izvor podataka: poirot

Razotkrivanje strukture hadrona pomoću tvrdih ekskluzivnih procesa

Revealing the hadron structure through hard exclusive processes


Nukleoni (protoni i neutroni koji su građevni blokovi materije koja nas okružuje), pioni, kaoni i drugi hadroni sastoje se od kvarkova i gluona, čije su interakcije dobro opisane teorijom jakih interakcija, tj. kvantnom kromodinamikom. No sveobuhvatno razumijevanje dinamike vezanih stanja hadrona i njihove strukture je još uvijek neuhvatljivo i izazovno. Štoviše, u akceleratorima čestica istraživanja Standardnog modela (SM) i istraživanja fizike izvan SMa se provode uglavnom koristeći protone i rastuća točnost tih mjerenja zahtijeva sve bolji opis strukture hadrona. U projektu REVESTRUCTURE istražit ćemo strukturu hadrona proučavanjem tzv. tvrdih ekskluzivnih procesa. Budući da se ti procesi izvode pri visokim energijama gdje jaka sila postaje slaba, u opisu partonskih potprocesa se može koristiti perturbativni pristup, a faktorizacija visoko i nisko energijske dinamike omogućuje nam pristup opisu hadrona preko distribucijskih amplituda i generaliziranih partonskih distribucija. Ovi potonji objekti fenomenološki su posebno zahvalni jer potencijalno nude trodimenzionalnu (3D) sliku hadrona za razliku od 1D slike dobivene iz dobro poznatih partonskih distribucijskih funkcija koje se susreću u duboko neelastičnom raspršenju. Predloženo fenomenološko istraživanje je pravovremeno jer je u zadnje vrijeme eksperimentalna aktivnost vrlo živa: mnogo podataka je već dostupno ili se očekuje u bliskoj budućnosti od JLab i COMPASS (CERN) grupa, a planirana su i nova postrojenja (EIC u SAD-u, LHeC u CERN-u). Mi planiramo razviti odgovarajuće softverske alate, poboljšati teorijski opis izmjerenih procesa i analizirati nove procese koji bi se mogli mjeriti. Teorijske ćemo rezultate usporediti s dostupnim eksperimentalnim podacima i koristeći prilagodbe ćemo dobiti nove informacije o strukturi hadrona. A sve to bi trebalo omogućiti značajan korak k boljem razumijevanju hadrona.

Nucleons, i.e., protons and neutrons that are the building blocks of the matter that surrounds us, pions, kaons and other hadrons consist of quarks and gluons, whose interactions are well described by the theory of strong interactions, i.e. quantum chromodynamics. But the comprehensive understanding of the bound state dynamic of hadrons and their structure is still elusive and challenging. Moreover, the experiments in particle accelerators used for Standard Model (SM) and beyond SM research are performed mostly using protons with ever higher accuracy demanding ever better description of hadron structure. In REVESTRUCTURE project we will investigate hadron structure by studying the, so-called, hard exclusive processes. Since these processes are performed at high energies where the strong force becomes weak the perturbative approach can be used in the description of the parton subprocesses and the factorization of the high and low energy dynamics enables us to access the hadron description of hadrons in terms of distribution amplitudes and generalized parton distributions. The latter objects are phenomenologically especially rewarding offering potentially a three-dimensional (3D) picture of hadrons in contrast to 1D obtained from well-known parton distribution amplitudes encountered in deeply inelastic scattering. Proposed phenomenological investigation is timely due to a recent vibrant experimental activity: a lot of data is already available or expected in the near future from JLab and COMPASS (CERN) groups, and new facilities are planned (EIC in USA, LHeC at CERN). We plan to develop the required software tools, to improve the theoretical description of the measured processes, and to analyze new processes to be measured in the future. We will confront the theoretical results with the available experimental data and through fits we will extract new informations about hadron structure. All this should make a significant step towards better understanding of hadrons.


teorijska fizika visokih energija, QCD, struktura hadrona, tvrdi ekskluzivni procesi, perturbativni račun, generalizirane partonske distribucije

theoretical high-energy physics, QCD, hadron structure, hard exclusive processes, perturbative calculation, generalized parton distributions

Znanstveno-istraživački projekti

REVESTRUCTURE

IP-2019-04-9709

01.02.2020

31.01.2024

nije evidentirano

HRK 868.500,00