19 research outputs found
Color Superconductivity at Moderate Density
The effect of color breaking on colored quarks' chiral condensates has been
investigated at zero temperature and moderate baryon density. It is found that
the influence of the diquark condensate on different colored quarks is very
small.Comment: 4 pages, 1 figure in eps, talk given at XXXI International Symposium
on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. See
http://ismd31.ccnu.edu.cn
Massive Meson Fluctuation in NJL Model
Based on the self-consistent scheme beyond mean-field approximation in the
large expansion, including current quark mass explicitly, a general
scheme of SU(2) NJL model is developed. To ensure the quark self-energy
expanded in the proper order of , an approximate internal meson propagator
is deduced, which is in order of . In our scheme, adopting the method
of external momentum expansion, all the Feynman diagrams are calculated in a
unified way by only expanding the quark propagator. Our numerical results show,
that different from the mean field approximation in which the explicitly chiral
symmetry breaking is invisible, the effect of finite pion mass can be seen
clearly when beyond mean-field approximation.Comment: 1 REVTeX file, 19 pages including 3 eps figure
The Mesonic Fluctuations and Corrections in the Chiral Symmetry Breaking Vacuum
The mesonic quantum fluctuations and their corrections on the chiral
condensate and pion polarization function are investigated in the
self-consistent scheme of SU(2) Nambu-Jona-Lasinio model by exactly calculating
the next-to-leading order (NLO) Feynman diagrams in expansion. While
the fluctuations and corrections depend strongly on the meson's three-momentum
cut-off , no chiral symmetry restoration is found since the
cancellation between the NLO and the one-quark-loop diagram with quark mass
deviated from the mean-field value.Comment: 15 pages with 3 figures, abstract, introduction, conclusion revise
S-wave Scattering Lengths in the SU(2) NJL Model Beyond Mean-field Approximation
The S-wave scattering lengths and are calculated to
the lowest order of expansion in the general framework of SU(2) NJL
model beyond mean-field approximation. It is shown that using the universal
curve of and the four NJL parameters, i.e., the current quark mass
, the four fermion coupling constant , the quark momentum cut-off
and the meson momentum cut-off , also the S-wave scattering lengths in NJL model can be uniquely determined.Comment: 12 pages, Revtex, 2 eps files, uses axodraw.st
Cross-Utterance Conditioned VAE for Speech Generation
Speech synthesis systems powered by neural networks hold promise for
multimedia production, but frequently face issues with producing expressive
speech and seamless editing. In response, we present the Cross-Utterance
Conditioned Variational Autoencoder speech synthesis (CUC-VAE S2) framework to
enhance prosody and ensure natural speech generation. This framework leverages
the powerful representational capabilities of pre-trained language models and
the re-expression abilities of variational autoencoders (VAEs). The core
component of the CUC-VAE S2 framework is the cross-utterance CVAE, which
extracts acoustic, speaker, and textual features from surrounding sentences to
generate context-sensitive prosodic features, more accurately emulating human
prosody generation. We further propose two practical algorithms tailored for
distinct speech synthesis applications: CUC-VAE TTS for text-to-speech and
CUC-VAE SE for speech editing. The CUC-VAE TTS is a direct application of the
framework, designed to generate audio with contextual prosody derived from
surrounding texts. On the other hand, the CUC-VAE SE algorithm leverages real
mel spectrogram sampling conditioned on contextual information, producing audio
that closely mirrors real sound and thereby facilitating flexible speech
editing based on text such as deletion, insertion, and replacement.
Experimental results on the LibriTTS datasets demonstrate that our proposed
models significantly enhance speech synthesis and editing, producing more
natural and expressive speech.Comment: 13 pages
Massive quark propagator and competition between chiral and diquark condensate
The Green-function approach has been extended to the moderate baryon density
region in the framework of an extended Nambu--Jona-Lasinio model, and the
thermodynamic potential with both chiral and diquark condensates has been
evaluated by using the massive quark propagator. The phase structure along the
chemical potential direction has been investigated and the strong competition
between the chiral and diquark condensate has been analyzed by investigating
the influence of the diquark condensate on the sharp Fermi surface. The
influence of the diquark condensate on the quark properties has been
investigated, even though the quarks in the color breaking phase are very
different from that in the chiral breaking phase, the difference between quarks
in different colors is very small.Comment: Revtex, 34 pages, 7 figures, section V revised, accepted by PR