000002876 001__ 2876
000002876 005__ 20220609133701.0
000002876 037__ $$aBELLE2-CONF-PROC-2022-007
000002876 041__ $$aeng
000002876 100__ $$aSeema Choudhury
000002876 245__ $$aMeasurement of branching fraction for B → K∗ℓℓ at Belle II
000002876 260__ $$a$$c2022-03-01
000002876 300__ $$amult. p
000002876 520__ $$aThis paper report the BR measurement of B → K∗ℓℓ decays using 189.26/fb of data collected during 2019–2021 by the Belle II experiment at the SuperKEKB e+e− asymmetric-energy collider, corresponding to (197.2±5.7)×106 BB ̄ events. The final states considered are B0 → K∗0(K+π−)ℓℓ, B+ → K∗+(KS0π+,K+π0)ℓℓ, where ℓ = e or μ. The yield of signal for the decays B → K∗μμ, B → K∗ee, and B → K∗ℓℓ are 22 ± 6, 18 ± 6, and 38 ± 9, respectively. The uncertainties quoted for the signal yield are statistical only. We report the branching fraction of these decays for the entire q2 (invariant mass square of lepton pair) range excluding the charmonium resonances to be: B(B → K∗μμ) = (1.19 ± 0.31±+0.09) × 10−6,  B(B → K∗ee) = (1.42 ± 0.48 ± 0.10) × 10−6,  B(B → K∗ℓℓ) = (1.25 ± 0.30±+0.09) × 10−6, here, the first and second uncertainties are statistical and systematic, respectively. The results are statistically limited, but are compatible with the world average within uncertainty. These are the first measurements of B → K∗ℓℓ decays from Belle II experiments.
000002876 6531_ $$aFCNC, BR, Belle II, EWP, K*ll
000002876 700__ $$aSoumen Halder
000002876 700__ $$aLopamudra Nayak
000002876 700__ $$aSaurabh Sandilya
000002876 700__ $$aGagan Mohanty
000002876 700__ $$aAnjan Giri 
000002876 8560_ $$fseema.choudhury@kek.jp
000002876 8564_ $$uhttps://docs.belle2.org/record/2876/files/BELLE2-CONF-PROC-2022-007.pdf