
Abreu, L. M., Dai, L. R., & Oset, E. (2023). J/Psi decay to omega, phi, K*0 plus f0(1370), f0(1710), K0*(1430), f2(1270), f'2 (1525) and K2*(1430): Role of the Dwave for tensor production. Phys. Lett. B, 843, 137999–10pp.
Abstract: We reassess the decay of the J/Psi into an omega, phi, K*0 and one of the f0(1370), f0(1710), f2(1270), f'2 (1525), K0*(1430) and K2*(1430) resonances. We benefit from previous works that considered this reaction as a J/Psi decay into three vector mesons, with a scalar or tensor resonance being formed from the interaction of two of these vectors. The novelty here with respect to former studies is the investigation of the relation between the scalar meson and tensor productions for the first time. To this end, the spin structure of the four vectors present in the production vertex is analyzed, and the Dwave mechanism in the tensor production is included. Then, beyond the ratios studied previously involving scalar states and tensor states independently, new ratios relating the scalar and tensor meson productions are estimated. Our results suggest that the Dwave mechanism of tensor production assumes a relevant contribution. New experimental data reporting the angular distributions of these processes will be important for checking this conclusion.



Aceti, F., Xie, J. J., & Oset, E. (2015). The K(K)overbar pi decay of the f(1) (1285) and its nature as a K*(K)overbar – cc molecule. Phys. Lett. B, 750, 609–614.
Abstract: We investigate the decay of f(1) (1285) > pi K (K) over bar with the assumption that the f(1) (1285) is dynamically generated from the K*(K) over bar – cc interaction. In addition to the tree level diagrams that proceed via f(1)(1285) > K*(K) over bar – cc > pi K (K) over bar, we take into account also the final state interactions of K (K) over bar > K (K) over bar and pi K > pi K. The partial decay width and mass distributions of f(1) (1285) > pi K (K) over bar are evaluated. We get a value for the partial decay width which, within errors, is in fair agreement with the experimental result. The contribution from the tree level diagrams is dominant, but the final state interactions have effects in the mass distributions. The predicted mass distributions are significantly different from phase space and tied to the K*(K) over bar – cc nature of the f(1) (1285) state.



Addazi, A., Marciano, A., Morais, A. P., Pasechnik, R., Srivastava, R., & Valle, J. W. F. (2020). Gravitational footprints of massive neutrinos and lepton number breaking. Phys. Lett. B, 807, 135577–8pp.
Abstract: We investigate the production of primordial Gravitational Waves (GWs) arising from First Order Phase Transitions (FOPTs) associated to neutrino mass generation in the context of typeI and inverse seesaw schemes. We examine both “highscale” as well as “lowscale” variants, with either explicit or spontaneously broken lepton number symmetry U(1)(L), in the neutrino sector. In the latter case, a pseudoGoldstone majoronlike boson may provide a candidate for cosmological dark matter. We find that schemes with softlybroken U(1)(L), and with single Higgsdoublet scalar sector lead to either no FOPTs or too weak FOPTs, precluding the detestability of GWs in present or near future measurements. Nevertheless, we found that, in the majoronlike seesaw scheme with spontaneously broken U(1)(L), at finite temperatures, one can have strong FOPTs and nontrivial primordial GW spectra which can fall well within the frequency and amplitude sensitivity of upcoming experiments, including LISA, BBO and uDECIGO. However, GWs observability clashes with invisible Higgs decay constraints from the LHC. A simple and consistent fix is to assume the majoronlike mass to lie above the Higgsdecay kinematical threshold. We also found that the majoronlike variant of the lowscale seesaw mechanism implies a different GW spectrum than the one expected in the highscale seesaw. This feature will be testable in future experiments. Our analysis shows that GWs can provide a new and complementary portal to test the neutrino mass generation mechanism.



Addazi, A., Valle, J. W. F., & VaqueraAraujo, C. A. (2016). String completion of an SU(3)(c) x SU(3)(L) x U(1)(X) electroweak model. Phys. Lett. B, 759, 471–478.
Abstract: The extended electroweak SU(3)(c) circle times SU(3)(L) circle times U(1)(X) symmetry framework “explaining” the number of fermion families is revisited. While 331based schemes can not easily be unified within the conventional field theory sense, we show how to do it within an approach based on Dbranes and (un)oriented open strings, on CalabiYau singularities. We show how the theory can be UVcompleted in a quiver setup, free of gauge and string anomalies. Lepton and baryon numbers are perturbatively conserved, so neutrinos are Diractype, and their lightness results from a novel TeV scale seesaw mechanism. Dynamical violation of baryon number by exotic instantons could induce neutronantineutron oscillations, with proton decay and other dangerous Rparity violating processes strictly forbidden. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.



AGATA Collaboration(Avigo, R. et al), DomingoPardo, C., Gadea, A., & Gonzalez, V. (2020). Lowlying electric dipole gammacontinuum for the unstable Fe62(,)64 nuclei: Strength evolution with neutron number. Phys. Lett. B, 811, 135951–6pp.
Abstract: The gammaray emission from the nuclei Fe62,Fe64 following Coulomb excitation at bombarding energy of 400440 AMeV was measured with special focus on E1 transitions in the energy region 48 MeV. The unstable neutronrich nuclei Fe62,Fe64 were produced at the FAIRGSI laboratories and selected with the FRS spectrometer. The gamma decay was detected with AGATA. From the measured gammaray spectra the summed E1 strength is extracted and compared to microscopic quasiparticle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1() states (threephonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy.



AGATA Collaboration(Pellegri, L. et al), & Gadea, A. (2014). Pygmy dipole resonance in Sn124 populated by inelastic scattering of O17. Phys. Lett. B, 738, 519–523.
Abstract: The gamma decay from the highlying states of Sn124 was measured using the inelastic scattering of O17 at 340 MeV. The emitted gamma rays were detected with high resolution with the AGATA demonstrator array and the scattered ions were detected in two segmented Delta EE silicon telescopes. The angular distribution was measured both for the gamma rays and the scattered O17 ions. An accumulation of E1 strength below the particle threshold was found and compared with previous data obtained with (gamma,gamma') and (alpha,alpha'gamma) reactions. The present results of elastic scattering, and excitation of E2 and E1 states were analysed using the DWBA approach. From this comprehensive description the isoscalar component of the 1excited states was extracted. The obtained values are based on the comparison of the data with DWBA calculations including a form factor deduced using a microscopic transition density.



AGATA Collaboration(Siciliano, M. et al), Gadea, A., PerezVidal, R. M., & DomingoPardo, C. (2020). Pairingquadrupole interplay in the neutrondeficient tin nuclei: First lifetime measurements of lowlying states in Sn106,Sn108. Phys. Lett. B, 806, 135474–7pp.
Abstract: The lifetimes of the lowlying excited states 2(+) and 4(+) have been directly measured in the neutrondeficient Sn106,Sn108 isotopes. The nuclei were populated via a deepinelastic reaction and the lifetime measurement was performed employing a differential plunger device. The emitted gamma rays were detected by the AGATA array, while the reaction products were uniquely identified by the VAMOS++ magnetic spectrometer. LargeScale ShellModel calculations with realistic forces indicate that, independently of the pairing content of the interaction, the quadrupole force is dominant in the B(E2; 2(1)(+) > 0(g.s)(+)) values and it describes well the experimental pattern for Sn104114 ; the B(E2;(+)(4) > 2(1)(+)) values, measured here for the first time, depend critically on a delicate pairingquadrupole balance, disclosed by the very precise results in Sn108.



Aguilar, A. C., Brito, N., Ferreira, M. N., Papavassiliou, J., Oliveira, O., & Silva, P. J. (2024). Lattice determination of the BatalinVilkovisky function and the strong running interaction. Phys. Lett. B, 858, 139054–8pp.
Abstract: The BatalinVilkovisky function is a central component in the modern formulation of the background field method and the physical applications derived from it. In the present work we report on novel lattice results for this particular quantity, obtained by capitalizing on its equality with the KugoOjima function in the Landau gauge. The results of the lattice simulation are in very good agreement with the predictions derived from a continuum analysis based on the corresponding SchwingerDyson equations. In addition, we show that an important relation connecting this function with the ghost propagator is fulfilled rather accurately. With the aid of these results, we carry out the first completely latticebased determination of the processindependent strong running interaction, employed in a variety of phenomenological studies.



Aguilar, A. C., De Soto, F., Ferreira, M. N., Papavassiliou, J., PintoGomez, F., Roberts, C. D., et al. (2023). Schwinger mechanism for gluons from lattice QCD. Phys. Lett. B, 841, 137906–8pp.
Abstract: Continuum and lattice analyses have revealed the existence of a massscale in the gluon twopoint Schwinger function. It has long been conjectured that this expresses the action of a Schwinger mechanism for gauge boson mass generation in quantum chromodynamics (QCD). For such to be true, it is necessary and sufficient that a dynamicallygenerated, massless, colourcarrying, scalar gluon+gluon correlation emerges as a feature of the dressed threegluon vertex. Working with results on elementary Schwinger functions obtained via the numerical simulation of latticeregularised QCD, we establish with an extremely high level of confidence that just such a feature appears; hence, confirm the conjectured origin of the gluon mass scale.



Aguilar, A. C., De Soto, F., Ferreira, M. N., Papavassiliou, J., PintoGomez, F., RodríguezQuintero, J., et al. (2024). Nonperturbative fourgluon vertex in soft kinematics. Phys. Lett. B, 858, 139065–7pp.
Abstract: We present a nonperturbative study of the form factor associated with the projection of the full fourgluon vertex on its classical tensor, for a set of kinematics with one vanishing and three arbitrary external momenta. The treatment is based on the SchwingerDyson equation governing this vertex, and a largevolume lattice simulation, involving ten thousand gauge field configurations. The key hypothesis employed in both approaches is the “planar degeneracy”, which classifies diverse configurations by means of a single variable, thus enabling their meaningful “averaging”. The results of both approaches show notable agreement, revealing a considerable suppression of the averaged form factor in the infrared. The deviations from the exact planar degeneracy are discussed in detail, and a supplementary variable is used to achieve a more accurate description. The effective charge defined through this special form factor is computed within both approaches, and the results obtained are in excellent agreement.

