The STAR experiment

Runs used: 6013134 (13 Jan) - 6081062 (22 Mar)

The procedure for performing the relative calibration can be divided into 3 steps:

1. Create a histogram of the pedestal-subtracted ADC values for minimum-ionizing particles in each tower
2. Identify the working towers (those with a clearly identifiable MIP-peak)
3. Use the peak of each histogram together with the location of the tower in eta to calculate a new gain
4. Create new gain tables and rerun the data, this time looking for electrons
5. Use the electrons to establish an absolute energy scale for each eta-ring

Using Mike's code from the calibration of the 2004 data, an executable was created to run over the 62GeV CuCu data from Run 5, produce the 2400 histograms, and calculate a new gain for each tower. It was necessary to check these histograms by hand to identify the working towers. The output of the executable is available as a 200 page PDF file:

Originally posted 26 September 2005

Catalog query:
input URL="catalog:star.bnl.gov?production=P05if,tpc=1,emc=1,trgsetupname=ppProduction,filename~st_physics,filetype=daq_reco_mudst,storage=NFS" nFiles="all"

note: 3915/4240 = 92.3% of the available towers were able to be used in the calibration. Lists of bad/weird towers in the pp run are available by tower id:
bad_towers_20050914.txt
weirdtowers_20050914.txt

The relative calibration procedure for pp data is identical to the procedure we used to calibrate the barrel with CuCu data (described below). The difference between pp and CuCu lies in the electron calibration. In the pp data we were able to collect enough electrons on the west side to get an absolute calibration. On the east side we used the procedure that we had done for the west side in CuCu. We used a function that goes like 1/sin(theta) to fit the first 17 eta rings, extrapolated this function to the last three eta rings, and calculated the scale factors that we should get in that region. Here is a summary plot comparing the cucu and pp calibrations for the 2005 run:

(2005_comparison.pdf)

Originally posted 11 October 2005

Previously we had calibrated the BEMC using data from all triggers. We now have enough data to restrict ourselves to minimum-bias triggers. Additionally, we have implemented a cut that requires the pedestal-subtracted ADC value of neighboring towers to be less than twice the width of the pedestal. This cut does an excellent job of removing background, especially in the high-eta region:

Introduction

To treat many-particle events (pp and AuAu), we need to know which particle generated which cluster/point before evaluating the reconstructed clusters and points.  StEmcAssoc

Introduction
Transfers where either the source or target are on the Birmingham cluster. I am keeping a log of these as they come up. I don't do them too often so it will take a while to accumulate enough data points to discern any patterns…

Update:  New B/EEMC embedding framework from Wei-Ming Zhang currently in peer review

All calibration information is stored in the STAR database.  We have the following tables for BEMC calibrations:

• For the BTOW and BPRS detectors:
• St_emcCalib - this table contains absolute gain information for each channel
• St_emcPed - this table contains pedestal values for each channel
• St_emcGain - this table contains a gain correction factor vs. time for each channel (not currently used)

This database stores all BEMC trigger information such as trigger status, masks and pedestals used to obtain the high tower and patch sum information.  The database is updated online while taking data.  We have the following table formats:

These pages describe how to use the BEMC database.  There is a browser-based tool that you can use to view any and all BEMC tables available at:

Ok, after working on porting the BEMC webpages to Drupal over the past couple of days I have a list of features that I hope we can implement in our Drupal installation:

• Performance Optimizations:  I don't know if it's Drupal settings, PHP settings, or what, but this CMS is awfully slow at times.  I've set up a couple of Joomla installations at MIT that are much snappier.  This is the number one complaint I hear from other people.  It's going to be a running joke at EMC phone meetings before too long.
• Trash Bin:  What do I do with pages that I decide I don't want?  I don't see any way to trash them, so for the moment the BEMC subsystem page has a "Trash Bin" of it's own.  It sure would be nice if I could hide it, though.
• Authorship changes:  Sometimes I create pages as kocolosk that would probably be better off as staruser pages, but I don't see any way to change the authorship myself, so I've resorted on at least occasion to "trashing" the old page as best I could and then recreating a new page with a different author.  Very convoluted.
• Restricted viewership:  I would like to post analysis results in Drupal, but I can't figure out how to restrict my pages to logged in users.  At the moment I have a folder called drupal_pics in protected/spin that I put plots in.  Users are then required to type a password to see them, but again, this is something Drupal must be able to handle by itself.

Introduction:

The recalibration of the BEMC towers for Run 4 includes the following improvements:

Introduction

The final BTOW calibration for Run 5 offers the following improvements over previous database calibrations:

Time	Talk	Presenter
09:00	Low- and intermediate-pT azimuthal di-hadron correlations ( 00:30 ) 0 files	Mark
09:30	Probing small-x gluons and large-x quarks: jet-like correlations between forward- and jet-like correlations ( 00:30 ) 1 file	Levente
10:00	3-particle correlations : Is there a Mach cone ? ( 00:30 ) 0 files	Claude
10:30	3-particle correlations ( 00:30 ) 0 files	Jason
11:00	TEA BREAK ( 00:30 ) 0 files
11:30	Spin Alignment of vector mesons (K*, phi) in Au+Au collisions ( 00:30 ) 1 file	Jinhui
12:00	Phi meson spin alignment wrt production plane / Global polarization of Lambda hyperons ( 00:30 ) 2 files	Ilya Selyuzhenkov (WSU)

Time	Talk	Presenter
11:30	High-pt delta-eta correlations in Au+Au (charged hadrons) ( 00:30 ) 0 files	Joern Putschke
12:00	Strange particle dphi,deta correlations ( 00:30 ) 0 files	Jana Bielcikova