相关论文: The "forgotten" decay S -> Z+h as a CP analyzer
Scalar particles $S$ which are singlets under the Standard Model gauge group are generic features of many models of fundamental physics, in particular as possible mediators to a hidden sector. We show that the decay $S\to Zh$ provides a…
As an interpretation of the 750 GeV diphoton excesses recently reported by both ATLAS and CMS collaborations, we consider a simple extension of the Standard Model with a Dirac fermion dark matter where a singlet complex scalar field…
Heavy vector-like quarks coupled to a scalar $S$ will induce a coupling of this scalar to gluons and possibly (if electrically charged) photons. The decay of the heavy quark into $Sq$, with $q$ being a Standard Model quark, provides, if…
LHC searches have revealed that the Higgs boson decay to a photon pair is nearly consistent with the Standard Model (SM), whereas recently, there is evidence for the decay of the Higgs boson to a $Z$-boson and a photon. These decays are…
The amplitude of the diphoton decay of the Higgs boson is considered in an extension of the Standard Model involving heavy vectorlike fermions, which was recently suggested in the literature in order to explain a possible enhancement of the…
In extensions of the Standard Model (SM) of particle physics a light scalar from a hidden sector can interact with known particles via mixing with the SM Higgs boson. If the scalar mass is of GeV scale, this coupling induces the scalar…
In this paper we explore the possibility of a pseudoscalar resonance to account for the 750 GeV diphoton excess observed both at ATLAS and at CMS. We analyze the ingredients needed from the low energy perspective to obtain a sufficiently…
Recently the ATLAS and CMS experiments have presented data hinting at the presence of a Higgs boson at $m_h\simeq125$ GeV. The best-fit $h\rightarrow\gamma\gamma$ rate averaged over the two experiments is approximately $2.1\pm0.5$ times the…
Recent LHC data hinted at a 750 GeV mass resonance that decays into two photons. A significant feature of this resonance is that its decays to any other Standard Model particles would be too low to be detected so far. Such a state has a…
A search for a hypothetical heavy scalar particle, $X$, decaying into a singlet scalar particle, $S$, and a Standard Model Higgs boson, $H$, using 140 fb$^{-1}$ of proton-proton collision data at the centre-of-mass energy of 13 TeV recorded…
We discuss possible signatures of the $CP$-odd scalar of two-doublet models at the LHC. We find that the inclusive two-photon decay mode and the decay sequence $A^0 \rightarrow Zh, h \rightarrow \gamma \gamma$, where $h$ is a $CP$-even…
We argue that extensions of the Standard Model (SM) with a warped extra dimension, which successfully address the hierarchy and flavor problems of elementary particle physics, can provide an elegant explanation of the 750 GeV diphoton…
A 750 GeV resonance has been observed at the Run 2 LHC in the diphoton channel. In this paper, we explain this resonance as a CP-even scalar, S, that triggers the spontaneous breaking of local $U(1)_B$ or $U(1)_{B+L}$ gauge symmetries. S…
The phenomenology entailed by a scalar resonance in a top partner model is analysed here in a $SO(5)$ Composite Higgs formalism. Heavy scalar resonances production and their decays modes are explored along a benchmark resonance mass range.…
A resonance near 750 GeV has been observed at both the ATLAS and CMS experiments in its diphoton decay channel. We propose a possible interpretation based on a simplified model: a 750 GeV singlet scalar resonance, and a minimal stealth…
We investigate the search prospects for new scalars beyond the Standard Model (SM) at the Large Hadron Collider (LHC). In these studies two real scalars $S$ and $\chi$ have been introduced in a two Higgs doublet model (2HDM), where $S$ is a…
The ATLAS and CMS collaborations have recently shown data suggesting the presence of a Higgs boson in the vicinity of 125 GeV. We show that a two-Higgs doublet model spectrum, with the pseudo-scalar state being the lightest, could be…
The couplings of the Standard Model sector to the scale invariant degrees of freedom can open the possibility to study dark photons (DP). The Dalitz-like decay of the (Higgs-like) scalar boson into a single photon and DP is studied. The…
In this short note, we revisit the model of a CP-even singlet scalar resonance proposed in arXiv:1507.02483, where the resonance appears as the lightest composite state made of scalar quarks participating in hidden strong dynamics. We show…
The ATLAS and CMS collaborations have recently released their new analyses of the diphoton searches. We look in detail the consequences of their results deriving strong constraints on models where a scalar resonance $s$ decays into two…