PINGU, MicroBooNE & LAr1-ND Justin Evans University of - PowerPoint PPT Presentation

PINGU, MicroBooNE 
 & LAr1-ND Justin Evans University of Manchester 11th May 2012

Neutrino oscillations Ø Sterile neutrinos Ø Neutrino mass hierarchy ±2.3x10 -3 eV 2 Ø CP violation 2

Neutrino oscillations Ø Sterile neutrinos Ø Neutrino mass hierarchy LBNE, T2HK, Ø CP violation CHIPS 3

Neutrino oscillations Ø Sterile neutrinos MicroBooNE & LAr1-ND Ø Neutrino mass hierarchy Ø CP violation PINGU 4

The MSW e fg ect Atmospheric neutrinos pass through the Earth Ø Feel an interaction with the Earth’s matter Electron neutrinos feel an additional interaction Ø Acts like a refractive index Ø This e fg ectively changes the mixing angles ν x ν x ν e e - W Z e - ν e e - e - Electron flavour All flavours 5

Neutrino oscillations in vacuum ✓ ∆ m 2 L ◆ P ( ν α → ν β ) = sin 2 (2 θ ) sin 2 4 E 32 = 2 . 32 × 10 − 3 eV 2 ∆ m 2 sin 2 (2 θ 23 ) = π 4 Lines of constant L/E 6

Neutrino oscillations in matter cos θ z = -0.84 Increasing Outer core density 32 = 2 . 32 × 10 − 3 eV 2 ∆ m 2 sin 2 (2 θ 23 ) = π 4 Neutrinos Normal hierarchy 7

Neutrino oscillations in matter cos θ z = -0.84 Increasing Outer core density 32 = 2 . 32 × 10 − 3 eV 2 ∆ m 2 sin 2 (2 θ 23 ) = π 4 Neutrinos Inverted hierarchy 8

IceCube Ø The world’s biggest neutrino detector Ø 1 km 3 of ice 9

PINGU 40 new strings in the central region of IceCube & DeepCore Ø 20 m between strings Ø 5 m vertically between DOMs Energy threshold down to a few GeV 10

DeepCore Ø DeepCore released impressive new oscillation measurements this summer 11

Hierarchy sensitivity At least 3 σ sensitivity after four years of running Ø Can be even easier to determine, depending on the value of θ 23 12

The global situation PINGU is the most competitive medium-term experiment Ø Supported in the recent P5 report A very a fg ordable option Ø <10% the price of LBNE 13 Ø A small contribution can make the UK a major player

UK groups Manchester Ø Convener of mass hierarchy group Ø Working on DeepCore oscillation analysis Queen Mary Ø Expertise in neutrino interactions and cross sections Oxford Ø Theory group Significant European involvement Ø Germany, Belgium, Sweden, Denmark This e fg ort is currently unfunded by STFC Ø Since it came along after the programmatic review Risk of losing a major opportunity for UK particle physics Ø To determine the mass hierarchy within the decade 14

Sterile neutrinos NC π 0 background LSND and MiniBooNE see ν e appearance signals consistent with short- baseline oscillations Ø But is this a non-neutrino background? Or an inherent ν e component of the beam? 15

MicroBooNE Gap indicates EM shower NC background ArgoNeuT event Repeat MiniBooNE Ø But with a superior detector: liquid argon TPC 16 Ø Greater ability to reject NC electromagnetic activity

MicroBooNE 87 ton active mass 2.5x2.4x10.4 m 3 TPC Ø Recently moved into its final location in the Booster Neutrino beam Ø Commissioning will occur this autumn Ø First neutrino events by the end of the year 17

UK involvement Oxford Ø Level-2 project manager for the TPC Ø Cosmic muon detector system for commissioning Ø Development of run control software Ø Event reconstruction Cambridge Ø Development of PANDORA event reconstruction chain Manchester Ø Not yet MicroBooNE members, but a new academic (Georgia Karagiorgi) will join in January Ø Convener of MicroBooNE oscillation group Ø Commissioning MicroBooNE readout Ø n-n and proton-decay analyses 18

The need for a Near Detector MicroBooNE alone may not answer the sterile neutrino question Ø It can tell us if the excess is really electron neutrinos Ø It can’t tell us if those electron neutrinos are intrinsically in the beam or arise via oscillation 19

LAr1-ND A liquid argon near detector for MicroBooNE Ø Characterize the beam composition Ø A near-far comparison cancels many systematic uncertainties (e.g. cross sections) 20

LAr1-ND Ø 82 t active mass Ø 3.65x4x4 m 3 TPC Ø 2 m drift Ø -100 kV bias voltage 21

The benefits of a Near Detector Using LAr1-ND to measure the MicroBooNE alone backgrounds 20% uncertainty on ν e background prediction 22

UK hardware contribution UK will build much of the TPC Ø She ffj eld: anode frame Ø Manchester: anode wiring Ø Liverpool: cathode plane Ø Lancaster: cold testing Ø UCL: high voltage feedthrough Vital part of our LBNE proposal Ø Sets us up to make a significant construction contribution to the LBNE FD Ø LAr1-ND builds IL experience and demonstrates that the UK can build a working TPC Oxford and Cambridge are also collaborators 23

Summary PINGU Ø Determining the neutrino mass hierarchy with atmospheric neutrinos MicroBooNE Ø Investigating the MiniBooNE low- energy excess with a liquid argon TPC LAr1-ND Ø Forming a highly sensitive two- detector search for sterile neutrinos 24