Observation of Pion Interferometry in Relativistic Nuclear Collisions

Fung, S. Y.; Gorn, W.; Kiernan, G.P.; Lu, J.J.; Oh, Y.T.; Poe, R.T.

doi:10.1103/physrevlett.41.1592

Cited by 92 publications

(20 citation statements)

References 9 publications

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“…Therefore, by determin~ ing the value of A and R experimentally we expect to gain a clearer understanding of the react ion dynamics. Recent measurelaents of two-pion correlations [5], composite particle productions [6] and pion inclusive spectra [7] have sug:sested that the reaction size in AA collisionf:l at rc,l GcV/nucleon is 3-4 fm.…”

mentioning

confidence: 99%

One- and two-proton inclusive spectra in 800 MeV proton-nucleus collisions and the mean free path of protons in nuclei

et al. 1981

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mentioning

confidence: 99%

One- and two-proton inclusive spectra in 800 MeV proton-nucleus collisions and the mean free path of protons in nuclei

et al. 1981

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“…From Eq. (2) the probability of observing two fragments with aziniuthal angles 4, and 4 2 is and the distribution probability of $, the angle between the transverse momenta of two correlated particles, has the form Adapting the approach of interferometry analysis [7], we define the azimuthal correlation function as where P",($) is the observed $ distribution for pairs in which both fragments are selected from the Same event and Punc0,($) is the distribution for uncorrelated pairs ge~ierated by "event mixing", i.e., by randomly selecting each member of a pair from a different event with the same multiplicity. Collective flow shows up as C ( $ ) > 1 at small $ and as C ( $ ) < 1 at large $, and the magnitude of an observed flow can be characterized by the value of h in Eq.…”

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confidence: 99%

Measurement of collective flow in heavy-ion collisions using particle-pair correlations

et al. 1991

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We present a new type of flow analysis, based on a particle-pair correlation function, in which there is no need for an event-by-event determination of the reaction plane. Consequently, the need to correct for dispersion in an estimated reaction plane does not arise. Our method also offers the option to avoid any influence from particle misidentification. Using this method, streamer chamber data for collisions of Ar+ KCl and Ari-BaI, at 1.2 GeV/nucleon are compared with predictions of a nuclear transport model.Many intermediate-energy heavy ion experiments have been directed toward the goal of inferring properties of the nuclear equation of state (EOS) [I]. In parallel with this effort, theoretical work in the area of nuclear transport models has focused on the task of identifying the most appropriate experimental observables for probing the EOS and on the related task of establishing a quantitative connection between such observables and the EOS [2]. Many factors, both theoretical and experimental, have contributed to the current lack of a Consensus on Data [3,4] from the Diogene and Plastic Ball detectors Support this assumption for rapidities other than the midrapidity region where the "squeeze-out" [5] effect can result in a more complex distribution. In the present study, we restrict our analysis to forward rapidities (see below). The maximum azimuthal anisotropy, as defined by Welke et al. [ 6 ] , is even a relatively coarse characterization of the compresl + h R=-sional potential energy at maximum density (in other 1-h ' words, a characterization of the EOS as relatively "hard" or "soft"). One such factor, for example, arises from the fact that detector inefficiencies and distortions can be difficult to simulate and quantify (particularly in the case of a 4n-detector), and this leads to systematic uncertainties in measurements of collective flow. This paper presents a new form of collective flow analysis for two data sets from the Bevalac streamer chamber. The most noteworthy feature of this new method is that it is designed to minimize the type of systematic uncertainty mentioned above; more specifically, the influences of particle misidentification and dispersion of the reaction plane can be removed.For a nonzero impact parameter, the beam direction ( z ) and the line joining the Centers of the nuclei determine the reaction plane, i.e., the X -2 plane. The azimuthal angle of a fragment in this coordinate system is We assume that the distribution function of 4 in an interval of rapidity centered on y , can be described by an expression of the form The method proposed by Welke et al. [6] for determining R in an experiment involves estimating 4 in Eqs. (1) and (2) using the relation 4=+obs-+R, where +obs is the observed azimuth of a fragment, and +R is the estimated azimuth of the reaction plane as deter.mined from the observed fragments in the final state. This method requires that the resulting R be corrected upward, to allow for the fact that 4R is distributed about + = O with a finite dispersion. Eac...

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“…15) (e.g. pion BremsstraBlung calculation (Vasak, 1979), independent nucleon-nucleon collsions (Bertsch,lg77), thermal models (Chapllne,1973;Helnz, ]978) ) does,howeveT, show qualitatively good agreement with the data (Fung, 1978). Therefore more refined calculations will be called for interpreting more exclusive experiments.…”

Section: Pion Productionmentioning

confidence: 75%

Shock waves in nuclear matter - proof by circumstantial evidence

Stöcker

Hofmann

Maruhn

et al. 1980

Progress in Particle and Nuclear Physics

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In the present paper we develop the essential theoretical tools for the treatment of the dynamics of High Energy Heavy Ion Collisions. We study the influence of the nuclear equation of state and discuss the new phenomena connected with phase transitions in nuclear matter (pion condensation). Furthermore we investigate the possibility of a transition from nuclear to quark matter in High Energy Heavy Ion Collisions. In this context we discuss exotic phenomena like strongly bound pionic states, limiting temperatures, and exotic nuclei.

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Observation of Pion Interferometry in Relativistic Nuclear Collisions

Cited by 92 publications

References 9 publications

One- and two-proton inclusive spectra in 800 MeV proton-nucleus collisions and the mean free path of protons in nuclei

One- and two-proton inclusive spectra in 800 MeV proton-nucleus collisions and the mean free path of protons in nuclei

Measurement of collective flow in heavy-ion collisions using particle-pair correlations

Shock waves in nuclear matter - proof by circumstantial evidence

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