Phenomenology of Twin Higgs Model

Hock-Seng Goh, Shufang SuWork in progress

Shufang Su • U. of ArizonaShufang Su • U. of Arizona

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Outline

Twin Higgs Model Twin Higgs Model Twin Higgs mechanismTwin Higgs mechanismLeft-right Twin Higgs modelLeft-right Twin Higgs modelNew particles and model New particles and model parametersparameters

Collider phenomenologyCollider phenomenologyHeavy top quarkHeavy top quarkHeavy gauge bosonsHeavy gauge bosonsHiggsesHiggses

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Twin Higgs mechanism

Higgs as pseudo-Goldstone boson of a global symmetryHiggs as pseudo-Goldstone boson of a global symmetryIts mass is protected against radiative correctionsIts mass is protected against radiative corrections

Little Higgs mechanism: Little Higgs mechanism: collective symmetry breakingcollective symmetry breaking

Twin Higgs mechanism: Twin Higgs mechanism: discrete symmetrydiscrete symmetry

Mirror symmetryMirror symmetryType IA TH: Chacko, Goh, Harnik, hep-ph/0506256Type IA TH: Chacko, Goh, Harnik, hep-ph/0506256Type IB TH: Chacko, Nomura, Papucci, Perez, hep-ph/0510273Type IB TH: Chacko, Nomura, Papucci, Perez, hep-ph/0510273

Left-right symmetryLeft-right symmetryType II TH: Chacko, Goh, Harnik, hep-ph/0512088Type II TH: Chacko, Goh, Harnik, hep-ph/0512088

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Left-right Twin Higgs model

Global Global U(4)U(4) , with subgroup , with subgroup SU(2)SU(2)LL SU(2) SU(2)R R U(1) U(1)B-LB-L gauged gauged

Left-right symmetry: Left-right symmetry: ggLL=g=gRR (y (yLL=y=yRR))

A linear realizationA linear realization

U(4)U(4) U(3) U(3)

SU(2)SU(2)LL SU(2) SU(2)RR U(1) U(1)B-L B-L SU(2) SU(2)LLU(1)U(1)YY

7 GB7 GB

SM Higgs doubletSM Higgs doublet EWSBEWSB

SM neutral Higgs: SM neutral Higgs: HH

3 eaten by heavy gauge bosons3 eaten by heavy gauge bosons

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Twin Higgs mechanism

Quadratic divergence forbidden by left-right symmetryQuadratic divergence forbidden by left-right symmetry

ggLL=g=gRR=g=g

U(4)U(4) invariant, does not contribute to the mass of GB invariant, does not contribute to the mass of GB

Log contribution:Log contribution:

mmHH g g22f / (4 f / (4 ),), natural for natural for f f TeV TeV

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Left-right Twin Higgs model

Fermion sector:Fermion sector:

EW precision constraints on EW precision constraints on SU(2)SU(2)RR gauge boson mass gauge boson mass f f 2 TeV 2 TeV

Top quark mass:Top quark mass:

Introduce another Higgs field that Introduce another Higgs field that only couples to gauge sectoronly couples to gauge sectorWhich has a larger VEV Which has a larger VEV

Top quark mass eigenstates: Top quark mass eigenstates: SM top and SM top and ttHH

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Left-right Twin Higgs model U(4) U(4) U(4), U(4), with gauged with gauged SU(2)SU(2)LLSU(2)SU(2)RRU(1)U(1)B-LB-L + LR symmetry + LR symmetry

U(4) U(4) U(3) U(3)

SU(2)SU(2)L L SU(2) SU(2)R R U(1) U(1)B-L B-L SU(2) SU(2)LLU(1)U(1)YY

7 GB7 GB

SM Higgs doubletSM Higgs doublet EWSBEWSB

SM neutral Higgs: SM neutral Higgs: HH

7 GB7 GBff22 f f11

Couple to gauge boson onlyCouple to gauge boson only

3 eaten by heavy gauge bosons3 eaten by heavy gauge bosons

SU(2)SU(2)LL Higgs Higgs doubletdoubletHH11

, H, H2200

U(4)U(4) U(3)U(3)

Left 3 Higgses:Left 3 Higgses: neutral Higgs neutral Higgs 00, charged Higgs , charged Higgs

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New particles

Heavy gauge bosons:Heavy gauge bosons: WWHH, Z, ZHH mm22WH,ZHWH,ZH g g22(f(f11

22+f+f2222))

Heavy top:Heavy top: ttHH mm22THTH M M22+y+y22ff11

22

Other SU(2)Other SU(2)RR Higgses: Higgses: mm22 g g44/(16/(1622)f)f22

22 log( log(/gf/gf22))

00 mm2200 B (f B (f22/f/f11))

B: small, (50-100 GeV)B: small, (50-100 GeV)22

Other SU(2)Other SU(2)LL HiggsHiggs HH11 mm22

H1H1, , H20 H20

HH2200 : soft symmetry breaking, O(f: soft symmetry breaking, O(f11))

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Model parameters

Model parameters: Model parameters: ff11, (f, (f22, y), , y), , M, , M, B, B,

Determine particle masses and interactionsDetermine particle masses and interactions

fixed by Higgs VEVfixed by Higgs VEV fixed by top quark massfixed by top quark mass = 4= 4ff1 1 or 2 or 2ff1 1

M=150 GeVM=150 GeVB=50 GeVB=50 GeV = f= f11/2/2

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Heavy top tH production

single heavy top productionsingle heavy top production

heavy top pair heavy top pair production production

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Heavy top tH decay

jj

WWttHH

bb

bb

tt

bb

ll

3 b + 1 j + 1 lepton + missing E3 b + 1 j + 1 lepton + missing ETT

jj

ttHH

WW

bb

ll

1 b + 1 j + 1 lepton + missing E1 b + 1 j + 1 lepton + missing ETT

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Heavy gauge boson production

Drell-Yan processDrell-Yan process

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ZH decay

ZZHH

2 b + 2 j + 1 lepton + missing E2 b + 2 j + 1 lepton + missing ETT

tt

qq

tt

bb

WW

bb

WW

qq

ll

ZZHH

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WH decay

WWHH ttHH bb: 4b + 1 lepton + missing E: 4b + 1 lepton + missing ETT

ttHH bW : 2b + 1 lepton + missing EbW : 2b + 1 lepton + missing ETT

ttHH tZ: 2b + 3 lepton + missing EtZ: 2b + 3 lepton + missing ETT

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Higgses

jj

mmHH 150-170 GeV 150-170 GeV, depending on , depending on ff11, , and M and M Higgs searches: Higgs searches:

1.1. gg gg H H ZZ* ZZ* llll llll

2.2. gg gg H H WW* WW* l lll

3.3. WBF WBF qqH qqH qqWW* qqWW* qql qqlll

SM HiggsSM Higgs

SU(2)SU(2)RR Higgs: Higgs: 00, ,

0 0 bb bb

tbtb2b + 1 lepton + missing E2b + 1 lepton + missing ETT

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0

Neutral Higgs Neutral Higgs 00

gg gg 00 bb bb, , QCD background overwhelmingQCD background overwhelming no no WW00, Z, Z00 associated production (no such coupling) associated production (no such coupling) bbbb00 , tb , tb00,, tttt00 cross section smallcross section small Produced via the decay of heavy particlesProduced via the decay of heavy particles

WWHH

bb

tt

bb

bb

bb

WW

00

ll

4 b + 1 lepton + missing E4 b + 1 lepton + missing ETT

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Neutral Higgs Neutral Higgs

no no WW, Z, Z associated production (no such coupling) associated production (no such coupling) bbbb , tb , tb,, tttt cross section smallcross section small Produced via the decay of heavy particlesProduced via the decay of heavy particles

jj

WWttHH

bb

bb

tt

bb

ll

3 b + 1 j + 1 lepton + missing E3 b + 1 j + 1 lepton + missing ETT

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H1, H2

0

Higgs that couple to gauge boson only:Higgs that couple to gauge boson only: HH11, H, H22

00

HH11HH22

00,, HH11HH11

, H, H2200HH22

00,, associated production (small) associated production (small) HH22

00 stablestable : missing energy: missing energy HH11

HH2200 + soft jets/leptons + soft jets/leptons

if decay fast enough: appears as missing energyif decay fast enough: appears as missing energy

if decay slow: track !if decay slow: track !

HH2200: good dark matter candidates: good dark matter candidates

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M=0 case

ff11 vv

Top Yukawa:Top Yukawa:

ttSM SM = (t= (tLL, T, TRR), m), mt t = yv= yvttH H = (T= (TLL, t, tRR), m), mtH tH = yf= yf11

Gauge couplingGauge coupling

W W t t b b W W t tH H bb WWH H t t b b WWH H ttH H bb

Z Z t t t t Z Z t tHH t t

HH

Z Z t tH H tt ZZH H t t t t ZZH H ttH H ttHH

ZZHH t tH H tt

Yukawa couplingYukawa coupling

00 t tHH t tHH

00 t t tt 00 t tH H tt

ttHH b b tt bb

H H t t t t H H t tH H ttH H (small)(small) H H t tH H tt

t + b (100%)t + b (100%)XX

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decay

No two body decayNo two body decay Leading decay: 3 bodyLeading decay: 3 body

off-shelloff-shell

0 0 bb: bb: bbqq final statesbbqq final states huge QCD bghuge QCD bg

HH ZZ ZZ**, WW, WW**

small signalsmall signal

For For M=0M=0discovery of almost all the particle are discovery of almost all the particle are difficult difficult except for except for ZZHH

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Conclusions

Left-right twin Higgs model: Higgs as pseudo-goldstone Left-right twin Higgs model: Higgs as pseudo-goldstone bosonboson

quadratic divergence forbidden by left-right symmetryquadratic divergence forbidden by left-right symmetryNew particlesNew particles

Heavy gauge boson: Heavy gauge boson: WWHH, Z, ZHH

Heavy top quark Heavy top quark ttHH

New Higgses: New Higgses: 00, , , H, H11, H, H22

00 (DM) (DM)MM00: rich collider phenomenology: rich collider phenomenologyM=0M=0: difficult except for : difficult except for ZZHH

Future workFuture workPick certain channel for detailed study: background, cuts,…Pick certain channel for detailed study: background, cuts,…Identify twin Higgs mechanismIdentify twin Higgs mechanismDark matter studyDark matter studyComparison with other models, e.g., little higgsComparison with other models, e.g., little higgs