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1.
On its passage through the nucleus a very high-energy hadron strikes several target nucleons. These recoil nucleons initiate an intranuclear cascade. “Grey particles”, mostly protons with energy between 40 and 400 MeV result from the cascade. We can describe the mean number and distribution of grey particles by truncating the intranuclear cascade after the second generation. The number Ng of grey particles is very simply related to the number ν of initial hadron-nucleon collisions: 〈ν〉Ng〈ν〉 = a(Ng〈Ng〉)12, where a is a numerical constant close to 1.  相似文献   

2.
We examine the effects of higher-order corrections on the universality between νμ and νe in the Weinberg-Salam model. The leading correction to neutral current amplitudes is an apparent difference in the values of sin2θ as measured by νμ and νe beams. The difference is sin2θ〉νμ ? 〈sin2θ〉νe = (α)ln(m2μm2e).  相似文献   

3.
By use of the generalized scaling sum rules the vector-axial vector interference terms in the scaling limit of the inelastic neutrino reactions are calculated from the absorptive parts of the single-pion photoproduction amplitudes at zero momentum transfer. The photoproduction amplitudes are evaluated by use of the results of multipole analysis. With the optimum values for the two parameters of the generalized scaling as determined in previous works, we have obtained F3νN(ω) which leads to good agreement with experiment in the ration of σνNνN. However, the zeroth moment in x( = 1/ω), ∫01dx(F3νp + F3νp) turns out to be smaller than half of the value predicted in the fractionally charged quark model.  相似文献   

4.
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   

5.
In the presence of right-handed currents including (cs)R, it is emphasized that the dominant parity-violating (-conserving) Hamiltonian for nonleptonic decays of charmed hadrons transforms like 45 + 451 (20″ + 84) of SU(4), and leads to distinctive results especially in D+ → KSπ+, F+μ+νμ and D0 → K?e+νe, etc.  相似文献   

6.
The small ω′ behaviour of F2en/F2ep and the apparent difference in the q2 dependences of the magnetic form factor of the proton and of the transition to Δ+(1236) are quantitatively correlated in a model where nucleon consistes of a quarks and a scalar or vector core. The proton and Δ transition form factors suggest that only the scalar core contributes at large q2 and small ω′. As a result the ω′ dependence of F2enF2ep is obtained for ω′ < 3 and predictions for the weak structure functions and polarisation asymmetries at smallω′ are presented. We predict FνpFνnω′→10 asymmetries ω′→11 and also expect that GmnGmp?12 as q2→∞.  相似文献   

7.
The order α(Q2) correction to the particle multiplicity ratio in gluon and quark jets is calculated in QCD. We find
r=941?αCA13+N?3CA?2N?CF3C2A
with r=〈ngluon jet/〈nquark jet. The method used is systematic and could be used for an order α(Q2) calculation.  相似文献   

8.
The Raman active fundamentals ν1(A1g), ν2(Eg), ν5(F2g), and the overtone 2ν6 of SF6 have been investigated with a higher resolution and the band origins were estimated to be: ν1 = 774.53 cm?1, ν2 = 643.35 cm?1, ν5 = 523.5 cm?1, and 2ν6 = 693.8 cm?1. Raman and infrared data have been combined for estimation of several anharmonicity constants. The ν6 fundamental frequency is calculated as 347.0 cm?1. From the analysis of the ν2 Raman band, the following rotational constants of both the ground and upper states have been calculated:
B0 = 0.09111 ± 0.00005cm?1; D0 = (0.16±0.08)10?7cm?1
;
B2 = 0.09116 ± 0.00005cm?1; D2 = (0.18±0.04)10?7cm?1
.  相似文献   

9.
The rotational motion of the OH? ion was studied in cubic NaOH at 575 K with quasielastic incoherent neutron scattering. The data are compared to two simple models yielding values for the radius of rotation R, the translational mean square displacement 〈u2H, the rotational jump rate τ?1 and the rotational diffusion coefficient DR. The following parameter values are obtained: (a) rotational jump model: R = 0.95 A?, 〈u2H = 0.052 A?2, τ?1 = 2 meV, (b) rotational diffusion model: R = 0.99 A?, 〈u2H = 0.046 A?2, DR = 0.72 meV.  相似文献   

10.
A study is presented of single πo production in neutrino and antineutrino interactions in Gargamelle filled with freon CF3Br. Limits on the neutral to charged current cross-section ratios Rv=σ(vN→vN′πo)/2 σ(vN→ μ -N′πo) and Rν = σ(νNνN′πo)/2 σ(νN → ω+N′πo) are found to be 0.10 < Rν < 0.20 and 0.26 < Rν < 0.44 at 68% confidence level.  相似文献   

11.
H. Yasuhara  Y. Kawazoe 《Physica A》1976,85(2):416-424
The one-electron momentum distribution function 〈a2a for an electron gas is investigated by a diagrammatic analysis of perturbation theory. It is shown that 〈a2a has the following exact asymptotic form for large k (k ? pF; pF, the Fermi momentum): 〈a2a〉 = 49(αrsπ)2×(pF8k8) g?(0) + ?, where g?(0) is the zero-distance value of the spin-up-spin-down pair correlation function. The physical implications of the above asymptotic form are discussed.  相似文献   

12.
The fine structures of the (ν1 + ν2) and (ν2 + ν3) combination bands of ozone in the 5.7-μm region have been recorded and analyzed. The two vibrational states are coupled through Coriolis and second-order distortion terms. The interaction has been treated by the numerical diagonalization of the secular determinant for the two coupled states. With the centrifugal distortion parameters fixed to the ground state values, the following constants have been obtained: ν1 + ν2 = 1796.266, A110 = 3.6104, B110 = 0.44145, C1110 = 0.39029, ν2 + ν3 = 1726.526, A011 = 3.5537, B011 = 0.43982, C1011 = 0.38844, Y13 = ?0.466, and X13 = ?0.010 cm?1. In addition, the following anharmonic constants have been obtained: x12 = ?7.821 and x23 = ?16.494 cm?1. The value of the dipole moment ratio, R = 〈011|μz|0〉〈110|μx|0〉, is 1.30 ± 0.10.  相似文献   

13.
The difference of the cross sections for deep inelastic scattering of muons with average momenta 21 GeV/c with right and left helicity at large angles, i.e., with large momentum transfer, has been measured. No statistically-significant dependence of cross sections on the longitudinal polarization of muons has been found, i.e. no parity-nonconservation effects in deep inelastic μN interaction have been observed. The magnitude of the cross-section asymmetry R = [〈σR〉 ? 〈σL〉][〈σR〉+ + 〈σL〉] may be represented as R = βQ2〉 = (? 4 ± 6) × 10?3Q2, (GeV/c)2〉. The limitations Go(μ) = (+ 6 ± 10)G have been obtained for the constant Go(μ) of vector-axial interaction (Go(μ)2) [μγα(1 + γ5)μ] Jαo (hadron, V-A).  相似文献   

14.
Elastic scattering through 180° from 9Be, 12C and 13C targets has been observed for electrons of 35 to 90 MeV. Magnetic scattering cross sections for 9Be and 13C have been obtained by subtracting charge scattering as deduced from the scattering from the spin-zero nucleus 12C. Theoretical shell model predictions for the magnetic cross sections are derived for (1s)4(1p)A?4 configurations and various coupling schemes. Both harmonic oscillator and Woods-Saxon radial wave functions are used. A comparison of our results with magnetic cross sections calculated in DWBA yields magnetic rms radii 〈r2M12 = 3.2 ± 0.3 fm and 〈r2M12 = 3.3 ± 0.3 fm for 9Be and 13C. For 13C a combined flt to our low-q data and to earlier high-q data, yields 〈r2M12 = 3.4 ± 0.1 fm and a strong preference for intermediate coupling (IC) wave functions. Magnetic dipole scattering from 9Be is also close to the IC prediction, as deduced from a fit to our data and earlier high-q data. The fitted value of the octupole moment Ω = 5±1 μNfm1 can only be explained by a deformation of the average nuclear potential. The radial size 〈r21p12 = 2.85 ± 0.05 fm for the 1p radial wave function is in agreement with both the 9Be and 13C data.  相似文献   

15.
Quark masses     
In quark gluon theory with very small bare masses, -ψMψ, spontaneous breakdown of chiral symmetry generates sizable masses Mu, Md, Ms, … We find (Mu + Md) /2 ≈ mp/ √6 ≈ 312 MeV, and Ms ≈ 432 MeV. Scalar densities have well determined non-zero vaccum expectations 〈0|ua|0〉 ≡ 〈0|ψ(x) (λa/2)ψ(x)/0〉 ≈ ?π2Ma, i.e〈0? uo/vb0〉 ≈ 8 × 10?3 (GeV)3 at an SU(3) breaking of the vacuum c′ ≡ 〈0|u8|〉/〈0|uo|0〉 ≈ ? 16%  相似文献   

16.
π+ and π? elastic and inelastic scattering from 18O have been measured at T(π)=164 MeV. Consistent with the results at 230 MeV, it is found that the ratio σ(π?)σ(π+) for the 21+ state is 1.86(16), while for the 31? state it is 0.89(6). These results are interpreted as indicating differences in neutron and proton deformations characterizing the 21+ transition and partial neutron blocking for the 31? transition. Optical model analysis of elastic scattering leads to the conclusion that 〈rn212?〈rp212=0.03(3) fm.  相似文献   

17.
Medium resolution infrared grating spectra of gaseous ketene, H2CCO were recorded between 1000 and 400 cm?1, both at instrument temperature (40°C) and with cooling (?40°C). Interferometric Fourier spectra were also measured at ?70°C with resolution 0.22 cm?1 between 450 and 330 cm?1. The K structure of the fundamentals ν5, ν6, ν8, and ν9 was assigned. These fundamentals are coupled by a-axis Coriolis interactions. These couplings were analysed on the symmetric top basis for setting up the perturbation matrix and by utilizing the K-dependent Coriolis shifts of levels. A preliminary analysis of the Coriolis intensity anomalies was also undertaken.Band center values from combination differences are ν50 = 587.30 (27) and ν60 = 528.36 (39) cm?1. Synthetic spectra indicate the band origins of ν8 and ν9 to be close to 977.8 and 439.0 cm?1, respectively. Estimates of Coriolis coupling constants obtained from synthetic spectra are ζ58a = + 0.33 (5), ζ68a = + 0.714 (20), ζ59a = ? 0.774 (20), and ζ69a = ? 0.30 (2). Approximate ratios of unperturbed vibrational transition moments obtained from spectral simulations are M80:±iM50:±iM60:M90 ≈ +2:?9:+10:+0.5.  相似文献   

18.
Line strengths and self- and nitrogen-broadened half-widths were measured for spectral lines in the ν3 and ν2 + ν4 bands of 12CH4 and 13CH4 from 2870–2883 cm?1 using a tunable diode laser spectrometer. From measurements made over a temperature range from 215 to 297 K, on samples of 12CH4 broadened with N2, we deduced that the average temperature coefficients n, defined as bL0(T) = bL0(T0)(TT0)?n, of the Lorentz broadening coefficients for the ν3 and ν2 + ν4 bands of 12CH4 were 0.97 ± 0.03 and 0.89 ± 0.04, respectively. A smaller increase is observed in line half-width with increasing pressure for E-species lines, for both self- and nitrogen-broadening, than for other symmetry species lines over the range of pressures measured, 70 to 100 Torr.  相似文献   

19.
The total νμ and νμ nucleon charged-current cross sections have been measured in BEBC filled with deuterium and exposed to the wide-band neutrino and antineutrino beams at the CERN-SPS. Assuming a linear energy dependence for the cross sections, σ = aE(?ν, we obtained the coefficients aνN = 0.62 ± 0.05 and aνN = 0.33 ± 0.03 (in units of 10?38 cm2/GeV), where the quoted error is mainly systematic. The ratio of the cross sections is σνNνN = 0.53 ± 0.03.We also determined the ratio of the charged-current cross section for neutrino interactions on neutrons and protons R = σνn/σνp = 2.10 ± 0.08 (statistical) ±0.22 (sysetmatic). The dependence of R on the variables x, y and Eν is discussed.  相似文献   

20.
To a good approximation, hyperfine splittings for F1 and F2 rotational levels of the ground vibrational state of 12CH4 depend linearly on three hyperfine interaction parameters. Coefficients in these linear expressions have been computed in a relatively simple manner and tabulated for levels with 1 ≤ J ≤ 20. The hyperfine pattern for the J = 7 F2(2) level computed from these expressions using values for the three hyperfine interaction parameters reported recently by Yi, Ozier and Ramsey (1) agrees well with the pattern obtained from new HeNe laser measurements of Hall and Bordé (2) on the P(7) F2(2) line of the ν3 band of methane.  相似文献   

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