物理最新文献

{"title":"Searching for gluino LSP at the LHC","authors":"Paulina Knees,&nbsp;Essodjolo Kpatcha,&nbsp;Iñaki Lara,&nbsp;Daniel E. López-Fogliani,&nbsp;Carlos Muñoz,&nbsp;Natsumi Nagata,&nbsp;Hidetoshi Otono","doi":"10.1140/epjc/s10052-025-14199-6","DOIUrl":"10.1140/epjc/s10052-025-14199-6","url":null,"abstract":"<div><p>We analyse relevant signals expected at the LHC, assuming that the gluino is the lightest supersymmetric particle (LSP) in the framework of the <span>(mu nu )</span>SSM. In this <i>R</i>-parity violating model, the presence of couplings involving right-handed neutrinos solves simultaneously the <span>(mu )</span> problem and the accommodations of neutrino masses and mixing angles. We study gluino pair production in quark-antiquark and gluon-gluon collisions. The main decay channels for the gluino LSP are the three-body decays to two quarks and a lepton or a neutrino. In both cases, the leading channels occur for the third family of quarks. We compare the predictions of this scenario with LHC searches for prompt and long-lived particles. To analyse the parameter space we sample the <span>(mu nu )</span>SSM for a gluino LSP, paying special attention to reproduce the current experimental data on neutrino and Higgs physics, as well as flavour observables. Our results imply a lower limit on the mass of the gluino LSP of about 2600 GeV, and an upper limit for the decay length of about 6 cm.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 5","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14199-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast and efficient adsorption of La(III) on magnetic carbon nitride-based HKUST-1 composites","authors":"Dan Xu,&nbsp;Feiyan Liu,&nbsp;Xiao Liu,&nbsp;Jiaming Wang,&nbsp;Xiancai Li","doi":"10.1007/s00339-025-08594-9","DOIUrl":"10.1007/s00339-025-08594-9","url":null,"abstract":"<div><p>In this study, using HKUST-1 as the base, g-C₃N₄ and HKUST-1 were mixed by solvothermal method to form graphitic carbon nitride MOF material, and then modified with Fe₃O₄ nanoparticles to form the final composite Fe₃O₄/g-C₃N₄/HKUST-1.The composite Fe₃O₄/g-C₃N₄/HKUST-1 was characterized by XRD, FT-IR, SEM, VSM, BET and XPS. By studying the adsorption properties of g-C₃N₄/HKUST-1 and Fe₃O₄/g-C₃N₄/HKUST-1 on La³⁺ under different conditions, the optimal adsorption conditions were established. Kinetic and isothermal thermodynamic models were used to evaluate the stability and regeneration capacity of the adsorbent. The results show that the composite Fe₃O₄/g-C₃N₄/HKUST-1 has excellent La³⁺ recovery performance and magnetic properties, and has good stability and recovery performance. Through a series of optimization experiments on adsorbents, when pH is 6, the adsorption effect of Fe₃O₄/g-C₃N₄/HKUST-1 is the best, and the adsorption saturation state is reached within 30 min, and the adsorption capacity can reach 225.11 mg/g, which has great potential in environmental management and resource recovery.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hysteresis loops in a mixed-spin (3/2, 3) nanotube with core-shell structure","authors":"A. El Abbassi,&nbsp;M. Salama,&nbsp;E. B. Choubabi,&nbsp;N. Hachem,&nbsp;M. El Bouziani","doi":"10.1007/s00339-025-08611-x","DOIUrl":"10.1007/s00339-025-08611-x","url":null,"abstract":"<div><p>This work investigates a ferrimagnetic Ising nanotube with a spin-3/2 core and a spin-3 shell. The Blume-Capel model and the mean-field approach based on the Gibbs-Bogoliubov inequality are used to examine numerically the hysteresis behavior of this system as a function of various parameters, namely exchange interactions, crystal fields, and temperature. Although the mean-field method, derived from statistical mechanics, neglects fluctuations, it has been successfully applied to describe various phase transition phenomena, particularly hysteresis. This nanotube exhibits first-order phase transitions for low values of magnetic field <i>h</i>, which disappear for higher values. The absolute increase in the crystal field <span>(D_C)</span> in the core causes deformation of the hysteresis loops (splitting and lateral broadening) and a significant decrease in remanent magnetization and coercive field, accompanied by the appearance of stability levels. Moreover, increasing the absolute value of <span>(D_S)</span> in the shell transforms the tri-loops into a single loop, and for <span>(D_S le -3)</span>, the loop becomes rectangular, displaying a well-defined and stable coercive field. Increasing the exchange interaction <span>(J_S)</span> in the shell leads to more complex loops, evolving from a single loop to multiple loops up to nine. Beyond <span>(J_S = 0.4)</span>, the system stabilizes with clear tri-loops. Concerning the increase in the absolute value of the interfacial exchange interaction <span>(J_{int})</span>, a single hysteresis loop with weak fluctuations is observed at low <span>(|J_{int}|)</span>, which transforms into multi-loops (three then five), then these loops merge into a broadened loop, with an area that continues to grow by increasing <span>(|J_{int}|)</span>. In addition, the remanent magnetization and coercive field increase with <span>(|J_{int}|)</span>. Finally, at low temperatures <i>T</i>, the system exhibits tri-loops, however, hysteresis decreases with rising temperature and vanishes beyond the critical temperature. Both remanent magnetization and coercive field gradually decrease with increasing <i>T</i>.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy spectrum and adapting the transmission coefficient of excitons in core–shell GaAs/AlxGa1-xAs spherical and cubic quantum dots","authors":"Z. A. El-Wahab,&nbsp;M. K. Abu-Assy,&nbsp;Juhaina M. Taha","doi":"10.1007/s00339-025-08583-y","DOIUrl":"10.1007/s00339-025-08583-y","url":null,"abstract":"<div><p>This study investigates the quantum size effect on the energy spectrum of the exciton as a charge carriers confined in a core–shell of spherical and cubic GaAs/Al_xGa_1-xAs quantum dots with finite potential barrier specified as a function of the doping material. The calculations indicated the inverse relationship between the confinement energy values of the first three energy levels and the dot volumes. In comparing the energy levels of the two shapes, results indicated that the energy values for the first two levels of the spherical dot are lower than those for the cubic one, however for the third level the energy of the spherical dot is larger than that for the cubic dot. Tunneling effects are studied by calculating the transmission coefficient related to each energy level. The results exhibited that larger values correspond to the excitons in the second excited state and small dot volumes. Additionally, increasing the doping values enhanced decreases in the transmission coefficient values. Finally, calculation to the wavelength of the emitted light from the ground state energy level illustrated that the emitted wavelengths more precisely affected by the dot compositions. The emitted light wavelength from the ground state energy level is also examined. For x = 0.2, the emitted wavelengths range from 658.7 to 721.8 nm for spherical Quantum dots and 649.5 to 720.3 nm for cubic Quantum dots across all volumes. For x = 0.4, the emitted wavelengths fall within the yellow light range (571–586.6 nm) for small Quantum dots (125–216 nm³), the orange light range (597.9–624.8 nm) for medium-sized Quantum dots (343–1728 nm³), and the red-light range (627.4–631.2 nm) for larger Quantum dots (2197–3375 nm³). These findings contribute to the development of more efficient optoelectronic devices and quantum computing components by providing insight into quantum confinement and light emission properties in nanostructured materials.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00339-025-08583-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning molecular dynamics for large-scale insights into yttrium's structural, thermal and diffusion properties","authors":"Li Ma,&nbsp;Haowen Wang,&nbsp;Yongzhi Wu,&nbsp;Keyuan Chen,&nbsp;Haoxiang Zhang,&nbsp;Xingkao Zhang,&nbsp;Ju Rong,&nbsp;Yudong Sui,&nbsp;Xiaohua Yu,&nbsp;Jing Feng","doi":"10.1007/s00339-025-08560-5","DOIUrl":"10.1007/s00339-025-08560-5","url":null,"abstract":"<div><p>Recently, machine learning techniques that employ neural networks have been extensively utilized in the study of interatomic potentials, exhibiting notable accuracy and efficiency. Among various materials, the rare earth element yttrium (Y) has gained increasing significance due to its extensive applications in both high-carbon technologies, such as battery manufacturing, and low-carbon technologies, such as new energy solutions. However, the substantial computational expense associated with ab initio molecular dynamics (AIMD) limits extensive investigations into these materials, thereby hindering their practical applications. To address this challenge, we employed a machine learning molecular dynamics approach, which achieves at least a 100-fold improvement in computational efficiency compared to conventional AIMD calculations while maintaining high accuracy. We systematically compared the deep potential (DP) model's predictions of lattice constants, melting point, defect formation energies, surface energies, elastic constants, and thermal transport properties with density functional theory (DFT) results to validate the exceptional accuracy of the developed DP model in predicting physical properties, which are approximately consistent with DFT results. Specifically, the predicted equilibrium lattice constant by the DP model deviates by less than 0.15% from the DFT result, the vacancy formation energy is 0.3 eV lower, and the interstitial formation energy is 0.9 eV higher. In terms of elastic properties, the absolute error in the predictions compared to DFT results is less than 4.7 GPa for over 90% of the cases. Furthermore, molecular dynamics simulations based on the DP framework demonstrated that increasing temperature significantly enhances the diffusivity of Y atoms, reaching a self-diffusion coefficient of 4.9 × 10^-12m²/s at the melting point, which exhibits diffusion behavior similar to that of typical hexagonal close-packed metals. Further analysis revealed that the phonon dispersion curves were accurately predicted, particularly in the low-frequency and high-frequency branches, with a relative error in lattice thermal conductivity as low as 3.1%. By developing a reliable and efficient structural prediction framework, our research paves the way for large-scale and open-ended exploration of complex material systems.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of heat engines with fixed heat fluxes at the hot or the cold side","authors":"J. J. Fernández","doi":"10.1140/epjp/s13360-025-06395-w","DOIUrl":"10.1140/epjp/s13360-025-06395-w","url":null,"abstract":"<div><p>We use the low dissipation model to optimize the power of heat engines in which the total amount of energy taken from the hot reservoir is kept fixed while the total amount of energy dissipated to the cold reservoir is optimizable. Then, we optimize heat engines working while they reject fixed amounts of energy to the cold reservoir. We find that under these operating conditions, the maximum power and efficiency at maximum power are different from those of thermal engines that are optimized without imposing restrictions. For both working situations, we analyze the effect that small perturbations changing the value of the fixed heat (on the hot or cold side) have on the heat engine work, efficiency, and power.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-025-06395-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigate the annealing effect on structural, optical and surface morphological properties of NiO/Co/Zn thin films prepared by e-beam deposition","authors":"Dhara Singh Meena,&nbsp;Madhu Yadav,&nbsp;Chhagan Lal,&nbsp;M. K. Jangid","doi":"10.1007/s00339-025-08533-8","DOIUrl":"10.1007/s00339-025-08533-8","url":null,"abstract":"<div><p>In this study the effect of annealing on structural, optical and surface morphological properties of NiO/Co/Zn thin films were investigated. NiO/Co/Zn thin films were deposited onto the glass substrate using e-beam deposition technique. The prepared thin films were then vacuum annealed at two different temperatures (300 °C and 400 °C) to assess the impact of annealing on their properties. The presence of the cubic NiO phase was verified using X-ray diffraction (XRD) analysis, with enhanced grain growth and improved crystallinity observed at higher annealing temperature (400 °C). UV–Vis spectroscopy was revealed a notable increase in emission intensity with annealing, particularly at 400 °C, suggesting reduced non-radiative recombination and improved electron–hole pair recombination efficiency. The energy bandgap of the films decreased from 4.34 eV (as-deposited) to 4.15 eV (annealing at 400 °C). This reduction into bandgap is attributed to improved crystallinity and fewer structural defects, enhancing photon absorption in the visible spectrum. Atomic force microscopy (AFM) provided insights into surface morphology. A noticeable transformation in grain size and surface features was observed as the annealing temperature increased. The FE-SEM images indicate that films were uniformly deposited across the substrate, exhibiting excellent adhesion. The presence of specific peaks in the EDX spectra for Ni, Co and Zn corroborates the successful deposition of Co and Zn alongside NiO. Hall Effect measurements were revealed the conductivity of the thin film experiences a notable rise from 1.38 Ω⁻¹ cm⁻¹ to 96.94 Ω⁻¹ cm⁻¹ after annealing. The findings confirm that annealing significantly enhances the structural, optical and surface morphological properties of NiO/Co/Zn thin films.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of additive-assisted texturing on surface morphology and interface defect density in silicon heterojunction solar cells","authors":"Honey Sharma,&nbsp;Shrestha Bhattacharya,&nbsp;Shahnawaz Alam,&nbsp;Silajit Manna,&nbsp;Ashutosh Pandey,&nbsp;Son Pal Singh,&nbsp;Vamsi Krishna Komarala","doi":"10.1007/s00339-025-08589-6","DOIUrl":"10.1007/s00339-025-08589-6","url":null,"abstract":"<div><p>The efficiency of silicon heterojunction (SHJ) solar cells depends critically on c-Si surface topography and defect passivation. This study optimizes the formation of random pyramids using chemical additives in the texturization solution, achieving pyramids with optimal base and vertex angles and a low surface reflectance of ∼ 10.51%. Interface defect states (D_it) and surface lifetime (τ_surf) were analysed at various cell fabrication stages. The deposition of i-a-Si: H layers on both sides of the textured wafer reduced D_it to ∼ 8.5 × 10⁸ eV^− 1cm^− 2 with τ_surf ∼ 4.9 ms indicating good chemical passivation of the defects. Adding the carrier-selective layers (p-a-Si: H and n-nc-Si: H) further reduced D_it to ∼ 7.0 × 10⁸ eV^− 1cm^− 2 and enhanced τ_surf to ∼ 21.0 ms. However, sputtering-induced plasma damage during ITO deposition increased D_it to ∼ 11.8 × 10⁸ eV^− 1cm^− 2, lowering τ_surf to ∼ 3.3 ms. Optimized c-Si surface conditioning led to a power conversion efficiency of ∼ 22.4% and an open-circuit voltage of ∼ 727 mV from an SHJ cell. Device dark current-voltage analysis also provided insights into the charge carrier recombination dynamics.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Line broadening analysis for open states: two- and three-photon spectroscopy","authors":"Dorothy Koki Mringie,&nbsp;Kipkorir Cornelius,&nbsp;Geoffrey Kihara Rurimo,&nbsp;Ogaro Elijah Nyakang’o","doi":"10.1140/epjd/s10053-025-01004-y","DOIUrl":"10.1140/epjd/s10053-025-01004-y","url":null,"abstract":"<p>In this paper, we present a theoretical analysis of line broadening mechanisms for open states in two-photon spectroscopy (a V-type atomic system). The effects of optical pumping of population to a dark state (or meta-stable states) and partial Doppler broadening due to wavelength mismatch are solved using electromagnetically induced absorption (EIA) effect in triple resonance spectroscopy. The finite linewidth of IR transition and opposite Doppler shifts of the fixed IR laser frequency fields in a counter-propagation <span>(Lambda )</span>-system, which restricts EIA effect to a narrow range of frequencies. For atomic vapor at a finite temperature, narrow dips with large amplitude are induced on the transparency spectra of the probe, effectively resolving closely spaced lines of the <span>(6text {P}_{3/2})</span> state in <span>(^{85})</span>Rb.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"79 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Returning back to Mukhanov parametrization of inflationary equation of state","authors":"Barun Kumar Pal","doi":"10.1140/epjc/s10052-025-14259-x","DOIUrl":"10.1140/epjc/s10052-025-14259-x","url":null,"abstract":"<div><p>We have re-examined Mukhanov parametrization for inflationary equation of state, <span>(1+omega =frac{beta }{({N}+1)^alpha })</span>, in the light of Planck 2018 results and latest bound of tensor-to-scalar ratio employing Hamilton–Jacobi formalism. We have found that the current observational values of scalar spectral index and tensor-to-scalar ratio can be used efficiently to constrain the model parameters. The recent bound of <span>(r&lt;0.032)</span> has been used to put an upper bound on one of the model parameter. Whereas 1-<span>(sigma )</span> bound of the scalar spectral index <span>(0.9607le n_{_S}le 0.9691)</span> along with the upper bound of tensor-to-scalar ratio provided restriction on the other model parameter <span>(1.50&lt;alpha le 2.20)</span>. These bounds however depend on the number of e-foldings still left before the end of inflation and whenever <span>(1.50&lt;alpha le 2.20)</span> we can find appropriate values of the other model parameter <span>(beta )</span> so that the observational predictions are in tune with the latest available inflationary observables. We have further utilized the predictions from forthcoming CMB missions in the likes of CMB-S4 and LiteBIRD in order to obtain bounds on the model parameters. We find that detection of gravity waves would help us constrain the model parameters further. But in the absence of detection of primordial gravity wave signal by these CMB missions may rule out Mukhanov parametrization.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 5","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14259-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}