We compute the quark and gluon momentum fraction for the pion and kaon. This is done by employing lattice quantum chromodynamics simulations. We use three gauge ensembles of twisted mass fermions generated by the Extended Twisted Mass Collaboration with two degenerate light quarks and non-degenerate strange and charm quarks. All quark masses are tuned to approximately their physical values....
We explore the phase structure of the lattice Schwinger model in the presence of a toplogical $\theta$-term, a regime in which conventional Monte Carlo simulations suffer from the sign problem, using the variational quantum eigensolver (VQE). Constructing a suitable variational ansatz circuit for the lattice model using symmetry-preserving 2-qubit gates, we perform classical simulations...
Axions and axion-like particles (ALPs) are one of the most widely discussed extensions of the Standard Model when it comes to the strong CP problem and dark matter candidates. Current experiments are focused on the indirect searches of invisible pseudoscalars in a wide parameter range. In this paper we investigate limits on ALP mass, and its couplings to photons and leptons from 3-photon...
Chern-Simons gauge theories have a deep and broad impact on a wide range of physics research, ranging from parity anomalies in quantum field theory to the theory of the integer and fractional quantum Hall effects, and the effective field theory description of chiral spin liquids in condensed matter physics. Despite the fact that Chern-Simons theories are well understood as a continuum field...
We evaluate the transverse momentum-dependent parton distribution functions for the pion and kaon by computing the quasi-beam functions with asymmetric staple-shaped quark bilinear operators and combine it with the soft function and Collins-Soper kernels. These are computed within lattice QCD using an $\mathcal{N}_f= 2 + 1 + 1$ twisted mass fermion ensemble of lattice size $24^3 \times 48$,...
Spectroscopy experiments at the precision frontier allow us to study low-energy nuclear structure, test bound-state QED, refine fundamental constants, and potentially find New Physics. As the experimental uncertainties are continuously improved, theory predictions need to follow suit.
The finite-size corrections to the spectra of hydrogen-like atoms are often expanded in terms of the moments...
A well-known challenge when simulating Lattice Gauge theories (LGT) is so-called critical slowing down, which refers to the exponential increase of the autocorrelation time as the lattice spacing is reduced and approaches the continuum limit. Previously, normalizing flows, combined with Lüscher’s trivializing maps, have been proposed as an alternative approach to Hybrid Monte Carlo (HMC),...
We propose a novel direct search experiment for the hypothetical X17 particle. In recent years researchers from the ATOMKI Collaboration have reported anomalous signals around 17 MeV in excited 8Be, 4He and 12C nuclear decays via internal pair creation. On the theory side this has set off a flurry of research, which found that the anomalies could be explained by a new light (~17 MeV)...
