7,246 research outputs found

    Cancellation of divergences in unitary gauge calculation of H→γγH \to \gamma \gamma process via one W loop, and application

    Full text link
    Following the thread of R. Gastmans, S. L. Wu and T. T. Wu, the calculation in the unitary gauge for the H→γγH \to \gamma \gamma process via one W loop is repeated, without the specific choice of the independent integrated loop momentum at the beginning. We start from the 'original' definition of each Feynman diagram, and show that the 4-momentum conservation and the Ward identity of the W-W-photon vertex can guarantee the cancellation of all terms among the Feynman diagrams which are to be integrated to give divergences higher than logarithmic. The remaining terms are to the most logarithmically divergent, hence is independent from the set of integrated loop momentum. This way of doing calculation is applied to H→γZH \to \gamma Z process via one W loop in the unitary gauge, the divergences proportional to MZ2/M3M_Z^2/M^3 including quadratic ones are all cancelled, and terms proportional to MZ2/M3M_Z^2/M^3 are shown to be zero. The way of dealing with the quadratic divergences proportional to MZ2/M3M_Z^2/M^3 in H→γZH \to \gamma Z has subtle implication on the employment on the Feynman rules especially when those rules can lead to high level divergences. So calculation without integration on all the δ\delta functions until have to is a more proper or maybe necessary way of the employment of the Feynman rules.Comment: 1 figure, 34 pages (updated

    Temperature-heat uncertainty relation for quantum thermometry

    Full text link
    We investigate the resource theory for temperature estimation. We demonstrate that it is the fluctuation of heat that fundamentally determines temperature precision through the temperature-heat uncertainty relation. Specifically, we find that heat is divided into trajectory heat and correlation heat, which are associated with the heat exchange along thermometer's evolution path and the correlation between the thermometer and the sample, respectively. Based on two type of thermometers, we show that both of these heat terms are resources for enhancing temperature precision. Additionally, we demonstrate that the temperature-heat uncertainty relation is consistent with the well known temperature-energy uncertainty relation in thermodynamics. By clearly distinguishing the resources for enhancing estimation precision, our findings not only explain why various quantum features are crucial for accurate temperature sensing but also provide valuable insights for designing ultrahigh-sensitive quantum thermometers.Comment: 6 pages, 1 figur

    Lifshitz effects on holographic pp-wave superfluid

    Get PDF
    In the probe limit, we numerically build a holographic pp-wave superfluid model in the four-dimensional Lifshitz black hole coupled to a Maxwell-complex vector field. We observe the rich phase structure and find that the Lifshitz dynamical exponent zz contributes evidently to the effective mass of the matter field and dimension of the gravitational background. Concretely, we obtain the Cave of Winds appeared only in the five-dimensional anti-de Sitter~(AdS) spacetime, and the increasing zz hinders not only the condensate but also the appearance of the first-order phase transition. Furthermore, our results agree with the Ginzburg-Landau results near the critical temperature. In addition, the previous AdS superfluid model is generalized to the Lifshitz spacetime.Comment: 14 pages,5 figures, and 1 table, accepted by Phys. Lett.
    • …
    corecore