A Miniature Spectrometer for a Hybrid Emulsion Experiment to Measure B-Particle Lifetimes

  • N. R. Stanton
Part of the Ettore Majorana International Science Series book series (EMISS, volume 14)


Nuclear emulsion is the only proven technique having position resolution ≲ 1µ, and therefore capable of relatively bias-free measurement of lifetimes down to ~ 10-15 sec for decaying particles with γ ~ 25. Hybrid experiments using spectrometers1–4 and bubble chambers5,6 to tag the location of events in emulsion have provided the first measurements of charmed particle lifetimes. These experiments have exploited the relatively large yield of charm in neutrino (~ 5%) and photon (~ 1%) interactions by searching the emulsion for every tagged event. Measuring the lifetimes of particles carrying the beauty quantum number will be much more difficult because of the tiny yield expected at energies available now or in the near future: ≲ 10-4 in neutrino beams, and ~ 1/500 of charm in photon and hadron beams’. Nevertheless, the hybrid emulsion technique can indeed provide the first measurements of B-particle lifetimes if hadronic production of BB̄ pairs has a cross section ≳ 10 nanobn, well within current estimates.


Silicon Detector Drift Chamber Neutrino Beam Hybrid Emulsion Downstream Drift 


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Copyright information

© Plenum Press, New York 1983

Authors and Affiliations

  • N. R. Stanton
    • 1
  1. 1.Ohio State UniversityColumbusUSA

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