E852 experiment

Analysis of Eta Pi0 system with the decay Eta -> Pi+ Pi- Pi0

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Draft 5

Date: 17 Apr 2006

From: Neal Cason

Hi all: I thought it might be helpful to compare the P^+D^+ phase difference in the eta pizero data compared to our old result for the eta piminus. See the attached pdf figure. It is clear that the phase difference shapes are quite consistent. (Rather than overlaying the plots, I scaled both figures to have the same scales and then drew horizontal and vertical lines which show that the phase difference shapes are consistent and that the mass dependences are consistent.) Neal

From: Neal Cason

Hi Vladimir: Note that in the figure I sent that your etapizero plot is listed as "P^+-D^+" wheras the etapiminus plot is labelled "D^+-P^+". Since the a2 is much narrower than the pi1, I think the labelling in the etapiminus is correct and that in the etapizero is not. Can you check this? Thanks............Neal

From: Suh-Urk

It seems to me that the phase difference plots worked out by Neal Cason is very illuminating... I urge you to include it in our paper.

Response

See Gary's comment and Note 6, Comparison the relative phases.

One more thning...have you had a chance to include t' dependence in your likelihood fits? This might be revealing...

Response

See Draft 3 and our discussion later

From: Gary Adams

Let's be a little careful here. As Vladimir has shown in "Note 5" a fit with only D+ resonant looks very similar to the final one. The slopes in the phase plot at low and hi mass are critical for determining resonance parameters. Therefore I think the differences between etapi- and etapi0 are significant. I'm not sure adding a comparison plot would help the paper.

Response

See Note 6, Comparison the relative phases.