Speaker
Description
In the context of quark mixing phenomenon, understanding Cabbibo-Kobayashi-Maskawa (CKM) matrix and related phenomenology has important implications for the Flavor Physics including discovery of physics beyond the Standard Model. With continuous refinements in the data, the CKM phenomenology has been saddled with several persistent ‘anomalies’ which motivate one to explore some of the aspects of CKM matrix. For example, it has been observed that there is a persistent $3\sigma$ difference between $(V_{ub})_{excl.}$ and $(V_{ub})_{incl.}$ values. Similarly, it has been found that $V_{cb}$, although quite precisely known, exhibits a significant divergence in $(V_{cb})_{excl.}$ and $(V_{cb})_{incl.}$ values. Also, recently divergence has been noticed in the unitarity constraints of the first row of the CKM matrix.
One possible way to explain this divergence, perhaps, is to go to fourth generation of quarks, for which there is no theoretical bar. In the present work, we attempt to constraint the fourth row and fourth column of the CKM matrix. Using the presently refined data of CKM elements, our preliminary results put upper limits on the elements of the fourth row and fourth column, e.g.,
$$ \begin{pmatrix} 0.9734-0.9740 & 0.2229-0.2261 & 0.0033-0.0043 & \le 0.0529\\
0.2130-0.2290& 0.9650-1.0090&0.0382-0.0438& \le 0.1480\\
0.0074-0.0086& 0.0366-0.0410&0.9530-1.0730& \le 0.3006\\
\le 0.0841& \le 0.1331 & \le 0.3005 & \le 0.9999
\end{pmatrix}.$$
| Session | Quark and Lepton Flavour Physics |
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