Neutrino Oscillation and CPT Violation: A Four Flavour Matter Effects

In a matter for the four flavour neutrino oscillation (3+1) scheme, the CPT violation is taken into consideration. Assuming that the mismatch between neutrino and anti-neutrino mass square discrepancies causes the CPT to be violated in matter. We suppose that the presence of matter causes the four flavour neutrino and anti-neutrino mass differences to square. For four flavour neutrino oscillation, we take into account the pertinent matter density profile. In this study, we calculate the upper bound constraint of the CPT violation in matter for a four flavour scheme. |Δm/21−Δm/21|=(1.21−3.44)×10−3)eV2,|Δm/31−Δm/31|=(1.68−6.41)×10−4)eV2 and |Δm/41−Δm/41|=(1.06−4.60)×10−5)eV2 In this paper, we examine the CPT violation in a framework with four flavours in matter.