H. Miyake

Muon identification in the Belle experiment at KEKB

Abstract This paper describes the muon identification method and its performance in the Belle experiment at KEKB. Muon and hadron likelihood are calculated for each track using its range and transverse scattering in the KL-and-muon detector (KLM). We apply a cut on the normalized muon likelihood L μ to identify the track as a muon. Above the detection threshold of 0.6 GeV /c , the measured muon detection efficiency and pion fake rate are approximately constant for momenta greater than 1.0 and 1.5 GeV /c , respectively. Between 1.0 and 3.0 GeV /c , the averaged muon detection efficiency is 89% and the pion fake rate per track is 1.4% over the KLM acceptance, using the standard selection criterion L μ >0.9 .

Deep sub-micron FD-SOI for front-end application

In order to confirm benefits of a deep sub-micron FD-SOI and to identify possible issues concerning front-end circuits with the FD-SOI, we have submitted a small design to Oki Electric Industry Co., Ltd. via the multi-chip project service of VDEC, the University of Tokyo. The initial test results and future plans for development are presented.

Study of B-+/--> DCPK +/- and (DCPK +/-)-K-* decays

We report a study of the modes B-+/--> DK +/- and B-+/-->(DK +/-)-K-* where D-(*) decays to CP eigenstates. The data sample used contains 275x10(6) B (B) over bar events at the Upsilon(4S) resonance collected by the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. The CP asymmetries obtained for DCPK are: A(1)=0.06 +/- 0.14(stat)+/- 0.05(sys), A(2)=-0.12 +/- 0.14(stat)+/- 0.05(sys) and for (DCPK)-K-*: A(1)(*)=-0.20 +/- 0.22(stat)+/- 0.04(sys), A(2)(*)=0.13 +/- 0.30(stat)+/- 0.08(sys).

The silicon vertex detector for the super B factory

The silicon vertex detector (SVD2) of the Belle experiment at KEK (Tsukuba, Japan) is currently close to its limits in terms of the occupancy of the innermost layer and the readout dead time. In order to cope with further increase in luminosity, different levels of upgrades are proposed: small improvements are possible in the short term by tuning the current system at the cost of signal-to-noise and crosstalk. In 2007, the two inner layers of the SVD2 will be replaced by similar detectors with faster readout electronics (SVD2.5) and in the long term, a major upgrade of the full silicon vertex detector (SVD3) is envisaged for the KEK Super B Factory. These upgrade scenarios will be discussed in detail from the hardware point of view along with the options under study.

Observation of the decays B0 → K+π -π0 and B0 → ρ-K +

We report the observation of B0 decays to the K+π-π0 final state using a data sample of 78 fb-1 collected by the Belle detector at the KEKB e+e- collider. With no assumptions about intermediate states in the decay, the branching fraction is measured to be (36.6-4.3+4.2±3.0)×10-6. We also search for B decays to intermediate two-body states with the same K+π-π0 final state. Significant B signals are observed in the ρ(770)-K+ and K*(892)+π- channels, with branching fractions of (15.1-3.3-1.5-2.1+3.4+1.4+2.0)×10-6 and (14.8-4.4-1.0-0.9+4.6+1.5+2.4) ×10-6, respectively. The first error is statistical, the second is systematic and the third is due to the largest possible interference. Contributions from other possible two-body states will be discussed. No CP asymmetry is found in the inclusive K+π-π0 or ρ-K+ modes, and we set 90% confidence level bounds on the asymmetry of -0.12

Search for B- → J/ ψΛp̄ decay 017101

We report the results of a search for

Measurement of the branching fractions for B- → D (*)+π-ℓ-v̄ℓ and B̄0 → D(*)0π+ℓ -v̄ℓ

B^{-} \to \jpsi \Lambda \pbar

Status of the Belle SVD detector

based on a data set of 78 fb

Measurements of time-dependent CP violation in B{sup 0}{yields}{omega}K{sub S}{sup 0}, f{sub 0}(980)K{sub S}{sup 0}, K{sub S}{sup 0}{pi}{sup 0} and K{sup +}K{sup -}K{sub S}{sup 0} decays

^{-1}

Evaluation of OKI SOI technology

data collected at the