Multisource Thermal Model Describing Transverse Momentum Spectra of Final-State Particles in High-Energy Collisions

Figure 1

The right-handed Cartesian coordinate system -. The beam direction which is along the axis points from the inside to the outside. The reaction plane is the plane , and the transverse plane is the plane which is perpendicular to the beam direction. In the figure, is the angle of vector measured with respect to the axis in the plane .