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Department of Physics and Astronomy
University of Mississippi


Event Information:

  • Tue

    Colloquium: Study of the Decay B± → Ks0π±π0 at the Belle Experiment

    4:00 pmLewis Hall 101

    Suravinda Kospalage
    Department of Physics and Astronomy
    University of Mississippi

    Study of the Decay B± → Ks0π±π0 at the Belle Experiment

    Belle is a particle physics experiment based at the KEK laboratory in Tsukuba Japan which ran from 1999 to 2010 and collected 1ab-1 of data. The Belle experiment is focused on studying the properties of particles called B mesons which are produced by accelerating and colliding electron and positron beams. These B mesons show the biggest differences between the properties of matter and anti-matter of any known particles. One of the main goals of the Belle experiments is to understand the differences between matter and anti-matter, specifically violations of charge-parity symmetry (CP violation) and how anti-matter vanished and we come to ive in a matter dominated universe.

    This project explores the charmless B decay B± → Ks0π±π0 with the Belle full Monti Carlo (full MC) simulation and Belle data corresponding to 571fb-1 of luminosity and measure the decay's branching fraction (BF). Charmless transitions can proceed by a b → u transition via a tree level diagram or b → s or d transition via the so-called penguin diagram. Both decay types are highly suppressed compared to the b → ctransition and we expect a small branching fraction, smaller than 10-5. The challenge in observing the B± → Ks0π±π0 decay is to suppress backgrounds from continuum events, which do not contain b quarks, and background from other B meson decays. Initial selections plus multi-variate analysis (MVA) machine learning/artificial intelligence technique called a boosted decision tree (BDT) used to reduce the backgrounds to the level to allow to clearly observe the decay and measure the BF.

    Additionally the Dalitz plot (DP) technique to study the intermediate resonance contributions in this decay using the Laura++ software to generate and fit toy Monte Carlo (toy MC), full Monte Carlo simulated data, and, based on the techniques developed on these simulations, the experimental data to study the resonance sub-structure of this decay.

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    Meeting ID: 919 282 27187