arXiv subjects

C. E. Vera

Publications and source records attributed to C. E. Vera.

3 recordsLinked to original sources

arXiv2023

Some remarks on projectile motion with a linear resistance force

In this article we revisit the projectile motion assuming a retarding force proportional to the velocity, $\vec{F_r} = -mk\vec{V}$. We obtain an analytical expression for the set of maxima of the trajectories, in Cartesian coordinates, without using the Lambert $W$ function. Also, we investigate the effect of the parameter $k$ on the radial distance of the projectile showing that the radial distance oscillates from a certain critical launch angle and find an approximate expression for it. In our analysis, we consider the impact of the parameter $k$ in the kinetic energy, the potential energy, the total energy and the rate of energy loss, and in the phase space. Our results can be included in an intermediate-level classical mechanics course.

physics.ed-ph↗

arXiv2013

Axial-vector mesons from $τ\to APν_τ$ decays

Axial-vector mesons $a_1(1260)$, $f_1(1285)$, $h_1(1170)$, $K_1(1270)$, and $K_1(1400)$ can be produced in semileptonic $τ\to A P ν_τ$ decays, where $P$ stands for the pseudoscalar mesons $π$ or $K$. We calculate the branching ratios based in a meson dominance model. The exclusive channels $τ^-\to a_1(1260)^-π^0ν$, $τ^-\to a_1(1260)^0π^-ν$, and $τ^-\to h_1(1170)π^-ν$ turn out to be of order ${\cal O}(10^{-3})$, the channel $τ^-\to f_1(1285)π^-ν$ of order ${\cal O}(10^{-4})$, and channels $τ^-\to K_1(1270)^-π^0ν$, $τ^-\to K_1(1270)^0π^-ν$, $τ^-\to K_1(1400)^-π^0ν$, and $τ^-\to K_1(1400)^0π^-ν$ of order ${\cal O}(10^{-6})$. These results indicate that the branching ratios could be measured in experiments.

hep-ph↗

arXiv2007

Nonleptonic two-body B-decays including axial-vector mesons in the final state

We present a systematic study of exclusive charmless nonleptonic two-body B decays including axial-vector mesons in the final state. We calculate branching ratios of B\to PA, VA and AA decays, where A, V and P denote an axial-vector, a vector and a pseudoscalar meson, respectively. We assume naive factorization hypothesis and use the improved version of the nonrelativistic ISGW quark model for form factors in B\to A transitions. We include contributions that arise from the effective ΔB=1 weak Hamiltonian H_{eff}. The respective factorized amplitude of these decays are explicitly showed and their penguin contributions are classified. We find that decays B^-to a_1^0π^-,\barB^0\to a_1^{\pm}π^{\mp}, B^-\to a_1^-\bar K^0, \bar B^0\to a_1^+K^-, \bar B^0\to f_1\bar K^0, B^-\to f_1K^-, B^-\to K_1^-(1400)\etap, B^-\to b_1^-\bar K^{0}, and \bar B^0\to b_1^+π^-(K^-) have branching ratios of the order of 10^{-5}. We also study the dependence of branching ratios for B \to K_1P(V,A) decays (K_1=K_1(1270),K_1(1400)) with respect to the mixing angle between K_A and K_B.

hep-ph↗