Young Scientists Meeting of the CRC TRR 257

Session

Young Scientist Talks

Sep 25, 2024, 1:00 PM

EBI Hörsaal (KIT)

Conveners

Young Scientist Talks: Session 1

• Marius Höfer (KIT ITP)

Young Scientist Talks: Session 2

• Hantian Zhang (Karlsruhe Institute of Technology)

Young Scientist Talks: Session 3

• Ivan Novikov (KIT)

Young Scientist Talks: Session 4

• Marco Vitti (Karlsruhe Institute of Technology - TTP & IAP)

Young Scientist Talks: Session 5

• Marco Bonetti (ITP IAP KIT)

Young Scientist Talks: Session 6

• Benedetta Belfatto (KIT)

Young Scientist Talks: Session 7

• Surabhi Tiwari (KIT)

22. Satisfiability modulo theories solvers and particle physics

Bakar Chargeishvili (KIT)

9/25/24, 1:00 PM

The field of Satisfiability Modulo Theories (SMT) focuses on techniques for determining the satisfiability of first-order logic formulas within formal theories. Despite its relatively short existence of approximately 20 years, SMT solvers have shown remarkable capabilities, combining expressive power with practical efficiency. They find successful applications across various research and...

5. AsyInt for massive two-loop four-point integrals at high energies

Hantian Zhang (KIT)

9/25/24, 1:25 PM

In this talk, I will present analytic techniques for massive two-loop four-point Feynman integrals at high energies and the toolbox AsyInt. In the high-energy region, the Feynman integrals involving massive particles, such as the top quark, Higgs and vector bosons, can be asymptotically expanded and directly calculated in the small-mass limit. With AsyInt, analytic results for higher-order...

8. Emulation of cosmic-ray antideuteron fluxes from dark matter annihilation

Lena Rathmann

9/25/24, 1:50 PM

Cosmic-ray antimatter, particularly low-energy antideuterons, constitute a sensitive probe of dark matter annihilating in our Galaxy. We study this smoking-gun signature and explore its complementary to indirect search via cosmic-ray antiprotons. We revisit the Monte Carlo simulation of antideuteron coalescence and cosmic-ray propagation, allowing us to assess uncertainties from both...

4. Higgs boson production in weak-boson fusion and $H\to b\bar{b}$ decay at NNLO with realistic event selection criteria

Ivan Novikov (KIT)

9/25/24, 4:10 PM

The b-quark Yukawa coupling $y_b$ can be measured in $H\to b\bar{b}$ decay. While $H\to b\bar{b}$ is the main decay mode of the Higgs boson, measuring it experimentally is challenging because of the large number of b-quarks from other QCD processes. However, Higgs boson production in weak-boson fusion (WBF) can be distinguished from those QCD backgrounds by the presence of two nearly...

2. Anomalous Couplings in Higgs plus Jet Production

Benjamin Campillo (KIT)

9/25/24, 4:35 PM

We present NLO QCD results for Higgs boson production in association with one jet, including anomalous Higgs-top and Higgs-gluon couplings, and with full top quark mass dependence. We will compare the full theory with varied anomalous couplings to the Standard Model. Of special interest will be the $p_{T,H}$ distribution, since the high-pT tail is sensitive to heavy new physics.

6. Quark-Mass Effects in Higgs Production

Tom Schellenberger (RWTH Aachen)

9/26/24, 9:30 AM

We present results for the Higgs production cross section in the gluon-gluon-fusion channel at next-to-next-to-leading order with finite quark masses. While the impact of finite quark masses are power-suppressed, the precision of state-of-the-art theory predictions makes an exact determination of this effect indispensable. With this result, we address one of the leading theory uncertainties of...

9. Towards HH at NNLO QCD: the $n_h^2$ contribution

Marco Vitti (Karlsruhe Institute of Technology - TTP & IAP)

9/26/24, 9:55 AM

The virtual corrections for $gg \to HH$ at NLO QCD have been efficiently approximated using a Taylor expansion in the limit of a forward kinematics. The same method has been recently applied to the calculation of a subset of the NNLO corrections, which are desirable given the significant impact, at NLO, of the uncertainty due to the choice of the top mass renormalization scheme.
In this talk,...

18. Yukawa- and Higgs self-coupling corrections to di-Higgs production

Augustin Vestner (KIT-ITP)

9/26/24, 10:20 AM

The upcoming HL-LHC phase gives hope to tighten the experimental
constraints on one of the core parameters of the SM: the Higgs
self-coupling. The most prolific process to consider in this context is
double Higgs boson production. Theoretical higher order calculations,
both QCD and electro-weak, are required to match the experimental precision.
In this talk we present our calculation of...

21. Heavy sterile Neutrinos from B decays and new QCD corrections to their semi-hadronic decay rates

Mr Tim Kretz (Karlsruher Institut für Technologie (KIT - TTP))

9/26/24, 11:30 AM

In modern experiments on flavour physics it is possible to search for the decays of $B$’s, $D$’s, or $\tau$’s into final states with heavy neutrinos $N$ (a.k.a. heavy neutral leptons). I present a common study of theorists and experimentalists from Belle II on constraints on $B \rightarrow D^{*} \ell N$. Next I discuss the status of the theory predictions of the various $N$ decay rates. In...

20. Nonleptonic B-decays at NNLO

Manuel Egner (KIT TTP)

9/26/24, 11:55 AM

The decay of B mesons can be predicted within the Heavy Quark Expansion as the decay of a free bottom quark plus corrections which are suppressed by powers of $1/m_b$. This talk describes the calculation of the NNLO QCD corrections to nonleptonic decays of a free bottom quark including charm quark mass effects. In particular I will outline the challenges in connection to the computation of...

17. A look into the f0(980) through the lens of rare B meson decays

Jaime del Palacio Lirola (University of Siegen)

9/26/24, 12:20 PM

The nature of many experimentally observed hadronic resonances has been a topic of debate ever since the 1960's. In this work, we focus on studying the $f_0(980)$, the second lightest unflavoured scalar resonance. We comment on the different descriptions for it in the quark model, and focus specifically on the pure $s\bar s$ picture. We mainly explore the $B_s^0 \rightarrow f_0(980)\mu^+\mu^-$...

13. N-jettiness soft function at NNLO in QCD

Prem Agarwal

9/27/24, 9:30 AM

We discuss the calculation of N-jettiness soft function at NNLO. Motivated by the connection between NNLO subtraction schemes and modern slicing methods, we derive a simple finite representation of the renormalized N-jettiness soft function, where the hard partons N acts as a parameter. We demonstrate the analytic cancellation between the bare soft function and its renormalization matrix in...

3. Four top final states - fixed order NLO vs. NLO+PS

Manal Alsairafi (RWTH Aachen)

9/27/24, 9:55 AM

Upon the observation of the four-top (4t) production in both ATLAS and CMS and the expected increase in precision in the upcoming HL-LHC runs, we are motivated to revisit the theoretical calculations of the process. We study the calculations from fixed order perturbative QCD using HELAC-NLO, which employs the Narrow Width Approximation (NWA) at NLO accuracy in both production and decay, in...

16. Heavy-to-light form factors to three loops

Jakob Müller

9/27/24, 10:20 AM

In this talk, we discuss the computation of form factors for decays of heavy into light quarks at third order in QCD for various currents. We describe the different steps of the calculation and use the results to compute the hard matching coefficients in Soft-Collinear Effective Theory for all currents. Further, we extract the hard function in the factorization formula of $B \to X_s \gamma$ to...

7. The gradient flow extended to the Standard Model

Janosch Borgulat (RWTH Aachen University)

9/27/24, 11:30 AM

The gradient flow (GF) has proven to be an effective tool in lattice QCD, with applications such as the extraction of thermodynamic quantities from the flowed energy-momentum tensor and the non-perturbative calculation of the QCD beta function. Additionally, it shows promise for determining operator renormalization matrices in effective field theories. However, its application has been largely...

15. Choosing the Right Features for Anomaly Detection

Marie Hein (RWTH Aachen University)

9/27/24, 11:55 AM

Weakly supervised methods have emerged as a powerful tool for model agnostic anomaly detection at the LHC. While remarkable performance has been achieved for specific sets of high-level input features, a further exploration of different input feature sets of various types will lead to more model agnostic and better performing setups. In this talk, we explore low-level features as well as some...

14. Lorentz-Equivariant Geometric Algebra Transformers for High-Energy Physics

Jonas Spinner

9/27/24, 12:20 PM

Extracting scientific understanding from particle-physics experiments requires solving diverse learning problems with high precision and good data efficiency. We propose the Lorentz Geometric Algebra Transformer (L-GATr), a new multi-purpose architecture for high-energy physics. L-GATr represents high-energy data in a geometric algebra over four-dimensional space-time and is equivariant under...

23. Higher-order QED×QCD Corrections To Semi-leptonic Decays

Francesco Moretti (TTP)

9/27/24, 2:15 PM

A systematic treatment of electromagnetic and strong corrections to the semi-leptonic decays is needed in order to have a precise determination of phenomenological parameters of the Standard Model (SM), such as CKM matrix elements. Under the presence of QED, the matrix element associated to the effective semi-leptonic operator on the lattice has to be renormalised, thus requiring a matching to...

19. Can we predict $B \rightarrow K a$ decay rate without specifying UV physics?

Xiyuan Gao (KIT)

9/27/24, 2:40 PM

We revisit the transition rate of $b \rightarrow s$ and a light axion-like particle $a$, to address overlooked contributions and ambiguities. Existing bottom-up approaches often lack clarity and predictive power. By recalculating the effective Hamiltonian in the minimal DFSZ model, we show that previous results are valid at one loop by coincidence, while significant two-loop contributions were...

1. NNLO QCD corrections to Delta Gamma in the B anti-B system

Pascal Reeck (KIT TTP)

9/27/24, 3:05 PM

In this talk I will present the newest results of the theoretical determination of Delta Gamma in the B anti-B system. This calculation is carried out as a matching calculation between two effective field theories, Delta B = 1 and Delta B = 2. Particular challenges in including penguin operators on the Delta B = 1 side as well as the computation of higher order corrections in mc/mb will be discussed.