相关论文: The angular momentum controversy: What's it all ab…

We propose that the mechanism responsible for the ``collapse of the wave function" (or "decoherence" in its broadest meaning) in quantum mechanics is the nonlinearities already present in the theory via nonabelian gauge interactions. Unlike…

An emergent theory of quantum measurement arises directly by considering the particular subset of many body wavefunctions that can be associated with classical condensed matter and its interaction with delocalized wavefunctions. This…

We compute the contribution of the gluonic component of the energy-momentum tensor (EMT) to the angular momentum density in various decompositions. We use the light-front Hamiltonian technique, and a two-component formalism in light-front…

Determination of the orbital angular momentum of the proton is a difficult but important part of understanding fundamental structure. Insight can be gained from suitable models of the gluon asymmetry applied to the Jz = 1/2 sum rule. We…

The data from the last seven experiments performed on polarized deep--inelastic scattering on proton and neutron (or deuteron) targets have been analyzed in search of a precise determination of the spin fraction carried by the quarks in the…

Quantum theory of spin relaxation in the elastic environment is revised with account of the concept of a phonon spin recently introduced by Zhang and Niu (PRL 2014). Similar to the case of the electromagnetic field, the division of the…

The problem of quantum gravity is treated from a radically new viewpoint based on a detailed mathematical analysis of what the constitution of physical space is, which has been carried out by Michel Bounias and the author. The approach…

We present a calculation of the proton momentum and angular momentum decompositions using overlap fermions on a $2+1$-flavor RBC/UKQCD domain-wall lattice at 0.143 fm with a pion mass of 171 MeV which is close to the physical one. A…

The intrinsic angular momentum ("spin") of the B mesons has not so far been measured, notwithstanding the large amount of experimental attention that these particles have received in the four decades since the first of them was discovered.…

The gauge symmetry is one of the most important concepts in modern physics, but there are two conflicting views on its meaning or interpretation. The standard view is that local gauge symmetry is the basis of the pursue of fundamental…

The twenty years since the announcement of the proton spin crisis by the European Muon Collaboration has seen tremendous progress in our knowledge of the distribution of spin within the proton. The problem is reviewed, beginning with the…

We discuss the orbital angular momentum of partons inside a longitudinally polarized proton in the recently proposed framework of spin decomposition. The quark orbital angular momentum defined by Ji can be decomposed into the `canonical'…

I begin with a general discussion about importance of constructing a picture of the nucleon in terms of QCD degrees of freedom, emphasizing the role of spin structure functions. I then give a short overview on the theoretical and…

We consider the production process e-e+ -> G\gamma of invisible gravitons (G) at future linear colliders. We discuss whether the angular distribution of the photon (\gamma) can be used to measure the spin of the invisible graviton, or of…

Elementary particle scatterings and decays in presence of a background magnetic field are very common in physics, specially after the observation that the core of the neutron stars can sustain a magnetic field of the order of $10^{13} {\rm…

The measurement problem in quantum mechanics is almost exclusively discussed in situations where gravity is ignored. We discuss some recent developments in our understanding of quantum gravity and argue that they significantly alter the…

Recently the spectacular result was derived quantum mechanically that the total angular momentum of photons in light beams with finite lateral extensions can have half-integer quantum numbers. In a circularly polarized Gauss light beam it…

The orbital angular momentum of quarks and gluons contributes significantly to the proton spin budget and attracted a lot of attention in the recent years, both theoretically and experimentally. We summarize the various definitions of…

The manifestation of equivalence principle (EP) in spin-gravity interactions, resulting in the nullification of the corresponding analog of Anomalous Magnetic moment is explored. Its tests in the experiments with atoms and cold neutrons are…

Measurements involving the gluon spin density, Delta G=G++ - G+-, can play an important role in the quantitative understanding of proton structure. To demonstrate this, we show that the shape of the gluon asymmetry, A(x,t)=Delta…