LDMX -- The Light Dark Matter eXperiment

/ Authors

T. Åkesson, Layan Alsaraya, S. Appert, Charles Bell, E. Berzin, Nikita Blinov, L'eo Borrel, C. Bravo, Liam Brennan, L. Bryngemark

and 139 more authors

P. Butti, Riccardo Catena, A. Chávez, O. Colegrove, G. Collura, Patill Daghlian, Filippo Delzanno, E. Dukes, V. Dutta, B. Echenard, Ralf Ehrlich, Thomas Eichlersmith, Jonathan Eisch, Einar El'en, Eric Fernandez, Erich Frahm, Cooper Froemming, A. Furmanski, Gr'eta Gajd'an, M. Ghrear, N. Gogate, Victor Gomez, Matt Graham, Taylor R. Gray, J. Greaves, C. Grieco, Craig Group, Peter Gyorgy, C. Hast, Axel Helgstrand, H. Herde, C. Herwig, D. Hitlin, T. Horoho, Cameron Huse, J. Incandela, David Jang, Nathan Jay, A. Jige, Joseph Kaminski, Wesley Ketchum, M. Kilpatrick, Kai Kristiansen, G. Krnjaic, S. Kyre, T.J. Lange, J. Lázaro, A. Li, Shirley Li, Shujin Li, Yuze Li, Ziqi Lin, Hongying Liu, M. Loh, L. Loman, Zihan Ma, Jeremiah Mans, Sanjit Masanam, P. Masterson, S. Metallo, Sophie Middleton, Noah Moran, Omar Moreno, G. Mullier, Joseph Muse, A. Nagar, T. Nelson, G. Niendorf, Rory O’Dwyer, W. Ortez, Lennart Osterman, L. Ostman, J. Oyang, P. Palit, D. Parmar, Jessica Pascadlo, Emrys Peets, A. Pele, R. Pottgen, H. Qu, M. Quinnan, Jaida Raffelsberger, Benjamin Reese, Chelsea Rodriguez, Eduardo Sánchez, Luis Sarmiento, P. Schuster, Chris Sellgren, H. Siegel, Pradyun Solai, M. Solt, Francisca Stedman, Cristina Mantilla Suarez, Lauren Tompkins, N. Toro, N. Tran, J. Trevor, T. Vámi, Kieran Wall, Erik Wallin, Z. Wan, Yuxuan Wang, A. Whitbeck, D. Wilmot, Xinyi Xu, Jihoon Yoo, Danyi Zhang, Guanglei Zhao, Weilong Zhou Lund University, Department of Applied Physics, Lund, Sweden, S. University, Menlo Park, Ca, USA., C. I. O. Technology., Pasadena, U. Michigan, Ann Arbor, Mi, F. N. A. Laboratory, Batavia, Il, S. N. Laboratory, U. C. S. Barbara, Santa Barbara, U. Virginia, Charlottesville, Va, C. University, Pittsburgh, Pa, U. Minnesota, Minneapolis, Mn, Texas Tech University, Lubbock, Tx

/ Abstract

The Light Dark Matter eXperiment (LDMX) is an electron fixed-target experiment optimized to search for sub-GeV dark matter production through the missing momentum signature. LDMX is designed to operate in End Station A at SLAC, using an 8 GeV electron beam accelerated alongside the LCLS-II drive beam. The design of the apparatus is strongly motivated by the performance requirements of a high-rate missing momentum search and leverages detector technologies and designs from other experiments along with existing facilities at SLAC. LDMX will improve on previous results by up to three orders of magnitude, enabling broad sensitivity to dark sector scenarios including the dark matter interaction strengths motivated by freeze-out of MeV-GeV mass dark matter to the observed relic abundance. With hermetic forward coverage, LDMX also has sensitivity to visible signatures of dark sectors and provides a unique probe of electron-nuclear interactions important to interpreting data from accelerator-based neutrino experiments. This report encompasses the technical design of the LDMX Detector, its simulated performance, and the physics capabilities of the experiment.