There is a recent growing interest in detecting gravitational waves (GWs) via lunar seismic measurements. It requires a precise understanding of the Moon’s response to passing GWs but previous studies derived two seemingly different response functions—one using a field-theory approach and the other based on tidal forces—raising questions about their equivalence. Here, we analytically and...
Firstly, we briefly discuss how the hypothetical beyond-the-Standard-Model particle, the axion, can produce gravitational waves through several mechanisms. Then we present some of our recent proposals for detecting axions/gravitational waves, including cryogenic quantum transport technology, traditional spin systems, and specially engineered artificial magnetoelectric materials. We demonstrate...
Ref. ATLAS-CONF-2025-012
This note presents a combination of searches for Higgs boson pair (HH) production performed by the ATLAS and CMS Collaborations using proton-proton collision data sets recorded at $\sqrt{s}$ = 13 TeV at the LHC Run 2, corresponding to integrated luminosities ranging between 126 and 140 fb$^{-1}$. The upper limit at the 95% confidence level on the total HH production...
We develop a general framework for the computation of light-portal dark matter direct detection, incorporating a consistent treatment of finite momentum transfer. In this framework, dark matter interacts with Standard Model matter through a light mediator, which simultaneously serves as the force carrier for dark matter self-interaction, potentially with a distinct coupling strength. The...
In this work we study the prospect of detecting light CP-even and CP-odd scalars. We develop the general formalism for the scalar production and decay from mesons at LHC, given modified couplings of the scalars to the SM particles, as well as summarizing the relevant GeV-scale experiment constraints. We then analyze the complete long-lived particle of 2HDM, and reaches of light scalars in...
Recent observations from the James Webb Space Telescope have revealed an unexpectedly high abundance of massive galaxies at very high redshifts, challenging the standard $\Lambda$CDM cosmological framework. Cosmic strings, which can act as nonlinear seeds in the early Universe, provide a promising explanation for this tension. In this talk, I will present our recent work on the impact of...
In this work we consider cosmological gravitational production of Dirac sterile neutrinos as dark matter candidates during and after inflation. In the former, the Higgs field experiences large quantum fluctuations driving its average field value to the Hubble scale and above facilitating the sterile neutrino production. However, the production efficiency due to classical gravity still remains...
Effective field theory (EFT) concept provides a necessary tool for obtaining general predictions of low energy theory valid below its unitarity breaking scale (cutoff scale). Early Universe inflation and subsequent reheating could be a unique setup for testing potentially observable effects coming from the derivative expansion of the corresponding EFT around the flat space vacuum. In this...
The amount of information propagated by an intermediate heavy particle exhibits characteristic features in inelastic scatterings with n≥3 final particles. As the total energy increases, the entanglement entropy, between its decay products and other final particles, exhibits a universal sharp dip, suppressed by its small decay rate. This indicates an entanglement suppression from a low-energy...
The ATLAS and CMS experiments are unique drivers of our fundamental understanding of nature at the energy frontier. In this contribution to the update of the European Strategy for Particle Physics, we update the physics reach of these experiments at the High-Luminosity LHC (HL-LHC) in a few key areas where they will dominate the state-of-the-art for decades to come.
Axions and axion-like particles can be probed through gravitational waves indirectly, often referred to as “audible axions”. The usual concept of audible axion relies on the coupling between the axions and the gauge fields. Here we consider an axion-like mechanism with coupling to the Nieh–Yan term. This interaction leads to the direct and efficient production of gravitational waves during the...
In this Letter we explore, for the first time, the constraints on lepton flavor violating (LFV) dark matter (DM) scenarios via the astrophysical photons and positrons, including both the annihilation and decay modes, ${\tt DM(+DM)}\to e^\pm \mu^\mp, e^\pm \tau^\mp, \mu^\pm \tau^\mp$. Given the presence of LFV interactions in various DM models and the challenge of probing such interactions at...
Red giants (RGs) efficiently capture dark matter (DM) through elastic scattering with stellar nuclei. Once accumulated in the helium core, the DM population can become self-gravitating and collapse, injecting energy through scattering and (when relevant) delayed annihilation. This localized heating can trigger a premature helium flash, reducing the luminosity at the tip of the RG branch. By...
We investigate whether collider experiments can reach the quantum limit of precision, defined by the quantum Fisher information (QFI), using only classical observables such as particle momenta. As a case study, we focus on the $\tau^+\tau^-$ system and the decay channel $\tau \to \pi \nu$, which offers maximal spin-analyzing power and renders the decay a projective measurement.
We develop a...
Dark matter is the dominant matter in the Universe while its particle nature is still unknown. In this talk, I will introduce two major scenarios of dark matter: Axion dark matter and WIMP (Weakly Interactive Massive Particle) and show how radio telescopes can search and put constraints on their parameters. The first one is Axion, which is a compelling dark matter candidate of increasing...
A comprehensive study of triple Higgs boson production in the 42 decay final state is performed for the first time at a future 100 TeV hadron collider. The analysis incorporates modified Higgs self-couplings via trilinear Higgs self-coupling 3 and quartic Higgs self-coupling 4, enabling for a model-independent investigation of potential new physics effects. Higgs bosons are reconstructed...
In cosmology, correlation functions on a late-time boundary can arise from both field redefinitions and bulk interactions, which are usually believed to generate distinct results. In this letter, we propose a counterexample showcasing that correlators from local field redefinitions can be identical to the ones from bulk interactions. In particular, we consider a two-field model in de Sitter...
