We study the new $Z'$ boson as a portal for the production of Higgs bosons $h_0$ and $H_0$ predicted by the Bestest Little Higgs Model through Higgs-strahlung processes $\mu^+\mu^- \to (Z, Z') \to Zh_0, ZH_0$ . We focus on the resonant and nonresonant effects of the $Zh_0, ZH_0$ signals. In our analysis, we consider the center-of-mass energies of $\sqrt{s}=3, 4, 6, 10, 30$ TeV and integrated luminosities of ${\cal{L}}=2, 4, 6, 10, 30$ ${ {\rm{ab}}^{-1}}$ projected for a future muon collider. The possibility of performing precision measurements for Higgs bosons $h_0$ and $H_0$ is very promising for the future muon collider. Furthermore, our results may be useful to the High Energy Physics community. Complementarily, we generate and provide the Feynman rules necessary for studying processes $\mu^+\mu^- \to (Z, Z') \to Zh_0, ZH_0$ .

J.M. Martínez-Martínez

A. Gutiérrez-Rodríguez

E. Cruz-Albaro

M.A. Hernández-Ruíz

New $\textit{Z}$' boson of the bestest little Higgs model as a portal to signatures of Higgs bosons $\textit{h}$ $_{0}$ and $\textit{H}$ $_{0}$ at the future muon collider

Both ATLAS and CMS have recently performed the first searches for a heavy new spin-0 resonance decaying into a lighter new spin-0 resonance and a $\textit{Z}$ boson, where the lighter spin-0 resonance subsequently decays into $$ t\overline{t} $$ pairs. These searches are of particular interest to probe Two Higgs doublet model (2HDM) parameter space regions that predict a strong first-order electroweak phase transition. In the absence of CP violation, the investigated decay is possible if the lighter and the heavier spin-0 particles have opposite CP parities. The analysis techniques employed by ATLAS and CMS do not distinguish between the two possible signatures $\textit{A}$ → $\textit{ZH}$ and $\textit{H}$ → $\textit{ZA}$, where $\textit{A}$ and $\textit{H}$ denote CP-odd and CP-even Higgs bosons, respectively, if both signals are predicted to have the same total cross sections. We demonstrate the capability of angular variables that are sensitive to spin correlations of the top quarks to differentiate between $\textit{A}$ → $\textit{ZH}$ and $\textit{H}$ → $\textit{ZA}$ decays, even in scenarios where both signals possess identical total cross sections. Focusing on masses of 600 GeV and 800 GeV as a representative 2HDM benchmark, we find that a distinction between the two possible channels is possible with high significance with the anticipated data from the high-luminosity LHC, if the invariant mass distribution of the $$ t\overline{t} $$ system is further binned in angular variables defined by the direction of flight of the leptons produced in the top-quark decays. Moreover, we find a moderate gain in experimental sensitivity due to the improved background rejection for both signals.

Germany

Francisco Arco

Spain

Thomas Biekötter

Panagiotis Stylianou

Georg Weiglein

Top-quark spin correlations as a tool to distinguish pseudoscalar $\textit{A}$ → $\textit{ZH}$ and scalar $\textit{H}$ → $\textit{ZA}$ signatures in $$ Zt\overline{t} $$ final states at the LHC

The $\textit{H}$ → $\textit{γγ}$ decay is an ideal process to study the structure of next-to-leading power logarithms induced by quarks due to its simple initial and final states. We perform a region analysis of this process up to two-loop level to inspect the origins of the logarithms. To deal with the endpoint singularities that are prevalent for the next-to-leading power logarithms, we have adopted two different kinds of regulators to exhibit the advantages and disadvantages of each regulator. In the analytic regulator we have chosen, the power of the propagator is changed by $\textit{η}$. And the endpoint singularities are regulated in the form of 1/$\textit{η}$. These poles cancel between the collinear and anti-collinear sectors since there is no soft mode in such a regulator. In the ∆ regulator, the soft sector is important. The leading and next-to-leading logarithms can be inferred from only this sector. Moreover, the symmetry between the collinear and anti-collinear sectors is preserved. After imposing a cut on the bottom quark transverse momentum, the leading order result is finite in each sector. We also discuss the next-to-next-to-leading power contributions and find that the potential factorization formulae involve two-dimensional endpoint singularities. Our region analysis could help to develop sophisticated factorization and resummation schemes beyond leading power.

China

Jun-Yao Hou

Jian Wang

Da-Jiang Zhang

Region analysis of $\textit{H}$ → $\textit{γγ}$ via a bottom quark loop

Using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>ψ</mi><mo stretchy="false">(</mo><mn>3686</mn><mo stretchy="false">)</mo><mo stretchy="false">→</mo><msup><mrow><mi>π</mi></mrow><mrow><mn>0</mn></mrow></msup><msub><mrow><mi>h</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math> decays from a data sample of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>27.12</mn><mo>±</mo><mn>0.14</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>8</mn></mrow></msup><mtext> </mtext><mtext> </mtext><mi>ψ</mi><mo stretchy="false">(</mo><mn>3686</mn><mo stretchy="false">)</mo></mrow></math> events collected by the BESIII detector at the BEPCII collider, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>c</mi></msub></math> radiative decays to multiple light hadrons below <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.8</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>/</mo><msup><mi>c</mi><mn>2</mn></msup></math>—<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><mi>η</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mn>2</mn><mo stretchy="false">(</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover></math>—are observed for the first time, each with a significance greater than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math>. The corresponding branching fractions are measured. Furthermore, intermediate states are investigated, leading to the first observation of the decay process of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>h</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><mi>γ</mi><msub><mrow><mi>f</mi></mrow><mrow><mn>2</mn></mrow></msub><mo stretchy="false">(</mo><mn>1270</mn><mo stretchy="false">)</mo><mo stretchy="false">→</mo><mi>γ</mi><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> with a significance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5.1</mn><mi>σ</mi></math>. This observation represents the first instance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>c</mi></msub></math> radiative decay to a tensor state.

M. Ablikim

Russia

M.N. Achasov

Sweden

P. Adlarson

X.C. Ai

R. Aliberti

Italy

A. Amoroso

Q. An

Y. Bai

JINR

O. Bakina

Y. Ban

H.R. Bao

Poland

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

United States

R.A. Briere

A. Brueggemann

H. Cai

M.H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

Türkiye

S.A. Cetin

X.Y. Chai

J.F. Chang

G.R. Che

Y.Z. Che

G. Chelkov

C. Chen

C.H. Chen

Chao Chen

G. Chen

H.S. Chen

H.Y. Chen

M.L. Chen

S.J. Chen

S.L. Chen

S.M. Chen

T. Chen

X.R. Chen

X.T. Chen

Y.B. Chen

Y.Q. Chen

Z.J. Chen

South Korea

S.K. Choi

X. Chu

G. Cibinetto

F. Cossio

J.J. Cui

H.L. Dai

J.P. Dai

A. Dbeyssi

R.E. de Boer

D. Dedovich

C.Q. Deng

Z.Y. Deng

A. Denig

I. Denysenko

M. Destefanis

F. De Mori

B. Ding

X.X. Ding

Y. Ding

Y.X. Ding

J. Dong

L.Y. Dong

M.Y. Dong

X. Dong

M.C. Du

S.X. Du

Y.Y. Duan

Z.H. Duan

P. Egorov

G.F. Fan

J.J. Fan

Y.H. Fan

J. Fang

S.S. Fang

W.X. Fang

Y.Q. Fang

R. Farinelli

L. Fava

F. Feldbauer

G. Felici

C.Q. Feng

J.H. Feng

Y.T. Feng

M. Fritsch

C.D. Fu

J.L. Fu

Y.W. Fu

Observation of Charmonium <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>h</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math> Radiative Decays to Multiple Light Hadrons and the Tensor State <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>f</mi></mrow><mrow><mn>2</mn></mrow></msub><mo stretchy="false">(</mo><mn>1270</mn><mo stretchy="false">)</mo></mrow></math>

Motivated by a small but intriguing excess observed in the decay mode $\textit{H}$ → $\textit{ℓ}$ $\textit{ℓ}$ $\textit{γ}$ reported by both the ATLAS and CMS collaborations, we explore the possibility that new physics contributes directly to the effective $$ H\overline{\mathcal{ll}}\gamma $$ coupling rather than modifying the $\textit{Z}$ peak. Concretely, we consider a dimension-8 operator that could arise from new particles via box diagrams. Such non-resonant contribution may provide an alternative origin for current or future excesses. We examine how experimental cuts may distinguish between possible modifications of the $\textit{Z}$ peak and non-resonant contributions. The currently measured excess requires that the new physics scale is relatively low (Λ ~ $\textit{v}$). However, we show that it may remain within current experimental bounds. In particular, we illustrate this using a simplified model, motivated by the dark matter problem, and discuss its other experimental constraints.

Belgium

Aliaksei Kachanovich

Jean Kimus

Steven Lowette

Michel Tytgat

On new physics off the Z peak in $\textit{H → ℓ}$

The decay <math altimg='si1.svg'><mi>H</mi><mo stretchy='false'>&#8594;</mo><mi>Z</mi><mi>Z</mi><mo stretchy='false'>&#8594;</mo><mn>4</mn><mi>&#8467;</mi></math>, with <math altimg='si2.svg'><mi>&#8467;</mi><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mi>e</mi><mo>,</mo><mi>&#956;</mi></math>, can be used to test quantum interference in analogy to the famous double-slit experiment. The observations corresponding to &#8216;covering a slit&#8217; can be extracted from data in the <math altimg='si3.svg'><mi>e</mi><mi>e</mi><mi>&#956;</mi><mi>&#956;</mi></math> channel, while the observations when both &#8216;slits&#8217; are open, which include the interference, are measured in the <math altimg='si4.svg'><mn>4</mn><mi>e</mi><mo stretchy='false'>/</mo><mn>4</mn><mi>&#956;</mi></math> channels. In this way, this process offers a unique opportunity to investigate identical-particle effects at high energies, and provides the first evidence of identical-particle behaviour for muons. Sensitivity at the 4 <italic>&#963;</italic> level could be achieved at the high-luminosity upgrade of the Large Hadron Collider.

J.A. Aguilar-Saavedra

<italic>H</italic>&#8239;&#8594;&#8239; <italic>ZZ</italic> as a double-slit experiment

We study the discovery potential for a light Higgs boson via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>g</mi><mi>g</mi><mo stretchy="false">→</mo><msub><mrow><mi>H</mi></mrow><mrow><mi>SM</mi><mtext>−</mtext><mi>like</mi></mrow></msub><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mrow><mi>b</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><mi>γ</mi><mi>γ</mi></mrow></math> process at the Large Hadron Collider (LHC). Focusing on the 2-Higgs Doublet Model Type-I, which can accommodate light neutral Higgs states, of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mn>100</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> or less in mass, while agreeing with theoretical and up-to-date experimental constraints, we explore the feasibility of a light <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math>-even Higgs state <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi></math> via the largely unexplored final state <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover><mi>γ</mi><mi>γ</mi></math> at Run-3 of the LHC. We further propose a few benchmark points for future searches.

Taiwan

Morocco

A. Arhrib

United Kingdom

S. Moretti

S. Semlali

C.H. Shepherd-Themistocleous

Y. Wang

Q.S. Yan

Probing a 2HDM type-I light Higgs state via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>H</mi><mrow><mi>SM</mi></mrow></msub><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover><mi>γ</mi><mi>γ</mi></math> at the LHC

We identify symmetries in a broad class of vectorlike confining dark sectors that forbid the leading electromagnetic moments that would ordinarily mediate dark baryon scattering with the Standard Model. The absence of these operators implies dark baryon dark matter has much smaller cross sections for elastic scattering off nuclei, leading to suppressed direct detection signals. In the confined description, we identify an “<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">H</mi></math>-parity” symmetry that exists in any dark sector with dark quarks transforming under a vectorlike representation of a new confining SU(<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>c</mi></msub></math>) gauge theory as well as a vectorlike representation of the electroweak group <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>SU</mi><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo></mrow><mi>L</mi></msub></mrow></math>. The parity is independent of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>c</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>f</mi></msub></math>, though it is essential that the dark quarks are neutral under hypercharge. This parity forbids dark hadron electric and magnetic dipole moments, charge radius, and anapole moment, while permitting dimension-7 operators that include polarizability, electroweak loop-induced interactions, and lower-dimensional electromagnetic transition moments between different neutral dark baryon states. We work out an explicit example, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>N</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><msub><mrow><mi>N</mi></mrow><mrow><mi>f</mi></mrow></msub><mo>=</mo><mn>3</mn></mrow></math>, that is the most minimal theory with fermionic dark baryons. In this specific model, we use the nonrelativistic quark model to show the magnetic dipole moment and charge radius vanish, while the transition moments are nonzero, consistent with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">H</mi></math>-parity. We discuss the implications of a suppressed direct detection signal, emphasizing that this broad class of models provide a well-motivated target for future colliders.

Pouya Asadi

Graham D. Kribs

Chester J. Hamilton Mantel

Direct detection of dark baryons naturally suppressed by <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">H</mi></math>-parity

The mass of the top quark is measured using top-quark-top-antiquark pair events with high transverse momentum top quarks. The dataset, collected with the ATLAS detector in proton–proton collisions at <math altimg='si2.svg'><msqrt><mrow><mi>s</mi></mrow></msqrt><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>13</mn></math> TeV delivered by the Large Hadron Collider, corresponds to an integrated luminosity of 140 fb &#8722;1. The analysis targets events in the lepton-plus-jets decay channel, with an electron or muon from a semi-leptonically decaying top quark and a hadronically decaying top quark that is sufficiently energetic to be reconstructed as a single large-radius jet. The mean of the invariant mass of the reconstructed large-radius jet provides the sensitivity to the top quark mass and is simultaneously fitted with two additional observables to reduce the impact of the systematic uncertainties. The top quark mass is measured to be <math altimg='si3.svg'><msub><mrow><mi>m</mi></mrow><mrow><mi>t</mi></mrow></msub><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>172.95</mn><mo>&#177;</mo><mn>0.53</mn></math> GeV, which is the most precise ATLAS measurement from a single channel.

France

G. Aad

Norway

E. Aakvaag

B. Abbott

United Arab Emirates

S. Abdelhameed

K. Abeling

N.J. Abicht

S.H. Abidi

M. Aboelela

A. Aboulhorma

Israel

H. Abramowicz

Y. Abulaiti

B.S. Acharya

A. Ackermann

C. Adam Bourdarios

L. Adamczyk

S.V. Addepalli

M.J. Addison

J. Adelman

A. Adiguzel

T. Adye

A.A. Affolder

Y. Afik

M.N. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

F. Ahmadov

S. Ahuja

X. Ai

G. Aielli

A. Aikot

M. Ait Tamlihat

B. Aitbenchikh

M. Akbiyik

T.P.A. Åkesson

A.V. Akimov

Japan

D. Akiyama

N.N. Akolkar

S. Aktas

G.L. Alberghi

Measurement of the top quark mass with the ATLAS detector using <math altimg='si1.svg'><mi>t</mi><mover accent='true'><mrow><mi>t</mi></mrow><mrow><mo stretchy='false'>&#175;</mo></mrow></mover></math> events with a high transverse momentum top quark