M. Fukawa

Inclusive Λ, Λ and Σ±(1385) production in 405 GeV/c pp interactions

We have investigated inclusive Λ, Λ and Σ±(1385) productions in 405 GeV/c pp interactions. The observed cross sections are σ(Λ)=4.05±0.39 mb, σ(Λ=0.63±0.17 mb, σ(Σ+(1385))=0.74±0.17 mb and σ(Λ−(1385))=0.56±0.17 mb. Λ production is dominant in a central region of ∣x∣≤0.4. The Λ/Λ production ratio at ∣x∣≈0 is found to be 1.2±0.5. The excess, about 0.2 mb, of σ(Λ+(1385)) over σ(Λ−(1385)) is most likely attributed to proton fragmentations (∣x∣≥0.4), and gives an evidence for scaling.

High mass meson resonance production in pp interactions at 405 GeV/c

Abstract We have observed high mass resonances with mass above 1.5 GeV in pp interactions at 405 GeV/ c . We obtain cross sections 13.2 ± 2.9, 5.1 ± 2.0, 2.5 ± 1.5 and 0.27 ± 0.18 mb for ϱ 0 , f, g 0 , and h meson production, respectively. The invariant x and p T 2 distributions for produced resonances are analysed. A relative comparison of the average 〈 p T 〉 distribution as a function of resonance masses with that for μ + μ − pair production shows remarkable similarity.

A Study of charged D* production in e+ e- annihilation at an average center-of-mass energy of 58-GeV

Abstract We have studied the production of charged D ∗ mesons in e + e − annihilation at an average center-of-mass energy of 58.0 GeV. Charged D ∗ mesons were identified using two independent methods; the mass-difference method and the detection of the low transverse-momentum pion. The forward-backward asymmetry of the charm quark production was measured to be A c = −0.61±0.13(stat.)±0.08(syst.). The cross section of inclusive D ∗ production was found to be σ(e + e − →D ∗ ± +X) = 24.5 ± 5.3 ( stat. )±3.0( syst. ) pb. If we assume the standard model prediction for the charm quark production, we obtain the branching ratio for the charm quark to produce a charged D ∗ meson to be Br (c→D ∗+ + X) = (22±5( stat. )±3( syst. ))% .

Measurement of the reactionse+e−→μ+μ− ande+e−→τ+τ− between\(\sqrt s = 50\) and 60.8 GeV

AbstractThe angular distributions of the reactione+e−→μ+μ− ande+e+→τ+τ− have been measured betweenn

Measurement of open charm production in two-photon processes with detection of electron-inclusive events

sqrt s = 50

Inclusive Λ production in\(\bar p\)p interactions at 3.0, 3.5, 4.0 and 4.5 GeV/c

n and 60.8 GeV with the VENUS detector at TRISTAN. The average total cross section and the forward-backward charge asymmetry for μ-pair production are observed to be 28.3±1.4±0.8 pb and (−29.0−4.8+5.0±0.5)%, and those for τ-pair production are 27.6±1.7±1.0 pb and (−32.8−6.2+6.4±1.5)% atn

Measurement of the charged multiplicity of bottom and light quark events in e+e− annihilation at s=58 GeV

langle sqrt s rangle