Status of the Standard Model
Jens Erler, Paul Langacker
TL;DR
The paper conducts a comprehensive assessment of the Standard Model's electroweak sector, performing a global electroweak fit using a self-consistent MSbar radiative-correction framework that integrates $Z$-pole data, LEP2/Tevatron results, DIS, and low-energy observables. It finds a best-fit Higgs mass of $M_H = 107^{+67}_{-45}$ GeV with a 95% upper limit of $255$ GeV, and a top-quark mass and strong coupling $igl(m_t=171.4\pm4.8\text{ GeV}, \alpha_s(M_Z)=0.1206\pm0.0030\bigr)$ in agreement with independent measurements. The analysis shows precision data constrain beyond-SM scenarios through oblique parameters $S$, $T$, and $U$, while SUSY gauge coupling unification remains favored and technicolor/compositeness are disfavored. The work underscores a coherent SM picture with a light Higgs and tight constraints on new physics, guiding future collider searches and measurements. Overall, the study demonstrates the SM's robustness at the electroweak scale and clarifies the landscape of viable beyond-SM scenarios.
Abstract
We review the experimental and theoretical status of the standard electroweak theory, and its fundamental parameters. We obtain the global best fit result for the Standard Model Higgs boson of M_H = 107^{+67}_{-45} GeV, and find the 95% upper limit of 255 GeV. Parameters describing physics beyond the Standard Model are discussed as well. Particular emphasis is given to implications for supersymmetric extensions of the Standard Model.