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Guang-jiong Ni

Publications and source records attributed to Guang-jiong Ni.

At least 19 recordsLinked to original sources
arXiv2015

Nambu--Jona-Lasinio Model Revisited with a Simple Regularization-Renormalization Method

According to the pioneering model proposed by Nambu and Jona-Lasinio (NJL) \cite{2,3}, a massless fermion acquires its mass via a vacuum phase transition (VPT) process. Our discussion is considerably simplified because an effective Hamiltonian for VPT is proposed and a simple regularization-renormalization method (RRM) is adopted. An unambiguous constraint is found as $\frac{π^2}{GΔ^2_1}=\frac{2}{3}$, where $G$ is the coupling constant first introduced in the NJL model while $Δ_1$ the mass of fermion ($f$) created after the VPT. The masses of bosons with spin-parity $J^P=0^+, 0^-,1^+$ and $1^-$ as collective modes composed of fermion-antifermion pairs ($f\bar{f}$s) are also calculated by the method of random phase approximation (RPA).

hep-th↗
arXiv2013

Discrete Symmetry in Relativistic Quantum Mechanics

EPR experiment on $K^0-\bar{K}^0$ system in 1998\cite{1} strongly hints that one should use operators $\hat{E}_c=-i\hbar\frac{\partial}{\partial t}$ and $\hat{\bf p}_c=i\hbar\nabla$ for the wavefunction (WF) of antiparticle. Further analysis on Klein-Gordon (KG) equation reveals that there is a discrete symmetry hiding in relativistic quantum mechanics (RQM) that ${\cal P}{\cal T}={\cal C}$. Here ${\cal P}{\cal T}$ means the (newly defined) combined space-time inversion (with ${\bf x}\to -{\bf x}, t\to-t$), while ${\cal C}$ the transformation of WF $ψ$ between particle and its antiparticle whose definition is just residing in the above symmetry. After combining with Feshbach-Villars (FV) dissociation of KG equation ($ψ=ϕ+χ$)\cite{2}, this discrete symmetry can be rigorously reformulated by the invariance of coupling equation of $ϕ$ and $χ$ under either the combined space-time inversion ${\cal P}{\cal T}$ or the mass inversion ($m\to -m$), which makes the KG equation a self-consistent theory. Dirac equation is also discussed accordingly. Various applications of this discrete symmetry are discussed, including the prediction of antigravity between matter and antimatter as well as the reason why we believe neutrinos are likely the tachyons.

physics.gen-ph↗
arXiv2012

Evolution of the CPT Invariance into a Basic Postulate in Physics

Einstein-Podolsky-Rosen's paper in 1935 is discussed in parallel with an EPR experiment on $K^0\bar{K}^0$ system in 1998, yielding a strong hint of distinction in both wave-function and operators between particle and antiparticle at the level of quantum mechanics (QM). Then it is proposed that the CPT invariance in particle physics leads naturally to a basic postulate that the (newly defined) space-time inversion (${\bf x}\to -{\bf x},t\to -t$) is equivalent to the transformation between particle and its antiparticle. The evolution of this postulate from nonrelativistic QM via relativistic QM till the quantum field theory is discussed in some detail. The Klein paradox for both Klein-Gordon equation and Dirac equation is also discussed. Keywords: CPT invariance, Antiparticle, Quantum mechanics, Quantum field theory

physics.gen-ph↗
arXiv2010

Essence of Special Relativity, Reduced Dirac Equation and Antigravity

The essence of special relativity is hiding in the equal existence of particle and antiparticle, which can be expressed by two discrete symmetries within one inertial frame --- the invariance under the (newly defined) space-time inversion (${\bf x}\to -{\bf x},t\to -t$), or equivalently, the invariance under a mass inversion ($m\to -m$). The problems discussed are: the evolution of the $CPT$ invariance into a basic postulate, an unique solution to the original puzzle in Einstein-Podolsky-Rosen paradox, the reduced Dirac equation for hydrogenlike atoms, and the negative mass paradox leading to the prediction of antigravity between matter and antimatter. {\bf Keywords}: Special relativity, Reduced Dirac Equation, Antiparticle, Antigravity

physics.gen-ph↗
arXiv2010

Puzzles of Divergence and Renormalization in Quantum Field Theory

A regularization renormalization method ($RRM$) in quantum field theory ($QFT$) is discussed with simple rules: Once a divergent integral $I$ is encountered, we first take its derivative with respect to some mass parameter enough times, rendering it just convergent. Then integrate it back into $I$ with some arbitrary constants appeared. Third, the renormalization is nothing but a process of reconfirmation to fix relevant parameters (mass, charge, \etc) by experimental data via suitable choices of these constants. Various $QFT$ problems, including the Lamb shift, the running coupling constants in $QED$ and $QCD$, the $λϕ^4$ model as well as Higgs mass in the standard model of particle physics, are discussed. Hence the calculation, though still approximate and limited in accuracy, can be performed in an unambiguous way with no explicit divergence, no counter term, no bare parameter and no arbitrarily running mass scale (like the $μ$ in $QCD$).

quant-ph↗
arXiv2010

Reduced Dirac Equation and Lamb Shift as an Off-mass-shell effect in Quantum Electrodynamics

Based on the precision experimental data of energy-level differences in hydrogenlike atoms, especially the 1S-2S transition of hydrogen and deuterium, the necessity of establishing a reduced Dirac equation (RDE) with reduced mass as the substitution of original electron mass is stressed. The theoretical basis of RDE lies on two symmetries, the invariance under the space-time inversion and that under the pure space inversion. Based on RDE and within the framework of quantum electrodynamics in covariant form, the Lamb shift can be evaluated (at one-loop level) as the radiative correction on a bound electron staying in an off-mass-shell state--a new approach eliminating the infrared divergence. Hence the whole calculation, though with limited accuracy, is simplified, getting rid of all divergences and free of ambiguity.

quant-ph↗
arXiv2005

Zero-point energy of vacuum fluctuation as a candidate for dark energy versus a new conjecture of antigravity based on the modified Einstein field equation in general relativity

In order to clarify why the zero-point energy associated with the vacuum fluctuations cannot be a candidate for the dark energy in the universe, a comparison with the Casimir effect is analyzed in some detail. A principle of epistemology is stressed that it is meaningless to talk about an absolute (isolated) thing. A relative thing can only be observed when it is changing with respect to other things. Then a new conjecture of antigravity --the repulsive force between matter and antimatter derived from the modified Einstein field equation in general relativity-- is proposed. this is due to the particle-antiparticle symmetry based on a new understanding about the essence of special relativity. Its possible consequences in the theory of cosmology are discussed briefly, including a new explanation for the accelerating universe and gamma-ray-bursts.

physics.gen-ph↗
arXiv2004

de'Broglie's paradox, relativistic Doppler effect, and the derivation of mass-energy relation in special relativity

Three related topics are discussed to show the "simplicity, harmony and beauty" of the theory of special relativity (SR): (1) How can de'Broglie discover his famous relation between the particle's momentum and a wave length -- a paradox stemming from the time dilatation effect of SR. (2) The relativistic Doppler effect, especially the distinction between the transverse Doppler effect and the time dilatation effect. (3) Three particular examples are examined to derive the general mass-energy relation in SR by induction method.

physics.ed-ph↗
arXiv2004

Principle of relativity in physics and in epistemology

The conceptual evolution of principle of relativity in the theory of special relativity is discussed in detail. It is intimately related to a series of difficulties in quantum mechanics,relativistic quantum mechanics and quantum field theory as well as to new predictions about antigravity and tachyonic neutrinos etc.

physics.gen-ph↗
arXiv2002

A New Interpretation on Quantum Mechanics

Based on new experiments about the "macroscopic Schrodinger's cat state" etc., a self-consistent interpretation on quantum mechanics is presented from the new point of view combining physics, philosophy and mathematics together.

hep-ph↗
arXiv2002

Superluminal Paradox and Neutrino

Einstein's theory of special relativity(SR) and the principle of causality imply that the speed of any moving object can not exceed that of light in a vacuum($c$).However,there were many attempts in literature discussing the particle moving with speed $u>c$(called as superluminal particle or tachyon)either in the scheme of SR or beyond it.These theories all encountered a series of insurmountable difficulties which will be named ``superluminal paradox''in this paper.We will analyze it in some detail and then prove that the paradox disappears unambiguously in quantum theory,which is compatible with SR.Most likely,the superluminal particle in real world is just a kind of known particle,the neutrino.

hep-ph↗
arXiv2002

The Decay Lifetime of Polarized Fermions in Flight

Based on the parity violation in Standard model, we study the dependence of lifetime on the helicity of an initial-state fermion in weak interactions. It is pointed out that if the initial fermions in the decays are longitudinally polarized, then the decay lifetime of left-handed polarized fermions is different from that of right-handed polarized fermions in flight with a same velocity in a same inertial system.

hep-ph↗
arXiv2002

There might be superluminal particles in nature

Based on experimental discovery that the mass-square of neutrino is negative, a quantum equation for superluminal neutrino is proposed in comparison with Dirac equation and Dirac equation with imaginary mass. A virtual particle may also be viewed as superluminal one. Both the basic symmetry of space-time inversion and the maximum violation of space-inversion symmetry are emphasized.

hep-th↗
arXiv2001

What Schrödinger's Cat is Telling

The recent experiment on superconducting quantum interference device provides new opportunity to clarify the fundamental interpretation of quantum mechanics. After analyzing this and relevant experiments, we claim the point of view that the quantum state in abstract sense contains no information and the wave function is the probability amplitude of fictitious measurement corresponding to the real one which is prepared to be done by the observer. Talking about the quantum state or wave function too materialized in ordinary language would often cause misunderstanding. So basically, the Schrödinger's cat paradox is over.

quant-ph↗
arXiv2001

Is Neutrino a Superluminal Particle?

Based on the experimental discovery that the mass-square of neutrino is negative, a quantum theory for superluminal neutrino is proposed. Two Weyl equations coupled together via a mass term respecting the maximum parity violation lead to a new equation which describes the superluminal motion of neutrino with permanent helicity. Various strange features of subluminal and superluminal particles can be ascribed to the relative variation of two contradictory fields superposing coherently inside the particle with the change of its speed u in the whole range ($0<u<\infty$). Being compatible with the theory of special relativity, this theory may have various applications.

hep-ph↗
arXiv2000

Comparison among Klein-Gordon equation, Dirac equation and Relativistic Stationary Schrodinger equation

A particle is always not pure. It always contains hiding antiparticle ingredient which is the essence of special relativity. Accordingly, the Klein-Gordon (KG) equation and Dirac equation are restudied and compared with the Relativistic Stationary Schrödinger Equation (RSSE). When an electron is bound in a Hydrogenlike atom with pointlike nucleus having charge number $Z$, the critical value of $Z, Z_c$, equals to 137 in Dirac equation whereas $Z_c=\sqrt{M/μ} (137)$ in RSSE with $M$ and $μ$ being the total mass of atom and the reduced mass of the electron.

quant-ph↗
arXiv1999

Let the New Experiments Tell the Quantum Theory

Several new physics experiments in 1998 were performed and analyzed to show the subtlety of quantum theory, including the "wave-particle duality" and the non-separability of two-particle entangled state. Here it is shown that the measurement is bound to change the object by destroying the original quantum coherence between the object and its environment. So the "physical reality" should be defined at two levels, the "thing in itself" and the "thing for us". The wave function in quantum mechanics is just playing the role for connecting the two levels of matter via the fictitious measurement.

quant-ph↗