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Author Cervantes-Cota, J.L.; de Putter, R.; Linder, E.V.
Title Induced gravity and the attractor dynamics of dark energy/dark matter Type Journal Article
Year 2010 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 12 Issue 12 Pages 019 - 20pp
Keywords modified gravity; dark energy theory
Abstract Attractor solutions that give dynamical reasons for dark energy to act like the cosmological constant, or behavior close to it, are interesting possibilities to explain cosmic acceleration. Coupling the scalar field to matter or to gravity enlarges the dynamical behavior; we consider both couplings together, which can ameliorate some problems for each individually. Such theories have also been proposed in a Higgs-like fashion to induce gravity and unify dark energy and dark matter origins. We explore restrictions on such theories due to their dynamical behavior compared to observations of the cosmic expansion. Quartic potentials in particular have viable stability properties and asymptotically approach general relativity.
Address [Cervantes-Cota, Jorge L.] Inst Nacl Invest Nucl, Dept Fis, Mexico City 11801, DF, Mexico, Email: jorge.cervantes@inin.gob.mx
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes ISI:000286930700019 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 533
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Author CDF Collaboration (Aaltonen, T. et al); Cabrera, S.
Title Search for the Production of Scalar Bottom Quarks in p(p)over-bar Collisions at root s=1.96 TeV Type Journal Article
Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 105 Issue 8 Pages 081802 - 7pp
Keywords
Abstract We report on a search for direct scalar bottom quark (sbottom) pair production in p (p) over bar collisions at root s = 1.96 TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a b quark. The study uses a collider detector at Fermilab Run II data sample corresponding to 2.65 fb(-1) of integrated luminosity. The data are in agreement with the standard model. In an R-parity conserving minimal supersymmetric scenario, and assuming that the sbottom decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits on the sbottom pair production cross section of 0.1 pb are obtained. For neutralino masses below 70 GeV/c(2), sbottom masses up to 230 GeV/c(2) are excluded at 95% confidence level.
Address [Aaltonen, T.; Mehtala, P.; Orava, R.; Osterberg, K.; Saarikko, H.; van Remortel, N.] Univ Helsinki, Dept Phys, Div High Energy Phys, FIN-00014 Helsinki, Finland
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000281071800002 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 276
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Author CDF Collaboration (Aaltonen, T. et al); Cabrera, S.
Title Studying the underlying event in Drell-Yan and high transverse momentum jet production at the Tevatron Type Journal Article
Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 82 Issue 3 Pages 034001 - 21pp
Keywords
Abstract We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles produced in association with a large transverse momentum jet (similar to 2: 2 fb(-1)) or with a Drell-Yan lepton pair (similar to 2.7 fb(-1)) in the Z-boson mass region [70 < M(pair) < 110 GeV/c(2)] as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton pair or the leading jet in each event to define regions of eta-phi space that are sensitive to the modeling of the underlying event. The data are corrected to the particle level to remove detector effects and are then compared with several QCD Monte Carlo models.
Address [Chen, Y. C.; Hou, S.; Martin, V.; Mitra, A.; Teng, P. K.; Tsai, S. -Y.; Wang, S. M.] Acad Sinica, Inst Phys, Taipei 11529, Taiwan
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes ISI:000280486500001 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 277
Permanent link to this record
 

 
Author CDF Collaboration (Aaltonen, T. et al); Cabrera, S.
Title Search for new color-octet vector particle decaying to t(t)over-bar in p(p)over-bar collisions at root s=1.96 TeV Type Journal Article
Year 2010 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 691 Issue 4 Pages 183-190
Keywords Massive gluon; Top quark
Abstract We present the result of a search for a massive color-octet vector particle, (e.g. a massive gluon) decaying to a pair of top quarks in proton-antiproton collisions with a center-of-mass energy of 1.96 TeV. This search is based on 1.9 fb(-1) of data collected using the CDF detector during Run II of the Tevatron at Fermilab. We study t (t) over bar events in the lepton + jets channel with at least one b-tagged jet. A massive gluon is characterized by its mass, decay width, and the strength of its coupling to quarks. These parameters are determined according to the observed invariant mass distribution of top quark pairs. We set limits on the massive gluon coupling strength for masses between 400 and 800 GeV/c(2) and width-to-mass ratios between 0.05 and 0.50. The coupling strength of the hypothetical massive gluon to quarks is consistent with zero within the explored parameter space.
Address [Nara, K.; Kim, S. H.; Kurata, M.; Miyake, H.; Nagai, Y.; Naganoma, J.; Nakamura, K.; Sato, K.; Shimojima, M.; Takeuchi, Y.; Tomura, T.; Ukegawa, F.] Univ Tsukuba, Tsukuba, Ibaraki 305, Japan, Email: junji@fnal.gov
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes ISI:000280328200002 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 278
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Author CDF Collaboration (Aaltonen, T. et al); Cabrera, S.
Title Measurement of W-Boson Polarization in Top-Quark Decay in p(p)over-bar Collisions at root s=1.96 TeV Type Journal Article
Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 105 Issue 4 Pages 042002 - 8pp
Keywords
Abstract We report measurements of the polarization of W bosons from top-quark decays using 2.7 fb(-1) of p (p) over bar collisions collected by the CDF II detector. Assuming a top-quark mass of 175 GeV/c(2), three measurements are performed. A simultaneous measurement of the fraction of longitudinal (f(0)) and right-handed (f(0)) W bosons yields the model- independent results f(0) =0. 88 +/- 0.11(stat) +/- 0.06(syst) and f(+) = 0.15 +/- 0.07(stat) +/- 0.06(syst) with a correlation coefficient of -0.59. A measurement of f(0) [f(+)] constraining f(+) [f(0)] to its standard model value of 0.0 [0.7] yields f(0) 0.70 + 0.07(stat) +/- 0.04(syst) [f(+) – 0.01 +/- 0.02(stat) +/- 0.05(syst)]. All these results are consistent with standard model expectations. We achieve the single most precise measurements of f(0) for both the model- independent and modeldependent determinations.
Address [Aaltonen, T.; Mehtala, P.; Orava, R.; Osterberg, K.; Saarikko, H.; Torre, S.; van Remortel, N.] Univ Helsinki, Div High Energy Phys, Dept Phys, FIN-00014 Helsinki, Finland
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes ISI:000280234400009 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 279
Permanent link to this record