| Records |
| Author |
Barenboim, G.; Bernabeu, J.; Mitsou, V.A.; Romero Adam, E.; Vives, O. |
| Title |
METing SUSY on the Z peak |
Type |
Journal Article |
| Year |
2016 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
76 |
Issue  |
2 |
Pages |
57 - 13pp |
| Keywords |
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| Abstract |
Recently the ATLAS experiment announced a 3 sigma excess at the Z-peak consisting of 29 pairs of leptons together with two or more jets, E-T(miss) > 225 GeV and H-T > 600 GeV, to be compared with 10.6 +/- 3.2 expected lepton pairs in the Standard Model. No excess outside the Z-peak was observed. By trying to explain this signal with SUSY we find that only relatively light gluinos, m((g) over bar) less than or similar to 1.2 TeV, together with a heavy neutralino NLSP of m((chi) over bar) greater than or similar to 400 GeV decaying predominantly to Z-boson plus a light gravitino, such that nearly every gluino produces at least one Z-boson in its decay chain, could reproduce the excess. We construct an explicit general gauge mediation model able to reproduce the observed signal overcoming all the experimental limits. Needless to say, more sophisticated models could also reproduce the signal, however, any model would have to exhibit the following features: light gluinos, or heavy particles with a strong production cross section, producing at least one Z-boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are pointed out. |
| Address |
[Barenboim, G.; Bernabeu, J.; Vives, O.] Univ Valencia, Dept Fis Teor, C Dr Moliner 50, E-46100 Burjassot, Spain, Email: oscar.vives@uv.es |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1434-6044 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000375278800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
2662 |
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| Author |
ATLAS Collaboration (Aad, G. et al); Alvarez Piqueras, D.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Fernandez Martinez, P.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Jimenez Pena, J.; Kaci, M.; King, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Mitsou, V.A.; Oliver Garcia, E.; Pedraza Lopez, S.; Perez Garcia-Estañ, M.T.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Valero, A.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Vos, M. |
| Title |
Search for single top-quark production via flavour-changing neutral currents at 8TeV with the ATLAS detector |
Type |
Journal Article |
| Year |
2016 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
76 |
Issue |
2 |
Pages |
55 - 30pp |
| Keywords |
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| Abstract |
A search for single top-quark production via flavour-changing neutral current processes from gluon plus up- or charm-quark initial states in proton-proton collisions at the LHC is presented. Data collected with the ATLAS detector in 2012 at a centre-of-mass energy of 8TeV and corresponding to an integrated luminosity of 20.3 fb(-1) are used. Candidate events for a top quark decaying into a lepton, a neutrino and a jet are selected and classified into signal- and background-like candidates using a neural network. No signal is observed and an upper limit on the production cross-section multiplied by the t -> Wb branching fraction is set. The observed 95% CL limit is sigma(qg -> t) x B(t -> Wb) < 3.4 pb and the expected 95% CL limit is sigma(qg -> t) x B(t -> Wb) < 2.9 pb. The observed limit can be interpreted as upper limits on the coupling constants of the flavour-changing neutral current interactions divided by the scale of new physics kappa(ugt)/Lambda < 5.8 x 10(-3) TeV-1 and kappa(cgt)/Lambda < 13x10(-3) TeV and on the branching fractions B(t -> ug) < 4.0 x 10(-5) and B(t -> cg) < 20 x 10(-5). |
| Address |
[Aleksa, M.; Gonzalez, B. Alvarez; Anders, G.; Anghinolfi, F.; Armbruster, A. J.; Arnaez, O.; Avolio, G.; Baak, M. A.; Backes, M.; Backhaus, M.; Barak, L.; Beermann, T. A.; Beltramello, O.; Bianco, M.; Bogaerts, J. A.; Boveia, A.; Boyd, J.; Burckhart, H.; Campana, S.; Garrido, M. D. M. Capeans; Carli, T.; Carrillo-Montoya, G. D.; Catinaccio, A.; Cattai, A.; Cerv, M.; Chromek-Burckhart, D.; Conti, G.; Dell'Acqua, A.; Deviveiros, P. O.; Di Girolamo, A.; Di Girolamo, B.; Dittus, F.; Dobos, D.; Dudarev, A.; Duehrssen, M.; Eifert, T.; Ellis, N.; Elsing, M.; Farthouat, P.; Fassnacht, P.; Feigl, S.; Fernandez Perez, S.; Fiascaris, M.; Francis, D.; Froidevaux, D.; Gadatsch, S.; Gillberg, D.; Glatzer, J.; Goossens, L.; Gorini, B.; Gray, H. M.; Hawkings, R. J.; Correia, A. M. Henriques; Hervas, L.; Hoecker, A.; Huhtinen, M.; Iengo, P.; Jaekel, M. R.; Jakobsen, S.; Jenni, P.; Klioutchnikova, T.; Krasznahorkay, A.; Lapoire, C.; Lassnig, M.; Miotto, G. Lehmann; Lenzi, B.; Lichard, P.; Macina, D.; Malyukov, S.; Mandelli, B.; Mapelli, L.; Marzin, A.; Milic, A.; Mornacchi, G.; Nairz, A. M.; Nakahama, Y.; Nessi, M.; Nicquevert, B.; Nordberg, M.; Oide, H.; Palestini, S.; Pauly, T.; Pernegger, H.; Peters, K.; Petersen, B. A.; Pommes, K.; Poppleton, A.; Poulard, G.; Poveda, J.; Prasad, S.; Rammensee, M.; Raymond, M.; Rembser, C.; Ritsch, E.; Roe, S.; Ruiz-Martinez, A.; Salzburger, A.; Schaefer, D.; Schlenker, S.; Schmieden, K.; Serfon, C.; Sforza, F.; Sfyrla, A.; Solans, C. A.; Spigo, G.; Stelzer, H. J.; Teischinger, F. A.; Kate, H. Ten; Tremblet, L.; Tricoli, A.; Tsarouchas, C.; Unal, G.; van Woerden, M. C.; Vandelli, W.; Voss, R.; Vuillermet, R.; Wells, P. S.; Wengler, T.; Wenig, S.; Werner, P.; Wilkens, H. G.; Wotschack, J.; Young, C. J. S.; Zwalinski, L.; ATLAS Collaboration] CERN, CH-1211 Geneva 23, Switzerland |
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| Publisher |
Springer |
Place of Publication |
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English |
Summary Language |
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Edition |
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| ISSN |
1434-6044 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
WOS:000375277900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2663 |
| Permanent link to this record |
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| Author |
ATLAS Collaboration (Aad, G. et al); Alvarez Piqueras, D.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Fernandez Martinez, P.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Jimenez Pena, J.; Kaci, M.; King, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Mitsou, V.A.; Pedraza Lopez, S.; Perez Garcia-Estañ, M.T.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M. |
| Title |
Search for the production of single vector-like and excited quarks in the Wt final state in pp collisions at root s=8 TeV with the ATLAS detector |
Type |
Journal Article |
| Year |
2016 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
02 |
Issue |
2 |
Pages |
110 - 46pp |
| Keywords |
Exotics; Hadron-Hadron scattering |
| Abstract |
A search for vector-like quarks and excited quarks in events containing a top quark and a W boson in the final state is reported here. The search is based on 20.3 fb(-1) of proton-proton collision data taken at the LHC at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector. Events with one or two leptons, and one, two or three jets are selected with the additional requirement that at least one jet contains a b-quark. Single-lepton events are also required to contain at least one large-radius jet from the hadronic decay of a high-PT W boson or a top quark. No significant excess over the expected background is observed and upper limits on the cross-section times branching ratio for different vector-like quark and excited-quark model masses are derived. For the excited-quark production and decay to Wt with unit couplings, quarks with masses below 1500 GeV are excluded and coupling-dependent limits are set. |
| Address |
[Jackson, P.; Lee, L.; Petridis, A.; Soni, N.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000375282900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2675 |
| Permanent link to this record |
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| Author |
ATLAS Collaboration (Aad, G. et al); Alvarez Piqueras, D.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Fernandez Martinez, P.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Jimenez Pena, J.; Kaci, M.; King, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Mitsou, V.A.; Oliver Garcia, E.; Pedraza Lopez, S.; Perez Garcia-Estañ, M.T.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Valero, A.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Vos, M. |
| Title |
A search for prompt lepton-jets in pp collisions at root s=8 TeV with the ATLAS detector |
Type |
Journal Article |
| Year |
2016 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
02 |
Issue |
2 |
Pages |
062 - 51pp |
| Keywords |
Hadron-Hadron scattering |
| Abstract |
A search is presented for a new, light boson with a mass of about 1 GeV and decaying promptly to jets of collimated electrons and/or muons (lepton-jets). The analysis is performed with 20.3 fb(-1) of data collected by the ATLAS detector at the Large Hadron Collider in proton-proton collisions at a centre-of-mass energy of 8 TeV. Events are required to contain at least two lepton-jets. This study finds no statistically significant deviation from predictions of the Standard Model and places 95% confidence-level upper limits on the contribution of new phenomena beyond the SM, incuding SUSY-portal and Higgs-portal models, on the number of events with lepton-jets. |
| Address |
[Jackson, P.; Lee, L.; Petridis, A.; Soni, N.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000375272300004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2676 |
| Permanent link to this record |
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| Author |
ATLAS Collaboration (Aaboud, M. et al); Alvarez Piqueras, D.; Barranco Navarro, L.; Cabrera Urban, S.; Castillo Gimenez, V.; Cerda Alberich, L.; Costa, M.J.; Fernandez Martinez, P.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Higon-Rodriguez, E.; Jimenez Pena, J.; Lacasta, C.; Mamuzic, J.; Marti-Garcia, S.; Melini, D.; Mitsou, V.A.; Pedraza Lopez, S.; Rodriguez Rodriguez, D.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M. |
| Title |
Measurements of top-quark pair to Z-boson cross-section ratios at root s=13, 8, 7 TeV with the ATLAS detector |
Type |
Journal Article |
| Year |
2017 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
02 |
Issue |
2 |
Pages |
117 - 54pp |
| Keywords |
Hadron-Hadron scattering (experiments) |
| Abstract |
Ratios of top-quark pair to Z-boson cross sections measured from proton-proton-collisions at the LHC centre-of-mass energies of root S = 13 TeV, 8 TeV, and 7 TeV are presented by the ATLAS Collaboration. Single ratios, at a given root S for the two processes and at different root S , for each process, as well as double ratios of the two processes at different root S , are evaluated. The ratios are constructed using previously published ATLAS measurements of the t (t) over bar and Z-boson production cross sections, corrected to a common phase space where required, and a new analysis of Z -> l(+)l(-) where l = e, μat root S = 13 TeV performed with data collected in 2015 with an integrated luminosity of 3.2 fb(-1). Correlations of systematic uncertainties are taken into account when evaluating the uncertainties in the ratios. The correlation model is also used to evaluate the combined cross section of the Z -> e (+) e (-) and the Z -> μ(+) μ(-) channels for each value. The results are compared to calculations performed at next-to-next-to-leading-order accuracy using recent sets of parton distribution functions. The data demonstrate significant power to constrain the gluon distribution function for the Bjorken-x values near 0.1 and the light-quark sea for x < 0.02. |
| Address |
[Jackson, P.; Lee, L.; Petridis, A.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000395022700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3014 |
| Permanent link to this record |
