In this paper we present the first measurement of a Gallium Arsenide (GaAs) crystal as a scintillating calorimeter with dual heat and light readout within the DAREDEVIL project. The experimental setup features a 4.3 g GaAs ( GaAs-1) crystal, operated at approximately 10 mK coupled with a Neutron Transmutation Doped (NTD) thermal sensor for phonon detection and an auxiliary calorimeter for the detection of scintillation light. For the GaAs-1 crystal, a baseline resolution of 121 ± 2 eV has been achieved. While, with a 3.5 g GaAs (GaAs-2) crystal an even better baseline resolution of 44.5 ± 0.8 eV was achieved. Alpha and X-ray calibration sources were used to study the scintillation light response to different types of interacting radiation. The GaAs crystal exhibits a strong particle discrimination capability based on the emitted scintillation light, featuring a light yield (LY) of 0.9 ± 0.2 keV/MeV for $$\alpha $$ induced events and 0.07 ± 0.01 keV/MeV for $$\beta $$ / $$\gamma $$ events, both measured at 1 MeV. The unusual luminescence behavior, i.e. more light being produced under irradiation by $$\alpha $$ particles warrants further investigation, particularly due to its potential to enhance sensitivity to low-energy nuclear recoils from light dark matter scattering.

Italy

A. Melchiorre

D. Helis

A. Puiu

G. Benato

P. Carniti

I. Colantoni

A. Continenza

N. Marco

A. Ferella

C. Ferrari

F. Giannessi

C. Gotti

E. Monticone

S. Nagorny

France

E. Olivieri

L. Pagnanini

G. Pessina

C. Petrucci

S. Pirro

A. Prajapati

G. Profeta

M. Rajteri

P. Settembri

A. Shaikina

C. Tresca

D. Trotta

First measurement of GaAs as a scintillating calorimeter: achievements and prospects

We present a prescription for computing tree-level scattering amplitudes in 10D super-Yang-Mills (SYM) theory using the pure spinor worldline formalism. The pure spinor formalism has proven to be a powerful framework for studying supersymmetric field theories, providing manifestly covariant and BRST-invariant formulations of amplitudes. By incorporating the worldline approach, we construct a first-quantized representation of SYM amplitudes in 10D, where interactions are encoded through the insertion of vertex operators along the particle’s trajectory. We explicitly compute the N-point function, demonstrating an agreement with the $\textit{α}$ $\textit{→}$ 0 limit of open superstring amplitudes and confirming that the kinematic numerators satisfy the expected BRST relations. Our results establish the pure spinor worldline formalism as a tool for studying scattering amplitudes and suggest further applications to 11D supergravity.

Sweden

Brazil

Max Guillen

United States

Marcelo Santos

United Kingdom

Spain

Eggon Viana

The pure spinor superparticle and 10D super-Yang-Mills amplitudes

In the present work, we perform a combined analysis of the cross sections for $$e^+ e^- \rightarrow K^+ K^-$$ and $$e^+ e^- \rightarrow K_S^0 K_L^0$$ by including the interference between direct coupling process and resonance intermediate process. When setting the isospin factor as a free parameter, we can well reproduce the structures in the cross sections for $$e^+ e^- \rightarrow K^+ K^-$$ and $$e^+ e^- \rightarrow K_S^0 K_L^0,$$ however, the isospin factor deviates with the isospin symmetry conservation predicted value of one. By fixing the isospin factor to be one, we find the cross sections for $$e^+ e^-\rightarrow K^+ K^-$$ can be accurately fitted, while the same model parameters fail to adequately reproduce the observed cross section for the process $$e^+ e^- \rightarrow K_S^0 K_L^0,$$ which indicate that there should be contributions from other vector meson states, such as $$\rho (2150)$$ and $$\omega (2220).$$ The combined analysis with $$\phi (2170),$$ $$\omega (2220)$$ and $$\rho (2150)$$ indicate that the inclusion of $$\rho (2150)$$ can improve the descriptions of the cross sections for $$e^+ e^-\rightarrow K^+ K^-$$ and $$e^+ e^- \rightarrow K_S^0 K_L^0.$$

China

Dian-Yong Chen

Jing Liu

Yu Bai

Chun-Hua Liu

Wen-Biao Yan

Zhao-Xia Meng

A combined analysis of $\textit{Y}$(2240) in the $$e^+ e^- \rightarrow K^+ K^-$$ and $$e^+ e^- \rightarrow K_S^0 K_L^0$$ processes

In this paper, we utilize the maximum entropy prescription to determine a quantum state of a small collision system at the kinetic freeze-out. We derive expressions for multiplicity-selected particle momentum spectra and correlation functions by applying a fixed particle number constraint to this state. The results of our analysis can be useful for interpreting the multiplicity dependence of the particle momentum spectra and correlations in high-multiplicity <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> collision events at a fixed LHC energy.

Ukraine

S.V. Akkelin

Particle momentum spectra, correlations, and maximum entropy principle in high-multiplicity collision events

We study the chiral symmetry breaking effects of helical magnetic fields in a simple bottom up AdS/CFT model. We explore the instability of the chirally symmetric solution in the presence of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> field and see how it switches off as the wave vector of the helix, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>k</mi></math>, rises, resulting in a first order transition. At low energies the model averages over the helix and the magnetic field is not seen. We show that other sources of chiral symmetry breaking are not directly affected by the helical <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> field. We provide examples of both magnetic catalysis and inverse magnetic catalysis which switch off at large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>k</mi></math>.

Nick Evans

Wanxiang Fan

Chiral symmetry restoration for helical magnetic fields in holography

Motivated by the work of Longhi and Materassi, who constructed a realization of the (centerless) <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra for the massive Klein-Gordon field in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mo>+</mo><mn>1</mn></math> dimensions, we build a realization of the (centerless) massless <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra including superrotations. This realization depends only on the momenta in the light cone expressed in celestial coordinates without any reference to the Klein-Gordon field. The quadratic Casimir of the Lorentz algebra is written in terms of a second order differential operator and the volume form plays an essential role in this construction. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra in terms of vector fields shows its kinematical nature, like the Poincaré algebra. We also construct a dynamical realization of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> from the symplectic structure on the solutions of the massless four-dimensional Klein-Gordon field in terms of quadratic expressions of the Fourier modes and plane waves invariant under translations. Using the Mellin transform, we rewrite the Klein-Gordon field in terms of the boost invariant basis, and write down the corresponding <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> realization. We also provide the relation with spherical harmonics, linking our results with the solutions of Longhi-Materassi, which are in fact a subset of ours.

Carles Batlle

Roberto Casalbuoni

Daniele Dominici

José Figueroa-O’Farrill

Joaquim Gomis

Celestial kinematical interpretation for an extended <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra

We investigate thermal properties of a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> lattice gauge theory in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>+</mo><mn>1</mn></math> dimensions through real-time simulations. We extract the spectral functions directly coupling to the pseudoscalar and scalar mesons, demonstrating the thermal modifications of these states with increasing temperatures. Introducing the notion of energy-flow operators, we quantify the temporal buildup of correlations in the energy flows across the lattice. We demonstrate that energy-energy correlators fail to factorize to products of energy flows, both in the vacuum and at nonzero temperature, indicating the presence of nontrivial correlations in the quantum states. Our results constitute a first real-time ab initio study of bound-state thermal broadening and finite temperature energy-flow correlations in a gauge theory, providing a benchmark for future studies of hadronic matter under extreme conditions.

CERN

João Barata

David Frenklakh

Swagato Mukherjee

Thermal modifications of mesons and energy-energy correlators from real-time simulations of a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></mrow></math> lattice gauge theory

We propose and study a purely inelastic scalar dark matter model, where two real scalars-dark matter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>1</mn></msub></math> and its excited partner <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>2</mn></msub></math> interact with the Standard Model via a Higgs portal. After mass diagonalization, only inelastic couplings remain, allowing the model to evade stringent bounds from direct detection. We show that thermal (co)annihilation between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>1</mn></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>2</mn></msub></math> naturally yields the observed dark matter relic abundance. The same interaction structure can induce a strongly first-order phase transition in the early Universe, generating detectable gravitational waves in upcoming experiments. Meanwhile, the slight mass splitting between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>1</mn></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>2</mn></msub></math>, along with the heavy off shell mediator SM Higgs, leads to long-lived particle signatures of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>2</mn></msub></math> at the HL-LHC via the displaced muon-jets technique. We pinpoint a feasible parameter space where the correct relic abundance, observable gravitational waves, and collider signals can all be achieved concurrently, presenting a valuable chance to validate this scenario through a comprehensive examination encompassing cosmological, astrophysical, and collider investigations.

Jinhui Guo

Jia Liu

Chenhao Peng

Xiao-Ping Wang

Probing purely inelastic scalar dark matter across colliders and gravitational wave observatories

In the heavy quarkonium decay process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi><mo>=</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mo>,</mo><mi mathvariant="normal">ϒ</mi></math>), making a definite prediction including relativistic corrections has so far remained a significant challenge. In this work, we study this decay process by taking into account the relativistic corrections in the Bethe-Salpeter formalism, where the relativistic bound-state wave function of quarkonium is obtained by solving the Bethe-Salpeter equation under the covariant instantaneous ansatz. Through analytical calculation, we find that some polarized decay widths vanish due to the helicity selection rule, which suppresses the corresponding helicity amplitudes. Owing to helicity flip symmetry and phase space symmetry, the nonvanishing polarized decay widths are not all independent; they are related through a set of symmetry relations. Then we obtain the unpolarized decay width formula <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi><mo stretchy="false">)</mo><mo>=</mo><mfrac><mrow><mn>80</mn><mo stretchy="false">(</mo><msup><mi>π</mi><mn>2</mn></msup><mo stretchy="false">−</mo><mn>9</mn><mo stretchy="false">)</mo><msubsup><mi>α</mi><mi>s</mi><mn>3</mn></msubsup><msubsup><mi>N</mi><mi>V</mi><mn>2</mn></msubsup><msubsup><mi>β</mi><mi>V</mi><mn>3</mn></msubsup></mrow><mrow><mn>81</mn><msup><mi>π</mi><mrow><mn>9</mn><mo stretchy="false">/</mo><mn>2</mn></mrow></msup><mi>M</mi></mrow></mfrac><mo stretchy="false">(</mo><mn>1</mn><mo>−</mo><mi>κ</mi><mfrac><msubsup><mi>β</mi><mi>V</mi><mn>2</mn></msubsup><msup><mi>M</mi><mn>2</mn></msup></mfrac><mo stretchy="false">)</mo></math>, where the factor <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>κ</mi><mfrac><msubsup><mi>β</mi><mi>V</mi><mn>2</mn></msubsup><msup><mi>M</mi><mn>2</mn></msup></mfrac></math> arises from the relativistic corrections with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>κ</mi><mo>≡</mo><mfrac><mrow><mn>3</mn><mo stretchy="false">(</mo><mn>112</mn><mo stretchy="false">+</mo><mn>25</mn><msup><mi>π</mi><mn>2</mn></msup><mo stretchy="false">)</mo></mrow><mrow><mn>16</mn><mo stretchy="false">(</mo><msup><mi>π</mi><mn>2</mn></msup><mo stretchy="false">−</mo><mn>9</mn><mo stretchy="false">)</mo></mrow></mfrac></math>. Furthermore, including both relativistic and QCD radiative corrections within the factorization assumption, our predictions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">)</mo></math> agree well with their experimental data. As a crossing check, with the experimental value of the ratio <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>R</mi><mi>V</mi></msub><mo>=</mo><mfrac><mrow><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi><mo stretchy="false">)</mo></mrow><mrow><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><mi>V</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo stretchy="false">+</mo></msup><msup><mi>e</mi><mo stretchy="false">−</mo></msup><mo stretchy="false">)</mo></mrow></mfrac></math> and our result for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>R</mi><mi>V</mi></msub></math>, we extract <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>α</mi><mi>s</mi></msub><mo stretchy="false">(</mo><msub><mi>M</mi><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></msub><mo>/</mo><mn>2</mn><mo stretchy="false">)</mo><mo>=</mo><mn>0.31</mn></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>α</mi><mi>s</mi></msub><mo stretchy="false">(</mo><msub><mi>M</mi><mi mathvariant="normal">ϒ</mi></msub><mo>/</mo><mn>2</mn><mo stretchy="false">)</mo><mo>=</mo><mn>0.20</mn></math>, respectively.

Hong-Mei Jiang

Chao-Jie Fan

Jun-Kang He

Cui Kong

Heavy quarkonium decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi><mo stretchy="false">→</mo><mi>g</mi><mi>g</mi><mi>g</mi></math> with both relativistic and QCD radiative corrections

We analyze the vacuum fluctuations and the stress-energy tensor of a scalar field of mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>M</mi></math> in a conical spacetime, where the topological singularity at the apex requires boundary conditions for the field equation. The necessity of boundary conditions was established by Kay and Studer in the early 1990s, while for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>M</mi><mo>=</mo><mn>0</mn></math> stability is achieved only under Dirichlet boundary conditions, and for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>M</mi><mo>&gt;</mo><mi>q</mi></math> the field is stable and a localized mode emerges. This mode admits a natural interpretation as a covariant model of an extended particle detector, which allows us to investigate how such detectors modify the local vacuum structure. In this framework, the renormalized stress-energy tensor offers a natural way to quantify the influence of the detector on the surrounding spacetime.

João Paulo M. Pitelli

Ricardo A. Mosna

Victor H.M. Ramos

João C.A. Barata

Vacuum fluctuations and the renormalized stress-energy tensor on a cone with arbitrary boundary conditions