2HDM and the new LHC data
Rui Santos
11 March 2013
Rencontres de Moriond QCD and High Energy Interactions
ISEL & CFTC (Lisbon)
A. Barroso, P.M. Ferreira, H. Haber, I. Ivanov, M. Sher and J.P. Silva
Why?
2�HDMSM � LikeLimit�
?
�1.0 �0.5 0.0 0.5 1.0
5
10
15
20
25
30
sinΑ
tanΒ
Best set of variables to present the results –
in this plane there is a very clear SM-like limit
If it is cornered into the SM-like limit within precision it is
as good as excluded
SM-like limit = limit where Yukawa and gauge coupling to lightest scalar are the SM ones
The softly broken Z2 symmetric 2HDM potential
7 free parameters + MW: €
φ1 =12
0v1
⎛
⎝ ⎜ ⎞
⎠ ⎟ ; φ2 =
12
0v2
⎛
⎝ ⎜
⎞
⎠ ⎟
ratio of vacuum expectation values
€
tanβ =v2v1
2HDM Lagrangian
scalars-gauge bosons couplings
Yukawa couplings
€
sinα
€
tanβ
€
gSM sin(β −α)
€
gSMf (α)g(β)
€
hW +W −
€
h f f
we use as independent parameters IV = II’ = X = Leptonic III = I’ = Y = Flipped
Extending the Z2 symmetry to the fermions – 4 independent
Yukawa Lagrangians
The Constraints - Experimental
Limits where the 2HDMs contributions
cancel
LEP
B factories
H-
Type II Best available bound on the charged Higgs mass
Experimental
Any
Experimental
€
pp → t t →b bW +H −
€
mt
tanβ€
mb tanβ
€
BR(H − →τν )Corrected for
Theoretical
No soft breaking term = strong constraint on tanβ
B. Gorczyca, M. Krawczyk, arXiv: 1112.5086 Z2 symmetric potential
If a 2HDM has only one “normal” minimum then this is the absolute minimum – all other SP if they exist are saddle points
Theoretical
But (at most) two “normal” minima possible – panic vacuum can occur
How to avoid the panic vacuum?
Global minimum – ALSO NORMAL
Local minimum –”NORMAL”
Not possible
Local minimum – “NORMAL”
Panic
€
v ≠ 246GeV
A.Barroso, P.Ferreira, RS, PLB603 (2004)
I.Ivanov, PRD75(2007)
A.Barroso, P.Ferreira, I.Ivanov, RS, J.P.Silva, arXiv:1211.6119
I.Ivanov, PRD75(2007)
• Set mh = 125 GeV.
• Generate random values for potential’s parameters such that
• Impose all experimental and theoretical constraints previously described.
• Calculate all branching ratios and production rates at the LHC.
• Impose averaged ATLAS and CMS results: Arbey, Battaglia, Djouadi, Mahmoudi, 1211.4004.
€
µXX =σ2HDM (pp→h) × BR2HDM (h→XX)σSM (pp→h) × BRSM (h→XX)
LHC data
Green – Allowed (1σ)
SM-like limit sin(β - α) = 1
sin(β + α) = 1
Comparison between type I and type II
Greater dispersion of points in Model I due to the difference in the μZZ expression
Blue – Allowed (2σ)
The green points all have a charged Higgs mass below 125 GeV
Model II excluded at 1σ and two regions are still allowed at 2σ (in blue) : - The region just below the SM-like limit
- The region just below the limit sin(β+α) = 1
We then took all masses except mh=125 GeV to be above 600 GeV.
Model I 1σ points killed.
At 2σ (in blue) the blue regions shrink moving closer to the SM-like limit.
After
Before
After
Correlation between μZZ and μγγ makes the one sigma allowed region much larger for ATLAS.
Updated plots for Model II with last week data
Green 1σ Blue 2σ
CMS ATLAS
Large positive values of sinα are definitely excluded in all 2HDMs
€
µXXVBF /RXX
Degenerate states?
P.M. Ferreira, H. E. Haber, R. S., J. P. Silva, 1211.3131 (to appear in PRD)
A. Drozd, B. Grzadkowski, J.F. Gunion and Y. Jiang, 1211.3580
Choices for the degenerate pairs: (h, A), (h, H), or (H,A)
Degenerate Higgs mass of 125 GeV
One of the neutral Higgs boson has SM-like couplings (±20%) to W and Z gauge bosons
Impose 2HDM constraints
Perform scan focusing on 0.5 <̰ tan β < ̰ 2.0
Is it possible that the excess in the h -> γγ is due to two 2HDMs degenerate states?
Is it possible that the excess in the h -> γγ is due to two 2HDMs degenerate states? Yes, but only for small tanβ.
If the results on h -> ττ and h -> ϒϒ are confirmed all the degenerate scenarios will soon be excluded
Model I (h, A) Model II (h, H)
Conclusions
In the CP-conserving 2HDM the lightest CP-even 125 GeV is being cornered into the SM-like limit although the region near sin(β+α)=1 is still allowed in type II.
When all masses but the one from the lightest CP-even scalar are above 600 GeV, the two models are even closer to the SM-like limit. However the sin(β+α)=1 region still survives in Type II.
Degenerate sates could enhance h->γγ but h-> ττ is also large.
Are we nearly there yet? No, there are still no constraints on the masses.
Same is true for the other masses except for the bound on the charged Higgs mass in type II.
100 200 300 400 500 600 700 800 900
5
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35
40Type I
mH!
tan
100 200 300 400 500 600 700 800 900
5
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40Type II
mA
tan
Red points β-α = π/2 + ε
Blue points 2σ
Again no special trend is observed for type II. In type I values of positive M2 seem to be preferred. We saw that the exact Z2 type I was
excluded at 2σ. Now we see that negative M2 is also excluded.
This is related to the h -> γγ constraint.
Red points β-α = π/2 + ε
Blue points before LHC
Green points 2σ
1 0.5 0 0.5 11
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
sin
tan
Model II Panic Effect
Panic points – the ones where two normal minima coexist and where the “bad” minimum is below the
“good” one.
In red we present the panic points. Excluding these points
goes unnoticed in a scan.
In type I the LHC already allow us to exclude these points at 2σ.
Experimental - not considered
SM – 3.4σ deviation
Type II Type X,Y
Type I
For most of the parameter space
2HDM=SM
1 0.5 0 0.5 11
1.5
2
2.5
3
3.5
4
4.5
5
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sin
tan
Model II Exact Z2 Symmetry
What about the exact Z2 symmetric scenario? A clear non-MSSM version of 2HDM
Type I is killed at 2σ
B. Gorczyca, M. Krawczyk
Type II is still allowed at 2σ
Maximum of Rγγ below 1
P. Posch PLB696
(2011) 447.
At 1σ everything is excluded.
At 2σ (in blue) two regions are still allowed:
- The region just below the SM-like limit
- The region just below the limit sin(β+α) = 1
SM-like limit sin(β - α) = 1
sin(β + α) = 1
Same plot now as a function of sin(β-α)
At 2σ (in yellow) and 3σ (in green)
Note that if tanβ >> 1 sin(β-α) ≅ sin(β+α) ≅ cos(α)
€
µγγ =cosαsinβ
⎛
⎝ ⎜
⎞
⎠ ⎟
2BR2HDM (h→γγ )BRSM (h→γγ )
The simplest example is to take model type I and consider that the production occurs only via gluon-gluon fusion
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µZZ ≈ sin2(β −α)
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RZZ → 1 SM - like limit
BR now depends on sinα, tanβ, charged Higgs mass and its coupling to neutral scalars.
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µγγ =σ2HDM (pp→h) × BR2HDM (h→γγ )σSM (pp→h) × BRSM (h→γγ )
In type II even gluon fusion has a different factor in the top and in the bottom loop – with different QCD corrections.
Higlu was used for gg and bb@nnlo for bb.
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if h→ bb dominates
μZZ in ATLAS has a larger central values – Model I is very sensitive to (large) values of μZZ
Updated plots with last week data
Green 1σ Blue 2σ
CMS ATLAS
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µXX =σ2HDM (pp→h) × BR2HDM (h→XX)σSM (pp→h) × BRSM (h→XX)
The value for each individual production process is
multiplied by the corresponding 2HDM factor.
What do we compare to data?
J. Baglio and A. Djouadi, JHEP 03 (2011) 055
2HDM branching ratios are calculated using our own code.
SM BR are calculated with the same code in the SM-like
limit.