this is only a short incomplete overview - please read a good book for a more detailed explanation :-)

An important goal of SuperBelle is to study the CP-Violation in the B anti-B meson pair system, which are produced in e+e- collisions, with a much better precision ( and therefore either verify the unitarity of the ckm-matrix or find physics beyond the standard model like new CP-violating phases, supersymmetry or extra dimensions). Another interesting topic is the tau-decays, where for example charged lepton flavor changing or the decay into strange particles can occur. Since those events, again, have a really small branching ratio, a high luminosity is needed. A better precision is achieved by increasing the number of events of interesting physics (ca. 50 billion B anti-B meson pairs) through the SuperBELLE upgrade (->higher luminosity, about two orders of magnitude!!).


C stands for charge and transforms a particle into its antiparticle, P stands for parity and switches the signs of the spacial components of a vector. If a process is not invariant under CP-transformation, CP is violated (e.g in the neutral Kaon decay). CP-Violation, which happens in weak interaction only, might be able to explain why there is matter at all since matter and antimatter (created in equal amounts -> bigbang) can decay differently under CP-Violating processes. If for example the B and Bbar behave differently when decaying into a finalstate where the transisionrate should be the same (eg "the golden channel": B -> J/psi +Ks is different then Bbar -> J/psi + Ks), CP is violated. This violation is described by a complex phase in the CKM-matrix, a matrix that 'rotates' the mass eigenstates of the quarks into their weak eigenstates. Because of the unitarity of the CKM-matrix the relation between certain matrix elements can be described by a triangle in the complex space, which has a non zero area when there is CP-Violation. The length of the sides and the angles of this triangle is measured at BELLE. If it turns out that this triangle is not closed (and therefor is no triangle anymore), it would be a hint for new physics beyond the standard model.

SBelle Detectors

some nice information about the detectors and more can be found here:

and here:

-- PitVanhoefer - 25 Mar 2009

This topic: BellePhysics > WebHome > Physics > PhysicsBELLE
Topic revision: r3 - 2009-03-31 - PitVanhoefer
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