Jun 5 – 9, 2023
Genova, Italy
Europe/Rome timezone

Spin-1 quarkonia in a rotating frame and their spin contents

Jun 8, 2023, 5:40 PM
DAD - Room 1B (Genova, Italy)

DAD - Room 1B

Genova, Italy

Contributed QCD and hadron structure QCD and hadron structure


Hyungjoo Kim (Yonsei University)


We propose a new way of studying the spin content of a hadron by looking at its response in a rotating frame. By collecting all responses of quarks and gluons in a rotating frame, we describe the spin-rotation coupling of spin-1 quarkonia and thereby reveal their spin contents in a fully relativistic way. We demonstrate that both the perturbative and non-perturbative contributions in the operator product expansion follow a universal formula that identifies the spin-rotation coupling with unit strength. This allows us to recognize the total spin-1 of the vector and axialvector quarkonia in terms of the total angular momentum of quarks and gluons. Specifically, we find the spin contents of $J/\psi$, $\chi_{c1}$, $\Upsilon(1S)$, and $\chi_{b1}$ are slightly different from the naive quark model picture. For example, the $J/\psi$ is traditionally considered as an S-wave particle, but we find quarks do not carry all of the total spin.

Primary author

Hyungjoo Kim (Yonsei University)


Prof. Su Houng Lee (Yonsei University) Prof. Sungtae Cho (Kangwon University)

Presentation materials

Peer reviewing