neutrino mass spectroscopy using atoms/molecules m. yoshimura @okayama univ
DESCRIPTION
On behalf of SPAN collaboration. Neutrino mass spectroscopy using atoms/molecules M. Yoshimura @Okayama Univ. Search for the missing link of micro- and macro- worlds. Plan of this talk. Introduction Experimental principles of neutrino mass spectroscopy using atoms/molecules - PowerPoint PPT PresentationTRANSCRIPT
Neutrino mass spectroscopy using atoms/molecules
M. Yoshimura @Okayama Univ.
yoshimura 02/05/2013 @Milano 1
Search for the missing link of micro- and macro- worlds
On behalf of SPAN collaboration
Plan of this talk
• Introduction • Experimental principles of neutrino mass spectroscopy using atoms/molecules
• Radiative emission of neutrino pair ( RENP ) vs Paired superradiance(PSR) • Measurables: largest neutrino mass, IH vs NH, Majorana vs Dirac distinction,
Majorana CP phases• Macro-coherence development , Formation of solitons• Experimental status on pH2 PSR, Xe RENP experiments
yoshimura 02/05/2013 @Milano2
vs
What our experiment can measure
• Indivisual masses; • Hierarchy pattern; NH vs IH• Distinction of Majorana vs Dirac mass type• CPV phases;
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Majorana MD common
( cosmic background of 1.9 K may also be measurable )
Principle of the experiment
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| |e g De-excitation of excited atom:
Observe photon spectrum:
Spectrum has information on:Absolute massMixing angle or phasesMajorana/Dirac distinctionCPV phases
( )12 13 13 12 13, , i i
eiU c c c s e s e
4
Table top exp.
Combined weak + QED
RENP amplitude• Atomic de-excitation: process certainly existing in electroweak theory, assuming finite neutrino masses and mixing
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E1 x M1 transition of atomic electron
weakQED
6 threshold locations
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Macro-coherence, needed for rate enhancement, assures the momentum and the energy conservation of 3-body process, giving the threshold locations (ignoring atomic recoil)
Decomposition into neutrino mass eigenstates made possible by precision of trigger laser frequency
Easily accurate to mu eV, hence sensitive to meV neuMass
Rate estimate of RENP
• RENP rate• For Xe
– n=1021/cc– V=100 cc
– Assumed: field energy efficiently stored in atomic system
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(1) Atomic factor with macro coherence
(3) Spectrum: mixing + kinematics
(2) Field energy stored in atomic system
2 26 1 5 50 2 1
6 , 5 6 3 / 2 , 5 6 3 / 2g p S e p s p p s
0 1 mHz (1) (2) (3)
8
222
0 3 2
1 ( )( )
pgF s ij ij
ijpg pg
n VC G B I E
E E E
Ε
Typical experiment would involve
• Measure increased CW signals, or• Measure emergence of PV quantities• Repeat with different to get spectrum
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RENP rate formula & spectrum
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Decomposed into 3 factors
Dynamical factor calculated by numerical integration of master eq.
interference term due to Majorana identical pair emission
Overall rate
Spectral shape
Rate amplification by macroscopic coherence
• Super-radiance coherent volume– In case of SR, coherent volume is proportional to 2L.– Phase decoherence time (T2) must be longer than TSR
• For a process with plural outgoing particlesPhase matching condition (momentum conservation) is satisfied.Coherent volume is not limited by ., can be macroscopic.
yoshimura 02/05/2013 @Milano
1 2 3
2
2( )1 2 3forRat 0e j
Ni r
ak k
tmj
ke M k kN k
2
2Rate for | |j
Nik r
atm j lj
e M N r r
11
Details confirmed by simulation of master equation in 1+1 dim
Threshold weights
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Determined by using oscillation exp. data
CPV phase dependence
Near the threshold region
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Absolute masses:
Thresholds for (mi,mj)
2
2 2i jeg
ijeg
eg e g
m mE
E
E E E
NH-IH distinction:
1, 2 3
2 2 223 12 13
Neutrino parameters:
( , ) (2,20,50) meV
, , 0.42,0.31,0.025
m m m
s s s
0
E [eV]
14
Dirac vs Majorana & CP phases
yoshimura 02/05/2013 @Milano
E[eV] E[eV]
15
0
We need to go to the lower energy to see M-D distinction or CP phases.
Eeg= 0.429 eVEpg= 0.446 eV
[ref] D.N. Dinh, S. Petcov, N. Sasao, M. Tanaka, and M. Yoshimura, PLB
A. Fukumi et al., PTEP (79 pages)
D-NHM-IH
CPV
How can Majorana vs Dirac distinction arise ?
yoshimura 02/05/2013 @Milano
Weight at thresholds
M1( ) x E1( )
16Majorana phases
Majorana field
Dirac field
(Majorana case)
Rate proportional to
Easiness of measurables
• Largest neutrino mass from the kink of spectrum
• IH vs NH distinction• Majorana vs Dirac distinction• Majorana CP phases
Last two requires < O(0.4) eV energy difference
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Twin process and its control
• PSR can be background ?
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RENP: E1 x M1 Weak PSR: E1 x M1
PSR can be dangerous, but controlable with soliton formation,giving confined field condensate that trigger RENP
Can coexist for heavy atoms/molecules
Paired Super-Radiance (PSR)
• Macro-coherent amplification– A new type of coherent phenomena– Should be established experimentally
• Two photon emission process
• Paired Super-Radiance– QED instead of weak process– Good experimental signature; i.e. back-to-back radiations with same
color.
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| |e g
19
We need weaker PSR for macro-coherence development of RENP
Master equations for PSR and trigger: medium polarization coupled with two-mode fields
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: 2 types of relaxation
Density matrix for mixed states
PSR dynamics clarified by simulations (MB eq.)
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[ref] M. Yoshimura, N. Sasao and M.Tanaka, arXiv:1203.5394v1 [quant-ph] PRA
With no coherence, a large target relaxation time is required
Recent progress in PSR dynamics 2
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Explosive events expected!.
~ 70% of stored energies are released within a few nsec.
Life time shortened by 1025
2 process natural life time : ~ 1016 sec.
Required relaxation time O[ns]
Dynamical factor for RENP
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Without soliton formation,large PSR outputs from target ends
With soliton formation,exponentially small PSR leakage
Spatial profiles of solitons
pH2 case
Time variation
From trigger to PSR, soliton formation and RENP
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Many solitons inside, butno PSR from edges
PSR experiment with para-H2
• Vibrational transitions of solid para-H2 are good candidates.– Well quantized rotational and
vibrational states– Dipole forbidden and two-photon
allowed– Long decoherence time
yoshimura 02/05/2013 @Milano
homonucleardiatomicmolecule
27
27 Dec. 2012, X00 meeting
Gas or Solid pH2?
Two photon Rabi frequency
g e
(v= 1)
(v= 0)
Realistic parameters:
27 Dec. 2012, X00 meeting
How much coherence can be expected?
v=1,J=0
v=0,J=0
532nm 683nm
pH2 1 atm at 77 K (density of ~1020 cm3 )532: 5 GW/cm2
683: 5 GW/cm2
detuning 5 mJ, 8 ns, Diam ~ 200 m
Numerical simulation solving Maxwell-Bloch equationF.L. Kien et al., Phys. Rev. A60, 1562 (1999)Simulation code by Prof. Ohfuti, Prof. Katsuragawa (UEC)
-4 -2 0 2 4 6 8 10
Raman sidebands
Nd:YAG out355nm (150mJ/p)
Dye-out(500nm)=24 mJ/p
Dye
BBOBBO-out (250nm)3.5 mJN
d: Y
AG
(106
4nm
→ 3
55nm
)
Xe gas inlet
UV lens
Vacuum gauge
Fluorescence detectorsMonochromator ・( CCD/Photo-diode/PMT )
Xe gas chamber
Pulsed Dye laser
Pulsed YAG laser
(1 – 100 Torr)
Dichroic mirror
Xe spectroscopy for RENP
823.10
827.98
834.68
881.90
895.24 904.51916.15
Transversedirection
λp=252.4nm1.2 mJ inputf=500mmXe 50 Torr1sec
Longitudinaldirection
λp=252.4nm2.0 mJ inputf=500mmXe 50 Torr1sec
840.92
Pump
823.18
895.26
calibrated
calibrated
Monochromator
Monochromator
Spectrum
823.27
827.99
834.67840.87
882.01
895.05
905.18916.74
980.30
992.46
Observed spectrum followingtwo-photon excitation
221
2/325 ][5/2p6)P(p5
121
2/325 ][1/2p6)P(p5
321
2/325 ][5/2p6)P(p5
121
2/325 ][3/2p6)P(p5
221
2/325 ][3/2p6)P(p5
021
2/325 ][1/2p6)P(p5
221
2/325 ][3/2s6)P(p5
121
2/325 ][3/2s6)P(p5
nm32.992
nm55.904
nm23.895
nm16.823
nm01.828
nm94.881
nm73.1083
nm97.979
nm27.916
nm92.840
121
2/325 ][1/2s6)P(p5
nm68.834
221
2/125 ][3/2p6)P(p5
021
2/325 ][1/2s6)P(p5
from
Pump wavelength : 252.4nmPump power : 1.8 mJ/pXe density: 100 TorrFocus: f500mm
excitation
①
②
③
④
⑤
⑥
⑦⑧
⑨
⑩
①
②
⑤
⑥
⑧
⑩
④
③
Monochromator
Pump
⑨
⑦
ND Filterslit φ1mm
Band-pass Filter(820nm)
Photo Diode (φ11.3mm)
225mm180
Gaussian-fitting:FWHM = 2.82 mm
focus lens removed823nm fluoreacense
Xe cell Dichroic
0 80
2θ=2.82/180 =0.01567rad=0.90°
1mm
2.822θ
180
Angular distribution of 823nm fluorescence in laser direction
summary
• Experimental detection of RENP possible with soliton formation (development and control of two-photon mode)
• Perhaps 1st discovery after RENP identification is the largest neutrino mass, NH vs IH distinction
• Next is MD distinction• Majorana CP measurement is harder
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37
Observability of relic neutrino hep-ph/0703019
• Pauli blocking effect
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38
Threshold reduction 1/2x1/2 = 1/4 Temperature measurement possible ?Case of laser irradiated pair emission
For m_1 < 1meV, temperature measurement is not difficult
Photon energy
Relative
rate
yoshimura 02/05/2013 @Milano
Soliton formation as static remnants
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R- , L-moving fields, and medium polarization are confined
41
Superradiance: 2 level and 1 photon case
Rate enhanced by N Delayed enhanced signalaccompanied by ringing
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Effective 2-level model for trigger and medium evolution
42yoshimura 02/05/2013 @Milano
2 level interaction with field
Ba
Bloch vector and Maxwell-Bloch equation
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Phase conditionBloch vector
Bilinears in amplitudes
Without relaxation
Present status of neutrino physics
• Oscillation experiments– Finite mass– Flavor mixing– Only mass-squared difference can
be measured.
yoshimura 02/05/2013 @Milano
e [|Uei|2]
[|Ui|2]
[|Ui|2]
Normal (NH) Inverted (IH)
m2atm=(50meV)2
sin213
sin213
m2sol
(Mass)
}
}or
m2sol=(10 meV)2
m2atm
45
Prospect of Neutrino Physics
Mixing ( angles ・
phases )
Majorana ( =, phases
)
_Mass structure
( Absolute: difference
NH/IH)
Neutrino Spectroscopywith Atoms
Neutrino-less Double beta-decay
Neutrino OscillationExperiments
Cosmology andParticle Physics
Known/unknownsIn neutrino Physics
Measured
Present and Future Neutrino Physics
( Understandings of matter-dominated Universe, origin of Mass, GUT)
Physics beyond Standard Model
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47
M vs D in 2-component equations
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In terms of 2-spinor
Lepton number manifestly violatedLepton number conserved
Lepto-genesis• Leading theory to explain the matter-antimatter
imbalance of our universe• Prerequisite: lepton number violation, CP violation• Enhanced expectation due to discovery of finite
neutrino mass in neutrino oscillation experiments• Sensitivity to low energy parameters Davidsson-Ibarra,
NPB648, 345(2003)
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For RENPTo RENP, minimize PSR output and maximize stored solitonsSoliton results as final static remnants of master eqs.Its analytic profile (spatial) is known for special cases.It has a spinorial topological character and stable against PSRBoth absorber and emitter existStationary solutions are aggregate of balanced absorbers and emitters
without net PSR at target ends (long target required).Ideal form of target for precision neutrino mass spectroscopy
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Topologically stable solitonStability guaranteed
Both absorber and emitter exist