21–25 Sept 2015
Laboratori Nazionali di Frascati
Europe/Rome timezone

Gravitational form factor, transverse spin sum rule and longitudinal momentum density in the transverse plane in a light front quark-diquark model of nucleons

21 Sept 2015, 16:50
20m
Aula Bruno Touschek (Laboratori Nazionali di Frascati)

Aula Bruno Touschek

Laboratori Nazionali di Frascati

Oral contribution 4.

Speaker

Dr Dipankar Chakrabarti (Indian Institute of Technology Kanpur, India)

Description

In lightcone framework, longitudinal angular momentum operator is kinematical but the transverse angular momentum operator is dynamical and thus understanding the transverse spin and transverse angular momentum of the proton is more complicated than longitudinal spin and angular momentum and frame dependent. Here, we evaluate the gravitational form factors for a transversely polarized proton from the energy momentum tensor and evaluate the Pauli-Lubanski operator to verify a sum rule for the transverse spin in a light front scalar quark-diquark model with the light front wave functions constructed from a soft-wall AdS/QCD model. Further, the Fourier transform of the gravitational form factor $A(Q^2)$ in the impact parameter space gives the longitudinal momentum density in the transverse impact parameter space. The longitudinal momentum densities in the transverse impact parameter space are discussed for both unpolarized and transversely polarized nucleons in the quark-diquark model. For the unpolarized nucleon, the distribution is axially symmetric whereas for the transversely polarized nucleon the distribution becomes distorted and our analysis shows that the distortion is dipolar in nature.

Primary author

Dr Dipankar Chakrabarti (Indian Institute of Technology Kanpur, India)

Co-authors

Dr Asmita Mukherjee (Indian Institute of Technology Bombay, India) Mr Chandan Mondal (Indian Institute of Technology Kanpur, India)

Presentation materials