Various decay processes that are forbidden in the vacuum by a combination of requirements such as angular momentum conservation and Lorentz invariance, can occur if the decaying particle is propagating in a medium, even if the medium is homogeneous and isotropic. Here we consider specifically the decay of a neutrino into another neutrino and a graviton, in a thermal background of electrons. The...

The structure of tree–level open and closed superstring amplitudes is analyzed. For the open superstring amplitude we find a striking and elegant form, which allows to disentangle its α–expansion into several contributions accounting for different classes of multiple zeta values. This form is bolstered by the decomposition of motivic multiple zeta values, i.e. the latter encapsulate the α–expan...

The strong decays of excited nonstrange baryons into the final states ΛK, ΣK, and for the first time into Λ(1405)K, Λ(1520)K, Σ(1385)K, ΛK∗, and ΣK∗, are examined in a relativized quark pair creation model. The wave functions and parameters of the model are fixed by previous calculations of Nπ and Nππ, etc., decays. Our results show that it should be possible to discover several new negative pa...

The rouge waves in an optically injected semiconductor lasers are receiving a lot of interest. In this work, the generating and controlling of the rogue waves in semiconductor lasers have been investigated. For this purpose, the laser’s rate equations are solved numerically in a specified time interval, then the field amplitude and the intensity versus time are calculated and analyzed. To solve...

the aim of this study was to determine the most suitable shaking frequency and amplitude for shake harvesting esfahan's edible fig (ficus carica cv. sabz). a hand held limb shaker with adjustable shaking frequency and amplitude was used for this study. a 3x3 factorial experiment with three levels of oscillating frequency (10, 12 and 14 hz) and three levels of shaking amplitude (20, 32.5 and 45 ...