HIGGS&AT&HADRON&COLLIDER

Transcription

1 IGGS&AT&ADRON&COLLIDER iggs&proper,es&and&precision&tes& Lecure&1& Shahram&Rahalou Fisica&delle&Par,celle&Elemenari,&Anno&Accademico& hp://

2 WY&AND&WIC&BOSON? Is i saisically significan? use of p-value. Pu hreshold a 5σ Is i a boson? deermined by decay producs Which is he mass? o be sudied wih modes wih good resoluion, i.e. ZZ and γγ Is i he SM iggs boson? sudy compaibiliy of BR*σ in differen decay modes Is i a iggs boson? sudy he iggs couplings o differen paricles 76

3 MASS&OF&TE&NEW&BOSON CMS:#m#=#15.3#±#0.4#(sa)#±#0.5#(sys)#GeV# ATLAS:#m#=#16.0#±#0.4#(sa)#±#0.4#(sys)#GeV 77

4 COMPATIBILITY&WIT&STANDARD&MODEL Same sign dimuons Bes fi SM srengh CMS μ = σ/σsm = 1.00 ± 0.13 a 15 GeV ATLAS μ = σ/σsm = 1.30 ± 0.18 a 16 GeV Good agreemen among modes 78

5 IGGS&MASS&RUN&1&(014) ± 0.37 (sa) ± 0.18 (sys) GeV 79

6 IGGS&WIDT 71 [arxiv: , acceped by PLB] [arxiv: ] m ZZ ~ m m ZZ m ZZ WW m W, m Z, and m op hreshold effecs 80

7 ! Two channels exploied:! ZZ 4 " D: m 4 and gg vs. discriminan.! ZZ ν " Je-inclusive m T shape.! Observed limi lower han expeced. Obs. (exp.) 4 ν Combined Γ /Γ SM (95% CL) < 8.0 (.1) < 8.1 (.6) <

8 IGGS&SPIN BEFORE SELECTION AFTER SELECTION 8

9 ANGULAR&DISTRIBUTION&IN&DATA 83

10 Scalar couplingdeviaions framework IGGS&COUPLINGS 61 [arxiv: ]!! Single sae, spin 0, and CP-even. Narrow-widh approximaion: (σ BR) =σ Γ/Γ Scalar coupling srucure secor Gauge secor Z W τ Toal SM iggs cross secions a he LC γ c $(pp % + X) [pb] gg % (NNLO) &s = 14 TeV b NLO / NNLO g _ ' % W -1 % _ - -3 MRST V Quark gg/ % (NLO) % Z V 1 _ loop a.david@cern.ch W, Z _ Loops (γ, g) are sensiive o 84

11 IGGS&PRODUCTION&MODES (pp +X) [pb] -1 iggs Producion Modes 1 κ'for'm '='15.5'GeV' pp (NNLO+NNLL QCD + NLO EW) pp (NNLO QCD + NLO EW) pp W (NNLO QCD + NLO EW) pp Z (NNLO QCD + NLO EW) pp (NLO QCD) LC IGGS XS WG 013 g g! g!1. " 06! # 0.07"!! b "! b!! (b) V Gluon fusion process NNnLO ~O(%) ~0.5 M evens produced Vecor Boson Fusion NLO T uncerainy ~O(5%) Two forward jes and a large rapidiy gap ~40 k evens produced s [TeV] g g Top Assoc. Prod. (b) g b!! ~3 k evs produced W, Z!! V W, Z W and Z Associaed Producion NNLO T uncerainy ~O(5%) ~0 k evens produced g b!! b b W b W B-uark Assoc. Prod.!3.3"! W # 5.1"!! W +.8"! ~5 k evs produced 8' 85

12 IGGS&DECAY&CANNELS iggs Decay Channels - Dominan: bb (57%) - WW channel (%) - ττ channel (6.3%) - ZZ channel (3%)!! b /!!! W /!!! " /!!! Z /! iggs BR + Toal Uncer bb WW gg cc ZZ LC IGGS XS WG cc channel (3%) Exremely difficul - The γγ channel (0.%)!! c /!!! " /! -3-4 Z µµ M [GeV] W γ γ γ γ! "!1.6 "! W # 0.7"!! W + 0.1"! (when'assuming'no'bsm'charged'in'he'loop)' - The Zγ (0.%)! Z"!1.1 "! W # 0.15"!! W "! - The µµ channel (0.0%)!! µ /! 9' 86

13 FIRST&LOOK&AT&IGGS&COUPLINGS Couplings of he iggs o each paricle can be derived he more he channels, he beer he sensiiviy informaion in boh producion and decay modes full likelihood and correlaions needed Firs exercise: group couplings in fermionic and vecorial (CF, CV) Use LO predicion for loops in γγ and gg couplings In agreemen wih SM wihin 95% CL Some ension o be sudied wih more exclusive channels and daa 87

14 CONSTRAINTS&ON&IGGS&COUPLINGS 88

15 IGGS&COUPLING&AND&PRODUCTION Take ino accoun boh cross secion and branching fracion for each final sae 89

16 b W l b b ν W b 90

17 OW&MANY&IGGS&ARE&OUT&TERE? iggs double was inroduced o cure missing mass erm for vecor bosons Yukawa coupling o fermions, again added inenionally, cured origin of fermion mass owever no consrain on how many iggs double mus/can/should exis! 91

18 TWO&IGGS&DOUBLETS Two doubles wih opposie hypercharge d = ( 1 d d ) = ( 8 oal degrees of freedom Differen coupling o uarks for each double u o up uarks d o down uarks Slighly more complicaed iggs poenial V = Φ 0 1 Φ 1 ), u = ( 1 u u Y = 1 Y =+1 ) = ( ) Φ + Φ 0 ( ) ( ) ( ) ( ) L Yukawa = h ij u (ū i Ru j L u ū i Rd j L 1 u) h ij d ( d i Rd j L 1 d d i Ru j L d)+h.c. ( ( m d + µ ) i d i d + m u + µ ) i ( ( ) ( ) g + g ) [ i ( d i d )[ ] j u j u + 1 u i u m ud g i d i u, (ϵ ij i d j u +h.c. ) ϵ 1 = ϵ 1 =1and ϵ 11 = ϵ =0, 9

19 FIVE&IGGS&BOSONS! Afer EW symmery breaking, 3 scalars are absorbed by W and Z 5 remaining scalar degrees of freedom and wo vacuum expecaion value ) ( ) d = 1 ( vd 0 ), u = 1 ( 0 v u ) v v d + v u =4m W /g =(46GeV). an β v u v d Combinaion of remaining fields ( resuls in 5 physical scalars ) CP-odd CP-even ± = ± d sin β + ± u cos β A 0 = ) (Im 0 d sin β +Im0 u cos β h 0 = ( Re 0 d v d)sinα +( Re 0 u v u)cosα, 0 =( Re 0 d v d)cosα +( Re 0 u v u)sinα, Mixing angle α due o diagonalizaion of original u and d fields o obain physical mass 93

20 IGGS&MASS&IERARCY 5 mass erms + angles + coupling erms for each new iggs bu only wo independen variables consrains provided by supersymmery (will be discussed in nex lecure) Typically use m A and anβ o parameerize oher parameers m,h = 1 ( ) M m ± = m A + m W (m A + mz ± (m A + m Z ) 4m Z m A cos β For m A >> m Z h decouples from remaining for iggs bosons! Lowes iggs h will behave like SM iggs similar coupling o fermions and vecor bosons m h m Z cos β m Z m A m m ±, )=0 ) m h m Z cos β, m m A + m Z sin β m ± = m A + m W, cos (β α) m4 Z sin 4β 4m 4 A. ~ 0 94

21 IGGS&PROPERTIES Enhanced cross secion for large anβ compared o Sandard Model 95