# 23rd MCnet Meeting

Dec 6 – 8, 2021
University of Manchester
Europe/London timezone

## Quarkonia showers in PYTHIA8

Dec 8, 2021, 10:45 AM
20m
Niels Bohr Common Room, 6th Floor Schuster Building (University of Manchester)

### Niels Bohr Common Room, 6th Floor Schuster Building

#### University of Manchester

Department of Physics & Astronomy Oxford Road, Manchester M13 9PL

### Speaker

Naomi Cooke (University of Birmingham (GB))

### Description

Quarkonia production has been a long-standing puzzle in particle physics. The polarisation measurement of $J/\psi$ is expected to have significant transverse polarisation at large $p_{T}$, but has been experimentally observed to be consistent with zero. Hard production of onia processes using NRQCD formalism are available in the Pythia8 framework. However, these processes alone cannot fully describe the data; LHCb and CMS have shown with normalised cross section measurements of $z$ = $p_{T}(J/\psi)/p_{T}(jet)$ that $J/\psi$'s are produced softer than expected. Hence the need to incorporate onia production within the parton shower. A status report for incorporating quarkonia showers into Pythia8 will be presented.

### Primary author

Naomi Cooke (University of Birmingham (GB))

### Co-authors

Leif Lönnblad (Lund University (SE)) Philip Ilten (University of Cincinnati (US)) Stephen Mrenna (FERMILAB)