E553 and E554 at Fermilab
Neutrino experiments with an emulsion / bubble chamber target
The experiments E-564 and E553 at the Fermilab National Accelerator Laboratory (FNAL) near Chicago in the U.S.A. were hybrid experiments in which an emulsion target was placed inside the 15-foot bubble chamber. This hybrid detector was exposed to a wide-band (up to 200 GeV) neutrino beam consisting of mainly muon type neutrinos.
Because the emulsion was placed inside the sensitive volume of the bubble chamber which operated at a temperature of 30 K, a cryogenically sensitive photoemulsion BR-2K (developed and prepared in the U.S.S.R.) had to be used. The sensitivity of this emulsion at these temperatures was 80%, nearly three times better than ordinary emulsion.
The bubble chamber operated with deuterium during a first run and with a neon-hydrogen mixture during a second run. A total of 194 muon-neutrino and 13 muon-antineutrino charged current (CC) interactions were observed during the exposures. The main aim of the experiment was to observe the production and decay of charmed particles from this data sample. A total of 13 decays from the muon-neutrino CC interactions were identified (none from the antineutrinos) as charm decays, making up (8.3+-2.3)% of the CC cross-section (taking into account efficiencies) at an average energy of (69+-14) GeV.
Of the 13 charmed events, four were identified as decays of a positive charmed lambda, five were identified as the decays of neutral D mesons, two were decays of positive D mesons, one was a novel decay of the excited state of a positive strange D meson and the origin of the last one was ambiguous (either a decay of a positive D or strange D meson). Some of the decay modes observed were novel, including the decay of a charmed neutral sigma baryon to a charmed positive lambda and a negative pion. A summary of these decays can be found in Y. Batusov et al., Z. Phys. C., 45, (1990), 557-565.
- W. Smart et al., Neutrino Interactions in Emulsion Stacks inside the Fermilab 15-Foot Bubble Chamber, Acta Physica Polonica, B17, (1986), 41-63.
- R.G. Ammar et al., Search for Charmed-Particle Decays in a Neutrino experiment with a Nuclear Emulsion Placed in the FNAL 15-Foot Bubble chamber, Soviet Journal of Nuclear Physics, 44, (1986), 421-428.
- R.G. Ammar et al., Nuclear emulsion Observation of the Decay of a Charmed Sigma Baryon into a Positive Charmed Lambda and a Negative Pion followed by a Charmed Sigma Decay into a Positive Sigma, a Negative Pion and a Positive Pion, JETP Letters, 43, (1986), 515-520.
- Y. A. Batusov et al., Resonant Production of Positive Charmed Lambda Baryons in Neutrino-Nucleus Interactions in a Photographic Emulsion, JETP Letters, 46, (1987), 268-271.
- Y. A. Batusov et al., Observation of Decays of Charmed D Mesons and a Charmed Sigma++(2450) Baryon Produced in Neutrino Interactions with Nuclei in Nuclear Emulsion, Soviet Journal of Nuclear Physics, 47, (1988), 639-642.
- Y. A. Batusov et al., Observation of the Production and Decay of an Excited Charm-Antistrange State with a Mass 2790 MeV in a Nuclear Emulsion, JETP Letters, 47, (1988), 569-573.
- R.G. Ammar et al., Production of Cumulative Protons in an Interaction of neutrinos and Emulsion Nuclei, JETP Letters, 49, (1989), 219-221.
- R.G. Ammar et al., Effect of the Nucleus on the Average Charged Particle Multiplicities in High Energy Neutrino Interactions, JETP Letters, 49, (1989), 480-482.
- R.G. Ammar et al., Neutrino Production of Charmed Particles in a Hybrid Experiment E-564, Zeitschrift fur Physik C (Particles and Fields), 45 (1990) 557-565.
- M. Dayson et al., Backward Emitted Protons in Interactions of Neutrinos with Nuclei in Photoemulsion, Zeitschrift fur Physik C (Particles and Fields), 56, (1992), 391-393.
Other results obtained from this experiment were the studies of intra-nuclear effects as a function of atomic mass and the observation of backward (from nuclear evaporation) and cumulative protons from the neutrino interactions.