LBNL Minutes: 24th February 1998                           Prepared by  G.R.


News Items:

1)      The NSD scientific program review is scheduled for March 26-27. A dry
        run is arranged for March,13. GR will represent the interests of E895.
        Action item: Groups should provide their latest physics results
        on transpancies (~3) to GR.

2)      Chris is working on the t0 calibrations for 6 and 8 A GeV. We should
        have the new files by next week.

3)      Nathan promises to take a look at CVS


Data Processing:

        Pentium Farm

        We have processed the files for testing JTF/BFT as agreed upon at the
        Davis meeting. Currently processing the 6 A GeV central trigger data.

        PDSF:

        Sun Platforms running 4 A GeV data. The HPs are heavily used
        by other users - no E895 data processing.


Physics Status Reports:

        Dieter: Gave statistics pertaining to data on Mass Storage. All of
        the 2,4,8 and most of 6 A GeV tapes have been copied.

        Showed some plots from analysing the E910 tape. Need to confer
        with Xihong before drawing any conclusions.

        Heng Liu showed the Pt vs Y plot for identfied protons with rigidity
        less than 2. A kinematic cutoff in acceptance is visible above
        mid-rapidity which has the effect of lowering <Px/A> near beam rapidity.

        The slope of the S-shape curve at ycm=0 is almost the same as that
        extracted from the data without a ragidity cut. GR: we have an
        understanding of the PID differences between the LBNL and SUNY analyses.

        The deuteron contamination must be removed or minimized as demonstrated
        by Heng. We should move ahead and settle on the cut for protons. Heng's
        prescription for cutting out the deuterons appears to be a reasonable
        one. He has since demonstrated <px/A> is not biased by selecting
        different regions of the PID band. GR suggested the slope at a
        midrapidity be extracted accurately usingfine binning in Y and
        increasing the statistics. Heng should do this. GR: Vital we pin down
        the 2 and 4 A GeV points.

        Dan Cebra: Gave a status of work underway at U.C Davis. Some of the
        work was done by Bill Caskey and Jim Draper (present). Concentrated
        on 4A GeV Au+Au data. The goal is to develop a procedure to extract
        flow for pions which is robust against the (complex) acceptance.
        Let's check it against protons first where the acceptance is good.
        The reaction plane is found using the weighting method. The
        acceptance correction is done in phi (18 bins) - rapidity (4 bins)
        space. Px/A is extracted after weighting each bin in { P(momentum),
        theta, phi } space. This reflects the natural gometrical losses in
        the TPC. Using this method we find a very small change in the proton
        slope compared with the 'normal' method - implies we have a good
        acceptance. This is work in progress and we'll have more to say later.
        Jim proposed taking the average on an event by event basis and then
        average over events. He was not sure this was necessary but
        mathematically it is different from taking the average of all
        tracks. Heng pointed out that a multiplicity selection should reduce
        fluctuations inherent to averaging over different event classes. Jim:
        it's an interesting problem.

        Juan Romero: Penny's tracker for MUSIC is now working. Verified against
        output from LBNL and SUNY pass 1 data.

        Action Items:

        1)      Get Vdrift data for the MUSIC detector
        2)      Conclusions from processing the E910 tape
        3)      Develop the vertex refit module
        4)      GR: contact Jeff regarding home common - Done