E. Nakano

Observation of Transverse Polarization Asymmetries of Charged Pion Pairs in e+e- Annihilation near √[s]= 10.58 GeV

The interference fragmentation function translates the fragmentation of a quark with a transverse projection of the spin into an azimuthal asymmetry of two final-state hadrons. In e(+)e(-) annihilation the product of two interference fragmentation functions is measured. We report nonzero asymmetries for pairs of charge-ordered π(+)π(-) pairs, which indicate a significant interference fragmentation function in this channel. The results are obtained from a 672 fb(-1) data sample that contains 711 × 10(6) π(+)π(-) pairs and was collected at and near the Υ(4S) resonance, with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.

Study of the Effect of Water Vapor on a Glass RPC with and without Freon

Abstract We studied the effects of freon (fluoride) in a chamber gas on damaging the glass electrodes combined with water vapor (1000– 2000 ppm ). The damage was observed only for the combination of freon and water vapor.

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).

Charged particle multiplicities of quark and gluon jets in e+ e- annihilation at TRISTAN

Abstract Charged-particle multiplicity was studied in e+e− annihilation at s = 57.8 GeV using the TOPAZ detector at TRISTAN. The average multiplicity was 〈nch〉 = 17.64± 0.05(stat.) ± 0.41(syst.). It was found that the multiplicity depends on the thrust (T) of an event. From extrapolating this relation to T = 2 3 , the multiplicity for three-fold symmetric events was estimated to be 〈n ch 〉 T = 2 3 = 23.50 −1.45 +1.25 . From this, the multiplicity ratio between gluon- and quark-jet was estimated to be r g q = 1.46 −0.13 +0.09 without any possible bias from jet clustering.

A study of single photon production in e+e− collisions at s=58 GeV with the TOPAZ detector at TRISTAN

Abstract We report a study of single photon production in e+e− collisions at s =58 GeV with the TOPAZ detector at TRISTAN. From data corresponding to an integrated luminosity of 213 pb−1, 5 single photon candidates remained after event selection, which can be compared with the expected 3.1 ν ν γ and 2.8 background events. These results exclude the selectron mass below 47.2 GeV at the 90% confidence level, if e L and e R are mass-degenerate and the photino is massless. When combined with results from other experiments, this limit improves to 75.0 GeV.

Measurement of the cross-section and forward-backward charge asymmetry for the b and c-quark in \(e^+e^-\) annihilation with inclusive muons at \(\sqrt{s} = 58\) GeV

Abstract. We have studied inclusive muon events using all the data collected by the TOPAZ detector at

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

\sqrt{s}=58

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

GeV with an integrated luminosity of 273pb

Measurement of the jet width in γγ collisions and in e+e− annihilation process at TRISTAN

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Study of baryon production mechanism in e+e− annihilation into hadrons

. From 1328 inclusive muon events, we measured the ratio