[Triumf-seminars] TRIUMF Colloquium today at 14:00

TRIUMF Seminars triumf-seminars at lists.triumf.ca
Thu Oct 30 05:00:01 PDT 2014


Date/Time: Thu 2014-10-30 at 14:00

Location:  Auditorium          

Speaker:   Chen Ji (TRIUMF)

Title:     Determining nuclear radii from exotic atoms

Abstract: The proton radius extracted from recent high-precision measurements of the Lamb shift in muonic hydrogen disagrees significantly with that determined from electronic hydrogen spectroscopy or electron-proton elastic scattering. Intrigued by the proton radius puzzle, new measurements of the Lamb shift in other light muonic atoms will be performed at PSI. These measurements aim to extract the nuclear charge radius with extremely high accuracies, limited by the uncertainty in the nuclear polarization corrections.

Nuclear polarizations are QCD effects that contribute to the Lamb shifts in muonic atoms. They need to be provided by theory with high accuracy. I will talk about how we perform ab-initio calculations of such nuclear polarizations using state-of-the-art nuclear Hamiltonians, with a precision that satisfies the experimental requirement. I will present results for muonic deuterium and 4He, and discuss the uncertainties from both atomic and nuclear physics. I will then discuss the extension to muonic 3He and 3H.

At last, I will discuss future extensions to calculating nuclear polarizations in electronic atoms containing light nuclei near the edge of stability. These nuclei are easier to be excited by the surrounding electron. As an example, I will discuss the calculation of 6He nucleus with the halo effective field theory, and the possible extension to obtain the nuclear polarizability, which is important in extracting the radius of a halo nucleus from spectroscopic measurements.

Refreshments 15 minutes before the talk.

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General TRIUMF seminar information available at http://www.triumf.ca/home/upcoming-events/about-seminars-lectures



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