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Km3 v4r5 OPA update. C.W.James , AWG meeting 17 th Dec 2012. Notes from last telecon (30 th Nov). Complete one-particle approximation testing Test effects of: Increasing absorption length by 5% Changing the low- cos -theta angular acceptance Still to-do:
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Km3 v4r5 OPA update C.W.James, AWG meeting 17th Dec2012
Notes from last telecon (30th Nov) • Complete one-particle approximation testing • Test effects of: • Increasing absorption length by 5% • Changing the low-cos-theta angular acceptance • Still to-do: • Implement read-out of hit tables for SIRENE • + New modifications requested C.W.James, AWG telecon, 17th Dec 2012
OPA testing • This has gone slowly! • Results for showers less well known • Finding bugs takes longer • Simulation chain: • Take 100 runs (need more stats for showers) • Simulate shower events • nue, anue, numu, anumu • 2 CC (nue& anue ) +4 NC (all) • ‘a’ (100-1e5 GeV) and ‘b’ (5e4-1e8 GeV) • Evaluate these 12x100 files using • Km3v4r5+geasim • Km3v4r5 w OPA (no geasim) • Process w standard reco + dusj shower reco C.W.James, AWG telecon, 17th Dec 2012
Other particles in OPA ~1 PeV electron-neutrino Pions, photons – and an anti-neutron! • Example file: C.W.James, AWG telecon, 17th Dec 2012
Treating non-standard particles • New OPA 1st run: • Charged pions: w(E) according to M. Dentler (was 0.2) • Neutral pions, gammas, electrons, K0 (short and long): w=1 • Others: w=0 • Physical problems: • K0 expect to interact before decaying (t_0 c = ~3cm for K0 short, >100m for K0 long) • K0: decay branching ratio to EM-only products ~30% • Other mesons/bosons also interact to produce ‘hadronic’ – and hence electromagnetic – products • Trial solution: treat all GEANT IDs >= 8 as charged pions C.W.James, AWG telecon, 17th Dec 2012
Results… still being run! • If everything goes well, in one day I will have proper comparison plots • Current philosophic question: • OPA uses particle kinetic energy to estimate Cherenkov yield • Charged pion fit -> minimum at 0.2 GeV (approx rest mass). • At low energies, other particles will behave similarly relative to their own rest masses. • How to estimate this? • Does NOT matter for ANTARES/km3net • WILL matter for ORCA C.W.James, AWG telecon, 17th Dec 2012
Results on angular efficiency • Use different low a_effs: • Run 4x106 runs with OPA facing away from the Cherenkov angle. C.W.James, AWG telecon, 17th Dec 2012
Results on angular efficiency • Results: photon arrival-time histograms C.W.James, AWG telecon, 17th Dec 2012
Results on angular efficiency • Results: histograms near the peak C.W.James, AWG telecon, 17th Dec 2012
Results on angular efficiency • Results: total number of photons C.W.James, AWG telecon, 17th Dec 2012