Precision Neutrino Studies in Astrophysics

1. Abingdon, Coseners House, 8 June, 2009 Flavour physics in the era of precision neutrino experiments: neutrinos in astrophysics and cosmology

2. What measurements on neutrino properties can we expect from cosmology/astrophysics? • How do they compare to terrestrial information? • How do we estimate the systematic errors in the measurement of neutrino parameters from cosmological observations? • What is the impact of a non-standard evolution of the Early Universe? • Are there particular models with interesting signatures in astrophysics/cosmology?

3. Neutrino masses: m1 < m2 < m3 Tritium  decay :me<2.3 eV (Mainz 95% CL) 0:m< 0.3 – 1.0 eV (Heidelberg-Moscow 90% CL, similar result by CUORICINO ) using the flat prior (0=1): CMB+BAO :  mi < 0.61 eV (WMAP5+SDSS) CMB+LSS + Ly : mi <0.17 eV (Seljak et al.)

7. USING WMAP3+SDSS-LRG+SNI-A HAMANN, STH, RAFFELT, WONG arXiv:0705.0979 (JCAP) IS EXCLUDED AT ABOUT 5 SIGMA! THIS RESULT IS CONSISTENT WITH WMAP-5

8. What measurements on neutrino properties can we expect from cosmology/astrophysics? • How do they compare to terrestrial information? • How do we estimate the systematic errors in the measurement of neutrino parameters from cosmological observations? • What is the impact of a non-standard evolution of the Early Universe? • Are there particular models with interesting signatures in astrophysics/cosmology?

9. A familiar starting point: neutrino oscillations 2-neutrino mixing „Solar“ neutrinos Atmospheric neutrinos Reactor Anti- Neutrinos (KAMLAND) SK-I+SK-II Best fit: Δm2 = 2.1 x 10-3 eV2 sin2 2θ = 1.02 Solar Neutrinos (SNO plus others) eV2

10. A more sofisticated description: 3-flavor mixing Maki-Nakagawa-Sakata-Pontecorvo matrix (Double b decay only) Solar,Reactor Atmospheric CP Violating Phase Reactor, Accel. Majorana Phases (Gonzalez-Garcia, Maltoni 08) Within a three-neutrino mixing framework different experimental observations get connected and new phenomenologies are potentially possible like CP violation

11. Combining the recent MINOS data with all other data there is an emerging preference for non-zero θ13 values (talk by Fogli at Neutrino Telescopes ´09)

12. Tri-bimaximal mixing This special form (Harrison, Perkins and Scott) corresponds to: and is currently compatible with the experimental data (barring the recent indication θ13  0 ) Tri-bimaximal mixing can be „rephrased“ in temrs of a m-t symmetry when one considers the neutrino mass matrix: Is tri-bimaximal mixing just a „game“ or could it be Regarded as a sign of „new Physics“ ?

13. Collective flavor transitions of supernova neutrinos

14. What measurements on neutrino properties can we expect from cosmology/astrophysics? • How do they compare to terrestrial information? • How do we estimate the systematic errors in the measurement of neutrino parameters from cosmological observations? • What is the impact of a non-standard evolution of the Early Universe? • Are there particular models with interesting signatures in astrophysics/cosmology?

15. (Steve Kingat Neutrino Telescopes ´09)

16. Leptogenesis and SO(10) models Using the parameterization: (PDB, Riotto ’08) • and assuming `SO(10)-inspired relations´: VL=1 and • the asymmetry produced from the lightest RH neutrinos is negligible andthe N2-dominated scenario is realized ! The green points correspond to at 2σ: 2=5

17. What measurements on neutrino properties can we expect from cosmology/astrophysics? • How do they compare to terrestrial information? • How do we estimate the systematic errors in the measurement of neutrino parameters from cosmological observations? • What is the impact of a non-standard evolution of the Early Universe? • Are there particular models with interesting signatures in astrophysics/cosmology?

18. A direct evidence for Dark Matter: the ‘bullet cluster’ Hot gas from X-ray observations Dark Matter from gravitational lensing

21. Astrophysical solution or new physics ?

27. Neutrinos are much lighter than all other fermions !

28. A minimal extension of the SM mD

29. See-saw mechanism: an open door to new Physics • Which is the origin (and the values and the number) of • the heavy neutrino masses Mi ? • How neutrino Yukawa couplings are related to those • of the other fermions ? • Why three families ? Reconstructing Mand mD would then provide a unique information on the theory beyond the SM embedding the see-saw mechanism

30. Is it possible to reconstruct mDand M from low energy neutrino experiments measuring mi and UPMNS ? An impossible task ? Parameter counting: On the other hand neutrino experiments give information only on the 9 parameters contained in  we need more information……from the R.H. or from the L.H. side !

31. Flavor symmetries Some basic features • Assume that the theory is invariant under transformations of a flavour symmetry group G (discrete or continuous) • ...and that this is spontaneously broken to a subgroup H through the VEV ‘s of a set of scalar fields φ (flavons) • η = <φ>/Λ << 1 • flavor symmetries can well embed the see-saw mechanism ! • In this case the matrices M and mD become functions of • η and in the limit η 0 they have special forms enforced • by the symmetry. For example defining • one has: Example:A4-symmetry  approximate tri-bimaximal mixing after symmetry breaking

32. (Albright, Chen)

33. (Albright, Chen)

34. (Steve Kingat Neutrino Telescopes ´09)

35. ¤CDM: a cosmological SM ? The mass-Energy budget today

36. A direct evidence for Dark Matter: the ‘bullet cluster’ Hot gas from X-ray observations Dark Matter from gravitational lensing

37. Cosmological Concordance Clusters of galaxies are a laboratory for studying and measuring Dark Matter in a variety of ways: gravitational lensing effects, x-ray, radio, optical ….

38. Dark matter Matter - antimatter asymmetry Inflation Accelerating Universe Puzzles of Modern Cosmology Leptogenesis  clash between the SM and CDM !

39. Matter-antimatter asymmetry of the Universe • Symmetric Universe with matter- anti matter domains ? Excluded by CMB + cosmic rays )B = (6.2 ± 0.15) x 10-10>> B • Pre-existing ? It conflicts with inflation ! (Dolgov ‘97) ) dynamical generation (baryogenesis) • A Standard Model Solution ? CMB (Sakharov ’67) by far too low ! New Physics is needed!

40. Leptogenesis (Fukugita,Yanagida ’86) Let us start from the simplest scenario („vanilla“ leptogenesis) (Blanchet,PDB ’08) 1) Flavor effects are negligible Total CP asymmetries If i≠ 0 alepton asymmetryis generated from Ni decays and partly converted into a baryon asymmetry by sphaleron processesif Treh 100 GeV ! (Kuzmin,Rubakov,Shaposhnikov, ’85) efficiency factors# of Ni decaying out-of-equilibrium

41. Total CP asymmetries (Flanz,Paschos,Sarkar’95; Covi,Roulet,Vissani’96; Buchmüller,Plümacher’98) It does not depend on U !

42. 2) Hierarchical heavy RH neutrino spectrum (Blanchet,PDB ’06) 3) N3 does not interfere with N2-decays: (PDB ’05) Under the last two assumptions In the end an unflavored N1-dominated scenario holds: It does not depend on U!

43. 4) Semi-hierarchical heavy neutrino spectrum )Upper bound on ε1 (Davidson, Ibarra ’02;Buchmüller,PDB,Plümacher’03;Hambye et al ’04;PDB’05 )

44. Main lessons from vanilla leptogenesis • The early Universe seems to „know“ neutrino masses... (Buchmüller,PDB,Plümacher ’04) decay parameter 2) ...and even better than we do  neutrino mass bounds ! Lower bound on M1 :M1  3x 109 GeV (Davidson,Ibarra;Buchmüller,PDB,Plümacher ’02) Lower bound on Treh :Treh  109 GeV (Buchmüller,PDB,Plümacher ’04) Upper bound on m1 :m1  0.12 eV (Buchmüller,PDB,Plümacher ’03)

45. Flavor effects (Nardi,Nir,Roulet,Racker ’06;Abada,Davidson,Losada,Josse-Michaux,Riotto’06) Flavor composition: It does not play any role only if If M1 1012 GeV-Yukawa interactions are fast enough to break the coherent evolution of and and  „tend“ to be projected one a 2-flavor basis: along the  and a coherent overposition of +e If M1 109 GeV then also- Yukawas in equilibrium 3-flavor regime heavy neutrino flavor index lepton flavor index

46. 2) The lower bounds on M1 and on Treh get relaxed: (Blanchet,PDB ’08) It dominates for |ij|1 but is upper bounded because of  orthogonality: It is usually neglected but since it is not upper bounded by orthogonality, for |ij|1 it can be important The usual lower bound gets relaxed

48. Beyond the hierarchical limit (Blanchet,PDB ‘06) Different possibilities, for example: • partial hierarchy: M3 >> M2 , M1 3 Effects play simultaneously a role for 2  1 : • Asymmetries add up • Wash-out effects add up as well • CP asymmetries get enhanced For 2  0.01 (degenerate limit) the first two effects saturate and:

49. N2-dominated scenario (PDB’05) 3 things happen simultaneously: For a special choice of =R23  The lower bound on M1 disappears and is replaced by a lower bound on M2 … that however stillimplies a lower bound on Treh ! Thanks to flavor effects the domain of applicability extends much beyond the particular choice =R23! ( Vives ’05; Blanchet, PDB ’06; Nardi,Nir ’07; Blanchet, PDB ’08)

50. N2-flavored leptogenesis ( Vives ’05; Blanchet, PDB ’06; Nardi,Nir ’07; Blanchet, PDB ’08) Thanks to flavor effects the domain of applicability extends much beyond the particular choice =R23! Wash-out is neglected Wash-out and flavor effects are both taken into account Unflavored case