности выхода оже-электронов. Для измерения глубины нарушенного слоя с помощью оже-спектроскопии снимается зависимость количества выходящих оже-электронов от времени распыления (профиль), и затем эта зависимость анализируется. Количество кремния в нарушенном слое меньше, чем в объеме. По мере углубления нарушенный слой уменьшается, что соответствует увеличению плотности атомов в одиночном слое. Сущность метода заключается в том, что нарушенный слой удаляется распылением пучком ионов, а выявление границы раздела осуществляется путем регистрации интенсивности выхода оже-электронов с распыляемой поверхности до достижения ею величины, равной интенсивности выхода оже-электронов для монокристаллического кремния. Регистрация интенсивности выхода оже-электронов с поверхности кремния при удалении поверхностных слоев кремния позволяет эффективно контролировать наличие нарушенного слоя на поверхности кремниевой пластины. Причем локальность контроля по глубине из-за особенностей метода оже-спектроскопии составляет около 1,0 нм. Интенсивность выхода оже-электронов определяется на оже-спектрометре автоматически, и по мере удаления нарушенного слоя она постепенно возрастает. Глубину нарушенного слоя определяют измерением высоты ступеньки, образованной в результате удаления нарушенного слоя с поверхности кремниевой пластины. Метод оже-спектроскопии обеспечивает эффективный контроль глубины повреждений поверхности на этапах изготовления кремниевых пластин и интегральных микросхем. Диапазон измерения глубины нарушений 0,001–1,000 мкм
Evidence for CP Violation in B0 -> D+D- Decays
We report measurements of the branching fraction and CP violation parameters
in B0 -> D+D- decays. The results are based on a data sample that contains 535
x 10^6 BBbar pairs collected at the Upsilon(4S) resonance, with the Belle
detector at the KEKB asymmetric-energy e+e- collider. We obtain [1.97 +- 0.20
(stat) +- 0.20 (syst)] x 10^(-4) for the branching fraction of B0 -> D+D-. The
measured values of the CP violation parameters are: S = -1.13 +- 0.37 +- 0.09,
A = 0.91 +- 0.23 +- 0.06, where the first error is statistical and the second
is systematic. We find evidence of CP violation in B0 -> D+D- at the 4.1 sigma
confidence level. While the value of S is consistent with expectations from
other measurements, the value of the parameter A favors large direct CP
violation at the 3.2 sigma confidence level, in contradiction to Standard Model
expectations.Comment: 12 pages, 3 figures, submitted to PR
Immunomodulating and Revascularizing Activity of Kalanchoe pinnata Synergize with Fungicide Activity of Biogenic Peptide Cecropin P1
© 2017 N. S. Zakharchenko et al. Previously transgenic Kalanchoe pinnata plants producing an antimicrobial peptide cecropin P1 (CecP1) have been reported. Now we report biological testing K. pinnata extracts containing CecP1 as a candidate drug for treatment of wounds infected with Candida albicans. The drug constitutes the whole juice from K. pinnata leaves (not ethanol extract) sterilized with nanofiltration. A microbicide activity of CecP1 against an animal fungal pathogen in vivo was demonstrated for the first time. However, a favorable therapeutic effect of the transgenic K. pinnata extract was attributed to a synergism between the fungicide activity of CecP1 and wound healing (antiscar), revascularizing, and immunomodulating effect of natural biologically active components of K. pinnata. A commercial fungicide preparation clotrimazole eliminated C. albicans cells within infected wounds in rats with efficiency comparable to CecP1-enriched K. pinnata extract. But in contrast to K. pinnata extract, clotrimazole did not exhibit neither wound healing activity nor remodeling of the scar matrix. Taken together, our results allow assumption that CecP1-enriched K. pinnata extracts should be considered as a candidate drug for treatment of dermatomycoses, wounds infected with fungi, and bedsores
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