d.forrest@physics.gla.ac.uk 21 October 2008 (CM22) Misalignment Study David Forrest University of Glasgow d.forrest@physics.gla.ac.uk 21 October 2008 (CM22) If you would like to use the grid tell me I would be happy to give you copious help in getting sorted out on it
Introduction to the study - Misalignment of the downstream spectrometer only (Step VI of MICE) - Translational and rotational misalignments studied - 10 mm, 3mrad and both combined. For x and y. - Independent MC simulations (G4MICE, Grid, Ganga) - 10,000 events
Cuts Cutting on single particle emittance Emittance 4D=mean(amplitude4D)/4 Cutting out muons that don’t make it to the second tracker – ~85% transmission (this is very very fresh, transmission graphs to follow at analysis meeting, mice note)
Baseline - bump. Explanations? Spline, cuts applied 4 up. No longer seeing muon collider type cooling now is of order 10 percent for a ten pi beam
3 mrad X 3mrad Rotational Misalignment (X)
3mrad rotation (Y) 3 mrad Rotation (Y)
Both in X Translational and Rotational (X)
Both in Y Translational and Rotational (Y)
What about statistics? - We calculate 4D emittance by taking the fourth root of a determinant of a matrix of covariances - What's the error on that? - Assume proportional to sqrt(1/N)... - What is the factor of proportionality?
Means 500 1k event runs 50 10k event runs
99% of statistics are made up
Stats conclusions - This is just a short attempt at probing the constant of proportionality, using the grid. - that constant is thankfully not 1, but it is not 0.1 either (proving jhc right when he said he was wrong), both of which are good to know. - I want to try and develop this - It's difficult to make statements about the effect of misalignment without an understanding of the affect of statistics
Misalignment conclusions Assume that effect scales linearly effect between 1-5% Higher than before. Previously predicted 3 mm, 1mrad alignment constraints. New ones will be stricter, perhaps 1mm, 0.3 mrad. Next analysis phone meeting and mice note will be more precise Misalignment conclusions
Future work - I should probably simulate that precise misalignment to confirm linear assumption - But I really want to try and separate the influence of statistics before doing much else - Finalise table and thump out a MICE note (+ one on GRID. Already written but volatile to change) - Digitisation, Reconstruction etc remains to be done