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Author Coloma, P.; Huber, P.; Schwetz, T.
Title Statistical interpretation of sterile neutrino oscillation searches at reactors Type Journal Article
Year 2021 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 81 Issue 1 Pages 2 - 13pp
Keywords
Abstract A considerable experimental effort is currently under way to test the persistent hints for oscillations due to an eV-scale sterile neutrino in the data of various reactor neutrino experiments. The assessment of the statistical significance of these hints is usually based on Wilks' theorem, whereby the assumption is made that the log-likelihood is chi 2-distributed. However, it is well known that the preconditions for the validity of Wilks' theorem are not fulfilled for neutrino oscillation experiments. In this work we derive a simple asymptotic form of the actual distribution of the log-likelihood based on reinterpreting the problem as fitting white Gaussian noise. From this formalism we show that, even in the absence of a sterile neutrino, the expectation value for the maximum likelihood estimate of the mixing angle remains non-zero with attendant large values of the log-likelihood. Our analytical results are then confirmed by numerical simulations of a toy reactor experiment. Finally, we apply this framework to the data of the Neutrino-4 experiment and show that the null hypothesis of no-oscillation is rejected at the 2.6 sigma level, compared to 3.2 sigma obtained under the assumption that Wilks' theorem applies.
Address [Coloma, Pilar] Univ Autonoma Madrid, CSIC, Inst Fis Teor UAM, Calle Nicolas Cabrera 13-15, Madrid 28049, Spain, Email: pilar.coloma@ift.csic.es;
Corporate Author Thesis
Publisher (down) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000606481000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4680
Permanent link to this record
 

 
Author ATLAS Collaboration (Aad, G. et al); Aparisi Pozo, J.A.; Bailey, A.J.; Cabrera Urban, S.; Castillo, F.L.; Castillo Gimenez, V.; 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.; Gonzalvo Rodriguez, G.R.; Guerrero Rojas, J.G.R.; Higon-Rodriguez, E.; Lacasta, C.; Lozano Bahilo, J.J.; Madaffari, D.; Mamuzic, J.; Marti-Garcia, S.; Martinez Agullo, P.; Mitsou, V.A.; Moreno Llacer, M.; Poveda, J.; Rodriguez Bosca, S.; Ruiz-Martinez, A.; Salt, J.; Santra, A.; Sayago Galvan, I.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M.
Title Measurements of top-quark pair single- and double-differential cross-sections in the all-hadronic channel in pp collisions at root s=13 TeV using the ATLAS detector Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 033 - 76pp
Keywords Hadron-Hadron scattering (experiments); Top physics
Abstract Differential cross-sections are measured for top-quark pair production in the all-hadronic decay mode, using proton-proton collision events collected by the ATLAS experiment in which all six decay jets are separately resolved. Absolute and normalised single- and double-differential cross-sections are measured at particle and parton level as a function of various kinematic variables. Emphasis is placed on well-measured observables in fully reconstructed final states, as well as on the study of correlations between the top-quark pair system and additional jet radiation identified in the event. The study is performed using data from proton-proton collisions at root s = 13 TeV collected by the ATLAS detector at CERN's Large Hadron Collider in 2015 and 2016, corresponding to an integrated luminosity of 36.1 fb(-1). The rapidities of the individual top quarks and of the top-quark pair are well modelled by several independent event generators. Significant mismodelling is observed in the transverse momenta of the leading three jet emissions, while the leading top-quark transverse momentum and top-quark pair transverse momentum are both found to be incompatible with several theoretical predictions.
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
Corporate Author Thesis
Publisher (down) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000607134800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4681
Permanent link to this record
 

 
Author Husek, T.; Monsalvez-Pozo, K.; Portoles, J.
Title Lepton-flavour violation in hadronic tau decays and mu-tau conversion in nuclei Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 059 - 48pp
Keywords Beyond Standard Model; Effective Field Theories
Abstract Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and l-tau conversion in nuclei, with l = e, mu. Based on available experimental limits, we establish constraints on the Wilson coefficients of the operators contributing to these processes. Our work paves the way to extract the related information from Belle II and foreseen future experiments.
Address [Husek, Tomas; Monsalvez-Pozo, Kevin; Portoles, Jorge] Univ Valencia, CSIC, Inst Fis Corpuscular, Apt Correus 22085, E-46071 Valencia, Spain, Email: Tomas.Husek@ific.uv.es;
Corporate Author Thesis
Publisher (down) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000609870600002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4686
Permanent link to this record
 

 
Author ATLAS Collaboration (Aad, G. et al); Aparisi Pozo, J.A.; Bailey, A.J.; Cabrera Urban, S.; Cardillo, F.; Castillo, F.L.; Castillo Gimenez, V.; 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.; Gonzalvo Rodriguez, G.R.; Guerrero Rojas, J.G.R.; Higon-Rodriguez, E.; Lacasta, C.; Lozano Bahilo, J.J.; Madaffari, D.; Mamuzic, J.; Marti-Garcia, S.; Martinez Agullo, P.; Mitsou, V.A.; Moreno Llacer, M.; Poveda, J.; Prades Ibañez, A.; Rodriguez Bosca, S.; Ruiz-Martinez, A.; Sabatini, P.; Salt, J.; Santra, A.; Sayago Galvan, I.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valls Ferrer, J.A.; Vos, M.
Title Search for phenomena beyond the Standard Model in events with large b-jet multiplicity using the ATLAS detector at the LHC Type Journal Article
Year 2021 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 81 Issue 1 Pages 11 - 29pp
Keywords
Abstract A search is presented for new phenomena in events characterised by high jet multiplicity, no leptons (electrons or muons), and four or more jets originating from the fragmentation of b-quarks (b-jets). The search uses 139fb(-1)of s root = 13 TeV proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider during Run 2. The dominant Standard Model background originates from multijet production and is estimated using a data-driven technique based on an extrapolation from events with low b-jet multiplicity to the high b-jet multiplicities used in the search. No significant excess over the Standard Model expectation is observed and 95% confidence-level limits that constrain simplified models of R-parity-violating supersymmetry are determined. The exclusion limits reach 950 GeV in top-squark mass in the models considered.
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
Corporate Author Thesis
Publisher (down) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000610446600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4690
Permanent link to this record
 

 
Author Bruschini, R.; Gonzalez, P.
Title Strong decays of the lowest bottomonium hybrid within an extended Born-Oppenheimer framework Type Journal Article
Year 2021 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 81 Issue 1 Pages 74 - 9pp
Keywords
Abstract We analyze the decays of the theoretically predicted lowest bottomonium hybrid H(1P) to open bottom two-meson states. We do it by embedding a quark pair creation model into the Born-Oppenheimer framework which allows for a unified, QCD-motivated description of bottomonium hybrids as well as bottomonium. A new 1P1 decay model for H(1P) comes out. The same analysis applied to bottomonium leads naturally to the well-known 3 P0 decay model. We show that H(1P) and the theoretically predicted bottomonium state Upsilon (5S), whose calculated masses are close to each other, have very different widths for such decays. A comparison with data from Upsilon (10860), an experimental resonance whose mass is similar to that of Upsilon (5S) and H(1P), is carried out. Neither a Upsilon (5S) nor a H(1P) assignment can explain the measured decay widths. However, a Upsilon (5S)-H(1P) mixing may give account of them supporting previous analyses of dipion decays of Upsilon (10860) and suggesting a possible experimental evidence of H(1P).
Address [Bruschini, R.; Gonzalez, P.] Univ Valencia, CSIC, Inst Fis Corpuscular, Unidad Teor, Valencia 46980, Spain, Email: roberto.bruschini@ific.uv.es;
Corporate Author Thesis
Publisher (down) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000612840500001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4695
Permanent link to this record