<p>In the heavy quarkonium decay process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi><mo>=</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mo>,</mo><mi mathvariant="normal">ϒ</mi></math>), making a definite prediction including relativistic corrections has so far remained a significant challenge. In this work, we study this decay process by taking into account the relativistic corrections in the Bethe-Salpeter formalism, where the relativistic bound-state wave function of quarkonium is obtained by solving the Bethe-Salpeter equation under the covariant instantaneous ansatz. Through analytical calculation, we find that some polarized decay widths vanish due to the helicity selection rule, which suppresses the corresponding helicity amplitudes. Owing to helicity flip symmetry and phase space symmetry, the nonvanishing polarized decay widths are not all independent; they are related through a set of symmetry relations. Then we obtain the unpolarized decay width formula <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi><mo stretchy="false">)</mo><mo>=</mo><mfrac><mrow><mn>80</mn><mo stretchy="false">(</mo><msup><mi>π</mi><mn>2</mn></msup><mo stretchy="false">−</mo><mn>9</mn><mo stretchy="false">)</mo><msubsup><mi>α</mi><mi>s</mi><mn>3</mn></msubsup><msubsup><mi>N</mi><mi>V</mi><mn>2</mn></msubsup><msubsup><mi>β</mi><mi>V</mi><mn>3</mn></msubsup></mrow><mrow><mn>81</mn><msup><mi>π</mi><mrow><mn>9</mn><mo stretchy="false">/</mo><mn>2</mn></mrow></msup><mi>M</mi></mrow></mfrac><mo stretchy="false">(</mo><mn>1</mn><mo>−</mo><mi>κ</mi><mfrac><msubsup><mi>β</mi><mi>V</mi><mn>2</mn></msubsup><msup><mi>M</mi><mn>2</mn></msup></mfrac><mo stretchy="false">)</mo></math>, where the factor <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>κ</mi><mfrac><msubsup><mi>β</mi><mi>V</mi><mn>2</mn></msubsup><msup><mi>M</mi><mn>2</mn></msup></mfrac></math> arises from the relativistic corrections with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>κ</mi><mo>≡</mo><mfrac><mrow><mn>3</mn><mo stretchy="false">(</mo><mn>112</mn><mo stretchy="false">+</mo><mn>25</mn><msup><mi>π</mi><mn>2</mn></msup><mo stretchy="false">)</mo></mrow><mrow><mn>16</mn><mo stretchy="false">(</mo><msup><mi>π</mi><mn>2</mn></msup><mo stretchy="false">−</mo><mn>9</mn><mo stretchy="false">)</mo></mrow></mfrac></math>. Furthermore, including both relativistic and QCD radiative corrections within the factorization assumption, our predictions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">)</mo></math> agree well with their experimental data. As a crossing check, with the experimental value of the ratio <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>R</mi><mi>V</mi></msub><mo>=</mo><mfrac><mrow><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi><mo stretchy="false">)</mo></mrow><mrow><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo stretchy="false">+</mo></msup><msup><mi>e</mi><mo stretchy="false">−</mo></msup><mo stretchy="false">)</mo></mrow></mfrac></math> and our result for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>R</mi><mi>V</mi></msub></math>, we extract <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>α</mi><mi>s</mi></msub><mo stretchy="false">(</mo><msub><mi>M</mi><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></msub><mo>/</mo><mn>2</mn><mo stretchy="false">)</mo><mo>=</mo><mn>0.31</mn></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>α</mi><mi>s</mi></msub><mo stretchy="false">(</mo><msub><mi>M</mi><mi mathvariant="normal">ϒ</mi></msub><mo>/</mo><mn>2</mn><mo stretchy="false">)</mo><mo>=</mo><mn>0.20</mn></math>, respectively.</p>

China

Hong-Mei Jiang

Chao-Jie Fan

Jun-Kang He

Cui Kong

Heavy quarkonium decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi></math> with both relativistic and QCD radiative corrections

We present a search for solar axions produced through the axion-electron coupling ($\textit{g}$ ) using data from a novel 7-GridPix detector installed at the CERN Axion Solar Telescope (CAST). The detector, featuring ultra-thin silicon nitride windows and multiple veto systems, collected approximately 160 hours of solar tracking data between 2017–2018. Using machine learning techniques and the veto systems, we achieved a background rate of 1.06 × 10 keV cm s at a signal efficiency of about 80% in the 0.2 to 8 keV range. Analysis of the data yielded no significant excess above background, allowing us to set a new upper limit on the product of the axion-electron and axion-photon couplings of $\textit{g}$ · $\textit{g}$ < 7.35 × 10 GeV at 95% confidence level for axion masses below 10 meV. This result improves upon the previous best helioscope limit and demonstrates the potential of GridPix technology for rare event searches. Additionally, we derived a limit on the axion-photon coupling of $\textit{g}$ < 9.0 × 10 GeV at 95% CL, which, while not surpassing CAST’s best limit, provides complementary constraints on axion models.

Spain

K. Altenmüller

Greece

V. Anastassopoulos

Switzerland

S. Arguedas-Cuendis

France

S. Aune

Germany

J. Baier

K. Barth

H. Bräuninger

Italy

G. Cantatore

F. Caspers

J. Castel

Türkiye

S. Çetin

Denmark

F. Christensen

C. Cogollos

T. Dafni

M. Davenport

United States

T. Decker

K. Desch

D. Díez-Ibáñez

B. Döbrich

E. Ferrer-Ribas

H. Fischer

W. Funk

J. Galán

J. García

A. Gardikiotis

I. Giomataris

J. Golm

C. Hailey

Canada

M. Hasinoff

D. Hoffmann

I. Irastorza

J. Jacoby

A. Jakobsen

Croatia

K. Jakovčić

J. Kaminski

M. Karuza

S. Kostoglou

C. Krieger

B. Lakić

J. Laurent

G. Luzón

C. Malbrunot

C. Margalejo

M. Maroudas

South Korea

L. Miceli

H. Mirallas

P. Navarro

L. Obis

A. Özbey

K. Özbozduman

T. Papaevangelou

O. Pérez

M. Pivovaroff

Romania

M. Rosu

E. Ruiz-Chóliz

J. Ruz

T. Schiffer

S. Schmidt

M. Schumann

Y. Semertzidis

S. Solanki

L. Stewart

T. Vafeiadis

J. Vogel

K. Zioutas

Search for solar axions produced through the axion-electron coupling $\textit{g}$

<p>A search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>H</mi></math> production is performed with data from the CMS experiment at the LHC corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>138</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> at a proton-proton center-of-mass collision energy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math>. The analysis focuses on the topology of a boosted Higgs boson recoiling against a high-energy photon. The final states of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mrow><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mn>4</mn><mo>ℓ</mo></math> are analyzed. This study examines effective <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>Z</mi><mi>γ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>γ</mi><mi>γ</mi></math> anomalous couplings within the context of an effective field theory. In this approach, the production cross section is constrained to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>σ</mi><mrow><mi>γ</mi><mi>H</mi></mrow></msub><mo>&lt;</mo><mn>16.4</mn><mtext> </mtext><mtext> </mtext><mi>fb</mi></math> at 95% confidence level (CL). Simultaneous constraints on four anomalous couplings involving <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>Z</mi><mi>γ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>γ</mi><mi>γ</mi></math> are provided. Additionally, the production rate for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mn>4</mn><mo>ℓ</mo></math> is examined to assess potential enhancements in the Yukawa couplings between light quarks and the Higgs boson. Assuming the standard model values for the Yukawa couplings of the bottom and top quarks, the following simultaneous constraints are obtained: <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>u</mi></msub><mo>=</mo><mo stretchy="false">(</mo><mn>0.0</mn><mo>±</mo><mn>1.5</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mn>3</mn></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>d</mi></msub><mo>=</mo><mo stretchy="false">(</mo><msubsup><mn>0.0</mn><mrow><mo>−</mo><mn>6.8</mn></mrow><mrow><mo>+</mo><mn>6.7</mn></mrow></msubsup><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mn>2</mn></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>s</mi></msub><mo>=</mo><msubsup><mn>0</mn><mrow><mo>−</mo><mn>32</mn></mrow><mrow><mo>+</mo><mn>30</mn></mrow></msubsup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>c</mi></msub><mo>=</mo><msubsup><mn>0.0</mn><mrow><mo>−</mo><mn>2.8</mn></mrow><mrow><mo>+</mo><mn>2.3</mn></mrow></msubsup></math>. This rules out the hypothesis that up- or down-type quarks in the first or second generation have the same Yukawa couplings as those in the third generation, with a CL greater than 95%.</p>

Armenia

V. Chekhovsky

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J.W. Andrejkovic

L. Benato

T. Bergauer

S. Chatterjee

K. Damanakis

M. Dragicevic

P.S. 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. Van Laer

P. Van Mechelen

N. Breugelmans

J. D’Hondt

S. Dansana

A. De Moor

M. Delcourt

F. Heyen

Y. Hong

S. Lowette

I. Makarenko

D. Müller

S. Tavernier

M. Tytgat

G.P. Van Onsem

S. Van Putte

D. Vannerom

B. Bilin

B. Clerbaux

A.K. Das

I. De Bruyn

G. De Lentdecker

H. Evard

L. Favart

P. Gianneios

A. Khalilzadeh

F.A. Khan

K. Lee

A. Malara

M.A. Shahzad

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

M. De Coen

D. Dobur

G. Gokbulut

J. Knolle

L. Lambrecht

D. Marckx

K. Skovpen

N. Van Den Bossche

J. van der Linden

J. Vandenbroeck

L. Wezenbeek

S. Bein

A. Benecke

A. Bethani

G. Bruno

C. Caputo

J. De Favereau De Jeneret

C. Delaere

I.S. Donertas

A. Giammanco

A.O. Guzel

Sa. Jain

V. Lemaitre

J. Lidrych

P. Mastrapasqua

T.T. Tran

S. Turkcapar

Brazil

G.A. Alves

E. Coelho

G. Correia Silva

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E.J. Tonelli Manganote

A. Vilela Pereira

W.L. Aldá Júnior

M. Barroso Ferreira Filho

H. Brandao Malbouisson

W. Carvalho

Search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>H</mi></math> production and constraints on the Yukawa couplings of light quarks to the Higgs boson

We propose a neural network training method capable of accounting for the effects of systematic variations of the data model in the training process and describe its extension towards neural network multiclass classification. The procedure is evaluated on the realistic case of the measurement of Higgs boson production via gluon fusion and vector boson fusion in the $${\uptau } {\uptau } $$ decay channel at the CMS experiment. The neural network output functions are used to infer the signal strengths for inclusive production of Higgs bosons as well as for their production via gluon fusion and vector boson fusion. We observe improvements of 12 and 16% in the uncertainty in the signal strengths for gluon and vector-boson fusion, respectively, compared with a conventional neural network training based on cross-entropy.

J. Andrejkovic

P. Hussain

T. Laer

P. Mechelen

A. Moor

G. Onsem

S. Putte

Development of systematic uncertainty-aware neural network trainings for binned-likelihood analyses at the LHC