相关论文: Hadron multiplicity in e+e- events induced by top …
Total hadron multiplicities and multiplicities of hadrons in events with heavy quarks in $e^+e^-$ annihilation at the energies of LEP-1.5 and LEP-2 are calculated on the basis of QCD.
The multiple hadron production in the events induced by the heavy primary quarks in $e^+e^-$ annihilation is reconsidered with account of corrected experimental data. New value for the multiplicity in $b\bar{b}$ events is presented on the…
The average charged hadron multiplicities induced by top quark decays are calculated in pQCD at LHC energies. Different modes of top production are considered. Proposed measurements can be used as an additional test of pQCD calculations…
After inserting the heavy quark mass dependence into QCD partonic evolution equations, we determine the mean charged hadron multiplicity of jets produced in high energy collisions. We thereby extend the so-called dead cone effect to the…
Measurements of primary charged hadron multiplicity distributions are presented for non-single-diffractive events in proton-proton collisions at centre-of-mass energies of sqrt(s) = 0.9, 2.36, and 7 TeV, in five pseudorapidity ranges from…
A simple fit of existing data for center-of-mass energies above the b-threshold shows that the average charged particle multiplicities in pp_bar and pp interactions can be parameterized by a simple power law N_ch = N_0*(s/s_0)^(gamma) with…
The DELPHI detector at LEP has collected 54 pb^{-1} of data at a centre-of-mass energy around 183 GeV during 1997, 158 pb^{-1} around 189 GeV during 1998, and 187 pb^{-1} between 192 and 200 GeV during 1999. These data were used to measure…
We compute the initial energy density and net baryon number density in 5% most central Pb+Pb collisions at $\sqrt s=5.5$ TeV from pQCD + (final state) saturation, and describe the evolution of the produced system with boost-invariant…
Experiments at the Large Hadron Collider (LHC) have measured multiplicity distributions in p+p and p+Pb collisions at a new domain of collision energy. Based on considering an energy-dependent broadening of the nucleon's density…
We review results on hadron multiplicities in high energy particle collisions. Both theory and experiment are discussed. The general procedures used to describe particle multiplicity in Quantum Chromodynamics (QCD) are summarized. The QCD…
A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV, and Cu+Cu collisions sqrt(s_NN) = 22.5, 62.4,…
We have measured the mean charged particle multiplicities separately for bbbar, ccbar and light quark (uubar, ddbar, ssbar) initiated events produced in e+e- annihilations at LEP. The data were recorded with the OPAL detector at eleven…
The present article reviews facts and problems concerning charge hadron production in high energy collisions. Main emphasis is laid on the qualitative and quantitative description of general characteristics and properties observed for…
In this contribution, the production rates and the transverse momentum distributions of strange hadrons are reported as a function of charged particle multiplicity. In this analysis, the data collected in proton-proton collisions at…
This article summarizes and critically reviews measurements of charged-particle multiplicity distributions and pseudorapidity densities in p+p(pbar) collisions between sqrt(s) = 23.6 GeV and sqrt(s) = 1.8 TeV. Related theoretical concepts…
The pseudorapidity distributions of charged hadrons in proton-lead collisions at nucleon-nucleon center-of-mass energies $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 and 8.16 TeV are presented. The measurements are based on data samples collected by…
The first measurements from proton-proton collisions recorded with the ATLAS detector at the LHC are presented. Data were collected in December 2009 using a minimum-bias trigger during collisions at a centre-of-mass energy of 900 GeV. The…
In this work we explore the possibility to perform ``effective energy'' studies in very high energy collisions at the CERN Large Hadron Collider (LHC). In particular, we focus on the possibility to measure in $pp$ collisions the average…
Using an impact parameter tag to select an enriched sample of $Z \rightarrow b \overline{b}$ events, we have measured the difference between the average charged multiplicity of $Z \rightarrow b \overline{b}$ and $Z^0 \rightarrow hadrons$ to…
We examine hadron multiplicity fluctuations in hard processes and confront analytic QCD predictions with the pattern of multiplicity fluctuations observed in $e^+e^-$ annihilation and high-$p_t$ jets produced in $pp$ collisions at the LHC.…