Particle Physics with Neutrino Telescope Aart Heijboer, Nikhef

Transcription

1 Particle Physics with Neutrino Telescope Aart Heijboer, Nikhef 1

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3 high energy Quanta from the Universe (why look for neutrinos) Universe contains very high Energy particle accelerators (E = up to 10 6 X LHC) ν protons are deflected by magnetic fields in the universe sources unknown high energy neutrinos: travel in straight lines point to their source are produced in proton accelerators are not absorbed on their way here ideal messenger particle

4 M87 Active Galactic Nucleus 5000 lightyear

5 Galactic: SN1006a Supernova Remnant TeV gamma Neutrino flux related to TeV gamma flux. Energies typically < 100 TeV hadronic scenario

6 neutrino science Supernova Remnants Micro quasars Active Galactic Nuclei Gamma Ray bursts Dark Matter Atmospheric neutrinos Cosmic ray physics Monopoles & Nuclearites Neutrino physics (mass hierarchy) protons are deflected by magnetic fields in the universe but how to detect them?

7 neutrino detection Upgoing muons are caused by neutrinos, downgoing atmspheric muons are background Neutrino telescopes look though the Earth! interaction improbable need huge detector!

8 neutrino detection

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10 neutrino telescopes Antares now KM3Ne T Lake Baikal, NT200+ Amanda IceCube 2007-now

11 ANTARES Buoy 350 m 3 total volume ~ 200 x 200 x 300 meter 100 m Junction box ~60-75 m Operational since 2007

12 Reconstruct neutrino direction from Cherenkov light arrival time Atmospheric neutrinos form a background, but also a free, well understood flux of neutrinos

13 Neutrino telescopes: IceCube

14 Cosmic neutrinos observed! Cosmic neutrinos seen with Icecube. Energies: PeV Sources unknown Reduced resolution for electronand tau neutrinos

15 Cosmic neutrinos seen! Is this a point source (arxiv: )? Antares says : no Most events have >10 deg resolution Cosmic neutrinos seen with Icecube. Energies: PeV = 10 6 GeV Sources unknown Oscillations!

16 Neutrino flavours ν μ ν e - Complementary experimentally - Measure flavour composition

17 Flavour ratios contain (astro) physics IceCube flavour ratio fit ν μ Phys.Rev.Lett. 115 (2015) SM New Physics } astro ν τ Fit to IceCube data consistent with 1:1:1 More data to come ν e Oscillations affect flavour ratios of cosmic neutrinos. non-standard interaction, Lorentz-invariance violation, ν-decay, steriles Works better when sources are understood (and then, can even probe δ cp ) KM3NeT will contribute a lot here 17

18 The next generation: KM3NeT The next generation

19 Our role in KM3eT We are not just participating Off-shore firm- and software On shore software (trigger, reconstruction) PMT bases, dcdc convertors...are all big efforts we do at nikhef 19

20 Light collection rings developed here in Groningen. Up to 40% gain in efficiency (most cost-effective device in science?)

21 Signal collection boards (Groningen) Light collection rings developed here in Groningen. Up to 40% gain in efficiency (most cost-effective device in science?)

22 Neutrino telescopes: KM3NeT

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24 Neutrino telescopes: KM3NeT

25 Neutrino telescopes: KM3NeT

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43 implications 3 neutrino masses 3 mixing angles 1 complex phase (CP violation) U PMNS U e3 = sinq 13 e -id U CKM

44 Next challenges Next big step: Mass hierarchy Holy grail: CP violation

45 Neutrino mass hierarchy Hierarchy important for theory, cosmology, 0νββ Foreseen to be measured at future accelerator-based experiments..or resolve matter effects in high-statistics atmospheric neutrino sample 45

46 Measure the mass hierarchy Vacuum oscillations : only measure Δm 2 Matter to the rescue only electron neutrino interact with electrons Forward scattering -> effective mass of ν e (analogous to index of refraction in optics)

47 The idea Event rate vs E and zenith Shows interesting pattern, which is different for IH/NH

48 The idea Event rate vs E and zenith Shows interesting pattern, which is different for IH/NH

49 The idea Subtle effect -> need a huge number of neutrinos Event rate vs E and zenith -> need 100x Super-Kamiokande, Shows interesting pattern, sensitive in 5-10 which GeV is energy different range for IH/NH Neutrino telescopes!

50 Dense setup to study GeV energies km 3 = 1 Gton 4 Mton Sensitivity in few GeV (rather than PeV) Denser detector Still: volume = 4 Mton (Super-kamiokande is 50 kton)

51 IceCube Precision IceCube Next Generation Upgrade KM3NeT Oscillations Research using Cosmics in the Abyss Very similar expected performance

52 Orca vs Pingu ;-)

53 That s better

54 How to compute

55 How to compute: simple, beatiful quantum mechanics Schrodinger equation for the mass eigenstates Free propogation easy in mass basis. Matter contribution simple in flavour basis Propagate states through a layer of constant densitity matrix exponentiation).

56 oscillograms

57 oscillograms 1GeV 20GeV NH NH mantle earth core IH wikipedia IH Result: zenith angle dependent distortions of the neutrino energy spectrum.

58 The real analysis

59 significance Cascades (ν e appearance) Dominate

60 Measuring other parameters

61 Other experiments Grains of salt Depends on funding, and Many, many other things It s a hard measurement, but it s hard for everybody ORCA & PINGU can be very competitieve First lines good prospects for more funding Fast deployment possible (no accelerator)

62 Concluding remarks Neutrino telescopes work and are versatile instruments not discussed: astronomy, dark matter searches, monopoles etc Flavour ratios probe oscillations physics, also at high energy KM3NeT Detector under constructions First line works! More to come soon. Will be unique instrument to take the next step (also IceCube gen-ii) Orientation toward GeV region allows to measure mass hierarchy using same technology Next milestone in neutrino physics : important for future experiments, and 0νββ ORCA will happen (partly funded, rest looks promising) 3 sigma in 3 years 62