Probing New Bosons and Nuclear Structure with Ytterbium Isotope Shifts

Area of Science:

• Atomic Physics
• Nuclear Physics
• Particle Physics

Background:

• Precise measurements of atomic properties are crucial for testing fundamental theories.
• Understanding nuclear charge distribution variations across isotopes is key to validating nuclear models.
• Searches for new fundamental forces require high-precision experimental data.

Purpose of the Study:

• To perform high-precision mass-ratio measurements on highly charged Ytterbium (Yb^{42+}) ions.
• To conduct isotope-shift measurements on Ytterbium ions (Yb^{+}) across multiple isotopes.
• To extract higher-order changes in nuclear charge distribution and constrain theories of a fifth force.

Main Methods:

• Utilizing precision mass-ratio measurements on Yb^{42+} ions.
• Employing isotope-shift measurements on Yb^{+} for specific atomic transitions.
• Applying King plot analysis to analyze the experimental data.

Main Results:

• Achieved a precision of 4×10^{-12} for mass-ratio measurements of Yb^{42+}.
• Obtained a precision of 4×10^{-9} for isotope-shift measurements on Yb^{+} for isotopes ^{168,170,172,174,176}Yb.
• Extracted higher-order changes in nuclear charge distribution and set bounds on a fifth force.

Conclusions:

• The study provides a benchmark for ab initio nuclear structure calculations.
• The results offer stringent constraints on potential fifth forces coupling to electrons and neutrons.
• This work demonstrates a novel method for probing nuclear structure and new physics.