14,042 research outputs found
Bound on Z' Mass from CDMS II in the Dark Left-Right Gauge Model II
With the recent possible signal of dark matter from the CDMS II experiment,
the Z' mass of a new version of the dark left-right gauge model (DLRM II) is
predicted to be at around a TeV. As such, it has an excellent discovery
prognosis at the operating Large Hadron Collider.Comment: 11 page
On the origin of the hump structure in the in-plane optical conductivity of high Tc cuprates based on a SU(2) slave-boson theory
An improved version of SU(2) slave-boson approach is applied to study the
in-plane optical conductivity of the two dimensional systems of high Tc
cuprates. We investigate the role of fluctuations of both the phase and
amplitude of order parameters on the (Drude) peak-dip-hump structure in the
in-plane conductivity as a function of hole doping concentration and
temperature. The mid-infrared(MIR) hump in the in-plane optical conductivity is
shown to originate from the antiferromagnetic spin fluctuations of short
range(the amplitude fluctuations of spin singlet pairing order parameters),
which is consistent with our previous U(1) study. However the inclusion of both
the phase and amplitude fluctuations is shown to substantially improve the
qualitative feature of the optical conductivity by showing substantially
reduced Drude peak widths for entire doping range. Both the shift of the hump
position to lower frequency and the growth of the hump peak height with
increasing hole concentration is shown to be consistent with observations.Comment: 7 pages, 6 figure
A joint time-invariant filtering approach to the linear Gaussian relay problem
In this paper, the linear Gaussian relay problem is considered. Under the
linear time-invariant (LTI) model the problem is formulated in the frequency
domain based on the Toeplitz distribution theorem. Under the further assumption
of realizable input spectra, the LTI Gaussian relay problem is converted to a
joint design problem of source and relay filters under two power constraints,
one at the source and the other at the relay, and a practical solution to this
problem is proposed based on the projected subgradient method. Numerical
results show that the proposed method yields a noticeable gain over the
instantaneous amplify-and-forward (AF) scheme in inter-symbol interference
(ISI) channels. Also, the optimality of the AF scheme within the class of
one-tap relay filters is established in flat-fading channels.Comment: 30 pages, 10 figure
How dsDNA breathing enhances its flexibility and instability on short length scales
We study the unexpected high flexibility of short dsDNA which recently has
been reported by a number of experiments. Via the Langevin dynamics simulation
of our Breathing DNA model, first we observe the formation of bubbles within
the duplex and also forks at the ends, with the size distributions independent
of the contour length. We find that these local denaturations at a
physiological temperature, despite their rare and transient presence, can lower
the persistence length drastically for a short DNA segment in agreement with
experiment
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