Atomic Parity Nonconservation and Nuclear Anapole Moments

Anapole moments are parity-odd, time-reversal-even moments of the E1 projection of the electromagnetic current. Although it was recognized, soon after the discovery of parity violation in the weak interaction, that elementary particles and composite systems like nuclei must have anapole moments, it proved difficult to isolate this weak radiative correction. The first successful measurement, an extraction of the nuclear anapole moment of 133Cs from the hyperfine dependence of the atomic parity violation, was obtained only recently. An important anapole moment bound in Tl also exists. We discuss these measurements and their significance as tests of the hadronic weak interaction, focusing on the mechanisms that operate within the nucleus to generate the anapole moment. The atomic results place new constraints on weak meson-nucleon couplings, ones we compare to existing bounds from a variety of p-p and nuclear tests of parity nonconservation.Comment: 35 pages; 8 figures; late

Double-logs, Gribov-Lipatov reciprocity and wrapping

We study analytical properties of the five-loop anomalous dimension of twist-2 operators at negative even values of Lorentz spin. Following L. N. Lipatov and A. I. Onishchenko, we have found two possible generalizations of double-logarithmic equation, which allow to predict a lot of poles of anomalous dimension of twist-2 operators at all orders of perturbative theory from the known results. Second generalization is related with the reciprocity-respecting function, which is a single-logarithmic function in this case. We have found, that the knowledge of first orders of the reciprocity-respecting function gives all-loop predictions for the highest poles. Obtained predictions can be used for the reconstruction of a general form of the wrapping corrections for twist-2 operators.Comment: 17 pages, references adde

Size- and temperature-independence of minimum life-supporting metabolic rates

1. Mass-specific metabolic rates of 173 animal species under various conditions of prolonged food deprivation (aestivation, hibernation, sit-and-wait existence) and/or living at temperatures near the freezing point of water were analysed. 2. These minimum life-supporting metabolic rates are independent of body mass over a nearly 80-million-fold body mass range and independent of temperature over a range of -1.7 to 30 degrees C, with a mean value of 0.1 W kg(-1) and 95% CI from 0.02 to 0.67 W kg(-1). 3. Additionally, 66 measurements of anoxic metabolic rates in 32 species capable of surviving at least 1 h of anoxia were analysed. While similarly mass-independent, anoxic metabolic rates are significantly more widely scattered (1200-fold 95% CI); they are on average one order of magnitude lower than during normoxia and depend on temperature with Q(10) = 2.8. 4. Energy losses at the time of 50% mortality during anoxia are 30-300 times smaller than the energy losses tolerated by normoxic organisms in the various energy-saving regimes studied. 5. These principal differences form the basis for proposing two alternative strategies by which organisms survive environmental stress: the regime of abandoned metabolic control ('slow death'), when, as in anoxic obligate aerobes, measured rates of energy dissipation can predominantly reflect chaotic processes of tissue degradation rather than meaningful biochemical reactions; and the regime of minimum metabolic control, when biochemical order is sustained at the expense of ordered metabolic reactions. Death or survival in the regime of abandoned metabolic control is dictated by the amount of accumulated biochemical damage and not by the available energy resources, as it is in the regime of minimum metabolic control.Ctr Invas Bio

Where do winds come from? a new theory on how water vapor condensation influences atmospheric pressure and dynamics

Phase transitions of atmospheric water play a ubiquitous role in the Earth\u27s climate system, but their direct impact on atmospheric dynamics has escaped wide attention. Here we examine and advance a theory as to how condensation influences atmospheric pressure through the mass removal of water from the gas phase with a simultaneous account of the latent heat release. Building from fundamental physical principles we show that condensation is associated with a decline in air pressure in the lower atmosphere. This decline occurs up to a certain height, which ranges from 3 to 4 km for surface temperatures from 10 to 30 °C. We then estimate the horizontal pressure differences associated with water vapor condensation and find that these are comparable in magnitude with the pressure differences driving observed circulation patterns. The water vapor delivered to the atmosphere via evaporation represents a store of potential energy available to accelerate air and thus drive winds. Our estimates suggest that the global mean power at which this potential energy is released by condensation is around one per cent of the global solar power – this is similar to the known stationary dissipative power of general atmospheric circulation. We conclude that condensation and evaporation merit attention as major, if previously overlooked, factors in driving atmospheric dynamics