LAr TPC: Status and progress in data analysis efforts Y. Ramachers (University of Warwick) IDS-NF, RAL 22/09/2010 Y. Ramachers

IDS-NF, RAL 22/09/2010 Y. Ramachers

IDS-NF, RAL 22/09/2010 Y. Ramachers

Update: A. Rubbia@EuroNu2010 IDS-NF, RAL 22/09/2010 Y. Ramachers

The Data Analysis Challenge Liquid argon TPC’s reconstruct events with bubble-chamber quality But, automatic reconstruction in software is still not established Why? IDS-NF, RAL 22/09/2010 Y. Ramachers

2. It’s not so easy! Tracks and showers develop side-by-side in the same volume  topologically complicated No well defined start point for what initiated the event Very high density of information: mm-scale energy deposits, delta- rays, vertices, kinks etc Multiple scattering occurring continuously throughout volume ICARUS, arxiv:0812:2373 IDS-NF, RAL 22/09/2010 Y. Ramachers

Past Developments: ICARUS ICARUS Collab., Phys. Rev. D74, 112001 (2006) Tools developed over the years by the ICARUS project: hit definition, clustering, 2D and 3D track fitting Low multiplicity neutrino events reconstructed from a 50L module exposed to the CERN WANF beam Some degree of visual scanning/selection involved before applying algorithms IDS-NF, RAL 22/09/2010 Y. Ramachers

Warwick work in progress Experimental programme: Purity control Measurements with SiPM arrays → spatial resolution Alternative: CMOS/CCD camera and optics Optical Fibre array readout Solid Argon test Cold electronics Computational programme: Monte-Carlo event generation Novel high-granularity tracking analysis Charge transport simulation – signal generation D.Y.Stewart et al., acc. for publ. in JINST Informal collaboration with LArsoft: ArgoNeuT, MicroBooNE, data analysis code A. Rubbia's group on data analysis (travel grant) IDS-NF, RAL 22/09/2010 Y. Ramachers

What do we need to do? J. Spitz Classify energy deposit information into shower-like and track-like objects Identify tracks (,p) and showers (e, ) from topology, kinematics and dE/dx in LAr IDS-NF, RAL 22/09/2010 Y. Ramachers

Clustering Aim to limit contamination of cluster with hits laid down by other particles Develop a hierarchy of clusters/super- clusters IDS-NF, RAL 22/09/2010 Y. Ramachers

Density-Based Clustering Clusters: a density of points considerably higher than outside the cluster DBSCAN* algorithm: the `density-neighbourhood’ (around each point in the cluster must contain at least Nmin other points Kinga Partyka (Yale/ArgoNEUT)‏ Implemented in ArgoNeuT data Issues with `over-clustering’ being addressed Colours → Cluster found by DBSCAN IDS-NF, RAL 22/09/2010 Y. Ramachers * Sander et al., Data Mining and knowledge Discovery 2, pp169-194 (1998)

Cellular Automata clustering Next 'Warwick Tool' to be quantified and published Toy-MC data Raw hits GENIE Simulated CCQE events Reconstructed IDS-NF, RAL 22/09/2010 Y. Ramachers

OPTICS Ordering Points To Identify the Clustering Structure* Reachability Distance plot Ordering Points To Identify the Clustering Structure* Extended DBSCAN clustering Reveals clusters on all scales Getting the scale correct helps in associating disjoint clusters in E- Mag showers Extend to cluster in more than spatial coordinates, e.g. dE/dx 3 clusters found dE/dx used since track density identical N data points IDS-NF, RAL 22/09/2010 Y. Ramachers * M. Ankerst et al., ACM SIGMOD Int. Conf. on Management of Data pp49-60 (1999)

Track Finding: Hough Transform Joshua Spitz ArgoNeuT/Yale Reasonable job of reconstructing multiple tracks in ArgoNeuT events Returns only gradient and intercept of line – definition of start/end-points of tracks continuing: IDS-NF, RAL 22/09/2010 Y. Ramachers

Track Finding: KDTREE KDTREE provides convenient data structure from which to launch a nearest-neighbour hit search Fit straight-line segments through groups of nearest hits in 3D Andrew Bennieston, Warwick Currently testing on toy Monte Carlo – observe change in direction cosine of line segments to tag kink/vertex with high efficiency IDS-NF, RAL 22/09/2010 Y. Ramachers

3D Track fitting Implemented a modified ICARUS Kalman filter: ICARUS, Eur. Phys. J. C48 (2006) 667 Momentum-measurement by multiple scattering! Momentum reconstruction ICARUS simulated tracks Warwick simulated track, Multiple scattering only Track slope reconstruction μ @ p=1.5 GeV/c IDS-NF, RAL 22/09/2010 Y. Ramachers

Key Point Detection Vertex IP  corner in charge density Delta-electron  corner in charge density Prior knowledge of vertex points, kinks, track end-points etc is useful in aiding reconstruction algorithms e.g. blank-off hits around a vertex point from a cluster search IDS-NF, RAL 22/09/2010 Y. Ramachers

Corner Finding GENIE generated CCQE events in 3T LAr TPC: Ben Morgan, JINST 5 (2010) P07006 Vertex picked out Proton Stop Delta Electron ID! IDS-NF, RAL 22/09/2010 Y. Ramachers

ArgoNeuT data update Recently completed >5 months physics run in the NuMI beamline ArgoNeuT, arXiv:1009.2515, implementing B. Morgan's corner finding IDS-NF, RAL 22/09/2010 Y. Ramachers

New toolbox target T. Dealtry, Warwick URSS- Project 2009 IDS-NF, RAL 22/09/2010 Y. Ramachers

Conclusion Great progress in expanding data analysis toolbox Work in progress@Warwick: Quantify performance using GENIE simulated data for liquid argon Next steps: Model Analysis Obtain Globes input parameters from Monte-Carlo data Analyse the effect of (absence of) a magnetic field Collaborate more closely with running experiments, testing analysis on real data Provide input to IDS on liquid argon detector IDS-NF, RAL 22/09/2010 Y. Ramachers