Progress and plans on PID simulation and reconstruction Yordan Karadzhov Sofia university St. Kliment Ohridski

Description of PID Simulation, Digitization and Reconstruction in G4MICE Simulation – Geant4 simulation of interactions of the particles with the materials of the MICE detector system. The wanted information from this simulation is stored in objects called “hits”, for example TofHit, CkovHit, etc.. In these “hits” we store numbers representing energy, position, time, momentum etc. of the particles. Digitization – the “hits” output from the Simulation are used to simulate the response of the detectors. The information for the detector response is stored in objects called “digits” (TofDigit, CkovDigit, etc. ). Usually in the “digits” we have things like TDC counts, ADC counts etc. The “digit” objects are designed to be used also to store in them the real response of the detectors (real data). Reconstruction – the information from the “digits” (simulation or real data) is used to reconstruct the event.

TOF sector Simulation and Digitization of the TOF sector are completed; Reconstruction for the simulated data is completed; TofHit, TofDigit, TofSlabHit and TofSpacePoint objects with the relevant pointer links between them are present in the output of the reconstruction.

Positions of the hits in the TOF stations taken from the Simulation events are simulated TURTLE beam is used

Comparison of the times from Simulation and Reconstruction This time difference is obtained by using 100 ps intrinsic time resolution for each PMT. This means that we expect 100/sqrt(2) ~ 70 ps intrinsic time resolution for each bar and 70/sqrt(2) ~ 50 ps intrinsic time resolution for each station.

Simulation of the Cherenkov detector in G4MICE is going forward Optical processes are implemented : G4Cerenkov, G4OpAbsorption, G4OpBoundaryProcess, G4OpRayleigh Optical properties for some of the materials of the detector. The materials with optical properties are OptAIR and AEROGEL_1 and the properties are refractive index and absorption length. The property Rayleigh scattering length is not implemented for the moment and because of this the Rayleigh scattering process is not active The surface of the mirror is defined to be a G4OpticalSurface Visualization of 240 MeV electron passing through the aerogel

Progress after the last collaboration meeting Definition of the ckov sensitive detectors. We take the decision only the windows of the four PMTs to be sensitive detectors. This means that hits will be created only if a photon passes through these windows. For the moment the windows are spherical with arbitrary radius and thickness.

Definition of CkovHits. The class CkovHit derives from the standard class MICEHit. The new data members are: 1. Plane number 2. PMT number 3. Wavelength of the photon 4. Angle of incidence of the photon and the PMT window

Definition of CkovDigit. Data members of the class CkovDigit are : 1. Plane number 2. PMT number 3. ADC counts 4. TDC counts 5. Vector with pointers to the mother CkovHits 6. Number of photoelectrons Definition of the class CkovDigits. This class manages the calculation of the CkovDigit objects from the CkovHit objects. For the moment we take into account only the dependence of probability to have photoelectron on the wavelength of the photon but not on the angle of incidence.

Still open questions Description of the shape of the PMT windows; Precise description of the dependence of Rayleigh scattering length of the aerogel on the energy (or wavelength) of the photons; Precise description of the dependence of the probability to have photoelectron on the wavelength of the photon; Description of the dependence of the probability to have photoelectron on the angle of incidence.