1. 1 PID status MICE Analysis phone conference 2006-05-18 Rikard Sandström

2. 2 Updating fits Fits for various parts of PID has been updated. –Sandwich design with a gap for iron shield: Barycenter as function of momentum Range (deepest layer hit by muon track) as function of energy Total ADC counts as function of energy –Energy loss in trackers as function of beta. Energy loss in absorbers more tricky -> work in progress. Energy loss in TOF2 will be done any time now. The setup used for this is –3 iron shield field map –the wide handwritten beam I used in earlier presentations –only muons good for tracking are included –TOF2 is huge in order to give all muons TOF2 energy loss.

3. 3

4. 4

5. 5

6. 6

7. 7 Time of flight For stage 1, time of flight is a good estimate of the particles longitudinal momentum. –This expected momentum is then used in the same way as the measured momentum from the tracker in Stage 6 for predicting calorimeter response (if muon). When we also have trackers, time of flight is used to compare with expected time of flight given momentum measured in trackers. –It could also be used to aid trackers in measuring longitudinal momentum, but then we lose the PID capability. –This expected time of flight is a delicate issue:

8. 8 Time of flight, Lorentz force Lorentz force rotates the momentum between pt and pz. –Most notable in field flips due to large transversal component. –x is very important too since cross product with p! –Field map dependent -> every central momentum will need its own fits.

9. 9 Time of flight, absorbers Since resonances occur, muons at certain momentum take longer trajectories through the absorbers and thus lose more energy. –If we would be able to exactly predict the track from upstream tracker this could be corrected for. –If not, we would again need separate fits all the different field settings.

10. 10 Time of flight, RF phase For particles on axis and empty absorbers, it is easy to predict at what phase a particles enters a cavity, and thus its energy gain and time at the exit of the cavity. If energy loss fluctuations in absorbers introduces errors, and after a full cooling channel these errors accumulate in a fashion it is difficult to correct for. If effect of magnetic field (momentum transfer) not exact, we will miss judge when, where and at what momentum a particle arrives at a RF cavity, thus further increasing the errors.

11. 11 Time of flight, conclusion As long as tracks are fairly straight and at nominal momentum region, time of flight can be well predicted (rms ~ hundred(s) ps). It is hard to cover all situations with simple fits for the time of flight, so a more intelligent way to predict tracks in the cooling channel is required. –“Swimming”? What we need is a tool that, given upstream tracker and TOF1 information, estimates the track as it leaves the cooling channel.