Lamb shift measurement

It is not obvious that the hadronic vacuum polarization contribution should be included in the phenomenological analysis of the Lamb shift measurements, since experimentally it is indistinguishable from an additional contribution to the proton charge radius. We will return to this problem below in Sect. 6.1.3. 

Prom the practical point of view, the difference between the results in (5.6) and (5.8) is about 0.18 kHz for lA level in hydrogen and at the current level of experimental precision the distinctions between the expressions in (5.6) and (5.8) may be ignored in the discussion of the Lamb shift measurements. These distinctions should, however, be taken into account in the discussion of the hydrogen-deuterium isotope shift (see below Subsect. 12.1.7). 

As in the case of a hyperfine structure, there is a wealth of new experimental data on Lamb shift measurements of such exotic systems as lithium-like uranium U89+, again encouraging the relevant calculations [164-166],... 

Lamb shift measurements on muonic hydrogen, as now pursued with a novel intense source of slow muons at the Paul Scherrer Institute [86,87] promise to yield an accurate rms charge radius of the proton, so that bound state QED can be tested to new levels of scrutiny. 

Future Prospects for Laser Lamb Shift Measurements... 

Historically, measurements of the IS Lamb shift in hydrogen have constituted the most accurate tests of bound-state QED. However, these recently calculated terms are obscured in hydrogen by the experimental error in the proton charge radius. This is because a non-QED correction to the Dirac levels due to the finite size of the nucleus is included in the Lamb shift, and the uncertainty in this term for the proton is comparable to the two-loop correction in the IS state. In He+, the error introduced by the experimental uncertainty in the alpha particle radius is relatively much smaller [14,15], making Lamb shift measure-... 

The purpose of this paper is to examine a similar coherent state mixing effect of the hydrogen atom in an applied electric field within the framework of atomic interferometer geometry for the Lamb shift measurement. The special attention... 

The simplest version of the atomic interferometer consists of two electrodes with the slits for passing the beam, separated with the variable gap L. For Lamb shift measurement corresponding interferometer is made of two two-electrode systems with longitudinal electric fields, mixing 2S and 2P-states. The systems were separated with a field-free gap of variable length L. This implies, that it is possible to write an exact expression for the probability W(L)e1,e2 of the yield I2P of 2P-atoms from the double system and determine, by processing the experimental dependence I2p(L), the Lamb shift value S. 

All previous 2S Lamb shift measurements for medium-Z hydrogen-like ions have been carried out using fast ion beams, and uncertainties associated with Doppler shifts form a significant source of error in all these experiments. Various methods have been employed or suggested for reducing the sensitivity of fast beam experiments to Doppler corrections [22]—[24]. A measurement of the 2S1/2-2P3/2 transition frequency in N6+ using a fast ion beam is currently under way at Florida State University [25]. Our approach, however, is to reduce such... 

In this paper, we summarise our progress towards Is Lamb shift measurements on medium Z hydrogen-like ions produced in an electron beam ion trap (EBIT), where the X-ray emission is free from the problems of satellite contamination and Doppler shifts. In this context, we note that a measurement of the Is Lamb shift in hydrogen-like Mg11+ has been performed at the Livermore EBIT using a quasimonolithic crystal setup, and reaching a precision of 13% for the Lamb shift dominated by counting statistics [14]. With our setup, the... 

Figure 21 Microwave resonance data for n=2 Lamb shift measurement, and the best fit line shape.

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