February 5, 2018, 12:00 PM, 112W
Martha Constantinou (Temple University)
The proton spin puzzle from Lattice QCD
Quantum Chromodynamics (QCD) is the theory of the strong interactions
that binds quarks and gluons to form the nucleons, the fundamental
constituents of the visible matter.
Understanding nucleon structure is considered a milestone of hadronic
physics and new facilities are planned devoted to its study. A future
Electron-Ion-Collider proposed by the scientific community will
greatly deepen our knowledge on the fundamental constituents of the
visible world. To achieve this goal, a synergy between the
experimental and theoretical sectors is imperative, and Lattice QCD is
in a unique position to provide input from first principle calculations.
Over the last years Lattice QCD has made significant progress
yielding results that can be compared to experimental measurements
with controlled systematics.
In this talk we will discuss recent progress in nucleon structure from
Lattice QCD using state-of-the-art simulations with pion mass tuned at
its physical value. Emphasis will be given on quantities that have
implication on the proton spin in order to address the question: "Where does the spin of proton come from?"
Along the line of
understanding this long-standing puzzle we will also highlight
developments on the evaluation of the gluon momentum fraction.