H. Boenish⁵, V. Buza¹⁰, B. Cantrall^8,2, J. R. Cheshire, IV⁶, J. Connors¹¹, J. Cornelison¹², M. Crumrine¹³, A. J. Cukierman⁶, E. Denison¹¹, L. Duband¹⁴, M. Echter⁵, M. Eiben¹⁵, B. D. Elwood^5,16, S. Fatigoni⁶, J. P. Filippini¹⁷, A. Fortes⁸, M. Gao⁶, C. Giannakopoulos⁷, N. Goeckner-Wald⁸, D. C. Goldfinger⁸, S. Gratton^18,19, J. A. Grayson⁸, A. Greathouse⁶, P. K. Grimes⁵, G. Hall^20,8, G. Halal⁸, M. Halpern⁴, E. Hand⁷, S. A. Harrison⁵, S. Henderson^2,3, T. D. Hoang¹³, J. Hubmayr¹¹, H. Hui⁶, K. D. Irwin⁸, J. H. Kang⁶, K. S. Karkare²¹, S. Kefeli⁶, J. M. Kovac^5,16, C. Kuo⁸, K. Lasko^13,20, K. Lau⁶, M. Lautzenhiser⁷, A. Lennox¹⁷, T. Liu^8,†, S. C. Mackey^10,22, N. Maher¹³, K. G. Megerian⁹, L. Minutolo⁶, L. Moncelsi⁶, Y. Nakato⁸, H. T. Nguyen^6,9, R. O’Brient^6,9, S. N. Paine⁵, A. Patel⁶, M. A. Petroff⁵, A. R. Polish^5,16, T. Prouve¹⁴, C. Pryke¹³, C. D. Reintsema¹¹, S. Richter⁵, T. Romand⁶, M. Salatino⁸, A. Schillaci⁶, B. Schmitt⁵, R. Schwartz¹³, C. D. Sheehy¹³, B. Singari^13,20, A. Soliman^6,9, T. St. Germaine⁵, A. Steiger⁶, B. Steinbach⁶, R. Sudiwala¹, G. Teply⁶, K. L. Thompson^2,8, C. Tucker¹, A. D. Turner⁹, C. Vergès²³, A. G. Vieregg^10,22, A. Wandui⁶, A. C. Weber⁹, J. Willmert¹³, C. L. Wong^5,16, W. L. K. Wu^2,3, H. Yang⁸, C. Yu^10,12, L. Zheng⁵, C. Zhang², and S. Zhang⁶ (BICEP/Keck Collaboration)

• ¹School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, United Kingdom
• ²Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, California 94305, USA
• ³SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
• ⁴Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada
• ⁵Center for Astrophysics, Harvard and Smithsonian, Cambridge, Massachusetts 01238, USA
• ⁶Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
• ⁷Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221, USA
• ⁸Department of Physics, Stanford University, Stanford, California 94305, USA
• ⁹Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
• ¹⁰Kavli Institute for Cosmological Physics, University of Chicago, Chicago, Illinois 60637, USA
• ¹¹National Institute of Standards and Technology, Boulder, Colorado 80305, USA
• ¹²High-Energy Physics Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
• ¹³School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
• ¹⁴Service des Basses Températures, Commissariat à l’Énergie Atomique, 38054 Grenoble, France
• ¹⁵Faculty of Physical Sciences, University of Iceland, 102 Reykjavík, Iceland
• ¹⁶Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
• ¹⁷Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
• ¹⁸Centre for Theoretical Cosmology, DAMTP, University of Cambridge, Cambridge CB3 0WA, United Kingdom
• ¹⁹Kavli Institute for Cosmology Cambridge, Cambridge CB3 0HA, United Kingdom
• ²⁰Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
• ²¹Department of Physics, Boston University, Boston, Massachusetts 02215, USA
• ²²Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
• ²³Physics Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

• ^*Contact author: dobeck@stanford.edu
• ^†Contact author: tongtianliu@stanford.edu