Inspired by the observation of the ${\eta}_{t}$ meson at the LHC and the promising prospect of the ${\eta}_{t}$ meson available at the approaching HL-LHC, branching ratios for the ${\eta}_{t}$ ${\to}$ $f\bar{f}$ , $gg$ , ${\gamma}{\gamma}$ , $W^{+}W^{-}$ , $Z^{0}Z^{0}$ , $Z^{0}{\gamma}$ , and $Z^{0}H$ decays are roughly estimated. It is found that tens of opposite-charge dilepton events from the ${\eta}_{t}$ ${\to}$ $W^{+}W^{-}$ decay and hundreds of events from the ${\eta}_{t}$ ${\to}$ $Z^{0}H$ ${\to}$ ${\ell}^{+}{\ell}^{-}H$ decay using the single $Z^{0}$ boson tagging method are expected to be accessible. This estimation provides a reference for future experimental study on the ${\eta}_{t}$ meson.

China

Yueling Yang

Bingbing Yang

Jiazhi Li

Zhaojie Lü

Junfeng Sun

Searching for the toponium ${{\boldsymbol\eta}_{\boldsymbol t}}$ with the ${{\boldsymbol\eta}_{\boldsymbol t}}$ ${\boldsymbol\to}$ ${{\boldsymbol W}^{\bf +}{\boldsymbol W}^{\bf -}}$ decay * Supported by the National Natural Science Foundation of China (12275068, 12275067), the National Key R&D Program of China (2023YFA1606000), the Natural Science Foundation of Henan Province (252300421491, 242300420250), and the Science and Technology R&D Program Joint Fund Project of Henan Province (225200810030), as well as the Science and Technology Innovation Leading Talent Support Program of Henan Province (254200510039)

One-loop contributions for the decay process $ H^{\pm} \rightarrow W^{\pm}Z $ within the Two-Higgs-Doublet Model (THDM) are computed in the general $ {\cal{R}}_{\xi} $ gauge, and its phenomenological applications at future muon–TeV colliders are investigated. Analytic results are confirmed by several consistency tests, including those of $\textit{ξ}$-independence, renormalization-scale stability, and the ultraviolet finiteness of the one-loop amplitude. We first perform an updated parameter scan of the Type-X THDM in phenomenological studies. The production of charged Higgs boson pairs at future muon–TeV colliders is then investigated through two processes: $ \mu^+\mu^- \rightarrow H^+H^- \rightarrow W^{\pm}W^{\mp}Zh $ and $ \mu^+\mu^- \rightarrow \gamma\gamma \rightarrow H^+H^- \rightarrow W^{\pm}W^{\mp}Zh $ . Both signal events and their significance are evaluated considering the corresponding Standard Model backgrounds. We find that the signal significances can exceed $ 5\sigma $ at several benchmark points in the viable parameter space of the Type-X THDM.

Vietnam

Dzung Tri Tran

Quang Hoang-Minh Pham

Khoa Ngo-Thanh Ho

Khiem Hong Phan

One-loop expressions for ${H^\pm \rightarrow W^\pm Z} $ and their implications at muon-TeV colliders * This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) (103.01-2023.16)

Triboson production processes play a crucial role in probing the electroweak sector of the Standard Model, as they involve quartic gauge-boson couplings already at the tree level. With these measurements entering the precision era at the Large Hadron Collider (LHC), accurate theoretical predictions become indispensable. We present the computation of the next-to-next-to-leading-order (NNLO) QCD radiative corrections to the production of a $\textit{W}$ boson in association with two photons ( $$W\gamma \gamma $$ ) at the LHC. The calculation is exact, except for the finite part of the two-loop contribution, which is included in the leading-colour approximation. Predictions for the fiducial cross section and selected kinematic distributions are provided at a centre-of-mass energy of $$\sqrt{s}=13$$ TeV, under standard experimental selection cuts. In line with observations for other multiboson processes involving direct photons, we find sizable NNLO corrections that enhance the next-to-leading-order predictions by about $$23\%$$ , with residual perturbative uncertainties that can be roughly estimated to be at the $$5\%$$ level.

Switzerland

Paolo Garbarino

Massimiliano Grazzini

Stefan Kallweit

Germany

Chiara Savoini

NNLO QCD predictions for $$W\gamma \gamma $$ production at the LHC

The production of heavy-flavor hadrons in association with a vector boson in proton-proton collisions is a powerful probe for studying Quantum Chromodynamics and the content of protons. In this article, we provide, for the first time, differential predictions through NNLO for the production of $\textit{W}$ $\textit{D}$ final states. The results are compared to recent ATLAS measurements, and the sensitivity to the strange content of the proton is investigated by PDF profiling. The results are found to be promising for including $\textit{W}$ $\textit{D}$ measurements in proton-proton collisions in PDF fits.

United Kingdom

Terry Generet

Poland

Rene Poncelet

Slovenia

Miha Muškinja

Associated production of a $\textit{W}$-boson and a charm meson at NNLO in QCD

In 2022, the collider detector at Fermilab (CDF) collaboration reported the $\textit{W}$-boson mass ( $ M_W= $ $ 80.4335\pm0.0094\; \text{GeV} $ ), which deviates from the standard model (SM) prediction ( $ M_W^{\rm SM}=80.357\pm0.006\; \text{GeV} $ ) by ~ $ 7\sigma $ . In contrast, the CMS collaboration obtained $ M_W=80.3602\pm0.0099\; \text{GeV} $ , which was very close to the SM global electroweak fit value of $ \sim80.357\; \text{GeV} $ . Motivated by this situation, we reassess the $\textit{W}$-boson mass within the lepton-specific two Higgs doublet model (LS-2HDM). To this end, we perform random scans (generated with SARAH 4.13.0 and evaluated with SPheno 4.0.3) and confront the results with up-to-date theoretical and experimental constraints. The scan enforces vacuum stability, perturbative unitarity, and perturbativity; electroweak precision observables via the oblique parameters $ (S,T,U) $ ; LEP bounds on $ H^\pm $ ; rare $\textit{B}$-meson decays; lepton flavor universality (LFU) in $\textit{Z}$ and $\textit{τ}$ decays; and 13 TeV LHC searches for additional Higgs bosons. Viable points are further tested with HiggsTools (HiggsSignals + HiggsBounds). In the LS-2HDM, if $ h_1 $ is the SM-like Higgs at $ m_{h_1}\simeq125 $ GeV with $ |\cos(\beta-\alpha)|\lesssim0.06 $ , $ 17\lesssim\tan\beta\lesssim39 $ , $ 144\lesssim m_{h_2}\lesssim414 $ GeV, and $ 435\lesssim m_{A,H^{\pm}}\lesssim685 $ GeV, the model reproduces the 2024 CMS $\textit{W}$-boson mass within $ 3\sigma $ . Solutions near the 2022 CDF value ( $ M_W=80.4335\pm0.0094\; \text{GeV} $ ) survive; however, after applying all constraints, including HiggsTools, they approach it at best within $ \lesssim2\sigma $ . Our findings emphasize that LS-2HDM favors the CMS results consistently with the current experimental results. Although one can theoretically accommodate the CDF results in this model, up-to-date electroweak precision bounds on oblique parameters $ (S,T,U) $ with the SM-like Higgs and LFU constraints exclude these solutions. Our results for $ W $ -boson mass can only be as close as about $ 2\sigma $ to $_{the CDF results}$.

Ali Çiçi

Hüseyin Dağ

Resolving the $\textit{W}$ boson mass in the lepton specific two Higgs doublet model * This work was supported in part by the Turkish Energy, Nuclear and Mineral Research Agency under project number 2022TENMAK(CERN)A5.H3.F2-02

<p>Recently, it has been suggested that the spectrum of physical states in the Standard Model may include an ultralight pseudoscalar, denoted by <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi mathvariant="normal">w</mi></msub></math>, in analogy with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>η</mi><mo>′</mo></msup></math> state arising from the strong interactions. We find that typical expectations for the properties of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi mathvariant="normal">w</mi></msub></math> get challenged by astrophysical constraints on the couplings of ultralight bosons. Our strongest limit sets a lower bound of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">O</mi><mrow><mo stretchy="false">(</mo><mrow><mn>100</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow><mo stretchy="false">)</mo></mrow></mrow></math> on the decay constant of the hypothesized pseudoscalar. We also briefly discuss whether <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi mathvariant="normal">w</mi></msub></math> could be a dark matter candidate, or the origin of dark energy, but conclude that those identifications appear unlikely. Given the important implications of a potentially overlooked <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi mathvariant="normal">w</mi></msub></math> state for a more complete understanding of the electroweak interactions and a fundamental description of nature, further theoretical and phenomenological investigations of this possibility and its associated physics are warranted.</p>

United States

Hooman Davoudiasl

Astrophysical consequences of an electroweak <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi>w</mi></msub></math> pseudoscalar

We develop a contour integral formalism for computing the K-theoretic equivariant 3-vertex. Within the Jeffrey-Kirwan (JK) residue framework, we show that, by an appropriate choice of the reference vector, both the equivariant Donaldson-Thomas (DT) and Pandharipande-Thomas (PT) 3-vertices can be extracted from the same integrand. We analyze three distinct limits of the PT 3-vertex, recovering the unrefined topological vertex, the refined topological vertex, and the Macdonald refined topological vertex. Higher-rank extensions of PT counting and the DT/PT correspondence are also explored. From a quantum algebraic perspective, we construct an operator version of the equivariant PT 3-vertex and term it the Pandharipande-Thomas $\textit{qq}$-character. We then discuss its connection with the quantum toroidal $${\mathfrak{g}\mathfrak{l}}_{1}$$ .

France

Taro Kimura

Japan

Go Noshita

Gauge origami and quiver W-algebras. Part IV. Pandharipande-Thomas $\textit{qq}$-characters

Measurements are presented of the W and Z boson production cross sections in proton-proton collisions at a center-of-mass energy of 13.6 TeV. Data collected in 2022 and corresponding to an integrated luminosity of 5.01 fb with one or two identified muons in the final state are analyzed. The results for the products of total inclusive cross sections and branching fractions for muonic decays of W and Z bosons are $${11}.{93}\pm 0.0{8}\left({\text{syst}}\right)\pm 0.{17}{\left({\text{lumi}}\right)}_{-0.07}^{+0.07}$$ (acceptance) nb for W boson production, $$8.86\pm 0.06\left({\text{syst}}\right)\pm 0.12{\left({\text{lu}}{\text{mi}}\right)}_{-0.06}^{+0.05}$$ (acceptance) nb for W boson production, and $$2.021\pm 0.009\left({\text{syst}}\right)\pm 0.028{\left({\text{lumi}}\right)}_{-0.013}^{+0.011}$$ (acceptance) nb for the Z boson production in the dimuon mass range of 60–120 GeV, all with negligible statistical uncertainties. Furthermore, the corresponding fiducial cross sections, as well as cross section ratios for both fiducial and total phase space, are provided. The ratios include charge-separated results for W boson production (W and W ) and the sum of the two contributions (W ), each relative to the measured Z boson production cross section. Additionally, the ratio of the measured cross sections for W and W boson production is reported. All measurements are in agreement with theoretical predictions, calculated at next-to-next-to-leading order accuracy in quantum chromodynamics.

Armenia

V. Chekhovsky

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J. Andrejkovic

L. Benato

T. Bergauer

S. Chatterjee

K. Damanakis

M. Dragicevic

P. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

T. Laer

P. Mechelen

N. Breugelmans

J. D’Hondt

S. Dansana

A. Moor

M. Delcourt

F. Heyen

Y. Hong

S. Lowette

I. Makarenko

D. Müller

S. Tavernier

M. Tytgat

G. Onsem

S. Putte

D. Vannerom

B. Bilin

B. Clerbaux

A. Das

I. Bruyn

G. Lentdecker

H. Evard

L. Favart

P. Gianneios

A. Khalilzadeh

F. Khan

A. Malara

M. Shahzad

L. Thomas

M. Vanden Bemden

C. Velde

P. Vanlaer

M. Coen

D. Dobur

G. Gokbulut

J. Knolle

L. Lambrecht

D. Marckx

K. Skovpen

N. Den Bossche

J. Linden

J. Vandenbroeck

L. Wezenbeek

S. Bein

A. Benecke

A. Bethani

G. Bruno

C. Caputo

J. De Favereau De Jeneret

C. Delaere

I. Donertas

A. Giammanco

A. Guzel

Sa. Jain

V. Lemaitre

J. Lidrych

P. Mastrapasqua

T. Tran

S. Turkcapar

Brazil

G. Alves

E. Coelho

G. Correia Silva

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E. Tonelli Manganote

A. Vilela Pereira

W. Aldá Júnior

M. Barroso Ferreira Filho

H. Brandao Malbouisson

W. Carvalho

J. Chinellato

Measurements of the inclusive W and Z boson production cross sections and their ratios in proton-proton collisions at $$\sqrt{s}=13.6$$ TeV

We present results for threshold resummation of the invariant mass distribution, for on-shell production of a pair of $\textit{W}$ bosons at next-to-next-to-leading order + next-to-next-to-leading logarithmic(NNLO+NNLL) accuracy in QCD. Owing to its sensitivity to the self-interactions between gauge bosons, this process is important to investigate at the energies of the Large Hadron Collider(LHC). We achieve this resummation by exploiting the factorization properties of the soft and virtual parts of the partonic cross-section. Our analysis has been carried out for the invariant mass distribution up to $\textit{Q}$ = 2500 GeV. At this highest $\textit{Q}$ we find that, for 13.6 TeV LHC, the NNLL resummation enhances the NNLO cross-sections by about $$6.3\%$$ and reduces the conventional scale uncertainties from $$6.8\%$$ at NNLO to $$4.1\%$$ at NNLO+NNLL. We also estimate the intrinsic uncertainties due to the non-perturbative parton distribution functions at the highest perturbative order, for both fixed-order and resummed results, to be around $$3\%$$ for $$Q \sim $$ 2000 GeV.

Italy

Pulak Banerjee

India

Chinmoy Dey

M. Kumar

Vaibhav Pandey

Threshold resummation for $\textit{W}$-boson pair production at NNLO+NNLL

<p>A low-mass right-handed neutrino could interact with electroweak bosons via mixing, a mediator particle, or loop corrections. Using an effective field theory, we determine constraints on these interactions from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math>-boson measurements at hadron colliders. Due to the difference in the initial states at the Tevatron and the LHC, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math>-boson decays to a right-handed neutrino would artificially increase the mass measured at the Tevatron while only affecting the difference between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>W</mi><mo>+</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>W</mi><mo>−</mo></msup></math> mass measurements at the LHC. Measurements from CDF and the LHC are used to infer the corresponding parameter values, which are found to be inconsistent between the two. The LHC experiments can improve sensitivity to these interactions by measuring the cosine of the helicity angle using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math> bosons produced with transverse momentum above <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≈</mo><mn>50</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>.</p>

Rodrigo Alonso

Michael Spannowsky

Sam Bates

Chris Hays

Chris Pollard

Sensitivity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math>-boson measurements to low-mass right-handed neutrinos