[Hps] Double peak in mass spectrum

[Sebouh Paul]

here's the mass distribution that i see.

This is from all the files in run 5772 chained into a TChain called
chain_W. The command I ran to get this histogram is:

chain_W->Draw("uc_v0_candidates.mass>>mass(500, 0, .2)",
"uc_v0_candidates.mass<1 && uc_v0_candidates.vtx_x>-1.5 &&
uc_v0_candidates.vtx_x<1.5
&& uc_v0_candidates.vtx_y>-1.3 &&uc_v0_candidates.vtx_y<1.3 &&
uc_v0_candidates.pz>.8 && uc_v0_candidates.pz<1.057");



On Fri, Sep 18, 2015 at 2:28 PM, Graham, Mathew Thomas <
mgraham at slac.stanford.edu> wrote:

> Can you post this to the group?  It may because of the acceptance or there
> may be some fake low energy tracks...
>
> > On Sep 18, 2015, at 11:13 AM, Sebouh Paul <sebouh.paul at gmail.com> wrote:
> >
> > I have looked at the mass spectrum of the trident events in the
> engineering run and have found that it is a bimodal distribution with peaks
> at ~22 and ~60 MeV.  Has anyone done any study as to why this is the case?
> Is it because of the shape of the geometric acceptance?
>
>
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