13-24 January 2020
Mainz Institute for Theoretical Physics, Johannes Gutenberg University
Europe/Berlin timezone

Gravitational form factors and light-cone distributions for pseudoscalar mesons

17 Jan 2020, 10:00
1h
02.430 (Mainz Institute for Theoretical Physics, Johannes Gutenberg University)

02.430

Mainz Institute for Theoretical Physics, Johannes Gutenberg University

Staudingerweg 9 / 2nd floor, 55128 Mainz

Speaker

Prof. Kazuhiro Tanaka

Description

The gravitational form factors for a hadron, the form factors for the hadron matrix element of the QCD energy-momentum tensor, not only describe the coupling of the hadron with a graviton, but also serve as unique quantities for describing the shape inside the hadron reflecting dynamics of quarks and gluons, such as the internal shear forces acting on the quarks/gluons and their pressure distributions. The gravitational form factors are also relevant to understanding the origin of hadron mass. We consider the quark/gluon contributions to the gravitational form factors for a pseudoscalar meson, and also for the nucleon. We derive the relations satisfied by the gravitational form factors as direct consequences of the symmetries and the equations of motion in QCD, and connections to the generalized (off-forward) parton distributions. Our results show the connections between the gravitational form factors and the higher-twist quark-gluon correlation effects inside the hadrons. Furthermore, we are able to constrain the twist-four gravitational form factors by the trace anomalies in QCD, and derive the corresponding relations at three loop. We mention properties of the gravitational form factors for a heavy meson in the heavy quark limit, and also prospects to calculate the gravitational form factors using the LCSRs.

Presentation Materials