The workshop “Shedding light on X17” brings together scientists looking for the existence of
a possible new light particle, often referred to as X17. This hypothetical particle can explain …

Angular correlation spectra of e+ e− pairs produced in the H 3 (p, e+ e−) He 4 nuclear
reaction have been studied at E p= 510, 610, and 900 keV proton energies. The main …

New light vectors with dimension-4 couplings to Standard Model states have (energy/vector
mass) 2-enhanced production rates unless the current they couple to is conserved. These …

We consider several extensions of the Standard Model (SM) which can explain the
anomalies observed by the Atomki collaboration in the decay of excited states of Beryllium …

This report summarizes the present status of neutrino non-standard interactions (NSI). After
a brief overview, several aspects of NSIs are discussed, including connection to neutrino …

The ALICE collaboration at the CERN LHC reports novel measurements of jet substructure
in pp collisions at s= 7 TeV and central Pb–Pb collisions at s NN= 2.76 TeV. Jet substructure …

A bstract The QCD axion is one of the most compelling solutions of the strong CP problem.
There are major current efforts into searching for an ultralight, invisible axion, which is …

Neutrinos may be the harbingers of new dark sectors, since the renormalizable neutrino
portal allows for their interactions with hidden new physics. We propose here to use this fact …

A bstract In view of the latest experimental results recently released by the ATOMKI
collaboration, we critically re-examine the possible theoretical interpretation of the observed …

We derive constraints on the couplings of light vector particles to all first-generation
Standard Model fermions using leptonic decays of the charged pion, π+→ e+ ν e X μ. In …