Resummation, Evolution, Factorization 2023 (REF2023)

Session

MC, event generators

27 Oct 2023, 09:30

Aula M1 (Facultad de Físicas)

55. Mellin Barnes for massive bubble diagrams

Alejandro Bris (IFT-UAM)

27/10/2023, 09:30

In this talk we present a procedure to deal with massive bubbles analoguos to the dispersive integral method but with the Mellin Barnes representation of the diagram. This allows us to simplify the needed previous loop order computations leading to the same ones as in renormalon calculus.
Furthermore, if we postpone the inverse Mellin integral until the very end we can easily get analytic...

18. The small $k_T$ region in Drell-Yan production at next-to-leading order with the Parton Branching Method

Itana Bubanja

27/10/2023, 10:00

Talk

The Parton-Branching method (PB) allows us to determine Transverse Momentum Dependent (TMD) parton densities from very small to large transverse momentum ($k_T$). In the small $k_T$ range, both intrinsic parton motion and soft gluons contribute. Our study highlights the importance of soft gluons below a resolvable scale for integrated and TMD parton densities.

PB TMD parton densities,...

39. Top Quark Mass Calibration for Monte Carlo Event Generators

Vicent Mateu (University of Salamanca)

27/10/2023, 10:30

Talk

We generalize and update our former top quark mass calibration framework for Monte Carlo event generators based on the e+e- hadron-level 2-jettiness distribution in the resonance region for boosted top production. The updated framework includes the addition of the shape variables sum of jet masses, modified jet mass and the treatment of two more gap subtraction schemes to remove the leading...

22. High precesion prediction of Drell-Yan production

Tongzhi Yang (University of Zurich)

27/10/2023, 11:30

Talk

In this talk, we will talk about the high-precision fixed order results for the Drell-Yan lepton pair production as well as W boson production with the fiducial cut of CDFII at N3LO accuracy in QCD. Such high precision is achieved by the qt slicing method, which sums up the large qt contribution obtained from event-generator NNLOJET and the small qt contribution from...

27. Current status and recent improvements in the Geneva event generator

Georgios Billis (University of Milan Bicocca & INFN Milan Bicocca)

27/10/2023, 12:00

Geneva is a Monte Carlo event generator that matches fixed-order NNLO predictions with higher-order (NNLL') resummation in the jet resolution variable (zero-jettiness), and further combines them with parton showers. In this talk, I will first discuss recent improvements in the Geneva framework and demonstrate their impact in selected color-singlet processes. Furthermore, I will present results...

2. A journey through the heavy-light Sudakov universality class arising in Lattice calculation of Parton distributions

Yizhuang Liu (Jagiellonian University)

Talk

In this talk we will provide a survey of three fundamental objects: quasi-TMDPDF, quasi-LFWF amplitudes and (quark non-singlet ) quasi-PDF matching kernel that appears naturally in lattice calculation of various parton distribution functions. We demonstrate how TMD factorization or threshold factorization works for the corresponding objects with a common perturbative hard kernel: the universal...