A transient radio jet in an erupting dwarf nova.
Science 320:5881 (2008) 1318-1320
Abstract:
Astrophysical jets seem to occur in nearly all types of accreting objects, from supermassive black holes to young stellar objects. On the basis of x-ray binaries, a unified scenario describing the disc/jet coupling has evolved and been extended to many accreting objects. The only major exceptions are thought to be cataclysmic variables: Dwarf novae, weakly accreting white dwarfs, show similar outburst behavior to x-ray binaries, but no jet has yet been detected. Here we present radio observations of a dwarf nova in outburst showing variable flat-spectrum radio emission that is best explained as synchrotron emission originating in a transient jet. Both the inferred jet power and the relation to the outburst cycle are analogous to those seen in x-ray binaries, suggesting that the disc/jet coupling mechanism is ubiquitous.First run II measurement of the W boson mass at the Fermilab Tevatron
Physical Review D - Particles, Fields, Gravitation and Cosmology 77:11 (2008)
Abstract:
We describe a measurement of the W boson mass mW using 200pb-1 of s=1.96TeV pp̄ collision data taken with the CDF II detector. With a sample of 63964 W→eν candidates and 51128 W→μν candidates, we measure mW=[80.413±0.034(stat)±0.034(sys)=80.413±0.048]GeV/c2. This is the single most precise mW measurement to date. When combined with other measured electroweak parameters, this result further constrains the properties of new unobserved particles coupling to W and Z bosons. © 2008 The American Physical Society.Determination of the strong phase in D0→K+π- Using quantum-correlated measurements
Physical Review Letters 100:22 (2008)
Abstract:
We exploit the quantum coherence between pair-produced D0 and D̄0 in ψ(3770) decays to study charm mixing, which is characterized by the parameters x and y, and to make a first determination of the relative strong phase δ between D0→K+π- and D̄0→K+π-. Using 281pb-1 of e+e- collision data collected with the CLEO-c detector at Ecm=3.77GeV, as well as branching fraction input and time-integrated measurements of RM(x2+y2)/2 and RWSΓ(D0→K+π-)/Γ(D̄0→K+π-) from other experiments, we find cosδ=1.03-0.17+0.31±0.06, where the uncertainties are statistical and systematic, respectively. By further including other mixing parameter measurements, we obtain an alternate measurement of cosδ=1.10±0.35±0.07, as well as xsinδ=(4.4-1.8+2. 7±2.9)×10-3 and δ=(22-12-11+11+9)°. © 2008 The American Physical Society.Hunting for the Building Blocks of Galaxies like our own Milky Way with FORS
The Messenger 132 (2008) 41-45-41-45