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

A loosely bound hadronic molecule produced by a relativistic heavy-ion collision has been described as a “snowball in hell” since it emerges from a hadron resonance gas whose temperature is orders of magnitude larger than the binding energy of the molecule. This remarkable phenomenon can be explained in terms of a novel thermodynamic variable called the “contact” that is conjugate to the binding momentum of the molecule. The production rate of the molecule can be expressed in terms of the contact density at the kinetic freeze-out of the hadron resonance gas. It approaches a nonzero limit as the binding energy goes to 0.

United States

Eric Braaten

Kevin Ingles

Justin Pickett

Explaining Snowball-in-Hell Phenomena in Heavy-Ion Collisions Using a Novel Thermodynamic Variable

In this work, we address the problem of longitudinal spin polarization of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="normal">Λ</mi></math> hyperons produced in relativistic heavy-ion collisions. We combine a relativistic kinetic-theory framework that includes spin degrees of freedom treated in a classical way with the freeze-out parametrization used in previous investigations. The use of the kinetic theory allows us to incorporate dissipative corrections (due to the thermal shear and gradients of thermal vorticity) into the Pauli-Lubanski vector that determines spin polarization and can be directly compared with the experimental data. As in earlier similar studies, it turns out that a successful description of data can only be achieved with additional assumptions—in our case, they involve the use of projected thermal vorticity and a suitably adjusted time for spin relaxation (<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>τ</mi><mi>s</mi></msub></math>). From our analysis, we find that <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>τ</mi><mi>s</mi></msub><mo>∼</mo><mn>5</mn></mrow><mspace width="4pt"></mspace><mrow><mi>fm</mi><mo>/</mo><mi>c</mi></mrow></math>, which is comparable with other estimates.

India

Soham Banerjee

Poland

Samapan Bhadury

Wojciech Florkowski

Amaresh Jaiswal

Radoslaw Ryblewski

Longitudinal spin polarization in a thermal model with dissipative corrections

We solve a system of massless fermions constrained to two space-time dimensions interacting via a $\textit{d}$ space-time dimensional Maxwell field. Through dimensional reduction to the defect and bosonization, the system maps to a massless scalar interacting with a nonlocal Maxwell field through a $\textit{Fϕ}$-coupling. The $\textit{d}$ = 2 dimensional case is the usual Schwinger model where the photon gets a mass. More generally, in 2 < $\textit{d}$ < 4 dimensions, the degrees of freedom map to a scalar which undergoes a renormalization group flow; in the ultraviolet, the scalar is free, while in the infrared it has scaling dimension (4 – $\textit{d}$)/2. The infrared is similar to the Wilson-Fisher fixed point, and the physically relevant case $\textit{d}$ = 4 becomes infrared trivial in the limit of infinite ultraviolet cut-off, consistent with earlier work on the triviality of conformal surface defects in Maxwell theory.

United Kingdom

Ludo Fraser-Taliente

Christopher Herzog

Abhay Shrestha

A nonlocal Schwinger model

We propose the possibility of discovering a light pseudoscalar particle $\textit{a}$, axion-like particle (ALP), interacting mainly with quarks using the electron and photon scattering reaction chain $\textit{e}$ + $\textit{Z}$ → $\textit{e}$ + $\textit{γ}$ + $\textit{Z}$; $\textit{γ}$ + $\textit{Z}$ → $\textit{a}$ + $\textit{Z}$ on nuclei in the NA64 experiment at the CERN SPS. We consider the mixing of ALP with light pseudoscalar mesons $\textit{P}$ = $\textit{π}$, $\textit{η}$, $\textit{η}$′ with taking into account of the ALP mass explicitly breaking the Peccei-Quinn symmetry. It could open invisible channels of ALP decaying into dark fermion matter by analogy with $\textit{P}$ mesons decays. New bounds on the coupling strengths of the ALP with quarks and of pseudoscalar mesons with dark fermions are obtained by using existing upper bounds on invisible decay modes of $\textit{P}$s including those recently derived by NA64. We also study a scenario when the $\textit{a}$ plays the role of a messenger in the communication between our world and the dark sector. New upper limits on axion couplings with quarks and its mixing parameters with $\textit{π}$, $\textit{η}$, $\textit{η}$′ mesons are established.

Russia

Sergei Gninenko

Dmitry Kirpichnikov

Nikolai Krasnikov

Chile

Sergey Kuleshov

Germany

Valery Lyubovitskij

Alexey Zhevlakov

Probing leptophobic dark sector with a pseudoscalar portal in the NA64 experiment at CERN

In this work, we expand the scope of the JETSCAPE framework to investigate the dependence of the jet nuclear modification factor, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>R</mi><mrow><mi>A</mi><mi>A</mi></mrow></msub></math>, on the jet radius parameter (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>R</mi></math>) for broader area jet cones, going all the way up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>R</mi><mo>=</mo><mn>1.0</mn></math>. This study presents a comprehensive analysis of high-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub></math> inclusive jets extending up to 1 TeV to probe the quark-gluon plasma medium at much shorter distance scales. It focuses on quenching effects observed in the quark-gluon plasma formed during Pb-Pb collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><msub><mi>s</mi><mrow><mi>NN</mi></mrow></msub></msqrt><mo>=</mo><mn>5.02</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, particularly for the most central (0%–10%) collisions. Jet-medium interactions represent a pivotal domain of both theoretical and experimental quark-gluon plasma studies, with various models offering different assumptions to describe these phenomena. To illustrate this modular approach, this work computes the nuclear modification factor for inclusive jets via coupling of the MATTER model (which simulates the high virtuality phase of the parton evolution) with the Linear Boltzmann Transport (LBT) model (which simulates the low virtuality phase of the parton evolution). Additionally, the two successful energy loss models; MARTINI and AdS/CFT are employed to characterize the jet suppression effectively within the JETSCAPE framework. The results are compared with the experimental data from the ATLAS and CMS detectors, covering jet transverse momentum (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub></math>) ranging from 100 GeV to 1 TeV for ATLAS and 300 GeV to 1 TeV for CMS. The predictions made by the JETSCAPE are consistent in the high <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub></math> range as well as for extreme jet cone sizes, showing deviation within 10%–25%. Our major focus is on calculating the double ratio (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mi>AA</mi></mrow><mrow><mi mathvariant="normal">R</mi></mrow></msubsup><mo>/</mo><msubsup><mrow><mi>R</mi></mrow><mrow><mi>AA</mi></mrow><mrow><mi mathvariant="normal">R</mi><mo>=</mo><mi>small</mi></mrow></msubsup></mrow></math>) as a function of jet-R and jet-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub></math>, where the experimental results align well with predictions from the JETSCAPE framework, which incorporates the multistage evolution of the parton shower and energy loss models.

Manaswini Priyadarshini

Om Shahi

Vaishnavi Sathe

Prabhakar Palni

Modular perspective to the jet suppression from a small to large radius in very high transverse momentum jets

We present a novel way to probe inelastic dark matter using cosmic-ray (CR) cooling in active galactic nuclei (AGNs). Dark matter (DM) in the vicinity of supermassive black holes may scatter off CRs, resulting in the rapid cooling of CRs for sufficiently large cross sections. This in turn can alter the high-energy neutrino and gamma-ray fluxes detected from these sources. We show that AGN cooling bounds obtained through the multimessenger data of NGC 1068 and TXS <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>0506</mn><mo>+</mo><mn>056</mn></mrow></math> allows us to reach unprecedently large mass splittings for inelastic DM (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≳</mo><mi>TeV</mi></math>), orders of magnitude larger than those probed by direct detection experiments and DM capture in neutron stars. Furthermore, we demonstrate that cooling bounds from AGNs can probe thermal light DM with small mass splittings. This provides novel and complementary constraints in parts of a parameter space accessible solely by colliders and beam-dump experiments.

Japan

R. Andrew Gustafson

Gonzalo Herrera

Mainak Mukhopadhyay

Kohta Murase

Ian M. Shoemaker

Cosmic-ray cooling in active galactic nuclei as a new probe of inelastic dark matter

We study the impact of the non-holomorphic (NH) soft supersymmetry-breaking terms <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi>T</mi></mrow><mrow><mn>33</mn></mrow><mrow><mo>′</mo><mi>D</mi></mrow></msubsup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>μ</mi><mo>′</mo></msup></math>, which introduce additional supersymmetry-breaking effects beyond the holomorphic structure of the superpotential, on the Higgs boson mass spectrum in the NH Minimal Supersymmetric Standard Model. The term <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>T</mi><mn>33</mn><mrow><mo>′</mo><mi>D</mi></mrow></msubsup></math> modifies the scalar bottom-quark mass matrix and Higgs couplings, while <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>μ</mi><mo>′</mo></msup></math> affects the mass matrices of charginos and neutralinos. In our analysis, we incorporate constraints from charge- and color-breaking minima where we find that a portion of the parameter space is excluded by these constraints. Focusing on the allowed parameter space, the NH contributions to the light <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">C</mi><mi mathvariant="script">P</mi></mrow></math>-even Higgs boson mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><mi>h</mi></msub></math> from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>μ</mi><mo>′</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>T</mi><mn>33</mn><mrow><mo>′</mo><mi>D</mi></mrow></msubsup></math> can reach up to 1.4 GeV and 90 MeV, respectively. For the heavy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">C</mi><mi mathvariant="script">P</mi></mrow></math>-even Higgs boson mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><mi>H</mi></msub></math> and the charged Higgs boson mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><msup><mi>H</mi><mo>±</mo></msup></msub></math>, these contributions can be substantially larger in certain regions of the parameter space, reaching up to 44 GeV for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><mi>H</mi></msub></math> and 42 GeV for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><msup><mi>H</mi><mo>±</mo></msup></msub></math> due to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>μ</mi><mo>′</mo></msup></math> and up to 60 GeV due to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>T</mi><mn>33</mn><mrow><mo>′</mo><mi>D</mi></mrow></msubsup></math> for both <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><mi>H</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><msup><mi>H</mi><mo>±</mo></msup></msub></math>. These corrections are significantly larger than the expected future experimental precision for Higgs boson masses and should therefore be considered in precision analyses for future experiments.

Pakistan

M. Rehman

Spain

S. Heinemeyer

Toward a refined understanding of nonholomorphic soft SUSY-breaking effects on the Higgs boson mass spectra

The derivative expansion of the effective action is considered in the model with two interacting real scalar fields in curved spacetime. Using the functional approach and local momentum representation, the coefficient of the derivative term is calculated up to the first order in curvature in the one-scalar theory. The two-scalar problem is solved by extracting normal modes and consequent reduction to the single-scalar case. The method can be applied to a larger number of scalars. In the theory with strong hierarchy of masses, the renormalized effective potential and the coefficients of the second-order derivative terms demonstrate the quantum decoupling in the low-energy limit.

Brazil

Alícia G. Borges

Ilya L. Shapiro

Derivative expansion in a two-scalar field theory

We propose a method for probing CP-violation in the heavy (pseudo)scalar sector of an extended Higgs model, in which we make simultaneous use of the $\textit{HVV}$ ( $$V=W^\pm , Z$$ ) and $$Ht\bar{t}$$ interactions of a heavy Higgs state $\textit{H}$. The CP-even component of $\textit{H}$ can be probed through the tree-level $\textit{HVV}$ interaction, while the CP-odd component of $\textit{H}$ can be probed if the final $$t\bar{t}$$ pair can be tested to form a $$^1S_0$$ state. We can then confirm CP-violation if both CP-even and CP-odd components of $\textit{H}$ are discovered. This is possible at the Compact Linear Collider (CLIC) by exploiting $\textit{H}$ production from vector-boson fusion (VBF) and decay to $$t\bar{t}$$ pairs. We analyze the distribution of the azimuthal angle between the leptons coming from top and antitop quarks, which allows one to disentangle the CP nature of such a heavy Higgs state. We also show its implications for the two-Higgs-doublet model (2HDM) with CP-violation.