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Z. Ong

Publications and source records attributed to Z. Ong.

7 recordsLinked to original sources

Intermittency in pp collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS collaboration

The intermittency-type fluctuations as outlined by Bialas and Peschanski in the 1980s is analysed in $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS collaboration at CERN. Our preliminary analysis shows that the intermittency exponents in the bin-averaged scaled factorial moments decrease in magnitude with increasing collision energy at the TeV scale, which suggests that the cascading nature of multiparticle production described by the $α$-model is weakening. We outline possible areas planned for future studies.

hep-ph

Multifractal behaviour in multiparticle production in $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment

Multifractal analysis was performed on $pp$ collision data at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment at CERN. The data was obtained and processed from the CERN Open Data Portal. Vertical analysis was used to compute the generalised dimensions $D_q$ and the multifractal spectra $f(α)$ of the data, which reveals the level of complexity of its pseudorapidity distribution. It was found that the $f(α)$ curves widen with increasing collision energy, signalling an increase in branching complexity.

hep-ph

Intermittency analysis of $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment

The method of horizontal scaled factorial moments as outlined by Bialas and Peschanski was used to conduct intermittency analysis for $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment. The data was obtained and processed from the CERN Open Data Portal. It was found from 1D analysis that the intermittency strength decreases with increasing energy, indicating that the signature of the $α$-model of random cascading that the former is based on seems to be weakening. Intermittency was stronger in 2D, but did not reveal any clear trend with increasing collision energy.

hep-ex

Forward-backward multiplicity distribution with the Chou-Yang model for $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment

A Chou-Yang type multiplicity distribution comprising a total multiplicity component and a binomial asymmetry component is used to describe charged hadron multiplicity data at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment at CERN. The data was obtained and processed from the CERN Open Data Portal. For the total multiplicity component, it was found that a convex sum of a Negative Binomial Distribution and a Furry-Yule Distribution is able to describe the shoulder-like structure characteristic of KNO scaling violation well. The mean cluster size produced from collisions was also found to increase with collision energy. A prediction is given for $pp$ collisions at $\sqrt{s}=$ 14 TeV.

hep-ph

Oscillations in Modified Combinants of Hadronic Multiplicity Distributions

Oscillations in modified combinants ($C_j$s) have been of interest to multiparticle production mechanisms since the 1990s. Recently, there has been a discussion on how these oscillations can be reproduced by compounding a binomial distribution with a negative binomial distribution. In this work, we explore a stochastic branching model based on a simple interaction term $λ\overlineψϕψ$ for partons and propose a hadronization scheme to arrive at the final multiplicity distribution. We study the effects that compounding our model with a binomial distribution has on $C_j$s and explore its physical implications. We find that there is a significant difference in the oscillations in $C_j$s between high energy $pp$ and $p\bar{p}$ scattering that our model can reproduce.

hep-ph

Numerical solutions to Giovannini's parton branching equation up to TeV energies at the LHC

Giovannini's parton branching equation is integrated numerically using the 4th-order Runge-Kutta method. Using a simple hadronisation model, a charged-hadron multiplicity distribution is obtained. This model is then fitted to various experimental data up to the TeV scale to study how the Giovannini parameters vary with collision energy and type. The model is able to describe hadronic collisions up to the TeV scale and reveals the emergence of gluonic activity as the centre-of-mass energy increases. A prediction is made for $\sqrt{s}$ = 14 TeV.

hep-ph

Effects of phase space variables on oscillations of modified combinants

It has been shown recently that additional information can be obtained from charged particle multiplicity distribution by investigating their modified combinants $C_j$, which exhibit periodic oscillatory behaviour. The modified combinants obtained from experimental data can be expressed in a recurrent form involving the probability of obtaining $N$ charged particles $P(N)$, scaled by the void probability $P(0)$. The effects of various experimental observables such as $|η|$, $p_T$ and centre-of-mass collision energy $\sqrt{s}$ on the oscillatory behaviour of $C_j$ will be discussed.

hep-ph