Related papers: Light Scalars at FASER
Many existing or proposed intensity-frontier search experiments look for decay signatures of light long-lived particles (LLPs), highly displaced from the interaction point, in a distant detector that is well-shielded from SM background.…
A light (GeV mass) long-lived ($c\tau$ around dozens of millimeters) CP-odd scalar can be readily predicted in new physics models. In this work we investigate the Higgs decay into such a light scalar plus a $Z$-boson and take the aligned…
The dark axion portal is a dimension-5 coupling between an axion-like particle (ALP), a photon, and a dark photon, which is one of the targets of the intensity frontier searches looking for $\sim\,$sub-GeV long-lived particles (LLPs). In…
We study the collider signatures of a long-lived massive colored scalar transforming trivially under the weak interaction and decaying within the inner sections of a detector such as ATLAS or CMS. In our study, we assume that the colored…
Particles beyond the Standard Model (SM) can generically have lifetimes that are long compared to SM particles at the weak scale. When produced at experiments such as the Large Hadron Collider (LHC) at CERN, these long-lived particles…
The most general renormalizable interaction between the Higgs sector and a new gauge-singlet scalar $S$ is governed by two interaction terms: cubic and quartic. The quartic interaction is only loosely constrained by invisible Higgs decays.…
Long-lived particles that are present in many new physics models beyond the standard model, can be searched for in a number of newly proposed lifetime frontier experiments at the LHC. The signals of the long-lived dark photons can be…
For decades, new physics searches in collider experiments have focused on the high-$p_T$ region. However, it has recently become evident that the LHC physics potential has not been fully exploited. To be specific, forward collisions, which…
Two far-forward experimental systems are currently taking data during Run 3 at the Large Hadron Collider (LHC): FASER + FASER$\nu$ and SND@LHC. They are sensitive to some classes of beyond-the-Standard Model (BSM) particles, muons and…
Searches for new low-mass matter and mediator particles have actively been pursued at fixed target experiments and at $e^+e^-$ colliders. It is challenging at the CERN LHC, but they have been searched for in Higgs boson decays and in $B$…
Neutral particles are notoriously difficult to observe through electromagnetic interactions. As a result, they naturally elude detection in most collider detectors. In this paper, we point out that neutral particles that interact through a…
A number of extensions of the Standard Model predict the existence of new light, weakly-coupled particles that couple to the visible sector through higher-dimensional operators containing one or two photons, suppressed by a high new physics…
The search for light and long-lived particles at the LHC will be intensified in the upcoming years with a prominent role of the new FASER experiment. In this study, we discuss how FASER could independently probe such scenarios relevant for…
FASER is one of the promising experiments which search for long-lived particles beyond the Standard Model. In this paper, we focus on dark photon associating with an additional U(1) gauge symmetry, and also a scalar boson breaking this U(1)…
We present a reinterpretation of selected ATLAS and CMS searches for Higgs boson decays into long-lived particles (LLPs) within the scalar portal framework, where the standard model is extended by a light scalar that mixes with the Higgs…
The FASER experiment is a new small and inexpensive experiment that is placed 480 meters downstream of the ATLAS experiment at the CERN LHC. FASER is designed to capture decays of new long-lived particles, produced outside of the ATLAS…
Searching for long-lived particles (LLPs) beyond the Standard Model (SM) is a promising direction in collider experiments. The Georgi-Machacek (GM) model extends the scalar sector in the SM by introducing various new scalar bosons. In this…
The ForwArd Search ExpeRiment (FASER) is an experiment searching for new light and weakly-interacting particles at CERN's Large Hadron Collider. FASER is composed of different sub-detectors, including silicon microstrip detectors,…
The LHC may produce light, weakly-interacting particles that decay to dark matter, creating an intense and highly collimated beam of dark matter particles in the far-forward direction. We investigate the prospects for detecting this dark…
FASER$\nu$ is a newly proposed experiment which will take data in run III of the LHC during 2021-2023. It will be located in front of the FASER detector, 480~m away from the ATLAS interaction point in the forward direction. Its main goal is…