Swift, high resolution CMOS pixel sensors are being developed for the ILC vertex detector, aiming to allow approaching the interaction point very closely. A major issue is the time resolution of the sensors needed to deal with the high occupancy gene
rated by the beam related background. A 128x576 pixel sensor providing digitised outputs at a read-out time of 92.5 us, was fabricated in 2008 within the EU project EUDET, and tested with charged particles at the CERN-SPS. Its prominent performances in terms of noise, detection efficiency versus fake hit rate, spatial resolution and radiation tolerance are overviewed. They validate the sensor architecture.
The impact of the incoherent electron-positron pairs from beamstrahlung on the occupancy of the vertex detector (VXD) for the International Large Detector concept (ILD) has been studied, based on the standard ILD simulation tools. The occupancy was e
valuated for two substantially different sensor technology in order to estimate the importance of the latter. The influence of an anti-DID field removing backscattered electrons has also been studied.
The beam spin asymmetry (BSA) in the exclusive reaction ep->ep pi0 was measured with the CEBAF 5.77 GeV polarized electron beam and Large Acceptance Spectrometer(CLAS). The xB, Q2, t and phi dependences of the pi0 BSA are presented in the deep inelas
tic regime. The asymmetries are fitted with a sin(phi) function and their amplitudes are extracted. Overall, they are of the order of 0.04 - 0.11 and roughly independent of t. This is the signature of a non-zero longitudinal-transverse interference. The implications concerning the applicability of a formalism based on generalized parton distributions, as well as the extension of a Regge formalism at high photon virtualities, are discussed.
