Observation of non-exponential orbital electron-capture 140 142 decay of H-like Pr and Pm ions and possible implications for the neutrino masses Fritz Bosch, GSI Darmstadt Nuclear physics seminar at Warsaw University, May 14, 2008 Bound-state beta decay first observed at GSI fifteen years ago → Outline 1. Production, storage and cooling of highly-charged ions at GSI 2. Two-body beta decay of stored and cooled highly-charged ions 3. Experimental results for orbital electron capture of H-like 140Pr and 142Pm by means of single-ion decay spectroscopy 4. Tentative explanation(s) of the observed non-exponential decays 5. Summary, questions and outlook Schottky Mass Spectrometry (SMS) - Collaboration F. Attallah, G. Audi, K. Beckert, P. Beller†, F. Bosch, D. Boutin, C. Brandau, Th. Bürvenich, L. Chen, I. Cullen, Ch. Dimopoulou, H. Essel, B. Fabian, Th. Faestermann, M. Falch, A. Fragner, B. Franczak, B. Franzke, H. Geissel, E. Haettner, M. Hausmann, M. Hellström, S. Hess, G. Jones, E. Kaza, Th. Kerscher, P. Kienle, O. Klepper, H.-J. Kluge, Ch. Kozhuharov, K.-L. Kratz, R. Knöbel, J. Kurcewicz, S.A. Litvinov, Yu.A. Litvinov, Z. Liu, K.E.G. Löbner†, L. Maier, M. Mazzocco, F. Montes, A. Musumarra, G. Münzenberg, S. Nakajima, C. Nociforo, F. Nolden, Yu.N. Novikov, T. Ohtsubo, A. Ozawa, Z. Patyk, B. Pfeiffer, W.R. Plass, Z. Podolyak, M. Portillo, A. Prochazka, T. Radon, R. Reda, R. Reuschl, H. Schatz, Ch. Scheidenberger, M. Shindo, V. Shishkin, J. Stadlmann, M. Steck, Th. Stöhlker, K. Sümmerer, B. Sun, T. Suzuki, K. Takahashi, S. Torilov, M.B.Trzhaskovskaya, S.Typel, D.J. Vieira, G. Vorobjev, P.M. Walker, H. Weick, S. Williams, M. Winkler, N. Winckler, H. Wollnik, T. Yamaguchi UniS ...back to our roots: stellar nucleosynthesis PathwaysPathways ofof stellarstellar nucleosynthesisnucleosynthesis • KeyKey parameters:parameters: • Masses,Masses, beta-lifetimes,beta-lifetimes, n-n- capture-,capture-, n-n-γγ cross-cross- sectionssections • MassesMasses determinedetermine thethe pathwayspathways • ofof s-,s-, p-,p-, rp-rp- andand r-r- processesprocesses • Beta-lifetimesBeta-lifetimes thethe accumulatedaccumulated abundancesabundances • HotHot stellarstellar environmentenvironment :: atomsatoms areare highly-ionizedhighly-ionized 1. Production, storage and cooling of HCI at GSI Secondary Beams of Short-Lived Nuclei Storage Ring ESR Linear Accelerator Fragment UNILAC Separator FRS Heavy-Ion Production Synchrotron target SIS Production & Separation of Exotic Nuclei Highly-Charged Ions In-Flight separation Cocktail or mono-isotopic beams 500 MeV/u primary beam 152Sm 400 MeV/u stored beam 140Pr, 142Pm The ESR : Emax = 420 MeV/u, 10 Tm, electron-, stochastic-, and laser cooling Specifications of the ESR Particle two rf- Two 5 kV rf-cavities detectors cavities Re-injection Fast Injection to SIS Schottky pick-ups │ e- cooler Gas jet I = 10...500 mA 0 L = 108 m =1/2 LSIS Six 60 dipoles Bρ ≤ 10 T· m p = 2· 10-11 mbar E = 3...420 MeV/u Extraction f ≈ 1...2 MHz β = 0.08...0.73 Qh,v ≈ 2.65 Stochastic cooling: Implementation at the ESR long. Kicker transv. Pick-up Combiner- Station transv. Kicker long. Pick-up ESR storage ring Stochastic cooling is in particular efficient for hot ion beams "Cooling": enhancing the phase space density Electron cooling: G. Budker, 1967 Novosibirsk Momentum exchange with a cold, collinear e- beam. The ions get the sharp velocity of the electrons, small size and small angular divergence "Phase transition" to a linear ion chain ESR: circumference ≈ 104 cm For 1000 stored ions, the mean distance amounts to about 10 cm At mean distances of about 10 cm and larger intra-beam-scattering disappeared M. Steck et al., PRL 77 (1996) 3803 Recording the Schottky-noise From the FR S T o t h e S I S Q uadrupole- H e x a p o l e - ∆v t r i p l e t m a g n e t s →0 v D ipole m agnet S e p t u m - m a g n e t am plification S chottky pick-ups S c h o t t k y s u m m a t i o n G a s - t a r g e t E l e c t r o n P i c k - u p s c o o l e r FFT Q uadrupole- f0 ~ 2 M H z d u b l e t S tored ion beam R F-A ccelerating F ast kicker c a v i t y m a g n e t Real time analyzer Sony-Tektronix 3066 ____________________________ 128 msec E x t r a c t i o n → FFT 64 msec_____________________ → FFT SMSSMS 4 particles with different m/q time SMSSMS ω Sin( 1) ω Sin( 2) Fast Fourier Transform ω ω ω ω time ω 4 3 2 1 Sin( 3) ω Sin( 4) + + Three-body beta decay, e.g. β : p → n + e + ve both, mass (m ) and charge state (q) change → quite different revolution frequencies and orbits - Two-body beta decay, e.g. EC: p + e b → n + νe only difference of mass, q remains the same → small difference in revolution frequency, (almost) same orbit I n t e n s i t y / a r b . u n i t s 0 0 0 0 1 5 3 6 8 0 2 4 7 1 Small-band Schottky frequency spectra I n t e n s i t y / a r b . u n i t s Small-band Schottky frequency spectra 1 7 1 7 4 1 0 1 0 1 0 1 0 0 5 0 0 0 5 5 5 1 6 0 . 0 W 2 4 0 . 0 8 0 . 0 1 6 4 7 1 + 0 1 8 8 7 8 + H f 2 0 4 8 4 + 0 0 0 0 2 A u 1 8 9 7 9 + 1 6 4 7 1 + P o 1 8 9 7 9 + L u H g 1 8 7 7 7 + 1 7 7 7 4 + A u 1 5 7 6 8 + A u W T m 1 8 7 7 7 + 196 82+ 20 0 83+ 1 8 8 7 8 + 1 5 7 6 8 + P t 1 99 82+ B i B i 1 2 7 5 5 + E r P t B i C s 1 7 0 . 0 2 5 0 . 0 9 0 . 0 1 8 0 7 8 + 1 0 . 0 1 9 9 8 2 + 1 9 6 8 2 + P t 18 3 76+ 1 5 0 6 5 + 198 81+ 1 8 4 7 7 + 1 8 3 7 6 + 0 0 0 0 3 D y P b P b I r 1 9 5 8 1 + B i P t O s 1 5 0 m , g 6 5 + 18 2 7 5+ P b T b 1 9 4 8 0 + 1 7 3 7 5 + 1 9 8 8 1 + I r 184 77+ R e P b P b 1 4 3 6 2 + I r E u 19 3 79+ 195 81+ 1 4 3 m , g 6 2 + T l S m 1 6 6 7 2 + T l 1 8 0 . 0 1 0 0 . 0 191 80+ 2 6 0 . 0 T a 1 6 6 7 2 + 2 0 . 0 1 9 4 8 0 + 19 4 80+ H f 1 9 3 7 9 + T l 0 0 0 0 4 H g T l H g 1 9 0 7 9 + 1 7 8 7 4 + H g 1 3 6 5 9 + 1 8 9 7 8 + R e 1 9 1 8 0 + 1 8 8 7 7 + P r 1 5 9 6 9 + H g 1 8 9 7 8 + A u H g Y b 1 5 9 6 9 + A u T m 1 8 8 7 7 + 1 9 0 7 9 + P t 1 8 9 7 8 + Frequency / kH z 1 9 0 . 0 A u 1 1 0 . 0 2 0 5 8 4 + 2 7 0 . 0 P t 1 7 5 7 6 + 3 0 . 0 0 0 0 0 5 198 83+ / z H / y c n e u q e r F O s 2 0 1 8 3 + P o B i P o 1 5 2 6 6 + 2 0 0 8 2 + 20 1 83 + H o 19 7 8 2+ 1 5 2 6 6 + P o B i B i 184 76+ D y 1 6 8 7 3 + 20 0 8 2+ I r 1 6 8 7 3 + W T a B i 1 8 4 7 6 + 2 0 0 8 2 + 1 9 7 8 2 + 1 4 5 6 3 + 1 8 5 7 7 + O s 2 0 0 . 0 1 2 0 . 0 P b 0 0 0 0 6 2 8 0 . 0 G d P b 4 0 . 0 P t 18 5 77+ 1 9 5 8 0 + 1 2 2 5 3 + P b I I r A q + 1 6 1 7 0 + A q + 19 6 81+ X X L u T l 19 2 80+ 1 6 1 7 0 + T l Y b 19 5 80+ unknown1 3 8m asses 6 0 + known m asses T l 1 9 1 7 9 + N d 1 9 0 7 8 + H g 0 0 0 0 7 H g 2 1 0 . 0 1 3 0 . 0 1 9 2 8 0 + 2 9 0 .