NLO Oriented Event-Shape Distributions for Massive Quarks

Abstract

In this article we compute the cross section for the process $e^{+}{e}^{-}\to Q\overline{Q}+X$, with $Q$ a heavy quark, differential in a given event shape $e$ and the angle ${\theta }_T$ between the thrust axis and the beam direction. These observables are usually referred to as oriented event shapes, and it has been shown that the ${\theta }_T$ dependence can be split in two structures, dubbed the unoriented and angular terms. Since the unoriented part is already known, we compute the differential and cumulative distributions in fixed-order for the angular part up to $\mathcal{O}({\alpha }_s)$. Our results show that, for the vector current, there is a non-zero $\mathcal{O}({\alpha }_s^0)$ contribution, in contrast to the axial-vector current or for massless quarks. This entails that for the vector current one should expect singular terms at $\mathcal{O}({\alpha }_s)$ as well as infrared divergences in real- and virtual-radiation diagrams that should cancel when added up. On the phenomenological side, and taking into account that electroweak factors enhance the vector current, it implies that finite bottom-mass effects are an important correction since they are not damped by a power of the strong coupling and therefore cannot be neglected in precision studies. Finally, we show that the total angular distribution for the vector current has a Sommerfeld enhancement at threshold.

arXiv commentv2: references added, new section on Monte Carlo strategy added, some typos fixed, matches journal version

References in corpus (35)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• A Brief Introduction to PYTHIA 8.1
• A General Algorithm for Calculating Jet Cross Sections in NLO QCD
• An effective field theory for collinear and soft gluons: heavy to light decays
• Soft-Collinear Factorization in Effective Field Theory
• Summing Sudakov logarithms in B -> X_s + gamma in effective field theory
• Invariant Operators in Collinear Effective Theory
• Hard Scattering Factorization from Effective Field Theory
• The two cutoff phase space slicing method
• Factorization at the LHC: From PDFs to Initial State Jets
• Jets from Massive Unstable Particles: Top-Mass Determination
• Top Jets in the Peak Region: Factorization Analysis with NLL Resummation
• Adaptive Multidimensional Integration: VEGAS Enhanced
• Infrared Renormalization Group Flow for Heavy Quark Masses
• Do the quark masses run? Extracting $m_b(m_Z)$ from LEP data
• Hadron masses and power corrections to event shapes
• Top Quark Mass Calibration for Monte Carlo Event Generators
• Next-to-Leading Order QCD Corrections to Three-Jet Cross Sections with Massive Quarks
• Next-to-Leading-Order Corrections to the Production of Heavy-Flavour Jets in e+e- Collisions
• Two-loop Jet-Function and Jet-Mass for Top Quarks
• The C parameter distribution in e+e- annihilation
• Consistent Measurements of alpha_s from Precise Oriented Event Shape Distributions
• The MSR Mass and the $\mathcal{O}({\Lambda }_{\mathrm{QCD}})$ Renormalon Sum Rule
• Quark-mass effects for jet production in e^+ e^- collisions at the next-to-leading order: results and applications
• Variable Flavor Number Scheme for Final State Jets in Thrust
• Secondary Heavy Quark Production in Jets through Mass Modes
• Boosted Top Quarks in the Peak Region with N${}^3$LL Resummation
• REvolver: Automated running and matching of couplings and masses in QCD
• Two-Loop Massive Quark Jet Functions in SCET
• Massive Event-Shape Distributions at N${}^2$LL
• Oriented Event Shapes at N3LL + O(as^2)
• NLO Massive Event-Shape Differential and Cumulative Distributions
• Angular distribution of thrust axis with power-suppressed contribution in e+e- annihilation

Cited by in corpus (2)

• Transverse Momentum-Dependent Heavy-Quark Fragmentation at Next-to-Leading Order
• Precision $e^{+}{e}^{-}$ Hemisphere Masses in the Dijet Region with Power Corrections