Researchers of MPIs offer new experimental and ideological results for electron G factor -binding in lithium -like tons that have more nuclear charge than any previous measurement. Experimental accuracy reached the level of 0.5 billion per billion. Using a better entry electronic QED method, theoretical forecasts for the G factor reached precision of 6 billion parts per billion.
Quantum Electrodianymics – precision competition
Quantum Electrodineamics (QED) is the basic theory that describes all electromagnetic phenomena, including light (photons). At the same time, this is very clearly a test theory in physics. It has been strictly tested in different ways per billion 0.1 parts. But it is the only power of the theory that forces physicians to test more strictly to test it and find its potential limits. Any important deviation will be a signal for new physics.
The QED considers the electromagnetic interaction between charged particles as the exchange of “virtual” photons – just as the electrons in an atom “speak” to each other and nucleus and “self -energy” by “self -energy” by emissions and maintenance. In addition, it was found that physical vacuum is not empty but full of virtual particles, such as electron positting couples that appear “nothing” at all times but have to disappear within the limits of quantum physics uncertainty. Although it may seem scary, it is only one way to explain the basic physics of experiments conducted in nuclear physics in the 1940s.
The sophisticated access to the QED reflection is so -called g-The electron factor that describes its mechanic (internal angular speed: spin) and the relationship of magnetic properties. Directory theory (related quantum mechanics), gave g-The free electron factor should be exactly 2. However, different QED interactions change g-A small but precise measurement of the factor and value 2 leads to deviation. QED effects depend on a strong non -liner method on the external sectors. Electrons experience a very high electric field due to high nuclear charge in heavy elements. The easiest systems are highly charged ions such as hydrogen, which have been investigated both theoretically and experimentally. [1].
In the experimental ideological work of the Commonwealth Cooperation, researchers at the Max Planck Institute for Nuclear Physics in Headburg have now been investigated. g-Outdoor binding electron factor in lithium -like tons. This system is like hydrogen but adds interaction with two tightly binding electrons of the internal nuclear shell.
Theory: ab initio Qed calculation
A ab initio The calculation takes into account all the electromagnetic interactions between the circles – a lithium -like ion here – at a basic level that includes QED effects up to a certain degree. The effects of electron structures where electrons exchange photons are included in the calculation, as well as QED screening effects, where the electron interacts both with other electrons and with vacuum itself. ab initio Predictions have been further improved by using two loop QED partnerships with recent measurements in hydrogen -like tons [33] Scale was screened in a lithium -like electron case. This gives a “experimentally enlarged” theoretical prediction
GThird = 1.980 354 797 (12)
With uncertainty given in the bracket. Compared to hydrogen -like case, this is 25 times a total improvement.
Experience: Counting spin flosses
The measurement of G The element of the binding electron was carried out using the Croatic Panning Trap Alphaterop in MPI. A small magnetic field inside the trap leads to the movement of a feature of the imprisoned ion, as well as a small magnetic spinning of the outdoor electron spin. G The factor can be removed from the proportion of the ion’s animation frequency and advance frequency, while the magnetic field is eliminated accordingly. The ion motion address can be detected directly from small -incentive electric signals in the “precision trap” trap electrode. To determine advance frequency, the microwave radiation is sent to the trap that can attract spin flip, changes to spin’s orientation (only two measurements due to quantity are “up” and “down”). When the microwave resembles, the rate of spin flips reaches more and more.
Results and outlook
Lithium -like tin ion’s G -element is experimental value
GDeducted = 1.980 354 799 750 (84)State(54)SYS(944)Boundary
Statistics given in the bracket, with organized and external uncertainty. External uncertainty dominates large -scale uncertainty, which currently limits experimental accuracy. Overall accuracy is 0.5 parts per billion. The experimental result is well agreed with the theoretical forecasts within the uncertainty of the calculation. On the experimental aspect, it is possible to improve the accuracy of mass prices much more than the order of expanding and consequently its precision is increased. G Factor if encourage the idea in theory. In the future, measure of heavy lithium -like system such as 208Pb79+ And the expected progress in the two loop QED calculations will provide even better tests in the strong electric field regime using highly charged ions. Modern theoretical methods developed here for intelligence electronic QED effects can be applied here g-Enforced transitions equivalent in the calculation of more complex ions (boron-or carbon-like) element, neutral atoms and other effects.
