In this article, I will summarise the work done so far in field of lattice QCD. I was assigned an interesting calculation to find the string tension between \(Q \overline{Q}\), where Q and \(\overline{Q}\) are heavy quark and heavy anti-quark respectively, placed in background of (2+1) flavour QCD. Since there are 2 degenerate light quarks (\(m_u=m_d\)), and one strange quark with mass \(m_s\) in background of static(infinitely massive) heavy quark anti-quark pair, there is some temperature depending upon the inverse gauge coupling \(\beta=2N/g^2\). We will calculate the string tension of static quark anti-quark pair for temperatures starting from 150MeV to 500MeV using HISQ action of Lattice-QCD, using \(N_\tau=8,10,12\). The spatial number of sites thus shall be \(N_\sigma \ge 4\).
Our quest of finding the calculation begun from the previous work done by Cheng et. al. The found the spatial string tension using P4 action for \(N_\tau=4,6,8\) for the temperature range [\(0.9 T_c,4 T_c\)], they then compared the results with 3 diamensional effective field theory at zero temperature.