Abstract

We discuss the status of resummation of large logarithmic contributions to groomed event shapes of hadronic final states in electron-positron annihilation. We identify the missing ingredients needed for next-to-next-to-next-to-leading logarithmic (NNNLL) resummation of the mMDT groomed jet mass in $e^+e^-$ collisions: the low-scale collinear-soft constants at two-loop accuracy, $c_{S_c}^{(2)}$, and the three-loop non-cusp anomalous dimension of the global soft function, $\gamma_S^{(2)}$. We present a method for extracting those constants using fixed-order codes: the EVENT2 program to obtain the color coefficients of $c_{S_c}^{(2)}$, and MCCSM for extracting $\gamma_S^{(2)}$. We present all necessary formulae for resummation of the mMDT groomed heavy jet mass distribution at NNNLL accuracy.

Highlights

  • At the Large Hadron Collider (LHC), quantum chromodynamics (QCD) has been studied at an unprecedented precision in both experiment and theory

  • Where we fix the number of active quarks to nf 1⁄4 5. These results enable resummation to nextto-next-to-next-to-leading logarithmic (NNNLL) accuracy for jet substructure observables for the first time, which we present in a companion paper [53]

  • Using numerical predictions at NLO and Next-to-next-to-leading fixed order (NNLO) accuracies, we were able to extract two-loop constants and threeloop anomalous dimensions for the mass mass drop tagger (mMDT) groomed mass factorization theorem in eþe− → hadrons events

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Summary

INTRODUCTION

At the Large Hadron Collider (LHC), quantum chromodynamics (QCD) has been studied at an unprecedented precision in both experiment and theory. × 1⁄2JðτRÞ ⊗ ScðτR; zcutފ; ð1Þ where σ0 is the leading-order eþe− → qqcross section, zcut is a parameter of the mMDT/soft drop groomer, and τL, τR are the left- and right-hemisphere masses, respectively Extending this factorization theorem beyond NNLL requires the two-loop constants for each of the functions on the right, as well as their three-loop anomalous dimensions. These results enable resummation to NNNLL accuracy for jet substructure observables for the first time, which we present in a companion paper [53]. Using the mMDT constraint, the value of the hemisphere mass for such an emission is ρ ≳ 2zcut; ð16Þ and mMDT strongly affects the cross section for values of ρ smaller than this

EXTRACTION OF TWO-LOOP CONSTANTS
Test at one-loop
Fit at two-loops
EXTRACTION OF THREE-LOOP ANOMALOUS DIMENSIONS
CONCLUSIONS AND OUTLOOK
Noncusp anomalous dimensions and constants
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