Mass measurements needed for neutrino physics

Transcription

1 Mass measurements needed for neutrino physics Coherent Neutrino Scattering Experiment Workshop 12 November 2015 A.A. Kwiatkowski Department of Physics & Astronomy and Cyclotron Institute Texas A&M University

2 Many disciplines require atomic mass measurements at different precisions. Neutrino Physics dm/m Nuclear Astrophysics dm/m 10-7 General Physics Metrology, tests of CPT dm/m Nuclear Physics Mass models & formulae dm/m 10-7 Weak Interactions Tests of fundamental symmetries dm/m 10-9 Atomic Physics Binding energies and tests of QED w/ HCI dm/m 10-9

3 Nuclear b decay is the most suitable process to investigate neutrinos. Neutrino Physics dq dm/m ~ ev Q = M i M f Total energy carried away by emitted neutrino is shared with emitted electron(s) in b & bb and is constant in e & ee. Neutrino Mass dq < 1 ev Neutrinoless Double-beta Decay dq = ev Search for Sterile Neutrinos dq 100 ev Neutrino Oscillometry dq = ev

4 Penning traps are trusted for high-accuracy and -precision mass spectrometry. Mass determination via cyclotron frequency 2pn c = (q/m) B end cap B B B V z 0 r0 = + = q/m ring electrode z ion n + = reduced cyclotron freq. ~ 1 MHz n - = magnetron freq. ~ 1 khz n z = axial freq. ~ 100 khz

5 Achievable precision distinguishes measurement techniques. δν c νc < δν c νc ν c 2 = ν ν 2 + ν z 2 ν c = ν + + ν stable or long-lived species short-lived species I I FFT n TOF t n

6 PTMS has spread worldwide. SHIPTRAP JYFLTRAP TITAN CPT FSU CHIP-TRAP LEBIT TRIGATRAP MLLTRAP ISOLTRAP THe-TRAP PENTATRAP short-lived nuclides dm/m ~ 10-9 long-lived & stable nuclides dm/m <10-10

7 KATRIN will directly measure m ν through kinematics of T β 3 He. THe-TRAP aim δq(t β 3 He) 20 mev δq m < N 1 E 0 3 PENTATRAP, CHIP-TRAP aim δq( 187 Re β 187 Os) ~ 1 ev Want lowest Q β : 3 H 3 He Q β = 18.6 kev T 1/2 = 12.3 y KATRIN 187 Re 187 Os Q β = 2.5 kev T 1/2 = 44 Gy MARE

8 Intensity ECHo will directly measure m ν through kinematics of 163 Ho ε 163 Dy SHIPTRAP (2015) δq ε = 16 ev De-Excitation Energy / kev PENTATRAP CHIP-TRAP aim δq ε ~ 1 ev Want lowest Q ε : 163 Ho 163 Dy 2.2 Q ε 2.8 kev T 1/2 = 4.6 ky ( Additional candidates whose Q ε < 100 kev since E ν = Q ε B i. )

9 The Double b-decay problem double-electron-capture nuclides double b-decay nuclides

10 dn/d (E/Q bb ) 0nbb experiments rely on kinematics n2b T 1/2 ~10-19 E/Q bb 0n2b T 1/2 > phase-space factor 0n 1 ( T1 / 2 ) G0 n ( Qbb, Z) M 0 effective Majorana mass nbb m nuclear matrix element bb m e FSU, LEBIT, JYFLTRAP, SHIPTRAP, TITAN, TRIGATRAP, (g.s. g.s.) δq ββ, δq εε 1 kev δq m 10 9

11 0νεε decay may be resonantly enhanced. 1 T 1/2 Γ Q εε B 2h E γ 2 + Γ 2 2 degeneracy Δ = Q εε B 2h E γ Γ < 100 ev requires δq εε 100 ev

12 Intensity Hunts for sterile neutrinos need Q ε & accurate electron wavefunctions. binding energy of i th, j th e- λ i λ j th = F(Q ε, B i, B j, U e4 ) contribution from sterile neutrino λ i λ j exp De-Excitation Energy / kev λ i λ j th requires accurate e- wavefunctions and high-accuracy & -precision Q ε -values.

13 Next steps in oscillometry depend on neutrino source. Oscillation length: L ij m E ν [MeV] m ij 2 [ev] If E n ~ kev then L 13 ~ m An intense tunable kev n source can be made with accelerated b emitters / electron-capture decay: LENA 50 kt liquid scintillator 37 Ar, 51 Cr, 75 Se, 113 Sn, 145 Sm, 169 Yb

14 Some Q-values for solar neutrino experiments require re-examination. SAGE & GALLEX measured solar n e flux via 71 Ga(n e,e - ) 71 Ge reaction over 15 year period source event ratio exp / theory GALLEX 51 Cr 0.882±0.078 SAGE 51 Cr 0.95± 0.12 SAGE 37 Ar 0.79±0.10 average 0.87±0.05 detector calibration with terrestrial sources Deficit in measured-topredicted event ratio of 13% or 2.6s TITAN measured δq ε = 1.2 kev & soon JYFLTRAP δq ε < 1 kev SAGE

15 Summary & status Neutrino mass Q-values needed: SMILE-TRAP measured δq 3 H = 1.2 ev THe-TRAP can do δq m ~ & will do < PENTATRAP & CHIP-TRAP are under construction & aim for δq 163 Ho, 187 Re ~ 1 ev 0νββ and 0νεε decay Q- values have largely been measured to desired precision at RIB PTMS Still need NME and E x to identify enhanced cases Hunt for sterile neutrinos Candidates identified but largely unmeasured to desired precision of δq 100 ev Mapping oscillations: Ongoing effort, beginning to be examined at RIB PTMS kev neutrino candidates require δq 100 ev Solar neutrino flux experiments require δq~ 100 ev

16 References S. Eliseev, Y.N. Norikov, K. Blaum, AdP 525 (2013) 707 S. Eliseev, T. Eronen, Y.N. Norikov, IJMS 349 (2013) 102 K. Blaum, S. Eliseev, T. Eronen, Y. Litvinov, JPCS 381 (2012) s shift in Q e ( 163 Ho) published this August! S. Eliseev et al., PRL 115 (2015) Many figures were taken from Sergey Eliseev thank you!