General Lab Information

Xiaoxuan Chu

Assistant Scientist, Cold QCD, Physics Department

Xiaoxuan Chu

Brookhaven National Laboratory

Physics Department
Bldg. 510D, Room 2-194
P.O. Box 5000
Upton, NY 11973-5000

(631) 344-2126
xchu@bnl.gov

I'm a physicist working in experimental high-energy and nuclear physics, with ongoing involvement in the STAR experiment at RHIC and the ePIC experiment at the EIC, both at Brookhaven National Laboratory. My research focuses on understanding nucleon structure, proton spin, and its 3D imaging to uncover the fundamental properties of matter. Outside of work, music plays a big part in my life. I play guitar and jazz drums and am currently learning the piano.

Research | Education | Appointments | Publications | Highlights | Awards

Research Activities

Nuclear science aims to understand the origin and structure of the nucleus and nucleons, which account for nearly all the mass of the visible universe. Decades of research have revealed that nucleons are composed of quarks bound together by gluons, leading to the development of the fundamental theory of Quantum Chromodynamics (QCD). While recent-generation colliders have provided precise measurements of quark momentum distributions inside the nucleon, the exploration of gluon dynamics remains limited. My work focuses on investigating gluon saturation, a phenomenon predicted by QCD to emerge in high-energy collisions. This reaserch aims to find definitive evidence of gluon saturation using data from STAR and to explore its universal properties across experiments at RHIC, the LHC, and the future EIC.

I am also deeply interested in understanding the intrinsic spin of nucleons. Within the QCD framework, nucleon spin is distributed among quark and gluon spins as well as their orbital angular momentum. RHIC, as the world’s only polarized proton collider, enables precise measurements of the gluon contribution to total proton spin using longitudinally polarized proton beams. The future EIC will open new opportunities for exploring nucleon spin with unprecedented precision.

Beyond these one-dimensional studies of nucleon structure, my work extends to 3D imaging of proton structure and tomography. By analyzing data from transversely polarized proton collisions at STAR and, in the future, deep inelastic scattering from transversely polarized protons at the EIC, we will better understand the complex dynamics of nucleon structure, including transverse momentum-dependent parton densities and fragmentation functions.

Achieving these physics goals requires sophisticated detectors capable of making precise measurements! I contribute to EIC detector simulations, with a specific focus on investigating the detector requirements of inclusive channels, for both the former ATHENA proto-collaboration and the current ePIC detector design. At RHIC, I am responsible for monitoring the p-Carbon polarimeters data acquisition during RHIC runs and providing rapid results of beam polarization.

Responsibilities

  • Convener of Spin/Cold QCD physics working group at STAR Collaboration
  • Mentor of the DOE’s SULI program
  • Peer review process for Phys. Rev. Lett, Phys. Rev. D, and JINST

Education

2018, Ph.D. from Central China Normal University & BNL

Professional Appointments

  • 2023 - present: Research Staff at BNL
  • 2019 - 2023: Postdoctoral Researcher at BNL

Selected Publications

  • STAR Collaboration, Measurements of the Z/γ cross section and transverse single spin asymmetry in 510 GeV p+p collisions, Phys. Lett. B 854 (2024) 138715, https://doi.org/10.1016/j.physletb.2024.138715
  • STAR Collaboration, Longitudinal and transverse spin transfer to Lambda and anti-Lambda hyperons in polarized p+p collisions at 200 GeV, Phys Rev D 109, 012004 (2024), https://doi.org/10.1103/physrevd.109.012004
  • P. Achenbach et al., The present and future of QCD, Nucl. Phys. A 1047 (2024) 122874, https://doi.org/10.1016/j.nuclphysa.2024.122874
  • STAR Collaboration, Evidence for Nonlinear Gluon Effects in QCD and Their Mass Number Dependence at STAR, Phys. Rev. Lett. 129 (2022) 9, 092501, https://doi.org/10.1103/physrevlett.129.092501
  • ATHENA proto-Collaboration, ATHENA detector proposal - a totally hermetic electron nucleus apparatus proposed for IP6 at the Electron-Ion Collider, JINST 17 (2022) 10, P10019, https://doi.org/10.1088/1748-0221/17/10/p10019
  • R. Abdul Khalek et al., Science Requirements and Detector Concepts for the Electron-Ion Collider, Nucl. Phys. A 1026 (2022) 122447, https://doi.org/10.1016/j.nuclphysa.2022.122447
  • STAR Collaboration, Measurement of transverse single-spin asymmetries of pion and electromagnetic jets at forward rapidity in 200 and 500 GeV transversely polarized proton-proton collisions, Phys. Rev. D 103 (2021) 92009, https://doi.org/10.1103/physrevd.103.092009
  • B. S. Page , X. Chu, and E. C. Aschenauer, Experimental aspects of jet physics at a future EIC, Phys. Rev. D 101, 072003 (2020), https://doi.org/10.1103/physrevd.101.072003
  • R. Chen et al., Hydrothermal synthesis of Nd3+-doped heterojunction ms/tz-BiVO 4 and its enhanced photocatalytic performance, Journal of Physics and Chemistry of Solids 117 (2018) 28-35, https://doi.org/10.1016/j.jpcs.2018.02.010
  • X. Chu, E. C. Aschenauer, J. H. Lee and L. Zheng, Photon structure studied at an electron ion collider, Phys. Rev. D 96, 074035 (2017), https://doi.org/10.1103/physrevd.96.074035

Research Highlights

Signs of gluon saturation emerge from particle collisions: BNL news, CERN Courier news, and DOE higlight

Awards & Recognition

BNL Laboratory Directed Research and Development (LDRD) Awards:

  • 2024 - 2026: Awarded $500,000 in funding
  • 2023 - 2024: Awarded $110,000
Xiaoxuan Chu

Brookhaven National Laboratory

Physics Department
Bldg. 510D, Room 2-194
P.O. Box 5000
Upton, NY 11973-5000

(631) 344-2126
xchu@bnl.gov