Coulomb gluons and the ordering variable

Ángeles-Martínez, René; Forshaw, Jeffrey R.; Seymour, Michael H.

doi:10.1007/jhep12(2015)091

Cited by 16 publications

(39 citation statements)

References 27 publications

(49 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 is expected to be violated at N 4 LO by Glauber gluons [58] which couple the different beam and jet functions. While the cancellation of Glauber gluons was shown for color singlet transverse moment distributions in the seminal works of [58][59][60][61][62][63][64], it is expected that factorization should not hold for a dijet event shape [31,32,[34][35][36][37][65][66][67][68][69][70][71][72][73][74][75]. Glauber contributions can potentially be incorporated in our formalism using [37], and indeed one of our primary motivations is to understand such violations by identifying a dijet observable with the simplest perturbative structure.…”

Section: Factorization Formulamentioning

confidence: 99%

Precision QCD Event Shapes at Hadron Colliders: The Transverse Energy-Energy Correlator in the Back-to-Back Limit

Gao

Moult

et al. 2019

Phys. Rev. Lett.

View full text Add to dashboard Cite

We present an operator based factorization formula for the transverse energy-energy correlator (TEEC) hadron collider event shape in the back-to-back (dijet) limit. This factorization formula exhibits a remarkably symmetric form, being a projection onto a scattering plane of a more standard transverse momentum dependent factorization. Soft radiation is incorporated through a dijet soft function, which can be elegantly obtained to next-to-next-to-leading order (NNLO) due to the symmetries of the problem. We present numerical results for the TEEC resummed to next-to-nextto-leading logarithm (NNLL) matched to fixed order at the LHC. Our results constitute the first NNLL resummation for a dijet event shape observable at a hadron collider, and the first analytic result for a hadron collider dijet soft function at NNLO. We anticipate that the theoretical simplicity of the TEEC observable will make it indispensable for precision studies of QCD at the LHC, and as a playground for theoretical studies of factorization and its violation.

show abstract

Section: Factorization Formulamentioning

confidence: 99%

Precision QCD Event Shapes at Hadron Colliders: The Transverse Energy-Energy Correlator in the Back-to-Back Limit

Gao

Moult

et al. 2019

Phys. Rev. Lett.

View full text Add to dashboard Cite

show abstract

“…The typical choices of using angle [14] or hardness-related variables like virtuality [2,14] or transverse momentum [2,11,12,14] are related to the on-shell propagator singularities induced by emissions. Transverse momenta measured with respect to the axes of a color dipole have favorable qualities in the soft limit [2,15] and to define consistent loop integration boundaries [16]. This article uses the soft transverse momentum-ordered final-state shower as outlined in [13] and implemented in Python in [17] as starting point.…”

Section: Parton Shower Basicsmentioning

confidence: 99%

Stochastically sampling color configurations

Isaacson

Prestel

2019

Phys. Rev. D

View full text Add to dashboard Cite

Parton shower algorithms are key components of theoretical predictions for high-energy collider physics. Work towards more accurate parton shower algorithms is thus pursued along many different avenues. The systematic treatment of subleading color corrections in parton shower algorithms is however technically challenging and remains elusive. In this article, we present an efficient and numerically stable algorithm to sample color configurations at fixed NC = 3, using the correct color factor including subleading corrections with a parton shower. The algorithm is implemented as stand-alone program that can be interfaced to the Pythia event generator. Preliminary comparisons to to LEP data are presented.

show abstract

“…According to the results in [27,32], which were performed to one-loop accuracy, the corresponding differential cross section has a similar structure to eq. (2.1) but with…”

Section: Jhep05(2018)044mentioning

confidence: 99%

“…(2.34) by cos(π ) + i sin(π δ ij ). It should be re-iterated that the calculations in [27,32] were performed only at one loop and it remains to be seen how the improved resummation proceeds to all orders.…”

Section: Jhep05(2018)044mentioning

confidence: 99%

“…momentum ordering should be used [32]. Interestingly, and working in the eikonal approximation, but only for gluons that couple to the original hard partons, explicit calculation of all relevant Feynman diagrams (at one loop) reveals that the corrections associated with the exact triple and four-gluon vertices can be largely subsumed into a Lorentz invariant ordering variable, in a potentially simple extension of the algorithm that we described in [27,32]. This intriguing physics may not be so clearly visible in an effective field theory treatment, where the evolution is in an arbitrary renormalization scale.…”

Section: The Ordering Variablementioning

confidence: 99%

See 1 more Smart Citation

Soft gluon evolution and non-global logarithms

Martinez

Angelis

Forshaw

et al. 2018

J. High Energ. Phys.

Self Cite

118

View full text Add to dashboard Cite

We consider soft-gluon evolution at the amplitude level. Our evolution algorithm applies to generic hard-scattering processes involving any number of coloured partons and we present a reformulation of the algorithm in such a way as to make the cancellation of infrared divergences explicit. We also emphasise the special role played by a Lorentzinvariant evolution variable, which coincides with the transverse momentum of the latest emission in a suitably defined dipole zero-momentum frame. Handling large colour matrices presents the most significant challenge to numerical implementations and we present a means to expand systematically about the leading colour approximation. Specifically, we present a systematic procedure to calculate the resulting colour traces, which is based on the colour flow basis. Identifying the leading contribution leads us to re-derive the BanfiMarchesini-Smye equation. However, our formalism is more general and can systematically perform resummation of contributions enhanced by the t'Hooft coupling α s N ∼ 1, along with successive perturbations that are parametrically suppressed by powers of 1/N . We also discuss how our approach relates to earlier work.

show abstract

Coulomb gluons and the ordering variable

Cited by 16 publications

References 27 publications

Precision QCD Event Shapes at Hadron Colliders: The Transverse Energy-Energy Correlator in the Back-to-Back Limit

Precision QCD Event Shapes at Hadron Colliders: The Transverse Energy-Energy Correlator in the Back-to-Back Limit

Stochastically sampling color configurations

Soft gluon evolution and non-global logarithms

Contact Info

Product

Resources

About