Neutrino Physics @Berkeley Alan Poon Group Leader, Neutrino Astrophysics Group http://neutrino.lbl.gov Neutrinos • Following the ATLAS (LHC) talk… Gino the Neutrino Professor Proton is the weakly interacting neutrino. The Berkeley Neutrino Puzzle Look for green bold-faced hints in this talk! Answer key at http://neutrino.lbl.gov/crossword Neutrino Physics @Berkeley • In the past decade, LBNL’s Nuclear Science and Physics Divisions played leadership roles in KamLAND and Sudbury Neutrino Observatory (SNO), which demonstrated non-zero neutrino mass and neutrino oscillations. • In the past few years, the Daya Bay reactor neutrino experiment measured the unknown mixing angle �13. [more later] Neutrino Physics @Berkeley • In the past decade, LBNL’s Nuclear Science and Physics Divisions played leadership roles in KamLAND and Sudbury Neutrino Observatory (SNO), which demonstrated non-zero neutrino mass and neutrino oscillations. • In the past few years, the Daya Bay reactor neutrino experiment measured the unknown mixing angle �13. [more later] SNO Daya Bay KamLAND Neutrino Physics @Berkeley • In the past decade, LBNL’s Nuclear Science and Physics Divisions played leadership roles in KamLAND and Sudbury Neutrino Observatory (SNO), which demonstrated non-zero neutrino mass and neutrino oscillations. • In the past few years, the Daya Bay reactor neutrino experiment measured the unknown mixing angle �13. • In 2015: – 1 Nobel Prize (SNO) – 3 Breakthrough Prizes (Daya Bay, KamLAND, SNO) SNO Daya Bay KamLAND Neutrino Physics @Berkeley • In the coming decade, we will try to answer the following fundamental questions concerning the neutrinos: – lepton number violation – CP violation in the neutrino sector – neutrino mass hierarchy – absolutely mass scale of the neutrinos – Dirac and/or Majorana nature of the neutrinos Graphics from Symmetry Magazine Neutrino mixing • A weak eigenstate ν α is a linear combination of mass eigenstates ν i : | 3 | ν = U ν | α αi| i i=1 where U = Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix. Ue1 Ue2 Ue3 ⎛ ⎞ U = Uµ1 Uµ2 Uµ3 ⎝ Uτ1 Uτ2 Uτ3 ⎠ 10 0 = ⎛ 0cosθ sin θ ⎞ 23 23 Atmospheric θ23 ~ 45° ⎝ 0 − sin θ23 cos θ23 ⎠ cos θ12 sin θ12 0 ⎛ − ⎞ × sin θ12 cos θ12 0 Solar θ12 ~ 34° ⎝ 001⎠ −iδCP cos θ13 0 e sin θ13 × ⎛ 010⎞ Reactor θ13 ~ 9° iδCP ⎝ −e sin θ13 0cosθ13 ⎠ You can measure the mixing angles with different sources Neutrino mixing If is on the Big Bang Theory, it must be important The discovery of neutrino oscillation (hence neutrino mass) provides the first direct evidence of physics beyond the Standard Model of Particle Physics. Neutrino mass questions Measuring the “mass” Determining the hierarchy [mi] mass 3 3 2 Cosmology: m = mi = m1 + m2 + m3 1 i=1 msmallest 3 β decays: m = U 2 m2 β ⌅ | ei| i ⇤i=1 Normal ⇤ mass ⇥ 2 3 1 2 ββ decays: mββ = Ueimi i=1 3 ⇥ msmallest 2 2 2 Oscillations: ∆mij = mj mi − Inverted Neutrino mass questions Measuring the “mass” Determining the hierarchy [mi] mass 3 3 2 Cosmology: m = mi = m1 + m2 + m3 1 i=1 msmallest 3 β decays: m = U 2 m2 β ⌅ | ei| i ⇤i=1 Normal ⇤ mass ⇥ 2 3 1 2 ββ decays: mββ = Ueimi i=1 3 ⇥ msmallest 2 2 2 Oscillations: ∆mij = mj mi − Inverted LBNL and UCB programs cover all these measurements Neutrino Oscillation Experiments • Daya Bay [Kam-Biu Luk] • DUNE [Kam-Biu Luk] • THEIA [Gabriel Orebi Gann] • IceCube [Spencer Klein] Daya Bay • Ongoing reactor antineutrino experiment focusing on • Precise measurement of mixing angle θ23 2 and mass splitting |Δm 32| • Precise measurement of absolute flux and energy spectrum of reactor antineutrinos • Search for a light sterile neutrino • Search for new neutrino phenomena • Search for supernova neutrinos • Continue collecting data until 2020. Neutrino oscillations - future Deep Underground Neutrino Experiment (DUNE) • A long-baseline neutrino experiment designed for studying • CP violation in neutrino oscillation • Neutrino mass-hierarchy problem 2 • Precise measurement of mixing angle θ23 and mass splitting Δm 32 • Nucleon decay • Supernova neutrinos • Berkeley involves in • ProtoDUNE – beam-test of full-scale liquid-argon TPC at CERN • Design and detector R&D of near detector • Simulation and physics analysis using NERSC supercomputers R. Bonventre, J. Caravaca, F. Descamps, B. Land, G. D. Orebi Gann, J. Wallig THEIA • Large WbLS detector (50-100 kton) • Fast, high-efficiency photon detection with high coverage • Deep underground (e.g. Homestake) • Isotope loading (Gd, Te, Li...) • Flexible! Target, loading, configuration ➡ Broad physics program! 1.4 ➡ long baseline, NLDBD, solar, geonu, 1.2 nucleon decay, supernova, DSNB…. 1 0.8 Concept paper - arXiv:1409.5864 0.6 0.4 Hit Time Residuals (ns) 0.2 Local R&D: CHESS 0 CHErenkov Scintillation Separation experiment ➡ Directional info in a low-threshold • Ring-imaging of cosmic muons detector Demonstrate separation in charge & time Unprecedented level • of in-situ background • Successful separation in LAB, LAB/PPO and WbLS! rejection Neutrinoless Double Beta Decay Experiments • CUORE (130Te) [Brian Fujikawa, Yury Kolomensky] • MAJORANA (76Ge) [Alan Poon] • SNO+ (130Te) [Gabriel Orebi Gann] Beta Decay Experiment • KATRIN (3H) [Alan Poon] Neutrinoless double-beta decay is a big deal Lepton number violation and Neutrinoless Double Beta Decays SM allowed process Lepton number violation 26 T1/2 ~1018-21 y T1/2 >10 y CUORE @ Berkeley • Located at LNGS (Gran Sasso) • TeO 2 crystal serves as both source of radioactive decay and detector for resultant electrons • Bolometer: • Electrons deposit energy in crystal • Energy converted into heat • Temperature of crystal read out using thermistor thermometers Cuoricino CUORE-0 CUORE 2003–2008 2013–2015 2016–2022 11 kg 130Te 11 kg 130Te 206 kg 130Te CUORE @ Berkeley • Detector assembly (complete) • Taking commissioning data • Data processing and monitoring (CUORE-0 and CUORE) • Neutrinoless double-beta decay analysis (CUORE-0 and CUORE) • Hardware R+D for future experiments Superconducting transition edge sensors (TES) for detecting heat pulse and Cherenkov light Dilution refrigerator on campus 18 MAJORANA DEMONSTRATOR • Physics: • To search for LNV via 76Ge 0νββ decay • To search for light WIMPs (<10 GeV/c2) • Status: – Production data taking in progress • LBNL contributions: – Development and procurement of 76Ge detectors – Design and fabrication of low-noise signal processing electronics; detector construction & commissioning – Simulation and analysis • Future: – R&D for a ton-scale experiment starting R. Bonventre, J. Caravaca, F. Descamps, C. Kefelian, B. Land, G. D. Orebi Gann, J. Wallig • Analysis (DBD, solar, SNO+ backgrounds) • DAQ leaders - HV control, alarm GUI, channel monitoring • Constructing optical calibration source 780 ton scintillator (LAB) • Responsible for calibration • of PMT array & • 9500 PMTs electronics • Load LAB with 0.5% natTe — NDBD search • Ultra-low background (solar ν dominates) • Large target mass, easy to scale • Sensitivity to bottom of IH in phase II! • Broad program of other physics! Solar, supernova, geoneutrino, nucleon decay • Water data taking ongoing right now! LS data — autumn 2017. Neutrino mass Knowing the neutrino mass is important! ⇡+ µ+ + ⌫ ! µ β decay: KATRIN • 3H beta decay • Sensitivity: mβ<0.2 eV (90% CL) • Commissioning in progress. • 3H Data taking will begin next year • LBNL involves in analysis activities β decay: KATRIN • 3H beta decay • Sensitivity: mβ<0.2 eV (90% CL) • Commissioning in progress. • 3H Data taking will begin next year • LBNL involves in analysis activities β decay: KATRIN • 3H beta decay • Sensitivity: mβ<0.2 eV (90% CL) • Commissioning in progress. • 3H Data taking will begin next year • LBNL involves in analysis activities The most energetic accelerators in the universe The UCB/LBNL IceCube Group ● Cosmic-rays have been observed with energies up to 3*1020 eV (50 joules!) ● Despite 100 years of effort, we have not found the accelerators that produce these particles ● Charged cosmic-rays bend in transit ● IceCube is a 1 km3 neutrino detector at the South Pole. ● 5,160 buried optical sensors detect Cherenkov light from the charged particles produced in high-energy (>100 GeV) neutrino interactions in the polar icecap. ● We have observed cosmic neutrinos with energies up to ~5 PeV (5*1015 eV) ● These neutrinos should (eventually) pinpoint these accelerators ● The flux is near the predicted upper limits, so sources should be easy to find. ● We have eliminated or disfavored most of the popular theories for the origins of these neutrinos: gamma-ray bursts, active galactic nuclei (galaxies containing supermassive black holes…), or supernovae. ● … a real science mystery… you can help solve it! ● IceCube also studies many other physics topics: dark matter, cosmic-ray anisotropies, magnetic monopoles, other exotica… IceCube @ LBNL ● A friendly group with 1 senior staff, 1 postdoc, 1-2 grad students and (usually) 1 undergrad ● LBNL played key roles in IceCube hardware ● Active in astrophysical neutrinos and cosmic-ray physics ● Measurement of the astrophysical neutrino flavor (νe:νµ:ντ) ratio* ● Measurement of the atmospheric νe energy spectrum ● First observation of neutrino absorption in the Earth and measurement of the neutrino- nucleon cross-section* ● Future interests include ● Characterization of TeV-PeV energy neutrino events (ν:ν ratio, etc.) via inelasticity measurements* and a more detailed energy spectra of the cosmic neutrino signal ● Precision measurement of the neutrino-nucleon cross-section ● Searches for leptoquarks, extra-dimensions or other exotica that