Study of B-S Mixing at the D-Zero Detector at Fermilab Using the Semi-Leptonic Decay B-S -> D-S Mu Nu X. (Thesis/Dissertation)

摘要

B(sub s)(sup 0) mixing studies provide a precision test of Charge-Parity violation in the Standard Model. A measurement of (Delta)m(sub s) constrains elements of the CKM quark rotation matrix (1), providing a probe of Standard Model Charge-Parity violation. This thesis describes a study of B(sub s)(sup 0) mixing in the semileptonic decay B(sub s)(sup 0) (yields) D(sub s)(sup -) (mu)(sup +)(nu)X, where D(sub s)(sup -) (yields) (phi)(pi)(sup -), using data collected at the D-Zero detector at Fermi National Accelerator in Batavia, Illinois. Approximately 2.8 fb(sup -1) of data collected between April 2002 and August 2007 was used, covering the entirety of the Tevatron's RunIIa (April 2002 to March 2006) and part of RunIIb (March 2006-August 2007). Taggers using both opposite-side and same-side information were used to obtain the flavor information of the B(sub s)(sup 0) meson at production. The charge of the muon in the decay B(sub s)(sup 0) (yields) D(sub s)(sup -)(mu)(sup +)(nu)X was used to determine the flavor of the B(sub s)(sup 0) at decay. The B(sub d)(sup 0) mixing frequency, (Delta)m(sub d), was measured to verify the analysis procedure. A log-likelihood calculation was performed, and a measurement of (Delta)m(sub s) was obtained. The final result was (Delta)m(sub s) = 18.86 (+-) 0.80(stat.) (+-) 0.37(sys.) with a significance of 2.6(sigma).