I review what is known about the quark and gluon spin distributions in the nucleon. I discuss in some detail (a) the existence of sum rules for angular momentum; (b) the interpretation and possible measurement of the nucleon's transversity distributions; and (c) the uses of spin-dependent fragmentation functions.

The role of hadronization mechanism in polarization phenomena in semi inclusive deep inelastic scattering (SIDIS) and a purity method for extraction of polarized distribution functions are discussed. According to the Monte Carlo (MC) event generator, on which this method is based, hadrons can be produced via quark (diquark) fragmentation or light cluster decays. In contrast, the purity method a...

Background Sperm DNA fragmentation is known as an important cause of male infertility. The influence of sperm DNA damage on reproductive potential has been subject of many studies indicating various results and remaining the subject controversial. In this study, we investigated differences of the semen parameters and intracytoplasmic sperm injection (ICSI) outcome according to sperm DNA fragmen...

We calculate the exact fragmentation functions for c and b quark fragmentation taking into account the spin orientation of the initial heavy quark in the form of analytical and rather simple expressions. Our calculations show that spin orientation may have an important effect on the fragmentation spectrum. This effect is more striking in the cases of c ?D, D*; c? ? , ? , and ?B , B *.

Quantitative application of digital in-line holography (DIH) to characterize multiphase fragmentation is demonstrated. DIH is applied to record sequential holograms of the breakup of an ethanol droplet in an aerodynamic flow field. Various stages of the breakup process are recorded, including deformation, bag growth, bag breakup, and rim breakup. A recently proposed hybrid method is applied to ...

A method is discussed to determine the hitherto unknown u-quark transversity distribution δu(x) from a planned HERMES measurement of a single target-spin asymmetry in semi-inclusive pion electroproduction off a transversely polarized target. Assuming u-quark dominance, the measurement yields the shapes of the transversity distribution δu(x) and of the ratio H 1 (z)/D u 1 (z), of polarized and u...