Figure 4. The adiabatic potentials corresponding to the model calculations: -, ( 3/2);- --, ( 1/2); and---, ( 1/2), the quantum numbers referring to the rotating frame; from left to right: low e, normal <, and high t case. close-lying potentials, i.e. for le and ne, lead to small differences in the channel energies and hence the wavenumbers of their nuclear wave functions are very similar. This leads to very efficient coupling of all three channels both in W+ and W". In the he case in each of these interaction matrices the first channel, referring to j = 1 /2, decouples very effectively from the other two with j = 3/2 due to the great difference in the channel energies. Carrying this line of arguments further, we set the corresponding coupling terms equal to zero and diagonalize the remaining 2X2 matrices. The resulting adiabatic potentials are not exactly but approxi-mately equal to the potential for + and the potential for ' in agreement with our calculated results. VII. SummaryThe measurement of total differential cross sections for the scattering of oriented alkali 2P3/2 atoms from ground-state, i.e., spherically symmetric, rare gas atoms shows a left/right asymmetry, if the initial state is chosen with m¡ = +3/2 or m¡ = -3/2 and the quantization axis is perpendicular to the scattering plane.The basics of this experimentally observed effect are discussed in detail in our report. First we have shown this feature to be qualitatively due to the fact that the two initial states refer, each exclusively, to the two parity sets of the corresponding interaction matrix. A closer look at the interaction matrix reveals that the centrifugal parts of the potentials with their different vector coupling coefficients are the only significant differences. A model calculation to reproduce the size of the asymmetry for various rare gas targets demonstrates that the decisive parameter for these variations is the ratio of spin-orbit and orbit-axis interaction.Finally we find from these calculations that orbital stereospecificity is indeed present in a certain case: namely the one with the spin-orbit interaction larger than the orbit-axis interaction at large internuclear separations.

The relaxation dynamics of carbon disulfide are investigated in mixtures with polystyrene (PS) using the time-resolved optical heterodyne-detected optical Kerr effect (OHD-OKE). The data are analyzed using both the model-dependent approach, which assumes four distinct temporal responses, and the model-independent Fourier transform approach, which generates a spectral response that can be compared with results obtained by depolarized Rayleigh scattering. A slow dynamics is observed for the OHD-OKE transient decaying exponentially with a time constant that varies from 1.68 ps for neat CS2 to 3.76 ps for the most concentrated CS2PS mixture. The increase of this time constant accompanies an increase in the viscosity of the mixture, so we can associate this component with the diffusive reorientation process of the induced polarizability anisotropy of the carbon disulfide in the mixture. The short-time nuclear response is characterized in the frequency domain by a broad band that peaks around 30 cm(-1) for neat carbon disulfide, and is associated with a complex relaxation pattern. The vibrational distribution shifts to higher frequencies when the PS concentration is increased in the mixture. This result is discussed in terms of an increase in the interaction strength between the PS phenyl rings and the carbon disulfide molecules.

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The measurement and characterization of ultrashort laser pulses remains an arduous task. The most commonly used pulse-measurement method is known as frequency-resolved optical gating (FROG), and another version with great experimental simplification and low-priced setup is known as gratingeliminated no-nonsense observation of ultrafast incident laser light E fields (GRENOUILLE). Nevertheless, there is interest in elaborating other, more accessible or simpler and cheaper, setups with equal or better assets. We explored modification of the GRENOUILLE method in which we replaced the original Fresnel biprism with a beam splitter and two mirrors and used a cheap webcam to measure the pulse traces. We have evaluated our system, and we propose a method to correct border effects caused by the beam intensity's profile based on the characterization of three pulse classes: Fourier-transform limited, double, and chirped. We compare the recovered electric field with further spectral and second-order correlation data of the corresponding pulses.

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