934,507 research outputs found
Measurement of the mixing rate with partial reconstruction
We report a measurement of the mixing parameter
based on a sample of resonance decays
collected by the Belle detector at the KEKB asymmetric collider. We
use events with a partially reconstructed candidate and where the flavor of the accompanying meson is
identified by the charge of the lepton from a decay. The proper-time difference between the two mesons is
determined from the distance between the two decay vertices. From a
simultaneous fit to the proper-time distributions for the same-flavor
(, ) and opposite-flavor (,
) event samples, we measure the mass difference between the two
mass eigenstates of the neutral meson to be = .Comment: 16 pages, 14 figure
B^0-\bar{B}^0 mixing with quenched lattice NRQCD
We present our recent results for the B-parameters, which parameterize the
\Delta B=2 transition amplitudes. Calculations are made in quenched QCD at
\beta=5.7, 5.9, and 6.1, using NRQCD for heavy quark and the -improved
action for light quark. The operators are perturbatively renormalized including
corrections of O(\alpha_s/am_Q). We examine scaling behavior of the
B-parameters in detail, and discuss the systematic uncertainties using scatter
of results with different analysis procedures adopted. As a result, we find
B_{B_d}(m_b)=0.84(2)(8), B_{B_s}/B_{B_d}=1.017(10)(^{+4}_{-0}) and
B_{S_s}(m_b)=0.87(1)(9)(^{+1}_{-0}) in the quenched approximation.Comment: Lattice 2000 (Heavy Quark Physics), 4 pages, 4 eps-figures, Latex,
typo correcte
Electroweak effects in the mixing
We compute analytically the complete electroweak two-loop corrections to the
mixing. These corrections fix the normalization of the
electroweak coupling employed in the extraction of and reduce the
theoretical uncertainty due to higher order electroweak effects from several
percent to a few parts in a thousand. If the LO result is expressed in terms of
or of the coupling , the two-loop corrections
are , the exact value depending on the mass of the Higgs boson. We
discuss in detail the renormalization procedure and the scheme and scale
dependence, and provide practical formulas for the numerical implementation of
our results. We also consider the heavy top mass expansion and show that in the
case at hand it converges very slowly.Comment: LaTeX, 29 pages, 6 postscript figures include
Two-Particle Correlations and Mixing
We study the EPR correlation implied by the entangled wavefunction of the
pair created by the (4S) resonance. The analysis uses
the basis provided by the mass eigenstates rather than the flavour
states . Data on the inclusive dilepton charge ratio are close
to the expectation of quantum mechanics, but nearly 8 standard deviations away
from that of complete decoherence.Comment: 10 pages, Latex, no figure
B^0-\bar B^0 Mixing in Gauge-Higgs Unification
We discuss flavor mixing and resulting Flavor Changing Neutral Current (FCNC)
in a five dimensional SU(3)_color \otimes SU(3) \otimes U'(1) gauge-Higgs
unification. Flavor mixing is realized by the fact that the bulk and brane
localized mass terms are not diagonalized simultaneously. As the concrete FCNC
processes, we calculate the rate of B^0_d-\bar B^0_d mixing and B^0_s-\bar
B^0_s mixing due to the exchange of non-zero Kaluza-Klein gluons at the tree
level. We obtain a lower bound on the compactification scale of order O(TeV) by
comparing our prediction on the mass difference of neutral B meson with the
recent experimental data.Comment: 18 pages, 6 figures. arXiv admin note: substantial text overlap with
arXiv:1103.5980 [hep-ph
Charge Asymmetry of Same-Sign Dileptons in - Mixing
We report a measurement of the charge asymmetry for same-sign dileptons in
- mixing, . The data were collected with the Belle
detector at KEKB. Using a data sample of 78 fb recorded at the
resonance and 9 fb recorded at an energy 60 MeV below the
resonance, we measure .Comment: 21 pages, 9 figures, 3 tables, submitted to Physical Review
Factorization of the charge correlation function in oscillations
Extraction of the mass difference from oscillations
involves tagging of bottom flavour at production and at decay. We show that the
asymmetry between the unmixed and mixed events factorizes into two parts, one
depending on the production-tag and the other on the decay-tag.Comment: 6 pages, Latex, no figure
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