REVIEW
Two-loop electroweak corrections to Higgs production at hadron colliders
High Energy Physics - Phenomenology · Submitted 21 Jul 2004 · 14 references
Pith's verdict: A genuine, competently executed completion of the two-loop electroweak correction to gg→H; the only real soft spot is the h4w truncation near m_H = 2m_W, which weakens the 'at most 15%' claim at the top of the range but not the headline 5-8%.
T0 · AI review
Why Pith says this
Highlight any text to comment on it.
Referee report
The paper
The paper claims
The paper computes the missing top-quark two-loop electroweak correction to gluon fusion Higgs production, finding total electroweak corrections of 5% to 8% for Higgs masses from 115 GeV up to twice the W mass.
The reading
What carries the argument
The authors work in the Background Field Method, a quantization scheme that splits each field into a classical background field and a quantum field that appears only in loops. In background Feynman gauge the reducible correction $K_r$—Higgs wave-function renormalization plus the expansion of $g_0/m_{W0}$—and the two-loop one-particle-irreducible amplitude $G^{2ell}_{1PI}$ are separately finite, so $G^{2ell}_t=K_r G^{1ell}+G^{2ell}_{1PI}$. The 1PI amplitude is then Taylor-expanded in $h_{4w}=q^2/(4m_W^2)$ through fourth order; the expansion is legitimate because helicity mismatch on the massless bottom line removes the would-be $q=0$ cut, pushing the first cut to $2m_W$. This is the device that makes the two-loop calculation tractable and produces the explicit series in Eq. (11).
Extended reading notes
Core claim
The central claim is that adding the top-quark two-loop piece to the known light-fermion piece gives a complete two-loop electroweak correction to $gg o H$ in the intermediate-mass region. The top piece is small and changes sign: in Table 2 it runs from $-0.22$ at 115 GeV to $+3.43$ at 160 GeV in units of $lpha/(4pi s^2)$, while one massless generation gives $-5.28$ to $-10.4$ over the same range. The resulting total relative correction $delta_{m ew}$ is 4.7% to 7.5%, which the abstract rounds to 5% to 8% for $115~GeV lesssim m_H lesssim 2m_W$. Above 120 GeV the top contribution has the opposite sign to the light-fermion contribution and remains at most 15% of its magnitude, so the light fermions dominate the electroweak correction.
Load-bearing premise
The load-bearing premise is that truncating the Taylor series in $h_{4w}=q^2/(4m_W^2)$ at fourth order is accurate enough for the 'bos' diagrams up to $m_H simeq 2m_W$, where Table 1 shows the terms decreasing slowly and the quoted 9% bos uncertainty is estimated by taking the last computed term as the error rather than by a bound.
Editorial extensions
If this is right
- Because the electroweak shift is 5% to 8%, it is comparable to the residual QCD uncertainty quoted for this process and must be included when a measured Higgs rate is converted into a Standard Model cross section.
- Above 120 GeV the top contribution opposes the light-fermion contribution and stays below 15% of it, so the light fermions, not the top, dominate the electroweak correction in the intermediate-mass region.
- The same correction applies to the $H o gg$ partial width through $Gamma(H o gg)=8m_H^3sigma(gg o H)/pi^2$, so the result feeds into Higgs decay branching-ratio predictions.
- For $m_H>2m_W$ the top correction is not computed here; the authors expect the total electroweak correction to be small there because the light-fermion part is small, but that remains to be checked.
- Near $2m_W$ the wave-function factor $K_r$ behaves as $1/sqrt{1-4w_H}$; replacing $m_W^2$ by $m_W^2-iGamma_W m_W$ removes the unphysical singularity and gives the quoted 160 GeV entry.
Reading between the lines
- If the 5-8% electroweak shift is included consistently, percent-level measurements of $gg o H$ could constrain the top-Higgs coupling only after the QCD normalization uncertainty is pushed below the electroweak size; until then the two corrections remain degenerate.
- Extending the calculation above $2m_W$ is primarily a problem of treating the $WW$ threshold, so keeping exact $W$ propagators or applying complex-pole resummation throughout, not just in $K_r$, is the natural next step.
- The split into a finite reducible factor and a separately finite 1PI piece in background Feynman gauge is a reusable template for other loop-induced Higgs processes that combine heavy-quark and light-fermion corrections.
Original abstract
We compute the two-loop electroweak corrections due to the top quark to the gluon fusion production cross section of an intermediate-mass Higgs boson. This result, together with the previously known contribution due to the light fermions, allows a complete determination of the two-loop electroweak corrections to this production cross section. For Higgs mass values above 120 GeV the top corrections have opposite sign of the light fermions contribution, however they are always smaller in size reaching at most 15% of the latter. The total electroweak corrections to the gluon fusion production cross section for 115 GeV < m_H < 2 m_W range from 5% to 8% of the lowest order term.
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 compute the two-loop electroweak corrections due to the top quark to the gluon fusion production cross section of an intermediate-mass Higgs boson. This result, together with the previously known contribution due to the light fermions, allows a complete determination of the two-loop electroweak corrections to this production cross section. For Higgs mass values above 120 GeV the top corrections have opposite sign of the light fermions contribution, however they are always smaller in size reaching at most 15% of the latter. The total electroweak corrections to the gluon fusion production cross section for 115 GeV < m_H < 2 m_W range from 5% to 8% of the lowest order term.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We compute the two-loop electroweak corrections due to the top quark to the gluon fusion production cross section of an intermediate-mass Higgs boson. | contribution 1.00 | 0.97 | 0.15 | asserted 1.00 |
| s1 | This result, together with the previously known contribution due to the light fermions, allows a complete determination of the two-loop electroweak corrections to this production cross section. | interpretation 0.48 | 0.52 | 0.22 | asserted 1.00 |
| s2 | For Higgs mass values above 120 GeV the top corrections have opposite sign of the light fermions contribution, however they are always smaller in size reaching at most 15% of the latter. | result 0.97 | 0.87 | 0.32 | asserted 1.00 |
| s3 | The total electroweak corrections to the gluon fusion production cross section for 115 GeV < m_H < 2 m_W range from 5% to 8% of the lowest order term. | result 1.00 | 0.87 | 0.33 | asserted 1.00 |
What was examined, and what was not
- arXiv listing abstract v1
- 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:hep-ph/0407249 by the authors.
References
How later papers used it
47 later papers cite it
1 paper by the same authors is listed below: 1 used its method or tool.
Uses its method or tool 1 of 4 papers with this label · 1 by the same authors
By the same authors
-
Followed the approach of this paper, which computed the corrections via a Taylor expansion in q^2/(4 m_t^2) and q^2/(4 m_H^2), in its computation of the C_1 coefficient.
Probing the Higgs self coupling via single Higgs production at the LHC (2016) (same authors) · 0.97 · paraphrased: the licence does not allow quoting
How the literature uses it
47 arXiv papers cite this in 59 sentences
Papers citing it · 32 sentences without a confident label
Uses its method or tool 4 papers
-
In our computation of the $C_1$ coefficient we followed the approach of Ref. [ref] where the corrections have been computed via a Taylor expansion in the parameters $q^2/(4 ^2), q^2/(4 ^2)$ where $q^2$ is the virtuality of the external Higgs momentum, to be set to $^2$ at the end of the computation.
Probing the Higgs self coupling via single Higgs production at the LHC · Computation of the $C_1$ coefficients · 0.97
-
The $ggH_i$ reduced couplings are assumed to take care of also the EW corrections [ref] , since HiggsBounds effectively obtains the approximate partonic cross section $σ(gg→H_i)$ by multiplying $ggH_i$ with the SM counterpart, $σ(gg→h_SM)$, evaluated including the EW corrections [ref] .
A light NMSSM pseudoscalar Higgs boson at the LHC redux · Methodology · 0.81
-
HiggsBounds uses a number of experimental analyses [ref] , and internally uses several SM results [ref] to convert between experimental limits with different normalizations.
Characterizing simplified models for heavy Higgs decays to supersymmetric particles · Analysis Setup · 0.80
Uses its data or values 12 papers
-
The two-loop EW corrections to $σ(gg→H)$ in the SM were obtained in Refs. [ref] .
Probing the Higgs self coupling via single Higgs production at the LHC · Computation of the $C_1$ coefficients · 0.90
-
The factor $C_hhf$ was computed[In [ref] $C_hhf$ is denoted by $C_1^σ_ggF$ ] in [ref] , so we use the value $C_hhf=0.0066$, which is independent of the centre of mass energy.
NLO electroweak corrections in general scalar singlet models · NLO gluon fusion cross section · 0.96
-
The various production cross sections and branching fractions for SM processes and their corresponding uncertainties are taken from references [ref] .
Evidence for the 125 GeV Higgs boson decaying to a pair of tau leptons · The CMS experiment · 0.99
Cites it as background 10 papers
-
Up to few years ago, mixed QCD-Electroweak corrections were known exactly only at LO [ref] , while NLO results were first computed using a HEFT approach [ref] , and later in a purely massless case [ref] .
Next-to-leading order mixed QCD-electroweak corrections to Higgs production at the LHC · Motivations · 0.95
-
The 2-loop LO and 3-loop virtual NLO corrections to $gg →H$ have been computed in [ref] and [ref] , respectively, while the 1-loop LO quark-initiated contributions $qqgH$ and the related 1-loop real contributions $qqHgg$ and $qqHqq$ have been addressed in [ref] .
Mixed QCD-electroweak corrections to Higgs plus jet production at the LHC · Tensor structure decomposition · 0.84
-
The knowledge of this process includes: the next-to-leading order (NLO) QCD contributions [ref] computed for arbitrary values of the Higgs and quark masses [ref] ; the next-to-next-to-leading order (NNLO) QCD contributions due to top-quark loops, in the heavy-top limit [ref] and including finite top-mass effects [ref] ; soft-gluon resummation effects [ref] and estimates of the next-to-next-to-next-to-leading order (NNNLO) QCD contributions [ref] ; the first-order electroweak (EW) contributions [ref] and estimates of the mixed QCD-EW contributions [ref] .
Towards precise predictions for Higgs-boson production in the MSSM · Introduction · 0.96
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.