NOºAThe NuMIOffaxisºe Appearance Experiment Andrew Norman for the NOºA Collaboration NuFACT07, Okayama Japan August 11, 2007 TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: AAAAAAAAA
O NOºA Collaboration ν ν O • Over 140 Physicists and Engineers from 28 institutions ν ν ν ν
Introduction • Physics Motivation • Sensitivities • Detector Design • R&D Progress • Status
Overview: NOvA Today (Baseline) • NOvA is an 18kTon far detector + 218Ton near detector + NuMI beam upgrade project. • Both detectors are “totally active” liquid scintillator designs • The detectors are 14mrad off the primary beam axis to achieve narrow º¹ energy spectrum, peaked at 2GeV. • The far detect sits on a 810km baseline between Chicago and Northern Minnesota at the first oscillation maximum • Designed to use the 320KW then 700KW NuMI beam with final upgrade to the 1.2MW “super-NuMI” beam from the Fermilab main injector. • Integrate ultimately 10£1020 pot/yr
Physics Program • The NOºA experimental program goals: • Observe º¹!ºe oscillations • Measure µ13 • Or improve the current limit on µ13 by a factor of 20. • Measure sin2(2µ23) to a precision of 0.5-1%. • Resolve the neutrino mass hierarchy • Measure the CP violating phase ± • Measurement of NC cross section at 2 GeV • Detection of near galactic supernova
The Effect of Going Off-Axis • By going off-axis, the neutrino flux from ¼!¹ + º is reduced at a distance z to: • But the energy narrows as µ2: • For NOνA, moving 14 mrad off axis makes the NuMI beam energy • peak at 2 GeV • Eº width narrows to 20% • This corresponds to the first the oscillation maximum 1stOsc. Max
The Effect of Going Off-Axis • This suppresses the high energy tail (NC background) • Significantly reduces the Kaon background contribution by shifting the neutrino energy away from the signal band • Energy spectrum in the signal region becomes almost insensitive to the /K ratio • Results in a neutrino peak primarily from decays º’s from K’s well above signal band º’s from ¼’s in 2GeV band
P(º¹!ºe) and Ue3 The Ue3 contribution to the third mass state is small, requiring a precision measurement of ºe appearance • Measuring a ºe excess in the NuMIº¹ beam will give evidence for º¹!ºe transitions and a non-zero Ue3 component to ¢m232 • This is done through the ºe CC channel • The º¹ NC is the dominant background, • Controlled through the identification of initial vertex and displaced shower conversion point. • NOºA’s energy (2GeV) and baseline (810km) and segmentation (0.15X0) are chosen to maximize the physics reach of accessing these transitions • Electron neutrino’s role in the º¹ flavor transitions is given an upper bound by CHOOZ limit at 5-10% of the total state.
ºe Charged Current Channel Event Parameters Reaction: Eº = 2.5GeV Ep = 1.1GeV E¼ = 0.2GeV Ee = 1.9GeV Shower spans »65 of the 1178 planes Primary Vertex Localized E&M Shower
º¹ Neutral Current Background Event Parameters Reaction: Eº = 10.6GeV Ep = 1.04GeV E¼ = 1.97GeV Suppressed by vertex/shower displacement identification Primary Vertex Localized E&M Shower Displacement
Sensitivity at 3¾ for µ13 from º¹!ºe • For the current 18kTon detector, with 700kW (dashed) and 1.2MW (solid) beam. • The physics reach for µ13 is shown for 3 years of running each on º and º-bar. • The reach of the 1.2MW is almost an order of magnitude beyond the CHOOZ bound, giving improvement over the 3¾ MINOS reach
Sensitivity to sin2(2µ23) • NOºA can perform the disappearance measurement to a precision of 0.5-1% • Proceeds as a parameterized analysis of quasielasticº¹ CC events • If 1, then resolve quadrant (µ23 > ¼/4 or µ23 < ¼/4, ) • Measure if º3 couples more to º¹ or º¿ • Resolve ambiguity by comparing NOºA to Daya Bay.
Mass Ordering Natural • From solar and atmospheric data we know: • This leads to two possible mass hierarchies • A “natural” order which follows the lepton mass ordering • An “inverted” order where m3 is actually the lightest • NOºA can solve this by measuring the sign of m23 using the MSW effect over the 810km baseline Inverted
Sensitivities for P(º¹!ºe) = 0.02 • Some CP phases create an ambiguity in the resolution of the mass hierarchy. • Combine with a second measurement to break ambiguities
CP Violation • Large Mixing Angle (LMA) solution gives sensitivity in º¹!ºe transitions to the CP violating phase ±. • In vacuum, the transition probability is shifted with ±. At the first oscillation maximum the shift is: • Since the shift is proportional to the importance of the sub-leading terms grow, as gets small. • The ultimate sensitivity of NOνA for resolving the CP ambiguities in matter depend on both sin θ13 and ± • Combining the NOºA result with other experiments lifts the ambiguities in some regions.
Resolution of Mass Hierarchy (95% CL) Normal Inverted
78 m 78 m 14.3 m 14.3 m 14.3 m 14.3 m 8.4 m 8.4 m 8.4 m 8.4 m 15.6 m 15.7 m 4.2 m 4.2 m 4.2 m 4.2 m 4.2 m 4.2 m 4.2 m 4.2 m 2.9 m 2.9 m 2.9 m 2.9 m 2.9 m 2.9 m 2.9 m 2.9 m The NOνA Detectors 1,178 planes Far Detector • 18 kTons • 1178 alternating X-Y planes • Grouped into 38 modular half kiloton “blocks” • Over 450,000 independent detection cells • > 70% of total mass is active 18,000 tons Alternating X-Y Planes form the detector blocks 218 tons 88 tons 45 tons Far Detector 15.0 m Near Detector Humpback Whale IPND IPND The “Integration Prototype Near Detector” will be built in Q1 2008 to show technological integration of all the NOvA subsystem How big is this? The NOvA far detector is big enough to fit Atlas, CMS, DØ, and CDF Inside it’s active volume.
NuMI Beam Options • Two intensity options • 700 kW (ANU baseline) • 1.2MW (super-NuMI) • 1 year of beam = 44 weeks of running • Duty factor = 0.6 (accel + NuMI down time) • Run 3 years each on º and º-bar • For 700kW this is 36£1020 pot • For 1.2MW this is 60£1020 pot
& Recycler NuMI Accelerator Upgrade Beamline Upgrade • Proton source upgraded from 320kW to 700kW • NuMI will deliver 4.9×1012 protons per pulse • 1.33s rep-rate. • This results in 6×1020 pot/yr. New extraction line from Recycler to MI New Injection line from MI to Recycler • Changes • Recycler runs proton not anti-protons • New injection/extraction lines for Recycler to Main Injector transfers • Main Injector cycle time reduced from 2.2s to 1.5s (stack in the recycler) • Cycle time reduced again to 1.33s with 2 more RF stations at MI-60 and with transition of the MI from 204 GeV/s to it’s design acceleration rate of 240 GeV/s. • NuMI target redesign for high flux New RF stations added and acceleration rate switched to 240GeV/s
Detector Modules PVC Extrusions Each extrusion is a single 15.7m (51.5ft) long set of 6x3.9cm cells. Two extrusions are joined to form a single 1.3m wide module Single Cell NOνA Modules • The NOνA detector module forms the base unit for the detector. • Each module is made from two 16 cell high reflectivity PVC extrusions bonded into a single 32 cell module • Includes readout manifold for fiber routing and APD housing • Combined 12 module wide X or Y measuring planes. • Each module is capped, and filled with the liquid scintillator. • These are the primary containment vessel for the 3.9 million gallons of scintillator material. • There are 14,136 detector modules with a total of 452,352 separate detection cells in the NOνA Far Detector. 15.7m One Module 6cm 1.3m 3.9cm Two 16 cell extrusions
NOºA Approval Status • CD-1 completed and signed. • Total project capped at $260M • Includes Accel. Upgrade to 700kW • FNAL Director’s review (Part 1) June ’07 • Baseline detector size 18kton • Physics & detector sub systems reviewed -- PASSED • Costs rolled up • Initial estimate placed detector over project cap • Included many obvious accounting errors • July/Aug costs for project “scrubbed” to remove anomalous entries, redundancies and errors… • FNAL Director’s review (Part 2) Aug. ‘07 • Primarily cost accounting review • DoE CD-2/CD-3a review scheduled for Oct. ’07
NOºA Time Line • Now Electronics, PVC, Scint, DAQ, DCS, SIM R&D ongoing and continues through 2008/9 • Q1/Q2 2008 IPND installation in MINOS assem. Building • Q1/Q2 2008 Far site infrastructure start • 2010 Collider shutdown, NuMI upgrades • 2011 Beneficial Occupancy at Far Site • 2011-13 Installation/Commisioning/Production data taking occur in parallel
The Far Site - Ash River, MN Ash River is chosen as the site for the massive 18kTon far detector because it is the farthest site from Fermilab that is still inside the United States and yet accessible by roadway. The site is 810.5km from Fermilab, 1.5 miles south of Voyageurs National Park, and 45minute away from the town of International Falls, known as “The Icebox of the Nation” for it’s record breaking winter time temperatures. The NOνA Site Today 810km NuMI Beam (14.6 mradoffaxis) Off Axis? By placing the detector at Ash River, 14.6mrad off of the NuMI beam axis, we obtain a sharp peak at 2GeV in the neutrino energy spectrum. NuMI at NOνA gives a 2GeV peak