9 Strangelets from Centauro Decay 5.2 < < 6.5Expected at LHC:Energy densities up to є ~ 25 GeV/fm3∆ystop ~HIJING,VENUS∆ystop ~ 2.3BRAHMS-RHIC several to ~ 25% strangelets with energies E > 7 TeV, sufficiently high to be detected.T = 350 MeVT = 300 MeVT = 250 MeV∆ystop ~ 2 – 3.5
10 Stable Strangelet interaction in CASTOR MC-algorithm Strangelet is considered with radius:Mean interaction path:Strangelets passing through the detector collide with W nuclei:Spectator part is continuing its passage.Wounded part produces particles in a standard way.Particles produced in successive interactions initiate electromagnetic-nuclear cascades.Process ends when strangelet is destroyed.E. Farhi, R. Jaffe, Phys.Rev.D30(1984)2379; M. Berger, R. Jaffe, Phys.Rev.C 35(1987)213, G.Wilky, Z.Wlodarczyk, J.Phys.G22(1996)L105; E. Gładysz, Z. Włodarczyk, J.Phys.G23(1997)2057The rescaled r0 is determined by the number density of thestrange matter: n = A/V = (1/3)(nu+nd+ns)where ni=- ∂Ωi/∂μi; Ω(mi,μi,αs), taking into account the QCD O(αs) corrections to the properties of SQM.sss
11 Unstable Strangelet in Pb chamber MC Simulation 7 Neutrons
12 Comparison Data with Simulation Similarity between the experimental data (squares) and simulated cascades produced by a bundle of seven neutrons (full histogram).Distribution of mutual distance between the consecutive maxima;Distribution of ratios of the energy contained in the particular maxima to the average energy of the humps.
13 MC - Stable Strangelet in CASTOR HIJINGCASTOR Geometry configuration1 layer: 5mm W+2mm quartz plate ~2.4 X01 RU = 7 layers per readout unit16 (in x 18 (in z) readout channelsTotal depth: ~ 10.5 ΛintLow Energy Strangelets (~5 TeV)may be seen above background.DepthHIJINGDepth
14 Stable Strangelet in CASTOR A=15, E=7.5 TeV60 pions, 1TeV eachA=10, E=5 TeV
15 Full CASTOR Calorimeter Segmentation: 14(depth) x 16(azimuth) = 224 channelsStage IIStage I
16 HIJING Pb+Pb Event at √s = 5.5 TeV ηGeVEtot ~ 130 TeV ~ 8 TeV/sectorN < 100/sector230906CMS-HI/ Apostolos D. PanagiotouηGeV
17 Fluctuations in Cascade Profile in Sectors Calorimeter Depth (RUs) HIJINGEnergy230906CMS-HI/ Apostolos D. PanagiotouCalorimeter Depth (RUs)
18 Fluctuations in Energy Distribution in Sectors HIJING12En. Distribution in sector / Average En. Distribution1516230906CMS-HI/ Apostolos D. Panagiotou
19 Strangelet identification & Analysis Event-by-event analysisAnalysis procedure in 2 steps:Strangelet signaturesAzimuthal asymmetryin energy depositionFluctuationsLongitudinaltransition curvesσsd = standard deviation of the distribution of the energies Ei<E> = mean energy in sectors(i = 1 – 16 sectors)energy distribution per RUaverage distributionLarge magnitude of energyfluctuations in RUs manifestabnormal transition curves
20 Analysis of HIJING Event Need to analyze 104 events
21 Energy distributions in CASTOR HIJINGStrangelet in one sectorTotal Energy in SectorsEnergy in RUsTotal Energy in SectorsEnergy in RUsAverage of 16 SectorsA = E = 7.5 TeV<E>Energy(Depth)RUSector(Depth)RUSector
25 Strangelet in between two Sectors Energy Distribution in Sectors Estr = 7.5 TeVSectors with Strangelet~ 14% with Ei/Ej = 50/50 – 75/25
26 Strangelet in between two Sectors Transition Curves Estr = 7.5 TeVHIJING + Strangelet<HIJING><HIJING>DepthDepth
27 Analysis with Strangelet in two Sectors Sectors with StrangeletEM-cut
28 Strangelets of various Energies 7.5 TeV10 TeVStrangelets of various Energies15 TeVEM-cut
29 CMS-HI/ Apostolos D. Panagiotou Comparison of Observed and Input MC Strangelet Efficiency of IdentificationObserved Strangelet ≡ Average Energy distribution of mixed event – Energy distribution in sector containing StrangeletEobs ~ 97%230906CMS-HI/ Apostolos D. Panagiotou
30 Cross Section Estimation for Strangelets The probability for a hadron-rich ‘Centauro-type’ event, estimated from statistics of Chacaltaya and Pamir experiments for cosmic ray families with visible energy greater than 100 TeV, is about 3%.In about 10% of these hadron-rich events, strongly penetrating cascades, clusters, or ”halo” were observed. We assume the total probability for “Long Flying Component” (Strangelet?) production in central nucleus-nucleus collisions to be approximately: 0.03 x 0.1 ~ O(10−3).At LHC kinematics, the percent of Strangelets falling in CASTOR phase space is ~ 10% of total number of Strangelets produced in central Pb-Pb collisions. This quantity depends on the mass and energy of the Strangelet, as calculated by the “Centauro model” MC code CENGEN.A rough estimation of the total probability for Strangelet production and detection in CASTOR is:PCASTOR strangelet ≈ 10−3 × 0.1 ≈ O(10−4)This number, even if it is uncertain by an order of magnitude down, is a very large number !
31 Summary Characteristics of a “Strangelet event”: 1. Sector(s) with much higher energy than the average.Strong fluctuations in the longitudinal cascade profile of the sector.Large Ehad/Eem for the event (Hadron-rich event).
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