List of Figures

• Strangelet stability as a function of Y and A for fixed  MeV,  MeV/c , and . From Ref. [23].
• Stability regions in the (Z,Y) plane for an A=15 strangelet. From Ref. [23].
• The sensitivity of E864, expressed in (S,A) space. Strangelets are expected to lie near S+A=0.
• The A=7 strangelets which are stable against strong and weak p, n, and decay. The species which are likely to be accessible with E864's sensitivity are shown by circled dots. We have assumed a Bethe-Weizacker strangelet mass formula with  MeV,  MeV, and estimated production rates with a simple coalescence model.
• Chart of steps used in Monte Carlo Simulations.
• E864 Apparatus as entered into GEANT.
• Typical central Au-Au interaction tracked by GEANT through the E864 Apparatus. Dashed or dotted lines are neutral particles.
• Central Au-Au interaction with tracks from shielding included. Dashed or dotted lines are neutral particles
• Longitudinal origin of all proton and neutron tracks which produced hits in any detector from GEANT tracing a sample of HIJET central Au-Au collisions. (Horizontal scale is meters from target.)
• Geometric dispersion of light pulse in scintillation counters. The flight time to the photocathode for each photon is calculated for the time of flight simulation.
• Photon production in the scintillators is taken to be a double exponential.
• Simulated pulse shapes for four successive hits in H1. The left and right plots are for the top and bottom phototubes.
• Typical distribution of times for 200000 particles striking the center of one counter. The solid curve is the best fit Gaussian.
• Mean time vs. pulse height (arbitrary units) from scintillation counter simulation. The slewing which is clearly visible is corrected in the analysis.
• Reconstructed tracks found in the scintillator hodoscopes per event.
• Number of tracks per event with confirming hits found in the downstream straw tube arrays.
• Number of tracks per event with confirming hits in the upstream straw tube array.
• Reconstructed mass (GeV/c ) spectrum for events with a charge +1 mass 12 GeV/c object.
• Reconstructed mass (GeV/c )spectrum for a charge +1 mass 12 GeV/c object. Solid curve is a Gaussian fit to the peak.
• Mass spectrum for all late tracks reconstructed in the background analysis. Every event was forced to have an interaction in S1, S2 or the vacuum window which sent a charged particle through the rest of the apparatus.
• Plan view of Monte Carlo Event. Only active volume of second magnet and hits in detectors are shown. Scale shows distance to target in meters.
• Monte Carlo event with reconstructed downstream track segments. Late track is indicated.
• Monte Carlo event with track segments projected upstream through second magnet. Reconstructed mass is shown for late track.
• Expanded view of Monte Carlo event at first straw tube array (S1). Late track is indicated.
• Monte Carlo event at S1 with late track projection assuming proton mass.
• Mass spectra for 72,000 late neutrons (open squares) and 100 strangelets of mass 15 amu (dark triangles) as determined from calorimeter energy deposit and time of flight. See text for further details.
• Scatter plot of reconstructed mass of particles interpreted as neutrons and as H 's. Dots are for neutrons and open circles are H 's
• Histogram of sum of the two mass hypotheses (neutron and H ) for neutrons (solid) and H 's (dashed).
• Expected apparent mass of neutrons reconstructed as H 's as a function of time of flight. Time for a v=c particle is subtracted.
• Scatter plot shows the apparent mass of neutrons reconstructed as H 's vs time of flight.
• Histogram of the apparent mass of neutrons reconstructed as H 's. with additional timing cuts.
• Sum of two mass hypotheses (neutron and H ) for two overlapping neutrons
• Sum of two mass hypotheses (neutron and H ) for three overlapping neutrons
• decay kinematics. Horizontal axis (Theta) is lab. angle of proton with respect to direction and vertical axis is proton lab. momentum.
• Schematic of the experimental apparatus used in the TOF tests.
• Recorded time (ns) versus pulse height (arbitrary units) for (top) raw and (bottom) slew-corrected time spectra. Also shown is the projection of the data onto the time axis for each plot.
• Relative timing characteristics of the Hamamatsu R1635 and R3478 photomultiplier tubes using the 5L1-408 scintillator and a source.
• Relative timing characteristics of the Hamamatsu R3478 photomultiplier tube as a function of (a) operating voltage (discriminator = -25 mV) and (b) discriminator threshold (HV = -1400 V). For this test, the 5L1-404 scintillator was used with a cosmic ray source.
• Relative timing characteristics of the Hamamatsu R3478 photomultiplier tube as a function of the photocathode - first dynode resistance (HV = -1400 V, discriminator = -25 mV). For this test, the 5L3-404 scintillator was used with a source.
• Mean time resolution as a function of length of the test scintillator.
• Mean time resolution as a function of trigger counter position along the length of the test scintillator (measured from PMTA). For this test, the 5L3-404 scintillator was used with a cosmic ray source.
• Schedule of present and future efforts in the development and construction of the TOF hodoscope system.
• Contents of one straw tube array.
• Cross-section of a single calorimeter tower using 1 mm diameter fibers and a lead-to-scintillator volume ratio of about 4:1. (Dimensions are in cm.)
• Cross-section of a grooved plate. Fifty stacked plates will make a single tower. (Dimensions are in cm.)
• (a)Hadronic and (b) electromagnetic energy resolutions obtained by the SPACAL collaboration and E864's GEANT simulation. Vertical axis is E/E (best fit Gaussian), horizontal axis is kinetic energy in GeV.
• Schematic diagram of the scintillating fiber tester.
• Correlation between integrated and impact parameter for 1000 events.
• (a) Distribution of impact parameters which pass a cut. (b) Trigger probability for a particular impact parameter event to pass the cut.