Faculty Scholarship

Showing 551 - 560 of 734 Items

Search for τ-→γμ-: A test of lepton number conservation

Date: 1993-01-01

Creator: A. Bean, J. Gronberg, R. Kutschke, S. Menary, R. J., Morrison, H. Nelson, J. Richman, H. Tajima, D. Schmidt, D. Sperka, M. Witherell, M. Procario, S. Yang, M. Daoudi, W. T. Ford, D. R. Johnson, K. Lingel, M. Lohner, P. Rankin, J. G. Smith, J. P. Alexander, C. Bebek, K. Berkelman, D. Besson, T. E. Browder, D. G. Cassel, D. M. Coffman, P. S. Drell, R. Ehrlich, R. S. Galik, M. Garcia-Sciveres

Access: Open access

A search for the lepton mumber violating decay of the τ lepton to the γμ final state has been performed with the CLEO II detector at the Cornell e+e- storage ring CESR. In a data sample that corresponds to an integrated luminosity of 1.55 fb-1, we observe no candidates in the signal region. We thus determine an upper limit of B(τ-→γμ-)<4. 2×10-6 at 90% confidence level. © 1993 The American Physical Society.


Atmospheric variability of methyl chloride during the last 300 years from an Antarctic ice core and firn air

Date: 2004-01-28

Creator: M. Aydin, E. S. Saltzman, W. J. De Bruyn, S. A. Montzka, J. H., Butler, M. Battle

Access: Open access

Measurements of methyl chloride (CH3Cl) in Antarctic polar ice and firn air are used to describe the variability of atmospheric CH3Cl during the past 300 years. Firn air results from South Pole and Siple Dome suggest that the atmospheric abundance of CH3Cl increased by about 10% in the 50 years prior to 1990. Ice core measurements from Siple Dome provide evidence for a cyclic natural variability on the order of 10%, with a period of about 110 years in phase with the 20th century rise inferred from firn air. Thus, the CH3Cl increase measured in firn air may largely be a result of natural processes, which may continue to affect the atmospheric CH3Cl burden during the 21st century. Copyright 2004 by the American Geophysical Union.


Measurement of decays involving mesons

Date: 1992-01-01

Creator: M. Artuso, M. Goldberg, N. Horwitz, R. Kennett, G. C., Moneti, F. Muheim, S. Playfer, Y. Rozen, P. Rubin, S. Stone, M. Thulasidas, W. M. Yao, G. Zhu, A. V. Barnes, J. Bartelt, S. E. Csorna, Z. Egyed, V. Jain, P. Sheldon, D. S. Akerib, B. Barish, M. Chadha, D. F. Cowen, G. Eigen, J. S. Miller, J. Urheim, A. J. Weinstein, D. Acosta, G. Masek, B. Ong, H. Paar

Access: Open access

The decay 0 has been observed for the first time using the CLEO-II detector at the Cornell Electron Storage Ring. The measured branching ratio (0.170.020.02)%, agrees with the CVC (conserved vector current) prediction based on e+e-+- data. Upper limits on the branching ratios for other decays to final states including mesons are improved by an order of magnitude compared to previous measurements. © 1992 The American Physical Society.


Observation of B0 decay to two charmless mesons

Date: 1993-01-01

Creator: M. Battle, J. Ernst, H. Kroha, Y. Kwon, S., Roberts, K. Sparks, E. H. Thorndike, C. H. Wang, J. Dominick, S. Sanghera, V. Shelkov, T. Skwarnicki, R. Stroynowski, I. Volobouev, P. Zadorozhny, M. Artuso, D. He, M. Goldberg, N. Horwitz, R. Kennett, G. C. Moneti, F. Muheim, Y. Mukhin, S. Playfer, Y. Rozen, S. Stone, M. Thulasidas, G. Vasseur, G. Zhu, J. Bartelt, S. E. Csorna

Access: Open access

We report results from a search for the decays B0→π+π-, B0→K+π-, and B0→K+K-. We find 90% confidence level upper limits on the branching fractions, Bππ<2.9×10-5, BKπ<2.6×10-5, and BKK<0.7×10-5. While there is no statistically significant signal in the individual modes, the sum of Bππ and BKπ exceeds zero with a significance of more than 4 standard deviations, indicating that we have observed charmless hadronic B decays. © 1993 The American Physical Society.


Observation of the charmed baryon c+ and measurement of the isospin mass splittings of the c

Date: 1993-01-01

Creator: G. Crawford, C. M. Daubenmier, R. Fulton, D. Fujino, K. K., Gan, K. Honscheid, H. Kagan, R. Kass, J. Lee, R. Malchow, F. Morrow, Y. Skovpen, M. Sung, C. White, J. Whitmore, P. Wilson, F. Butler, X. Fu, G. Kalbfleisch, M. Lambrecht, W. R. Ross, P. Skubic, J. Snow, P. L. Wang, M. Wood, D. Bortoletto, D. N. Brown, J. Fast, R. L. McIlwain, T. Miao, D. H. Miller

Access: Open access

We observe the c+ baryon decaying to Λc+π0 and measure the mass difference M(c+)-M(Λc+) to be 168.5±0.2 MeV/c2. We also measure the mass differences M(c++)-M(Λc+) and M(c0-M(Λc+) with improved precision and determine the isospin mass splittings M(c++)-M(c0) and M(c+)-M(c0) to be 1.1±0.4±0.1 MeV/c2 and 1.4±0.5±0.3 MeV/c2, respectively. Our results indicate that the light quark mass difference does not dominate the isospin mass splitting in c. © 1993 The American Physical Society.


Ds+ decays to + and +

Date: 1992-01-01

Creator: J. Alexander, C. Bebek, K. Berkelman, D. Besson, T. E., Browder, D. G. Cassel, E. Cheu, D. M. Coffman, P. S. Drell, R. Ehrlich, R. S. Galik, M. Garcia-Sciveres, B. Geiser, B. Gittelman, S. W. Gray, D. L. Hartill, B. K. Heltsley, K. Honscheid, J. Kandaswamy, N. Katayama, P. C. Kim, D. L. Kreinick, J. D. Lewis, G. S. Ludwig, J. Masui, J. Mevissen, N. B. Mistry, S. Nandi, C. R. Ng, E. Nordberg, C. Grady

Access: Open access

Using the CLEO II detector, we have accurately measured Ds decay branching ratios relative to the mode for the and states, for which there are conflicting claims; our results are 0.540.090.06 and 1.200.150.11, respectively. © 1992 The American Physical Society.


SU(N) group-theory constraints on color-ordered five-point amplitudes at all loop orders

Date: 2012-05-21

Creator: Alexander C. Edison, Stephen G. Naculich

Access: Open access

Color-ordered amplitudes for the scattering of n particles in the adjoint representation of SU(N) gauge theory satisfy constraints arising solely from group theory. We derive these constraints for n=.5 at all loop orders using an iterative approach. These constraints generalize well-known tree-level and one-loop group theory relations. © 2012 Elsevier B.V.


Level-rank duality of D-branes on the SU(N) group manifold

Date: 2006-04-17

Creator: Stephen G. Naculich, Howard J. Schnitzer

Access: Open access

The consequences of level-rank duality for untwisted D-branes on an SU(N) group manifold are explored. Relations are found between the charges of D-branes (which are classified by twisted K-theory) belonging to su (N)K and su (K)N theories, in the case of odd N + K. An isomorphism between the charge algebras is also demonstrated in this case. © 2006 Elsevier B.V. All rights reserved.


Wilson line approach to gravity in the high energy limit

Date: 2014-01-14

Creator: S. Melville, S. G. Naculich, H. J. Schnitzer, C. D. White

Access: Open access

We examine the high energy (Regge) limit of gravitational scattering using a Wilson line approach previously used in the context of non-Abelian gauge theories. Our aim is to clarify the nature of the Reggeization of the graviton and the interplay between this Reggeization and the so-called eikonal phase which determines the spectrum of gravitational bound states. Furthermore, we discuss finite corrections to this picture. Our results are of relevance to various supergravity theories, and also help to clarify the relationship between gauge and gravity theories. © 2014 American Physical Society.


Thermodynamics of the localized D2-D6 system

Date: 2005-05-02

Creator: Marta Gómez-Reino, Stephen G. Naculich, Howard J. Schnitzer

Access: Open access

An exact fully-localized extremal supergravity solution for N2 D2-branes and N6 D6-branes, which is dual to 3-dimensional supersymmetric SU(N2) gauge theory with N6 fundamentals, was found by Cherkis and Hashimoto. In order to consider the thermal properties of the gauge theory we present the non-extremal extension of this solution to first order in an expansion near the core of the D6-branes. We compute the Hawking temperature and the black-brane horizon area/entropy. The leading-order entropy, which is proportional to N23/2N61/2 TH2, is not corrected to first order in the expansion. This result is consistent with the analogous weak-coupling result at the correspondence point N2 ∼ N6. © 2005 Elsevier B.V. All rights reserved.