Hard exclusive photoproduction of Φ\Phi and J/ΨJ/\Psi mesons

We present predictions for differential cross sections for the reaction $\gamma p \to \Phi p$ and give an outlook to which extent our calculations may be generalized to the photoproduction of $J/\Psi$ mesons. Our results are obtained within perturbative QCD treating the proton as a quark-diquark system.Comment: 4 pages, 1 figure, uses Elsevier style espcrc1.st

Construction and commissioning of a room-temperature electron beam ion trap and development of a wire probe injection system

The high-precision Penning-trap mass spectrometer Pentatrap aims at measurements of mass ratios of highly charged ions with an uncertainty of 10−11 and below. An application in neutrino physics is the measurement of the mass ratio of 163Ho and 163Dy for the ECHo collaboration aiming at the determination of an upper limit of the neutrino mass in the sub-eV range. This master thesis reports on the construction and commissioning of a compact room-temperature electron beam ion trap (EBIT) providing highly charged ions of 163Ho for the Pentatrap experiment. For the efficient injection of very small samples of the synthetic radioisotope 163Ho in the range of tens of ng into the EBIT a setup employing the wire probe injection technique was developed and constructed. For the first tests, the EBIT is integrated into a test setup including a Wien filter and an MCP detector as diagnostic equipment for commissioning. Through injection of argon gas, the Wien filter was calibrated and used for the identification of the charge states of extracted xenon ions. Simulations of the charge state evolution for argon and holmium have been performed showing a good agreement with the measurements in the case of argon and giving an estimate of the reachable charge states for holmium. Finally, the developed wire probe injection setup was taken into operation and the first measurements using a gold coated copper wire as wire probe are presented

Universal Control of Nuclear Spins Via Anisotropic Hyperfine Interactions

We show that nuclear spin subsystems can be completely controlled via microwave irradiation of resolved anisotropic hyperfine interactions with a nearby electron spin. Such indirect addressing of the nuclear spins via coupling to an electron allows us to create nuclear spin gates whose operational time is significantly faster than conventional direct addressing methods. We experimentally demonstrate the feasibility of this method on a solid-state ensemble system consisting of one electron and one nuclear spin.Comment: RevTeX4, 8 pages, 8 figure

Effect of a rotating propeller on the separation angle of attack and distortion in ducted propeller inlets

The present study represents an extension of an earlier wind tunnel experiment performed with the P&W 17-in. Advanced Ducted Propeller (ADP) Simulator operating at Mach 0.2. In order to study the effects of a rotating propeller on the inlet flow, data were obtained in the UTRC 10- by 15-Foot Large Subsonic Wind Tunnel with the same hardware and instrumentation, but with the propeller removed. These new tests were performed over a range of flow rates which duplicated flow rates in the powered simulator program. The flow through the inlet was provided by a remotely located vacuum source. A comparison of the results of this flow-through study with the previous data from the powered simulator indicated that in the conventional inlet the propeller produced an increase in the separation angle of attack between 4.0 deg at a specific flow of 22.4 lb/sec-sq ft to 2.7 deg at a higher specific flow of 33.8 lb/sec-sq ft. A similar effect on separation angle of attack was obtained by using stationary blockage rather than a propeller

Genomics and epigenomics: new promises of personalized medicine for cancer patients

Recent years have brought about a marked extension of our understanding of the somatic basis of cancer. Parallel to the large-scale investigation of diverse tumor genomes the knowledge arose that cancer pathologies are most often not restricted to single genomic events. In contrast, a large number of different alterations in the genomes and epigenomes come together and promote the malignant transformation. The combination of mutations, structural variations and epigenetic alterations differs between each tumor, making individual diagnosis and treatment strategies necessary. This view is summarized in the new discipline of personalized medicine. To satisfy the ideas of this approach each tumor needs to be fully characterized and individual diagnostic and therapeutic strategies designed. Here, we will discuss the power of high-throughput sequencing technologies for genomic and epigenomic analyses. We will provide insight into the current status and how these technologies can be transferred to routine clinical usage

Trapped ion mobility spectrometry and PASEF enable in-depth lipidomics from minimal sample amounts

A comprehensive characterization of the lipidome from limited starting material remains very challenging. Here we report a high-sensitivity lipidomics workflow based on nanoflow liquid chromatography and trapped ion mobility spectrometry (TIMS). Taking advantage of parallel accumulation-serial fragmentation (PASEF), we fragment on average 15 precursors in each of 100 ms TIMS scans, while maintaining the full mobility resolution of co-eluting isomers. The acquisition speed of over 100 Hz allows us to obtain MS/MS spectra of the vast majority of isotope patterns. Analyzing 1 mu L of human plasma, PASEF increases the number of identified lipids more than three times over standard TIMS-MS/MS, achieving attomole sensitivity. Building on high intra- and inter-laboratory precision and accuracy of TIMS collisional cross sections (CCS), we compile 1856 lipid CCS values from plasma, liver and cancer cells. Our study establishes PASEF in lipid analysis and paves the way for sensitive, ion mobility-enhanced lipidomics in four dimensions

Transport and recombination through weakly coupled localized spin pairs in semiconductors during coherent spin excitation

Semi-analytical predictions for the transients of spin-dependent transport and recombination rates through localized states in semiconductors during coherent electron spin excitation are made for the case of weakly spin-coupled charge carrier ensembles. The results show that the on-resonant Rabi frequency of electrically or optically detected spin-oscillation doubles abruptly as the strength of the resonant microwave field gamma B_1 exceeds the Larmor frequency separation within the pair of charge carrier states between which the transport or recombination transition takes place. For the case of a Larmor frequency separation of the order of gamma B_1 and arbitrary excitation frequencies, the charge carrier pairs exhibit four different nutation frequencies. From the calculations, a simple set of equations for the prediction of these frequencies is derived

Direct Observation of Quantum Coherence in Single-Molecule Magnets

Direct evidence of quantum coherence in a single-molecule magnet in frozen solution is reported with coherence times as long as T2 = 630 ns. We can strongly increase the coherence time by modifying the matrix in which the single-molecule magnets are embedded. The electron spins are coupled to the proton nuclear spins of both the molecule itself and interestingly, also to those of the solvent. The clear observation of Rabi oscillations indicates that we can manipulate the spin coherently, an essential prerequisite for performing quantum computations.Comment: 5 Pages, 4 Figures, final version published in PR