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Xie, J. J., & Oset, E. (2012). The DN, pi Sigma(c) interaction in finite volume and the Lambda(c)(2595) resonance. Eur. Phys. J. A, 48(10), 146–10pp.
Abstract: In this work the interaction of the coupled channels DN and pi Sigma(c) in an SU(4) extrapolation of the chiral unitary theory, where the Lambda(c)(2595) resonance appears as dynamically generated from that interaction, is extended to produce results in finite volume. Energy levels in the finite box are evaluated and, assuming that they would correspond to lattice results, the inverse problem of determining the phase shifts in the infinite volume from the lattice results is solved. We observe that it is possible to obtain accurate pi Sigma(c) phase shifts and the position of the Lambda(c)(2595) resonance, but it requires the explicit consideration of the two coupled channels. We also observe that some of the energy levels in the box are attached to the closed DN channel, such that their use to induce the pi Sigma(c) phase shifts via Luscher's formula leads to incorrect results.
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ATLAS Collaboration(Aad, G. et al), Amoros, G., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Escobar, C., et al. (2012). Performance of missing transverse momentum reconstruction in proton-proton collisions at root s=7 TeV with ATLAS. Eur. Phys. J. C, 72(1), 1844–35pp.
Abstract: The measurement of missing transverse momentum in the ATLAS detector, described in this paper, makes use of the full event reconstruction and a calibration based on reconstructed physics objects. The performance of the missing transverse momentum reconstruction is evaluated using data collected in pp collisions at a centre-of-mass energy of 7 TeV in 2010. Minimum bias events and events with jets of hadrons are used from data samples corresponding to an integrated luminosity of about 0.3 nb(-1) and 600 nb(-1) respectively, together with events containing a Z boson decaying to two leptons (electrons or muons) or a W boson decaying to a lepton (electron or muon) and a neutrino, from a data sample corresponding to an integrated luminosity of about 36 pb(-1). An estimate of the systematic uncertainty on the missing transverse momentum scale is presented.
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ATLAS Collaboration(Aad, G. et al), Amoros, G., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Escobar, C., et al. (2012). Performance of the ATLAS Trigger System in 2010. Eur. Phys. J. C, 72(1), 1849–61pp.
Abstract: Proton-proton collisions at root s = 7 TeV and heavy ion collisions at root(NN)-N-s = 2.76 TeV were produced by the LHC and recorded using the ATLAS experiment's trigger system in 2010. The LHC is designed with a maximum bunch crossing rate of 40 MHz and the ATLAS trigger system is designed to record approximately 200 of these per second. The trigger system selects events by rapidly identifying signatures of muon, electron, photon, tau lepton, jet, and B meson candidates, as well as using global event signatures, such as missing transverse energy. An overview of the ATLAS trigger system, the evolution of the system during 2010 and the performance of the trigger system components and selections based on the 2010 collision data are shown. A brief outline of plans for the trigger system in 2011 is presented.
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Cappiello, L., Cata, O., D'Ambrosio, G., & Gao, D. N. (2012). K+ -> pi(+) pi(0)e(+) e(-): a novel short-distance probe. Eur. Phys. J. C, 72(1), 1872–16pp.
Abstract: We study the decay K+ -> pi(+) pi(0)e(+) e(-), currently under analysis by the NA62 Collaboration at CERN. In particular, we provide a detailed analysis of the Dalitz plot for the long-distance, gamma*-mediated, contributions (Brems-strahlung, direct emission and its interference). We also examine a set of asymmetries to isolate genuine short-distance effects. While we show that charge asymmetries are not required to test short distances, they provide the best environment for its detection. This constitutes by itself a strong motivation for NA62 to study K- decays in the future. We therefore provide a detailed study of different charge asymmetries and the corresponding estimated signals. Whenever possible, we make contact with the related processes K+ -> pi(+) pi(0)gamma and K-L -> pi(+) pi(0)e(+) e(-) and discuss the advantages of K+ -> pi(+) pi(0)e(+) e(-) over them.
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Calibbi, L., Hodgkinson, R. N., Jones Perez, J., Masiero, A., & Vives, O. (2012). Flavour and collider interplay for SUSY at LHC7. Eur. Phys. J. C, 72(2), 1863–26pp.
Abstract: The current 7 TeV run of the LHC experiment shall be able to probe gluino and squark masses up to values larger than 1 TeV. Assuming that hints for SUSY are found in the jets plus missing energy channel by the end of a 5 fb(-1) run, we explore the flavour constraints on three models with a CMSSM-like spectrum: the CMSSM itself, a seesaw extension of the CMSSM, and Flavoured CMSSM. In particular, we focus on decays that might have been measured by the time the run is concluded, such as B-s -> μμand μ-> e gamma. We also analyse constraints imposed by neutral meson bounds and electric dipole moments. The interplay between collider and flavour experiments is explored through the use of three benchmark scenarios, finding the flavour feedback useful in order to determine the model parameters and to test the consistency of the different models.
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