Mohamad-Ziad Charif - Antares

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Figure 2.5: Combination of the WMAP, type Ia supernova, X-ray band, and clustermeasurement for Ω Λ and Ω m .• Hot dark matter, which has relativistic velocities. One candidate for hotdark matter are neutrinos. However, neutrinos are already disfavored asa candidate[21] as their contribution to the matter density is bound to beΩ neutrino < 0.014 much smaller than the expected density of matter in theUniverse. In addition simulations of the large scale structures formation ofthe universe does not favor hot dark matter[26].• Warm dark matter, with the mass being from 300 eV to 3000 eV. However,with extensive searches in colliders (proton and electron) no particle hasever been found in this mass range. Main candidate for warm dark matter isa sterile neutrino.• Cold dark matter, which has non-relativistic velocities (< 1000 km/s) is favoredby simulations of the large scale structures formation of the universe[26].The lower bound mass of cold dark matter is above 1 GeV. The main candidatesfor CDM are the WIMP or Weakly Interacting Massive Particle, andaxions which are theoretical solutions to the strong CP problem in QCD.The most favored model of dark matter is the Weakly Interacting Massive Particle,which we will discuss in the next section.12
2.2 WIMPs2.2.1 Standard ScenarioThe standard view of WIMPs is that it is an electrically neutral particle that itsexistence can not be inferred by direct electromagnetic radiations, and since wealready established it can not be a baryonic then it should be colorless (no stronginteraction). In addition, this particle has to be stable or at least if it is not then itshalf-life should be extremely long (at least the current age of the Universe). Unfortunatelythese characteristics do not apply to any known particle in the StandardModel of particle physics. Several extensions of this model offer candidates toWIMPs such as the lightest SuperSymmetric particle (LSP) in Supersymmetry(section 2.2.2), in addition to the lightest Kaluza-Klein particle (LKP) in UniversalExtra Dimension[27, 28] models.The main attraction for WIMPs as a candidate for cold dark matter comes fromthe fact that if we try to calculate the WIMPs annihilation cross-section in orderto get the same order of magnitude of the density we have now Ω c (t 0 ) = 0.227we would get a cross section similar to that of the weak force (eq 2.9), the orderof magnitude of a weak cross-section 10 −9 GeV −2 (∼ ( gM W) 4 ) where g couplingconstant of the weak interaction and M W is the W boson mass. M WIMP is the massof the WIMP, N WIMP (t 0 ) is the number of WIMP particles at the present time.Ω WIMP (t 0 ) = M WIMP.N WIMP (t 0 )ρ c (t o )≃10−10 GeV −2< σv >(2.9)(2.10)Equation 2.9 is obtained by first deriving the number of WIMP particles as afunction of time. Standard scenario of WIMPs puts them in thermal equilibriumwith other particles, after their creation in the early Universe. After the Universecools down by expanding, the temperature drops below the WIMP mass haltingtheir creation and resulting in an rapid decrease of their abundance. Eventuallythe thermal equilibrium of WIMPs can not be maintained as the expansion of theUniverse reaches a point where it is larger than the WIMP rate of annihilation,consequently this results in a relic WIMP density that can account for the valuewe have now. This evolution can be described using Boltzmann equation shown inequation 2.11, where H is the Hubble parameter, N WIMP is the number of WIMPsas a function of time and N eqWIMPis the number of WIMPs at thermal equilibrium,and < σv > is the thermally averaged annihilation cross-section of WIMPs multipliedby its velocity.dN WIMPdt+ 3H.N WIMP = < σv > [(N eqWIMP )2 − N 2 WIMP] (2.11)13
Page 2 and 3: "The most exciting phrase to hear i
Page 4 and 5: 3.2.1.4 Performance and characteris
Page 6 and 7: Chapter 1IntroductionThe early hist
Page 8 and 9: Chapter 2Dark MatterIn this chapter
Page 10 and 11: Figure 2.2: Comparison of the measu
Page 12 and 13: Figure 2.4: CMB anisotropy observed
Page 17: Figure 2.6: Temporal evolution of t
Page 20 and 21: Figure 2.9: Parameter space of m 1/
Page 22 and 23: Figure 2.10: Limits on spin-indepen
Page 26 and 27: Figure 2.14: Detected gamma ray flu
Page 28 and 29: 600km/s. If we assume the worst cas
Page 30 and 31: Figure 2.17: Conversion factor from
Page 32 and 33: The eigenstate mixing can be writte
Page 34 and 35: Figure 2.19: Flux of ν µ / ¯ν
Page 36 and 37: Figure 3.1: The neutral current (NC
Page 38 and 39: Muon Energy (GeV )1p| dEdx | (GeV.c
Page 40 and 41: Figure 3.4: Energy loss of per dist
Page 42 and 43: Figure 3.6: Effective muon range as
Page 44 and 45: Figure 3.8: Differential flux of at
Page 46 and 47: 3.2.1.1 Detector layoutOptical Modu
Page 48 and 49: • The LED (light emitting diode)
Page 50 and 51: Anchor & BuoyEach line is anchored
Page 52 and 53: Figure 3.17: Distribution of azimut
Page 54 and 55: Figure 3.20: Height and radial disp
Page 56 and 57: Figure 3.22: Distribution of sea cu
Page 58 and 59: Figure 3.24: Time offset among OMs
Page 60 and 61: Figure 3.26: Distribution of time d
Page 62 and 63: Line number Connection Date Mainten
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Figure 3.29: Comparison between sky
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Figure 3.31: The effective area for
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Figure 4.1: Median counting rate of
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Figure 4.4: Average neutrino events
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2. All hits on the same floor are m
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4.2.1 Neutrino simulationFigure 4.6
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• Multiplicity range of the muon
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Chapter 5Dark Matter search in the
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Figure 5.2: Annihilation spectrum f
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Livetime(days) 5 Lines 9 Lines 10 L
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Figure 5.4: Monte Carlo Truth distr
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Figure 5.7: Tchi2 distribution for
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Figure 5.9: Tchi2 distribution for
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Figure 5.11: Sun’s position taken
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Figure 5.13: Comparison between the
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Figure 5.15: Estimation of the back
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Figure 5.16: Mean angle between the
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Figure 5.18: A comparison of the di
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a look at figure 5.22 we find a cle
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The resulting optimized sensitiviti
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Figure 5.26: A comparison plot of t
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dΦ µdE ν= dΦ νdE νP earth ρN
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Figure 5.31: Limits on the muon flu
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Chapter 6Dark Matter search in the
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Figure 6.1: . True Position of the
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Figure 6.3: Comparison of the three
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For BBFit all variables mentioned i
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Figure 6.6: The distribution of χ
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annihilation channel W + W − the
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lowering the total contribution of
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6.4.2 BBFit Single-line analysisThe
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Figure 6.15: Comparison between the
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Figure 6.17: Comparison of Nhit dis
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Figure 6.19: The estimation of the
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Figure 6.21: Comparison of the opti
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Figure 6.23: Comparison of sensitiv
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Figure 6.25: Estimation of our back
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Figure 6.28: Comparison of the mult
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Figure 6.29: Comparison of the Λ d
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Figure 6.31: Comparison of the cos(
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Figure 6.34: Comparison of the esti
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The optimal Λ cut for all dark mat
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Figure 6.40: Sensitivity to neutrin
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6.7 Comparison with 2007-2008 analy
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mass of 200 GeV and a cross-section
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Chapter 7ConclusionsThe limits pres
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Bibliography[1] Volders, L. M. J. S
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[22] S. Burles et al., “Big bang
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[46] G. Debrassi, S. Heinemeyer, W.
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[74] C. Hettlage, K. Mannheim, and
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[102] D. Heck and J. Knapp, “Fors
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Mohamad-Ziad Charif - Antares

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