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Author Belver, D.; Blanco, A.; Cabanelas, P.; Diaz, J.; Fonte, P.; Garzon, J.A.; Gil, A.; Gonzalez-Diaz, D.; Koenig, W.; Kolb, B.; Kornakov, G.; Lopes, L.; Palka, M.; Pereira, A.; Traxler, M.; Zumbruch, P. doi  openurl
  Title Analysis of the space-time microstructure of cosmic ray air showers using the HADES RPC TOF wall Type Journal Article
  Year 2012 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.  
  Volume 7 Issue Pages P10007 - 9pp  
  Keywords Resistive-plate chambers; Timing detectors; Data analysis; Particle detectors  
  Abstract Cosmic rays have been studied, since they were discovered one century ago, with a very broad spectrum of detectors and techniques. However, never the properties of the extended air showers (EAS) induced by high energy primary cosmic rays had been analysed at the Earth surface with a high granularity detector and a time resolution at the 0.1 ns scale. The commissioning of the timing RPC (Resistive Plate Chambers) time of flight wall of the HADES spectrometer with cosmic rays, at the GSI (Darmstadt, Germany), opened up that opportunity. During the last months of 2009, more than 500 millions of cosmic ray events were recorded by a stack of two RPC modules, of about 1.25 m(2) each, able to measure swarms of up to similar to 100 particles with a time resolution better than 100 ps. In this document it is demonstrated how such a relative small two-plane, high-granularity timing RPC setup may provide significant information about the properties of the shower and hence about the primary cosmic ray properties.  
  Address [Belver, D.; Cabanelas, P.; Garzon, J. A.; Kornakov, G.] USC, LabCAF, Santiago De Compostela, Spain, Email: georgui.kornakov@usc.es  
  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 1748-0221 ISBN Medium  
  Area Expedition Conference  
  Notes (up) WOS:000310834800017 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1277  
Permanent link to this record
 

 
Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S. url  doi
openurl 
  Title Antennas for the detection of radio emission pulses from cosmic-ray induced air showers at the Pierre Auger Observatory Type Journal Article
  Year 2012 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.  
  Volume 7 Issue Pages P10011 - 49pp  
  Keywords Large detector systems for particle and astroparticle physics; Antennas  
  Abstract The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal.  
  Address [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Diogo, F.; Espadanal, J.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] Univ Tecn Lisboa, LIP, Lisbon, Portugal  
  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 1748-0221 ISBN Medium  
  Area Expedition Conference  
  Notes (up) WOS:000310834800021 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1276  
Permanent link to this record
 

 
Author BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. url  doi
openurl 
  Title Search for resonances decaying to eta(c)pi(+) pi(-) in two-photon interactions Type Journal Article
  Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 86 Issue 9 Pages 092005 - 10pp  
  Keywords  
  Abstract We report a study of the process gamma gamma -> X -> eta(c)pi(+)pi(-) , where X stands for one of the resonances chi(c2)(1P), eta(c)(2S), X(3872), X(3915), or chi(c2)(2P). The analysis is performed with a data sample of 473.9 fb(-1) collected with the BABAR detector at the PEP-II asymmetric-energy electron-positron collider. We do not observe a significant signal for any channel, and calculate 90% confidence-level upper limits on the products of branching fractions and two-photon widths Gamma B-x ->gamma gamma(X -> eta(c)pi(+) pi(-)): 15.7 eV for chi(c2)(1P), 133 eV for eta(c)(2S), 11.1 eV for X(3872) (assuming it to be a spin-2 state), 16 eV for X(3915) (assuming it to be a spin-2 state), and 18 eV for chi(c2)(2P). We also report upprt limits on the rations of branching fractions B(eta(c)(2S) -> eta(c)pi(+) pi(-))/B(eta(c)(2S) -> (KSK+)-K-0 pi(-)) < 10.0 and B(chi(c2)(1P) -> eta(c)pi(+) pi(-))/B(chi(c2)(1P) -> (KSK+)-K-0 pi(-)) < 32.9 at the 90% confidence level.  
  Address [Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, Lab Annecy le Vieux Phys Particules LAAP, CNRS, IN2P3, F-74941 Annecy Le Vieux, France  
  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 (up) WOS:000310845200002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1225  
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Author Hoang, A.H.; Ruiz-Femenia, P.; Stahlhofen, M. url  doi
openurl 
  Title Renormalization group improved bottom mass from (gamma) sum rules at NNLL order Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 10 Issue 10 Pages 188 - 30pp  
  Keywords Heavy Quark Physics; Sum Rules; QCD  
  Abstract We determine the bottom quark mass from non-relativistic large-n gamma sum rules with renormalization group improvement at next-to-next-to-leading logarithmic order. We compute the theoretical moments within the vNRQCD formalism and account for the summation of powers of the Coulomb singularities as well as of logarithmic terms proportional to powers of alpha(s) ln(n). The renormalization group improvement leads to a substantial stabilization of the theoretical moments compared to previous fixed-order analyses, which did not account for the systematic treatment of the logarithmic alpha(s) ln(n) terms, and allows for reliable single moment fits. For the current world average of the strong coupling (alpha(s) (M-Z) = 0.1183 +/- 0.0010) we obtain M-b(1S) = 4.755 +/- 0.057(pert) +/- 0.009 alpha(s) +/- 0.003(exp) GeV for the bottom 1S mass and (m) over bar (b) ((m) over bar (b)) = 4.235 +/- 0.055(pert) +/- 0.003(exp) GeV for the bottom (MS) over bar mass, where we have quoted the perturbative error and the uncertainties from the strong coupling and the experimental data.  
  Address [Hoang, Andre H.; Ruiz-Femenia, Pedro; Stahlhofen, Maximilian] Univ Vienna, Fac Phys, A-1090 Vienna, Austria, Email: Andre.Hoang@univie.ac.at;  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes (up) WOS:000310851300011 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1231  
Permanent link to this record
 

 
Author Bordes, J.; Dominguez, C.A.; Moodley, P.; Peñarrocha, J.; Schilcher, K. url  doi
openurl 
  Title Corrections to the SU(3) x SU(3) Gell-Mann-Oakes-Renner relation and chiral couplings L-8(r) and H-r(2) Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 10 Issue 10 Pages 102 - 11pp  
  Keywords Sum Rules; QCD  
  Abstract Next to leading order corrections to the SU(3) x SU(3) Gell-Mann-OakesRenner relation (GMOR) are obtained using weighted QCD Finite Energy Sum Rules (FESR) involving the pseudoscalar current correlator. Two types of integration kernels in the FESR are used to suppress the contribution of the kaon radial excitations to the hadronic spectral function, one with local and the other with global constraints. The result for the pseudoscalar current correlator at zero momentum is psi(5)(0) = (2.8 +/- 0.3) x 10(-3) GeV4, leading to the chiral corrections to GMOR: delta(K) = (55 +/- 5)%. The resulting uncertainties are mostly due to variations in the upper limit of integration in the FESR, within the stability regions, and to a much lesser extent due to the uncertainties in the strong coupling and the strange quark mass. Higher order quark mass corrections, vacuum condensates, and the hadronic resonance sector play a negligible role in this determination. These results confirm an independent determination from chiral perturbation theory giving also very large corrections, i.e. roughly an order of magnitude larger than the corresponding corrections in chiral SU(2) x SU(2). Combining these results with our previous determination of the corrections to GMOR in chiral SU(2) x SU(2), delta(pi), we are able to determine two low energy constants of chiral perturbation theory, i.e. L-8(r) = (1.0 +/- 0.3) x 10(-3), and H-2(r) = -(4.7 +/- 0.6) x 10(-3), both at the scale of the rho-meson mass.  
  Address [Bordes, J.; Penarrocha, J.] Univ Valencia, Dept Fis Teor, Valencia, Spain, Email: Jose.M.Bordes@uv.es;  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes (up) WOS:000310851600031 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1257  
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