The leading diagrams for these processes are shown in Figure 1. Emphasis has been placed on speed of execution, preferring to perform as much of the calculation analytically as is practicable. If the partial width for a Higgs boson to decay via a virtual massive particle can be measured, this gives a measurement of that massive particle's width. The detectors observed the decay of just a few dozen Higgs bosons into photons, Ws and Zs, which revealed a bump in the data at 125 billion electronvolts (GeV), about 125 times the mass of the proton. Higgs boson mass is only parameter unconstrained by SM But crucial in SM prediction of Higgs production and decay rates Measurement based on H!ZZ* and H! nal states, for which invariant mass can be reconstructed with high precision Wouter Verkerke, NIKHEF 6 Eur . The two most sensitive decay channels at the LHC are H ZZ 4 and H , the so called golden channels of the Higgs boson decays. ); where the refers to partial decay width. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): We present an analytical calculation of the next-to-next-to-leading order corrections to the partial decay width H gg for a Higgs boson in the intermediate mass range. The present paper describes a signicant extension in functionality in SOFTSUSY: to calculate and output the various partial widths for the decays of sparticles and Higgs bosons in the MSSM and in the NMSSM. They are one-loop leading processes and the contribution of Kaluza-Klein particles is considered to be . For h0!ff you have to include only the following fermions: b b, + and c c (why? We consider the change of the Higgs width decay into a fermion pair with respect to the standard model, due to the four-fermion contact interaction coming from the existence of gravitational torsion within the context of extra dimension scenarios. 6a. The value of the Higgs boson lifetime is inferred to be (2.1 +2.3-0.9) x 10 -22 seconds where the two extra numbers give the uncertainty of the measurement. It is shown that this decay provides an additional possibility for charged Higgs searches. Higgs-decay into two photons important detection channel in this mass range at Large Hadron Collider (LHC) due to clear signature, though . The branching ratio of the Higgs boson decaying toZZ cancels out in the FV ratio. The main focus lies on the electroweak (EW) contributions. In particular, an E ective Field Theory (EFT) framework has been adopted for a model independent parametrization . 6.2 D= 6 contributions to Higgs decay into four charged leptons .107 . I show that the W and Z bosons which result from the decay of these heavy particles are . Please check Proposal on how to provide reference "Higgs" cross sections for BSM applications; Full mass scan should be provided for major Higgs production processes: The decay width of Higgs boson into massless bottom quarks is known up to the next-to-next-to-next-to-next-to-leading order in QCD [3-5]. The former is expressed in terms of cross section, , which is a measure of the probability of a specic scattering process under some given set of initial and nal conditions, such as momenta and spin . We reproduce also the plot for Higgs branching ratios for di erent decay channels as a function of its mass. C 74 (2014) 3076 . We consider the Higgsstrahlung process in hadronic collisions and present the computation of next-to-next-to-leading order predictions matched to parton showers for both production and H b b $$ b\\overline{b} $$ decay employing the MiNNLOPS method. of this, perturbative corrections to the H bb decay are most interesting for the inclusive rate, due to its contribution to the total decay width and the branching ratios of other decays. in intermediate-mass . Phys. The calculation is carried out using integration-by-parts identities for the reduction to master integrals of the scalar integrals, in terms of which we express the amplitude. Higgs - boson production. D. 90, 052004 (2014) In this ratio the terms due to the loop integration cancel out. Naoyuki Haba 1, Kunio Kaneta 1, 3, Yukihiro Mimura 2, and Ryo

The accelerator, the experiments and the Higgs. The Basic Idea (1st version) 2. Our e ect is also complementary to the o -shell method [12{14], since it is independent of new physics e ects that may distort the measurements in the far o -shell region.

We present an analytical calculation of the next-to-next-to-leading order corrections to the partial decay width Hgg for a Higgs boson in the intermediate mass range. This result shows how the value FV = 0, which would correspond to a fermiofobic Higgs boson, is disfavoured at the 4 level. In this paper, we calculated the decay width and decay branch ratio of Higgs decay to h c plus a photon in the theoretical framework of NRQCD. 48~ sin6 Bw co@ Bw . [30-32] and are summarised in Table1. EPHOU-12-005 [-1mm] OU-HET 754/2012. (EW) calculation!! How Particles and Fields Interact (an introduction) How the Higgs Field Works (with math) 1. In this work, we calculate the next-to-leading order (NLO) electroweak corrections to the 125 GeV Higgs decay width into two dark matter particles. Global measurement of Higgs width 12/5/2014 21 . We present the analytic calculation of the two-loop QCD corrections to the decay width of a Higgs boson into a photon and a Z boson. The number of Higgs-related events is given by the product of the Higgs boson production cross section in a particular channel and the Higgs boson decay rate to a particular nal state. . For f = 4 TeV and c = 0.3, the NLO QCD corrected decay width reaches 75.099 keV and the NLO QCD relative correction is about 11.0%. weak coupling is shared by two neutral Higgs states, as would be the case in supersymmetry [15], or if the Higgs has invisible decay modes. Feynman diagrams are the recipe for setting up the integrals necessary to be calculated for finding widths and crossections in particle physics.

Top-quark-induced corrections Higgs Decay to Photons at Two Loops Calculation of leading term proportional GFm2 t Bottom-quark massless . W signal [W 16-20] and that of the closely related h ! From numerical results, we find that the decay width of process H b J= b at leading order (LO) mainly comes from the contribution of the Fock state 3S8 1, and the NLO QCD corrections

We have performed a one-loop calculation of the width of the rare decay H -> Z Z \gamma in the standard model for Higgs boson masses 190 GeV \leq m_H \leq 250. the h decay rate, and the total Higgs width. HDECAY HDECAY is a self-contained and fast program for calculating the decay widths and branching ratios of the SM Higgs boson, and the Higgs bosons of the MSSM according to the current theoretical knowledge. The new result by the CMS collaboration sets a milestone in testing the properties of the Higgs boson. Decay Widths and Scattering Cross Sections We are now ready to calculate the rates of some simple scattering and decay processes. The WW signal identica-tion with leptonic W decay is challenging .

In Fig. We find that there is a considerable enhancement in the decay width and neutral Higgs effects are detectable for large values of . Original language: English (US) Pages (from-to) 2157-2159: Number of pages: 3: Journal: Physical Review D: We determine the width for radiative decay of heavy Higgs bosons HW+W- for hard photons as a function of the Higgs-boson mass and the photon-energy cutoff, and correct the result of a previous calculation. Decays of the Higgs boson are understood very well for all practical (LHC) purposes. particles. The calculation of the rare t-quark decay t!b bbW + within the Standard Model as well as the charged Higgs contribution to this decay is presented. The Higgs invisible decay width may soon become a powerful tool to probe extensions of the Standard Model with dark matter candidates at the Large Hadron Collider. Mass scan: s = 7 and 8 TeV (for updates) and 13 and 14 TeV . formation on the Higgs total decay width from an on-shell Higgs boson cross section measurement. 20. Enter the email address you signed up with and we'll email you a reset link. We analyze this with recent data from LEP and compute the contribution of the model.

A straightforward calculation leads us to the following decay width: r(v + 2-O + Hl+t-) = aM;MiAf(ai + bi) . Total decay width and branching fraction of the Higgs boson (a) (5P.) aim: calculate all 2HDM Higgs boson decays @1-loop (electroweak) use perturbation theoryto solve the scattering matrix S at 1-loop level 2HDM electroweak Lagrangian" Processes, e.g. Phys .

The total width is dominated by Higgs decays to b quark pairs. 0.6 0.8 1 1.2 1.4 1 . aa r X i v : . We investigate also the possibility that the electroweak vacuum could be destabilized by unwanted wrong . Abstract We calculate decays of a standard model Higgs boson via a virtual massive particle and discuss how this depends on the massive particle total width.

Prophecy4f and our calculation(Hto4l ) for the Higgs decay width (in KeV), for dierent values of the Higgs mass and nal states.The numbers in parenthesis are the statistical uncertainty on the last digit due to MC integration. the input to the combined measurement includes the latest results from the decay modes that initially led to the higgs boson discovery: h zz ++ decays 28 with two z bosons that. in the triangle loop, contribute to the decay width of. 2 a comparison between. The calculation of the two-loop corrections to the partial width of an intermediate-mass Higgs boson decaying into a pair of photons is reviewed. Precise prediction of decay width ( H ! ) The differ- . . (N.Y.); (United States) W and Z boson pairs are the signals of the production of many types of new, heavy particles, e.g., heavy Higgs bosons, new Z' bosons, heavy quark and lepton pairs, and heavy gaugino pairs.

e ects in the H!4'decay width. The rst observation one can do is that the decay width increases with M A. We found that the branch ratio is about 0.187 10 8 , and there will not be enough events to produce with integrated luminosity 3000 fb 1 at the 14 TeV LHC. In this work, we investigate the parameter space of the Georgi-Machacek (GM) model, where we consider many theoretical and experimental constraints such as the perturbativity, vacuum stability, unitarity, electroweak precision tests, the Higgs di-photon decay and the Higgs total decay width. Interference e ects and sensitivity to the Higgs Abstract: We calculate loop-induced Higgs production and decay processes which are relevant for the LHC in various six-dimensional Universal Extra Dimension models. For the calculation of the case where the Higgs couples to the internal charm quark, i.e., equal masses as- .

. Chicken and Egg; Matter and Field; 7. "I . We calculate decays of a standard model Higgs boson via a virtual massive particle and discuss how this depends on the massive particle total width. We perform the numerical calculation by taking the LHM input parameters f = 3, 4 TeV and 0.1 < c < 0.6, and discuss the numerical results of the decay width up to the QCD NLO within the recent experimentally constrained LHM parameter space region. The theoretical calculations of the Higgs boson production cross sections and decay branching ratios have been compiled in Refs. To this end we compute four-loop QCD corrections in the large top quark mass expansion to the Higgs boson--photon form factor, which . Amplitudes FeynmanModel rulesfile Decay Widths @1-loop HDECAY QCD, off-shell, loop-induced 2HDECAY Full result The results obtained are identical (and differ by a factor of 2 from the original calculation) but the diagonal-basis derivation is pedagogically useful for clarifying . In the Standard Model of particle physics, the Higgs mechanism is essential to explain the generation mechanism of the property "mass" for gauge bosons.Without the Higgs mechanism, all bosons (one of the two classes of particles, the other being fermions) would be considered massless, but measurements show that the W +, W , and Z 0 bosons actually have relatively large masses of around 80 . Our results show that the two-loop QCD correction always reduces the LO decay width and the top-induced QCD correction is the dominant contribution at the QCD NLO. Higgs decay candidates to various final states 12/5/2014 . From numerical results, we find that the decay width of process H b + J / + b at leading order (LO) mainly comes from the contribution of the Fock state S 3 1 (8), and the NLO QCD . As the rst part of this paper we get to analyze Standard Model (SM) Higgs boson main decay channels, at tree level for massive nal state particles and at one loop for gluons. Evaluate the Feynman integrals in the above calculations (numerically) with Mathematica/Maple for m h = 125 GeV and add up all contributions to get the total decay width of the Higgs boson. Evidence for a new particle with the mass of about 125 GeV and the properties of the Standard Model Higgs boson was present in the three decay modes H ZZ* , H , and H WW* in both experiments. The leading term confirms the results present in the . We discuss how one would go about measuring these partial widths of a Higgs boson . 7a. "I was actually shaking," said Mitesh Patel, a particle physicist at Imperial College, London, as he describes the moment he saw the results. 2.5% would decay to charm (c) quark/antiquark pairs 2.5% would decay to Z particles (though see below!) Figure 3: Standard Model Higgs boson production cross section times branching ratio at Ecm= 8 TeV. The framework - the total width Note that total H width scales all observed cross-sections The sum of the EW corrections ranges from -4% to 0% for a Higgs mass between 100 GeV and 150 GeV, while the complete correction at two-loop order amounts to less than pm 1.5% in this regime. Prophecy4f and The natural width of the Higgs boson is expected to be very small (<< resolution) . The total width is dominated by Higgs decays to b quark pairs.

For a light Higgs with a mass less than 140 GeV, this can cause a large change in the . They can be decomposed into W-boson contributions, AW, as well as fermionic The leading-order (LO) (one-loop) contributions to As have been known for a long time [11,12]. You can see that the decay modes change in prominance depending on the mass of the Higgs, M H. Effectively, this diagram expresses how likely the Higgs is to decay into a certain particle, or group of particles, depending on the mass of the Higgs. Ratio of observed rate to predicted standard model event rate for different combinations of Higgs boson production and decay processes The horizontal bar on each point denotes the 68% confidence . The Higgs boson discovery was announced by the ATLAS and CMS collaborations on 4 th July 2012. in non-perturbative Higgs model .

4. We apply an asymptotic expansion for MH 2Mt and compute three terms in the expansion.

Original language: English (US) Pages (from-to) 2157-2159: Number of pages: 3: Journal: Physical Review D: In order to identify the Higgs sector using future precision data, we calculate the partial decay widths of the discovered Higgs boson with the mass o