TY  - JOUR
AU  - Albertus, C.
AU  - Hernandez, E.
AU  - Hidalgo-Duque, C.
AU  - Nieves, J.
PY  - 2014
DA  - 2014//
TI  - (B)over-bar(s) -> K semileptonic decay from an Omnes improved constituent quark model
T2  - Phys. Lett. B
JO  - Physics Letters B
SP  - 144
EP  - 149
VL  - 738
PB  - Elsevier Science Bv
AB  - We study the f(+) form factor for the semileptonic (B) over bar (s) -> K+ l(-) (V) over bar (l) decay in a constituent quark model. The valence quark estimate is supplemented with the contribution from the (B) over bar* pole that dominates the high q(2) region. We use a multiply-subtracted Omnes dispersion relation to extend the quark model predictions from its region of applicability near q(max)(2) = (M-Bs – M-K)(2) similar to 23.75 GeV2 to all q(2) values accessible in the physical decay. To better constrain the dependence of f(+) on q(2), we fit the subtraction constants to a combined input from previous light cone sum rule by Duplancic and Melic (2008) [11] and the present quark model results. From this analysis, we obtain Gamma ( (B) over bar (s) -> K+ l(-) (V) over bar (l)) = (5.47(-0.46)(+0.54)) vertical bar Vub vertical bar(2) x 10(-9) MeV, which is about 10% and 20% higher than the predictions based on Lattice QCD and QCD light cone sum rules respectively. The former predictions, for both the form factor f(+) (q(2)) and the differential decay width, lie within the 1 sigma band of our estimated uncertainties for all q(2) values accessible in the physical decay, except for a quite small region very close to q(max)(2). Differences with the light cone sum results for the form factor f(+) are larger than 20% in the region above q(2) = 15 GeV2.
SN  - 0370-2693
UR  - http://arxiv.org/abs/1404.1001
UR  - https://doi.org/10.1016/j.physletb.2014.09.037
DO  - 10.1016/j.physletb.2014.09.037
LA  - English
N1  - WOS:000344624900022
ID  - Albertus_etal2014
ER  -