04/19/23 Jonathan Couchman 1

UCL Atlas Software Work

• Atlas Fast Simulation (Atlfast)

• Jet Reconstruction Pt.1 (KtJet)

• Jet Reconstruction Pt. 2 (JetRec)

• Physics Analysis Package (PAP)

• Quality Assurance (QA)

• Graphics (JiveXML & Atlantis)

• Physics Studies

04/19/23 Jonathan Couchman 2

UCL Atlas Software Team

• Jon Butterworth

• Jon Couchman

• Janice Drohan

• Nikos Konstantinidis

• Peter Sherwood

• Ben Waugh

04/19/23 Jonathan Couchman 3

AtlfastJ. Couchman & P. Sherwood

• Fast Simulation of Atlas Detector• Objected Orientated C++ implementation• Basic Reconstruction• Simple Smearing Parameterizations

• Extensions– Massive Jets– KT Clustering Algorithm– Fast Shower

04/19/23 Jonathan Couchman 4

AtlfastJ. Couchman & P. Sherwood

04/19/23 Jonathan Couchman 5

AtlfastJ. Couchman & P. Sherwood

UnsmearedSmeared

04/19/23 Jonathan Couchman 6

KtJetJ. Butterworth, J. Couchman, B. Waugh & B. Cox (Man.)

• OO implementation of KT clustering Algorithm• Written in C++• Optimized For Performance• Identical Results to Fortran• Much Faster That Fortran• Easily Extendable• www.ktjet.org

04/19/23 Jonathan Couchman 7

KtJetJ. Butterworth, J. Couchman, B. Waugh & B. Cox (Man.)

Program

Fortran (DP)KtJet (DP)KtJet (SP)

04/19/23 Jonathan Couchman 8

KtJetJ. Butterworth, J. Couchman, B. Waugh & B. Cox (Man.)

04/19/23 Jonathan Couchman 9

KtJetJ. Butterworth, J. Couchman, B. Waugh & B. Cox (Man.)

04/19/23 Jonathan Couchman 10

JetRecJ. Couchman

• Interface Atlfast With Jet Reconstruction

• Implement KtJet in Atlas Frame Work– KtJet Main (only?) reconstruction Algorithm!

Develop new JetRec Algorithms– Seeded Cone– Seedless Cone

04/19/23 Jonathan Couchman 11

PAPJ. Couchman, P. Sherwood

Physics Analysis Package

Analysis Objects Utilities Analysis Algorithms

• Common Atlas Analysis Interfaces• Useful C++ Utility Programs• Example Analysis Algorithms

04/19/23 Jonathan Couchman 12

Atlas QAP. Sherwood

• Improve Productivity By Increasing Quality

RequirementsCapture

Analysis

Design

Implementation

testing

Release

ReviewsStandardsToolsDocumentation

04/19/23 Jonathan Couchman 13

JiveXML & AtlantisJ. Couchman, J. Drohan, N. Konstantinidis, P. Sherwood,

H. Drevermann (CERN) & G. Taylor (Santa Cruz)

• Atlas Graphical Event Display (and much more!)

04/19/23 Jonathan Couchman 14

04/19/23 Jonathan Couchman 15

04/19/23 Jonathan Couchman 16

04/19/23 Jonathan Couchman 17

Physics StudiesJ. Couchman, J. Butterworth, B. Cox (Man.) & F. Nauyock (Man.)

• WW scattering

04/19/23 Jonathan Couchman 18

Physics StudiesJ. Couchman, J. Butterworth, B. Cox (Man.) & F. Nauyock (Man.)

• Using Atlfast Generate– 500K Signal Events– 5M+ Background Events

• Use Both Kt and Cone Clustering Algo’s

• Find Parameters For “Best” Resolutions

• Compare Results– Cone to Kt– Simulated to Generated Events

04/19/23 Jonathan Couchman 19

Physics StudiesJ. Couchman, J. Butterworth, B. Cox (Man.) & F. Nauyock (Man.)

04/19/23 Jonathan Couchman 20

Physics StudiesJ. Couchman, J. Butterworth, B. Cox (Man.) & F. Nauyock (Man.)

04/19/23 Jonathan Couchman 21