Neutrino mass spectroscopy using atomsmolecules M Yoshimura Okayama

Neutrino mass spectroscopy using atoms/molecules M. Yoshimura @Okayama Univ. On behalf of SPAN collaboration Search for the missing link of micro- and macro- worlds yoshimura　02/05/2013 @Milano 1

Plan of this talk • Introduction　　 • Experimental principles of neutrino mass spectroscopy using atoms/molecules 　　　 • Radiative emission of neutrino pair （RENP） vs 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 p. H 2 PSR, Xe RENP experiments 　　　　 　　 yoshimura　02/05/2013 @Milano 2

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 ) yoshimura　02/05/2013 @Milano 3

Principle of the experiment Table top exp. De-excitation of excited atom: Combined weak + QED Observe photon spectrum: Spectrum has information on: Absolute mass Mixing angle or phases Majorana/Dirac distinction CPV phases yoshimura　02/05/2013 @Milano 4

Theory of experimental principles and numerical results yoshimura　02/05/2013 @Milano 5

RENP amplitude • Atomic de-excitation: process certainly existing in electroweak theory, assuming finite neutrino masses and mixing QED weak E 1 x M 1 transition of atomic electron yoshimura　02/05/2013 @Milano 6

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 e. V, hence sensitive to me. V neu. Mass yoshimura　02/05/2013 @Milano 7

Rate estimate of RENP • RENP rate • For Xe – n=1021/cc – V=100 cc (1) (2) (3) (1) Atomic factor with macro coherence (2) Field energy stored in atomic system – Assumed: field energy efficiently stored in atomic system (3) Spectrum: mixing + kinematics yoshimura　02/05/2013 @Milano 8

Typical experiment would involve • Measure increased CW signals, or • Measure emergence of PV quantities • Repeat with different to get spectrum yoshimura　02/05/2013 @Milano 9

RENP rate formula & spectrum Decomposed into 3 factors Overall rate Spectral shape interference term due to Majorana identical pair emission Dynamical factor calculated by numerical integration of master eq. yoshimura　02/05/2013 @Milano 10

Rate amplification by macroscopic coherence • Super-radiance coherent volume – In case of SR, coherent volume is proportional to l 2 L. – Phase decoherence time (T 2) must be longer than TSR • For a process with plural outgoing particles Phase matching condition (momentum conservation) is satisfied. Coherent volume is not limited by l. , can be macroscopic. Details confirmed by simulation of master equation in 1+1 dim yoshimura　02/05/2013 @Milano 11

Threshold weights Determined by using oscillation exp. data CPV phase dependence yoshimura　02/05/2013 @Milano 12

Observables: photon energy spectrum NH IH Xe yoshimura　02/05/2013 @Milano 13

Near the threshold region Absolute masses: Thresholds for (mi, mj) G/G 0 NH-IH distinction: Eg [e. V] yoshimura　02/05/2013 @Milano 14

[ref] D. N. Dinh, S. Petcov, N. Sasao, M. Tanaka, and M. Yoshimura, PLB A. Fukumi et al. , PTEP (79 pages) Dirac vs Majorana & CP phases G/G 0 We need to go to the lower energy to see M-D distinction or CP phases. D-NH M-IH Eg [e. V] CPV Eeg= 0. 429 e. V Epg= 0. 446 e. V yoshimura　02/05/2013 @Milano Eg [e. V] 15

How can Majorana vs Dirac distinction arise ? M 1( 　)　 x E 1( 　) Majorana field Dirac field (Majorana case) Rate proportional to Weight at thresholds yoshimura　02/05/2013 @Milano Majorana phases 16

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) e. V energy difference yoshimura　02/05/2013 @Milano 17

Twin process and its control • PSR can be background ? RENP: E 1 x M 1 Weak PSR: E 1 x M 1 Can coexist for heavy atoms/molecules PSR can be dangerous, but controlable with soliton formation, giving confined field condensate that trigger RENP yoshimura　02/05/2013 @Milano 18

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-toback radiations with same color. We need weaker PSR for macro-coherence development of RENP yoshimura　02/05/2013 @Milano 19

Master equations for PSR and trigger: medium polarization coupled with two-mode fields Density matrix for mixed states : 　2 types of relaxation yoshimura　02/05/2013 @Milano 20

[ref] M. Yoshimura, N. Sasao and M. Tanaka, ar. Xiv: 1203. 5394 v 1 [quant-ph] PRA PSR dynamics clarified by simulations (MB eq. ) With no coherence, a large target relaxation time is required yoshimura　02/05/2013 @Milano 21

Recent progress in PSR dynamics 2 n Explosive events expected!. n n ~ 70% of stored energies are released within a few nsec. Life time shortened by 1025 n 2 g process natural life time : ~ 1016 sec. Required relaxation time O[ns] yoshimura　02/05/2013 @Milano 22

How target population and polarization is developed yoshimura　02/05/2013 @Milano 23

Dynamical factor for RENP p. H 2 case Without soliton formation, large PSR outputs from target ends Time variation With soliton formation, exponentially small PSR leakage Spatial profiles of solitons yoshimura　02/05/2013 @Milano 24

From trigger to PSR, soliton formation and RENP Many solitons inside, but no PSR from edges yoshimura　02/05/2013 @Milano 25

Experimental status yoshimura　02/05/2013 @Milano 26

PSR experiment with para-H 2 • Vibrational transitions of solid para-H 2 are good candidates. – Well quantized rotational and vibrational states – Dipole forbidden and two-photon allowed – Long decoherence time homonuclear diatomic molecule yoshimura　02/05/2013 @Milano 27

Gas or Solid p. H 2? Realistic parameters: g e Two photon Rabi frequency (v = 1) (v = 0) 27 Dec. 2012, X 00 meeting

How much coherence can be expected? 532 nm v=1, J=0 683 nm d v=0, J=0 p. H 2 1 atm at 77 K (density of ~10 20 cm 3) 532: 5 GW/cm 2 683: 5 GW/cm 2 detuning d 5 m. J, 8 ns, Diam ~ 200 m Raman sidebands -4 -2 0 2 4 6 8 10 Numerical simulation solving Maxwell-Bloch equation F. L. Kien et al. , Phys. Rev. A 60, 1562 (1999) Simulation code by Prof. Ohfuti, Prof. Katsuragawa (UEC) 27 Dec. 2012, X 00 meeting

yoshimura　02/05/2013 @Milano 30

Nd: YAG (1064 nm → 355 nm) Xe spectroscopy for RENP Pulsed YAG laser Pulsed Dye laser Nd: YAG out 355 nm (150 m. J/p) BBO-out (250 nm) 3. 5 m. J Dye-out(500 nm)=24 m. J/p Xe gas chamber Xe gas inlet (1 – 100 Torr) UV lens Vacuum gauge Dichroic mirror Fluorescence detectors Monochromator・（CCD/Photo-diode/PMT）

Spectrum Transverse direction λp=252. 4 nm 2. 0 m. J input f=500 mm Xe 50 Torr 1 sec 881. 90 calibrated 823. 10 916. 15 827. 98 895. 24 904. 51 Monochromator 834. 68 840. 92 Pump Longitudinal direction λp=252. 4 nm 1. 2 m. J input f=500 mm Xe 50 Torr 1 sec 823. 18 calibrated 895. 26 Monochromator

② Observed spectrum following two-photon excitation ⑥ excitation ① Pump wavelength： 252. 4 nm Pump power : 1. 8 m. J/p Xe density: 100 Torr Focus: f 500 mm ⑧ ④ ⑤ ⑩ ⑦ from ③ ⑨ ① ⑤ 823. 27 882. 01 ② 827. 99 ③ 834. 67 ④ 840. 87 Pump Monochromator ⑦ 905. 18 ⑧ ⑥ 916. 74 895. 05 ⑩ ⑨ 992. 46 980. 30

Angular distribution of 823 nm fluorescence Band-pass Filter (820 nm) in laser direction Photo Diode (φ11. 3 mm) slit φ1 mm ND Filter Dichroic Xe cell 0 80 180 225 mm focus lens removed 823 nm fluoreacense 2θ 2. 82 Gaussian-fitting: FWHM = 2. 82 mm 180 2θ=2. 82/180 =0. 01567 rad=0. 90° 1 mm

summary • Experimental detection of RENP possible with soliton formation (development and control of two-photon mode) • Perhaps 1 st discovery after RENP identification is the largest neutrino mass, NH vs IH distinction • Next is MD distinction • Majorana CP measurement is harder yoshimura　02/05/2013 @Milano 35

backup yoshimura　02/05/2013 @Milano 36

Observability of relic neutrino hep-ph/0703019 • Pauli blocking effect yoshimura　02/05/2013 @Milano 37

Threshold reduction 1/2 x 1/2 = 1/4 Temperature measurement possible ? Case of laser irradiated pair emission Relative rate Photon energy For m_1 < 1 me. V, temperature measurement is not difficult yoshimura　02/05/2013 @Milano 38

Soliton formation as static remnants R- , L-moving fields, and medium polarization are confined yoshimura　02/05/2013 @Milano 39

PSR dynamics (1) yoshimura　02/05/2013 @Milano 40

Superradiance: 2 level and 1 photon case Rate enhanced by N yoshimura　02/05/2013 @Milano Delayed enhanced signal accompanied by ringing 41

Effective 2 -level model for trigger and medium evolution 2 level interaction with field Ba yoshimura　02/05/2013 @Milano 42

Bloch vector and Maxwell-Bloch equation Bilinears in amplitudes Phase condition Bloch vector Without relaxation yoshimura　02/05/2013 @Milano 43

yoshimura　02/05/2013 @Milano 44

• Oscillation experiments Present status of neutrino physics – Finite mass – Flavor mixing – Only mass-squared difference can be measured. (Mass) sin 2 13 2 3 } m 1 m 2 atm=(50 me. V)2 2 1 } or m 2 atm m 2 sol=(10 me. V)2 2 sol e [|Uei|2] [|U i|2] 3 sin 2 13 Normal (NH) Inverted (IH) yoshimura　02/05/2013 @Milano 45

　　Prospect of Neutrino Physics beyond Standard Model （Understandings of matter-dominated Universe, origin of Mass, GUT） Known/unknowns In neutrino Physics Present and Future Neutrino Physics Majorana _ Mass structure （ = , phases a, b） Neutrino Spectroscopy with Atoms （Absolute: difference NH/IH) Neutrino-less Double beta-decay yoshimura　02/05/2013 @Milano Cosmology 　　 and Particle Physics Mixing （angles ・phases d） Measured Neutrino Oscillation Experiments 46

M vs D in 2 -component equations In terms of 2 -spinor Lepton number manifestly violated Lepton number conserved yoshimura　02/05/2013 @Milano 47

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, NPB 648, 345(2003) yoshimura　02/05/2013 @Milano 48

For RENP To RENP, minimize PSR output and maximize stored solitons Soliton 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 PSR Both absorber and emitter exist Stationary 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 soliton Stability guaranteed Both absorber and emitter exist yoshimura　02/05/2013 @Milano 49