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

On the basis of computer simulation, the ionization energy loss distributions (spectra) of high-energy positrons impinging on a silicon crystal at various angles $$\psi $$ with respect to the axis $$\langle 100\rangle $$ are considered. The method of simulation of high-energy particle ionization loss in oriented crystals is presented in detail. It is demonstrated that along with the probability of particle close collisions with atoms, the probability of distant collisions can be also sensitive to the particle position in the crystal lattice. Evolution of the ionization loss spectra with the change of crystal orientation relative to the incident particle momentum from the axial $$\langle 100\rangle $$ to the planar (100) and (110) with the increase of $$\psi $$ is investigated. It is shown that in the transition $$\langle 100\rangle \rightarrow (100)$$ the most probable energy loss $$E_\mathrm{{MP}}$$ experiences a sharp maximum and discontinuity, while in the transition $$\langle 100\rangle \rightarrow (110)$$ the amplitude of its variation is much smaller. Behavior of the average restricted energy loss $$E_\mathrm{{AV}}$$ in these transitions is investigated as well. Correlation of the dependences of $$E_\mathrm{{MP}}$$ and $$E_\mathrm{{AV}}$$ on $$\psi $$ with the change of the particle motion regime is discussed.

Ukraine

S. Trofymenko

I. Kyryllin

Evolution of high-energy positron ionization loss spectra in a silicon crystal with the change of its orientation from axial to planar

A precise determination of the CKM angle $\textit{γ}$ from $$ {B}_s^0 $$ oscillations in $$ {B}_s^0\to {D}_s^{\mp }{K}^{\pm } $$ decays offers a critical test of the Standard Model and probes for new physics. We present a comprehensive study on the prospects of measuring $\textit{γ}$ at a future Tera-$\textit{Z}$ factory, utilizing the baseline detector concept of the Circular Electron Positron Collider (CEPC). A two-dimensional simultaneous fit framework, incorporating flavor tagging, decay time resolution modeling, and acceptance corrections, is developed using full Monte Carlo simulations of $$ {B}_s^0\to {D}_s^{\mp}\left(\to {K}^{\mp }{K}^{\pm }{\pi}^{\mp}\right){K}^{\pm } $$ decays and inclusive background processes. The effective flavor tagging power reaches 23.6%, while the decay time resolution is determined to be 26 fs. Projecting to full statistics of signal events across three dominant $$ {D}_s^{-} $$ decay channels, we estimate a statistical precision of $\textit{σ}$($\textit{γ}$) = 0$\textit{.}$69 , which corresponds to 4.1 Tera-$\textit{Z}$ boson equivalent data. This study has established the feasibility of sub-degree level $\textit{γ}$ measurements at a $\textit{Z}$ factory, highlighting its unique advantages in time-dependent $\textit{CP}$ violation studies through ultra-precise vertexing and background suppression capabilities.

China

Ji Peng

Mingrui Zhao

Xiaolin Wang

Manqi Ruan

Hengne Li

Shanzhen Chen

Prospect for measurement of $\textit{CP}$-violating observables in $$ {B}_s^0\to {D}_s^{\mp }{K}^{\pm } $$ decays at a future $\textit{Z}$ factory

We show that the Mathieu groups $\textit{M}$ and $\textit{M}$ in the isometry group of the odd Leech lattice do not lift to subgroups of the automorphism group of its lattice vertex operator (super)algebra. In other words, the subgroups 2 .$\textit{M}$ and 2 .$\textit{M}$ of the automorphism group of the odd Leech lattice vertex operator algebra are non-split extensions. Our method can also confirm a similar result for the Conway group Co and the Leech lattice, which was already shown by Griess in [1]. This study is motivated by the moonshine-type observation on the $$ \mathcal{N} $$ = 2 extremal elliptic genus of central charge 24 by Benjamin, Dyer, Fitzpatrick, and Kachru [2]. We also investigate weight-1 and weight- $$ \frac{3}{2} $$ currents invariant under the subgroup 2 .$\textit{M}$ or 2 .$\textit{M}$ of the automorphism group of the odd Leech lattice vertex operator algebra, and revisit an $$ \mathcal{N} $$ = 2 superconformal algebra in it.

Japan

Masaki Okada

On the symmetry of odd Leech lattice CFT

Aiming to uncover the CP properties of spin-0 particle Dark Matter (DM), we explore a two-component DM scenario within the framework of 3-Higgs Doublet Models (3HDMs), a well-motivated set-up previously studied due to the complementarity of its collider and astrophysical probes. We devise benchmark points in which the two components of DM have same CP in one case and opposite CP in another. We then show several cross section distributions of observables at collider experiments where the two cases are clearly distinguishable.

Ireland

A. Dey

Mexico

J. Hernández-Sánchez

Finland

V. Keus

United Kingdom

Sweden

S. Moretti

T. Shindou

On the CP properties of spin-0 dark matter

Gravitational chiral anomaly connects the topological charge of spacetime and the chirality of fermions. It has been known that the chirality is carried by the particles (or the excited states) and also by vacuum. While the gravitational anomaly equation has been applied to cosmology, distinction between these two contributions has been rarely discussed. In the study of gravitational leptogenesis, for example, lepton asymmetry associated with the chiral gravitational waves (GWs) sourced during inflation is evaluated only by integrating the anomaly equation. This approach, however, does not reveal how these two contributions are distributed in this scenario. Meanwhile, the dominance of vacuum contribution is observed in some specific types of Bianchi spacetime with parity-violating gravitational fields. One may wonder whether such a vacuum dominance takes place also in the system with chiral GWs around the flat background, which is more suitable for application to realistic cosmology. In this work, we apply an analogy between U(1) electromagnetism and the weak gravity to the spacetime that captures the characteristics of the one considered in the gravitational leptogenesis. With this approach, we try to obtain intuitive understanding of the fermion chirality generation under the parity-violating spin-2 gravitational field. By assuming the emergence of Landau level-like dispersion relation in our setup, we observe that spin-2 nature seems to make the level-crossing inefficient, indicating that the chrial charge is likely to accumulate in the vacuum. On this basis, phenomenological implications for gravitational leptogenesis are discussed.

Kohei Kamada

Italy

Jun’ya Kume

On the inefficiency of fermion level-crossing under the parity-violating spin-2 gravitational field

We study soliton and black hole solutions with scalar hair in AdS in a theory with a Maxwell field and a charged scalar field with double trace boundary conditions, which can trigger the dual boundary theory to become a superconductor. We investigate the phase diagram as a function of the temperature $\textit{T}$ and of the double trace coupling $\textit{κ}$ and we find a rich pattern of phase transitions, which can be of the Hawking-Page kind or can be due to the condensation of the order parameter. We also find a transition between vortex solutions and the zero temperature limit of the black hole for a critical value of the double trace coupling $\textit{κ}$. The Little-Park periodicity is realized for the dual of the black hole solution with hair as a shift in the winding number and in the gauge field.

Roberto Auzzi

Stefano Bolognesi

Giuseppe Nardelli

Chile

Gianni Tallarita

Nicolò Zenoni

Solitonic vortices and black holes with vortex hair in AdS

This work is an extension of a previous publication [1] where we fitted the strong coupling $\textit{α}$ together with the non-perturbative parameter $\textit{α}$ from event-shape and jet-shape distributions using power corrections computed in the three-jet region. In ref. [1] only ALEPH data at the $\textit{Z}$-pole were used in the fit. Here, instead, we include a large data sample from various $\textit{e}$ $\textit{e}$ experiments at energies ranging from 22 to 207 GeV and revisited the treatment of theoretical uncertainties. We find that the inclusion of different energies, while not changing the central fit result considerably, helps to disentangle the dependence of perturbative and non-perturbative corrections. Our best fit result is $\textit{α}$ ($\textit{M}$ ) = $$ {0.1181}_{-0.0005-0.0021}^{+0.0002+0.0018} $$ , where the first error includes experimental uncertainties and the second one includes uncertainties associated with scale variation, mass effects, fit limits, non-perturbative schemes and non- perturbative uncertainties.

Germany

Paolo Nason

Giulia Zanderighi

Fits of $\textit{α}$

The current status of ‘fat-brane’ minimal Universal Extra Dimension (fat-mUED) is studied in light of recent results reported by the ATLAS experiment. At the Large Hadron Collider (LHC), color charged first-level Kaluza–Klein (KK) particles (first-level excited quarks and gluons) can be abundantly pair-produced due to conserved quantity, viz., KK-parity, and the strong interaction. The cascade decay of these particles to one or more Standard Model (SM) particle(s) and lighter first-level KK particle(s) stops after producing the lightest excited massive state, named as the lightest KK particle (LKP). In the presence of gravity induced decays, the stability of the LKP is lost, allowing it to decay to photon or Z-boson by radiating KK-excited gravitons, leading to final states with photon(s) at the LHC. A variant signal topology emerges when pair-produced first-level colored KK particles undergo direct decay to their associated SM partners together with KK-excitations of gravitons resulting in a signature characterized by two hard jets and substantial missing energy. The ATLAS experiment lately reported two relevant searches at the 13 TeV LHC with 139 inverse-femtobarn of data: (i) multi-jet, and (ii) photon and jets accompanied by missing energy. Neither search observed substantial deviations from SM background expectations. Provided the absence of any number of excess events in both searches, we constrained parameters of the fat-mUED model, viz., the higher-dimensional Planck mass and the compactification scale.

Türkiye

Esra Akyumuk

Durmus Karabacak

‘Fat-brane’ universal extra dimension model confronted with the ATLAS multi-jet and photonic searches at 13 TeV LHC

In this paper, we extend the study of wave packets from the AdS /CFT correspondence to AdS /CFT and examine properties of their energy density. We find that, while the energy still localizes on the light cone, its spatial distribution exhibits momentum dependence and is no longer localized in higher dimensions. This result is significant as it reflects leading 1/$\textit{N}$ corrections to the generalized free field theory associated with the free bulk theory at $\textit{N}$ = ∞. Our findings are consistent with previous studies on entanglement wedge reconstruction including 1/$\textit{N}$ corrections, and also provide new insights into the structure of wave packets in higher-dimensional holography.

Norihiro Tanahashi

Seiji Terashima

Shiki Yoshikawa

Holographic description of bulk wave packets in AdS