Mixing effects of Σ0−Λ0 in Λc+ decays

Abstract

We analyze the mixing between Σ 0 and Λ 0 based on the baryon masses. We distinguish the contributions from QCD and QED in the baryon mass splittings. We find that the mixing angle between Σ 0 and Λ 0 is ð2.07 AE 0.03Þ × 10 −2 , which leads to the decay branching fraction and up-down asymmetry of Λ þ c → Σ 0 e þ ν e to be BðΛ þ c → Σ 0 e þ ν e Þ ¼ ð1.5 AE 0.2Þ × 10 −5 and αðΛ þ c → Σ 0 e þ ν e Þ ¼ −0.86 AE 0.04, respectively. Moreover, we obtain that ΔB ≡ BðΛ þ c → Σ 0 π þ Þ − BðΛ þ c → Σ þ π 0 Þ ¼ ð3.8 AE 0.5Þ × 10 −4 and Δα ≡ αðΛ þ c → Σ 0 π þ Þ − αðΛ þ c → Σ þ π 0 Þ ¼ ð−1.6 AE 0.7Þ × 10 −2 , which should vanish without the mixing.

Measurement of the branching fraction of $Λ_c^+ \to p ω$ decay at Belle

“…We measure the ratio of branching fractions where the first uncertainty is statistical, the second systematic, and the third from the reference mode Λ + c → pK − π + . This result is consistent with the LHCb result (9.4 ± 3.9) × 10 −4 [12], and agrees with the theoretical predictions of (11.4 ± 5.4) × 10 −4 [13] and (6.3 ± 3.4) × 10 −4 [14] within uncertainties based on the SU(3) F flavor symmetry. However, our result contradicts the QCD dynamical model prediction of (3.4 − 3.8) × 10 −4 [15].…”

“…They measured a branching fraction value of B(Λ + c → pω) = 9.4 ± 3.9) × 10 −4 [12]. Theoretical predictions exist, for this particular decay, based either on SU(3) F flavor symmetry [13,14] or QCD dynamical model predictions [15].…”

Study of charmless two-body baryonic $B$ decays

“…On the other hand, the nonfactorizable amplitudes do contribute in those decays, providing possibilities to explore the nonfactorizable parts. However, it has to be emphasized that the argument would not hold once the Σ 0 − Λ mixing are considered [32], which would cause deviations at O(10 −2 ) level.…”

Time-reversal asymmetries and angular distributions in $Λ_b \to ΛV$

“…In two-body decays, T-odd observables can be constructed in the spin correlations among the particles [1][2][3][4][5][6][7][8][9][10]. Since the particle spins could not be directly measured in the current high energy physics experiments, we have to extract their effects through the angular distributions in the cascade decays [11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”