نتایج جستجو برای: interferon υ ifn υ
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Colombi et al. 1999 (paper I) investigated the counts-in-cells statistics and their respective errors in the τCDM Virgo Hubble Volume simulation. This extremely large N -body experiment also allows a numerical investigation of the cosmic distribution function, Υ(Ã) itself for the first time. For a statistic A, Υ(Ã) is the probability density of measuring the value à in a finite galaxy catalog. ...
The spectrum of the Υ system is investigated using the Nonrelativistic Lattice QCD approach to heavy quarks and ignoring light quark vacuum polarization. We find good agreement with experiment for the Υ, Υ, Υ and for the center of mass and fine structure of the χb-states. The lattice calculations predict bb̄ D-states with center of mass at (10.20 ± 0.07 ± 0.03)GeV. Fitting procedures aimed at ex...
We report the first observation of Υ(2S) → ηΥ(1S), with branching fraction B = (2.1 −0.6 (stat.)± 0.3 (syst.))×10−4 and statistical significance 5.3σ. Data were acquired with the CLEO III detector at the CESR e+e− symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10−4 are B[Υ(2S) → π0Υ(1S)] < 1.8, B[Υ...
I present two analyses done with the CLEOIII detector at CESR. The first is a search for the LFV decay Υ → µτ with preliminary results, and the second constrains Lepton Universality in Υ → τ τ relative to Υ → µµ. This second analysis, whose results are final, has dramatically improved uncertainties relative to other such measurements, and is also the first observation of the decay Υ(3S) → τ τ. ...
In the last few years, the CLEO III experiment has recorded a large collection of data sets at the Υ(1S), Υ(2S), Υ(3S) and ψ(2S) resonances. Preliminary results of studies of these data sets are shown here, which include the observation of a new Υ(1D) state, as well as several hadronic and radiative transitions of Υ and ψ(2S) states. In addition, precision branching ratio measurements of charmo...
Decay Υ(1s) → γf2(1270) is studied by an approach in which the tensor meson, f2(1270), is strongly coupled to gluons. Besides the strong suppression of the amplitude Υ(1s) → γgg, gg → f2 by the mass of b-quark, d-wave dominance in Υ(1s) → γf2(1270) is revealed from this approach, which provides a large enhancement. The combination of these two factors leads to larger B(Υ(1s) → γf2(1270)). The d...
Using a temperature-dependent potential obtained from lattice gauge calculations, we study the stability of heavy quarkonia in the quark-gluon plasma. We find that only Υ(1S) and ηb(1S) are bound in the quark-gluon plasma, and have a small binding energy. The quark-gluon plasma may be revealed by an Υ(1S) dilepton peak with an invariant mass close to twice the current b quark mass, which is low...
We examine the electronic width ratios of Υ resonances below the BB̄ threshold by means of an effective (Cornelltype) QCD potential incorporating 1/mb corrections obtained from a prior fit to the bottomonium spectrum. From our analysis we conclude that the Υ(2S) and Υ(3S) states should belong to the strong-coupling (nonperturbative) regime while the Υ(1S) state should belong to the weak-coupling...
Random variation in reproduction causes random fluctuation in allele frequencies. Can describe this process as diffusion: (Wright 1931) showed that the equilibrium distribution of the allele frequency of p, where alleles mutate: P → Q at rate µ and Q → P at rate υ, can be described by:) 1 4 () 1 4 () Pr(− − = µ υ e e N N q cp p (c is a constant that normalizes the area under the curve to one) D...
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