1,535 research outputs found
CP Phases in Supersymmetric Tri-lepton Signals at the Tevatron
We have analyzed the supersymmetric tri-lepton signals for sparticle searches
at the Tevatron in the minimal supersymmetric standard model with general CP
phases without generational mixing. The CP phases may affect very strongly the
chargino and neutralino mass spectrums and
as well as and . Even under the stringent
constraints from the electron electric dipole moment the CP phases can lead to
a minimum of the tri-lepton event rate for their non-trivial values.Comment: 10 pages, 3 eps figures, largely revised by including the electron
EDM constraint
QCD sum rule analysis of excited mass parameter
The mass parameter of orbitally excited baryons is calculated by
using QCD sum rule in the framework of heavy quark effective theory. Two kinds
of interpolating current for the excited heavy baryons are introduced. It is
obtained that GeV for the non-derivative
current and GeV for the current with
derivative. These results are consistent with experimental data.Comment: 12 pages, 3 figures, to appear in PL
Polarization Effects on the process with Large Extra Dimensions
We study large extra dimension effects on the polarizations of the pair
and electron beam at the process. It is shown that the
measurements of the cross section for transversely polarized pair with the
right-handed electron beam remarkably enhance the possibilities to see the low
scale quantum gravity effects. Higher Linear Collider bounds on the string
scale in this model can be obtained by using the left-handed electron beam.Comment: Final version to appear in Phys.Lett.B. More references are adde
Novel 1.5 GPa-strength with 50%-ductility by transformation-induced plasticity of non-recrystallized austenite in duplex steels
Needs for steel designs of ultra-high strength and excellent ductility have been an important issue in worldwide automotive industries to achieve energy conservation, improvement of safety, and crashworthiness qualities. Because of various drawbacks in existing 1.5-GPa-grade steels, new development of formable cold-rolled ultra-high-strength steels is essentially needed. Here we show a plausible method to achieve ultra-high strengths of 1.0~1.5 GPa together with excellent ductility above 50% by actively utilizing non-recrystallization region and TRansformation-Induced Plasticity (TRIP) mechanism in a cold-rolled and annealed Fe-Mn-Al-C-based steel. We adopt a duplex microstructure composed of austenite and ultra-fine ferrite in order to overcome low-yield-strength characteristics of austenite. Persistent elongation up to 50% as well as ultra-high yield strength over 1.4 GPa are attributed to well-balanced mechanical stability of non-crystallized austenite with critical strain for TRIP. Our results demonstrate how the non-recrystallized austenite can be a metamorphosis in 1.5-GPa-grade steel sheet design. ? 2017 The Author(s).114Ysciescopu
Brane Fluctuation and anomalous muon magnetic moment
We study the effects of extra dimensions on the muon anomalous magnetic
moment with brane fluctuation. Since the coupling is naturally suppressed if
brane fluctuation is considered by exponential softening factor for heavier
states, the contribution from the whole Kaluza-Klein graviton tower is shown to
be finite. The recent BNL E821 result is accomodated with
dimensional gravitational scale, , in the range of
TeV (), and TeV () with the brane
tension parameter , in the range TeV.Comment: 8 pages, LaTeX, 2 eps Figures, references added, version to appear in
PL
Chiral perturbation theory vs. vector meson dominance in the decays and
It is pointed out that the radiative decays of a meson, \phirho and
\phiom, receive dominant contributions from the pseudoscalar () exchanges. Using the vector meson dominance model, we find that B
(\phirho) \approx 1.3 \times 10^{-4} and B (\phiom) \approx 1.5 \times
10^{-5}, which are mainly from the pole. Thus, these decays are
well within the reach of the factory. Our estimates are a few orders of
magnitude larger than the chiral loop contributions in the heavy vector meson
chiral lagrangian, which is about ( a few ) .Comment: 10 pages, 2 Encapsuled-Postscript figures, uses epsfig.st
The dissipative dynamics of the field of two-photon Jaynes-Cummings model with Stark shift in dispersive approximation
We present the dissipative dynamics of the field of two-photon
Jaynes-Cummings model (JCM) with Stark shift in dispersive approximation and
investigate the influence of dissipation on entanglement. We show the coherence
properties of the field can be affected by the dissipative cavity when
nonlinear two-photon process is involved.Comment: 8 pages,3 figure
The non-perturbative corrections to the photon spectrum in a parton-like model
We derive a new parton-like formula, which establishes a simple connection
between the electroweak decay rate ) and the rate
of a free b-quark decay. The main features of our approach are the treatment of
the b-quark as an on-mass-shell particle and the inclusion of the effects
arising from the b-quark transverse motion in the -meson. Using various
b-quark light-front (LF) distribution functions, both phenomenological one and
the ones derived from current constituent quark models, and neglecting
perturbative corrections we compute the photon energy spectra and the moments
of the shape function. It is shown that the parton-like approach is fully
consistent with the Heavy Quark Effective Theory (HQET) provided the b-quark
constituent mass is redefined in the way similar to that used in HQET to define
the pole mass of the b quark. In this way the correction to first order in
can be eliminated from the total width in agreement with the general
statement of HQET. We have also found that the photon energy spectra calculated
in the LF approach agree well with the ones obtained in the ACM model, provided
the same distribution function is used as input in both cases. In spite of the
simplicity of the model our results show a fair good agreement both with the
HQET predictions and available experimental data.Comment: 14 pages, LaTeX, 3 ps figure
Dilepton Production at SPS-energy Heavy Ion Collisions
The production of dileptons is studied within a hadronic transport model. We
investigate the sensitivity of the dilepton spectra to the initial
configuration of the hadronic phase in a ultrarelativistic heavy ion collision.
Possible in medium correction due to the modifications of pions and the pion
form factor in a hadronic gas are discussed.Comment: Dedicated to Gerry Brown in honor of the 32nd celebration of his 39th
birthday. 31 pages Latex including 13 eps-figures, uses psfig.sty and
epsf.st
Single-filament Composite MgB2/SUS Ribbons by Powder-In-Tube Process
We report the successful fabrication of single-filament composite MgB2/SUS
ribbons, as an ultra-robust conductor type, employing the powder-in-tube (PIT)
process, by swaging and cold rolling only. The remarkable transport critical
current (Ic) of the non-sintered MgB2/SUS ribbon has observed, as an unexpected
result. Transport critical currents Ic ~ 316 A at T = 4.2 K and Ic ~ 82 A at T
= 20 K were observed at self-field, for the non-sintered composite MgB2/SUS
ribbon. In addition, the persistent current density Jp values, that were
estimated by Bean formula, were more than ~ 7  105 A/cm2 at T = 5 K,
and ~ 1.2  105 A/cm2 at T = 30 K, for the sintered composite MgB2/SUS
ribbon, at H = 0 G.Comment: 10 pages, 4 figure
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