Ahmed Al-Jamel, Dynamics of heavy quarkonia in memory-dependent dissipative environment from Bohmian trajectory perspective, International Journal of Modern Physics AVol. 33, No. 28, 1850164 (2018) .
In this work, we study the dynamics of particles coupled to a dissipative environment
from Bohmian trajectory perspective.
The dissipation is modeled using the concept of memory-dependent derivative (MDD),
which is characterized by its time-delay constant $\tau$ and non-singular kernel
$K(x,t)$ of two parameters $a,b$. By assuming a Gaussian packet wavefunction, we
derived a MDD-Langevin equation (MDDLE). The general behavioral solution $x_c(t)$
of the MDDLE is investigated for the case of Gaussian fluctuation force. Based on the
miscellaneous choices of $a,b,\tau$, the findings is that $x_c(t)$ can exhibit distinct
behaviors, such as monotonic and non-monotonic decay without zero crossings,
oscillatory-like without zero and with zero crossing. Therefore, we have either diffusion
or oscillatory dominate based on the problem parameters. For a harmonically bound
heavy quarkonium, characterized by the angular frequency $\omega$, the position
correlation function $C_x(t)$ is then obtained and analyzed numerically. The analysis
shows that this correlation function is also sensitive to the various choices of $\tau$
and kernel parameters. Based on these choices, the correlation function exhibits
distinct behaviors: oscillation without damping, damping, and enhanced. This wide
range of behavior coverage increases the versatility to fit nonlinear or memorydependent
experimental findings. The results are compared with the fractional
Langevin equation.