Model-independent access to the structure of quark flavor mixing

Abstract

We show that the observed pattern of quark flavor mixing, such as |V_{us}| \simeq |V_{cd}|, |V_{cb}| \simeq |V_{ts}|, |V_{cd}/V_{td}| \simeq |V_{cs}/V_{ts}| \simeq |V_{tb}/V_{cb}| and |V_{ub}/V_{cb}| < |V_{td}/V_{ts}|, can essentially be understood in the chiral and heavy quark mass limits. In particular, the phenomenologically successful relations |V_{ub}/V_{cb}| \sim \sqrt{m_u/m_c} and |V_{td}/V_{ts}| \simeq \sqrt{m_d/m_s} can be reasonably conjectured in the m_b \to \infty and m_t \to \infty limits, respectively. We stress that the strength of weak CP violation in the quark sector is determined by the moduli of the four corner elements of the Cabibbo-Kobayashi-Maskawa matrix. A comparison between strong and weak CP-violating effects in the standard model is also made.