Hou Wei-Shu, Li Hsiang-nan, Mishima Satoshi, Nagashima Makiko
Department of Physics, National Taiwan University, Taipei, Taiwan 106, Republic of China.
Phys Rev Lett. 2007 Mar 30;98(13):131801. doi: 10.1103/PhysRevLett.98.131801. Epub 2007 Mar 26.
We study the effect from a sequential fourth generation quark on penguin-dominated two-body nonleptonic B meson decays in the next-to-leading order perturbative QCD formalism. With an enhancement of the color-suppressed tree amplitude and possibility of a new CP phase in the electroweak penguin amplitude, we can account better for A(CP)(B(0)-->K+ pi-)-A(CP)(B+-->K+ pi0). Taking |V(t's)V(t'b)| approximately 0.02 with a phase just below 90 degrees, which is consistent with the b-->sl+ l- rate and the B(s) mixing parameter Deltam(B)(s), we find a downward shift in the mixing-induced CP asymmetries of B(0)-->K(S)(pi 0) and phi(K)(S). The predicted behavior for B(0)-->rho(0)(K)(S) is opposite.
我们在次领头阶微扰量子色动力学形式体系下，研究了顺序第四代夸克对企鹅主导的两体非轻子B介子衰变的影响。随着色压低树图振幅的增强以及弱电企鹅振幅中出现新的CP相位的可能性，我们能够更好地解释(A_{CP}(B^0\to K^+\pi^-)-A_{CP}(B^+\to K^+\pi^0))。取(|V_{ts}V_{tb}|\approx0.02)，相位略低于(90)度，这与(b\to s\ell^+\ell^-)衰变率和(B_s)混合参数(\Delta m_{B_s})一致，我们发现(B^0\to K_S\pi^0)和(\phi K_S)的混合诱导CP不对称性出现向下偏移。对于(B^0\to\rho^0K_S)的预测行为则相反。
