Angular distributions of higher order splitting functions in the vacuum and in dense QCD matter

Abstract

We study the collinear splitting functions needed for next-to-next-to-leading order calculations of jet production in the vacuum and in dense QCD matter. These splitting functions describe the probability of a parton to evolve into three-parton final state and are generalizations of the traditional DGLAP splitting kernels to a higher perturbative order. Of particular interest are the angular distributions of such splitting functions, which can elucidate the significance of multiple parton branching for jet observables and guide the construction of parton shower Monte Carlo generators. We find that to $\mathcal{O}({\alpha }_s^2)$ both the vacuum and the in-medium collinear splitting functions are neither angular ordered nor anti-angular ordered. Specifically, in dense QCD matter they retain the characteristic broad angular distribution already found in the $\mathcal{O}({\alpha }_s)$ result.

39 pages, 15 pdf figures

References in corpus (19)

• Herwig++ Physics and Manual
• Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV
• Antiangular Ordering of Gluon Radiation in QCD Media
• Medium Modification of γ-jets in High-energy Heavy-ion Collisions
• Non-Abelian energy loss in cold nuclear matter
• Transverse Momentum Broadening and the Jet Quenching Parameter, Redux
• Jet tomography of high-energy nucleus-nucleus collisions at next-to-leading order
• $\mathcal{O}({\alpha }_s^3)$ analysis of inclusive jet and di-jet production in heavy ion reactions at the Large Hadron Collider
• Momentum imbalance of isolated photon-tagged jet production at RHIC and LHC
• Extending Soft-Collinear-Effective-Theory to describe hard jets in dense QCD media
• Large Angle Hadron Correlations from Medium-Induced Gluon Radiation
• The physics of $Z^0/{\gamma }^{\ast }$-tagged jets at the LHC
• Gauge invariant definition of the jet quenching parameter
• Jet coherence in QCD media: the antenna radiation spectrum
• N-Jettiness as a probe of nuclear dynamics
• Probing nuclear dynamics in jet production with a global event shape
• Towards detailed tomography of high energy heavy-ion collisions by $\gamma$-jet
• Medium-induced splitting kernels from SCET_G
• Prompt photon in association with a heavy-quark jet in Pb-Pb collisions at the LHC

Cited by in corpus (3)

• Jet charge modification in dense QCD matter
• Theoretical Developments in QCD Jet Energy Loss
• Parton energy loss in QCD matter