Azimuthally Integrated HBT Parameters for Charged Pions in Nucleus-Nucleus Interactions versus Collision Energy

Figure 1

Dependence of chaoticity parameter (a), HBT radii (b–d), and ratio (e) on collision energy for central heavy ion interactions at midrapidity and  GeV/ [6]. Experimental results are demonstrated for pairs of mesons (in the cases of ALICE and STAR at and 200 GeV, for pairs) and for standard Coulomb correction (in the cases of ALICE, NA44, NA45, PHOBOS, and STAR at and 200 GeV, for correction ). Statistical errors are shown (for NA44, total uncertainties). The solid lines (a–d) correspond to the fits by function (7) and dashed lines to the fits by specific case , . Fitted data samples for (a) and for (d) do not include the point of the WA97 experiment [11], while the fits for transverse HBT radii (b, c) are shown for samples with point from [11]. Smooth solid and dashed curves at (e) correspond to the ratio calculated from the fit results for and , and dotted line is the level .

(a)

(b)

(c)

(d)

(e)