Neutrino Experiments at Fermilab Ø Physics Motivation Ø Fermilab/NuMI neutrino beam(s) Ø Experimental Program § MINOS § Off-axis experiment § ‘Other’ experiments Ø Synergy of Neutrino Experiments and Opportunities for Collaborative efforts November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab 11 Greatest Unanswered Questions of Physics Ø What is dark matter ? Ø What is dark energy ? Ø How were the elements from iron to uranium made? Ø Do neutrinos have mass ? Ø … Ø Are protons unstable ? Ø What is gravity ? Ø Are there additional dimensions ? Discover Ø How did the Universe begin ? February 2002 November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Mass Generation: Central Problem in Particle Physics (II) Version 2 (circa 2000) 1. Particles are massless 2. Higgs Peter (Pan?) comes and dispenses mass 3. Others get from their share (0.05 eV – 175 GeV) Mass generation mechanism = payroll scheme with for workers with salaries ranging from <$0.00005 to $175,000,000. Bizarre ! Why such a colossal disparity ?? Perhaps, if we knew the salary pattern of the lowest paid workers we can get some insight into the underlying rules è need to measure masses of the order of 0.01 eV and less November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Interferometry: a technique for precise measurement of mass differences Three slit interference experiment detector source A~ eikL12++eeikL ikL3 IA= 2 I(x) – interference pattern is a result of phase differences due to optical path differences (optics) or due to different masses of the neutrino components (neutrino oscillations). 0 0 Analogous to K S-K L mass difference measurement. November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Episode I: Before the “New Era” Theory: Ø Neutrino mass differences 1-100 eV2 WRONG!! Ø Neutrino mixing matrix similar to quarks (small or very small mixing angles) Experiment: Ø No evidence for neutrino oscillations in accelerator (BEBC, CDHS, CHARM, CCFR) or reactor (Bugey, Gosgen) experiments Ø Confusing ‘solar neutrino problem’ New Era started by “SuperK revolution”: ØNeutrinos have mass, mass differences are very small ØNeutrino mixing angles are very large November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Neutrino Physics after the SuperK Revolution Muon neutrinos disappear (SuperK, K2K,Soudan II, Macro) Electron neutrinos disappear (Homestake, SAGE, GNO, SuperK, SNO) Electron antineutrinos disappear (KamLand) Electron neutrinos convert into ‘other’ types of neutrinos (SNO + SuperK) ØNeutrinos have non-zero mass (*****) ØWeak neutrino eigenstates are coherent mixtures of mass eigenstates (****) *** æöUUe1e21Ue3 éùn ne ç÷***êú éùnnnn= UUU n3 ëûe mtç÷mmm1232êú n n ç÷** * m t UUUttt1233ëûêún èø 2 Dm atm ØMagnitude of mixing matrix elements defines composition of electron/muon/tau neutrinos n2 Ø Mass differences determine the oscillation length n1 2 Dm sun November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab What do we know/want to know better (I) Ø There are two mass scales: Ø Is the disappearance of muon § Dm2 ~ 7x10-5 eV2 neutrinos indeed due to 12 neutrino oscillations (see the 2 -3 2 § Dm 23 ~ 1.5-3x10 eV characteristic oscillation Ø Two mixing angles are large: pattern) o Ø Do other possible mechanisms § q12 ~ 35 contribute (decays, extra § q ~ 90o (sin22q >0.9) 23 23 dimensions,..)? Ø Third mixing angle is not Ø What is the precise value of very large sin22q <0.1 2 13 Dm 23? Ø Physics of neutrino mixing is o Ø Is q23 = 90 ? Full mixing èNew similar to quark mixing, yet symmetry? the pattern is completely Ø What is the value of q13? different Ø Do neutrinos and antineutrinos oscillate the same way? (CPT!) November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab A Tool: NuMI Beam Ø 120 GeV Protons from Fermilab Main 1270 events/kt-yr 2740 events/kt-yr Injector Ø 10ms pulse, every 1.9s Ø Proton Intensity: § 4x1013 protons/pulse design § 2.5x1013 p/p expected at startup Ø Hadrons focused with 2 horns § Flexible: select beam energy spectrum by adjusting horn and target positions 1040 m 470 events/kt-yr Main Injector Rock: 240m, Target, n muon monitors 103 m Horns Not to scale Decay pipe: Hadron 678m x 1m radius Absorber: Near Detector 4.7 m Al/Fe November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab NuMI Beam Status Ø Excavation of underground complex complete Ø Decay Pipe installed Ø Tunnel/Hall Outfitting in progress Ø Target has been fabricated Ø Horns have been assembled Ø Project will be complete/ commissioning starts Dec. MINOS Near Detector Hall (100m underground) 2004 Some of the NuMI Shielding - Much more than mass of Near and Far Detectors combined! November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab NuMI Beam Status Decay Pipe Horn 2 Assembly Decay Pipe encased in concrete to protect groundwater November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab MINOS Main Injector Neutrino Oscillation Search 2 2 Ø Precision Dm23 and sin (2q23) measurement in nm disappearance Ø 2 detectors, functionally identical, separated by 735km baseline § Near Detector: 1kt detector at Fermilab § Far Detector: 5.4kt detector at Soudan 735 km November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Far Detector Ø 5.4kt total § 484 planes in two ~14.5m long “super modules” § Each plane 8m octagon § 2.54cm Fe, 1cm Scintillator § ~1.5T Magnetic field 8m Ø Readout § 2 ended readout § 8x optical multiplexing into M16 multi-anode PMTs 1 supermodule Magnet Coil § ~92k strips, 23k channels Ø Overburden § 710 m (2090 mwe) November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Far Detector Status Ø Far Detector construction A person completed! § 1st supermodule operational since 7/02 Ø Veto Shield § Build from same scintillator used in detector Completed MINOS § Far Detector Help ID Atmospheric neutrino interactions November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Far Detector Data Ø Up Going Muons: n Example: 5.4 GeV/c up going m interactions below detector § Use timing to select Time vs. Y up going muons Y Ø Magnetic Field X - + § Distinguish m , m Z Up Going m Other One log10(p) sign m distributionssign m MINOS PRELIMINARY UPGOING MUON DATA November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Near Detector Ø Same sampling/structure as far detector Ø 980 t Ø High rate (10ms spill) § HE beam: 20 interactions/m/spill § LE beam: 3.2 interactions/m/spill § High speed electronics § 4x multiplexing in spectrometer only Ø All Planes have been assembled in a surface building November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab MINOS n Event Topologies Ø nm identified by m in Charged Current interactions MIP energy loss = 30MeV/plane Interaction length»6 planes n CC n NC 1.2m m ~1.0m 4.7m 1.7m Example Monte Carlo events Pulse height vs. Strip & plane 4-5 GeV neutrinos 1 plane » 1.4 X0 ne CC November 12, 2003 Indo-US Interaction Meeting0.7m on Neutrino Physics, Delhi Adam Para, Fermilab Oscillation measurements Comparison of the observed spectrum of nm charged current events with the expected one provides a direct measure of the survival probability as a function of neutrino energy 2 2 2 1.27Dm L Does the disappearance follow P =-1sin2J23 sin this functional form? En Neutrinos and antineutrinos? 2 Ø Dip depth çè oscillation amplitude (sin 2q23) 2 2 Ø Dip position çè Dm 23 (p/2 = 1.27xDm 23xL/Edip) November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Electron Neutrino Appearance For Dm2 = 0.0025 eV2, sin2 2q = 0.067 13 For Dm2 = 0.0025 eV2 Observed number of ne CC 3 s discovery potential versus candidates with and without oscillations. systematic uncertainty 25x1020 protons on target. on the background. November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab n What do we want to know (II) e nm nt 1. Neutrino mass pattern: This ? Or that? n3 n2 n1 2. Electron component 2 Dm atm 2 of n3 (sin 2q13) mass n2 n1 n3 2 Dm sun “Normal” mass hierarchy “Inverted” mass hierarchy s æBB öéùn1 3. Complex phase of s(?) çè ç÷ éùnnnn= BBBêú CP violation in a neutrino ëûe mt ç÷êú2 ç÷ sector ßà (?) baryon èBBBøëûêún 3 number of the universe November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab The key: nm Þ ne oscillation experiment 2 Dmij P()nn®=+++PPPP D=ij ; m e 1234 2En A= 2;GnFe 2 Oscillation at the 222 æöD13 BL± BA± = ± D13 ; P1= sinq23 sin q ç÷sin ‘atmospheric’ frequency 13 B 2 èø± J = cosqqqq13sin212sin213sin2 23 2 Oscillation at the 222æöD12 AL P2= cosqq23sin12 ç÷sin ‘solar’ frequency èøA 2 æöD12 æöDD1313L AL BL± PJ3 = cosd ç÷ç÷cossinsin èøABèø± 222 Interference of these two amplitudes è CP violation æöD12 æöDD1313 L AL BL± PJ4 = sin d ç÷ç÷sinsinsin èøABèø± 222 222222 PL= fE(sin2qd13,,sgn()Dm13 ,DDm12,m13,sin2,qq12sin223 ,,) 3 unknowns, 2 parameters under control L, E, neutrino/antineutrino Need several independent measurements to learn about underlying physics parameters November 12, 2003 Indo-US Interaction Meeting on Neutrino Physics, Delhi Adam Para, Fermilab Matter Effects in Neutrino Propagation • Matter