Related papers: Light Scalars at FASER
A search is presented for long-lived particles decaying into an oppositely charged lepton pair, $\mu^{+}\mu^{-}$, $e^{+}e^{-}$, or $e^{\pm}\mu^{\mp}$, that form a vertex within the inner tracking system of the ATLAS detector at the Large…
Using two suitable benchmark scenarios that satisfy the experimental constraints on the total decay width of the $125 \, {\rm GeV}$ Higgs boson, we determine the bounds on light CP-odd spin-0 states in the 2HDM+$a$ model that arise from…
A renormalizable UV model for Axion-Like Particles (ALPs) or hidden photons, that may explain the dark matter usually involves a dark Higgs field which is a singlet under the standard model (SM) gauge group. The dark sector can couple to…
The FASER experiment at CERN has opened a new window in collider neutrino physics by detecting TeV-energy neutrinos produced in the forward direction at the LHC. Building on this success, this document outlines the scientific case and…
A wealth of physics results have already been obtained from the LHC, due to the excellent performance of the collider and its experiments. Even more results are expected to be achievable in the phase of the high-luminosity LHC (HL-LHC). It…
Composite Higgs models feature new strong dynamics leading to the description of the Higgs boson as a bound state arising from the breaking of a global (flavour) symmetry. These models generally include light states generated by the same…
The $LQ\bar D$ operator in R-parity-violating supersymmetry can lead to meson decays to light neutralinos and neutralino decays to lighter mesons, with a long lifetime. Since the high-luminosity LHC is expected to accumulate as much as 3/ab…
After the discovery of the Higgs boson in 2012, particle physics has entered an exciting era. An important question is whether the Standard Model of particle physics correctly describes the scalar sector realized by nature, or whether it is…
A model based on a $U(1)_{T^3_R}$ extension of the Standard Model can address the mass hierarchy between generations of fermions, explain thermal dark matter abundance, and the muon $g - 2$, $R_{(D)}$, and $R_{(D^*)}$ anomalies. The model…
Models with light dark sector and dark matter particles motivate qualitatively new collider searches. Here we carry out a comprehensive study of hadrophilic models with U(1)$_B$ and U(1)$_{B-3L_{\tau}}$ gauge bosons coupled to light dark…
The precision determination of scalar top quark properties will play an important role at a future International Linear Collider (ILC). Recent and ongoing studies are discussed for different experimental topologies in the detector. First…
The physics motivation for a very forward detector for the ALICE heavy ion experiment at the CERN LHC is discussed. A phenomenological model describing the formation and decay of a Centauro fireball in nucleus-nucleus collisions is…
Yukawa production of a light scalar can be explored at a linear collider. Light (pseudo)scalar can exist in extended Higgs models and an interesting example is the light pseudoscalar in Type-X two Higgs doublet model. The model can explain…
Several models of physics beyond the Standard Model predict the existence of dark photons, light neutral particles decaying into collimated leptons or light hadrons. This paper presents a search for long-lived dark photons produced from the…
In the type-I two-Higgs-doublet model, the pseudoscalar $A$ can act as a long-lived particle (LLP) for sufficiently large values of $\tan\beta$. At the LHC, the $A$ particles are predominantly produced in pairs through $pp \to W^*/Z^* \to…
COMPASS is a fixed-target experiment at the CERN SPS that studies the spectrum of light-quark hadrons. In 2009, it collected a large dataset using a $190\,$GeV$/c$ positive hadron beam impinging on a liquid-hydrogen target in order to…
In this paper, we propose a dedicated forward detector, FOREHUNT (FORward~Experiment~for~HUNdred~TeV), for 100 TeV FCC-hh for the detection of light long-lived particles (LLP) coming from $B$-meson decay. We calculate the signal acceptance…
A search for scalar particles decaying via narrow resonances into two photons in the mass range $65-600$ GeV is performed using 20.3 fb$^{-1}$ of $\sqrt{s}$ = 8 TeV $pp$ collision data collected with the ATLAS detector at the Large Hadron…
The future Large Hadron electron Collider (LHeC) would allow collisions of an intense electron beam with protons or heavy ions at the High Luminosity-Large Hadron Collider (HL-LHC). Owing to a center of mass energy greater than a TeV and…
We study the pair production of the long-lived mediator particles from the decay of the SM Higgs boson and their subsequent decay into standard model particles. We compute the projected sensitivity, both model-independently and with a…