681,570 research outputs found
Using Charge Asymmetries to Measure Single Top Quark Production at the LHC
Electroweak production of single top quarks is an as-yet-unverified
prediction of the Standard model, potentially sensitive to new physics. Two of
the single top quark productions channels have significant charge asymmetries
at the LHC, while the much larger background from is nearly
charge-symmetric. This can be used to reduce systematic uncertainties and make
precision measurements of single top quark production.Comment: 4 pages, 1 figur
Trailing Edge Unification via an Intermediate Pati-Salam Group
We demonstrate to two-loop order that an intermediate symmetrically embedded
Pati-Salam level of symmetry is all that
is necessary to accommodate empirical values of
and within a grand unification context but with a high
(10^{14} GeV) intermediate mass scale and with a concomitant higher GUT scale.Comment: 7 pages, 4 embedded eps figur
Study of the double non linear quantum resonances in diatomic molecules
We study the quantum dynamics of diatomic molecule driven by a circularly
polarized resonant electric field. We look for a quantum effect due to
classical chaos appearing due to the overlapping of nonlinear resonances
associated to the vibrational and rotational motion. We solve the Schr\"odinger
equation associated with the wave function expanded in term of proper
stationary states, (vibrationalangular momentum
states). Looking for quantum-classic correspondence, we consider the Liouville
dynamics in the two dimensional phase space defined by the coherent -like state
of vibrational states, and it is found some similarities when the quantum
dynamics is pictured in terms of number and phase operators.Comment: 15 pages, 4 figure
Wavelet-based cross-correlation analysis of structure scaling in turbulent clouds
We propose a statistical tool to compare the scaling behaviour of turbulence
in pairs of molecular cloud maps. Using artificial maps with well defined
spatial properties, we calibrate the method and test its limitations to
ultimately apply it to a set of observed maps. We develop the wavelet-based
weighted cross-correlation (WWCC) method to study the relative contribution of
structures of different sizes and their degree of correlation in two maps as a
function of spatial scale, and the mutual displacement of structures in the
molecular cloud maps. We test the WWCC for circular structures having a single
prominent scale and fractal structures showing a self-similar behavior without
prominent scales. Observational noise and a finite map size limit the scales
where the cross-correlation coefficients and displacement vectors can be
reliably measured. For fractal maps containing many structures on all scales,
the limitation from the observational noise is negligible for signal-to-noise
ratios >5. (abbrev). Application of the WWCC to the observed line maps of the
giant molecular cloud G333 allows to add specific scale information to the
results obtained earlier using the principle component analysis. It confirms
the chemical and excitation similarity of CO and CO on all
scales, but shows a deviation of HCN at scales of up to 7' (~7 pc). This can be
interpreted as a chemical transition scale. The largest structures also show a
systematic offset along the filament, probably due to a large-scale density
gradient. The WWCC can compare correlated structures in different maps of
molecular clouds identifying scales that represent structural changes such as
chemical and phase transitions and prominent or enhanced dimensions.Comment: 26 pages, 41 figures, accepted to A&
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