Lifetime difference in the B$$0\atop{s}$$ system from untagged B$$0\atop{s}$$ → J/ΨΦ decay at √s= 1.96 TeV at D0 detector
- Tata Inst. of Fundamental Research (TIFR), Mumbai (India)
In this dissertation, they present a study of the untagged decay of B$$0\atop{s}$$ → J/ΨΦ, the final state of which is a superposition of the CP-even and CP-odd states. Within the framework of the standard model (SM), to a good approximation, the two CP eigenstates of the (B$$0\atop{s}$$, $$\bar{B}$$$$0\atop{s}$$) system are equivalent to mass eigenstates. The data collected by the D0 detector between June 2002 to August 2004 (an integrated luminosity of approximately 450 pb-1) has been used for the analysis presented in this thesis. From a simultaneous fit to the B$$0\atop{s}$$ candidate mass, lifetime, and the angular distribution of the decay products, they obtain the CP-odd fraction in the final state at production time to be 0.16 ±} 0.10(stat) ± 0.02(syst). The average lifetime of the (B$$0\atop{s}$$, $$\bar{B}$$$$0\atop{s}$$) system is measured to be 1.39$$+0.13\atop{-0.16}$$(stat)$$+0.01\atop{-0.02}$$(syst) ps, with the relative width difference between the heavy and light mass eigenstates, Δγ/$$\bar{γ}$$ = (γL/γH)/$$\bar{γ}$$ = 0.24$$+0.16\atop{-0.38}$$(stat)$$+0.03\atop{-0.04}$$(syst). With the additional constraint from the world average of the B$$0\atop{s}$$ lifetime measurements using semileptonic decays, they find average lifetime of the (B$$0\atop{s}$$, $$\bar{B}$$$$0\atop{s}$$) system 1.39 ± 0.06 ps with Δγ/$$\bar{γ}$$ = 0.25$$+0.14\atop{-0.15}$$. They have also done B0 lifetime measurement for its analogous decay mode to J/Ψ}K*. With this measurement they get B0 lifetime 1.530 ± 0.043(stat) ± 0.023(syst) ps. Using above results, they get 0.91 ± 0.09(stat) ± 0.003(syst), for the ratio of the B$$0\atop{s}$$ and B0 lifetimes ($$\bar{γ}$$(B$$0\atop{s}$$)/γ(B0)). These measurements are consistent with the predictions of SM within the measurement uncertainty.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 907797
- Report Number(s):
- FERMILAB-THESIS-2006-40; TRN: US0703314
- Country of Publication:
- United States
- Language:
- English
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