Bs,d→ππ,πK,KK: status and prospects

Several years ago, it was pointed out that the U-spin-related decays B_d→π⁺π^-, B_s→K⁺K^- and B_d→π^∓K^±, B_s→π^±K^∓ offer interesting strategies for the extraction of the angle γ of the unitarity triangle. Using the first results from the Tevatron on the B_s decays and the B-factory data on B_u,d modes, we compare the determinations of γ from both strategies, study the sensitivity on U-spin-breaking effects, discuss the resolution of discrete ambiguities, predict observables that were not yet measured but will be accessible at LHCb, explore the extraction of the width difference ΔΓ_s from untagged B_s→K⁺K^- rates, and address the impact of new physics. The data for the B_d→π⁺π^-, B_s→K⁺K^- system favour the BaBar measurement of direct CP violation in B_d→π⁺π^-, which will be used in the numerical analysis and result in a fortunate situation, yielding γ=(66.6^+4.3+4.0 _-5.0-3.0)^°, where the latter errors correspond to a generous estimate of U-spin-breaking effects. On the other hand, the B_d→π^∓K^±, B_s→π^±K^∓ analysis leaves us with 26°≤γ≤70°, and points to a value of the B_s→π^±K^∓ branching ratio that is larger than the current Tevatron result. An important further step will be the measurement of mixing-induced CP violation in B_s→K⁺K^-, which will also allow us to extract the B⁰ _s–B̄⁰ _s mixing phase unambiguously with the help of B_s→J/ψφ at the LHC. Finally, the measurement of direct CP violation in B_s→K⁺K^- will make the full exploitation of the physics potential of the B_s,d→ππ,πK,KK modes possible.     

Characterization of the morphology and composition of commercial negative resists used for lithographic processes

We present a spectroscopic and microscopic characterization of the chemical composition, structure, and morphology of two commercial negative resists using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). For this purpose, films of a novolak-based resist (ma-N 2400) and hydrogen silsesquioxane (HSQ) are treated under different conditions (temperature, deep ultraviolet (DUV) exposure, CHF₃ plasma). Topographic AFM images show that both heating and DUV exposure strongly affect the surface morphology of as-prepared ma-N 2400 resist films. These different treatment conditions also lead to decreasing roughnesses, which indicates structural reorganization. Furthermore, the decrease of the photoactive compound (bisazide) in the ma-N 2400 resist films, observed in FTIR spectra, suggests cross-linking of the resist after CHF₃ plasma treatment, heating, or DUV exposure. XPS measurements on different CHF₃ plasma-treated surfaces reveal that a structurally homogeneous fluorine-containing polymer is generated that is responsible for an enhanced etch resistance. FTIR measurements of HSQ films show a correlation between the degree of HSQ cross-linking and baking time.     

Self-diffusion of multiarm star polymers in solution far from and near the ordering transition

The self-diffusion of three 128-arm polybutadiene star solutions in toluene was investigated over a broad concentration range from dilute to the ordering region with pulsed field gradient NMR (PFG-NMR). The strong concentration dependence of the self-diffusion coefficient in the fluid state is distinguished clearly from that of linear chains and can be described by a non-Arrhenius VFT-like equation with the concentration playing the role of inverse temperature. In the concentrated regime, the observation of two dynamic phases reflects the coexistence of crystalline and liquid phases over a limited concentration region. The concentration dependences of both the ordinary (fluid-like) diffusion and the completely restricted in-cage motion of these hyper stars are in agreement with the behavior of concentrated colloidal suspensions.     

Bestimmung des Kalis in Form von Weinstein und Trennung des Kalis vom Natron

Ohne Zusammenfassung     

Die Erhöhung des lichtelektrischen Effektes von Kalium durch Wasserstoff

Zeitschrift für Physik A Hadrons and nuclei - Es werden Versuche beschrieben, die den Schluß zulassen, daß zur Herstellung einer lichtelektrisch hochempfindlichen...     

Probing angular correlations in sequential double ionization

We study electron correlation in sequential double ionization of noble gas atoms and HCl in intense, femtosecond laser pulses. We measure the photoelectron angular distributions of Ne+ relative to the first electron in a pump-probe experiment with 8 fs, 800 nm, circularly polarized laser pulses at a peak intensity of a few 10(15) W/cm2. Using a linear-linear pump-probe setup, we further study He, Ar, and HCl. We find a clear angular correlation between the two ionization steps in the sequential double ionization intensity regime.     

Molecular orientation and alignment by intense single-cycle THz pulses

Intense single-cycle THz pulses resonantly interacting with molecular rotations are shown to induce field-free orientation and alignment under ambient conditions. We calculate and measure the degree of both orientation and alignment induced by the THz field in an OCS gas sample, and correlate between the two observables. The data presents the first observation of THz-induced molecular alignment in the gas phase.