Power Expansions on the Lightcone: From Theory to Phenomenology

19 Sept 2022, 09:00 → 30 Sept 2022, 16:00 Europe/Berlin

02.430 (Mainz Institute for Theoretical Physics, Johannes Gutenberg University)

Systematic power expansions on the lightcone, typically formulated as factorization theorems, are the key theoretical ingredients for achieving precise predictions for particle physics experiments, such as the LHC, B-factories, and gravitational wave detectors. The main goal of this workshop is to unify recent progress by different groups related to understanding subleading power corrections to lightcone expansions, and resolve a number of outstanding technical issues that are currently hindering further advances. The program will be also an opportunity to coordinate these theoretical advances with phenomenological predictions for experiments to ensure maximum impact. The program will consist of five major themes dedicated to various aspects of developing a systematic understanding of power expansions on the lightcone:

• Renormalization Group Properties of Non-Local Lightcone Operators
• Resolving Endpoint Singularities in Soft-Collinear Factorization
• Power Expansion for the Regge Limit in Gauge Theory and Gravity
• Phenomenological Applications of Power Suppressed Contributions
• Physics of Soft Fermion Radiation

Monday, 19 September

Welcome

Overview

1 QCD Beyond Leading Power

In this talk, I will discuss about the infrared limits of QCD beyond leading power.

I'll motivate the interest for studying this subject both as a tool to deepen our understanding of the infrared structure of gauge theory amplitudes and cross sections in the soft, collinear and Regge limit as well as to improve predictions for collider observables.

I'll explore the ingredients of factorization beyond leading power in SCET in momentum space, constructing subleading hard scattering operators and radiative jet and soft functions for processes such as Higgs production and Drell-Yan.

I'll introduce new subleading power gauge invariant objects, the θ-jet and θ-soft functions, which arise in the renormalization of subleading power operators and employ them to discuss the resummation of collinear and soft logarithms beyond leading power for a collider observable in QCD.

I'll give an overview of the work on perturbative power corrections to differential distributions for color singlet production at hadron colliders, which are crucial to systematically improve differential predictions for the LHC using qt and N-Jettiness subtraction.

I'll analyze subtleties related to the regularization of rapidity divergences beyond leading power and show an elegant resolution with the employment of a new regulator, the pure rapidity regulator.

Finally, I will talk about the Regge limit beyond leading power both at the amplitude and at the cross section level. I'll discuss the construction of a Lagrangian formalism for the treatment of fermion mediated forward scattering processes in QCD and applying it to obtain the quark reggeization and BFKL resummation.

Speaker: Gherardo Vita

VITA_MITP_NLP.pdf

Overview

2 SCET beyond LP: Basics, Renormalization, Resummation

Speaker: Martin Beneke

mainz.pdf

Tuesday, 20 September

Endpoint singularities in muon-electron backward scattering (and the soft-overlap form factor for exclusive B decays)

Convener: Philipp Böer

MITP_Boeer.pdf

Power corrections in off-forward hard processes

Convener: Vladimir Braun

Braun-MITP-Sept-2022.pdf

Renormalizaiton of the soft quark function and radiative jet function

Convener: Xiangpeng Wang

talk_XPWang.pdf

Wednesday, 21 September

Virtual

3 Factorization, resummation and endpoint divergences in Higgs to diphoton decay

Speaker: Ze Loong Liu

slides_workshop_MITP.pdf

Thursday, 22 September

4 Automating Calculations in Soft-Collinear Effective Theory

Speaker: Guido Bell

MITP.pdf

5 QED Corrections in Leptonic B-Meson Decays

Speaker: Matthias König

koenig_slides.pdf

6 Quarkonium decays: endpoint divergencies and colour-octet mechanism: a lesson from the \Chi_{QJ} —> K*K decays

Speaker: Nikolay Kivel (TUM)

Friday, 23 September

Diagrammatic methods

7 TMD factorization beyond the leading power

Speaker: Alexey Vladimirov

Vladimirov.pdf

Monday, 26 September

Overview

8 Diagrammatic methods for threshold resummation beyond leading power

Speaker: Leonardo Vernazza

Mainz-2022.pdf

Tuesday, 27 September

9 Analytic two-loop soft and beam functions for leading-jet pT

Speaker: Samuel Abreu (CERN)

abreu.pdf

10 Precision Standard Model Phenomenology at N3LO and beyond

Speaker: Gherardo Vita

11 Coherent regions for composite objects, and all orders amplitudes in the static limit

Speaker: Ryan Plestid

Wednesday, 28 September

Virtual

12 QCD calculations for B to gamma gamma and B to gamma l l

Speaker: Yu-Ming Wang

13 Higgs decaying to diphoton via light quarks: a calculation aspect

Speaker: Xing Wang

PEOL Xing Wang.pdf

Thursday, 29 September

QED

14 QED calculations at NNLO (and beyond)

Speaker: Yannick Ulrich

peol-yu.pdf

15 The LBK theorem in QED

Speaker: Tim Engel

mitp_peol.pdf

Diagrammatic methods

16 Worldline methods at NLP in gauge theories and gravity

Speaker: Domenico Bonocore

Friday, 30 September

17 TBA

Speaker: Sebastian Jaskiewicz