Commission des Communautes Europeennes: Groupe du Porte-Parole. Reunion de la Commission du mercredi 29 octobre 1980 = Commission of European Communities: Spokesman Group. Meeting of the Commission on Wednesday, 29 October 1980. Spokesman Service Note to National Offices Bio No. (80) 432, 30 October 1980

We study strong-field ionization and rescattering beyond the long-wavelength limit of the dipole approximation with elliptically polarized mid-IR laser pulses. Full three-dimensional photoelectron momentum distributions (PMDs) measured with velocity map imaging and tomographic reconstruction revealed an unexpected sharp ridge structure in the polarization plane (2018 Phys. Rev. A 97 013404). This thin line-shaped ridge structure for low-energy photoelectrons is correlated with the ellipticity-dependent asymmetry of the PMD along the beam propagation direction. The peak of the projection of the PMD onto the beam propagation axis is shifted from negative to positive values when the sharp ridge fades away with increasing ellipticity. With classical trajectory Monte Carlo simulations and analytical analysis, we study the underlying physics of this feature. The underlying physics is based on the interplay between the lateral drift of the ionized electron, the laser magnetic field induced drift in the laser propagation direction, and Coulomb focusing. To apply our observations to emerging techniques relying on strong-field ionization processes, including time-resolved holography and molecular imaging, we present a detailed classical trajectory-based analysis of our observations. The analysis leads to the explanation of the fine structure of the ridge and its non-dipole behavior upon rescattering while introducing restrictions on the ellipticity. These restrictions as well as the ionization and recollision phases provide additional observables to gain information on the timing of the ionization and recollision process and non-dipole properties of the ionization process.ISSN:1361-6455ISSN:0368-3508ISSN:0953-4075ISSN:0022-370

Tasting and labeling meat substitute products can affect consumers’ product evaluations and preferences

Moving towards plant-based diets and reducing meat consumption is key to achieving the Paris climate targets. One option for reducing meat consumption is replacing meat products with substitutes. In two field experiments, we tested how labeling and tasting experiences with substitutes affected omnivores’ evaluations of such products and investigated the latter's stated and revealed preferences regarding the consumption of meat substitutes and reduction of meat consumption. In our first experiment, we randomly labeled meat substitutes vegetarian or meat products, finding that this labeling resulted in more positive evaluations of the effects of the product on the environment, animal welfare, and health. However, labeling did not directly affect the assessment of the products’ taste or participants’ stated and revealed preferences regarding modifications to their food consumption. Nevertheless, we find evidence that vegetarian labeling indirectly affects the intention to consume more meat substitutes by enhancing climate and health-related product evaluations (i.e., significant mediation effects). Our second experiment shows that tasting meat substitutes results in a more positive assessment of the product's taste and texture than not tasting them. However, tasting did not directly affect the perceived effect of meat substitutes on health, the environment, and animal welfare, nor stated and revealed preferences. In contrast, we find strong indirect effects of the tasting experience on stated and revealed preferences regarding consuming more meat substitutes and plant-based dishes mediated by improvements in product taste and texture evaluations (i.e., significant mediation effects). The theoretical and policy implications of these findings are discussed.ISSN:0950-3293ISSN:1873-634

Attosecond timing of the dynamical Franz–Keldysh effect

To what extent do intra- or inter-band transitions dominate the optical response of dielectrics when pumped by a few-cycle near-infrared transient electric field? In order to find an answer to this question we investigate the dynamical Franz–Keldysh effect in polycrystalline diamond and discuss in detail the attosecond delay of the induced electron dynamics with regard to the driving transient electric field while the peak intensity is varied between 1 × 1012 and 10 × 1012 W cm−2. We found that the main oscillating feature in transient absorption at 43 eV is in phase with the electric field of the pump, to within 49 ± 78 as. However, the phase delay shows a slightly asymmetric V-shaped linear energy dispersion with a rate of about 200 as eV–1. Theoretical calculations within the dipole approximation reproduce the data and allow us to conclude that intra-band motion dominates under our experimental conditions.ISSN:2515-764