Vladimir Kravtsov Particles of the “”

Within the SM there are 3 different families of particles. Each has a associated with it.

Neutrinos are one of the fundamental particles and have only week interaction.

Neutrino has a zero mass, a zero charge and a 1/2.

Direct measurement of the neutrino mass by kinematical analysis of weak decays m 2.3eV e < m <170keV

m <18.2MeV

3/24/2011 2 CSU The sources of

Natural sources

10 2 ĭȞ = 6 × 10 Ȟcm 3 ʌʆ = 330/cm EȞ ׽ 0.1–20 MeV Eʆ =0.0004 eV

S-Kamiokande Relic Neutrinos Sun Neutrinos Solar Atmospheric Earth (Geo Ȟ) Supernovae BigBang

Artificial sources

Accelerators Reactors 3/24/2011 3 CSU A Brief History of the Neutrino

1914 The ȕ-decay energy conservation crisis. 1930 Pauli proposes a new neutral particle is emitted in ȕ-decay. 1932 Fermi names the new particle “neutrino” and introduces four-fermion interaction. 1956 The first observation of electron anti-neutrinos by Reines and Cowan. 1957 Bruno Pontecorvo proposes neutrino-antineutrino oscillations. 1962 Ziro Maki, Masami Nakagawa and Sakata introduce neutrino flavor mixing and flavor oscillations (MNSP matrix). 1962 The neutrino is observed at BNL. 1973 Discovery of neutral currents at CERN. 1998 Super-Kamiokande announced the evidence of atmospheric neutrino oscillations 2000 First direct evidence for the neutrino

3/24/2011 4 CSU Neutron ȕ decay Measured ɴ spectra Niels Bohr even suggested that perhaps energy were continuous instead of conservation did not hold inside the nucleus. discrete for 2-body decay “At the present stage of atomic theory, however, we may say that 1914 we have no argument, either empirical or theoretical, for upholding the energy principle in the case of ȕ-ray disintegrations”. - e 2 M nc E p + Ee Niels Bohr - n ĺSH 1930 Pauli proposed that a neutral particle shared the energy of beta decay with the emitted electron.

Wolfgang Pauli - e 2 M nc = E p + Ee + E - Ȟ 1934 n ĺSH + Ȟ Fermi builds a new theory of to explain ɴ-decay based on the current-current interaction and named a new particle “neutrino”.

Enrico Fermi 3/24/2011 5 CSU Discovery of Electron Neutrino (1956) The fist experimental detection came dŚĞŝŶǀĞƌƐĞɴĚĞĐĂLJƉƌŽĚƵĐĞƐƚǁŽƐŝŐŶĂůƐŝŶƚĂŶŬƐ from the high flux of neutrinos created ’s + in Savannah River reactor. e + p n + e Ȟ Cd e+ n p+ e+ + e + Scintillator Prompt signal producing two n+108Cd 109Cd 108Cd + 's 0.511 MeV Ȗ’s 110 5” PMTs Delayed signal from n capture on A few s later cadmium producing 9 MeV in Ȗ’s ʅ

Positron scope = (1.1 0.3) 10 43 cm2 Science 124 (1956) 103; Phys. Rev. 113 (1959) 273

The Nobel Prize in 1995 Water + CdCl 2 was awarded to Frederick Reines Liquid3/24/2011 scintillator tanks Neutron6 scope "for the detection ofCSU the neutrino" Discovery of Muon Neutrino (1962)

In 1962, Schwartz, Steinberger and Lederman built the very first Neutrino beam neutrino beam and presented evidence for the muon neutrino Main sources + + + + + K + Secondary sources + 0 + K + + + 0 + K + e + e + + e + e + 10-tonn spark chamber detector with Al plates

The Nobel Prize 1998 was awarded to Leon Lederman, ȝ- Melvin Schwartz and "for the neutrino beam method and the demonstration of the doublet + n + p structure of the through the discovery of the 3/24/2011 7 CSU 29 Ȟȝ interactions were registered muon neutrino " Discovery of (2000) 800 GeV from (FNAL) on Tungsten target produce Ds mesons

Decay of Ds meson DQGQH[WIJ lepton decay give ȞIJ

Ds + l + l + , l = e,

-13 IJIJ=2.9x10

ȞIJ

+ N + X

DONUT

e

IJ

9 clean ȞIJ CC events were observed 3/24/2011 8 CSU Phys. Rev. D 78 (2008) 052002 Neutral currents: triumph of the electro-weak unification (1973)

Weinberg and Salam develop a theory of electroweak interactions, but it requires a “neutral” weak current. CC NC The model introduces two types of weak interaction: Charged current (CC) and (NC).

+ e + e

Ȟȝ 1973

First example of + N + X NC CERN Ȟȝ - BEBC e

Big European Gargamelle bubble chamber Bubble Chamber 3/24/2011 9 CSU filled with freon (CF3Br) Large neutrino calorimeter type detectors

A large sampling calorimeters can measure large statistics CC and NC data

Neutrino cross section is very low

FNAL (700 GeV) CITF, HPWF, CCFR/NuTeV BNL (28 GeV) E-776, E-816 CERN (400 GeV) Aachen-Padova, CDHS, CHARM IHEP (70 GeV) IHEP-ITEP, IHEP-JINR

3/24/2011 10 CSU Large neutrino calorimeter type detectors goals 1. Cross section measurements

+ N + X - CC DIS + N + X - NC DIS + e + e - Ȟe-scattering

+ n + p - CC QE + p + p - NC Elastic + e + e - Inverse ȝ-decay 2. structure functions measurements

Bjorken scaling variables in the laboratory system - Energy transferred to nucleon - 4-momentum transfer In terms of the distribution functions

2 3. Measurement of sin șW SM parameters

Paschos–Wolfenstein relation removes NuTeV - the effects of sea quark scattering and is much less sensitive to heavy quark production 4. Beam-dump experiments Search prompt neutrinos from charm particles production, Higgs, axion, heavy neutrino, … 3/24/2011 11 CSU 5. Neutrino oscillations CERN: CHARM and CHARM-II (1986-1991) experiments

CHARM has a fine grained calorimeter with low Z target planes for good identification of electron from elastic Lje-scattering

/ Ee = 0.20 / Ee (GeV ) - electrons

/ E = 0.53/ E (GeV ) -

/ E = 0.09 + 0.15/ E (GeV ) - electrons Marble planes e e / E = 0.07 + 0.31/ E (GeV ) - hadrons

Glass planes

M=692 t 3/24/2011 12 CSU CERN: CDHS (1977-1983) experiment

CDHS experiment was designed to study CC DIS and NC DIS neutrino interactions. Detector combined the functions of a muon spectrometer and calorimeter.

CERN + N + X + N + X DORTMUND Di-muon event

HEIDELBERG / Ee = 0.23/ Ee (GeV ) - electrons

SACLAY / E = 0.56 / E (GeV ) - hadrons WARSAW

19 magnetized iron modules

M=1250 ton CSU FV=700 ton 13 FNAL: HPWF and NuTeV experiments

Calorimeter Neutrino target: liquid scintillator Active detector: spark chamber and scintillator planes / E =10 12%, 10 150GeV

Neutrino target: iron planes Active detector: drift chamber and scintillator planes

M=700 ton

3/24/2011 14 CSU Neutrino Oscillations 2 At t=0 we have a flavor eigenstates and 1 e which are both mixtures of mass eigenstates and 1 2: e e (0) = cos 1 + sin 2

(0) = sin 1 + cos 2 1 According to Schrödinger equation the mass 2 iE1t iE2t eigenstates 1 and 2 with energy E1 and E2 e (t) = 1 e cos + 2 e sin evolve in time as plane waves: r m2 (t) = e iE1t sin + e iE2t cos For relativistic E = p2 + m2 = p + 1 2 neutrinos (E >> m) 2E 3 Assuming the same energy for both 2 2 Ȟ (t) e i(p+m1 /2E Ȟ )t Ȟ sinș Ȟ e-it m /E Ȟ sinș neutrino components we can write: ȝ = 1 + 2 4 The transition probability is, then, given by with m2 m2 m2 2 2 = 1 2 2 it m / 2E P( e ) =| e (t) | = sin cos (1 e ) Fraction of remaining neutrinos 2 2 5 If we measure ȴŵ in eV , L in km, and E in GeV we can write the above as:

2 2 2 1.27 m L P( e ) = sin 2 sin ( ) E 2 2 2 1.27 m L 3/24/2011P( ) =1 sin 2 sin ( ) 15 CSU E Atmospheric Neutrinos Neutrino Oscillations Discovery (1998) Neutrinos are produced by cosmic ray interactions in Earth’s atmosphere

+ + + + + , e + + e Expectation ( + ) 2

+ , e + e + ( e + e ) SK was measured the

number of Ȟȝ and Ȟe interactions as a function of zenith angle 41.4m x 39.3m (Diameter) MC simulation 50 ktons of pure water tank with уϭϭ͕ϬϬϬ20” PMTs

Super-Kamiokande Particle identification is based on the pattern recognition of Cherenkov rings arising in water Muon - clean ring Electron – fuzzy ring

3/24/2011 16 CSU ( / e) Neutrino Oscillations Discovery (1998) R = Data ( / e)MC The registration efficiency for and electrons is very different R=1 if no oscillation Takeuchi, Neutrino 2010 At the Neutrino 98 conference, SK experiment presented new data on the deficit in muon neutrinos produced in the Earth's atmosphere. This deficit depends on the distance the neutrinos travel - an indication that neutrinos oscillate and have mass. R = 0.63 ± 0.03 ± 0.05 (sub-GeV) ȴm2=2.1x10-3 2 2 R = 0.65 ± 0.05 ± 0.08 (multi-GeV) sin ɽ13=0.0, sin ɽ13=0.5

June 5, 1998

The Nobel Prize in Physics 2002 was awarded to Masato Koshiba Ȟȝ–ȞIJ oscillation (best fit) “… for pioneering contribution to no oscillation astrophysics, in particular for the 3/24/2011 17 CSU detection of cosmic neutrinos" Member of the IHEP-JINR Collaboration from 1979 to 2000

Neutrino Detector Beam dump Experiment Search of the light Higgs bosons and Axion Limit on the charm production cross section Oscillation Experiment Total cross section measurement

3/24/2011 18 CSU IHEP-JINR Neutrino Detector Magnetic frame X DC Y DC LSC Al Plate

Ȟ

ȝ - spectrometer e/Ȗ - detector M=104 t 1.04 X0 Target calorimeter 0.35 LJabs LSC

The 70 mkm Mylar container with liquid scintillator is inserted into 3mm Al box. Amplitude vs Coordinate

MIP position resolution 3/24/2011 ѐX = 16 cm 19 CSU Neutrino Detector Calibration

Test beam with low momentum spread

The examples of events from pion, electron, Energy resolution vs momentum muon and neutrino interactions.

Hadrons

7.3%+34%/E1/2(GeV) e Ȟȝ

Electrons

0.1%+9.9%/E1/2(GeV)

Momentum, GeV/c 3/24/2011 20 CSU Beam dump Experiment

70 GeV beam

The 70 GeV proton beam with 1.21x1013 average proton intensity per accelerator pulse. Iron beam dump target was located in front of the 54 m long iron muon shield. The neutrino detector followed at a distance of 64 m downstream of the beam dump. In two runs 1.1x1018 and 0.6x1018 protons on target were collected with relative target densities of ʌ = 1 and ʌ = 3/24/2011 21 CSU Beam dump: Search of Light Higgs and Axion

Two Higgs doublets with 3 neutral Higgs. Two from these Four possible processes of production MSSM particles (one scalar H and one pseudoscalar A) can be light.

1/ 2 The couplings of (pseudo)scalar to fermions g Hf = i( 2GF ) m f s f g i( 2G )1/ 2 m p sf, pf – model dependent coupling constants Af = F f f

MSSM sf = FRVĮVLQȕpf FRWȕ [ for f = u, c, t 1. Coherent proton nucleus interaction sf = -VLQĮFRVȕSf WDQȕ [ for I GVEHȝIJ [ ȣȣ – ratio of vacuum expectations of Higgs doublets

SM sf = 1, pf = 0 PQ axion pf is the same as in MSSM The search was performed for decays into ȖȖ-, e+e-- and ȝ+ȝ-- pairs Cuts for ȖȖ- and e+e—

p1.a Eirelms > 3 GeV 2. No track at primary vertex 2. Parton parton interaction 3. Ehad < 1.5 GeV – resolution limit of reconstruction program

4. șelm < 0.05 rad

3. Initial state bremsstrahlung Cuts for ȝ+ȝ--pairs 1. Two long tracks (muons)

2. Pȝ > 3 GeV 2. ¨3ȝ/Pȝ < 30% 3. |Edep – Emip| < 0.5 GeV 3/24/2011 4. cosșmax22> 0.99 CSU 4. Bethe-Heitler process Beam dump: Search of Light Higgs and Axion, end x Scalar x Pseudoscalar

95% CL

mH, MeV mA, MeV

Higgs boson of SM was excluded for mH < 80 MeV a) Excluded by e+e- and ȖȖ decays b) Excluded by the e+e- Bethe-Heitler process Standard axion was excluded c) Excluded by the ȝ+ȝ- Bethe-Heitler process in the range 0.008 < X < 32 95% CL d) Excluded by a combined fit using a) and b) and for mass range 0.2 - 3.2 MeV for most x > 1 Particle Data Group, J. Phys. G 33, 1 (2006) 3/24/20110.2 - 11 MeV for most x < 1 23 CSU Beam dump: Charm Production Cross Section Three types of interaction were studied for estimation Cuts for Ȟe events of charm production cross section: 1. Eelm > 3 GeV 1. Prompt ʆe charged current interaction 3. Y = Ehad/(Eelm+Ehad) < 0.4 2. Prompt ʆʅ charged current interaction 3. “Equilibrium” or “rock” muons produced in neutrino Cuts for Ȟ events interaction at the end of muon iron shield. ȝ

1. Track length in ND • 3 Ȝabs 2. Track length in magnetized steel • 50 cm

Calculation of ”prompt” events number 3. Pȝ •*H9 a) Extrapolation method 4. Start of track in the fist plane of ND The charm production does not depend from target (for muons from muon shield only) density. The production of conventional neutrinos is proportionally to the inverse target density.

Nprompt = 2NNj  - NNj  – Ķ 1Nj  - NNj ) Ķ – correction for the leakage of hadrons shower Third order QCD b) Subtraction method at mc = 1.2 GeV and m = 1.5 GeV Subtraction of calculated contribution of conventional c neutrino interactions from the total number IHEP-ITEP of measured events.

ıcharm < 2.4 ȝb/nucleon (90% CL) SCAT at s = 11.5 GeV IHEP-JINR

3/24/2011 24 CSU Oscillation Experiment Measurement of Neutrino Total Cross Section Osc. experiment was initiated by paper of Prof. Conforto from Italy. He studied the results of 3 CERN experiments and was seeing some indication for oscilla- tions. These detectors where exposed at the same time but located at the different distance from target.

2 2 2 L P( e x ) = sin 2 sin 1.27 m E

G. Conforto, Nuo. Cim. 103 (1990) 751 Special neutrino beam with 12 m short decay length was

developed. The fraction of ʆe for such beam was 3.25% which is much higher than for standard neutrino beams.

The length of the decay cavity (L = 12 m) is short when compared to the distance from decay point to the detector (72 m average) and to the length of the neutrino detector (L = 25 m) .

Minimization of 2 = ( 1 R ) 2 with different L/E parameters Give possibility to study N exp (L / E) N bgd (L / E) 3/24/2011 L/E25 dependency R = CSU N MC (L / E) ND280 detector P0D calibration with ‘rock’ muons CC QE events in P0D First preliminary results of T2K experiment

3/24/2011 26 CSU T2K (Tokai to Kamioka) experiment First off-axis long baseline oscillation neutrino experiment with high power 30 GeV proton beam of J-PARC Main Ring

50-kT water Japan Cherenkov detector Proton Accelerator Research Complex

Kamioka Tokai 295 km

Tokyo J-PARC

3/24/2011 27 CSU Main Physics Goals

The Maki–Nakagawa–Sakata–Pontecorvo (MNSP) lepton mixing matrix

relates the mass eigenstates (Ȟ1,Ȟ2,Ȟ3) to the flavor eigenstates (Ȟe,Ȟȝ,ȞIJ)

1 0 0 cos 0 sin e i CP cos sin 0 e cos13 13sin 12 12 1 = 0 cos sin 0 1 0 sin cos 0 23 U23 = 12 12 2 i CP 0 sin cos sin e 0 cos 0 0 1 23 23 13 sin cos13 3 atmospheric, beam solar, reactor SK atm,K2K,MINOS, T2K , T2K SNO, KamLAND o o o o 2 = 45 8 12 = 33.9 1.2 23 sin 2 13 < 0.14(90%CL) 2 3 2 2 5 2 m23 ~ 2.5 10 eV m12 ~ 8 10 eV Measurements

Measure the mixing parameter DŽ13 by search Lje appearance 2 2 2 2 P( e ) sin 2 13 sin 23 sin (1.27 m13L / E )

2 Precise measurement DŽ23,|¨m23 | by observing LjĂ disappearance P( ) 1 sin 2 2 sin 1.27 m2 L / E 3/24/2011 23 28( 23 ) CSU Off-axis beam

• Neutrino energy depends on the angle relative • Narrow neutrino spectrum reduces the backgrounds to the beam axis in the electron neutrino measurement from DIS high • Increasing of the angle gives narrower neutrino energy interaction and the high energy beam spectrum like monochromatic narrow beam contamination • Off-axis angle was set to 2.5° where peak of • CC QE is dominant process in region of neutrino has an oscillation maximum spectrum at 2.5°

NuFact09

OA2.5° Neutrino flux, au flux, Neutrino

3/24/20110 0.5 1 1.5 2 2.5 3 3.5 4 CSU Energy, GeV 29 Sensitivity to ș13 Detection of appearance:

Reconstructed EȞ in CC QE interaction

8.3x1021 POT

0.006 at įCP = 0 5 years at 750 kW

2.4 10 3 eV 2

Main backgrounds

• beam Ȟe contamination

• NC ʌ0 events

3/24/2011 30 CSU 2 Sensitivity to ș23 and ǻm23 Detection of disappearance SK with oscillation

SK w/o oscillation Oscillation changes a form of neutrino spectrum

Present limits

21 K2K 8 x 10 POT SK

MINOS 90% CL T2K sensitivity

2 į sin 2ș23) <0.01 į ǻm 2) < 1 x 10-4 eV2 23 stat. error only

3/24/2011 31 CSU J-PARC accelerator facility

Near detectors

30 GeV proton accelerator

3/24/2011 32 CSU Near detectors

INGRID ND280

On-axis Off-axis Neutrino Beam Neutrino Detector Monitor

3/24/2011 33 CSU ND280 off-axis detector

SMRD ND280 detector consists of 5 subdetectors: • ›0 detector (PØD) - Optimized for CC ›0 and NC ›0 measurements

- Measures Lje contamination • Tracker: fine-grained detector (FGD) and time projection chambers (TPC) measures CC QE, CC 1› and NC 1› interactions • Electromagnetic calorimeter (ECAL) detects EM activities coming from PØD/Tracker • Side muon range detector (SMRD) identification of side-going muons All detectors housed in UA1/NOMAD magnet with field 0.2 T Detector was commissioned in March 2010 and now taking the data during 1 year

3/24/2011 34 CSU Top view of ND280 detector

FGDs

DSECAL P0D

TPCs

3/24/2011 35 CSU ʌ0 detector (P0D)

4 supermodules (p0dules) Upstream and Central Ecal Ȗ-catchers Lead/Scint sandwich

Upstream and Central Water Target Ecals P0D Water/Scint sandwich

17x35.5mm triangular bars

Scintillator detectors read out via WLS fiber coupled to Si MPPC: 667 pixel avalanche photodiode, area of 1.3x 1.3mm2 First large-scale use in HEP experiments: ~50,000 MPPCs for ND280

ǍP 3/24/2011 36 CSU Water Target SuperP0Dule First neutrino event at ND280

Magnet off

First neutrino event (INGRID)

CCQE event at Tracker

ȝ-

p

3/24/2011 37 CSU First neutrino event at SK

3rd ring

1st ring

nd 2010/2/24 6:00:06 2 ring 1st ring 2nd ring 3rd ring 3/24/2011 38 CSU P0D calibration with ‘rock’ muons ‘Rock’ muons are going outside to P0D muons produced at neutrino interaction on the outer matter that is mainly magnet steel, pit construction concrete and rock ground.

Bottom

Top X, mm

Y, mm

Energy deposition of muon was corrected by path length in scintillator y cosșX cosșY

z µ-

3/24/2011 Corrected 39 CSU path length cosșZ Charged current quasielastic neutrino interaction (CCQE) in P0D

CC QE

CC QE is dominant process in the region of T2K off-axis neutrino spectra at 2.5° and has simple 2-body kinematics

In the simplest case of invisible proton

EȞ can be calculated from measured momentum and angle of ȝ-

3/24/2011 40 CSU CCQE: POT’s, requirements, cuts, …

NEUT MC for study of backgrounds, reconstruction efficiency and purity of 1-track and 2-track CCQE events The total data PoT’s number is 2.84x1019 The total PoT’s number of NEUT MC is 1.3x1020 MC distributions were normalized to the total number of data PoT’s

Fiducial Volumes 1. Full P0D -3224 < Z < -1016 mm First 3 and last 1 P0Dules were excluded 2. Water Target -1236 < Z < -1348 mm 24 internal P0Dules 3. Central Ecal -3224 < Z < -1016 mm 5 internal P0Dules

Requirements and cuts 1. 1 or 2 track segments in TPC 2. Vertex should be at P0D Fiducial Volume 3. Long track should be negative 4. TPC PID corresponds to muon

Good PID via TPC dE/dx 3/24/2011 41 CSU CCQE: Full P0D True Vertex position Y, mm Y,

X, mm

Z, mm 3/24/2011 42 CSU CCQE: 1-track CCQE and backgrounds for selected events

Full P0D Water

~200-300 MeV shift b/w Data and MC due to the Global reconstructed CEcal momentum is not corrected for track energy loss in P0D

Small ~50-100 MeV shift b/w Data and MC for Cecal due to the short track length in P0D

The shift will be corrected in upcoming version of nd280 software 3/24/2011 43 CSU CCQE: 1-track CCQE and backgrounds angles for selected events

Full P0D Water

CEcal Nice agreement between Data and MC

3/24/2011 44 CSU First T2K preliminary results 2010a data were collected during Jan – June 2010.

2010a data • Total SK data: 3.23x1019 PoT (15.5 kW x 107s) • Stable running at 3.8x1013 PoT/spill (уϱϰŬtͿ shots up to 100 kW

SK event pre-selection was based on FV cuts, ring counting and PID.

ϴʆʅ and 2 ʆe candidates were selected for next analysis

3/24/2011 45 CSU Ȟȝ disappearance analysis

Number of events consistent with oscillation parameters measured by MINOS/SK/K2K

3/24/2011 46 CSU Final Ȟe event selection

Additional background rejection • no decay electron

• mȖȖ < 105 MeV assuming second ring exist

• reconstructed EȞ < 1250 MeV

When # of decay electron cut was applied only 1 candidate of ʆe event remains

3/24/2011 47 CSU Ȟe appearance analysis 90% CL upper limit at Upper bound of ș13 are evaluated m2 =2.4 10-3eV2, = 0 by 2 independent methods: 23 CP A: Feldman-Cousins B: Classical one-sided limit A Systematic uncertainties are took into account for both analysis. B

Normal hierarchy Inverted hierarchy

3/24/2011 48 CSU Backup slides

3/24/2011 49 CSU Future prospects

Run 2010b (from Nov 2010 – March 2011) • 9.3x1013 p/spill (8 bunches/spill/3.04s) • Max beam power: ~145 kW • Total data collected up to Mar 11: 1.45x1020 PoT (including run 2010a)

3/24/2011 50 CSU