13–16 Jan 2025
Asia/Kolkata timezone

First measurement of high $p_\mathrm{T}$ azimuthal anisotropy using subevent cumulants in pPb collisions at CMS

15 Jan 2025, 09:13
7m
6. Collectivity in small systems Parallel D

Speaker

Rohit Kumar Singh (Indian Institute of Technology Madras (IN))

Description

Measurements at the LHC have provided evidence for collective behavior in high-multiplicity proton-lead (pPb) collisions through multiparticle correlation techniques. Yet, no conclusive evidence of jet quenching, indicating the energy loss of high-$p_\mathrm{T}$ partons as they traverse the medium, has been detected in pPb. This raises the intriguing question: How can a medium described by hydrodynamics, and that significantly modifies the distribution of final-state hadrons, yet has no significant impact on the distribution of high-pT particles? To investigate this, a comprehensive study of differential Fourier coefficients ($v_{n}$) in particle transverse momentum ($p_\mathrm{T}$) and event multiplicity is presented in pPb collisions recorded by the CMS experiment at a nucleon-nucleon center-of-mass energy $\sqrt{s_{_{\mathrm{NN}}}} = 8.16$ TeV. In particular, new measurements of $p_\mathrm{T}$-differential multiparticle cumulants using the subevent method probes an extended phase space region up to a high particle $p_\mathrm{T}$. Additionally, we compare the results between pPb and PbPb collisions in the same multiplicity window. This comparison will help assess similarities and differences in the medium's interaction with high-$p_\mathrm{T}$ particles in these two collision types.

Author

Rohit Kumar Singh (Indian Institute of Technology Madras (IN))

Presentation materials