Related Experiment Video
Updated: Jul 15, 2026
07:46
Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
Radiative B meson decays into kpigamma and kpipigamma final states
Physical Review Letters
|December 18, 2002
Summary
Researchers observed radiative B meson decays, finding evidence for tensor meson contributions in B0 decays and measuring branching fractions for B+ decays. These findings advance understanding of B meson physics.
Area of Science:
- Particle Physics
- High Energy Physics
- Quantum Chromodynamics
Background:
- B mesons are subatomic particles crucial for testing the Standard Model of particle physics.
- Radiative decays provide a window into the underlying quark structure and dynamics of B mesons.
Purpose of the Study:
- To investigate radiative decays of B mesons into specific final states.
- To search for and characterize intermediate meson states contributing to these decays.
- To measure the branching fractions of observed decay channels.
Main Methods:
- Analysis of a large dataset (29.4 fb^-1) collected by the Belle experiment.
- Identification and reconstruction of B meson decays into K+pi(-)gamma and K+pi(-)pi(+)gamma final states.
- Application of statistical methods to determine branching fractions and evidence for intermediate states.
Main Results:
- Evidence for B0 decays proceeding through an intermediate tensor meson state K*(2)(1430)0, with a branching fraction of (1.3 ± 0.5(stat) ± 0.1(syst)) x 10^-5.
- Measurement of the branching fraction for B+ decays into K+pi(-)pi(+)gamma as (2.4 ± 0.5(stat) +0.4-0.2(syst)) x 10^-5.
- Dominance of B+-->K*0pi(+)gamma and B+-->K+rho0gamma channels within the K+pi(-)pi(+)gamma final state.
Conclusions:
- The study provides significant insights into the mechanisms of radiative B meson decays.
- The observation of tensor meson contributions in B0-->K+pi(-)gamma decays offers a new probe of B meson structure.
- The measured branching fractions contribute valuable data for refining theoretical models in particle physics.
Related Concept Videos
03:18Radioactivity and Nuclear Equations
Nuclear chemistry is the study of reactions that involve changes in nuclear structure. The nucleus of an atom is composed of protons and, except for hydrogen, neutrons. The number of protons in the nucleus is called the atomic number (Z) of the element, and the sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are isotopes of the same element.
A nuclide of an element has a specific number of protons and...
A nuclide of an element has a specific number of protons and...
03:23Types of Radioactivity
The most common types of radioactivity are α decay, β decay, γ decay, neutron emission, and electron capture.
Alpha (α) decay is the emission of an α particle from the nucleus. For example, polonium-210 undergoes α decay:
Alpha (α) decay is the emission of an α particle from the nucleus. For example, polonium-210 undergoes α decay:
03:20Nuclear Transmutation
Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed protons being...
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
01:29Positron Emission Tomography
Positron emission tomography (PET) is a medical imaging technique involving radiopharmaceuticals — substances that emit short-lived radiation. Although the first PET scanner was introduced in 1961, it took 15 more years before radiopharmaceuticals were combined with the technique and revolutionized its potential.
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body being...
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body being...
01:25Deactivation Processes: Jablonski Diagram
Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...