"Cosmogenic neutrinos detection"

Transcription

1 "Cosmogenic neutrinos detection" P. Spillantini, INFN and University, Firenze Round Table discussion Exciting neutrino: from Pauli, Fermi and Pontecorvo to nowadays prospect 16 th Lomonov conference on Elementary Particle Physics, Moscow August, /8/2013 1

2 Continued from: Observation of Ultra High Energy neutrinos Sergio Bottai, INFN, Firenze, Italy Piero Mazzinghi, INOA, Firenze, Italy Piero Spillantini, University and INFN, Firenze, Italy 11 th Lomonosov Conference on Elementary Particle Physics Moscow, August 21 27, /8/2013 2

3 Continued from: 10th Lomonosov Conference on Elementary Particle Physics, Moscow, August 2001 From the Extreme Universe Space Observatory (EUSO) to the Extreme Energy Neutrino Observatory 9/8/2013 3

4 Cosmogenic neutrinos component Protons coming from distances >20-50 Mpc interact with the CMB (GKZ effect) producing pions, and finally neutrinos. Protons with E>10 20 ev interact several times before degrading under the GKZ cut-off producing many ν e and ν μ neutrinos. The energy of produced neutrinos is ev or more 9/8/2013 4

5 This is the less unprobable neutrino component expected at the extreme energies. It is not model dependent (i.e. it only depends from UHECR E max and the proton source distribution) 9/8/2013 5

6 9/8/2013 6

7 Fig. 2.1 Artist view of the EUSO concept. The shower development occurs in the atmosphere layers below km a.s.l.; the isotopic fluorescence emission is proportional at any depth to the number of 9/8/2013 charged particles (mainly electrons) present in the shower front: N e E ev / (1.4x10 9 ). The UV yield is 7 4 photons per meter of electron track, almost independent from air pressure and temperature.

8 9/8/2013 8

9 The most complete work was Ultra High Energy Neutrino Fluxes and Their Constraints (Kalashek, Kuzmin, Semokov, Sigl) [arxiv:hep ph/ v3 13 Dec 2002] [Model consistent with gamma s and UHECR data (Fly seye, Haverah Park, Yakytsk, AGASA)] 9/8/2013 9

10 p + γ Δ + (1232) πn μν eνν EUSO min Max 9/8/

11 ... 9/8/

12 p + γ Δ + (1232) πn μν eνν EUSO EUSO x 10 min Max 9/8/

13 Is it possible to increase the number of detected neutrino events? (EUSO-like from ISS) -Decrease the energy threshold (5 x ev ev) by improving the sensor efficiency ( ) by improving the light collection (pupil 2m 6m) (what implies reflective systems and modularity) -Increase the target volume -by increasing the FOV ( ) but limited to 90º by attenuation by air and by distance. x 1.5 x 9 (x 90) x 3 9/8/

14 p + γ Δ + (1232) πn μν eνν EUSO EUSO x 30 Extreme min Max 9/8/

15 One optical system (EUSO like) Multi mirror H (km) Total FoV ( o ) Radius on ground (km) Area on ground (10 3 km 2 ) Target volume (km 3 ) Pixel on ground (km * km) 0.8 x x0.8 number of pixels) (.8x.8 km2) 270k 786k Pupil diameter (m) Photo detection efficiency 20% 50% 50% 50% 50% E threshold (EeV) Proton events/year, GKZ + uniform source distrib k 300k 2000k with E p >100 EeV) Neutrino events per year ( min) Neutrino events per year ( Max) /8/

16 After 2004: new data: GZK confirmed + (?) primary UHECR heavier than p (?) Fermi LAT Ahlers et al. bestfit, consistent with HiRes spectrum and Fermi LAT diffuse gamma s GZK neutrinos after Fermi LAT diffuse photon flux measurement M.Ahlers et al., Astropart. Phys. 34, 106 (2010) Ahlers and Halsen updates of lower limits (normalization to Auger data) Minimal Cosmogenic Neutrinos arxiv: v1, 21 Aug /8/

17 K+al p Max K+al p extreme (A+H (A+H p 10%) p 1%) A+H p A+al p best fit 9/8/

18 K+al p extreme K+al p Max IC 86 (10years) AUGER (Xyears) ARA (3years) 30xEUSO (1year) (A+H (A+H p 10%) p 1%) A+H p A+al p best fit 9/8/

19 K+al p extreme K+al p Max IC 86 (10years) AUGER (Xyears) ARA (3years) 30xEUSO 800 km 1 year 1200 km (A+H (A+H p 10%) p 1%) A+H p A+al p best fit 9/8/

20 IC 86 (10years) AUGER (Xyears) ARA(3years) 30xEUSO 800 km 1 year 1200 km Fe Si N He p 9/8/

21 One optical system (EUSO like) Multi mirror H (km) Total FoV ( o ) Radius on ground (km) Area on ground (10 3 km 2 ) Target volume (w.e. km 3 ) Pixel on ground (km x km) 0.8 x x x x0.8 number of pixels) (.8x.8 km 2 ) 270k 786k 3000k 7000k Pupil diameter (m) Photo detection efficiency 50% 50% 50% 50% 50% 50% E threshold (EeV) Proton events/year, GKZ + uniform source distrib k 300k 2000k 1200K 2700k with E p >100 EeV) Neutrino events per year ( min) Neutrino events per year ( Max) Neutrino events per year (bestfit) Neutrino events per year (px100%) Neutrino events per year (px10%) Neutrino events per year (px1%) /8/

22 h= 1200 km h= 400 km (EUSO Φ=2m) Px1% Px10% Px100% best fit min Max 1 seuso x 2.5 ø=10 ø=30 seuso x 2.5 ø=6 ø=18 seuso x 2.5 ø=4 ø=12 9/8/

23 Conclusions: Cosmogenic neutrino detection is crucial for the neutrino entering the scene as a new instrument for Astrophysics, Cosmology and Particle Physics New data have diminished their foreseen flux by at least 2 orders of magnitude If the p component in UHECR is abundant, complex large optical systems can observe cosmogenic neutrinos from space, but high altitude orbits could be necessary If the heavy nuclei component prevails its daugter cosmogenic neutrino flux is out of reach for any system. (also because the neutrino energy becomes too small for detection by radio systems) In next few years the increase of UHECR statistics and the definition of their charge should help in clarifying the situation. 9/8/

24 Could you follow me? Thank you! 9/8/

25 golden Fluorescence only Xmax Select. Shape Select. Rejection > /8/

26 Florescence light attenuation as a function of the FoV Area of the calotta (10 6 Km 2 ) (EUSO) Attenuation factor (respect to Nadir) attenuation due to geometry attenuation due to atmosphere * TOTAL attenuation Area of the calotta Area seen by EUSO (EUSO x 3) 0 (EUSO) distance from Nadir (Km) 1/2 FoV (EUSO=1.7x10 6 km 2 ) *Considered from the sea level 9/8/2013 HORIZON 26

27 INOA 8 7 Resolution of 5 m EDP reflecting system Spherical mirror with ± 25 FOV gres (km) Spherical mirror with ± 15 FOV Spherical mirror + Schmidt corrector Spherical mirror + Schmidt corrector optimized at marginal field angles spot radius size (micron) Aspherical mirror + Schmidt corrector 0 0 0,0 5,0 10,0 15,0 20,0 25,0 FOV (deg) 9/8/

28 Active thin mirror concept Ideal form Strutture is deformed and deforms the membrane Attuators compensate the deformation The optical surface is coupled to a structure of light rigid supports by a matrix of actuators, adjusted on the measurements of the wave front 9/8/

29 9/8/

30 deployment d trigger data handling telemetry sensors single mirror field of view total field of view 9/8/