Δrand the W-boson mass in the singlet extension of the standard model

Abstract

The link between the electroweak gauge boson masses and the Fermi constant via the muon lifetime measurement is instrumental for constraining and eventually pinning down new physics. We consider the simplest extension of the Standard Model with an additional real scalar SU (2) L ⊗ U (1) Y singlet and compute the electroweak precision parameter ∆r, along with the corresponding theoretical prediction for the Wboson mass. When confronted with the experimental W-boson mass measurement, our predictions impose limits on the singlet model parameter space. We identify regions, especially in the mass range which is accessible by the LHC, where these correspond to the most stringent experimental constraints that are currently available.

Higgs boson mass and electroweak observables in the MRSSM

“…[61] for the SM; a major difference is the appearance of the additional Higgs triplet with non-vanishing vev, which enters already at lowest order (for computations of m W in models with Higgs triplets and singlets see refs. [62,63] and [64], respectively). Beyond tree-level the W boson pole mass m W can be obtained from the precisely known muon decay constant using the relation…”

Singlet-catalyzed electroweak phase transitions and precision Higgs boson studies

“…In this work, we revisit the viability of a SFOEWPT in the simplest extension of the SM scalar sector involving one real gauge singlet scalar S, dubbed the "xSM", and analyze its implications for future, precision Higgs studies (for earlier studies of the EWPT dynamics and/or phenomenology of the xSM, see e.g., [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] and references therein). The xSM cannot account for the BAU on its own as it does not contain new sources of CP violation.…”

Interference effects in heavy Higgs production via gluon fusion in the singlet extension of the Standard Model

“…This is in agreement with the limits obtained in refs. [26,30] which conclude that the largest possible value for the absolute value of sin α is 0.46 for M H between 160 and 180 GeV. This limit becomes slowly more stringent for increasing heavy Higgs masses reaching about 0.2 at M H = 700 GeV.…”

“…The strongest limits on the parameters of the 1HSM come from measurements of the coupling strengths of the light Higgs [3][4][5][6], which dominate for small masses of the heavy Higgs, and from the contribution of higher order corrections to precision measurements, in particular to the mass of the W boson [26], which provides the tightest constraint for large M H . The most precise result for the overall coupling strength of the Higgs boson from CMS [3] readsμ =σ/σ SM = 1.00 ± 0.13.…”