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
tt
bb
WW
bb
WW
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
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