79 research outputs found
General Structure of Relativistic Vector Condensation
We study relativistic massive vector condensation due to a non zero chemical
potential associated to some of the global conserved charges of the theory. We
show that the phase structure is very rich. More specifically there are three
distinct phases depending on the value of one of the zero chemical potential
vector self interaction terms. We also develop a formalism which enables us to
investigate the vacuum structure and dispersion relations in the spontaneously
broken phase of the theory. We show that in a certain limit of the couplings
and for large chemical potential the theory is not stable. This limit,
interestingly, corresponds to a gauge type limit often employed to economically
describe the ordinary vector mesons self interactions in QCD. We finally
indicate for which physical systems our analysis is relevant.Comment: RevTex4 14 pages,4 figure
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Risk of infections in renal cell carcinoma (RCC) and non-RCC patients treated with mammalian target of rapamycin inhibitors
Background: Mammalian target of rapamycin (mTOR) inhibitors are used in a variety of malignancies. Infections have been reported with these drugs. We performed an up-to-date meta-analysis to further characterise the risk of infections in cancer patients treated with these agents. Methods: Pubmed and oncology conferences' proceedings were searched for studies from January 1966 to June 2012. Studies were limited to phase II and III randomised controlled trials (RCTs) of everolimus or temsirolimus reporting on cancer patients with adequate safety profiles. Summary incidences, relative risks (RRs), and 95% confidence intervals (CIs) were calculated. Results: A total of 3180 patients were included. The incidence of all-grade and high-grade infections due to mTOR inhibitors was 33.1% (95% CI, 24.5–43.0%) and 5.6% (95% CI, 3.8–8.3%), respectively. Compared with controls, the RR of all-grade and high-grade infections due to mTOR inhibitors was 2.00 (95% CI, 1.76–2.28, P<0.001) and 2.60 (95% CI, 1.54–4.41, P<0.001), respectively. Subgroup analysis found no difference in incidences or risks between everolimus and temsirolimus or between different tumour types (renal cell carcinoma (RCC) vs non-RCC). Infections included respiratory tract (61.7%), genitourinary (29.4%), skin/soft tissue (4.2%), and others (4.9%). Conclusion: Treatment with mTOR inhibitors is associated with a significant increase in risk of infections. Close monitoring for any signs of infections is warranted
Tau mesonic decays and strong anomaly of PCAC
Strong anomaly of the PCAC is found in and
in the chiral limit. It originates in WZW anomaly. Theoretical
result of agrees with data well and the
measurement of will confirm the strong anomaly
of PCAC. The strong anomaly of PCAC is studied.Comment: 27 page
Vacuum stability and the Cholesky decomposition
We discuss how the Cholesky decomposition may be used to ascertain whether a
critical point of the field theory scalar potential provides a stable vacuum
configuration. We then use this method to derive the stability conditions in a
specific example.Comment: 7 page
Fate of Vector Dominance in the Effective Field Theory
We reveal the full phase structure of the effective field theory for QCD,
based on the hidden local symmetry (HLS) through the one-loop renormalization
group equation including quadratic divergences. We then show that vector
dominance (VD) is not a sacred discipline of the effective field theory but
rather an accidental phenomenon peculiar to three-flavored QCD. In particular,
the chiral symmetry restoration in HLS model takes place in a wide phase
boundary surface, on which the VD is realized nowhere. This suggests that VD
may not be valid for chiral symmetry restoration in hot and/or dense QCD.Comment: 4 pages, 3 figures. One reference added. Minor modification to
shorten the manuscript. This is the version to appear in Physical Review
Letter
Effective chiral Lagrangians for spin-1 mesons
The commonly used types of effective theory for vector mesons are reviewed
and their relationships clarified. They are shown to correspond to different
choices of field for spin-1 particles and the rules for transforming between
them are described. The importance of respecting chiral symmetry is stressed.
The choice of fields that transform homogeneously under the nonlinear
realisation of chiral symmetry imposes no preconceptions about the types of
coupling for the mesons. This representation thus provides a convenient
framework for relating different theories. It is also used to elucidate the
nature of the assumptions in specific hidden-gauge and massive Yang-Mills
models that have been widely used.Comment: 46 pages (RevTeX
Electroweak Physics for Color Superconductivity
We construct the effective theories describing the electroweak interactions
for the low energy excitations associated with the color superconductive phases
of QCD at high matter density. The main result, for the 3 flavor case, is that
the quasiparticle Goldstone boson decay into two physical massless
photons is identical to the zero density case once we use the new Goldstone
decay constant and the modified electric charge ,
with and the strong coupling constant. For 2
flavors we find that the coupling of the quarks to the neutral vector boson
is modified with respect to the zero density case. We finally point out
possible applications of our result to the physics of compact objects.Comment: 23 pages, 1 Figure, RevTex. More discussion and references adde
Role of Light Vector Mesons in the Heavy Particle Chiral Lagrangian
We give the general framework for adding "light" vector particles to the
heavy hadron effective chiral Lagrangian. This has strong motivations both from
the phenomenological and aesthetic standpoints. An application to the already
observed D \rightarrow \overbar{K^*} weak transition amplitude is discussed.Comment: 19 pages, LaTeX documen
The Superfluid and Conformal Phase Transitions of Two-Color QCD
The phase structure of two-color QCD is examined as a function of the
chemical potential and the number of light quark flavors. We consider effective
Lagrangians for two-color QCD containing the Goldstone excitations, spin-one
particles and negative intrinsic parity terms. We discuss the possibility of a
conformal phase transition and the enhancement of the global symmetries as the
number of flavors is increased. The effects of a quark chemical potential on
the spin-one particles and on the negative intrinsic parity terms are analyzed.
It is shown that the phase diagram that is predicted by the linearly realized
effective Lagrangian at tree-level matches exactly that predicted by chiral
perturbation theory.Comment: ReVTeX, 23 pages, 3 figures. Discussion of vector condensation
extended, two figures added, references adde
The Pion Decay Constants and the Rho-Meson Mass at Finite Temperature in the Hidden Local Symmetry
We study the temperature dependence of the pion decay constant and rho-meson
mass in the hidden local symmetry model at one loop. Using the standard
imaginary time formalism, we include the thermal effect of rho meson as well as
that of pion. We show that the pion gives a dominant contribution to the pion
decay constant and rho-meson contribution slightly decreases the critical
temperature. The rho-meson pole mass increases as T^4/m_\rho^2 at low
temperature dominated by the pion-loop effect. At high temperature, although
the pion-loop effect decreases the rho-meson mass, the rho-loop contribution
overcomes the pion-loop contribution and rho-meson mass increases with
temperature. We also show that the conventional parameter a is stable as the
temperature increases.Comment: We added a comment on the correction to the rho-meson mass from the
omega-pi loop. This is the final version to be published in Phys. Rev. D. 19
pages (LaTeX-RevTeX), 7 PostScript figure
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