# EPS HEP 2015

22-29 July 2015
Europe/Vienna timezone

## Re-examining $\sin 2 \beta$ and $\Delta m_d$ from evolution of $B^0_d$ mesons with decoherence

Jul 23, 2015, 5:00 PM
15m
HS21

### HS21

talk Flavour Physics and Fundamental Symmetries

### Speaker

Prof. Sankagiri Umasankar (Indian Institute of Technology Bombay)

### Description

In the time evolution of neutral meson systems, a perfect quantum coherence is usually assumed. The important quantities of the $B^0_d$ system, such as $\sin 2 \beta$ and $\Delta m_d$, are determined under this assumption. However, the meson system interacts with its environment. This interaction can lead to decoherence in the entangled mesons even before they decay. In our formalism this decoherence is modelled by a single parameter $\lambda$. It is desirable to re-examine the procedures of determination of $\sin 2 \beta$ and $\Delta m_d$ in meson systems with decoherence. We find that the present values of these two quantities are modulated by $\lambda$. Re-analysis of $B^0_d$ data from B-factories and LHCb can lead to a clean determination of $\lambda$, $\sin 2 \beta$ and $\Delta m_d$.

eprint number: arXiv:1504:02893

### Primary author

Prof. Sankagiri Umasankar (Indian Institute of Technology Bombay)

### Co-authors

Prof. Ashutosh Kumar Alok (Indian Institute of Technology Jodhpur) Prof. Subhashish Banerjee (Indian Institute of Technology)

### Presentation materials

 uma-abs462.pdf uma-lambda.pdf