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1.
Charge properties of the hadronic systems from νp and νp scattering in BEBC are studied in the framework of the quark-parto model (QPM). The average charges 〈Qjetν and 〈Qjetν of a quark jet and a d-qua jet, respectively, are determined according to two different methods. The difference 〈Qjetν ? 〈Qjetν is in agreement with e QPM value of 1. Scaling of charge and energy flow in the angular variable λ is demonstrated. The ratios ΔQν/ΔQν of charge flows in νp a νp scattering are in accord with the QPM in both hemispheres.  相似文献   

2.
The Coriolis interactions between ν1 and ν3, and between ν2 and ν3 in SO2 have been analyzed to obtain the signs of the products ζ3.1c(a?Q3)(b?Q1) and ζ3.2c(a?Q3)(b?Q2). It has been found that both of the signs of these products are positive. Then, relative signs of (?Q1) have been determined using the calculated values of the Coriolis zeta constants for the present definition of the normal coordinates. The obtained sign combination of (?Qi) is ±(+?+), which agrees with the one predicted by the molecular orbital calculations. Using the sign combination (+?+), the polar tensors of S and O atoms were also calculated.  相似文献   

3.
The activation barrier ΔE1ABfor dissociation AB → A + B on transition-metal surfaces is analyzed within an additive Morse-type approach based on the bond-order conservation. It is shown that ΔE1AB = DAB?(QA + QB + QAQB/(QA + QB) where DAB is the gas-phase dissociation energy and QA(QB) is the heat of atomic chemisorption. Estimates of ΔE1 for H2, N2, O2, and NO are shown to be in reasonable agreement with experiment. The two-dimensional potential diagram of the metal-AB interactions is defined analytically and discussed in some detail.  相似文献   

4.
We calculate the QCD evolution equations for structure functions with supersymmetric particles excited for the following models: light gluinos, g? and heavy squarks q? with mg? ? Q2 ? mq?2; light squarks, and heavy gluinos with mg? ? Q2 ? mg?2; and mg?2, mg?2 ? Q2. The momentum sum rules and the behaviour of structure functions as x → 1 are particularly discussed.  相似文献   

5.
It is shown that for spinorial charges Q(L))α (α = 1, 2, L = 1, …, S) satisfying the commutation relations
{Q(L)α, Q(M)β} = εαβaLMQ,
{Q(L)α, Q(M)+β} = cσμαβPμδLM,
[Q(L))α, Pμ] = 0,
where Q is a scalar charge commuting with the spinor charges as well aswith the energy- momentum vector Pμ, there can exist several different multiplets for free massive scalar and spinor fields.  相似文献   

6.
Though high twist terms are becoming important as x→1, or equivalently, in large n moments, their detection in this regime in deep inelastic lepton scattering needs special caution. The high order terms in the twist two component are strongly dependent on n; one finds that at Q2?Q272akexpk(log n)2?1k(1+bklog n)] the perturbative expansion is invalid whereas higher twist terms are important at Q2?Q12 = Λ2nC. Since Q72 grows very fast with n the necessary requirement for any deep inelastic phenomenological analysis, namely Q12?Q72, cannot hold for too large moments. The scheme dependence of ak, αk and bk is also discussed.  相似文献   

7.
We use semiclassical methods to discuss the scaling behaviour of quarkonium level splittings up to M(QQ) = 200 GeV. Special emphasis is laid on the effects of asymptotic freedom which are found to be essential for M(QQ) ? 30 GeV. The bound tt system will almost look like the ? system except that R = ΔM (3P2 ? 3P1)/ΔM(3P1 ? 3P0) is larger than 0.8. In the ? system R will already be close to 0.8.  相似文献   

8.
9.
The predictions of perturbative QCD are derived in the deep euclidean region, whereas the physical region for most observables is timelike. The confrontation of these predictions with experiment thus necessitates an analytic continuation. This we find introduces large higher order corrections in terms of αs(|Q2|), the usual choice ofperturbative expansion parameter. These corrections are naturally absorbed by changing to the expansion parameter a(Q2) = |αs(Q2)|(Re αs(Q2)/|αs(Q2)|)(n?2)3, where αs(Q2)n is the leading term in the spacelike region. For the intermediate range of Q2 experimentally accessible at present, where a(Q2) is significantly smaller than αs(|Q2|), we find the resulting phenomenology is improved. In particular, we demonstrate how the values of ΛMS obtained from analyses of quarkonium decays become consistent.  相似文献   

10.
If KS1,Lis a K1 resonance decaying into KS,L (the short- and long-lived kaon) and a neutral system So of pions, one can isolate the C-even and C-odd, crossed-channel contributions to KN → K1N by using the reactions KLN → KS1, LN whether So is a C-eigenstate, or a mixture of C-even and C-odd states. Applications to the production of K1(890) and the Q-meson are discussed, and simple numerical predictions made for QS,L production. Q-production data indicate approximate t-channel helicity conservation for the ω and P' exchanges at vertices involving a spin change, in similarity to the belief for the pomeron. QS,L production data can give information also on Q-decays.  相似文献   

11.
The Callan-Gross relation is shown to be consistent with MIT-SLAC data for σL(Q2)σT(Q2) for x ? 0.33 in deep inelastic eN scattering, despite the fact that these data are taken in the large Q2 region where F1 and F2 individually exhibit scaling violation. Comparison is made with asymptotic freedom predictions, and color excitation is proposed to explain large values of σLσT at small x.  相似文献   

12.
Nuclear spectroscopic quadrupole moments of the radioactive isotopes 131Cs, 132Cs, and 136Cs have been determined from the hyperfine structure of the 62P32 state by the level crossing method. The results including a Sternheimer correction are: Qs(131Cs) = ?0.625(6) b, Qs(132Cs) = +0.508(7) b, Qs(136Cs) = +0.225(10) b. The quadrupole moments of all the Cs isotopes from A = 131 to A = 137 are recalculated. It is shown, that nuclear quadrupole moments of a specific isotope obtained from different atomic P-states only agree within the limits of error after application of the Sternheimer correction. The increase of Qs with decreasing neutron number conforms with other observations and theoretical calculations stating that for elements around Z = 55 nuclear deformation develops below N = 82. The staggering of the sign of Qs may be interpreted as consequence of an oblate-prolate degeneracy of the nuclear energy surface. Some magnetic moments have been slightly improved: μI(132Cs) = 2.219(7) μN, μI(136Cs) = 3.705(15)μN (corrected for diamagnetism).  相似文献   

13.
In an effort to develop a quantitative check of asymptotically free color-gauge theories, we analyze the logarithmic corrections to ξ-scaling coming from anomalous dimensions and coefficient functions of twist-two operators and compare with electroproduction data for 1 ? Q2 ? 16 GeV2. Excellent agreement is obtained using g2(2 GeV)2 = 0.17 for the effective quark-gluon coupling in the color-gauge theory. Effects of higher-twist operators are suppressed by powers of M02Q2. We use data from the resonance region to show M0 ? 400 MeV, in agreement with theoretical expectations. Our fit to νW2 in the scaling region also describes the resonance region in the sense of Bloom-gilman local duality. We show that local duality is a consequence of the moment predictions obtained from the operator-product expansion in quantum chromodynamics. We resolve a paradox associated with local duality and spin-zero targets. Present measurements of R = σLσT at large x and Q2 are systematically higher than our predictions.  相似文献   

14.
We argue that pion and nucleon structure functions differ principally due to their different numbers of quarks and different scales of confinement. The former generates an x rescaling while the latter, in QCD, gives rise to a Q2 rescaling. Together these lead to the relation
Fπ(x, Q2) = FN(23x, ξ NπQ2)
with ξNπ ? 0.16, for x values away from the end points. This relation is in good agreement with data.  相似文献   

15.
We calculate helicity amplitudes and decay rates for Zweig-forbidden radiative decays of a 3S1(QQ) bound state into 1S0(qq) and3PJ(qq) states in lowest-order QCD. We employ a new technique of scalarizing loop integrals by using covariant helicity projectors. Thereby we are able to integrate analytically all occuring loop integrals.When applied to Jψ decays our results are in reasonable agreement with present experimental results. ψ′ decays will provide a further test of the model. Transitions from bottonium to charmonium are most interesting since there all dynamical assumptions are well satisfied. Unfortunately the transitions rates are very small.  相似文献   

16.
Cross sections for42P12-42P32 mixing in potassium, induced by collisions with noble gas atoms, were determined using the methods of fluorescence spectroscopy. The experiments were carried out at an optical depth of ≤3×10-2 in the absence of radiation trapping and at noble gas pressures in the mtorr region and yielded the cross sections Q1(42P12→42P32) and Q2(42P12« 42P32) (in units of 10-16 cm2) respectively, as follows: for He, 26.3 and 17.8; for Ne, 6.4 and 4.4; for Ar, 16.0 and 11.2; for Kr, 24.9 and 17.7; for Xe, 44.9 and 31.7. These values supersede those reported previously by Chapman and Krause (1966).  相似文献   

17.
We consider a neutrino field with geodesic rays in interaction with a gravitational field admitting a Killing vector field nμ. It is found that for solutions of the Einstein-Weyl field equations the neutrino field ξA and the neutrino flux vector lμ are restricted by the equations: LnξA = ?12is ξA and Lnlμ = 0, whereas s is a real constant. In the case of pure radiation neutrino fields these equations become: LξA = case12(p ? is)ξA, Lnlμ = plμ, where p and s are in general real functions of the coordinates.  相似文献   

18.
Recent experimental results on electroproduction off protons show that the ratio σ(ep → eK+Σ0)/σ(ep → eK+Λ) decreases strongly with increasing Q2. A simple argument is given in the framework of the quark parton model which could provide a qualitative understanding of this fact. The decrease of the Σ0/Λ ratio is related to the decrease of the ratio F1γn/F1γp as Q2 increases, where F1γp and F1γn are the usual structure functions for deep inelastic electron-nucleon scattering.  相似文献   

19.
The Coriolis resonance between ν4 and ν7 in CH3CN and between ν1 and ν5, ν3 and ν6, and ν4 and ν7 in CD3CN has been analyzed, applying the technique developed by DiLauro and Mills, to obtain the signs of [ζr,say(?p?Qr)(?p?Qsa)] and the ratio of ?Qr to ?Qs for the interacting pairs in CD3CN. For (ν4, ν7) in both CH3CN and CD3CN, the sign of [ζr,say(?p?Qr)(?p?Qsa)] is found to be negative as it is also for (ν1, ν5) in CD3CN. For (ν3, ν6) the sign of this interaction term is found to be positive. For a given definition of normal coordinates the signs of these interaction terms give the relative signs of ?p?Qr and ?p?Qsa; our study also gives approximate values for the corresponding ratio [(?p?Qr)(?p?Qsa)]  相似文献   

20.
A three-loop calculation is presented for the jet multiplicity of produced slightly-off-shell gluons for a pure Yang-Mills theory. Planar and non-planar graphs are found to be equally important in an axial gauge. If the three-loop calculation is indicative of what happens at higher orders n(Q2) ∝ exp {[(2CAπb) 1n Q2]12} where CA = 3 and b = (33 ? 2nf)12π in QCD.  相似文献   

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