The high-intensity setup and detector performance make the NA62 experiment at CERN particularly suited for searching new physics effects from different scenarios involving feebly interacting particles in the MeVGeV mass range.
A search for the K+→π+X decay, where X is a long-lived feebly interacting particle, is performed through an interpretation of the K+→π+νν¯ analysis of data collected in...
While the QCD axion is often considered to be necessarily light (eV), recent work has opened a viable and interesting parameter space for heavy axions, which solve both the Strong CP and the axion Quality Problems. These well-motivated heavy axions, as well as the generic axion-like-particles, call for explorations in the GeV mass realm at collider and beam dump environments. The primary...
Axion-like particles (ALPs) provide a promising direction in the search for new physics, while a wide range of models incorporate ALPs. We point out that neutrino and dark matter experiments, such as DUNE and CCM, possess competitive sensitivity to ALP signals. High-intensity proton beams can not only produce copious amounts of neutrinos, but also cascade photons that are created from charged...
The discrepancy between the muon g−2 measurement and the Standard Model prediction points to new physics around or below the weak scale. It is tantalizing to consider the loop effects of a heavy axion (in the general sense, also known as an axion-like particle) coupling to leptons and photons as an explanation for this discrepancy. We provide an updated analysis of the necessary couplings,...
I will talk about a ``heavy'' QCD axion whose coupling to the standard model is dominated by $a G \widetilde{G}$ but with $m_a \gg m_\pi f_\pi / f_a$. This is well motivated as it can solve the strong CP problem while evading the axion quality problem. Such axion with mass around a GeV is kinematically inaccessible or poorly constrained by most experimental probes except B-factories. We study...
Axion-like particles (ALPs) are pseudo-Nambu-Goldstone bosons of spontaneously broken global symmetries in theories attempting to address the incompleteness of the Standard Model (SM). In particular, ALPs arise in theoretical resolutions to the strong CP problem, offer explanations for the dark matter (DM) relic abundance, and are ubiquitous in string theory. The ALP mass $m_a$ can range from...
While supernovae and cooling neutron stars have long been fruitful environments for constraining dark sector particles such as axions, neutron star mergers offer a novel territory to explore BSM physics and look for its signatures in the electromagnetic and gravitational wave signals from the merger. Axions interact weakly with hot, dense nuclear matter and therefore will escape from the...
Top quark production in association with additional particles at CMS: tt+bb, tt+cc, ttZ, ttW, ttgamma, tZ and tttt production