arXiv subjects

Enis Yazici

Publications and source records attributed to Enis Yazici.

4 recordsLinked to original sources

arXiv2025

Mass and Decay-Constant Evolution of Heavy Quarkonia and $B_c$ States from Thermal QCD Sum Rules

We analyze the thermal behavior of heavy vector and axial-vector mesons ($J/\psi$, $\Upsilon$, and $B_c$) within the finite-temperature QCD sum-rule framework. Using updated PDG-2024 quark masses, modern lattice-informed gluon condensates, and a temperature-dependent continuum threshold constrained by vacuum stability, we compute the evolution of the masses $m(T)$ and decay constants $f(T)$ up to $T/T_c \lesssim 0.9$. At $T=0$ the sum rules are calibrated to reproduce the experimental and LHCb masses and reference decay constants within the expected $\mathcal{O}(10\%)$ accuracy of a leading-order $+$ $D{=}4$ phenomenological analysis. The subsequent finite-temperature evolution should therefore be interpreted as a calibrated model prediction within this framework rather than as a fully parameter-free determination. Near the critical temperature, the relative suppression follows a clear hierarchy $\Upsilon < J/\psi < B_c$, consistent with their binding energies and lattice spectral trends. The predicted $1P$--$1S$ splitting for the $B_c$ system, $0.477~\mathrm{GeV}$, is consistent with the LHCb observation of orbitally excited $B_c^{+}$ states. The results provide a coherent finite-temperature baseline for future extensions including radiative, higher-dimensional, and width effects.

hep-ph↗

arXiv2025

A Pedagogical Framework for Physics-Informed Machine Learning: From Classical Pendulum to Quantum Anharmonic Oscillator Using PyTorch on Modern GPU Hardware

We present a five-module pedagogical framework for teaching physics-informed machine learning (ML) through two progressively complex physical systems: a driven, damped nonlinear pendulum and a one-dimensional quantum anharmonic oscillator. Five model architectures are implemented and compared: a standard artificial neural network (ANN), a one-dimensional convolutional neural network (CNN), a long short-term memory (LSTM) network, and two physics-informed neural networks (PINNs) -- one per physical system. All models are implemented in PyTorch~2.9 and executed on an NVIDIA RTX~5090 GPU, making the framework directly applicable to modern deep learning laboratory courses. Quantitative benchmarks show that data-driven models achieve mean absolute errors of $1.3\times10^{-2}$~rad (pendulum ANN) and $4.4\times10^{-5}$~a.u.\ (quantum CNN), while the curriculum-trained pendulum PINN reaches an MAE of $3.1\times10^{-2}$~rad using only collocation points. A systematic CPU-vs-GPU benchmark reveals speedups ranging from $1.2\times$ (small ANN) to $24.6\times$ (LSTM), providing a concrete pedagogical demonstration of when GPU acceleration is -- and is not -- warranted. The framework is packaged as self-contained Jupyter notebooks designed for a graduate-level \emph{Deep Neural Networks for Physical Systems} course, with embedded reflection questions that guide students from data-driven thinking toward physics-constrained formulations.

quant-ph↗

arXiv2016

Thermal Spectrum of Heavy Vector and Axial Vector Mesons in the Framework of QCD Sum Rules Method

The masses and the leptonic decay constants of vector and axial vector heavy-heavy mesons are calculated using the thermal QCD sum rules approach. While obtaining the QCD sum rules, additional operators in the Wilson expansion and also temperature dependency of the continuum threshold are taken into account. The masses and the decay constants remained unchanged up to $T\simeq100~MeV$. After that point, they start to diminish. At the critical temperature, the masses decreased about $3\%$, $5\%$ and $14\%$ for the vector mesons $Υ$, $B_{c}$ and $J/ψ$; $6\%$, $7\%$ and $22\%$ for the axial vector mesons $χ_{b1}$, $B_{c}$ and $χ_{c1}$, respectively. The decay constants reached about less than $20\%$ of their vacuum values. The obtained results of the thermal mass and decay constant calculations at zero temperature are in a very good agreement with the other non-perturbative calculations at vacuum as well as with the experimental data.

hep-ph↗

arXiv2014

A geometric method of constructing exact solutions in modified f(R,T)-gravity with Yang-Mills and Higgs interactions

We show that a geometric techniques can be elaborated and applied for constructing generic off-diagonal exact solutions in $f(R,T)$--modified gravity for systems of gravitational-Yang-Mills-Higgs equations. The corresponding classes of metrics and generalized connections are determined by generating and integration functions which depend, in general, on all space and time coordinates and may possess, or not, Killing symmetries. For nonholonomic constraints resulting in Levi-Civita configurations, we can extract solutions of the Einstein-Yang-Mills-Higgs equations. We show that the constructions simplify substantially for metrics with at least one Killing vector. There are provided and analyzed some examples of exact solutions describing generic off-diagonal modifications to black hole/ellipsoid and solitonic configurations.

gr-qc↗