M. A. Louka | Searcharxiv

arXiv2021

Search for dark matter production in association with the Z$^{\prime}$ boson at the LHC in pp collisions at $\sqrt{s}$ = 8 TeV using Monte Carlo simulations

This analysis presents the possibility for the search for Dark Matter (DM) particles using events with a Z$^{\prime}$ heavy gauge boson and a large missing transverse momentum at the Large Hadron Collider (LHC). We consider the muonic decay of Z$^{\prime}$. The analyzed Monte Carlo samples were the Open simulated files produced by the CMS collaboration for proton-proton collisions correspond to an integrated luminosity of the LHC run-I with 19.7 fb$^{-1}$ at $\sqrt{s} = $ 8 TeV. Two scenarios, one simplified benchmark scenario so called Dark Higgs and the effective field theory (EFT) formalism, were used for interpretations. Limits are set on both Z$^{\prime}$, dark matter masses and the cutoff scale of the EFT.

hep-ex↗

arXiv2015

A comparison of the Extrapolated Successive Overrelaxation and the Preconditioned Simultaneous Displacement methods for augmented linear systems

In this paper we study the impact of two types of preconditioning on the numerical solution of large sparse augmented linear systems. The first preconditioning matrix is the lower triangular part whereas the second is the product of the lower triangular part with the upper triangular part of the augmented system's coefficient matrix. For the first preconditioning matrix we form the Generalized Modified Extrapolated Successive Overrelaxation (GMESOR) method, whereas the second preconditioning matrix yields the Generalized Modified Preconditioned Simultaneous Displacement (GMPSD) method, which is an extrapolated form of the Symmetric Successive Overrelaxation method. We find sufficient conditions for each aforementioned iterative method to converge. In addition, we develop a geometric approach, for determining the optimum values of their parameters and corresponding spectral radii. It is shown that both iterative methods studied (GMESOR and GMPSD) attain the same rate of convergence. Numerical results confirm our theoretical expectations.

math.NA↗