REVIEW
Carving Out Parameter Space in Type-II Two Higgs Doublets Model
High Energy Physics - Phenomenology · Submitted 29 Mar 2013 · 52 references
Pith's verdict: An honest 2HDM-II scan whose qualitative point — the model is a ~1 TeV effective theory — is sturdier than the sharp numbers it quotes.
T0 · AI review
Why Pith says this
Highlight any text to comment on it.
Referee report
The paper
The paper claims
If the 125 GeV particle is the light CP-even Higgs of a Type-II two-Higgs-doublet model, combining Higgs data, $B$ to $X_s$ gamma, electroweak precision, vacuum stability, and perturbativity leaves only a narrow viable window, and none at a
The reading
What carries the argument
The machinery is a constrained global scan. Higgs production and decay rates are rescaled from the Standard Model by coupling factors $c_t=cos alpha/sin beta$, $c_b=sin alpha/cos beta$, and $c_V=sin(alpha+beta)$, and these are fitted to the reported signal strengths. The scalar couplings are then run from the weak scale to $Lambda$ with one-loop $\beta$ functions, and each point is tested against vacuum-stability inequalities and the perturbativity conditions $lambda_i/(4 pi)<=1$ and $y_i^2/(4 pi)<=1$. The viable region is the intersection of that theoretical survival region with the experimental cuts from $B$ to $X_s$ gamma, the $S$ and $T$ parameters, and direct mass bounds. Related coupling factors then control the phenomenology of $H$, $A$, and $H^pm$.
Extended reading notes
Core claim
On the paper's own terms, the result is that the Type-II two-Higgs-doublet model does not remain viable over a broad parameter range once one insists that it be a consistent effective theory up to a cutoff. The global Higgs fit alone prefers very small $tan beta$, where the top Yukawa is non-perturbative, so the authors instead ask where the model can satisfy all constraints simultaneously. The intersection is narrow: the charged Higgs is pushed above 380 GeV by $B$ to $X_s$ gamma and below about 420 GeV by perturbativity, and $tan beta$ is confined to roughly 0.75 to 2.75 for $Lambda=1$ TeV. Raising the cutoff to 2 TeV eliminates the parameter space entirely, which the authors read as evidence that if the two-Higgs-doublet model describes electroweak symmetry breaking, new particles should appear around 1 TeV.
Load-bearing premise
That the model must remain perturbative and vacuum-stable all the way to a chosen cutoff, with perturbativity defined by the hand-set thresholds $lambda_i/(4 pi)<=1$ and $y_i^2/(4 pi)<=1$, is the load-bearing premise; the paper itself shows that tightening the threshold to $1/2$ removes all viable points and relaxing it to $3/4$ leaves only $tan beta=1$ and $1.25$.
Editorial extensions
If this is right
- If the result holds, the Type-II two-Higgs-doublet model can be only a low-energy description: some new physics should enter near 1 TeV, since a 2 TeV cutoff admits no consistent point.
- The charged Higgs is predicted to sit in a narrow band, 380 to 420 GeV, heavy enough that its main production is with top and bottom quarks and its dominant decay is to $t bar b$, making it hard to see at the LHC.
- The heavy CP-even $H$ and CP-odd $A$ can still be light; when $H$ to $A Z$ opens, it can dominate and lead to photon-plus-lepton or multiphoton signatures.
- A low-mass pseudoscalar $A$ has enhanced $gamma gamma$ and $gamma Z$ rates relative to a Standard Model Higgs of the same mass, so existing diphoton and $Z gamma$ searches can test this corner.
Reading between the lines
- The claimed window is conditional on the cutoff and perturbativity threshold; embedding the model in a supersymmetric or composite completion with new states below 1 TeV would change which parameter points are counted as viable.
- The paper neglects the charged-Higgs loop in $h$ to $gamma gamma$; a full calculation could shift the fitted $alpha$-$tan beta$ region and therefore the boundaries of the surviving window, especially where $M_{H^pm}$ is near 380 GeV.
- Reanalyzing existing 8 TeV data above 150 GeV in the $gamma gamma$ and $Z gamma$ channels would test the low-mass pseudoscalar corner without waiting for a new run.
Original abstract
We analyze the Type-II two Higgs doublets model in light of the newly discovered Higgs-like particle with mass 125 GeV. The observed 125 GeV particle is identified with the light CP-even Higgs boson in the two Higgs doublets model. We study the parameter space of the model consistent with the Higgs data, branching ratio of $\bar{B}\to X_s\gamma$ as well as precision electroweak measurements. We also incorporate theoretical constraints--- perturbativity of the couplings and vacuum stability, in our study. We find that only a small parameter space of the model remains viable. The phenomenology of the heavy Higgs bosons in the surviving parameter space is studied.
The compiled record
The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
The abstract, sentence by sentence
We analyze the Type-II two Higgs doublets model in light of the newly discovered Higgs-like particle with mass 125 GeV. The observed 125 GeV particle is identified with the light CP-even Higgs boson in the two Higgs doublets model. We study the parameter space of the model consistent with the Higgs data, branching ratio of $\bar{B}\to X_s\gamma$ as well as precision electroweak measurements. We also incorporate theoretical constraints--- perturbativity of the couplings and vacuum stability, in our study. We find that only a small parameter space of the model remains viable. The phenomenology of the heavy Higgs bosons in the surviving parameter space is studied.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We analyze the Type-II two Higgs doublets model in light of the newly discovered Higgs-like particle with mass 125 GeV. | contribution 0.68 | 0.84 | 0.03 | asserted 0.94 |
| s1 | The observed 125 GeV particle is identified with the light CP-even Higgs boson in the two Higgs doublets model. | background 0.34 | 0.31 | 0.05 | asserted 1.00 |
| s2 | We study the parameter space of the model consistent with the Higgs data, branching ratio of $\bar{B}\to X_s\gamma$ as well as precision electroweak measurements. | contribution 0.70 | 0.92 | 0.04 | asserted 0.87 |
| s3 | We also incorporate theoretical constraints--- perturbativity of the couplings and vacuum stability, in our study. | method 0.83 | 0.91 | 0.03 | asserted 0.99 |
| s4 | We find that only a small parameter space of the model remains viable. | result 1.00 | 0.96 | 0.86 | asserted 1.00 |
| s5 | The phenomenology of the heavy Higgs bosons in the surviving parameter space is studied. | contribution 0.98 | 0.90 | 0.07 | asserted 0.83 |
What was examined, and what was not
- arXiv listing abstract v2
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
Figures
Figures reproduced from arXiv:1304.0028 by the authors.
References
How later papers used it
58 later papers cite it
1 later paper by other authors is listed below: 1 used its method or tool.
Uses its method or tool 1 paper
-
Used the approximate expressions for the signal strengths given in this paper for loop level processes.
Standard Model EFT and Extended Scalar Sectors (2017) · 0.92 · paraphrased: the licence does not allow quoting
How the literature uses it
58 arXiv papers cite this in 72 sentences
Papers citing it · 24 sentences without a confident label
Contests it 1 paper
-
Contrary to statements in e.g. [ref] we find that scenarios where $β-α$ deviates significantly from $π/2$ are disfavoured at one standard deviation and excluded at two standard deviations for $tanβ<5$.
Status of the two-Higgs-doublet model of type II · Conclusions · contest 0.83
Uses its method or tool 1 paper
-
For loop level processes, we use the approximate expressions for the signal strengths given in Ref. [ref] .
Standard Model EFT and Extended Scalar Sectors · Single Higgs Production · 0.92
Compares with it 3 papers
-
If we remove the flavour observables and $R_b$ from our fit we confirm the results of previous analyses (e.g. [ref] ) where the lower strip in Fig. [ref](a) is still allowed at one standard deviation.
Status of the two-Higgs-doublet model of type II · Results · 0.95
-
This section is dedicated to the comparison of the ATHDM, with CP-conseving Yukawas and potential, with the usual THDMs with $𝒵_2$ symmetries [ref] .
Constraining the two-Higgs doublet models with the LHC data · ATHDM versus $𝒵_2$ models · 0.89
-
Points cluster along the ST line $α=β$, confirming the results in [ref] , see also [ref] .
Bounds to the Higgs Sector Masses in Minimal Supersymmetry from LHC Data · Introduction · 0.82
Cites it as support 1 paper
-
The choice of and $$ final states is motivated by the large branching fractions predicted in most of the 2HDM phase space [ref] .
Search for neutral resonances decaying into a Z boson and a pair of b jets or tau leptons · Introduction · 0.99
Cites it as background 38 papers
-
Various scenarios in the THDM have been analyzed by using the Higgs boson search data at the LHC before the Moriond conference [ref] , and those afterwards [ref] .
Implications of Higgs boson search data on the two-Higgs doublet models with a softly broken $Z_2$ symmetry · Introduction · 0.96
-
Ref. [ref] fit the observed Higgs signals in various 2HDM scenarios, taken into account theoretical and experimental constraints.
Constraining Type II 2HDM in Light of LHC Higgs Searches · Introduction · 0.93
-
A large number of papers [ref] performed fits of current data for the 125.5 GeV Higgs-like state (as per the status post Moriond 2013) within the context of 2HDMs, and investigated the consequent phenomenology of the other Higgs states present in the models.
Constraints on and future prospects for Two-Higgs-Doublet Models in light of the LHC Higgs signal · Introduction · 0.87
What it cites · 17 sentences without a confident label
Uses the method or tool of 1 paper
-
Experimental data are reported in terms of a signal strength, $μ$, defined as [equation] When the signal strength is not directly reported by the experimental collaboration, we extract it from the reported 95% exclusion limit following the procedure given in Ref. [ref] .
Reconstructing Higgs boson properties from the LHC and Tevatron data · Fit to the Higgs Data · 1.00
Uses data or values from 4 papers
-
By analyzing the branching ratio $Br(B̅→X_sγ)$, Ref. [ref] obtained the bound $M_H^±≥380$ GeV at 95% confidence level.
$\bar{B}\to X_s \gamma$ in the Two Higgs Doublet Model up to Next-to-Next-to-Leading Order in QCD · Experimental Bounds · 0.97
-
The theoretical SM Higgs boson predictions for the cross-sections and branching ratios are taken from the LHC Higgs Cross-section Working Group [ref] .
Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables · Global Fit · 0.96
-
In the Standard Model, the best fit values for the $S$ and $T$ parameters for $M_h∼125$ GeV and $M_t=173$ GeV, as well as their correlation matrix ($M_corr$) are [ref] .
The Electroweak Fit of the Standard Model after the Discovery of a New Boson at the LHC · Experimental Bounds · 1.00
Cites as background 8 papers
-
There exists a large literature on the properties of the neutral scalar boson couplings of the two Higgs doublets model in light of the Higgs data; see for example Ref. [ref] .
Dark matter in the Inert Doublet Model after the discovery of a Higgs-like boson at the LHC · Introduction · 0.98
-
There exists a large literature on the properties of the neutral scalar boson couplings of the two Higgs doublets model in light of the Higgs data; see for example Ref. [ref] .
Constraining parameter space in type-II two-Higgs doublet model in light of a 126 GeV Higgs boson · Introduction · 0.98
-
There exists a large literature on the properties of the neutral scalar boson couplings of the two Higgs doublets model in light of the Higgs data; see for example Ref. [ref] .
A Minimal Flavor Violating 2HDM at the LHC · Introduction · 0.98
Discussion
Disagree with the review, or know something it missed? Leave a comment, highlight any passage above to comment on it, or challenge this review formally.