We studied the collider phenomenology of third-generation scalar leptoquarks at the Large Hadron Collider (LHC) with a 14 TeV center-of-mass energy. The analysis focuses on leptoquarks decaying exclusively into top quarks and tau leptons, employing machine learning-based tagging techniques for identifying hadronically decaying boosted top quarks, W/Z, and Higgs bosons, as well as a multivariate classifier to distinguish signal events from Standard Model (SM) backgrounds. The expected 95% confidence level (CL) upper limits on the leptoquark production cross-section are computed assuming integrated luminosities of 200 and 500 inverse femtobarns at the 14 TeV LHC. The results demonstrate significant sensitivity improvements for detecting leptoquarks at masses beyond the current experimental limits.

India

Debabrata Sahoo

Rameswar Sahu

Kirtiman Ghosh

A comprehensive search for leptoquarks decaying into top- <italic>&#964;</italic> final states at the future LHC

A two-decade-old puzzle in heavy-ion one-nucleon knockout reactions is the strong correlation between the reduction factor <math altimg='si1.svg'><mrow><msub><mi>R</mi><mi>s</mi></msub><mo linebreak='goodbreak'>=</mo><msub><mi>&#963;</mi><mi>exp</mi></msub><mo linebreak='goodbreak'>/</mo><msub><mi>&#963;</mi><mrow><mrow><mi mathvariant='normal'>t</mi></mrow><mi>h</mi></mrow></msub></mrow></math> and the Fermi surface asymmetry &#916; <italic>S</italic>. Theoretical cross sections typically rely on spectroscopic factors (SFs) from shell model (SM) calculations, which neglect continuum coupling effects. Here, we employ the Gamow shell model (GSM), which explicitly incorporates continuum coupling, to compute SFs for <italic>p</italic>-shell nuclei and predict corresponding theoretical cross sections. Systematic calculations demonstrate that using GSM-derived SFs substantially reduces discrepancies between theoretical and experimental results. This improvement is particularly significant for deeply bound nucleon knockout in nuclei near the dripline, where traditional SM-based calculations fall short. As a result, using GSM SFs, the ratio <italic>R<inf>s</inf></italic> exhibits no pronounced dependence on &#916; <italic>S</italic>. Furthermore, both the ratio of GSM SFs to SM SFs and their corresponding reaction cross sections ratios exhibit a strong &#916; <italic>S</italic> dependence. We have also compared GSM SFs and cross sections with those from the no-core shell model calculations, giving a similar pronounced sensitivity to &#916; <italic>S</italic>. Detailed analysis attributes these correlations to threshold effects for SFs in weakly bound systems. Overall, incorporating continuum coupling via GSM enhances the reliability of SF predictions for exotic, weakly bound nuclei and provides key insights toward resolving the enduring puzzle in heavy-ion knockout reactions from a nuclear structure perspective.

China

M.R. Xie

J.G. Li

United States

C.A. Bertulani

N. Michel

Y.Z. Sun

W. Zuo

How threshold effects in spectroscopic factors influence heavy-ion knockout reactions

We present an analysis of six differential cross-section measurements of top-quark pair production in the dilepton channel from the ATLAS and CMS experiments. The data are compared to state-of-the-art QCD predictions with and without the inclusion of toponium formation effects. This contribution is modelled via a re-weighting of fixed-order matrix elements using the Green’s function of the non-relativistic QCD Hamiltonian, and we employ a statistical model to quantify the preference of the data for the toponium hypothesis. All observables yield Bayes factors larger than unity, with two exceeding 20, yielding strong evidence for the toponium hypothesis in top-quark pair production at the LHC.

France

Benjamin Fuks

South Africa

Aminul Hossain

Ireland

James Keaveney

Statistical indications of toponium formation in top quark pair production

In this paper, we investigate the possibility of thermal equilibrium between Hawking radiation emitted by a RN-AdS black hole and dust like matter absorbing thermal energy surrounding it, called thermal dust, in the context of Rastall gravity with cosmological constant term. The energy density of thermal dust increases linearly with its temperature. Therefore, thermal dust represent the dust like matter that absorb thermal energy and gets heated up linearly with temperature. In the context of Rastall gravity, we derive the metric of RN-AdS black hole surrounded by thermal dust and it possesses the temperature term of the thermal dust. Hence, using this metric we can check if there exists thermal equilibrium between Hawking radiation emitted by a RN-AdS black hole and surrounding thermal dust by simply demanding the temperature of thermal dust equal to Hawking temperature. Then, we show that the entropy term become unphysical for positive Hawking temperature, when we demand this thermal equilibrium condition. Hence, we conclude that there cannot exist thermal equilibrium between Hawking radiation emitted by a RN-AdS black hole and its surrounding thermal dust background in the context of Rastall gravity.

Dhiman Kumar Kalita

Debojit Sarma

On the non existence of thermal equilibrium between Hawking radiation and thermal dust in the context of Rastall gravity

The coherent reaction, <italic>&#947;d</italic>&#8239;&#8594;&#8239; <italic>&#960;</italic> 0 <italic>&#951;d</italic> was studied with the BGOOD experiment at ELSA from threshold to a centre-of-mass energy of 3200 MeV for forward deuteron angles. A full kinematic reconstruction was made, with final state deuterons identified in the Forward Spectrometer and <italic>&#960;</italic> 0 and <italic>&#951;</italic> decays in the central BGO Rugby Ball. The strength of the differential cross section exceeds what can be described by phenomenological models of coherent photoproduction due to the large momentum transfer to the deuteron. The origin of this enhancement is unresolved, whether this is due, for example, to intermediate dibaryon formation or pion re-scattering terms. A toy model of quasi-free &#916; and <italic>N</italic>(1535) photoproduction with final state interactions is discussed, which gives a qualitative description of the differential cross section.

Germany

A.J. Clara Figueiredo

T.C. Jude

S. Alef

P.L. Cole

Italy

R. Di Salvo

D. Elsner

A. Fantini

O. Freyermuth

F. Frommberger

F. Ghio

J. Groß

K. Kohl

P. Levi Sandri

G. Mandaglio

P. Pedroni

B.E. Reitz

Ukraine

M. Romaniuk

G. Scheluchin

H. Schmieden

A. Sonnenschein

C. Tillmanns

Coherent <italic>&#960;</italic> 0 <italic>&#951;d</italic> photoproduction at forward deuteron angles measured at BGOOD

Given the current absence of new physics signals at the LHC, it is increasingly important to investigate alternative scenarios beyond those commonly explored. In this work, we study a variant of the 331 model that predicts the existence of vector bileptons with electric charge and lepton number ± 2, as well as TeV-scale exotic quarks carrying charges ± 5/3 and ± 4/3. Specifically, we focus on the primary production of heavy quarks with charge ± 5/3, which decay into a bottom quark and a bilepton, followed by the bilepton’s decay into same-sign muon pairs. As a case study, we select a benchmark point that complies with current experimental exclusion limits and theoretical expectations for the bilepton mass. Our analysis shows that the resulting signal stands out clearly from Standard Model backgrounds and could be observed at a future 100 TeV hadron collider such as FCC- <italic>hh</italic>. In contrast, the LHC, even in its high-luminosity phase, lacks the sensitivity required to detect this signal.

Gennaro Corcella

Claudio Corianò

Paul H. Frampton

Dario Melle

Heavy quark decays in the bilepton model

By employing Duan’s topological method, we can classify critical points based on their topological charge as <math altimg='si27.svg'><mrow><mi>Q</mi><mo linebreak='goodbreak'>=</mo><mo>&#177;</mo><mn>1</mn><mo>,</mo><mn>0</mn></mrow></math>. Previous work [Wei et al., PRD 105, 104,003 (2022)] investigate two typical anti-de Sitter (AdS) black hole: Reissner-Nordstr&#246;m (RN) case (with only one critical point <math altimg='si8.svg'><mrow><mi>Q</mi><mo linebreak='goodbreak'>=</mo><mo>&#8722;</mo><mn>1</mn></mrow></math>) and Born-Infeld (BI) case (with two critical points <math altimg='si28.svg'><mrow><mi>Q</mi><mo linebreak='goodbreak'>=</mo><mo>&#177;</mo><mn>1</mn></mrow></math>). In this work, we first find that all three types of critical points exhibit in quantum anomalous black holes for 4-D spacetime. We then compute the quasinormal modes of massless scalar perturbations near these critical points, and find that both oscillation frequency and damping rate increase with black hole radii at the critical temperature. Besides such common behavior, though the <math altimg='si29.svg'><mrow><mi>Q</mi><mo linebreak='goodbreak'>=</mo><mo>+</mo><mn>1</mn><mo>,</mo><mn>0</mn></mrow></math> cases do not have a discernible pattern due to few samples, the <math altimg='si8.svg'><mrow><mi>Q</mi><mo linebreak='goodbreak'>=</mo><mo>&#8722;</mo><mn>1</mn></mrow></math> case shows very similar dynamical characteristics across all three black hole solutions, which implies a non-trivial connection between topological thermodynamics and dynamics.

Yue Chu

Chen-Hao Wu

Ya-Peng Hu

Imprints of topological thermodynamics on black hole dynamics

Recently, the concept of quantum atmosphere has been introduced as a potential origin of Hawking quanta. This study investigates the properties of quantum fields by exploring the quantum coherence of a two-mode Gaussian state near a black hole, where Hawking quanta originate from the quantum atmosphere region. It is demonstrated that both physically accessible and inaccessible quantum coherence for continuous variable quantum states distinctly exhibit hallmark features of the quantum atmosphere. Specifically, the quantum coherence for these states varies continuously with changes in the normalized distance; it undergoes rapid decreases (or increases) just outside the event horizon before gradually stabilizing through subsequent increases (or decreases). This behavior contrasts with the behaviors of quantum coherence where originates solely from the black hole’s event horizon. The quantum features of the fields distinctly reflect characteristics attributable to the quantum atmosphere, thereby deepening our understanding of the origins of Hawking radiation. We also find that the continuous variable coherence is highly dependent on both the squeezing parameter and field frequency of the prepared state; therefore, appropriately adjusting these values can enhance our ability to detect features within the quantum atmosphere. It is noteworthy to observe that quantum features of fields do not entirely dissipate in the quantum atmosphere region, indicating that tasks related to quantum information processing can still be executed there.

Xiaofang Liu

Cuihong Wen

Jieci Wang

Quantum coherence of continuous variables in the black hole quantum atmosphere

We propose a novel quantum algorithm for solving nuclear resonances, which is based on the iterative Harrow-Hassidim-Lloyd algorithm and eigenvector continuation with complex scaling. To validate this approach, we compute the resonant states of <math altimg='si4.svg'><mrow><mi>&#945;</mi><mo linebreak='goodbreak'>&#8722;</mo><mi>&#945;</mi></mrow></math> system and achieve results in good agreement with traditional methods. Our study offers a new perspective on calculating eigenvalues of non-Hermitian operators and lays some groundwork for further exploration of nuclear resonances using quantum computing.

Hantao Zhang

Dong Bai

Zhongzhou Ren

Iterative Harrow-Hassidim-Lloyd quantum algorithm for solving resonances with eigenvector continuation

We construct and analyze charged and magnetized extensions of the axially symmetric exponential metric, that is known as the Curzon-Chazy spacetime (CCS) within the Weyl class. Working within the Einstein-Maxwell framework, we first derive an exact charged axially symmetric exponential metric by directly solving the coupled field equations for a dyonic monopole configuration. The solution is shown to reduce smoothly to the vacuum CCS in the neutral limit and to the extremal Reissner-Nordström spacetime in a special parameter regime. We then rederive the same charged geometry using the Harrison transformation in the Ernst formalism, establishing the equivalence between the direct and solution-generating approaches. Subsequently, we apply the magnetic Harrison transformation to obtain a Melvin-type magnetized deformation of the spacetime. Finally, by implementing the Ehlers transformation, we generate a stationary but nonrotating swirling geometry endowed with a nonvanishing NUT charge, which we identify invariantly via the Komar dual mass. A further magnetic Harrison transformation yields a magnetized swirling (NUT-type) spacetime. These results demonstrate how electric, magnetic, and gravitomagnetic charges arise systematically from the CCS through exact solution-generating techniques.

Türkiye

S. Habib Mazharimousavi

Charged axially symmetric exponential metric: Exact solutions to the Einstein-Maxwell equations