R. J. Cence

Determination of ±s from a differential-jet-multiplicity distribution in e+e- collisions at ss =29 and 91 GeV

We measured the differential jet-multiplicity distribution in {ital e}{sup +}{ital e}{sup {minus}} annihilation with the Mark II detector. This distribution is compared with the second-order QCD prediction and {alpha}{sub {ital s}} is determined to be 0.123{plus minus}0.009{plus minus}0.005 at {radical}{ital s}{approx}{ital M}{sub {ital Z}} (at the SLAC Linear Collider) and 0.149{plus minus}0.002{plus minus}0.007 at {radical}{ital s}=29 GeV (at the SLAC storage ring PEP). The running of {alpha}{sub {ital s}} between these two center-of-mass energies is consistent with the QCD prediction.

Determination of. alpha. sub s from a differential-jet-multiplicity distribution in e sup + e sup minus collisions at radical s =29 and 91 GeV

We measured the differential jet-multiplicity distribution in {ital e}{sup +}{ital e}{sup {minus}} annihilation with the Mark II detector. This distribution is compared with the second-order QCD prediction and {alpha}{sub {ital s}} is determined to be 0.123{plus minus}0.009{plus minus}0.005 at {radical}{ital s}{approx}{ital M}{sub {ital Z}} (at the SLAC Linear Collider) and 0.149{plus minus}0.002{plus minus}0.007 at {radical}{ital s}=29 GeV (at the SLAC storage ring PEP). The running of {alpha}{sub {ital s}} between these two center-of-mass energies is consistent with the QCD prediction.

A MEASURING DEVICE FOR HOLOGRAMS FROM LARGE VOLUME BUBBLE CHAMBERS

Measuring full-size reconstructed holographic images of bubbles from a large bubble chamber presents problems of size, rapid location of the desired event, and precise measurement of a local region. We present a conceptual design of a practical system using computer-controlled mirrors to align the desired vertex region along the axis of motion of a vidicon whose field of view includes the local region. Precise measurements of short-decay paths are then made by fine adjustments of the vidicon position. This method requires normal stereo photography for scanning and preliminary reconstruction of the event.

Anti‐neutrino‐nucleon Charged Current Interaction Cross Sections Measured by the Fermilab 15′ Ne‐H2 Bubble Chamber in a Dichromatic Beam

Fermilab experiment E388 measurements of antineutrino‐nucleon total charged‐current interaction cross sections are reported for 20 < Eν¯ < 200 GeV. E388 used the Fermilab 15′ Neon (56.5% atomic)‐hydrogen bubble chamber (plus external muon identifier), exposed to the N30 dichromatic beam. E388 ran downstream of the CCFRR experiment E616 in this beam and used the same flux monitoring information. No evidence is seen for any variation of σν¯/Eν¯ in this Eν¯ range. The preliminary average σν¯/Eν¯= [0.30 ± 0.02(stat.)±0.02(sys.)±0.02(flux)] × 10−38 cm2GeV/nucleon, is in good agreement with most other measurements, but 20% below the E616 result presented at this conference.