Clustering properties of galaxies at z similar to 4 in the Subaru/XMM deepsurvey field

We study the clustering properties of about 1200 z similar to 4 Lyman break galaxy (LBG) candidates with i < 26 that are selected by color from deep B Ri' imaging data of a 618 arcmin(2) area in the Subaru/XMM-Newton Deep Fiel d taken with Subaru Prime Focus Camera. The contamination and completeness of our LBG sample are evaluated, on the basis of the Hubble Deep Field-Nort h (HDF-N) objects, to be 17% and 45%, respectively. We derive the angular c orrelation function over <theta> = 2"-1000" and find that it is fitted fair ly well by a power law, omega(theta) = A(omega)theta (-0.8), with A(omega) = 0.71 +/- 0.26. We then calculate the correlation length r(o) (in comoving units) of the two-point spatial correlation function xi (r) = (r\r(o))(-1. 8) from A(omega) using the redshift distribution of LBGs derived from the H DF-N and find that r(o) = 2.7(-0.6)(+0.5) h(-1) Mpc in a Lambda -dominated universe (Omega (m) = 0.3 and Omega (Lambda) = 0.7). This is twice as large as the correlation length of the dark matter at z similar or equal to 4 pr edicted from an analytic model by Peacock and Dodds but about twice as smal l as that of bright galaxies predicted from a semianalytic model by Baugh a nd coworkers. We find an excess of omega(theta) on small scales (theta less than or similar to 5"), departing from the power-law fit by over 3 sigma s ignificance levels. Interpreting this as being due to galaxy mergers, we es timate the fraction of galaxies undergoing mergers in our LBG sample to be, which is significantly smaller than those of galaxies 3.0% +/- 0.9% at int ermediate redshifts.