2,371 research outputs found
Anonymity, efficiency wages and technological progress
Although the industrial revolution is often characterized as the culmination of a process of commercialisation, the precise nature of such a link remains unclear. This paper provides an analysis of one such link: the role of commercialisation in raising wages as impersonal labour market transactions replace personalized customary relations. In the presence of an aggregate capital externality, we show that the resulting shift in relative factor prices will, under certain conditions, lead to higher capital-intensity in the production technology and hence, a faster rate of technological progress. We provide historical evidence using European data to show that England was among the most urbanized and the highest wage countries at the onset of the industrial revolution. The model highlights the effects of changes in the availability of information, typical of a modernising country, on efficiency wages and technological progress
Lepton Flavor Violating Z Decays in the Zee Model
We calculate lepton flavor violating (LFV) Z decays Z \to {{e_i^\pm}}e_j^\mp
(i, j = e, \mu, \tau ; i\neq j) in the Zee model keeping in view the radiative
leptonic decays e_i\to e_j\gamma (i = \mu, \tau ; j = e, \mu ; i\neq j), \mu
decay and anomalous muon magnetic moment (\mu AMM). We investigate three
different cases of Zee f_{ij} coupling (A) f_{e\mu}^2 = f_{\mu\tau}^2= f_{\tau
e}^2, (B) f_{e\mu}^2 \gg f_{\tau e}^2 \gg f_{\mu\tau}^2, and (C) f_{\mu\tau}^2
\gg f_{e\mu}^2 \gg f_{\tau e}^2 subject to the neutrino phenomenology.
Interestingly, we find that, although the case (C) satisfies the large excess
value of \mu AMM, however, it is unable to explain the solar neutrino
experimental result, whereas the case (B) satisfies the bi-maximal neutrino
mixing scenario, but confronts with the result of \mu AMM experiment. We also
find that among all the three cases, only the case (C) gives rise to largest
contribution to the ratio B(Z\to e^\pm\tau^\mp)/B(Z\to \mu^\pm \mu^\mp) \simeq
{10}^{-8} which is still two order less than the accessible value to be probed
by the future linear colliders, whereas for the other two cases, this ratio is
too low to be observed even in the near future for all possible LFV Z decay
modes.Comment: 12 pages, RevTex, 2 figures, 3 Tables, typos corrected, reference
added, version to appear in Phys. Rev.
Effect of high-temperature heat treatment duration on the purity and microstructure of MWCNTs
The effect of high-temperature heat treatment on purity and structural changes of multiwalled carbon nanotubes (MWCNTs) were studied by subjecting the raw MWCNTs (pristine MWCNTs) to 2600∘C for 60 and 120 min. Thermogravimetric analysis (TGA), X-ray diffraction, Raman spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to study the effect of heat-treatment duration on the purity and structural changes of MWCNTs. Results show that high-temperature heat treatment can be used to purify MWCNTs with proper optimization of treatment time. It was observed that 60 min heat treatment of raw MWCNTs imparts high purity and structural perfection to MWCNTs, while 120 min heat treatment imparts structural degradation to MWCNTs with collapse of the innermost shells. The present study indicates that metal impurities act as moderators in controlling the degradation of MWCNTs up to certain duration, and once the metal impurities escape completely, further heat treatment degrades the structure of MWCNTs
Long-term stability test of a triple GEM detector
The main aim of the study is to perform the long-term stability test of gain
of the single mask triple GEM detector. A simple method is used for this long-
term stability test using a radioactive X-ray source with high activity. The
test is continued till accumulation of charge per unit area > 12.0 mC/mm2. The
details of the chamber fabrication, the test set-up, the method of measurement
and the test results are presented in this paper.Comment: 8 pages, 5 figure
Phase Separation and the Phase Diagram in Cuprates Superconductors
We show that the main features of the cuprates superconductors phase diagram
can be derived considering the disorder as a key property of these materials.
Our basic point is that the high pseudogap line is an onset of phase separation
which generates compounds made up of regions with distinct doping levels. We
calculate how this continuous temperature dependent phase separation process
occurs in high critical temperature superconductors (HTSC) using the
Cahn-Hilliard approach, originally applied to study alloys. Since the level of
phase separation varies for different cuprates, it is possible that different
systems with average doping level pm exhibit different degrees of charge and
spin segregation. Calculations on inhomogeneous charge distributions in form of
stripes in finite clusters performed by the Bogoliubov-deGennes superconducting
approach yield good agreement to the pseudogap temperature T*(pm), the onset of
local pairing amplitudes with phase locked and concomitantly, how they develop
at low temperatures into the superconducting phase at Tc(pm) by percolation.Comment: 9 pages, 9 figures. Submitted to Phys. Rev.
Neutrino Mixing and Neutrino Telescopes
Measuring flux ratios of ultra-high energy neutrinos is an alternative method
to determine the neutrino mixing angles and the CP phase delta. We conduct a
systematic analysis of the neutrino mixing probabilities and of various flux
ratios measurable at neutrino telescopes. The considered cases are neutrinos
from pion, neutron and muon-damped sources. Explicit formulae in case of mu-tau
symmetry and its special case tri-bimaximal mixing are obtained, and the
leading corrections due to non-zero theta_{13} and non-maximal theta_{23} are
given. The first order correction is universal as it appears in basically all
ratios. We study in detail its dependence on theta_{13}, theta_{23} and the CP
phase, finding that the dependence on theta_{23} is strongest. The flavor
compositions for the considered neutrino sources are evaluated in terms of this
correction. A measurement of a flux ratio is a clean measurement of the
universal correction (and therefore of theta_{13}, theta_{23} and delta) if the
zeroth order ratio does not depend on theta_{12}. This favors pion sources over
the other cases, which in turn are good candidates to probe theta_{12}. The
only situations in which the universal correction does not appear are certain
ratios in case of a neutron and muon-damped source, which depend mainly on
theta_{12} and receive only quadratic corrections from the other parameters. We
further show that there are only two independent neutrino oscillation
probabilities, give the allowed ranges of the considered flux ratios and of all
probabilities, and show that none of the latter can be zero or one.Comment: 29 pages, 8 figures. Minor changes, to appear in JCA
Single Photon Signals for Warped Quantum Gravity at a Linear e+-e- Collider
We study the `single photon' process e+- e- -> gamma nu nubar with
contributions due to exchange of massive gravitons in the Randall- Sundrum
model of low-scale quantum gravity. It is shown that for significant regions in
the parameter space, this process unambiguously highlights the resonance
structure of the graviton sector. Even in the non-resonant part of the
parameter space, we show that comparison with the benchmark process e+- e- ->
mu+- mu- can clearly distinguish signals for warped gravity from similar
signals for large extra dimensions.Comment: Published version; figures change
Width of the Zero-Field Superconducting Resistive Transition in the Vicinity of the Localization Threshold
Resistive superconducting zero-field transition in amorphous In-O films in
states from the vicinity of the insulator-superconductor transition is analyzed
in terms of two characteristic temperatures: the upper one, , where the
finite amplitude of the order parameter is established and the lower one,
, where the phase ordering takes place. It follows from the
magnetoresistance measurements that the resistance in between, ,
cannot be ascribed to dissipation by thermally dissociated vortex pairs. So, it
is not Kosterlitz-Thouless-Berezinskii transition that happens at .Comment: 4 pages, 3 figure
'Mu-Tau' symmetry, tribimaximal mixing and four zero neutrino Yukawa textures
Within the type-I seesaw framework with three heavy right chiral neutrinos
and in the basis where the latter and the charged leptons are mass diagonal, a
near `mu-tau' symmetry in the neutrino sector is strongly suggested by the
neutrino oscillation data. There is further evidence for a close to the
tribimaximal mixing pattern which subsumes `mu-tau' symmetry. On the other
hand, the assumption of a (maximally allowed) four zero texture in the Yukawa
coupling matrix Y_nu in the same basis leads to a highly constrained and
predictive theoretical scheme. We show that the requirement of an exact
`mu-tau' symmetry, coupled with observational constraints, reduces the `seventy
two' allowed textures in such a `Y_nu' to 'only four' corresponding to just two
different forms of the light neutrino mass matrix `m_nu'. The effect of each of
these on measurable quantities can be described, apart from an overall factor
of the neutrino mass scale, in terms of two real parameters and a phase angle
all of which are within very constrained ranges. The additional input of a
tribimaximal mixing reduces these three parameters to `only one' with a very
nearly fixed value. Implications for both flavored and unflavored leptogenesis
as well as radiative lepton flavor violating decays are discussed. We also
investigate the stability of these conclusions under small deviations due to
renormalization group running from a high scale where the four zero texture as
well as `mu-tau' symmetry or the tribimaximal mixing pattern are imposed.Comment: Typographical changes,accepted for publication in JHE
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