The dependence of Bose–Einstein correlations, on energy, multiplicity and hadronic jets

Abstract

The dependence of the one-dimensional Bose–Einstein correlation R1D derived from proton–proton collisions is examined in terms of energy, hadron multiplicity and number of emerging hadronic jets. It is argued that the observed rise of R1D with energy is the result of the increase of the average number of hadronic jets. It is further shown that by the relatively straightforward measurements of R1D and its chaoticity parameter λ one should be able to estimate the average number of outgoing hadronic jets emitted over the entire final state phase space without the need to rely on a particular jet finding algorithm and its associated parameters.

On Bose–Einstein correlations inAAcollisions versus energy, transverse mass and momentum

“…The R A long energy-dependent K(s/s o ) factor, evaluated here at k T = 0, is similar within errors to the R p 1D energy dependence deduced from pp collisions reported in [16], namely…”

“…The R A long values obtained from Pb-Pb collisions are plotted as reported whereas those obtained from the Au-Au collision samples are multiplied by the factor (A Pb /A Au ) 1/3 . For the dependence of R Pb long on energy, we adopt for K(s/s 0 ) the parametrization which was successful in describing in pp collisions [16] the energy dependence of R p 1D , namely…”

Two-particle Bose–Einstein correlations in pp collisions at $$\mathbf {\sqrt{s} =}$$ s = 0.9 and 7 TeV measured with the ATLAS detector

“…While this dependence is natural in nucleus–nucleus collisions, the increase of size with multiplicity has also been observed in hadronic and leptonic interactions. In the latter, it is understood as a result of superposition of many sources [8, 23–27] or related to the number of jets [28, 29]. High-multiplicity data in proton–proton interactions can serve as a reference for studies of nucleus–nucleus collisions.…”

The energy dependence of the chaoticity $λ$ parameter from BEC of $π$-pairs produced in $pp$ collisions

“…Recently the one dimension R dependence on the pp collision center of mass energy energy was observed to increase from low energies of less than 100 GeV to those reached by the LHC at 7 TeV. This rise was fitted [7] to yield…”

“…With the recent operation of the Large Hadron Collider (LHC) at CERN the opportunity to study the Bose -Einstein Correlations (BEC) of identical bosons at very high hadron-hadron collision energy has been opened [1][2][3][4][5][6]. In particular the energy dependence of the BEC dimension R has recently been investigated and was found to increase with log( √ s N N ) both in proton-proton (pp) and in heavy ion (AA) collisions [7][8][9]. In the present work we investigate the energy behavior of the chaoticity parameter λ in pp collisions which determines the strength of the measured BEC effect.…”