Song, J., Liang, W. H., Xiao, C. W., Dias, J. M., & Oset, E. (2024). Testing the molecular nature of the Ω (2012) with the ψ (3770) → (Ω)over-bar(K)over-barΞ and ψ (3770) → (Ω)over-bar(K)over-barΞ* (1530) ((Ω)over-bar(K)over-barπΞ) reactions. Eur. Phys. J. C, 84(12), 1311–7pp.
Abstract: We report on the reactions psi(3770) -> (Omega) over bar+(K) over bar Xi and psi(3770) -> (Omega) over bar (+)(K) over bar Xi*(1530) (Xi* (1530) -> pi Xi), and calculate the mass distributions d Gamma/dM(inv)((K) over bar Xi) and d Gamma/dM(inv)(K Xi*), respectively. We obtain clear peaks corresponding to the Omega(2012). From the decay of psi(3770) -> (Omega) over bar (+)(K) over bar Xi*, we also get a second, broader, peak around 2035MeV, which comes from the Omega(2012) decay to (K) over bar Xi*. This second peak is closely tied to the molecular picture of the Omega(2012) with the (K) over bar Xi* (1530) and eta Omega components. Its observation would provide a boost to the molecular picture of the Omega (2012).
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Song, J., Yang, Z. Y., & Oset, E. (2025). Searching for signals of an exotic I=1,JP=2+ state of D*K* nature and the structure of the Pc(4312) in the Λb→Σc plus plus D-K- reaction. Phys. Lett. B, 861, 139294–7pp.
Abstract: This paper investigates the decay process Lambda-Sigma++-- with the objective of finding a predicted molecular state with isospin = 1, = 2+ of nature, plus finding support for the (4312) state as made out of Sigma. The mass distribution of the -- system shows distinct features as a consequence of the existence of this 2+ state, while the Sigma distribution exhibits a significant peak near the threshold, much bigger than phase space expectations, which is linked to our assumed Sigma nature of the (4312) state below the Sigma threshold. The reaction has been measured at LHCb Collaboration, but only the branching ratio is measured. The present study shows that much valuable information can be obtained about the predicted 2+ (2834) of nature and the (4312) states from the measurements of the mass distributions in this reaction, which will be accessible in the planned updates of LHCb.
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Song, J., Yang, Z. Y., & Oset, E. (2025). Searching for the 2+partner of the Tcs0(2870) in the B- -> D- D0 K0S reaction. Phys. Rev. D, 111(9), 094004–7pp.
Abstract: We study the B- -> D- D0 K0S reaction, recently analyzed by the LHCb Collaboration, where a clear signal for the exotic Tcs0(2870) state was reported. We call attention to a small peak in the D0K0S mass distribution that could correspond to a state of the same nature as the Tcs0(2870) (D*K<overline>* nature in the molecular picture), but with JP = 2+. In order to magnify the signal for the state, we calculate the moments of the angle-mass distribution, which are linear in the resonance signal, rather than quadratic for the angle integrated mass distribution. We find spectra for the moments with a strength far bigger than that for the angle integrated mass distribution, which should encourage the evaluation of these moments from the present measurements of the reaction.
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Song, J., Yang, Z. Y., & Oset, E. (2025). Role of a0(1710) in the Ds plus -> ρ plus φ;ρ plus ω decays. Phys. Rev. D, 111(9), 094047–7pp.
Abstract: We look into the D+s-* rho+phi and D+s-* rho+omega weak decays recently measured by the BESIII collaboration, which proceed very differently in a first step of the weak decay. While the first reaction proceeds directly via external emission, the second one does not go via external nor internal emission, what prompted the experimental team to claim that it proceeds via W-annihilation. We show in this work that the unexpectedly large rate of the D+s-* rho+omega has a different explanation since is it naturally obtained once final state interaction of the rho+phi; rho+omega and K*+K*0 channels is taken into consideration. The interaction of these channels produces the a0(1710) resonance, predicted long ago as a molecular state of these coupled channels, and only recently observed, and it is the presence of this resonance what makes the effect of the final state interaction very important in the weak decays and provides a natural explanation of the experimental decay rates at a quantitative level. We also take into account the D+s-* rho+omega decay in P-and D-waves empirically, and show that a good reproduction of the experimental results is obtained in this case.
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Solevi, P., Muñoz, E., Solaz, C., Trovato, M., Dendooven, P., Gillam, J. E., et al. (2016). Performance of MACACO Compton telescope for ion-beam therapy monitoring: first test with proton beams. Phys. Med. Biol., 61(14), 5149–5165.
Abstract: In order to exploit the advantages of ion-beam therapy in a clinical setting, delivery verification techniques are necessary to detect deviations from the planned treatment. Efforts are currently oriented towards the development of devices for real-time range monitoring. Among the different detector concepts proposed, Compton cameras are employed to detect prompt gammas and represent a valid candidate for real-time range verification. We present the first on-beam test of MACACO, a Compton telescope (multi-layer Compton camera) based on lanthanum bromide crystals and silicon photo-multipliers. The Compton telescope was first characterized through measurements and Monte Carlo simulations. The detector linearity was measured employing Na-22 and Am-Be sources, obtaining about 10% deviation from linearity at 3.44 MeV. A spectral image reconstruction algorithm was tested on synthetic data. Point-like sources emitting gamma rays with energy between 2 and 7 MeV were reconstructed with 3-5 mm resolution. The two-layer Compton telescope was employed to measure radiation emitted from a beam of 150 MeV protons impinging on a cylindrical PMMA target. Bragg-peak shifts were achieved via adjustment of the PMMA target location and the resulting measurements used during image reconstruction. Reconstructed Bragg peak profiles proved sufficient to observe peak-location differences within 10 mm demonstrating the potential of the MACACO Compton Telescope as a monitoring device for ion-beam therapy.
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