R{sub b} and R{sub c} in the two Higgs Doublet Model with flavor changing neutral currents

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Phys.Rev. D54 (1996) 3296-3308

OSTI ID:756633

Atwood, D; Reina, L; Soni, A

A study of R{sub b} and R{sub c} is presented in the context of a Two Higgs Doublet Model (2HDM) with flavor changing scalar currents (FCSC). Implications of the model for the {rho}-parameter and for b {r_arrow} s{gamma} are also considered. The experimental data on R{sub b} places stringent constraints on the model parameters. The configuration of the model needed to account for R{sub b} is found to be irreconcilable with constraints from b {r_arrow} s{gamma} and {rho}. In particular, if R{sub b}{sup exp} > R{sub b}{sup SM} persists then this version of 2HDM will be ruled out or require significant modifications. Noting that aspects of the experimental analysis for R{sub b} and R{sub c} may be of some concern, the authors also disregard R{sub b}{sup exp} and R{sub c}{sup exp} and give predictions for these using constraints from b {r_arrow} s{gamma} and {rho} parameter only. They emphasize the theoretical and experimental advantages of the observable R{sub b+c} {equivalent_to} {Gamma}(Z {r_arrow} b{anti b} or c{anti c})/{Gamma}(Z {r_arrow} hadrons). They also stress the role of R{sub t} {equivalent_to} {Gamma}(Z {r_arrow} hadrons)/{Gamma}(Z {r_arrow} l{sup =}l{sup {minus}}) in testing the Standard Model (SM) despite its dependence on QCD corrections. Noting that in models with FCNC the amplitude for Z {r_arrow} c{anti c} receives a contribution which grows with m{sub t}{sup 2}, the importance and uniqueness of precision Z {r_arrow} c{anti c} measurements for constraining flavor changing t{anti c} currents is underscored.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (US)
• Sponsoring Organization: USDOE Office of Energy Research (ER) (US)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 756633
• Report Number(s): DOE/ER/40150-1593; CEBAF-TH-96-01; hep-ph/9603210
• Journal Information: Phys.Rev. D54 (1996) 3296-3308, Journal Name: Phys.Rev. D54 (1996) 3296-3308
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
B QUARKS
BRANCHING RATIO
HADRONIC PARTICLE DECAY
HIGGS MODEL
NEUTRAL CURRENTS
RADIATIVE DECAY
STANDARD MODEL
Z NEUTRAL BOSONS