Nucleon form factors: From the space-like to the time-like region
نویسندگان
چکیده
منابع مشابه
Nucleon form factors: From the space–like to the time–like region
I discuss how dispersion relations can be used to analyse the nucleon electromagnetic form factors, with particular emphasis on the constraints from unitarity and pQCD. Results for nucleon radii, vector-meson couplings, the onset of pQCD and bounds on the strangeness form factors are presented. The em form factors in the time–like region reveal some interesting physics which is not yet understo...
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Recent experimental data on space-like and time-like form factors of the nucleon are reviewed in light of a model of the nucleon with an intrinsic (quark-like) structure and a meson cloud. The analysis points to the astonishing result that the proton electric space-like form factor vanishes at Q ∼ 8 (GeV/c) and becomes negative beyond that point. The intrinsic structure is estimated to have a r...
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We perform a global analysis of the experimental data of the electromagnetic nucleon form factors, in space-like and time-like regions. We give the expressions of the observables in annihilation processes, such as p + p → l + l−, l = e or μ, in terms of form factors. We discuss some of the phenomenological models proposed in the literature for the space-like region, and consider their analytica...
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The Nucleon electromagnetic form factors (em ff’s) represent a relevant chapter in our path towards the understanding of hadron dynamics. It is striking that, after almost half a century of experimental investigations, this field could still hold a number of surprises (e.g., the intriguing fall-off of the proton charge ff more rapid than the assumed dipole one), or have some kinematical regions...
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The process p̄p → ee is considered in the general case of polarized initial particles. A relation between the difference of the phases of the electromagnetic form factors GM and GE in the time-like region and measurable asymmetries is derived. It is shown that the moduli of the form factors can be determined from measurements of the total unpolarized cross section and of the integral asymmetry f...
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ژورنال
عنوان ژورنال: Nuclear Physics A
سال: 1997
ISSN: 0375-9474
DOI: 10.1016/s0375-9474(97)00453-3