Birth pangs, Adolescence, & Maturity of Directional Calorimetry...the inside story of the 2015 (and 2002) Physics Prize

by Lawrence R Sulak

Thursday 17 Dec 2015, 15:15 → 16:15 Europe/Stockholm

Å12167

Abstract:
Dreams of grand unified and cosmological theories predict that neutrinos cannot be massless, that those elusive particles power supernova explosions, and that protons die after 10²⁹ years. The nucleons in our bones must live longer than 10²⁶ years -- our universe is 10¹⁰ years old. Otherwise, we'd all succumb to radiation poisoning.
Testing these hypotheses drove a new detector technology optimized to search for rare interactions. It demanded fast, isochronous, single photoelectron photomultiplier tubes, nitrogen calibration lasers, reverse osmosis purification of water, fast waveform digitizers... ushering in an era of massive, totally-active, Cherenkov ring-imaging calorimeters. The target medium, water, of the pioneering detector has morphed into pure ice, heavy water, seawater, and clear and scintillating oil. The sources of neutrinos in the seminal experiment, the atmosphere and a supernova, have evolved to include accelerators, the sun, nuclear reactors, and cosmic rays.
I will detail the death of the simplest unifying theories and trace the tortuous path from an atmospheric muon-neutrino deficit to a definitive measurement of neutrino mass.