Centre de Physique Théorique


Vendredi 5 mai 2017

Hot topics in Modern Cosmology

Hot Topics in Modern Cosmology, Spontaneous Workshop XI,

Co-organisée par R. Triay (CPT)

Spontaneous Workshop (SW) brings together specialists on recent insights in Particle Physics, Astrophysics and Cosmology. The aim is to stimulate debate on common topics in views of providing us with innovating ideas on emerging problems. The workshop’s organization is based on an optimal number of concise presentations and with enough space for discussions in order to favour interactions among participants. Postdocs and PhD students are encouraged to attend.

11h00 – 12h00, Amphi 5 du CPT

Strange charge, magnetism, and spin in the proton

Jeremy Green (DESY)

The proton is a bound state of quarks and gluons, interacting as described by the theory of quantum chromodynamics (QCD). Beyond the valence (uud) quark content, quantum fluctuations also allow strange quarks to contribute to the structure of the proton. Using lattice QCD, ab initio calculations of proton structure can be performed. However, studying strange quarks in the proton has been difficult because this requires the computationally challenging stochastic estimation of disconnected diagrams. We have found that a new technique called hierarchical probing is highly effective at reducing noise in disconnected diagrams. Results will be shown from a recent calculation that obtained a clear signal, for the first time, for the proton strange vector and axial form factors. From these we determine the contribution from strange quarks to the proton’s charge radius, magnetic moment, and spin.