High-precision mass measurement of 168Yb for verification of nonlinear isotope shift

Abstract

The absolute mass value of 168 Yb has been directly determined with the JYFLTRAP Penning trap mass spectrometer at the Ion Guide Isotope Separator On-Line (IGISOL) facility. A more precise value of the mass of 168 Yb is needed to extract possible signatures of beyond standard model physics from high-precision isotope shift measurements of Yb atomic transition frequencies. The measured mass-excess value, ME( 168 Yb) = −61579.846(94) keV, is 12 times more precise and deviates from the Atomic Mass Evaluation 2016 value by 1.7σ. The impact on precision isotope shift studies of the stable Yb isotopes is discussed.

Study of radial motion phase advance during motion excitations in a Penning trap and accuracy of JYFLTRAP mass spectrometer

“…This level of accuracy is enough for the mass values of radioactive nuclides far from stability needed for astrophysics or nuclear structure studies. For more precise mass measurement at the level of 10 −9 and better, the ion of interest and reference should be within | m| ≤ 2 u [55] or ideally A/q doublets. The mass measurements with the carbon-cluster ions are in-line with the earlier measurements [19].…”

“…However, it is worth noting, that in mass measurements with the mass doublets (A re f = A ioi ) these systematic uncertainties are cancelled out [47] and the accuracy level better than 10 −9 [59] can be reached. Such accuracy can also be obtained in mass measurements with ions differing by m = 2 u [5,55]. In general, it is very rare that reference mass is more than 12u away from the ion-of-interest.…”

“…In addition to the measurements with the carbon clusters two previous PI-ICR measurements with 85,87 Rb + and 170,172 Yb + ions, which have very well-known mass values [35], were included in the analysis. The cyclotron frequency ratios r = ν c ( 85 Rb + )/ν c ( 87 Rb + ) [5] and r = ν c ( 172 Yb + )/ν c ( 170 Yb + ) [55] were measured with a relative uncertainty of 0.64 and 0.5 ppb, respectively.…”

Study of radial motion phase advance during motion excitations in a Penning trap and accuracy of JYFLTRAP mass spectrometer

“…However, it is worth noting, that in mass measurements with the mass doublets (A ref = A ioi ) these systematic uncertainties are cancelled out [39] and the accuracy level better than 10 −9 [51] can be reached. Such accuracy can also be obtained in mass measurements with ions differing by ∆m = 2 u [8,47]. In general, it is very rare that reference mass is more than 12u away from the ion-of-interest.…”

“…In addition to the measurements with the carbon clusters two previous PI-ICR measurements with 85,87 Rb + and 170,172 Yb + ions, which have very well-known mass values [26], were included in the analysis. The cyclotron frequency ratios r = ν c ( 85 Rb + )/ν c ( 87 Rb + ) [8] and r = ν c ( 172 Yb + )/ν c ( 170 Yb + ) [47] were measured with a relative uncertainty of 0.64 and 0.5 ppb, respectively.…”