B. Barish

Measurement of the ratio of the proton form factors, GE/GM, at high momentum transfers and the question of scaling☆

Abstract Electron-proton elastic scattering cross sections have been measured at the Stanford Linear Accelerator Center at four-momentum transfers squared (q2) of 1.0, 1.5, 2.0, 2.5and 3.75 (GeV/c)2. The angular distributions at q2 = 2.5 and 3.75 (GeV/c)2are sufficient to provide values of the ratio GE/GMindependent of the results from other laboratories. Our results are compatible with scaling, GE(q2) = GM(q2)/μ, within the experimental errors.

Determination of ±s from a differential-jet-multiplicity distribution in e+e- collisions at ss =29 and 91 GeV

We measured the differential jet-multiplicity distribution in {ital e}{sup +}{ital e}{sup {minus}} annihilation with the Mark II detector. This distribution is compared with the second-order QCD prediction and {alpha}{sub {ital s}} is determined to be 0.123{plus minus}0.009{plus minus}0.005 at {radical}{ital s}{approx}{ital M}{sub {ital Z}} (at the SLAC Linear Collider) and 0.149{plus minus}0.002{plus minus}0.007 at {radical}{ital s}=29 GeV (at the SLAC storage ring PEP). The running of {alpha}{sub {ital s}} between these two center-of-mass energies is consistent with the QCD prediction.

Calibration of the Advanced LIGO detectors for the discovery of the binary black-hole merger GW150914

In Advanced LIGO, detection and astrophysical source parameter estimation of the binary black hole merger GW150914 requires a calibrated estimate of the gravitational-wave strain sensed by the detectors. Producing an estimate from each detector’s differential arm length control loop readout signals requires applying time domain filters, which are designed from a frequency domain model of the detector’s gravitational-wave response. The gravitational-wave response model is determined by the detector’s opto-mechanical response and the properties of its feedback control system. The measurements used to validate the model and characterize its uncertainty are derived primarily from a dedicated photon radiation pressure actuator, with cross-checks provided by optical and radio frequency references. We describe how the gravitational-wave readout signal is calibrated into equivalent gravitational-wave-induced strain and how the statistical uncertainties and systematic errors are assessed. Detector data collected over 38 calendar days, from September 12 to October 20, 2015, contain the event GW150914 and approximately 16 days of coincident data used to estimate the event false alarm probability. The calibration uncertainty is less than 10% in magnitude and 10° in phase across the relevant frequency band, 20 Hz to 1 kHz.

Limits on D0-D0 mixing and bottom particle production cross section from hadronically produced same-sign dimuon events☆

Abstract The rates for same-sign and opposite-sign dimuon events with missing energy (indicative of final-state neutrinos) have been measured in 278 GeV π − -Fe and 350 GeV proton-Fe collisions. The main source of opposite-sign events is two semi-leptonic decays of hadronically produced charm states. The same-sign events are consistent with background from pion and kaon decays. We obtain a limit of 0.044 (90% CL) on the fraction of D 0 semileptonic decays that result in the wrong-sign muon and conclude that less than 9% (90% CL) of same-sign dimuon events produced in neutrino interactions can be attributed to D 0 - D 0 mixing. The data imply δm −4 eV and δλ λ for the difference in mass and inverse lifetime of the CP eigenstates of the D 0 . Limits on diffractive bottom production cross sections in proton and pion collisions are also presented.

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}

anti pp BACKWARD ELASTIC SCATTERING FROM 0.7 TO 2.16 GeV/c.

Elastic scattering of p on p has been studied for cosθc.m. between -0.88 and -1.0 and Plab(p ) between 0.70 and 2.16 GeV/c. The momentum dependence of the cross section shows a sharp dip at 0.9 GeV/c and a broad peaking around 1.4 GeV/c. The possibility of the peak resulting from direct formation of boson resonances has been studied. Alternatively, a diffraction model agrees qualitatively with our data and other elastic data at different angles.

Forward production of charm states and prompt single muons in 278 GeV π− Fe interactions☆

Abstract The forward production of charm states in 350 GeV p-Fe interactions has been studied via the production of prompt single muons with momentum p ≳ 20 GeV/ c . The data indicate equal production of single μ + and μ − events. The observed momentum distributions can be fit with the hypothesis that D mesons are produced with an invariant cross section proportional to (1 − x F ) 5.0±0.8 exp[−(2 ± 0.3) P t ] and do not favor a large diffractive cross section predicted by intrinsic charm models. Extrapolation of the distributions to x F = 0 yields a total D D production cross section of 22.6 ± 2.1(±3.6)ωb/nucleon on the assumption of a linear A dependence and 8% average semileptonic branching ratio of charm states.

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*.

All-sky search for long-duration gravitational wave transients with LIGO

We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10 - 500 seconds in a frequency band of 40 - 1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. We also report upper limits on the source rate density per year per Mpc^3 for specific signal models. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves.