| Records |
| Author |
ATLAS Collaboration (Aad, G. et al); Alvarez Piqueras, D.; 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.; 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 flavour-changing neutral current top quark decays t -> Hq in pp collisions at root s=8 TeV with the ATLAS detector |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
12 |
Issue |
12 |
Pages |
061 - 65pp |
| Keywords |
Hadron-Hadron Scattering; Top Physics; Higgs Physics; FCNC Interactions |
| Abstract |
A search for flavour-changing neutral current decays of a top quark to an up-type quark (q = u; c) and the Standard Model Higgs boson, where the Higgs boson decays to b (b) over bar, is presented. The analysis searches for top quark pair events in which one top quark decays to W b, with the W boson decaying leptonically, and the other top quark decays to Hq. The search is based on pp collisions at root s = 8TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider and uses an integrated luminosity of 20.3 fb(-1). Data are analysed in the lepton-plus-jets final state, characterised by an isolated electron or muon and at least four jets. The search exploits the high multiplicity of b quark jets characteristic of signal events, and employs a likelihood discriminant that uses the kinematic differences between the signal and the background, which is dominated by t (t) over bar -> WbWb decays. No significant excess of events above the background expectation is found, and observed (expected) 95% CL upper limits of 0.56% (0.42%) and 0.61% (0.64%) are derived for the t -> Hc and t -> Hu branching ratios respectively. The combination of this search with other ATLAS searches in the H -> gamma gamma and H -> WW*, tau tau decay modes significantly improves the sensitivity, yielding observed (expected) 95% CL upper limits on the t -> Hc and t -> Hu branching ratios of 0.46% (0.25%) and 0.45% (0.29%) respectively. The corresponding combined observed (expected) upper limits on the vertical bar lambda(tcH)vertical bar and vertical bar lambda(tuH)vertical bar couplings are 0.13 (0.10) and 0.13 (0.10) respectively. These are the most restrictive direct bounds on t q H interactions measured so far. |
| Address |
[Jackson, P.; Lee, L.; Petridis, A.; Soni, N.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia |
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| Publisher |
Springer |
Place of Publication |
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| Language |
English |
Summary Language |
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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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Expedition |
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Conference |
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| Notes |
WOS:000366831600001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial  |
2505 |
| Permanent link to this record |
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| Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
| Title |
Search for long-lived heavy charged particles using a ring imaging Cherenkov technique at LHCb |
Type |
Journal Article |
| Year |
2015 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
75 |
Issue |
12 |
Pages |
595 - 14pp |
| Keywords |
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| Abstract |
A search is performed for heavy long-lived charged particles using 3.0 fb(-1) of proton-proton collisions collected at root s = 7 and 8 TeV with the LHCb detector. The search is mainly based on the response of the ring imaging Cherenkov detectors to distinguish the heavy, slow-moving particles from muons. No evidence is found for the production of such long-lived states. The results are expressed as limits on the Drell-Yan production of pairs of long-lived particles, with both particles in the LHCb pseudorapidity acceptance, 1.8 < eta < 4.9. The mass-dependent cross-section upper limits are in the range 2-4 fb (at 95 % CL) for masses between 14 and 309 GeV/c(2). |
| Address |
[Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Massafferri, A.; Osorio Rodrigues, B.; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil, Email: aurelio.bay@epfl.ch |
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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 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 |
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:000366629800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2504 |
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| Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
| Title |
Collins asymmetries in inclusive charged KK and K pi pairs produced in e(+)e(-) annihilation |
Type |
Journal Article |
| Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
92 |
Issue |
11 |
Pages |
111101 - 8pp |
| Keywords |
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| Abstract |
We present measurements of Collins asymmetries in the inclusive process e(+)e(-) -> h(1)h(2)X, h(1)h(2) = KK, K pi, pi pi, at the center-of-mass energy of 10.6 GeV, using a data sample of 468 fb(-1) collected by the BABAR experiment at the PEP-II B factory at SLAC National Accelerator Center. Considering hadrons in opposite thrust hemispheres of hadronic events, we observe clear azimuthal asymmetries in the ratio of unlike sign to like sign, and unlike sign to all charged h(1)h(2) pairs, which increase with hadron energies. The K pi asymmetries are similar to those measured for the pi pi pairs, whereas those measured for high-energy KK pairs are, in general, larger. |
| Address |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, CNRS IN2P3, LAPP, F-74941 Annecy Le Vieux, France |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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| Language |
English |
Summary Language |
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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 |
1550-7998 |
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:000367070900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2503 |
| Permanent link to this record |
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| Author |
de Salas, P.F.; Lattanzi, M.; Mangano, G.; Miele, G.; Pastor, S.; Pisanti, O. |
| Title |
Bounds on very low reheating scenarios after Planck |
Type |
Journal Article |
| Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
92 |
Issue |
12 |
Pages |
123534 - 9pp |
| Keywords |
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| Abstract |
We consider the case of very low reheating scenarios [T-RH similar to O(MeV)] with a better calculation of the production of the relic neutrino background (with three-flavor oscillations). At 95% confidence level, a lower bound on the reheating temperature T-RH > 4.1 MeV is obtained from big bang nucleosynthesis, while T-RH > 4.7 MeV from Planck data (allowing neutrino masses to vary), the most stringent bound on the reheating temperature to date. Neutrino masses as large as 1 eV are possible for very low reheating temperatures. |
| Address |
[de Salas, P. F.; Pastor, S.] Univ Valencia, CSIC, Inst Fis Corpuscular, Paterna 46980, Valencia, Spain, Email: lattanzi@fe.infn.it |
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Thesis |
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| Publisher |
Amer Physical Soc |
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 Volume |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
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:000367078600010 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2502 |
| Permanent link to this record |
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| Author |
Adams, D. et al; Vos, M. |
| Title |
Towards an understanding of the correlations in jet substructure |
Type |
Journal Article |
| Year |
2015 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
75 |
Issue |
9 |
Pages |
409 - 52pp |
| Keywords |
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| Abstract |
Over the past decade, a large number of jet substructure observables have been proposed in the literature, and explored at the LHC experiments. Such observables attempt to utilize the internal structure of jets in order to distinguish those initiated by quarks, gluons, or by boosted heavy objects, such as top quarks and W bosons. This report, originating from and motivated by the BOOST2013 workshop, presents original particle-level studies that aim to improve our understanding of the relationships between jet substructure observables, their complementarity, and their dependence on the underlying jet properties, particularly the jet radius and jet transverse momentum. This is explored in the context of quark/gluon discrimination, boosted W boson tagging and boosted top quark tagging. |
| Address |
[Adams, D.] Brookhaven Natl Lab, Upton, NY 11973 USA, Email: b.cooper@ucl.ac.uk |
| 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 |
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:000366305400001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2500 |
| Permanent link to this record |
