Spin PWG
This is a feed of Drupal items targeting the "Spin" Audience.
DIS 2008 Presentation
Below you will find a link to a draft my DIS 2008 presentation.
Revised Eta Systematic
After some discussion in the spin pwg meeting and on the spin list, it appears I have been vastly overestimating my eta systematic as I was not properly weighing my thrown single etas.
Non-Longitudinal Beam Components Systematic
Documentation for a systematic uncertainty in the Run 5 charged pion A_{LL} based on non-longitudinal components in the beam polarization vector.
Energy Subtracted A_LL Calculation
For my single particle Monte Carlo studies, I argued (here) that I needed to ad
Alternate Calculation of Eta Systematic
At the moment I am calculating the systematic error on ALL from the presence of Etas in the signal reigon using theoretical predictions to estimate ALLeta. Th
Mass Windows
The nominal mass window was chosen 'by eye' to maximize the number of pion candidates extracted while minimizing the backgrounds (see yield extraction page.) I wanted to check to see how this
Single Spin Asymmetries
The plots below show the single spin asymmetries (SSA) for the blue and yellow beams, as a function of run index. These histograms are then fit with flat lines. The SSA's are consistent
Sanity Checks
Below there are links to various 'sanity' type checks that I have performed to make sure that certain quantities behave as they should
PID Background Systematic
Documentation for a systematic uncertainty in the Run 5 charged pion A_{LL} based on contamination from non-pions in the PID selection window.
Eta Systematic
For the eta background systematic we first estimate the background contribution (or contamination factor) to the signal reigon. That is we integrate our simulated background to discern the pr
Relative Luminosity Systematic
Documentation for a systematic uncertainty introduced in the Run 5 charged pion A_{LL} based on uncertainties in our measurement of the relative luminosity.
Combinatoric Systematic
For the combinatoric background systematic we first estimate the background contribution (or contamination factor) to the signal reigon. That is we integrate our simulated background to disce
Low Mass Systematic
For the low mass background systematic we first estimate the background contribution (or contamination factor) to the signal reigon. That is we integrate our simulated background to discern t
Systematics
We need to worry about a number of systematic effects that may change our measurement of ALL. These effects can be broadly separated into two groups: backgrounds and non background
Combinatoric Background
The last piece of the invariant mass distribution is the combinatoric background. This is the result of combining two non-daughter photons into a pion candidate. Since each photon in an
Low Mass Background
The low mass background is the result of single photons being artifically split by the detector (specifically the SMD.) The SMD fails in it's clustering algorithm and one photon is reconstruc
Yield Extraction
After all the pion candidates have been found and all the cuts applied, we need to extract the number of pions in each bin (in each spin state for ALL.) To do this we simply
Pt Dependent Mass
The two-photon invariant mass is given (in the lab frame) by
M = Sqrt(2E1E2(1 - Cos(theta)))