Today's Progress 19. July. 2006

(stoppedK^-,n) semi-inclusive spectrum W/W.O. VETO

Here we present the 100% statistics (stopped K^-,n) semi-inclusive spectrum with/without VETO.

Time spectrum/Count rate of VETO counters

First, TDC channel spectrum of VETO counters are shown.
VDC VETO
PDC VETO
Upstream VETO
Degrader VETO

Beta-inverse VS light output

Two-dimensional correlation between inverse velocity and light output are shown below. It looks as if two triangles are overlayed with 1/beta shift.

Semi-inclusive (stoppedK^-, n) momentum spectrum

Here, arm-by-arm neutron momentum spectrum under semi-inclusive condition is shown. Three kinds of sectrum is presented. The condition is as follows:

  • Black:No father selection
  • Red: with VDC VETO (i.e. when at least 1 of VDC VETO is fired, then the event is eliminated) - which is really comparable to E570 data.
  • Green: with VDC VETO and PDC VETO (i.e. under the condition of Red, those events in which at least one of PDCVETO is fired are eliminated.)

    • Larm 5MeVee
    Rarm 5MeVee
    Larm 7MeVee
    Rarm 7MeVee
    Larm 10MeVee
    Rarm 10MeVee

    Comparison between PDCVETO-eliminated spectrum and the complement

    Here, we compare the spectrum under PDCVETO-fired (black) and NOT.PDCVETO-fired (red) conditions, under NOT.VDCVETO-fired condition with 5/7/10 MeVee threshold values.

    Larm 5MeVee
    Rarm 5MeVee
    Larm 7MeVee
    Rarm 7MeVee
    Larm 10MeVee
    Rarm 10MeVee

    At this moment, it is not obvious whether PDCVETO-fired events (about 20 % of NOT.VDC-fired events) should be really dropped from the spectrum or not.

    Run-by-run arm-by-arm 1/beta global spectrum for neutral particles

    Run-by-run arm-by-arm 1/beta spectra for neutral particles are found here.

    Segment-by-segment 1/beta global spectrum

    Segment-by-segment 1/beta spectra for neutral particles are found here.