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Author DELPHI Collaboration (Abdallah, J. et al); Costa, M.J.; Ferrer, A.; Fuster, J.; Garcia, C.; Oyanguren, A.; Perepelitsa, V.; Salt, J.; Tortosa, P.
Title Search for single top quark production via contact interactions at LEP2 Type Journal Article
Year 2011 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 71 Issue 2 Pages 1555 - 13pp
Keywords
Abstract Single top quark production via four-fermion contact interactions associated to flavour-changing neutral currents was searched for in data taken by the DELPHI detector at LEP2. The data were accumulated at centre-of-mass energies ranging from 189 to 209 GeV, with an integrated luminosity of 598.1 pb(-1). No evidence for a signal was found. Limits on the energy scale Lambda, were set for scalar-, vector- and tensor-like coupling scenarios.
Address [Lamsa, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA, Email: timmerma@mail.cern.ch
Corporate Author Thesis
Publisher Springer Place of Publication (down) Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes ISI:000291694100014 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 654
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Author Fomichev, A.S.; Mukha, I.; Stepantsov, S.V.; Grigorenko, L.V.; Litvinova, E.V.; Chudoba, V.; Egorova, I.A.; Golovkov, M.S.; Gorshkov, A.V.; Gorshkov, V.A.; Kaminski, G.; Krupko, S.A.; Parfenova, Y.L.; Sidorchuk, S.I.; Slepnev, R.S.; Ter-Akopian, G.M.; Wolski, R.; Zhukov, M.V.
Title Lifetime of (26)S and a limit for its 2p decay energy Type Journal Article
Year 2011 Publication International Journal of Modern Physics E Abbreviated Journal Int. J. Mod. Phys. E
Volume 20 Issue 6 Pages 1491-1508
Keywords Properties of nuclei; nuclear energy
Abstract The unknown isotope (26)S, expected to decay by two-proton (2p) emission, was studied theoretically and searched experimentally. The structure of this nucleus was examined within the relativistic mean field (RMF) approach. A method for taking into account the many-body structure in the three-body decay calculations was developed. The results of the RMF calculations were used as an input for the three-cluster decay model optimized for the study of a possible 2p decay branch of this nucleus. The experimental search for (26)S was performed by fragmentation of a 50.3 A MeV (32)S beam. No events of a particles table (26)S or (25)P (a presumably proton-unstable subsystem of (26)S) were observed. Based on the obtained production systematics, an upper half-life limit of T(1/2) < 79 ns was established from the time-of-flight through the fragment separator. Together with the theoretical lifetime estimates for two-proton decay, this gives a decay energy limit of Q(2p) > 640 keV for (26)S. Analogous limits for (25)P are found as T(1/2) < 38 ns and Q(p) > 110 keV. In the case that the one-proton emission is the main branch of the (26)S decay, a limit Q(2p) > 230 keV would follow for this nucleus. According to these limits, it is likely that (26)S resides in the picosecond life time range
Address [Fomichev, AS; Stepantsov, SV; Grigorenko, LV; Chudoba, V; Golovkov, MS; Gorshkov, AV; Gorshkov, VA; Kaminski, G; Krupko, SA; Parfenova, YL; Sidorchuk, SI; Slepnev, RS; Ter-Akopian, GM; Wolski, R] JINR, Flerov Lab Nucl React, RU-141980 Dubna, Russia, Email: fomichev@jinr.ru
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication (down) Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0218-3013 ISBN Medium
Area Expedition Conference
Notes WOS:000292644900010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 693
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Author DELPHI Collaboration (Abdallah, J. et al); Costa, M.J.; Ferrer, A.; Fuster, J.; Garcia, C.; Oyanguren, A.; Perepelitsa, V.; Salt, J.; Tortosa, P.
Title A study of the b-quark fragmentation function with the DELPHI detector at LEP I and an averaged distribution obtained at the Z Pole Type Journal Article
Year 2011 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 71 Issue 2 Pages 1557 - 29pp
Keywords
Abstract The nature of b-quark jet hadronisation has been investigated using data taken at the Z peak by the DELPHI detector at LEP. Two complementary methods are used to reconstruct the energy of weakly decaying b-hadrons, E-B(weak). The average value of x(B)(weak) = E-B(weak)/E-beam is measured to be 0.699 +/- 0.011. The resulting x(B)(weak) distribution is then analysed in the framework of two choices for the perturbative contribution (parton shower and Next to Leading Log QCD calculation) in order to extract measurements of the non-perturbative contribution to be used in studies of b-hadron production in other experimental environments than LEP. In the parton shower framework, data favour the Lund model ansatz and corresponding values of its parameters have been determined within PYTHIA 6.156 from DELPHI data: a = 1.84(-0.21)(+0.23) and b = 0.642(-0.063)(+0.073) GeV-2, with a correlation factor rho = 92.2%. Combining the data on the b-quark fragmentation distributions with those obtained at the Z peak by ALEPH, OPAL and SLD, the average value of x(B)(weak) is found to be 0.7092 +/- 0.0025 and the non-perturbative fragmentation component is extracted. Using the combined distribution, a better determination of the Lund parameters is also obtained: a = 1.48(-0.10)(+0.11) and b = 0.509(-0.023)(+0.024) GeV-2, with a correlation factor rho = 92.6%.
Address [Lamsa, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA, Email: timmerma@mail.cern.ch
Corporate Author Thesis
Publisher Springer Place of Publication (down) Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes ISI:000291694100016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 655
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Author ATLAS Collaboration (Aad, G. et al); Amoros, G.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Ferrer, A.; Fuster, J.; Garcia, C.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Kaci, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Miñano, M.; Mitsou, V.A.; Moles-Valls, R.; Moreno Llacer, M.; Oliver Garcia, E.; Perez Garcia-Estañ, M.T.; Ros, E.; Salt, J.; Solans, C.A.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M.; Wildauer, A.
Title Search for a Heavy Particle Decaying into an Electron and a Muon with the ATLAS Detector in sqrt(s)=7 TeV pp collisions at the LHC Type Journal Article
Year 2011 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 106 Issue 25 Pages 251801 - 18pp
Keywords
Abstract This Letter presents the first search for a heavy particle decaying into an e(+/-)mu(-/+) final state in root s = 7 TeV pp collisions at the LHC. The data were recorded by the ATLAS detector during 2010 and correspond to a total integrated luminosity of 35 pb(-1). No excess above the standard model background expectation is observed. Exclusions at 95% confidence level are placed on two representative models. In an R-parity violating supersymmetric model, tau sneutrinos with a mass below 0.75 TeV are excluded, assuming all R-parity violating couplings are zero except lambda(311)' = 0.11 and lambda(312) = 0.07. In a lepton flavor violating model, a Z'-like vector boson with masses of 0.70-1.00 TeV and corresponding cross sections times branching ratios of 0.175-0.183 pb is excluded. These results extend to higher mass R-parity violating sneutrinos and lepton flavor violating Z's than previous constraints from the Tevatron.
Address [Aad, G.; Ahles, F.; Beckingham, M.; Bernhard, R.; Bitenc, U.; Bruneliere, R.; Caron, S.; Carpentieri, C.; Christov, A.; Dahlhoff, A.; Dietrich, J.; Eckert, S.; Fehling-Kaschek, M.; Flechl, M.; Glatzer, J.; Guler, H.; Hartert, J.; Heldmann, M.; Herten, G.; Horner, S.; Jakobs, K.; Ketterer, C.; Kollefrath, M.; Kononov, A. I.; Kuehn, S.; Lai, S.; Landgraf, U.; Lohwasser, K.; Ludwig, I.; Ludwig, J.; Lumb, D.; Mahboubi, K.; Meinhardt, J.; Mohr, W.; Nilsen, H.; Parzefall, U.; Bueso, X. Portell; Rammensee, M.; Runge, K.; Rurikova, Z.; Schmidt, E.; Schumacher, M.; Siegert, F.; Stoerig, K.; Sundermann, J. E.; Temming, K. K.; Thoma, S.; Tobias, J.; Tsiskaridze, V.; Venturi, M.; Vivarelli, I.; von Radziewski, H.; Warsinsky, M.; Weiser, C.; Werner, M.; Wiik, L. A. M.; Winkelmann, S.; Xie, S.; Zimmermann, S.] Univ Freiburg, Fak Math & Phys, Freiburg, Germany
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication (down) 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:000291942400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 659
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Author Giusarma, E.; Corsi, M.; Archidiacono, M.; de Putter, R.; Melchiorri, A.; Mena, O.; Pandolfi, S.
Title Constraints on massive sterile neutrino species from current and future cosmological data Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 83 Issue 11 Pages 115023 - 10pp
Keywords
Abstract Sterile massive neutrinos are a natural extension of the standard model of elementary particles. The energy density of the extra sterile massive states affects cosmological measurements in an analogous way to that of active neutrino species. We perform here an analysis of current cosmological data and derive bounds on the masses of the active and the sterile neutrino states, as well as on the number of sterile states. The so-called (3 + 2) models, with three sub-eV active massive neutrinos plus two sub-eV massive sterile species, is well within the 95% CL allowed regions when considering cosmological data only. If the two extra sterile states have thermal abundances at decoupling, big bang nucleosynthesis bounds compromise the viability of (3 + 2) models. Forecasts from future cosmological data on the active and sterile neutrino parameters are also presented. Independent measurements of the neutrino mass from tritium beta-decay experiments and of the Hubble constant could shed light on sub-eV massive sterile neutrino scenarios.
Address [Giusarma, Elena; de Putter, Roland; Mena, Olga] Univ Valencia, CSIC, IFIC, Valencia 46071, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication (down) 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:000292039800003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 660
Permanent link to this record
 

 
Author BABAR Collaboration (Lees, J.P. et al); Lopez-March, N.; Martinez-Vidal, F.; Oyanguren, A.
Title Amplitude analysis of B0 -> K+ pi- pi0 and evidence of direct CP violation in B -> K * pi decays Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 83 Issue 11 Pages 112010 - 21pp
Keywords
Abstract We analyze the decay B-0 -> K+ pi(-) pi(0) with a sample of 4.54 x 10(8) B (B) over bar events collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, and extract the complex amplitudes of seven interfering resonances over the Dalitz plot. These results are combined with amplitudes measured in B-0 -> K-S(0)pi(+)pi(-) decays to construct isospin amplitudes from B-0 -> K* pi and B-0 -> rho K decays. We measure the phase of the isospin amplitude Phi(3/2), useful in constraining the Cabibbo-Kobayashi-Maskawa unitarity triangle angle gamma and evaluate a CP rate asymmetry sum rule sensitive to the presence of new physics operators. We measure direct CP violation in B-0 -> K*(+) pi(-) decays at the level of 3 sigma when measurements from both B-0 -> K+ pi(-) pi(0) and B-0 -> K-S(0) pi(+) pi(-) decays are combined.
Address [Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.] Univ Savoie, CNRS IN2P3, Lab Annecy Le Vieux Phys Particules LAPP, F-74941 Annecy Le Vieux, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication (down) 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:000292240300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 661
Permanent link to this record
 

 
Author ATLAS Collaboration (Aad, G. et al); Amoros, G.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Ferrer, A.; Fuster, J.; Garcia, C.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Kaci, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Miñano, M.; Mitsou, V.A.; Moles-Valls, R.; Moreno Llacer, M.; Oliver Garcia, E.; Perez Garcia-Estañ, M.T.; Ros, E.; Salt, J.; Solans, C.A.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M.; Wildauer, A.
Title Luminosity determination in pp collisions at sqrt(s)=7 TeV using the ATLAS detector at the LHC Type Journal Article
Year 2011 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 71 Issue 4 Pages 1630 - 37pp
Keywords
Abstract Measurements of luminosity obtained using the ATLAS detector during early running of the Large Hadron Collider (LHC) at root s = 7 TeV are presented. The luminosity is independently determined using several detectors and multiple algorithms, each having different acceptances, systematic uncertainties and sensitivity to background. The ratios of the luminosities obtained from these methods are monitored as a function of time and of mu, the average number of inelastic interactions per bunch crossing. Residual time- and mu-dependence between the methods is less than 2% for 0 < μ< 2.5. Absolute luminosity calibrations, performed using beam separation scans, have a common systematic uncertainty of +/- 11%, dominated by the measurement of the LHC beam currents. After calibration, the luminosities obtained from the different methods differ by at most +/- 2%. The visible cross sections measured using the beam scans are compared to predictions obtained with the PYTHIA and PHOJET event generators and the ATLAS detector simulation.
Address [Aad, G.; Ahles, F.; Beckingham, M.; Bernhard, R.; Bitenc, U.; Bruneliere, R.; Caron, S.; Carpentieri, C.; Christov, A.; Dahlhoff, A.; Dietrich, J.; Eckert, S.; Fehling-Kaschek, M.; Flechl, M.; Glatzer, J.; Hartert, J.; Heldmann, M.; Herten, G.; Horner, S.; Jakobs, K.; Ketterer, C.; Koenig, S.; Kollefrath, M.; Kononov, A. I.; Kuehn, S.; Lai, S.; Landgraf, U.; Lohwasser, K.; Ludwig, I.; Ludwig, J.; Lumb, D.; Maassen, M.; Mahboubi, K.; Meinhardt, J.; Mohr, W.; Nilsen, H.; Parzefall, U.; Bueso, X. Portell; Rammensee, M.; Runge, K.; Rurikova, Z.; Schmidt, E.; Schumacher, M.; Siegert, F.; Stoerig, K.; Sundermann, J. E.; Temming, K. K.; Thoma, S.; Tobias, J.; Tsiskaridze, V.; Venturi, M.; Vivarelli, I.; von Radziewski, H.; Warsinsky, M.; Weiser, C.; Werner, M.; Wiik, L. A. M.; Winkelmann, S.; Xie, S.; Zimmermann, S.] Univ Freiburg, Fak Math & Phys, D-79104 Freiburg, Germany, Email: atlas.secretariat@cern.ch
Corporate Author Thesis
Publisher Springer Place of Publication (down) Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes ISI:000291698800013 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 656
Permanent link to this record
 

 
Author Courtoy, A.; Scopetta, S.; Vento, V.
Title Non-perturbative momentum dependence of the coupling constant and hadronic models Type Journal Article
Year 2011 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 47 Issue 4 Pages 49 - 7pp
Keywords
Abstract Models of hadron structure are associated with a hadronic scale which allows by perturbative evolution to calculate observables in the deep inelastic region. The resolution of Dyson-Schwinger equations leads to the freezing of the QCD running coupling (effective charge) in the infrared, which is best understood as a dynamical generation of a gluon mass function, giving rise to a momentum dependence which is free from infrared divergences. We use this new development to understand why perturbative treatments are working reasonably well despite the smallness of the hadronic scale.
Address [Courtoy, A.] Ist Nazl Fis Nucl, Sez Pavia, I-27100 Pavia, Italy, Email: Aurore.Courtoy@pv.infn.it
Corporate Author Thesis
Publisher Springer Place of Publication (down) Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes ISI:000291659500003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 657
Permanent link to this record
 

 
Author HADES Collaboration (Agakishiev, G. et al); Diaz, J.; Gil, A.
Title pp and pi pi intensity interferometry in collisions of Ar+KCl at 1.76A GeV Type Journal Article
Year 2011 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 47 Issue 5 Pages 63 - 8pp
Keywords
Abstract Results on pp, pi(+) pi(+), and pi-pi-intensity interferometry are reported for collisions of Ar+KCl at 1.76A GeV beam energy, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. The experimental correlation functions as a function of the relative momentum are compared to model calculations allowing the determination of the space-time extent of the corresponding emission sources. The pp source radii are found significantly larger than the pp emission radius. The present radii do well complement the beam-energy dependences of Gaussian source radii of the collision system of size A + A similar or equal to 40 + 40. The pp source radius at fixed beam energy is found to increase linearly with the cube root of the number of participants. From this trend, a lower limit of the pp correlation radius is deduced.
Address [Finocchiaro, P.] Ist Nazl Fis Nucl, Lab Nazl Sud, I-95125 Catania, Italy, Email: kotte@fzd.de
Corporate Author Thesis
Publisher Springer Place of Publication (down) Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes ISI:000291659900005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 658
Permanent link to this record
 

 
Author de Azcarraga, J.A.; Kamimura, K.; Lukierski, J.
Title Generalized cosmological term from Maxwell symmetries Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 83 Issue 12 Pages 124036 - 8pp
Keywords
Abstract By gauging the Maxwell spacetime algebra, the standard geometric framework of Einstein gravity with cosmological constant term is extended by adding six four-vector fields A(mu)(ab)(x) associated with the six Abelian tensorial charges in the Maxwell algebra. In the simplest Maxwell extension of Einstein gravity this leads to a generalized cosmological term that includes a contribution from these vector fields. We also consider going beyond the basic gravitational model by means of bilinear actions for the new Abelian gauge fields. Finally, an analogy with the supersymmetric generalization of gravity is indicated. In an appendix, we propose an equivalent description of the model in terms of a shift of the standard spin connection by the A(mu)(ab)(x) fields.
Address [de Azcarrraga, Jose A.] Univ Valencia, Dept Theoret Phys, E-46100 Burjassot, Valencia, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication (down) 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:000291936200003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 662
Permanent link to this record