We present a systematic analysis of the Higgs signal strengths at 125 GeV and 95 GeV in a non-supersymmetric $ U(1)_X $ model with vector-like fermions ( $ U(1)_X $ VLFM). This framework extends the Standard Model (SM) by introducing an additional $ U(1)_X $ gauge symmetry, three right-handed neutrinos, two singlet Higgs fields ($\textit{ϕ}$ and $\textit{S}$), and one generation of vector-like quarks and leptons. The scalar fields mix in the neutral CP-even sector, yielding two Higgs-like states around 95 GeV and 125 GeV. We perform a $ \chi^2 $ analysis that combines the Higgs signal strength measurements at 125 GeV from ATLAS and CMS, including the $ \gamma\gamma $ , $ WW^* $ , $ ZZ^* $ , $ b\bar{b} $ , and $ \tau\bar{\tau} $ channels, together with the 95 GeV excesses observed in the diphoton and $ b\bar{b} $ final states reported by CMS and LEP. Our results indicate that the $ U(1)_X $ VLFM successfully reproduces the observed signal strengths of the 125 GeV Higgs while simultaneously explaining the 95 GeV excess. The parameters $ g_X $ , $ g_{YX} $ , $ v_S $ , $ v_P $ , and the new Yukawa couplings play a crucial role in achieving this consistency.

China

Rong-Zhi Sun

Shu-Min Zhao

Meng-Zi Cao

Song Gao

Portugal

Xing-Xing Dong

Higgs Bosons at 95 and 125 GeV in the $\textit{U}$(1) $\textit{X}$ VLFM * Supported by National Natural Science Foundation of China (NNSFC) (2075074), Natural Science Foundation of Hebei Province (A2023201040, A2022201022, A2022201017, A2023201041), Natural Science Foundation of Hebei Education Department (QN2022173), the Project of the China Scholarship Council (CSC) (202408130113). This work is also supported by Fundação para a Ciência e a Tecnologia (FCT, Portugal) through the project UID/00777/2025 (https://doi.org/ 10.54499/UID/00777/2025)

In this article, we present projected 95% C.L. limits on axion-like particle (ALP) couplings from ALP production at a future $$e^+e^-$$ collider operating at $$\sqrt{s} = 250~\text {GeV}$$ with integrated luminosity $$L = 0.5~\text {ab}^{-1}$$ . We constrain the effective couplings $$g_{\gamma \gamma }$$ , $$g_{Z\gamma }$$ , $$g_{ZZ}$$ , and $$g_{WW}$$ over the ALP mass range $$20~\text {GeV} \le m_a \le 100~\text {GeV}$$ , finding projected bounds at the level of $$\mathcal {O}(10^{-1})~\text {TeV}^{-1}$$ for $$g_{\gamma \gamma }/f_a$$ . Given that the latest muon anomalous magnetic moment measurement ( $$\Delta a_\mu $$ ) shows no statistically significant deviation from the Standard Model prediction, we reinterpret the ALP contributions to $$\Delta a_\mu $$ as a stringent consistency requirement. We then derive the corresponding allowed regions for $$g_{\gamma \gamma }$$ and the ALP–muon coupling $$C_{\mu \mu }$$ , and apply them to a fermionic dark matter scenario in which the relic density depends on both the dark matter mass $$m_\chi $$ and $$m_a$$ . The same parameter space is further constrained by Higgs signal strength measurements through $$h \rightarrow \gamma \gamma $$ and $$h \rightarrow Z\gamma $$ . A comparative analysis with existing experimental and theoretical bounds highlights the complementarity of $$\Delta a_\mu $$ , dark matter, and Higgs observables in restricting ALP couplings, demonstrating that even in the absence of a $$\Delta a_\mu $$ anomaly, these constraints provide essential guidance for viable ALP parameter space.

South Africa

India

Pramod Sharma

Soham Singh

Mukesh Kumar

Ashok Goyal

Comprehensive constraints on ALP couplings from future $$e^+e^-$$ colliders, muon $$g-2$$ , thermal dark matter and Higgs measurements

<p>The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>JSNS</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> (J-PARC Sterile Neutrino Search at the J-PARC Spallation Neutron Source) experiment at the Material and Life Science Facility (MLF) of J-PARC is designed to directly test an excess on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>e</mi></msub></math> events which was indicated by the Liquid Scintillator Neutrino Detector (LSND). The combination of a short-pulsed proton beam and a gadolinium-loaded liquid scintillator provides an excellent signal-to-noise ratio. In this article, we report the first results of a direct test based on data collected in 2022. After applying all event selection criteria, two events are observed, consistent with the expected background of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.3</mn><mo>±</mo><mn>0.4</mn></math> events. No excess of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>e</mi></msub></math> events are seen in this report, however the expected number of events due to LSND anomaly is <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1.1</mn><mo>±</mo><mn>0.5</mn></math>, thus this result is not yet conclusive. Data taking has been ongoing since 2021 and will continue in future runs. In addition, a new far detector has recently been constructed for the second phase experiment, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>JSNS</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math>-II, marking an important milestone toward forthcoming measurements.</p>

Japan

D.H. Lee

S. Ajimura

United States

A. Antonakis

M. Botran

South Korea

M.K. Cheoun

J.H. Choi

J.W. Choi

J.Y. Choi

T. Dodo

H. Furuta

J.H. Goh

M. Harada

S. Hasegawa

Y. Hino

T. Hiraiwa

W.S. Hwang

T. Iida

E. Iwai

S. Iwata

H.I. Jang

J.S. Jang

M.C. Jang

H.K. Jeon

S.H. Jeon

K.K. Joo

D.E. Jung

S.K. Kang

Y. Kasugai

T. Kawasaki

E.M. Kim

E.J. Kim

J.Y. Kim

S.Y. Kim

S.B. Kim

W. Kim

H. Kinoshita

T. Konno

K. Kuwata

S. Lee

I.T. Lim

C. Little

T. Maruyama

E. Marzec

S. Masuda

S. Meigo

S. Monjushiro

D.H. Moon

T. Nakano

M. Niiyama

K. Nishikawa

M. Noumachi

M.Y. Pac

B.J. Park

H.W. Park

J.B. Park

Jisu Park

J.S. Park

R.G. Park

United Kingdom

S.J.M. Peeters

G. Roellinghoff

C. Rott

J.W. Ryu

K. Sakai

S. Sakamoto

T. Shima

C.D. Shin

J. Spitz

I. Stancu

F. Suekane

Y. Sugaya

K. Suzuya

M. Taira

Y. Takeuchi

W. Wang

J. Waterfield

W. Wei

R. White

Y. Yamaguchi

M. Yeh

I.S. Yeo

C. Yoo

I. Yu

A. Zohaib

First results from the search for an excess of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>e</mi></msub></math> events in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>JSNS</mi></mrow><mn>2</mn></msup></mrow></math>

<p>Using a data sample of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>427.9</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> collected by the Belle II detector at or near the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">ϒ</mi><mo stretchy="false">(</mo><mn>4</mn><mi>S</mi><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">ϒ</mi><mo stretchy="false">(</mo><mn>10753</mn><mo stretchy="false">)</mo></math> resonances, the cross sections for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>h</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>h</mi></mrow><mrow><mo>−</mo></mrow></msup><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">(</mo><mi>h</mi><mo>=</mo><mi>π</mi><mo>/</mo><mi>K</mi><mo>/</mo><mi>p</mi><mo stretchy="false">)</mo></mrow></math> at center-of-mass energies ranging from 3.8 GeV or the production threshold to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><mn>5.5</mn><mo>/</mo><mn>6.0</mn></mrow><mo>/</mo><mn>7.0</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math> have been measured via initial-state radiation. The cross sections for the processes <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><mi>J</mi><mo>/</mo><mi>ψ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></math> are consistent with previously published results. The cross sections for these channels obtained by combining with previous Belle results are also given. The process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">→</mo><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover><mi>J</mi><mo>/</mo><mi>ψ</mi></math> is investigated for the first time. The yields are small and no significant structure is observed in the cross section versus energy. Searches for vector charmoniumlike states in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>h</mi><mo>+</mo></msup><msup><mi>h</mi><mo>−</mo></msup><mi>J</mi><mo>/</mo><mi>ψ</mi></math> systems, and for associated intermediate states in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>h</mi><mo>±</mo></msup><mi>J</mi><mo>/</mo><mi>ψ</mi></math> systems, are also presented.</p>

M. Abumusabh

I. Adachi

A. Aggarwal

L. Aggarwal

H. Ahmed

Y. Ahn

H. Aihara

N. Akopov

S. Alghamdi

M. Alhakami

A. Aloisio

N. Althubiti

K. Amos

N. Anh Ky

C. Antonioli

D.M. Asner

H. Atmacan

T. Aushev

R. Ayad

V. Babu

H. Bae

N.K. Baghel

S. Bahinipati

P. Bambade

Sw. Banerjee

M. Barrett

M. Bartl

J. Baudot

A. Baur

A. Beaubien

F. Becherer

J. Becker

J.V. Bennett

F.U. Bernlochner

V. Bertacchi

M. Bertemes

E. Bertholet

M. Bessner

S. Bettarini

V. Bhardwaj

F. Bianchi

T. Bilka

D. Biswas

A. Bobrov

D. Bodrov

A. Bondar

G. Bonvicini

J. Borah

A. Boschetti

A. Bozek

M. Bračko

P. Branchini

R.A. Briere

T.E. Browder

A. Budano

S. Bussino

Q. Campagna

M. Campajola

G. Casarosa

C. Cecchi

M.C. Chang

P. Chang

P. Cheema

C. Chen

L. Chen

B.G. Cheon

C. Cheshta

H. Chetri

K. Chilikin

J. Chin

K. Chirapatpimol

H.E. Cho

K. Cho

S.J. Cho

S.K. Choi

S. Choudhury

S. Chutia

J. Cochran

J.A. Colorado-Caicedo

I. Consigny

L. Corona

J.X. Cui

E. De La Cruz-Burelo

S.A. De La Motte

G. De Nardo

G. De Pietro

R. de Sangro

M. Destefanis

S. Dey

R. Dhayal

A. Di Canto

J. Dingfelder

Z. Doležal

I. Domínguez Jiménez

Study of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>h</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>h</mi></mrow><mrow><mo>−</mo></mrow></msup><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi><mo>=</mo><mi>π</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi></math>) via initial-state radiation at Belle II