Annual Meeting of the CRC TRR 257

Session

Young Scientists Forum

May 26, 2021, 5:00 PM

Conveners

Young Scientists Forum: Part 1

• Elias Bernreuther (RWTH Aachen University)
• Martin Gabelmann (KIT)
• Oscar Cata

Young Scientists Forum: Part 2

• Elias Bernreuther (RWTH Aachen University)
• Martin Gabelmann (KIT)
• Oscar Cata

Young Scientists Forum: Part 3

• Martin Gabelmann (KIT)
• Elias Bernreuther (RWTH Aachen University)
• Oscar Cata

21. NLO QCD corrections for off-shell ttbb

Michele Lupattelli (Aachen)

5/26/21, 5:00 PM

I will present next-to-leading order QCD predictions for the process of top quark pair production in association with a b-jet pair at the LHC with center of mass energy of 13 TeV. In the calculation we concentrated on the di-leptonic decay channel of the top quark pair and we considered full off-shell effects. This study is particularly relevant for the measurements of the Higgs properties,...

22. ttW: Correlations and Asymmetries

Jasmina Nasufi (Aachen)

5/26/21, 5:20 PM

The ttW^{+/-} process in the multi-lepton plus b-jet final state has shown discrepancies between experiment and theory as reported by the ATLAS collaboration. To this end, we employ NLO QCD off-shell results for this process to investigate the cross section ratio between ttW^+ and ttW^- which is a precision observable. Using these results we obtain theoretical errors of order 1%-2%,...

23. NNLO QCD corrections to the B-meson mixing

Vladyslav Shtabovenko (Karlsruhe)

5/26/21, 5:40 PM

In this talk I will discuss selected aspects of our calculation of the previously unknown NNLO QCD corrections to the $B_s-{\overline{B}}_s$ mixing process. These contributions are required to reduce the existing theory uncertainty on $\mathrm{\Delta }{\mathrm{\Gamma }}_{12}^s$, the flavor mixing parameter governing lifetime differences of neutral $B_s$ mesons.

24. Cornering the Two-Higgs-Doublet II Model

Matthew Black (Siegen)

5/27/21, 2:00 PM

We perform a comprehensive study of the allowed parameter space of the Two-Higgs doublet model (2HDM) of type II. Using the theoretical framework flavio, we combine the most recent flavour, collider and electro-weak precision observables with theoretical constraints to obtain bounds on the mass spectrum of the theory. In particular we find that the wrong-sign limit is excluded and potential...

25. Top-quark fragmentation into a Higgs boson with next-to-leading order accuracy

Colomba Brancaccio (Aachen)

5/27/21, 2:20 PM

We computed the tth fragmentation function at order O(yt2 αs). Real and virtual corrections have been computed by using modern loop computation techniques. In particular, we combined the unitary cut method with the differential equation approach. Moreover, we found a strategy for calculating the master integrals analytically, order by order in the dimensional regulator ε, in canonical basis.

26. Top-Pair Events with B-hadrons at the LHC

Terry Generet (Aachen)

5/27/21, 2:40 PM

In this talk, I will present NNLO QCD predictions for several differential distributions of B-hadrons in top-pair events at the LHC. Among other things, these predictions allow for a precise determination of the top-quark mass. The results also offer positive prospects for extracting heavy-flavour fragmentation functions from LHC data. On the technical side, I will demonstrate how to...

27. (g-2)𝜇, B anomalies and DM: a loop model tale

Marco Fedele (Karlsruhe)

5/27/21, 3:00 PM

In this talk I will review how the anomalous magnetic moment of the muon and the B anomalies can be addressed by a combined explaination, by means of loop models characterized by minimal field content. Moreover, I will show how some of these model can also provide a viable DM candidate, accounting for the measured relic density while evading direct and indirect DM constraints.

28. Exact top-quark mass dependence in hadronic Higgs production

Marco Niggetiedt (Aachen)

5/28/21, 2:00 PM

The impact of the finite top-quark mass on the inclusive Higgs production cross section at higher perturbative orders has been an open question for almost three decades. I will report on the computation of this effect at NNLO QCD. This result eliminates one of the main theoretical uncertainties to inclusive Higgs production cross section at the LHC.

29. Third order corrections to the semi-leptonic $b\to c$ and the muon decays

Kay Schoenwald (Karlsruhe)

5/28/21, 2:20 PM

In this talk we present our recent calculation of order ${\alpha }_s^3$ corrections to the semi-leptonic $b\to c$ and the muon decays. The calculation has been performed in an expansion around the heavy-daughter limit $m_c\sim m_b$, but also shows decent convergence for $m_c=0$ from which the contribution to the muon decay can be extracted.

30. Automated calculation of beam functions in SCET

Marcel Wald (Siegen)

5/28/21, 2:40 PM

Over the last decades, factorization theorems became an important method to tackle problems in perturbative QCD, especially within the framework of effective field theories. In Soft-Collinear Effective Theory, these factorization theorems include beam functions accounting for the initial-state collinear interactions. While these functions have been calculated case by case for different...