ENCONTRANDO O BÓSON DE HIGGS ENCONTRANDO O BÓSON DE HIGGS ATRAVÉS DE SUPERSIMETRIAATRAVÉS DE SUPERSIMETRIA

Maurício B. Magro (CUFSA – Santo André)Maurício B. Magro (CUFSA – Santo André)F. de Campos (FEG / UNESP - Guaratinguetá)F. de Campos (FEG / UNESP - Guaratinguetá)

Oscar Éboli (IFUSP – São Paulo)Oscar Éboli (IFUSP – São Paulo)D. Restrepo (U. Antioquia - Colômbia)D. Restrepo (U. Antioquia - Colômbia)J. W. F. Valle (U. Valência - Espanha)J. W. F. Valle (U. Valência - Espanha)

SUPERSYMMETRY AND THE HIGGS BOSONSUPERSYMMETRY AND THE HIGGS BOSON

The CERN LHC will test the origin of mass and the nature of The CERN LHC will test the origin of mass and the nature of electroweak symmetry breaking electroweak symmetry breaking Higgs BosonHiggs Boson Hierarchy Hierarchy

ProblemProblem

Supersymmetry (SUSY) is a possible solution to the hierarchy problem;

Weak scale Supersymmetry breaking unifies gauge Weak scale Supersymmetry breaking unifies gauge coupling constants and can include gravity;coupling constants and can include gravity;

SUSY is broken via SuperGravity

↓↓↓↓New physics beyond the Standard ModelNew physics beyond the Standard Model

THE BILINEAR R-PARITY MODEL IN mAMSBTHE BILINEAR R-PARITY MODEL IN mAMSB

In SUSY there is a multiplicative quantum number called In SUSY there is a multiplicative quantum number called R-parity:R-parity:

RRPP = (-1) = (-1)2J+3B+L2J+3B+L

If R-parity is conserved:If R-parity is conserved:

1. SUSY particles are produced in pairs.1. SUSY particles are produced in pairs.

2. SUSY particles must decay into antother SUSY particles.2. SUSY particles must decay into antother SUSY particles.

3. There is a stable SUSY particle: LSP 3. There is a stable SUSY particle: LSP (neutralino)(neutralino).. We introduced a bilinear term in the SUSY superpotential:We introduced a bilinear term in the SUSY superpotential:

εεiiLLiiHHuu

that breaks R-parity explicitly.that breaks R-parity explicitly.

ConsequencesConsequences

22,

22

1

0det4

gMgMm

1.1. Only one neutrino aquires mass at Only one neutrino aquires mass at tree level. The neutrino mass tree level. The neutrino mass spectrum can be cosistent with spectrum can be cosistent with neutrino oscillation data, favouring neutrino oscillation data, favouring

→→ ..

2.2. The neutrino mass is given by: The neutrino mass is given by:

with with ΛΛii = = ννii + + εεiiννdd

3.3. The neutrino mixing angles are given The neutrino mixing angles are given by: and by: and

4.4. The lightest nuetralino is unstable, The lightest nuetralino is unstable, therefore can decay inside the therefore can decay inside the present detector colliders present detector colliders New New signatures at colliderssignatures at colliders..

5.5. The Neutralino branching ratio into The Neutralino branching ratio into Higgs is:Higgs is:

13tan

2/12212tan

e

13tan

HIGGS SEARCHHIGGS SEARCH

Neutralino DecaysNeutralino Decays It can decay through Higgs boson as:It can decay through Higgs boson as:

χχ00 → → H H** .→ .→ νν bb bb The model backgrounds are:The model backgrounds are:

χχ00 → → Z Z** .→ .→ νν bb and bb and χχ00 .→ .→ νν bb bb

χχ00 → → ττWW.→ .→ νν qq (mistaged b´s) qq (mistaged b´s)

The LSP can live long enough to produce a displaced vertex at The LSP can live long enough to produce a displaced vertex at detectors.detectors.

The displaced vertices have litte if none background at LHCThe displaced vertices have litte if none background at LHC We have considered a neutralino that lives long enough to We have considered a neutralino that lives long enough to

decay out the primary vertex and before the tracking detectors. decay out the primary vertex and before the tracking detectors. We have applied the following kinematic cuts:We have applied the following kinematic cuts:

1. All charged tracks must be inside the region of |1. All charged tracks must be inside the region of |ηη| < 2.5;| < 2.5;

2. We considered a b-tagging efficiency of either 50% or 30%;2. We considered a b-tagging efficiency of either 50% or 30%;

3. We required an isolated electon(muon) with p3. We required an isolated electon(muon) with ptt > 20(6) GeV; > 20(6) GeV;

or a jet with por a jet with ptt > 100 GeV; > 100 GeV;

or missing tranverse energy Eor missing tranverse energy Etmisstmiss > 100 GeV; > 100 GeV;

4. We required an invariant mass inside the range 4. We required an invariant mass inside the range

100 GeV < M100 GeV < MHH < 125 GeV; < 125 GeV;

THE RESULTSTHE RESULTS

The parameters are:The parameters are:

mm1/21/2; m; m00; Tan; Tanββ = 10; sign( = 10; sign() > 0; ) > 0; εεii; ; ΛΛii..

- We have used SPheno code to calculate the R-Parity violating branching ratios and - We have used SPheno code to calculate the R-Parity violating branching ratios and Pythia code to calculate the cross sections.Pythia code to calculate the cross sections.

- We required at least 5 background free events, consistent with neutrino data.- We required at least 5 background free events, consistent with neutrino data.

Reach for LHC Reach for TevatronReach for LHC Reach for Tevatron10 fb-1 (stars) and 100 fb-1 (squares) 2 fb-1 (stars) and 8 fb-1 (squares)10 fb-1 (stars) and 100 fb-1 (squares) 2 fb-1 (stars) and 8 fb-1 (squares)

ResultsResults

For more details, see Phys. Rev. D80, 015002 For more details, see Phys. Rev. D80, 015002 (2009).(2009).

Reach for LHC Reach for TevatronReach for LHC Reach for Tevatron10 fb-1 (stars) and 100 fb-1 (squares) 2 fb-1 (stars) and 8 fb-1 (squares)10 fb-1 (stars) and 100 fb-1 (squares) 2 fb-1 (stars) and 8 fb-1 (squares) low efficienciylow efficienciy