117063918
Recent physics results at BES
¢ 2 S£ and 33 pb¤ 1 ψ ¥¥ events collected at BES-II detector, some charm physics results are obtained. In J ¡ ψ decay, we observed an unknown resonance X(1835) and study the controversial particle σ and κ. In ψ ¢ 2 S£ decay, we test the " 12% rule " via many decay modes and find many new χ cJ decay channels. In ψ ¥¥ decay, we observed the non-D ¯ D decay via ψ ¥¥ § ¦ π ¨ π ¤ J ¡ ψ and study the semi-leptonic decay of D meson. In addition, we give the preliminary ψ ¥¥ resonance parameters with higher precision. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.
124658034
Field-theoretical space-time position operator
A field-theoretical space-time position operator can be properly defined for the Dirac field, the Klein-Gordon field and the photon field, where its temporal component can also represent an observable according to the formalism of POVMs. To achieve this, the 6×1 spinor representation of the photon field and the Feshbach-Villars representation of the Klein-Gordon field are used. Such a space-time position operator plays the role of a generalized Noether charge associated with a local U(1) symmetry, and its second-quantized form shows that quantum fields possess zero-point times, which implies that a zero-point fluctuation of energy must be accompanied with a zero-point fluctuation of time, and then in agreement with the time-energy uncertainty principle. In practice, some possible physical effects associated with the presence of zero-point times, remain to be found. PACS numbers: 03.65.Pm, 03.70.+k
99565521
Study of the psi(2S) decay to p anti-p pi+ pi- (pi0)
119791200
Zero-Point Time of Quantum Fields
Based on the first principles and without resorting to any additional assumption, a new physical quantity describing the space-time position of particle-number center of quantum fields is introduced, which can be regarded as a generalized Noether charge related to the symmetry under a local gauge transformation. As an interesting result, one can show that quantum fields have a zero-point time, which is related to the zero-point energy of quantum fields via the Heisenberg uncertainty principle.
118425528
Time operator in QFT with Virasoro constraints
Abstract Time operator is studied on the basis of field quantization, where the difficulty stemming from Pauliʼs theorem is circumvented by borrowing ideas from the covariant quantization of the bosonic string, i.e., one can remove the negative energy states by imposing Virasoro constraints. Applying the index theorem, one can show that in a different subspace of a Fock space, there is a different self-adjoint time operator. However, the self-adjoint time operator in the maximal subspace of the Fock space can also represent the self-adjoint time operator in the other subspaces, such that it can be taken as the single, universal time operator. Furthermore, a new insight on Pauliʼs theorem is presented.
117918704
Some new insights on the statistical origin of the Bekenstein-Hawking entropy I: Some heuristic arguments
Now that the Bekenstein-Hawking entropy has been found within the traditional theory, its physical interpretation should hide in quantum field theory in curved spacetime (only its quantum corrections require a detailed knowledge of quantum gravity). However, to interpret the statistical origin of the Bekenstein-Hawking entropy, there have developed many microscopic pictures, some of them are based on the theories that themselves remain to be experimentally verified, while some cite the Hawking temperature formula and actually argue in circle (and then they have not provided more information than the seminal work of Bekenstein and Hawking). Within quantum field theory in curved spacetime (without introducing any new hypothesis), it is inevitable for us to attribute the Bekenstein-Hawking entropy to entanglement entropy. In the first part we just provide a heuristic argument, a rigorous theoretical model will be presented in our next work.
119184427
Analysis of the vector and axialvector Bc mesons with QCD sum rules
In this article, we study the vector and axialvector Bc mesons with QCD sum rules, and make reasonable predictions for the masses and decay constants, then calculate the leptonic decay widths. The present predictions for the masses and decay constants can be confronted with the experimental data in the future. We can also take the masses and decay constants as basic input parameters and study other phenomenological quantities with the three-point vacuum correlation functions via QCD sum rules.
119293149
Particle-number fractionalization of a one-dimensional atomic Fermi gas with synthetic spin-orbit coupling
We propose an experimental scheme to simulate the fractionalization of the particle number by using a one-dimensionalspin-orbit-coupledultracoldfermionicgas.Thedesiredspin-orbitcoupling,akinklikepotential, andaconjugation-symmetry-breakingmasstermareproperlyconstructedbylaser-atominteractions,leadingtoan effectivelow-energyrelativisticDiracHamiltonianwithatopologicallynontrivialbackgroundfield.Thedesigned system supports a localized soliton excitation with a fractional particle number that is generally irrational and experimentally tunable, providing a direct realization of the celebrated generalized Su-Schrieffer-Heeger model. In addition, we elaborate on how to detect the induced soliton mode with the fractional particle number in the system.
118394396
Analysis of strong decays of the charmed mesons $D_J(2580), D^*_J(2650), D_J(2740), D^*_J(2760), D_J(3000), D^*_J(3000)$
In this article, we tentatively identify the charmed mesons $D_J(2580)$, $D_J^*(2650)$, $D_J(2740)$, $D^*_J(2760)$, $D_J(3000)$, $D_J^*(3000)$ observed by the LHCb collaboration according to their spin, parity and masses, then study their strong decays to the ground state charmed mesons plus light pseudoscalar mesons with the heavy meson effective theory in the leading order approximation, and obtain explicit expressions of the decay widths. The ratios among the decay widths can be used to confirm or reject the assignments of the newly observed charmed mesons. The strong coupling constants in the decay widths can be fitted to the experimental data in the future at the LHCb, BESIII, KEK-B and $\rm{\bar{P}ANDA}$.
119625166
Construction of the Noncommutative Rank I Bergman Domain
In this paper we present a harmonic oscillator realization of the most degenerate discrete series representations of the SU(2,1) group and the deformation quantization of the coset space \(D = SU(2,1)/U(2)\) with the method of coherent state quantization. This short article is based on a talk given at the 9-th International Workshop, Varna “Lie Theory and Its Applications in Physics” (LT-9).
117522082
First results on dilepton production at the Bevalac
We report on preliminary results of direct electron pair measurements in p+Be at 4.9 GeV and 2.1 GeV and Ca+Ca at 1.95 GeVA collisions at the Bevalac. The results are compared to existing data in p+Be at 12.1 GeV and ..pi../sup -/p at 15.9 and 16.9 GeV.