P. L. Jain

Intermittency in multiparticle production at ultra-relativistic heavy ion collisions

Abstract Scaled factorial moments were calculated for multiplicity distributions in the pseudorapidity intervals of secondary particles produced by the interactions of 16O beams at 60 and 200 GeV/n, 32S at 200 GeV/n and protons at 800 GeV/c in nuclear emulsion. The extracted moments exhibit a power-law dependence on the pseudorapidity bin size, which is consistent with intermittent behavior. At a given incident energy, the intermittency strength decreases with the increase in multiplicity.

Factorial, multifractal moments and short-range correlation of shower particles at relativistic energies

Abstract We have computed factorial, F q , and the multifractal, G q , moments for the shower particles produced in the interactions of 197 Au emulsion at 10.6 A GeV and 28 Siemulsion at 14.5 A GeV in terms of a new scaled variable X suggested by Bialas and Gazdzicki. Power-law dependencies of the moments on the number of bins M of the new variable ( X ) are observed in pseudorapidity η as well as in two-dimensional product (η·φ) phase spaces. The exponents φ q for F q , and τ q for G q moments are determined and their relationships are discussed. The normalized factorial moments of the multiplicity distribution exhibit universal scaling behavior. When ordinary factorial moments are decomposed into cumulant moments, we find that for 197 Au ions the cumulant moments of order three are non-zero, contrary to the observations of most of the relativistic heavy-ion beams used so far.

Multifractality of inelastic nuclear interactions at 1–6 TeV

Abstract The multifractal approach has been applied to particles produced in central collisions of 16 O ions at 60 and 200 GeV/n and 32 S ions at 200 GeV/n in nuclear emulsion. A new set of multiplicity moments G q is measured and from these moments the dimensional function D q is extracted which is found to decrease with the order q of the moment. From D q , the f ( α q ) spectra are determined for all the three projectiles, which are smooth functions characterizing the fluctuations of the experimental pseudorapidity distributions. These results are compared with the simulated events obtained from the Lund Monte Carlo code FRITIOF.

Multiplicity distributions and their fluctuations in pseudo-rapidity windows at relativistic heavy-ion collisions

Abstract Charged particle multiplicity distributions for inelastic, nonsingle-diffractive interactions induced by 32S at 200A GeV and 16O at 200A and 60AGeV are presented for various pseudo-rapidity intervals. The data are well described by a KNO distribution at each energy. The C2-moments along with the universality of the plot (C2〈ns〉 − 1) versus Δηs in the nucleus-nucleus and p p collisions are discussed.

Observation of scaling in nucleus-nucleus interactions at ultra-relativistic energies

Abstract The minimum bias events produced by interactions of 32S ions at 200 GeV/n and 16O ions at 200 and 60 GeV/n with emulsion target exhibit scaling not only in multiplicity distributions of the produced particles but also in their pseudorapidity distributions in the target (for all projectiles) as well as in the projectile rest frames (for 16O projectiles). Similar scalings are also seen in central events of 16O beams in their corresponding pseudorapidity distributions. The data agree well with the predictions of the Lund model FRITIOF.

Behavior of secondary particles emitted in relativistic heavy-ion interactions

Abstract The interaction mean free paths in nuclear emulsions of relativistic projectile fragments, 3 ⩽ Z ⩽ 26 emitted from heavy-ion beams of 40 Ar and 56 Fe at an energy of ∼ 2 GeV/nucleon have been measured and they are found to be shorter when determined from fragments interacting in the first few centimeters after their emissions as compared with interactions occurring within larger distances or with predictions from experiments on accelerated primary beams. There appears to be a threshold for this abnormal effect in the energy region of about 1 GeV/nucleon.

Factorial moments and short range correlation at relativistic energies

We present the results on cumulant moments obtained from horizontally and vertically averaged factorial moments for the shower particles, produced in32S-emulsion at 200 A GeV,16O-emulsion at 200 A GeV,16O-emulsion at 60 A GeV,28Si-emulsion at 14.5 A GeV and proton-emulsion at 800 GeV. Except the cumulants of order two, all other moments are consistent with zero within their statistical uncertainties. The strength of correlation length for each beam is higher than the previously observed values.

On the production of helium fragments in ultra-relativistic heavy-ion collisions☆

Abstract Partial production cross sections of projectile alpha fragments produced in high-energy interactions of 16 O and 32 S at 200 GeV/n and 16 O at 60 GeV/n in emulsion are studied. Evidence of multiplicity scaling of such produced fragments is presented in the energy range 2–200 GeV/n for various projectiles.

K+p elastic scattering at 12.7 GeV/c

Abstract We have measured the elastic K+p scattering cross section at an incident K+ beam momentum of 12.7 GeV/c. The experimental data for four-momentum transfers −t⩽3.5 rmGeV2 are well described by a distribution of the form (ifdσ/dt)o exp(At+Bt2), with ifdσ/dto=25−4+2 mb/GeV2, A=7.2±0.3 GeV−2 and B=1.2±0.2 GeV−4. The cross section for scattering in the backward direction is 0.3 μb (one event).

Fractal analysis of projectile fragments in nuclear collisions at (1–2) A GeV

Abstract Horizontal technique of multifractals has been employed to investigate the dynamical properties of the produced projectile fragments of charge Z ⩾ 2 in the interactions of 84Kr ions at 1.52 A GeV, 238U ions at 0.96 A GeV, and 56Fe ions at 2.1 A GeV in nuclear emulsion. The dynamical fluctuations in multiplicity distributions of projectile fragments are characterized by continuous multifractal spectra.