Supersymmetric dark matter: implications for colliders and

astroparticle

G. Bélanger

LAPTH-Annecy

PLAN Evidence for dark matter Cosmology and SUSY dark matter

• Constraining models SUSY dark matter at colliders

• SUSY signal and determination of parameters

Direct/Indirect detection• DM signal and complementarity to collider

searches Final remarks

Evidence for dark matter Most of the matter in the universe cannot be detected from

the light emitted (dark matter) Presence of dark matter is inferred from motion of

astronomical objects• If we measure velocities in some region there has to be enough

mass for gravity to hold objects together

• The amount of mass needed is more than luminous mass• The galactic scale

• Scale of galaxy clusters Dark matter is required to amplify the small fluctuations in

Cosmic Microwave background to form the large scale structure in the universe today• Cosmological scales

Evidence for dark matter:Rotation curves of galaxies Negligible luminosity in galaxy

halos, occasional orbiting gas clouds allow measurement of rotation velocities and distances

Newton

r> rluminous, M(r) =constant

v should decrease Observations of many galaxies:

rotation velocity does not decrease

Dark matter halo would provide with M(r)~r v-> constant

Galaxy clusters

1933: Zwicky got first evidence of dark matter in galaxy clusters

Confirmed by many observations on galaxy clusters• Determine total mass required to provide self-gravity

necessary to stop system from flying apart

• Mass/Light ratio 200-300 (two orders of magnitude more than in solar system)

Cosmic microwave backgroundand total amount of dark matter in the universe

Background radiation originating from propagation of photons in early universe (once they decoupled from matter) predicted by Gamow in 1948

Discovered Penzias&Wilson 1965

CMB is isotropic at 10-5 level and follows spectrum of a blackbody with T=2.726K

Anisotropy to CMB tell the magnitude and distance scale of density fluctuation when universe was 1/1000 of present scale

Study of CMB anisotropies provide accurate testing of cosmological models, puts stringent constraints on cosmological parameters

Cosmic microwave background

CMB – density fluctuations

CMB anisotropy maps• Precision determination of

cosmological parameters All information contained in

CMB maps can be compressed in power spectrum

To extract information : start from cosmological model with small number of parameters and find best fit

What is the universe made of? In recent years : new

precise determination of cosmological parameters

Data from CMB (WMAP) agree with the one from clusters and supernovae • Dark matter: 23+/- 4%• Baryons: 4+/-.4%• Dark energy 73+/-4%• Neutrinos < 1%

With WMAP cosmology has entered precision era, can quantify amount of dark matter. In 2007 PLANCK satellite will go one step further (expect to reach precision of 2-3%). This strongly constrain some of the proposed solutions for cold dark matter

Has triggered many direct/indirect searches for dark matter

At colliders one can search for the particle proposed as dark matter candidates

So far no evidence (LEP-Tevatron) but in 2007 with Large Hadron Collider (LHC) at CERN will really start to explore a large number of models and might find a good dark matter candidate

.094 < ΩCDMh2 <.129

What is dark matter/dark energy Dark matter

• Related to physics at weak scale

• New physics at weak scale can also solve EWSB

• Many possible solutions: new particle that exist in some NP models, not necessarily designed for DM

Dark energy• Related to Planck scale physics

• NP for dark energy might affect cosmology and dark matter

• Neutrinos (they exist but only small component of DM)

• Supersymmetry with R parity conservation

• Neutralino LSP

• Gravitino

• Axino

• Kaluza-Klein dark matter• UED (LKP )

• LZP is neutrino-R (in Warped Xdim models with matter in the bulk)

• Branons

• Little Higgs with T-parity• Wimpzillas, Q-balls, cryptons…

Relic density of wimps

In early universe WIMPs are present in large number and they are in thermal equilibrium

As the universe expanded and cooled their density is reduced through pair annihilation

Eventually density is too low for annihilation process to keep up with expansion rate

• Freeze-out temperature LSP decouples from standard

model particles, density depends only on expansion rate of the universe

Freeze-out

Relic density

A relic density in agreement with present measurements Ωh2 ~0.1 requires typical weak interactions cross-section

Dark matter : cosmo/astro/pp Wimps have roughly right value for relic density Neutralinos are wimps but not all SUSY models are

acceptable Precise measurement of relic density constrain models

• Generic class of SUSY models that are OK Direct/Indirect detection : search for dark matter establish

that new particle is dark matter constrain models Colliders : which model for NP/ confront cosmology

• LHC: discovery of new physics, dark matter candidate and/or new particles

• ILC: extend discovery potential of LHC

How well this can be done strongly depends on model for NP

Supersymmetry

Motivation: unifying matter (fermions) and interactions (mediated by bosons)• Symmetry that relates fermions and bosons

Prediction: new particles supersymmetric partners of all known fermions and bosons• Not discovered yet

Hierarchy problem• Electroweak scale (100GeV) << Planck scale

• SUSY particles (~TeV) to stabilize Higgs mass against radiative corrections should be within reach of LHC

Unification of couplings

Evidence for supersymmetry?

Coupling constants “run” with energy

Precise measurements of coupling constants of Standard Model SU(3),SU(2), U(1) at electroweak scale (e.g. LEP) indicate that they do not unify at high scale (GUT scale)

SM coupling constants unify within MSSM

Minimal Supersymmetric Standard Model

Minimal field content: partner to SM particles (also need two Higgs doublets)

Neutralinos: neutral spin ½ partners of gauge bosons (Bino, Wino) and Higgs scalars (Higgsinos)

R-parity

Proton decay To prevent this introduce R parity

• R=(-1) 3B-3L+2S; R=1: SM particles R=-1 SUSY The LSP is stable

Neutralino LSP Prediction for relic density depend on parameters of

model• Mass of neutralino LSP

• Nature of neutralino : determine the coupling to Z, h, A …• M1 <M2< bino <M1,M2 Higgsino

• M2<M1< Wino

Neutralino annihilation

3 typical mechanisms for χ annihilation• Bino annihilation into ff

• σ ~ mχ2/mf

4

• Mixed bino-Higgsino (wino)

• Coupling depends on Z12,Z13,Z14, mixing of LSP

• Annihilation near resonance (Higgs)

Neutralino annihilation

3 typical mechanisms for χ annihilation• Bino annihilation into ff

• σ ~ mχ2/mf

4

• Mixed bino-Higgsino (wino)• Coupling depends on

Z12,Z13,Z14

• Annihilation near resonance (Higgs)• Need some coupling to A,

some mixing with Higgsino

Coannihilation

If M(NLSP)~M(LSP) then maintains thermal equilibrium between NLSP-LSP even after SUSY particles decouple from standard ones

Relic density depends on rate for all processes involving LSP/NLSP SM

All particles eventually decay into LSP, calculation of relic density requires summing over all possible processes

Important processes are those involving particles close in mass to LSP Public codes to calculate relic density: micrOMEGAs, DarkSUSY, IsaRED

Exp(- ΔM)/T

Neutralino co-annihilation

Can occur with all sfermions, gauginos• Bino LSP (sfermion

coannihilation)

• Higgsino LSP- coannihilation with chargino and neutralinos

What happens in generic SUSY models, does one gets the right value for the relic density?

• mSUGRA (only 5 parameters)

• M0, M1/2, tan β, A0,

• Other models MSSM (at least 19 parameters)

WMAP constraining NP: mSUGRA example

bino – LSP• In most of mSUGRA parameter

space• Annihilation in fermion pairs• Works well for light sparticles

but hard to reconcile with LEP/Higgs limit (small window open)

Sfermion coannihilation• Staus or stops• More efficient, can go to higher

masses Mixed bino-Higgsino:

annihilation into W/Z/t pairs Resonance (Z, light/heavy

Higgs)

Mt=175GeV

Mt=178Mt=178

WMAP – constraining mSUGRA

Bino – LSP Sfermion Coannihilation Mixed Bino-Higgsino

• Annihilation into W pairs

• In mSUGRA unstable region, mt dependence, works better at large tanβ

Resonance (Z, light/heavy Higgs)• LEP constraints for light Higgs/Z

• Heavy Higgs at large tanβ (enhanced Hbb vertex)

WMAP and SUSY dark matter

In mSUGRA might conclude that the model is fine-tuned (either small ΔM or Higgs resonance) . • The LSP is mostly bino

Not generic of other SUSY models, in fact what WMAP is telling us might be that a good dark matter candidate is a mixed bino/Higgsino or mixed bino/wino….• In particular, main annihilation into gauge boson pairs works well

for Higgsino (or wino) fraction ~25%

What does that tell us about models?

Some examples

mSUGRA-focus point• Ellis, Baer, Balazs , Belyaev, Olive,

Santoso, Spanos, Nath, Chattopadhyay, Lahanas, Nanopoulos, Roskowski, Drees, Djouadi, Tata…

Non universal SUGRA String inspired: moduli-

dominated Split SUSY NMSSM

Feng, hep-ph/0405479

Gaugino fraction

Some examples

GB, et al, NPB706(2005)

M1=1.8M2|GUT

mixed bino/wino

Higgs exchange

mSUGRA-focus point• Ellis, Baer, Balazs , Belyaev, Olive, Santoso, Spanos,

Nath, Chattopadhyay, Lahanas, Nanopoulos, Roskowski, Drees, Djouadi, Tata…

Non universal SUGRA, e.g. non universal gaugino or scalar masses• GB, Boudjema, Cottrant, Pukhov, Bertin,Nezri,

Orloff, Baer, Belyaev, Birkedal-Hansen, Nelson, Mambrini, Munoz…

String inspired moduli-dominated : LSP has important wino component • Binetruy et al, hep-ph/0308047

Split SUSY : Large M0, LSP is mixed Higgsino/wino/bino• Masiero, Profumo, Ullio, hep-ph/0412058

NMSSM• GB, Boudjema, Hugonie, Pukhov, Semenov

PLAN Evidence for dark matter Cosmology and SUSY dark matter

• Constraining models SUSY dark matter at colliders

• SUSY signal and determination of parameters

Direct/Indirect detection• Dark matter signal and complementarity to

collider searches Final remarks

Which scenario? Potential for SUSY discovery at LHC/ILC

Some of these scenarios will be probed at LHC/ILC and/or direct /indirect detection experiments

Corroborating two signals SUSY dark matter

LHC• Squarks, gluinos < 2- 2.5 TeV• Sparticles in decay chains• mSUGRA: probe significant parameter

space, heavy Higgs difficult, large m0-m1/2 also.

• Other models : similar reach in masses ILC

• Production of any new sparticles within energy range

• Extend the reach of LHC in particular in “focus point” of mSUGRA Baer et al., hep-ph/0405210

Probing cosmology using collider information

Within the context of a given model can one make precise predictions for the relic density at the level of WMAP(10%) and even PLANCK (3%) (2007) therefore test the underlying cosmological model.

• Assume discovery SUSY, precision from LHC?

• Precision from ILC?

Answer depends strongly on underlying NP scenario, many parameters enter computation of relic density, only a handful of relevant ones for each scenario – work is going on in North America, Asia and Europe both for LHC and ILC• Moroi, Bambade, Richard, Zhang, Martyn, Tovey, Polesello, Lari, D. Zerwas,

Allanach, Belanger, Boudjema, Pukhov, Battaglia, Birkedal, Gray, Matchev, Alexander, Fields, Hertz, Jones, Meyraiban, Pivarski, Peskin, Dutta, Kamon, Arnowitt, Khotilovith…

The simplest example: mSUGRA/coannihilation (staus)

Challenge: measuring precisely mass difference

Why? Ωh2 dominated by Boltzmann factor exp(- ΔM/T)• Although masses are predicted at

1-2% level, still leads to large uncertainties in relic density

Precision required on mSUGRA parameters to predict Ωh2 at 10% level• M0, M1/2 ~2%

LHC: roughly this precision can be achieved in “bulk” region• Tovey, Polesello, hep-ph/0403047

For coannihilation region errors on mass could be larger (more difficult with staus

Allanach et al, JHEP 2005

Determination of parameters LHC : bulk+coannihilation

Decay chain

Signal: jet +dilepton pair Can reconstruct four masses

from endpoint of ll and qll Global fit to model parameters For this particular point,

ΔM0~2%, ΔM1/2~0.6% --> ΔΩ/Ω~3%

For WMAP compatible point this precision will be barely sufficient for ΔΩ/Ω~10% and errors on masses could be larger (more difficult with staus)

Tovey, Polesello, hep-ph/0403047

M0=100, M1/2=250, tanβ=10

MSSM: coannihilation Stau-neutralino mass difference

is crucial parameter need to be measured to ~1 GeV

LHC: in progress

ILC: can match the precision of WMAP and even better• Stau mass at threshold

• Bambade et al, hep-ph/040601• Stau and Slepton masses

• Martyn, hep-ph/0408226• Stau -neutralino mass difference

(~1GeV)• Khotilovitch et al, hep-ph/0503165

Allanach et al, JHEP2005

In mSUGRA at large M0, decrease rapidly, the LSP has large Higgsino component• Annihilation into W pairs• Neutralino/chargino NLSP:

gaugino coannihilation

With ~25-40% Higgsino just enough dark matter

Within mSUGRA strong dependence on SM input parameters (mt): no reliable prediction of the relic density

Another example: Focus (Higgsino LSP)

Higgsino in MSSM: mSUGRA-inspired focus point

No dependence on mt except near threshold

Relic density depend on 4 neutralino parameters, M1, M2, , tanβ

To achieve WMAP precision on relic density must determine

• (M1,) 1% .

• tanβ~10%

• Is it possible?

…. Higgsino LSP If squarks are heavy difficult

scenario for LHC • only gluino accessible,

chargino/neutralino in decays

• mass differences could be measured from neutralino leptonic decays,

• How well can gaugino parameters can be reconstructed?

Light Higgsinos possibly many accessible states at ILC

•Baltz, et al , hep-ph/0602187

… Higgsino LSP Recent study of determination

of parameters and reconstruction of relic density in this scenario

LHC: not enough precision

ILC: chargino pair production sensitive to bino/Higgsino mixing parameter

ILC: roughly 10% precision on Ωh2

Baltz et al hep-ph/0602187

Colliders and relic density For neutralino LSP, in favourable scenarios LHC will give

precise information on the parameters of MSSM and this will allow to refine the predictions for relic density of neutralinos.

In other scenarios, will have to wait for ILC @TeV

What about precise predictions for direct/indirect detection?

Direct/indirect detection Indirect/direct detection can find (some hints from Egret, Hess..) signal

for dark matter Many experiments under way, more are planned

• Direct: CDMS, Edelweiss, Dama, Cresst, Zeplin Xenon, Genius, Picasso… • Indirect: Hess, Veritas, Glast, HEAT, Pamela, AMS, Amanda, Icecube,

Antares … Can check if compatible with some SUSY or other scenario Complementarity with LHC/ILC:

• Establishing that there is dark matter• Probing SUSY dark matter candidates• LHC: good signal if light squarks/gluinos, direct/indirect detection good

signal for (mixed bino/Higgsino LSP) Assuming some signals are discovered: corroborating

information from colliders/astroparticle• Also tests of assumptions about dark matter distribution in

the halo…

Direct detection of dark matter Detect dark matter through

interaction with nuclei in large detector.

Depends on local density and velocity distribution of dark matter

Dependence on coupling of LSP to quarks and gluons• s-channel squark exchange• t-channel Higgs (Z)

exchange Large cross-sections found for

• light squarks• large tanβ, not too heavy

“heavy Higgses” + mixed Higgsino/bino LSP

Direct detection of dark matter Typical LSP-proton scalar cross-

sections range from 10-10 pb in coannihilation region to 10-8-10-6 pb in focus point region of mSUGRA

Present detector (including DAMA) not sensitive enough to probe mSUGRA

With next generation of detectors, direct searches can probe regions of mSUGRA parameter space inaccessible to LHC• Focus point scenarios (large m0)

especially at large tan().• Some coannihilation region remains out

of reach Models with mixed Higgsino or wino

have largest cross-sections

Baer et al. hep-ph/0305191

ZEPLIN-MAX

Expect sensitivity 10-9 -10-10pb by 2011

Next generationNext generation

Present bound

Direct detection: non-universal models

In models where LSP is not pure bino: good prospect for direct detection even if squarks heavy• Example: model with non-

universal gaugino mass

• Models with heavy Higgs out of reach of even ton-scale detectors

GB, Boudjema, Cottrant, Pukhov, Semenov, NPB706(2005)

Indirect detection Pair of dark matter particles

annihilate and their annihilation products are detected in space• Positrons from neutralino

annihilation in the galactic halo• Photons from neutralino

annihilation in center of galaxy• Neutrinos from neutralino in sun

Best signal for hard positrons or hard photons from neutralino annihilation ->WW,ZZ• Favoured for mixed

bino/Higgsino or bino/wino• Hard Photons also from

annihilation of neutralino pair in photons (loop suppressed)

Positrons from AMS

Photons from GLAST

mSUGRA

LHC + direct detection

With measurements from LHC can we refine predictions for direct/indirect detection?

Consider our first example:

• M0=100, M1/2=250 A0=-100

Prediction for spin-dependent cross-section

E. Baltz et al hep-ph/0602187

Final remarks

Other DM candidates: KK UED

• Minimal UED: LKP is B (1), partner of hypercharge gauge boson• s-channel annihilation of LKP (gauge boson) typically more

efficient than that of neutralino • Compatibility with WMAP means rather heavy LKP• Within LHC range, relevant for > TeV linear collider

Warped Xtra-Dim (Randall-Sundrum)• GUT model with matter in the bulk• Solving baryon number violation in GUT models stable

Kaluza-Klein particle• Example based on SO(10) with Z3 symmetry: LZP is KK right-

handed neutrino• Agashe, Servant, hep-ph/0403143

Dark matter in Warped X-tra Dim Compatibility with WMAP for

LZP range 50- >1TeV LZP is Dirac particle,

coupling to Z through Z-Z’ mixing and mixing with LH neutrino

Large cross-sections for direct detection• Signal for next generation of

detectors in large area of parameter space

What can be done at colliders : identify model, determination of parameters and confronting cosmology?? Agashe, Servant, hep-ph/0403143

Cosmological scenario Different cosmological

scenario might affect the relic density of dark matter

Example: quintessence• Quintessence contribution

forces universe into faster expansion

• Annihilation rate drops below expansion rate at higher temperature

• Increase relic density of WIMPS

• In MSSM: can lead to large enhancements Profumo, Ullio, hep-ph/0309220

Conclusions Cosmology provides accurate determination of

properties of dark matter

LHC has good opportunities to discover new physics In some favourable scenarios LHC might be able to

make precise enough measurement to give accurate prediction of relic density of dark matter –confront cosmology

Complementarity astroparticle/colliders

Expect lots exciting results soon