The pion structure function and jet production in γp → nX
نویسنده
چکیده
Despite its theoretical and practical importance, the pion structure is still badly constrained, particularly at low x π and in the sea-quark and gluon sectors. Recently ZEUS have presented data on dijet photoproduction with a leading neutron, which is dominated by slightly off-shell pion exchange and can be used to constrain the pion densities down to x π ≃ 0.01. We compare a recent NLO calculation to the ZEUS data and find that the lower gluon densities of SMRS seem to be preferred by the data. Theoretical uncertainties, in particular from the pion flux, are discussed in some
منابع مشابه
Perturbative Pion Wave function in Coherent Pion - Nucleon Di - Jet Production
A perturbative QCD treatment of the pion wave function is applied to computing the scattering amplitude for coherent high relative momentum di-jet production from a nucleon.
متن کاملar X iv : h ep - p h / 97 07 27 7 v 1 8 J ul 1 99 7 PRA – HEP / 97 – 10 VIRTUAL PHOTON STRUCTURE FROM JET PRODUCTION
Some aspects of extracting the information on the structure of virtual photons from jet production in ep and e + e − collisions are discussed. 1 Virtual particles-why, where and how? Measuring the dependence of the structure of the photon at short distance on its virtuality provides new information on strong interaction dynamics. The results of first attempts in this direction have recently bee...
متن کامل- th / 0 01 20 65 v 2 2 4 M ay 2 00 1 The role of ∆ ( 1700 ) excitation and ρ production in double pion photoproduction
Recent information on invariant mass distributions of the γp → π + π 0 n reaction, where previous theoretical models had shown deficiencies , have made more evident the need for new mechanisms, so far neglected or inaccurately included. We have updated a previous model to include new necessary mechanisms. We find that the production of the ρ meson, and the ∆(1700) excitation, through interferen...
متن کاملComparative Regge analysis of Λ , Σ 0 , Λ ( 1520 ) and Θ + production in γp , πp and pp reactions
Comparative Regge analysis of Λ, Σ 0 , Λ(1520) and Θ + production in γp, πp and pp reactions Abstract. Using the Quark-Gluon Strings Model – combined with Regge phenomenology – we perform a comparative analysis of Λ, Σ 0 , Λ(1520) and Θ + production in binary reactions induced by photon, pion and proton beams on the nucleon. We find that the existing experimental data on the γp → K + Λ differen...
متن کاملar X iv : n uc l - th / 9 40 90 09 v 1 1 3 Se p 19 94 Threshold Photo / Electro Pion Production – Working Group Summary
Over the last few years, pion production off nucleons by real or virtual photons has become a central issue in the study of the non–perturbative structure of the nucleon, i.e. at low energies. Here, developments in detector and accelerator technology on the experimental side as well as better calculational tools on the theoretical one have allowed to gain more insight into detailed aspects of t...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2001