( ( astronomy ( particle physics ) ) ( ( stars ( ( ( A ( RECORD ( HIGH ( MATTER DENSITY ) ) ) ) ( in ( an ( inertial-confinement ( fusion experiment ) ) ) ) ) ( has ( been achieved ) ) ) ) . ) )
(ROOT (S (NP (JJ astronomy) (NN particle) (NNS physics)) (VP (VBZ stars) (SBAR (S (NP (NP (DT A) (NNP RECORD) (NNP HIGH) (NNP MATTER) (NNP DENSITY)) (PP (IN in) (NP (DT an) (JJ inertial-confinement) (NN fusion) (NN experiment)))) (VP (VBZ has) (VP (VBN been) (VP (VBN achieved))))))) (. .)))
astronomy particle physics stars A RECORD HIGH MATTER DENSITY in an inertial-confinement fusion experiment has been achieved.
(ROOT (S (NP (NP (NNP Density)) (PP (IN of) (NP (NN matter)))) (VP (VBZ reflects) (SBAR (WHADVP (WRB how) (RB closely)) (S (VP (VBD packed) (SBAR (S (NP (NP (DT the) (NNS particles)) (PP (IN of) (NP (NN matter)))) (VP (VBP are)))))))) (. .)))