The target fragmentation region of semi-inclusive deep inelastic scattering is described at leading twist, taking beam and target polarizations into account. The formalism of polarized and transverse-momentum dependen...
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The target fragmentation region of semi-inclusive deep inelastic scattering is described at leading twist, taking beam and target polarizations into account. The formalism of polarized and transverse-momentum dependent fracture functions is developed and the observables for some specific processes are presented. (C) 2011 Published by Elsevier B.V.
We show that a new beam-spin asymmetry appears in deep inelastic inclusive lepto-production at low transverse momenta when a hadron in the target fragmentation region is observed in association with another hadron in ...
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We show that a new beam-spin asymmetry appears in deep inelastic inclusive lepto-production at low transverse momenta when a hadron in the target fragmentation region is observed in association with another hadron in the current fragmentation region. The beam leptons are longitudinally polarized while the target nucleons are unpolarized. This asymmetry is a leading-twist effect generated by the correlation between the transverse momentum of quarks and the transverse momentum of the hadron emitted by the target. Experimental signatures of this effect are discussed. (c) 2012 Elsevier B.V. All rights reserved.
We study the inclusive production of two hadrons in deep inelastic processes, lN -> lh(1)h(2)X, with h(1) in the current fragmentation region (CFR) and h(2) in the target fragmentation region (TFR). Assuming a fact...
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We study the inclusive production of two hadrons in deep inelastic processes, lN -> lh(1)h(2)X, with h(1) in the current fragmentation region (CFR) and h(2) in the target fragmentation region (TFR). Assuming a factorized scheme, the recently introduced polarized and transverse momentum dependent fracture functions couple to the transverse momentum dependent fragmentation functions. This allows the full exploration of the fracture functions for transversely polarized quarks. Some particular cases are considered. (C) 2011 Elsevier B.V. All rights reserved.
We propose a collinear factorization formula for the associated production of one particle and a Drell-Yan pair in hadronic collisions. It is shown that additional collinear singularities appearing in the next-to-lead...
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We propose a collinear factorization formula for the associated production of one particle and a Drell-Yan pair in hadronic collisions. It is shown that additional collinear singularities appearing in the next-to-leading order calculations that cannot be factorized into parton and fragmentation functions are systematically renormalized by introducing fracture functions. Next-to-leading order coefficient functions for cross-sections double differential in the fractional energy of the identified hadron and lepton pair invariant mass are presented. (C) 2011 Elsevier By. All rights reserved.
We briefly discuss the collinear factorization formula for the associated production of one particle and a Drell-Yan pair in hadronic collisions. We outline possible applications of the results to three different rese...
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Ordinary fracture functions, describing the deep inelastic scattering target, fragmentation region, are generalized to account for the production of hadrons in arbitrary number, thus offering a new framework for deali...
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Ordinary fracture functions, describing the deep inelastic scattering target, fragmentation region, are generalized to account for the production of hadrons in arbitrary number, thus offering a new framework for dealing with QCD initial state radiation. We propose further a new jet-like observable which measures beam remnants and low-p(perpendicular to) scattering fragments and derive its QCD evolution equations by using jet calculus formalism. Applications to semi-inclusive deep inelastic scattering and hadron-hadron collisions are shortly discussed. (c) 2007 Elsevier B.V. All rights reserved.
Within a perturbative approach to Quantum Chromodynamics (QCD), we show how to extend ordinary DGLAP longitudinal evolution equations to include the radiative transverse momentum generated in the collinear branching r...
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Within a perturbative approach to Quantum Chromodynamics (QCD), we show how to extend ordinary DGLAP longitudinal evolution equations to include the radiative transverse momentum generated in the collinear branching regime. Considering Semi-inclusive Deep Inelastic Scattering as a reference process, we perform such a generalization both in the current and in the target fragmentation region. These distributions are then used to predict semi-inclusive Deep Inelastic Scattering cross-sections onto the whole phase space of the detected hadron.
A new formalism for the description of (un)polarized semi-inclusive deep inelastic scattering (DIS) at moderate energies is developed. Hadron production is modeled as a product of distribution functions and hadronizat...
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A new formalism for the description of (un)polarized semi-inclusive deep inelastic scattering (DIS) at moderate energies is developed. Hadron production is modeled as a product of distribution functions and hadronization functions (HFs) weighted by the hard scattering cross sections, as has been done in the LEPTO event generator. The correct treatment of polarization effects shows that the description of semi-inclusive DIS (SIDIS) within this formalism includes a new non-perturbative input: polarized HFs. It is shown that this approach does not correspond to that commonly adopted with the independent quark fragmentation. The purity method used by the HERMES collaboration mixes the two approaches and ignores the contributions from polarized HFs. This method cannot be considered a precise tool for the extraction of polarized quark distributions from measured SIDIS asymmetries.
We analyze the contribution from excitation of the (), (q(q) over bar )g(1)...g(n)(f(f) over bar) Fock states of a photon to high-mass diffraction in DIS. We show that the large-Q(2) behavior of this contribution can ...
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We analyze the contribution from excitation of the (), (q(q) over bar )g(1)...g(n)(f(f) over bar) Fock states of a photon to high-mass diffraction in DIS. We show that the large-Q(2) behavior of this contribution can be described by DLLA evolution from the nonperturbative f(f) over bar valence state of the pomeron. Although of higher order in pQCD, the new contribution to high-mass diffraction is comparable to that from the excitation of the q(q) over barg Fock state of the photon. (C) 2004 MAIK "Nauka/Interperiodica".
We analyze the order-alpha(s)(2) QCD corrections to semi-inclusive deep inelastic scattering and present results for processes initiated by a gluon. We focus in the most singular pieces of these corrections in order t...
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We analyze the order-alpha(s)(2) QCD corrections to semi-inclusive deep inelastic scattering and present results for processes initiated by a gluon. We focus in the most singular pieces of these corrections in order to obtain the hitherto unknown NLO evolution kernels relevant for the non-homogeneous QCD scale dependence of these cross sections, and to check explicitly factorization at this order. In so doing we discuss the prescription of overlapping singularities in more than one variable. (C) 2003 Elsevier Science B.V. All rights reserved.
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