Title: Leveraging on-shell interference to search for FCNCs of the top quark and the Z boson

Journal Article · · European Physical Journal. C, Particles and Fields (Online)
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Abstract Flavour-changing-neutral currents (FCNCs) involving the top quark are highly suppressed within the Standard Model (SM). Hence, any signal in current or planned future collider experiments would constitute a clear manifestation of physics beyond the SM. We propose a novel, interference-based strategy to search for top-quark FCNCs involving the Z boson that has the potential to complement traditional search strategies due to a more favourable luminosity scaling. The strategy leverages on-shell interference between the FCNC and SM decay of the top quark into hadronic final states. We estimate the feasibility of the most promising case of anomalous tZc couplings using Monte Carlo simulations and a simplified detector simulation. We consider the main background processes and discriminate the signal from the background with a deep neural network that is parametrised in the value of the anomalous tZc coupling. We present sensitivity projections for the HL-LHC and the FCC-hh. We find an expected 95% CL upper limit of $$$${\mathcal {B}}_{\textrm{excl}}(t\rightarrow Zc) = 6.4 \times 10^{-5}$$$$ B excl ( t → Z c ) = 6.4 × 10 - 5 for the HL-LHC. In general, we conclude that the interference-based approach has the potential to provide both competitive and complementary constraints to traditional multi-lepton searches and other strategies that have been proposed to search for tZc FCNCs.

Research Organization:
Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
Sponsoring Organization:
USDOE; USDOE Office of Science (SC), High Energy Physics (HEP)
Grant/Contract Number:
AC02-07CH11359; SC0009924
OSTI ID:
2006707
Report Number(s):
DO-TH--23/04; FERMILAB-PUB--23-261-T; arXiv:2305.12172; 871; PII: 11982
Journal Information:
European Physical Journal. C, Particles and Fields (Online), Journal Name: European Physical Journal. C, Particles and Fields (Online) Journal Issue: 9 Vol. 83; ISSN 1434-6052
Publisher:
Springer Science + Business MediaCopyright Statement
Country of Publication:
Germany
Language:
English

References (48)

Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at s = 7 $$ \sqrt{s}=7 $$ and 8 TeV journal February 2017
Search for anomalous single top quark production in association with a photon in pp collisions at s = 8 $$ \sqrt{s}=8 $$ TeV journal April 2016
Search for heavy Higgs bosons decaying to a top quark pair in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV journal April 2020
Precision from the diphoton Zh channel at FCC-hh journal April 2021
Constraints on anomalous tcZ coupling from $ \overline{\mathrm{B}}\to {{\overline{\mathrm{K}}}^{*}}{\mu^{+}}{\mu^{-}} $ and B s →μ + μ − decays journal May 2013
Searching for t → c(u)h with dipole moments journal June 2014
The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations journal July 2014
Search for associated production of a Z boson with a single top quark and for tZ flavour-changing interactions in pp collisions at s = 8 $$ \sqrt{s}=8 $$ TeV journal July 2017
Search for flavour-changing neutral current top-quark decays t → qZ in proton-proton collisions at s = 13 $$ \sqrt{s}=13 $$ TeV with the ATLAS detector journal July 2018
Dimension-six terms in the Standard Model Lagrangian journal October 2010
Automated event generation for loop-induced processes journal October 2015
Measurements of differential cross sections of top quark pair production in association with jets in pp collisions at s = 13 $$ \sqrt{s}=13 $$ TeV using the ATLAS detector journal October 2018
On the flavor structure of natural composite Higgs models & top flavor violation journal December 2014
Top-quark decay via flavor-changing neutral currents at hadron colliders journal November 1995
A new evaluation of the decay width in the standard model journal September 1998
UFO – The Universal FeynRules Output journal June 2012
Top++: A program for the calculation of the top-pair cross-section at hadron colliders journal November 2014
Top quark rare decays via loop-induced FCNC interactions in extended mirror fermion model journal February 2018
Searching for new physics with triple-top signal at the LHC journal September 2014
First measurement of the cross section for top quark pair production with additional charm jets using dileptonic final states in pp collisions at s=13TeV journal September 2021
Search for flavour-changing neutral-current couplings between the top quark and the photon with the ATLAS detector at s=13 TeV journal July 2023
Presentation of search results: the CL s technique journal September 2002
Performance of the ATLAS muon triggers in Run 2 journal September 2020
Jet flavour classification using DeepJet journal December 2020
Performance of the CMS muon trigger system in proton-proton collisions at √(s) = 13 journal July 2021
On the Problem of the Most Efficient Tests of Statistical Hypotheses
  • Neyman, J.; Pearson, E. S.
  • Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 231, Issue 694-706 https://doi.org/10.1098/rsta.1933.0009
journal January 1933
I. The Bakerian Lecture. Experiments and calculations relative to physical optics journal January 1804
Weak Interactions with Lepton-Hadron Symmetry journal October 1970
Rare decays of the top quark in the standard and two-Higgs-doublet models journal September 1991
Constraints on top-quark flavor changing neutral couplings from electroweak precision measurements journal September 2005
Higgs mediated flavor violating top quark decayst→uiH,uiγ,uiγγ, and the processγγ→tcin effective theories journal April 2010
Top-quark decay into Higgs boson and a light quark at next-to-leading order in QCD journal September 2013
Direct and indirect searches for top-Higgs FCNC couplings journal December 2015
Constraining top quark flavor violation and dipole moments through three and four top quark productions at the LHC journal November 2018
Next-to-Leading-Order QCD Corrections to the Top-Quark Decay via Model-Independent Flavor-Changing Neutral-Current Couplings journal February 2009
Search for Heavy Higgs Bosons A / H Decaying to a Top Quark Pair in p p Collisions at s = 8     TeV with the ATLAS Detector journal November 2017
Search for Flavor-Changing Neutral Current Interactions of the Top Quark and Higgs Boson in Final States with Two Photons in Proton-Proton Collisions at s=13  TeV journal July 2022
Parameterized neural networks for high-energy physics journal April 2016
Muon reconstruction performance of the ATLAS detector in proton–proton collision data at $$\sqrt{s}$$ s =13 TeV journal May 2016
Ultraboosted Zt and $$\gamma t$$ γ t production at the HL-LHC and FCC-hh journal November 2017
Top quark decays with flavor violation in the B-LSSM journal June 2018
Performance of missing transverse momentum reconstruction with the ATLAS detector using proton–proton collisions at $$\sqrt{s}=13~\hbox {TeV}$$ s = 13 TeV journal November 2018
Jet energy scale and resolution measured in proton–proton collisions at $$\sqrt{s}=13$$ TeV with the ATLAS detector journal August 2021
Search for flavour-changing neutral-current interactions of a top quark and a gluon in pp collisions at $$\sqrt{s}=13$$ TeV with the ATLAS detector journal April 2022
FCC-hh: The Hadron Collider: Future Circular Collider Conceptual Design Report Volume 3 journal July 2019
Handbook of LHC Higgs cross sections: 4. Deciphering the nature of the Higgs sector text May 2017
Flavour-Changing Neutral Scalar Interactions of the Top Quark journal November 2022
High-Luminosity Large Hadron Collider (HL-LHC) Preliminary Design Report null January 2015

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