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Physics at the LHC Abdelhak Djouadi and Dirk Zerwas LPT and LAL Orsay Monday: The standard model I LHC and the Detectors Tuesday: The standard model II (theory) The Top Quark (exp) Wednesday The Higgs Boson (theory) The Higgs Boson (exp) Thursday Higgs+SUSY (theory) Higgs+SUSY (exp) Friday Xtra Dimensions (theory) Exotics (exp) LAL Orsay Salle 101 LPT Amphi2, 210 LAL Orsay Salle 101 http://indico.lal.in2p3.fr/conferenceDisplay.py?confId=399
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Extended Symmetries Compositeness Little Higgs Extra Dimensions Exotics Fabienne Ledroit, LPSC Grenoble
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Monte Carlo Generators (incomplete) PYTHIA :Z’, W’, symmetry Left/Right, compositeness, technicolor, leptoquarks, graviton, (heavy leptons) PYTHIA-UED HERWIG : resonant graviton production, (heavy leptons) ISAJET : technicolor, graviton production (direct) CHARYBDIS : black holes CATFISH : black holes http://www.ippp.dur.ac.uk/montecarlo/BSM/
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Extended Symmetries, GUT new fermions Heavy charged leptons pp γ/Z/Z’ L + L -, L ± Zl ± Parameters : m(L), m(Z’), BR(L lZ) Background : tt, VV’+jets 300 fb -1 30 fb -1 Alexa 03
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Heavy neutrinos in the LR model SU(2) L xSU(2) R xU(1) B-L SU(2) L xU(1) Y Right-handed fermions in doublets N=n R heavy Majorana pp W R l,lN N lW pp Z R ll,NN Parameters : m(V R ), m(N), k=g R /g L Background : tt, VV’+jets Ferrari 00 m(N) m(Z’) accessible heavy quarks (E 6 ) pp D D ; D dZ, uW Parameters : m(D), quark mixing angles Mehdiyev 05 Integrated Lumi m(Z’)= 3 TeV M(N)= 1 TeV
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(l) new gauge bosons At least Z’, freuqently W’ (if SU(2)) Production : “Drell Yan” Decay : Z’ l + l -, qq W’ l, qq’ Parameters : boson mixing angles and/or coupling constant ratio Background : Drell Yan standard M T = invariant mass calculated from transverse momenta M(W’)= 1 TeV M(Z’)= 1.5 TeV
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new scalar and /or vector bosons: Lepto-Quarks Groups SU(4), SU(5), SO(10) ; squarks (RpV); … LQ lq q 2 types of final states : 2l + jets, l + jets + missing E T Parameters : m(LQ), Λ 2 eff = Λ 2 L (lq)+ Λ 2 R (lq)+ Λ 2 L ( q) 300 fb -1 Belyaev 05 new Higgs sector: doubly charged Higgs! qq q H T = scalar sum of p T eff
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Compositeness QCD + contact interaction 4 fermions Parameters : compositeness scale L, (sign of the interference) excited fermions quarks q* qg, qγ, qZ, q’W leptons l* lγ, lZ Final states llγ(γ), llj(j) Quark substructure ? Jet inclusive cross section 15 TeV 3 TeV 5 TeV 20 TeV QCD 10 TeV Difficulties: Jet definition, energy scale, QCD cross section, PDF, …
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Little Higgs Gauge sector [SU(2) U(1)] 2 Higgs standard Effective Model: treats the hierarchy problem enlarged symmetry, broken a large scale introduces a heavy top T (~1 TeV), heavy Higgs f (~10 TeV), heavy gauge bosons Z H,W H, A H (~1 TeV) Divergences cancel at first ordre Parameters : scale f, l 1 /l 2 (top Yukawa), v’ (Higgs coupling), q, q’ (gauge angles) q q Z H,W H Discovery Test of the model Z H l + l -, qq Z H Zh, W + W - W H l, qq’ W H W ± h, W ± Z
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++ W + W +, W Zt (25%), Wb (50%) T Zt (25%), Wb (50%) ht (25%) ht (25%) W + ++ W + q q T Wb Azuelos 04 5σ signal for M(T) < 2000 GeV Impossible to detect for the allowed parameters…
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Extra Dimensions String Theories : 10 (or 11) dimensions ! Only route today to include quantified gravity Gravitation experimentally ok to ~0.2 mm Extra Dimensions compactified on circles of radius R G’ ~ R n G Newton M Pl 2 ~ R n M D 2+n + graviton field periodical in the XD Kaluza Klein (KK) towers : M (k) ~k/R Some numbers : M D = 1 TeV, n = 2 R = 0.08 mm R -1 = 2.6 10 -3 eV LHC n = 4 R = 1600 fm R -1 = 120 keV Continuum of graviton states Gauge interactions verified up to ~1 fm gravity can propagate in the ‘bulk’ (XD), SM particles on the 3D-brane ADD Models/ large XD
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ADD : direct production of KK graviton Parameters : M D, n Background : jet + Z , jet +W l (l lost) 100 fb -1 Vacavant 01
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ADD : virtual KK graviton exchange Parameters : Cut at M S (=M D ) to avoid divergences Excess in distribution of dilepton, diphoton invariant mass, etc G KK Kabachenko 01 Combination of ll and γγ for 100 fb -1 Sensitivity attains M S = 7.4 TeV
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Suppose that the XD are small : ħc x 1 TeV -1 = 2 10 -4 fm << fm access to SM particles, in particular gauge bosons, in the bulk not excluded KK Excitations de KK of gauge bosons: (m (k) ) 2 = (m (0) ) 2 + k 2 M C 2 ≈ k 2 M C 2 excitations are more distant!! Indirect limits (EW contraints) from gauge coupling of gauge bosons R -1 ≥ 3.3 – 6.8 TeV TeV -1 : excitations de KK des bosons de jauge (Z KK,W KK ) Resonant production Z KK l + l - W KK l Observable up to M C ~ 6 TeV Also g KK tt, bb Excess in the distribution p T of di-jets due to the Gluon excitations Observable up to M C ~ 15 TeV Azuelos 04 4TeV Balasz 02
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Universal Extra Dimensions (UED) All fields in the bulk: conservation of momentum in the XD conservation of the number of KK in 4D pair production of KK states “Lightest Kaluza Klein Particle” (LKP): * !!! Cosmologie !!! Solution = gravity mediated decay : * G Co-existence of large XD with small XD possible : “thick brane” in a bulk of n large XD (“asymmetric compactification”) q° / ● = q (1) right/left ~ heavy Signal = 2 γ + X + missing energy
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The Randall Sundrum (RS) family of models 1 XD “left” or “warped” because metric non factorisable 5D-space delimited by 2 branes: Standard Model and Planck 2 parameters : r, curbature k -1, distance between branes r c ~ 1/M pl Same procedure as XD plates : o first, only the graviton propagates in the XD o then models appear where all Standard Model fields are in the bulk Randall Sundrum : thin width resonance of the graviton Signals : c= k/M Pl Radion : scalar field f stabilises the brane distance, f hh (thin width) Light b KK, final state with 4 W ( )
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Black holes at Colliders Objects confined in R<R S If impact parameter < R S, black hole production ! Cross section ~ p R S M D ~ TeV, cross section ~ 100 pb (lumi fb-1)!!! Decay : “democratic” (non-republican) all particles produced, incl. Higgs black hole factory = Higgs factory H bb CMS Attention : approximations contentious theory errors ++ also in the decay m H =130GeV W/Z M(bb)
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Summary Signatures : invariant masses, missing energy (cf SUSY), spectra in p T Final State ll, γγ Z’, Z KK, Z H (little Higgs), G (resonant+virtual), H ++ Final State ll + jets L ±, N, D (E 6 ), Lepto-Quarks, compositeness, “LFV”, technicolor Final State l (or γ or jet) + E T miss W’, G direct production Very high multiplicity (l, γ,jets,…) + sphericity Black Holes
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General Statement : heavy objects low production cross section very high energies or p T calibration of electrons, photons, jets identification of particles : b-jets, electrons, photons reconstruction of jet pairs no reference process… Difficult tasks, therefore fun !
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Search for ExtraDimensions Graviton Kopplung Randall Sundrum (RS): warped Extra Dimensions 1 additional dimension (kompactified) Search for Graviton resonance Decay: ee,μμ,γγ (mass rekonstruction) Arkani-Hamed, Dvali, Dimopoulos (ADD): n ExtraDim macroskopic (LED) Search for deviations from the Standard Model in Drell-Yan e.g. muon pairs ~3TeV CMS 7TeV 4.8TeV Theorie: Λ π = M pl e kL <10TeV, R: Radius kompakt Search for Gravitons: virtual effects: deviation from standard model real effects: Graviton emission with SM Particles (Jet+MET, DrellYan+MET) Graviton Resonance decay Gravitation connected with Particle Physics at the TeV Scale?
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Search for extra Gauge Bosons W’ Tevatron Limits: W’ SSM >965 GeV Z’ SSM >850 GeV Models with Z’: Sequential Standard Model (SSM) copy Z Left-Right Model (LRM,ALRM) SU(2) χ,ψ,η (E6 and/or SO(10)) U(1) M(W’)>4.6TeV
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