|
ATLAS Collaboration(Aad, G. et al), Amoros, G., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Escobar, C., et al. (2011). Study of jet shapes in inclusive jet production in pp collisions at sqrt(s)=7 TeV using the ATLAS detector. Phys. Rev. D, 83(5), 052003–29pp.
Abstract: Jet shapes have been measured in inclusive jet production in proton-proton collisions at root s = 7 TeV using 3 pb(-1) of data recorded by the ATLAS experiment at the LHC. Jets are reconstructed using the anti-k(t) algorithm with transverse momentum 30 GeV < p(T) < 600 GeV and rapidity in the region vertical bar y vertical bar < 2.8. The data are corrected for detector effects and compared to several leading-order QCD matrix elements plus parton shower Monte Carlo predictions, including different sets of parameters tuned to model fragmentation processes and underlying event contributions in the final state. The measured jets become narrower with increasing jet transverse momentum and the jet shapes present a moderate jet rapidity dependence. Within QCD, the data test a variety of perturbative and nonperturbative effects. In particular, the data show sensitivity to the details of the parton shower, fragmentation, and underlying event models in the Monte Carlo generators. For an appropriate choice of the parameters used in these models, the data are well described.
|
|
|
n_TOF Collaboration(Lederer, C. et al), Domingo-Pardo, C., & Tain, J. L. (2011). Au-197(n,gamma) cross section in the unresolved resonance region. Phys. Rev. C, 83(3), 034608–11pp.
Abstract: The cross section of the reaction Au-197(n,gamma) was measured with the time-of-flight technique at the n_TOF (neutron time-of-flight) facility in the unresolved resonance region between 5 and 400 keV using a pair of C6D6 (where D denotes H-2) liquid scintillators for the detection of prompt capture gamma rays. The results with a total uncertainty of 3.9%-6.7% for a resolution of 20 bins per energy decade show fair agreement with the Evaluated Nuclear Data File Version B-VII.0 (ENDF/B-VII.0), which contains the standard evaluation. The Maxwellian-averaged cross section (MACS) at 30 keV is in excellent agreement with the one according to the ENDF/B-VII.0 evaluation and 4.7% higher than the MACS measured independently by activation technique. Structures in the cross section, which had also been reported earlier, have been interpreted as being due to clusters of resonances.
|
|
|
Sun, B. X., Garzon, E. J., & Oset, E. (2010). Radiative decay into gamma-baryon of dynamically generated resonances from the vector-baryon interaction. Phys. Rev. D, 82(3), 034028–11pp.
Abstract: We study the radiative decay into gamma and a baryon of the SU(3) octet and decuplet of nine and ten resonances that are dynamically generated from the interaction of vector mesons with baryons of the octet and the decuplet, respectively. We obtain quite different partial decay widths for the various resonances, and for different charge states of the same resonance, suggesting that the experimental investigation of these radiative decays should bring much information on the nature of these resonances. For the case of baryons of the octet we determine the helicity amplitudes and compare them with experimental data when available.
|
|
|
CDF Collaboration(Aaltonen, T. et al), & Cabrera, S. (2010). Search for anomalous production of events with two photons and additional energetic objects at CDF. Phys. Rev. D, 82(5), 052005–27pp.
Abstract: We present results of a search for anomalous production of two photons together with an electron, muon, tau lepton, missing transverse energy, or jets using p (p) over bar collision data from 1.1-2.0 fb(-1) of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs of new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis
|
|
|
ATLAS Collaboration(Aad, G. et al), Amoros, G., Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Escobar, C., et al. (2011). Measurement of inclusive jet and dijet cross sections in proton-proton collisions at 7 TeV centre-of-mass energy with the ATLAS detector. Eur. Phys. J. C, 71(2), 1512–59pp.
Abstract: Jet cross sections have been measured for the first time in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector. The measurement uses an integrated luminosity of 17 nb(-1) recorded at the Large Hadron Collider. The anti-k(t) algorithm is used to identify jets, with two jet resolution parameters, R = 0.4 and 0.6. The dominant uncertainty comes from the jet energy scale, which is determined to within 7% for central jets above 60 GeV transverse momentum. Inclusive single-jet differential cross sections are presented as functions of jet transverse momentum and rapidity. Dijet cross sections are presented as functions of dijet mass and the angular variable chi. The results are compared to expectations based on next-to-leading-order QCD, which agree with the data, providing a validation of the theory in a new kinematic regime.
|
|