The evaluation of the number of ways we can distribute energy among a collection of particles in a system is important in many branches of modern science. In particular, in multiparticle production processes the measurements of particle yields and kinematic distributions are essential for characterizing their global properties and to develop an understanding of the mechanism for particle production. We demonstrate that energy distributions are connected with multiplicity distributions by their generating functions.
The two parameters Weibull function is used to describe the charged particle multiplicity distribution in $e^{+}e^{-}$ collisions at the highest available energy measured by TASSO and ALEPH experiments. The Weibull distribution has wide applications in naturally evolving processes based on fragmentation and sequential branching. The Weibull model describes the multiplicity distribution very well, as particle production processes involve QCD parton fragmentation. The effective energy model of particle production was verified using Weibull parameters and the same was used to predict the multipli…
The multiplicity distribution of the gluons produced at the high energy is evaluated in BFKL approach. The distribution has Poisson form that can explain experimentally observed KNO scaling.
We compute the proton-proton multiplicity distributions at LHC energies in the framework of a multiple scattering model assuming a Poisson distribution for each inelastic collision. Multiple scattering is essential to broaden the multiplicity distribution. We obtain approximate KNO scaling for small pseudo-rapidity intervals ($|η| < 0.5$) and sizable KNO scaling violations for larger ones, in agreement with experiment.
Analytical formula for multiplicity distribution is derived in the QO approach, where chaotic and coherent fields are contained. Observed charged multiplicity distributions in Au+Au collisions at $\sqrt{s}=200$ AGeV and in pp collisions at $\sqrt{s}=900$ GeV are analyzed by the formula. Chaoticity parameters in the inclusive events estimated from the analysis of multiplicity distributions are compared with those estimated from the analysis of observed two-particle inclusive identical particle correlations.
Secondary charged hadrons multiplicity distributions in proton-proton and proton-antiproton collisions differ on principle. There are three types of inelastic processes in proton-antiproton scattering. The first type is production of secondary hadrons shower at gluon string decay. The second type is shower produced from two quark strings decay, the third type is shower produced from three quark strings decay. At the same time there are only two types of inelastic processes for proton-proton scattering - gluon string shower and two quark strings shower. Theoretical description of multiplicity d…
The CMS data on the multiplicity distributions are compared with the results from the 8.142 version of the PYTHIA MC event generator with the default tuning and realistic impact parameter profile. The agreement is reasonable. However, it seems to be difficult to improve further this agreement by tuning the parameters determining the multiple parton interactions.
A new approach to phenomenological description of the charged particle multiplicity distributions in proton-(anti)proton and electron-positron collisions is presented. The observed features of the data are interpreted on the basis of stochastic-physical ideas of multiple production. Besides the processes of parton immigration and absorption, two and three patron incremental and decremental recombinations are considered. The complex behaviour of the multiplicity distributions at different energies is described by four parametric generalized hypergeometric distribution (GHD). Application of the …
Phenomenological Parametrization of the Charged Particle Multiplicity Distributions in Restricted Rapidity Intervals in e+e- Annihilation into Hadrons and e+p Scattering at HERA
In this paper we derived in QCD the BFKL linear, inhomogeneous equation for the factorial moments of multiplicity distribution($M_k$) from LMM equation. In particular, the equation for the average multiplicity of the color-singlet dipoles($N$) turns out to be the homogeneous BFKL while $M_k \propto N^k$ at small $x$. Second, using the diffusion approximation for the BFKL kernel we show that the factorial moments are equal to: $M_k=k!N( N-1)^{k-1}$ which leads to the multiplicity distribution:$ \frac{σ_n}{σ_{in}}=\frac{1}{N} ( \frac{N\,-\,1}{N})^{n - 1}$. We also suggest a procedure for finding…
Multiplicity distributions of charged particles measured by the ATLAS Collaboration in proton-proton collisions at $\sqrt{s}=8$ and 13 TeV are analyzed in the framework of a weighted superposition of three negative binomial distribution functions. The examination of the experimental data confirms the existence of a narrow peak at low multiplicities found earlier at $\sqrt{s}=0.9$ and 7 TeV. The peak is described by the third separate component of the total distribution. The energy dependence of the multiplicity characteristics of the three-component scenario is studied. It is demonstrated that…
Measured multiplicity distributions of primary charged particles produced in the forward rapidity region of the $proton-proton$ ($pp$) collisions at the centre-of-mass energy, $\sqrt {s}$ = 7 TeV at the Large Hadron Collider (LHC) have been analyzed in terms of the Negative Binomial Distribution (NBD) function. Like the multiplicity distributions in the mid-rapidity region for the $pp$ collisions at $\sqrt {s}$ = 7 TeV, the distributions for the minimum bias events in the forward region also are better described with the superposition of two-NBDs, as proposed by a two-component model of partic…
Charged-particle multiplicity distributions are an interesting tool to study both soft- and hard-QCD processes in hadronic collisions. Since last century a significant range of center-of-mass energies has been probed, ranging from a few GeV to 13 TeV in the latest LHC run. Common analysis of multiplicity distributions at different energies, in different phase space regions and from sufficiently different experiments provides a way to systematize and review existing phenomenological models of multiple particle production. In this work a phenomenological model is suggested, that can describe sim…
The recent PHENIX mid-rapidity measurements of multiplicity distributions for centrality bins are analyzed in the framework of superposition models. A simple superposition of pp events is shown to disagree with the heavy ion data for dispersion as a function of centrality. However, it is suggested that a model describing properly the pp data and based in the "wounded quark" idea may be compatible with the multiplicity data for heavy ion collisions.
Charged multiplicity distribution in a pseudo-rapidity window is formulated under the assumption that the charge conservation is satisfied in the full phase space. At first, we analyze measured charged particle multiplicity distributions in pseudo-rapidity windows in LHC by CMS and ALICE collaborations with the two probability distributions. One is the convolution of negative binomial and Poisson distributions, and the other is the Glauber-Lachs formula. Each distribution is considered as an analogy of the quantum optics. Next, we analyze the data with the double GL formulae for $|η|<2.4$ at 7…
Analyses of multiplicity distributions of e^+e^- and e-p collisions by means of modified negative binomial distribution and Laguerre-type distribution: Interrelation of solutions in stochastic processes
We analyse the multiplicity distributions of charged particles at Tevatron (p\bar p) and LHC (pp) energies in the framework of the independent pair parton interactions (IPPI) model. It is shown that the number of soft pair parton interactions (and therefore the density of the partonic medium) is large and increases with energy. The mean multiplicity at each parton interaction grows also with energy. This growth depends on the width of the rapidity window. The similar conclusions are obtained in the multiladder exchange model (QGSM).
The ALICE and CMS data on the multiplicity distributions are compared with the lower energy data and with the results from the 8.142 version of the PYTHIA MC event generator with two tunings. The ALICE data for moments are used to calculate the factorial cumulants. It is suggested that the data on moments or cumulants are well suited to specify the optimal tuning of the model parameters.
In this work we show that the proper analysis and interpretation of the experimental data on the multiplicity distributions of charged particles produced in jets measured in the ATLAS experiment at the LHC indicates their sub-Poissonian nature. We also show how, by using the recurrent relations and combinants of these distributions, one can obtain new information contained in them and otherwise unavailable, which may broaden our knowledge of the particle production mechanism.
In this work we show that the latest LHC data on multiplicity moments $C_2-C_5$ are well described by a two-step model in the form of a convolution of the Poisson distribution with energy-dependent source function. For the source function we take $Γ$ Negative Binomial Distribution. No unexpected behavior of Negative Binomial Distribution parameter $k$ is found. We give also predictions for the higher energies of 10 and 14 TeV.
A possible signal of new phenomena emerging in the global characteristics of multiparticle production in hadron interactions at TeV energies is studied. The multiplicity distributions of charged particles measured in proton-proton collisions at the Large Hadron Collider at CERN are analyzed in the phenomenological framework of the weighted superposition of three negative binomial distribution functions. The examination of the experimental data indicates the existence of a narrow peak at low multiplicities which can be described by a separate component in the total distribution. The multiplicit…
