Simulation and experimental qualification of the response of microstrip detectors to ion beams
In the framework of the construction of a novel Femtoscope Array for Correlation and Spectroscopy, named FARCOS, aiming at the identification in charge and mass even of particles stopping in the first detection layer, we are performing a thorough characterization of the silicon detector layers in terms of the collection properties as a function of the point of incidence. We have experimental evidence - as previously observed also in the literature for other strip detectors - that interstrip incidence alters the signal shape not only for the trivial effect of charge sharing but also because of induction effects on neighbor strips. In order to clarify this issue we developed a custom simulation suite of the electron-hole transport and signal formation able to properly describe 3-D Coulomb interaction and thermal diffusion in semiconductor detectors. We ran a batch of significant and representative simulations presenting the qualitative correct interpretation and the quantitative validation as proved by the comparison of the simulation results with the experimental data.
Correlations and characterization of emitting sources
Abstract.Dynamical and thermal characterizations of excited nuclear systems produced during the collisions between two heavy ions at intermediate incident energies are presented by means of a review of experimental and theoretical work performed in the last two decades. Intensity interferometry, applied to both charged particles (light particles and intermediate mass fragments) and to uncharged radiation (gamma rays and neutrons) has provided relevant information about the space-time properties of nuclear reactions. The volume, lifetime, density and relative chronology of particle emission from decaying nuclear sources have been extensively explored and have provided valuable information about the dynamics of heavy-ion collisions. Similar correlation techniques applied to coincidences between light particles and complex fragments are also presented as a tool to determine the internal excitation energy of excited primary fragments as it appears in secondary-decay phenomena.
Relations between Heavy-light Meson and Quark Masses
The study of heavy-light meson masses should provide a way to determine renormalized quark masses and other properties of heavy-light mesons. In the context of lattice QCD, for example, it is possible to calculate hadronic quantities for arbitrary values of the quark masses. In this paper, we address two aspects relating heavy-light meson masses to the quark masses. First, we introduce a definition of the renormalized quark mass that is free of both scale dependence and renormalon ambiguities, and discuss its relation to more familiar definitions of the quark mass. We then show how this definition enters a merger of the descriptions of heavy-light masses in heavy-quark effective theory and in chiral perturbation theory ($\chi$PT). For practical implementations of this merger, we extend the one-loop $\chi$PT corrections to lattice gauge theory with heavy-light mesons composed of staggered fermions for both quarks. Putting everything together, we obtain a practical formula to describe all-staggered heavy-light meson masses in terms of quark masses as well as some lattice artifacts related to staggered fermions. In a companion paper, we use this function to analyze lattice-QCD data and extract quark masses and some matrix elements defined in heavy-quark effective theory.