#### Monte Carlo Tuning for Hadronic States in e+e- Collisions

- Event time: 2:00pm
- Event date: 29th March 2017
- Speaker: Jennifer Kile (Lisbon)
- Location: Higgs Centre Seminar Room, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB

### Event details

We perform two tunes of the SHERPA Monte Carlo generator for the simulation of annihilation of e+e- to hadrons using the publicly-available LEP analyses in Rivet. In each of these tunes, we generate events at a center-of-mass energy of 91.25 GeV with matrix elements for final states containing up to six partons. In the first, ``LO'' tune, all final states are generated using leading-order matrix elements; in the second, ``NLO'' tune, states with up to four partons are generated with next-to-leading order matrix elements using BlackHat, while states with five and six partons are generated at leading order. The tunes are accomplished using Professor, and comparisons with unfolded LEP1 and LEP2 data are produced with Rivet. We also compare the data with events generated with KK2f interfaced to PYTHIA using a LEP-era tune. We find that both SHERPA samples show improvement relative to KK2f for observables related to multi-jet final states, which are of interest for analyses at future lepton colliders. At the same time, all three samples produce comparable results for event-shape variables.

The Particle Physics Theory seminar is a weekly series of talks reflecting the diverse interests of the group. Topics include analytic and numerical calculations based on the Standard Model of elementary particle physics, theories exploring new physics, as well as more formal developments in gauge theories and gravity..