modifying higgs productionpages.uoregon.edu/soper/terahiggs2012/martin.pdfboson. these...

Modifying Higgs production

Adam Martin([email protected])

Terascale 2012, University of OregonApril 6th, 2012

based on 1112.2208 withB. Dobrescu and G. Kribs

1Friday, April 6, 2012

mailto:[email protected]

mailto:[email protected]

got Higgs?

• too early to tell...

• so, let’s think of various ways simple extensions of SM can change Higgs physics

• Paddy showed us how to ‘fake’ or ‘friend’ the Higgs with other states (also Higgs-portal)


got Higgs?

I want to do something slightly different:

• keep the Higgs (nearly) SM as far as EWSB, # states, just change production with new physics


got Higgs?

I want to do something slightly different:

• Some familiar conclusions:--> importance of VBF and associated production

• distinct correlated signals

find:

• keep the Higgs (nearly) SM as far as EWSB, # states, just change production with new physics


mH=125

altered production --> will look at a wider range of mH


Higgs production

SM Higgs production is predominantly gluon fusion

[GeV] HM100 200 300 400 500 1000

H+X

) [pb

]

(pp

-210

-110

1

10= 7 TeVs

LHC

HIG

GS

XS W

G 2

010

H (NNLO+NNLL QCD + NLO EW)

pp

qqH (NNLO QCD + NLO EW)

pp

WH (NNLO QCD + NLO EW)

pp ZH (NNLO QCD +NLO EW)

pp

ttH (NLO QCD)

pp

σ @ LHC 7 TeVg

g

ht

Ht, b

g

g

H

q

q

W, Z

W, Z

H

g

g

Q

Q̄

Hq̄

q

W, Z

W, Z

QQ̄

W, Z

Ht, b

g

g

H

q

q

W, Z

W, Z

H

g

g

Q

Q̄

Hq̄

q

W, Z

W, Z

QQ̄

W, Z

[GeV] HM100 200 300 400 500 1000

H+X

) [pb

]

(pp

-210

-110

1

10= 7 TeVs

LHC

HIG

GS

XS W

G 2

010


pp


pp



pp

ttH (NLO QCD)

pp

•  !!"#$%#&'(#)*+$,-,&#./*)012*,#+(1'-,$%+#3*/#45#"$!!%#-&#6"78#

–  -%%*1$-&()#9(&%#./*)01()#$,#%*:#!;0*,#/-)$-2*,#<=6>?#

–  #'$!'#@A3-1&*/#<BC?#–  #;-/!(#&'(*/(21-;#0,1(/&-$,2(%#

DDEDFEDD# G8H(@*I$1J#6*K#5-%%#"$!!%#4(-/1'#-&#754J#"7L# M#

q

g

Hgg fusion:

gWW, ZZ fusion:

t

g

g

H

t

tt fusion:

q

q q

qq

W, Z

W, Z

W, ZH

H

W*, Z*W, Z strahlung:

87.4 %

5.4 % 0.5 %

6.7 %@120 GeV

H-&(%#-,)#7/*%%#4(12*,%#3*/#45#"$!!%#


Gluon fusion

[GeV] HM100 200 300 400 500 1000

H+X

) [pb

]

(pp

-210

-110

1

10= 7 TeVs

LHC

HIG

GS

XS W

G 2

010


pp


pp



pp

ttH (NLO QCD)

pp

σ @ LHC 7 TeVg

g

ht

Ht, b

g

g

H

q

q

W, Z

W, Z

H

g

g

Q

Q̄

Hq̄

q

W, Z

W, Z

QQ̄

W, Z

Ht, b

g

g

H

q

q

W, Z

W, Z

H

g

g

Q

Q̄

Hq̄

q

W, Z

W, Z

QQ̄

W, Z

[GeV] HM100 200 300 400 500 1000

H+X

) [pb

]

(pp

-210

-110

1

10= 7 TeVs

LHC

HIG

GS

XS W

G 2

010


pp


pp



pp

ttH (NLO QCD)

pp

•  !!"#$%#&'(#)*+$,-,&#./*)012*,#+(1'-,$%+#3*/#45#"$!!%#-&#6"78#

–  -%%*1$-&()#9(&%#./*)01()#$,#%*:#!;0*,#/-)$-2*,#<=6>?#

–  #'$!'#@A3-1&*/#<BC?#–  #;-/!(#&'(*/(21-;#0,1(/&-$,2(%#

DDEDFEDD# G8H(@*I$1J#6*K#5-%%#"$!!%#4(-/1'#-&#754J#"7L# M#

q

g

Hgg fusion:

gWW, ZZ fusion:

t

g

g

H

t

tt fusion:

q

q q

qq

W, Z

W, Z

W, ZH

H

W*, Z*W, Z strahlung:

87.4 %

5.4 % 0.5 %

6.7 %@120 GeV

H-&(%#-,)#7/*%%#4(12*,%#3*/#45#"$!!%#

• loop level• driven by top quark in the loop• as an operator, generates

we can add in a new operator

depending on sign(c0), get constructive/destructive interference with SM piece ->more space allowed for

destructive

but what possible physics gets us Onew with minimal impact elsewhere? (changing just Δg)

αshGaµνG

a,µν

v~

(Manohar, Wise)Onew =

c0H†H G

aµνG

a,µν

Λ2


Class of models

+

g

g

h

- cutoff operators (Manohar-Wise)- “fermiophobic” (also affects decays)- “gluophobic” MSSM (e.g., Djouadi)- composite Higgs (e.g. Low-Rattazzi-Vechi)

Decreasing Productiong

g

ht

Many Implementations ...

stuff in the blob• must be colored• must talk to Higgs• easier if bosonic• could be multiple fields• could carry EW charge

Class of ModelsOne or more colored scalars in some representations of QCD.

4

IV. OCTET MODEL

Extensive higher-order calculations of the effects ofa real color octet scalar on Higgs production were car-ried out in Ref. [4]. These heroic calculations were ap-plied exclusively to consider enhancements in the Higgsproduction rate, and the extent to which they can bebounded from data. Our interest in color octet scalars isorthogonal – we seek reductions in the Higgs productionrate, demonstrating that natural parameter ranges per-mit substantial if not complete destructive interferencebetween the top loop and the color octet scalar.

Aside from the kinetic term of the octet, we add octetself-interactions and interactions of S with the SM Higgsboson. These “Higgs-portal” interactions are the onlyrenormalizable link between SM matter and the octet.

LS =1

2(DµSa)

2−1

2M

2S SaS

a−κ

2H

†H SaS

a−ωS

4(SaS

a)2

100 120 140 160 180 20010

50

100

500

1000

5000

1�104

mS �GeV�

Σ�pp�S

S��pb�

cross section at LHC7

FIG. 5. Limits on color octet pair production from the AT-LAS search on pairs of dijet resonances (magenta) comparedwith the predicted S production cross section (blue). We areinterested in real scalars so the cross sections are half of thosepresented in (Mahoar /Wise, Sgluons, etc.).

In order for the octets to decay, we must include one (ormore) Z2 violating operator. We add the renormalizableinteraction

λS dabc

SaSbSc, (4)

where a, b, c label the color index and λS has dimensionof mass.

Appendix A: Other mass points

Appendix B: Scalar contribution to box and triangle

The scalar contribution to the ggh coupling consists of a triangle diagram and a bubble diagram. Note that, unlikein the fermionic loop case, for the scalar loop the crossed-gluon diagram is redundant with the uncrossed diagramso we do not add it separately. Also, the bubble diagram comes with a symmetry factor of 1/2. Combining bothdiagrams, we find

κ v αsCAδab4π

�2MS C0(p1, p2 : MS) + 1

��ηµν − p1 ν p2µ

(p1 · p2)

�, (B1)

where CA is the Casimir of the representation of the scalar in the loop (CA = 3 for the octet), the function C0 is thePasarino-Veltman scalar three-point integral, and a, b refer to the color indices of the incoming gluons. Adding thisterm to the fermionic triangle, we can solve for the critical value of κ.

4

IV. OCTET MODEL



LS =1

2(DµSa)

2−1

2M

2S SaS

a−κ

2H

†H SaS

a−ωS

4(SaS

a)2

100 120 140 160 180 20010

50

100

500

1000

5000

1�104

mS �GeV�

Σ�pp�S

S��pb�




λS dabc

SaSbSc, (4)





κ v αsCAδab4π

�2MS C0(p1, p2 : MS) + 1


(p1 · p2)

�, (B1)


“Higgs portal” self quartic

2

of electroweak symmetry breaking itself, which not sur-prisingly, can easily affect Higgs production as well asdecay. There is a large literature on this; some whohave considered reductions in the Higgs production ratethrough changes in electroweak symmetry breaking in-clude Refs. [big list]. An extreme limit, namely elec-troweak symmetry breaking through technicolor, has ofcourse no Higgs at all. Yet, the standard lore if no Higgsis found is that presumably some strongly-coupled elec-troweak symmetry breaking mechanism is present. Thisclass of models provides a concrete counter-example –and a set of definitive tests to discover it or rule it out.

It is interesting to consider that single Higgs produc-tion may then proceed only through Higgstralung for rel-atively low Higgs masses, and vector-boson-fusion (VBF)throughout the mass range. This suggests rethinking thestrategies for Higgs detection, and the extent to whichthey have been over -optmized for a gluon fusion source.For instance, the current search strategies for Higgs toWW for xx < mh < yy GeV at ATLAS [cite] and CMS[cite] employ dilepton plus 0 or 1 jets. If the VBF channelwere the source of single Higgs, the WW signal accompa-nied by at least 2 (forward) jets, and thus be overwhelm-ingly rejected by their analyses.

————-Finally, while there are piles upon piles of litera-

ture stealthifying the Higgs by modifying its decay rateswhen the Higgs is relatively light [cite a bunch], ourmodel permits moderate to heavier Higgses, up to mh �Min(2mS , 2mt), to be stealth.

This suggests completely rethinking the search strat-egy for the Higgs

In addition, the more general question of how to inter-pret a future observation of a particle consistent with aHiggs (in some decay channels, for example) and yet in-consistent with one or more Standard Model predictions(in the production rate or branching fraction) remainsparamount. Understanding the full range of possibilitiesfor how new physics modifies Higgs properties

is vital to distinguish it from an “imposter” [cite PaddyNeal].

It is well known that the LEP limits on the Higgs arestringent and not easily avoided. This is because the pro-duction mode, e+e− → Z

∗ → Zh, is directly related toelectroweak symmetry breaking, while most of the decayrates are easily measurable. (The older exceptions [cite],namely h → aa → 4τ and h → aa → 4τ

————

II. MODELS LEADING TO

UNDERPRODUCTION

The general class of models that naturally lead to mod-ifications in Higgs production consist of extending theStandard Model to include a set {i} of real φr,i and aset {j} of complex scalar fields φc,j transforming in realor complex representations Ra

, Rα of QCD respectively.

The renormalizable interactions consist of

L =�

i

L(φc,i) +�

j

L(φr,j) (1)

L(φc,i) = Dµφ†c,iD

µφc,i −M2c,i φ

†c,iφc,i

− κc,iφ†c,iφc,i H

†H − ωc,i(φ

†c,iφc,i)

2 (2)

L(φr,i) =1

2(Dµφr,i)

2 − 1

2M

2r,i φ

2r,i

− κr,i

2φ2r,i H

†H − ωr,i

4(φ2

r,i)2 (3)

where the color contractions for a scalar in a given rep-resentation are implicit. For compactness we have notwritten mixed colored scalar self-interactions such asφ†c,iφc,iφ

†c,jφc,j or φ2

r,iφ2r,j .

The “Higgs-portal” interactions proportional to κ arewhat interest us.Aside from the kinetic terms of the scalars (which we

have rotated into a diagonal kinetic basis), we add theself-interactions andAside from the kinetic term of the octet, we add octet

self-interactions and interactions of S with the SM Higgsboson. These “Higgs-portal” interactions are the onlyrenormalizable link between SM matter and the octet.

LS =1

2(DµSa)

2−1

2M

2S SaS

a−κ

2H

†H SaS

a−ωS

4(SaS

a)2

For octet-Higgs coupling κ < 0 the interference betweenthe top quark loop and the scalar octet loop is alwaysdestructive. Dialing κ, we reach a critical value where thecancellation is exact (at LO). This critical value dependson the octet and Higgs masses.

50 100 150 200 250 300�3.0

�2.5

�2.0

�1.5

�1.0

�0.5

0.0

mS �GeV�

Κ �

FIG. 1. The critical value of the coupling κ where gluon

fusion gg → h exactly vanishes. The value of the coupling

depends on MS , but it is perturbative for octet masses in

the ∼ few hundred GeV range. Three different Higgs masses

are shown (mH = 120GeV, 140GeV, 160GeV), however the

critical coupling is fairly insensitive to Higgs mass.

• The value of the critical coupling seems large. How-ever, NLO effects have been calculated in [4] andcan be shown to enhance the scalar loop signifi-cantly, leading to a reduction in the critical couplingκ∗ of the order 25%.

See alsoY. Bai’s talk

Our working example, considerreal scalar octet Sa with interactions:

“Higgs portal”interaction

self-quarticgets mass w/out Higgs

As an example, consider a color octet, EW singlet real scalar

(for other possibilities: Bai, Fan Hewitt 1112.1964, Burgess, Trott, Zuberi 0907.2696)


Class of models

EW singlets S do not effect EWSB in any way

100 150 200 250 300 350 400

�2.0

�1.5

�1.0

�0.5

0.0

mS �GeV�Κ

pp � h contours, mh�200 GeV

Gluon Fusion Suppression σ(gg->h; LHC)/σSM

+g

g

h

g

g

h 0.1

0.25

0.5

g

g

ht

100 150 200 250 300 350 400

�2.0

�1.5

�1.0

�0.5

0.0

mS �GeV�

Κ



+g

g

h

g

g

h 0.1

0.25

0.5

g

g

ht

blob = κ< 0 leads to destructive interference with top loop

EW singlet scalars decouple, top quark doesn’tAt(gg->h) ~ αs/v AS(gg->h) ~ αs κv/μS2

so expect underproduction only if scalars are light

only Higgs BR effected is h->ggBUT


Underproducing

100 150 200 250 300 350 400

�2.0

�1.5

�1.0

�0.5

0.0

mS �GeV�

Κ



+g

g

h

g

g

h 0.1

0.25

0.5

g

g

ht

50 100 150 200 250 300 350 400�2.0

�1.5

�1.0

�0.5

0.0

MS �GeV�Κ

Mh� 125 GeV

0.50.25

0.1

0.75

0.9

50 100 150 200 250 300 350 400�2.0

�1.5

�1.0

�0.5

0.0

MS �GeV�

ΚMh� 250 GeV

0.50.25

0.1

0.75

0.9


50 100 150 200 250 300 350 400�2.0

�1.5

�1.0

�0.5

0.0

MS �GeV�

Κ

Mh� 450 GeV

0.50.25

0.1

0.75

0.9

50 100 150 200 250 300 350 400�2.0

�1.5

�1.0

�0.5

0.0

MS �GeV�Κ

Mh� 250 GeV

0.50.25

0.1

0.75

0.9

Features in Underproductionthree regions

mh < 2 mt, mh < 2 mS

mh < 2 mt, mh >2 mS

mh > 2 mt, mh >2 mS

mh > 2 mt, mh <2 mS

1.)

2.)

3.)

OR

limited regions when

Im(At(gg->h)) ≠ 0, Im(AS(gg->h))=0

or vice versa


in other terms...

��

��

��

��

��

��

��

� ��

150 200 250 3000.001

0.01

0.1

1

mH �GeV�

95�C.L.Σ�gg�

h��Σ�gg�h� SM

CMS�ATLAS 1.0�2.3 fb�1

MS � 300, Κ � �1.0MS � 200, Κ � �1.0MS � 160, Κ � �1.0

HCP limit + 2σ band

Features in Underproduction


Higgs overproductionchanging the sign of κ, we get more Higgses than in the SM

50 100 150 200 250 300 350 4000.0

0.5

1.0

1.5

2.0

mS �GeV�

Κ � 4.0

� 2.0 �1.5

� 1.25

Mh � 125 GeV


how low/how well/how general?

we need relatively light scalars, is there a limit?

depends on how these octets decay (so far, Z2 symmetry present, so no decay)

one choice, add

4 jet final state

2 pairs of equal-mass dijet resonances

λ dabcSa Sb Sc

Octet DecayBreak Z2 (S -> -S) through:

leads to decay into two gluons:

4

IV. OCTET MODEL



LS =1

2(DµSa)

2−1

2M

2S SaS

a−κ

2H

†H SaS

a−ωS

4(SaS

a)2

100 120 140 160 180 20010

50

100

500

1000

5000

1�104

mS �GeV�

Σ�pp�S

S��pb�




λS dabc

SaSbSc, (4)





κ v αsCAδab4π

�2MS C0(p1, p2 : MS) + 1


(p1 · p2)

�, (B1)


g

g

hS

leads to S -> gg

so we have

Octet Production

•

•

g

g

Sa

Sa

g

g

g

g

Four jet production

with Sa invariant mass among two pairs.+...

}g

g


Limits from LHCmulti-jet final state = large background, few handles

!!"#$%&'()*#(+ ,$&-'./&01(23(4&5*&67$8#6#/0(9:;(!:<<

!"#"$%

&'(%% %)*$"(+ ,"#"$- . +/ 0$ .11 2)3 0+4 561 7/ 0$ .81 2)39:*,;4) %<,;(+ ="$> .11 ? @ ? .A6 2)3 0$ 86B &C!C ="$> 0 #0%% ="+4(=(D 6 2)3 0'(;+4 .E1 2)3

Bounds on 4-jet Signal

35 pb-1 no Tevatron limit

improvements?



!!"#$%&'()*#(+ ,$&-'./&01(23(4&5*&67$8#6#/0(9:;(!:<<

!"#"$%

&'(%% %)*$"(+ ,"#"$- . +/ 0$ .11 2)3 0+4 561 7/ 0$ .81 2)39:*,;4) %<,;(+ ="$> .11 ? @ ? .A6 2)3 0$ 86B &C!C ="$> 0 #0%% ="+4(=(D 6 2)3 0'(;+4 .E1 2)3

Bounds on 4-jet Signal

35 pb-1 no Tevatron limit

improvements?

!!"#$%&'()*#(+ ,$&-'./&01(23(4&5*&67$8#6#/0(9:;(!:<<

!"#"$%

&'(%% %)*$"(+ ,"#"$- . +/ 0$ .11 2)3 0+4 561 7/ 0$ .81 2)39:*,;4) %<,;(+ ="$> .11 ? @ ? .A6 2)3 0$ 86B &C!C ="$> 0 #0%% ="+4(=(D 6 2)3 0'(;+4 .E1 2)3

100

1000

10000

Bound on Real Scalar Color Octet

σ color octet(at LO)



more data in CMS, but higher trigger means can’t go down to low mS


so far, all LO -- what about NLO, NNLO...?

for large mt, mS, scalar contributions to gg->H studied to NNLO (Petriello & Boughezal)

using their calculations, find same degree of cancelation for smaller κ (~25%) than at LO

... κ is a free parameter for us, so NNLO, etc, do not change the fact that we can get altered

production

...captures the most important higher order corrections (at least for mH < mS)

(Bonciani, Degrassi, Vicini)(Harlander, Degrassi et al)


we need relatively large coupling

2

of electroweak symmetry breaking itself, which not sur-prisingly, can easily affect Higgs production as well asdecay. There is a large literature on this; some whohave considered reductions in the Higgs production ratethrough changes in electroweak symmetry breaking in-clude Refs. [big list]. An extreme limit, namely elec-troweak symmetry breaking through technicolor, has ofcourse no Higgs at all. Yet, the standard lore if no Higgsis found is that presumably some strongly-coupled elec-troweak symmetry breaking mechanism is present. Thisclass of models provides a concrete counter-example –and a set of definitive tests to discover it or rule it out.

It is interesting to consider that single Higgs produc-tion may then proceed only through Higgstralung for rel-atively low Higgs masses, and vector-boson-fusion (VBF)throughout the mass range. This suggests rethinking thestrategies for Higgs detection, and the extent to whichthey have been over -optmized for a gluon fusion source.For instance, the current search strategies for Higgs toWW for xx < mh < yy GeV at ATLAS [cite] and CMS[cite] employ dilepton plus 0 or 1 jets. If the VBF channelwere the source of single Higgs, the WW signal accompa-nied by at least 2 (forward) jets, and thus be overwhelm-ingly rejected by their analyses.

————-Finally, while there are piles upon piles of litera-

ture stealthifying the Higgs by modifying its decay rateswhen the Higgs is relatively light [cite a bunch], ourmodel permits moderate to heavier Higgses, up to mh �Min(2mS , 2mt), to be stealth.

This suggests completely rethinking the search strat-egy for the Higgs

In addition, the more general question of how to inter-pret a future observation of a particle consistent with aHiggs (in some decay channels, for example) and yet in-consistent with one or more Standard Model predictions(in the production rate or branching fraction) remainsparamount. Understanding the full range of possibilitiesfor how new physics modifies Higgs properties

is vital to distinguish it from an “imposter” [cite PaddyNeal].

It is well known that the LEP limits on the Higgs arestringent and not easily avoided. This is because the pro-duction mode, e+e− → Z

∗ → Zh, is directly related toelectroweak symmetry breaking, while most of the decayrates are easily measurable. (The older exceptions [cite],namely h → aa → 4τ and h → aa → 4τ

————

II. MODELS LEADING TO

UNDERPRODUCTION

The general class of models that naturally lead to mod-ifications in Higgs production consist of extending theStandard Model to include a set {i} of real φr,i and aset {j} of complex scalar fields φc,j transforming in realor complex representations Ra

, Rα of QCD respectively.

The renormalizable interactions consist of

L =�

i

L(φc,i) +�

j

L(φr,j) (1)

L(φc,i) = Dµφ†c,iD

µφc,i −M2c,i φ

†c,iφc,i

− κc,iφ†c,iφc,i H

†H − ωc,i(φ

†c,iφc,i)

2 (2)

L(φr,i) =1

2(Dµφr,i)

2 − 1

2M

2r,i φ

2r,i

− κr,i

2φ2r,i H

†H − ωr,i

4(φ2

r,i)2 (3)

where the color contractions for a scalar in a given rep-resentation are implicit. For compactness we have notwritten mixed colored scalar self-interactions such asφ†c,iφc,iφ

†c,jφc,j or φ2

r,iφ2r,j .

The “Higgs-portal” interactions proportional to κ arewhat interest us.Aside from the kinetic terms of the scalars (which we

have rotated into a diagonal kinetic basis), we add theself-interactions andAside from the kinetic term of the octet, we add octet

self-interactions and interactions of S with the SM Higgsboson. These “Higgs-portal” interactions are the onlyrenormalizable link between SM matter and the octet.

LS =1

2(DµSa)

2−1

2M

2S SaS

a−κ

2H

†H SaS

a−ωS

4(SaS

a)2

For octet-Higgs coupling κ < 0 the interference betweenthe top quark loop and the scalar octet loop is alwaysdestructive. Dialing κ, we reach a critical value where thecancellation is exact (at LO). This critical value dependson the octet and Higgs masses.

50 100 150 200 250 300�3.0

�2.5

�2.0

�1.5

�1.0

�0.5

0.0

mS �GeV�

Κ �

FIG. 1. The critical value of the coupling κ where gluon

fusion gg → h exactly vanishes. The value of the coupling

depends on MS , but it is perturbative for octet masses in

the ∼ few hundred GeV range. Three different Higgs masses

are shown (mH = 120GeV, 140GeV, 160GeV), however the

critical coupling is fairly insensitive to Higgs mass.

• The value of the critical coupling seems large. How-ever, NLO effects have been calculated in [4] andcan be shown to enhance the scalar loop signifi-cantly, leading to a reduction in the critical couplingκ∗ of the order 25%.

120160200250

Total Cancellation“Critical” size of κ

mh

can get O(1) suppression with small κ...

large negative κ --> may worry about vacuum stability

for ‘total’ cancelation..

λ h4 and ω S4 terms stabilize certain directions, but are all directions safe?

(Petriello, Boughezal)bounded ? ?|κ| < 2

�ω λh


at large field value, running of κ, ω is important

dκ

dt= c0 κ

2 + · · ·positive constant

other terms, all ∝ κ

as usual for a quartic coupling, but we start with κ < 0


at large field value, running of κ, ω is important

dκ

dt= c0 κ

2 + · · ·positive constant

other terms, all ∝ κ

κ

Λ0

-1.5

... so as energy is increased, |κ| gets smaller

an asymptotically free coupling

as usual for a quartic coupling, but we start with κ < 0


stability of the RG-improved potential doesn’t limit parameter space of our simple setup

simultaneously, the self-quartic ω gets bigger

running is enhanced by color factors

though story can get complicated quickly for more fields, interactions

κ

Λ0

-1.5

ω

|κ(µ)| < 2�

ω(µ)λh(µ)


just octets?

of course not, any colored scalar with (-ve) Higgs portal couplings will work

BUT: octets work well

• large Casimir -> κ can be smaller• can be SU(2)xU(1) singlets and still decay• connected to other (Tevatron) excesses?• helpful for EW phase transition?

• EW-charged fields are more constrained• EW-charged will also change BR(h->γγ)• SUSY with mstop = mt? nope, wrong sign κ


just octets?

of course not, any colored scalar with (-ve) Higgs portal couplings will work

BUT: octets work well

• large Casimir -> κ can be smaller• can be SU(2)xU(1) singlets and still decay• connected to other (Tevatron) excesses?• helpful for EW phase transition?

• EW-charged fields are more constrained• EW-charged will also change BR(h->γγ)• SUSY with mstop = mt? nope, wrong sign κ

!!


how low can you go?

so far the only SM contribution we’ve talked about is the top loop

there are other contributions to gg->h, such as bottom quark loops, ~few % effect

mh > 2 mb so Ab(gg->h) has an imaginary part...need to cancel Im(Ab) and Re(At)..

hard without extreme tuning or more fields

ALSO: VBF and associated Higgs production not

effected by S


Correlated signals: Enhanced di-Higgs

O(κ) O(κ2)cancels top piece at Q2 = mH2,

not at Q2 > 4 mH2doesn’t care about

sign of κ

(operator level explored by Pierce, Thaler, Wang ’08)


Enhanced di-Higgsin the (MS, κ) region

where gg->h is suppressed find

enhancements ofgg->hh

O(5-200)

(Kribs, AM, in progress)

both box and triangle

contributions enhanced

10

2050

100

200

100 150 200 250 300 350 400�2.0

�1.5

�1.0

�0.5

0.0

MS �GeV�Κ

Mh� 120 GeV

1020

50

100

200

100 150 200 250 300 350 400�2.0

�1.5

�1.0

�0.5

0.0

MS �GeV�

ΚMh� 160 GeV


Enhanced di-Higgs

(Kribs, AM, in progress)

at low mHconstructive

interference between box, triangle (unlike SM)

--> bigger enhancement

... becomes destructive interference

at high mH

10

2050

100

100 150 200 250 300 350 400�2.0

�1.5

�1.0

�0.5

0.0

MS �GeV�Κ

Mh� 300 GeV

0.5

0.25

0.1

10

20

50

100

500

1000

100 150 200 250 300 350 4000.0

0.5

1.0

1.5

2.0

mS �GeV�

Κ � 4.0

� 2.0 �1.5

� 1.25

Mh � 125 GeV


Enhanced di-Higgs

150 200 250 30010�4

0.001

0.01

0.1

1

mH �GeV�

Σ�gg�

hh��pb�

Higgs pair production for fixed MS, Κ LHC7

SMMS � 200, Κ � �1.0MS � 200, Κ � �1.4MS � 160, Κ � �1.0MS � 160, Κ � �1.4

depending on mh:

pp -> hh -> { 4b2b + 2W/Z4W...

CTEQ6.6, μF =μR= 2mH


130 140 150 160 170 180 190 20010

20

50

100

200

500

1000

mS �GeV�

Σ�pp�

SSH��fb�

mh = 120 GeV, √s = 7 TeV, κ = -1

pp -> t t̅ h

pp->SS h

Correlated signals: SSh production

leads to h+4j signals

enhanced by large color factor

for light S, comparable to, or

greater than pp -> t t̅ h

interesting?

( Kribs, AM, in progress)

g

g

h

!

!

New Higgs Production Mode

Important when scalars light?

S

S +...


Conclusionsjust by adding a single particle, we can completely

change gluon fusion while leaving much of the SM/EWSB undisturbed

requirements for this particle are fairly loose: colored, Higgs portal

plenty of allowed parameter space

Interesting correlated signals:

• enhanced di-Higgs production (O(5-100xSM))• SSh associated production• SS->4 jet signals


modifying higgs productionpages.uoregon.edu/soper/terahiggs2012/martin.pdfboson. these...

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