The pure diamagnetic spectrum of strontium

Abstract

We report on one-photon laser spectroscopy experiments in which we have obtained the even z-parity diamagnetic spectrum of Sr by actively cancelling the motional Stark effect. This spectrum differs from previous experimental studies in that it contains no electric-field-induced structure. New calculations are reported at a resolution comparable with the experimental data, and an excellent agreement between theory and experiment is obtained.

Core effect on the diamagnetic spectrum of barium Rydberg states

“…On the contrary, the p state is recoiled to lower energy with acceleration. Generally speaking, the quantum defect of f states has a much stronger effect on the high-k states than the p-predominant ones [24]. In our case, the diamagnetic effect makes some higher-k states of higher n manifold intrude toward lower energy and "collide" with the p-predominant peak (k = 0) in the neighborhood of a lower principal quantum state n − 1.…”

“…Since the value of the reduced quantum defect for p states is almost zero in the examined energy range, the zero-field states with odd parity are nearly degenerate, resulting the line positions and intensities of the mixed states having a nearly regular structure. It is similar to the case of hydrogen [40], but different from the case of strontium in a magnetic field of 2.465 T, where the quantum defect of the p channel is large enough to separate the p component from the satellites of higher l partial waves (l 3) in the same manifold [24]. We will return to the discussion about the effect of the quantum defect δ p on the diamagnetic spectrum later.…”

“…Lu et al [15] presented a densitometer mapping of diamagnetic effects on barium and strontium and discussed the effects of perturbation states (4d5p 1 P 1 for strontium and 5d8p 1 P 1 for barium) on the intensity and spacing of principle series spectra. The group of Connerade in Imperial College contributed much to the investigations of the diamagnetic effect of alkaline earths [21][22][23][24][25], giving a lot of inspiration to our work on the core scattering of the quadratic Zeeman spectrum of barium [26].…”

Further studies of the multiplicity derivative in models of heavy ion collision at intermediate energies as a probe for phase transitions

“…Recognition of phase transition in intermediate energy collisions has been an interesting and intriguing problem of long standing. A popular approach was to try to best fit individual multiplicity n a to a form suggestive of critical phenomenon: n a = a −τ f (a σ ((T − T c )) [12,13,[17][18][19]. It is impossible to get a very good fit as the masses a need to be big for the model to work and in heavy ion collisions in the lab fragment sizes are limited.…”

Nonlinear spectroscopy of barium in parallel electric and magnetic fields

“…[2] Researchers have developed a semiclassical method [7,8] and quantum calculation [9,10] to treat this problem and explain the correlative experiments. [11,12] Although there is a quadratic term in the Hamiltonian, the atom in a magnetic field has a simpler structure [13,14] than the Stark spectrum [6,15] for its higher symmetry.…”