Related papers: Light Scalars and the KOTO Anomaly
Weakly interacting K --> pi X^0 emission with m_{X^0} \simeq m_{pi^0} is out of sight of the current K^+ --> pi^+ nu nubar study, but it can be sensed by the K_L --> pi^0 nu nubar search. This evades the usual Grossman-Nir bound of B(K_L…
The new particle recently discovered at the Large Hadron Collider has properties compatible with those expected for the Standard Model (SM) Higgs boson. However, this does not exclude the possibility that the discovered state is of…
We consider a simple renormalizable dark matter model consisting of two real scalars with a mass splitting $\delta$, interacting with the SM particles through the Higgs portal. We find a viable parameter space respecting all the bounds…
We present a comprehensive phenomenological analysis of the Radion in the Randall-Sundrum model, focusing on its production via light-by-light scattering in ultra-peripheral proton-proton collisions at the LHC. We provide a consistent…
The most important hint of physics beyond the Standard Model (SM) from the 1995 precision electroweak data is that the most precisely measured quantities, the total, leptonic and hadronic decay widths of the $Z$ and the effective weak…
Both the ATLAS and CMS experiments at the LHC have reported the observation of the particle of mass around 125GeV which is consistent to the Standard Model (SM) Higgs boson, but with an excess of events beyond the SM expectation in the…
I give a pedagogical introduction into flavour-changing neutral current interactions of kaons and their role to reveal or constrain physics beyond the Standard Model (SM). Then I discuss the measure $\epsilon_K^\prime$ of direct CP…
The new measurement of the $W$ boson mass performed by the CDF experiment at the Tevatron shows a significant deviation not only with the expectation in the Standard Model but also with other precision measurements performed at LEP, the…
We define a minimal model with Universal Extra Dimensions, and begin to study its phenomenology. The collider signals of the first KK level are surprisingly similar to those of a supersymmetric model with a nearly degenerate superpartner…
A detailed phenomenological analysis of neutral kaon mixing in "little Randall-Sundrum" models is presented. It is shown that the constraints arising from the CP-violating quantity epsilon_K can, depending on the value of the ultra-violet…
The exceptionally accurate Standard Model (SM) theory of fundamental interactions is known to be incomplete. Many new theories extend the SM, trying to solve some of the most compelling puzzles of nature. Since the start of LHC experiments,…
We propose a new explanation for excess events observed in the search for a high-mass resonance decaying into dibosons by the ATLAS experiment. The resonance is identified as a composite spin-$0$ particle that couples to the Standard Model…
It is widely believed that existing electroweak data requires a Standard Model Higgs to be light while electroweak and flavour physics constraints require other scalars charged under the Standard Model gauge couplings to be heavy. We…
The Standard Model (SM) is augmented with a $\mathrm{U}(1)_{B-3L_\mu} $ gauge symmetry spontaneously broken above the TeV scale when an SM-singlet scalar condenses. Scalar leptoquarks $S_{1(3)} = (\overline{\mathbf{3}},\, \mathbf{1}…
From a theoretical point of view it is not hard to imagine gaugino masses being much lighter than scalar masses. The dominant contributions to gaugino masses are then their anomaly-mediated values. Given current lower bounds on gauginos,…
A light scalar $\phi$ with mass $\lesssim 1$ GeV and muonic coupling $\mathcal{O}(10^{-3})$ would explain the 3.5 $\sigma$ discrepancy between the Standard Model (SM) muon $g-2$ prediction and experiment. Such a scalar can be associated…
The recent excess over the Standard Model prediction in the \mu \gamma missing-E_T channel reported by CDF can be well-explained by resonant smuon production with a single dominant R-parity violating coupling \lambda'_{211}, in the context…
Cascade decays of new scalars into final states with multiple photons and possibly quarks may lead to distinctive experimental signatures at high-energy colliders. Such signals are even more striking if the scalars are highly boosted, as…
The kinetic mixing (KM) portal is a popular mechanism which allows light dark matter (DM) in the mass range below $\sim 1$ GeV to achieve the observed relic density by thermal means and can be effectively described by only a few parameters,…
The rare kaon decay $K^+ \to \pi^+\ell^+\ell^-$ offers insights into Standard Model (SM) physics and beyond. Driven by vector form factor in the SM, it can also probe non-standard contributions. In this letter we study the scalar…