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

We present a self-consistent dynamical holographic quantum chromodynamics (QCD) model to investigate the mass spectra and melting behavior of heavy and exotic mesons at finite temperature and finite density. Our approach is based on the Einstein-Maxwell-dilaton (EMD) framework and incorporates an elsewhere already introduced, albeit by hand, phenomenological nonquadratic dilaton profile. This allows one to capture the nonlinear Regge trajectories of heavy-flavor mesons and model certain exotic states. We show how to construct such models by actually solving the coupled Einstein, Maxwell, and dilaton field equations, ensuring mathematical self-consistency to replace any ad hoc input. At finite temperature, we analyze the confinement-deconfinement transition via a Hawking-Page phase transition. We compute the spectral functions, revealing the sequential melting of quarkonia as the temperature is increased. Extending to finite density, we explore the impact of baryon chemical potential on meson stability, showing significant modifications in spectral peaks and effective potentials that indicate a more rapid melting of mesonic states as the chemical potential increases in the deconfined phase. The dual of the small/large black hole transition now indicates toward a first order phase transition line ending at a second order critical point. Interestingly, the spectral functions smoothly cross this phase transition line.

Brazil

Belgium

Bruno Toniato

David Dudal

India

Subhash Mahapatra

Roldao da Rocha

Siddhi Swarupa Jena

Holographic QCD model for heavy and exotic mesons at finite density: A self-consistent dynamical approach

A series of vector charmonium(like) states, accompanied by a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math> meson, have been observed in the decays of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi></mrow></math> meson. These processes are color-suppressed at the quark level, as inferred from topological diagram analysis. In this work, we calculate the branching fractions of the decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>ψ</mi><mi>K</mi></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi></math> denotes the charmonium(like) states <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>1</mn><mi>S</mi><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>4040</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>3770</mn><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>4160</mn><mo stretchy="false">)</mo></math>. Our analysis incorporates both short-distance (naive factorization approach) and long-distance (final-state interactions) contributions. Within reasonable parameters, our results align with experimental data except for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>4160</mn><mo stretchy="false">)</mo></math>, suggesting its possible exotic nature. Furthermore, we find that long-distance contributions dominate these decay processes, highlighting the crucial role of final-state interactions in the productions of charmonium(like) states in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> decays.

China

Qi-Wei Yuan

Qi Wu

Ming-Zhu Liu

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math>-meson decays to vector charmoniumlike states and a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math> meson: The role of final-state interactions

In this work, we revisit the possible new physics solutions by analyzing the observables associated with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi><mo stretchy="false">→</mo><msup><mrow><mi>D</mi></mrow><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup><mi>τ</mi><msub><mrow><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub></mrow></math> decays. To explore the structure of new physics, the form factors of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup></math> decays play a crucial role. In this study, we utilize the form factor results obtained from a simultaneous fit to Belle data and lattice QCD calculations. Using these form factors, we conduct a global fit of the new physics Wilson coefficients, incorporating the most recent experimental data. Additionally, we use the form factors and Wilson coefficients to make predictions for physical observables, including the lepton flavor universality ratio <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>R</mi><msup><mi>D</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup></msub></math>, polarized observables, and the normalized angular coefficients <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">⟨</mo><mi>I</mi><mo stretchy="false">⟩</mo></math>’s related to the fourfold decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mo>*</mo></msup><mo stretchy="false">(</mo><mo stretchy="false">→</mo><mi>D</mi><mi>π</mi><mo>,</mo><mi>D</mi><mi>γ</mi><mo stretchy="false">)</mo><mi>τ</mi><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub></math>. These predictions are calculated in both model independent scenarios and for three different leptoquark models.

Zhuo-Ran Huang

Pakistan

Faisal Munir Bhutta

Nimra Farooq

M. Ali Paracha

Ying Li

Reinvestigating the semileptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup><mi>τ</mi><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub></math> decays in the model independent scenarios and leptoquark models

We discuss the low-energy properties of binary superfluids with density-dependent interactions. Adding an intraspecies coupling that induces an explicit soft symmetry breaking, we determine the background pressure, and we show that the low-energy spectrum consists of a massless Nambu-Goldstone boson and a massive (pseudo) Nambu-Goldstone boson. When the background velocities of the two superfluids are transonic, the system is characterized by two distinct acoustic horizons: the hydrodynamic analog of the black hole event horizon. The Hawking-like emission occurring at these horizons produces an effective friction on the fluids. We compute the viscosity-to-entropy ratios close to the two acoustic horizons, finding that the emission of pseudo Nambu-Goldstone bosons violates the bound conjectured by Kovtun, Son, and Starinet.

Italy

Silvia Trabucco

Luca Lepori

Maria Luisa Chiofalo

Massimo Mannarelli

Binary superfluids: Low-energy properties and dissipative processes from spontaneous emission of massive phonons

We study the time evolution governed by the two-sided chord Hamiltonian in the double-scaled SYK model, which induces a probability distribution over operators in the double-scaled algebra. Through the bulk-to-boundary map, this distribution translates into dynamical profiles of bulk states within the chord Hilbert space. We derive analytic expressions for such profiles, valid across a broad parameter range and all time scales. Additionally, we demonstrate how distinct semi-classical behaviors emerge by localizing within specific energy regions in the semi-classical limit. We revisit the doubled Hilbert space formalism as an isometric map between the one-particle sector of the chord Hilbert space and the doubled zero-particle sector. Utilizing this map, we obtain analytic results for correlation functions and investigate the dynamical evolution for chord operators. Specifically, we establish an equivalence between the chord number generating function in presence of matter chords and the crossed four-point correlation function, the latter is closely related to the 6$\textit{j}$-symbol of $$ {U}_{\sqrt{q}}\left(\mathfrak{su}\left(1,1\right)\right) $$ . We also explore finite-temperature effects, showing that operator spreading slows as temperature decreases. In the semi-classical limit, we perform a saddle point analysis and incorporate the one-loop determinant to derive the normalized time-ordered four-point correlation function at infinite temperature. The leading correction reproduces the 1/$\textit{N}$ connected contribution observed in the large-$\textit{p}$ SYK model. Finally, we examine the time evolution of total chord number in presence of matter in the triple-scaled regime, linking it to the renormalized two-sided length in JT gravity with matter.

United States

Jiuci Xu

On chord dynamics and complexity growth in double-scaled SYK

We perform a detailed study of the current phenomenological status of baryon number violating operators within the framework of the $\textit{R}$-parity violating Minimal Supersymmetric Standard Model (RPV-MSSM). This study aims to identify any gaps in the experimental coverage of the RPV landscape. We identify the unique final states for all possible LSPs decaying via four different benchmark UDD operators. Both the direct production of the LSP and its production via gauge-cascades are considered. For each LSP, we assume that only one UDD coupling is non-zero at a time and confront the signals with existing ATLAS and CMS searches implemented in the recasting framework CheckMATE 2. We find that the UDD colored LSP sector is well covered with the mass bounds on the gluino LSP being the strongest, and with possible improvements for some of the right-handed squark LSPs. We also point out that there is limited coverage for electroweakino and slepton LSPs with UDD decays. This limitation may be due to the lack of targeted experimental searches for these specific final states or the appropriate recasting of existing searches.

Germany

Herbi Dreiner

Michael Hank

Sweden

Yong Koay

Martin Schürmann

Rhitaja Sengupta

Apoorva Shah

Nadja Strobbe

Evelyn Thomson

The ABC of RPV. Part II. Classification of R-parity violating signatures from UDD couplings and their coverage at the LHC

A large primordial lepton asymmetry can lead to successful baryogenesis by preventing the restoration of electroweak symmetry at high temperatures, thereby suppressing the sphaleron rate. This asymmetry can also lead to a first-order cosmic QCD transition, accompanied by detectable gravitational wave (GW) signals. By employing next-to-leading order dimensional reduction we determine that the necessary lepton asymmetry is approximately one order of magnitude smaller than previously estimated. Incorporating an updated QCD equation of state that harmonizes lattice and functional QCD outcomes, we pinpoint the range of lepton flavor asymmetries capable of inducing a first-order cosmic QCD transition. To maintain consistency with observational constraints from the Cosmic Microwave Background and Big Bang Nucleosynthesis, achieving the correct baryon asymmetry requires entropy dilution by approximately a factor of ten. However, the first-order QCD transition itself can occur independently of entropy dilution. We propose that the sphaleron freeze-in mechanism can be investigated through forthcoming GW experiments such as $\textit{μ}$Ares.

Fei Gao

Julia Harz

Spain

Chandan Hati

Yi Lu

Isabel Oldengott

United Kingdom

Graham White

Baryogenesis and first-order QCD transition with gravitational waves from a large lepton asymmetry

We study the Borel plane of the topological string free energy on all hypergeometric one-parameter Calabi-Yau models close to singular points in moduli space, focusing on the location of Borel singularities and the value of the associated Stokes constants. We find in particular that in models which exhibit massless D-branes at a singular point, the central charge of the D-brane close to the singular point coincides with the location of the leading Borel singularity, and the generalized Donaldson-Thomas invariant associated to the charge of the D-brane, in as far as its value is known, coincides with the Stokes constant associated to the Borel singularity.

France

Simon Douaud

Amir-Kian Kashani-Poor

Borel singularities and Stokes constants of the topological string free energy on one-parameter Calabi-Yau threefolds

We perform a model-independent measurement of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>D</mi></mrow><mrow><mn>0</mn></mrow></msup><mtext>−</mtext><msup><mrow><mover accent="true"><mrow><mi>D</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mn>0</mn></mrow></msup></mrow></math> mixing parameters using samples of <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></math> -collision data collected by the Belle and Belle II experiments that have integrated luminosities of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>951</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>408</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, respectively. Approximately <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.05</mn><mo>×</mo><msup><mn>10</mn><mn>6</mn></msup></math> neutral <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math> mesons are reconstructed in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi mathvariant="normal">S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></math> channel, with the neutral <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math> flavor tagged by the charge of the pion in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mrow><mo>*</mo><mo>+</mo></mrow></msup><mo stretchy="false">→</mo><msup><mi>D</mi><mn>0</mn></msup><msup><mi>π</mi><mo>+</mo></msup></math> decay. Assuming charge-parity symmetry, the mixing parameters are measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>x</mi><mo>=</mo><mo stretchy="false">(</mo><mn>4.0</mn><mo>±</mo><mn>1.7</mn><mo>±</mo><mn>0.4</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>y</mi><mo>=</mo><mo stretchy="false">(</mo><mn>2.9</mn><mo>±</mo><mn>1.4</mn><mo>±</mo><mn>0.3</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math>, where the first uncertainties are statistical and the second systematic. The results are consistent with previous determinations.

I. Adachi

L. Aggarwal

H. Ahmed

H. Aihara

N. Akopov

A. Aloisio

N. Althubiti

N. Anh Ky

D.M. Asner

H. Atmacan

V. Aushev

M. Aversano

R. Ayad

N.K. Baghel

P. Bambade

Sw. Banerjee

S. Bansal

M. Barrett

M. Bartl

J. Baudot

A. Beaubien

J. Becker

J.V. Bennett

V. Bertacchi

M. Bertemes

E. Bertholet

M. Bessner

S. Bettarini

B. Bhuyan

D. Biswas

D. Bodrov

A. Bolz

A. Bondar

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

P. Chang

R. Cheaib

P. Cheema

B.G. Cheon

K. Chilikin

K. Chirapatpimol

H.E. Cho

K. Cho

S.J. Cho

S.K. Choi

S. Choudhury

J. Cochran

L. Corona

J.X. Cui

S. Das

E. De La Cruz-Burelo

S.A. De La Motte

G. De Pietro

R. de Sangro

M. Destefanis

A. Di Canto

F. Di Capua

J. Dingfelder

Z. Doležal

T.V. Dong

M. Dorigo

D. Dossett

G. Dujany

P. Ecker

D. Epifanov

J. Eppelt

P. Feichtinger

T. Ferber

T. Fillinger

C. Finck

G. Finocchiaro

A. Fodor

F. Forti

B.G. Fulsom

A. Gabrielli

E. Ganiev

M. Garcia-Hernandez

R. Garg

G. Gaudino

V. Gaur

A. Gaz

A. Gellrich

G. Ghevondyan

D. Ghosh

H. Ghumaryan

G. Giakoustidis

R. Giordano

A. Giri

P. Gironella Gironell

A. Glazov

Model-independent measurement of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mtext>−</mtext><msup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup></math> mixing parameters in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></math> decays at Belle and Belle II