2 research outputs found
Narrow-band search of continuous gravitational-wave signals from Crab and Vela pulsars in Virgo VSR4 data
In this paper we present the results of a coherent narrow-band search for continuous gravitational-wave signals from the Crab and Vela pulsars conducted on Virgo VSR4 data. In order to take into account a possible small mismatch between the gravitational-wave frequency and two times the star rotation frequency, inferred from measurement of the electromagnetic pulse rate, a range of 0.02 Hz around two times the star rotational frequency has been searched for both the pulsars. No evidence for a signal has been found and 95% confidence level upper limits have been computed assuming both that polarization parameters are completely unknown and that they are known with some uncertainty, as derived from x-ray observations of the pulsar wind torii. For Vela the upper limits are comparable to the spin-down limit, computed assuming that all the observed spin-down is due to the emission of gravitational waves. For Crab the upper limits are about a factor of 2 below the spin-down limit, and represent a significant improvement with respect to past analysis. This is the first time the spin-down limit is significantly overcome in a narrow-band search.by Anand Sengupta et al
{Measurement of charm production at central rapidity in proton-proton collisions at TeV}
he pt-differential inclusive production cross sections of the prompt charmed
mesons D0, D+, and D∗+ in the rapidity range |y| < 0.5 were measured in proton-proton
collisions at √s = 7 TeV at the LHC using the ALICE detector. Reconstructing the decays
D0 → K−π+, D+ → K−π+π+, D∗+ → D0π+, and their charge conjugates, about 8,400 D0,
2,900 D+, and 2,600 D∗+ mesons with 1 < pt < 24 GeV/c were counted, after selection
cuts, in a data sample of 3.14×108 events collected with a minimum-bias trigger (integrated
luminosity Lint = 5 nb−1). The results are described within uncertainties by predictions
based on perturbative QCD