论文标题
质子尺度的颜色电荷波动在由三个夸克和gluon制成的质子中
Sub-femtometer scale color charge fluctuations in a proton made of three quarks and a gluon
论文作者
论文摘要
计算由三个夸克组成的质子和扰动性gluon的光线波函数。然后将其用于得出颜色电荷密度相关器$ \langleρ^a（\ vec q_1）\，ρ^b（\ vec q_2）\ rangle $ at $ {\ cal o}（g^4）$的表达式。相关器表现出柔软的奇异性。尽管如此，我们采用了精确的gluon发射和吸收顶点，因此，不需要gluon携带很小的轻度动量，也不需要在发射夸克上划线。 我们验证相关器是否满足病房的身份，并且它独立于重新归一化量表，即紫外线差异取消。我们的表达式为Balitsky-Kovchegov的X依赖性初始条件提供了偶极子散射基质的C-E-E-Kovchegov演化，以至于更高的能量。也就是说，我们确定了颜色电荷波动的第一个非平凡力矩，该量充当质子柔软颜色场的源，波长大于$ 1/x \ sim 10-100 $。
The light-front wave function of a proton composed of three quarks and a perturbative gluon is computed. This is then used to derive expressions for the color charge density correlator $\langleρ^a(\vec q_1)\, ρ^b(\vec q_2)\rangle$ at ${\cal O}(g^4)$ due to the emission of a gluon by one of the quarks in light-cone gauge. The correlator exhibits the soft and collinear singularities. Albeit, we employ exact gluon emission and absorption vertices, and hence the gluon is not required to carry very small light-cone momentum, or to be collinear to the emitting quark. We verify that the correlator satisfies the Ward identity and that it is independent of the renormalization scale, i.e. that ultraviolet divergences cancel. Our expressions provide x-dependent initial conditions for Balitsky-Kovchegov evolution of the C-even part of the dipole scattering matrix to higher energies. That is, we determine the first non-trivial moment of the color charge fluctuations which act as sources for soft color fields in the proton with wavelengths greater than approximately $1/x \sim 10 - 100$.
