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CASTOR Centauro And Strange Object Research

Strangelet hunt at CMS Panos Katsas University of Athens, Nuclear & Particle Physics Department for the CASTOR collaboration Adana, Athens, Krakow, Demokritos, INR, Ioannina, MSU, Northeastern COSMIC QCD II, Skopelos, 25/09-1/10 2005. CASTOR Centauro And Strange Object Research. Outline.

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CASTOR Centauro And Strange Object Research

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  1. Strangelet hunt at CMS Panos Katsas University of Athens, Nuclear & Particle Physics Department for the CASTOR collaboration Adana, Athens, Krakow, Demokritos, INR, Ioannina, MSU, Northeastern COSMIC QCD II, Skopelos, 25/09-1/10 2005 CASTORCentauro And Strange Object Research

  2. Outline • CASTOR detector description • Motivation & Physics • Experimental data & model description of strangelets • Monte Carlo results (CNGEN, HIJING) • Simulations results & CASTOR • Strangelet analysis • Summary

  3. CASTOR CALORIMETER CONCEPTUAL DESIGN - Cerenkov light is generated inside the quartz plates as they are traversed by the fast charged particles in the shower (shower core detector) developing in tungsten absorber - Azimuthal and longitudinal sampling sufficient for a study of structures in longitudinal development of cascades - High depth for detection of strongly penetrating objects • EM = 2RU (~ 28 X0) HAD = 16 RU (~10 ΛI ) RU ~ 7 Sampling U ~ .544 ΛI ~ 14 X0 (16 azimuthal sectors)

  4. Detectors near beamline: Forward Physics in p+p, p+A, A+A • Hermetic coverage up to |h| ~ 6.6 • Zero degree neutral energy • Physics: Centrality, Low-x, Limiting fragmentation, Strangelets, DCC ZDC @ 140 m CASTOR

  5. CMS Very-Forward Region T2 Tracker 5.32 << 6.71 CASTOR 5.31 << 6.84 Inner radius ~ 38 mm Outer radius ~ 135 mm active Outer radius ~ 280 mm total Option 2 (preferred) HF 3 << 5.3

  6. H CASTOR A L EM - PROTOTYPE W-PLATES + Q-FIBRE / PLATES ~ 20 Xo

  7. CASTOR PROTO BEAM TEST 2003

  8. 5mm W + 2mm Q H Octant 3mm W + 1.5mm Q EM Semi-Octant CASTOR PROTO II

  9. CASTOR PROTO II 4(6)-APDs 4-APDs 4-APDs 4-APDs 4-APDs APDsPMT

  10. 2004 Test – Beam Results

  11. STRONGLY PENETRATING COMPONENT: cascades, clusters, halos, frequently accompanying hadron-rich events Review: E.G.-D. Phys. Part. Nucl34(2003)285 CENTAURO RELATED PHENOMENAat MtChacaltaya (5200 m) and Pamir (4300 m) CENTAURO SPECIES: Abnormal hadron dominance (in N and E), high pT, low multiplicity • CENTAUROS of original type (5 “classical” Chacaltaya + over a dozen others) Nh ~ 100, PT ~ 1.75 GeV/c • MINI-CENTAUROS • CHIRONS

  12. First observation: Krakow group,17th ICRC, 1981 2 exotic cascades in Centauro-like event Other events Arisawa et al.,Nucl. Phys. B424(1994)241 STRONGLY PENETRATING CASCADES in Pb CHAMBERSSTRANGELETS? End of usual hadronic cascade ~1.5 Λint 60 cm Pb~3.6 Λ int Cascades pass through the chamber practically without attenuation and revealed many-maxima character with small distances between humps

  13. (Strangelet ??) Hadron 1.5 λI 3.6 λI Long penetrating hadronic component in CR events 3.6 λI 3.2 λI Hadron

  14. Estimated for LHC Centauros: • Energy density ε ~ 3 - 25 GeV/fm 3, • Temperature T ~ 130 - 300 MeV • Baryon chemical potential µb ~ 0.9 - 1.8 GeV/fm3 Possible STRANGELET FORMATION CNGEN Centauro generator + Strangelet formation

  15. Stablestrangelet interaction in CASTORMC-algorithm Code implemented in CMS environment Strangelet is considered with radius: Mean interaction path: Passing through the detector strangelets collide with W nuclei: Spectator part is continuing a passage; Wounded part produces particles in a standard way. Particles produced in successive interaction points initiate a development of electromagnetic-nuclear cascades. Process ends when strangelet is destroyed. E. Gładysz, Z. Włodarczyk, J. Phys. G23(1997)2057

  16. MULTIPLICITY in CASTOR’s acceptance CENTAUROHIJING Low multiplicity High multiplicity mostly baryons + kaons dominated by pions Simulations with CNGEN (S. . Sadovsky et al..,Phys. Atom. Nucl. 67(2004)396 ) 5.3 < < 6.8 N = 2300 N = 58

  17. Probability of CENTAURO and STRANGELET detection T=300 MeV CASTOR • ~70 % of Centauro fireball decay products and substantial part of created strangelets are within CASTOR’s acceptance • Even very high energy strangelets (E ~ 30 TeV) are expected to be produced 5.3 << 6.8 Ewa Gladysz

  18. Probability of CENTAURO and STRANGELET detection T=250 MeV CASTOR • ~65 % of Centauro fireball decay products and substantial part of strangelets are within CASTOR’s acceptance • Even very high energy strangelets (E ~ 20 TeV) are expected to beproduced 5.3 <  < 6.8

  19. Simulation results& CASTOR

  20. HIJING Pb + Pb Event (background) E ~ 130 TeV ~ 8 TeV/sector <N> ~ 100/sector CASTOR CASTOR

  21. Energy distribution in CASTOR Energy in sectors Energy in RU’s Energy in sectors Energy in RU’s HIJING Strangelet in one sector

  22. Strangelet simulations in the CMS environment (OSCAR) Geometry configuration: 1 layer: 5 mm W + 2 mm quartz plate ~2.37 X0 1 SU = 7 layers per readout unit 16 (in  x 18 (in z) readout channels Total depth: ~300 X0, 10.5 Λint EVEN LOW ENERGY STRANGELETS (~5 TeV) ARE APPARENTLY SEEN ABOVE THE BACKGROUND ! 300 X0

  23. Strangelet identification & Analysis Strangelet signatures Azimuthal asymmetry In energy deposition Longitudinal transition curves energy distribution per RU average distribution Large magnitude of fluctuations manifest abnormal transition curves • Event-by-event analysis • Analysis procedure in 2 steps:

  24. HIJING + strangelet HIJING+strangelet 1 2 3 4 5 6 7 8 9 10 11 12 HIJING 16 13 14 15 Transition curves & fluctuations

  25. Sector containing strangelet Fluctuations in energy distribution RU’s

  26. Analysis results: I Estr = 10 TeV Estr = 7,5 TeV sector containing strangelet EM+H section EM-cut only H-section

  27. Two Stage Construction & Implimentation STAGE I STAGE II

  28. STAGE I STAGE II

  29. Reducing the number of RU’s 16x18 channels 16x9 channels

  30. Conclusions • CASTOR is the experimental tool for strangelets • Strangelet detection through measurement of: • extreme imbalance between the hadronic and electromagnetic component (multiplicity & energy) • non-uniform azimuthal energy deposition • penetrating objects beyond the range of normal hadrons, abnormal longitudinal energy deposition pattern

  31. Observed: Energy ~ 231 TeV 7 cascades in upper chamber 43 cascades in lower chamber Lattes,Fujimoto, Hasegawa, Phys. Rep. 65, 151 (1980) CENTAURO I Ohsawa, Shibuya, Tamada, Phys.Rev.D70,074028(2004)

  32. Energy in CASTOR reading channels Continuous numbering schemes: 16 x 18 = 256 channels ID2 ID1 ID1 ID2 HIJING Strangelet

  33. Analysis results: II ~ 14% of strangelets deposit their energy in two sectors Estr = 7,5 TeV Sectors with strangelet Strangelet in two sectors Ε1 ~ 3.3TeV E2 ~ 4 TeV

  34. A=15, E=7.5 TeV A=10, E=5 TeV 60 pions, 1TeV each

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