Семинар «Физика адронов»

Дата и время: пятница, 17 июня 2022 г., в 11:00

Место: аудитория им. Д.И. Блохинцева (4 этаж), Лаборатория теоретической физики им. Н. Н. Боголюбова; oнлайн конференция в Zoom

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Тема семинара: «Parton distributions in QCD: methods of dispersion relations and integral geometry»

Докладчик: Ильнур Габдрахманов

Аннотация:

The amplitudes of exclusive hard processes are represented as a convolution of the amplitude of a parton subprocess with generalized parton distributions (GPD), which can be expanded into a non-physical domain due to their t-channel analog — generalized distribution amplitudes (GDA). This makes it possible to apply the methods of integral geometry — the inverse Radon transform (RT) — to obtain double distributions (DD) — a variant of GPD parametrization, as well as to obtain holographic sum rules based on analyticity with finite subtraction associated with the gravitational form factors of the hadron. Various variants of the inverse RT are investigated, the formulas obtained are applicable for both analytical and numerical DD production. These methods are generalized and tested on the example of photonic GPDs. The results obtained are in agreement with the criterion of mechanical stability of elementary particles and allow us to conclude about the stability of a cloud of virtual quarks in a photon. Analyticity and dispersion relations for inclusive processes are also applied to the analysis of the contributions of higher twists to the sum rule Bjorken.