Search for doubly charged Higgs bosons with lepton-flavor-violating decays involving tau leptons

We search for pair production of doubly charged Higgs particles (H+/- +/-) followed by decays into electron-tau (etau) and muon-tau (mutau) pairs using data (350 pb(-1) collected from [over]pp collisions at sqrt[s]=1.96 TeV by the CDF II experiment. We search separately for cases where three or four final-state leptons are detected, and combine results for exclusive decays to left-handed etau (mutau) pairs. We set an H+/- +/- lower mass limit of 114(112) GeV/c(2) at the 95% confidence level.     

Pattern formation in the ferrocyanide-iodate-sulfite reaction: the control of space scale separation

We revisit the conditions for the development of reaction-diffusion patterns in the ferrocyanide-iodate-sulfite bistable and oscillatory reaction. This hydrogen ion autoactivated reaction is the only example known to produce sustained stationary lamellar patterns and a wealth of other spatio-temporal phenomena including self-replication and localized oscillatory domain of spots, due to repulsive front interactions and to a parity-breaking front bifurcation (nonequilibrium Ising-Bloch bifurcation). We show experimentally that the space scale separation necessary for the observation of stationary patterns is mediated by the presence of low mobility weak acid functional groups. The presence of such groups was overlooked in the original observations made with hydrolyzable polyacrylamide gels. This missing information made the original observations difficult to reproduce and frustrated further experimental exploitation of the fantastic potentialities of this system. Using one-side-fed spatial reactors filled with agarose gel, we can reproduce all the previous pattern observations, in particular the stationary labyrinthine patterns, by introducing, above a critical concentration, well controlled amounts of polyacrylate chains in the gel network. We use two different geometries of spatial reactors (annular and disk shapes) to provide complementary information on the actual three-dimensional character of spatial patterns. We also reinvestigate the role of other feed parameters and show that the system exhibits both a domain of spatial bistability and of large-amplitude pH oscillations associated in a typical cross-shape diagram. The experimental method presented here can be adapted to produce patterns in the large number of oscillatory and bistable reactions, since the iodate-sulfite-ferrocynide reaction is a prototype of these systems.     

A version of Stöber synthesis enabling the facile prediction of silica nanospheres size for the fabrication of opal photonic crystals

A sol-gel synthesis procedure based on the method proposed by Stöber et al. (J Colloid Interface Sci 26:302–315, 1968) has been adopted for the one-step preparation of mono-dispersed silica nanospheres. An excellent control of the particle diameter over a wide range is obtained by varying the amount of silicon alkoxide only, while the concentration of all other components is kept fixed: this allows the fabrication of artificial opals with a finely tuned and precisely predictable lattice parameter.     

The perihelion of Mercury advance and the light bending calculated in (enhanced) Newton’s theory

Quantum fluctuations of a real massless scalar field are studied in the context of the generalized uncertainty principle (GUP). The dynamical finite vacuum energy is found in spatially flat Friedmann–Robertson–Walker spacetime which can be identified as dark energy to explain late time cosmic speed-up. The results show that a tiny deviation from the standard uncertainty principle is necessary on cosmological ground. By using the observational data we have constraint the GUP parameter even more stronger than ever.     

Analytic solution for the nondegenerate quantum control problem

We present an analytic solution for the nondegenerate quantum control problem, i.e., the transfer of a deliberate amount of population, 0%-100%, between arbitrary initial Psi(t)> and final Psi'(t)> states, which can be expanded in terms of nondegenerate energy eigenstates k>. The solution constitutes a robust two-photon multicomponent adiabatic passage, via an intermediate eigenstate 0>, which relies on three types of "null states."     

Exclusive measurement of the pp --> pppi(+)pi(-) reaction near threshold

The pp-->pp pi(+) pi(-) reaction has been measured exclusively near threshold at CELSIUS. The total cross sections are nearly an order of magnitude lower than expected from previous inclusive measurements. The differential cross sections reveal pp-->pp(*)(1440)-->pp sigma = pp(pi(+)pi(-))(I = l = 0) as the dominant process as well as significant contributions from p(*)-->Delta(++)pi(-)-->psigma. The observed anisotropy in the proton angular dependence is consistent with heavy-meson exchange. In the invariant mass spectra, no narrow structures of statistical relevance (3sigma) are found.