446 research outputs found
The charge asymmetry from Pomeron-Odderon interference in hard diffractive pi+pi- -electroproduction
The interference of Pomeron and Odderon amplitudes gives rise to a charge
asymmetry in the diffractive electroproduction of a pi+pi- -pair. We calculate
this charge asymmetry in perturbative QCD in the Born approximation and on the
leading Q^2-level. The numerical evaluation shows a sizeable asymmetry in an
experimentally accessible kinematical region. We find a characteristic
m_{pi+pi} -dependence mainly dictated by the relevant Breit-Wigner-amplitudes
and the corresponding phase-shifts.Comment: 4 pages, 3 .eps-figures; Talk given by Ph.H. at the QCD-N'02 workshop
in Ferrara; Typos corrected, one reference adde
On The Application of Flow Forming to the Fabrication of Type B Radioactive Material Package Containment Vessels, Rev. 1
Eddy current studies from the undulator-based positron source target wheel prototype
The efficiency of future positron sources for the next generation of high-energy particle colliders (e.g. ILC, CLIC, LHeC) can be improved if the positron-production target is immersed in the magnetic field of adjacent capture optics. If the target is also rotating due to heat deposition considerations then eddy currents may be induced and lead to additional heating and stresses. In this paper we present data from a rotating target wheel prototype for the baseline ILC positron source. The wheel has been operated at revolution rates up to 1800rpm in fields of the order of 1 Tesla. Comparisons are made between torque data obtained from a transducer on the target drive shaft and the results of finite-element simulations. Rotordynamics issues are presented and future experiments on other aspects of the positron source target station are considered
Substantial reduction in defibrillation thresholds in dogs using a one capacitor dual biphasic waveform and multielectrode nonthoracotomy lead configurations
Heavy Quark production at the TEVATRON and HERA using k_t-factorization with CCFM evolution
The application of k_t-factorization supplemented with the CCFM small-x
evolution equation to heavy quark production at the TEVATRON and at HERA is
discussed. The bb_bar production cross sections at the TEVATRON can be
consistently described using the k_t-factorization formalism together with the
unintegrated gluon density obtained within the CCFM evolution approach from a
fit to HERA F_2 data. Special attention is drawn to the comparison with
measured visible cross sections, which are compared to the hadron level Monte
Carlo generator CASCADEComment: 13 pages, updated references and updated Fig. 9, Fig. 2 replace
Study of the Linked Dipole Chain Model in heavy quark production at the Tevatron
We present calculations of charm and beauty production at Tevatron within the
framework of kT-factorization, using the unintegrated gluon distributions as
obtained from the Linked Dipole Chain model. The analysis covers transverse
momentum and rapidity distributions and the azimuthal correlations between b
and bbar quarks (or rather muons from their decay) which are powerful tests for
the different unintegrated gluon distributions. We compare the theoretical
results with recent experimental data taken by D0 and CDF collaborations at the
Tevatron Run I and II.Comment: 16 page
Odderon in baryon-baryon scattering from the AdS/CFT correspondence
Based on the AdS/CFT correspondence, we present a holographic description of
various C-odd exchanges in high energy baryon-baryon and baryon-antibaryon
scattering, and calculate their respective contributions to the difference in
the total cross sections. We predict that, due to the warp factor of AdS_5, the
total cross section in pp collisions is larger than in p\bar{p} collisions at
asymptotically high energies.Comment: 23 pages, v2: minor changes, to be published in JHE
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