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 $N_c$ 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 $N_c$, an approximate internal meson propagator is deduced, which is in order of $O(1/N_c)$. 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 $1/N_c$ expansion. While the fluctuations and corrections depend strongly on the meson's three-momentum cut-off $\Lambda_M$, 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 π−π\pi - \pi Scattering Lengths in the SU(2) NJL Model Beyond Mean-field Approximation

The S-wave $\pi - \pi$ scattering lengths $a_0$ and $a_2$ are calculated to the lowest order of $1/N_c$ expansion in the general framework of SU(2) NJL model beyond mean-field approximation. It is shown that using the universal curve of $a_0$ and $a_2$ the four NJL parameters, i.e., the current quark mass $m_0$, the four fermion coupling constant $G$, the quark momentum cut-off $\Lambda_f$ and the meson momentum cut-off $\Lambda_b$, also the S-wave $\pi - \pi$ 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