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SPLIT SUPERSYMMETRY

G.F. Giudice CERN

• Motivazioni per Split Supersymmetry

• Conseguenze osservative di Split Supersymmetry

Arkani-Hamed Dimopoulos hep-th/0405159Giudice Romanino hep-ph/0406088

Arkani-Hamed Dimopoulos Giudice Romanino hep-ph/0409232

IFAE Catania, 31 marzo 2005

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MW << MPl nuova fisica a ~ TeV

Problema del sapore 10 34 TeV

Piccola gerarchia TeVEW precision data

Contact int. at LEP2

mK

eK bs

CC << MPl nuova fisica a 10-3 eV

Gravità modificata a questa scala oppure fallimento del criterio di naturalezza

Riconsideriamo il problema della gerarchia: la scala elettrodebole è determinata dalla

dinamica o dalla statistica ?

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Idea del multiverso emerge dalla teoria dell’inflazione

Landscape delle teorie di stringa: 10100 vuoti che corrispondono a diverse costanti di accoppiamento

Come la vita si è sviluppata su un pianeta con acqua liquida, con massa tale da trattenere l’atmosfera, con campo magnetico tale da proteggere dal vento solare, in un’orbita galattica con limitato impatto di comete, …così il nostro universo si è sviluppato in un vuoto con CC ~ 10-3 eV , v ~ 102 GeV

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Proposal of SPLIT SUPERSYMMETRY: retain at the weak scale only gauginos, higgsinos and one Higgs boson (squarks, sleptons and extra Higgs at the scale m)

Abandon hierarchy problem (speculations on probability distributions of theories) and use only observational hints

Gauge-coupling unification: motivated by theory that addresses fundamental structure of SM and by measurements on i

Dark matter: connection between weak scale and new particle masses

vh

pb 1.02

rel

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Gauge-coupling unification as successful (or better) than in ordinary SUSY

Eliminate :

• Excessive flavour and CP violation

• Fast dim-5 proton decay

• Tight constraints on the Higgs mass

Retain :

• DM & gauge-coupling unification

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Not unique solution, however…

• Minimality: search for unification with single threshold, only fermions in real reps, and 1015 GeV < MGUT < 1019 GeV SpS has the minimal field content consistent with gauge-coupling unification and DM

• Splitting of GUT irreps: in SpS no need for new split reps either than SM gauge and Higgs• Light particles: R-symmetry protects fermion masses• Existence and stability of DM: R-parity makes stable• Instability of coloured particles: coloured particles are necessary, but they decay either by mixing with quarks (FCNC!) or by interactions with scale < 1013 GeV

SpS not unique, but it has all the necessary features built in

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Why Supersymmetry?

)by broken forbidden)

symmetry-R 0,](R[ that so 0]R[ (choose

soft terms violating-R soft termsinvariant -R

~

~~

~~~

~1

212

21

21*4

32221

*4

~222**4

2

X

gQ

FHHd

XHH

mHHXd

mAQXdmBHHXXd

mMWWXdmmQQXXd

mX

• R-symmetry “splits” the spectrum (Mg and mix through renorm.)

• R-invariant dim = 2 R-violating dim = 3

~

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Split Supersymmetry determined by susy-breaking pattern

*

2

2124

**

234

*

*

2

~4

*

221

422*4

24

~1

~1

~1 operators renorm.Non

~~~

~1 breaking-D

M

mHHYDd

MM

mAYQd

M

M

mMWYWd

M

mBHYHdmmQYQd

mY

g

Q

• Analogy: in SM, L not imposed but accidental. m small, although L-breaking is O(1) in underlying theory

• In supergravity, not generated at O(MPl) but only O(MS2/MPl)

• Here, Mg and not generated at O(m) but only O(m2/M*)~ ~

~

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OBSERVATIONAL CONSEQUENCES OF SPLIT SUPERSYMMETRY

• Only one Higgs boson with SM properties

• With respect to MSSM, larger log corrections to =g2

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Heavy squarks and sleptons suppress flavour & CP violation, dim-5 proton decay

New source of flavour-diagonal CP violation remains

h.c.~~

2

~~~

2

~~~

2* d

du

udu HWH

gHWH

gHHWW

M L

CP violation in Mgg du** ~~Im

Effects on SM matter at two loops: EDM

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Eliminate phases in chargino mass matrix

ggM

ggMMFF

e

dW

uW

~2

~2~det arg

32 2

2

MM

FFHHH

~*O mixes with EDM operator

23log

~~Im

16 H

dufff

m

M

M

ggmQ

e

d

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Present limit: de < 1.7 × 10-27 ecm at 95% CL (DeMille et al.)

Future: DeMille et al. (Yale) 10-29 ecm in 3 years and 10-31 ecm in 5 years.

Lamoreaux et al. (Los Alamos): 10-31 ecm and eventually 10-35 ecm.

Results from Hinds et al. (Sussex) and Semertzidis et al. (Brookhaven) plans to improve by 105 sensitivity on EDM

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• not determined by EWSB• at LHC produced in DY, not in cascades• decay chains with Higgs bosons• couplings violate susy relations

GLUINO: decays through intermediate heavy scalars

qq~

q_

g~

Gyr0.4GeV10

m~

M

TeVτ

4

13

5

g~g~

CHARGINOS AND NEUTRALINOS:

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DARK MATTER IN SPLIT SUPERSYMMETRY

With respect to ordinary susy• not determined by EWSB

• B only interacts with Higgs-Higgsino

• mixed state

• Higgsino

• Wino

42221

22 TeV1.0 mMh

TeV2.10.1forDMTeV/09.0 22 h

TeV5.20.2forDMTeV/02.0 22

22 MMh

~

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Upper bound on m from thermal relic abundance retained also when gravitino decay contributes to DM

Spin-independent scattering cross section off protons is mediated by Higgs exchange

Present: CDMS & EDELWEISS: cm2

Future:CDMS II: cm2; ZEPLIN, XENON, GENIUS: cm2

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CONCLUSIONS

• Failure of naturalness argument for CC casts doubts on the existence of a physical threshold at the weak scale

• Split Supersymmetry abandons hierarchy problem, but retains gauge-coupling unification and dark matter

• Not unique solution but, under certain assumption, it is the simplest option

• Certain patterns of susy breaking automatically lead to the spectrum of Split Supersymmetry

• Observational consequences for collider searches, EDM, dark matter and gravitino cosmology