Name: EIC PL meetings
Start: 2024-02-10T15:00:00+01:00
End: 2026-06-30T16:00:00+02:00
Location: No location set

Monday, 22 April
- 15:00 → 16:00
  
  The electron-ion collider: A collider to unravel the mysteries of visible matter 1h
  
  Understanding the properties of nuclear matter and its emergence through the underlying partonic structure and dynamics of quarks and gluons requires a new experimental facility in hadronic physics known as the Electron-Ion Collider (EIC). The EIC will address some of the most profound questions concerning the emergence of nuclear properties by precisely imaging gluons and quarks inside protons and nuclei such as their distributions in space and momentum, their role in building the nucleon spin and the properties of gluons in nuclei at high energies. The polarised EIC beams do not only allow to study the longitudinal and transverse polarized nucleon spin structure, but also to use polarization as a vehicle to access nucleon/nuclei structure difficult to study with unpolarized beams. This presentation will give highlights on the EIC science program, introduce the needed experimental equipment and describe the components of the EIC accelerator critical for the science program. The talk will end summarizing the status of the EIC project.
  
  Speaker: Elke-Caroline Aschenauer (Brookhaven National Lab )
  
  eca.EIC.Poland.Seminar.pdf
Monday, 24 June
- 13:00 → 14:00
  
  Synergies between the Electron-Ion Collider and the Large Hadron Collider experiments 1h
  
  After a brief introduction to the Electron-Ion Collider (EIC) and the Joint ECFA-NuPECC-APPEC Activity on "Synergies between the Electron-Ion Collider and the Large Hadron Collider experiments", I will go into examples of such synergies, focusing mostly on the QCD related ones: parton densities of protons and nuclei, quarkonium production, transverse momentum dependent parton distributions (TMDs) and generalized TMDs, double parton scattering and diffraction. Other synergies for electroweak and BSM studies and with astroparticle physics will also be touched upon briefly.
  
  Speaker: Daniël Boer (University of Groningen)
  
  Polish QCD community-presentation-Boer-June2024-v3.pdf
Monday, 4 November
- 15:00 → 16:00
  
  Small-x Quark and Gluon Helicity and OAM Contributions to the Proton Spin Puzzle 1h
  
  One of the fundamental questions in our understanding of the proton structure is the proton spin puzzle. Theoretically, adding all the helicities and orbital angular momenta (OAM) of the quarks and gluons in the proton should give us 1/2, the spin of the proton. At the same time, adding the experimentally measured spin carried by the quarks and gluons in the proton comes up short, presently giving us a number in the 0.3-0.4 range. This decades-old discrepancy is known as the "proton spin puzzle". In this talk we will discuss the possibility that the missing spin of the proton can be carried by quarks and gluons carrying a small fraction x of the proton momentum. This contribution is mostly beyond the reach of current experiments and is very hard to calculate numerically on the lattice. It appears that an improved theoretical understanding of quark and gluon helicity and OAM distributions at small x is needed to assess the amount of proton spin coming from this region. In this talk I will describe the work of my group to construct such a theory: I will derive the novel small-x evolution equations for helicity and solve them to find the small-x asymptotics of the quark and gluon helicity and OAM distributions. I will show how these equations can be used to obtain a first-ever fit of the world polarized DIS and SIDIS data for x<0.1 based solely on small-x helicity evolution. The resulting amount of the proton spin coming from the small-x region appears to be significant, opening a tantalizing possibility that the proton spin puzzle can be resolved by including this small-x contribution. We will conclude by describing how the upcoming Electron-Ion Collider (EIC) can further test our theoretical formalism and its predictions.
  
  Speaker: Yuri Kovchegov ( Department of Physics, The Ohio State University)
Monday, 10 February
- 15:00 → 16:00
  
  Spinning gluon and long range correlation at RHIC, LHC, and EIC 1h
  
  In this talk, we will present a proposal to unveil the hadron tomography through the nucleon energy-energy correlators (NEEC) at hadron colliders (RHIC and LHC) and the future electron-ion collider (EIC), focusing on spinning gluon effects and small-x saturation. We will show that the gluon saturation at small-x predicts a significantly different shape for the angular distribution of the NEEC. We further discuss the long range azimuthal angle asymmetries to probe the spinning (linearly polarized) gluon distributions inside the nucleon.
  
  Speaker: Feng Yuan (Lawrence Berkeley National Laboratory)
  
  EEC_EIC-PL.pdf
Monday, 5 May
- 15:00 → 16:00
  
  Spin-orbit entanglement in QCD 1h
  
  Spin-orbit coupling is a ubiquitous phenomenon across many areas of contemporary science. I discuss aspects of the spin-orbit coupling of quarks and gluons orbiting inside hadrons. In the first part, I derive a novel momentum sum rule where the spin-orbit correlation plays a crucial role. This is the momentum version of the Jaffe-Manohar spin sum rule. In the second part, I point out the connection to quantum entanglement. I show that the spin and orbital angular momentum of individual partons at small-x are maximally entangled, forming the Bell states. The extension to finite x will also be discussed.
  
  Speaker: Yoshitaka Hatta (BNL, USA)
  
  Poland.pdf
Monday, 16 March
- 15:00 → 16:00
  
  Nucleon and nuclear PDFs, from HERA to EIC 1h
  
  The discovery of the pointlike constituents of the proton inspired massive experimental efforts to use deep inelastic scattering (DIS) to understand the partonic structure of hadrons. Early experiments were performed at fixed-target facilities, which made important findings but were limited in accessible kinematics. The Hadron-Electron Ring Accelerator (HERA), operated at DESY between 1991-2007, pioneered high-energy DIS as the first facility to collide electron (and positron) beams with proton beams at center of mass energies up to 320 GeV. The data from HERA revolutionized our understanding of the proton’s internal structure, and continue to provide critical constraints on global analyses of parton distribution functions (PDFs) of the proton. The electron-ion collider (EIC), under development at Brookhaven National Laboratory, will succeed HERA as a next-generation DIS collider facility. The EIC will facilitate fully polarized collisions between electrons and protons, at lower center of mass energies but two orders of magnitude higher luminosity than HERA. Further, the EIC will allow collisions with ions, ranging from deuterium and helium to heavy nuclei such as lead. This talk will discuss our evolving understanding of the partonic structure of nucleons and nuclei, from the lasting legacy of HERA to the projected impact of the EIC.
  
  Speaker: Tyler Kutz (Johannes Gutenberg-Universität, Mainz, Germany)
Monday, 27 April
- 16:00 → 17:00
  
  A unified derivation of JIMWLK, DGLAP, and CSS evolution from one-loop corrections to the Weizsäcker–Williams gluon distribution 1h
  
  Azimuthal correlations in inclusive dijet production in electron–nucleus collisions provide a powerful and direct probe of the Weizsäcker–Williams (WW) gluon transverse-momentum dependent (TMD) distribution in nuclei. In particular, at small Bjorken x, this observable is a key tool to investigate gluon saturation at the future Electron–Ion Collider (EIC). To reliably extract the WW gluon TMD and the associated saturation scale from future measurements, high theoretical precision is essential, including a consistent treatment of quantum evolution effects across different kinematic regimes.
  
  In this talk, I revisit the calculation of next-to-leading order (NLO) corrections to dijet production at small x. Focusing on the back-to-back limit, I present a complete result for real NLO corrections associated with gluon radiation outside the jet cones. The result preserves TMD factorisation, with the same hard factor as at leading order, multiplying the one-loop correction to the WW gluon TMD at small x. By exploring different kinematic regimes, I show how the calculation naturally incorporates the relevant quantum evolution effects, unifying small-x, Collins-Soper-Sterman, and collinear dynamics. In the dilute limit, the result also connects to the unintegrated gluon distribution of the target and provides access to transverse-momentum dependent gluon splitting function.
  
  Speaker: Paul Caucal (SUBATECH, Universite de Nantes, France)