Conveners
Monday: Monday 1
- Miguel Echevarria (University of Alcala)
Monday: Monday 2
- Riccardo Nagar (University of Milan-Bicocca)
Monday: Monday 3
- José Manuel Alarcón (Universidad de Alcalá)
Monday: Monday 4
- Werner Vogelsang (University of Tübingen)
Nature has two sources of mass. One is the Higgs boson, which is responsible for every mass scale that appears explicitly in the Standard Model Lagrangian. The Higgs was discovered at CERN in 2012; and with that discovery, the Standard Model became complete.
However, in connection with everyday matter, the material which constitutes our computers and ourselves, the Higgs produces little...
With $e^-$ constituents in a classical potential atoms are at the borderline between hard processes and soft classical physics. Data and phenomenology indicate that hadrons are similar. The importance of this cannot be overemphasized: It suggests a first-principles, analytic QCD approach to strong dynamics analogous to that long developed for QED atoms.
Bound state perturbation theory is...
Originally conceived for precise luminosity measurements, the gas injection system SMOG currently allows the unique LHCb detector capabilities to be exploited for fixed-target studies in proton-gas collisions at $\sqrt{s}$ ∼ 100 GeV. The first results obtained with SMOG data are reported: antiproton production with a He target and $J/\psi$, $D^0$ productions in p-He and p-Ar collisions. The...
For a long time, lattice QCD was unable to address the x-dependence of partonic distributions, direct access to which is impossible in Euclidean spacetime. Recent years have brought a breakthrough for such calculations when it was realized that partonic light-cone correlations can be accessed through spatial correlations computable on the lattice. Appropriately devised observables can be...
We develop a procedure to renormalize the quasi parton distribution in the recently proposed hybrid scheme and match it to the $\overline{\rm MS}$ scheme light-cone parton distribution at next-to-next-to-leading-order in perturbation theory. Under this procedure we calculate the pion valence quark
distribution using two fine lattices with spacing
$a=0.04$ fm and $0.06$ fm and valence pion...
The structure of nucleons as well as nuclei at large longitudinal momenta, x, is crucial for understanding QCD confinement, the origin of non-perturbative charm and beauty in the proton, or for explaining the origins of the nuclear EMC effect. Parton distribution functions (PDFs), which describe the longitudinal structure of hadrons, are typically determined in global analysis of experimental...
We developed a non-perturbative model for valence parton distribution functions (PDFs) based on the mean field interactions of valence quarks in the nucleonic interior. The model is based on the separation of the valence three-quark cluster and residual system in the nucleon. Then the nucleon structure function is calculated within the effective light-front diagrammatic approach ...
In 2010, precise determination of the proton radius from muonic lamb shift data, a result that systematically disagreed with previous atomic lamb shift and electron scattering data, sparked what was to become known as the proton radius puzzle. Since then, there have many new measurements and new theory calculations done to understand the source of the discrepancy. A preponderance of the new...
Effective field theories are exceptionally suited to define and determine the proton radius and its relatives from low energy observables. They not only provide a unified and unambiguous definition of the low energy constants that naturally includes electromagnetic corrections, but they also yield a robust determination of the theoretical uncertainty. In this talk, I will present the...
The Generalized Polarizabilities (GPs) are fundamental properties of the
nucleon. They characterize the nucleon's response to an applied
electromagnetic field, offering access to the polarization densities inside
the nucleon, and as such they represent an essential part for a complete
understanding of the nucleon structure and dynamics. The GPs can be
explored through the measurement of...
In this talk, I will present the details of a new factorized approach to inclusive lepton-hadron scattering, in particular to semi-inclusive deep-inelastic scattering, which treats QED and QCD radiation on equal footing, and provides a systematically improvable approximation to the extraction of transverse momentum dependent parton distributions. We demonstrate how the QED contributions can be...
It has been more than 30 years since the EMC published a surprising result on the spin structure of the proton: the spins of its three quark components account for only a small part of the spin of the proton. In this talk, we discuss what has been learned so far, what is still missing and what could be learned from the upcoming experiments, including the Jefferson Lab 12 GeV upgrade and the...
The structure of hadrons depends strongly on the confinement mechanism. This talk illustrates the dynamics of confinement at the border between the interior and exterior of hadrons. The extended chiral structure is illustrated in chromostatics and amplified by a discussion of vortices and the orbital angular momentum resulting in the pion tornado.
I will report on recent developments in the extraction of the transversity distribution from various methodologies, including transverse momentum dependent (TMD) and collinear twist-3 observables, collinear dihadron fragmentation processes, and lattice QCD. Connected to this is the calculation of the tensor charges of the nucleon, which are important quantities that sit at the intersection of...