scholarly journals Higher-order QCD corrections to H → b$$ \overline{b} $$ from rational approximants

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Diogo Boito ◽  
Cristiane Y. London ◽  
Pere Masjuan
Keyword(s):  
Standard Model ◽  
Higher Order ◽  
Massless Scalar ◽  
Model Parameters ◽  
Renormalization Scale ◽  
Foreseeable Future ◽  
Rational Approximants ◽  
The Standard Model ◽  
Current Quark ◽  
Scalar Current

Abstract We use rational approximants to study missing higher orders in the massless scalar-current quark correlator. We predict the yet unknown six-loop coefficient of its imaginary part, related to Γ(H → b$$ \overline{b} $$ b ¯ ), to be c5 = −6900 ± 1400. With this result, the perturbative series becomes almost insensitive to renormalization scale variations and the intrinsic QCD truncation uncertainty is tiny. This confirms the expectation that higher-order loop computations for this quantity will not be required in the foreseeable future, as the uncertainty in Γ(H → b$$ \overline{b} $$ b ¯ ) will remain largely dominated by the Standard Model parameters.

scholarly journals A CALCULATION OF HIGGS MASS IN THE STANDARD MODEL

2000 ◽  
Vol 15 (26) ◽  
pp. 1605-1610 ◽  
Author(s):  
J. PASUPATHY
Keyword(s):  
Standard Model ◽  
Yukawa Coupling ◽  
Higgs Mass ◽  
Renormalization Scale ◽  
The Standard Model ◽  
Gauge Couplings ◽  
Top Mass

The assumption that the ratio of the Higgs self-coupling to the square of its Yukawa coupling to the top is (almost) independent of the renormalization scale fixes the Higgs mass within narrow limits at m H =160 GeV using only the values of gauge couplings and top mass.

scholarly journals Trying to understand the standard model parameters

2003 ◽  
Vol 18 (1-4) ◽  
pp. 55-75 ◽  
Author(s):  
C.D. Froggatt* ◽  
H.B. Nielsen†
Keyword(s):  
Standard Model ◽  
Model Parameters ◽  
The Standard Model

scholarly journals mr : A C++ library for the matching and running of the Standard Model parameters

2016 ◽  
Vol 206 ◽  
pp. 84-96 ◽  
Author(s):  
Bernd A. Kniehl ◽  
Andrey F. Pikelner ◽  
Oleg L. Veretin
Keyword(s):  
Standard Model ◽  
Model Parameters ◽  
The Standard Model

scholarly journals STATUS OF HIGHER-ORDER CORRECTIONS IN THE STANDARD ELECTROWEAK THEORY

1995 ◽  
Vol 10 (04) ◽  
pp. 443-464 ◽  
Author(s):  
BERND A. KNIEHL
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Higher Order ◽  
Threshold Effects ◽  
Electroweak Theory ◽  
Radiative Corrections ◽  
Gauge Sector ◽  
The Standard Model ◽  
Text Mode ◽  
Higher Order Corrections

We review recent theoretical progress in the computation of radiative corrections beyond one loop within the standard model of electroweak interactions, in both the gauge and Higgs sectors. In the gauge sector, we discuss universal corrections of [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text], and those due to virtual [Formula: see text]-threshold effects, as well as specific corrections to [Formula: see text] of [Formula: see text], [Formula: see text] and [Formula: see text] including finite-mb effects. We also present an update of the hadronic contributions to Δα. Theoretical uncertainties, other than those due to the lack of knowledge of MH and mt, are estimated. In the Higgs sector, we report on the [Formula: see text] corrections to [Formula: see text] including those which are specific for the [Formula: see text] mode, the [Formula: see text] corrections to [Formula: see text] including the finite-mq terms, and the [Formula: see text] corrections to Γ(H → gg).

scholarly journals HIGGS MASS FROM A CASIMIR ENERGY INDUCED COSMOLOGICAL CONSTANT IN THE STANDARD MODEL

2004 ◽  
Vol 19 (13n16) ◽  
pp. 1195-1201
Author(s):  
XIAO-GANG HE
Keyword(s):  
Standard Model ◽  
Symmetry Breaking ◽  
Cosmological Constant ◽  
Spontaneous Symmetry Breaking ◽  
Particle Physics ◽  
Higgs Mass ◽  
Vacuum Energy ◽  
Casimir Energy ◽  
Renormalization Scale ◽  
The Standard Model

Casimir vacuum energy is divergent. It needs to be regularized. The regularization introduces a renormalization scale which may lead to a scale dependent cosmological constant. We show that the requirement of physical cosmological constant is renormalization scale independent provides important constraints on possible particle contents and their masses in particle physics models. In the Standard Model of strong and electroweak interactions, besides the Casimir vacuum energy there is also vacuum energy induced from spontaneous symmetry breaking. The requirement that the total vacuum energy to be scale independent dictates the Higgs mass to be [Formula: see text] where the summation is over fermions and Ni equals to 3 and 1 for quarks and leptons, respectively. The Higgs mass is predicted to be approximately 382 GeV.

scholarly journals Higher order dilaton interactions in the nearly conformal limit of the Standard Model

2012 ◽  
Vol 717 (1-3) ◽  
pp. 182-187 ◽  
Author(s):  
Claudio Corianò ◽  
Luigi Delle Rose ◽  
Carlo Marzo ◽  
Mirko Serino
Keyword(s):  
Standard Model ◽  
Higher Order ◽  
The Standard Model

scholarly journals Precision Electroweak Data: Present Status and Future Prospects

1997 ◽  
Vol 12 (23) ◽  
pp. 4109-4154 ◽  
Author(s):  
Peter B. Renton
Keyword(s):  
Standard Model ◽  
Present Status ◽  
Model Parameters ◽  
Second Phase ◽  
Independent Variables ◽  
The Standard Model ◽  
Model Independent ◽  
The Impact ◽  
Precision Electroweak Data

The present status of precision electroweak data is reviewed. These data include LEP measurements of the mass and width of the Z, together with various measurements on the Z-fermion couplings. These data are compared to, and combined with, data from the SLC on the left–right polarized asymmetry, A LR , and the left–right forward–backward asymmetries for b and c quarks. These measurements are combined with hadron collider measurements from the Tevatron and CERN on the mass of the W boson, mW, as well as other electroweak data, in global electroweak fits in which various Standard Model parameters are determined. A comparison is made between the results of direct measurements of mW and the top-quark mass, mt, as determined from the Tevatron, with the indirect results coming from electroweak radiative corrections. Using all precision electroweak data, fits are also made to determine limits on the mass of the Higgs boson, mH. The influence on these limits of specific measurements, particularly those which are somewhat inconsistent with the Standard Model, is explored. The data are also analyzed in terms of the quasi model independent ∊ variables. Improvements in the determination of all of these quantities are expected when the Z data at LEP are fully analyzed, and further measurements on A LR and related asymmetries performed at the SLC. In addition, substantial improvements in the determination of mW are expected from measurements at the Tevatron and in the second phase of LEP. An estimate is made of the likely precision of these data, and the implications of the impact of these data on precision electroweak tests are discussed. This discussion is made both in terms of the Standard Model and also in the context of the quasi model independent ∊ variables.

scholarly journals Effect of higher-order stress gradients on the centennial mass evolution of the Greenland ice sheet

2012 ◽  
Vol 6 (4) ◽  
pp. 2961-3010
Author(s):  
J. J. Fürst ◽  
H. Goelzer ◽  
P. Huybrechts
Keyword(s):  
Standard Model ◽  
Ice Sheet ◽  
Coupled Model ◽  
Greenland Ice Sheet ◽  
Signal Propagation ◽  
Higher Order ◽  
Force Balance ◽  
Appreciable Effect ◽  
Model Version ◽  
The Standard Model

Abstract. We use a three-dimensional thermo-mechanically coupled model of the Greenland ice sheet to assess the effects of marginal perturbations on volume changes on centennial time scales. The model is designed to allow for five ice dynamic formulations using different approximations to the force balance. The standard model is based on the shallow ice approximation for both ice deformation and basal sliding. A second model version relies on a higher-order Blatter/Pattyn type of core that resolves effects from gradients in longitudinal stresses and transverse horizontal shearing, i.e. membrane-like stresses. Together with three intermediate model versions, these five versions allow for gradually more dynamic feedbacks from membrane stresses. Idealised experiments were conducted on various resolutions to compare the time-dependent response to imposed accelerations at the marine ice front. If such marginal accelerations are to have an appreciable effect on total mass loss on a century time scale, a fast mechanism to transmit such perturbations inland is required. While the forcing is independent of the model version, inclusion of direct horizontal coupling allows the initial speedup to reach several tens of kilometres inland. Within one century, effects from gradients in membrane stress alter the inland signal propagation and transmit additional dynamic thinning to the ice sheet interior. But the centennial overall volume loss differs only by some percents from the standard model as the dominant response is a diffusive inland propagation of geometric changes. In our experiments, the volume response is even attenuated by direct horizontal coupling. The reason is a faster adjustment of the sliding regime by instant stress transmission in models that account for the effect of membrane stresses. Ultimately, horizontal coupling decreases the reaction time to perturbations at the ice sheet margin.

STATUS OF STANDARD MODEL PARAMETERS

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 25-40
Author(s):  
ANTHONY R. BARKER
Keyword(s):  
Standard Model ◽  
Experimental Methods ◽  
Model Parameters ◽  
Ckm Matrix ◽  
Precision Determination ◽  
The Standard Model ◽  
Electroweak Sector

Recent experimental progress in determining the parameters of the electroweak sector of the Standard Model is summarized. The principal topics addressed include the precision determination of electroweak parameters using LEP and SLD data at the Z0 pole, measurements of the W mass by LEP-II, CDF, and D0, and determination of the elements of the CKM matrix using a variety of experimental methods.

POSSIBLE EFFECTS OF ADDITIONAL VECTOR BOSONS IN $e^+ e^- \to f\bar{f}$ AT THE TRISTAN ENERGIES

1992 ◽  
Vol 07 (22) ◽  
pp. 5537-5548
Author(s):  
A.A. LIKHODED ◽  
A.A. PANKOV ◽  
O.P. YUSHCHENKO
Keyword(s):  
Standard Model ◽  
Composite Structure ◽  
Model Parameters ◽  
Electroweak Interactions ◽  
The Standard Model ◽  
Model Predictions ◽  
Vector Bosons

The phenomenological manifestation of the additional Y(YL) boson arising in models with the composite structure of electroweak interactions is studied for the process [Formula: see text] at the TRISTAN energies [Formula: see text]. It is shown that the experimentally observed deviation of Rμ from the Standard Model predictions can be explained by the presence of the additional isoscalar Y boson in the region of a small mixing paramenter. The increase of statistics for the above processes at TRISTAN will permit one to set an additional limit on the model parameters.

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