NuMI MINOS Status of MINOS Alec Habig for the MINOS Collaboration Neutrino Workshop, IIT-Mumbai, India Tuesday, August 2, 2005 Argonne • Athens • Benedictine Brookhaven • Caltech.
Download ReportTranscript NuMI MINOS Status of MINOS Alec Habig for the MINOS Collaboration Neutrino Workshop, IIT-Mumbai, India Tuesday, August 2, 2005 Argonne • Athens • Benedictine Brookhaven • Caltech.
NuMI MINOS Status of MINOS Alec Habig for the MINOS Collaboration Neutrino Workshop, IIT-Mumbai, India Tuesday, August 2, 2005 Argonne • Athens • Benedictine Brookhaven • Caltech • Cambridge Campinas • Fermilab • College de France Harvard • IIT Indiana • ITEP-Moscow Lebedev • Livermore • Minnesota-Twin Cities • Minnesota-Duluth • Oxford Pittsburgh • Protvino • Rutherford Sao Paulo • South Carolina • Stanford Sussex • Texas A&M • Texas-Austin Tufts • UCL • Western Washington William & Mary • Wisconsin 32 institutions 175 physicists NuMI MINOS MINOS Main Injector Neutrino Oscillation Search • Investigate atmospheric nm oscillations using intense, wellunderstood NuMI beam • Two similar magnetized ironscintillator calorimeters – Near Detector • 980 tons, 1 km from target, 90 m deep – Far Detector • 5400 tons, 735 km away, 700 m deep 735 km NuMI Physics Goals MINOS • Confirm nm↔nt flavor oscillations – Provide high statistics discrimination against alternatives such as decoherence, n decay, etc • Precise (~10%) measurement of Dm223 • Search for subdominant nm↔ne oscillations – a shot at measuring q13 • Directly compare atmospheric n vs n oscillations (a test of CPT) – MINOS is first large underground detector with a magnetic field for m+/m- tagging NuMI MINOS nm Disappearance Sensitivity • Measure nm flux at Near Det, see what’s left at Far Det • Simulated results plotted as ratio – Position of dip gives Dm2 – Depth of dip gives sin22q • Spectral ratio shapes differ in alternative models Data simulated at: Dm2 = 0.0025eV2, sin22q = 1.0 Top: after 3 years at nominal intensity Bottom: after possible intensity upgrades NuMI ne Appearance Sensitivity MINOS • Detection of ne at Dm2atm is evidence for non-zero q13 • If q13 close to CHOOZ limit: – MINOS will see a ~3s signal in 3 years of running • Otherwise, will improve limit by factor of several Dm2 = 0.0025 eV2; sin2 2q = 0.067 25 x 1020 POT limit q13 @CHOOZ Dm2 = 0.0025 eV2 Background dominated by NC events (+ some intrinsic beam nes) NuMI Far Detector MINOS • 486 planes, 5400 tons total – Each 1” steel + 1 cm plastic scintillator thick – 8 m diameter, torodial ~1.5 T Bfield – 31 m long total, in two 15 m sections – 192 scintillator strips across A module of 20 strips • Alternating planes orthogonal for stereo readout – Scint. CR veto shield on top/sides • Light extracted from scint. strips by wavelength shifting optical fiber – Both strip ends read out with Hamamatsu M16 PMTs – 8x multiplexed 16 mm M16 PMT 8 fibers on a pixel …on a plane NuMI MINOS Soudan Mine Underground Lab • Soudan Iron Mine has been a state historical park since the 1960’s • A new cavern has been excavated at the bottom of the mine • 700 m (2070 mwe) deep – Adjacent to site of former Soudan-2 experiment – Cryogenic Dark Matter Search (CDMS 2) in Soudan-2 hall NuMI Near Detector MINOS • 282 planes, 980 tons total – Same 1” steel,1 cm plastic scintillator planar construction, B-field – 3.8x4.5 m, some planes partially instrumented, some fully, some steel only – 16.6 m long total • Light extracted from scint. strips by wavelength shifting optical fiber – One strip ended read out with Hamamatsu M64 PMTs, fast QIE electronics – No multiplexing upstream, 4x multiplexed in spectrometer region 4.8 m 3.8 m n NuMI Caldet MINOS • 60-plane ‘micro-MINOS’ – has taken data at T7 & T11 test beam lines at CERN during 2001, 2002, 2003 • Instrumented with both Near and Far Detector electronics – To provide cross-calibrations – 2% relative, 5% absolute energy scale are the goals of the total MINOS calibration EM Hadronic Hadronic MC expectation EM NuMI Scintillator MINOS • Polystyrene strips co-extruded with TiO2 reflective coating – 1% PPO, 0.030% POPOP – Wavelength shifting fiber glued into groove to remove light without self re-absorption Photo of a scintillator strip 41 mm 10 mm A blue LED lights up the Scintillator NuMI Main Injector MINOS • The Main Injector accelerator – rapid cycling (up to 204 GeV/c/s) – 120 GeV protons • • Current NuMI intensity 1.9-2.2 x1013 protons per pulse every 2-4 sec 5 (6) proton batches are: – injected from Booster into MI – Accelerated – single-turn extracted to the NuMI target in ~ 8 (10) ms – NuMI gets that 6th batch when pbar do not need to be made • Intensity goals: – This year: 2.5x1013 ppp every 2 s – NuMI design goal: 4x1013 protons every 1.9 s (0.4 MW) – 2008-9 expected rate: ~3.4x1020 protons/year NuMI NuMI Beamline MINOS Target Hall Muon Monitors (x3) Carrier Tunnel Absorber Horn Two Target Carrier Horn One Near Detector NuMI NuMI Beam MINOS • H2O cooled graphite target – 2 interaction lengths absorb ~ 90% of primary protons • Flexible configuration of 2 parabolic horns – H2O cooled, pulsed with a 2.6 ms half-sine wave pulse of 200 kA • Target, horns movable in beam direction – Allows tuning of focused pion energy • 675 m long decay pipe – radius of 1 m, evacuated to 1 Torr • 1 hadron monitor and 3 muon monitor stations NuMI NuMI Spectrum MINOS • Three standard beam configurations – Obtained by changing target and horn 2 locations – Target easy to move, used to approximate ME, HE with “pME”, “pHE” beams – Horn 2 harder to move, has not yet been adjusted • At L of 735 km and Dm2 indicated by Super-K, the “Low” energy beam is closest to the first oscillation minima – And unfortunately also the least intense Fardet νµ CC Events/year (@2.5x1020 pot) (with no oscillations) Low Medium 1,600 4300 High 9250 NuMI First Beam nm MINOS • In the Near Detector: – During beam engineering runs January 21, 2005 • In the Far Detector: – Soon after nominal intensity first reached, March 20, 2005 See http://www.sudan.umn.edu/ for live MINOS events! n beam U view direction V view First beam n seen in the Far Detector, an entering “rock m” Face-on Note the curvature: this is a m- NuMI MINOS Lots of n in the Near Detector • Many n interactions per spill (in 8 ms) • Near Detector Electronics gates for 19 ms during the entire spill – Digitizes continuously every 19 ns, no dead time n beam U view direction V view A typical pHE spill: Events per spill at different beam energies – from real data! Face-on NuMI Event Slicing MINOS Slice 1 Slice 2 Slice 3 Slice 4 Slice 5 NuMI Sanity Checks MINOS Using Near Det n events: Coil hole Fiducial volume Events have correct time structure wrt the beam spill: 5 batches over 8 ms Events coming from expected direction: 3o above horizon, 156o in azimuth Event vertices where they should be (beam direction out of page) NuMI n in Far Detector MINOS Using Far Det n events from pHE beam to validate: From ~150,000 spills in pHE beam ~30 n candidates Far Det. Beam contained vertex neutrino candidate Beam n Cosmics Time difference between n candidate and far spill signal (require 50 ms) They came from Fermilab Rather than many per spill @NearDet, only one interaction per thousands of spills @FarDet! Track angle w.r.t. beam direction NuMI Beam Status MINOS • Steady running, around 1.9-2.2x1013 protons every 2 seconds – In April, coolant leak in target stopped things – >10,000 events/day in Near Detector! • Goal by Fermilab’s annual shutdown this fall: – 1x1020 pot – >100 Far Detector nm CC events (if no osc.) LE pHE pME Reco’d neutrino energy (GeV) Preliminary NuMI End of Year Sensitivity MINOS • Comparable to K2K statistics by end of 2005! NuMI Atmospheric n MINOS • n oscillations depend upon baseline and energy: 2 1 . 27 D m L 2 2 P(nm nt ) sin (2q ) sin En • B-field, m range determine pm (correlated to En), arrival direction determines L (from geometry of Earth) Plot data by momentum and cos(qzen) for best oscillation sensitivity Atmospheric n Classes NuMI MINOS ν Fully Contained Sneaky Stopping Cosmic Muons FC μ Cut: Containment, topology ν Partially Contained Downward-going Sneaky Thru-going Cosmic Muons PCDN Cut: Containment, topology μ Partially Contained upward-going Stopping Cosmic Muons (Direction Wrong) μ PCUP Cut: timing neutrino induced rock muon Up-μ ν μ Thru-going Cosmic Muons (Direction wrong) Cut: timing ν NuMI MINOS Contained Vertex Atmospheric n • Data from commissioning of Far Detector July 2003 through March of this year – After data quality cuts, 418 live-days or 6.18 kton-yr • Monte Carlo data for signal and background – GMINOS GEANT3 Detector simulation, Barr'04 neutrino flux at solar maximum, NEUGEN 3 cross-section models, GCALOR used as default hadronic package. – Cosmic muons reweighted for azimuth/zenith – 19M Cosmic MC (280 days), full spectrum. – 2M Cosmic MC, Eµ<2GeV ~ 4.1 years – 1300 years of atmospheric n signal MC. NuMI MINOS Contained Vertex Atmospheric n Data • 28 upward vs 49 downward – up/down Rdata = 0.571±0.135 – Selection not up-down symmetric • expect RMC = 0.92 ± 0.03 (no osc.) – Rdata/RMC = 0.62±0.14±0.02 (2.6 sigma from 1) • (Currently no sys error for up-down flux uncertainties, likely around 5%) Contained n Vertex Data Low res timing 30 Expect Expect (no osc) (Dm2=0.0025 eV2) 37±4 28±3 Ambiguous nm/nm 25 26±3 20±2 nm 34 42±4 31±3 nm 18 23±2 17±2 Good timing subtotal 77 92±9 69±7 Total 107 129±13 97±9 NuMI MINOS Contained Vertex Atmospheric n Data NuMI Upward-going m MINOS • High energy atmospheric nm interacting in the rock surrounding the detector produce an entering m CR μ 700 m (2070 mwe) – Cosmic ray induced m come downward through smaller rock overburdens – Any m going up is from a nm • Long m range in rock at high energies allows a much larger target volume of rock than the detector itself μ nm NuMI m Direction MINOS • Cosmic Ray m give 1/b Gaussian distributed about +1 – Arrive at a rate of one every couple seconds • m going in the reverse direction (up!) are Gaussian distributed about -1 – Arrive at a rate of about once per week • The two types of events are clearly separated – Good timing resolution prevents tails of CR events from contaminating n events Upward-going n-induced m mean b-1.0, sb=0.051 Downward-going CR-induced m Mean b=1.0, sb=0.049 NuMI Up-m Data MINOS • Data collected from July 2003 till April 2005 – 464 live-days • 304 with normal B-field • 160 with reversed B-field for cross-checks • Cuts applied: – – – – <2.0 m track length, <20 planes crossed Vertex, endpoint of track within 50 cm of detector surface Tracking, timing quality criteria 72% efficient • 91 n-induced up-m found – 1 per 5.1 days NuMI Zenith Angles MINOS All data Low pm Medium pm Up (long L) High pm Horizontal (short L) Up (long L) Horizontal (short L) NuMI n vs n MINOS • First deep underground detector with a magnetic field – Can get m charge ID on an event by event basis • Thus able to check that n oscillate the same as n, a probe of CPT violation – Can also measure cosmic ray m+/m- ratio n-induced up-m charge results – 25 m-,16 m+: rest too stiff to get a reliable charge ID NuMI Summary MINOS • MINOS is alive, the NuMI beam is beaming – Gobs of Near Detector data already – Far Detector interactions ticking along, will be able to compare to K2K this year • Atmospheric n data continues to be acquired during beam running – Charge and momentum determination hold promise as more data is acquired for Oscillation, CPT analyses – Atmospheric data consistent with Oscillations, proper oscillation fits in progress This work was supported by the U.S. Department of Energy, the U..K. Particle Physics and Astronomy Research Council, and the State and University of Minnesota. We gratefully acknowledge the Minnesota Department of Natural Resources for allowing us to use the facilities of the Soudan Underground Mine State Park. This presentation was directly supported by NSF RUI grant #0354848. NuMI Extra Slides MINOS NuMI Timing Calibrations MINOS • Timing can tell the direction – Use downgoing CR m to calibrate timing – Adjust timing constants (electronics offsets, cable lengths, timewalk, etc.) to properly reconstruct them with b = v/c = 1 – Crosscheck time light seen at opposite ends of same strip with position from track, get difference D • sD=0.17 m → st=2.4 ns resolution • Composed of 1.56 ns clock granularity, 2.0 ns inherent signal resolution D < 1m for 99.8% of hits NuMI Target Leak MINOS • Target filled with water in March due to coolant leak • Currently back-pressurized with He • Have spare target, but no spare target carrier • Building new spare carrier; will be ready in August Graphite segment Cooling pipes NuMI Moon Shadow MINOS HE primary cosmic rays shadowed by moon • Far Det has been taking Cosmic Ray data since July 2003 • Observing the shadow of the moon validates muon tracking, surveying, ability to project tracks onto the sky – >10 million cosmic m – Demonstrates angular resolution <1o – High-momentum m give better resolution All tracks Pm > 20 GeV/c