On the lifetime of the 3ΛH ypernucleus

Measurement of Hypertriton Lifetime at STAR

“…From Fig 2, we can find that some of the measurements [12,13,15,16] show lifetime values close to that of Λ, while others [8,11,14,17,18] show shorter lifetime value than the Λ. The measurements in [12][13][14]16] used nuclear emulsion technique. Their results are close to the Λ lifetime except for [14].…”

“…Our lifetime value is shorter than the free Λ's, which calls for further theoretical study of 3 Λ H structure. [8,[11][12][13][14][15][16][17][18]. The magenta shadow is the theoretical calculation by Dalitz in 1966 [22].…”

“…Since 1960s, there have been several measurements for the lifetime of 3 Λ H [8,[11][12][13][14][15][16][17][18]. We draw a summary plot in Fig 2. For a long time, the 3 Λ H is believed to be a weakly bound state of a Λ and a deuteron, so the lifetime of 3 Λ H should be close to that of a free Λ.…”

“…The measurements in [12][13][14]16] used nuclear emulsion technique. Their results are close to the Λ lifetime except for [14]. They discussed that this may be due to dissociation of the lightly bound Λ and deuteron when traveling in a dense medium.…”

Introduction to the Topical Session on the Lifetime Measurement of the Hypertriton

“…The projectile fragmentation reactions of 6 Li at 2 AGeV on a C target were studied. The invariant mass technique coupled to precise t.o.f.…”