Recent developments in jet clustering - Matteo Cacciari - LPTHE

jeudi 1 févr. 2007, 16:30 → 18:00 Europe/Paris

LPNHE, Jussieu Tour 33 RdC, salle bernard Grossete

Didier Lacour

I will present work in progress with Gavin Salam on a modern approach to jet-finding in high multiplicity environments. I will first briefly compare the two main kinds of jet-finders: cone algorithms and recombination algorithms, highlighting pros and cons of the original formulations and implementations. I will also briefly discuss a seedless infrared-safe cone jet-finder recently introduced by Salam and Soyez. I will then present our fast implementation for the kt and Cambridge/Aachen jet finders. It is based on geometrical methods and it can cluster N particles in N ln N time. The speed of the code allows one to extend the scope of jet-finding: I'll show how one can define the concept or "area" of a jet and use it for performing a subtraction of a uniform background.