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Wigner FK RMI Elméleti Osztály Szemináriuma
Tisztelettel meghívjuk


            Suraj Prasad
            (Indian Institute of Technology)


"Segregating inclusive, prompt and non-prompt production of J/𝜓 at the LHC 
energies using machine learning”


címmel tartandó szemináriumára.


Kivonat:



In collider experiments, the production of J/𝜓, a bound state of charm and 
anti-charm quarks (c\𝑏𝑎𝑟𝑐), can serve as the testing ground for the theory of 
strong interaction. In experiments, J/𝜓 meson production yield is preferably 
estimated by reconstructing it from its electromagnetic decays to dileptons, 
i.e., J/𝜓→𝜇++𝜇− or J/𝜓→𝑒++𝑒−. This inclusive production of J/𝜓 includes both 
prompt and non-prompt contributions. The prompt J/𝜓 are produced in the 
initial hadronic collisions or via feed-down from directly produced higher 
charmonium states. In contrast, the non-prompt J/𝜓 are the products of weak 
decays of the beauty hadrons. This study uses machine learning (ML) based 
models such as the XGBoost and LightGBM to identify the inclusive, prompt and 
non-prompt production of J/𝜓 from the uncorrelated background dimuon pairs. 
The model is trained using PYTHIA8 generated data for proton-proton (pp) 
collisions at 𝑠√=13 TeV. The inputs to both the ML models include the 
observables that are easily obtained in the experiments. Both models attain a 
prediction accuracy of up to 99% while retaining the transverse momentum, 
pseudorapidity and collision energy dependence. In addition, the models can 
be applied to identify each dimuon pair separately having any value of 
transverse momentum in any rapidity range. Thus, it can probe the production 
fraction of non-prompt J/𝜓 (𝑓𝐵) in smaller 𝑝𝑇 and rapidity bins. In addition, 
this dimuon level tagging can help us study many physics aspects, such as 
polarization and flow measurements of prompt and nonprompt  J/𝜓 with ease 
experimentally, which is an advantage of using this method.

Reference: S. Prasad, N. Mallick and R. Sahoo, Phys. Rev. D 109, 014005 
(2024).



Helye: Wigner FK RMI III. ép. Tanácsterem
Ideje: 2024 április 19. péntek d.u. 2 óra

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