NEMO3 analysis and SuperNEMO development Benjamin Richards D14

Brief Nemo3 Intro The Neutrino Ettore Majorana Observatory (NEMO 3) detector, which is now running in the Frejus Underground Laboratory and was begun more than ten years ago.

Description of detector parts Tracking wires PMTsSource foil Scintillator blocks wrapped in mylar

Last year: PMT coating / Analysis fit Development of PMT coating. Development of PMT coating. Shows Shows 10% ~ 15% increase in Q.E. Wrote an automated fit for Bi 207 energy spectrum Wrote an automated fit for Bi 207 energy spectrum Experimented with Phoswich idea Experimented with Phoswich idea Photons From LED Coating Photo cathode layer dynodes No. of Events ADC counts (Energy)

This year: Uniformity study of scintillator block for SuperNEMO PMT 8” Source Energy bins Frequency Scintilator wrapped in PTFE 976 KeV electron peak

Model of NEMO3 from TDR TDR Drawings 3D Reconstruction

Model of NEMO3 from TDR

Neutrinoless double beta decay

Theory for molybdenum to ground state and excited states We can calculate the matrix elements of other decay modes of 100 Mo, To more accurately estimate the matrix element for the neutrinoless double beta decay. We can calculate the matrix elements of other decay modes of 100 Mo, To more accurately estimate the matrix element for the neutrinoless double beta decay. 100 Mo γ γ 100 Ru 2e2ν

Cuts Made No. of scintillator hits = 2 No. of scintillator hits = 2 No. of tracks = 2 No. of tracks = 2 Check if scintillator hits have associated tracks Check if scintillator hits have associated tracks Both tracks are from negatively charged particles Both tracks are from negatively charged particles Cut if track reconstruction fails Cut if track reconstruction fails Cut on the source used (Mo only) Cut on the source used (Mo only) Cut if PMT is above max energy threshold Cut if PMT is above max energy threshold Cut if electrons are below 200KeV Cut if electrons are below 200KeV Check track starts from first 4 tracking wires Check track starts from first 4 tracking wires Check track end on last 3 tracking wires Check track end on last 3 tracking wires TOF cut to check its an internal electron TOF cut to check its an internal electron Check if scintillator is isolated Check if scintillator is isolated

Results Energy (MeV) Frequency Cos (θ) 1 Months data

Results Active time over which data was used = days Active time over which data was used = days No. of events that passed cuts = ±135 No. of events that passed cuts = ±135 Efficiency calculated from MC = Efficiency calculated from MC = Half-life calculated = (6.90 ± 0.05) x10 18 yr Half-life calculated = (6.90 ± 0.05) x10 18 yr

What I will do in the future Understand the backgrounds of the experiment Understand the backgrounds of the experiment Make analysis of 100 Mo transitions to excited states for Ph II Make analysis of 100 Mo transitions to excited states for Ph II Work on development for SuperNemo, including work on the module prototype. Work on development for SuperNemo, including work on the module prototype.