Production of the omega meson in the pd --> 3He omega reaction at 1450 MeV and 1360 MeV
K. Schonning, Chr. Bargholtz, M. Bashkanov, M. Berlowski, D. Bogoslawsky, H. Calen, H. Clement, L. Demirors, C. Ekstrom, K. Fransson, L. Geren, L. Gustafsson, B… 展开作者
K. Schonning, Chr. Bargholtz, M. Bashkanov, M. Berlowski, D. Bogoslawsky, H. Calen, H. Clement, L. Demirors, C. Ekstrom, K. Fransson, L. Geren, L. Gustafsson, B. Hoistad, G. Ivanov, M. Jacewicz, E. Jiganov, T. Johansson, S. Keleta, O. Khakimova, K. P. Khemchandani, F. Kren, S. Kullander, A. Kupsc, A. Kuzmin, K. Lindberg, P. Marciniewski, B. Morosov, W. Oelert, C. Pauly, H. Petren, Y. Petukhov, A. Povtorejko, R. J. M. Y. Ruber, W. Scobel, R. Shafigullin, B. Shwartz, T. Skorodko, V. Sopov, J. Stepaniak, P. -E. Tegner, P. Thorngren Engblom, V. Tikhomirov, A. Turowiecki, G. J. Wagner, C. Wilkin, M. Wolke, J. Zabierowski, I. Zartova, J. Zlomanczuk
本文研究了$pd \to{}^3$ He $ ω$反应中在运动学阈附近的两个能量（$T_p=1450$ MeV和$T_p=1360$ MeV）下$ω$介子的产生。在整个角度范围内，在两种能量下测量微分截面作为$ω$ cm角的函数。而在1360 MeV的结果是一致的各向同性，观察到强烈的上升，在1450 MeV的向前和向后的方向附近。使用一个两步模型与一个中间的π介子的计算未能再现的测量角分布的形状，也低估了总的截面。
英文摘要：
The production of $ω$ mesons in the $pd \to{}^3$He$ ω$ reaction has been studied at two energies near the kinematic threshold, $T_p=1450$ MeV and $T_p=1360$ MeV. The differential cross section was measured as a function of the $ω$ cm angle at both energies over the whole angular range. Whereas the results at 1360 MeV are consistent with isotropy, strong rises are observed near both the forward and backward directions at 1450 MeV. Calculations made using a two-step model with an intermediate pion fail to reproduce the shapes of the measured angular distributions and also underestimate the total cross sections.
Near-threshold production of omega mesons in the pn -> d omega reaction
用氘团簇-喷流靶首次测量了Q = 28和57 MeV的pn-> d Ω总截面。快氘的动量是在COSY-Juelich的ANKE光谱仪中测量的，而慢“旁观者”质子p（sp）的动量是在靠近目标的硅望远镜中测量的，该质子来自p d -> p（sp）d Ω反应。截面高于p p -> p p Ω的测量值，但似乎低于理论预测值。
This work is a pioneering study of backward-angle omega cross sections through the exclusive 1H(e,e'p)omega reaction using the missing mass reconstruction technique. The extracted cross sections are separated into the transverse (T), longitudinal (L), and LT, TT interference terms. The analyzed data were part of experiment E01-004 (Fpi-2), which used 2.6-5.2GeV electron beams and HMS+SOS spectrometers in Jefferson Lab Hall C. The primary objective was to detect coincidence pion in the forward-angle, where the backward-angle omega events were fortuitously detected. The experiment has central Q2…
Backward-angle meson electroproduction above the resonance region, which was previously ignored, is anticipated to offer unique access to the three quark plus sea component of the nucleon wave function. In this letter, we present the first complete separation of the four electromagnetic structure functions above the resonance region in exclusive omega electroproduction off the proton, e + p -> e' + p + omega, at central Q^2 values of 1.60, 2.45 GeV^2 , at W = 2.21 GeV. The results of our pioneering -u ~ -u min study demonstrate the existence of a unanticipated backward-angle cross section peak…
The recent exclusive backward-angle electroproduction of omega from Jefferson Lab Hall C electron-proton fixed-target scattering experiments above the resonance region hints at a new domain of applicability of QCD factorization in a unique u-channel kinematics regime. Thanks to this effort, the interest in studying nucleon structure through u-channel meson production observables has grown significantly. In the fixed target configuration, the u-channel meson electroproduction observables feature a unique interaction picture: the target proton absorbs nearly all momentum induced by virtual photo…
