Auswahl der wissenschaftlichen Literatur zum Thema „Electron-Ion Collider (EIC)“

Abstract The Compton-like production of massive dark photons is investigated in ultrarelativistic electron–ion collisions by considering the kinetic mixing between the dark photon and the standard model photon. The quasi-real photons in the heavy ion are described by the equivalent photon approximation, and the model is employed to calculate the integrated cross section and event rates as a function of the dark photon mass, m γ′, and mixing parameter, ɛ. Predictions are shown for electron–ion colliders (EICs) in the mass range 100 ⩽ m γ′ ⩽ 500 MeV. Numerical results are provided within the kinematic coverage of the planned machines: an EIC in China (EicC), a polarized EIC at Jefferson Lab (JLEIC), an EIC/USA (EIC), a large hadron electron collider (LHeC) and a future circular collider (FCC-eA). It complements existing search strategies for dark photons in the considered mass interval.

We investigate Collins asymmetry in the Λ hyperon produced semi-inclusive deep inelastic scattering (SIDIS) process based on the kinematical region of Electron-ion collider in China (EicC) and Electron–ion collider (EIC) within the transverse momentum dependence (TMD) factorization framework at next-to-leading-logarithmic order. The asymmetry is contributed by the convolution of the target proton transversity distribution function and the Collins function of the final-state Λ hyperon. The TMD evolution effect of the corresponding parton distribution functions (PDFs) and fragmentation functions (FFs) is considered with the help of parametrization of the non-perturbative Sudakov form factors for the proton PDFs and Λ fragmentation functions. We apply the parametrization of the collinear proton transversity distribution function and the model results of Λ Collins function from the diquark spectator model as the inputs of the TMD evolution to numerically calculate Collins asymmetry in Λ produced SIDIS process at the kinematical configurations of EIC and EicC. It can be shown that the asymmetry is significant and can be measured at EIC and EicC. The flavor dependence of transversity distribution functions could be further constrained by studying the Λ hyperon produced SIDIS process in the future to improve our understanding of the spin structure within nucleons.

In this talk, I demonstrate that the proposed Electron-Ion Collider (EIC) will be an ideal and unique future facility to address many overarching questions about QCD and strong interaction physics at one place. The EIC will be the world's first polarized electron-proton (and light ion), as well as the first electron-nucleus collider at flexible collision energies. With its high luminosity and beam polarization, the EIC distinguishes itself from HERA and the other fixed target electron-hadron facilities around the world. The EIC is capable of taking us to the next QCD frontier to explore the glue that binds us all.

We outline key objectives and capabilities of an Electron-Ion Collider (EIC) — a high-energy and high-luminosity electron-proton/nucleus collider with polarized electron and proton beams. One of goals of a future EIC is to map the 3D (in configuration and momentum spaces) structure of sea quarks and gluons in the nucleon and nuclei. We briefly present and discuss key observables and measurements pertaining to the program of 3D imaging at an EIC.

The proposed high-energy and high-luminosity Electron–Ion Collider (EIC) will provide one of the cleanest environments to precisely determine the nuclear parton distribution functions (nPDFs) in a wide x–Q2 range. Heavy flavor production at the EIC provides access to nPDFs in the poorly constrained high Bjorken-x region, allows us to study the quark and gluon fragmentation processes, and constrains parton energy loss in cold nuclear matter. Scientists at the Los Alamos National Laboratory are developing a new physics program to study heavy flavor production, flavor tagged jets, and heavy flavor hadron-jet correlations in the nucleon/nucleus going direction at the future EIC. The proposed measurements will provide a unique way to explore the flavor dependent fragmentation functions and energy loss in a heavy nucleus. They will constrain the initial-state effects that are critical for the interpretation of previous and ongoing heavy ion measurements at the Relativistic Heavy Ion Collider and the Large Hadron Collider. We show an initial conceptual design of the proposed Forward Silicon Tracking (FST) detector at the EIC, which is essential to carry out the heavy flavor measurements. We further present initial feasibility studies/simulations of heavy flavor hadron reconstruction using the proposed FST.

In this presentation I will give brief overview of the main physics topics which will be explored at the new Deep Inelastic Scattering facility, the Electron Ion Collider (EIC), planned for the construction at Brookhaven National Laboratory in the United States.

The Electron-Ion Collider (EIC) is a future particle accelerator to be built at the Brookhaven National Laboratory, and the primary purpose of experiments at the EIC is to resolve the question of partonic structure of nucleons and nuclei. To achieve the physics goals of the EIC, a hadron calorimeter of high energy resolution is required at forward rapidity. A Dual-readout Calorimeter (DRC) which has been developed for future collider experiments is considered as an upgrade option of the forward hadron calorimeter for the ECCE experiment at the EIC. The DRC consisting of two types of optical fiber, Cherenkov and Scintillation fibers, can achieve high energy resolution by measuring a fraction of electromagnetic shower in a hadronic shower. A performance study of DRC for the EIC such as geometry, material, and energy resolution is ongoing based on the existing simulation framework for high energy experiments, and the DRC simulation details will be transported to the EIC simulation framework. In this presentation, we will introduce the simulation study of the DRC for the EIC.

In this work, we present a systematic study on the feasibility of probing the largely unexplored gluon Sivers function (GSF) based on the open charm production, charged dihadron and dijet method at a future high energy, high luminosity Electron-Ion Collider (EIC). Sivers function describes the anisotropy of parton distributions inside a transversely polarized nucleon in the momentum space and provides us a complete picture of the 2+1D structure of the nucleons. It is proposed that the GSF can be studied through the single spin asymmetry (SSA) measurement in the photon-gluon fusion channel with electron proton collisions at the EIC. Using a well tuned Monte Carlo model for deep inelastic scatterings, we estimate the possible constraints of the gluon Sivers effect one can draw from the future EIC data. Comparisons of all the possible measurements further illustrate that the dijet method is the most promising way to demonstrate the presence of GSF and pin down its evolution effect.

The Electron Ion Collider (EIC) is the project for a new US-based, high-energy, high-luminosity facility, capable of a versatile range of beam energies, polarizations, and ion species. Its primary goal is to precisely image quarks and gluons and their interactions inside hadrons, in order to investigate their confined dynamics and elucidate how visible matter is made at its most fundamental level. I will introduce the main physics questions addressed by such a facility, and give some more details on the topic of Transverse Momentum Dependent parton distributions (TMDs).

Les programmes de recherche du laboratoire Jefferson (JLab) et du futur Collisionneur Électron-Ion (EIC) se concentrent sur l'une des thématiques majeures de la physique de l'interaction forte : la compréhension de la structure des nucléons en termes des quarks et des gluons qui les constituent. Cette structure est encodée dans des fonctions telles que les Distributions de Partons Généralisées (GPDs), qui décrivent comment la position transverse et l'impulsion longitudinale des partons sont distribuées dans les nucléons. Les GPDs permettent d'obtenir des images en trois dimensions des nucléons et de comprendre des propriétés fondamentales telles que les forces de pression qui règnent en leur sein ou la façon dont leur spin émerge de la dynamique des partons qui les composent. À JLab et à l'EIC, des faisceaux d'électrons sont utilisés pour sonder l'intérieur des nucléons. La mesure des réactions exclusives d'électroproduction, telles que la Diffusion Compton Profondément Virtuelle (DVCS), donne accès aux GPDs.En 2022-2023, la première expérience sur cible polarisée du programme CLAS12 à JLab a eu lieu. En combinant des faisceaux d'électrons et des cibles de nucléons polarisés longitudinallement, cette expérience offre un accès unique à des observables permettant de mesurer différents types de GPDs. En particulier, les asymétries de spin de faisceau et de cible pour le DVCS sur le proton et le neutron dans le deutérium seront mesurées pour la première fois. Elles donnent accès à des types de GPDs encore peu connus, et la comparaison entre le proton et le neutron permet d'extraire la contribution des différentes saveurs de quarks à la structure des nucléons. Des méthodes d'analyse spécifiques ont été implémentées pour travailler avec une cible nucléaire polarisée et sont présentées dans cette thèse. Ces méthodes permettent d'obtenir des résultats préliminaires sur les asymétries, en attendant que la totalité des statistiques soit disponible.À plus long terme, le programme expérimental de l'EIC a été établi avec une emphase importante sur les mesures de la structure des nucléons à haute énergie. La mesure de réactions telles que le DVCS impose notamment des contraintes strictes pour le calorimètre électromagnétique qui permettra de mesurer l'énergie des électrons et des photons diffusés. Ce calorimètre, dont le développement est en cours, sera basé sur des cristaux scintillants lus par des multiplicateurs de photon à pixels (MPPC). Un nouveau type de matériel scintillant à base de verre a été testé, évaluant les possibilités de répondre aux exigences techniques pour le calorimètre, en particulier concernant le rendement en lumière et la résistance aux radiations. Plusieurs modèles de MPPCs ont été caractérisés, établissant qu'ils peuvent opérer sur la large plage dynamique nécessaire pour atteindre les objectifs scientifiques de l'EIC et donnant les lignes directrices pour le développement de leur électronique de lecture<br>The research programs of Thomas Jefferson Laboratory (JLab) and the future Electron-Ion Collider (EIC) focus on one of the main goals of strong interaction studies: understanding the structure of nucleons in terms of the quarks and gluons composing them. Their structure is encoded in functions such as Generalized Parton Distributions (GPDs), which describe how quarks and gluons' transverse position and longitudinal momentum are distributed inside nucleons. GPDs allow to obtain three-dimensional pictures of nucleons and to understand some of their fundamental properties, such as their internal pressure or the emergence of their spin from the dynamics of the partons composing them. At JLab and the EIC, electron beams are used to probe nucleons. Measurement of reactions such as Deeply Virtual Compton Scattering (DVCS) allows access to GPDs.The first longitudinally polarized-target experiment of the CLAS12 program at Jlab took place in 2022-2023. Combining polarized electron beams and nucleon targets, this experiment offers unique access to observables that allow the measurement of different types of GPDs. In particular, the DVCS beam- and target-spin asymmetries for protons and neutrons in deuterium will be measured for the first time. They give access to kinds of GPDs that are still poorly known, and the comparison between proton and neutron data will allow the extraction of the flavor dependence of the structure of nucleons. Specific analysis methods have been implemented to work with a polarized nuclear target and are presented in this thesis. These methods allow to obtain preliminary results for the asymmetries, waiting for the complete statistics to be available.In the long term, the experimental program for the EIC has been established with a strong emphasis on the measurement of the structure of nucleons at high energy. Measurements of reactions such as DVCS impose strict requirements on the electromagnetic calorimeter that will allow to measure the energy of the scattered electrons and photons. This calorimeter, which is under development, will be based on scintillating crystals read by Silicon Photomultipliers (SiPMs). A new type of glass-based scintillating material was tested, evaluating the possibilities to meet the technical requirements concerning their light yield and resistance to radiation damage in particular. Several models of SiPMs have been characterized, demonstrating they can operate over the vast energy range necessary to address the physics case at the EIC and providing guidelines for developing their readout electronics

La formation des hadrons est, dans le cadre de la théorie quantique de couleur (QCD), un processus non-perturbatif ; cette caractéristique entraîne d’importantes difficultés théoriques. C’est pourquoi, les mesures expérimentales de fragmentation dans différents noyaux sont une nécessité afin d’obtenir des progrès tangibles dans la compréhension des mécanismes de formation des hadrons. La thèse commence par les bases théoriques nécessaires à une telle approche, suivies des principaux modèles qui lui sont associés.La thèse se poursuit par l’analyse de données de Jefferson Lab obtenues à l’aide d’un faisceau d’électrons de 5 GeV incident sur différentes cibles (2H, C, Al, Fe, Sn et Pb). Les produits de la réaction sont mesurés avec le spectromètre CLAS. Les principaux résultats de cette expérience sont : (a) l’analyse multi-dimensionnelle des observables mesurées, qui permet une meilleure confrontation avec les modèles théoriques et l’extraction d’informations temporelles sur la fragmentation, et (b) l’observation d’une atténuation hadronique non-linéaire en fonction du rayon du noyau cible. Dans une partie plus théorique, le générateur d’événements PyQM, développé dans le but de reproduire les données de la collaboration HERMES, est présenté. Les résultats sont mitigés, en effet la base théorique utilisée ne semble pas s’appliquer au cas étudié, néanmoins certaines caractéristiques des données sont reproduites permettant de comprendre leurs origines parfois inattendues. Enfin, les possibilités d’expériences futures, à Jefferson Lab et dans un collisionneur ion-électron (EIC), sont explorées<br>The hadron formation is, in the framework of the quantum chromodynamics theory (QCD), a non-perturbative process; this characteristic leads to important theoretical challenges. This is why experimental measurements of fragmentation in nuclei are a necessity in order to obtain substantial progress in our understanding of the mechanisms of hadron formation. The thesis begins with the introduction of theoretical background, followed by an overview of theoretical models. The thesis continues with the analysis of Jefferson Lab data obtained with a 5 GeV electron beam incident on various targets (2H, C, Al, Fe, Sn and Pb). The reaction products are measured with the CLAS spectrometer of Hall B. The main results are: (a) a multi-dimensional analysis of the measured observables, which permits a better confrontation with theoretical models and the extraction of temporal information on fragmentation, and (b) the observation of a non linear hadronic attenuation as a function of the target’s nuclear radius. The PyQM event generator, developed to reproduce the data from the HERMES collaboration, is also presented. The results are ambivalent, the theoretical basis used does not seem to apply to the studied case, however, some characteristics of the data are reproduced allowing to understand their origin, which is sometimes unexpected. Finally, the possibilities for future experiments, at Jefferson Lab and at an Electron-Ion Collider (EIC), are explored