Diffusion of resonance particles in strong plasma turbulence

This paper derives an expression for the velocity space diffusion tensor (time asymptotic) for resonant particles in the weak-coupling limit of strong plasma turbulence theory. The analysis is based on an improved approximation scheme for the determination of the actual particle trajectories, rather than the determination of &ensemble averaged particle orbits’ with the help of the &average Vlasov propagator’. Except for numerical factors of order unity, the results agree with those of Birmingham & Bornatici, both when Tc → 0 (Tc is the correlation width of the fluctuating field as seen by the resonant particles), and when Tc is finite but small. The paper indicates the limits of this method, as well as those of Birmingham & Bornatici.

Download Full-text

Determination of α(Mz) from an hyperasymptotic approximation to the energy of a static quark-antiquark pair

Journal of High Energy Physics ◽

10.1007/jhep09(2020)016 ◽

2020 ◽

Vol 2020 (9) ◽

Cited By ~ 3

Author(s):

Cesar Ayala ◽

Xabier Lobregat ◽

Antonio Pineda

Keyword(s):

Perturbation Theory ◽

Energy Range ◽

Short Distance ◽

Weak Coupling ◽

Strong Consistency ◽

Lattice Data ◽

Static Potential ◽

Static Energy ◽

Static Quark

Abstract We give the hyperasymptotic expansion of the energy of a static quark-antiquark pair with a precision that includes the effects of the subleading renormalon. The terminants associated to the first and second renormalon are incorporated in the analysis when necessary. In particular, we determine the normalization of the leading renormalon of the force and, consequently, of the subleading renormalon of the static potential. We obtain $$ {Z}_3^F $$ Z 3 F (nf = 3) = $$ 2{Z}_3^V $$ 2 Z 3 V (nf = 3) = 0.37(17). The precision we reach in strict perturbation theory is next-to-next-to-next-to-leading logarithmic resummed order both for the static potential and for the force. We find that the resummation of large logarithms and the inclusion of the leading terminants associated to the renormalons are compulsory to get accurate determinations of $$ {\Lambda}_{\overline{\mathrm{MS}}} $$ Λ MS ¯ when fitting to short-distance lattice data of the static energy. We obtain $$ {\Lambda}_{\overline{\mathrm{MS}}}^{\left({n}_f=3\right)} $$ Λ MS ¯ n f = 3 = 338(12) MeV and α(Mz) = 0.1181(9). We have also MS found strong consistency checks that the ultrasoft correction to the static energy can be computed at weak coupling in the energy range we have studied.

Download Full-text

An obstacle to sub-AdS holography for SYK-like models

Journal of High Energy Physics ◽

10.1007/jhep03(2021)094 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

Pengfei Zhang ◽

Yingfei Gu ◽

Alexei Kitaev

Keyword(s):

Lyapunov Exponent ◽

Weak Coupling ◽

Kinetic Coefficient ◽

Weak Coupling Limit ◽

Branching Time ◽

Quasiparticle Lifetime

Abstract We argue that “stringy” effects in a putative gravity-dual picture for SYK-like models are related to the branching time, a kinetic coefficient defined in terms of the retarded kernel. A bound on the branching time is established assuming that the leading diagrams are ladders with thin rungs. Thus, such models are unlikely candidates for sub-AdS holography. In the weak coupling limit, we derive a relation between the branching time, the Lyapunov exponent, and the quasiparticle lifetime using two different approximations.

Download Full-text

Modes of Interannual Tropical Ocean–Atmosphere Interaction—a Unified View. Part II: Analytical Results in the Weak-Coupling Limit

Journal of the Atmospheric Sciences ◽

10.1175/1520-0469(1993)050<3504:moitoi>2.0.co;2 ◽

1993 ◽

Vol 50 (21) ◽

pp. 3504-3522 ◽

Cited By ~ 78

Author(s):

J. David Neelin ◽

Fei-Fei Jin

Keyword(s):

Weak Coupling ◽

Weak Coupling Limit ◽

Tropical Ocean ◽

Analytical Results ◽

Ocean Atmosphere ◽

Unified View ◽

Ocean Atmosphere Interaction ◽

Atmosphere Interaction

Download Full-text

ENERGY BAND OVERLAPPING IN HIGH-Tc SUPERCONDUCTORS

Modern Physics Letters B ◽

10.1142/s0217984996001681 ◽

1996 ◽

Vol 10 (30) ◽

pp. 1483-1490 ◽

Cited By ~ 10

Author(s):

M. MORENO ◽

R. M. MÉNDEZ-MORENO ◽

M. A. ORTIZ ◽

S. OROZCO

Keyword(s):

Weak Coupling ◽

Cuprate Superconductors ◽

Weak Coupling Limit ◽

Band Model ◽

Coupling Constant ◽

High Tc Superconductors ◽

Energy Bands ◽

Effective Coupling ◽

High Tc ◽

Two Band Model

Multi-band superconductors are analyzed and the relevance of overlapping energy bands to the high-T c of these materials is studied. Within the BCS framework, a two band model with generalized Fermi surface topologies is developed. Values of the overlapped occupancy parameters for typical cuprate superconductors are obtained as a function of the ratio R and the effective coupling constant, λ, in the weak-coupling limit. The overlap scale is of the order or lower than the cutoff (Debye) energy. The typical behavior of the isotope effect is obtained. As these superconductors have transition temperatures above the phonon barrier, the results of this approach are important to the generic understanding of the high-T c superconducting mechanism.

Download Full-text