STAR HardProbes PWG

["Mooney, Isaac" <isaac.mooney AT yale.edu>]

Hi Dandan,

I was thinking the same thing as Yi on the two points I highlighted below. But we had a discussion just now and I agree that the first point could be addressed after QM and the second point is probably okay. 

As for the rest of the preliminary request slides, I am happy with them.

Thanks,

Isaac

On Aug 28, 2023, at 2:00 AM, Yi Yang via Star-hp-l <star-hp-l AT lists.bnl.gov> wrote:

- p9: I was thinking about what you explain about the difference in statistical errors between HX and CS. I still think that the statistical uncertainty should be the same in different frames. The argument you have is that the phase spaces are different, in CS you are limited to smaller phase spaces (Figure 2), so you have large uncertainty from the fit (to determine the polarization parameter). But (to me) it should be taken into account to the systematics uncertainty, in particular the polarization parameter extraction. This is the problem of the definition, not the statistics. As Zebo mentioned, if you have infinite statistics but you only have one phase space point (extreme case), you still can not determine the polarization. And it is due to the definition, not statistics (increasing statistics won't help). You can use a large statistics sample to study the effect, for example you can say in the CS frame, we will only be able to distinguish certain parameters in certain precision. 

We can leave it now for the preliminary, and we can discuss it in the publication phase. 

 - As we discussed in the meeting, the result in p9, the lambda_theta in CS frame looks very consistent with 0, but in p10, when you integrated all certaility, you see ~2 sigma effect. We might need to think of an explanation about it.