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 model

New particles and model New particles and model parametersparameters

Collider phenomenologyCollider phenomenologyHeavy top quarkHeavy top quarkHeavy gauge bosonsHeavy gauge bosonsHiggsesHiggses

Goh’s talkGoh’s talk

Chacko, Goh, Harnik, hep-ph/0512088Chacko, Goh, Harnik, hep-ph/0512088

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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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Left-right Twin Higgs model

Fermion sector:Fermion sector:

Top quark mass:Top quark mass:

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

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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 (t + b (100%)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

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discovery

DifficultDifficultLarge QCD bg Large QCD bg or small signalor small signal

small signalsmall signal

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0 discovery

absentabsent

difficultdifficult

small signalsmall signal

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Heavy top tH discovery

single, pair production does not change much.single, pair production does not change much. decay: only decay: only ttHH b b (100%) (100%)

100%100%either huge QCD bgeither huge QCD bgOr small signalOr small signal

absentabsent

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Heavy gauge boson discovery

ZZHH, W, WHH drell-yan cross section does not change drell-yan cross section does not change ZZHH: : ZZHH ll ll does not change much does not change much Br(Br(ZZHH t t t tHH) =0 ) =0

WWHH: : difficult difficult

either huge QCD bgeither huge QCD bgOr small signalOr small signal

absentabsent

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