25th International Spin Symposium (SPIN 2023)

Studying high pT momentum azimuthal anisotropies in unpolarized proton-proton collisions using transverse momentum dependent (TMD) parton distribution and fragmentation functions

Sep 26, 2023, 11:55 AM

25m

Junior Ballroom C (Durham Convention Center)

Talk Spin physics in Nuclear Reactions and Nuclei Joint Nuclear/Heavy Ion

Speaker

ismail soudi (Wayne State University)

Description

Unpolarized protons can generate transversely polarized quarks or linearly polarized gluons through a distribution known as the Boer-Mulders' function. The fragmentation of similarly polarized partons to unpolarized hadrons is called the Collins' function. Both of these functions include correlations between the spin or polarization and the relative transverse momentum of the incoming or outgoing parton, with respect to the parent or final hadron.

We explore the effect of including these and other Transverse Momentum Dependent (TMD) distributions on the production of high-$p_T$ (unpolarized) hadrons from (unpolarized) proton-proton scattering. The resulting initial state anisotropies, coupled with similar final state effects, may account for the observed azimuthal anisotropy of the produced high transverse momentum hadrons, without modification to the angle integrated spectra. This may be an explanation for the existence of a $v_2$ in high-$p_T$ hadron spectra in $p$-$A$ collisions without any observable nuclear modification of the spectra.

Presentation materials

Anisotropy_highpT_Ismail_Soudi.pdf