Direct dark matter search by annual modulation in XMASS-I
  A search for dark matter was conducted by looking for an annual modulation
signal due to the Earth's rotation around the Sun using XMASS, a single phase
liquid xenon detector. The data used for this analysis was 359.2 live days
times 832 kg of exposure accumulated between November 2013 and March 2015. When
we assume Weakly Interacting Massive Particle (WIMP) dark matter elastically
scattering on the target nuclei, the exclusion upper limit of the WIMP-nucleon
cross section 4.3$\times$10$^{-41}$cm$^2$ at 8 GeV/c$^2$ was obtained and we
exclude almost all the DAMA/LIBRA allowed region in the 6 to 16 GeV/c$^2$ range
at $\sim$10$^{-40}$cm$^2$. The result of a simple modulation analysis, without
assuming any specific dark matter model but including electron/$\gamma$ events,
showed a slight negative amplitude. The $p$-values obtained with two
independent analyses are 0.014 and 0.068 for null hypothesis, respectively. we
obtained 90\% C.L. upper bounds that can be used to test various models. This
is the first extensive annual modulation search probing this region with an
exposure comparable to DAMA/LIBRA.
