Precision atomic/nuclear physics measurements in Penning traps and - PowerPoint PPT Presentation

Winter Meeting Nuclear Physics, Bormio 2018 Precision atomic/nuclear physics measurements in Penning traps and tests of fundamental symmetries Precision atomic/nuclear masses The (anti)proton charge-to-mass ratio g -factors of bound electrons and m e Klaus Blaum Jan 22 nd , 2018 Klaus.blaum@mpi-hd.mpg.de

Why measuring atomic masses? Relative mass precision of 10 -9 and below can presently ONLY be reached by Penning-trap mass spectrometry.

Atomic and nuclear masses Masses determine the atomic and nuclear binding energies reflecting all forces in the atom/nucleus. m Atom = N • m neutron + Z • m proton + Z • m electron - ( B atom + B nucleus )/ c 2 δ m / m = 10 -6 – 10 -8 δ m / m < 10 -10

How to weigh an atom ν c,1 ν c,1 ν c,2 ν c,2

Storage of ions in a Penning trap B U Ion q/m ion Charge q Mass m ion ω c = The free cyclotron frequency is inverse qB / m ion proportional to the mass of the ion! ω c = ω + + ω - ω c 2 = ω + 2 + ω - 2 + ω z 2 Invariance theorem: L.S. Brown, G. Gabrielse, Rev. Mod. Phys. 58, 233 (1986).

Detection techniques R ∝ 1/ T obs δ m / m ≈ 10 -9 7 T Destructive time-of-Flight 0 detection R ∝ 1/ T obs ∙ ∆φ /2 π 7 T # detected ions Destructive δ m / m ≈ 10 -10 phase-imaging 0 detection S. Eliseev et al ., Phys. Rev. Lett. 110, 082501 (2013) δ m / m ≈ 10 -11 hot ion cold ion cold ion 4.2 K Non-destructive Signal amplitude Signal amplitude Signal amplitude Signal amplitude induced image current detection Ion in thermal equilibrium Ion in thermal equilibrium with the tank circuit at 4K with the tank circuit at 4K Frequency S. Sturm et al ., Phys. Rev. Lett. 107, 143003 (2011) Frequency Frequency Frequency

BASE: A Penning-trap setup at CERN A balance for protons and antiprotons. Spokesperson: Stefan Ulmer

Atomic masses I Nuclear magic numbers ISOLTRAP (CERN), SHIPTRAP (GSI), TRIGATRAP (Mainz) M. Block, S. Eliseev, V. Manea, L. Schweikhard, A. Schwenk

Atomic and nuclear structure: Basics

New magic number ( N =32) and 3N-forces Nuclear binding energy B nucl T 1/2 = ms – s m Atom = N • m neutron + Z • m proton + Z • m electron - ( B atom + B nucl )/ c 2 Yield = 1-10 p/s S 2n (MeV) Ca: One-neutron separation energy S 1n A.T. Gallant et al ., PRL 109, 032506 (2012) F. Wienholtz et al ., Nature 498, 346 (2013) S 1n = B nucl ( Z , N ) – B nucl ( Z , N -1) K: M. Rosenbusch et al ., PRL 114, 202501 (2015) Two-neutron separation energy S 2n ISOLTRAP (CERN) S 2n = B nucl ( Z , N ) – B nucl ( Z , N -2) TITAN (TRIUMF)

Masses II Neutrino physics applications m ( ν e ) < 2 eV/c 2 (95% CL)

THe-TRAP for KATRIN A high-precision Q ( 3 T- 3 He)-value measurement − → + + ν 3 3 H He e Q lit =18 589.8 (1.2) eV 1 2 Q lit =18 592.01(7) eV [E. Myers, PRL (2015)] We aim for: δ Q ( 3 T  3 He) = 20 meV ∆ T < 0.02 K/d at 24°C δ m / m = 7·10 -12 ∆ B/B < 10 ppt / h ∆ x ≤ 0.1 µ m First 12 C 4+ / 16 O 6+ mass ratio measurement at δ m / m = 1.4∙10 -11 performed.

Atomic masses III Test of CPT symmetry BASE: CERN, GSI, Hannover, Mainz, MPIK, RIKEN A. Mooser, Ch. Ospelkaus, W. Quint, S. Smorra, S. Ulmer, J. Walz

Most stringent baryonic CPT test Compare charge-to-mass ratios R of p and p: ( q / m ) p / ( q / m ) p = 1.000 000 000 001 (69) S. Ulmer et al ., Nature 524, 196 (2015) Remarkable: It is not that easy! Temperature: T = -270°C Pressure: p < 4∙10 -19 mbar Storage time: years Experiment: BASE @ AD/CERN

A 3-fold improved proton mass F. Heiße et al ., Phys. Rev. Lett. 119, 033001 (2017)

Atomic masses IV The mass of the electron – A fundamental constant HCI-Trap: GSI, Mainz, MPIK, St. Petersburg Z. Harman , Ch. Keitel , F. Köhler-Langes, W. Quint, V. Shabaev , S. Sturm

Quantum electrodynamics of bound states 28 Si 13 + 208 Pb 81 + 12 C 5 + 40 Ca 19 + High to ultra-high Low field strength field strength Extract fundamental The Standard Model in constants (electron mass, extreme conditions fine structure constant)

Measurement principle Measurement of the free cyclotron Measurement of the Larmor frequency frequency to determine the in a well-known magnetic field: B magnetic field: B q g e ω c = ω = ion B B L m 2 m ion e ω q m q m = 2 ω = Γ L ion e ion e g 2 m e m e c ion ion Measured by has to be independent determined precision experiments

Continuous Stern-Gerlach effect  Larmor frequency cannot be detected directly  Microwaves probe spin transition How to detect a successful spinflip ?  Magnetic inhomogeneity results in a spin-dependent potential 2 e U  Tiny axial frequency difference between spin up and down ω z = 0 0 2 md 0 Ferromagnetic ring Spin dependent Tiny axial frequency difference  magnetic bottle trapping potential between spin up and down.

g -factor measurement process One measurement cycle 0.5 0.5 Fractional axial frequency difference (Hz) ▪ Detection of spin-orientation 0.4 0.4 Fractional axial frequency difference (Hz) in analysis trap 2-3min 0.3 0.3 0.2 ▪ Transport to precision trap 20s 0.2 0.1 0.1 ▪ Measurement of 0.0 0.0 eigenfrequencies and -0.1 -0.1 simultaneous irradiation with -0.2 -0.2 microwaves 10min -0.3 -0.3 ▪ Transport to analysis trap 20s -0.4 -0.4 ▪ Detection of spin orientation -0.5 -0.5 0 10 20 30 40 50 60 70 80 90 100 in analysis trap Measurement number Measurement number  Spin flip in the precision trap?

g -factor resonance of a single 28 Si 13+ ion 60 q m = 2 Γ e g 28 Si 13+ 50 e m ion Spinflip propability (%) 40 30 20 10 0 -150 -100 -50 0 50 100 150 200 Γ−Γ -6 ) theo (10 Experiment limited by uncertainty Electron mass can be g exp = 1.995 348 958 7 (5)(3)(8) of electron mass improved by a factor of Theory limited by nuclear g theo = 1.995 348 958 0 (17) >10 if repeated for 12 C 5+ . structure effects Most stringent test of BS-QED in strong fields. S. Sturm et al ., Phys. Rev. Lett. 107, 023002 (2011) Theory colleagues: Harman, Keitel, Zatorski A. Wagner et al ., Phys. Rev. Lett. 110, 133003 (2013)

A 13-fold improved electron mass Electron mass from ultra-high precision g -factor of hydrogenlike carbon: ω g e = theo c m m ω e ion q 2 L ion Harman, Keitel, Zatorski m e = 0.000 548 579 909 067 (14)(9)(2)u A factor of 13 CODATA 2016 improved value ! S. Sturm et al ., Nature 506, 467 (2014)

The (anti-)proton magnetic moment ω = L 2 g ω c μ p = 2.792 847 344 62(82) μ N μ p = −2.792 847 344 1(42) μ N (0.3 ppb) (1.5 ppb) G. Schneider et al ., Science 358, 1081 (2017) Ch. Smorra et al ., Nature 550, 371 (2017)

Conclusion Exciting results in high-precision experiments with stored and cooled exotic ions have been achieved! Presently running or planned experiments: the mass of the neutron improved E = m c² test improved value for α (anti-)p g -factor measurement Thanks a lot for the invitation and your attention! Max Planck Society IMPRS-PTFS Helmholtz Alliance Adv. Grant MEFUCO