Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userPhysics potential of the decays Bs;d -> J/psi eta and Bs -> J/psi phi in the ATLAS experiment at the LHC
61
0
0.0
(
0
)
Authors
C. Driouichi
Ask ChatGPT about the research
No Arabic abstract
The CP asymmetry predicted by the Standard Model in the decay modes Bs;d -> J/psi eta and Bs -> J/psi phi is very small, and the observation of a sizeable e ect would be a clear indication of new physics beyond the Standard Model. Contrary to the final state J/psi phi, the former final state is a CP eigenstate, and therefore complex angular distribution analyses are not necessary for the asymmetry measurement. In this paper, the approaches for the study of these two decay channels are presented.
rate research
Read More
Study of CP violation in the decay channel Bs->J/psi phi is essential to exploring and constraining physics beyond the Standard Model in the quark flavour sector. The experimental progress in this area of activity at the LHC and Tevatron is discussed.
We briefly discuss measurements of CP violation in Bs --> J/psi phi decay. Both the phenomenology of Bs mixing and the importance of the measurement to searches for new physics, as well as technical details and issues with the analysis are included. While current results are consistent with the standard model, even large contributions from new physics cannot be excluded.
Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the hadronic decay Bs -> J/psi f0(980) is observed. This CP eigenstate mode could be used to measure mixing-induced CP violation in the B_s system. Using a fit to the pi+ pi- mass spectrum with interfering resonances gives R_{f0/phi} = [Gamma(Bs -> J/psi f0, f0 -> pi+ pi-)]/[Gamma(Bs -> J/psi phi, phi -> K+K-)] = 0.252^{+0.046+0.027}_{-0.032-0.033}, where the uncertainties are statistical and systematic, respectively.
The decay Bs -> J/psi K+ K- is investigated using 0.16/fb of data collected with the LHCb detector using 7 TeV pp collisions. Although the J/psi phi channel is well known, final states at higher K+K- masses have not previously been studied. In the K+K- mass spectrum we observe a significant signal in the f2(1525) region as well as a non-resonant component. After subtracting the non-resonant component, we find B(Bs->J/psi f_2(1525))/B(Bs->J/psi phi)=(26.4 +/- 2.7 +/- 2.4)%.
The effective lifetime of the Bs meson in the decay mode Bs->J/psi f0(980) is measured using 1.0/fb of data collected in pp collisions at sqrt(s) = 7 TeV with the LHCb detector. The result is 1.700 +/- 0.040 +/- 0.026 ps where the first uncertainty is statistical and the second systematic. As the final state is CP-odd, and CP violation in this mode is measured to be small, the lifetime measurement can be translated into a measurement of the decay width of the heavy Bs mass eigenstate, Gamma_H = (0.588 +/- 0.014 +/- 0.009)/ps.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
