Bernard Stern

Pion-pion correlations at low relative momentum produced in p-p collisions at 27.5 GeV/c.

We have measured the momentum correlation of pion pairs produced in the collisions of 27.5 GeV/[ital c] protons in liquid hydrogen. By considering events for which all final state particles have been measured, we have succeeded in reducing backgrounds due to particle misidentification below 5% for [pi][sup +] and 1% for [pi][sup [minus]]. Our use of a precision magnetic spectrometer has provided an accurate determination of particle momenta and excellent acceptance for particle pairs with small relative momentum essential for correlations studies. A large data sample of fully reconstructed events (1[times]10[sup 6]) allows us to analyze the correlations for [pi][sup +][pi][sup +] and [pi][sup [minus]][pi][sup [minus]] pairs separately, and also as a function of the final state multiplicity. We find that the pion pair correlations scale 0.98 fm describes the data well. We do not find any indication of multiplicity dependence of the correlation scale for multiplicities from 6 to 14 final state particles.

Pion-pion correlations at low relative momentum produced in [ital p]-[ital p] collisions at 27. 5 GeV/[ital c]

We have measured the momentum correlation of pion pairs produced in the collisions of 27.5 GeV/[ital c] protons in liquid hydrogen. By considering events for which all final state particles have been measured, we have succeeded in reducing backgrounds due to particle misidentification below 5% for [pi][sup +] and 1% for [pi][sup [minus]]. Our use of a precision magnetic spectrometer has provided an accurate determination of particle momenta and excellent acceptance for particle pairs with small relative momentum essential for correlations studies. A large data sample of fully reconstructed events (1[times]10[sup 6]) allows us to analyze the correlations for [pi][sup +][pi][sup +] and [pi][sup [minus]][pi][sup [minus]] pairs separately, and also as a function of the final state multiplicity. We find that the pion pair correlations scale 0.98 fm describes the data well. We do not find any indication of multiplicity dependence of the correlation scale for multiplicities from 6 to 14 final state particles.

High speed simultaneous measurement of pulse area and time-of-flight for photomultiplier signals

Abstract A modular system to provide high speed simultaneous measurements of pulse area and time-of-flight for photomultiplier signals is described. By requiring a minimum pulse size and a time-of-flight signal within a gate before recording either measurement, the system achieves several advantages over other techniques. In particular, since no time is wasted reading channels without useful information, readout speed is enhanced. The system permits accurate measurements at rates exceeding 10 MHz per channel and can be read out without excessive dead time at rates up to approximately 100 kHz. Data storage problems are also reduced. Both pulse area and time-of-flight are measured using 128 bins (7 bits). Costs are less than

Some preliminary results from BNL E766 on pp−→pp KS0 Kπ

40 US per channel. Other advantages and design features are discussed.

Study of Λ0 polarization in exclusive pp reactions at 27.5 GeV/c

This brief talk will present the very preliminary results of an ongoing data analysis of the data from BNL E766. BNL E766 was an experiment to study heavy particle spectroscopy in np(15−24 GeV) and pp interactions (28 GeV). The following discussion pertains to the pp → ppKsoKπ run.  (AIP)

Λ0 polarization in exclusive pp reactions at 27.5 GeV/c

We report a measurement of the xF and PTΛ0 polarization dependence; Λ0’s were produced in the specific channels: pp→pΛ0K+π+π−, pp→pΛ0K+π+π−π+π−, pp→pΛ0K+π+π−π+π−π+π−, and pp→pΛ0K+π+π−π+π−π+π−π+π− with 27.5 GeV/c protons incident on a liquid hydrogen target. We find that Λ0 polarization is independent of the final state.

A new approach to data acquisition and analysis and its effect on hadron spectroscopy

In Λ0’s created from the specific reactions: pp→pΛ0K+π+π−, pp→pΛ0K+π+π−π+π−, pp→pΛ0K+π+π−π+π−π+π−, and pp→pΛ0K+π+π−π+π−π+π−π+π−, using 27.5 GeV/c proton beam incident on a liquid hydrogen target, we measured Λ0 polarization as a function of xF and PT. We found that Λ0 polarization is independent of any particular final state and of any specific mechanism responsible of producing Λ0.

Study of [Lambda][sup 0] Polarization in Four Different Exclusive pp Reactions at 27. 5 GeV/c

The status and progress of experiments BNL E766 and Fermilab FNAL E690 are presented. This program which utilizes a system capable of analyzing as many as 105 complex events per second may have a significant impact on the future of experimental hadron spectroscopy.