119579398
Probing the photon polarization in Bs->phi gamma at LHCb
17596778
Formalism for Simulation-based Optimization of Measurement Errors in High Energy Physics
Miminizing errors of the physical parameters of interest should be the ultimate goal of any event selection optimization in high energy physics data analysis involving parameter determination. Quick and reliable error estimation is a crucial ingredient for realizing this goal. In this paper we derive a formalism for direct evaluation of measurement errors using the signal probability density function and large fully simulated signal and background samples without need for data fitting and background modelling. We illustrate the elegance of the formalism in the case of event selection optimization for CP violation measurement in B decays. The implication of this formalism on choosing event variables for data analysis is discussed.
62798341
Some Statistical Issues in the LHCb Experiment
This paper describes statistical issues that are of particular importance and interest to the LHCb experiment in probing new physics beyond the Standard Model through study of CP violation and rare phenomena in B decays. A wish list for statistical methods and tools that will help LHCb to exploit its full physics potential is given at the end.
117857921
CP Violation in Bs->J/psi phi
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.
16071220
Determination of 2beta(s) in B0(s) ---> J/psi K+ K- Decays in the Presence of a K+ K- S-Wave Contribution
We present the complete differential decay rates for the process B_s -> J/psi K^+ K^- including S-wave and P-wave angular momentum states for the K^+ K^- meson pair. We examine the effect of an S-wave component on the determination of the CP violating phase 2beta_s. Data from the B-factories indicate that an S-wave component of about 10% may be expected in the phi(1020) resonance region. We find that if this contribution is ignored in the analysis it could cause a bias in the measured value of 2beta_s towards zero of the order of 10%. When including the K^+K^- S-wave component we observe an increase in the statistical error on 2beta_s by less than 15%. We also point out the possibility of measuring the sign of cos2beta_s by using the interference between the K^+K^- S-wave and P-wave amplitudes to resolve the strong phase ambiguity. We conclude that the S-wave component can be properly taken into account in the analysis.
122356377
The use of the discriminant analysis method for e π μ separation in BES
Abstract We use the discriminant analysis method in multivariate statistical theory to handle the e π μ separation in BES, describing the principle of the discriminant analysis method, deriving the unstandardized discriminant functions (responsible for particle separation), giving the discriminant efficiency for e π μ and comparing the results from the discriminant analysis method with those obtained in a conventional way.
118877705
Poisson-Like Shape and Shoulder Structure of Hadron Multiplicity Distributions in e+ e- Annihilation at Z0 Energy
16361011
KLOE first results on hadronic physics
The KLOE detector (1) at DAΦNE, the Frascati φ-factory, has started taking data in April 1999 and a total integrated luminosity of 2.4 pb has been collected by the end of ’99, corresponding to ∼8 millions φ decays. With these data a preliminary measurement of φ radiative decays φ → ηγ, φ → πγ, φ → ηγ, φ → ππγ, φ → ππγ, φ → ηπγ and of the hadronic decay φ → πππ has been performed. The energy spectrum of the radiated photon in case of the ππγ, ππγ, ηπγ final states allows us to extract the information on the contribution of the direct decays φ → f0γ, φ → a0γ. The measurement of BR( φ → f0γ), BR(φ → a0γ) can help in understanding the nature of f0(980) and a0(980) which is still under debate. The value of BR(φ → η γ) can be related to the gluonic content of the η(958) while the ratio R=BR(φ → ηγ)/BR(φ → ηγ) can help in establishing the value of the η − η mixing angle θp. Furthermore a high statistics analysis of the Dalitz plot in the φ → πππ decay allows us to extract a possible contribution of the direct decay with respect to the dominant ρπ mode and to obtain a new measurement of the parameters of the ρ line shape, including the ρ − ρ mass difference. Contributed paper N.503 to the XXX International Conference on High Energy Physics, Osaka 27 jul 2 aug 2000.