the constrained e ssmmctp/sciprgpgs/events/2008/lhc2008/king-cems… · 2 loop, 3(mz)=0.118 sfk,...

07/01/2008 Steve King, LHC New Physics Signatures Workshop, MCTP

The Constrained EThe Constrained E66SSMSSMand its signatures at the LHCand its signatures at the LHC

Work with Moretti and Nevzorov; Howl; Athron, Miller, Moretti, Nevzorov

Related work:

Demir, Kane, T.Wang; Langacker, Nelson; Morrissey, Wells; Bourjaily; Cvetic, Demir, Espinosa, Everett, Langacker; J.Wang; Keith, Ma; Daikoku, Suematsu; Demir, Everett; Hewett, Rizzo; Barger, Langacker, Lee, Shaughnessy, many others (apologies)

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�MSSM solves �technical hierarchy problem� (loops)

�But no reason why Higgs/Higgsino mass » msoft the � problem�.

�In the NMSSM =0 but singlet allows SHuHd <S> Hu Hd where <S>»

�S3 term required to avoid a massless axion due to global U(1) PQ symmetry

�S3 breaks PQ to Z3 resulting in cosmo domain walls (or tadpoles if broken)

The The problemproblem

�One solution is to forbid S3 and gauge U(1) PQ symmetry so that the dangerous axion is eaten to form a massive Z� gauge boson U(1)� model

�Anomaly cancellation in low energy gauged U(1)� models implies either extra low energy exotic matter or family-nonuniversal U(1)� charges

�For example can have an E6 model with three complete 27�s at the TeV scale to cancel anomalies with a U(1)� broken by singlets which solve the problem

�This is an example of a model where Higgs triplets are not split from doublets


Minimal EMinimal E66SSM: Unification at MSSM: Unification at MPPHowl, SFK

(10) (4) (2) (2)PS L RSO SU SU SU6 (10) (1)E SO U

MGUT

TeV U(1)X broken, Z� and triplets get mass, term generated

MPlanck

Quarks, leptons

Triplets and Higgs

Singlet

MW SU(2)L£ U(1)Y broken

E6! SU(4)PS£ SU(2)L £ SU(2)R

SU(4)PS£ SU(2)L £ SU(2)R £ U(1)! SM £ U(1)X

(4,2,1) (4,1,2) (6,1,1) (1,2,2) (1,1,1) 27

Three families of 27�s survive to low energy (minus the RH �s)

£ U(1)

Extra U(1)X survives to TeV scale

RH masses

M1

M2

M3

E6 broken via Pati-Salam chain

Unification at MUnification at MPP in Minimal Ein Minimal E66SSMSSM

Low energy (below MGUT) three complete families of 27�s of E6

High energy (above MGUT» 1016 GeV) this is embedded into a left-right symmetric Pati-Salam model and additional heavy Higgs are added.

Howl, SFK

MPlanck MPlanck


EE66SSM: Unification at MSSM: Unification at MGUTGUTSFK, Moretti, Nevzorov

15 14 4(1) (1) (1) NU U U

(10) (5) (1)SO SU U 6 (10) (1)E SO U

E6 ! SU(5)£U(1)N MGUT

TeV U(1)N broken, Z� and triplets get mass, term generated

27',27'

To achieve GUT scale unification

we add non-Higgs

Quarks, leptons

Triplets and Higgs

Singletsand RH s

H�,H�-bar

MW SU(2)L£ U(1)Y broken

Right handed neutrinos are neutral under:

! SM £ U(1)N

RH masses

M1

M2

M3

E6 broken via SU(5) chain

Unification at MUnification at MGUTGUT in Ein E66SSMSSM

3

2

1

250 GeV

1.5 TeV

Blow-up of GUT region2 loop, 3(MZ)=0.118

SFK, Moretti, Nevzorov

162 10XM

GeV


Low energy matter content of ELow energy matter content of E66SSMSSM��s s

Exotic D,D-bar

Three families of Higgs Singlets Right-handed neutrinos

Quarks and Leptons

27i . .

Optional non-Higgs from incomplete reps 27�+27�-bar � and doublet-triplet problems (absent in minimal E6SSM)

H H


EE66SSM couplingsSSM couplings

SDD HSH FF D FH FW

, ,

, , , , ,

i i

c c c ci i i i i i

D D D

F Q L U D E N

,

,

i

u di i

S S

H H H

Singlet-Higgs-Higgs couplings includes effective term

Singlet-D-D couplings includes effective D mass terms

Yukawa couplings but extra Higgs give FCNCs

DQQ, DQL allows D decay but also proton decay

Two potential problems: rapid proton decay + Two potential problems: rapid proton decay + FCNCsFCNCs

� FCNC problem may be tamed by introducing a Z2 under which third family Higgs and singlet are even all else odd only allows Yukawa couplings involving third family Higgs and singlet Hu , Hd , S

� Z2 also forbids all DFF and hence forbids D decay (and p decay) Z2 cannot be an exact symmetry!How do we reconcile D decay with p decay? Two strategies: extra exact discrete symmetries or small D Yukawas

� In E6SSM can have extra discrete symmetries, two possibilities:

I. Z2L under which L are odd forbids DQL, allows DQQ exotic D are diquarks

II. Z2B with L & D odd forbids DQQ, allows DQL exotic D are leptoquarks

� Small DFF couplings <10-8 will suppress p decay sufficiently but couplings >10-12 will allow D decay with lifetime <0.1 s (nucleosynth) N.B. D / g2, p / g4 (this is the only possibility in the minimal E6SSM)

Henceforth assume problems solved by one of these approachesHenceforth assume problems solved by one of these approaches


The Constrained EThe Constrained E66SSMSSM, ,

, ,

i u i d i i i i

j u d u d

t u b d d

W SH H SD D

f S H H h S H H

h QH t h QH b h LH

Assume universal soft masses m0, A, M1/2 at MGUT

In practice, input SUSY and exotic threshold scale S then select tan andsinglet VEV <S>=s and run up third family Yukawas from S to MGUT

Then choose m0, A, M1/2 at MGUT and run down gauge couplings, Yukawas and soft masses to low energy and minimise Higgs potential for the 3 Higgs fields S, Hu, Hd (even under Z2)

EWSB is not guaranteed, but remarkably there is always a solution for sufficiently large to drive mS

2 <0 (c.f. large ht to drive mH2<0 )

Athron, SFK, Miller, Moretti, Nevzorov

Hu, Hd, S without indices are third family Higgs and singlet, Hu,, Hd,, S are non-Higgs

The Z2 allowed couplings



P1

P1

P1

tan 3, 6 , 0.7s TeV

Consider a particular EWSB solution P1 with = -0.5


Spectrum for P1 Spectrum for P1

12 0700 , 1.6 , 1M GeV m TeV A TeV

1.4TeV

1.8TeV

2.2TeV

03,4 2,

02, ,H h A

0 05,6 3, ,h Z

tan 3, 6 , 0.7, 0.5s TeV

01

02 1, g

97GeV

174GeV

460GeV

01h120GeV


4.7TeV3D3D5TeV

1,2D1.5TeV

1,2D300GeV

1.4TeV 1t

2, , ,Q t b L 1.8TeV1.7TeV

non-Higgsinos

non-Higgs

??GeV



P2 P2Expt excluded

Theor excluded

tan 10, 6 , 0.7s TeV




12 0420 , 2 , 20M GeV m TeV A GeV

tan 10, 6 , 0.7, 0.3s TeV


1.0TeV

1.8TeV

2.2TeV

03,4 2,

02, ,H h A

0 05,6 3, ,h Z

01

02 1,

g

65GeV

125GeV

300GeV0

1h116GeV

4.6TeV3D

1.5TeV 1t

2, , ,Q t b L 2.0TeV

3D4.9TeV

1,2D1.5TeV

1,2D300GeV

non-Higgs

non-Higgsinos??GeV



tan 10, 20 , 1.8s TeV

P3 P3




12 01 , 5.5 , 4.6M TeV m TeV A TeV

tan 10, 20 , 1.8, 0.6s TeV


3.5TeV

4.9TeV

7.5TeV

03,4 2,

02, ,H h A

0 05,6 3, ,h Z

0 01 1,h

02 1,

g

130GeV

650GeV

230GeV

4TeV 1t

2, , ,Q t b L 5.5TeV

3 3,D D17TeV

1,2D4TeV

1,2D300GeV

non-Higgs

non-Higgsinos??GeV


Note the characteristic spectrumNote the characteristic spectrumFor a given low energy M1, M2, M3 need a larger M1/2 than in the MSSM

Lightest states are h10 and gauginos:

Generally m0>M1/2 heavy squarks,sleptons with

2Remaining gauginos, Higgs and Z� are much heavier(ignoring non-Higgs and non-Higgsinos)


Consider the lightest Consider the lightest gauginogaugino statesstates

01 1N

02 2 1 1,N C

g123 0.7M M

122 0.25M M

121 0.15M M

12

400 1000M GeV

» Wino

» Bino

Gluino


CharginoChargino and and neutralinoneutralino production and decayproduction and decay

2N

1N

l l

1C

1N

l

N.B. Wino production only is allowed (no Bino production via W,Z)

Expect N2N2 , N2C1 , C1C1 pair production (not involving the N1» Bino )

However the decays must involve N1


e.g. Ne.g. N22NN22 production and decay production and decay

2N

1N

( )l p

( )l p Three body decays M < MZ

22llm p p

2 1max ll N Nm M M M

End point gives mass differenceFor absolute masses see Choi, Kim talks

Y=N2, N=N1

2 2missTN N l l l l E

2 2pp N N V


g

1N

qq

5

4g

q

m

m

1

,Y g

N N

pp gg V

GluinosGluinos are light < 1 are light < 1 TeVTeV and easily producedand easily produced

missTgg qqqq E

For gluino mass see Choi, Kim talks


'1 ZM g S

SFK,Moretti,Nevzorov

ZZ�� < 5 < 5 TeVTeV can be discovered can be discovered


Exotic DExotic D--quarks in Equarks in E66SSMSSM

300Dm GeV

Inv. mass distribution


Total cross section


Usual case is of scalar leptoquarks, here we have novel case of D being fermonic leptoquarks or diquarks


Novel signatures of D quarksNovel signatures of D quarksIn E6SSM it is possible that the D fermions decay rapidly as leptoquarksor diquarks giving missing energy in the final state (Brent Nelson�s talk)

However it is also possible that DFF couplings are highly suppressed giving rise to long lived D quarks giving jets containing heavy long lived D-hadron

D-hadrons resemble protons or neutrons but with mass >300 GeV:

p p

Clean events with two D-jets containing a pair of stable D-hadrons

Dp or Dn

Dp or Dn

,p nD Du D Dd


ConclusionsConclusions

E6 SSM�s are well motivated from string theory

Generally lead to lower fine tuning

Unification at GUT scale or Planck scale (ME6SSM)

ME6SSM solves problem without doublet-triplet splitting

CE6SSM has successful EWSB and leads to a characteristic SUSY spectrum with light gauginos, and heavy Z�

D quarks can either decay promptly as fermionic leptoquarksor diquarks, or can be long lived spectacular LHC signals


Some details about ESome details about E66SSMSSM��ss

Extra U(1)Nsurviving to TeV scale

Hypercharge

Most general E6 allowed couplings from 273:

Allows p and D decay

FCNC�sfrom extra Higgs

SHH terms SDD terms

Yukawas of quarks, leptons

DFF terms (F=Q,L)

RH chargeless Optional non-Higgs


EWSB minimisation conditions

With , , s , v1 , v2 fixed these fix m1 , m2 and ms which are given by

Leading to quadratic equations for m0 , M1/2 , A with two solutions

the constrained e ssmmctp/sciprgpgs/events/2008/lhc2008/king-cems… · 2 loop, 3(mz)=0.118 sfk,...

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