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

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

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 Λ I ) RU ~ 7 Sampling U ~ .544 Λ I ~ 14 X0 (16 azimuthal sectors)

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

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

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

CASTOR PROTO BEAM TEST 2003

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

CASTOR PROTO II 4(6)-APDs 4-APDs 4-APDs 4-APDs 4-APDs APDs PMT

2004 Test – Beam Results

cascades, clusters, halos, frequently accompanying hadron- rich events CENTAURO RELATED PHENOMENA at Mt Chacaltaya (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 STRONGLY PENETRATING COMPONENT: cascades, clusters, halos, frequently accompanying hadron- rich events Review: E.G.-D. Phys. Part. Nucl34(2003)285

STRONGLY PENETRATING CASCADES in Pb CHAMBERS STRANGELETS? First observation: Krakow group,17th ICRC, 1981 2 exotic cascades in Centauro-like event Other events Arisawa et al.,Nucl. Phys. B424(1994)241 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

(Strangelet ??) Long penetrating hadronic component in CR events

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

Stable strangelet interaction in CASTOR MC-algorithm 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 Code implemented in CMS environment

MULTIPLICITY in CASTOR’s acceptance CENTAURO HIJING 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

Probability of CENTAURO and STRANGELET detection T=300 MeV 5.3 << 6.8 CASTOR Ewa Gladysz ~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

Probability of CENTAURO and STRANGELET detection T=250 MeV 5.3 <  < 6.8 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

Simulation results & CASTOR

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

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

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

Results for finer sampling of the geometry 12 TeV 9 TeV

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

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

Fluctuations in energy distribution RU’s Sector containing strangelet

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

Two Stage Construction & Implimentation STAGE I STAGE II

STAGE I STAGE II

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

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

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

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

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

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