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Violent collisions can reveal hexadecapole deformation of nuclei

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Nuclear Science and Techniques 2024年第7期35卷 1-3页

作者： Björn Schenke physics department Brookhaven National LaboratoryUptonNY 11973USA

A new observable in heavy ion collision experiments was identified to be sensitive to the hexadecapole deformation of the colliding *** deformation is difficult to measure in traditional nuclear electric transition measurements,as it is often overwhelmed by the nuclear quadrupole *** opens the door to gain new insight into nuclear structure with experiments that were designed to study hot and dense nuclear matter.

关键词： deformation collision insight

Magnetic field regression using artificial neural networks for cold atom experiments

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Chinese physics B 2024年第2期33卷 46-51页

作者：陈子霆黃建陶 Bojeong Seo 黄明琛 Mithilesh K.Parit 何逸飞甄浩廷 Jensen Li Gyu-Boong Jo department of physics The Hong Kong University of Science and TechnologyKowloon 999077China

Accurately measuring magnetic fields is essential for magnetic-field sensitive experiments in areas like atomic,molecular,and optical physics,condensed matter experiments,and other ***,since many experiments are often conducted in an isolated environment that is inaccessible to experimentalists,it can be challenging to accurately determine the magnetic field at the target ***,we propose an efficient method for detecting magnetic fields with the assistance of an artificial neural network(NN).Instead of measuring the magnetic field directly at the desired location,we detect fields at several surrounding positions,and a trained NN can accurately predict the magnetic field at the target *** training,we achieve a below 0.3%relative prediction error of magnetic field magnitude at the center of the vacuum chamber,and successfully apply this method to our erbium quantum gas apparatus for accurate calibration of magnetic field and long-term monitoring of environmental stray magnetic *** demonstrated approach significantly simplifies the process of determining magnetic fields in isolated environments and can be applied to various research fields across a wide range of magnetic field magnitudes.

关键词： ultracold gases trapped gases measurement methods and instrumentation

A new gravitational theory and dark matter problem

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Communications in Theoretical physics 2024年第6期76卷 129-136页

作者： Xiong Zhao Yongge Ma department of physics Beijing Normal UniversityBeijing 100875China

We propose a new gravitational theory with torsion based on Riemann-Cartan geometry,in which all physical quantities are *** addition to the spacetime metric,the gravitational degrees of freedom in this theory also include the torsion and two scalar *** energy-momentum tensor of the matter fields in this theory is also proposed.A spherically symmetric static vacuum solution of the theory is *** turns out that this solution can fit the observational data of the rotation curve outside the stellar disk in the Milky ***,the galactic dark matter may just be the gravitational effect of the theory with torsion.

关键词： gravity torsion dark matter

The quasi-Gramian solution of a non-commutative extension of the higher-order nonlinear Schr?dinger equation

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Communications in Theoretical physics 2024年第3期76卷 51-61页

作者： H W A Riaz J Lin department of physics Zhejiang Normal UniversityJinhua 321004China

The nonlinear Schr?dinger(NLS)equation,which incorporates higher-order dispersive terms,is widely employed in the theoretical analysis of various physical *** this study,we explore the non-commutative extension of the higher-order NLS *** treat real or complex-valued functions,such as g_(1)=g_(1)(x,t)and g_(2)=g_(2)(x,t)as non-commutative,and employ the Lax pair associated with the evolution equation,as in the commutation *** derive the quasi-Gramian solution of the system by employing a binary Darboux *** soliton solutions are presented explicitly within the framework of *** visually understand the dynamics and solutions in the given example,we also provide simulations illustrating the associated ***,the solution can be used to study the stability of plane waves and to understand the generation of periodic patterns within the context of modulational instability.

关键词： integrable systems Darboux transformation solitons

Nonlocal coherence harvesting from quantum vacuum

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Communications in Theoretical physics 2024年第7期76卷 44-51页

作者： Rui-Di Wang Shu-Min Wu Xiao-Li Huang department of physics Liaoning Normal UniversityDalian 116029China

It is well known that nonlocal coherence reflects nonclassical correlations better than quantum entanglement. Here, we analyze nonlocal coherence harvesting from the quantum vacuum to particle detectors adiabatically interacting with a quantum scalar field in Minkowski *** find that the harvesting-achievable separation range of nonlocal coherence is larger than that of quantum entanglement. As the energy gap grows sufficiently large, the detectors harvest less quantum coherence, while the detectors could extract more quantum entanglement from the vacuum state. Compared with the linear configuration and the scalene configuration, we should choose the model of equilateral triangle configuration to harvest tripartite coherence from the vacuum. Finally, we find a monogamous relationship, which means that tripartite l_(1)-norm of coherence is essentially bipartite types.

关键词： nonlocal coherence quantum vacuum monogamous relationship

The 5αcondensate state in 20Ne

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Nuclear Science and Techniques 2024年第2期35卷 3-5页

作者： Takahiro Kawabata department of physics Osaka UniversityToyonakaOsaka 560-0043Japan

Theclustering phenomenon,in which nucleons are arranged intoparticles(4 He nuclei)within a nuclear system,is one of the most intriguing aspects of nuclear *** has been observed in various light nuclei,such as^(8)Be,^(12)C,^(16)O,and^(20)Ne,and is responsible for many exotic and fascinating phenomena,such as the Hoyle state in^(12)C,which plays an essential role in stellar nucleosynthesis[1-6]as well as in heavy-ion collisions[7-9].

关键词： structure state

ρ-meson longitudinal leading-twist distribution amplitude revisited and the D→ρsemileptonic decay

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Chinese physics C 2024年第6期48卷 82-91页

作者：钟涛代亚红付海冰 department of physics Guizhou Minzu UniversityGuiyang 550025China

Motivated by our previous study[***.D 104(1),016021(2021)]on the pionic leading-twist distribution amplitude(DA),we revisit theρ-me son leading-twist longitudinal DAφ_(2;ρ)^(‖)(x,μ)in this study.A model proposed by Chang based on the DYyson-Schwinger equations is adopted to describe the behavior ofφ_(2;ρ)^(‖)(x,μ).However,theξ-moments ofφ_(2;ρ)^(‖)(x,μ)are calculated with the QCD sum rules in the framework of the background field *** sum rule formulas for these moments are *** accurate values for the first five nonzeroξ-moments at the typical scaleμ=(1.0,1.4,2.0,3.0)GeV are given,e.g.,atμ=1 GeV,(ξ^(2))>_(2;ρ)^(‖)=0.220(6),(ξ^(4))>_(2;ρ)^(‖)=0.103(4),(ξ^(6))>_(2;ρ)^(‖)=0.066(5),(ξ^(8))>_(2;ρ)^(‖)=0.046(4),and(ξ^(10))>_(2;ρ)^(‖)=0.035(3).By fitting these values with the least squares method,the DSE model forφ_(2;ρ)(x,μ)is *** taking the left-handed current light-cone sum rule approach,we obtain the transition form factor in the large recoil region,i.e.,A_(1)(0)=0.498_(-0.012)^(+0.014),A_(2)(0)=0.460_(-0.047)^(+0.055),and V(0)=0.800_(-0.014)^(+0.015),and the ratio r_(2)=0.923_(-0.119)^(+0.133),rV=1.607_(-0.071)^(+0.071).After extrapolating with a rapidly converging series based on z(t)-expansion,we present the|V_(cd)|-independent decay width for the semileptonic decays D→ρ^(l+)v_(l).Finally,the branching fractions are B(D^(0)→ρ^(-)e+v_(e))=1.825_(-0.162)^(+0.170)±0.004,B(D^(+)→ρ^(0)e+v_(e))=2.299_(-0.204)^(+0.214)±0.011,B(D^(0)→ρ^(-)μ^(+)v_(μ))=1.816_(-0.160)^(+0.168)±0.004,and B(D^(+)→ρ^(0)μ+v_(μ))=2.288_(-0.201)^(+0.212)±0.011.

关键词： QCD sum rule charmed meson semileptonic decay Rho meson light-cone distribution amplitude

Massive Dirac particles based on gapped graphene with Rosen-Morse potential in a uniform magnetic field

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Chinese physics B 2024年第8期33卷 170-178页

作者： A.Kalani Alireza Amani M.A.Ramzanpour department of physics Ayatollah Amoli BranchIslamic Azad UniversityAmolIran

We explore the gapped graphene structure in the two-dimensional plane in the presence of the Rosen-Morse potential and an external uniform magnetic *** order to describe the corresponding structure,we consider the propagation of electrons in graphene as relativistic fermion quasi-particles,and analyze it by the wave functions of two-component spinors with pseudo-spin symmetry using the Dirac ***,to solve and analyze the Dirac equation,we obtain the eigenvalues and eigenvectors using the Legendre differential *** that,we obtain the bounded states of energy depending on the coefficients of Rosen-Morse and magnetic potentials in terms of quantum numbers of principal n and spin-orbit ***,the values of the energy spectrum for the ground state and the first excited state are calculated,and the wave functions and the corresponding probabilities are plotted in terms of coordinates *** what follows,we explore the band structure of gapped graphene by the modified dispersion relation and write it in terms of the two-dimensional wave vectors K_(x) and K_(y).Finally,the energy bands are plotted in terms of the wave vectors K_(x) and K_(y) with and without the magnetic term.

关键词： massive Dirac equation Rosen–Morse potential Legendre polynomial gapped graphene pseudospin symmetry

Rotating effects on the thermophysical properties of a two-dimensional GaAs quantum ring

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Communications in Theoretical physics 2024年第6期76卷 165-173页

作者： Ahmad Ghanbari department of physics College of ScienceYasouj UniversityYasoujIran

In this work,we have investigated the rotating effect on the thermodynamic properties of a 2D quantum ***,we have considered the radial potential of a 2D quantum ring and solved the Schrödinger equation in the presence of the Aharonov-Bohm effect and a uniform magnetic field for the considered *** to the solution of the equation,we calculated the eigenvalues and eigenfunctions of the considered *** the calculated energy spectrum,we obtained the partition function and thermodynamic properties of the system,such as the mean energy,specific heat,entropy and free *** results show that the rotating effect has a significant influence on the thermophysical properties of a 2D quantum *** also study other effects of the rotating term:(1)the effect of different values of rotating parameters,and(2)the effect of negative rotation on the thermodynamic properties of the *** results are discussed in detail.

关键词： Schrodinger equation quantum ring rotation effect thermophysical properties