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1. JUNO sensitivity to invisible decay modes of neutrons

   https://doi.org/10.1140/epjc/s10052-024-13638-0  

   Abusleme, Angel; Adam, Thomas; Adamowicz, Kai; Ahmad, Shakeel; Ahmed, Rizwan; Aiello, Sebastiano; An, Fengpeng; An, Qi; Andronico, Giuseppe; Anfimov, Nikolay; et al (January 2025, The European Physical Journal C)

   Abstract We explore the decay of bound neutrons in the JUNO liquid scintillator detector into invisible particles (e.g.,$$n\rightarrow 3 \nu $$ $n\to 3\nu$ or$$nn \rightarrow 2 \nu $$ $nn\to 2\nu$ ), which do not produce an observable signal. The invisible decay includes two decay modes:$$ n \rightarrow { inv} $$ $n\to \mathrm{inv}$ and$$ nn \rightarrow { inv} $$ $nn\to \mathrm{inv}$ . The invisible decays ofs-shell neutrons in$$^{12}\textrm{C}$$ $_{}^{12}\text{C}$ will leave a highly excited residual nucleus. Subsequently, some de-excitation modes of the excited residual nuclei can produce a time- and space-correlated triple coincidence signal in the JUNO detector. Based on a full Monte Carlo simulation informed with the latest available data, we estimate all backgrounds, including inverse beta decay events of the reactor antineutrino$${\bar{\nu }}_e$$ ${\overline{\nu }}_e$ , natural radioactivity, cosmogenic isotopes and neutral current interactions of atmospheric neutrinos. Pulse shape discrimination and multivariate analysis techniques are employed to further suppress backgrounds. With two years of exposure, JUNO is expected to give an order of magnitude improvement compared to the current best limits. After 10 years of data taking, the JUNO expected sensitivities at a 90% confidence level are$$\tau /B( n \rightarrow { inv} ) > 5.0 \times 10^{31} \, \textrm{years}$$ $\tau /B(n\to \mathrm{inv})>5.0\times {10}^{31}\text{years}$ and$$\tau /B( nn \rightarrow { inv} ) > 1.4 \times 10^{32} \, \textrm{years}$$ $\tau /B(nn\to \mathrm{inv})>1.4\times {10}^{32}\text{years}$ . 

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2. Simulation of the background from ¹³C(α,n)¹⁶O reaction in the JUNO scintillator

   https://doi.org/10.1140/epjc/s10052-025-14333-4  

   Adam, Thomas; Adamowicz, Kai; Ahmad, Shakeel; Ahmed, Rizwan; Aiello, Sebastiano; An, Fengpeng; Andreopoulos, Costas; Andronico, Giuseppe; Anfimov, Nikolay; Antonelli, Vito; et al (September 2025, The European Physical Journal C)

   Abstract Large-scale organic liquid scintillator detectors are highly efficient in the detection of MeV-scale electron antineutrinos. These signal events can be detected through inverse beta decay on protons, which produce a positron accompanied by a neutron. A noteworthy background for antineutrinos coming from nuclear power reactors and from the depths of the Earth (geoneutrinos) is generated by ($$\alpha ,\,n$$ $\alpha ,n$ ) reactions. In organic liquid scintillator detectors,$$\alpha $$ $\alpha$ particles emitted from intrinsic contaminants such as$$^{238}$$ $_{}^{238}$ U,$$^{232}$$ $_{}^{232}$ Th, and$$^{210}$$ $_{}^{210}$ Pb/$$^{210}$$ $_{}^{210}$ Po, can be captured on$$^{13}$$ $_{}^{13}$ C nuclei, followed by the emission of a MeV-scale neutron. Three distinct interaction mechanisms can produce prompt energy depositions preceding the delayed neutron capture, leading to a pair of events correlated in space and time within the detector. Thus, ($$\alpha ,\,n$$ $\alpha ,n$ ) reactions represent an indistinguishable background in liquid scintillator-based antineutrino detectors, where their expected rate and energy spectrum are typically evaluated via Monte Carlo simulations. This work presents results from the open-source SaG4n software, used to calculate the expected energy depositions from the neutron and any associated de-excitation products. Also simulated is a detailed detector response to these interactions, using a dedicated Geant4-based simulation software from the JUNO experiment. An expected measurable$$^{13}$$ $_{}^{13}$ C$$(\alpha ,\,n)^{16}$$ ${(\alpha ,n)}^{16}$ O event rate and reconstructed prompt energy spectrum with associated uncertainties, are presented in the context of JUNO, however, the methods and results are applicable and relevant to other organic liquid scintillator neutrino detectors. 

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3. Sensitivity of the CUPID experiment to $$0\nu \beta \beta $$ decay of 100Mo

   https://doi.org/10.1140/epjc/s10052-026-15296-w  

   Alfonso, K; Armatol, A; Augier, C; Avignone, F T; Azzolini, O; Barabash, A S; Bari, G; Barresi, A; Baudin, D; Bellini, F; et al (June 2026, The European Physical Journal C)

   Abstract CUPID is a next-generation bolometric experiment to search for neutrinoless double-beta decay ($$0\nu \beta \beta $$ $0\nu \beta \beta$ ) of¹⁰⁰Mo using Li$$_2$$ $_2^{}$ MoO$$_4$$ $_4^{}$ scintillating crystals. It will operate 1596 crystals at$$\sim $$ $\sim$ 10 mK in the CUORE cryostat at the Laboratori Nazionali del Gran Sasso in Italy. Each crystal will be facing two Ge-based bolometric light detectors for$$\alpha $$ $\alpha$ rejection. We compute the discovery and the exclusion sensitivity of CUPID to$$0\nu \beta \beta $$ $0\nu \beta \beta$ in a Frequentist and a Bayesian framework. This computation is done numerically based on pseudo-experiments. For the CUPIDbaselinescenario, with a background and an energy resolution of$$1.0 \times 10^{-4}$$ $1.0\times {10}^{-4}$ counts/keV/kg/yr and 5 keV FWHM at the Q-value, respectively, this results in a Bayesian exclusion sensitivity (90% c.i.) of$$\hat{T}_{1/2} > 1.6 \times 10^{27} \ \textrm{yr}$$ ${\hat{T}}_{1/2}>1.6\times {10}^{27}\text{yr}$ , corresponding to the effective Majorana neutrino mass of$$\hat{m}_{\beta \beta } < \ 9.6$$ ${\hat{m}}_{\beta \beta }<9.6$ –$$28 \ \textrm{meV}$$ $28\text{meV}$ . The Frequentist discovery sensitivity (3$$\sigma $$ $\sigma$ ) is$$\hat{T}_{1/2}= 1.0 \times 10^{27} \ \textrm{yr}$$ ${\hat{T}}_{1/2}=1.0\times {10}^{27}\text{yr}$ , corresponding to$$\hat{m}_{\beta \beta }= \ 12$$ ${\hat{m}}_{\beta \beta }=12$ –$$36 \ \textrm{meV}$$ $36\text{meV}$ . 

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4. CUPID, the Cuore upgrade with particle identification

   https://doi.org/10.1140/epjc/s10052-025-14352-1  

   Alfonso, K; Armatol, A; Augier, C; Avignone_III, F T; Azzolini, O; Barabash, A S; Bari, G; Barresi, A; Baudin, D; Bellini, F; et al (July 2025, The European Physical Journal C)

   Abstract CUPID, the CUORE Upgrade with Particle Identification, is a next-generation experiment to search for neutrinoless double beta decay ($$0\mathrm {\nu \beta \beta }$$ $0\nu \beta \beta$ ) and other rare events using enriched Li$$_{2}$$ $_2^{}$ $$^{100}$$ $_{}^{100}$ MoO$$_{4}$$ $_4^{}$ scintillating bolometers. It will be hosted by the CUORE cryostat located at the Laboratori Nazionali del Gran Sasso in Italy. The main physics goal of CUPID is to search for$$0\mathrm {\nu \beta \beta }$$ $0\nu \beta \beta$ of$$^{100}$$ $_{}^{100}$ Mo with a discovery sensitivity covering the full neutrino mass regime in the inverted ordering scenario, as well as the portion of the normal ordering regime with lightest neutrino mass larger than 10 meV. With a conservative background index of 10$$^{-4}$$ $_{}^{-4}$  cts$$/($$ $/($ keV$$\cdot $$ $·$ kg$$\cdot $$ $·$ yr$$)$$ $)$ , 240 kg isotope mass, 5 keV FWHM energy resolution at 3 MeV and 10 live-years of data taking, CUPID will have a 90% C.L. half-life exclusion sensitivity of$$1.8\cdot 10^{27}$$ $1.8·{10}^{27}$  yr, corresponding to an effective Majorana neutrino mass ($$m_{\beta \beta }$$ $m_{\beta \beta }$ ) sensitivity of 9–15 meV, and a$$3\sigma $$ $3\sigma$ discovery sensitivity of$$1\cdot 10^{27}$$ $1·{10}^{27}$  yr, corresponding to an$$m_{\beta \beta }$$ $m_{\beta \beta }$ range of 12–21 meV. 

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5. $$\overline{\Sigma }^{\pm }$$ production in $$\text {pp}$$ and $$\text {p}{-}\text {Pb}$$ collisions at $$\sqrt{s_{\textrm{NN}}} = 5.02$$ TeV with ALICE

   https://doi.org/10.1140/epjc/s10052-025-15129-2  

   Abualrob, I J; Acharya, S; Aglieri_Rinella, G; Aglietta, L; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahuja, I; Akbar, ZUL; et al (February 2026, The European Physical Journal C)

   Abstract The transverse momentum spectra and integrated yields of anti-$$\Sigma $$ $\Sigma$ hyperons ($$\overline{\Sigma }^{\pm } $$ ${\overline{\Sigma }}^{\pm }$ ) have been measured in$$\text {pp}$$ $\text{pp}$ and$$\text {p}{-}\text {Pb}$$ $\text{p}-\text{Pb}$ collisions at$$\sqrt{s_{\textrm{NN}}}=5.02$$ $\sqrt{s_{\text{NN}}}=5.02$ TeV with the ALICE experiment. Measurements are performed via the newly accessed decay channel$$\overline{\Sigma }^{\pm } \!\!\rightarrow \mathrm{\overline{n}} \pi ^{\pm }$$ ${\overline{\Sigma }}^{\pm }\to \overline{n}{\pi }^{\pm }$ . A new method of antineutron reconstruction with the PHOS electromagnetic spectrometer is developed and applied to this analysis. The$$p_{\textrm{T}}$$ $p_{\text{T}}$ spectra of$$\overline{\Sigma }^{\pm } $$ ${\overline{\Sigma }}^{\pm }$ are measured in the range$$0.5 $0.5<p_{\text{T}}<3$ GeV/$$c$$ $c$ and compared to predictions of the PYTHIA 8, DPMJET, PHOJET, EPOS LHC and EPOS4 models. The EPOS LHC and EPOS4 models provide the best descriptions of the measured spectra both in$$\text {pp}$$ $\text{pp}$ and$$\text {p}{-}\text {Pb}$$ $\text{p}-\text{Pb}$ collisions, while models which do not account for multiparton interactions provide a considerably worse description at high$$p_{\textrm{T}}$$ $p_{\text{T}}$ . The total yields of$$\overline{\Sigma }^{\pm } $$ ${\overline{\Sigma }}^{\pm }$ in both$$\text {pp}$$ $\text{pp}$ and$$\text {p}{-}\text {Pb}$$ $\text{p}-\text{Pb}$ collisions are compared to predictions of the Thermal-FIST model and dynamical models PYTHIA 8, DPMJET, PHOJET, EPOS LHC and EPOS4. All models reproduce the total yields in both colliding systems within uncertainties. The nuclear modification factors$$R_\textrm{pPb}$$ $R_{\text{pPb}}$ for both$$\overline{\Sigma }^{+} $$ ${\overline{\Sigma }}^{+}$ and$$\overline{\Sigma }^{-} $$ ${\overline{\Sigma }}^{-}$ are evaluated and compared to those of protons,$$\Lambda $$ $\Lambda$ and$$\Xi $$ $\Xi$ hyperons, and predictions of EPOS LHC and EPOS4 models. No deviations of$$R_\textrm{pPb}$$ $R_{\text{pPb}}$ for$$\overline{\Sigma }^{\pm } $$ ${\overline{\Sigma }}^{\pm }$ from the model predictions or measurements for other hadrons are found within uncertainties. 

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