Timing Calibration Efforts in Cosmic Ray Veto for Mu2e Experiment - PowerPoint PPT Presentation

Timing Calibration Efforts in Cosmic Ray Veto for Mu2e Experiment Payton Beeler

Standard Model • Charged lepton flavor violation • Why is it important? • Breaks standard model

How it’s supposed to work

How it actually works (maybe) ฀฀ ฀฀ e - Why is this important? Means that the standard model needs some work.

Mu2e • Run by Department of Energy • Located in Batavia, Illinois Detector • Will hopefully have results by 2020

Resolution Problems • Extremely rare decay Events Energy

PROBLEM: it’s raining apples

Solution: Cosmic Ray Veto (CRV)

Layout

Counters • 1,632 on CRV-T • 4 fibers run through each • Fibers connect to SiPMs 5600 mm 15 mm 20 mm 20 mm 50 mm

Noise Problems 3 1 t 3 t 1 t 4 4 t 2 2

Oscilloscope Readout (ideal world) 1 t 1 2 t 2 3 t 3 4 t 4

Oscilloscope Readout (real world) Timing error ≈ ±300 ps

Method • Shoot cosmic ray at specific point in counter • Find theoretical time it takes to get to detector • Introduce error to theoretical time to simulate measured time • Try to get original position from simulated time using chi squared test

Method

Results Average Difference vs. Position 0.004 0.002 0 0 1 2 3 4 5 6 -0.002 Difference (m) -0.004 y=0.025 m y=0.015 m y=0.050 m -0.006 -0.008 -0.01 -0.012 -0.014 Position (m)

Results RMS vs Position 0.009 0.008 0.007 0.006 Root Mean Squared 0.005 0.004 0.003 0.002 0.001 0 0 1 2 3 4 5 6 Position (m)

Next Problem • Attenuation • Amplitudes

Scenario • When a cosmic ray hits the polystyrene 25 photoelectrons come out Number of Photoelectrons vs. Position Number of PE to Counters 1 and 2 Number of PE to Counters 3 and 4 30 25 20 Number of Photoelectrons 15 10 5 0 0 1 2 3 4 5 6 Position (m)

Oscilloscope Readout 1 t 1 t 1 2 t 2 t 2 t 3 3 t 3 t 4 4 t 4

Results Difference vs Position 0.02 0.015 0.01 0.005 Differnece 0 0 1 2 3 4 5 6 -0.005 -0.01 -0.015 -0.02 Position

Results RMS vs Position 0.0035 0.003 0.0025 0.002 RMS 0.0015 0.001 0.0005 0 0 1 2 3 4 5 6 Position (m)

Results Difference vs Position 0.035 0.03 0.025 0.02 Difference (m) 0.015 0.01 0.005 0 0 1 2 3 4 5 6 -0.005 -0.01 Position (m)

Acknowledgements • Big thanks to Glenn Horton-Smith and Tim Bolton for allowing me to work with them this Summer • Thank you to the NSF for funding