| Records |
| Author |
NA62 Collaboration (Cortina Gil, E. et al); Husek, T. |
| Title |
Search for production of an invisible dark photon in (0) decays |
Type |
Journal Article |
| Year |
2019 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
05 |
Issue |
5 |
Pages |
182 - 20pp |
| Keywords |
Beyond Standard Model; Exotics; Fixed target experiments; Rare decay |
| Abstract |
The results of a search for (0) decays to a photon and an invisible massive dark photon at the NA62 experiment at the CERN SPS are reported. From a total of 4.12 x 10(8) tagged (0) mesons, no signal is observed. Assuming a kinetic-mixing interaction, limits are set on the dark photon coupling to the ordinary photon as a function of the dark photon mass, improving on previous searches in the mass range 60-110 MeV/c(2). The present results are interpreted in terms of an upper limit of the branching ratio of the electro-weak decay 0improving the current limit by more than three orders of magnitude. |
| Address |
[Gil, E. Cortina; Kleimenova, A.; Minucci, E.; Padolski, S.; Petrov, P.; Shaikhiev, A.; Volpe, R.] Catholic Univ Louvain, Louvain, Belgium, Email: tommaso.spadaro@cern.ch; |
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| Publisher |
Springer |
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English |
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| ISSN |
1029-8479 |
ISBN |
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Expedition |
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Conference |
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| Notes |
WOS:000469459200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration  |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4028 |
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| Author |
ATLAS Collaboration (Aaboud, M. et al); Alvarez Piqueras, D.; Aparisi Pozo, J.A.; Bailey, A.J.; Barranco Navarro, L.; Cabrera Urban, S.; Castillo, F.L.; Castillo Gimenez, V.; Cerda Alberich, L.; Costa, M.J.; Escobar, C.; Estrada Pastor, O.; Ferrer, A.; Fiorini, L.; Fullana Torregrosa, E.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Higon-Rodriguez, E.; Jimenez Pena, J.; Lacasta, C.; Lozano Bahilo, J.J.; Madaffari, D.; Mamuzic, J.; Marti-Garcia, S.; Melini, D.; Miñano, M.; Mitsou, V.A.; Rodriguez Bosca, S.; Rodriguez Rodriguez, D.; Ruiz-Martinez, A.; Salt, J.; Santra, A.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M. |
| Title |
Search for top-quark decays t -> Hq with 36 fb(-1) of pp collision data at root s=13 TeV with the ATLAS detector |
Type |
Journal Article |
| Year |
2019 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
05 |
Issue |
5 |
Pages |
123 - 67pp |
| Keywords |
Hadron-Hadron scattering (experiments); Rare decay; Top physics |
| Abstract |
A search for flavour-changing neutral current decays of a top quark into an up-type quark (q = u, c) and the Standard Model Higgs boson, t Hq, is presented. The search is based on a dataset of pp collisions at = 13 TeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider and corresponding to an integrated luminosity of 36.1 fb(-1). Two complementary analyses are performed to search for top-quark pair events in which one top quark decays into Wb and the other top quark decays into Hq, and target the Hbb and H (+-) decay modes, respectively. The high multiplicity of b-quark jets, or the presence of hadronically decaying -leptons, is exploited in the two analyses respectively. Multivariate techniques are used to separate the signal from the background, which is dominated by top-quark pair production. No significant excess of events above the background expectation is found, and 95% CL upper limits on the t Hq branching ratios are derived. The combination of these searches with ATLAS searches in diphoton and multilepton final states yields observed (expected) 95% CL upper limits on the t Hc and t Hu branching ratios of 1.1 x 10(-3) (8.3 x 10(-4)) and 1.2 x 10(-3) (8.3 x 10(-4)), respectively. The corresponding combined observed (expected) upper limits on the |(tcH)| and |(tuH)| couplings are 0.064 (0.055) and 0.066 (0.055), respectively. |
| Address |
[Banerjee, S.; Dang, N. P.; Duvnjak, D.; Jackson, P.; Oliver, J. L.; Petridis, A.; Qureshi, A.; Sharma, A. S.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia |
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Springer |
Place of Publication |
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English |
Summary Language |
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Original Title |
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Abbreviated Series Title |
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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:000468948900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4033 |
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| Author |
NEXT Collaboration (Fernandes, A.F.M. et al); Alvarez, V.; Benlloch-Rodriguez, J.M.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Herrero, P.; Kekic, M.; Lopez-March, N.; Martinez-Lema, G.; Muñoz Vidal, J.; Novella, P.; Palmeiro, B.; Querol, M.; Renner, J.; Romo-Luque, C.; Sorel, M.; Uson, A.; Yahlali, N. |
| Title |
Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield |
Type |
Journal Article |
| Year |
2020 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
034 - 18pp |
| Keywords |
Particle correlations and fluctuations; Photon production; Dark Matter and Double Beta Decay (experiments); Rare decay |
| Abstract |
High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe-He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by similar to 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures. |
| Address |
[Hauptman, J.] Iowa State Univ, Dept Phys & Astron, 12 Phys Hall, Ames, IA 50011 USA, Email: cristinam@uc.pt |
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Springer |
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English |
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1029-8479 |
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Expedition |
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Conference |
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| Notes |
WOS:000525257400001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4366 |
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| Author |
LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C. |
| Title |
Test of lepton universality with Lambda(0)(b) -> pK(-) l(+)l(-) |
Type |
Journal Article |
| Year |
2020 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
05 |
Issue |
5 |
Pages |
40 - 27pp |
| Keywords |
B physics; Branching fraction; Flavour Changing Neutral Currents; Hadron; Hadron scattering (experiments); Rare decay |
| Abstract |
The ratio of branching fractions of the decays -> pK(-)mu(+)mu(-),RpK-1}, is measured for the first time using proton-proton collision data corresponding to an integrated luminosity of 4.7 fb(-1) recorded with the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV. In the dilepton mass-squared range 0.1 < q(2)< 6.0 GeV2/c(4) and the pK(-) mass range m(pK(-)) < 2600 MeV/c(2), the ratio of branching fractions is measured to be RpK-1=1.17-0.16+0.18 +/- 0.0$$ {R}{pK}<^>{-1}={1.17}{-0.16}<^>{+0.18}\pm 0.07 $$\end{document}, where the first uncertainty is statistical and the second systematic. This is the first test of lepton universality with b baryons and the first observation of the decay -> pK(-)e(+)e(-). |
| Address |
[Bediaga, I; Cruz Torres, M.; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Erri, A. Massa; Soares Lavra, L.; Torres Machado, D.] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil, Email: vitalii.lisovskyi@cern.ch |
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Springer |
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English |
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1029-8479 |
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Conference |
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| Notes |
WOS:000534629900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4415 |
| Permanent link to this record |
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| Author |
LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C. |
| Title |
Search for the lepton flavour violating decay B+ -> K+mu(-)tau(+) using Bs20 decays |
Type |
Journal Article |
| Year |
2020 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
06 |
Issue |
6 |
Pages |
129 - 19pp |
| Keywords |
B physics; Beyond Standard Model; Flavor physics; Hadron-Hadron scattering (experiments); Rare decay |
| Abstract |
A search is presented for the lepton flavour violating decay B+ -> K+mu (-)tau (+) using a sample of proton-proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9 fb(-1). The tau leptons are selected inclusively, primarily via decays with a single charged particle. The four-momentum of the tau lepton is determined by using B+ mesons from Bs20 -> B+K- decays. No significant excess is observed, and an upper limit is set on the branching fractionB(B+-> K+mu (-)tau (+))<3.9x10(-5)at90%confidence level.The obtained limit is comparable to the world-best limit. |
| Address |
[Bediaga, I.; Cruz Torres, M.; De Miranda, J. M.; Gomes, A.; Massafferri, A.; dos Reis, A. C.; Soares Lavra, L.; Tourinho Jadallah Aoude, R.] CBPF, Rio De Janeiro, Brazil, Email: maria.vieites.diaz@cern.ch |
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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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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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Expedition |
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Conference |
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| Notes |
WOS:000545615700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4454 |
| Permanent link to this record |
