[Theory-seminars] Theory Seminar Monday (remote) - Víctor Martínez-Fernández

[Zheng-Yang Li]

Dear all,

On Monday, November 4th, 2024 at 1:00PM EST, we will have a virtual seminar given by Víctor Martínez-Fernández of IRFU/CEA Paris-Saclay on the Zoom for Government link:

https://jlab-org.zoomgov.com/j/1601003408?pwd=JIv7MSpqcMOF56Up66bHTS0sCwtotO.1

Although it’s not an in-person seminar, you can also join your colleagues for a remote streaming of the seminar in CEBAF Center F324/325.

Please see below for the title and abstract.

Theory Seminar: November 4th, 1:00PM EST (virtual)

Speaker: Víctor Martínez-Fernández (IRFU/CEA Paris-Saclay)

Title: Precise hadron structure

Abstract: Quantum Chromodynamics (QCD) is the theoretical framework to study hadrons by means of their fundamental degrees of freedom, namely quarks and gluons which are collectively referred to as partons. QCD defines many types of distributions describing a given hadron in terms of partons. In this talk, we will begin by reviewing the concept of a forward parton distribution function (PDF) and the "golden channel" for its extraction: deep inelastic scattering (DIS). Next, we will explore another function called the generalized off-foward parton distribution (GPD). These ones are crucial elements of the theory for two main reasons: 1) they are related to the total angular momentum of partons within the hadron, and 2) the Fourier transform with respect to the transverse momentum transfer of a particular GPD provides a transverse imaging of the hadron. We like to call this image as the hadron tomography. GPDs are accesesed thorugh different processes among which the most promising ones are: deeply virtual Compton scattering (DVCS), timelike Compton scattering (TCS) and double deeply virtual Compton scattering (DDVCS).


PDFs and GPDs arise from factorization that takes place in scattering cross-sections (for PDFs) and amplitudes (for GPDs) when a particle probing the hadron, typically a virtual photon, is considered in the limit of infinite virtuality. This is known as the kinematic leading twist (LT). Current and future data can not be considered as a practical realization of the aforementioned LT approximation, suggesting the need for corrections inversely proportional to the photon virtuality. Modern methods allowing these corrections to be restored to all orders will also be presented in this talk. Moreover, we will discuss relationships between different processes described by the same GPDs beyond leading order in the strong coupling constant. These corrections are crucial for the precise extraction of partonic distributions and for testing their universality, i.e. their independence from the process through which they are extracted. Phenomenological predicitons for current and future experimental facilities will also be presented.


In summary, in this talk we will study different partonic distributions and the tools to access them beyond the lowest order approximation, including phenomenological predictions for different possible experiments.

See you on Monday.

Best regards,
Joe, Zheng-Yang, and Gloria
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/theory-seminars/attachments/20241101/84a147b5/attachment.html>