Searching for long-lived particles: A compact detector for exotics at LHCb
Vladimir V. Gligorov (LPNHE, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3, Paris, France); Simon Knapen (Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA, Department of Physics, University of California, Berkeley, California 94720, USA); Michele Papucci (Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA, Department of Physics, University of California, Berkeley, California 94720, USA); Dean J. Robinson (Physics Department, University of Cincinnati, Cincinnati, Ohio 45221, USA)
We advocate for the construction of a new detector element at the LHCb experiment, designed to search for displaced decays of beyond Standard Model long-lived particles, taking advantage of a large shielded space in the LHCb cavern that is expected to soon become available. We discuss the general features and putative capabilities of such an experiment, as well as its various advantages and complementarities with respect to the existing LHC experiments and proposals such as SHiP and MATHUSLA. For two well-motivated beyond Standard Model benchmark scenarios—Higgs decay to dark photons and meson decays via a Higgs mixing portal—the reach either complements or exceeds that predicted for other LHC experiments.
