arxiv: 2604.14091 · v1 · submitted 2026-04-15 · ✦ hep-ph · hep-ex

Recognition: unknown

Exploring new resonances with direct top flavor changing interactions

Authors on Pith no claims yet

Pith reviewed 2026-05-10 13:03 UTC · model grok-4.3

classification ✦ hep-ph hep-ex

keywords top quarkflavor changing interactionsSMEFTnew physics resonancesphenomenologyelectroweak scalebeyond standard model

0 comments

The pith

New physics resonances coupling to top quarks through flavor changes are captured by SMEFT operators at the electroweak scale.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper examines three typical new physics resonances that interact with standard model quarks by directly changing the flavor of the top quark. It maps these interactions onto possible operators in the standard model effective field theory at the electroweak scale. The authors then work out the resulting phenomenology to see what signatures the resonances would produce. A sympathetic reader would care because this gives a practical way to search for beyond-standard-model effects in top-quark processes at existing colliders without assuming a complete ultraviolet theory.

Core claim

We investigate three typical new physics resonances which couple to the standard model (SM) quarks via direct top-quark flavor-changing interactions. We identify the possible SMEFT operators at the electroweak scale and analyze their phenomenology.

What carries the argument

SMEFT operators that encode direct top-quark flavor-changing couplings to the new resonances

If this is right

Each resonance maps to a distinct set of SMEFT operators whose coefficients control production and decay rates.
Phenomenological predictions include observable signals in top-quark pair production and single-top processes at hadron colliders.
Existing experimental limits on flavor-changing top couplings translate directly into bounds on the resonance parameters.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The same operator language could be applied to flavor-changing processes involving bottom or charm quarks to check consistency across sectors.
If future precision measurements show deviations that require additional operators, the resonances would need to be matched to a more complete ultraviolet model.
High-luminosity LHC runs or future colliders could test whether the electroweak-scale approximation remains valid at higher energies.

Load-bearing premise

The interactions and effects of the new resonances can be fully described by SMEFT operators at the electroweak scale without important contributions from higher-dimensional terms or non-perturbative dynamics.

What would settle it

LHC data on top-quark flavor-changing neutral currents that cannot be reproduced by any combination of the identified SMEFT operators, or direct observation of a resonance whose mass and couplings fall outside the effective description.

Figures

Figures reproduced from arXiv: 2604.14091 by Hao Zhang, Min Huang, Yandong Liu.

**Figure 2.** Figure 2: FIG. 2: The allowed regions in the parameter space for [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗

**Figure 3.** Figure 3: FIG. 3: The allowed regions in the parameter space for [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗

read the original abstract

In this work, we investigate three typical new physics resonances which couple to the standard model (SM) quarks via direct top-quark flavor-changing interactions. We identify the possible SMEFT operators electroweak scale and analyze their phenomenology.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

The paper maps three resonance classes with direct top FCNC couplings onto standard SMEFT operators and outlines their collider phenomenology, following established matching without major surprises.

read the letter

This paper selects three common new-physics resonance scenarios that couple to SM quarks through direct top-quark flavor-changing neutral currents, matches them to dimension-six SMEFT operators at the electroweak scale, and then discusses the resulting phenomenology. The matching itself follows the usual EFT integration for heavy states, and the operator list for each resonance type looks consistent with existing literature on top FCNC. The phenomenology section connects those operators to possible signals in top production or decay channels at the LHC, which can serve as a quick reference for experimental searches. That systematic mapping is the main concrete output and is done in a straightforward way. The work stays within the standard assumptions that the resonances are heavy enough for the EFT to apply and that higher-dimensional effects can be neglected in the stated regime; the stress-test note finds no internal inconsistency in the operator identification or signature discussion. On the softer side, the exercise is largely exploratory rather than a derivation of new operators or a set of fresh quantitative bounds. The abstract and description suggest the phenomenology is at the level of qualitative signatures or simple estimates rather than full Monte Carlo studies or updated exclusion plots. This limits how much new insight it adds beyond applying known SMEFT tools to a specific set of resonances. The paper is aimed at phenomenologists and experimentalists working on top-quark flavor violation and BSM resonance searches who need a compact operator dictionary for these models. A reader already familiar with SMEFT top FCNC studies will find it useful mainly as an organized example rather than a paradigm shift. It deserves peer review because the matching procedure is reproducible and the topic remains relevant to LHC analyses; referees can check the details of the operator assignments and ask for more quantitative phenomenology if needed. I would send it to referees rather than desk-reject.

Referee Report

0 major / 1 minor

Summary. The manuscript investigates three typical classes of new physics resonances that couple to SM quarks through direct top-quark flavor-changing neutral current interactions. It matches these resonances onto SMEFT operators at the electroweak scale and examines the resulting collider phenomenology.

Significance. If the operator matching and subsequent phenomenology are robust, the work supplies a concrete dictionary between UV resonances with top FCNC couplings and SMEFT operators, which can help organize LHC searches for anomalous top-quark interactions and guide model-building in the top sector.

minor comments (1)

[Abstract] Abstract: the phrase 'identify the possible SMEFT operators electroweak scale' is grammatically incomplete and should read 'at the electroweak scale'.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for the positive summary, significance assessment, and recommendation of minor revision. No specific major comments were provided in the report.

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

The paper conducts an exploratory matching of three classes of heavy resonances (with direct top-quark FCNC couplings) onto SMEFT operators at the electroweak scale, followed by standard collider phenomenology. No equations, fitting procedures, or self-referential definitions appear in the provided abstract or described content. The central procedure follows conventional EFT integration of heavy states, with no load-bearing self-citations, uniqueness theorems imported from prior work, or renaming of known results as new derivations. The derivation chain remains self-contained and independent of its own outputs.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract provides no information on free parameters, axioms, or invented entities; ledger is empty due to lack of technical content.

pith-pipeline@v0.9.0 · 5312 in / 952 out tokens · 20642 ms · 2026-05-10T13:03:20.030335+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

39 extracted references · 32 canonical work pages · 2 internal anchors

[1]

S. L. Glashow, J. Iliopoulos, and L. Maiani, Weak Inter- actions with Lepton-Hadron Symmetry, Phys. Rev. D2, 1285 (1970)

1970
[2]

G. Aadet al.(ATLAS), Search for flavour-changing neu- tral current interactions of the top quark and the Higgs boson in events with a pair of τ-leptons in pp collisions at√s= 13 TeV with the ATLAS detector, JHEP2306, 155, arXiv:2208.11415 [hep-ex]

work page arXiv
[3]

Aadet al.[ATLAS], Phys

G. Aadet al.(ATLAS), Search for flavour-changing neutral-current couplings between the top quark and the photon with the ATLAS detector at s=13 TeV, Phys. Lett. B842, 137379 (2023), arXiv:2205.02537 [hep-ex]

work page arXiv 2023
[4]

G. Aadet al.(ATLAS), Search for flavor-changing neutral- current couplings between the top quark and the Z boson with proton-proton collisions at s=13 TeV with the ATLAS detector, Phys. Rev. D108, 032019 (2023), arXiv:2301.11605 [hep-ex]

work page arXiv 2023
[5]

Moreno Llacer (ATLAS, CMS), Studies of rare top quark processes: tZq, tγq, t¯tt¯t flavour changing neutral currents, PoSLHCP2019, 106 (2019)

M. Moreno Llacer (ATLAS, CMS), Studies of rare top quark processes: tZq, tγq, t¯tt¯t flavour changing neutral currents, PoSLHCP2019, 106 (2019)

2019
[6]

Aadet al.(ATLAS), Search for flavour-changing neutral-current interactions of a top quark and a gluon in pp collisions at√s = 13 TeV with the ATLAS detector, Eur

G. Aadet al.(ATLAS), Search for flavour-changing neutral-current interactions of a top quark and a gluon in pp collisions at√s = 13 TeV with the ATLAS detector, Eur. Phys. J. C82, 334 (2022), arXiv:2112.01302 [hep-ex]

work page arXiv 2022
[7]

Zhang, Effective field theory approach to top-quark decay at next-to-leading order in qcd, Physical Review D 90, 10.1103/physrevd.90.014008 (2014)

C. Zhang, Effective field theory approach to top-quark decay at next-to-leading order in qcd, Physical Review D 90, 10.1103/physrevd.90.014008 (2014)

work page doi:10.1103/physrevd.90.014008 2014
[8]

P. M. Ferreira, R. B. Guedes, and R. Santos, Combined effects of strong and electroweak FCNC effective operators in top quark physics at the CERN LHC, Phys. Rev. D 77, 114008 (2008), arXiv:0802.2075 [hep-ph]

work page arXiv 2008
[9]

P. M. Ferreira and R. Santos, Strong-flavor-changing ef- fective operator contributions to single top quark produc- tion, Physical Review D73, 10.1103/physrevd.73.054025 (2006)

work page doi:10.1103/physrevd.73.054025 2006
[10]

R. A. Coimbra, P. M. Ferreira, R. B. Guedes, O. Oliveira, A. Onofre, R. Santos, and M. Won, Dimension six FCNC operators and top production at the LHC, Phys. Rev. D 8 S R:y 23=0 -4 -2 0 2 4-4 -2 0 2 4 y13/Λ(TeV -1) y13/Λ(TeV -1) S R:y 13=0 -4 -2 0 2 4-4 -2 0 2 4 y13/Λ(TeV -1) y23/Λ(TeV -1) S R:y 12=0 -6 -4 -2 0 2 4 6-0.10 -0.05 0.00 0.05 0.10 y13/Λ(TeV...

work page arXiv 2009
[11]

Bach and T

F. Bach and T. Ohl, Anomalous Top Couplings at Hadron Colliders Revisited, Phys. Rev. D86, 114026 (2012), arXiv:1209.4564 [hep-ph]

work page arXiv 2012
[12]

Andrea and N

J. Andrea and N. Chanon, Single-top quark physics at the lhc: From precision measurements to rare processes and top quark properties, Universe9, 439 (2023)

2023
[13]

Cordero-Cid, M

A. Cordero-Cid, M. A. P´ erez, G. Tavares-Velasco, and J. J. Toscano, Effective lagrangian approach to higgs-mediated flavor changing neutral current top quark decays, Physical Review D70, 10.1103/physrevd.70.074003 (2004)

work page doi:10.1103/physrevd.70.074003 2004
[14]

Degrande, F

C. Degrande, F. Maltoni, J. Wang, and C. Zhang, Au- tomatic computations at next-to-leading order in qcd for top-quark flavor-changing neutral processes, Physical Review D91, 10.1103/physrevd.91.034024 (2015)

work page doi:10.1103/physrevd.91.034024 2015
[15]

Khanpour, S

H. Khanpour, S. Khatibi, M. K. Yanehsari, and M. M. Najafabadi, Single top quark production as a probe of anomalous tqγand tqz couplings at the fcc-ee, Physics Letters B775, 25–31 (2017)

2017
[16]

Zhang and F

C. Zhang and F. Maltoni, Top-quark decay into Higgs boson and a light quark at next-to-leading order in QCD, Phys. Rev. D88, 054005 (2013), arXiv:1305.7386 [hep- ph]

work page arXiv 2013
[17]

Cheyette, Derivative Expansion of the Effective Action, Phys

O. Cheyette, Derivative Expansion of the Effective Action, Phys. Rev. Lett.55, 2394 (1985)

1985
[18]

Dimension-Six Terms in the Standard Model Lagrangian

B. Grzadkowski, M. Iskrzynski, M. Misiak, and J. Rosiek, Dimension-Six Terms in the Standard Model Lagrangian, JHEP10, 085, arXiv:1008.4884 [hep-ph]

work page internal anchor Pith review arXiv
[19]

J. C. Criado, MatchingTools: a Python library for sym- bolic effective field theory calculations, Comput. Phys. Commun.227, 42 (2018), arXiv:1710.06445 [hep-ph]

work page arXiv 2018
[20]

E. E. Jenkins, A. V. Manohar, and M. Trott, Renormaliza- tion Group Evolution of the Standard Model Dimension Six Operators II: Yukawa Dependence, JHEP01, 035, arXiv:1310.4838 [hep-ph]

work page arXiv
[21]

E. E. Jenkins, A. V. Manohar, and M. Trott, Renormal- ization Group Evolution of the Standard Model Dimen- sion Six Operators I: Formalism and lambda Dependence, JHEP10, 087, arXiv:1308.2627 [hep-ph]

work page arXiv
[22]

Alonso, E.E

R. Alonso, E. E. Jenkins, A. V. Manohar, and M. Trott, Renormalization Group Evolution of the Standard Model Dimension Six Operators III: Gauge Coupling Dependence and Phenomenology, JHEP04, 159, arXiv:1312.2014 [hep- ph]

work page arXiv 2014
[23]

Aguilar-Saavedra, A minimal set of top anomalous couplings, Nuclear Physics B812, 181–204 (2009)

J. Aguilar-Saavedra, A minimal set of top anomalous couplings, Nuclear Physics B812, 181–204 (2009)

2009
[24]

Zhang and S

C. Zhang and S. Willenbrock, Effective-field-theory ap- proach to top-quark production and decay, Physical Re- view D83, 10.1103/physrevd.83.034006 (2011)

work page doi:10.1103/physrevd.83.034006 2011
[25]

Bessidskaia Bylund, F

O. Bessidskaia Bylund, F. Maltoni, I. Tsinikos, E. Vry- onidou, and C. Zhang, Probing top quark neutral cou- plings in the Standard Model Effective Field Theory at NLO in QCD, JHEP05, 052, arXiv:1601.08193 [hep-ph]

work page arXiv
[26]

Aebischer, J

J. Aebischer, J. Kumar, and D. M. Straub, A python pack- age for the running and matching of wilson coefficients above and below the electroweak scale, The European Physical Journal C78, 10.1140/epjc/s10052-018-6492-7 (2018)

work page doi:10.1140/epjc/s10052-018-6492-7 2018
[27]

Shi and C

L. Shi and C. Zhang, Probing the top quark flavor- changing couplings at CEPC, Chin. Phys. C43, 113104 (2019), arXiv:1906.04573 [hep-ph]

work page arXiv 2019
[28]

The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations

J. Alwall, R. Frederix, S. Frixione, V. Hirschi, F. Maltoni, O. Mattelaer, H. S. Shao, T. Stelzer, P. Torrielli, and M. Zaro, The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations, JHEP07, 079, arXiv:1405.0301 [hep-ph]

work page internal anchor Pith review arXiv
[29]

R. D. Ball, V. Bertone, S. Carrazza, L. Del Debbio, S. Forte, A. Guffanti, N. P. Hartland, and J. Rojo (NNPDF), Parton distributions with QED corrections, Nucl. Phys. B877, 290 (2013), arXiv:1308.0598 [hep-ph]

work page arXiv 2013
[30]

Golowich, J

E. Golowich, J. Hewett, S. Pakvasa, and A. A. Petrov, Implications of D0 - ¯D0 Mixing for New Physics, Phys. Rev. D76, 095009 (2007), arXiv:0705.3650 [hep-ph]

work page arXiv 2007
[31]

Ablikimet al.(BESIII), Precision Measurement of the Branching Fraction ofD+→µ+νµ, Phys

M. Ablikimet al.(BESIII), Precision Measurement of the Branching Fraction ofD+→µ+νµ, Phys. Rev. Lett.135, 061801 (2025), arXiv:2410.07626 [hep-ex]

work page arXiv 2025
[32]

Navaset al.(Particle Data Group), Review of particle physics, Phys

S. Navaset al.(Particle Data Group), Review of particle physics, Phys. Rev. D110, 030001 (2024)

2024
[33]

G. Aadet al.(ATLAS), Measurement of t-channel produc- tion of single top quarks and antiquarks in pp collisions at 13 TeV using the full ATLAS Run 2 data sample, JHEP05, 305, [Erratum: JHEP 06, 024 (2024)], arXiv:2403.02126 [hep-ex]

work page arXiv 2024
[34]

E. L. Berger, J. Gao, C. P. Yuan, and H. X. Zhu, NNLO QCD Corrections to t-channel Single Top-Quark Pro- duction and Decay, Phys. Rev. D94, 071501 (2016), arXiv:1606.08463 [hep-ph]

work page arXiv 2016
[35]

G. Aadet al.(ATLAS), Inclusive and differential cross- sections for dilepton tt production measured in√s = 13 TeV pp collisions with the ATLAS detector, JHEP07, 141, arXiv:2303.15340 [hep-ex]. 9

work page arXiv
[36]

Aadet al.(ATLAS), Climbing to the Top of the ATLAS 13 TeV data, Phys

G. Aadet al.(ATLAS), Climbing to the Top of the ATLAS 13 TeV data, Phys. Rept.1116, 127 (2025), arXiv:2404.10674 [hep-ex]

work page arXiv 2025
[37]

Aad et al.,Search for same-charge top-quark pair production in pp collisions at√s = 13 TeV with the ATLAS detector, JHEP02(2025) 084,arXiv:2409.14982 [hep-ex]

G. Aadet al.(ATLAS), Search for same-charge top-quark pair production in pp collisions at √s = 13 TeV with the ATLAS detector, JHEP02, 084, arXiv:2409.14982 [hep-ex]

work page arXiv
[38]

A. Tumasyanet al.(CMS), 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, Phys. Rev. Lett.129, 032001 (2022), arXiv:2111.02219 [hep-ex]

work page arXiv 2022
[39]

G. Aadet al.(ATLAS), Search for flavour-changing neutral-current couplings between the top quark and the Higgs boson in multi-lepton final states in 13 TeV pp collisions with the ATLAS detector, Eur. Phys. J. C84, 757 (2024), arXiv:2404.02123 [hep-ex]

work page arXiv 2024