Cara Esposito Saint Joseph’s University Dr. Kate Scholberg Duke University
Brief background on neutrinos, supernovae, and the HALO detector Efficiency and the important information gained from examining the efficiency Sensitivity for HALO Summary
The Equation above is for the probability of detecting flavor g at L for a two flavor case. Although there are three flavors, the Δ m 2 remains Normal Mass Hierarchy (NMH) has one heavy and two light mass states, while IMH has two heavy and one light mass state
Supernovae happen when a massive star can no longer sustain itself and it explodes 99% of the energy of core collapse supernovae is neutrinos BeforeAfter
SNOLab in Canada 79 tons of lead 128 helium detectors 2 km underground HALO 2 is currently in the developing phase and will most likely use 1 kiloton of lead Helium Detectors Lead
Visualization of the simulation using Geant4
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The left panel is for inverted mass hierarchy The right panel is for normal mass hierarchy
From the energy deposited in the detector we can determine whether it’s a 1N or a 2N event.
1N 2n
Tells us how well the detector works
HALO 1’s sensitivity for 5kpc supernovae Contours in which ninety percent of the number of one- neutron and two- neutron events fall The different colored curves correspond to different spectral parameters
For 10 kpc supernovae HALO 1 can only constrain extreme models
HALO 2 ‘s discriminatory power will increase with a greater number of counts for 10 kpc supernovae.
Simulated neutron events in the HALO Geant4 simulator Efficiency for 1N events is approximately 36% Efficiency for 2N events is approximately 56% HALO 1 has good sensitivity for 5 kpc supernovae, but can only constrain extreme models for 10 kpc supernovae HALO 2 the larger the number of counts, the greater the yield for the discriminatory power
K.Scholberg, C.Walter, A.Himmel, Duke University High Energy Physics Neutrino Group Triangle Universities Nuclear Laboratory's Research Experience for Undergraduates Halo Collaboration/SNOLab