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The well-known statistical distribution function, Weibull distribution function, has been employed to study the multiplicity distribution and multiplicity moments for the backward shower particles produced in case of total disintegrated events of [Formula: see text]O–AgBr, [Formula: see text]Ne–AgBr and [Formula: see text]Si–AgBr interactions at (4.1–4.5) AGeV/c. Multiplicity fluctuation of backward shower particles in case of total disintegrated events by the method of scaled variance and the forward–backward asymmetry parameter had also been investigated.

A detailed study of centrality dependence of event-by-event fluctuations of maximum pseudo-rapidity gap of the produced particles has been carried out in terms of the scaled variance ω for 22Ne-emulsion interactions at 4.1 AGeV/c and 28Si-emulsion interactions at 4.5 AGeV/c. Depending on the values of the total charges or sum of the charges of non interacting projectile fragments, event samples were classified into three different centrality classes. Presence of centrality dependence of event-by-event fluctuations of maximum pseudo-rapidity gap is reflected in the multiparticle production process from this analysis. The event-by-event fluctuations are found to increase with decreasing centrality of collisions. Experimental analysis has been compared with the results obtained from the analysis of Monte Carlo simulated (MC-RAND) events in order to extract dynamical fluctuations. The difference between the experimental and simulated values of event-by-event fluctuations establishes the existence of true dynamical correlation among the produced particles.

This paper presents a study of bin–bin correlation of the produced shower particles in the pseudo-rapidity space by the method of factorial correlator in [Formula: see text]O-AgBr and [Formula: see text]S-AgBr interactions at 4.5[Formula: see text][Formula: see text]GeV/[Formula: see text]. The correlated moments are found to increase with decreasing bin–bin separation D, following a power law. Strong bin–bin correlation is exhibited by the experimental data. Experimental data also supports the validity of log normal approximation. Experimental analysis has been compared with the results obtained from the analysis of events simulated by UrQMD model.

A detailed study on the multiplicity distribution of helium (He) fragments emitted in projectile fragmentation of 22Ne, 28Si, and 32S projectiles on interactions with H, CNO, and AgBr targets in a nuclear emulsion track detector has been presented at an incident momentum of (4.1–4.5) AGeV/c. The percentage of events with He fragments increases with increase in projectile mass for all three targets. Studies of multiplicity moments, dispersion of multiplicity distribution, and the investigation of dynamical fluctuations of the projectile He fragments have also been carried out.

In the present paper a detailed investigation of the multiplicity distribution of the produced shower particles in the backward hemisphere ( $$\theta _{\mathrm {Lab}} \ge 90^{\circ }$$ ) in nuclear emulsion track detector has been carried out. The present study involves interactions of $$^{\mathrm {16}}\hbox {O}$$ and $$^{\mathrm {32}}\hbox {S}$$ projectiles with CNO, AgBr and composite emulsion target at 4.5 AGeV/c. We have compared our results with the results obtained from the analysis of modified Fritiof model. Present study reveals that the production of single shower particle is the most dominant production mode of shower particles in the backward direction. This probability increases with the increase of target mass. The percentage of events having backward shower particles remains almost independent of the projectile beam. But it increases with the increase of target size. Average multiplicity of the shower particles in the backward direction reflects a weaker dependence on the mass number of the projectile beam. Multiplicity distribution of backward shower particles for both experimental and modified Fritiof model can be described by an expression $$\mathrm {P}_{\mathrm {N}} = {\mathrm {P}_{\mathrm {s}}\mathrm {N}_{\mathrm {B}}}^{-{\uplambda }_{\mathrm {B}}}$$ . The fitting parameter $${\uplambda }_{\mathrm {B}}$$ decreases as the target size increases. The decay constant has lower value for the heavier projectile. Higher order multiplicity moments and scaled variance of multiplicity distribution for the backward shower particles showed strong target dependence. Multiplicity distributions of the backward shower particles violate KNO scaling law. Modified Fritiof model failed to reproduce the various features of the multiplicity distribution.

Charged particle multiplicity fluctuations in simulated pp collisions at $$\sqrt s = 13\;{\text{TeV}}$$ have been studied by the method of scaled factorial moment for the minimum bias events generated by Ultra-Relativistic Quantum Molecular Dynamics (UrQMD) model in the pseudo-rapidity $$(\eta )$$ , azimuthal angle ( $$\phi$$ ) and two-dimensional anisotropic $$(\eta - \phi )$$ phase space. Strong intermittent types of fluctuations have been observed for the UrQMD simulated data. Systematic studies of intermittent fluctuations in terms of scaled factorial moments have been utilized to extract the anomalous fractal dimension in the pseudo-rapidity $$(\eta )$$ , azimuthal angle ( $$\phi$$ ) and two-dimensional anisotropic $$(\eta - \phi ) $$ phase space. Search for the quark-hadron phase transition in the framework of Ginzburg–Landau theory of the second-order phase transition in the light of the scaled factorial moment method has also been performed.

A study of Renyi entropy of shower particles has been carried out using 16O, 28Si, and 32S projectiles in interaction with AgBr and CNO target present in nuclear emulsion at an incident momentum of 4.5 AGeV/c. The analysis reveals interesting experimental observations for both groups of targets. A comparison of the experimental results with the results obtained from analyzing the event sample generated by the UrQMD code is also presented. Renyi entropy values increase with the increase of projectile mass. This increase is weaker in case of CNO target. The calculated values of second-order Renyi entropy H2 are shown to vary linearly with the logarithm of average particle multiplicity ln⟨n⟩ for both targets. The dependence of Renyi entropy on the logarithm of average particle multiplicity ln⟨n⟩ indicates the presence of long-range correlation in high-energy nucleus–nucleus interactions. The variation is found to be stronger in the case of experimental events in comparison to the UrQMD simulated events indicating stronger long-range correlation for the experimental data.

A detailed study on the centrality dependence of the different aspects multiplicity distribution of the shower particles produced in the backward direction ([Formula: see text] in nuclear emulsion track detector has been carried out for [Formula: see text]Ne-emulsion interactions at 4.1 AGeV/c. Depending on the values of the total charges or sum of the charges of noninteracting projectile fragments, event samples were classified into four centrality classes. From the analysis presented in this paper, qualitative information about the assembly of shower particles in the backward direction has been extracted.

A study of centrality dependence of target fragmentation and multiparticle production has been carried out in 16O–AgBr, 22Ne–AgBr, and 28Si–AgBr interactions at 4.1–4.5 AGeV/c for the total disintegrated (TD) events. Average multiplicity of black particles increases linearly with decreasing centrality while average multiplicity of grey and shower particles decreases with decreasing centrality for the TD events. The decrease of average multiplicity of grey particles is linear; on the other hand, in the case of shower particles, the increase is nonlinear. With the increase of the mass of the projectile beam, the average multiplicity of black particles decreases and the average multiplicity of grey particles increases for the TD events. This observation has been explained on the basis of the fireball model; however, in the case of shower particles, average multiplicity increases with increase of projectile mass.

A detailed study of energy dependence of event-by-event pseudorapidity fluctuations of the produced kaons in Au + Au collisions at $$\sqrt {^SNN} $$ = 19.6–200 GeV in terms of the Φ measure has been carried out in the framework of the UrQMD model. The study of event-by-event kaon fluctuation in pseudorapidity space reveals energy dependence. It has been seen that as energy increases event-by-event fluctuation increases for both positive and negative kaons. Moreover, the positive kaons show larger event-by-event fluctuations than the negative kaons.

A detailed study of centrality dependence of event-by-event fluctuations of maximum particle density of the produced particles in narrow pseudo-rapidity interval in terms of the scaled variance [Formula: see text] has been carried out for [Formula: see text]O-emulsion interactions at 4.5[Formula: see text]AGeV/[Formula: see text]. Depending on the values of the total charges or sum of the charges of noninteracting projectile fragments, event samples were classified into four centrality classes. Presence of event-by-event fluctuations of maximum particle density is reflected in the multiparticle production process for different centrality classes. The event-by-event fluctuations are found to decrease with the increase of pseudo-rapidity interval. The event-by-event fluctuations are found to decrease with decreasing centrality of collisions. A comparison with the analyzed results of the total disintegration events has also been carried out. Experimental analysis results have been compared with those obtained from the analysis of Monte Carlo simulated (MC-RAND) events in order to extract the dynamical fluctuations.

The decay scheme of $^{160}$Yb nucleus populated in the $^{148}$Sm($^{16}$O, 4n)$^{160}$Yb reaction at 90 MeV has been studied. The gamma-coincidence data have been collected by using Indian National Gamma Array (INGA) composed of twenty Compton-suppressed Clover-Germanium detectors. Compared to the prior publications, the level scheme has been significantly modified owing to the observation of triple $\gamma$-coincidences and the measurements of $\gamma$ intensities, R$_{\theta}$ (asymmetry ratio), DCO (Directional Correlation of Oriented States) and IPDCO (Integrated Polarisation Directional Correlation of Oriented States) ratios. Theoretical results relevant for the exotic shape-coexistence related to the present context are presented and discussed. They illustrate the consequences of the fact that $^{160}$Yb is expected to be a doubly-magic (Z=70 and N=90) tetrahedral-symmetry nucleus as predicted by other authors. The historical criteria of identification of such a symmetry in nuclei are critically revisited in the context of the actual measurement and interpretation of its results and the precise new criteria are formulated employing recent results of the Fukuoka-Strasbourg collaboration. The experimental results are interpreted and discussed in detail. Limiting values of branching ratios for transitions observed by other authors but unseen in the present work are estimated. The population criteria of the $\beta$ and $\gamma$ vibration bands are revisited and discussed. Although no indication of the presence of the stable tetrahedral configuration has been obtained, arguments are given towards the possible presence of the $Y_{32}$ (`tetrahedral component') vibrations around the ground-state equilibrium. With the improvement of the spectroscopic information provided by the new data the way is opened for designed experiment(s) based on the unambiguous identification criteria of tetrahedral symmetry presented in this article.

A study of multiplicity distribution of singly charged, doubly charged, multi charged projectile fragments and shower particles have been carried out for the peripheral collisions in 16O-emulsion,22Ne-emulsion and 28Si-emulsion interactions at an incident momentum of (4.1-4.5) AGeV/c. Events having no target fragments have been designated as peripheral collision events. Percentage of peripheral events has been found to increase with the increase of projectile mass. Dispersion of the multiplicity distribution and its dependence on projectile mass for projectile fragments and shower particles has also been investigated. Dependence of average multiplicity of projectile fragments and shower particles on the mass of the projectile beam has been studied. Study of different fragmentation mode during the emission of multi charged projectile fragments has also been carried out., arXiv admin note: text overlap with arXiv:nucl-ex/0604007 by other authors

A detailed study of the centrality dependence of pseudo-rapidity distribution has been carried out for [Formula: see text]O-emulsion interactions at 4.5[Formula: see text]AGeV/c and [Formula: see text]Ne-emulsion interactions at 4.1[Formula: see text]AGeV/c using nuclear emulsion track detector. Depending on the values of the total charges or sum of the charges of noninteracting projectile fragments, event samples were classified into four centrality classes. Maximum pseudo-rapidity density, average pseudo-rapidity values, moments of pseudo-rapidity distribution along with skewness and kurtosis of the distributions have been investigated for different centrality classes.

A dipole sequence has been observed and investigated in the $^{143}\mathrm{Sm}$ nucleus populated through the heavy-ion-induced fusion-evaporation reaction and studied using the Indian National Gamma Array as the detection system. The sequence has been established as a magnetic rotation (MR) band primarily from lifetime measurements of the band members using the Doppler shift attenuation method. A configuration based on nine quasiparticles with highly asymmetric angular momentum blades has been assigned to the shears band in light of the theoretical calculations within the framework of the shears mechanism with the principal axis cranking (SPAC) model. This is hitherto the maximum number of quasiparticles along with the highest asymmetricity associated with a MR band. Furthermore, as it has followed from the SPAC calculations, the contribution of the core rotation to the angular momentum of this shears band is substantial and greater than in any other similar sequence, at least, in the neighboring nuclei. This band can thus be perceived as a unique phenomenon of shears mechanism in operation at the limits of quasiparticle excitations as manifested in MR bandlike phenomena, evolving into collectivity.

A study of Event by Event analysis of maximum Pseudo-rapidity Gap Fluctuation in heavy-ion collisions in terms of the scaled variance {\omega} has been carried out for relativistic AA collisions with multiplicity cut (N >10) using nuclear emulsion data at 4.5 AGeV/c. The values of scaled variance are found to be greater than zero indicating the presence of strong fluctuation of maximum rap gap values in the multiparticle production process. The event by event fluctuations are found to decrease with the increase of average multiplicity of the interactions. Experimental analysis has been compared with the results obtained from the analysis of events simulated by generating random numbers (MC-RAND events) and also by Ultra Relativistic Quantum Molecular Dynamics (UrQMD) model. UrQMD model simulated values of event by event fluctuations of maximum rapidity gap are less than the corresponding experimental values., Comment: 1 figure. arXiv admin note: substantial text overlap with arXiv:1802.06752

Dipole sequences in the 143 Sm nucleus have been investigated via the 124 Sn ( 24 Mg, 5n) reaction at E lab = 107 MeV using the Indian National Gamma Array (INGA). The spin-parity of the associated levels have been firmly established from the spectroscopic measurement. Level lifetimes of several levels in the dipole bands have been measured using the Doppler Shift Attenuation Method. The decreasing trend of the measured B(M1) and B(E2) transition strengths in one of the sequence (DB I) spells out its origin as Magnetic Rotation (MR). The trends of B(M1) and B(E2) in DB I are reproduced well in the theoretical calculations using the Shears mechanism with the Principal Axis Cranking (SPAC) model. However, the calculations fail to reproduce the sharp rise in the B(M1)/B(E2) ratio at the highest spins in DB I and the same has been interpreted from the decreasing of the core rotation along the sequence. The experimental observations along with the the theoretical calculations for the second dipole band (DB II), indicate that the core rotation, rather than the shears mechanism, is being favored for angular momentum generation. This represents a unique observation of forking of the shears band DB I from an abrupt phase change of the core from spherical into the deformed one., 7 pages, 4 figures

A detailed study on multiplicity distribution has been carried out using 16O (at an incident momentum of 4.5A GeV/c, 22Ne (at an incident momentum of 4.1 A GeV/c, 28Si (at an incident momentum of 4.5 A GeV/c and 32S (at an incident momentum of 4.5 A GeV/c projectiles in interaction with AgBr target present in nuclear emulsion. A comparison of the experimental results with the results obtained from analyzing the event sample generated by the UrQMD model is also presented.

A detailed study of event-by-event pseudo-rapidity fluctuations in relativistic heavy-ion collisions in terms of the Φ measure and its multiplicity and target dependence has been carried out for heavy (AgBr) and light (CNO) groups of targets present in the nuclear emulsion using O 16 (at an incident momentum of 4.5 A GeV/c), Ne 22 (at an incident momentum of 4.1 A GeV/c), Si 28 (at an incident momentum of 4.5 A GeV/c) and S 32 (at an incident momentum of 4.5 A GeV/c) projectiles. For all the interactions, the total ensemble of events has been divided into three overlapping multiplicity classes depending on the number of shower particles. For all the interactions and for each multiplicity class, the Φ values are found to be greater than zero indicating the presence of strong correlation in the multiparticle production at Dubna energy. The measured Φ values are found to decrease with the increase of average multiplicity for all the interactions. The Φ values for the AgBr target are found to be greater than that for the CNO target for all the projectiles. This observation indicates the presence of stronger correlation for heavier projectiles. The experimental results have been compared with the modified FRITIOF model. It has been seen that the modified FRITIOF model cannot reproduce the experimental results.

A study of pion correlation and fluctuation has been carried out in terms of normalised factorial cumulant moment of second and third order in 16 O-AgBr, 28 Si-AgBr and 32 S-AgBr interactions at 4.5AGeV/c. Two-particle pion correlations were found to be stronger than the three-particle correlation. Experimental analysis has been compared with the results obtained from the analysis of events simulated by generating random numbers (Monte Carlo Simulation). A comparison of our results with the UrQMD, modified FRITIOF and AMPT models has also been performed. The UrQMD model completely failed to reproduce the experimental results. The modified FRITIOF model also cannot reflect all the features of the experimental outcome. The AMPT model in comparison to the other two models can qualitatively reproduce the experimental results although the strength of the observed correlation in the case of the AMPT model is less than the experimental values.

A detailed study of Event-by-Event pseudorapidity fluctuation of the pions produced in 16O -AgBr interactions at 60A GeV and 32S -AgBr interactions at 200A GeV has been carried out in terms of $ \phi$ , a variable defined as a measure of fluctuation. Non-zero $ \phi$ values indicate the presence of strong correlation among the pions for both interactions. Multiplicity and rapidity dependence of the Event-by-Event pseudorapidity fluctuation has been investigated. A decrease of $ \phi$ with average multiplicity and increase of the same variable with pseudorapidity width are observed. Decrease of $ \phi$ with average multiplicity is concluded as the particle emission by several independent sources occurs for higher-multiplicity events. The increase in $ \phi$ values with pseudorapidity width, taken around central rapidity, might hint towards the presence of long-range correlation and its dominance over short range one. We have compared our experimental results with Monte Carlo simulation generated assuming independent particle emission. Comparison shows that the source of correlation and fluctuation is the dynamics of the pion production process. We have also compared our results with events generated by FRITIOF code. Such events also show the presence of fluctuation and correlation; however they fail to replicate the experimental findings.

The multifractal analysis of charged pion produced in 16 O–AgBr interactions at 2.1 AGeV and 24 Mg–AgBr interactions at 4.5 AGeV has been investigated using the Takagi moment method in pseudo-rapidity space. The generalized fractal dimensions D q are determined for these two interactions for different orders of moment. Experimental data reflects multifractal geometry in the multipion production process. From the knowledge of the generalized fractal dimensions D q , the multifractal specific heat has also been evaluated for these data. A detailed comparison is presented with the results obtained from 12 C–AgBr and 28 Si–AgBr interactions at 4.5 AGeV/c, 28 Si–AgBr interactions at 14.5 A GeV/c, 16 O–AgBr interactions 60 AGeV and 32 S–AgBr interactions 200 AGeV from the recent literatures.

The multiplicity fluctuations of the produced pions were studied using scaled vari- ance method in 16 O-AgBr interactions at 2.1 AGeV, 24 Mg-AgBr interactions at 4.5 AGeV, 12 C- AgBr interactions at 4.5 AGeV, 16 O-AgBr interactions at 60 AGeV and 32 S-AgBr interactions at 200 AGeV at two different binning conditions. In the first binning condition, the rapidity interval was varied in steps of one centring about the central rapidity until it reached 14. In the second case, the rapidity interval was increased in steps of 1.6 up to 14.4. Multiplicity distributions and their scaled variances were presented as a function of the dependence on the rapidity width for both the binning conditions. Multiplicity fluctuations were found to increase with the increase of rapidity interval and later found to saturate at larger rapidity window for all the interactions and in both the binning conditions. Multiplicity fluctuations were found to increase with the energy of the projec- tile beam. The values of the scaled variances were found to be greater than one in all the cases in both the binning conditions indicating the presence of correlation during the multiparticle production process in high-energy nucleus-nucleus interactions. Experimental results were compared with the results obtained from the Monte Carlo simulated events for all the interactions. The Monte Carlo simulated data showed very small values of scaled variance suggesting very small fluctuations for the simulated events. Experimental results obtained from 16 O-AgBr interactions at 60 AGeV and 32 S- AgBr interactions at 200 AGeV were compared with the events generated by Lund Monte Carlo code (FRITIOF model). FRITIOF model failed to explain the multiplicity fluctuations of pions emitted from 16 O-AgBr interactions at 60 AGeV for both the binning conditions. However, the experimental data agreed well with the FRITIOF model for 32 S-AgBr interactions at 200 AGeV.

This work presents a study on the multiplicity distribution of shower and compound multiplicity (pions + target protons) emitted from 12 C – AgBr and 24 Mg – AgBr interactions at 4.5 AGeV in terms of negative binomial distribution (NBD) and also on the fluctuation pattern of shower and compound multiplicity in the frame work of two-dimensional factorial moment methodology using the concept of Hurst exponent.

In this paper we have studied the multiplicity distribution of black and grey particles emitted from 16 O – AgBr interactions at 2.1 AGeV and 60 AGeV. We have also calculated the multiplicity moment up to the fifth order for both the interactions and for both kinds of emitted particles. The variation of multiplicity moment with the order number has been investigated. It is seen that in the case of black particles multiplicity moment up to fourth order remains almost constant as energy increases from 2.1 AGeV to 60 AGeV. Fifth order multiplicity moment increases insignificantly with energy. However in the case of grey particles no such constancy of multiplicity moment with energy of the projectile beam is obtained. Later we have extended our study on the basis of Regge–Mueller approach to find the existence of second order correlation during the emission of black as well as the grey particles. The second Mueller moment is found to be positive and it increases as energy increases in the case of black particles. On the contrary in the case of grey particles the second Mueller moment decreases with energy. It can be concluded that as energy increases correlation among the black particles increases. On the other hand with the increase of energy correlation among the grey particles is found to diminish.

Continuous wavelet transform approach has been applied to the pseudo-rapidity distribution of shower tracks produced in [Formula: see text]O–AgBr interactions at 60[Formula: see text]AGeV and [Formula: see text]S–AgBr interactions at 200[Formula: see text]AGeV. Multiscale analysis of wavelet pseudo-rapidity spectra has been performed in order to find out the overabundance of produced tracks at some preferred pseudo-rapidity values, i.e., production of particle clusters. Presence of ring-like correlation is not confirmed from the analysis in pseudo-rapidity space only. The clusterization effect may be attributed to the presence of Bose–Einstein correlation among the produced tracks. Comparison of experimental results with that obtained from analyzing events generated by FRITIOF and UrQMD codes is not reproduced.

The search for genuine two-particle dynamical correlations among the target evaporated slow particles in 12C-AgBr and 24Mg-AgBr interactions at 4.5 AGeV and 28Si-AgBr interactions at 14.5 AGeV in the emission angle space has been carried out using the method of normalized factorial cumulant moments. The analysis reveals the presence of genuine two-particle dynamical correlations among the target fragments in 12C-AgBr, 24Mg-AgBr, and 28Si-AgBr interactions. The correlations among the target evaporated slow particles are found to decrease with an increase in mass and energy of the projectile beam.

In this paper, a detailed study of two-particle rapidity correlation has been presented by measuring the dynamical fluctuation variable [Formula: see text] in forward and backward pseudo-rapidity window of shower particles produced in the relativistic heavy ion collision, [Formula: see text]O–AgBr interactions at 60[Formula: see text]AGeV and [Formula: see text]S–AgBr interactions at 200[Formula: see text]AGeV. Variations of [Formula: see text] with rapidity gap between forward and backward zones and with the width of each zone have been studied. For both cases, [Formula: see text] increase with increasing either width of the zone or gap between the zones. Our findings show the presence of strong long-range correlation. Comparison of experimental results with MC-RAND events confirms the present correlation to be dynamical in nature. We have also compared our results with FRITIOF and UrQMD events. Such events also show the presence of correlation, but found to fail to reproduce the experimental results both quantitatively and qualitatively. Strength of correlation is dependent on the centrality of collision for experimental events, it decreases with centrality.

In this article a brief review on nuclear fragmentation has been presented on both theoretical and experimental ground. On the theoretical aspects discussion on different models has been done. On experimental overview the multiplicity distribution, angular distribution, correlation and intermittent type of fluctuations have been discussed for black and grey particles is presented. An experimental review on projectile fragments is also given.

We have studied the multifractality of pion emission process in16O-AgBr interactions at 2.1 AGeV and 60 AGeV,12C-AgBr and 24Mg-AgBr interactions at 4.5 AGeV, and32S-AgBr interactions at 200 AGeV using Multifractal Detrended Fluctuation Analysis (MFDFA) method which is capable of extracting the actual multifractal property filtering out the average trend of fluctuation. The analysis reveals that the pseudorapidity distribution of the shower particles is multifractal in nature for all the interactions; that is, pion production mechanism has inbuilt multiscale self-similarity property. We have employed MFDFA method for randomly generated events for32S-AgBr interactions at 200 AGeV. Comparison of expt. results with those obtained from randomly generated data set reveals that the source of multifractality in our data is the presence of long range correlation. Comparing the results obtained from different interactions, it may be concluded that strength of multifractality decreases with projectile mass for the same projectile energy and for a particular projectile it increases with energy. The values of ordinary Hurst exponent suggest that there is long range correlation present in our data for all the interactions.

A self-affine analysis of charged-particle multiplicity distribution (protons + pions) in π−-AgBr interaction at 350 GeV/c is performed according to the two-dimensional factorial moment methodology using the concept of Hurst exponent in Xcosθ-Xϕ phase space. Comparing with the results obtained from self-similar analysis, the self-affine analysis shows a better power-law behaviour. Corresponding results are compared with shower multiplicity distribution (pions). Multifractal behaviour is observed for both types of distributions.

A study of azimuthal angle void probability of produced pions has been carried out in relativistic and ultra relativistic nucleus–nucleus interactions (32S–AgBr interactions at 200 A GeV, 16O–AgBr interactions at 60 A GeV , 24Mg–AgBr interactions at 4.5 A GeV and 12C–AgBr interactions at 4.5 A GeV). The study reveals a very interesting observation-void probability showing scaling behaviour at significantly lower energy (24Mg–AgBr interactions at 4.5 A GeV and 12C–AgBr interactions at 4.5 A GeV) whereas the behaviour is not so pronounced at higher energy in 16O–AgBr interactions at 60 A GeV and the data do not reveal scaling behaviour at all in case of 32S–AgBr interactions at 200 A GeV.

We have measured the hadron-hadron correlation in the multiparticle production process of 16O-AgBr interactions at 60A GeV and 32S-AgBr interactions at 200A GeV in the forward and backward zone of the pseudo-rapidity space using the normalized factorial cumulant moment method. The experimental results have been compared with the Monte Carlo data generated according to the independent emission model. The results reveal that the observed correlation between the produced hadrons is purely dynamical. Correlation is found to be stronger in the backward zone than that in the forward zone of the pseudo-rapidity space for both interactions. Factorial cumulant moments for the experimental data show a power law rise with decreasing phase space bin size. The results obtained from the experimental data have also been compared with those obtained from analyzing FRITIOF data. Though FRITIOF data itself show the presence of a measured correlation among the hadrons, in most of the cases the values of the factorial cumulant moments are much less than the experimental values and they remain constant with phase space bin size. The study might hint towards the Bose-Einstein correlation as the origin of the observed behavior of the measured correlation. The failure of FRITIOF data to reproduce the exact experimental behavior in terms of factorial cumulant moment also supports this notion as the model does not take the BE correlation into account.

This paper reports an investigation of two- and three-particle dynamical correlation in multiparticle production processes in terms of compound multiplicity (proton and pion) distributions. The data have been taken from 24Mg–AgBr and 12C–AgBr interactions at 4.5 AGeV. The experimental results are compared with those of Monte Carlo simulated events, assuming an independent emission of the compound multiplicity. The data exhibit strong two- and three-particle correlation in both forward and backward hemispheres in emission angle space for both data sets. PACS Nos.: 25.75–q, 24.60 Ky

This paper reports a detailed study on self-affine behavior of multiplicity fluctuation in the pionization process at relativistic and ultrarelativistic nuclear collisions. The study was performed over a wide range of energy from 2.1–200 AGeV. The data used are 16 O-AgBr interactions at 2.1 AGeV and 60 AGeV, 32 S-AgBr interactions at 200 AGeV, 24 Mg-AgBr , and 12 C-AgBr interactions at 4.5 AGeV. All these data show a clear evidence of self-affine pion production over the entire energy regime.

Different fractal methods (Factorial moment, Takagi moment) have been used for the analysis of fractal behavior of multiparticle production in π-- AgBr interaction at 350 GeV/c of compound multiplicity distribution in emission angle (cos θ) space and azimuthal angle (ϕ) space. The generalized fractal dimensions Dq are determined according to two methods. Results indicate multifractal behavior in compound multiplicity distribution. From the knowledge of Dq, the multifractal specific heat is calculated. Results are compared with the corresponding results of shower multiplicity.

This paper reports an investigation on the occurrence of the non-thermal phase transition in the target fragmentation of 28 Si – AgBr interactions at 14.5 AGeV in azimuthal angle space using the method of factorial moment. Clear evidence of the non-thermal phase transition is obtained.

This study reports the scaling behaviour of void probability in limited phase space during the emission of slow target fragments in 12C–AgBr and 24Mg–AgBr interactions at 4.5 A GeV. This study will also enable us to check the validity of linked pair ansatz.

This paper presents an investigation on the occurrence of non-thermal phase transition in the target fragmentation of 12C–AgBr interactions at 4.5 A GeV. This analysis is performed considering the anisotropy of (cos θ - ) phase space. An indication of non-thermal phase transition is obtained where the anisotropic scaling behavior (self affinity) of dynamical fluctuations is best revealed.

The multifractal analysis of data on nuclear fragments obtained from 28 Si-AgBr interactions at 14.5 A GeV is performed using three different methods (the factorial moments, G-moments and Takagi moments). The generalized fractal dimensions Dq is determined from all these methods. Data reflects multifractal geometry for the nuclear fragments. From the knowledge of Dq, the multifractal specific heat is calculated for this data and also for 16 O-AgBr interactions at 60 A GeV and 32 S-AgBr interactions at 200 A GeV.

This paper reports an analysis on fractality using the experimental data of compound multiplicity (pions + target protons) distribution in 24Mg-AgBr interactions at 4.5 AGeV following the method proposed by F. Takagi. Takagi moments have been calculated for 2nd, 3rd, 4th, and 5th order in the emission angle and azimuthal angle space. The results of our study reveal the multi-fractal structure of compound multiplicity distribution.