Analysis of Bose–Einstein correlation at 7 TeV by LHCb collaboration based on stochastic approach

The Bose–Einstein correlation (BEC) in forward region [Formula: see text] measured at 7 TeV in the Large Hadron Collider (LHC) by the LHCb collaboration is analyzed using two conventional formulas of different types named CF[Formula: see text] and CF[Formula: see text]. The first formula is well known and contains the degree of coherence [Formula: see text] and the exchange function [Formula: see text] from the BE statistics. The second formula is an extended formula (CF[Formula: see text]) that contains the second degree of coherence [Formula: see text] and the second exchange function [Formula: see text] in addition to CF[Formula: see text]. To examine the physical meaning of the parameters estimated by CF[Formula: see text], we analyze the LHCb BEC data by using a stochastic approach of the three-negative binomial distribution and the three-generalized Glauber–Lachs formula. Our results reveal that the BEC at 7 TeV consisted of three activity intervals defined by the multiplicity [Formula: see text] ([8, 18], [19, 35], and [36, 96]) can be well explained by CF[Formula: see text].

Two-pion Bose-Einstein Correlations data analysis for the CMS Pb-Pb nucleon collisions

From the data collected in the Compact Muon Solenoid (CMS) Pb-Pb nucleon collisions experiment, the two-pion Bose-Einstein correlation functions for different combination of same charges and different charges are plotted. The influence of repulsion and attraction through Coulomb interaction between charged pions is reduced after applying the standard Gamow-factor Coulomb correction on Gaussian function C(Qinv). According to the Yano-koonin-Podgoretski parametrization, the five-dimensional components of the invariant momentum difference between two pions are calculated. One of the five components, the momentum difference in the transverse plane QT, can be further divided into Qside and Qout. Q0, Qlong, Qside and Qout were then separately plotted and fitted with the Gaussian function. The sizes of pion source or the effective interferometric source can be extracted from the fitting finally.

A continuous wavelet transform analysis of multiparticle emission data at SPS energies

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.

Wavelet analysis of particle density functions in nucleus–nucleus interactions

A continuous wavelet analysis is performed for pattern recognition of the pseudorapidity density profile of singly charged particles produced in [Formula: see text]O+Ag/Br and [Formula: see text]S+Ag/Br interactions, each at an incident energy of [Formula: see text] GeV per nucleon in the laboratory system. The experiments are compared with a model prediction based on the ultra-relativistic quantum molecular dynamics (UrQMD). To eliminate the contribution coming from known source(s) of particle cluster formation like Bose–Einstein correlation (BEC), the UrQMD output is modified by “an algorithm that mimics the BEC as an after burner.” We observe that for both interactions particle clusters are found at same pseudorapidity locations at all scales. However, the cluster locations in the [Formula: see text]O+Ag/Br interaction are different from those found in the [Formula: see text]S+Ag/Br interaction. Significant differences between experiments and simulations are revealed in the wavelet pseudorapidity spectra that can be interpreted as the preferred pseudorapidity values and/or scales of the pseudorapidity interval at which clusters of particles are formed. The observed discrepancy between experiment and corresponding simulation should therefore be interpreted in terms of some kind of nontrivial dynamics of multiparticle production.