Thermoelectric transport phenomena in magnetized QCD matter and study of $\phi$(1020) meson production at $\sqrt{s_{\mathrm{NN}}}$ = 5.36 TeV in Pb-Pb collisions at forward rapidity with ALICE

Understanding the behavior of strongly interacting matter under extreme conditions of temperature, density, and electromagnetic fields remains one of the central challenges in modern high-energy physics. Quantum Chromodynamics (QCD), the fundamental theory governing the strong interaction, predicts the existence of an intricate phase structure of matter, including the transition from hadronic matter to a deconfined state known as the quark--gluon plasma (QGP). Such conditions are believed to have prevailed in the early universe shortly after the Big Bang and can be recreated in laboratory environments through ultra-relativistic heavy-ion collisions at facilities such as the Large Hadron Collider (LHC).
This thesis presents a comprehensive investigation of QCD matter by integrating theoretical, phenomenological, experimental, and applied perspectives. The work begins with a detailed overview of the Standard Model of particle physics, with particular emphasis on QCD as the underlying framework for strong interactions. The QCD phase diagram is introduced to illustrate the possible phases of strongly interacting matter as functions of temperature and baryon density, along with the expected phase transitions, including deconfinement and chiral symmetry restoration. Heavy-ion collisions are discussed as a unique tool to probe these extreme conditions, and the spacetime evolution of the collision system is described, highlighting key experimental signatures of QGP formation.

A significant part of this thesis is devoted to the study of transport phenomena in QCD matter under the influence of strong magnetic fields, which are known to be generated in non-central heavy-ion collisions. Within a kinetic theory framework extended to relativistic hydrodynamics, the transport properties of both confined and deconfined phases are systematically analyzed. In particular, transport coefficients such as electrical conductivity and thermal conductivity are evaluated, providing insights into the dissipative properties of the medium. 
Building upon this, the thesis further explores thermoelectric phenomena in QCD matter. The thermoelectric response is investigated for both hadronic matter and quark--gluon plasma, considering scenarios with and without external magnetic fields. This study includes the computation of leading-order as well as higher-order thermoelectric coefficients, offering a deeper understanding of non-equilibrium processes in strongly interacting matter. These studies are particularly relevant in the context of heavy-ion collisions, where non-zero gradients and transient electromagnetic fields can give rise to novel transport effects.

In addition to the study of QCD matter, this thesis also addresses practical aspects of accelerator physics. An overview of particle accelerators and detectors, with particular focus on the LHC and the ALICE experiment, is presented. The design and optimization of novel materials for beampipe applications in accelerator technology are investigated, considering the demanding operational conditions involving high radiation length, thermal loads, and mechanical stresses. The proposed material design, basically Al and Mg-rich ternary alloys, aims to enhance the efficiency, durability, and cost-effectiveness of beampipe structures, with potential implications for both current and future high-energy physics experiments.
The final part of the thesis is dedicated to an experimental analysis of $\phi(1020)$ meson production in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.36~\mathrm{TeV}$ in forward rapidity using Run-3 data from the ALICE detector at the LHC. The $\phi$ meson, composed of a strange quark--antiquark pair ($s\bar{s}$), serves as an important probe of the medium due to its sensitivity to strangeness production and its relatively small hadronic interaction cross section.
A detailed description of the detector setup, including standalone and global muon tracking, is provided along with the selection criteria and kinematic cuts applied in the analysis. The invariant mass spectra are reconstructed, and the $\phi$ meson yield is extracted after careful background subtraction and efficiency corrections using Monte Carlo simulations. The results contribute to the understanding of strangeness production and medium effects in heavy-ion collisions.

Overall, this thesis establishes a coherent link between the theoretical foundations, phenomenological modeling, experimental investigations, and technological aspects of accelerator and detector systems used to study QCD matter. By bridging these diverse aspects, it provides a comprehensive and unified exploration of strongly interacting matter under extreme conditions.