Abstract
I present the first isolation of azimuth quadrupole components from published data (called elliptic flow) as spectra on transverse rapidity for identified pions, kaons, and Λ's/protons from minimum-bias Au-Au collisions at 200 GeV. The form of the spectra on indicates that the three hadron species are emitted from a common boosted source with boost . The quadrupole spectra have a Lévy form similar to the soft component of the single-particle spectrum, but with significantly reduced ( times) slope parameters . Comparison of quadrupole spectra with single-particle spectra suggests that the quadrupole component comprises a small fraction (<5%) of the total hadron yield, contradicting the hydrodynamic picture of a thermalized, flowing bulk medium. The form of is, within a constant factor, the product of ( in the boost frame) times the ratio of quadrupole spectrum to single-particle spectrum. That ratio in turn implies that above , the form of is dominated by the hard component of the single-particle spectrum (interpreted as being due to minijets). It is therefore unlikely that the so-called constituent-quark scaling attributed to is relevant to soft hadron production mechanisms (e.g., chemical freeze-out).
11 More- Received 27 March 2008
DOI:https://doi.org/10.1103/PhysRevC.78.064908
©2008 American Physical Society