7-12 June 2021
Europe/Paris timezone

Extension of Glauber-like model for Proton-Proton collisions using anisotropic and inhomogeneous density profile

Jun 10, 2021, 6:45 PM


Theory poster QCD physics Poster Session


Suman Deb (Indian Institute of Technology Indore (IN))


The formation of partonic medium in the relativistics heavy-ion collisions is always marked by the values of the ratio of certain observables assuming $p+p$ collisions as a reference. But recent studies of small systems formed in $p+p$ collisions at the LHC energies hint towards the possibility of production of medium with collective behaviour. Results from $p+p$ collisions have routinely been used as baseline to analyse and understand the production of QCD matter expected to be produced in nuclear collisions. Therefore, results from $p+p$ collisions required more careful investigation to understand whether QCD matter is produced in high multiplicity $p+p$ collisions. With this motivation, the Glauber model traditionally used to study the heavy-ion collision dynamics at high-energies is applied to understand the dynamics of $p+p$ collisions. We have used anisotropic and inhomogeneous quark/gluon based proton density profile, a realistic picture obtained from the results of deep inelastic scattering, and found that this model explains the charged-particle multiplicity distribution of $p+p$ collisions at LHC energies very well. Collision geometric properties like impact parameter and mean number of binary collisions ($\langle N_{coll} \rangle$), mean number of participants ($\langle N_{part} \rangle$) at different multiplicities are determined for $p+p$ collisions. We further used these collision geometric properties to estimate average charged-particle pseudorapidity density ($\langle dN_{ch}/d\eta \rangle$) and found it to be comparable with the experimental results. Knowing $\langle N_{coll} \rangle$, we have for the first time obtained nuclear modification-like factor ($R_{HL}$) in $p+p$ collisions. We also estimated eccentricity and elliptic flow as a function of charged-particle multiplicity using the linear response to initial geometry and found a good agreement with experimental results.

Primary author

Suman Deb (Indian Institute of Technology Indore (IN))


Dr Golam Sarwar (Department of Physics, Indian Institute of Technology Indore, Simrol, Indore 453552, India) Dhananjaya Thakur (Indian Institute of Technology Indore (IN)) Mr Pavish S. (Department of Physics, Indian Institute of Technology Indore, Simrol, Indore 453552, India) Prof. Raghunath Sahoo (Indian Institute of Technology Indore (IN)) Prof. Jan-e Alam (Variable Energy Cyclotron Centre, 1/AF, Bidhan Nagar, Kolkata 700064, India)

Presentation materials