PaperPanorama
FAQ

Nuclear Theory·nucl-th

Tuesday·January 27, 2015

16 papers—11 primary·5 cross-listed

All16Primary11Cross-lists5
  1. 12

    Chaoticity and Coherence in Bose-Einstein Condensation and Correlations

    Cheuk-Yin Wong🇺🇸 · Wei-Ning Zhang🇨🇳 · Jie Liu🇨🇳 · Peng Ru🇨🇳

    We review the properties of chaoticity and coherence in Bose-Einstein condensation and correlations, for a dense boson system in its mean-field represented approximately by a harmonic oscillator potential. The order parameter and the nature of the phase transition from the chaotic to the condensate states are studied for different fixed numbers of bosons. The two-particle correlation function in momentum space is calculated to investigate how the Bose-Einstein correlation depends on the degree of condensation and other momentum variables. We generalize the Bose-Einstein correlation analysis to three-particle correlations to show its dependence on the degree of condensation.

    ↳ hep-phcond-mat.quant-gasnucl-thphysics.atom-ph1 citation
  2. 13

    Single-particle spectral density of the unitary Fermi gas: Novel approach based on the operator product expansion, sum rules and the maximum entropy method

    Philipp Gubler🇮🇹 · Naoki Yamamoto🇯🇵 · Tetsuo Hatsuda🇯🇵 · Yusuke Nishida🇯🇵

    Making use of the operator product expansion, we derive a general class of sum rules for the imaginary part of the single-particle self-energy of the unitary Fermi gas. The sum rules are analyzed numerically with the help of the maximum entropy method, which allows us to extract the single-particle spectral density as a function of both energy and momentum. These spectral densities contain basic information on the properties of the unitary Fermi gas, such as the dispersion relation and the superfluid pairing gap, for which we obtain reasonable agreement with the available results based on quantum Monte-Carlo simulations.

    ↳ cond-mat.quant-gashep-phnucl-thAnnals Phys.(2015)·8 citations
  4. 15

    Quantum and stringy corrections to the equation of state of holographic QCD matter and the nature of the chiral transition

    T. Alho🇮🇸 · M. Jarvinen🇫🇷 · K. Kajantie🇫🇮 · E. Kiritsis🇫🇷 · K. Tuominen🇫🇮

    We consider the finite temperature phase diagram of holographic QCD in the Veneziano limit (Nc large, Nf large with xf=Nf/Nc fixed) and calculate one string-loop corrections to the free energy in certain approximations. Such corrections, especially due to the pion modes are unsuppressed in the Veneziano limit. We find that under some extra assumptions the first order transition following from classical gravity solutions can become second order. If stringy asymptotics are of a special form and there are residual interactions it may even become of third order. Operationally these computations imply modelling the low temperature chiral symmetry breaking phase with a hadron gas containing Nf^2 massless Goldstone bosons and an exponential spectrum of massive hadrons. A third order transition is possible only if repulsive hadron interactions via the excluded volume effect are included.

    ↳ hep-phhep-lathep-thnucl-thPRD(2015)·50 citations
  5. 16

    Instantons and Monopoles

    Adriano Di Giacomo🇮🇹 · Masayasu Hasegawa🇷🇺

    This study is part of a research program aimed to investigate the relations between instantons, monopoles, and chiral symmetry breaking. Monopoles are important 3-dimensional topological configurations existing in QCD, which are believed to produce colour confinement. Instantons are 4-dimensional topological configurations and are known to be related to chiral symmetry breaking. To study the relation between monopoles and instantons we generate configurations adding to the vacuum state static monopole-antimonopole pairs of opposite charges by use of a monopole creation operator. We observe that the monopole creation operator only adds long monopole loops to the configurations. We then count the number of fermion zero modes using Overlap fermions as a tool. As a result we find that each monopole-antimonopole pair of magnetic charge one adds one zero mode of chirality , i.e. one instanton of topological charge .

    ↳ hep-lathep-phhep-thnucl-thPRD(2015)·20 citations

Affiliations

first authorsco-authorsvia INSPIRE