Damping signatures in future neutrino oscillation experiments

Transcription

1 Damping signatures in future neutrino oscillation experiments Based on JHEP 06(2005)049 In collaboration with Tommy Ohlsson and Walter Winter Mattias Blennow Division of Mathematical Physics Department of Physics School of Engineering Sciences Royal Institute of Technology (KTH) Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.1/16

2 Outline Motivation and general introduction Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.2/16

3 Outline Motivation and general introduction Introduction and physical interpretation of damping factors Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.2/16

4 Outline Motivation and general introduction Introduction and physical interpretation of damping factors Suppressing θ 13 measurements Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.2/16

5 Outline Motivation and general introduction Introduction and physical interpretation of damping factors Suppressing θ 13 measurements Telling different damping effects apart Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.2/16

6 Outline Motivation and general introduction Introduction and physical interpretation of damping factors Suppressing θ 13 measurements Telling different damping effects apart Summary Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.2/16

7 Oscillation vs. other effects Not only neutrino oscillations have been considered as descriptions of the solar and atmospheric neutrino problems Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.3/16

8 Oscillation vs. other effects Not only neutrino oscillations have been considered as descriptions of the solar and atmospheric neutrino problems Examples of other options considered: Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.3/16

9 Oscillation vs. other effects Not only neutrino oscillations have been considered as descriptions of the solar and atmospheric neutrino problems Examples of other options considered: Neutrino decoherence Lisi et al., Phys. Rev. Lett. 85 (2000), 1166 Morgan et al., astro-ph/ Adler, Phys. Rev. D62 (2000), Ohlsson, Phys. Lett. B502 (2001), 159 Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.3/16

10 Oscillation vs. other effects Not only neutrino oscillations have been considered as descriptions of the solar and atmospheric neutrino problems Examples of other options considered: Neutrino decoherence Lisi et al., Phys. Rev. Lett. 85 (2000), 1166 Morgan et al., astro-ph/ Adler, Phys. Rev. D62 (2000), Ohlsson, Phys. Lett. B502 (2001), 159 Neutrino decay Bahcall et al., Phys. Rev. Lett. 28 (1972), 316 Barger et al., Phys. Rev. D25 (1982), 907 Valle, Phys. Lett. B131 (1983), 87 Barger et al., Phys. Rev. Lett. 82 (1999), 2640 Pakvasa, AIP Conf. Proc. 542 (2000), 99 Barger et al., Phys. Lett. B462 (1999), 109 Lindner et al., Nucl. Phys. B607 (2001), 326 Lindner et al., Nucl. Phys. B622 (2002), 429 Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.3/16

11 Oscillation vs. other effects Not only neutrino oscillations have been considered as descriptions of the solar and atmospheric neutrino problems Examples of other options considered: Neutrino decoherence Lisi et al., Phys. Rev. Lett. 85 (2000), 1166 Morgan et al., astro-ph/ Adler, Phys. Rev. D62 (2000), Ohlsson, Phys. Lett. B502 (2001), 159 Neutrino decay Bahcall et al., Phys. Rev. Lett. 28 (1972), 316 Barger et al., Phys. Rev. D25 (1982), 907 Valle, Phys. Lett. B131 (1983), 87 Barger et al., Phys. Rev. Lett. 82 (1999), 2640 Pakvasa, AIP Conf. Proc. 542 (2000), 99 Barger et al., Phys. Lett. B462 (1999), 109 Lindner et al., Nucl. Phys. B607 (2001), 326 Lindner et al., Nucl. Phys. B622 (2002), 429 Fits to experimental data favors neutrino oscillations, i.e.,... Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.3/16

12 Oscillation vs. other effects (2)... Super-Kamiokande data... Data/Prediction (null osc.) L/E (km/gev) Super-Kamiokande collaboration, Phys. Rev. Lett. 93, (2004), hep-ex/ Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.4/16

13 Oscillation vs. other effects (3)... and KamLAND data MeV prompt analysis threshold KamLAND data best-fit oscillation best-fit decay best-fit decoherence Ratio L 0 /E νe (km/mev) KamLAND collaboration, Phys. Rev. Lett. 94, (2005), hep-ex/ Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.5/16

14 General idea Even if effects are non-leading, they may still be present Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.6/16

15 General idea Even if effects are non-leading, they may still be present Attempt to describe a number of effects in a unified framework Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.6/16

16 General idea Even if effects are non-leading, they may still be present Attempt to describe a number of effects in a unified framework Probability level damping factor approach Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.6/16

17 General idea Even if effects are non-leading, they may still be present Attempt to describe a number of effects in a unified framework Probability level damping factor approach Caveat: Many, but not all effects can be described in this framework Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.6/16

18 Formalism The standard neutrino oscillation formula P αβ = ( ) J ij αβ exp i m2 ij 2p L i j Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.7/16

19 Formalism The damped neutrino oscillation formula P αβ = i j D ij J ij αβ exp ( i m2 ij 2p L ) D ij = exp ( α ij m 2 ij ξ L β E γ ) Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.7/16

20 Formalism The damped neutrino oscillation formula P αβ = i j D ij J ij αβ exp ( i m2 ij 2p L ) D ij = exp ( α ij m 2 ij ξ L β E γ ) The parameters α ij, β, ξ and γ are dependent on the particular effect Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.7/16

21 Formalism The damped neutrino oscillation formula P αβ = i j D ij J ij αβ exp ( i m2 ij 2p L ) D ij = exp ( α ij m 2 ij ξ L β E γ ) The parameters α ij, β, ξ and γ are dependent on the particular effect In many cases, the effective number of free parameters is reduced to one or two Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.7/16

22 Different effects Examples of different effects are: Damping type β γ ξ Wave packet decoherence Decay Oscillations to ν s Absorption Quantum decoherence I Quantum decoherence II 1 or Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.8/16

23 Two types of damping Most types of damping falls into one of two categories Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.9/16

24 Two types of damping Most types of damping falls into one of two categories Decoherence-like damping damps only the interference terms: Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.9/16

25 Two types of damping Most types of damping falls into one of two categories Decoherence-like damping damps only the interference terms: D ii = 1 α ii = 0 Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.9/16

26 Two types of damping Most types of damping falls into one of two categories Decoherence-like damping damps only the interference terms: D ii = 1 α ii = 0 β P αβ = 1 Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.9/16

27 Two types of damping Most types of damping falls into one of two categories Decoherence-like damping damps only the interference terms: D ii = 1 α ii = 0 β P αβ = 1 Includes: Neutrino wave-packet decoherence, neutrino quantum decoherence Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.9/16

28 Two types of damping Most types of damping falls into one of two categories Decoherence-like damping damps only the interference terms: D ii = 1 α ii = 0 β P αβ = 1 Includes: Neutrino wave-packet decoherence, neutrino quantum decoherence Decay-like damping acts independently on the mass eigenstates: Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.9/16

29 Two types of damping Most types of damping falls into one of two categories Decoherence-like damping damps only the interference terms: D ii = 1 α ii = 0 β P αβ = 1 Includes: Neutrino wave-packet decoherence, neutrino quantum decoherence Decay-like damping acts independently on the mass eigenstates: D ij = A i A j α ij = α i + α j Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.9/16

30 Two types of damping Most types of damping falls into one of two categories Decoherence-like damping damps only the interference terms: D ii = 1 α ii = 0 β P αβ = 1 Includes: Neutrino wave-packet decoherence, neutrino quantum decoherence Decay-like damping acts independently on the mass eigenstates: D ij = A i A j α ij = α i + α j β P αβ < 1 Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.9/16

31 Two types of damping Most types of damping falls into one of two categories Decoherence-like damping damps only the interference terms: D ii = 1 α ii = 0 β P αβ = 1 Includes: Neutrino wave-packet decoherence, neutrino quantum decoherence Decay-like damping acts independently on the mass eigenstates: D ij = A i A j α ij = α i + α j β P αβ < 1 Includes: Neutrino decay, neutrino absorption Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.9/16

32 Damped formulas (2f) Standard oscillation: P αβ = δ αβ +(1 2δ αβ ) sin 2 (2θ) sin 2 ( ) [ = m 2 /(4E)] Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.10/16

33 Damped formulas (2f) Decoherence-like damping: P αβ = δ αβ + (1 2δ αβ ) sin 2 (2θ) 1 D cos(2 ) 2 [ = m 2 /(4E)] Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.10/16

34 Damped formulas (2f) Decoherence-like damping: P αβ = δ αβ + (1 2δ αβ ) sin 2 (2θ) 1 D cos(2 ) 2 [ = m 2 /(4E)] Decay-like damping (only one decaying mass eigenstate): P αα = [ (c 2 + As 2 ) 2 A sin 2 (2θ) sin 2 ( ) ], P ββ = [ (Ac 2 + s 2 ) 2 A sin 2 (2θ) sin 2 ( ) ], P αβ = 1 4 sin2 (2θ)[1 + A 2 2A cos(2 )], Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.10/16

35 Damped probabilities (2f) The effect of damping on the neutrino survival probability P αα : 1 Pure oscillation 0.8 Survival probability Oscillation phase ( ) Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.11/16

36 Damped probabilities (2f) The effect of damping on the neutrino survival probability P αα : 1 Pure oscillation Oscillation + decoherence 0.8 Survival probability Oscillation phase ( ) Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.11/16

37 Damped probabilities (2f) The effect of damping on the neutrino survival probability P αα : Pure oscillation Oscillation + decoherence Oscillation + decay I Survival probability Oscillation phase ( ) Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.11/16

38 Damped probabilities (2f) The effect of damping on the neutrino survival probability P αα : Pure oscillation Oscillation + decoherence Oscillation + decay I Oscillation + decay II Survival probability Oscillation phase ( ) Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.11/16

39 Damped probabilities (3f) The general three-flavor formulas are complicated Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.12/16

40 Damped probabilities (3f) The general three-flavor formulas are complicated Series expansions in s 13 Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.12/16

41 Damped probabilities (3f) The general three-flavor formulas are complicated Series expansions in s 13 Approximations valid at different types of experiments Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.12/16

42 Damped probabilities (3f) The general three-flavor formulas are complicated Series expansions in s 13 Approximations valid at different types of experiments Example, for decoherence-like damping at a beam experiment, approximating 21 0: P eµ = 2s 2 23[1 D cos(2 )] s O(s 3 13) P µµ = sin2 (2θ 23 )[1 D cos(2 )] + O(s 2 13) Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.12/16

43 Larger θ 13? Phenomenological effects of damping? Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.13/16

44 Larger θ 13? Phenomenological effects of damping? Short-baseline reactor experiment measuring θ 13 Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.13/16

45 Larger θ 13? Phenomenological effects of damping? Short-baseline reactor experiment measuring θ 13 Effect with wave-packet decoherence signature Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.13/16

46 Larger θ 13? Phenomenological effects of damping? Short-baseline reactor experiment measuring θ 13 Effect with wave-packet decoherence signature One additional parameter necessary to fit to entire parameter space Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.13/16

47 Larger θ 13? (2) The result of including the decoherence parameter: 10 sin 2 2Θ 13 Σ E sensitivity for Reactor I 5 sin 2 2Θ 13 Σ E sensitivity for Reactor II 8 4 3Σ Fit value of ΣE MeV 6 4 1Σ 2Σ 3Σ Fit value of ΣE MeV 3 2 1Σ 2Σ Fit value of sin 2 2Θ Fit value of sin 2 2Θ 13 Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.14/16

48 What type of effect? How to identify the specific effect? Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.15/16

49 What type of effect? How to identify the specific effect? Baseline length fixed no information on β Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.15/16

50 What type of effect? How to identify the specific effect? Baseline length fixed no information on β Energy dependence is a better candidate Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.15/16

51 What type of effect? How to identify the specific effect? Baseline length fixed no information on β Energy dependence is a better candidate For a neutrino factory with L = 3000 km: Decoherence Decay Oscillations PΜΜ 0.4 PΜΜ 0.4 PΜΜ Σ E 0,1,2,3,4,5 GeV 0.2 Α 0,2,4,6,8, GeV km 0.2 Ε 0,1,2,3,4, ev E GeV E GeV E GeV Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.15/16

52 What type of effect? How to identify the specific effect? Baseline length fixed no information on β Energy dependence is a better candidate For a neutrino factory with L = 3000 km: Decoherence Decay Oscillations PΜΜ 0.4 PΜΜ 0.4 PΜΜ Σ E 0,1,2,3,4,5 GeV 0.2 Α 0,2,4,6,8, GeV km 0.2 Ε 0,1,2,3,4, ev E GeV E GeV E GeV Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.15/16

53 What type of effect? How to identify the specific effect? Baseline length fixed no information on β Energy dependence is a better candidate For a neutrino factory with L = 3000 km: Decoherence Decay Oscillations PΜΜ 0.4 PΜΜ 0.4 PΜΜ Σ E 0,1,2,3,4,5 GeV 0.2 Α 0,2,4,6,8, GeV km 0.2 Ε 0,1,2,3,4, ev E GeV E GeV E GeV Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.15/16

54 What type of effect? How to identify the specific effect? Baseline length fixed no information on β Energy dependence is a better candidate For a neutrino factory with L = 3000 km: Decoherence Decay Oscillations PΜΜ 0.4 PΜΜ 0.4 PΜΜ Σ E 0,1,2,3,4,5 GeV 0.2 Α 0,2,4,6,8, GeV km 0.2 Ε 0,1,2,3,4, ev E GeV E GeV E GeV Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.15/16

55 Summary and conclusions General formalism for treating effects such as neutrino decay and neutrino decoherence along with neutrino oscillations Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.16/16

56 Summary and conclusions General formalism for treating effects such as neutrino decay and neutrino decoherence along with neutrino oscillations Two classes of different damping types, decoherence-like and decay-like Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.16/16

57 Summary and conclusions General formalism for treating effects such as neutrino decay and neutrino decoherence along with neutrino oscillations Two classes of different damping types, decoherence-like and decay-like Formulas for the damping effects in two- and three-flavor scenarios Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.16/16

58 Summary and conclusions General formalism for treating effects such as neutrino decay and neutrino decoherence along with neutrino oscillations Two classes of different damping types, decoherence-like and decay-like Formulas for the damping effects in two- and three-flavor scenarios How damping effects may alter the determination of fundamental neutrino oscillation parameters Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.16/16

59 Summary and conclusions General formalism for treating effects such as neutrino decay and neutrino decoherence along with neutrino oscillations Two classes of different damping types, decoherence-like and decay-like Formulas for the damping effects in two- and three-flavor scenarios How damping effects may alter the determination of fundamental neutrino oscillation parameters How different damping effects may be distinguished Damping signatures in future neutrino oscillation experiments Mattias Blennow, KTH NuFact05, Frascati, Italy p.16/16