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1.
The scale breaking phenomena in deep inelastic electron (muon)-nucleon scattering experiments are analyzed using the naive parton model in broken color gauge theory.  相似文献   

2.
The temperature dependence of inelastic ultracold-neutron scattering on beryllium and copper surfaces at low energy transfers (about 10?7 eV) is investigated, and the results of this investigation are presented. The recorded flux of neutrons inelastically scattered by these surfaces at liquid-nitrogen temperature is less than that at room temperature by a factor of about two.  相似文献   

3.
Elastic polarized muon scattering is considered as an independent source of information on weak neutral currents involving muons. At low energies and high intensities cross section asymmetries are measurable which are sensitive to the right-handed weak muon charge, involve new combinations of coupling constants and depend remarkably on the details of weak nucleon form factors.  相似文献   

4.
The production ofK 0, and particles is studied in the E665 muon-nucleon experiment at Fermilab. The average multiplicities and squared transverse momenta are measured as a function ofx F andW 2. Most features of the data can be well described by the Lund model. Within this model, the data on the K0/± ratios and on the averageK 0 multiplicity in the forward region favor a strangeness suppression factors/u in the fragmentation process near 0.20. Clear evidence for QCD effects is seen in the average squared transverse momentum ofK 0 and particles.Deceased  相似文献   

5.
We have measured at 500 GeV the cross section d2σdt dMX2 for the inclusive reaction p + p → + X. We determine the mass spectrum of the diffractive peak to be 1M3.8±0.2 and the scaling part of the cross section to be /dMX2 = (15.7±1.1)/smb/GeV2.  相似文献   

6.
A Monte Carlo-based method for computing electron-target inelastic interaction is presented. It uses the double-differential inelastic scattering cross section. A resource-saving algorithm that simulates the interaction using the double-differential cross section was elaborated. The cross section was calculated from data on the optical permittivity of the target.  相似文献   

7.
The idea that the pomeron has partonic structure similar to any other hadron has been given strong support by recent measurements of the diffractive structure function at HERA. We present a detailed theoretical analysis of the diffractive structure function under the assumption that the diffractive cross section can be factorized into a pomeron emission factor and the deep inelastic scattering cross section of the pomeron. We pay particular attention to the kinematic correlations implied by this picture, and suggest the measurement of an angular correlation which should provide a first test of the whole picture. We also present two simple phenomenological models for the quark and gluon structure of the pomeron, which are consistent with various theoretical ideas and which give equally good fits to recent measurements by the H1 collaboration, when combined with the pomeron emission factor of Donnachie and Landshoff. We predict that a large fraction of diffractive deep inelastic events will contain charm, and discuss how improved data will be able to distinguish the models.  相似文献   

8.
9.
Starting from a microscopic deformed picture of the 12C nucleus, and using angular momentum projected wave functions, the elastic and inelastic 1 GeV p-scattering differential cross sections have been analysed within the framework of the Glauber theory. From a comparison of the results obtained in a full Glauber calculation and in the optical limit, it has been shown that the elastic scattering and, to a lesser extent, the transition to the 2+(4.44 MeV) level are only weakly affected by the long-range correlations. In contrast the scattering to the 4+(14.08 MeV) state includes crucial multi-step contributions which affect the differential cross section both in shape and magnitude. Similarly the corrections to the DWIA are essential for the transition to the 3?(9.64 MeV) state and a satisfactory explanation of the qualitative differences observed between the 2+ and 3? inelastic cross sections in 12C is given. The great sensitivity of the cross sections to the nuclear deformation is shown and a generally good agreement with experiment for both the electron form factors and 1 GeV p cross sections has been obtained for the ground-state intraband transitions using a single oblate intrinsic state. The importance of a correct treatment of the rotational motion through the angular momentum projection is underlined and the use of the adiabatic approxmation is critically examined.  相似文献   

10.
Using data of the European Muon Collaboration on muon-proton and muon-deuteron scattering at 280 GeV, an intermittency analysis in one, two and three phase space dimensions is carried out. In addition, a factorial correlator analysis and a multifractal analysis, both in one dimension (rapidity), are presented.  相似文献   

11.
12.
Spin asymmetries in deep inelastic scattering with longitudinally polarized electron and proton beams are examined. These predictions are a good testing ground for the nucleon spin structure and for the electroweak theory. Some of them will be measured in polarization experiments at future colliders.  相似文献   

13.
Theoretical differential cross-sections are obtained for the elastic scattering of fast (E i ⩾ 200 eV) positrons by oxygen molecules. Employing the independent atom model, the atomic scattering amplitudes are calculated with the (static + polarization) model potentials, in the partial wave analysis (PWA). Comparisons made with the theory and experiments on the incident electrons, show significant differences at small angles.  相似文献   

14.
A hybrid model of lepton-nuclear interactions is constructed; energy loss spectra and average muon and tau lepton energy losses in inelastic scattering off nuclei in rock and water in the energy range 102–109 GeV are calculated in the framework of this model. Charge asymmetry of scattering due to processes with weak neutral current is discussed. Comparison with calculations in the framework of other models is presented.  相似文献   

15.
We study two examples of infrared-safe quantities in deep inelastic scattering: the flow of energy in a given angular range and the energy-energy angular pattern. We derive expressions for these quantities in perturbative QCD, to order αs, and show explicitly their infrared safety. Our formulas for the angular energy flow and the energy-energy angular pattern depend only on well-defined QCD factors and on the deep inelastic structure functions. To gauge whether or not these perturbative QCD results are applicable to present day data, we estimate in a simple model the effects of hadronization and primordial parton transverse momentum. In general these non-perturbative effects mask the resulting QCD pattern at present energies, but vanish more rapidly at higher energies than the QCD effects. However, we point out two examples where it may be possible to test the perturbative QCD predictions with available data. One of them involves studying the x-dependence of the azimuthal asymmetry of the energy flow. The other involves studying the angular width of the energy-energy correlation function.  相似文献   

16.
Theoretical results for the energy distributionP() of atoms scattered by solid surfaces are presented. An exact expression for the first moment (the average energy loss) ofP() is derived involving the force-force correlation of the scattering particle and the susceptibility of the lattice. An approximate result forP() is derived in which the same two quantities occur. The forces are treated statically (i.e. neglecting the response of the lattice) and semiclassically (i.e. neglecting their noncommutativity). Quantum effects of the lattice are taken into account properly. No approximations are made concerning the number of excited phonons. An expression for the reduction of elastic scattering due to inelastic processes (generalized Debye-Waller factor) is found containing the dynamic and finite size effects discussed in the literature.  相似文献   

17.
The differential cross sections for the elastic and inelastic scattering of protons on deuterium have been measured for scattering angles less than 14° at 198.5, 297.6 and 456.6 MeV. These quantities were determined relative to dσ / dΩ for pp elastic scattering with a precision of typically 2%. The range of excitation energies for the (p, p') reaction was chosen to emphasize the region near the np threshold dominated by the final-state interaction in the 1S0 channel. Particular attention was given to the dependence on excitation energy of the spectra at 198.5 MeV to examine the sensitivity to the 1S0 scattering length, anp In this paper all data are compared with a new, detailed formulation of a simple model of the reaction mechanism based on the impulse approximation. The experimental results differ from the predictions by typically 10% and the differential cross sections exhibit a sensitivity to the intermediate-energy nucleon-nucleon amplitudes. If the impulse approximation is used to estimate anp from the data at 198.5 MeV a value of − 24.7 ± 0.4 fm is obtained.  相似文献   

18.
The shapes of jets with transverse energies, , up to 45 GeV produced in neutral- and charged-current deep inelastic scattering (DIS) at GeV have been measured with the ZEUS detector at HERA. Jets are identified using a cone algorithm in the - plane with a cone radius of one unit. The jets become narrower as increases. The jet shapes in neutral- and charged-current DIS are found to be very similar. The jets in neutral-current DIS are narrower than those in resolved processes in photoproduction and closer to those in direct-photon processes for the same ranges in and jet pseudorapidity. The jet shapes in DIS are observed to be similar to those in interactions and narrower than those in collisions for comparable . Since the jets in interactions and DIS are predominantly quark initiated in both cases, the similarity in the jet shapes indicates that the pattern of QCD radiation within a quark jet is to a large extent independent of the hard scattering process in these reactions. Received: 2 April 1998 / Published online: 7 April 1999  相似文献   

19.
Medium energy proton elastic and inelastic scattering to states of 58Ni and 208Pb, and 4He elastic and inelastic scattering to states of 40Ca, are analyzed using the partial wave approach, by solving the Schrödinger equation with relativistic kinematics and using the distorted wave Born approximation. Our results can be compared with results of several previous analyses of the nucleon inelastic data using the Glauber approximation. Our calculations are absolute, using nuclear collective parameters obtained from a survey of a large number of low-energy analyses of inelastic scattering of electrons, nucleons and nuclei from 40Ca, 58Ni and 208Pb.  相似文献   

20.
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