Precision measurement of the Λc+ , Ξc+ , and

First branching fraction measurement of the suppressed decay Ξc0→π−Λc+

“…The well-known Ξ 0 c baryon consists of the c, s, and d quarks, and has a lifetime of 154.5 AE 1.7 AE 1.6 AE 1.0 fs [3]. The branching fraction BðΞ 0 c → π − Λ þ c Þ has not been previously measured.…”

“…Based on the measured BðΞ − b → π − Λ 0 b ) [4], and using charmed-baryon lifetimes available at that time, they predict BðΞ 0 c → π − Λ þ c Þ ¼ ð0.19 AE 0.07Þ% for constructive interference and BðΞ 0 c → π − Λ þ c Þ ⪅ 0.01% for destructive interference between the SUUD and WS contributions. We have redone their calculation using updated lifetime measurements [3,7], finding BðΞ 0 c → π − Λ þ c Þ ¼ ð0.14 AE 0.07Þ% for constructive interference and BðΞ 0 c → π − Λ þ c Þ ⪅ ð0.018 AE 0.015Þ% for destructive interference. Faller and Mannel, on the other hand, predict BðΞ 0 c → π − Λ þ c Þ < 0.3%, an upper limit obtained by assuming constructive interference [8].…”

“…A. Zhelezov, 16 Y. Zheng, 5 X. Zhou, 5 Y. Zhou, 5 X. Zhu, 3 V. Zhukov, 13,39 J. B. Zonneveld,57 S. Zucchelli, 19,e D. Zuliani, 27 and G. Zunica 61 (LHCb Collaboration) 1 Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brazil…”

Latest LHCb measurements of semileptonic b-hadron decays

“…LHCb has recently measured the lifetimes of charmed baryons using inclusive semileptonic H b → H c µ − X decays collected during Run 1 [2],where H b represents a Λ 0 b , Ξ 0 b or Ξ − b baryon and H c corresponds to a Λ + c , Ξ + c or Ξ 0 c baryon, respectively. The charmed baryons are reconstructed as Λ + c →pK − π + , Ξ + c →pK − π + and Ξ 0 c →pK − K + π + .…”

Charm baryons at LHCb

“…The lifetime hierarchy is predicted to be either ( + ) > ( + ) > ( 0 ) > ( 0 ) or ( + ) > ( 0 ) > ( + ) > ( 0 ), depending on the treatment of those higher-order effects. Recently, the LHCb collaboration performed a measurement of charmed baryon lifetimes using semileptonic -hadron decays [3,4], where the lifetime of the 0 was measured to be 268 ± 24 (stat) ± 10 (syst) ± 2( + ) fs, almost four times larger than the world average [5] and inconsistent with it at the level of 7 standard Gaussian deviations ( ), and the lifetime of the 0 baryon was measured to be 54.5 ± 1.7 (stat) ± 1.6 (syst) ± 1.0( + ) fs and in tension with the world average [5] at the level of 3.3 . Additional measurements to confirm or rule out these results and to establish the lifetime hierarchy of the charmed baryons from the experimental side are therefore essential.…”