From atoms to nuclei, quarks and bejond...

Latest Results for Few-Body Systems

08 December 2022

• Meson Masses in a QCD Inspired Approximation Scheme

  Abstract

  Mass being a fundamental entity of any physical system and a major part of the present work is attributed to estimate masses of heavy flavour mesons in a potential model formalism of Quantum chromo dynamics (QCD). Determination of wave function of the concerned \(q\bar{q}\) system is very essential. We use Dalgarno’s perturbation theory (DPT) and variationally improved perturbation theory (VIPT) to solve the Schrodinger equation in a QCD inspired potential model with the Cornell potential, which consists of coulomb and linear potential. We use both the options, Linear as perturbation and then Coulomb as perturbation while using the method. Comparison of both these methods and also with experimental results are done in the calculation of masses and decay constants.

• Hyperspherical Quantum Mechanic

  Abstract

  In the Newtonian mechanic a time is associated to each element of space. By starting from the existence of time-independent states a method where states are defined by polynomials associated with space elements and second order differential operators quantizing the states is proposed. The many body wave equation is an extension of the Schrödinger equation written in polar spherical coordinates, where the Hyperspherical Potential Harmonics are substituted for spherical Harmonics. Applications to bosons and fermions systems are given.

• Measurement Device Independent Multi-carrier Continuous Variable Quantum Key Distribution

  Abstract

  The measurement device independent continuous variable quantum key distribution (MDI CV-QKD) is defined to eliminate all security holes that exist due to mismatch between practical systems and their ideal models and imperfections originating from detection. However, up to this moment the practical MDI CV-QKD systems have some inevitable imperfections. In this article we introduced a Multi-carrier mode of the MDI CV-QKD in complex communication environments. Our protocol can defend all detector side channels, which seriously threaten the security of a practical Multi-carrier CV-QKD system. Its security analysis against denial-of-service attack is derived based on the fact that the transmission is through N Gaussian sub-channels with a specific variance. We show the evaluated results when the channel transmittance respectively obeys the uniform and two-point distribution. Then, we analyzed the secret key rate of the MDI Multi-carrier CV-QKD system when the sub-channels transmittance obey the two above distributions. MDI Multi-carrier CV-QKD shows a comparable performance to that of its other counterpart MDI CV-QKD protocols, which will facilitate the simplification and practical implementation of the MDI CV-QKD protocols.