44,370 research outputs found
Is MS1054-03 an exceptional cluster? A new investigation of ROSAT/HRI X-ray data
We reanalyzed the ROSAT/HRI observation of MS1054-03, optimizing the channel
HRI selection and including a new exposure of 68 ksec. From a wavelet analysis
of the HRI image we identify the main cluster component and find evidence for
substructure in the west, which might either be a group of galaxies falling
onto the cluster or a foreground source. Our 1-D and 2-D analysis of the data
show that the cluster can be fitted well by a classical betamodel centered only
20arcsec away from the central cD galaxy. The core radius and beta values
derived from the spherical model(beta = 0.96_-0.22^+0.48) and the elliptical
model (beta = 0.73+/-0.18) are consistent. We derived the gas mass and total
mass of the cluster from the betamodel fit and the previously published ASCA
temperature (12.3^{+3.1}_{-2.2} keV). The gas mass fraction at the virial
radius is fgas = (14[-3,+2.5]+/-3)% for Omega_0=1, where the errors in brackets
come from the uncertainty on the temperature and the remaining errors from the
HRI imaging data. The gas mass fraction computed for the best fit ASCA
temperature is significantly lower than found for nearby hot clusters,
fgas=20.1pm 1.6%. This local value can be matched if the actual virial
temperature of MS1054-032 were close to the lower ASCA limit (~10keV) with an
even lower value of 8 keV giving the best agreement. Such a bias between the
virial and measured temperature could be due to the presence of shock waves in
the intracluster medium stemming from recent mergers. Another possibility, that
reconciles a high temperature with the local gas mass fraction, is the
existence of a non zero cosmological constant.Comment: 12 pages, 5 figures, accepted for publication in Ap
production at NNLO including anomalous couplings
In this paper we present a next-to-next-to-leading order (NNLO) QCD
calculation of the processes and that we have implemented in MCFM. Our calculation includes
QCD corrections at NNLO both for the Standard Model (SM) and additionally in
the presence of and anomalous couplings. We compare
our implementation, obtained using the jettiness slicing approach, with a
previous SM calculation and find broad agreement. Focusing on the sensitivity
of our results to the slicing parameter, we show that using our setup we are
able to compute NNLO cross sections with numerical uncertainties of about
, which is small compared to residual scale uncertainties of a few
percent. We study potential improvements using two different jettiness
definitions and the inclusion of power corrections. At TeV we
present phenomenological results and consider as a background to
production. We find that, with typical cuts, the inclusion of
NNLO corrections represents a small effect and loosens the extraction of limits
on anomalous couplings by about .Comment: 30 pages, 14 figure
Strong entanglement causes low gate fidelity in inaccurate one-way quantum computation
We study how entanglement among the register qubits affects the gate fidelity
in the one-way quantum computation if a measurement is inaccurate. We derive an
inequality which shows that the mean gate fidelity is upper bounded by a
decreasing function of the magnitude of the error of the measurement and the
amount of the entanglement between the measured qubit and other register
qubits. The consequence of this inequality is that, for a given amount of
entanglement, which is theoretically calculated once the algorithm is fixed, we
can estimate from this inequality how small the magnitude of the error should
be in order not to make the gate fidelity below a threshold, which is specified
by a technical requirement in a particular experimental setup or by the
threshold theorem of the fault-tolerant quantum computation.Comment: 4 pages, 3 figure
Alfalfa Snout Beetle, \u3ci\u3eOtiorhynchus Ligustici\u3c/i\u3e L. (Coleoptera: Curculionidae): Methods for Egg Collection and Larval Rearing
The alfalfa snout beetle, Otiorhynchus ligustici L., is the most serious pest of alfalfa in northern New York State. Recent research efforts focused on the biological control of this insect require the availability of all life stages. With a 2-year lifecycle and a mandatory diapause, the artificial rearing of a laboratory culture appears to be a non-viable option at present, but methods described here can be used to obtain sufficient numbers of eggs and larvae over an extended period of time for research purposes. The crowding of adult beetles in egg production units (cups) had a significant, negative effect on egg production per beetle but the total egg production per cup was still higher with higher number of beetles per cup resulting in a significant saving of labor per egg produced. Larval survival rates in alfalfa-planted cans were surprisingly low given the protected conditions of the greenhouse. The larval survival rates were not significantly different among the dates for the second instar and later instars, suggesting that larval mortality occurs in the first instar in alfalfa-planted cans
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