4,625 research outputs found
Ordered bicontinuous double-diamond morphology in subsaturation nuclear matter
We propose to identify the new "intermediate" morphology in subsaturation
nuclear matter observed in a recent quantum molecular dynamics simulation with
the ordered bicontinuous double-diamond structure known in block copolymers. We
estimate its energy density by incorporating the normalized area-volume
relation given in a literature into the nuclear liquid drop model. The
resulting energy density is higher than the other five known morphologies.Comment: 4 pages, 4 figures, published in Phys. Rev.
A Derivation of the Fermi Function in Perturbative Quantum Field Theory
We postulate that the Fermi function should be derived from the amplitude,
not from the solution of the Dirac equation, in the quantum field theory.
Then, we obtain the following results.
1, We give the amplitude and the width of the neutron beta decay, to one loop order. It is carried out by the Feynman
parameter integration.
2, As the result, we find the terms which can be interpreted as the Fermi
function expanded to order .
3, We also give the same result using complex analysis.
4, We check that there are no such terms in the similar process, .
5, We perform the Fermi function expanded to order using complex
analysis.Comment: 8 page
Integrating out Holographic QCD back to Hidden Local Symmetry
We develop a previously proposed gauge-invariant method to integrate out
infinite towers of vector and axialvector mesons arising as Kaluza-Klein (KK)
modes in a class of holographic models of QCD (HQCD). We demonstrate that HQCD
can be reduced to the chiral perturbation theory (ChPT) with the hidden local
symmetry (HLS) (so-called HLS-ChPT) having only the lowest KK mode identified
as the HLS gauge boson, and the Nambu-Goldstone bosons. The
terms in the HLS-ChPT are completely determined by integrating out infinite
towers of vector/axialvector mesons in HQCD: Effects of higher KK modes are
fully included in the coefficients. As an example, we apply our method to the
Sakai-Sugimoto model.Comment: To appear in proceedings of SCGT09, Nagoya, Japan, 8 page
Modeling with structure of resins in electonic compornents
In recent years, interfacial fracture becomes one of the most important
problems in the assessment of reliability of electronics packaging. Especially,
underfill resin is used with solder joints in flip chip packaging for
preventing the thermal fatigue fracture in solder joints. In general, the
interfacial strength has been evaluated on the basis of interfacial fracture
mechanics concept. However, as the size of devices decrease, it is difficult to
evaluate the interfacial strength quantitatively. Most of researches in the
interfacial fracture were conducted on the basis of the assumption of the
perfectly bonding condition though the interface has the micro-scale structure
and the bonding is often imperfect. In this study, the mechanical model of the
interfacial structure of resin in electronic components was proposed.
Bimaterial model with the imperfect bonding condition was examined by using a
finite element analysis (FEA). Stress field in the vicinity of interface
depends on the interfacial structure with the imperfect bonding. In the front
of interfacial crack tip, the behavior of process zone is affected by
interfacial structure. However, the instability of fracture for macroscopic
crack which means the fracture toughness is governed by the stress intensity
factor based on the fracture mechanics concept.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Holographic QCD Integrated back to Hidden Local Symmetry
We develop a previously proposed gauge-invariant method to integrate out
infinite tower of Kaluza-Klein (KK) modes of vector and axialvector mesons in a
class of models of holographic QCD (HQCD). The HQCD is reduced by our method to
the chiral perturbation theory with the hidden local symmetry (HLS) having only
the lowest KK mode identified as the HLS gauge boson. We take the
Sakai-Sugimoto model as a concrete HQCD, and completely determine the terms as well as the terms from the DBI part and the
anomaly-related (intrinsic parity odd) gauge-invariant terms from the CS part.
Effects of higher KK modes are fully included in these terms. To demonstrate
power of our method, we compute momentum-dependences of several form factors
such as the pion electromagnetic form factors, the - and
- transition form factors compared with experiment, which was
not achieved before due to complication to handle infinite sums. We also study
other anomaly-related quantities like --- and
--- vertex functions.Comment: 4 eps figures, 37 pages, latex, typos fixed; some discussions and
references added; fig.4 replace
Does the three site Higgsless model survive the electroweak precision tests at loop?
We complete the list of one loop renormalization group equations and matching
conditions relevant for the computation of the electroweak precision parameters
and in the three site Higgsless model. We obtain one-loop formulas for
and expressed in terms of physical observables such as the KK gauge
boson mass , the KK fermion mass , and the KK gauge boson ()
couplings with light quarks and leptons . It is shown that these
physical observables, , and are severely constrained by
the electroweak precision data. Unlike the tree level analysis on the ideally
delocalized fermion, we find that perfect fermiophobity of is ruled out by
the precision data. We also study the cutoff dependence of our analysis.
Although the model is non-renormalizable, the dependence on the cutoff
parameter is shown to be non-significant.Comment: 13pages, 5figures, minor corrections made, references adde
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