Glides and initial vowels within the onset prominence representational environment
This paper discusses the notion of "onsets" within the Onset Prominence representational environment (OP; e.g. Schwartz 2010, 2013), with empirical focus on the representation of glides and initial vowels. Both glides and initial vowels have been shown to exhibit ambiguous behavior across languages, which has been problematic for representational theories based on a linear string of segments. The OP environment is based on a hierarchy of phonetic events, incorporating structural ambiguities that may serve as parameter settings for the dual behavior of both glides and initial vowels. This approach eliminates the need for an ONSET constraint, and offers an explicit reference point by which the concept of markedness in prosodic structure may be defined.
We study in perturbative QCD the helicity amplitudes of the process ${\ensuremath{\gamma}}^{*}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\rho}p$ at large virtualities Q of the photon ${\ensuremath{\gamma}}^{*}.$ We estimate all spin-flip amplitudes taking into account an important effect of the scale behavior of the gluon density. The transition of a transverse virtual photon to a longitudinal vector meson is not small at typical conditions at the DESY ep collider HERA. This helicity nonconserving amplitude leads by interference to a measurable effect in the distribution of the angle between the electron scattering and the meson production planes.