STAR task force for evaluating tracking efficiency uncertainty

["Van Buren, Gene" <gene AT bnl.gov>]

Hi,

> On Oct 20, 2022, at 3:53 PM, Ma, Rongrong <marr AT bnl.gov> wrote:
> 
> Hello Gene
> 
> Looking at this resolution plot for primary tracks, the p1 value is about 
> 0.003 between 1-3 GeV/c, which is compatible with embedding. So the numbers 
> in your previous email kind of make sense now, as they are for global 
> tracks while what I have been showing in my slides are for primary tracks 
> which are expected to be much better. Am I missing something? 

OK, thanks for clarifying yours. 

> 
> So the Run18 study shows that the momentum resolution of global tracks in 
> cosmic ray is similar to that of primary tracks in data. Is this expected?

Not expected - the primary vertex adds a strong constraint and significant 
length in determining the sagitta (curvature).

-Gne