Evalutating Cp-Violation In The B-Meson Decay Mode

Jeffrey Chen

School Name

Governor's School for Science and Math

Grade Level

12th Grade

Presentation Topic

Physics

Presentation Type

Mentored

Mentor

Mentor: Dr. Purohit; Department of Physics and Astronomy, University of South Carolina

Abstract

It has been postulated that there were equal amounts of matter and anti-matter during the creation of the universe. This matter and anti-matter annihilated together to form pure energy (photons), but not all of the matter was annihilated into photons, which resulted in the predominance of matter over antimatter in the universe. A study of CP-violation, the violation of the combination of charge-conjugation symmetry and parity symmetry, can be used to understand this phenomenon. However, CP-violation is very difficult to detect due to its rare occurrence, approximately 0.1% of interactions, and the presence of background noise during detection. In my research, I created a decay simulation using a fraction of the B-meson decay mode, whose data was obtained from the Belle Detector at the asymmetric positron-electron collider KEKB in Japan. The objective was to determine the number of events required to yield a definite distinction between the decays of the B+ and B- mesons by using relativistic Breit-Wigner distributions. Through statistical fits to the resulting data, the experiment found that it takes approximately 15000 events to reliably determine an occurrence of CP-violation in the decays of charged B-mesons. An additional simulation was run to detect CP-violation in a different, arbitrary decay mode, but it did not prove to be a valid method.

Location

Owens 104

Start Date

4-16-2016 9:45 AM

COinS
 
Apr 16th, 9:45 AM

Evalutating Cp-Violation In The B-Meson Decay Mode

Owens 104

It has been postulated that there were equal amounts of matter and anti-matter during the creation of the universe. This matter and anti-matter annihilated together to form pure energy (photons), but not all of the matter was annihilated into photons, which resulted in the predominance of matter over antimatter in the universe. A study of CP-violation, the violation of the combination of charge-conjugation symmetry and parity symmetry, can be used to understand this phenomenon. However, CP-violation is very difficult to detect due to its rare occurrence, approximately 0.1% of interactions, and the presence of background noise during detection. In my research, I created a decay simulation using a fraction of the B-meson decay mode, whose data was obtained from the Belle Detector at the asymmetric positron-electron collider KEKB in Japan. The objective was to determine the number of events required to yield a definite distinction between the decays of the B+ and B- mesons by using relativistic Breit-Wigner distributions. Through statistical fits to the resulting data, the experiment found that it takes approximately 15000 events to reliably determine an occurrence of CP-violation in the decays of charged B-mesons. An additional simulation was run to detect CP-violation in a different, arbitrary decay mode, but it did not prove to be a valid method.