30 research outputs found
Limits on Anomalous Couplings from Events at TeV
We have measured the gauge boson coupling parameters using
() events at TeV. The
data, corresponding to an integrated luminosity of 89.1 pb^{-1}, were collected
using the D0 detector at the Fermilab Tevatron Collider. The measured cross
section times branching ratio for with >
10 GeV/c and is pb, in
agreement with the Standard Model prediction. The one degree of freedom 95%
confidence level limits on individual CP-conserving parameters are
and . Similar limits are set on
the CP}violating coupling parameters.Comment: 10 pages, including two figures. Paper submitted to Phys. Rev. Let
Lawson criterion for ignition exceeded in an inertial fusion experiment
For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37Â MJ of fusion for 1.92Â MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion
Role of terbium hydride additions in the formation of microstructure and magnetic properties of sintered Nd-Pr-Dy-Fe-B magnets
Structure and properties of chromium-molybdenum steel modified by the addition of fullerenes and carbon nanotubes
Advanced-ignition-concept exploration on OMEGA
Advanced ignition concepts, such as fast ignition and shock ignition, are being investigated at the Omega Laser Facility. Integrated fast-ignition experiments with room-temperature re-entrant cone targets have begun, using 18 kJ of 351 nm drive energy to implode empty 40 νm thick CD shells, followed by 1.0 kJ of 1053 nm wavelength, short-pulse energy. Short pulses of 10 ps width have irradiated the inside of a hollow gold re-entrant cone at the time of peak compression. A threefold increase in the time-integrated, 2 to 7 keV x-ray emission was observed with x-ray pinhole cameras, indicating that energy is coupled from the short-pulse laser into the core by fast electrons. In shock-ignition experiments, spherical plastic-shell targets were compressed to high areal densities on a low adiabat, and a strong shock wave was sent into the converging, compressed capsule. In one experiment, 60 beams were used with an intensity spike at the end of the laser pulse, and the implosion performance was studied through neutron-yield and areal-density measurements. In a second experiment, the 60 OMEGA beams were split into a 40+20 configuration, with 40 low-intensity beams used for fuel assembly and 20 delayed beams with a short, high-intensity pulse shape (up to 1 × 1016 W cm-2) for shock generation. © 2009 IOP Publishing Ltd
Structural evolution of CaF2 nanoparticles during the photoinduced crystallization of a Na2O–K2O–CaO–CaF2–Al2O3–ZnO–SiO2 glass
4.1N is involved in a flotillin-1/β-catenin/Wnt pathway and suppresses cell proliferation and migration in non-small cell lung cancer cell lines
Bulgaria: sea-level change and submerged settlements on the Black Sea
The Black Sea is recognised as having great potential for the preservation of submerged prehistoric sites because of the large area of land exposed on the continental shelf at lowest sea levels, especially along its western and north-western coastlines. However, very few have been discovered to date, and those that are known are located in Bulgaria. Because of the complexities associated with the periodic isolation of the Black Sea from the Mediterranean and its reconnection, offshore research has tended to focus on geological and geophysical investigation of inundation history, with unresolved and strongly-held disagreements about the timing and rapidity of sea level rise at the end of the Last Glacial and its potential human impact. In Bulgaria, a rich concentration of underwater prehistoric sites has been discovered thanks to dredging activities earlier in the 20th century and a long tradition of underwater archaeological investigations going back to the 1970s. These demonstrate the presence of substantial in situ village settlements of Eneolithic and Early Bronze Age date in shallow water (< 10 m), with excellent preservation of large ceramic assemblages, wooden structures, and faunal and palynological data on palaeodiet and palaeoeconomy. More recently, large scale marine-geological and archaeological projects have begun, aimed at integrating shallow-water inshore investigations with offshore survey in deeper water