146,133 research outputs found
Quantum radiation by an Unruh-DeWitt detector in oscillatory motion
Quantum radiated power emitted by an Unruh-DeWitt (UD) detector in linear
oscillatory motion in (3+1)D Minkowski space, with the internal harmonic
oscillator minimally coupled to a massless scalar field, is obtained
non-perturbatively by numerical method. The signal of the Unruh-like effect
experienced by the detector is found to be pronounced in quantum radiation in
the highly non-equilibrium regime with high averaged acceleration and short
oscillatory cycle, and the signal would be greatly suppressed by quantum
interference when the averaged proper acceleration is sufficiently low. An
observer at a fixed angle would see periods of negative radiated power in each
cycle of motion, while the averaged radiated power over a cycle is always
positive as guaranteed by the quantum inequalities. Coherent high harmonic
generation and down conversion are identified in the detector's quantum
radiation. Due to the overwhelming largeness of the vacuum correlators of the
free field, the asymptotic reduced state of the harmonics of the radiation
field is approximately a direct product of the squeezed thermal states.Comment: 30 pages, 10 figures, partly based on [arXiv:1601.07006
Measurement of the ZZ production cross section and limits on anomalous neutral triple gauge couplings in proton-proton collisions at sqrt{s} =7 TeV with the ATLAS detector
A measurement of the ZZ production cross section in proton-proton collisions
at sqrt{s} = 7 TeV using data collected by the ATLAS experiment at the LHC is
presented. In a data sample corresponding to an integrated luminosity of
1.02fb-1, 12 events containing two Z boson candidates decaying to electrons
and/or muons were observed. The expected background contribution is
0.3^{+0.9}_{-0.3} (stat) ^{+0.4}_{-0.3} (syst) events. The total cross section
for on-shell ZZ production has been determined to be \sigma_{ZZ}_{tot}=
8.4^{+2.7}_{-2.3}(stat) ^{+0.4}_{-0.7}(syst)\pm 0.3 (lumi) pb$ and is
compatible with the Standard Model expectation of 6.5^{+0.3}_{-0.2} pb
calculated at the next-to-leading order in QCD. Limits on anomalous neutral
triple gauge boson couplings are derived.Comment: 8 pages, Proceedings of the DPF-2011 Conference, Providence, RI,
August 8-13, 201
Interrelationships between consumers’ attitudes, behaviour toward organic food and dietary habits
This study examined the relationship between Taiwanese consumers’ attitudes and purchase behaviour toward organic food. A preliminary effort was made to identify the influence of consumers’ socio-demographic backgrounds on the variations in their responses. The dietary habits of organic product consumers are another aspect of this study
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