Measurement of the Charm-Mixing Parameter y_{CP}

Area of Science:

• Particle Physics
• High-Energy Physics
• Quantum Mechanics

Background:

• Charm mixing describes the oscillation between different charm meson states.
• Understanding charm mixing is crucial for testing the Standard Model of particle physics.
• Previous measurements have provided constraints on charm mixing parameters.

Purpose of the Study:

• To measure the charm-mixing parameter y_CP.
• To utilize D0 decays originating from B meson semimuonic decays.
• To enhance the precision of charm mixing measurements.

Main Methods:

• Analysis of proton-proton collision data at 7 and 8 TeV from the LHCb experiment.
• Reconstruction of D0 mesons decaying into K+K-, pi+pi-, and K-pi+ final states.
• Selection of D0 mesons originating from semimuonic B- and B0 decays.

Main Results:

• The charm-mixing parameter y_CP was measured to be (0.57 ± 0.13(stat) ± 0.09(syst))%.
• The measured value is in agreement with the current world-average value for y_CP.
• The precision of this measurement is comparable to the current world average.

Conclusions:

• The study provides a precise measurement of the charm-mixing parameter y_CP.
• The results contribute to the ongoing efforts to understand charm mixing phenomena.
• This measurement validates current theoretical frameworks within particle physics.