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Осцилации на неутрината: феноменология и експериментални наблюдения (Лекция 3 ). Lotus Lola. Lotus Lola. Матрица на Pontecorvo-Maki-Nakagawa-Sakata. 4 реални параметъра : 3 ъгли на смесване и една фаза δ. състояния :. където. и. n e. n 1. n 2. n m. n 3. n t. Normal. Inverted.
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Осцилации на неутрината:феноменология и експериментални наблюдения(Лекция 3) Lotus Lola Lotus Lola
Матрица на Pontecorvo-Maki-Nakagawa-Sakata 4 реални параметъра: 3 ъгли на смесванеи една фазаδ. състояния: където и
ne n1 n2 nm n3 nt
Normal Inverted • Global fit provides: • sin2q12=0.320.23 • Dm122 =7.60.20×10-5 eV2 • sin2q23=0.500.063 • Dm232=2.40.15×10-3 eV2 • Unknown quantities: • sin2q13< 0.031 (@90%CL), • Mass hierarchy: sign Dm132 • CP violation phase d
T2K Future Long Baseline Accelerator Neutrino Experiments NOvA
Measurement ne n3 nt nm Dm2atm n2 n1 Dm2sun Oscillation Probabilities when • q23: nm disappearance ~1 common • q13: ne appearance ~0.5 • d: CP violation (in future) ~0.18 (sin22q13=0.1) ~0.58 (sin22q13=0.01) 7 • P(nm➝ne) at the 1st and 2nd osc. peaks could be different by d!
T2K Neutrino Beams(to Kamioka) Main ring J-PARC Facility (KEK/JAEA) South to North Construction JFY2001~2008 Design Intensity 750kW • J-PARC starts operation toward the world highest intensity proton accelerator. • The high power beam could produce the intense neutrino beam. Bird’s eye photo in January of 2008
Osc. Prob.@ Dm2=3x10-3eV2 Off-axis beam configuration OA0° OA2° • The n beam energy is tuned at the oscillation maximum. • Higher signal yield. • Less background from high energy neutrinos. nm flux OA2.5° OA3° • Quasi Monochromatic Beam Intense and high-quality neutrino beam 9
Neutrino event timing ( INGRID) Near Detectors
Super-K(Far detector) neutrino events LE: Low energy triggered events OD: Outer detector events FC: Fully contained events FC OD LE FC Clean beam timing structure confirmed in FC events Twenty-two FC events observed by Mid. May Non-beam BG estimated to be <10-3evts 11
T2K Physics Run begins in 2010. ~100kW ~50kW Beam Power Delivered POT: 3.35×1019 (3.28×1019 for physics) Continuous run @ ~50kW level Trial up to 100kW successful. 12
Expected Sensitivity of T2K nm➝ nm disappearance nm➝ ne appearance T2K Full Statistic goal: 3.75MW×107 sec. 13
FAR and NEAR FAR only
1st step: transition era • Improve the precision on the atmospheric parameters looking at νμ disappearance • Confirm (atm. osc)=(νμ → ντ ) and first look at νμ → νe Ongoing: 2005-2012 • Conventional beams • MINOS • OPERA • Reactors • D-Chooz • RENO • DayaBay • Super-beams • T2K • NOvA Under construction: 2008-2015 • 2 nd step: θ13 era • Demonstrate visibility of sub-leading transitions: • νμ → νe , νe →νe • Explore θ13 down to 20 (today <100) 3 rd step: precision era To be prepared: 2015-2030 θ13> 3 0 θ13< 3 0 Known by 2012 Super-beams II Beta-beams Neutrino Factory • Existing facilities could reach it • … but with very small sensitivity to δCP and mass hierarchy • No access for ongoing experiments at that time Cleaner and more intense beams + bigger detectors
3 rd step: Precision era Channels of interest • Disappearance for Dm312, q23: nm nm • Appearance for q13, CPV, MH: • Golden: ne nm or anti-nm anti-ne; • Silver: ne nt ; • Platinum: nm ne ; • Neutral currents for new physics
Peτ Antineutrinos: Magic baseline: Silver: Golden & Silver
Solving solution degeneracy Linevs Dashed = neutrinos and anti-neutrinos red vs blue = different baseline and energy bin (most powerful is around matter resonance @ ~12 GeV) red vs blue = golden and silver
Example: CPV discovery • Any value of dCP(except for 0 and p)violates CP • Sensitivity to CPV:Exclude CP-conservingsolutions 0 and pfor any choiceof the other oscillationparameters in their allowed ranges
CP violation discovery example … in (true) sin22q13 and dCP Best performanceclose to max. CPV (dCP = p/2 or 3p/2) Sensitive region as a function of trueq13 anddCP dCP values now stacked for each q13 No CPV discovery ifdCP too close to 0 or p No CPV discovery forall values of dCP 3s Read: If sin22q13=10-3, we expect a discovery for 80% of all values of dCP
Decay Pipe Detector Target Horns q Super-beams • Super-beams: 1-4 MW proton intensity to generate beam of neutrinos from the decays of pion and kaons. ne’s: m+→e+nenm K+→p0e+ne nm’s: p+→m+nm K+→m+nm • Off-axis for better determination neutrino energy. Nona off-axis (~750 km) or T2K (~250 km) Off-axis: narrower energy band
β- beams • Beta beam: beta decay of accelerated radioactive nuclei (P. Zucchelli, Phys. Lett. B, 532 (2002), 166-172.) • He-6 for neutrino production: g ~ 100 • Ne-18 for antineutrino production: g ~ 60 Only one neutrino species do not need magnetic detector! High Eurisol study Low
IDS-NF: • Initiative from ~ 2007-2012 to present a design report, schedule, cost estimate, risk assessment for a neutrino factory.
Target: Em ~ 25 GeV, 2.5 1020 usful muon decays/polarity/ring/year = 1021 total
Йонизационно охлаждане: • Чрез енергетични загуби мюонът губи надлъжен и напречен импулс (px, py, pz). • Радиочестотни резонатори възстановяват надлъжния импулс (pz).
Квази-еластично разсейване на неутрина върху електрони • Разпределения по енергия на неутрината, попадащи в близкия детектор. • Процеси на квази-еластично разсейване на неутрина върху електрони. • Квази-еластичното разсейване на неутрина върху електрони е праговпроцес с праг ~11 GeV.
Разделяне на сигнала от фона • Ако искаме да измерваме потока неутрина чрез квази-еластично разсейване на неутрина върху електрони, то близкият детектор трябва да може да различава тези две събития. Дълбоко-нееластично разсейване върху нуклон Квази-еластично разсейване върху електрон за 20 GeV νμто е ~10-3отσtotal(νN)