Direct phase-sensitive identification of a d-form factor density wave in underdoped cuprates

K. Fujita, M. H. Hamidian, S. D. Edkins, Chung Koo Kim, Y. Kohsaka, M. Azuma, M. Takano, H. Takagi, H. Eisaki, S. Uchida, A. Allais, M. J. Lawler, E. -A. Kim, Subir Sachdev, J. C. Séamus Davis