1. LHCb Simulation Day 23rd & 24th May 2013 Simulation Commissioning, Validation, Data Quality A brain dump to prompt discussion Many points applicable to any of LHCb software but some simulation specificities Gloria Corti

2. What is what? Commissioning Validation Data Quality t = Before releasing t = with productions that could be PRODUCTIONS To adopt a new version of Gauss FOR PRODUCTION is a long process with a set of tests at different levels We have tools but what is the best tool and what should be do?

3. My definitions - Commissioning • Commissioning of the software per-se, i.e. make a new version of Gauss compile and run • New compilers, new Gaudi version, new (version of) generators, new Geant4 version • For some of these changes the outcome of the application should not change • For the geometry for example checking overlaps are part of this

4. Commissioning Gauss (and Boole) • … Once things that are suppose to work are committed • Not always possible • Gauss is in the nightlies but is the winner for red squares! • Even when it is successful …. Part of it because Gauss relies on random numbers • We (us Gauss managers) need to review what we want to test • Each test should look at one thing only, for example we just test that a new event type can run • We can customize tests • Need to disentangle reference tests that should give identical output and those for evolution • We have been using many slots recently • Support for various Sim05, Sim06, Sim08 • Exploring new versions of Geant4

5. My definitions – Validation of simulation • Checking that only changes in physics and detector modeling as expected are there or Physics validation • Checking output with special productions • Need at least few 1000 events • Particle guns productions • Productions with different simulation settings of few 100k events • Checking that performance is ‘as expected’ and ‘acceptable’ or Software validation – and keep track of its evolution • Again need at least few 1000 events • Check that the whole simulation processing chain works • Integration tests with old and new conditions • ‘Commissioning’ with smallish samples, few 1000 events • Validating that the ‘final(s)’ configurations are not worse than

6. Recent validation of Sim08 • In Sim08 we did change a lot in Gauss and simulation conditions • New version of Pythia6, Pythia8 at production quality, new EvtGen, new Gaudi version, new compilers, new version of Geant4, new hadronicphyics list used • Start out with building in the nightlies • As usual compilation errors (new Gaudi, new Geant4, new compiler…) • Made private test productions for new interesting features and understand how to use new functionalities • Gauss stand alone studies • To investigate new Pythia8, new EvtGen, new hadronic physics list cross sections, dE/dx for various EM physics lists • Central productions for systematic studies and effect on physics and verify calibrations • Particle guns studies (Gauss and Gauss+Boole) • Check effects of dE/dx on tracking and calorimetry • Check effect of hadronic physics on asymmetries

7. Data Quality for MC • But still things slip through! • Some things can only be caught in production • Jobs getting stuck • All reconstruction distributions make sense • Need Data Quality for the MC • See Marco A.’s slides • Investigated in the past how to use Data Quality tools for Validation and Regressions tests • Far from ideal for MC as not really a single reference • See Ben’s slides on tools for validation test infrastructure

8. LHCbPR tool