Related papers: $R_b$ -- $R_c$ Crisis and New Physics
After the observation in 2012 of a new scalar particle closely resembling the Higgs boson of the Standard Model of particle physics, there is a general consensus that there must be Physics Beyond the Standard Model, with present experiments…
The Standard Model of Particle Physics has been verified to unprecedented precision in the last few decades. However there are still phenomena in nature which cannot be explained, and as such new theories will be required. Since terrestrial…
An extension of the Standard Model by extra scalar singlets was considered. Theoretical (unitarity, vacuum stability, triviality) and cosmological (dark matter relic abundance, direct detection experiments, constraints on dark matter…
New large colliders will probe scales up to few TeV, indicating the way Nature has chosen to extend the Standard Model. We review alternative scenarios to the traditional Minimal Supersymmetric Standard Model: the little Higgs model, split…
There are two aspects to the 1995 summer update of the combined preliminary electroweak data from LEP and SLC. On the one hand, agreement between experiments and the Standard Model (SM) has improved for the line-shape and the asymmetry…
We analyse the allowed range of values of chi, both in the Standard Model and in models with New Physics, pointing out that a relatively large value of chi, e.g. of order lambda, is only possible in models where the unitarity of the 3x3…
Electroweak precision data have been extensively used to constrain models containing physics beyond that of the Standard Model. When the model contains Higgs scalars in representations other than singlets or doublets, and hence rho not…
Some new physics beyond the Standard Model of particle physics, like Supersymmetry, Extra-dimensions etc., and their effect on the nature of different standard model phenomena are explored in this thesis. We discuss the power law scaling of…
As an alternative to the standard model, we couple two scalar doublets such that, in the third family, one (${\cal H}$) couples only to the top quark, the other ($H$), that is identified as the 126 GeV state already observed, to the bottom…
I review some aspects of $K$ and $B$ physics both in the context of the standard model and in some cases in a scenario which is rather different from the standard model. I discuss, in particular, where we are likely to see deviations from…
We examine the collider and dark matter phenomenology of the Standard Model extended by a hypercharge-zero SU(2) triplet scalar and gauge singlet scalar. In particular, we study the scenario where the singlet and triplet are both charged…
We explore the radiative corrections to the process Z --> b b-bar in models with extended Higgs sectors. The observables R_b (the Z hadronic branching fraction to b b-bar) and the b-quark asymmetry A_b = (g_L^2 - g_R^2)/(g_L^2 + g_R^2) are…
Semileptonic $b \to c$ transitions, and in particular the ratios $R(D^{(*)}) = \frac{\Gamma(B \rightarrow D^{(*)} \tau \nu )}{\Gamma(B \rightarrow D^{(*)} \ell \nu )}$, can be used to test the universality of the weak interactions. In light…
Experiments have confirmed the presence of a mass gap between the Standard Model and potential New Physics. Consequently, the exploration of effective field theories to detect signals indicative of Physics Beyond the Standard Model is of…
When collecting spectroscopic data on at least four isotopes, nonlinearities in the King plot are a possible sign of Physics beyond the Standard Model. In this work, an improved approach to the search for hypothetical new interactions with…
The solar and atmospheric neutrino anomalies constitute the only solid and most remarkable evidence for physics beyond the Standard Model, indicating that the lepton mixing matrix is fundamentally distinct from that describing the quarks.…
We study collider signatures for extra scalar bosons in the inert doublet model at the international linear collider (ILC). The inert doublet model is a simple extension of the standard model by introducing an additional isospin-doublet…
Content 1. Why we do Believe in the Standard Model 2. Why we do not Believe in the Standard Model 2.1Conceptual Problems 2.2Hints from Experiment --2.2.1 Unification of Couplings --2.2.2 Dark Matter --2.2.3 Baryogenesis --2.2.4 Neutrino…
The discovery of the Standard Model Scalar Boson (Brout-Englert-Higgs particle) opens a new field of research, namely the structure of the scalar sector. Numerous extensions exist, and imply extra particles, including additional scalars.…
This note discusses the matter of probing Beyond the Standard Model physics and how, to succeed in this quest, the interpretations of the Standard Model regarding observed phenomena must be utilized with caution. We give several specific…