Charged Hadron Multiplicity Distributions Research Articles

The determination of total multiplicity distribution ine + e ? annihilation via charged hadron multiplicity distribution

The correspondence between the moments of distribution of primary particles total multiplicity and the moments of partial distribution of charged hadrons multiplicity is obtained. This dependence permits to describe the data on the charged hadrons multiplicity moments by means of negative binomial distribution (NBD) for total hadron multiplicity. The NBD parameterk is fitted as a rational function of c.m. energy.

An accurate, analytical description of the full multiplicity distribution for charged hadrons created ine + e − collisions at 35 GeV and 91 GeV

We presen the most accurate, detailed description of the data for the full multiplicity distributions of charged hadrons produced ine+e− annihilations, using a theoretically-motivated, simple analytical formula involving the negative-binomial form and two (k) parameters. The new data from LEP at 91 GeV is represented with a χ2 of 32 for 24 measured points; the most precise data, from PETRA at 34.8 GeV, is represented with a χ2 of 9 for 18 data points. We discuss the physical interpretation of the parameters and their energy variation, in the context of the increased energy at LEP II.

Multiplicity distributions of charged hadrons invp and charged current interactions

Using data onvp and $$\bar vp$$ charged current interactions from a bubble chamber experiment with BEBC at CERN, the multiplicity distributions of charged hadrons are investigated. The analysis is based on ∼20000 events with incidentv and ∼10000 events with incident $$\bar v$$ . The invariant massW of the total hadronic system ranges from 3 GeV to ∼14 GeV. The experimental multiplicity distributions are fitted by the binomial function (for different intervals ofW and in different intervals of the rapidityy), by the Levy function and the lognormal function. All three parametrizations give acceptable values forX 2. For fixedW, forward and backward multiplicities are found to be uncorrelated. The normalized moments of the charged multiplicity distributions are measured as a function ofW. They show a violation of KNO scaling.

Predictions of LEP hadronic multiplicity distributions using the maximum entropy principle

Prior knowledge of the four lowest moments of the charged hadron multiplicity distribution enables one to predict reliably the complete hadronic multiplicity distribution using the maximum entropy principle. Use of a QCD inspired parametrization to extrapolate these moments to other energies then enables us to predict the corresponding hadron multiplicity distributions. Theoretical predictions are given for 90 GeV.

Clan structure as a source of intermittency in high energy multihadron production

Recently the systematic study of charged hadron multiplicity distributions in high energy hadronic and leptonic collisions has revealed the general occurence of negative binomial regularities in symmetric CM rapidity windows and of intermittency in very small windows in the central region. The negative binomial regularities imply a particular form of clustering called clan structure, which embodies all Mueller multiparticle correlations. We show that this clan structure leads to intermittency when the simplest assumptions are made on the behaviour of the clans in very small windows.

Multiplicity distributions of charged hadrons produced in (anti)neutrino-deuterium charged- and neutral-current interactions

Results are presented on the multiplicity distributions of charged hadrons produced in νn, νp,\(\bar \nu n\) and\(\bar \nu p\) charged-current interactions for the hadronic energy range 2GeV≤W≤14GeV (corresponding approximately to the neutrino energy range 5GeV≤Ev≤150GeV). The experimental distributions are analysed in terms of binomial distributions. With increasing hadronic energy we find a smooth transition from an ordinary binomial via Poissonian to the negative binomial function. KNO scaling holds approximately for the multiplicity distribution for the whole phase space. Data on the multiplicity distributions for neutral-current interactions are also presented.

Comparison of multiplicity distributions to the negative binomial distribution in muon-proton scattering

The multiplicity distributions of charged hadrons produced in the deep inelastic muon-proton scattering at 280 GeV are analysed in various rapidity intervals, as a function of the total hadronic centre of mass energy W ranging from 4–20 GeV. Multiplicity distributions for the backward and forward hemispheres are also analysed separately. The data can be well parameterized by binomial distributions, extending their range of applicability to the case of lepton-proton scattering. The energy and the rapidity dependence of the parameters is presented and a smooth transition from the negative binomial distribution via Poissonian to the ordinary binomial is observed.

Charged-particle multiplicity distributions inνnandνpcharged-current interactions

Charged-hadron multiplicity distributions in $\ensuremath{\nu}n$ and $\ensuremath{\nu}p$ interactions are measured in an exposure of the Fermilab deuterium-filled 15-foot bubble chamber to a wide-band neutrino beam. Multiplicity moments are studied as functions of the invariant mass of the hadronic system $W$ in the range $1lWl15$ GeV. The mean multiplicities for both $\ensuremath{\nu}n$ and $\ensuremath{\nu}p$ are found to increase logarithmically with ${W}^{2}$ with identical slopes but slightly different intercepts. A linear rise of the dispersion $D$ with the mean multiplicity $〈{n}_{\mathrm{ch}}〉$ is observed with an approximate slope of 0.35. This value is similar to that found in ${e}^{+}{e}^{\ensuremath{-}}$ and $\overline{p}p$ annihilation and is much less than the asymptotic prediction of QCD. A close similarity between ${D}_{\ensuremath{-}}$ vs $〈{n}_{\ensuremath{-}}〉$ in $\ensuremath{\nu}n$ and $\ensuremath{\nu}p$ interactions is seen. Negative correlations between the multiplicity distributions in the forward and backward hadronic center-of-mass hemispheres are found and discussed.

Simple derivation of the hadronic multiplicity distribution for e +e − annihilations from the distribution for pp collisions

We point out, and discuss the geometrical basis for a new striking empirical relationship between the full multiplicity distributions of charged hadrons produced in e +e − annihilations and in pp collisions.

Charged hadron multiplicities in high energy $$\bar v_\mu n$$ and $$\bar v_\mu p$$ interactions

Charged hadron multiplicity distributions in $$\bar v_\mu n$$ and $$\bar v_\mu p$$ interactions in the energy range $$5< E_{\bar v}< 150GeV$$ GeV are presented. They are obtained from about $$6000\bar v_\mu $$ charged current events produced in BEBC filled with deuterium. Multiplicity moments are studied as a function of the invariant mass of the hadronic systemW. Results on multiplicity distributions in the forward and backward directions in the hadronic c.m.s. are presented and discussed within the framework of the quark parton model. Values for the average charge of the forward jet are also determined and compared with other experimental data.

Quark models for hadronic reactions. Nucleon-nucleon scattering

A model for the development of scattered quarks into final-state hadrons is extended for application to hadronic reactions, focusing on nucleon-nucleon scattering in particular. Numerical calculations show that the model reproduces the main features of experimental data on secondary-hadron production in low-transverse-momentum nucleon-nucleon scattering at c.m. energies above about 3 GeV, including the variation of sigma/sub el//sigma/sub tot/ with energy, the average charged-hadron multiplicity, the moments of the charged-hadron multiplicity distribution, and the longitudinal-momentum distribution of final-state hadrons. In anticipation of the future availability of higher-energy nucleon colliding-beam machines, charged-hadron multiplicities are estimated for c.m. energies up to 2000 GeV.

Multiplicity distributions in neutrino-hydrogen interactions

Multiplicity distributions of charged hadrons produced in νp interactions are studied using a sample of 7850 charged current interactions in BEBC. Multiplicity moments are studied as functions of the invariant mass of the hadronic system, W, and a comparison is made with other lepton- and hadron-induced reactions. The mean charged multiplicity 〈 n ch〉 is found to increase linearly with ln W 2. The other multiplicity moments indicate a close similarity between the neutrino scattering and the class of annihilation processes. A study of the multiplicity distributions in the forward and backward directions in the hadronic c.m.s. gives results in qualitative agreement with the quark parton model.

Inelastic muon-proton scattering: Multiplicity distributions and prong cross sections

In a streamer chamber experiment at SLAC, hadron production was observed in inelastic collisions of 14 GeV positive muons in a liquid hydrogen target. Experiment, analysis, and resulting cross-sections are reported for hadronic prongs as well as charged hadron multiplicity distribution.