An $\textit{SU}$(3) flavor projection operator technique is implemented to construct the baryon-meson scattering amplitude within the framework of the $1/N_c$ expansion of quantum chromodynamics (QCD), where $N_c$ represents the number of color charges. The operator technique is implemented to evaluate not only the lowest-order scattering amplitude but also effects from the first-order perturbative $\textit{SU}$(3) flavor symmetry breaking and strong isospin breaking. The most general expression is obtained by explicitly accounting for the effects of the decuplet-octet baryon mass difference. At order ${\cal{O}}(1/N_c^2)$ , a large number of unknown operator coefficients appear, and therefore, there is little additional predictive power unless leading and subleading terms are retained. Although the resultant expression is sufficiently general that it can be applied to any incoming and outgoing baryons and pseudo scalar mesons, provided that the Gell-Mann--Nishijima scheme is respected, results for $N\pi\to N\pi$ scattering processes are explicitly considered.

Víctor Miguel Banda Guzmán

Rubén Flores-Mendieta

Johann Hernández

Use of $\textit{SU}$(3) flavor projection operators to construct baryon-meson scattering amplitudes in the 1/ N$_{c}$ expansion * The authors are grateful to Consejo Nacional de Humanidades, Ciencias y Tecnologías (Mexico) for support through the $\textit{Ciencia de Frontera}$ project CF-2023-I-162

Axion inflation is a well-motivated model of cosmic inflation with a rich phenomenology. The abundant production of gauge fields during axion inflation notably sources a stochastic gravitational-wave (GW) background signal, which nourishes the hope that future GW searches might have a chance to probe the model. In this paper, we scrutinize GW production during axion inflation in the gradient expansion formalism (GEF), a powerful numerical technique that captures the nonlinear dynamics of the system in the limit of vanishing axion gradients. We focus on single-field axion inflation coupled to a pure Abelian gauge sector, i.e., pure axion inflation (PAI), and perform the first-ever detailed parameter scan of GW production in the Abelian PAI model close to the onset of strong backreaction. We approximate the axion potential around its minimum by a quadratic mass term and study the tensor modes that exit the Hubble horizon as the axion rolls down this potential. Remarkably enough, we find that GW signals within the reach of future GW interferometers can only be realized in parameter regions that also lead to strong backreaction and that are in conflict with the upper limit on ∆$\textit{N}$ , i.e., the allowed energy density of dark radiation. This observation defines a clear target for future lattice studies of axion inflation that may confirm or improve the predictions of our GEF benchmark.

Germany

Richard Eckardstein

Japan

Kai Schmitz

Ukraine

Oleksandr Sobol

Gravitational waves from axion inflation in the gradient expansion formalism. Part I. Pure axion inflation

The electroweak sphaleron is a static, unstable solution of the Standard Model classical field equations, representing the energy barrier between topologically distinct vacua. In this work, we present a comprehensive updated analysis of the sphaleron using current Standard Model parameters with the physical Higgs boson mass of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>H</mi></msub><mo>=</mo><mn>125.1</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>W</mi></msub><mo>=</mo><mn>80.4</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, rather than the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>H</mi></msub><mo>=</mo><msub><mi>m</mi><mi>W</mi></msub></math> approximation common in earlier studies. The study includes: (i) a complete derivation of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo><mo>×</mo><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> electroweak Lagrangian and field equations without gauge fixing constraints, (ii) high-precision numerical solutions for the static sphaleron configuration yielding a sphaleron energy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>E</mi><mi>sph</mi></msub><mo>≃</mo><mn>9.1</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, (iii) an analysis of the minimum energy path in field space connecting the sphaleron to the vacuum (a 1D “potential barrier” as a function of Chern-Simons number), and (iv) calculation of the sphaleron single unstable mode with negative eigenvalue <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>ω</mi><mo>−</mo><mn>2</mn></msubsup><mo>=</mo><mo>−</mo><mn>2.7</mn><msubsup><mi>m</mi><mi>W</mi><mn>2</mn></msubsup></math>, providing analytical fits for its eigenfunction. We find that using the measured Higgs mass modifies the unstable mode frequency, with important implications for baryon number violation rates in both early universe cosmology and potential high-energy collider signatures. These results provide essential input for accurate lattice simulations of sphaleron transitions and precision calculations of baryon number violation processes.

United States

Konstantin T. Matchev

Sarunas Verner

Electroweak sphaleron revisited. I. Static solutions, energy barrier, and unstable modes

Extending the Standard Model (SM) with three right-handed neutrinos, the type-I seesaw model serves as the simplest and most natural scenario to successfully explain both tiny neutrino masses and the baryon number asymmetry in the Universe. In this paper, we perform a complete one-loop renormalization of the type-I seesaw model in the modified minimal-subtraction ( <math altimg='si1.svg'><mover><mrow><mrow><mi mathvariant='normal'>M</mi></mrow><mi>S</mi></mrow><mo stretchy='true'>&#8254;</mo></mover></math>) scheme. The one-loop self-energy corrections of charged leptons and Majorana neutrinos are calculated in the <math altimg='si2.svg'><msub><mi>R</mi><mi>&#958;</mi></msub></math> gauge, and the explicit expressions of all the counterterms for wave functions, fermion masses and the leptonic flavor mixing matrix are given. Furthermore, adopting the Euler-like parametrization of the 6&#8239;&#215;&#8239;6 unitary leptonic flavor mixing matrix, we derive one-loop renormalization-group equations for all the physical parameters in the <math altimg='si1.svg'><mover><mrow><mrow><mi mathvariant='normal'>M</mi></mrow><mi>S</mi></mrow><mo stretchy='true'>&#8254;</mo></mover></math> scheme, including neutrino masses, mixing angles and CP-violating phases. The modification of the one-loop renormalization of the original SM parameters due to the presence of heavy Majorana neutrinos is investigated as well. In this way, we provide a self-consistent theoretical framework to thoroughly test the type-I seesaw model at the one-loop level with future precision data.

China

Jihong Huang

Shun Zhou

One-loop renormalization of the type-I seesaw model in the modified minimal-subtraction scheme

A search for a dark baryon is performed for the first time in the two-body decay <math altimg='si14.svg'><mrow><msup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mo>&#8722;</mo></msup><mo>&#8594;</mo><msup><mi>&#960;</mi><mo>&#8722;</mo></msup><mo linebreak='goodbreak'>+</mo><mrow><mrow><mi mathvariant='normal'>i</mi></mrow><mi>n</mi><mi>v</mi><mi>i</mi><mi>s</mi><mi>i</mi><mi>b</mi><mi>l</mi><mi>e</mi></mrow></mrow></math> using (10.087&#8239;&#177;&#8239;0.044)&#8239;&#215;&#8239;10 9 <italic>J</italic>/ <italic>&#968;</italic> events collected at a center-of-mass energy of <math altimg='si23.svg'><mrow><msqrt><mi>s</mi></msqrt><mo linebreak='goodbreak'>=</mo><mn>3.097</mn><mspace width='0.16em' /><mtext>GeV</mtext></mrow></math> with the BESIII detector at the BEPCII collider. No significant signal is observed, and the 90% (95%) confidence level upper limits on the branching fraction <math altimg='si24.svg'><mrow><mi mathvariant='script'>B</mi><mo>(</mo><msup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mo>&#8722;</mo></msup><mo>&#8594;</mo><msup><mi>&#960;</mi><mo>&#8722;</mo></msup><mo linebreak='goodbreak'>+</mo><mrow><mrow><mi mathvariant='normal'>i</mi></mrow><mi>n</mi><mi>v</mi><mi>i</mi><mi>s</mi><mi>i</mi><mi>b</mi><mi>l</mi><mi>e</mi></mrow><mo>)</mo></mrow></math> are determined to be <math altimg='si25.svg'><mrow><mn>4.2</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>5</mn></mrow></msup></mrow></math> ( <math altimg='si26.svg'><mrow><mn>5.2</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>5</mn></mrow></msup></mrow></math>), <math altimg='si27.svg'><mrow><mn>6.9</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>5</mn></mrow></msup></mrow></math> ( <math altimg='si28.svg'><mrow><mn>8.4</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>5</mn></mrow></msup></mrow></math>), <math altimg='si29.svg'><mrow><mn>6.5</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>4</mn></mrow></msup></mrow></math> ( <math altimg='si30.svg'><mrow><mn>7.6</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>4</mn></mrow></msup></mrow></math>), <math altimg='si31.svg'><mrow><mn>1.1</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>4</mn></mrow></msup></mrow></math> ( <math altimg='si32.svg'><mrow><mn>1.3</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>4</mn></mrow></msup></mrow></math>) and <math altimg='si33.svg'><mrow><mn>4.5</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>5</mn></mrow></msup></mrow></math> ( <math altimg='si34.svg'><mrow><mn>5.5</mn><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>5</mn></mrow></msup></mrow></math>), under the dark baryon mass hypotheses of 1.07&#8201;GeV/ <italic>c</italic> 2, 1.10&#8201;GeV/ <italic>c</italic> 2, <math altimg='si19.svg'><msub><mi>m</mi><mstyle mathvariant='normal'><mi>&#923;</mi></mstyle></msub></math> (1.116&#8201;GeV/ <italic>c</italic> 2), 1.13&#8201;GeV/ <italic>c</italic> 2, and 1.16&#8201;GeV/ <italic>c</italic> 2, respectively. The constraints obtained on the Wilson coefficients <math altimg='si17.svg'><msubsup><mi>C</mi><mrow><mi>u</mi><mi>s</mi><mo>,</mo><mi>s</mi></mrow><mi>L</mi></msubsup></math> and <math altimg='si18.svg'><msubsup><mi>C</mi><mrow><mi>u</mi><mi>s</mi><mo>,</mo><mi>s</mi></mrow><mi>R</mi></msubsup></math> are more stringent than the previous limits derived from the LHC searches for the colored mediators.

M. Ablikim

Russia

M.N. Achasov

Sweden

P. Adlarson

X.C. Ai

R. Aliberti

Italy

A. Amoroso

Q. An

Y. Bai

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

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

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

X.Y. Chen

Y.B. Chen

Y.Q. Chen

Z. Chen

Z.J. Chen

Z.K. Chen

South Korea

S.K. Choi

X. Chu

G. Cibinetto

F. Cossio

United Kingdom

J. Cottee-Meldrum

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

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

L. Feng

Q.X. Feng

Search for a dark baryon in the <math altimg='si14.svg'><mrow><msup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mo>&#8722;</mo></msup><mo>&#8594;</mo><msup><mi>&#960;</mi><mo>&#8722;</mo></msup><mo linebreak='goodbreak'>+</mo><mrow><mrow><mi mathvariant='normal'>i</mi></mrow><mi>n</mi><mi>v</mi><mi>i</mi><mi>s</mi><mi>i</mi><mi>b</mi><mi>l</mi><mi>e</mi></mrow></mrow></math> decay

In this paper, we continue to carry out the one-loop renormalization of the type-I seesaw model in the on-shell scheme. Different from the modified minimal-subtraction ( <math altimg='si1.svg'><mover><mrow><mrow><mi mathvariant='normal'>M</mi></mrow><mi>S</mi></mrow><mo stretchy='true'>&#8254;</mo></mover></math>) scheme, such an investigation is mainly motivated by the fact that the on-shell scheme has been widely adopted in the renormalization of the standard electroweak theory and implemented for its precision tests. We first specify the physical parameters in the on-shell scheme, and then fix the corresponding counterterms through on-shell renormalization conditions. In the presence of massive Majorana neutrinos, we propose a practical method to determine gauge-independent counterterms for the lepton flavor mixing matrix. With the explicit counterterms in both the <math altimg='si1.svg'><mover><mrow><mrow><mi mathvariant='normal'>M</mi></mrow><mi>S</mi></mrow><mo stretchy='true'>&#8254;</mo></mover></math> and on-shell schemes, we establish the matching relations of the electric charge, physical masses and flavor mixing matrix elements between these two schemes. Our results in the present and previous papers lay the foundation for precision calculations in the type-I seesaw model.

One-loop renormalization of the type-I seesaw model in the on-shell scheme

We propose a generalization of the Bogomol’ny–Prasad–Sommerfield Skyrme model [L. A. Ferreira, Exact self-duality in a modified Skyrme model, <a href="http://dx.doi.org/10.1007/JHEP07(2017)039">J. High Energy Phys. 07 (2017) 039</a>] for simple compact Lie groups <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>G</mi></math> that leads to Hermitian symmetric spaces. In such a theory, the Skyrme field takes its values in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>G</mi></math>, while the remaining fields correspond to the entries of a symmetric, positive, and invertible <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>dim</mi><mtext> </mtext><mi>G</mi><mo>×</mo><mi>dim</mi><mtext> </mtext><mi>G</mi></math>-dimensional matrix <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi></math>. We also use the holomorphic map Ansatz between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>S</mi><mn>2</mn></msup><mo stretchy="false">→</mo><mi>G</mi><mo>/</mo><mi>H</mi><mo stretchy="false">⊗</mo><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> proposed in Ferreira and Livramento [Harmonic, holomorphic and rational maps from self-duality, <a href="http://arXiv.org/abs/2412.02636">arXiv:2412.02636</a>] to study the self-dual sector of the theory, which generalizes the holomorphic Ansatz between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>S</mi><mn>2</mn></msup><mo stretchy="false">→</mo><mi>C</mi><msup><mi>P</mi><mi>N</mi></msup></math> proposed in Ioannidou [Low-energy states in the SU(N) Skyrme models, in International Meeting on Mathematical Methods in Modern Theoretical Physics (ISPM 98) (1998), pp. 91–123, <a href="http://arXiv.org/abs/hep-th/9811071">arXiv:hep-th/9811071</a>]. This Ansatz is constructed using the fact that stable harmonic maps of the two <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>S</mi><mn>2</mn></msup></math> spheres for compact Hermitian symmetric spaces are holomorphic or antiholomorphic [J. Eells and L. Lemaire, Two Reports on Harmonic Maps (World Scientific Publishing Company, Singapore, 1995)]. Apart from some special cases, the self-duality equations do not fix the matrix <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi></math> entirely in terms of the Skyrme field, which is completely free, as it happens in the original self-dual Skyrme model for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>G</mi><mo>=</mo><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo></math>. In general, the freedom of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi></math> fields tend to grow with the dimension of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>G</mi></math>. The holomorphic Ansatz enable us to construct an infinite number of exact self-dual Skyrmions for each integer value of the topological charge and for each value of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo>≥</mo><mn>1</mn></math>, in case of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><msup><mi>P</mi><mi>N</mi></msup></math>, and for each values of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>p</mi></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>q</mi><mo>≥</mo><mn>1</mn></mrow></math> in case of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mrow><mo stretchy="false">(</mo><mi>p</mi><mo>+</mo><mi>q</mi><mo stretchy="false">)</mo></mrow><mo>/</mo><mi>S</mi><mi>U</mi><mrow><mo stretchy="false">(</mo><mi>p</mi><mo stretchy="false">)</mo></mrow><mo stretchy="false">⊗</mo><mi>S</mi><mi>U</mi><mrow><mo stretchy="false">(</mo><mi>q</mi><mo stretchy="false">)</mo></mrow><mo stretchy="false">⊗</mo><mi>U</mi><mrow><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></mrow></math>.

Brazil

L.A. Ferreira

L.R. Livramento

Self-duality and the holomorphic ansatz in a generalized BPS Skyrme model

We show how the 2-Higgs Doublet Model (2HDM) Type-I can explain some excesses recently seen at the Large Hadron Collider (LHC) in <italic>&#947;&#947;</italic> and <math altimg='si29.svg'><mrow><msup><mi>&#964;</mi><mo>+</mo></msup><msup><mi>&#964;</mi><mo>&#8722;</mo></msup></mrow></math> final states in turn matching Large Electron Positron (LEP) data in <math altimg='si30.svg'><mrow><mi>b</mi><mover accent='true'><mi>b</mi><mo>&#175;</mo></mover></mrow></math> signatures, all anomalies residing around 95&#8239;GeV. The explanation to such anomalous data is found in the aforementioned scenario when in inverted mass hierarchy, in two configurations: i) when the lightest CP-even Higgs state is alone capable of reproducing the excesses; ii) when a combination of such a state and the CP-odd Higgs boson is able to do so. To test further this scenario, we present some Benchmark Points (BPs) of it amenable to phenomenological investigation.

India

Akshat Khanna

Stefano Moretti

Agnivo Sarkar

Explaining 95 GeV anomalies in the 2-Higgs doublet model type-I

The particle origin of dark matter (DM) remains elusive despite decades of direct, indirect, and collider searches. Several groups have reported a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi></math>-ray excess toward the Galactic Center commonly referred to as the Galactic Center excess (GCE). Its spectrum is consistent with annihilation of weakly interacting massive particles (WIMPs) of mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mn>10</mn><mo>−</mo><mn>100</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math> and a thermal-relic cross section. Although many concrete WIMP models reproduce the GCE spectrum, most are now excluded by direct detection experiments that are approaching the neutrino floor. We investigate a class of anomaly-free extensions of the Standard Model featuring gauged differences of lepton number, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><msub><mi>L</mi><mi>i</mi></msub><mo>−</mo><msub><mi>L</mi><mi>j</mi></msub></mrow></msub></math>, and gauged baryon minus lepton number, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><mi>B</mi><mo>−</mo><mi>L</mi></mrow></msub></math>. We show that these models can reproduce the GCE while remaining compatible with the observed relic abundance. We then impose collider and direct detection constraints, accounting for both tree-level and loop-induced kinetic mixing. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>L</mi><mi>μ</mi></msub><mo>−</mo><msub><mi>L</mi><mi>e</mi></msub></math> model gives the best fit to the GCE: a DM mass of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>m</mi></mrow><mrow><mi>χ</mi></mrow></msub><mo>∼</mo><mn>40</mn><mo>−</mo><mn>50</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math> remains consistent with the muon and electron magnetic moment anomalies, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mi>g</mi><mo>−</mo><mn>2</mn><msub><mo stretchy="false">)</mo><mrow><mi>μ</mi><mo>,</mo><mi>e</mi></mrow></msub></math>, as well as current collider and direct detection limits, for mediator masses in the range <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>m</mi></mrow><mrow><msup><mrow><mi>A</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></msub><mo>∼</mo><mn>70</mn><mo>−</mo><mn>86</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math> and a DM mediator coupling of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>1</mn><mo>−</mo><mn>5</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math>. By contrast, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>L</mi><mi>e</mi></msub><mo>−</mo><msub><mi>L</mi><mi>τ</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>L</mi><mi>μ</mi></msub><mo>−</mo><msub><mi>L</mi><mi>τ</mi></msub></math> models yield poorer fits; satisfying both the relic density and experimental bounds forces the DM mass to lie very close to resonance (i.e. approximately half the mediator mass). Finally, while the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>−</mo><mi>L</mi></math> model also matches the GCE well, its parameter space is almost entirely ruled out by strong direct detection limits, except for the narrow resonance region where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>χ</mi></msub></math> should be equal to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msup><mi>A</mi><mo>′</mo></msup></msub><mo>/</mo><mn>2</mn></math> requiring a fine-tuning at the few-percent level.

Jordan Koechler

Mattia Di Mauro

Leptophilic dark matter in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><msub><mi>L</mi><mi>i</mi></msub><mo>−</mo><msub><mi>L</mi><mi>j</mi></msub></mrow></msub></math> models: A solution to the Fermi-LAT Galactic Center excess consistent with cosmological and laboratory observations

We construct backreacted geometries dual to the supersymmetric mass deformation of the IKKT matrix model. They are Euclidean type IIB supergravity solutions given in terms of an electrostatic potential, having SO(7) × SO(3) isometry and 16 supersymmetries. Quantizing the fluxes, we find that the supergravity solutions are in one-to-one correspondence with fuzzy sphere vacua of the matrix model.