B,B(s)-> K form factors: An update of light-cone sum rule results

Duplančić, Goran; Melić, Blaženka (2008) B,B(s)-> K form factors: An update of light-cone sum rule results. Physical Review D, 78 (5). 054015-1. ISSN 1550-7998

Preview

PDF - Published Version Download (421kB) | Preview

Abstract

We present an improved QCD light-cone sum rule (LCSR) calculation of the B -> K and B(s) -> K form factors by including SU(3)-symmetry breaking corrections. We use recently updated K meson distribution amplitudes which incorporate the complete SU(3)-breaking structure. By applying the method of direct integration in the complex plane, which is presented in detail, the analytical extraction of the imaginary parts of LCSR hard-scattering amplitudes becomes unnecessary and therefore the complexity of the calculation is greatly reduced. The values obtained for the relevant B((s)) -> K form factors are as follows: f(BK)(+)(0) = 0.36(-0.04)(+0.05), f(BsK)(+)(0) = 0.30(-0.03)(+0.04) and f(BK)(T)(0) = 0.30 +/- 0.05. By comparing among the B -> pi form factors extracted recently by the same method, we find the following SU(3) violation among the B -> light form factors: f(BK)(+)(0)/f(B pi)(+)(0) = 1.38(-0.10)(+0.11), f(BsK)(+)(0)/f(B pi)(+)(0) = 1.15(-0.09)(+0.17), f(BK)(T)(0)/f(B pi)(T)(0) = 1.49(-0.06)(+0.18), and f(BsK)(T)(0)/f(B pi)(T)(0) = 1.17(-0.11)(+0.15).

Item Type:	Article
Uncontrolled Keywords:	distribution amplitude; qcd; decays; pion; accuracy; b->pi; twist
Subjects:	NATURAL SCIENCES > Physics NATURAL SCIENCES > Physics > Astronomy and Astrophysics
Divisions:	Theoretical Physics Division
Projects:	Project title Project leader Project code Project type Fundamentalne interakcije u fizici elementarnih čestica i kozmologiji [3635] Nevenko Bilić 098-0982930-2864 MZOS
Depositing User:	Blaženka Melić
Date Deposited:	02 May 2013 10:34
URI:	http://fulir.irb.hr/id/eprint/525
DOI:	10.1103/PhysRevD.78.054015

Actions (login required)

View Item