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1.
We present the α s corrections to quark vacuum condensate contributions to various types of current correlation functions. Their relevance to the first Weinberg sum rule is discussed. A new derivation of the relation between theA 1-mass and the ?-mass is presented. The higher order corrections to the socalled non-perturbative quark mass are also discussed.  相似文献   

2.
We discuss which part of information about hadron structure encoded in the Generalized Parton Distributions (GPDs) [part of total GPD image] can be restored from the known amplitude of a hard exclusive process. The physics content of this partial image is analyzed. Among other things, we show that this partial image contains direct information about how the target hadron responses to the (string) quark–antiquark operator of arbitrary spin J. Explicit equations relating physics content of the partial image of GPDs directly to the data are derived. Also some new results concerning the dual parametrization of GPDs are presented.  相似文献   

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It has been claimed that gluon emission can raise weak annihilation contributions to heavy quark decays by powers of (mQhad), the ratio of the heavy quark mass to a light hadron mass scale. We show that such powerlike enhancements of annihilation, interference and other preasymptotic effects do not arise for fully inclusive transitions, only for partial rates. The leading corrections are then logarithmic; even so they are crucial for determining the impact of these effects. We establish a non-trivial relation between euclidean renormalization and real decay processes in Minkowski space. Phenomenological consequences are briefly discussed, e.g. we expect the Bd and B lifetimes to differ by only a few percent with interference being the maon driving force. The (hybrid) log corrections are essential for the degree of interference by effectively cancelling non-leading terms in a 1/Nc expansion.  相似文献   

5.
In ab initio studies of the impact of electron correlation effects of f ? f transition probabilities much numerical work is concerned with evaluating radial factors. These terms are expressed as products of the radial integrals summed over all excited orbitals including those in the continuum. To simplify the evaluation of these sums, for the first time in f ? f transition theory, the perturbed-function approach has been applied. The detailed analysis of numerical results obtained for the radial factors contributing to the transition amplitudes for Pr3+ are presented. Special attention is paid to studying the impact of the incompleteness of the radial basis set upon the radial factors occurring in f ? f electric-dipole transition theory.  相似文献   

6.
指出Pomeron可以被看作为具有Regge轨道αp(t)=1.08+0.2GeV-2t的Regge化的胶子球.理论成功地预言了实验上观测到的质子一质子弹性散射的总截面.理论与实验的最好符合给出了张量胶子球到质子反质子道的衰变宽度为9±3MeV,其总宽度大于50MeV.并且排除了张量胶子球的自旋为4的可能性.  相似文献   

7.
A complete expression for the f?f transition amplitude defined up to the third order in perturbation theory is presented. The third-order contributions are due to electron correlation inside the rare earth ion and arise from the static and dynamic models. The approach is formulated by means of double perturbation theory and in terms of effective tensor operators expressed by unit tensor operators. The discussion of the relative importance of various kinds of effective operators is based on the numerical results of test ab initio calculations performed within the perturbed function approach for the Pr+3 ion.  相似文献   

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9.
Badalian  A. M.  Nefediev  A. V.  Simonov  Yu. A. 《JETP Letters》2008,88(9):558-563

The vacuum gluonic correlation length is extracted from recent lattice data on spin-dependent interquark potentials in heavy quarkonia. It is shown that the data are consistent with extremely small values of the correlation length, T g ? 0.1 fm.

  相似文献   

10.
We give a systematic treatment of relativistic corrections to a Coulomb system of heavy quarks in a colour background field with a finite correlation time. The relativistic corrections turn out to be significant. Comparison with experiment favors a correlation time of 0.2−0.5 fm. We predict the 3S11S0 and 3P11P1 hyperfine splitting.  相似文献   

11.
The vacuum gluonic correlation length is extracted from recent lattice data on spin-dependent interquark potentials in heavy quarkonia. It is shown that the data are consistent with extremely small values of the correlation length, T g ≲ 0.1 fm. The article is published in the original.  相似文献   

12.
We calculate one-gluon corrections to the decay rate of heavy quarkonium states into lepton pairs. We find that the correction due to one-gluon exchange is not very significant for charmonium, and for practical purposes only the relativistic kinematical effects need to be taken into account. For theY family the gluonic corrections are, relatively, of greater importance.  相似文献   

13.
[1]J.D. Bjorken, Phys. Rev. D 47 (1993) 101. [2]T. Regge, Ⅱ Nuovo 14 (1959) 951. [3]P.D.B. Collins, Introduction to Regge Theory, Cambridge University Press, Cambridge (1977). [4]G.F. Chew and S.C. Frautschi, Phys. Rev. Lett. I (1961)394. [5]A. Donnachie and P.V. Landshoff, Phys. Lett. B 231(1987) 189; Nucl. Phys. B 244 (1984) 322. [6]A. Donnachie and P.V. Landshoff, Nucl. Phys. B 311(1989) 509; J.R. Cudell, Nucl. Phys. B 336 (1990) 509. [7]D.G. Cassel, et al., Phys. Lett. B 136 (1985) 203; B 133(1983) 370. [8]Ma Wei-Xing and Zhou Li-Juan, Commun. Theor. Phys.(Beijing, China) 36 (2002) 577. [9]J.J. Aubert, et al., Phys. Lett. B 161 (1985) 203. [10]J.M. Carget, et al., Nucl. Phys. A 581 (1995) 397. [11]T.D. Meng, et al., Phys. Rev. Lett. 82 (1999) 2044. [12]H. Terazawa, Gluons, Glueballs, Odderons, Pomerons and Color-ball, KEK, preprint 99-47, July, (1999). [13]F.E. Lowm Ogts, Phys. Rev. D 12 (1975) 16; S. Nussikov,Phys. Rev. Lett. 34 (1975) 1286. [14]E.A. Kuraev, L.N. Lipatov, and V.S. Fadin, Phys. Lett.B 60 (1975) 50. [15]P.V. Landshoff and O. Nachtmann, Z. Phys. C 35 (1987)405. [16]J.Z. Bai, et al., Phys. Rev. Lett. 76 (1996) 3502. [17]R.M. Baltkusaitis, et al., Phys. Rev. Lett. 56 (1986) 107. [18]Ma Wei-Xing, et al., Commun. Theor. Phys. (Beijing,China) 43 (2005) 504. [19]L.C. Liu and W.X. Ma, J. Phys. G: Nucl. Part. Phys. 26(2000) L59. [20]A.H. Mueller, Phys. Rep. 73 (1981) 237. [21]V.A. Novikov, M. A. Shifman, A.L. Vainstein, and V.I.Zakharov, Nucl. Phys. B 165 (1980) 67; Nucl. Phys. B 191 (1981) 301; L.S. Kisslinger and J. Gardnei, Phys.Lett. B 410 (1997) 1. [22]H. Kavaum and R. Nakuyama, Nucl. Phys. B 189 (1981)40. [23]L.C. Liu and W.X. Ma, J. Phys. G: Nucl. Part. Phys. 26(2000) L59.  相似文献   

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15.
We use the light-cone sum rule technique to calculate the contribution of the gluonic penguin operator O 8g to the decay of the B-meson to two pions. Leading-order perturbative and non-perturbative corrections are included, corresponding to hard and soft exchanged gluons, respectively. While the overall contribution of this operator to the decay is small as expected before, we find that the so-called soft-gluon part of this contribution is of the order of the hard-gluon one. This implies that the inclusion of soft gluons in the calculation of matrix elements may be important.Received: 30 September 2002, Published online: 22 October 2003PACS: 13.25.Hw Hadronic decays of mesons: Decays of bottom mesons - 11.55.Hx Sum rules  相似文献   

16.
We study a typical complete gluonic phase (LGP) in two-flavour colour superconductivity (2SC) by calculating the essential cubic and quartic interfering term between the gluonic condensates (Az^(8)) and/Az^(6)) with a gauged NJL model. It is proven that the coefficients of the cubic interfering term and the vacuum contributions of the cubic and quartic interfering term are all equal to zeroes. The coefficients of the quartic interfering term and the /Az^(6)) 's quartic self-interaction term at stationary points of Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) phase are calculated. Comparisons among the effective potentials of LOP, g2SC and LOFF phase indicate that LOP could be the genuine ground state of 2SC for some reasonable paxameters.  相似文献   

17.
The Pomeron-nucleon coupling vertex is theoretically derived from the fundamental theory of strong interaction QCD. The empirical vertex βγ^μF1 (t) used commonly in diffractive processes with a coupling strength β = 6.0 GeV^-1 is initially obtained from QCD theoretically. Our study not only reproduces the Pomeron-nucleon coupling from QCD but also clearly shows the gluonlc origin and glueball nature of Pomeron, which is a longstanding puzzle. From this investigation, we claim that Pomeron can be regarded as a Reggeized tensor glueball ζ(2230) with quantum numbers of I^GJ^PC = 0+2++. Since the tensor glueball ζ(2230) lies on the Pomeron trajectory αp(t = Mζ^2) = 2, the longstanding puzzle that no physical particle lies on the Pomeron trajectory, αp(t) = 1.08 + 0.20 GeV^-2 .t, seems to be solved.  相似文献   

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20.
The consequences of the inclusive dipole-Pomeron for the exclusive processes are investigated. In the weak coupling limit a two component picture for the production mechanism is obtained and self-consistency of the inclusive Pomeron dipole is found.  相似文献   

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