LHC TOP WG meeting

Session

LHC top WG Open Meeting

25 Apr 2024, 09:00

4/3-006 - TH Conference Room (CERN)

Conveners

LHC top WG Open Meeting: Introduction and top-quark mass

• Wolfgang Wagner (Bergische Universitaet Wuppertal (DE))
• Jose Enrique Palencia Cortezon (Universidad de Oviedo (ES))
• Fabio Maltoni (Universite Catholique de Louvain (UCL) (BE) and Università di Bologna)
• Maria Aldaya Martin (DESY)

LHC top WG Open Meeting: Flavour changing neutral currents / lepton flavour violation

• There are no conveners in this block

LHC top WG Open Meeting: Interference effects in Top+X processes

• There are no conveners in this block

LHC top WG Open Meeting

• There are no conveners in this block

LHC top WG Open Meeting: Four-top-quark production

• There are no conveners in this block

LHC top WG Open Meeting: Observation of entanglement in top-quark-antiquark pair production

• There are no conveners in this block

9. Introduction

Prof. Fabio Maltoni (Universite Catholique de Louvain (UCL) (BE) and Università di Bologna), Jose Enrique Palencia Cortezon (Universidad de Oviedo (ES)), Maria Aldaya Martin (DESY), Wolfgang Wagner (Bergische Universitaet Wuppertal (DE))

25/04/2024, 09:00

10. Combination of measurements of the top quark mass from data collected by the ATLAS and CMS experiments at √s = 7 and 8 TeV

Mark Andrew Owen (University of Glasgow (GB)), Martijn Mulders (CERN), Matteo Defranchis (CERN)

25/04/2024, 09:30

Reference: https://arxiv.org/abs/2402.08713
A combination of fifteen top quark mass measurements performed by the ATLAS and CMS experiments at the LHC is presented. The data sets used correspond to an integrated luminosity of up to 5 and 20−1 of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, respectively.

11. Top-quark pole mass extraction at NNLO accuracy, from total, single- and double-differential cross sections for ttˉ+X production at the LHC

Oleksandr Zenaiev, Oleksandr Zenaiev (Hamburg University)

25/04/2024, 10:00

Reference: https://arxiv.org/abs/2311.05509

We extract the top-quark mass value in the on-shell renormalization scheme from the comparison of theoretical predictions for pp→tt_bar+X at next-to-next-to-leading order (NNLO) QCD accuracy with experimental data collected by the ATLAS and CMS collaborations for absolute total, normalized single-differential and double-differential...

15. A blueprint for understanding the Monte-Carlo top quark mass parameter

Andre Hoang, Andre Hoang (Austrian Academy of Sciences (AT))

25/04/2024, 10:30

Reference: https://arxiv.org/abs/2404.09856

To control the scheme of the Monte-Carlo (MC) top quark mass parameter several ingredients are mandatory, concerning the knowledge of the IR dynamics of the top mass sensitive observable, the MC parton shower and the MC hadronization evolution. I discuss these ingredients and their interplay for the simple case of 2-jettiness for boosted top...

12. ATLAS-CMS comparison: Search for flavour-changing neutral-current couplings between the top quark and Higgs boson in multi-lepton final states

Marvin Emin Geyik (Bergische Universitaet Wuppertal (DE))

25/04/2024, 11:30

A search for flavour-changing neutral-current interactions involving the top quark, the Higgs boson and an up-type quark (q = u,c) with the ATLAS detector at the Large Hadron Collider is presented. The analysis considers leptonic decays of the top quark along with Higgs-boson decays into two W bosons, two Z bosons or a τ+τ− pair. It focuses on final states containing either two leptons...

13. ATLAS-Highlight-1: Precise test of lepton flavour universality in W-boson decays into muons and electrons in pp collisions at √s = 13 TeV with the ATLAS detector

Richard Hawkings (CERN)

25/04/2024, 12:00

Reference: https://arxiv.org/abs/2403.02133

The ratio of branching ratios of the W boson to muons and electrons, Rμ/eW = B(W→μν)/B(W→eν), has been measured using 140 fb−1 of pp collision data at s√=13 TeV collected with the ATLAS detector at the LHC, probing the universality of lepton couplings.

14. Dark matter as the trigger of flavor changing neutral current decays of the top quark

Dr Adil Jueid (Institute for Basic Science)

25/04/2024, 12:30

Reference: https://arxiv.org/abs/2402.08652

In this talk, I will discuss a possible between dark matter (DM) and one-loop induced top quark FCNC decays. In a simplified t-channel DM model that extends the SM with one colored scalar mediator and one right-handed fermion both odd under an ad-hoc Z_2 symmetry, I will show that that moderate to large rates of the top quark FCNC decays are...

16. Theory predictions for tZj production

Davide Pagani (Universita e INFN, Bologna (IT))

25/04/2024, 14:30

17. CMS-Highlight-1: Measurement of inclusive and differential cross sections for single top quark production in association with a W boson in proton-proton collisions at 13.6 TeV

Alejandro Soto Rodriguez (Universidad de Oviedo (ES))

25/04/2024, 15:00

Reference: CMS-PAS-TOP-23-008 (https://cds.cern.ch/record/2893766)

18. CMS-Highlight-2: Inclusive and differential measurement of top quark cross sections in association with a Z boson

Federica Colombina (Deutsches Elektronen-Synchrotron (DE))

25/04/2024, 15:30

Reference: CMS-PAS-TOP-23-004 (https://cds.cern.ch/record/2893862)

25. Top-Quark Decay at Next-to-Next-to-Next-to-Leading Order in QCD

Xiang Chen (Peking University)

25/04/2024, 16:00

Reference: https://arxiv.org/abs/2309.01937

We present the first complete high-precision QCD corrections to the inclusive decay width Γ_t, the W-helicity fractions f_{L,R,0} and semi-inclusive distributions for the top-quark decay process t → b + W+ + X_QCD at NNNLO in the strong coupling constant α_s.

20. CMS-Highlight-3: Measurement of the inclusive tt cross section in final states with one lepton and additional jets and combination with the final states with two leptons at 5.02 TeV with 2017 data

Javier Del Riego Badas (Universidad de Oviedo (ES))

25/04/2024, 17:00

Reference: CMS-PAS-TOP-23-005 (https://cds.cern.ch/record/2895219)

21. The rise and fall of light stops in the LHC top quark sample

Roberto Franceschini (Rome 3 U.)

25/04/2024, 17:30

Reference: https://arxiv.org/abs/2312.09794

We discuss the possibility that light new physics in the top quark sample at the LHC can be found by investigating with greater care well known kinematic distributions, such as the invariant mass m_bℓ of the b-jet and the charged lepton in fully leptonic tt_bar events. We demonstrate that new physics can be probed in the rising part of the already...

22. 3t vs 4t calculation at C-NLO

Hesham El Faham (The University of Manchester)

26/04/2024, 09:30

23. Plans for 4-top-quark LHCtopWG combination

Baptiste Ravina (Georg August Universitaet Goettingen (DE)), Kirill Skovpen (Ghent University (BE))

26/04/2024, 10:00

24. Four top final states with NLO accuracy in perturbative QCD: 4 lepton channel

Malgorzata Maria Worek (Rheinisch Westfaelische Tech. Hoch. (DE)), Nikolaos Dimitrakopoulos

26/04/2024, 10:30

Reference: https://arxiv.org/abs/2401.10678

Triggered by the observation of four top-quark production at the LHC by the ATLAS and CMS collaboration we report on the calculation of the next-to-leading order QCD corrections to the Standard Model process pp→tt¯tt¯ in the 4ℓ top-quark decay channel. We take into account higher-order QCD effects in both the production and decays of the four top...

27. Probing entanglement in top quark production with the CMS detector

Andreas Werner Jung (Purdue University (US)), Giulia Negro (Purdue University (US))

26/04/2024, 11:30

Reference: CMS-PAS-TOP-23-001 (https://cds.cern.ch/record/2893854)

Entanglement is an intrinsic property of quantum mechanics and its measurement probes the current understanding of the underlying quantum nature of elementary particles at a fundamental level. A measurement of the extent of entanglement in top quark-antiquark events produced in proton-proton collisions at a center-of-mass...

28. Comparison of the ATLAS and CMS measurements of entanglement in top-quark-antiquark pair production

Yoav Afik (University of Chicago (US))

26/04/2024, 12:00

29. Threshold and bound state effects in tt

Claudio Severi (Universita e INFN, Bologna (IT)), Claudio Severi (University of Manchester)

26/04/2024, 12:30

19. ATLAS highlight