The Story of Neutrinos. Naba K Mondal DAE Raja Ramanna Fellow Saha Institute of Nuclear Physics, Kolkata

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1 The Story of Neutrinos Naba K Mondal DAE Raja Ramanna Fellow Saha Institute of Nuclear Physics, Kolkata

3 Elementary particles + Higgs 3

4 Birth of Neutrino 4

5 Project Poltergeist 1956 v e p e e n o e o n Cd (several) Signal, then several ~few ms later Reines Cowan 5

6 Where neutrinos come from? Neutrinos from Big bang: 330 n/cm 3 ; E n ~ 4 X 10-4 ev Decoupled about 1 min. after the Big bang Neutrinos from Sun: Sun burns through nuclear Reaction E n ~ 0.1 ~ 0 MeV; Flux ~10 1 /cm /s 4p 4 He + e - +n e + Explosion of Star: Most of the binding energy released When a neutron star is born is emitted in the form of neutrinos E b ~10 53 ergs, E n ~10-30 MeV, T ~10 sec 6

accelerators UHE ( 10 1 ) ev Neutrinos : AGN, GRBs Cosmic Ray sources ( > 5 X 10 19 ev)

7 Where do neutrinos come from? Atmospheric neutrinos: Neutrinos from Man made activities: Neutrinos produced by particle accelerators UHE ( 10 1 ) ev Neutrinos : AGN, GRBs Cosmic Ray sources ( > 5 X ev) Radioactivity at the core of the earth: Power ~16 Terra Watts. Flux ~ 6 X 10 6 /cm /sec. Reactor Neutrinos: E n ~ 4 MeV, Flux ~5 X 10 0 /sec from a standard nuclear plant. 7

8 Close Encounter with Neutrinos Every second Your body receives About a trillion neutrinos from the sun 50 billion neutrinos from the natural radioactivity of the earth billion neutrinos from nuclear plants all over the world Our body contains about 0 milligrams of 40 K which is b radioactive. We emit about 340 millions neutrinos/day. Which run from our body at the speed of light until the end of the universe. Good news - Typically a neutrino has to zip through 10,000,000,000,000,000,000 people before doing anything. 8

How to Detect Neutrinos from Sun? 1946: B. Pontecorvo : 37 Cl + n e 37 Ar + e -, E th = 0.

9 How to Detect Neutrinos from Sun? 1946: B. Pontecorvo : 37 Cl + n e 37 Ar + e -, E th = MeV First Attempt by Ray Davis: Burried a 1000 gallon tank of C Cl 4 near the reactor at Brookhaven. Put limits on neutrinos from Sun as < neutrinos-cm - sec : Davis built 100,000 Gallon Chlorine Experiment in Homestake mine. 9

10 Homestake Solar Neutrino Detector 10

11 Homestake results 11

12 We don t get enough Something wrong with our understanding of the Sun? or may be Neutrino behaves differently compared to other particles? 1

13 13 For neutrinos weak eigenstates may be different from mass eigenstates. In a weak decay one produces a definite weak eigenstate Neutrino Oscillations n n n n n n m cos sin sin cos 1 1 e n n e (0) n n n sin cos ) ( 1 1 t ie ie t e e t f f e e t C t C n n ) ( ) ( E L m L P E m E m m E E t E E t P f e f e sin sin ) ; ( ] ) ( 1 [ sin sin ) ; ( n n n n First proposed by Bruno Pontecorvo in 1957, followed by Maki, Nakagawa & Sakata in 196 and finally refined by Pontecorvo in 1967

14 KamLAND SNO Super-K 14

15 Puzzle solved 15

16 Atmospheric Neutrinos 16

17 Atmospheric neutrinos India connection Physics Letters 18, (1965) 196, dated 15th Aug 1965 Atmospheric neutrino detector at Kolar Gold Field

18 Atmospheric neutrinos at KGF Proton Decay Detector

19 3 flavor neutrino mixing PMNS matrix km/gev 500 km/gev Mass Eigenstates labelled by decreasing n e content Flavor States Mass Eigenstates 19

20 Representation in terms of mixing angles U = x diag( ) Atmospheric Reactor & Interference Solar U = 0

21 Flavor content of mass eigenstates m sol m atm ev ev sin 1 sin 3 ~ ~

22 Three flavor oscillation probabilities Survival probabilities: (in vacuum) P n n ) 1 4 U i U j sin ji mij L 4E i j m 1.7 ev ij ij L km GeV E P n n ) e e 4 1 sin sin cos 13 sin 1 sin 1 13 ee n m n ) P m 1 4cos sin 1 cos sin ) sin mm 1) ee and mm 3 31

23 Measurement of 13 Daya Bay RENO Double Chooz 3

24 Nu_e Disappearance P n n ) e e 1 sin sin 13 ee 4 cos sin 13 1 sin 1 4

25 Measuring 13 with reactor neutrinos P ee 1 sin 13 sin m 31 L 4E n m cos 4 13 sin 1 sin 1 4E n L 5

26 Most important questions in neutrino physics today Neutrino mass ordering Mass Hierarchy What is the absolute mass of neutrinos? Why it is so small? CP violation in neutrino sector. Is neutrino its own antiparticle? The fun has just begun

27 Direct Measurement of neutrino mass 7

NOvA Detectors 9 PVC+Liquid Scintillator Mineral Oil

planes of orthogonal views muon crossing far end ~40

triggers for beam, SNEWS, cosmic ray calibration

29 NOvA Detectors 9 PVC+Liquid Scintillator Mineral Oil 5% pseudocumene Read out via WLS fiber to APD Layered planes of orthogonal views muon crossing far end ~40 PE 0.17 X 0 per layer DAQ runs with zero deadtime triggers for beam, SNEWS, cosmic ray calibration samples, exotic searches 150kHz of cosmic induced events APD

30 Extrusions 30

32 TK Experiment

33 33

34 Dominant flavour content of n 3 34

35 n m n ) n m disappearance in NOnA P m 4cos sin 1 cos sin ) sin mm 1 1) 1 sin sin mm 3 35

37 CP violation in neutrino sector

38 CP & 3 contour 38

39 Long Base Line Neutrino Facility, Fermilab to Sanford 39

40 DUNE Experiment at South Dakota

41 DUNE CP violation sensitivity

42 NP0

44 44

45 Proposed JUNO Experiment in China 45

47 INO INO Facilities at Pottipuram 47

48 A journey through RPC road 00 cm x 00 cm 30 cm x 30 cm 10 cm x 30 cm 100 cm x 100 cm 48

49 Fabrication of 1m x 1m RPCs 49

50 Final RPC Frontier - Making of m x m RPCs 5050

51 Prototype RPC Stack tracking Muons 51

52 Industrial production of RPC

53 Running of Prototype RPC Stack at Madurai ertionl since lst one yer 53

54 Some big astrophysics questions of our time which neutrino observations can help answer: Cosmic ray acceleration sites TeV gamma-ray sources Gamma-ray bursts GZK cutoff Dark matter, Supersymmetry 54

55 ICE CUBE South Pole 55

56 Making of ICECUBE 56

57 Ice Cube Amundsen-Scott South Pole station 57

58 58

59 Why India should be interested in a project like INO? Excitement of carrying out front ranking research in the exciting area of neutrino physics. Will address a key question in neutrino physics- Neutrino mass ordering. Help us to pick up the correct theory beyond Standard Model of particle Physics. Will learn how matter behaved at extremely high energies existed in the early stage of our universe. Will develop various cutting edge technologies for developing state of the art particle detectors. Massive 50 kton magnet particle detectors Sophisticated state of the art electronics Online monitoring and Data Acquisition System Science students across the country will have the opportunity to participate in building each of these components from scratch. Many are already doing it. It will create an ambiance of doing things with our own hands. A culture that is lacking in India 59

60 Collaborative Science Project No single institute in India has the ability or resources of doing it alone. Already 5 research institutes, universities and IITs have joined hands to build INO laboratory and ICAL detector. Some developing detectors. Some electronics Some working on various engineering aspects. Some optimising the detector using computer simulation. Culture of cooperation and collaboration is another benefit that will emerge from a mega science project like INO. 60

61 Thank You Thank You 61

62 Some interesting cosmic ray tracks 6

63 Prototype Magnet with RPC layers 63

64 RPC-DAQ 64

65 Block diagram of RPCDAQ 5V IN P/S 3.3V.5V 1.V ISP JTAG Header Config System + Flash Mem Reset POR Push Button 50MHz Osc 18 LVDS IN FrontEnd Connector LVDS IN Wiznet W5300 RJ45 MagJack FPGA Hits + Trigger EP4CE115F9C7 PreTrigger CalibOut LVDS Driver Backend Connector HPTDC TrigIn CalibIn Data Bus TrigIn G Clock JTAG 40 MHz CLK LEDs TPH Sensor System Spare Connections

66 NUANCE Simulation Framework Neutrino Event Generation ν a + X -> A + B +... Generates particles that result from a random interaction of a neutrino with matter using theoretical models. Output: i) Reaction Channel ii) Vertex Information Iii) Energy & Momentum of all Particles GEANT Event Simulation A + B +... through RPCs + Mag.Field Simulate propagation of particles through the detector (RPCs + Magnetic Field) Output: i) x,y,z,t of the particles at their interaction point in detector ii) Energy deposited iii) Momentum information Event Digitisation (x,y,z,t) of A + B noise + detector efficiency Add detector efficiency and noise to the hits Output: i) Digitised output of the previous stage (simulation) Event Reconstruction (E,p) of ν + X = (E,p) of A + B +... Fit the tracks of A + B +... to get their energy and momentum. Output: i) Energy & Momentum of the initial neutrino 66

67 Simulated Neutrino events in INO-ICAL Detector 67

68 KM3NeT ANTARES + NEMO + NESTOR - KM3NeT 68

Neutrino Physics: an Introduction

Neutrino Physics: an Introduction Lecture 2: Neutrino mixing and oscillations Amol Dighe Department of Theoretical Physics Tata Institute of Fundamental Research, Mumbai SERC EHEP School 2017 NISER Bhubaneswar,