Neutrino mass spectroscopy using atoms/molecules M. Yoshimura @Okayama Univ.

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;


Majorana MD common

( cosmic background of 1.9 K may also be measurable )

Principle of the experiment

yoshimura 　 02/05/2013 @Milano

| |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

Theory of experimental principles and numerical results


RENP amplitude• Atomic de-excitation: process certainly existing in electroweak theory, assuming finite neutrino masses and mixing


E1 x M1 transition of atomic electron

weakQED

6 threshold locations


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


(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


RENP rate formula & spectrum


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.


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


Determined by using oscillation exp. data

CPV phase dependence

Observables: photon energy spectrum


Xe

NH

IH

Near the threshold region


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


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 ?


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


Twin process and its control

• PSR can be background ?


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.


| |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


: 　 2 types of relaxation

Density matrix for mixed states

PSR dynamics clarified by simulations (MB eq.)


[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


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]

How target population and polarization is developed


Dynamical factor for RENP


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


Many solitons inside, butno PSR from edges

Experimental status


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


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


backup


37

Observability of relic neutrino hep-ph/0703019

• Pauli blocking effect


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


Soliton formation as static remnants


R- , L-moving fields, and medium polarization are confined

PSR dynamics (1)


41

Superradiance: 2 level and 1 photon case

Rate enhanced by N Delayed enhanced signalaccompanied by ringing


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


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.


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


47

M vs D in 2-component equations


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)


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


Topologically stable solitonStability guaranteed

Both absorber and emitter exist

Neutrino mass spectroscopy using atoms/molecules M. Yoshimura @Okayama Univ.

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