A precision measurement of the mass of the h{sub c}({sup 1}P{sub 1}) state of charmonium has been made using a sample of 24.5x10{sup 6} {psi}(2S) events produced in e{sup +}e{sup -} annihilation at ...the Cornell Electron Storage Ring (CESR). The reaction used was {psi}(2S){yields}{pi}{sup 0}h{sub c}, {pi}{sup 0}{yields}{gamma}{gamma}, h{sub c}{yields}{gamma}{eta}{sub c}, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which {eta}{sub c} decays are reconstructed in 15 hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of the present measurements are M(h{sub c})=3525.28{+-} 0.19(stat.){+-}0.12(syst.) MeV, and B({psi}(2S){yields}{pi}{sup 0}h{sub c})xB(h{sub c}{yields}{gamma}{eta}{sub c})=(4.19{+-}0.32{+-}0.45)x10{sup -4}. Using the {sup 3}P{sub J} centroid mass, {delta}M{sub hf}(1P){identical_to}<M({chi}{sub cJ})>-M(h{sub c})=+0.02{+-}0.19{+-}0.13 MeV.
We search for a non-SM-like CP-odd Higgs boson (a{sub 1}{sup 0}) decaying to {tau}{sup +}{tau}{sup -} or {mu}{sup +}{mu}{sup -} in radiative decays of the {upsilon}(1S). No significant signal is ...found, and upper limits on the product branching ratios are set. Our {tau}{sup +}{tau}{sup -} results are almost 2 orders of magnitude more stringent than previous upper limits. Our data provide no evidence for a Higgs state with a mass of 214 MeV decaying to {mu}{sup +}{mu}{sup -}, previously proposed as an explanation for 3 {sigma}{sup +}{yields}p{mu}{sup +}{mu}{sup -} events observed by the HyperCP experiment. Our results constrain NMSSM models.
Using a sample of tagged D{sub s}{sup +} decays collected near the D{sub s}*{sup {+-}}D{sub s}{sup {+-}} peak production energy in e{sup +}e{sup -} collisions with the CLEO-c detector, we study the ...leptonic decay D{sub s}{sup +}{yields}{tau}{sup +}{nu}{sub {tau}} via the decay channel {tau}{sup +}{yields}e{sup +}{nu}{sub e}{nu}{sub {tau}}. We measure B(D{sub s}{sup +}{yields}{tau}{sup +}{nu}{sub {tau}})=(6.17{+-}0.71{+-}0.34)%, where the first error is statistical and the second systematic. Combining this result with our measurements of D{sub s}{sup +}{yields}{mu}{sup +}{nu}{sub {mu}} and D{sub s}{sup +}{yields}{tau}{sup +}{nu}{sub {tau}} (via {tau}{sup +}{yields}{pi}{sup +}{nu}{sub {tau}}), we determine f{sub D{sub s}}=(274{+-}10{+-}5) MeV.
The decay {psi}(2S){yields}{eta}J/{psi} is used to measure, for the first time, all prominent {eta}-meson branching fractions with the same experiment in the same dataset, thereby providing a ...consistent treatment of systematics across branching fractions. We present results for {eta} decays to {gamma}{gamma}, {pi}{sup +}{pi}{sup -}{pi}{sup 0}, 3{pi}{sup 0}, {pi}{sup +}{pi}{sup -}{gamma} and e{sup +}e{sup -}{gamma}, accounting for 99.9% of all {eta} decays. The precision of several of the branching fractions and their ratios is improved. Two channels, {pi}{sup +}{pi}{sup -}{gamma} and e{sup +}e{sup -}{gamma}, show results that differ at the level of three standard deviations from those previously determined.
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