The precise determination of the $\textit{W}$ boson mass, $$m_W$$ , is a cornerstone of electroweak precision tests and a critical input to global fits of the Standard Model (SM). While most existing measurements of $$m_W$$ are in agreement with SM predictions, the recent result from the CDF collaboration exhibits a significant deviation from the SM prediction but also exceeding $$4\sigma $$ from the global average of all other high precision measurements. This prompts renewed scrutiny of potential sources of systematic bias. In this study, we investigate the modeling of the $\textit{Z}$ boson background, which is particularly relevant in the muon decay channel of the $\textit{W}$ boson, where undetected muons can mimic missing transverse momentum. Using updated theoretical predictions and high-precision simulations, we construct reweighted templates to evaluate the impact of possible mismodeling in the $\textit{Z}$ background. Our analysis suggests that such effects can induce a shift in the extracted $$m_W$$ value of up to 8 MeV in the muon decay channel. While this shift is non-negligible and exceeds the originally quoted uncertainty from this source, it remains insufficient to explain the full discrepancy observed in the CDF measurement.

France

Maarten Boonekamp

Matthias Schott

Germany

Chen Wang

Modeling uncertainties on the Z boson background in the context of high precision W boson mass measurements

We study constraints imposed by four-dimensional unitarity (formalised as graded unitarity in recent work by the first author) on possible $$ {\mathcal{W}}_3 $$ vertex algebras arising from four-dimensions via the SCFT/VOA correspondence. Under the assumption that the $$ \mathbf{\mathfrak{R}} $$ -filtration is a weight-based filtration with respect to the usual strong generators of the vertex algebra, we demonstrate that all values of the central charge other than those of the (3, $\textit{q}$ + 4) minimal models are incompatible with four-dimensional unitarity. These algebras are precisely the ones that are realised by performing principal Drinfel’d-Sokolov reduction to boundary-admissible $$ {\mathbf{\mathfrak{sl}}}_3 $$ affine current algebras; those affine algebras were singled out by a similar graded unitarity analysis in [1]. Furthermore, these particular vertex algebras are known to be associated with the ($\textit{A}$ , $\textit{A}$ ) Argyres-Douglas theories.

United Kingdom

Christopher Beem

Harshal Kulkarni

Towards a classification of graded unitary $$ {\mathcal{W}}_3 $$ algebras

The jet mass of W bosons decaying to a quark-antiquark pair is measured in W+jets events from proton-proton collisions at a center-of-mass energy of 13 TeV. The data used were collected by the CMS experiment at the CERN LHC and correspond to an integrated luminosity of 138 fb . Hadronic decays of W bosons with high momenta produce strongly collimated decay products due to the large Lorentz boost, and are reconstructed as single large-radius jets. These jets have a characteristic substructure that is exploited to distinguish them from the large background of quark- and gluon-initiated jets. The jet mass is computed using the soft-drop algorithm, which suppresses soft wide-angle radiation that leads to a broadening of the jet mass distribution. For the first time, unfolded measurements are presented of the double-differential W+jets cross section as a function of the jet transverse momentum and soft-drop mass. From these distributions, the W boson mass is obtained, with a value of 80.83 ± 0.55 GeV in a scheme with mass-dependent width, achieving the smallest uncertainty available today from an all-jets final state at a hadron collider.

Armenia

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J. Andrejkovic

L. Benato

T. Bergauer

M. Dragicevic

C. Giordano

P. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

M. Matthewman

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Shooshtari

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

D. Ocampo Henao

T. Laer

P. Mechelen

J. Bierkens

N. Breugelmans

J. D’Hondt

S. Dansana

A. Moor

M. Delcourt

F. Heyen

Y. Hong

P. Kashko

S. Lowette

I. Makarenko

D. Müller

J. Song

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

A. Sharma

L. Thomas

M. Bemden

C. Vander Velde

P. Vanlaer

F. Zhang

M. Coen

D. Dobur

G. Gokbulut

J. Knolle

D. Marckx

K. Skovpen

A. Tomaru

N. Bossche

J. Linden

J. Vandenbroeck

L. Wezenbeek

H. Aarup Petersen

S. Bein

A. Benecke

A. Bethani

G. Bruno

A. Cappati

J. De Favereau De Jeneret

C. Delaere

F. Gameiro Casalinho

A. Giammanco

A. Guzel

V. Lemaitre

J. Lidrych

P. Malek

P. Mastrapasqua

S. Turkcapar

Brazil

G. Alves

M. Barroso Ferreira Filho

E. Coelho

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E. Tonelli Manganote

Measurement of the jet mass in hadronic decays of boosted W bosons at 13 TeV and extraction of the W boson mass

<p>We present high-precision predictions for associated <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mi>W</mi></math> production at the LHC that incorporate the next-to-next-to-leading-order hard and soft functions as well as the complete next-to-next-to-next-to-leading-order scale-dependent terms derived from the corresponding anomalous dimensions. These higher-order corrections, which dominate the full perturbative results, increase the next-to-leading-order cross section by more than 10%. Based on the comparison with ATLAS and CMS measurements, we directly extract the Cabibbo-Kobayashi-Maskawa matrix element <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">|</mo><msub><mrow><mi>V</mi></mrow><mrow><mi>t</mi><mi>b</mi></mrow></msub><mo stretchy="false">|</mo><mo>=</mo><mn>0.99</mn><mo>±</mo><mn>0.03</mn><mo stretchy="false">(</mo><mrow><mi>expt</mi></mrow><mo stretchy="false">)</mo><mo>±</mo><mn>0.03</mn><mo stretchy="false">(</mo><mtext>theor</mtext><mo stretchy="false">)</mo></mrow></math> without assuming unitarity, achieving a precision comparable with the current world average value.</p>

China

Jia-Le Ding

Hai Tao Li

Jian Wang

Approximate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>LO</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">N</mi><mn>3</mn></msup><mi>LO</mi></math> QCD predictions for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mi>W</mi></math> production

<p>A search is presented for the electroweak production of a top-quark pair in association with a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math> boson and at least one additional jet known as the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover><mi>W</mi><msub><mi>j</mi><mi>EW</mi></msub></math> process. This process has embedded within it a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mi>W</mi></math>-scattering vertex, which is probed directly for the first time. The collision data were collected with the ATLAS detector during Run 2 of the LHC and correspond to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>140</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>. The search uses same-charge pairs of electrons and muons together with jets, of which at least one is <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math>-tagged. The properties of the most forward jet relative to the rest of the event are used to discriminate the electroweak <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover><mi>W</mi><msub><mi>j</mi><mi>EW</mi></msub></math> production process from its strong <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover><mi>W</mi></math> production counterpart. A measured (expected) 95% CL upper limit on the cross section is set at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>σ</mi><mrow><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover><mi>W</mi><msub><mi>j</mi><mi>EW</mi></msub></mrow></msub><mo>&lt;</mo><mn>251</mn><mtext> </mtext><mtext> </mtext><mi>fb</mi></math> (230 fb), to be compared with the expected Standard Model (SM) cross section of 47.7 fb. Limits are set on the SM effective field theory (EFT) operators <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>O</mi><mrow><mi>H</mi><mi>t</mi></mrow></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>O</mi><mrow><mi>H</mi><mi>Q</mi></mrow><mrow><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></mrow></msubsup></math>, which modify the electroweak couplings of the top quark through contributions to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mi>W</mi></math>-scattering vertex. The interpretation acts as a case study to emphasize the importance of energy-dependent sensitivity, multiprocess, and multioperator EFT contributions.</p>

G. Aad

Norway

E. Aakvaag

United States

B. Abbott

United Arab Emirates

S. Abdelhameed

K. Abeling

N.J. Abicht

S.H. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Y. Abulaiti

Italy

B.S. Acharya

A. Ackermann

C. Adam Bourdarios

Poland

L. Adamczyk

S.V. Addepalli

M.J. Addison

J. Adelman

Türkiye

A. Adiguzel

T. Adye

A.A. Affolder

Y. Afik

Spain

M.N. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

CERN

F. Ahmadov

S. Ahuja

X. Ai

G. Aielli

A. Aikot

M. Ait Tamlihat

B. Aitbenchikh

Sweden

T.P.A. Åkesson

A.V. Akimov

Japan

D. Akiyama

N.N. Akolkar

S. Aktas

G.L. Alberghi

Canada

J. Albert

Switzerland

U. Alberti

P. Albicocco

G.L. Albouy

S. Alderweireldt

Z.L. Alegria

M. Aleksa

I.N. Aleksandrov

C. Alexa

Greece

T. Alexopoulos

F. Alfonsi

M. Algren

M. Alhroob

Czechia

B. Ali

H.M.J. Ali

S. Ali

S.W. Alibocus

South Africa

M. Aliev

G. Alimonti

W. Alkakhi

Search for electroweak <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover><mi>W</mi><mi>j</mi></math> production in multileptonic final states at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math> with the ATLAS detector and bounds on effective field theory operators