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

In this article, the vector, axial vector, and tensor form factors of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>c</mi></msub><mo stretchy="false">→</mo><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>=</mo><mn>0</mn></math>, 1, 2) and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>c</mi></msub><mo stretchy="false">→</mo><msub><mi>h</mi><mi>c</mi></msub></math> are analyzed within the framework of three-point QCD sum rules. With the calculated vector and axial vector form factors, we directly study the decay widths and branching ratios of semileptonic decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>−</mo></msubsup><mo stretchy="false">→</mo><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><mi>l</mi><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>l</mi></msub><mo>,</mo><msub><mi>h</mi><mi>c</mi></msub><mi>l</mi><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>l</mi></msub></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mi>l</mi><mo>=</mo><mi>e</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>μ</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math>) and analyze the nonleptonic decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>−</mo></msubsup><mo stretchy="false">→</mo><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><msup><mi>π</mi><mo>−</mo></msup><mo>,</mo><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><msup><mi>K</mi><mo>−</mo></msup><mo>,</mo><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><msup><mi>ρ</mi><mo>−</mo></msup><mo>,</mo><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><msup><mi>K</mi><mrow><mo>*</mo><mo>−</mo></mrow></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>−</mo></msubsup><mo stretchy="false">→</mo><msub><mi>h</mi><mi>c</mi></msub><msup><mi>π</mi><mo>−</mo></msup><mo>,</mo><msub><mi>h</mi><mi>c</mi></msub><msup><mi>K</mi><mo>−</mo></msup><mo>,</mo><msub><mi>h</mi><mi>c</mi></msub><msup><mi>ρ</mi><mo>−</mo></msup><mo>,</mo><msub><mi>h</mi><mi>c</mi></msub><msup><mi>K</mi><mrow><mo>*</mo><mo>−</mo></mrow></msup></math> by using the naive factorization approach. These results can provide more information to understand the properties of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>c</mi></msub></math> meson and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave charmonia and to study the heavy quark dynamics.

China

Jie Lu

Dian-Yong Chen

Guo-Liang Yu

Zhi-Gang Wang

Bin Wu

Systematic analysis of the form factors of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>c</mi></msub></math> to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave charmonia and corresponding weak decays

We present a first-principles lattice QCD investigation of second-order fluctuations of and correlations among conserved charges—baryon number (B), electric charge (Q), and strangeness (S)—in the presence of external magnetic fields. Our study employs lattice simulations of (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math>)-flavor QCD with physical pion masses using highly improved staggered fermions on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>48</mn><mn>3</mn></msup><mo>×</mo><mn>12</mn></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>32</mn><mn>3</mn></msup><mo>×</mo><mn>8</mn></math> lattices, covering a wide range of magnetic field strengths up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi><mi>B</mi><mo>≃</mo><mn>0.8</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>GeV</mi></mrow><mrow><mn>2</mn></mrow></msup></math>. We identify clear signals of magnetic field-induced modifications to these fluctuations and correlations, with the baryon-electric charge correlation, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>χ</mi><mn>11</mn><mrow><mi>BQ</mi></mrow></msubsup></math>, exhibiting particularly strong sensitivity to the magnetic field. To bridge theoretical predictions with experimental observables, we implement systematic kinematic cuts that emulate detector acceptances of the STAR and ALICE experiments within the hadron resonance gas (HRG) model and construct proxy observables for fluctuations measurable in heavy-ion collision experiments. Our findings highlight <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>χ</mi><mn>11</mn><mrow><mi>BQ</mi></mrow></msubsup></math> as a promising “magnetometer” for probing the presence of magnetic fields in QCD matter. Furthermore, we explore experimentally relevant ratios involving <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>χ</mi><mn>11</mn><mrow><mi>BQ</mi></mrow></msubsup></math>, demonstrating their potential in mitigating volume effects and enhancing sensitivity to magnetic fields in collision environments. Additionally, we assess the limitations of the HRG model at strong magnetic fields, revealing deviations that indicate nontrivial modifications to hadronic degrees of freedom. These results offer new insights into the interplay between thermal and magnetic effects in the QCD phase diagram and provide experimentally relevant guidance for the detection of magnetic fields in heavy-ion collisions.

Heng-Tong Ding

Jin-Biao Gu

Arpith Kumar

Sheng-Tai Li

Second order fluctuations of conserved charges in external magnetic fields

We study the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>+</mo><mn>1</mn></math> flat spacetime dynamics of a classical field configuration corresponding to an ensemble of sine-Gordon kinks and antikinks, semiclassically coupled to a quantum field. This coupling breaks the integrability of the sine-Gordon model resulting in the background’s decay into quantum radiation as kink-antikink pairs annihilate. We find evidence that, on average, the energy of the ensemble scales as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>t</mi><mrow><mo>−</mo><mi>α</mi></mrow></msup></math> with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>α</mi><mo>&lt;</mo><mn>1</mn></math> and independent of the coupling strength or the mass of the quantum field. The generalization of this result to domain wall networks in higher spacetime dimensions could be relevant to particle production in the early universe.

United States

Mainak Mukhopadhyay

Japan

Kohta Murase

South Korea

Atsushi Naruko

Poland

George Zahariade

Evolution of a kink-antikink ensemble in a quantum vacuum

We calculate the possible scalar, vector, and tensor form factors (FFs) for pion and kaon in the light-cone quark model (LCQM). These FFs are calculated from the leading and subleading twist generalized parton distribution functions (GPDs) of the pion and kaon. The vector and tensor FFs correspond to twist-2 GPDs, whereas the scalar FFs correspond to twist-3 scalar GPDs. We calculate the FFs from the GPDs quark-quark correlator and express them in the form of light-front wave functions. The behavior of these FFs was found to be in agreement with experimental data, other model predictions, and lattice simulation results. We have also calculated the charge radii corresponding to different FFs and compared them with other models, lattice simulation results, and experimental data. The scalar radii of the pion and kaon of our model are found to be 0.528 and 0.409 fm, respectively.

India

Satyajit Puhan

Harleen Dahiya

Scalar, vector, and tensor form factors of pion and kaon

The magnetic moments, magnetic form factors, and transition magnetic form factors of doubly charmed baryons are studied within heavy baryon chiral perturbation theory. We regulate the loop integrals using the finite-range regularization. The contributions of vector mesons are taken into account to investigate the dependence of form factors on the transferred momentum. The finite volume and lattice spacing effects are considered to analyze the lattice QCD simulations which can be understood well in our framework.

Jiong-Jiong Liu

Zhan-Wei Liu

Germany

Xiu-Lei Ren

Yu Zhuge

Chiral extrapolation of the doubly charmed baryons magnetic properties

We investigate the classical and quantum dynamics of $\textit{f}$($\textit{R}$) gravity’s rainbow in the presence of a perfect fluid, employing Schutz’s formalism to establish a well-defined notion of time. In the classical regime, we derive and solve the equations of motion, obtaining both analytical and numerical solutions. Through canonical quantisation, we formulate the Schrödinger–Wheeler–DeWitt (SWD) equation for the quantum model. By solving its eigenfunctions, we construct the wave function of the Universe and obtain analytical solutions in scenarios dominated by stiff matter. Our results highlight the impact of rainbow gravity on quantum evolution, particularly in modifying the structure of the wave function and shaping the transition from the quantum to the classical regime.

Chile

Andrés Burton-Villalobos

Giovanni Otalora

Manuel Gonzalez-Espinoza

Yoelsy Leyva

Classical and quantum cosmology of $\textit{f}$($\textit{R}$) gravity’s rainbow in Schutz’s formalism

Utilizing the Tomita–Takesaki modular theory, we derive a closed-form analytic expression for the Araki–Uhlmann relative entropy between a single-mode squeezed state and the vacuum state in a free relativistic massive scalar Quantum Field Theory within wedge regions of Minkowski spacetime. Similarly to the case of coherent states, this relative entropy is proportional to the smeared Pauli–Jordan distribution. Consequently, the Araki–Uhlmann entropy between a single-mode squeezed state and the vacuum satisfies all expected properties: it remains positive, increases with the size of the Minkowski region under consideration, and decreases as the mass parameter grows.

Brazil

Marcelo Guimaraes

Itzhak Roditi

Silvio Sorella

Arthur Vieira

Relative entropy of single-mode squeezed states in Quantum Field Theory

In the phase space perspective, scalar field slow roll inflation is described by a heteroclinic orbit from a saddle type fixed point to a final attractive point. In many models the saddle point resides in the scalar field asymptotics, and thus for a comprehensive view of the dynamics a global phase portrait is necessary. For this task, in the literature one mostly encounters dynamical variables that either render the initial or the final state singular, thus obscuring the full picture. In this work we construct a hybrid set of variables which allow the depiction of both the initial and final states distinctly in nonsingular manner. To illustrate the method, we apply these variables to portray various interesting types of scalar field inflationary models like metric Higgs inflation, metric Starobinsky inflation, pole inflation, and a nonminimal Palatini model.

Estonia

Laur Järv

Dmitri Kraiko

Global portraits of inflation in nonsingular variables

In this work, we propose a topological quantum field theory phase for four-dimensional gravity. We show it is able to generate, not only General Relativity, but the whole family of Lovelock–Cartan theories of gravity. This is accomplished due to the existence of a topological symmetry which, when explicitly broken via the introduction of a mass scale, releases the local degrees of freedom of gravity. Additionally, we introduce an extended notion of the (anti-)self-dual Landau gauge conditions to evaluate the Ward identities, counterterms, and prove the quantum stability of the model, to all orders in perturbation theory, using the algebraic renormalization technique.

Guilherme Sadovski

Rodrigo Sobreiro

Topological symmetry-restored phase of gravity