Resent results from Antares Aart Heijboer, Nikhef on behalf of the Antares collaboration.

Transcription

1 Resent results from Antares Aart Heijboer, Nikhef on behalf of the Antares collaboration. 1

2 Neutrino Astronomy Protons/ Cosmic Rays (CR): Detected on Earth up to extremely high energies: 108 TeV Hard to study sources due to deflection by magnetic fields Photons Ubiquitous tool for astronomy, up to TeV energies (Hess, Magick, etc) Absorbed at higher energies Neutrinos: Unambiguous probe of hadronic processes } identify Cosmic ray sources Not affected by B fields or dust Horizon not limited by interaction with CMB/IR 2

3 Neurino Sources Binary systems SNR GRB Micro-quasars AGN Look for sources of neutrinos associated with Cosmic Ray Accelerators p + γ/p π± + X ν + X Allow identification of CR sources Many interesting candidate objects SNRs, GRBs, microquazars, AGN Also: Dark matter, Monopoles.. Earth & Sea science atmospheric neutrino's and muons AGN 3

4 Detection principle atmospheric muons atmospheric neutrinos: cosmic neutrinos: ~10 per second. few per day few per year (maybe) look for up-going events 4

5 The ANTARES Collaboration NIKHEF, Amsterdam Utrecht KVI Groningen NIOZ Texel University of Erlangen Bamberg Observatory ITEP,Moscow Moscow State Univ IFIC, Valencia UPV, Valencia UPC, Barcelona ISS, Bucarest CPPM, Marseille DSM/IRFU/CEA, Saclay APC, Paris LPC, Clermont-Ferrand IPHC (IReS), Strasbourg Univ. de H.-A., Mulhouse IFREMER, Toulon/Brest C.O.M. Marseille LAM, Marseille GeoAzur Villefranche University/INFN of Bari University/INFN of Bologna University/INFN of Catania LNS Catania University/INFN of Pisa University/INFN of Rome University/INFN of Genova 7 countries 29 institutes ~150 scientists+engineers 5 5

6 ANTARES site Shore station / control room Toulon e bl ca to te de La Seyne sur Mer 0 (4 or ct harbour infrastructure at Fosilev and Iremer Toulon km ) 6

7 ANTARES site Shore station / control room Toulon e bl ca to te de La Seyne sur Mer 0 (4 or ct harbour infrastructure at Fosilev and Iremer Toulon km ) 7

8 detecting neutrinos from the Mediterranean...as opposed to the South Pole Mkn 421 Mkn 501 Mkn 501 CRAB RX J CRAB SS433 GX339-4 VELA Galactic Centre SS433 Full sky coverage requires detector in Northern Hemisphere Good view of galaxy (including galactic center) with upgoing neutrinos -> at relevant energies (~100 GeV 100 Tev) Good view of the Sun: for dark matter searches Water properties -> good angular resolution improves discovery potential IceCube much larger, but Antares may lead the way to KM3NeT: an even larger detector in the Mediteranean. 8

9 Layout 2500m 900 PMTs 12 lines 25 storeys / line 3 PMTs / storey V. Bertin - CPPM - Roma 40 km to shore 450 m Junction Box 70 m Interlink cables 9

10 Layout Local Control Module (inside a titanium cylinder) Hydrophone RX (5 per line) Optical Beacon (blue LEDs) for timing calibration (4 per line) Optical Module: 17 glass sphere 10 PMT Ham. R (14 stages) 10

11 Layout 2500m few storeys with hydrophones for R&D into acoustic neutrino detection 900 PMTs 12 lines 25 storeys / line 3 PMTs / storey V. Bertin - CPPM - Roma 40 km to shore 450 m Junction Box 70 m Interlink cables 11

12 few storeys with hydrophones for R&D into acoustic neutrino detection Layout 2500m V. Bertin - CPPM - Roma Diverse Physics Program 70 m 900 PMTs 12 lines 25 storeys / line 3 PMTs / storey 'Associated science' Atmospheric muon flux Search for diffuse cosmic neutrinos450 m Point source search Searches for monopoles & nuclearites Searches for neutrinos from GRB looking for n from DM annhilation in the Sun Correlations with optical measurements optical follow up of neutrino events 'neutrino follow up' of GRB joint analysis effort with Gravitational wave detectors. 40 km to shore Junction Box Interlink cables 12

13 Backgrounds & associated Science bioluminescence radio active decays count rate dominated by bioluminescence & radioactive deyays K40 -> time calibration biolumiscense related to vertical convection events 40 γ K e- (β decay) check of time calibration relative efficiency measurement Ca 40 13

14 Muons 2,5km 6km Astroparticle Physics 34 (2010), pp see also Astroparticle Physics 33 (2010) pp

15 atmospheric muons and neutrinos After quality cuts, upgoing tracks left are: Atmospheric neutrinos Good agreement with flux model & MC 15

16 Search for a Diffuse Flux component idea: Background atmospheric neutrinos have steeply falling energy spectrum : N E-3.5 Many cosmic neutrino models predict much harder spectra, typically N E-2\ => Look for High-energy diffuse flux component analysis: Live time: 334 days Stringent selection: 134 high energy candidates, ~no 's Energy estimator R: a measure of number delayed photons energy estimate: can't see the neutrino, only the muon when it reaches the detector muons above 1 TeV produce additional Cherenkov light via secondaries ( E) Energy estimate R based on number of repeating hits 16

17 Search for a Diffuse Flux component signal region control region icecube No excess of high energy events found over expectation from atmospheric ν's set flux limit: E2 Φ(E) < GeV cm-2 s-1 sr-1 for 20 TeV < E < 2.5 PeV submitted to Physics Letters B [arxiv: ] 17

18 Combinations with other experiments GRB detecting satalites look for coincident neutrino signal huge reduction of backgrounds few events = discovery used to lower the trigger threshold for few minutes around the GRB detection time. Tarot telescope La Silla, Chile Tattoo/Tarot project quick optical follow up of Antares high energy neutrino events or doublets of neutrinos from ~same direction and time hope to find transient source early. Combining analyses with Auger (in progress) Virgo / Ligo (planning) 18

19 Dark matter search dark matter annihilations in the sun χ Sun WIMPs gravitational trapped via elastic collisions in the sun χ χ χ χ χ Earth ν Antares E M /3 -> few degrees between ν and µ Look for muons in a 4-degree cone around the sun. No excess observed -> compare with n flux predictions from Msugra models. (G. Lim) 19

20 Dark matter search from the Sun antares preliminary 68 days 5 lines limit assuming 'soft' spectrum: bb limit assuming 'hard' spectrum: W+W- green models: ok with WMAP focus point region: expect hard spectra. sweet spot for Antares: - large area compared to SuperK - low E-threshold compared to IceCube (but deep core!) not yet sensitive enough to exclude msugra models but only only small subset of data. projections for (near) future look good 20

21 visibility fraction Point source search events are: 60% atm. neutrinos 40% downgoing muons, reconstructed as upgoing 21

22 Point source search median angular resolution degree data from 5-line detector(2007) included. loose selection for optimal sensitivity: error estimate < 1 degree reconstruction quality variable Angular resolution estimated from MC, but constrained using data. comparable to IceCube, despite much smaller detector advantage of water over ice. 22

23 Search method fit for unknown parameters: µsig δs αs (unless candidate search) Compute discriminating value log-likelihood ratio Q test on pseudoexperiments 23

24 Point source search actually 2 searches: full sky search 24 canidate objects most signal-like cluster from candidate search, p = 7% most signal-like cluster from full sky search, p = 2.4 % (2 after trial) no significant excess found 24

25 Point source search preliminary result: no significant signal found limits reported for a number of candidate neutrino sources interesting gamma/x-ray sources for which models predict neutrinos galactic center: see no events within resolution Best limits from northern hemisphere detectors IceCube competative, but energy range for decl<0 is very different. preliminary 25

26 Conclusions ANTARES completed since May 2008 several successful string recoveries + repairs (since Nov 12 lines again!) Operating smoothly, understanding of detector and data analysis progressing Largest neutrino detector in the northern hemisphere Search for galactic sources with unprecedented sensitivity (at relevant energies) Exciting physics program in progress Muons, neutrinos, dark matter, monopoles, Diffuse flux search Best limits for point sources in the southern sky More data (x2) already on tape. Multi-messenger approaches strongly pursued Important step towards the KM3NeT multi-disciplinary deep-sea research infrastructure 26

27 'Low level' studies 2 measure Muons with no reconstruction very low (4 GeV) energy threshold directly see depth dependence Δt = L / c = 50 ns (for vertical muon) submitted to Astrop. Phys. 27

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29 Detector construction MILOM: 17th Mar 2005 Line 1: 2nd Mar 2006 Line 2: 21st Sep 2006 Line 3, 4, 5: 29th Jan 2007 Line 6, 7, 8, 9, 10 + IL07: 7th Dec 2007 Line 11, 12: 30th May 2008 Aug 20, 2009 ~60 m : detector R&D, site exploration 2001: Deployment of 40 km main electrooptical cable (Alcatel) 2002: Deployment and connection of Junction Box : Various prototype lines : deployment and connection of 12 detector lines Apparatus completed!29 D. Zaborov, ANTARES experiment and its first results 29

30 Detector construction Aug 20, 2009 D. Zaborov, ANTARES experiment and its first results 30 30

31 Aug 20, 2009 D. Zaborov, ANTARES experiment and its first results 31 31