Conveners
Research Talks: Students and Postdocs
- Yannick Wunderlich (Helmholtz-Institut für Strahlen- und Kernphysik)
Research Talks: Research Talks: Students and Postdocs
- Phoebe Sharp (George Washington University)
Research Talks
- Yannick Wunderlich (Helmholtz-Institut für Strahlen- und Kernphysik)
Research Talks: Research Talks: Students and Postdocs
- Yannick Wunderlich (Helmholtz-Institut für Strahlen- und Kernphysik)
Research Talks
- Phoebe Sharp (George Washington University)
Short Range Correlations (SRCs) are a phenomenon found in all nuclei where two nucleons form a strongly interacting, close-proximity pair in the nucleus, leading to a large relative momentum between the nucleons. Electron-scattering experiments, many of them conducted at Jefferson Lab, have determined that the prevalence of SRCs increase with nuclear size, and furthermore that most SRCs form...
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)...
Over the past two decades a plethora of new exotic states containing heavy quarks have been discovered above open heavy-flavor thresholds.
For these states, which cannot be interpreted as quark anti-quark bound states, a number of different explanations have been put forward in terms of tetraquark states based on QCD diquarks, QCD hybrids, hadronic molecules, among others. In the past couple...
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...
The search for Dark Matter is an integral part of New Physics searches, however, Dark Matter has yet to be observed directly. Theoretical models provide a large parameter space for Dark Matter and allow for different properties of the particles. Models incorporating so-called portal interactions, where Dark Matter interacts with Standard Model particles through a mediator particle, are of...
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...
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...
The anomalous magnetic moment of the muon, $a_\mu = (g-2)_\mu/2$, is one of the most precisely measured observables of the Standard Model. However, its value shows a sizeable discrepancy to the Standard Model prediction. It is still under discussion whether this discrepancy is a hint for New Physics or a proof for the limited understanding of strong interaction at low energies. To get a better...
The anomalous magnetic moment of the muon $a_\mu=(g_\mu-2)/2$ is one of the most precisely measured quantities in modern physics. However, there is a sizable discrepancy between the Standard Model (SM) prediction of the Muon $g-2$ Theory Initiative and the experimental average of the latest direct measurements at BNL and FNAL. This discrepancy is known as the Muon $g-2$ puzzle. For the SM...
Lepton-flavor-violating decays of light pseudoscalars, $P = \pi^0, \eta,\eta' \to \mu e$, are stringently suppressed in the Standard Model up to tiny contributions from neutrino oscillations, so that their observation would be a clear indication for physics beyond the Standard Model.
However, in effective field theory such decays proceed via axial-vector, pseudoscalar, or gluonic operators,...
We investigate contributions of excited states to nucleon matrix elements by studying the two- and three-point functions using nucleon and pion-nucleon interpolating fields. This study is made using twisted mass fermion ensembles with pion masses 346 MeV and 131 MeV. We construct an improved nucleon interpolating field with the generalized eigenvalue problem of two-point functions, and use it...
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),...
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 $24^3 \times 48$,...
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....
Neutrons play a dominant role in the stellar nucleosynthesis of heavy elements. We review a scheme for the experimental determinations of neutron-induced reaction cross sections using a high-intensity neutron source based on the 18O(p,n)18F reaction with an 18O-water target at SARAF’s upcoming Phase II. The quasi-Maxwellian neutron spectrum with effective thermal energy kT ≈ 5 keV,...
Short Range Correlations (SRCs) are a phenomenon found in all nuclei where two nucleons form a strongly interacting, close-proximity pair in the nucleus, leading to a large relative momentum between the nucleons. Electron-scattering experiments, many of them conducted at Jefferson Lab, have determined that the prevalence of SRCs increase with nuclear size, and furthermore that most SRCs form...
