R&D for a Dedicated Fast Timing Layer in the CMS Endcap Upgrade

The PhaseII Upgrades of CMS are being planned for the High Luminosity LHC (HL-LHC) era when the mean number of interactions per beam crossing ("in-time pileup") is expected to reach ~140-200. The potential backgrounds arising from mis-associated jets and photon showers, for example, during event reconstruction could be reduced if physics objects are tagged with an "event time". This tag is fully complementary to the "event vertex" which is already commonly used to reduce mis-reconstruction. Since the tracking vertex resolution is typically ~10^{-3} (50 micron/4.8cm) of the rms vertex distribution, whereas only ~10^{-1} (i.e. 20 vs.170 picoseconds (psec)) is demonstrated for timing, it is often assumed that only photon (i.e. EM calorimeter or shower-max) timing is of interest. We show that the optimal solution will likely be a single timing layer which measures both charged particle and photon time (a pre-shower layer).Comment: Proceedings of the 2014 Workshop on Picosecond Photon Sensors for Physics and Medical Applications, Clermont Ferrand. 9 pages, 4 figure

Diffraction Dissociation - 50 Years Later

The field of Diffraction Dissociation, which is the subject of this workshop, began 50 years ago with the analysis of deuteron stripping in low energy collisions with nuclei. We return to the subject in a modern context- deuteron dissociation in $\sqrt{s_{NN}}= 200$ GeV d-Au collisions recorded during the 2003 RHIC run in the PHENIX experiment. At RHIC energy, d$\to$n+p proceeds predominantly (90%) through Electromagnetic Dissociation and the remaining fraction via the hadronic shadowing described by Glauber. Since the dissociation cross section has a small theoretical error we adopt this process to normalize other cross sections measured in RHIC.Comment: Submitted to: Proceedings of DIS05 conference, Diffraction and Vector Meson Working Group. 5 pages,2 figure

Tenure Profiles and Efficient Separation in a Stochastic Productivity Model

This paper provides a new way of analyzing tenure profiles in wages, by modelling simultaneously the evolution of wages and the distribution of tenures. We develop a theoretical model based on efficient bargaining, where both log outside wage and log wage in the current job follow a random walk, as found empirically. This setting allows the application of real option theory. We derive the efficient separation rule. The model fits the observed distribution of job tenures well. Since we observe outside wages only at job start and job separation, our empirical analysis of within job wage growth is based on expected wage growth conditional on the outside wages at both dates. Our modelling allows testing of the efficient bargaining hypothesis. The model is estimated on the PSID.random productivity growth, efficient bargaining, job tenure, inverse gaussian, wage-tenure profiles, option theory