M. Chadha

Search for inclusive b -> sl(+)l(-)

We have searched for the effective FCNC decays b->s l+l- using an inclusive method. We set upper limits on the branching ratios B(b->s e+e-)<5.7 10^{-5}, B(b->s mu+mu-)<5.8 10^{-5}, and B(b->s e+-mu-+)<2.2 10^{-5} (at 90 %\ C.L.). Combining the di-electron and di-muon decay modes we find: B(b->s l+l-)<4.2 10^{-5} (at 90 % C.L.).We have searched for the effective flavor changing neutral-current decays b{r_arrow}sl{sup +}l{sup {minus}} using an inclusive method. We set upper limits on the branching ratios B(b{r_arrow}se{sup +}e{sup {minus}}){lt} 5.7{times}10{sup {minus}5} , B(b{r_arrow}s{mu}{sup +}{mu}{sup {minus}} ){lt}5.8{times}10{sup {minus}5} , and B(b{r_arrow}se{sup {plus_minus}}{mu}{sup {minus_plus} }){lt}2.2{times}10{sup {minus}5} [at 90{percent} confidence level (C.L.)]. Combing the dielectron and dimuon decay modes we find B(b{r_arrow}sl{sup +}l{sup {minus}}){lt} 4.2{times}10{sup {minus}5} (at 90{percent} C.L.). {copyright} {ital 1998} {ital The American Physical Society}

Investigation of Semileptonic {ital B} Meson Decays to {ital p} -Wave Charm Mesons

We have studied semileptonic B meson decays with a P-wave charm meson in the final state using 3.29 × 10 BB̄ events collected by the CLEO II detector at the Cornell Electron-positron Storage Ring. We find a value for the exclusive semileptonic product branching fraction: B(B− → D 1`ν̄`)B(D 1 → Dπ) = (0.373 ± 0.085 ± 0.052 ± 0.024)% and an upper limit for B(B− → D 2 `ν̄`)B(D 2 → Dπ) < 0.16% (90% C.L.). These results indicate that at least 20% of the total B− semileptonic rate is unaccounted for by the observed exclusive decays, B− → D`ν̄, B− → D`ν̄, B− → D 1`−ν̄, and B− → D 2 `−ν̄. (Submitted to Physical Review Letters) SLAC-PUB-9836 hep-ex/9708035 Work supported in part by Department of Energy Contract DE-AC03-76SF00515 Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94309, USA A. Anastassov, J. E. Duboscq, D. Fujino, K. K. Gan, T. Hart, K. Honscheid, H. Kagan, R. Kass, J. Lee, M. B. Spencer, M. Sung, A. Undrus, R. Wanke, A. Wolf, M. M. Zoeller, B. Nemati, S. J. Richichi, W. R. Ross, P. Skubic, M. Bishai, J. Fast, J. W. Hinson, N. Menon, D. H. Miller, E. I. Shibata, I. P. J. Shipsey, M. Yurko, S. Glenn, S. D. Johnson, Y. Kwon, S. Roberts, E. H. Thorndike, C. P. Jessop, K. Lingel, H. Marsiske, M. L. Perl, V. Savinov, D. Ugolini, R. Wang, X. Zhou, T. E. Coan, V. Fadeyev, I. Korolkov, Y. Maravin, I. Narsky, V. Shelkov, J. Staeck, R. Stroynowski, I. Volobouev, J. Ye, M. Artuso, A. Efimov, M. Goldberg, D. He, S. Kopp, G. C. Moneti, R. Mountain, S. Schuh, T. Skwarnicki, S. Stone, G. Viehhauser, X. Xing, J. Bartelt, S. E. Csorna, V. Jain, K. W. McLean, S. Marka, R. Godang, K. Kinoshita, I. C. Lai, P. Pomianowski, S. Schrenk, G. Bonvicini, D. Cinabro, R. Greene, L. P. Perera, G. J. Zhou, B. Barish, M. Chadha, S. Chan, G. Eigen, J. S. Miller, C. O’Grady, M. Schmidtler, J. Urheim, A. J. Weinstein, F. Würthwein, D. W. Bliss, G. Masek, H. P. Paar, S. Prell, V. Sharma, D. M. Asner, J. Gronberg, T. S. Hill, D. J. Lange, S. Menary, R. J. Morrison, H. N. Nelson, T. K. Nelson, C. Qiao, J. D. Richman, D. Roberts, A. Ryd, M. S. Witherell, R. Balest, B. H. Behrens, W. T. Ford, H. Park, J. Roy, J. G. Smith, J. P. Alexander, C. Bebek, B. E. Berger, K. Berkelman, K. Bloom, D. G. Cassel, H. A. Cho, D. S. Crowcroft, M. Dickson, P. S. Drell, K. M. Ecklund, R. Ehrlich, A. D. Foland, P. Gaidarev, L. Gibbons, B. Gittelman, S. W. Gray, D. L. Hartill, B. K. Heltsley, P. I. Hopman, S. L. Jones, J. Kandaswamy, P. C. Kim, D. L. Kreinick, T. Lee, Y. Liu, N. B. Mistry, C. R. Ng, E. Nordberg, M. Ogg, J. R. Patterson, D. Peterson, D. Riley, A. Soffer, B. Valant-Spaight, C. Ward, M. Athanas, P. Avery, C. D. Jones, M. Lohner, C. Prescott, J. Yelton, J. Zheng, G. Brandenburg, R. A. Briere, A. Ershov, Y. S. Gao, D. Y.-J. Kim, R. Wilson, H. Yamamoto, aPermanent address: Lawrence Livermore National Laboratory, Livermore, CA 94551. bPermanent address: BINP, RU-630090 Novosibirsk, Russia. cPermanent address: Yonsei University, Seoul 120-749, Korea. dPermanent address: Brookhaven National Laboratory, Upton, NY 11973. ePermanent address: University of Texas, Austin TX 78712

Measurement of the Decay Amplitudes and Branching Fractions of {ital B} {r_arrow} {ital J/}{psi}{ital K*} and {ital B} {r_arrow} {ital J/}{psi}{ital K} Decays

Using data taken with the CLEO II detector, we present the first full angular analysis in the color-suppressed modes B{sup 0} {yields} J/{psi} K*{sup 0} and B{sup +} {yields} J/{psi} K*{sup +}. This leads to a complete determination of the decay amplitudes of these modes. In addition, we update the branching fractions for B {yields} J/{psi} K and B {yields} J/{psi} K*.

Studies of radiation damage to CAMEX64 preamplifiers exposed to γ-rays at the Cornell high energy synchrotron source

Abstract CAMEX64 preamplifiers, developed at the MPI-Munich for use in the readout of silicon strip detectors, have been exposed to well-measured doses of monochromatic γ-rays from the Cornell high energy synchrotron source (CHESS) and measurements of the resulting radiation damage have been made. Silicon strip detectors with their associated CAMEXes will be installed close to the interaction region in the CLEO-II experiment at Cornell University, where they will be exposed to both charged particle and photon fluences. Powered and unpowered CAMEXes were irradiated and after each exposure measurements of pedestals, gains, coherent and incoherent noise were made, until the devices could no longer be read out. Results are quoted for noise and gain degradation as a function of dose.

Study of the B0 semileptonic decay spectrum at the Y(4S) resonance

We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral Bs through a partial reconstruction of B{sup 0} {yields} D*{sup -}{ell}{sup +}{nu}. This spectrum, measured with 2.38 fb{sup -1} of data collected at the {Upsilon}(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all {Upsilon}(4S) events in the same data set. These two spectra are consistent with having the same shape above 1.5 GeV/c. From the two spectra and two other CLEO measurements, we obtain the B{sup 0} and B{sup +} semileptonic branching fractions, b{sub 0} and b{sub +}, their ratio, and the production ratio f{sub +-}/f{sub 00} of B{sup +} and B{sup 0} pairs at the {Upsilon}(4S). We report b{sub +}/b{sub 0} = 0.950{sub -0.080}{sup +0.117} {+-} 0.091, b{sub 0} = (10.78 {+-} 0.60 {+-} 0.69)%, and b{sub +} = (10.25 {+-} 0.57 {+-} 0.65)%. b{sub +}/b{sub 0} is equivalent to the ratio of charged to neutral B lifetimes, {tau}{sub +}/{tau}{sub 0}.

Search for Inclusive {ital b{r_arrow}sl}{sup + }{ital l}{sup {minus}}

We have searched for the effective FCNC decays b->s l+l- using an inclusive method. We set upper limits on the branching ratios B(b->s e+e-)<5.7 10^{-5}, B(b->s mu+mu-)<5.8 10^{-5}, and B(b->s e+-mu-+)<2.2 10^{-5} (at 90 %\ C.L.). Combining the di-electron and di-muon decay modes we find: B(b->s l+l-)<4.2 10^{-5} (at 90 % C.L.).We have searched for the effective flavor changing neutral-current decays b{r_arrow}sl{sup +}l{sup {minus}} using an inclusive method. We set upper limits on the branching ratios B(b{r_arrow}se{sup +}e{sup {minus}}){lt} 5.7{times}10{sup {minus}5} , B(b{r_arrow}s{mu}{sup +}{mu}{sup {minus}} ){lt}5.8{times}10{sup {minus}5} , and B(b{r_arrow}se{sup {plus_minus}}{mu}{sup {minus_plus} }){lt}2.2{times}10{sup {minus}5} [at 90{percent} confidence level (C.L.)]. Combing the dielectron and dimuon decay modes we find B(b{r_arrow}sl{sup +}l{sup {minus}}){lt} 4.2{times}10{sup {minus}5} (at 90{percent} C.L.). {copyright} {ital 1998} {ital The American Physical Society}

Observation of the Radiative Decay {ital D}{sup *+}{r_arrow}{ital D}{sup +}{gamma}

We have observed a signal for the decay D{sup *+}{r_arrow}D{sup +}{gamma} at a significance of 4standard deviations. From the measured branching ratio B(D{sup *+}{r_arrow}D{sup +}{gamma}) /B(D{sup *+}{r_arrow}D{sup +}{pi}{sup 0})=0.055{plus_minus}0.014{plus_minus}0.010 we find B(D{sup *+}{r_arrow}D{sup +}{gamma}) =0.017{plus_minus}0.004{plus_minus}0.003, where the first uncertainty is statistical and the second is systematic. We also report the highest precision determination of the remaining D{sup *+} branching fractions. {copyright} {ital 1998} {ital The American Physical Society}

Measurement of the branching fractions of {Lambda}{sub c}{sup +}{r_arrow}p{bar K}n({pi})

Using data recorded by the CLEO-II detector at CESR, we report new measurements of the branching fractions for the decays of the charmed baryon {Lambda}{sub c}{sup +} into pK{sup {minus}}{pi}{sup +}{pi}{sup 0}, p{bar K}{sup 0}, p{bar K}{sup 0}{pi}{sup +}{pi}{sup {minus}}, and p{bar K}{sup 0}{pi}{sup 0}, all measured relative to pK{sup {minus}}{pi}{sup +}. The relative branching fractions are 0.67{plus_minus}0.04{plus_minus}0.11,0.46{plus_minus}0.02{plus_minus}0.04,0.52 {plus_minus}0.04{plus_minus}0.05, and 0.66{plus_minus}0.05{plus_minus}0.07, respectively. {copyright} {ital 1998} {ital The American Physical Society}Using data recorded by the CLEO-II detector at CESR, we report new measurements of the branching fractions for the decays of the charmed baryon

Study of gluon versus quark fragmentation in {Upsilon}{r_arrow}gg{gamma} and e{sup +}e{sup {minus}}{r_arrow}q{bar q}{gamma} events at {radical}(s)=10 GeV

\Lambda_c^+

Search for {ital CP} violation in {ital D}{sup 0} decay

into