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1.
Kunji Nakayama 《International Journal of Theoretical Physics》2008,47(7):2065-2094
This paper deals with topos-theoretic truth-value valuations of quantum propositions. Concretely, a mathematical framework
of a specific type of modal approach is extended to the topos theory, and further, structures of the obtained truth-value
valuations are investigated. What is taken up is the modal approach based on a determinate lattice
, which is a sublattice of the lattice
of all quantum propositions and is determined by a quantum state e and a preferred determinate observable R. Topos-theoretic extension is made in the functor category
of which base category
is determined by R. Each true atom, which determines truth values, true or false, of all propositions in
, generates also a multi-valued valuation function of which domain and range are
and a Heyting algebra given by the subobject classifier in
, respectively. All true propositions in
are assigned the top element of the Heyting algebra by the valuation function. False propositions including the null proposition
are, however, assigned values larger than the bottom element. This defect can be removed by use of a subobject semi-classifier.
Furthermore, in order to treat all possible determinate observables in a unified framework, another valuations are constructed
in the functor category
. Here, the base category
includes all
’s as subcategories. Although
has a structure apparently different from
, a subobject semi-classifier of
gives valuations completely equivalent to those in
’s. 相似文献
2.
A.?Sibirtsev J.?Haidenbauer F.?Huang S.?Krewald U.?-G.?Mei?ner 《The European Physical Journal A - Hadrons and Nuclei》2009,40(1):65-75
We present a systematic analysis of backward pion photoproduction for the reactions
p
p and
p
n . Regge phenomenology is applied at invariant collision energies above 3GeV in order to fix the reaction amplitude. A comparision
with older data on - and -photoproduction at = 180° indicates that the high-energy limit as given by the Regge calculation could be reached possibly at energies of around ≃ 3 GeV. In the energy region of
2.5 GeV, covered by the new measurements of
p
p differential cross-sections at large angles at ELSA, JLab, and LEPS, we see no clear signal for a convergence towards the
Regge results. The baryon trajectories obtained in our analysis are in good agreement with those given by the spectrum of
excited baryons. 相似文献
3.
G. Gritzner J. Ammer K. Kellner V. Kavečanský M. Mihalik S. Maťaš M. Zentková 《Applied Physics A: Materials Science & Processing》2008,90(2):359-365
La0.67Pb0.33(Mn1-xCox)O3-δ ceramics with x=0, 0.01, 0.03, 0.06, 0.1 and 0.15 have been prepared in a two-step procedure. Precursor gels were made by
the wet chemical malic acid method. The gels were calcined and then converted into ceramics by heat treatment at 950 °C and
1000 °C in air. X-ray diffraction showed that the compounds were phase pure. The crystal structure symmetry of the compounds
was confirmed to be rhombohedral (space group R3̄c) for the whole investigated range of x. All compounds undergo a paramagnetic–ferromagnetic
phase transition between 335 K and 225 K. The basic magnetic characteristics such as the Curie temperature , the paramagnetic Curie temperature θ, the effective magnetic moment and the saturated magnetization decrease with increasing Co doping. The ferromagnetic transition is accompanied by an anomaly in the electrical resistance
for all compounds. The high-temperature insulator–metal transitions () do not coincide with the relevant . A large magnetoresistance peak of about 15% was observed for all compounds at .
PACS 72.80.Ga; 75.47.Lx; 75.60.Ej 相似文献
4.
Serguei I. Iakovlev 《Mathematical Physics, Analysis and Geometry》2006,9(2):109-134
In we consider a family of selfadjoint operators of the Friedrichs model: . Here is the operator of multiplication by the corresponding function of the independent variable , and (perturbation) is a trace-class integral operator with a continuous Hermitian kernel satisfying some smoothness condition. These absolute type operators have one singular point of order . Conditions on the kernel are found guaranteeing the absence of the point spectrum and the singular continuous one of such operators near the origin. These conditions are actually necessary and sufficient. They depend on the finiteness of the rank of a perturbation operator and on the order of singularity . The sharpness of these conditions is confirmed by counterexamples. 相似文献
5.
First measurements of
mesons production properties and their spin alignment in
charged current (CC) and neutral current (NC) interactions are presented. The analysis of the full data sample of the NOMAD
experiment is performed in different kinematic regions. For
and
mesons produced in
CC interactions and decaying into
we have found the following yields per event:
and
respectively, while for the
and
mesons produced in
interactions the corresponding yields per event are:
and
. The results obtained for the
parameter,
and
for
and
produced in
CC interactions, are compared to theoretical predictions tuned on LEP measurements in
annihilation at the
pole. For
mesons produced in
interactions the measured
parameter is
.
PACS 13.15.+g, 13.60.Le, 13.87.Fh, 13.88.+e, 14.40.Ev 相似文献
6.
H.-U. Martyn 《The European Physical Journal C - Particles and Fields》2006,48(1):15-24
A study of various SUSY scenarios is presented in which the lightest supersymmetric particle is the gravitino and the next-to-lightest supersymmetric particle is a scalar tau with lifetimes ranging from seconds to years. Gravitinos are interesting dark matter candidates which can be produced in decays of heavier sparticles at the International Linear Collider (ILC), but remain undetected in direct searches of astrophysical experiments. We investigate the detection and measurement of metastable staus, which may be copiously produced at the ILC either directly or via cascade decays. A proper choice of the experimental conditions will allow one to collect large samples of s coming to rest in the calorimeters of the ILC detector and to study the subsequent decays . Detailed simulations show that the properties of the stau and the gravitino, such as mass and lifetime and mass, can be accurately determined at a future ILC and may provide direct access to the gravitational coupling, respectively Planck scale. 相似文献
7.
Chao-Hsi Chang Jiao-Kai Chen Zhen-Yun Fang Bing-Quan Hu Xing-Gang Wu 《The European Physical Journal C - Particles and Fields》2007,50(4):969-978
The light top-squark may be the lightest squark, and its lifetime may be ‘long enough’ in a kind of SUSY models that have not been ruled out yet
experimentally, so colorless ‘supersymmetric hadrons (superhadrons)’ (q is a quark excluding the t-quark) may be formed as long as the light top-squark can be produced. The fragmentation function of into heavy ‘supersymmetric hadrons (superhadrons)’ (Q̄=c̄ or b̄) and hadronic production of the superhadrons are investigated quantitatively. The fragmentation function is
calculated precisely. Due to the difference in spin of the SUSY component, the asymptotic behavior of the fragmentation function
is different from those of the existing ones. The fragmentation function is also applied to compute the production of heavy
superhadrons at the hadronic colliders Tevatron and LHC in the so-called fragmentation approach. The resultant cross-section
for the heavy superhadrons is too small to observe at Tevatron, but large enough at LHC, when all the relevant parameters
in the SUSY models are taken within the favored region for the heavy superhadrons. The production of ‘light superhadrons’
(q=u,d,s) is also roughly estimated with the same SUSY parameters. It is pointed out that the production cross-sections of
the light superhadrons may be much greater than those of the heavy superhadrons, so that even at Tevatron the light superhadrons may be produced
in great quantities.
PACS 12.38.Bx; 13.87.Fh; 12.60.Jv; 14.80.Ly 相似文献
8.
K.J. Ozeren W.J. Stirling 《The European Physical Journal C - Particles and Fields》2006,48(1):159-168
We study the QCD scattering amplitudes for and where q is a massive fermion. Using a particular choice of massive fermion spinor we derive compact expressions for the partial spin amplitudes for the 2→2 process. We then investigate the corresponding 2→3 amplitudes using the BCFW recursion technique. For the helicity conserving partial amplitudes we present new expressions, but we were unable to treat the helicity-flip amplitudes recursively, except for the case where all the gluon helicities are the same. We therefore evaluate the remaining partial amplitudes using standard Feynman diagram techniques. 相似文献
9.
10.
Keitaro Nagata Atsushi Hosaka V. Dmitrašinović 《The European Physical Journal C - Particles and Fields》2008,57(3):557-567
We study the chiral transformation properties of all possible local (non-derivative) interpolating field operators for baryons
consisting of three quarks with two flavors, assuming good isospin symmetry. We derive and use the relations/identities among
the baryon operators with identical quantum numbers that follow from the combined color, Dirac and isospin Fierz transformations.
These relations reduce the number of independent baryon operators with any given spin and isospin. The Fierz identities also
effectively restrict the allowed baryon chiral multiplets. It turns out that the non-derivative baryons’ chiral multiplets
have the same dimensionality as their Lorentz representations. For the two independent nucleon operators the only permissible
chiral multiplet is the fundamental one,
. For the Δ, admissible Lorentz representations are
and
. In the case of the
chiral multiplet, the
Δ field has one
chiral partner; otherwise it has none. We also consider the Abelian (U
A(1)) chiral transformation properties of the fields and show that each baryon comes in two varieties: (1) with Abelian axial
charge +3; and (2) with Abelian axial charge −1. In case of the nucleon these are the two Ioffe fields; in case of the Δ, the
multiplet has an Abelian axial charge −1 and the
multiplet has an Abelian axial charge +3. 相似文献
11.
R. K. Niven 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,70(1):49-63
We examine the combinatorial or probabilistic definition (“Boltzmann’s principle”) of the entropy or cross-entropy function
H ∝ or D ∝ - , where is the statistical weight and the probability of a given realization of a system. Extremisation of H or D, subject to any constraints, thus selects the
“most probable” (MaxProb) realization. If the system is multinomial, D converges asymptotically (for number of entities N
↦∞) to the Kullback-Leibler cross-entropy DKL; for equiprobable categories in a system, H converges to the Shannon entropy HSh. However, in many cases or is not multinomial and/or does not satisfy an asymptotic limit. Such systems cannot meaningfully be analysed with DKL or HSh, but can be analysed directly by MaxProb. This study reviews several examples, including (a) non-asymptotic systems; (b)
systems with indistinguishable entities (quantum statistics); (c) systems with indistinguishable categories; (d) systems represented
by urn models, such as “neither independent nor identically distributed” (ninid) sampling; and (e) systems representable in
graphical form, such as decision trees and networks. Boltzmann’s combinatorial definition of entropy is shown to be of greater
importance for “probabilistic inference” than the axiomatic definition used in information theory. 相似文献
12.
H. Chavez J.A. Martins Simões 《The European Physical Journal C - Particles and Fields》2007,50(1):85-90
In this paper we present a model for the spontaneous breaking of parity with two Higgs doublets and two neutral Higgs singlets
which are even and odd under -parity. The condition can be satisfied without introducing bidoublets, and it is induced by the breaking of -parity through the vacuum expectation value of the odd Higgs singlet. Examples of left–right symmetric and mirror fermions
models in grand unified theories are presented.
PACS 12.60.Cn; 14.80.Cp; 12.10.Dm 相似文献
13.
A. Borowiec J. Lukierski V.N. Tolstoy 《The European Physical Journal C - Particles and Fields》2006,48(2):633-639
We describe in detail the two-parameter nonstandard quantum deformation of the D=4 Lorentz algebra , linked with a Jordanian deformation of . Using the twist quantization technique we obtain the explicit formulae for the deformed co-products and antipodes. Further extending the considered deformation to the D=4 Poincaré algebra we obtain a new Hopf-algebraic deformation of four-dimensional relativistic symmetries with a dimensionless deformation parameter. Finally, we interpret as the D=3 de Sitter algebra and calculate the contraction limit (R is the de Sitter radius) providing an explicit Hopf algebra structure for the quantum deformation of the D=3 Poincaré algebra (with mass-like deformation parameters), which is the two-parameter light-cone κ-deformation of the D=3 Poincaré symmetry. 相似文献
14.
15.
We calculate the one-photon loop radiative corrections to virtual pion Compton scattering
→
, that subprocess which determines in the one-photon exchange approximation the pion-nucleus bremsstrahlung reaction
Z →
Z
. Ultraviolet and infrared divergencies of the loop integrals are both treated by dimensional regularization. Analytical
expressions for the O() corrections to the virtual Compton scattering amplitudes, A(s, u, Q) and B(s, u, Q) , are derived with their full dependence on the (small) photon virtuality Q from 9 classes of contributing one-loop diagrams. Infrared finiteness of these virtual radiative corrections is achieved
(in the standard way) by including soft photon radiation below an energy cut-off . In the region of low
center-of-mass energies, where the pion-nucleus bremsstrahlung process is used to extract the pion electric and magnetic
polarizabilities, we find radiative corrections up to about -3% for = 5 MeV. Furthermore, we extend our calculation of the radiative corrections to virtual pion Compton scattering
→
by including the leading pion-structure effect in the form of the polarizability difference - . Our analytical results are particularly relevant for analyzing the data of the COMPASS experiment at CERN which aims at
measuring the pion electric and magnetic polarizabilities with high statistics using the Primakoff effect. 相似文献
16.
Alexis Pokrovski 《Mathematical Physics, Analysis and Geometry》2007,10(3):197-203
Let be the spectrum of in L
2(ℝ), where q is an even almost-periodic complex-valued function with bounded primitive and derivative. It is known that , where is the spectrum of the unperturbed operator. Suppose that the asymptotic approximation to the first asymptotic correction
is given. We prove the formula that recovers the frequencies and the Fourier coefficients of q in terms of Δμ
n
.
相似文献
17.
Shao-Long Chen Xiao-Gang He Xue-Peng Hu Yi Liao 《The European Physical Journal C - Particles and Fields》2009,60(2):317-321
An unparticle
with scaling dimension
has peculiar thermal properties due to its unique phase space structure. We find that the equation of state parameter
, the ratio of pressure to energy density, is given by
providing a new form of energy in our universe. In an expanding universe, the unparticle energy density
evolves dramatically differently from that for photons. For
, even if
at a high decoupling temperature T
D is very small, it is possible to have a large relic density
at present photon temperature T
γ
0, large enough to play the role of dark matter. We calculate T
D and
using photon–unparticle interactions for illustration. 相似文献
18.
A.?Sibirtsev J.?Haidenbauer S.?Krewald U.?-G.?Mei?ner A.?W.?Thomas 《The European Physical Journal A - Hadrons and Nuclei》2009,41(1):71-84
A Regge model with absorptive corrections is employed in a global analysis of the world data on the reactions
p
p and
n
n for photon energies from 3 to 18GeV. In this region resonance contributions are expected to be negligible so that the available
experimental information on differential cross-sections and single and double polarization observables at - t
2 GeV2allows us to determine the reaction amplitude reliably. The model amplitude is then used to predict observables for photon
energies below 3GeV. A detailed comparison with recent data from the CLAS and CB-ELSA Collaborations in that energy region
is presented. Furthermore, the prospects for determining the radiative decay width via the Primakoff effect from the reaction
p
p are explored. 相似文献
19.
F. Benedosso 《The European Physical Journal C - Particles and Fields》2007,49(1):61-64
We present measurements of azimuthal correlations between photons (from π0 decay) and charged hadrons in d+Au collisions at =200 GeV. We use di-hadron correlations to study parton fragmentation in d+Au collisions at RHIC. Specifically, the near-side
and away-side peaks of the azimuthal angular difference distribution are used to measure the root-mean-squared (RMS) fragmentation
transverse momentum and the mean intrinsic parton transverse momentum . The measurements with leading photons are compared to results using leading charged particles.
PACS 25.75.-q 相似文献
20.
Tadayoshi Adachi 《Letters in Mathematical Physics》2007,82(1):1-8
For an N-body Stark Hamiltonian , the resolvent estimate holds uniformly in with Re and Im , where , and is a compact interval. This estimate is well known as the limiting absorption principle. In this paper, we report that by
introducing the localization in the configuration space, a refined resolvent estimate holds uniformly in with Re and Im .
Dedicated to Professor Hideo Tamura on the occasion of his 60th birthday 相似文献