On p ⊥-broadening of high energy partons associated with the LPM effect in a finite-volume QCD medium

Self Cite

Abstract:We study the connection between radiative energy loss and radiative p ⊥ -broadening of a high-energy quark or gluon passing through QCD matter. The generalized Baier-Dokshitzer-Mueller-Peigne-Schiff-Zakharov (BDMPS-Z) formalism is used to calculate energy loss due to multiple gluon emission. With L the length of the matter and l 0 the size of constituents of the matter we find a double logarithmic correction ∝ ln 2 L l 0 to parton energy loss due to two-gluon emission. We also show that the radiative energy loss per unit length − dE dz = αsNc 12 p 2 ⊥ by carrying out a resummation of the double logarithmic terms. Here, the transverse momentum broadening p 2 ⊥ is obtained by resumming terms ∝ α s ln 2 L l 0 in ref. [11]. Our result agrees with that by the renormalization ofq proposed in refs. [15,16].

“…[10]. Double logarithmic terms due to the recoil effect of one-gluon emission are found in the kinetic region of single scattering.…”

Section: Introductionmentioning

confidence: 94%

Section: Review Of the Generalized Bdmps-z Formalism For Radiative Enmentioning

confidence: 99%

Section: Contributions From Diagrams With Fully-overlapping Emissionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Radiative energy loss and radiative p ⊥-broadening of high-energy partons in QCD matter

2014

Self Cite

“…This enhancement has been previously recognized in ref. [9], where the respective correction to the transverse momentum broadening has been first computed (see also [14,71]). …”

Section: The Double Logarithmic Approximationmentioning

confidence: 99%

The non-linear evolution of jet quenching

Iancu

2014

146

Abstract:We construct a generalization of the JIMWLK Hamiltonian, going beyond the eikonal approximation, which governs the high-energy evolution of the scattering between a dilute projectile and a dense target with an arbitrary longitudinal extent (a nucleus, or a slice of quark-gluon plasma). Different physical regimes refer to the ratio L/τ between the longitudinal size L of the target and the lifetime τ of the gluon fluctuations. When L/τ 1, meaning that the target can be effectively treated as a shockwave, we recover the JIMWLK Hamiltonian, as expected. When L/τ 1, meaning that the fluctuations live inside the target, the new Hamiltonian governs phenomena like transverse momentum broadening and radiative energy loss, which accompany the propagation of an energetic parton through a dense QCD medium. Using this Hamiltonian, we derive a non-linear equation for the dipole amplitude (a generalization of the BK equation), which describes the high-energy evolution of jet quenching. As compared to the original BK-JIMWLK evolution, the new evolution is remarkably different: the plasma saturation momentum evolves much faster with increasing energy (or decreasing Bjorken's x) than the corresponding scale for a shockwave. This widely opens the transverse phase-space for the evolution in the vicinity of the saturation line and implies the existence of large radiative corrections, enhanced by the double logarithm ln 2 (LT ), with T the temperature of the medium. This confirms from a wider perspective a recent result by Liou, Mueller, and Wu (arXiv:1304.7677). The dominant, double-logarithmic, corrections to the dipole amplitude are smooth enough to be absorbed into a renormalization of the jet quenching parameterq. This renormalization is universal: it applies to all the phenomena, like the transverse momentum broadening or the radiative energy loss, which can be computed from the dipole amplitude.

Classical vs quantum corrections to jet broadening in a weakly-coupled Quark-Gluon Plasma

Ghiglieri

Weitz

2022

The transverse momentum broadening coefficient $$ \hat{q} $$ q ̂ receives both soft, classical and radiative, quantum corrections. The former are responsible for a large $$ \mathcal{O} $$ O (g) correction, whereas the latter enter at relative order αs, but are enhanced by a double logarithm of the length of the medium over the thermal wavelength. We analyze radiative corrections for a weakly-coupled quark-gluon plasma. We find that a thermal population of dynamical gluons changes the boundaries and reduces the size of the double-logarithmic phase space. It also provides new subdominant logarithmic corrections. We also show how the quantum, double-logarithmic and classical, soft phase spaces are smoothly connected once the radiated gluon becomes soft enough. Finally, we discuss a pathway to a determination of radiative corrections beyond the harmonic-oscillator approximation.