Status and Prospects of HARP Malcolm Ellis On behalf of the HARP Collaboration NuFact02 Imperial College, July 2002

2 The HARP Collaboration: Università degli Studi e Sezione INFN, Bari, Italy Rutherford Appleton Laboratory, Chilton, Didcot, UK Institut für Physik, Universität Dortmund, Germany Joint Institute for Nuclear Research, JINR Dubna, Russia Università degli Studi e Sezione INFN, Ferrara, Italy CERN, Geneva, Switzerland Section de Physique, Université de Genève, Switzerland Laboratori Nazionali di Legnaro dell' INFN, Legnaro, Italy Institut de Physique Nucléaire, UCL, Louvain-la- Neuve, Belgium Università degli Studi e Sezione INFN, Milano, Italy P.N. Lebedev Institute of Physics (FIAN), Russian Academy of Sciences, Moscow, Russia Institute for Nuclear Research, Moscow, Russia Università "Federico II" e Sezione INFN, Napoli, Italy Nuclear and Astrophysics Laboratory, University of Oxford, UK Università degli Studi e Sezione INFN, Padova, Italy LPNHE, Université de Paris VI et VII, Paris, France Institute for High Energy Physics, Protvino, Russia Università "La Sapienza" e Sezione INFN Roma I, Roma, Italy Università degli Studi e Sezione INFN Roma III, Roma, Italy Dept. of Physics, University of Sheffield, UK Faculty of Physics, St Kliment Ohridski University, Sofia, Bulgaria Institute for Nuclear Research and Nuclear Energy, Academy of Sciences, Sofia, Bulgaria Università di Trieste e Sezione INFN, Trieste, Italy Univ. de Valencia, Spain

3 Outline Motivation Timeline The Detector Data taking: –2001 –2002 Software/Analysis Prospects

4 Motivation Neutrino Factory Atmospheric Neutrinos Monte Carlo K2K and MiniBooNE Experiments Aim: –Measure Hadronic d  /dP T /dP L over range of momenta, target Z and thickness –Few% accuracy over all phase space, requires ~10 6 events per setting and low systematics.

5 Timeline Proposed: November 1999 Approved: February 2000 Technical Run: September 2000 Data Taking: –Solid Targets: 2001 –Solid & Cryogenic Targets: 2002

6 The Detector Main Requirements: –Acceptance, PID, Redundancy Beam instrumentation provides tracking and PID of incoming particle. TPC surrounds target to provide close to 4  coverage. Forward Spectrometer covers insensitive region of TPC. PID completed with Cherenkov, TOF and Calorimetry.

7 The HARP Detector

8 Particle ID Coverage TPC TOF Cherenkov

9 CERN PS East Hall

10 HARP in 2001

11 Beam and Targets target tube target holder Extrapolated position of MWPC tracks at the target Beam: ±3 ±5 ±8 ±12 ±15 GeV/c Solid Targets: Be, C, Al, Cu, Sn, Ta, Pb Thin (2%) Thick (100%) 5% Targets (New) MiniBooNE K2K Skew Copper Alignment Cryogenic Targets: H 2 /D 2 N 2 /O 2

12 Cryogenic Targets elementH2H2 D2D2 N2N2 O2O2 boiling temp  K23.6  K77.4  K99.2  K # 0.84 %2.13 %5.52 %7.52 % Targets 2cm diameter, 6cm long. Two distinct setups:  N 2 /O 2 – Mid July  H 2 /D 2 – Early August Filling takes 4-6 hours. Emptying takes ~1 hour.

Data Taking Completed 1/3 of Solid Target Programme:

Data Taking Programme (May-September): –Thick Targets –5% Targets +ve and –ve beams –Remaining Solid Targets –Cryogenic Targets (start 8 th July) –MiniBooNE Programme (12 th August) –K2K Programme (26 th August)

15 Trigger beam Forward trigger plane (FTP) Inner Trigger Cilinder (ITC) Consequence: 1/2 to 2/3 of our thin-target data are non- interacting beam particles   Solution: Non-Interacting Beam (NIB) veto counters – under study 5% Targets

16 Software Processes Stringent time schedule required adoption of software engineering standards. Domains identification & dependency structure lead to: –definition of releasable units (libraries and source code), –definition of working groups (and schedules), –definition of ordering for unit&system testing and for release. DetResponse HarpUI ObjyHarp Reconstruction ObjectCnv ROOT GEANT4 DetRep Gaudi Framework Gaudi Framework HarpEvent HarpDD CLHEP + STL CLHEP + STL DAQ Simulation DATE Event Selector Event Selector Objy Persistency Objy Persistency HEPODBMS Objectivity HEPODBMS Objectivity

17 Software/Analysis DAQ and detectors readout (DATE). Storage and retrieval of physics data and settings (Objectivity DB, AMS-HPSS interface). Framework including application manager, interfaces & data exchange for the components, and event model (GAUDI). Physics Simulation & Detector Model (GEANT4). Physics Reconstruction for all detectors. Online Monitoring & Offline Calibration of detectors. User Interface and Event Display (ROOT). Foundation libs & Utilities (STL, CLHEP).

18 Beam Instrumentation Beam Particles tracked by 4 MWPCs Particle ID performed by: Cherenkov, TOF,  identifier

19 TPC Gas Choice: 90% Ar, 10% C0 2 Gas Speed 5cm/  s Total drift time: 32  s  320 time samples Cross-Talk problems under investigation

20 TPC – Reconstructed Tracks P T vs P L for Thick Target Data P T for all TPC Tracks

21 RPCs

22 RPC/TPC Matching 2 mm stesalite wall Target (fixed to the magnet) (fixed to the TPC) RPC are fully efficient and noise-free RPC timing removes off-time tracks

23 NOMAD Drift Chambers Efficiency reduced due to change of gas: 90% Ar, 9% CO 2, 1% CH 4 Calibration and Alignment ongoing

24 Cherenkov  2.6 GeV/c  9.3 GeV/c p17.6 GeV/c Thresholds: Gas Leakage problem emerged in the commissioning phase: Support structure re-welded Epoxy-treatment of inner surfaces. Leak rate ~ 4L/hour Specifications:  4 L/hour. Density monitored by sonar techniques (acoustic wave phase shift) <1% precision.

25 TOF Wall pions protons Calibration: Laser Cosmic Rays Pulse Calibration Example: time separation and resolution for 3 GeV/c beam particles.

26 Calorimeter Three modules: 62 EM (4cm), 80 HAD (8cm) & Muon Identifier Electron Identifier (EM+HAD) 6.72m wide x 3.3m high. Muon Identifier is 6.44 Interaction Lengths of Iron and Scintillator slabs.

27 Prospects Complete Data-Taking 30 th September Analyses Initially Separated: –Large Angle (TPC/RPC) –Small Angle (Forward Spectrometer) Expect to overcome TPC cross-talk problems, thus achieve design accuracy. Aiming for initial results by the end of this year.