Theoretical estimate of the Higgs boson mass

It is assumed that the Higgs particle distorts space-time in its own neighborhood and generates a self-referential nonlinear field. Its almost flat space-time metric form gives a nonlinear equation of motion admitting soliton-like solutions. This in turn gives rise to a new type of wave—space-time (mass-transmitting) interactions allowing particles to acquire mass. The curvature of the (pseudo-) Riemannian manifold of a Higgs space-time yields the mass formulam ₂ ^WZ =d ³ x detGR _H (x)=1/4m ₂ ^H orm _H =182 GeV.     

The equivalent vector boson approximation for intermediate mass Higgs boson production

We consider the equivalent vector boson approximation (EVBA) for the processqq→qqWW→qqH andqq→qqZZ→qqH. It is shown that the contributions σT and σL, of the transversely and longitudinally polarized vector bosonsV respectively, are comparable with each other for intermediate values ofm _H viz. 0.3 TeV to 0.6 TeV. σT can be as large as 1.5–2 times σL in this mass range. As a result the leading EVBA for σ=σL+σT overestimates the exact total cross-section by a factor, upto 2–3 even, at high energies. σT is negligible with respect to the leading contribution σL only form _H≧0.6 TeV, where EVBA is correct within 15–20%. Further the effect of the corrections to EVBA, which are naively of nonleading order, on these conclusions in the framework of the EVBA is discussed.     

A numerical estimate of the upper limit for the Higgs boson mass

TheSU (2) Higgs model with a scalar doublet field is studied by Monte Carlo calculations on 12⁴ and 16⁴ lattices. The gauge coupling is chosen to be similar in magnitude to the physical value in the standard model. The numerical results at large scalar self-coupling imply an upper limitm _H /m _W ?9 for the ratio of the Higgs boson mass to the W-mass.     

Perturbation constraint on the Higgs boson mass

It is shown that a systematic perturbation expansion of spontaneously broken gauge theory imposes a constraint on the upper as well as the lower limit of the Higgs boson mass. In the standard SU(2) × U(1) model, the Higgs boson mass is calculated to be between 13 GeV and 500 GeV for the weak mixing angle, θ ≈ 35°.     

Higgs boson production in two photon processes

We discuss some properties of the (instanton—anti-instanton) solution of the SU(2) gauge theory with a massless Higgs doublet recently found by Lipatov, Bukhvostov and Malkov.     

Higgs boson mass in supersymmetry to three loops

Within the minimal supersymmetric extension of the standard model, the mass of the light CP-even Higgs boson is computed to three-loop accuracy, taking into account the next-to-next-to-leading order effects from supersymmetric quantum chromodynamics. We consider two different scenarios for the mass hierarchies of the supersymmetric spectrum. Our numerical results amount to corrections of about 500 MeV, which is of the same order as the experimental accuracy expected at the CERN Large Hadron Collider.     

Renormalization group estimate of the hadronic decay width of the Higgs boson

The total hadronic decay width of the Weinberg-Salam type Higgs boson is estimated in QCD for the Higgs boson mass much larger than the ordinary hadronic mass scale, by use of the operator product expansion and renormalization group equation. We give an explicit formula for the decay width in terms of quark masses including strong interaction corrections up to the next-to-leading order. A numerical analysis of the hadronic decay width of the Higgs boson is made in the six-quark model. The next-to-leading order correction is found to be significant, e.g., 30-20% of the leading term for m_H of oue interest, m_H ? 1 TeV. Application of our scheme to the decay rates of heavy Higgs bosons of other types is also discussed.     

Higgs boson masses in the model with two Higgs doublets and spontaneous CP-violation

The renormalization group equations are investigated for two Higgs doublet extension of a standard model with spontaneous CP violation. Assuming the validity of perturbation theory up to unification energies, the restrictions for the Higgs boson masses are found.     

On the lattice approach to the maximum Higgs boson mass

If the triviality upper bound on the Higgs boson mass m_H occurs for strong self-coupling, inferring properties of the Higgs from the euclidean propagator is in principle theoretically difficult whether in coordinate or momentum space. In that case, common methods of identifying m_H in lattice field theory simulations may produce a value for which is at best distantly related to the true upper limit. We discuss some shortcomings and ambiguities of recent results suggesting that the maximum occurs for weak coupling and emphasize potential complications due to finite-size and non-Lorentz-invariant effects of the lattice. The situation is illustrated by reference to the behavior in an analytically soluble approximation based on a 1/N expansion.     

Vector boson decays of the Higgs boson

We derive the width of the Higgs boson into vector bosons. General formulas are derived both for the on–shell decay as well for the off–shell decays, and , where . For the off-shell decays the width of the decaying vector boson is properly included. The formulas are valid both for the Standard Model as well as for arbitrary extensions. As an example we study in detail the gauge-invariant effective Lagrangian models where we can have sizable enhancements over the Standard Model that could be observed at LEP. Received: 31 July 1998 / Revised version: 23 September 1998 / Published online: 6 November 1998     

New fermions at the LHC and mass of the Higgs boson

Unification at MGUT∼3×¹⁰¹⁶ GeV$M_{\mathrm{GUT}}\sim 3\times {10}^{16}\text{GeV}$ of the three Standard Model (SM) gauge couplings can be achieved by postulating the existence of a pair of vectorlike fermions carrying SM charges and masses of order 300 GeV–1 TeV. The presence of these fermions significantly modifies the vacuum stability and perturbativity bounds on the mass of the SM Higgs boson. The new vacuum stability bound in this extended SM is estimated to be 117 GeV, to be compared with the SM prediction of about 128 GeV. An upper bound of 190 GeV is obtained based on perturbativity arguments. The impact on these predictions of type I seesaw physics is also discussed. The discovery of a relatively ‘light’ Higgs boson with mass ∼117 GeV$\sim 117\text{GeV}$ could signal the presence of new vectorlike fermions within reach of the LHC.     

Bound on the Higgs boson mass with no zero-charge behaviour in a magnetic field

The upper boundm<280 GeV/c² on the Higgs boson mass is obtained by considering the requirement that the electroweak theory must be consistent in a magnetic fieldH. The restriction emerges naturally by studying the effective potential in a magnetic field as a function of mass, and the values ofm when there is no zero-charge, in the fieldsH～H ₀=M _w ² /e are obtained.     

Search for a Higgs boson decaying into two photons in the CMS detector

A search for a Higgs boson decaying into two photons in pp collisions at the LHC at a centre-of-mass energy of 7 TeV is presented. The analysis is performed on a dataset corresponding to 1.66 fb^?1 of data recorded in 2011 by the CMS experiment. Limits are set on the cross-section of a Standard Model Higgs boson decaying into two photons, and on the cross-section of a fermiophobic Higgs boson decaying into two photons.     

Background and signal estimation for a low mass Higgs boson at the LHC

The discovery of the Higgs boson(s) is the major goal of the LHC which will start taking data in 2008. In this work a data driven extraction of the background and statistical signal significance in the H→ZZ→4ℓ decay channel is presented. The background for Higgs masses as low as 130 GeV can be extracted with an error of 20%, using a sideband measurement from a single 30 fb^-1 experiment. The predicted background distribution is best described by a double asymmetric Gaussian. An analytic formula is introduced which provides an accurate p-value that a Higgs discovery claim is consistent with a background fluctuation. The formula can be used in a single real measurement at LHC using as input the measured background and the profile likelihood asymmetric errors of this measurement. The method presented here can be applied to the general case of extrapolating from a signal-free data region to a candidate signal region. This is the case of supersymmetry searches at the LHC. PACS  14.80.Bn; 06.20.Dk