Measurement of b-quark fragmentation fractions in p(p)over-bar collisions at root s=1.8 TeV

We have studied the production of B hadrons in 1.8-TeV <p(p)over bar> collisions. We present measurements of the fragmentation fractions, f(u), f(d), f(s), and f(baryon), of produced b quarks that yield B+, B-0, B-s(0), and <(Lambda)over bar(b)(0)> hadrons. Reconstruction of five electron-charm final states yields f(s)/(f(u) + f(d)) = 0.213 +/- 0.068 and f(baryon)/(f(u) + f(d)) = 0.118 +/- 0.042, assuming f(u) = f(d). If all B hadrons produced in <p(p)over bar> collisions cascade to one of these four hadrons, we determine f(u) = f(d) = 0.375 +/- 0.023, f(s) = 0.160 +/- 0.044, and f(baryon) = 0.090 +/- 0.029. If we do not assume f(u) = f(d), we find f(d)/f(u) = 0.84 +/- 0.16.