Response of AMANDA-II to Cosmic Ray Muons and study of Systematics Newt,Paolo and Teresa

Outline Motivation : Study of Cosmic Ray muons as a test beam to check the experiment systematics and enhance understanding of our detector response Muon Angular and Vertical Depth intensity and Data/MC normalization : Comparison of experimental data (2001) and simulation with a large statistics Methodology and Assumptions Angular Reconstruction Some notes on Convoluted Pandel Likelihood

Motivation We have huge statistics of down going muon data and this could be used to get a better understanding of AMANDA- II performance and could enhance our filtering,Event Reconstruction and Systematics. Compare a measurement of the intensity of down going muon flux as a function of the zenith angle and demonstrate good agreement within systematics Possibly a flat component of Charm induced muons could be detected(If we have angular resolution under control) at large Zenith angles

Muon Angular Distribution

Depth-Intensity Distribution

Normalization

Methodology Cosmic Ray muons are simulated using Corsika 6.03 and QGSJET01 hadronic interaction model and detector response obtained using trigger conditions and events are reconstructed. Now from the experimental data if we want to make a Physics measurement of the muon Intensity we will have to account for Triggering & reconstruction efficiencies. Triggering efficiency accounted by looking at actual events generated from the mmc files Assumed that the ratio of events forwhich the detector triggers (reconstructed events) to the true events generated remains the same in the data and the simulation to get the Physical measurement of the flux from experimental data

Methodology Now we have a finite angular resolution so what we reconstruct is not the true angle, but however if we make the bin size large enough in such a way as to minimize the overlapping than the correlations between the bins of the zenith angle could be ignored and each bin could be treated independently Prior to doing this we could also use some basic quality cuts to improve reconstruction Track Length,Chi Square,Difference of Odd and Even hits from a time ordered hit sample.

Angular Resolution Cos(truezen) -Cos(Reco) Cos(Reco)Cos(truezen)- Cos(Reco)> % % % % %

Convoluted Vs Patched Pandel Negative Time Delay Distributions The Convoluted Pandel Convoluting Gaussian PMT noise smearing with Pandel function using Confluent Hyper geometric functions (George and Mathieu) Much better Angular resolution and description of time delay distributions “1-fold iterated Convoluted Pandel has approximately same angular resolution Of a 16-fold ppandel” - Mathieu Ribordy (AMANDA collaboration meeting,Mons) High energy Muon With nhits>200 Time delay (ns) (16-fold ppandel)

Convoluted Vs Patched Pandel Data Agreement Number Of Hits Data B.G Signal Cut out To speeden up Proceessing time Number Of Hits