arXiv subjects

Aswathy Menon Kavumpadikkal Radhakrishnan

Publications and source records attributed to Aswathy Menon Kavumpadikkal Radhakrishnan.

5 recordsLinked to original sources

arXiv2026

Constraining $α$-cluster compactness in $^{16}\rm O$ and $^{20}\rm Ne$ at TeV energies using azimuthal anisotropy

Anisotropic flow in ultra-relativistic light-ion collisions is sensitive to the initial geometry of the colliding nuclei. We investigate whether elliptic flow measurements can constrain the parameters of the proposed $α$-clustered nuclear density distributions of $^{16}$O and $^{20}$Ne at LHC energies. Using the hybrid framework IP-Glasma+MUSIC+iSS+UrQMD, we simulate OO and Ne--Ne collisions at $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV for the Woods--Saxon and $α$-clustered configurations with varying cluster compactness. The elliptic flow coefficient $v_2\{2,|Δη|>1\}$ is calculated in the kinematic acceptances of ALICE, CMS, and ATLAS detectors and is compared with the Run~3 OO and Ne--Ne experimental measurements. It is observed that the final-state elliptic flow is significantly sensitive to the nuclear geometry, especially in OO collisions, where different configurations lead to distinct centrality dependencies and peak positions of $v_{2}$. By performing a systematic variation of the cluster size and inter-cluster separation in $^{16}$O and $^{20}$Ne nuclei, this work attempts to identify the cluster parameter range that provides the best agreement with the experimental data. These results show that the flow observables in TeV-energy light-ion collisions can be used to optimize the nuclear structure parameters of light nuclei.

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arXiv2026

Topological production of charmonia with event-shape engineering in $pp$ collisions at $\sqrt{s} = 13$ TeV using PYTHIA8

The production of heavy quarks (charm and beauty) in high-energy hadronic and nuclear collisions provides an excellent testing ground for the theory of strong interactions and validates models based on quantum chromodynamics (QCD). In this work, prompt and nonprompt production of $\rm{J/}ψ$ in $pp$ collisions at $\sqrt{s}=13$ TeV are studied as a function of transverse spherocity using PYTHIA8. $\rm{J/}ψ$ is reconstructed via its electromagnetic decay to dielectrons and dimuons, in mid- and forward-rapidity, respectively. Transverse spherocity, an event shape observable, is used to distinguish hard QCD events from the softer, isotropic ones. In PYTHIA8, the production of $\rm{J/}ψ$ can be influenced by the average number of multiple parton interactions ($\langle N_{\rm mpi} \rangle$), owing to the underlying events (UE), which have a dominant contribution to particle production at lower transverse momentum. Since transverse spherocity is correlated to $\langle N_{\rm mpi} \rangle$, this can serve as an experimentally accessible tool for event selection to study the underlying QCD processes influencing the prompt and nonprompt $\rm{J/}ψ$ production. This study reveals the correlation between heavy-flavor production dynamics and topological event selection in $pp$ collisions using PYTHIA8, whose relevance awaits experimental validation.

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arXiv2026

Probing the microscopic origin of prompt and non-prompt $D^{0}$ production through event-shape engineering in proton-proton collisions at the LHC

Heavy-flavour hadrons are produced in the early stages of ultra-relativistic collisions at the LHC via hard partonic interactions and experience the whole system evolution. The study of prompt and non-prompt $D^{0}$ mesons provides an independent avenue to test the theories of quantum chromodynamics and to investigate beauty hadron production. Moreover, the production of both prompt and non-prompt $D^{0}$ is influenced by microscopic processes such as multi-partonic interactions (MPI) and hadronisation through fragmentation. In this study, an attempt is made to understand the production of prompt and non-prompt $D^{0}$ mesons in proton-proton collisions at $\sqrt{s}=13.6$ TeV using the PYTHIA8 event generator, which offers a qualitative description of charm production. The role of the transverse momentum transfer in the hardest partonic scattering ($\hat{p}_{\rm T}$), MPI, and color reconnection is systematically explored. In addition, the charged particle production in different topological regions with respect to the leading $D^{0}$ meson is studied to assess the influence of the $D^{0}$ meson on the event topology and to examine the selection biases arising from the use of charged particle multiplicity as an event classifier.

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arXiv2025

Probing the sensitivity of anisotropic flow coefficients to the initial nuclear structure in pO and OO collisions at the LHC

RHIC and LHC have injected $^{16}\rm O$ nuclei in their accelerator complexes with a focus on investigating collectivity and the origin of quark-gluon plasma signatures in small collision systems. The $^{16}\rm O$ nuclei are known to possess clusters of $α$-particles ($^{4}\rm He$) inside the nucleus. This paper attempts to study the clustered-nuclear-geometry dependence of anisotropic flow coefficients such as elliptic flow ($v_2$) and triangular flow ($v_3$), which are sensitive to the nuclear geometry of colliding nuclei. The study is performed in pO and OO collisions at $\sqrt{s_{\rm NN}}=9.61$~TeV and 7~TeV respectively, employing a hybrid model encompassing IP-Glasma + MUSIC + iSS + UrQMD. The results of the clustered nuclear geometry are compared with those of the Woods\,--\,Saxon nuclear profile. Both initial and final state anisotropies are estimated. This study is thus one of its first kind, where the study of anisotropic flow coefficients for pO and OO collisions is presented using a hybrid hydrodynamics model. While the effect of $α$-clustering in pO is found to be small, it is significant for each observable studied in OO collisions. It is also observed that the magnitude of this effect has a noteworthy dependence on the size of the \textsuperscript{4}He.

hep-ph↗

arXiv2025

Investigating radial flow-like effects via pseudorapidity and transverse spherocity dependence of particle production in pp collisions at the LHC

Recent observations of quark-gluon plasma (QGP) like signatures in high multiplicity proton-proton (pp) collisions, have compelled the heavy-ion physics community to re-examine small collision systems for proper baseline studies. Event-shape-based studies in pp collisions have succeeded to a certain extent in identifying the rare events mimicking such heavy-ion-like behaviour. In this study, we incorporate PYTHIA8 and AMPT to study radial flow-like signatures in pp collisions at $\sqrt{s} = 13$ TeV as a function of transverse spherocity and pseudorapidity. The selection of softer events possibly carrying heavy-ion-like features is performed using the transverse spherocity event-shape observable. As the particle production mechanism in midrapidity differs greatly from the forward rapidity, a pseudorapidity-dependent study is meaningful. Keeping ALICE 3 upgrades at the LHC in mind, this study aims to demonstrate the transverse spherocity and pseudorapidity dependence of the mean transverse momentum, particle ratios, and kinetic freezeout parameters in pp collisions at $\sqrt{s}$ = 13 TeV using PYTHIA8. We observe that the isotropic events show enhanced radial-flow effects in all multiplicity classes, however, the jetty events show signatures of the radial flow-like effects only in high-multiplicity events. For the first time, we show the transverse spherocity and pseudorapidity dependence of partonic modification factor in pp collisions, which clearly shows that by choosing transverse spherocity, one can directly probe the radial flow-like effects in pp collisions at the LHC.

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