Flavour and CP Violation in Supersymmetric Models John Ellis Theory Division, CERN @ LHCb, Jan. 27 th, 2009.

Flavour and CP Violation in Supersymmetric Models

John Ellis

Theory Division, CERN

@

LHCb, Jan. 27th, 2009

Flavour and CP Violation

- CKM model successful atpresent

- A pillar of the Standard Model

- What lies beyond it?

2008 Nobel Physics Prize: Kobayashi & Maskawa

Possible Discrepancies?

B vs sin 2

Bs mixing phaseBs 0?

K vs sin 2

Where does the Matter come from?

Dirac predicted the existence of antimatter:same massopposite internal properties:

electric charge, …Discovered in cosmic raysStudied using accelerators

Matter and antimatter not quite equal and opposite: WHY?

Need additional matter-antimatter difference to explainwhy the Universe contains mainly matter, not antimatter?

LHCb and other experiments will look for answer

How to Create the Matter in the Universe?

• Need a difference between matter and antimatterobserved in the laboratory

• Need interactions able to creat matterpresent in unified theories not yet seen by experiment

• Must break thermal equilibriumPossible in the decays of heavy

particles

Sakharov

Will we be able to calculate using laboratory data?

Why Supersymmetry (Susy)?

• Intrinsic beauty• Hierarchy/naturalness problem • Unification of the gauge couplings• Predict light Higgs < 150 GeV

– As suggested by precision electroweak data

• Cold dark matter• Essential ingredient in string theory (?)

SUSY Stabilizes the Higgs Mass2

• Consider generic fermion and boson loops:

• Each is quadratically divergent: ∫Λd4k/k2

• Leading divergence cancelled if

2

x 2 Supersymmetry!

Reasons to like Susy

It enables the gauge couplings to unify

It predicts mH < 150 GeV

JE, Nanopoulos, Olive + Santoso: hep-ph/0509331As suggested by EW data

Astronomers tell us that most of the matter in the universe is invisible

We will look for it

with the LHC

Dark Matter in the Universe

Astronomers saythat most of thematter in theUniverse isinvisible Dark Matter

‘Supersymmetric’ particles ?

We shall look for them with the

LHC

Dark Matter in the Universe

• Particles + spartners

• 2 Higgs doublets, coupling μ, ratio of v.e.v.’s = tan β• Unknown supersymmetry-breaking parameters:

Scalar masses m0, gaugino masses m1/2, trilinear soft couplings Aλ, bilinear coupling Bμ

• Assume universality? constrained MSSM = CMSSMSingle m0, single m1/2, single Aλ, Bμ: not string?

Minimal Supersymmetric Extension of Standard Model (MSSM)

Mass Renormalizations

• Assuming universality at the GUT scale• Gaugino masses:

– Ma = (αa / αGUT) m1/2, e.g., → M2 / M3 = α2 / α3

• Squark and slepton masses:– Squark mass2: m0

2 + 6 m1/22

– Left-handed slepton mass2: m02 + 0.5 m1/2

2

– Right-handed slepton mass2: m02 + 0.15 m1/2

2

• Minimal flavour violation (MFV):– Flavour mixing of squarks and sleptons induced by CKM,

neutrino mixing

Possible Nature of SUSY Dark Matter Particle

• No strong or electromagnetic interactionsOtherwise would bind to matterDetectable as anomalous heavy nucleus

• Possible weakly-interacting scandidatesSneutrino

(Excluded by LEP, direct searches)Lightest neutralino χ (partner of Z, H, γ)Gravitino

(nightmare for astrophysical detection)

Current Constraints on the Simplest Minimal SUSY Model (CMSSM)

Excluded because stau LSP

Excluded by b s gamma

Favoured (?) by latest g - 2

assuming neutralino LSP

WMAP constraint on relic density

How Soon Might the CMSSM be Detected?

O.Buchmueller et al

Non-Universal Scalar Masses

• Different sfermions with same quantum #s?e.g., d, s squarks?disfavoured by upper limits on flavour-

changing neutral interactions

• Squarks with different #s, squarks and sleptons?disfavoured in various GUT models

e.g., dR = eL, dL = uL = uR = eR in SU(5), all in SO(10)

• Non-universal susy-breaking masses for Higgses?Why not! 1 or 2 extra parameters in NUHM1,2

How Soon Might the NUHM1 be Detected?

O.Buchmueller et al

Bs +- in the CMSSM & NUHM1

• Small difference from Standard Model in CMSSM

• Big increase possible in NUHM1

Minimal Flavour Violation (MFV) & Maximal CP Violation (MCP)

• All squark mixing due to CKM matrix• Universal scalar masses at high scale for

sparticles with same quantum numbers• Parametrization:

• Maximally CP-violating MFV (MCPMFV) model has 19 parameters, of which 6 violate CP:

• Often assume universal ImMa, ImAf, but non-universality compatible with MFV: MCPMFV

JE, Lee & Pilaftsis

Complexification of CMSSM

• With universality, just two new CP-violating parameters:

– Arg(Ma ), Arg(Af )

• Loop-induced mixing ~

– (h,H,A) → (H1,H2,H3) with indefinite CP

• Effects on masses, couplings

J.E. + Lee + Pilaftsis

From LEP, from electric dipole moments

Experimental Constraints

red: n, blue: Tl

Olive et al

Prospective Searches @ LHC

Effects of CP Phases in MCPMFV

Renormalization

of phases Ino masses

Heavy Higgs masses

Bs mixing

JE + Lee + Pilaftsis: arXiv:0708.2078

Effects of CP Phases in MCPMFV

Bs

b s

Bu

Different

regions

allowed for

different

phases … … and hence

ACP in

b sJE + Lee + Pilaftsis, arXiv:0708.2078

Thallium and Electron EDMs in the MCPMHV

• Possibility of non-trivial cancellations between the contributions of different phases

JE, Lee & Pilaftsis, arXiv:0808.1819

Neutron EDM in the MCPMHV

• Possibility of non-trivial cancellations between the contributions of different phases

JE, Lee & Pilaftsis, arXiv:0808.1819

Mercury EDM in the MCPMHV

• Possibility of non-trivial cancellations between the contributions of different phases

JE, Lee & Pilaftsis, arXiv:0808.1819

SUSY Electroweak Baryogenesis?

• Exploit phases in SUSYMCPMFV model

• Require light stopfor first-order electroweak transition

• Higgs and stop masses tightly constrained bytheory and experiment

Carena, Nardini, Quiros and Wagner: arXiv:0809.3760

Summary

• Observed CP violation described well by Kobayashi and Maskawa– Some hints of discrepancies?

• More CPV needed to explain matter in Universe

• Supersymmetry offers new CPV mechanisms– New CPV phases

• Opportunities in B decays, EDMs, …

Papers with J.S. Lee and A. Pilaftsis

• CERN LHC signatures of resonant CP violation in a minimal supersymmetric Higgs sector: hep-ph/0404167

• Resonant CP violation in MSSM Higgs production and decay at gamma gamma colliders: hep-ph/0411379

• Diffraction as a CP and lineshape analyzer for MSSM Higgs bosons at the LHC: hep-ph/0502251

• Resonant CP violation in Higgs radiation at e+ e- linear collider: hep-ph/0507046

• B-Meson Observables in the Maximally CP-Violating MSSM with Minimal Flavour Violation: arXiv:0708.2079

• Electric Dipole Moments in the MSSM Reloaded: arXiv:0808.1819• CPsuperH2.0: an Improved Computational Tool for Higgs Phenomenology in

the MSSM with Explicit CP Violation (with M. Carena and C. Wagner): arXiv:0712.2360

• http://www.hep.man.ac.uk/u/jslee/CPsuperH.html