T. Kitagaki

A new method to investigate the nuclear effect in leptonic interactions

Abstract High energy neutrino interactions in a heavy liquid bubble chamber were classified by the presence or absence of dark tracks (stubs) at the interaction vertices. Quark distributions, σ ( x ), were compared in the two groups of data. Those with dark tracks, presumably indicative of an interaction with a deeply bound nucleon, show an enhanced nuclear effect.

Evidence for a narrow NN state at 2.02 GeV/c2 in 6 and 9 GeV/c antiproton interactions

Abstract We report evidence for the existence of a charged narrow state of mass M ∼ 2.02 GeV/ c 2 and widtt Γ ⪅ 0.04 GeV/ c 2 , decaying into N N . The state is observed in the reaction p p → p fast n π + π − π − at 6 GeV/ c and in p p →π fast + p n π + π − at 9 GeV/ c in a triggered bubble chamber experiment at the SLAC Hybrid Facility.

Current and target jets produced in high energy neutrino-deuterium interactions☆

Abstract In an analysis of ≈ 7000 charged current events produced in high energy neutrino-deuterium interactions, we observe that the struck quark jet has a wider spread in Pt than that from the recoiling diquark jet for events with hadronic energy W > 9 GeV. This suggests that the effect signals the onset of gluon emission from the single quark.

Leading particle distributions in 200 GeV/c p+A interactions

Abstract Distributions of the leading positive particle have been measured in collisions of a 200 GeV/ c proton beam with hydrogen, Mg, Ag and Au targets using the FNAL Hybrid Spectrometer. Estimates of the rapidity loss of the projectile have been obtained as a function of the target mass, the multiplicity of negative particles and the number of recoil protons. We obtained a lower limit of the rapidity loss of 2.0±0.2 for central p+Au collisions. The impact parameter dependence of the momenta of the first few leading particles has also been investigated with important implications to estimates of energy densities obtained in central collisions.

Search for a Ks0 π±π+π− resonance near 2.6 GeV in 14.75 GeV/ c pp interactions

Abstract We present the results of a search for a resonance at 2.6 GeV decaying into K S 0 π ± π + π − in the six-prong plus K S 0 final state in 14.75 GeV/ c p p interactions. We do not find confirming evidence, and with 95% confidence we quote an upper limit of σ·BR

Search for Charmed Particles in 14.75 GeV/c p̄p Interactions

A search for the production of charmed particles in 14.75 GeV/c pp interactions has been carried out. The search was sensitive to charmed particles in the 1.5 to 4.0 GeV mass region, decaying into a strange particle with up to eight additional pions and a strange particle with an associated positron or electron. Preliminary analyses on production of such particles are presented.