The STAR experiment

I've had a chance to incorporate the st_upsilon production into my check on the BEMC tower calibration.  There are now enough statistics to look at individual towers (see

This is my first post to drupal so I will limit it to two graphs
of the multiplicities for nTracks and nPoints for jets, comparing

So we now have access to a wide variety of gluon polarization parameterizations in our Pythia afterburner covering the regions between GRSV -std and -max and between GRSV -zero and -min.  Dave Staszak documents the details of the new distributions at

http://www.star.bnl.gov/protected/spin/staszak/2006/Sims/trigBias/trigBias.html

Here are plots of the raw charged pion asymmetries obtained from these grids (p070 excluded because of a bug on my part):

I suspect the problem with the pi-minus asymmetries can be traced to a lack of gg contributions.  For more information see Agreement Between "Polarized" Pythia and NLO pQCD.  In the remainder of this document I'll stick to analyzing pi-plus data.

I've attached multi-page PDF at the bottom of the page.  Each page of the PDF plots, for a give input gluon polarization distribution A_{LL}(trigger) - A_{LL}(no trigger) as a function of pion p_T.  There are six plots on each page; one for each trigger in (minbias, HT1, HT2, JP1, JP2) and then the raw A_{LL}(no trigger) distribution itself in the bottom right.  I believe one way we can obtain a systematic uncertainty from plots such as these is to calculate a double-sided max( delta A_{LL}, uncertainty on triggered A_{LL} ) for each pT bin we use to make our measurement.

One question is which grids are appropriate ones to use for calculating the systematic.  GRSV-max has been excluded in other measurements, so I don't think it's appropriate.  All other grids are fair game, which means the systematic will likely be derived from GRSV-min and p070 (once I rerun; use p060 for now).

Title : Pion HBT in AuAu@19.6 GeV
PWG: HBT
PAs: Z. Chajecki, M. Lisa
Target Journal: PRC

The question of why the pion maker is so inefficient came up this morning in the photon group.  I'm posting this to try and shed a little light on where these inefficiencies arise.

I have been working on developing a point maker to work in conjunction with StGammaMaker.  The idea (from my end) was that you would input gamma candidates to the point maker and you would get ou

Data Collection

• MB || JP1 || JP2
• BBC timebin in {7, 8, 9} -- roughly equivalent to 60 cm offline vertex cut (see BBC Vertex)
  

I'm attaching a pdf of the talk given by Dima Kharzeev and sent to the BES list by Helen Caines:

http://www.star.bnl.gov/HyperNews-star/protected/get/bescan/26/1/2.html

Here I give rough estimates for the radiation we can expect for the inner ring on the currently considered forward TOF rings. Rates are taken from run 7.