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, 1.37 MJ of fusion for 1.92 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

First measurement of the left-right cross-section asymmetry in Z boson production by e+ e- collisions

We present the first measurement of the left-right cross section asymmetry (A(LR)) for Z boson production by e+e- collisions. The measurement was performed at a center-of-mass energy of 91.55 GeV with the SLD detector at the SLAC Linear Collider which utilized a longitudinally polarized electron beam. The average beam polarization was (22.4 +/- 0.6)%. Using a sample of 10224 Z decays, we measure A(LR) to be 0.100 +/- 0.044(stat) +/- 0.004(syst), which determines the effective weak mixing angle to be sin2theta(W)eff=0.2378 +/- 0.0056(stat) +/- 0.0005(syst)