28,818 research outputs found
Left-Right Asymmetry of Weak Interaction Mass of Polarized Fermions in Flight
The left-right polarization-dependent asymmetry of the weak interaction mass
is investigated. Based on the Standard Model, the calculation shows that the
weak interaction mass of left-handed polarized fermions is always greater than
that of right-handed polarized fermions in flight with the same velocity in any
inertial frame. The asymmetry of the weak interaction mass might be very
important to the investigation of neutrino mass and would have an important
significance for understanding the parity nonconservation in weak interactions.Comment: 8 pages, 2 figures, corrected calculatio
Experimental tests on the lifetime Asymmetry
The experimental test problem of the left-right polarization-dependent
lifetime asymmetry is discussed. It shows that the existing experiments cannot
demonstrate the lifetime asymmetry to be right or wrong after analyzing the
measurements on the neutron, the muon and the tau lifetime, as well as the
experiment. However, It is pointed out emphatically that the SLD and the
E158 experiments, the measurements of the left-right integrated cross section
asymmetry in boson production by collisions and by
electron-electron M{\o}ller scattering, can indirectly demonstrate the lifetime
asymmetry. In order to directly demonstrate the lifetime asymmetry, we propose
some possible experiments on the decays of polarized muons. The precise
measurement of the lifetime asymmetry could have important significance for
building a muon collider, also in cosmology and astrophysics. It would provide
a sensitive test of the standard model in particle physics and allow for
exploration of the possible interactions.Comment: 11 pages, 1 figur
SU(4) Theory for Spin Systems with Orbital Degeneracy
The isotropic limit of spin systems with orbital degeneracy is shown to have
global SU(4) symmetry. On many 2D lattices, the ground state does not posses
long range order, which may explain the observed spin liquid properties of
. In the SU(4) Neel ordered state, spin-spin correlations can be
antiferromagneitc between two neighboring sites with parallel magnetic moments.Comment: 11 pages, 2 figures. submitted to PR
Geometric entanglement from matrix product state representations
An efficient scheme to compute the geometric entanglement per lattice site
for quantum many-body systems on a periodic finite-size chain is proposed in
the context of a tensor network algorithm based on the matrix product state
representations. It is systematically tested for three prototypical critical
quantum spin chains, which belong to the same Ising universality class. The
simulation results lend strong support to the previous claim [Q.-Q. Shi, R.
Or\'{u}s, J. O. Fj{\ae}restad, and H.-Q. Zhou, New J. Phys \textbf{12}, 025008
(2010); J.-M. St\'{e}phan, G. Misguich, and F. Alet, Phys. Rev. B \textbf{82},
180406R (2010)] that the leading finite-size correction to the geometric
entanglement per lattice site is universal, with its remarkable connection to
the celebrated Affleck-Ludwig boundary entropy corresponding to a conformally
invariant boundary condition.Comment: 4+ pages, 3 figure
Learning Points and Routes to Recommend Trajectories
The problem of recommending tours to travellers is an important and broadly
studied area. Suggested solutions include various approaches of
points-of-interest (POI) recommendation and route planning. We consider the
task of recommending a sequence of POIs, that simultaneously uses information
about POIs and routes. Our approach unifies the treatment of various sources of
information by representing them as features in machine learning algorithms,
enabling us to learn from past behaviour. Information about POIs are used to
learn a POI ranking model that accounts for the start and end points of tours.
Data about previous trajectories are used for learning transition patterns
between POIs that enable us to recommend probable routes. In addition, a
probabilistic model is proposed to combine the results of POI ranking and the
POI to POI transitions. We propose a new F score on pairs of POIs that
capture the order of visits. Empirical results show that our approach improves
on recent methods, and demonstrate that combining points and routes enables
better trajectory recommendations
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