JRA14-MPGD_HP: Micropattern Gaseous Detectors for Hadron Physics

There are currently many open fundamental questions and puzzles in physics, which require input or progress in hadron physics. One example is the transverse-momentum dependent inner structure of the proton, which, apart from being a fundamental question of QCD itself, is relevant for many analyses at proton colliders such as the LHC. Another example is the proton radius puzzle, where a very large discrepancy between its determination from elastic electron scattering and a new result from the spectroscopy of muonic hydrogen is yet unexplained. Possible explanations range from uncertainties in the extrapolation of the electric form factor towards zero momentum transfer to new physics beyond the standard model. A third example is the question of the existence of exotic bound states of quarks and antiquarks, a plethora of which is predicted by QCD, but very few have been unambiguously identified until now. Progress towards answering these questions requires new or upgraded accelerator facilities as well as detectors with improved capabilities in tracking, identification of charged particles, photon detection and timing in the picosecond region. A coherent effort towards these goals by world experts in MPGDs is proposed in this JRA. Its research tasks have important connections with existing and future facilities in hadron physics: MPGDs are being considered as baseline solution for tracking and photon detection in many of the new experiments at TJNAF, RHIC, EIC or FAIR. Our research on stability and performance of these devices will have an impact on all these efforts. Within this application, there are important synergies with the Next-DIS Work Package, which is examining the requirements for EIC physics, and the TIIMM Work Package, which is studying complementary detector concepts for these goals. Our contribution to the proton radius puzzle, which is also the focus of a networking activity within this application, the PREN Work Package, will be the simulation and optimization of a TPC for measuring the proton radius via elastic scattering of highenergy muons at CERN. The detection technologies for which this JRA will lay the foundations will have widespread applications also outside physics, from homeland security and medical physics, to elemental mapping of biological, cultural and industrial samples. The proposed activities are organized in four tasks.