h1. 2017-12-05-physics-shifter

*Start Date:* 2017-12-05

*End Date:* 

*Start Run:* 10432

*End Run:* 

*Physics shifter*: Chris Rogers

h2. Summary

The aim was to get the empty data for corresponding LiH full settings:

* 5th December - possibly recover magnets following a quench

* 6th December - 2016-05.1 setting (flip mode, 140 MeV/c)

* 7th December - 2017-02-7 setting (flip mode, 140 MeV/c)

* 8th December - 2017-02-8 setting (flip mode, 170 MeV/c)

* 9th December+ - absorber changeover

h3. Elog, CDB

h3. Online reco

h2. Analysis

h3. 5th December

No data

h3. 6th December

Checked:

* TOF1 dt is around 50 ps (depending on the run setting), still not great; TOF0 and TOF2 slab conversion to space point efficiency ~ 97-98 %

* TKU, TKD has no obvious dead area

* Amplitude change looks okay. Notice more scraping than with M2D data sets.

* I spend some time staring at the chi2 plots in TKD. TKD has a longer tail, but I think it is not significant. Comparing e.g. chi2/ndf = 4, with the peak chi2, the ratio is < 10^-3 for both TKU and TKD. But TKD has a longish tail beyond - all at < 10^-3 level, so did not dig further. I also note TKD has fewer ndf, potentially indicating less successful track finding from PR; again, something to dig into (but data is probably okay).

** The p-value plot shows p-value around 0 for events that pass cuts. Why is this? Bug in my script?

* I noted onrec shows lots of electrons in EMR for the diff8 setting. Why is that? This setting has slightly lower pz, maybe lots of stopping muons in KL?

h3. 7th December

Similar comments to 7th Dec. The amplitude upstream vs downstream looks better, because M2D is on!