Lithuanian Journal of Physics https://lmaleidykla.lt/ojs/index.php/physics <p>Published quarterly by the Lithuanian Academy of Sciences. The main aim of the <em>Lithuanian Journal of Physics</em> is to reflect the most recent advances in various fields of theoretical, experimental, and applied physics, including: <br>•&nbsp;mathematical and computational physics <br>•&nbsp;subatomic physics <br>•&nbsp;atoms and molecules <br>•&nbsp;chemical physics <br>•&nbsp;electrodynamics and wave processes <br>•&nbsp;nonlinear and coherent optics <br>•&nbsp;spectroscopy</p> <p style="font-weight: 400;">2024 impact factor 0.6</p> <p style="font-weight: 400;">5-year impact factor 0.4</p> en-US lfz@lma.lt (Editorial Secretary) leidyba@lma.lt (Lithuanian Academy of Sciences Publishers) Tue, 12 Aug 2025 00:00:00 +0300 OJS 3.1.2.0 http://blogs.law.harvard.edu/tech/rss 60 Title https://lmaleidykla.lt/ojs/index.php/physics/article/view/6481 Copyright (c) https://lmaleidykla.lt/ojs/index.php/physics/article/view/6481 Tue, 12 Aug 2025 00:00:00 +0300 Contents https://lmaleidykla.lt/ojs/index.php/physics/article/view/6482 Copyright (c) https://lmaleidykla.lt/ojs/index.php/physics/article/view/6482 Tue, 12 Aug 2025 00:00:00 +0300 New generalized Hermite polynomials with three variables obtained via quantum optics method and their applications https://lmaleidykla.lt/ojs/index.php/physics/article/view/6484 <p>Special polynomials (e.g. Hermite polynomials) are very important for the&nbsp;development of physics and mathematics. As a&nbsp;further extension of ordinary Hermite polynomials, we introduce new generalized Hermite polynomials with three variables and find their generating functions using the&nbsp;operator ordering method in quantum optics. Also, some new operator identities and integral formulas are obtained. As applications, the&nbsp;normalization, Wigner functions and evolutions for certain quantum states are analytically presented. These analytical results can provide conveniences for numerically studying the&nbsp;properties and applications of such quantum states.</p> An-peng Wang, Yi-xing Wang Copyright (c) https://lmaleidykla.lt/ojs/index.php/physics/article/view/6484 Tue, 12 Aug 2025 00:00:00 +0300 Second-order Rayleigh–Schrödinger perturbation theory for the GRASP2018 package: Three-particle Feynman diagram contribution to valence–valence correlations https://lmaleidykla.lt/ojs/index.php/physics/article/view/6485 <p>The method based on the&nbsp;second-order perturbation theory to identify the&nbsp;most important configuration state functions of various correlations is extended to include valence–valence correlations, which are described by the&nbsp;three-particle Feynman diagram. The&nbsp;extension presented in this work complements the&nbsp;core–valence, core, core–core and valence–valence correlations which were developed in a&nbsp;series of previous papers by G.&nbsp;Gaigalas, P.&nbsp;Rynkun, and L.&nbsp;Kitovienė. Whereas these valence–valence correlations are described by the&nbsp;three-particle Feynman diagram, additional developments to calculate the&nbsp;spin-angular parts of this diagram have been made to the&nbsp;program library librang of the&nbsp;Grasp. As an example of the&nbsp;application of the&nbsp;developed method, the&nbsp;atomic calculations of the&nbsp;energy structure for the&nbsp;Se III ion are presented. In the&nbsp;present work, this method was also used to select the&nbsp;most significant configuration state functions and to use this basis to solve the&nbsp;self-consistent field equations.</p> Gediminas Gaigalas, Pavel Rynkun, Laima Kitovienė Copyright (c) https://lmaleidykla.lt/ojs/index.php/physics/article/view/6485 Tue, 12 Aug 2025 00:00:00 +0300 Radiography and radiotherapy of the simulated human tissue environment with high-energy protons: A theoretical study https://lmaleidykla.lt/ojs/index.php/physics/article/view/6486 <p>In this research, the&nbsp;diagnostic imaging and therapy of the&nbsp;environment of selected human tissues by the&nbsp;produced protons from fusion reactions have been simulated by using the&nbsp;Geant4 tool. As a&nbsp;result, the&nbsp;stopping power and range of protons with different energies in these tissues have been obtained. As an example, Bragg peaks caused by protons with energies of 60 to 150&nbsp;MeV have been shown in breast tissue. Further, the&nbsp;penetration depth of protons, proton flux, and the&nbsp;secondary particle flux of neutrons and gamma with energies of 20 to 70&nbsp;MeV (in the&nbsp;therapeutic energy range) have been investigated in the&nbsp;breast tissue. Finally, a&nbsp;comparison of the&nbsp;residual dose in breast tissue without a&nbsp;tumour and with a&nbsp;tumour at 60&nbsp;MeV energy has been done. Therefore, with such simulations, calculations, and creative approaches, effective measures can be taken in the&nbsp;fields of proton imaging and proton therapy because proton radiography is a&nbsp;method that can be used to extract the&nbsp;maximum required information from different human tissues. Also, tumours located in different human tissues can be targeted and destroyed by using different energies of protons.</p> N.  Niknam, Mahdi Eshghi, Seyede Nasrin Hosseini Motlagh, Zohreh Parang Copyright (c) https://lmaleidykla.lt/ojs/index.php/physics/article/view/6486 Tue, 12 Aug 2025 00:00:00 +0300