Measurement of the spin structure of the deuteron in the DIS region [rapid communication]

We present a new measurement of the longitudinal spin asymmetry A₁^d and the spin-dependent structure function g₁^d of the deuteron in the range 1<Q²<100 GeV² and 0.004<x<0.7. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarised muon beam and a large polarised ⁶LiD target. The results are in agreement with those from previous experiments and improve considerably the statistical accuracy in the region 0.004<x<0.03.