Neutrino Physics – a theoretical Perspective Manfred Lindner 8. Mai 2013 M. Lindner, MPIK . , Oct. 10-12, 2017 1
Neutrino Sources Astronomy: à ß Sun Supernovae GRBs UHE n ‘s ß Cosmology Reactors à ß Atmosphere Accelerators à b -Sources à ß Earth M. Lindner, MPIK . 2
n ’s as Messangers: Two Pictures of the Sun Fusion processes: Surface:6000 ° K 15 million degrees Energy à surface: < 170.000 years > Neutrinos à surface: 2.3 seconds light neutrinos à Important contributions to the understanding of the sun (a star) M. Lindner, MPIK . 3
SOHO Surprise: Rapidly Rotating Solar Core SOHO - g-mode pressure waves: Differential rotation grows inside the sun: factor ~4 Will have impact on Standard Solar Model: - energy transport - metallicity (may resolve problems or make them bigger) M. Lindner, MPIK . 4
Neutrino Astronomy IceCube: exciting results no identified point sources yet – maybe soon… see talks by E. Resconi and K. Mannheim M. Lindner, MPIK . 5
Neutrino Picture of the Earth geo-neutrinos – an interesting subject, but no time reactor-neutrinos – later in the talk M. Lindner, MPIK . 6
Bottom-up: Add Neutrino Masses to the SM Simplest and suggestive possibility: add 3 right handed singlets (1 L ) n R n R n L n R g N x n _ _ c æ ö æ c ö 0 m è ( ) n n ç D ÷ ç L ÷ ç ÷ ç ÷ x Majorana L R n m M è ø è ø R / < f > = v D R L like quarks and charged +9+ new ingredients: è SM+ 6x6 block mass matrix leptons è Dirac mass terms 1) Majorana mass = scales block diagonalization M R heavy è 3 light n ’s (including NMS mixing) 2) lepton number violation M. Lindner, MPIK . 7
Other Possibilities add scalar triplets (3 L ) or add fermionic (1 L ) or (3 L ) n L n L n L n L è left-handed Majorana 1,3 3 x x mass term: M L LL c x x _ Both n R and new singlets / triplets: m n =M L - m D M R -1 m D T è see-saw type II, III Higher dimensional operators: d=5, … _ è M L LL c M. Lindner, MPIK . 8
Radiative neutrino mass generation Add: more neutrinos, SUSY, extra dimensions, … è huge number of papers on neutrino masses... ... but we know only two D m 2 ... (plus mass & unitarity bounds) è neutrino masses can/may solve two of the SM problems: - leptogenesis as explanation of BAU - keV sterile neutrinos as excellent warm dark matter candidate even for n R è BSM physics often connections to LFV, LHC, DM M. Lindner, MPIK . 9
3 Light massive Neutrinos (...assumed) Mass & mixing parameters: m 1 , D m 2 21 , | D m 2 31 | , sign( D m 2 31 ) diag(e i a , , e i b ,1 ,1) n e n µ µ n t Known: - two D m 2 , three mixing angles - bounds on m 1 - weak indications for d CP and MH questions: è Dirac ~ SM / Majorana = BSM è mass scale: m 1 è mass ordering: sgn( D m 2 31 ) è is q 23 maximal? normal inverted è CP violation hierarchical or degenerate M. Lindner, MPIK . 10
The Status of Neutrino Parameters (assume 3 flavours) See e.g. Esteban, Gonzalez-Garcia, Maltoni, Martinez-Soler, Schwetz Absolute mass limits: Tritium decay: Mainz and Troitsk experiments: m 1 < 2.2 eV Limits from cosmology: 0.17-0.25 eV Future: KATRIN è will start measurements soon è 0.2eV ECHO, Project8 , … M. Lindner, MPIK . 11
The future of three Neutrino Oscillations Precision oscillation physics now and in the next years Now: Reactors: Double Chooz, Daya Bay, RENO + Beams: T2K, NO n A 1709.10252 Rodejohann, ML, Xu è global fits...: better q ij and certain significance for d CP (no mass hierarchy) Future: JUNO, T2HK, DUNE, PINGU, ORCA, … Precision çè çè how much do we learn about flavour, fermion masses, …? Depends on obtained precision and values: E.g. d CP = 0+1 ° or d CP =76+1 ° M. Lindner, MPIK . 12
The Value of Precision 3 Flavour n Physics • Remember: Many theoretical options… • Precise measurements test mass models e.g. based on flavour symmetries ßà many models... ßà exclude some or learn something generic? • Majorana masses ßà ßà leptogenesis = explanation of BAU ßà ßà related to heavy Majorana CP phases ßà detection of d CP phase makes this more plausible ßà BUT: Don‘t forget it is only the light Dirac-like phase AND: Leptogenesis works also for Dirac neutrinos • Neutrinos are a 0.6% HDM component ßà ßà cosmological structure formation ßà ßà DM in the universe • Precision may open the door for more new physics ßà ßà test of 3 flavour unitarity, over-constraining, ... M. Lindner, MPIK . 13
Sterile Neutrinos: Mass Spectra (for n R ) - N per se arbitrary 3x3 matrix 3xN NxN - M L , m D , M R could have 3 0 … N almost any form / values: - zeros (symmetries) ! $ ! $ _ c _ M L m D ν L - 0 + tiny corrections ( ) c # & # & ν L ν R - scales: M W , M GUT , … # & # & m D M R ν R " % " % è diagonalization: 3+N EV data: 3x3 PMNS matrix almost unitary (few %) M L =0, m D =O(GeV) M R singular M L =M R = 0 M R =high: see-saw singular-SS Dirac UPMNS ~ active sterile O( e ) O( e ) O(1) Antusch, Fischer M. Lindner, MPIK . 14
è at most small admixtures of sterile neutrinos Weak indications for sterile neutrinos: Particle Physics: LSND,Gallium, MiniBooNE, reactor anomaly,… BBN: Extra n ’s possible: N n ~ 3.7 + 1 E. Aver, K. Olive, E. Skillman, Y. Izotov, T. Thuan, … Astrophysics: keV-ish sterile neutrinos could explain pulsar kicks Kusenko, Segre, Mocioiu, Pascoli, Fuller et al., Biermann & Kusenko, Stasielak et al., Loewenstein et al., Dodelson, Widrow, Dolgov, … BUT: Tensions with cosmology… How to compare 2 s in cosmology with 2 s in particle physics? Certainly not all evidences true, but one would be enough: VERY IMPORTANT è experiments see talk by T. Lasserre M. Lindner, MPIK . 15
Searches for new Physics: NSI’s NSI’s ßà ßà new physics at high scales which is integrated out Z’, new scalars, … è e ij è tests high energy scales: e = = 0.01 ßà ßà TeV Grossman, Bergmann+Grossman, Ota+Sato, Honda et al., Friedland+ Lunardini, Blennlow+Ohlsson+Skrotzki, Huber+Valle, Huber+Schwetz+ Valle, Campanelli+Romanino, Bueno et al., Kopp+ML+Ota, … M. Lindner, MPIK . 16
NSIs interfere with Oscillations NSI contributions to the “golden” channel the “golden” oscillation channel interference in oscillations ~ e çè çè FCNC effects ~ e 2 M. Lindner, MPIK . 17
NSI: Offset and Mismatch in q 13 Redundant measurements: Double Chooz + T2K *=assumed ‘true’ values of q 13 scatter-plot: e values random - below existing bounds - random phases NSIs can lead to: - offset - mismatch è redundancy è interesting potential Kopp, ML, Ota M. Lindner, MPIK . 18
Double Beta Decay If neutrinos have Majorana masses è Lepton Number Violation è Neutrinoless Double Beta Decay BUT: Be careful about the inverted reasoning! M. Lindner, MPIK . 19
Double b -Decay & Mass Parabolas S Q Special nuclei: odd-odd even-even • single b decay nergeticallyforbidden 76 Zn 76 Rb • double b decay allowed è GG-nuclei: 76 Ge, … b + b - 76 Ga 76 Kr 76 Br EC b - 76 As 76 Ge b - b + Q bb bb = 2039 keV 76 Se 30 31 32 33 34 35 36 37 Z Important: Isotopes with forbidden single b decay 76 Ge: Only double b decay è SM: 2 n + 2e - *OR* 2e - Further double beta isotopes… M. Lindner, MPIK . 20
The Standard Picture of Double Beta Decay 2 nb nbb 2 nbb decay seen for diff. isotopes (Kirsten,…) T 1/2 = O(10 18 - 10 21 years) è up to 10 11 ⊗ T Universe SM 0 nb nbb decay 0 nb nbb 2 nb nbb decay M ajorana mass T 1/2 > O(10 25 y) • observe 2 nb nbb • look for 0 nb nbb signal at Q bb bb 1/ t = G(Q,Z) |M nucl | 2 <m ee > 2 1/ • large amount of 0 nb nbb nuclei • extreme low backgrounds! NMEs have è signal = Majorana mass uncertainties… M. Lindner, MPIK . 21
m ee : The Effective Neutrino Mass Comments: • cosmology: m < 0.2-0.3 eV • 0 nbb nbb : m ee < 0.1-0.3 eV • NMEs è unavoidable theory errors • known D m 2 from oscillations è yellow/blue areas è improved sensitivity is very promising! • warnings: - assumes no *other* D L=2 physics - assumes no sterile neutrinos, ... M. Lindner, MPIK . 22
More general: L Violating Processes 2 nb nbb exp. search unchanged… 0 nb nbb decay SM 2 nb nbb decay 0 nb nbb …interpretation changes: BSM T 1/2 > 0 nb nbb O(10 25 y) some D L=2 operator M. Lindner, MPIK . 23
Other Double Beta Decay Processes Standard Model: + è 2 electrons + 2 neutrinos 2 nb nbb Majorana n -masses or other D L=2 physics: è 2 electrons 0 nb nbb … SM+Higgs triplet SUSY SM + Higgs triplet SUSY Majorana neutrino masses important connections to LHC and LFV … ßà ßà Dirac? ßà TeV scale physics sub eV Majorana mass ßà M. Lindner, MPIK . 24
Extreme Cases m e m e from other D L=2 physics m ee from Majorana neutrinos only and no other D L=2 physics with Dirac neutrino masses and anything in-between M. Lindner, MPIK . 25
m e m’ ee interferences growing m e for fixed 0 nb nbb à shifts of masses, mixings and CP phases à destroys ability to extract Majorana phases à sensitivity to TeV M. Lindner, MPIK . 26
Recommend
More recommend
