Studying B1(12+)→B2(1

Abstract

Motivated by recent anomalies in flavor changing neutral current b → sℓ + ℓ − transitions, we study B1 → B2ℓ + ℓ − (ℓ = e, µ, τ ) semileptonic weak decays with the SU(3) flavor symmetry, where B1,2 are the spin-1 2 baryons of single bottomed antitriplet T b3 , single charmed antitriplet Tc3, or light baryons octet T8. Using the SU(3) irreducible representation approach, we first obtain the amplitude relations among different decay modes and then predict the relevant not-yet measured observables of T b3 → T8ℓ + ℓ − , Tc3 → T8ℓ + ℓ − , and T8 → T ′ 8 ℓ + ℓ − decays. (a) We calculate the branching ratios of the T b3 → T8µ + µ − and T b3 → T8τ + τ − decay modes in the whole q 2 region and in the different q 2 bins by the measurement of Λ 0 b → Λ 0 µ + µ − . Many of them are obtained for the first time. In addition, the longitudinal polarization fractions and the leptonic forward-backward asymmetries of all T b3 → T8ℓ + ℓ − decays are very similar to each other in certain q 2 bins due to the SU( 3) flavor symmetry. (b) We analyze the upper limits of B(Tc3 → T8ℓ + ℓ − ) by using the experimental upper limits of B(Λ + c → pµ + µ − ) and B(Λ + c → pe + e − ), and find the experimental upper limit of B(Λ + c → pµ + µ − ) giving the effective bounds on the relevant SU(3) flavor symmetry parameters. The predictions of B(Ξ 0 c → Ξ 0 e + e − ) and B(Ξ 0 c → Ξ 0 µ + µ − ) will be different between the single-quark transition dominant contributions and the W -exchange dominant ones. (c) As for T8 → T ′ 8 ℓ + ℓ − decays, we analyze the single-quark transition contributions and the W -exchange contributions by using the two experimental measurements of B(Ξ 0 → Λ 0 e + e − ) and B(Σ + → pµ + µ − ), and give the branching ratio predictions by assuming either single-quark transition dominant contributions or the W -exchange dominant contributions. According to our predictions, some observables are accessible to the experiments at BESIII, LHCb and Belle-II. −0.21 2.7 ± 2.7 0.04 +0.18 −0.02 0.47 +0.31 −0.27 0.50 +0.26 −0.240.5 ± 0.7 2.2 ± 0.6 1.7 ± 0.5 7.0 ± 2.9 2.44 ± 0.57 6.0 ± 1.3+0.42 −0.41 0.41 +0.43 −0.31 3.91 +4.00 −3.85 0.058 +0.270 −0.030 0.68 +0.47 −0.40 0.73 +0.40 −0.36 0.73 +1.06 −1.02 3.21 +0.97 −0.92 2.47 +0.80 −0.77 10.18 +4.53 −4.35 3.23 +0.85 −0.81 8.46 +2.12 −2.01 B(Ξ 0 b → Ξ 0 µ + µ − ) S 2 1.14 +0.49 −0.46 0.45 +0.48 −0.34 4.39 +4.58 −4.32 0.065 +0.302 −0.033 0.76 +0.54 −0.45 0.81 +0.45 −0.39 0.81 +1.20 −0.81 3.60 +1.14 −1.06 2.83 +0.91 −0.89 11.46 +5.29 −4.96 3.82 +1.01 −1.03 9.81 +2.45 −2.55 B(Ξ − b → Ξ − µ + µ − ) S 1 1.09 +0.46 −0.43 0.43 +0.45 −0.32 4.15 +4.28 −4.08 0.062 +0.289 −0.032 0.72 +0.51 −0.42 0.77 +0.43 −0.38 0.77 +1.13 −1.09 3.40 +1.04 −0.99 2.62 +0.86 −0.82 10.80 +4.89 −4.65 3.40 +0.91 −0.87 8.94 +2.30

Probing for new physics with rare charm baryon (Λc, Ξc, Ωc) decays

“…On the other hand, the Ξ 0 c → Σ 0 form factors receive a factor 1/ √ 2 relative to the Ξ + c → Σ + ones due to isospin [25]. Then, U-spin relates Ξ 0 c → Σ 0 form factors to Ξ 0 c → Λ 0 ones [26,27] with a relative factor of √ 3. For Ω 0 c decays no relation with the Λ c exists since the Ω 0 c sits in another SU(3) F -multiplet [20].…”

Forward-backward asymmetries in in the Bethe-Salpeter equation approach *

“…In this study, we investigate the of in the Bethe-Salpeter equation (BSE) approach. Theoretically, only a few studies have been conducted on [6][7][8][9][10][11][12][13][14][15][16][17]. References [6] ( [7]) provided the integrated forwardbackward asymmetries ( ) and ( ), whereas the results of Ref.…”

“…tracted from a constituent quark model, Ref. [16] investigated the rare weak dileptonic decays of the baryon. Ref.…”