1,976 research outputs found
Non-Universality and Evolution of the Sivers Function
We examine the large-x QCD evolution of the twist-three gluonic-pole strength
defining an effective T-odd Sivers function, where evolution of the T-even
transverse-spin DIS structure function g2 is multiplicative. The result
corresponds to a colour-factor modified spin-averaged twist-two evolution.Comment: Presented at the ECT* Workshop on Recent Advances in Perturbative QCD
and Hadronic Physics (20-25 July 2009} - final version (minor modifications
Study of correlation of production and decay planes in diffractive dissociation process on nuclei
A large correlation of production and decay planes of
(\pi^-\pi^+\pi^-)-system in dissociation of -beam 40 GeV/c on nuclear
targets was observed. The dependence of the correlation on atomic number,
Feynmann variable and transversal momentum as well as on invariant mass of the
pion triple and neutral pion pair were investigated. It was shown that the
phenomenon has a clear dynamic origin and resembles the single spin asymmetry
behavior.Comment: 8 pages, latex epsfig.sty, 5 eps figures. Submitted to Yad. Fiz
Quantum eigenstate tomography with qubit tunneling spectroscopy
Measurement of the energy eigenvalues (spectrum) of a multi-qubit system has
recently become possible by qubit tunneling spectroscopy (QTS). In the standard
QTS experiments, an incoherent probe qubit is strongly coupled to one of the
qubits of the system in such a way that its incoherent tunneling rate provides
information about the energy eigenvalues of the original (source) system. In
this paper, we generalize QTS by coupling the probe qubit to many source
qubits. We show that by properly choosing the couplings, one can perform
projective measurements of the source system energy eigenstates in an arbitrary
basis, thus performing quantum eigenstate tomography. As a practical example of
a limited tomography, we apply our scheme to probe the eigenstates of a kink in
a frustrated transverse Ising chain.Comment: 8 pages, 4 figure
Search for Anomaly at High x in Polarized Deep Inelastic Scattering Data
An idea of possible anomalous contribution of non-perturbative origin to the
nucleon spin was examined by analysing data on spin asymmetries in polarized
deep inelastic scattering of leptons on nucleons. The region of high Bjorken x
was explored. It was shown that experimental data available at present do not
evidence for this effect.Comment: Submitted to Mod.Phys.Lett.
QCD factorization for forward hadron scattering at high energies
We consider the QCD factorization of DIS structure functions at small x and
amplitudes of 2->2 -hadronic forward scattering at high energy. We show that
both collinear and k_T-factorization for these processes can be obtained
approximately as reductions of a more general (totally unintegrated) form of
the factorization. The requirement of ultraviolet and infrared stability of the
factorization convolutions allows us to obtain restrictions on the fits for the
parton distributions in k_T- and collinear factorization.Comment: 18 pages, 10 figures In the present version misprints found in the
prevcious version are corrected and some more details are explaine
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