Abstract: In this paper we perform an amplitude analysis of eta ' -> pi(+)pi(-)gamma and confront it with the latest BESIII data. Based on the final-state interaction theorem, we represent the amplitude in terms of an Omnes function multiplied by a form factor that corresponds to the contributions from left-hand cuts and right-hand cuts in the inelastic channels. We also take into account the isospin violation effect induced by rho-omega mixing. Our results show that the anomaly contribution is mandatory in order to explain the data. Its contribution to the decay width of Gamma(eta ' -> pi pi gamma) is larger than that induced by isospin violation. Finally we extract the pole positions of the rho and omega as well as their corresponding residues.

Abstract: The decay of Lambda(+)(c) into pi(+)pi(0) Lambda(1405) with the Lambda(1405) decay into pi(0)Sigma(0) through a triangle diagram is studied. This process is initiated by Lambda(+)(c) -> pi(+) (K) over bar N-*, and then the (K) over bar (*) decays into (K) over bar (pi) and (K) over bar N produce the Lambda(1405) through a triangle loop containing (K) over bar N-* (K) over bar which develops a singularity around 1890 MeV. This process is prohibited by the isospin symmetry, but the decay into this channel is enhanced by the contribution of the triangle diagram, which is sensitive to the mass of the internal particles. We find a narrow peak in the pi(0)Sigma(0) invariant mass distribution, which originates from the (K) over bar amplitude, but is tied to the mass differences between the charged and neutral (K) over bar or N states. The observation of the unavoidable peak of the triangle singularity in the isospin- violating Lambda(1405) production would provide further support for the hadronic molecular picture of the Lambda(1405) and further information on the (K) over bar N interaction.

Abstract: We study the amplitudes of the -VP decay for the different polarizations of the vector meson V, using a formalism where the mapping from the quark degrees of freedom to the meson ones is done with the P-3(0) model. We extend the formalism to a case, with the operator -5, that can account for different models beyond the Standard Model and study in detail the -K*0K- reaction for the different polarizations of the K*0. The results are shown in terms of the parameter that differs for each model. We find that is very different for each of the third components of the vector spin, M=+/- 1,0, and in particular the magnitude |M=-1 is very sensitive to the parameter, which makes the investigation of this magnitude very useful to test different models beyond the Standard Model.

Abstract: We study discovery prospects for long-lived sterile neutrinos at the LHC with multitrack displaced vertices, with masses below the electroweak scale. We reinterpret current displaced vertex searches making use of publicly available, parametrized selection efficiencies for modeling the detector response to displaced vertices. We focus on the production of right-handed WR bosons and neutrinos N in a left-right symmetric model, and find poor sensitivity. After proposing a different trigger strategy ( considering the prompt lepton accompanying the neutrino displaced vertex) and optimized cuts in the invariant mass and track multiplicity of the vertex, we find that the LHC with root s = 13 TeV and 300 fb(-1) is able to probe sterile neutrino masses between 10 GeV < m(N) < 20 GeV ( for a right-handed gauge boson mass of 2 TeV < m(WR) < 3.5 TeV). To probe higher masses up to m(N) similar to 30 GeV and m(WR) < 5 TeV, 3000 fb(-1) will be needed. This work joins other efforts in motivating dedicated experimental searches to target this low sterile neutrino mass region.

Abstract: This work is a brief presentation of the theory based on the SU(3)(c) circle times SU(3)(L) circle times U(1)(X) gauge group in the presence of heavy leptons. Recent studies [1] have considered a set of four possible variants for the 3-3-1HL, whose content arises according to the so-denoted variable beta. Since it has been argued about the presence of stable charged particles in this sort of model, we divide the different sectors of the Lagrangian between universal and specific vertices, and conclude that the omission of beta-dependent terms in the potential may induce discrete symmetry for the versions defined by vertical bar beta vertical bar = root 3 . In the context of vertical bar beta vertical bar = 1/root 3, where the new degrees of freedom have the same standard electric charges, additional Yukawa interactions may create decay channels into the SM sector. Furthermore, motivated by a general consequence of the Goldstone theorem, a method of diagonalization by parts is introduced in the Scalar sector and provides a clarification on the definition of mass eigenstates. In summary, we develop the most complete set of terms allowed by the symmetry group and resolve their definitive pieces in order to justify the model description present in the literature.