14,111 research outputs found
Quons as su(2) Irreducible Tensor Operators
We prove that, for the quon algebra, which interpolates between the Bose and
Fermi statistics and depends on a free parameter q,it is possible to build an
su(2) irreducible representation. One of the consequences of this fact is that
the quons couple via the same angular momentum coupling rules obeyed by
ordinary bosons and fermions.Comment: 8 pages,Late
Non-Invariant Ground States, Thermal Average, and generalized Fermionic Statistics
We present an approach to generalised fermionic statistics which relates the
existence of a generalised statistical behaviour to non-invariant ground
states. Considering the thermal average of an operatorial generalization of the
Heisenberg algebra, we get an occupation number which depends on the degree of
mixing between symmetric and antisymmetric sectors of the ground state. A
natural prescription is given for the construction of a supersymmetric
statistics. We also show that the structure of the vacuum, and therefore the
statistical behaviour of the system, can be accounted for in terms of a second
order phase transition.Comment: 11 pages, accepted in Physics Letters
Applications of the Quon Algebra: 3-D Harmonic Oscillator and the Rotor Model
In this work we present a method to build in a systematic way a many-body
quon basis state. In particular, we show a closed expression for a given number
N of quons, restricted to the permutational symmetric subspace, which belongs
to the whole quonic space. The method is applied to two simple problems: the
three-dimensional harmonic oscillator and the rotor model and compared to
previous quantum algebra results. The differences obtained and possible future
applications are also discussed.Comment: 13 pages, 2 figure
Many-body States and Operator Algebra for Exclusion Statistics
We discuss many-body states and the algebra of creation and annihilation
operators for particles obeying exclusion statistics.Comment: 14 pages, plainTex. The first few pages have been modified. Note and
references added. (This version will appear in Nucl. Phys. B.
Possible violation of the spin-statistics relation for neutrinos: checking through future galactic supernova
We use the detection of neutrinos from a future galactic type-II supernova
event in a water Cerenkov detector like Super-Kamiokande to constrain the
possible violation of spin-statistics by neutrinos resulting in their obeying a
mixed statistics instead of Fermi-Dirac.Comment: Discussion on "pinching" of Fermi-Dirac spectrum for supernova
neutrinos added. Version to appear in PL
Deformed Heisenberg algebra with reflection
A universality of deformed Heisenberg algebra involving the reflection
operator is revealed. It is shown that in addition to the well-known
infinite-dimensional representations related to parabosons, the algebra has
also finite-dimensional representations of the parafermionic nature. We
demonstrate that finite-dimensional representations are representations of
deformed parafermionic algebra with internal Z_2-grading structure. On the
other hand, any finite- or infinite-dimensional representation of the algebra
supply us with irreducible representation of osp(1|2) superalgebra. We show
that the normalized form of deformed Heisenberg algebra with reflection has the
structure of guon algebra related to the generalized statistics.Comment: 16 pages, LaTeX, to appear in Nucl. Phys.
Why quarks cannot be fundamental particles
Many reasons why quarks should be considered composite particles are found in
the book Preons by D'Souza and Kalman. One reason not found in the book is that
all the quarks except for the u quark decay. The electron and the electron
neutrino do not decay. A model of fundamental particles based upon the weak
charge is presented.Comment: 3 pages - PDF file. to be published Proceedings of the 6th
International Conference Hyperons, Charm and Beauty Hadron
Search for exchange-antisymmetric two-photon states
Atomic two-photon J=0 J'=1 transitions are forbidden for
photons of the same energy. This selection rule is related to the fact that
photons obey Bose-Einstein statistics. We have searched for small violations of
this selection rule by studying transitions in atomic Ba. We set a limit on the
probability that photons are in exchange-antisymmetric states:
.Comment: 5 pages, 4 figures, ReVTeX and .eps. Submitted to Phys. Rev. Lett.
Revised version 9/25/9
Diquarks and antiquarks in exotics: a menage a trois and a menage a quatre
A menage a trois is very different from an ordinary family. Similarly, exotic
hadrons with both qq and qbar q pairs have important color-space correlations
that are completely absent in ordinary mesons and baryons. The presence of both
types of pairs requires attention to the basic QCD physics that the q qbar
interaction is much stronger than the qq interaction. This new physics in
multiquark systems produces color structures totally different from those of
normal hadrons, for example the ud system is utterly unlike the ud diquark in
the uds Lambda baryon. The color-space correlations produce unusual
experimental properties in tetraquarks with heavy quark pairs which may be
relevant for newly discovered mesons like the X(3872) resonance. Tetraquark
masses can be below the two-meson threshold for sufficiently high quark masses.
A simple model calculation shows the b q bbar ubar and b q cbar qbar
tetraquarks below the B Bbar and B Dbar thresholds. Some of these states have
exotic electric charge and their decays might have striking signatures
involving monoenergetic photons and/or pions.Comment: Journal version (PLB
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