Observation of a nonspherical pion source in relativistic heavy-ion collisions

Intensity interferometry in subatomic physics

“…These experiments use pions or protons to construct the two-particle correlation function. Extensive measurements involving predominantly pion pairs have been made at kinetic energies per nucleon of several GeV, using not only heavy-ion beams (Fung et al, 1978;Angelov et al, 1980;Lu et al, 1981;Zarbakhsh et al, 1981;Beavis et al, 1983aBeavis et al, , 1983bBeavis et al, , 1986Agakishiev et al, 1984;Akhababian et al, 1984;Zajc et al, 1984;Liu et al, 1986;Chacon et al, 1988) but also d and He beams (Agakishiev et al, 1984). These results and some aspects of their theoretical interpretation are presented in Sec.…”

Two-pion correlations and multiplicity effects in La on La collisions

“…3a and 3b. Previous results for Ar, Fe, and Nb have been taken from Chacon et al [28,34]. The x 2 given here is restricted so that more than five counts in a bin were required for the bin to be included in the calculation.…”

“…1, insert). The electronic event trigger was the same as in previous experiments [28,34]. That is, the coincidence condition requires ( 1) a coincidence signal from the two scintillation counters before the Janus magnet, (2) two separated hits in the two-plane scintillator array after the magnet and (3) the prompt signals signal from the tracking wire chambers [34].…”

“…Since the discovery by Goldhaber et al [l, 2] that proton-antiproton annihilations produce more like-charged than oppositely charged pion pairs with small momentum difference; many theoretical [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and experimental [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] studies have been done to investigate the "Goldhaber-Goldhaber-Lee-Pais" (GGLP) effect. The intensity correlation of two like particles is a consequence of the quantum mechanical symmetry requirement imposed on the wave functions of bosons.…”

Pion correlations in relativistic heavy ion collisions for three symmetric systems

“…To verify that the assumption that the interactions can be separated is acceptable for the acceptances used, fits were made systematically including and excluding each of the two corrections. 9 Based on this test it is concluded that the corrections may be calculated separately if, in the 0° data, IPprojl > 50 MeV Ic.…”