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Related papers: Spin Effects in Diffractive $Q \bar Q$ Production …

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A single-spin asymmetry in the distribution of exclusively produced pi^+ mesons azimuthally around the virtual photon direction relative to the lepton scattering plane has been measured for the first time in deep-inelastic scattering of…

High Energy Physics - Experiment · Physics 2008-11-26 HERMES Collaboration , A. Airapetian

We discuss possible measurements and origins of single spin asymmetries in DIS and of some unusual spin properties of vector mesons produced in lepton- nucleon, photon-nucleon and photon-photon interactions. Such effects have already been…

High Energy Physics - Phenomenology · Physics 2007-05-23 Mauro Anselmino , Francesco Murgia

In this work we investigate the single- and the double- spin asymmetries at the collisions of polarized protons $pp \to (\gamma*, Z^0,Z')+X within the scope of QCD, electroweak interaction and superstring E_6 theory. The helicity amplitude…

High Energy Physics - Phenomenology · Physics 2009-11-10 R. Kh. Muradov , A. I. Ahmadov

We demonstrate that the distinctive features of the forward differential cross section of diffractive leptoproduction of a vector meson can be legitimately calculated in perturbative QCD in terms of the light-cone $q \bar q$ wave function…

High Energy Physics - Phenomenology · Physics 2009-09-25 Stanley J. Brodsky , L. Frankfurt , J. F. Gunion , A. H. Mueller , M. Strikman

We present the first measurement of the cross section and the double longitudinal spin asymmetry of inclusive pi0 production in polarized p+p collisions at Sqrt(s) = 200 GeV at mid-rapidity with the STAR detector, using the barrel…

High Energy Physics - Experiment · Physics 2019-08-14 Frank Simon

We propose to probe light-quark dipole interactions at lepton colliders using the azimuthal asymmetry of a collinear dihadron pair $(h_1h_2)$ produced in association with another hadron $h'$. This asymmetry, arising from quantum…

High Energy Physics - Phenomenology · Physics 2025-09-17 Xin-Kai Wen , Bin Yan , Zhite Yu , C. -P. Yuan

The inclusive double-spin asymmetry, A_1^p, has been measured at COMPASS in deepinelastic polarised muon scattering off a large polarised NH3 target. The data, collected in the year 2007, cover the range Q2 > 1 (GeV/c)^2, 0.004 < x < 0.7…

High Energy Physics - Experiment · Physics 2014-11-20 The COMPASS Collaboration , M. G. Alekseev

We study the production asymmetry of charm versus anticharm mesons in photon-proton interactions. We consider photon gluon fusion plus higher order corrections in which light quarks through vector meson-proton interactions contribute to the…

High Energy Physics - Phenomenology · Physics 2009-11-07 G. Herrera , A. Sanchez-Hernandez , E. Cuautle , J. Magnin

We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeV < W < 1.910 GeV) at an average four momentum transfer of Q^2 = 1.3 GeV^2. Using the Jefferson Lab polarized electron beam, a spectrometer,…

We present a study on the beam single spin asymmetries $A_{LU}^{\sin\phi_h}$ of $\pi^+$, $\pi^-$ and $\pi^0$ production in semi-inclusive deep inelastic scattering process, by considering Collins effect and the $g^\perp D_1$ term…

High Energy Physics - Phenomenology · Physics 2015-06-16 Wenjuan Mao , Zhun Lu

We investigate the possibility to measure the nonforward gluon distribution function by means of diffractively produced \pi^+\pi^- and K^+K^- pairs in polarized lepton nucleon scattering. The resulting cross sections are small and are…

High Energy Physics - Phenomenology · Physics 2011-07-19 B. Lehmann-Dronke , M. Maul , S. Schaefer , E. Stein , A. Schäfer

In this talk, we present novel methods to investigate light-quark dipole interactions at colliders. Our approach includes: (1) measuring azimuthal asymmetries of a collinear dihadron in semi-inclusive deep inelastic lepton scattering off an…

High Energy Physics - Phenomenology · Physics 2026-03-20 Xin-Kai Wen , Bin Yan , Zhite Yu , C. -P. Yuan

We consider the leading order result for polarized leptoproduction, putting emphasis on transverse momentum dependent effects appearing in azimuthal asymmetries. Measurements of weighted cross sections enable extraction of the distribution…

High Energy Physics - Phenomenology · Physics 2009-10-30 A. M. Kotzinian , P. J. Mulders

Spin-dependent pomeron effects are analyzed for elastic $pp$ scattering and calculations for spin-dependent differential cross sections, analyzing power and double-spin correlation parameters are carried out for the energy range of the…

High Energy Physics - Phenomenology · Physics 2008-02-03 N. Akchurin , S. V. Goloskokov , O. V. Selyugin

Spin observables may reveal much deeper properties of non perturbative hadronic physics than unpolarized quantities. We discuss here possible origins of single spin asymmetries in DIS, absent in the elementary lepton-quark interactions, and…

High Energy Physics - Phenomenology · Physics 2016-09-06 Mauro Anselmino

The proton diffractive structure function $F_2^{D(3)}$ measured in the H1 and ZEUS experiments at HERA are analysed in terms of perturbative QCD in the perspective of the QCD extrapolation to the Tevatron and the LHC. It is shown that both…

High Energy Physics - Phenomenology · Physics 2010-03-25 C. Royon , L. Schoeffel , R. Peschanski , E. Sauvan

We use perturbative QCD and parton-hadron duality to estimate the cross sections for the diffractive electroproduction of rhoprime(1-) and rho(3-) resonances which occur in the 1.3-1.8 GeV mass interval. We present the cross sections and…

High Energy Physics - Phenomenology · Physics 2009-10-30 A. D. Martin , M. G. Ryskin , T. Teubner

Predictions for the single transverse spin asymmetry A_N in semi-inclusive DIS processes are given; non negligible values of A_N may arise from spin effects in the fragmentation of a polarized quark into a final hadron with a transverse…

High Energy Physics - Phenomenology · Physics 2011-09-13 M. Anselmino , M. Boglione , J. Hansson , F. Murgia

The diffractive 2-jet production reactions in the proton-proton and lepton-proton processes are discussed. It is shown that they may be very suitable for studying the properties of the pomeron couplings with quarks and hadrons in future…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. V. Goloskokov

We analyze the impact of effective axial-vector coupling of the gluon on spin polarization observables in $t\bar{t}$ pair production at the LHC. Working at leading order in QCD, we compute the $t\bar{t}$ spin-correlation and left-right spin…

High Energy Physics - Phenomenology · Physics 2013-04-10 E. Gabrielli , A. Racioppi , M. Raidal , H. Veermae