# Presentation: 087941

## MSSM Higgs Sector with CP Violation

- Marcela Carena
- Fermilab
- TeV4LHC Higgs WG
- BNL, January 2005

## Motivation for CP-Violation in SUSY Models

- In low energy SUSY, there are extra CP-violating phases beyond the CKM ones, associated with complex SUSY breaking parameters.
- These  CP-violating phases  may induce effects on observables such as new contributions to the e.d.m. of the electron and the neutron.
-      However, effects on observables are small in large regions of parameter space, where either first or second generation scalars are heavy,  cancellations occur or simply the relevant CP-violating phase for such a given observable vanishes.
- One of the most important consequences of CP-violation is its possible impact on the explanation of the matter-antimatter asymmetry.
-       Electroweak baryogenesis may be realized even in the simplest  SUSY  extension of the SM, but demands  new sources of CP-violation associated with the third generation  sector and/or the gaugino-Higgsino sector.

_**Effects of CP-violation on Higgs physics associated with third generation scalars and/or gaugino-Higgsino sector, are worth studying.**_

## Minimal Supersymmetric Extensions

- In the minimal SUSY extension, there are one charged and three neutral Higgs boson degrees of freedom.
- If CP is conserved, there are two CP-even and one CP-odd neutral Higgs bosons.
- At tree-level, all CP-violating phases, if present, may
-     be absorved into a redefinition of the fields.
- CP-violation in the Higgs sector appears at the loop-level, but can still have important consequences for Higgs physics

## Slide 4

## Slide 5

## Higgs Potential  Quantum Corrections

**Main effect of CP-Violation is the mixing**
**of the three neutral Higgs bosons**

**In the base**

- Gluino phase relevant at two-loop level. Guagino effects may be enhanced for large tan beta

## Comments on Higgs Boson Mixing

- a
- Elements of matrix O are similar to                                     in the CP-conserving case.  But third row and column are zero in the non-diagonal
-       elements in such a case.
- Couplings of the Higgs bosons to vector bosons still depend on projection of Higgs that acquires v.e.v. to the different Higgs bosons.
- Three neutral Higgs bosons can now couple to the vector bosons in a way
-       similar to the SM Higgs.
- Similar to the decoupling limit in the CP-conserving case, for large values
-       of the charged Higgs mass, light Higgs boson with Standard Model properties.

##    Interaction Lagrangian of W,Z bosons with mixtures     of CP even and CP odd Higgs bosons

** ****Effective mixing between the lightest Higgs and the heavy ones is zero ******** H****1**** is SM-like**
**  ****Mixing in the heavy sector still relevant !**

-  All couplings as a function of two:

## Yukawa Couplings: CP violating vertex effects 

- coupling          generated by
- SUSY breaking effects

- The one loop effects to the Yukawa couplings introduce CP-violating
-  effects which are independent of the Higgs mixing

- the phase of the superfield
- bR is real and positive:

## Higgs boson-quark Lagrangian

**taking into account both CP-violating  self-energy and vertex effects **
- (similar vertex effects in the up quark sector, but no tan     enhancement)

**with:**

## Decoupling limit:  
CP violation effects in the Higgs-fermion  couplings 

hence: 
H1bb and H1uu pseudoscalar couplings  tend to zero while their scalar couplings tend to SM-like
with the bottom mass:

Heaviest Higgs Scalar and Pseudoscalar couplings to up and down quarks do not vanish

 non decoupling of CP-violating vertex effects as well as self energy ones 

- CP violation effects in the Higgs-fermion  couplings
- hence:
- H1bb and H1uu pseudoscalar couplings  tend to zero while their scalar couplings tend to SM-like
- with the bottom mass:
- Heaviest Higgs Scalar and Pseudoscalar couplings to up and down quarks do not vanish
-  non decoupling of CP-violating vertex effects as well as self energy ones

## H1bb Scalar and Pseudoscalar couplingsas a function of phases

-  **Analyze behaviour in term of CP-even   **
**  ****quantities: BR’s**
**  ****and CP- odd quatinties: Asymmetries**
-  **Effects depend both on the dominant**
**squark sector phases, as well as on the**
**subdominant gaugino phases, affecting**
**the vertex corrections.**
-   **Cases with gluino mass phase zero **
**(solid lines) and 90 degrees (dashed lines)**
**shown in figures: stronger effects of**
** ****gluino  phase for larger tanb**

**CP-Violating phases affect **
**both masses and couplings **
**in relevant ways.**

## Strong suppresion of H1bb Coupling depending on the gluino phase

- Strong suppresion of H1bb Coupling depending on the gluino phase

-   Suppression of Higgs coupling to
-   bb for a Higgs with SM-like
-   couplings to vector bosons
- Region of parameter space consistent
-      with electroweak Baryogenesis

- Carena, Ellis, Pilaftsis, C.W. ‘00

- Searches at LEP excluded a mass up to about 112 GeV in the flavour independent analysis

##  CP-Violating Higgs bosons at LEP: a challenging scenario

- Mi mama

-  _**CP-Violating Higgs bosons at LEP: a challenging scenario**_

- H1 decouples from the Z and
- H2 and H3 may be out of kinematic reach.

## CPX scenario: no lower bound on MH1 from LEP! 

** **H1 decouples from the Z and  H2 and H3 may be out of kinematic reach.
-  or reduced couplings of Hi to Z and extended regions were H2 decays              H1H1 and the H1’s decay into b’s

- mH2 < 130 GeV   major role of CP-violating effects
-  Example: mH1 = 45 GeV,  mH2 = 110 GeV,                        Not excluded
**No Universal lower limit on mH1 but                                  (mt dep.)**

**Including**
**with**
**in the analyses**

## Impact of the top quark mass on the results

- main effect for                       is due to opening of
- H1Z, H2Z channels  as well as H1H2

##  CP-Violating Higgs bosons at the Tevatron

-  _**CP-Violating Higgs bosons at the Tevatron**_

- Example:
-  MH1 about 90 GeV  but out of the
- reach of LEP.
-  All other channels
- kinematically unaccessible
-  MH1 also hopeless at teh Tevatron due
- to reduced W/Z H1 coupling
-  H1 and H2 masses have little variation
- with phase of At, but couplings to gauge
- bosons vary importantly
- The Tevatron has a chance of having
- a first glance at  H2.

- Most crucial however, explore similar regions but
- for

## low tanb and low mHi region
remains uncover in the
absence of the
 H2 H1H1 analysis

**low tanb and low m****Hi ****region**
**remains uncover in the**
**absence of the**
-  **H****2******** H****1****H****1 ****analysis**

## Slide 19

## Light Higgs Boson H1

##             Looking for 

- Standard signatures not sufficient to probe the presence of  Higgs bosons decaying into lighter Higgs states.
- Lighter states have weak couplings to the weak gauge bosons, but
-      large couplings to third generation down quarks and leptons.
- Possibility of looking for  two taus and two bottoms (jets) signatures
-      at LHC in the weak boson fusion production channel of two CP-odd  like Higgs bosons.  (J. Gunion et al. with 300 inverse fb at the  LHC)
- A detailed  experimental simulation should be performed to test
-      this possibility.

## CPsuperH

- Code to compute Higgs spectrum, couplings and decay modes in the presence of CP-violation
-                                                    Lee, Pilaftsis, M.C., Choi, Drees,Ellis, Lee,Wagner.’03
- CP-conserving case: Set phases to zero. Similar to HDECAY, but with the advantage that charged and neutral sector treated with same rate of accuracy.
- Combines calculation of masses and mixings by M.C., Ellis,
-      Pilaftsis, Wagner.  with analysis of decays by Choi, Drees, Hagiwara,
-      Lee and Song.
- Available at
-     http://theory.ph.man.ac.uk/~jslee/CPsuperH.html

## Conclusions

- Low energy supersymmetry has an important impact on Higgs physics.
-  It leads to definite predictions to the Higgs boson couplings to
-       fermions and gauge bosons.
- Such couplings, however, are affected by radiative corrections induced by supersymmetric particle loops.
- CP-violation in low energy SUSY: Electroweak Baryogenesis.
- CP-violation in the Higgs sector is well motivated and should be studied in detail. It affects the searches for Higgs bosons at hadron and lepton colliders in an important way.
- At a minimum, it stresses the relevance of studying non-standard Higgs boson production and decay channels at lepton and hadron colliders.

## Slide 24

## Interaction Lagrangian of W,Z vector bosons with mixtures of CP even and CP odd Higgs bosons

**Yukawa Interactions**