840 research outputs found
Criticality in one dimension with inverse square-law potentials
It is demonstrated that the scaled order parameter for ferromagnetic Ising
and three-state Potts chains with inverse-square interactions exhibits a
universal critical jump, in analogy with the superfluid density in helium
films. Renormalization-group arguments are combined with numerical simulations
of systems containing up to one million lattice sites to accurately determine
the critical properties of these models. In strong contrast with earlier work,
compelling quantitative evidence for the Kosterlitz--Thouless-like character of
the phase transition is provided.Comment: To appear in Phys. Rev. Let
Complex experiment on studying the microphysical, chemical, and optical properties of aerosol particles and estimating the contribution of atmospheric aerosol-to-earth radiation budget
The primary objective of this complex aerosol experiment was the measurement of microphysical, chemical, and optical properties of aerosol particles in the surface air layer and free atmosphere. The measurement data were used to retrieve the whole set of aerosol optical parameters, necessary for radiation calculations. Three measurement cycles were performed within the experiment during 2013: in spring, when the aerosol generation is maximal; in summer (July), when atmospheric boundary layer altitude and, hence, mixing layer altitude are maximal; and in late summer/early autumn, during the period of nucleation of secondary particles. Thus, independently obtained data on the optical, meteorological, and microphysical parameters of the atmosphere allow intercalibration and inter-complement of the data and thereby provide for qualitatively new information which explains the physical nature of the processes that form the vertical structure of the aerosol field
Моделирование и прогнозирование комплексных экологических ситуаций на примере Черкасской области
Збільшення антропогенного тиску на навколишнє середовище вимагає комплексного
підходу до прийняття рішень з метою контролю та прогнозування його забруднення. Слід
брати до уваги вплив багатьох факторів, які можуть мати значний вплив, і велика
кількість інформації, яку необхідно враховувати в процесі прийняття рішень. Тому
актуальним завданням є створення методів та програмних засобів для обробки всієї наявної
інформації та надання обґрунтованих рекомендацій для прийняття ефективних рішень,
особливо в екологічно несприятливому регіоні, наприклад, у Черкаській області.The increase in anthropogenic pressure on the environment requires an integrated approach
to decision-making in order to control and predict its pollution. The influence of many factors that
can have a significant impact and large amounts of information that must be considered in the
decision-making process should be taken into account. Therefore, the creation of methods and
software tools for processing all the available information and giving reasonable recommendations
for making effective decisions, especially in an environmentally unfriendly region such as the
Cherkasy region, is an urgent task.Повышение антропогенной нагрузки на окружающую среду требует комплексного
подхода к принятию решений с целью контроля и прогнозирования ее загрязнения. Влияние
многих факторов, которые могут оказать значительное влияние, и большое количество
информации, которая должна учитываться в процессе принятия решений, должны быть
приняты во внимание. Поэтому создание методов и программных средств для обработки
всей доступной информации и предоставления разумных рекомендаций для принятия
эффективных решений, особенно в экологически неблагоприятном регионе, таком как
Черкасская область, является актуальной задачей
Search for and a measurement of the branching fraction for
We search for the decay and measure the
branching fraction for using
121.4~ of data collected at the
resonance with the Belle detector at the KEKB asymmetric-energy
collider. The branching fraction is measured
to be , where is the fraction of
in events. Our result is in good
agreement with the theoretical predictions as well as with a recent measurement
from LHCb. We observe no statistically significant signal for the decay
and set a confidence-level upper
limit on its branching fraction at . This constitutes a
significant improvement over the previous result.Comment: 6 pages, 3 figure
Energy scan of the cross sections and evidence for decays into charged bottomonium-like states
Using data collected with the Belle detector at the KEKB asymmetric-energy
collider, we measure the energy dependence of the cross sections from thresholds up to GeV.
We find clear and peaks with little or no
continuum contribution. We study the resonant substructure of the
transitions and find evidence that they
proceed entirely via the intermediate isovector states and
. The relative fraction of these states is loosely constrained by
the current data: the hypothesis that only is produced is excluded
at the level of 3.3 standard deviations, while the hypothesis that only
is produced is not excluded at a significant level.Comment: 8 pages, 4 figures, submitted to Physical Review Letter
Search for the decay at Belle
We report a search for the rare charmless decay
using a data sample of
pairs collected at the resonance with
the Belle detector at the KEKB asymmetric-energy collider. No
statistically significant signal is found and a 90% confidence-level upper
limit is set on the decay branching fraction as .Comment: 8 pages, 3 figures, submitted to PRD(RC
First Observation of CP Violation in B0->D(*)CP h0 Decays by a Combined Time-Dependent Analysis of BaBar and Belle Data
We report a measurement of the time-dependent CP asymmetry of B0->D(*)CP h0
decays, where the light neutral hadron h0 is a pi0, eta or omega meson, and the
neutral D meson is reconstructed in the CP eigenstates K+ K-, K0S pi0 or K0S
omega. The measurement is performed combining the final data samples collected
at the Y(4S) resonance by the BaBar and Belle experiments at the
asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The
data samples contain ( 471 +/- 3 ) x 10^6 BB pairs recorded by the BaBar
detector and ( 772 +/- 11 ) x 10^6, BB pairs recorded by the Belle detector. We
measure the CP asymmetry parameters -eta_f S = +0.66 +/- 0.10 (stat.) +/- 0.06
(syst.) and C = -0.02 +/- 0.07 (stat.) +/- 0.03 (syst.). These results
correspond to the first observation of CP violation in B0->D(*)CP h0 decays.
The hypothesis of no mixing-induced CP violation is excluded in these decays at
the level of 5.4 standard deviations.Comment: 9 pages, 2 figures, submitted to Physical Review Letter
Search for a dark vector gauge boson decaying to using decays
We report a search for a dark vector gauge boson that couples to
quarks in the decay chain , . No signal is found and we set a
mass-dependent limit on the baryonic fine structure constant of in the mass range of 290 to 520 MeV/. This analysis is
based on a data sample of 976 fb collected by the Belle experiment at
the KEKB asymmetric-energy collider.Comment: 6 pages, 4 figure
Study of e+e- => B(*) B(*)-bar pi+- at sqrt(s)=10.866 GeV
We report the analysis of the three-body e+e- => B B-bar pi, B B*-bar pi, and
B* B*-bar pi processes, including the first observation of the Zb+-(10610) =>[B
B*-bar+c.c.]+- and Zb+-(10650) => [B*B*-bar]+- transitions. We measure visible
cross sections for the three-body production of sigma_vis(e+e- => [B
B*-bar+c.c.]+-pi-+=(11.2+-1.0(stat.)+-1.2(syst.)) pb and sigma_vis(e+e- =>
[B*B*-bar]+-pi-+)=(5.61+-0.73(stat.)+-0.66(syst.)) pb and set a 90% C.L. upper
limit of sigma_vis(e+e- => [BB-bar]+-pi-+)<2.1 pb. The results are based on a
121.4 1/fb data sample collected with the Belle detector at a center-of-mass
energy near the Y(5S) peak.Comment: 8 pages, 2 figure
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