Search

The physics programme and the design are described of a new collider for particle and nuclear physics, the Large Hadron Electron Collider (LHeC), in which a newly built electron beam of 60 GeV, to possibly 140 GeV, energy collides with the intense hadron beams of the LHC. Compared to the first ep collider, HERA, the kinematic range covered is extended by a factor of twenty in the negative four-momentum squared, Q^2, and in the inverse Bjorken x, while with the design luminosity of 1e33 cm-2 s-1 the LHeC is projected to exceed the integrated HERA luminosity by two orders of magnitude. The physics programme is devoted to an exploration of the energy frontier, complementing the LHC and its discovery potential for physics beyond the Standard Model with high precision deep inelastic scattering measurements. These are designed to investigate a variety of fundamental questions in strong and electroweak interactions. The LHeC thus continues the path of deep inelastic scattering (DIS) into unknown areas of physics and kinematics. The physics programme also includes electron-deuteron and electron-ion scattering in a (Q^2 1/x) range extended by four orders of magnitude as compared to previous lepton-nucleus DIS experiments for novel investigations of neutron's and nuclear structure, the initial conditions of Quark-Gluon Plasma formation and further quantum chromodynamic phenomena. The LHeC may be realised either as a ring-ring or as a linac-ring collider. Optics and beam dynamics studies are presented for both versions, along with technical design considerations on the interaction region, magnets including new dipole prototypes, cryogenics, RF, and further components. A design study is also presented of a detector suitable to perform high precision DIS measurements in a wide range of acceptance using state-of-the art detector technology, which is modular and of limited size enabling its fast installation. The detector includes tagging devices for electron, photon, proton and neutron detection near to the beam pipe. Civil engineering and installation studies are presented for the accelerator and the detector. The LHeC can be built within a decade and thus be operated while the LHC runs in its high-luminosity phase. It so represents a major opportunity for progress in particle physics exploiting the investment made in the LHC.

The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is carrying out a spin physics program in high-energy polarized $\vec{p}+\vec{p}$ collisions at $\sqrt{s}=200-500\,$GeV to gain a deeper insight into the spin structure and dynamics of the proton. One of the main objectives of the spin physics program at RHIC is the extraction of the polarized gluon distribution function based on measurements of gluon initiated processes, such as hadron and jet production. The STAR detector is well suited for the reconstruction of various final states involving jets, $\pi^{0}$, $\pi^{\pm}$, e$^{\pm}$ and $\gamma$, which allows to measure several different processes. Recent results will be shown on the measurement of jet production and hadron production at $\sqrt{s}=200\,$GeV. The RHIC spin physics program has recently completed the first data taking period in 2009 of polarized $\vec{p}+\vec{p}$ collisions at $\sqrt{s}=500\,$GeV. This opens a new era in the study of the spin-flavor structure of the proton based on the production of $W^{-(+)}$ bosons. Recent STAR results on the first measurement of $W$ boson production in polarized $\vec{p}+\vec{p}$ collisions will be shown., Comment: 10 pages, 9 figures, Talk presented at the 26th Winter Workshop on Nuclear Dynamics, Ocho Rios, Jamaica, January 2-9, 2010 to be published in Journal of Physics: Conference Series (JPCS) The author may be contacted via: surrow@mit.edu

The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is carrying out a spin physics program colliding transverse or longitudinal polarized proton beams at s√ = 200 − 500 GeV to gain a deeper insight into the spin structure and dynamics of the proton. These studies provide fundamental tests of Quantum Chromodynamics (QCD). One of the main objectives of the STAR spin physics program is the determination of the polarized gluon distribution function through a measurement of the longitudinal double-spin asymmetry, ALL, for various processes. Recent results will be shown on the measurement of ALL for inclusive jet production, neutral pion production and charged pion production at s√ = 200 GeV.