Nonabelian plasma instabilities in Bjorken expansion

Bjorken unpolarized and polarized sum rules: comparative analysis of large-N_F expansions

Analytical all-orders results are presented for the one-renormalon-chain contributions to the Bjorken unpolarized sum rule for the F_1 structure function of nu N deep-inelastic scattering in the large-N_F limit. The feasibility of estimating higher order perturbative QCD corrections, by the process of naive nonabelianization (NNA), is studied, in anticipation of measurement of this sum rule at a Neutrino Factory. A comparison is made with similar estimates obtained for the Bjorken polarized sum rule. Application of the NNA procedure to correlators of quark vector and scalar currents, in the eu…

Bjorken Flow, Plasma Instabilities, and Thermalization

At asymptotically high energies, thermalization in heavy ion collisions can be described via weak-coupling QCD. We present a complete treatment of how thermalization proceeds, at the parametric weak-coupling level. We show that plasma instabilities dominate the dynamics, from immediately after the collision until well after the plasma becomes nearly in equilibrium. Initially they drive the system close to isotropy, but Bjorken expansion and increasing diluteness makes the system again become more anisotropic. At time τ~ α^(-12/5) Q^(-1) the dynamics become dominated by a nearly-thermal bath; a…

QCD Plasma Instabilities: The Nonabelian Cascade

Magnetic plasma instabilities appear to play an important role in the early stages of quark-gluon plasma equilibration in the high energy (weak coupling) limit. Numerical studies of the growth of such instabilities from small seed fluctuations have found initial exponential growth in their energy, followed by linear growth once the associated color magnetic fields become so large that their non-abelian interaction are non-perturbative. In this paper, we use simulations to determine the nature of this linear energy growth. We find that the long-wavelength modes associated with the instability h…

Manifestation of Infrared Instabilities in High-Energy Processes in Nonabelian Gauge Theories

We show that a high frequency standing wave in SU(2) gauge theory is unstable against decay into long wavelength modes. This provides a non-perturbative mechanism for energy transfer from initial high momentum modes to final states with low momentum excitations. The abelian case does not manifest such instability. Our analysis is supported by lattice simulations.

Adler函数、Bjorken极化求和规则：对$\u003cβ\u003e$-展开式元素及费曼图的验证

Adler function, Bjorken polarized sum rule: confirmation of elements of the $\{β\}$-expansion and the diagrams

本研究在标准QCD框架下独立验证了非单态Adler函数、Bjorken极化求和规则的$\u003cβ\u003e$-展开式元素至N⁴LO阶的既有结果，还提出基于朴素非阿贝尔化推广、用少量特定类型费曼图估算高阶QCD计算结果的方法。

反向流动非阿贝尔流体中的新型不稳定性

Novel Instabilities in Counter-Streaming Nonabelian Fluids

本文研究反向流动的非阿贝尔流体中的流不稳定性，发现除电动力学类似物外，还出现新型非阿贝尔模式，其增长率可能更大，且存在不受介质影响的传播模式。