Front-end Electronics for the CALICE/EUDET Calorimeters

The CALICE collaboration is involved in the design of compact calorimeters featuring a high granularity. The technical developments have to overcome various design issues such as the power dissipation, the integration of the front-end electronics inside the detector and connections between the parts. A huge collaborative work is required to achieve the devices using common tools and designs.Comment: 4 pages, 5 figures, talk given at LCWS0

Understanding mixing efficiency in the oceans: Do the nonlinearities of the equation of state matter?

There exist two central measures of turbulent mixing in turbulent stratified fluids, both caused by molecular diffusion: 1) the dissipation rate D(APE) of available potential energy (APE); 2) the turbulent rate of change Wr,turbulent of background potential energy GPEr. So far, these two quantities have often been regarded as the same energy conversion, namely the irreversible conversion of APE into GPEr, owing to D(APE)=Wr,turbulent holding exactly for a Boussinesq fluid with a linear equation of state. It was recently pointed out, however, that this equality no longer holds for a thermally-stratified compressible fluid, the ratio \xi=Wr,turbulent/D(APE) being then lower than unity and sometimes even negative for water/seawater. In this paper, the behavior of the ratio \xi is examined for different stratifications having the same buoyancy frequency N(z), but different vertical profiles of the parameter \Upsilon = \alpha P/(\rho C_p), where \alpha is the thermal expansion, P the hydrostatic pressure, \rho the density, and C_p the isobaric specific heat capacity, the equation of state considered being that for seawater for different particular constant values of salinity. It is found that \xi and Wr,turbulent depend critically on the sign and magnitude of d\Upsilon/dz, in contrast with D(APE), which appears largely unaffected by the latter. These results have important consequences for how the mixing efficiency should be defined and measured.Comment: 17 pages, 5 figures, 1 Table, accepted in Ocean Science (special issue on seawater) on July 10th 200

Remarks on nonlinear Schroedinger equations with harmonic potential

Bose-Einstein condensation is usually modeled by nonlinear Schroedinger equations with harmonic potential. We study the Cauchy problem for these equations. We show that the local problem can be treated as in the case with no potential. For the global problem, we establish an evolution law, which is the analogue of the pseudo-conformal conservation law for the nonlinear Schroedinger equation. With this evolution law, we give wave collapse criteria, as well as an upper bound for the blow up time. Taking the physical scales into account, we finally give a lower bound for the blow up time.Comment: 16 pages, no figur

Bs0 Decays at Belle

The large data sample recorded with the Belle detector at the Y(5S) energy provides a unique opportunity to study the poorly-known Bs0 meson. Several analyses, made with a data sample representing an integrated luminosity of 23.6 /fb, are presented. We report the study of the large-signal Bs0 -> Ds(*)- h+ (h+ = pi+ or rho+) decays including the first observations of Bs0 -> Ds*- pi+ and Bs0 -> Ds(*)- rho+. In addition, several results on CP-eigenstate Bs0 decays are described. These include the study of the Bs0 -> J/psi eta(') and Bs0 -> J/psi f0(980) decays, the charmless Bs0 -> K+ K-, Bs0 -> pi+ pi pi- and Bs0 -> Kshort Kshort decays and the simultaneous fit of the three Bs0 -> Ds(*)Ds(*) modes from which Delta(Gamma_s)/Gamma_s is extracted. The preliminary measurement of B(Bs0 -> J/psi f0(980))<1.63x10^-4 (at 90% C.L.) is presented for the first time.Comment: 10 pages, 7 figures. To appear in the proceedings of the "Flavor Physics and CP Violation 2010" (FPCP2010) conference, May 25-29, Turin, Italy. v2: Accepted version, Ref. [27] and [42] adde