cosmological constraints on20100220-kek... · cosmological constraints on r-parity violating susy...

Cosmological Constraints on

R-Parity violating SUSY

under Lepton Flavor Violation

岩本 祥 [Sho Iwamoto]

2010/02/20

KEK-PH 2010 @ KEK/筑波 [Tsukuba]

along the paper

M. Endo, K. Hamaguchi and SI.

Cosmological Constraints on R-parity violation.

arXiv: 0912.0585 [hep-ph] (2009).

The University of Tokyo

Outline

1. R-Parity violating SUSY

2. Cosmological Constraints

3. Our Results

4. Application for LHC

<2>

along the paper

M. Endo, K. Hamaguchi and SI.

Cosmological Constraints on R-parity violation.

arXiv: 0912.0585 [hep-ph] (2009).

(about to be published)

JUMP

JUMP

JUMP

JUMP

<3>

1. R-parity violating SUSY

“To avoid the Proton Decay in the MSSM,

we usually impose the R-parity.

But actually, we have other two choices. ”

INDEX

MSSM and R-parity

MSSM

Hierarchy problem → solved!

Proton decay problem

<4>

(Minimal Supersymmetric Standard Model)

Why does Proton decay?

Superpotential of the MSSM

Both and Proton Decay

Proton Decay Problem

<5>

R-parity

Superpotential of the MSSM

<6>

( s: spin )

with R-Parity conservation

Both and Proton Decayis stable.

SUSY without R-parity

However, since proton decay needs both and ,

we have other two possibilities!

To forbid with Baryon-parity etc.

To forbid with Lepton-parity etc.

with assuming

<7>

(Allowing )

(Allowing )

SUSY without R-parity

That is, we can install RpV interactions additionally.

MSSM with R-parity →

-MSSM →

-MSSM →

<8>

MSSM without R-parity

Introductive Diagram

<9>

Standard Model

Supersymmetry

MSSM

Dark Matter!!

R-parity

conservation

MSSM with R-parity

-MSSM

-MSSM

B-conservation

MSSM without R-parity

L-conservation

(Here we need other DM candidates.)

What I studied

Can we constraint such exotic couplings?

<10>

Collider experiments → various constraints

of order .

We analyzed cosmological constraints

→ much more stringent!(as we will see later…)

YES!!

<11>

2. Cosmological Constraints

“The violation of R-parity may spoil

the current Baryon Asymmetry of the Universe.”

INDEX

Baryon Asymmetry of the Universe

Current universe:

<12>

There’s Baryon,and no anti-baryon.

Baryon

Baryon Asymmetry of the Universe

Note:

Today we assume that

Current Baryon Asym. is generated

before EWPT.

<13>

Baryon Asymmetry of the Universe

Current universe:

<14>

There’s Baryon,and no anti-baryon.

Baryon

Wash-out with B-viol.

However, if we have interaction,

in the early universe.

And if frequently enough,

→ achieve Equilibrium :

→ No Baryon Asymmetry!

→ must be small enough!

<15>

“WASH-OUT”

Wash-out with B-viol.

That is, if

<16>

LARGE , then

“WASH-OUT” occurs!!

Bouquet and Salati, 1987

But this is a bit naïve view…

We have to consider “sphaleron.”

Sphaleron

In the early universe (temperature )

→ the sphaleron process is frequent. (by thermal effects)

Sphaleron converts

Baryon Anti-lepton

→ Equilibrium.

<17>

Kuzmin, Rubakov, Shaposhnikov, 1985; Ringwald, 1988

Manton, 1983; Klinkhamer and Manton, 1984; ’t Hooft, 1976

Sphaleron’s Effect

If Baryon is short…

sphaleron works right to left

<18>

sphaleron

(anti-lepton)

(baryon)

Sphaleron’s Effect

If Baryon is short…

sphaleron works right to left

<19>

(anti-lepton)(baryon)

and achieve Equilibrium.

Sphaleron’s Effect

Also when (anti-)Lepton is short,

sphaleron does left to right

<20>

sphaleron

(anti-lepton)(baryon)

Sphaleron’s Effect

Also when (anti-)Lepton is short,

sphaleron does left to right

<21>

(anti-lepton)(baryon)

and achieve Equilibrium.

Wash-out with B-viol.

Thus, actually the previous wash-out by

is…

<22>

(anti-lepton)(baryon)

Wash-out with B-viol.

Thus, actually the previous wash-out by

is…

<23>

sphaleron

(anti-lepton)

(baryon)

Wash-out with B-viol.

Thus, actually the previous wash-out by

is…

<24>

(anti-lepton)(baryon)

“WASH-OUT”

Wash-out with L-viol.

This story

does not end here!

<25>

Kuzmin, Rubakov and Shaposhnikov, 1985Campbell, Davidson, Ellis and Olive, 1992

Wash-out with L-viol.

If

large (in the sphaleron era),

<26>

(anti-lepton)(baryon)

Wash-out with L-viol.

If

large (in the sphaleron era),

<27>

sphaleron

(anti-lepton)(baryon)

Wash-out with L-viol.

If

large (in the sphaleron era),

<28>

(anti-lepton)(baryon)

Wash-out occurs!!

Wash-out with L-viol.

But

NOTE ONE IMPORTANT POINT!

<29>

Campbell, Davidson, et al., 1992; Dreiner and Ross, 1983

(anti-lepton)(baryon)

Wash-out with L-viol.

Imagine this case.

<30>

Campbell, Davidson, et al., 1992; Dreiner and Ross, 1983

If the Lepton Flavor is NOT violated,

and

if at least one of is conserved,

Wash-out with L-viol.

<31>

Campbell, Davidson, et al., 1992; Dreiner and Ross, 1983

Wash-out with L-viol.

<32>

sphaleron

Campbell, Davidson, et al., 1992; Dreiner and Ross, 1983

Wash-out with L-viol.

<33>

Campbell, Davidson, et al., 1992; Dreiner and Ross, 1983

Wash-out with L-viol.

<34>

sphaleron

Campbell, Davidson, et al., 1992; Dreiner and Ross, 1983

Wash-out with L-viol.

<35>

Baryon SURVIVES!!!

Campbell, Davidson, et al., 1992; Dreiner and Ross, 1983

Wash-out with L-viol.

<36>

Baryon Survives.Wash-out!

The “leptonic” wash-out needs three sif there’s no LFV.

Wash-out with L-viol.

But remember!

In MSSM,

We have LFVs in general!!!

The Standard Model The MSSM

<37>

Endo, Hamaguchi, and SI, 2009

As Shimomura-san mentioned.

Wash-out with L-viol.

Therefore,

Only One would…

<38>

(anti-lepton)(baryon)

Wash-out with L-viol.

<39>

sphaleron

(anti-lepton)(baryon)

Therefore,

Only One would…

Wash-out with L-viol.

<40>

(anti-lepton)(baryon)

Do “WASH-OUT”!!

Therefore,

Only One would…

Wash-out with L-viol.

<41>

(baryon)

Therefore,

Only One would…

Wash-out with L-viol.

<42>

(baryon)

Therefore,

Only One would…

Now We Know

To avoid the WASH-OUT,

All must be small enough, and

If all flavors are mixed

→ All must be small enough.

<43>

These are what we studied!

Now We Know

To avoid the WASH-OUT,

All must be small enough, and

If all flavors are mixed

→ All must be small enough.

<44>

These are what we studied!

How SMALL must be?

When MIX?

Now We Know

To avoid the WASH-OUT,

All must be small enough, and

If all flavors are mixed

→ All must be small enough.

<45>

And we will claim that…

This is naturally expected!

All of them areseverely constrained!

<46>

3. Our Results

INDEX

Methods

We calculated

by Boltzmann Eq.

<47>

Lepton number density in i-th generation

Large LFV Tiny LFV

(All must be small.)

Methods

<48>

LFV

Generally NOT diagonal

As Shimomura-san discussed.

Methods

<49>

LFV

Diagonalizeby rotation

“mixing angle”

LFV

Methods

<50>

For example

(We know , because we know the lepton masses.)

LFV causes Mixing.

Not mixed

Result

<51>

Fully Mixed!

“Mixed”

Conclusion

<52>

→ MIXED

This corresponds to

Remember:

By the way,

Conclusion

<53>

Right-handed neutrino

SU(5) GUT (Colored Higgs)

Conclusion

<54>

→ MIXED

Expected Value

Naturally Expected!Experimental Reach

Now We Know

To avoid the WASH-OUT,

All must be small enough, and

If all flavors are mixed

→ All must be small enough.

<55>

This is naturally expected!

These are ALLseverely constrained!

Constraints on RpVs

In a similar manner…

→ calculated by the Boltzmann Eq.

We obtained the bounds for

R-parity violating couplings.

<56>

Just the results…

<57>

(For all i, j, k)

For

<58>

4. Application for LHC

“Now we have a good tool

to study LHC phenomenology of RpV-MSSM.”

INDEX

SUSY Detection @ LHC

SUSY detection in LHC is important.

R-parity is Conserved → LSP Signal

Then if not?

→ LSP decays!How to detect RpV-SUSY?

<59>

Application for LHC

Stringent RpV-constraint of order

→ LSP is a bit “long-lived.”

Example: ( -LSP)

<60>

Decay Length

(cf. tau-lepton: )

To be a good signal of RpV-SUSY?→ Future works!

That’s all.

Thank you

for listening.<61>

Summary

<62>

MSSM

& areALL small.

LFV!!

LSP would bea bit long-livedeven if

NO R-Parity.

R-parity is not a must.

Appendices

A) Hierarchy Problem

B) Weak points of RpV-MSSM

C) Collider Constraints

D) The RpV Results

E) Several Details

F) Experimental LFV Bounds

<63>

INDEX

JUMP

JUMP

JUMP

JUMP

JUMP

JUMP

<64>

A. Hierarchy Problem

“In the Standard Model,

the quantum correction for the mass of the Higgs

requires a miraculous cancellation as

”

INDEX

APPENDICES

Hierarchy Problem

In the

Standard Modelwith Higgs,

<65>

Hierarchy Problem

<66>

Hierarchy Problem

In

MSSM(or other SUSY models),

<67>

Hierarchy Problem

<68>

And its superpartner goes round! Cancelled!

<69>

B. Weak Points of RpV-MSSM

“The RpV-MSSM has some weak points,

but anyway important for the SUSY detection.”

INDEX

APPENDICES

Weak point of “RpV-MSSM”

Weak Points

Anyway we need “some symmetry.”

Dark Matter → left unsolved.

GUT compatibility… (´・ω・｀)

<70>

<71>

C. Collider Constraints

“The RpV interactions are constrainedby several experimental facts.”

INDEX

APPENDICES

Constraints

The RpV parameters

→ experimental constraints

And the constraints are important

to study RpV-MSSM.

<72>

Constraints

Example:

<73>

Standard Model RpV-MSSM

Additional Contribution!

Constraints

Example:

<74>

Standard Model RpV-MSSM

Additional Contribution!

<75>

D. RpV Results

INDEX

APPENDICES

RpV Result

<76>

[GeV]

RpV Result

<77>

[GeV]

RpV Result

<78>

[GeV]

RpV Result

<79>

[GeV]

<80>

E. Several Details

Approximations we used

Set up

MSSM; before EWPT (sphaleron era: )

Approximations

We consider only the decay of Higgsino

and the antiparticles’ processes.

Mass of Higgs bosons → Ignored

Fermi/Bose distribution → Boltzmann distribution

Sphaleron → Shut off at .

<81>

Some Loophole

We can avoid any “wash-out”

with creating the current B-asymmetry

HERE.

<82>

<83>

F. Experimental LFV Bounds

MEGA Result / MEG Prospect

<84>