M. Kobayashi

Search for narrow peaks in inclusive π0 spectra from pp annihilation at rest

Abstract By using modularized NaI(Tl) detectors, we carried out a high statistics measurement of inclusive π0 spectra from p p annihilation at rest. We did not observe any narrow π0 peaks arising from baryonium production, p p →π 0 B . The σ upper limit of the yield varied between 10−2 and 10−4 depending on the mass and oncharge multiplicity. Three narrow peaks at 2 σ levels were seen at approximately the same masses as in the previous measurement of p p → γ B .We also derived the yield of p p annihilation into π0M forM = o, η′, ω, ϱ0, η and π0.

Search for narrow states by detection of monochromatic gamma rays in p̄p annihilation at rest

Abstract An inclusive γ ray spectrum in pp annihilation at rest has been measured with modularized NaI(Tl) detectors with statistics several times higher than before. The aim of the experiment was to search for baryonium B in pp → γB by detection of narrow lines in the γ ray spectrum. We have not observed any narrow state B with yield greater than 1.5 × 10 −3 per annihilation and with statistical significance higher than 2σ.

Measurement of B (D(s)+ ---> mu+ muon-neutrino) / B (D(s)+ ---> phi mu+ muon-neutrino) and determination of the decay constant f(D(s))

We have observed

Direct observation of sequential weak decay of a double hypernucleus

23.2 \pm 6.0_{-0.9}^{+1.0}

Search for the H dibaryon in (K-,K+) reactions.

purely-leptonic decays of

Antiproton-proton annihilation at rest into. pi. /sup 0/M and. gamma. M with M = phi, eta',. omega. , rho/sup 0/, eta, and. pi. /sup 0/

D_s^+ ->\mu^+ \nu_\mu

Evidence of Weak Decay of Heavy Double Hypernuclei

from a sample of muonic one prong decay events detected in the emulsion target of Fermilab experiment E653. Using the

Measurement of the relative branching fraction Gamma (D0-->K micro nu )/ Gamma (D0--> microX).

D_s^+ ->\phi \mu^+ \nu_\mu

eta and eta ' production in p-barp annihilation at rest.

yield measured previously in this experiment, we obtain

Two single hypernuclei production by XI- capture

B(D_s^+ -->\mu^+ \nu_\mu) / B(D_s^+ -->\phi \mu^+ \nu_\mu) =0.16 \pm 0.06 \pm 0.03