摘要:

AbstractThe experimental status of measrerments of neutrino masses and lepton flavour mixing is summarised. Limits of mass and mixing parameters obtained by different experimental techniques are given and the possibilities and limits of the different methods are discussed. Future projects are presented and their ability to verify existing results or to explore further regions of the mass and mixing parameter space is discussed.

ISSN:0015-8208    

DOI:10.1002/prop.2190450502

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractProof is given for gauge independence of the (Belinfante's) symmetric energy‐momentum tensor in QED. Under the covariant LSZ‐formalism it is shown that expectation values, supplemented with physical state conditions, of the energy‐momentum tensor are gauge independent to all orders of the purturbation theory (the loop expansion). A study is also made, in terms of the gauge invariant operators of electron (known as the Dirac's or Steinmann's electron) and photon, in expectation of gauge invariant result without any restriction. It is, however, shown that singling out gauge invariant quantities is merely synonymous to fixing a gauge, then there needs again a use of the asymptotic condition to obtain gauge independent re

ISSN:0015-8208    

DOI:10.1002/prop.2190450503

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractUsing a quark model scheme of ‘least Dynamics’, an inclusive determination of the total widths of mesonsandbaryons is proposed via the following mechanism: There exists a short (breathing) mode for the temporary dissociation of a hadron into a pair of “qausi‐free” quarks and/or diquarks which eventually hadronize with certainty, so that the requisite widths correspond to this “first stage” dissociation itself. A detailed model (described elsewhere) based on the momentum dependence of the quark's mass functionm(p) suggests a significant mass reduction of these quasi‐free quarks w.r.t their “constituent” valuesm(O). Using this logic, a phenomenological coupling scheme for the meson‐(quasifree)quark‐vertex function is derived from Schwinger's Partial (broken chiral). Symmetry which incorporates the conservation of isospin, baryonic charge and hypercharge with respective ‘gauge mesons’ rho, omega, phi. A very similar structure is found for baryon couplings to quark (q)‐diquark (D) pairs, withthe same overall coupling constant(gs) forbothsystems. Its tentative identification with the QCD value yields a surprisingly goodpatternof agreement with data for both hadron types, using two “quasi‐free” masses (mudandms) as inputs, with the corresponding d

ISSN:0015-8208    

DOI:10.1002/prop.2190450504

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0015-8208    

DOI:10.1002/prop.2190450501

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY