Search for resonant tt̄ production in pp̄ collisions at s=1.96TeV
Physical Review Letters 100:23 (2008)
Abstract:
We report on a search for narrow-width particles decaying to a top and antitop quark pair. The data set used in the analysis corresponds to an integrated luminosity of 680pb-1 collected with the Collider Detector at Fermilab in run II. We present 95% confidence level upper limits on the cross section times branching ratio. Assuming a specific top-color-assisted technicolor production model, the leptophobic Z′ with width ΓZ′=0.012MZ′, we exclude the mass range MZ′<725GeV/c2 at the 95% confidence level. © 2008 The American Physical Society.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)