THESE` Pour obtenir le grade de DOCTEUR DE L’UNIVERSITE´ DE GRENOBLE Specialit´ e´ : Physique Theorique´ Arretˆ e´ ministeriel´ : 7 aoutˆ 2006 Present´ ee´ par Jonathan DA SILVA These` dirigee´ par Genevieve` BELANGER´ prepar´ ee´ au sein du Laboratoire d’Annecy-le-Vieux de Physique Theorique´ (LAPTh) et de l’Ecole´ Doctorale de Physique de Grenoble Supersymmetric Dark Matter candidates in light of constraints from collider and astroparticle observables These` soutenue publiquement le 3 juillet 2013, devant le jury compose´ de : arXiv:1312.0257v1 [hep-ph] 1 Dec 2013 Dr. Rohini GODBOLE Professeur, CHEP Bangalore, Inde, Presidente´ Dr. Farvah Nazila MAHMOUDI Maˆıtre de Conferences,´ LPC Clermont, Rapporteur Dr. Ulrich ELLWANGER Professeur, LPT Orsay, Rapporteur Dr. Celine´ BŒHM Charge´ de recherche, Durham University, Royaume-Uni, Examinatrice Dr. Anupam MAZUMDAR Professeur, Lancaster University, Royaume-Uni, Examinateur Dr. Genevieve` BELANGER´ Directeur de Recherche, LAPTh, Directeur de these` A meus av´os. Contents Acknowledgements - Remerciements vii List of Figures xi List of Tables xvii List of Abbreviations xix List of Publications xxiii Introduction1 I Status of particle physics and cosmology ... and beyond5 1 From the infinitely small : the Standard Model of particle physics ...7 1.1 Building of the model : gauge sector . .8 1.2 Matter sector . 10 1.2.1 Leptons . 10 1.2.2 Quarks . 12 1.3 The Higgs mechanism . 13 1.4 Full standard picture . 16 1.5 Successes of the SM . 18 1.6 SM issues . 19 1.6.1 Theoretical problems . 19 1.6.2 Experimental discrepancies . 20 1.6.3 Cosmological connexion . 22 2 ... To the infinitely large : the Lambda Cold Dark Matter model 23 2.1 Theoretical framework . 24 2.1.1 Cosmological principle and its consequences . 24 2.1.2 Cosmological parameters . 26 2.2 Cosmological observations . 27 2.2.1 Methods . 27 2.2.2 Success of the ΛCDM model . 27 i 2.3 Dark Matter . 29 2.3.1 DM evidences . 30 2.3.2 Equilibrium . 31 2.3.3 Freeze-out . 34 2.3.4 Precise calculation . 34 2.4 Cosmic inflation . 35 2.4.1 Cosmological puzzles . 35 2.4.2 Inflationary Universe . 36 2.4.3 Cosmological perturbations and constraints . 37 2.5 Thermal history of the Universe in the ΛCDM model . 38 2.6 ΛCDM drawbacks . 39 2.7 Some solutions to the ΛCDM and SM issues . 40 3 Supersymmetry 43 3.1 SUSY responses to SM problems . 44 3.2 Elements on the theoretical construction of exact SUSY . 45 3.2.1 Super-Poincar´ealgebra . 46 3.2.2 Chiral supermultiplet . 48 3.2.3 Gauge supermultiplet . 49 3.3 SUSY breaking . 50 3.4 The Minimal Supersymmetric Standard Model . 51 3.4.1 Lagrangian at low energy . 51 3.4.2 Higgs sector . 53 3.4.3 Sfermion sector . 54 3.4.4 Gaugino and higgsino sector . 55 3.4.4.1 Gluinos and charginos . 55 3.4.4.2 Neutralinos . 55 3.5 Constraints on SUSY . 56 3.5.1 Cosmological and astroparticle constraints . 57 3.5.1.1 DM Direct Detection . 57 3.5.1.2 DM Indirect Detection . 59 3.5.2 Collider constraints . 60 3.5.2.1 Bounds on supersymmetric particles . 60 3.5.2.2 Low energy observables . 61 II Neutralino Dark Matter in the (N)MSSM 63 4 Unification with non-universal Higgs masses and the supersymmetric inflaton 65 4.1 Introduction . 66 4.2 Gravity-mediation of SUSY breaking . 66 4.2.1 The NUHM2 model . 67 4.2.2 Benchmark points with neutralino DM in the NUHM2 . 67 ii 4.2.3 A broader scan of the parameter space . 70 4.2.3.1 A Markov Chain Monte Carlo inspired algorithm . 70 4.2.3.2 Characteristics of the scan . 72 4.2.3.3 Results . 73 4.3 Supersymmetric inflaton . 78 4.3.1 Inflaton candidates : flat directions of squarks and sleptons . 79 4.3.2 Gaussian fluctuations and tensor to scalar ratio . 82 4.3.3 Renormalization Group Equations . 83 4.3.4 Indirect detection of the inflaton at LHC . 84 4.3.4.1 Inflaton mass for benchmark points . 85 4.3.4.2 LHC predictions and Inflaton mass . 85 4.4 Conclusions . 87 5 The phenomenological MSSM confronting Indirect Detection of Dark Matter 89 5.1 Introduction . 90 + 5.2 Anti-proton and γ-ray bounds on σDM DM ! W W − ............ 91 + 5.2.1 Generic bounds on σDM DM ! W W − fromp ¯ ............ 91 + 5.2.2 Generic bounds on σDM DM ! W W − from gamma-rays . 95 5.2.2.1 Continuum . 95 5.2.2.2 Internal bremsstrahlung and final state radiation . 95 5.2.2.3 Line(s) . 96 5.3 Chargino-neutralino mass degeneracy . 96 5.3.1 Neutralino pair annihilations into W +W − ............. 96 5.3.2 Exploring the supersymmetric parameter space . 97 5.4 Results . 99 5.4.1 Bounds on the NLSP-LSP mass splitting . 99 5.4.2 Final state radiation in the pMSSM . 105 5.4.3 130 GeV line . 106 5.4.4 The case of no DM regeneration . 107 5.5 Conclusions . 108 6 Direct SUSY searches at LHC and a singlet extension of the MSSM 111 6.1 Going beyond the minimal supersymmetric scenario . 112 6.1.1 The µ-problem ............................ 112 6.1.2 MSSM limitations . 112 6.1.3 The Next-to-MSSM . 113 6.2 Previous scans on the NMSSM parameter space . 114 6.3 Squarks and gluinos searches at the LHC . 115 6.3.1 Relevant NMSSM region in light of ATLAS jets + ET searches . 116 6.3.2 Light squark masses . 116 6.4 Higgs boson signal strength with light LSP . 119 6.5 The case of heavy LSP . 122 6.6 Conclusions . 123 iii III U(1) extensions of the MSSM 125 7 The UMSSM 127 7.1 Another solution to the µ-problem ...................... 128 7.2 An E6 inspired model . 128 7.3 Description of the UMSSM . 129 7.3.1 Gauge bosons . 131 7.3.2 Higgs sector . 133 7.3.3 Sfermions . 136 7.3.4 Neutralinos . 137 7.4 Constraints on the UMSSM . 137 7.4.1 Collider constraints on the Z0 .................... 137 7.4.2 Other constraints on Z0 physics . 139 8 The Right-Handed sneutrino as thermal Dark Matter in the UMSSM141 8.1 Introduction . 142 8.2 Constraints imposed . 144 8.3 Relic abundance of sneutrinos . 145 8.4 Direct Detection . 147 8.5 Results . 149 8.5.1 The case of the U(1) model . 149 8.5.1.1 A case study with MZ2 = 1:6 TeV . 149 8.5.1.2 Exploration of U(1) parameter space . 152 8.5.2 The case of the U(1)η model . 154 8.5.2.1 A case study with MZ2 = 1:6 TeV . 155 8.5.2.2 Exploration of U(1)η parameter space . 156 8.5.3 A global scan of the parameter space . 158 8.6 Conclusions . 160 9 The Higgs sector and low energy observables in the UMSSM 163 9.1 The Higgs sector in the UMSSM . 164 9.1.1 Radiative corrections through an effective potential . 164 9.1.2 Higgs bosons signal strengths in the UMSSM . 166 9.2 Flavour constraints on the UMSSM . 169 9.2.1 B(B± τ ±ν )............................ 169 ! τ 9.2.2 B(B0 µ+µ−)............................ 171 s ! 9.2.3 ∆Ms and ∆Md ............................ 173 9.2.4 B(B¯0 X γ)............................. 175 ! s 9.2.5 B(B¯0 X µ+µ−).......................... 178 ! s 9.3 The anomalous magnetic moment of the muon in the UMSSM . 179 9.3.1 Standard prediction . ..