Theoretical Assessment of F-wave Bottom Mesons and Their Properties

In recent years, many studies have been conducted, both experimental and theoretical, on heavy-light hadrons, subatomic particles made of quarks. These include studies on the several new states of the D-meson family in facilities like the Large Hadron Collider beauty (LHCb)and others. Researchers have characterized the mass, decay width, and quantum numbers of these states for D mesons, which are the lightest particles containing a charm quark. However, the bottom meson (B-meson) family has remained relatively less explored.

The Particle Data Group lists only a few ground states and orbitally excited states for B-mesons, with very little experimental data for higher excited states. Various theoretical studies have been conducted on the B-meson family for 1S and 1P states. But, the theoretical models disagree on the placement of the newly observed B_J(5840)^0,+ and B_J(5960)^0,+ ,and the strange bottom mesons, B_sJ(6064) and B_sJ(6114). Thus, there is a need to re-examine the higher excited states from a theoretical perspective.

In this study, we examine the properties of the 1F state using heavy quark effective theory (HQET), an effective theory describing the dynamics of heavy-light hadrons. HQET implements two approximate symmetries: the heavy quark symmetry and the chiral symmetry of light quarks. Using the HQET Lagrangians, we estimate the two body strong decays of heavy-light mesons and the coupling coefficients.

Further, using the experimental data from different experimental facilities, the 1F B-meson states are analyzed. This is done on the basis of two aspects, the masses of non-strange and strange 1F bottom meson states, and the decay behavior and channels of these states.

We first calculate the masses using averaged masses for charm mesons and heavy quark symmetry parameters. Thereafter, we estimate the masses of non-strange and strange 2⁺(1³F₂), 3⁺(1F₃), 3⁺(1F’₃), and 4⁺(1³F₄). The calculated masses are in good agreement with the existing theoretical models.

We next use the masses to compute the decay widths using pseudoscalar particles in the form of coupling constants. By comparing the calculated strong decay widths with the theoretical total decay widths, we find the upper bounds for associated couplings. While the lack of experimental data does not allow the calculation of the coupling constants from heavy quark symmetry, we are able to estimate the upper bounds for them. Finally, we construct Regge trajectories in the (J, M²) plane and our predictions fit nicely on Regge lines.

Overall, our findings can provide new directions to high energy experiments that are on the lookout for new particles and open doors to a deeper understanding of the fundamental structure of matter.