MOLLER Pion Background Meeting Friday, February 17, 2017 9:00am EST

MOLLER wiki home:MOLLER_at_11_GeV_E09-005

Previous Meeting: MOLLER_Pion_Background_Meeting_Friday,_February_10,_2017_9:00am_EST

Meeting Information

BlueJeans Call Information

URL: https://bluejeans.com/624029893

Phone Number: 1-888-240-2560

Meeting ID: 624029893

Agenda

• Wouter: General simulation updates.
• Scott: Lead wall thickness determination.
• Jacob: Pion detector optimization.
• Any new business?

Minutes

Attendees: Seamus, Kurtis, David, KK, Wouter

Not Attending: Jacob(class)

Scribe: Kurtis

• Wouter: General Pion and remoll simulation updates
  • Has improved the overall optical photon treatment in remoll, by removing the separate optical physics class and just letting Geant4's optical physics code due it's duty.
  • Scott is using a plane detector just beyond the lead wall for his wall thickness studies. It is made from kryptonite so that all track stop in the detector. This improves the simulation speed.
  • Still using the same moller scattering generator and Wiser pion generator.
  • Also working on developing a muon generator using MadGraph, currently a separate piece of code, will be ported into remoll once the bugs are worked out. Note this isn't muon production from pion decay, but direct muon production from the target.
  • Have created a new branch where the input ouput layer of the simulation(the way the rootfile stores data) has been rewritten. This allows us to get away from the limit of storing 10,000 hits. Now it can store a variable amount of hits for each detector leaf.
• David: Present plan is to continue with developing the Lucite detector system . Performing optimization studies and such. Also continue to do lead wall thickness studies.
• KK: Shouldn't really focus on the pion to electron ratio, but we need to focus on pulse height differences. The Lucite has to be thick enough so that the signal can be differentiated from the electron background. Shower Max can be used as a possible electron veto, but as David points out the flux has to be low enough during the dilution study to avoid accidentals.
• KK: In regards to the muon detector, with this new muon generator can we determine if there are muons seen in the pion detector that are not seen in the main detector. Also what is the asymmetry for this muons? Where does it come from. Wouter, points out that MadGraph does predict a channel for muon production that involves the Z, thus an asymmetry could come about from that.
• David/Seamus: Really don't need to worry about pi^0 as the branching ratio for muon production is so low. As for charged pions, they are already taken into account with Geant4 and present itself as a single muon carrying the same asymmetry as the original pion.
• David: Scott can determine, with the Wiser and moller generators, the muon production rates. At least an order of magnitude estimate. Wouter, isn't sure we would get a good result as Geant4 doesn't really like to do hard brem. without a nucleus. Might have to do some detailed simulations with radiative corrections.
• Seamus: We already do a radiated treatment in the EP generator, that could be ported over to something else with some work.