from towards new physics Neutrino

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(1)from. Neutrino towards new physics Fabrizio Nesti for rica o G a 1 v 2 o 0 N 2/2 0. L’Aquila University. _. LHC. Astrophysics WR. νR. Flavor j. WR. j ℓ−. WL. WR. ℓ−. Cosmology. Higgs. 0νββ e−. WR. ν. e−. ν. νR h. ℓ− jets. WR. νR. ℓ−.

(2) Neutrinos, fundamental particles, are invisible. Optical microscope Eyes. Cosmology…. Electron microscope. Accelerators….. They don’t constitute matter, but they play an important role in nuclear reactions. Like radioactivity….

(3) So, the beginning: A Puzzle 1914 James Chadwick measures an unexpected continuous spectrum of beta rays. [Chadwick, Verh.Phys.Gesell. 1914]. 10 years of controversy. Experiments confirm in mid ‘20s… …energy not conserved???.

(4) So, the beginning: A Puzzle 1914 James Chadwick measures an unexpected continuous spectrum of beta rays. [Chadwick, Verh.Phys.Gesell. 1914]. 10 years of controversy. Experiments confirm in mid ‘20s… …energy not conserved???.

(5) The Beginning: Hypothesis 1930 Pauli introduces the missing particle, calls it “neutron”. (…aber nur wer wagt, gewinnt…). 1930-34 Chadwick discovers the real neutron (Nobel 1935) 1932-33 Fermi theory. He coins the new name: Neutrino (1933-37 Majorana… see later).

(6) How to see neutrinos They interact with matter Weakly - veeeery weakly:. • Inverse beta decay. ⌫e + n ! p + e. or. ⌫¯e + p ! n + e. +. • In water, it would take 1021cm ~ 1600 light years to interact. • …Pauli to his friend Walter Baade: Today I have done something which no theoretical physicist should ever do in his life: I have predicted something which shall never be detected experimentally! Baade, astronomer, apparently had great respect for experimentalists and so he bet Pauli that it will one day be detected..

(7) Where do they come from • Big Bang (very low energy, speed ~ 300km/s) • Stars and Supernovae (a lot but they are far) • Sun. (produces 1037 per second…. here “only” 1–10 billion per cm2 per second). • Nuclear plants (> 1023 per second !) • Natural radioactivity, including our body (~5000 per second from Potassium).

(8) The beginning: Discovery 1956 Reines+Cowan confirm antineutrinos from reactor (Reines nobel 1995) Poltergeist experiment: 400 l of a mixture of water and cadmium chloride (Cd) neutrinos (6 x1020 per second) very rarely interacted with the protons in the target (2.8 hr -1). γ γ. γ. n. γ. e. Scintillator H2O + CdCl2. +. γ. Scintillator. ν Pauli paid his bet to Baade (a case of Champagne)!.

(9) From today Grand Unified Neutrino Spectrum.

(10) Neutrino cross section. From eV to EeV: Neutrino Cross-Sections Across Energy Scales A. Formaggio, G. P. Zeller [1305.7513].

(11) The resonant W s=Q. 2. µ = (pe = m2e. µ 2 + p⌫ e ) + m2⌫ +. 2pe · p⌫ ' 2E⌫ me. Peak at E ~ MW2/2me ~ 802 103 GeV ~ 6.4 1015 eV.

(12) The resonant W s=Q. 2. µ = (pe = m2e. µ 2 + p⌫ e ) + m2⌫ +. 2pe · p⌫ ' 2E⌫ me. Peak at E ~ MW2/2me ~ 802 103 GeV ~ 6.4 1015 eV.

(13) IceCube finds W !. [Halzen 2021].

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(15) Their mass and Oscillations • It was theoretically clear that there had to be more (discovered νµ and ν𝜏 in 1962 and 2000). • 1957 - Pontecorvo predicts neutrino oscillations … •. …if they have mass.. • 1962 - Maki, Nakagawa, Sakata; 1969 - Gribov, Pontecorvo full theory. What are oscillations….

(16) Neutrino Oscillations Quantum Mechanics. • Nuclear reactions create superposition of states evolve with different energies: interference into νµ • Probability of transformation  P (⌫e ! ⌫µ ) = sin2 (2✓) sin2. (m21. m22 )L 4E. Mass! (Quantum mechanics at macroscopic distances! ). Distance E=Energy.

(17) Neutrino Oscillations Quantum Mechanics. • Nuclear reactions create superposition of states evolve with different energies: interference into νµ • Probability of transformation  P (⌫e ! ⌫µ ) = sin2 (2✓) sin2. (m21. m22 )L 4E. Mass! (Quantum mechanics at macroscopic distances! ). Distance E=Energy.

(18) Solar & “Atmospheric” neutrinos. A great flux of νe expected from fusion reactions.

(19) Mystery of solar neutrinos 1960-90 Bahcall predicts, Davis find solar neutrinos Homestake (Gold Mine in South Dakota) 1,478m underground, 380.000 liters of perchloroethylene, a common dry-cleaning fluid.. …but 2/3 missing…???. 2002 Nobel: Davis and Koshiba (Kamiokande) for their pioneering work on solar neutrinos after Bahcall’s model..

(20) Mystery of solar neutrinos 1960-90 Bahcall predicts, Davis find solar neutrinos Homestake (Gold Mine in South Dakota) 1,478m underground, 380.000 liters of perchloroethylene, a common dry-cleaning fluid.. …but 2/3 missing…???. 2002 Nobel: Davis and Koshiba (Kamiokande) for their pioneering work on solar neutrinos after Bahcall’s model.. 2020: last confirmation, observation of CNO neutrinos @ LNGS, L’Aquila.

(21) • The atmospheric neutrinos result from the interaction of cosmic rays with. “Atmospheric” neutrinos. ATMOSPHERIC NEUTRINOS atomic nuclei in the Earth atmosphere. • A shower of particles results from the interaction, the unstable particles ATMOSPHERIC NEUTRINOS produce neutrinos when they decay • Neutrinos reach the Earth at a certain Zenith angle. ✓ = 0 (downward) ✓ = ⇡ (upward). Atmospheric flux of νµ.

(22) MACRO • At LNGS, L’Aquila underneath soil as target looking for upgoing muons. • They found νµ disappearance! • .73 ± .09stat. ± .06sys. ± .12th. [S.Ahlen et al., Phys.Lett.B 1995 ]. • Needed more statistics… • They did not claim discovery..

(23) SuperKamiokande Started 1997 (T Kajita leader experiment, with M. Koshiba) 1,000 metres underground 50,000 tons of water, surrounded by 11,000 phototubes to detect flashes of light in the water. Actually built to observe Proton Decay - NDE=NucleonDecayExperiment.

(24) SuperKamiokande • νµ from above have no time to oscillate νµ from below yes. Do they disappear?. • Water detector = Cherenkov = directional!. • cuts background with direction (meaning they see well high energy νµ and not well solar νµ) So they measured variation of νµ with angle….

(25) TABLE I. Summary of the sub-GeV, multi-GeV, and PC event samples compared with the Monte Carlo prediction based on the neutrino flux calculation of Ref. [2].. SuperKamiokande result Sub-GeV Single-ring e-like m-like Multi-ring Total. Data. Monte Carlo. 2389 1231 1158 911. 2622.6 1049.1 1573.6 980.7. 3300 3603.3 R ≠ 0.63 6 0.03 sstat.d 6 0.05 ssyst.d. Multi-Gev Single-ring e-like m-like Multi-ring. • Up-down asymmetry. 520 290 230 533. 531.7 236.0 295.7 560.1. 1053. 1091.8. “less νµ from below”, confirms the oscillations. (and estimates parameters). Total. Partially contained 301 371.6 R FC1PC ≠ 0.65 6 0.05 sstat.d 6 0.08 ssyst.d. exhibit no excess of e-like events close to the fiducial boundary [6,7]. The prediction of the ratio of the nm flux to the ne flux is dominated by the well-understood decay chain of mesons and contributes less than 5% of the uncertainty in R. Different neutrino flux models vary by about 620% in the prediction of absolute rates, but the ratio is robust [13]. Uncertainties in R due to a difference in cross sections for ne and nm have been studied [14]; however, lepton universality prevents any significant difference in cross sections at energies much above the muon mass and thus errors in cross sections could not produce a small value of R in the multi-GeV energy range. Particle identification was estimated to be * 98% efficient for both m-like and e-like events based on Monte Carlo studies. Particle identification was also tested in Super-Kamiokande on Michel electrons and stopping cosmic-ray muons and the m-like and e-like events used in this analysis are clearly separated [6]. The particle identification programs in use have also been tested using beams of electrons and muons incident on a water Cherenkov detector at KEK [15]. The data have been analyzed independently by two groups, making the possibility of significant biases in data selection or event reconstruction algorithms remote. • Joint announcement:. MACRO: M.Ambrosio et al., Phys. Lett. B434(1998)451, hep-ex/9807005.. SOUDAN: Soudan 2 Coll., W.W.M. Allison et al., Phys. Lett. B449 (1999) 137 SuperKamiokande:Y.Fukuda et al., Phys. Rev. Lett. 81(1998)1562; Phys. Lett. B433(1998)9; …. FIG. 1. The sU 2 DdysU 1 Dd asymmetry as a functi of momentum for FC e-like and m-like events and P events. While it is not possible to assign a momentum a PC event, the PC sample is estimated to have a me neutrino energy of 15 GeV. The Monte Carlo expec tion without neutrino oscillations is shown in the hatch region with statistical and systematic errors added in quad ture. The dashed line for m-like is the expectation nm $ nt oscillations with ssin2 2u ≠ 1.0, Dm2 ≠ 2.2 1023 eV2 d.. sU 2 DdysU 1 Dd where U is the number of upwar going events s21 , cos Q , 20.2d and D is the num ber of downward-going events s0.2 , cos Q , 1d. T asymmetry is expected to be near zero independent of t flux model for En . 1 GeV, above which effects due the Earth’s magnetic field on cosmic rays are small. Bas on a comparison of results from our full Monte Carlo sim lation using different flux models [1,2] as inputs, tre ment of geomagnetic effects results in an uncertainty roughly 60.02 in the expected asymmetry of e-like a m-like sub-GeV events and less than 60.01 for multi-Ge events. Studies of decay electrons from stopping muo show at most a 60.6% up-down difference in Cherenk light detection [17]. Figure 1 shows A as a function of momentum f both e-like and m-like events. In the present data, t asymmetric as a function of momentum for e-like events.

(26) Sudbury Neutrino Observatory SNO.

(27) N. Tagg,6,11 N. W. Tanner,11 R. K. Taplin,11 M. Thorman,11 P. M. Thornewell,11 P. T. Trent,11 Y. I. Tserkovnyak,2 R. Van Berg,12 R. G. Van de Water,9,12 C. J. Virtue,7 C. E. Waltham,2 J.-X. Wang,6 D. L. Wark,15,11,9 N. West,11 J. B. Wilhelmy,9 J. F. Wilkerson,17,9 J. R. Wilson,11 P. Wittich,12 J. M. Wouters,9 and M. Yeh3 (SNO Collaboration). Sudbury Neutrino Observatory SNO 1. Atomic Energy of Canada, Limited, Chalk River Laboratories, Chalk River, Ontario K0J 1J0, Canada Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada 3 Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000 4 Department of Physics, University of California, Irvine, California 92717 5 Carleton University, Ottawa, Ontario K1S 5B6, Canada 6 Physics Department, University of Guelph, Guelph, Ontario N1G 2W1, Canada 7 Department of Physics and Astronomy, Laurentian University, Sudbury, Ontario P3E 2C6, Canada 8 Institute for Nuclear and Particle Astrophysics and Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 9 Los Alamos National Laboratory, Los Alamos, New Mexico 87545 10 National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada 11 Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom 12 Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396 13 Department of Physics, Princeton University, Princeton, New Jersey 08544 14 Department of Physics, Queen’s University, Kingston, Ontario K7L 3N6, Canada 15 Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, United Kingdom and University of Sussex, Physics and Astronomy Department, Brighton BN1 9QH, United Kingdom 16 TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada 17 Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, Washington 98195 (Received 19 April 2002; published 13 June 2002) 2. • Started 1997 (Arthur McDonald leader experiment) • 2,000 metres underground, • 2,000 tons of heavy water, • 11,000 phototubes to detect flashes of light • 1 nu per hour one third remain after oscillations. • Heavy water to see the appearance of the missing neutrinos!. Observations of neutral-current n interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard 8 B shape, the ne component of the 8 B solar flux is 10.09 P H Y S I6 C A22 VOLUME 89,fNeUMBER 1 Ls21R for E VaI kinetic E W Lenergy E T T threshold E R S of 5 MeV. The non-ne 1 JULY 2002 ! 1.7610.05 20.05 !stat"20.09 !syst" 3 10 cm 10.45 10.48 component is fmt ! 3.4120.45 !stat"20.45 !syst" 3 106 cm22 s21 , 5.3s greater than zero, providing strong evidence for solar ne flavor transformation. The total flux measured with the NC reaction is 10.46 6 22 21 fNC ! 5.0910.44 s , consistent with solar models. 20.43 !stat"20.43 !syst" 3 10 cm. 011301-1. 0031-9007#02# 89(1)#011301(6)$20.00. DOI: 10.1103/PhysRevLett.89.011301. The Sudbury Neutrino Observatory (SNO) detects 8 B solar neutrinos through the reactions:. © 2002 The American Physical Society. PACS numbers: 26.65. +t, 14.60.Pq, 95.85.Ry. [Phys Rev. Letters (2002)]. 011301-1. source. The deduced efficiency for neutron captures on deuterium is 29.9 6 1.1% for a uniform source of neu-.

(28) Kamland (2002).

(29) T2K (now). Beam of 0.6 GeV muon neutrinos.

(30) T2K (now). Beam of 0.6 GeV muon neutrinos. Latest results.

(31) Still (Reactor) anomalies….. [Dentler Hernandez JK Machado Maltoni Martinez Schwetz, 1803.10661].

(32) Oscillations nowadays confirmed completely •. Gallex/GNO-SAGE (solar νe, low Eν) (1990). •. SK (νatm), K2K & MINOS (νµ accel.) (1998). θ23 ∼ 45◦. •. KamLAND (anti νe react.) (2002). θ12 ∼ 34◦. •. Daya Bay and RENO T2K (anti νe react.) (2012). •. T2K (2020-21) excludes zero CP violation. •. LSND (νe from π+ at rest) DayBay. θ13 ~ 8.5◦ 𝛿CP ~ −2 ± 1.5. 1eV, θ14 ∼ few◦ ???.

(33) Oscillations nowadays confirmed completely • Thus neutrinos have a mass. • We find their mass differences, very tiny 2 m12. ' (0.01eV). 2. 2 m23. ' (0.05eV). 2. • The absolute value is still unknown (limited to be below ~0.2-0.5eV… cosmology, etc.).

(34) Graphical representation. (T2K preliminary result, mildly prefers normal ordering…).

(35) Intermezzo - Applications ? :) •. Probing inside the sun and stars (present) help understanding nuclear reactions, e.g. fusion. •. Neutrino astronomy (ongoing) e.g. IceCube - high energy neutrinos from outside our galaxy. •. Earth: Geoneutrinos, Earth Oscillograms. Radiogenic composition, study of Earth's density distribution… http:// arxiv.org/abs/hep-ph/0612285 http://arxiv.org/abs/1201.6080. •. Detection of undeclared nuclear plants (maybe?) (Secret Neutrino Interactions Finder - http://arxiv.org/abs/1011.3850). •. Communication… (hard) Demonstration of Communication using Neutrinos http://arxiv.org/abs/1203.2847. •. As energy source ( flat-earthers - high-profile pirates 🥺 ) https://neutrino-energy.com/.

(36) Multimessenger. Next frontier, neutrino + gravitational waves :).

(37) Theory… Theory is lagging behind. After 60 years, still no theory of neutrino masses, we ignore whether they are Majorana particles… Note. •. It would be easy to see the difference if one could stop them…. •. but the small mass and cross section makes this almost impossible.

(38) …theory.

(39) Theory for fundamental masses Look at the Standard Model. • Higgs field spontaneously breaks the symmetry [Nambu ‘60 Goldstone ’61 Higgs ’64 Weinberg ’67]. • …and provides the mass. coupling: 𝝀e H eL eR. Electron:. ⟷. mass: me eL eR. Mass m and coupling should be related….

(40) del are profiled. (Right) The 2D likelihood scan for the M and parameiled in the text. The cross indicates the best-fit values. The solid, dashed, show the 68%, 95%, and 99.7% CL confidence regions, respectively. The he SM expectation, ( M, ) = (v, 0), where v is the SM Higgs vacuum = 246.22 GeV.. LHC - The last triumph of the SM -1. -1. CMS. t. 1. V. λf or (g /2v)1/2. 19.7 fb (8 TeV) + 5.1 fb (7 TeV). WZ 68% CL. 10-1. 95% CL SM Higgs. τ. -2. 10. s u s r e v s e s s y s a Ma s dec g d g i e t c H e p x e s a. b. µ. (M, ε) fit. -3. 10. 68% CL 95% CL. 10-4. 0.1. 1. 10. 100. Particle mass (GeV). epresentation of the results obtained for the models considered in Fig. 12..

(41) Anything similar for neutrino masses? • We saw: neutrino mass differences (oscillations) ...thus nonzero neutrino mass.. • SM has only left neutrinos... ...no Higgs coupling M⌫ = 0. Need to go Beyond the Standard Model....

(42) 1937 Majorana disappears. ?. ho. W. His legacy goes on…. w a s. m i h.

(43) Masa nevtrinov Neutrino Masa gradnikov snovi. mass choice. 1928 - Dirac postavi relativisticno teorijo za elektron 1928 - Dirac postavi relativisticno teorijo za elektron. • 1928 - Dirac theory of the electron e- , mass defined by: mD eL eR mD eL eR. it predicts antimatter, i.e. the 1932 - Anderson odkrije pozitron (1932 - Anderson 1932 - Anderson odkrijediscovers pozitron it!). ⨂. ’31 napove antimaterijo ’31 napove antimaterijo positron e+. 1937 - Majorana najde enostavnejši opis za nevtrino. • 1937 Majorana theory of neutral particles mM ⌫ L ⌫ L. neutrinos can be their own antiparticles. ⨂ ⌫ ⌘ ⌫¯. Difference intimately linked to breaking of Parity….

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