Axions, grand unification, and string theory are each compelling extensions of the Standard Model. We show that combining these frameworks imposes strong constraints on the QCD axion mass. Using perturbative unitarity arguments and explicit string compactifications—such as those from the Kreuzer-Skarke (KS) type IIB ensemble—we find that the axion mass is favored to lie within the range <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>10</mn><mrow><mo>−</mo><mn>11</mn></mrow></msup><mtext> </mtext><mtext> </mtext><mi>eV</mi><mo>≲</mo><msub><mi>m</mi><mi>a</mi></msub><mo>≲</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>8</mn></mrow></msup><mtext> </mtext><mtext> </mtext><mi>eV</mi></math>. This range is directly relevant for near-future axion dark matter searches, including ABRACADABRA/DMRadio and CASPEr. We argue that grand unification and the absence of proton decay suggest a compactification volume that keeps the string scale above the unification scale (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>∼</mo><msup><mn>10</mn><mn>16</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>), which in turn limits how heavy the axion can be. The same requirements limit the KS axiverse to have at most <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>∼</mo><mn>47</mn></math> axions. As an additional application of our methodology, we search for axions in the KS axiverse that could explain the recent Dark Energy Spectroscopic Instrument hints of evolving dark energy but find none with high enough decay constant (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>f</mi><mi>a</mi></msub><mo>≳</mo><mn>2.5</mn><mo>×</mo><msup><mn>10</mn><mn>17</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>); we comment on why such high decay constants and low axion masses are difficult to obtain in string compactifications more broadly.

United States

Joshua N. Benabou

Katherine Fraser

United Kingdom

Mario Reig

Benjamin R. Safdi

String theory and grand unification suggest a submicroelectronvolt QCD axion

We present a new equation of state for QCD in which the temperature <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math> and the three chemical potentials for baryon number <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>μ</mi><mi>B</mi></msub></math>, electric charge <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>μ</mi><mi>Q</mi></msub></math>, and strangeness <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>μ</mi><mi>S</mi></msub></math> can be varied independently. This result is based on a generalization of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>T</mi><mo>′</mo></msup></math> expansion scheme, thanks to which the diagonal <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>μ</mi><mi>B</mi></msub></math> extrapolation was pushed up to a baryo-chemical potential <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>μ</mi><mi>B</mi></msub><mo>/</mo><mi>T</mi><mo>∼</mo><mn>3.5</mn></math> for the first time. This considerably extended the coverage of the Taylor expansion, limited to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>μ</mi></mrow><mrow><mi>B</mi></mrow></msub><mo>/</mo><mi>T</mi><mo>&lt;</mo><mn>2.5</mn><mi>–</mi><mn>3</mn></mrow></math>. As a consequence, we are able to offer a substantially larger coverage of the four-dimensional QCD phase diagram as well, compared to previously available Taylor expansion results. Our findings are based on new continuum estimated lattice data on the full set of second- and fourth-order fluctuations.

Ahmed Abuali

Germany

Szabolcs Borsányi

Hungary

Zoltán Fodor

Johannes Jahan

Micheal Kahangirwe

Italy

Paolo Parotto

Attila Pásztor

Claudia Ratti

Hitansh Shah

Seth A. Trabulsi

New 4D lattice QCD equation of state: Extended density coverage from a generalized <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>T</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></math> expansion

Motivated by the possible 95 GeV diphoton excess, we investigate the capability of the Type-I two-Higgs-doublet model (2HDM-I) to explain this signal under current theoretical and experimental constraints. Using full Monte Carlo simulations for the process of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><mi>t</mi><mo stretchy="false">(</mo><mo stretchy="false">→</mo><msup><mi>W</mi><mo>+</mo></msup><mi>b</mi><mo stretchy="false">)</mo><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">(</mo><mo stretchy="false">→</mo><msup><mi>W</mi><mo>−</mo></msup><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">)</mo><mi>h</mi><mo stretchy="false">(</mo><mo stretchy="false">→</mo><mi>γ</mi><mi>γ</mi><mo stretchy="false">)</mo></math>, we evaluate the discovery potential of a 95 GeV Higgs boson at future colliders. Direct Higgs searches strongly constrain the parameter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>α</mi></math>, excluding the region with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>α</mi><mo>≲</mo><mn>0.95</mn></math>. Monte Carlo results indicate that a minimum cross section of 0.3 fb is required to achieve a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math> signal statistical significance at the high-luminosity LHC (HL-LHC) with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>L</mi><mo>=</mo><mn>3</mn><mtext> </mtext><mtext> </mtext><msup><mi>ab</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. For the same luminosity, high-energy LHC (HE-LHC) and future circular collider-hadron-hadron (FCC-hh) require 0.67 fb and 2.36 fb, respectively. At the 14 TeV HL-LHC with an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mtext> </mtext><mtext> </mtext><msup><mi>ab</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, parameter regions with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>sin</mi><mo stretchy="false">(</mo><mi>β</mi><mo>−</mo><mi>α</mi><mo stretchy="false">)</mo><mo>≳</mo><mn>0.4</mn></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>sin</mi><mo stretchy="false">(</mo><mi>β</mi><mo>−</mo><mi>α</mi><mo stretchy="false">)</mo><mo>≳</mo><mn>0.25</mn></math> can be probed at the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>σ</mi></math> significance levels, respectively. At the 27 TeV HE-LHC with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>L</mi><mo>=</mo><mn>10</mn><mtext> </mtext><mtext> </mtext><msup><mi>ab</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, the sensitivity improves to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>sin</mi><mo stretchy="false">(</mo><mi>β</mi><mo>−</mo><mi>α</mi><mo stretchy="false">)</mo><mo>≳</mo><mn>0.25</mn></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math>) and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≳</mo><mn>0.15</mn></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>σ</mi></math>). For the 100 TeV FCC-hh with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>L</mi><mo>=</mo><mn>30</mn><mtext> </mtext><mtext> </mtext><msup><mi>ab</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, even regions with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>sin</mi><mo stretchy="false">(</mo><mi>β</mi><mo>−</mo><mi>α</mi><mo stretchy="false">)</mo><mo>≳</mo><mn>0.1</mn></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>sin</mi><mo stretchy="false">(</mo><mi>β</mi><mo>−</mo><mi>α</mi><mo stretchy="false">)</mo><mo>≲</mo><mo>−</mo><mn>0.05</mn></math> can be covered at the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math> level. Parameter regions near <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>sin</mi><mo stretchy="false">(</mo><mi>β</mi><mo>−</mo><mi>α</mi><mo stretchy="false">)</mo><mo>≈</mo><mn>0</mn></math> remain challenging to probe in the diphoton channel, even with increased energy or luminosity.

China

Yabo Dong

Kun Wang

Jingya Zhu

Probing a type I 2HDM light Higgs boson in the top-pair-associated diphoton channel

Employing the gauge-invariant formalism in the two-Higgs-doublet model (THDM) offers profound insights into the model’s fundamental structure. A specific set of gauge-invariant bilinear combinations, constructed from the Higgs doublets, establishes a one-to-one correspondence between the components of the doublet fields and real-valued bilinears. This formalism provides a compact and consistent framework to study various aspects of the THDM, including stability, electroweak symmetry breaking, basis transformations, and general symmetries of the Higgs potential.

France

T. Guerandel

Chile

M. Maniatis

L. Sartore

I. Schienbein

The two-Higgs doublet model beyond tree-level: a gauge-invariant formalism

We analyze the contribution of hypothetical quark electric dipoles to the electric dipole moment (EDM) of the neutron. Particular emphasis is devoted to the strange quark contribution. Considerations based on perturbative QCD, the large N expansion, a critical reassessment of the non-relativistic quark model as well as a next to leading order calculation in heavy baryon effective field theory, all consistently indicate that, barring accidental cancellations, the matrix element of the strange quark dipole should be of the order of a tenth of those of the valence quarks. This implies that the strange EDM provides the dominant contribution to the neutron EDM in many scenarios beyond the Standard Model.

Luca Vecchi

A strange contribution to the neutron EDM

Using the data samples of 102 million Υ(1$\textit{S}$) and 158 million Υ(2$\textit{S}$) events collected by the Belle detector, we search for a pentaquark state in the $\textit{pJ/ψ}$ final state from Υ(1$\textit{,}$ 2$\textit{S}$) inclusive decays. Here, the charge-conjugate $$\overline{p }J/\psi $$ is included. We observe clear $\textit{pJ/ψ}$ production in Υ(1$\textit{,}$ 2$\textit{S}$) decays and measure the branching fractions to be $$\mathcal{B}[\Upsilon (1S)\to pJ/\psi +anything]=[8.1\pm 0.6(stat.)\pm 0.5(syst.)]\times {10}^{-5}$$ and $$\mathcal{B}[\Upsilon (2S)\to pJ/\psi +anything]=[4.3\pm 0.5(stat.)\pm 0.4(syst.)]\times {10}^{-5}$$ . We also measure the cross section of inclusive $\textit{pJ/ψ}$ production in $\textit{e}$ $\textit{e}$ annihilation to be $\textit{σ}$($\textit{e}$ $\textit{e}$ → $\textit{pJ/ψ}$ + $\textit{anything}$) = [108 ± 11($\textit{stat.}$) ± 6($\textit{syst.}$)] fb at $$\sqrt{s}=10.52$$ GeV using an 89$\textit{.}$5 fb continuum data sample. There is no significant $\textit{P}$ (4312) , $\textit{P}$ (4440) or $\textit{P}$ (4457) signal found in the $\textit{pJ/ψ}$ final states in Υ(1$\textit{,}$ 2$\textit{S}$) inclusive decays. We determine the upper limits of $$\mathcal{B}\left[\Upsilon \left({1},{2}S\right)\to {P}_{c}^{+}+anything\right]\cdot \mathcal{B}\left({P}_{c}^{+}\to pJ/\psi \right)$$ to be at the 10 level.

X. Dong

S. Zou

H. Zhang

X. Wang

I. Adachi

J. Ahn

H. Aihara

S. Said

D. Asner

H. Atmacan

R. Ayad

S. Bahinipati

Sw. Banerjee

M. Bessner

V. Bhardwaj

D. Biswas

D. Bodrov

A. Bozek

M. Bračko

P. Branchini

T. Browder

A. Budano

M. Campajola

D. Červenkov

M.C. Chang

P. Chang

B. Cheon

H. Cho

K. Cho

S.K. Choi

Y. Choi

S. Choudhury

S. Das

G. Nardo

G. Pietro

R. Dhamija

F. Capua

J. Dingfelder

Z. Doležal

T. Dong

P. Ecker

D. Epifanov

T. Ferber

D. Ferlewicz

B. Fulsom

R. Garg

V. Gaur

A. Giri

P. Goldenzweig

E. Graziani

T. Gu

Y. Guan

K. Gudkova

C. Hadjivasiliou

H. Hayashii

S. Hazra

M. Hedges

W.S. Hou

C.L. Hsu

K. Inami

N. Ipsita

A. Ishikawa

R. Itoh

M. Iwasaki

W. Jacobs

S. Jia

Y. Jin

D. Kalita

T. Kawasaki

D. Kim

K.H. Kim

Y. Kim

Y.K. Kim

K. Kinoshita

P. Kodyš

A. Korobov

S. Korpar

E. Kovalenko

P. Križan

P. Krokovny

T. Kuhr

R. Kumar

T. Kumita

A. Kuzmin

Y.J. Kwon

Y.T. Lai

T. Lam

J. Lange

D. Levit

L. Li

Y. Li

L. Gioi

J. Libby

D. Liventsev

Y. Ma

M. Masuda

T. Matsuda

S. Maurya

F. Meier

Search for a pentaquark state decaying into $\textit{pJ/ψ}$ in Υ(1$\textit{,}$ 2$\textit{S}$) inclusive decays at Belle

Lepton-number-violating interactions occur in the Standard Model Effective Field Theory (SMEFT) at odd dimensions starting from the dimension-5 Weinberg operator. Although the operators at dimension-7 and higher are more suppressed by the heavy new scale, they can be crucial when traditional seesaw mechanisms leading to tree-level dimension-5 contributions are absent. We identify all minimal tree-level UV-completions for dimension-7 ∆$\textit{L}$ = 2 SMEFT operators without covariant derivatives and propose a new simplified approach for estimating the radiative neutrino masses arising from such operators. This dimensional-regularisation-based approach provides a more accurate estimate for the loop neutrino masses when the new physics fields are hierarchical in mass, as compared to the cut-off-regularisation-based approach often employed in the literature. This allows us to identify viable regions of parameter space in the full list of relevant simplified models close to the current limits set by neutrinoless double beta decay and the LHC that would previously have been thought to be excluded by neutrino-mass constraints.

Japan

Kåre Fridell

Netherlands

Czechia

Lukáš Gráf

Julia Harz

Spain

Chandan Hati

Radiative neutrino masses from dim-7 SMEFT: a simplified multi-scale approach

We perform a detailed comparison between three formalisms used in recent studies of $\textit{DD}$ scattering at heavier-than-physical pion masses, which aim to understand the properties of the doubly-charmed tetraquark, $$ {T}_{cc}^{+}(3875) $$ . These methods are the three-particle relativistic field theory (RFT) formalism, the two-body Lippmann-Schwinger (LS) equation with chiral effective field theory potentials, and the two-particle relativistic framework proposed by Baião Raposo and Hansen (BRH approach). In a simplified single-channel setting, we derive the conditions under which the infinite-volume integral equations from the RFT and BRH approaches reduce to the LS form. We present numerical examples showing that differences between these methods can be largely removed by adjusting short-range couplings. We also address a number of technical issues in the RFT approach.

Sebastian Dawid

Switzerland

Fernando Romero-López

Stephen Sharpe

Comparison of integral equations used to study $$ {T}_{cc}^{+} $$ for a stable $\textit{D}$

Canada

D. Gallacher

A. St. Croix

S. Bron

B. Rebeiro

T. McElroy

S. Al Kharusi

T. Brunner

C. Chambers

B. Chana

Z. Charlesworth

E. Egan

M. Francesconi

L. Galli

P. Giampa

D. Goeldi

S. Lavoie

J. Lefebvre

X. Li

C. Malbrunot

P. Margetak

N. Massacret

S. Nowicki

H. Rasiwala

K. Raymond

F. Retière

S. Rottoo

L. Rudolph

X. Shang

M. Tétrault

T. Totev

S. Viel

N. Viet

Publisher Erratum: Characterization of external cross-talk from silicon photomultipliers in a liquid xenon detector

Using the AdS/CFT correspondence, we compute the tree-level four-point boundary scalar correlation function for a scalar field conformally coupled to the graviton field on Euclidean AdS . We assume that the dynamics of the graviton field is governed by the Einstein-Hilbert action. We carry out the computation in momentum space and check that the result so obtained is consistent with the conformal Ward identities.

Carmelo Martin

Tree-level four-point function for a scalar field conformally coupled to Einstein’s gravity on Euclidean AdS