I've been reading articles about Zeeman's effect on TMDs specifically on WSe$_2$. In the article: Srivastava, Ajit, Sidler, Meinrad, Allain, Adrien, Lembke, Dominik, Kis, Andras, Imamoğlu, A., Valley Zeeman effect in elementary optical excitations of monolayer WSe$_2$. Nature Physics, 11:141-147, 2015 in the first two curves, the blue curve representing the K valley is shifted to the higher energy region while the red curve representing the K' valley is shifted to the lower energy region.
However, in an article on the same topic: Aivazian, G., Zhirui, Gong, Jones, Aaron, Chu, Rui-Lin, Yan, J., Mandrus, D., Zhang, Chuanwei, Cobden, David, Yao, Wang, Xu, X., Magnetic control of valley pseudospin in monolayer WSe$_2$. Nature Physics, 11:148-152, 2015 the red line is in the region of higher energy while the blue line is in the region of lower energy.
Are the two articles not contradicting each other as it is the same material (WSe$_2$) and the applied magnetic field is positive? Which of the two representations is right?