Zobrazeno 1 - 10
of 66
pro vyhledávání: '"Isgur, Nathan"'
Publikováno v:
Phys.Lett.B515:333-340,2001
Photoproduction of neutral-kaon pairs is studied from the perspective of CP and CPT studies. Interference of the P and S waves, with the former due to diffractive phi production and the latter to f_0/a_0 production, is shown to enhance the CPT reach.
Externí odkaz:
http://arxiv.org/abs/hep-ph/0106353
Publikováno v:
Phys.Rev.D65:014502,2002
The low-lying eigenmodes of the Dirac operator associated with typical gauge field configurations in QCD encode, among other low-energy properties, the physics behind the solution to the $U_A(1)$ problem (i.e. the origin of the $\eta'$ mass), the nat
Externí odkaz:
http://arxiv.org/abs/hep-lat/0102003
Autor:
Close, Frank E., Isgur, Nathan
Publikováno v:
Phys.Lett.B509:81-86,2001
Bloom-Gilman duality demonstrates empirically that the electroproduction of $N^*$'s at low momentum transfers averages smoothly around the scaling curve measured at large momentum transfers. The latter is proportional to the sum of the squares of the
Externí odkaz:
http://arxiv.org/abs/hep-ph/0102067
Autor:
Isgur, Nathan
The study of N*'s can provide us with critical insights into the nature of QCD in the confinement domain. The keys to progress in this domain are the identification of its important degrees of freedom and the effective forces between them. I report o
Externí odkaz:
http://arxiv.org/abs/nucl-th/0007008
Autor:
Isgur, Nathan, Thacker, H. B.
Publikováno v:
Phys.Rev.D64:094507,2001
The OZI rule is prominent in hadronic phenomena only because OZI violation is typically an order of magnitude smaller than expected from large N_c arguments. With its standard ^3P_0 pair creation operator for hadronic decays by flux tube breaking, th
Externí odkaz:
http://arxiv.org/abs/hep-lat/0005006
Autor:
Isgur, Nathan
Publikováno v:
Phys.Rev.D62:014025,2000
I describe a special class of meson-like \Lambda_Q excited states and present evidence supporting the similarity of their spin-independent spectra to those of mesons. I then examine spin-dependent forces in these baryons, showing that predicted effec
Externí odkaz:
http://arxiv.org/abs/hep-ph/9910272
Autor:
Isgur, Nathan
Publikováno v:
Phys.Rev.D62:054026,2000
I describe four serious defects of a widely discussed pion exchange model for interquark forces: it doesn't solve the "spin-orbit problem" as advertised, it fails to describe the internal structure of baryon resonances, it leads to disastrous conclus
Externí odkaz:
http://arxiv.org/abs/nucl-th/9908028
Autor:
Isgur, Nathan
Publikováno v:
Phys.Rev.D61:118501,2000
I criticize certain conclusions about the physics of hadrons drawn from a "valence QCD" approximation to QCD.
Comment: 12 pages, 8 figures; some minor improvements made to the text
Comment: 12 pages, 8 figures; some minor improvements made to the text
Externí odkaz:
http://arxiv.org/abs/hep-lat/9908009
Autor:
Isgur, Nathan
Publikováno v:
Phys.Rev.D60:114016,1999
Flux tube zero-point motion produces quark displacements transverse to the flux tube which make significant contributions to hadronic charge radii. In heavy quark systems, these contributions can be related by Bjorken's sum rule to the rates for semi
Externí odkaz:
http://arxiv.org/abs/hep-ph/9904494
Autor:
Isgur, Nathan
Publikováno v:
Phys.Rev.D60:074030,1999
In both the large N_c limit and the valence quark model, semileptonic decays are dominated by resonant final states. Using Bjorken's sum rule in an "unquenched" version of the quark model, I demonstrate that in the heavy quark limit nonresonant final
Externí odkaz:
http://arxiv.org/abs/hep-ph/9904398