SIMDET - Version 4 A Parametric Monte Carlo for a TESLA Detector

A new release of the parametric detector Monte Carlo program \verb+SIMDET+ (version 4.01) is now available. We describe the principles of operation and the usage of this program to simulate the response of a detector for the TESLA linear collider. The detector components are implemented according to the TESLA Technical Design Report. All detector component responses are treated in a realistic way using a parametrisation of results from the {\em ab initio} Monte Carlo program \verb+BRAHMS+. Pattern recognition is emulated using a complete cross reference between generated particles and detector response. Also, for charged particles, the covariance matrix and $dE/dx$ information are made available. An idealised energy flow algorithm defines the output of the program, consisting of particles generically classified as electrons, photons, muons, charged and neutral hadrons as well as unresolved clusters. The program parameters adjustable by the user are described in detail. User hooks inside the program and the output data structure are documented.Comment: 30 pages, 7 figure

Influence of electron-ion collisions on Coulomb crystallization of ultracold neutral plasmas

While ion heating by elastic electron-ion collisions may be neglected for a description of the evolution of freely expanding ultracold neutral plasmas, the situation is different in scenarios where the ions are laser-cooled during the system evolution. We show that electron-ion collisions in laser-cooled plasmas influence the ionic temperature, decreasing the degree of correlation obtainable in such systems. However, taking into account the collisions increases the ion temperature much less than what would be estimated based on static plasma clouds neglecting the plasma expansion. The latter leads to both adiabatic cooling of the ions as well as, more importantly, a rapid decrease of the collisional heating rate

Dynamical Crystallization in the Dipole Blockade of Ultracold Atoms

We describe a method for controlling many-body states in extended ensembles of Rydberg atoms, forming crystalline structures during laser excitation of a frozen atomic gas. Specifically, we predict the existence of an excitation number staircase in laser excitation of atomic ensembles into Rydberg states. Each step corresponds to a crystalline state with a well-defined of regularly spaced Rydberg atoms. We show that such states can be selectively excited by chirped laser pulses. Finally, we demonstarte that, sing quantum state transfer from atoms to light, such crystals can be used to create crystalline photonic states and can be probed via photon correlation measurements

Charged Current Neutrino Nucleus Interactions at Intermediate Energies

We have developed a model to describe the interactions of neutrinos with nucleons and nuclei, focusing on the region of the quasielastic and Delta(1232) peaks. We describe neutrino nucleon collisions with a fully relativistic formalism which incorporates state-of-the-art parametrizations of the form factors for both the nucleon and the N-Delta transition. The model has then been extended to finite nuclei, taking into account nuclear effects such as Fermi motion, Pauli blocking (both within the local density approximation), nuclear binding and final state interactions. The in-medium modification of the Delta resonance due to Pauli blocking and collisional broadening have also been included. Final state interactions are implemented by means of the Boltzmann-Uehling-Uhlenbeck (BUU) coupled-channel transport model. Results for charged current inclusive cross sections and exclusive channels as pion production and nucleon knockout are presented and discussed.Comment: 26 pages, 24 figures; v2: 2 figures and discussion added, version accepted for publication in Phys. Rev.

Relaxation to non-equilibrium in expanding ultracold neutral plasmas

We investigate the strongly correlated ion dynamics and the degree of coupling achievable in the evolution of freely expanding ultracold neutral plasmas. We demonstrate that the ionic Coulomb coupling parameter $\Gamma_{\rm i}$ increases considerably in later stages of the expansion, reaching the strongly coupled regime despite the well-known initial drop of $\Gamma_{\rm i}$ to order unity due to disorder-induced heating. Furthermore, we formulate a suitable measure of correlation and show th at $\Gamma_{\rm i}$ calculated from the ionic temperature and density reflects the degree of order in the system if it is sufficiently close to a quasisteady state. At later times, however, the expansion of the plasma cloud becomes faster than the relaxation of correlations, and the system does not reach thermodynamic equilibrium anymore