Neutrino mass spectroscopy using atoms/molecules M. Univ. yoshimura 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 2 vs

What our experiment can measure Indivisual masses; Hierarchy pattern; NH vs IH Distinction of Majorana vs Dirac mass type CPV phases; yoshimura 3 Majorana MD common ( cosmic background of 1.9 K may also be measurable )

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

Theory of experimental principles and numerical results yoshimura 5

RENP amplitude Atomic de-excitation: process certainly existing in electroweak theory, assuming finite neutrino masses and mixing yoshimura 6 E1 x M1 transition of atomic electron weak QED

6 threshold locations yoshimura 7 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=10 21 /cc – V=100 cc – Assumed: field energy efficiently stored in atomic system yoshimura (1)Atomic factor with macro coherence (3) Spectrum: mixing + kinematics (2) Field energy stored in atomic system (1) (2) (3) 8

Typical experiment would involve Measure increased CW signals, or Measure emergence of PV quantities Repeat with different to get spectrum yoshimura 9

RENP rate formula & spectrum yoshimura 10 Decomposed into 3 factors Dynamical factorcalculated 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 2 L. – Phase decoherence time (T 2 ) must be longer than T SR For a process with plural outgoing particles Phase matching condition (momentum conservation) is satisfied. Coherent volume is not limited by., can be macroscopic. yoshimura 11 Details confirmed by simulation of master equation in 1+1 dim

Threshold weights yoshimura 12 Determined by using oscillation exp. data CPV phase dependence

Observables: photon energy spectrum yoshimura 13 Xe NH IH

Near the threshold region yoshimura Absolute masses: Thresholds for (m i,m j ) NH-IH distinction:  0 E  [eV] 14

Dirac vs Majorana & CP phases yoshimura E  [eV] 15  0 We need to go to the lower energy to see M-D distinction or CP phases. Eeg= eV Epg= eV [ref] D.N. Dinh, S. Petcov, N. Sasao, M. Tanaka, and M. Yoshimura, PLB A. Fukumi et al., PTEP (79 pages) D-NH M-IH CPV

How can Majorana vs Dirac distinction arise ? yoshimura Weight at thresholds M1( ) x E1( ) 16 Majorana 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 yoshimura 17

Twin process and its control PSR can be background ? yoshimura 18 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. yoshimura 19 We need weaker PSR for macro-coherence development of RENP

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

PSR dynamics clarified by simulations (MB eq.) yoshimura 21 [ref] M. Yoshimura, N. Sasao and M.Tanaka, arXiv: v1 [quant-ph] PRA With no coherence, a large target relaxation time is required

Recent progress in PSR dynamics 2 yoshimura 22 Explosive events expected!. ~ 70% of stored energies are released within a few nsec. Life time shortened by  process natural life time :  ~ sec. Required relaxation time O[ns]

How target population and polarization is developed yoshimura 23

Dynamical factor for RENP yoshimura 24 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 yoshimura 25 Many solitons inside, but no PSR from edges

Experimental status yoshimura 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 yoshimura homonuclear diatomic molecule 27

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  532nm683nm pH 2 1 atm at 77 K (density of ~10 20 cm 3 ) 532:5 GW/cm 2 683:5 GW/cm 2 detuning  5 mJ, 8 ns, Diam ~ 200  m 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) Raman sidebands

yoshimura 30

Nd:YAG out 355nm (150mJ/p) Dye-out(500nm)=24 mJ/p Dye BBO BBO-out (250nm) 3.5 mJ Nd: YAG (1064nm → 355nm) Xe gas inlet UV lens Vacuum gauge Fluorescence detectors Monochromator ・（ CCD/Photo-diode/PMT ） Xe gas chamber Pulsed Dye laser Pulsed YAG laser (1 – 100 Torr) Dichroic mirror Xe spectroscopy for RENP

Transverse direction λ p =252.4nm 1.2 mJ input f=500mm Xe 50 Torr 1sec Longitudinal direction λ p =252.4nm 2.0 mJ input f=500mm Xe 50 Torr 1sec Pump calibrated Monochromator Spectrum

Observed spectrum following two-photon excitation from Pump wavelength ： 252.4nm Pump power : 1.8 mJ/p Xe density: 100 Torr Focus: f500mm excitation ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ① ② ⑤ ⑥ ⑧ ⑩ ④ ③ Monochromator Pump ⑨ ⑦

ND Filter slit φ1mm Band-pass Filter (820nm) Photo Diode (φ11.3mm) 225mm180 Gaussian-fitting: FWHM = 2.82 mm focus lens removed 823nm fluoreacense Xe cell Dichroic θ=2.82/180 = rad=0.90° 1mm θ 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 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 35

backup yoshimura 36

37 Observability of relic neutrino hep-ph/ Pauli blocking effect yoshimura

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

Soliton formation as static remnants yoshimura 39 R-, L-moving fields, and medium polarization are confined

PSR dynamics (1) yoshimura 40

41 Superradiance: 2 level and 1 photon case Rate enhanced by N Delayed enhanced signal accompanied by ringing yoshimura

Effective 2-level model for trigger and medium evolution 42 yoshimura 2 level interaction with field Ba

Bloch vector and Maxwell-Bloch equation yoshimura 43 Phase condition Bloch vector Bilinears in amplitudes Without relaxation

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Present status of neutrino physics Oscillation experiments – Finite mass – Flavor mixing – Only mass-squared difference can be measured. yoshimura e [|U ei | 2 ]  [|U  i | 2 ]  [|U  i | 2 ] Normal (NH)Inverted (IH)  m 2 atm =(50meV) 2 sin 2  13  m 2 sol    (Mass) }    } or  m 2 sol =(10 meV) 2  m 2 atm 45

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

47 M vs D in 2-component equations yoshimura In terms of 2-spinor Lepton number manifestly violated Lepton 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) yoshimura 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 yoshimura 49 Topologically stable soliton Stability guaranteed Both absorber and emitter exist