Hydrogen hyperfine structure

Hydrogen Hyperfine Structure and Related CPT Invariant Quantities... 

N. Ramsey Atomic Hydrogen Hyperfine Structure Experiments . In Quantum Electrodynamics, ed. by T. Kinoshita (World Scientific, Singapore 1990) pp. 673-695... 

Experimental support for Breit s suggestion comes not only from hydrogen hyperfine structure, but also from experiments in which atomic magnetic moments are compared directly through their precessional frequencies in the same field. Kusch and Foley [78] compared the moments of gallium in the... 

We have been concerned with the absolute value of hydrogen hyperfine structure. Comparison of Ar between hydrogen and deuterium in the ground state eliminates uncertainty in the values of a, (7rei and CQ, and discloses a discrepancy of a kind different from any we have yet considered [111]. 

E. de Rafael, 1971, The hydrogen hyperfine structure and inelastic electron-proton scattering experiments,... 

Figure Bl.4.9. Top rotation-tunnelling hyperfine structure in one of the flipping inodes of (020)3 near 3 THz. The small splittings seen in the Q-branch transitions are induced by the bound-free hydrogen atom tiiimelling by the water monomers. Bottom the low-frequency torsional mode structure of the water duner spectrum, includmg a detailed comparison of theoretical calculations of the dynamics with those observed experimentally [ ]. The symbols next to the arrows depict the parallel (A k= 0) versus perpendicular (A = 1) nature of the selection rules in the pseudorotation manifold.

EPR studies showed that RsSi radicals (R = Me, Et, i-Pr and t-Bu), obtained by hydrogen abstraction from the parent silanes by photogenerated t-BuO radicals, add to Ceo to form the corresponding adducts [29], The spectra of MesSi- and t-Bus Si-adducts have hyperfine structure due to 9 and 27 equivalent protons, respectively, at 27 °C suggesting free rotation of Si—C bonds on the EPR time scale. On the other hand, the middle members of the series, EtsSi-and z-Pr3 Si-adduct radicals, showed a unexpected hyperfine manifold which has been accommodated with free rotation about the Si—Ceo and frozen rotation about the Si—R bonds on the EPR time scale. 

The proton is the lightest nucleus, with atomic number one. Other singly charged nuclei are the deuteron and the triton, which are nearly two and three times as heavy as the proton, respectively, and are the nuclei of the hydrogen isotopes deuterium (stable) and tritium (radioactive). The difference in the nuclear masses of the isotopes accounts for a part of the hyperfine structure called the isotope shift. 

Later, after experiments performed by Rabi, Lamb and Kusch and their colleagues, it was discovered that the actual hydrogen spectrum was in part in contradiction to Dirac theory (see Fig. 1). In particular, the theory predicted a value of hyperfine structure interval in the ground state of the hydrogen atom, different from the actual one by one part in 103, and no splitting between 2si/2 and... 

The hyperfine structure interval in hydrogen is known experimentally on a level of accuracy of one part in 1012, while the theory is of only the 10 ppm level [9]. In contrast to this, the muonium hfs interval [12] is measured and calculated for the ground state with about the same precision and the crucial comparison between theory and experiment is on a level of accuracy of few parts in 107. Recoil effects are more important in muonium (the electron to nucleus mass ratio m/M is about 1/200 in muonium, while it is 1/2000 in hydrogen) and they are clearly seen experimentally. A crucial experimental problem is an accurate determination of the muon mass (magnetic moment) [12], while the theoretical problem is a calculation of fourth order corrections (a(Za)2m/M and (Za)3m/M) [11]. 

The latter presents the largest sources of uncertainty in the theory of the muo-nium hfs interval, positronium energy spectrum and the specific nuclear-structure-independent difference for the hfs in the helium ion. The former are crucially important for the theory of the Lamb shift in hydrogen and medium-Z ions, for the difference in Eq. (2) applied to the Lamb shift and hyperfine structure in hydrogen and helium ion, and for the bound electron (/-factor. In the case of high-Z, the Lamb shift, (/-factor and hyperfine structure require an exact treatment of the two-loop correction. 

Abstract. Muonium is a hydrogen-like system which in many respects may be viewed as an ideal atom. Due to the close confinement of the bound state of the two pointlike leptons it can serve as a test object for Quantum Electrodynamics. The nature of the muon as a heavy copy of the electron can be verified. Furthermore, searches for additional, yet unknown interactions between leptons can be carried out. Recently completed experimental projects cover the ground state hyperfine structure, the ls-2s energy interval, a search for spontaneous conversion of muonium into antimuonium and a test of CPT and Lorentz invariance. Precision experiments allow the extraction of accurate values for the electromagnetic fine structure constant, the muon magnetic moment and the muon mass. Most stringent limits on speculative models beyond the standard theory have been set. 

Ground-state Hyperfine Structure of High-Z Hydrogen-like Ions... 

So far, we have considered each atomcule state as a single state with quantum numbers (n, l). More precisely speaking, however, since an electron in the Is orbital is coupled to the antiproton, each state has a hyperfine structure, as is well known for the hydrogen atom. In the present atomcule case, the situation is... 

Abstract. The usefulness of study of hyperfine splitting in the hydrogen atom is limited on a level of 10 ppm by our knowledge of the proton structure. One way to go beyond 10 ppm is to study a specific difference of the hyperfine structure intervals 8Au2 — Avi. Nuclear effects for axe not important this difference and it is of use to study higher-order QED corrections. 

Abstract. We consider the hyperfine structure of the Is and 2s states in muonic hydrogen and muonic deuterium. We put emphasis on two particular topics a possibility to measure the hfs interval in the ground state and a calculation of a specific difference. Ehfs(ls) — 8 Ehfa(2s). Such a measurement and the calculations are of interest in connection with an upcoming experiment at PSI in which different 2s — 2p transitions in muonic hydrogen shall be determined. Together all these investigations will improve the knowledge of the internal structure of proton and deuteron. 

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