arXiv subjects
Publications and source records attributed to Robert J. Oakes.
The cross sections for the production of $B_s$ and $B_s^*$ mesons through the fragmentation process in $\bar{p}p$ collisions were calculated. The input parameters were determined from the measured $B_s$ and $B_s^*$ production rates in $e^+e^-$ annihilation. The transverse momentum distributions $dσ/dp_{T}$ are given for $\sqrt{s}=1.8$ TeV, the Fermilab Tevatron energy.
A formula for an improved spin--dependent potential between a heavy quark and a heavy antiquark was developed using Heavy Quark Effective Theory techniques. The leading logarithmic quark mass terms emerging from loop contributions were explicitly extracted and summed up. There is no renormalization scale dependence in this new formula and it includes both the Eichten--Feinberg formula as well as the one--loop QCD result as special cases. The hyperfine splittings were calculated using the spin--spin part of this improved formula. For charmonium the $J/ψ$-$η_c$ $S$-wave splitting agrees well with the data while the energy difference $ΔM_P$ between the center of gravity of the $1^3P_{0,1,2}$ states and the $1^1P_1$ state has the correct sign but is somewhat larger than the experimental value; however, there are also several other contributions to $ΔM_P$ of comparable magnitude ($\sim 1$ MeV), which we discuss. The corresponding mass differences for the $b\bar{b}$ and $b\bar{c}$ mesons are also predicted.
The production rates and transverse momentum distributions of the strange-beauty mesons $B_s$ and $B_s^*$ at $p\bar p$ colliders are calculated assuming fragmentation is the dominant process. Results are given for the Tevatron in the large transverse momentum region, where fragmentation is expected to be most important.
The hyperfine spin splittings in heavy quarkonia are studied using the recently developed renormalization group improved spin-spin potential which is independent of the scale parameter $μ$. The calculated energy difference between the $J/ψ$ and the $η_c$ fits the experimental data well, while the predicted energy difference $ΔM_p$ between the center of the gravity of $1^3P_{0,1,2}$ states and the $1^1P_1$ state of charmonium has the correct sign but is somewhat larger than the experimental data. This is not surprising since there are several other contributions to $ΔM_p$, which we discuss, that are of comparable size ($\sim 1$ MeV) that should be included, before precise agreement with the data can be expected. The mass differences of the $ψ'-η_c'$, $Υ(1S)-η_b$, $Υ(2S)-η_b'$, and $B_c^*-B_c$ are also predicted.
A new formula for the heavy quark-antiquark spin dependent potential is given by using the techniques developed in the heavy quark effective theory. The leading logarithmic quark mass terms emerging from the loop contributions are explicitly extracted and summed up. There is no renormalization scale ambiguity in this new formula. The spin-dependent potential in the new formula is expressed in terms of three independent color-electric and color-magnetic field correlation functions, and it includes both the Eichten-Feinberg's formula and the one-loop QCD result as special cases.
Using the recent measurement of the total production rate for $B_s$ and $B_s^*$ mesons in electron-positron annihilation to determine the strange quark mass parameter in the $\bar b\to B_s,\, B_s^*$ fragmentation functions we calculate the momentum distributions of the $B_s$ and $B_s^*$ mesons.