1. Large Magnetic Calorimeters Anselmo Cervera Villanueva University of Geneva (Switzerland) in a Nufact Nufact04 (Osaka, 1/8/2004)

2. 2 Aim of the talk Present the 2 studies in the market Combine them because they are complementary Demonstrate that the technique works LMD ( Large Magnetic Detector ) Monolith B B Monolith: Monolith: detector resolution LMD: LMD: background studies known technology (MINOS) 10 x MINOS

3. 3 Studies in the market  Fast simulation and reconstruction based on MINOS smearing  Muon identification  Charge identification  Study of background rejection power and efficiencies  Variation of smearing parameters B B MonolithLMD M. Selvi M. Garbini H. Menghetti A. Cervera F. Dydak J.J. Gomez-Cadenas  Full simulation and reconstruction  Careful study of the hadronic angular resolution, including test beam  Charge identification

4. 4wrongsignmuon Stored  + not detected charge misidentified Charge misidentification Backgrounds NC CC Hadron decay 50% in the final state no other lepton ‘Golden’ signature : wrong sign muons detector

5. 5 Detector requirements PP E had    had ~40 KTons  Large statistics Large mass: ~40 KTons from range  Muon identification: from range B~1 Tesla  Charge identification: B~1 Tesla  Kinematic quantities (for background rejection) 3-momentum  From the muon: 3-momentum energy and angle  Hadron shower: energy and angle every ~5-10 cm 1.Reasonable number of spatial measurements: every ~5-10 cm ~1 cm 2.Reasonable transverse resolution: ~1 cm

6. 6 Challenges Good Muon identification Large mass Good Charge identification Good Hadron background rejection Low Cost

7. 7 The MONOLITH Detector Large mass ~ 35 kton Magnetized Fe spectrometer B = 1.3 Tesla (toroidal) Space resolution ~ 1 cm (3cm pitch in x and y) Time resolution ~ 1 ns (for up/down discrimination) Momentum resolution (  p/p) ~ 20% from track curvature for outgoing muons ~ 6% from range for stopping muons Hadron E resolution (  E h /E h ) ~ 90%/  E h  30% 30 m 13.1 m 14.5 m 8 cm 2.2 cm Fe B B Glass Spark Counters (RPC’s with glass electrodes beam

8. 8 The Large Magnetic Detector  Geant3 simulation:  Multiple scattering and energy loss  Decays  Nuclear interactions  Full reconstruction is not practical since one has to simulate ~10 7 events for each setting  Smearing according to the MINOS proposal Conceptual design Simulation iron (4 cm) scintillators (1cm) beam 20 m 10 m B=1 T 1cm transverse resolution

9. 9 Challenges Good Muon identification Large mass Good Charge identification Good Hadron background rejection Low Cost

10. 10 Massive detector 30 m 5.4 KT 40 KT fully operational since July 2003 MINOS

11. 11 Challenges Good Muon identification Large mass Good Charge identification Good Hadron backgrounds rejection Low Cost

12. 12 Muon identification  At these energies, muons can be easily identified by range Length traveled by the longest pion/kaon Length versus muon momentumLMD stored 50 GeV/c  +

13. 13 Challenges Good Muon identification Large mass Good Charge identification Good Hadron backgrounds rejection Low Cost

14. 14 Charge in Monolith Selection cuts: P  (from range) > 7.5 GeV In each region: At least 4 points Track length > 300 cm Same charge assigned in each region Fractional bkg. 1 x 10 -6 Efficiency35% top view side viewMonolith Multiple scattering and Energy loss Kalman filter fit

15. 15 Charge in LMD transverseresolution distancebetweenplanes percentage of lost hits 25cm 15 5 20% 1% 2 cm 0.5 cm 100 10 40 50% efficiencyLMD Multiple scattering and Energy loss Kalman filter fit parallel-8cm normal-15cm LMD Monolith Conclusion: 10 -6 effect charge misidentification bkg

16. 16 Challenges Good Muon identification Large mass Good Charge identification Good Hadron backgrounds rejection Low Cost

17. 17 Hadronic backgrounds  Kinematic analysis p ,  had,  had  MC reconstructed variables : p ,  had,  had  Variables used in the analysis PP hadron-jet   LMD P  Q t =P  sin 2   Philosophy  “Real” wrong sign muons are harder  And are more isolated from the hadronic jet

18. 18 Hadronic angular resolution Hadronic angular resolution Minos/LMD parallel-8cm parallel-4cm normal-8cm B B beam normal-10cm normal-5cm Iron (5cm) + RPC (2cm) Monte Carlo Data (Test Beam) (Monolith proposal)Monolith

19. 19  CC interactions  CC interactions not detectedLMD

20. 20 e CC interactions e CC interactions Assuming no electron id identified as pion or not detectedLMD

21. 21 (   e ) NC  interactions LMD

22. 22 Sensitivity to   Sensitivity to   BaselineP cutQ t cut signal eff  CC (x10 -7 ) e CC (x10 -7 ) (   e ) NC (x10 -7 ) surviving signal & background 7325.01.40.2411125000 50 35005.00.70.455412330000 10 73005.00.60.52741308000 2LMD 10 21 useful 50 GeV/c  + decays 732 Km 3500 Km

23. 23 Challenges Good Muon identification Large mass Good Charge identification Good Hadron backgrounds rejection Low Cost

24. 24 Naive Cost estimate cost ~ 5-10 x MINOS 30 m known technology working detector scintillator module extruded polystyrene scintillator multi-pixel PMTs

25. 25 CONCLUSIONS Challenges Good muon identification Large mass Good charge identification Good hadron backgrounds rejection Reasonable Cost Anselmo Cervera Villanueva University of Geneva (Switzerland)