|   | 
Details
   web
Records
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 (up) 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 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 Lerendegui-Marco, J.; Babiano-Suarez, V.; Balibrea-Correa, J.; Caballero, L.; Calvo, D.; Ladarescu, I.; Domingo-Pardo, C.
Title Simultaneous Gamma-Neutron Vision device: a portable and versatile tool for nuclear inspections Type Journal Article
Year 2024 Publication EPJ Techniques and Instrumentation Abbreviated Journal EPJ Tech. Instrum.
Volume 11 Issue 1 Pages (up) 2 - 17pp
Keywords Gamma imaging; Neutron imaging; Nuclear inspections; Homeland security; Nuclear waste characterization
Abstract This work presents GN-Vision, a novel dual gamma-ray and neutron imaging system, which aims at simultaneously obtaining information about the spatial origin of gamma-ray and neutron sources. The proposed device is based on two position sensitive detection planes and exploits the Compton imaging technique for the imaging of gamma-rays. In addition, spatial distributions of slow- and thermal-neutron sources (<100 eV) are reconstructed by using a passive neutron pin-hole collimator attached to the first detection plane. The proposed gamma-neutron imaging device could be of prime interest for nuclear safety and security applications. The two main advantages of this imaging system are its high efficiency and portability, making it well suited for nuclear applications were compactness and real-time imaging is important. This work presents the working principle and conceptual design of the GN-Vision system and explores, on the basis of Monte Carlo simulations, its simultaneous gamma-ray and neutron detection and imaging capabilities for a realistic scenario where a Cf-252 source is hidden in a neutron moderating container.
Address [Lerendegui-Marco, Jorge; Babiano-Suarez, Victor; Balibrea-Correa, Javier; Caballero, Luis; Calvo, David; Ladarescu, Ion; Domingo-Pardo, Cesar] Univ Valencia, Inst Fis Corpuscular, CSIC, Valencia, Spain, Email: jorge.lerendegui@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2195-7045 ISBN Medium
Area Expedition Conference
Notes WOS:001171512700001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5975
Permanent link to this record
 

 
Author Barberis, D. et al; Fernandez Casani, A.; Garcia Montoro, C.; Gonzalez de la Hoz, S.; Salt, J.; Sanchez, J.; Villaplana Perez, M.
Title The ATLAS EventIndex: A BigData Catalogue for All ATLAS Experiment Events Type Journal Article
Year 2023 Publication Computing and Software for Big Science Abbreviated Journal Comput. Softw. Big Sci.
Volume 7 Issue Pages (up) 2 - 21pp
Keywords
Abstract The ATLAS EventIndex system comprises the catalogue of all events collected, processed or generated by the ATLAS experiment at the CERN LHC accelerator, and all associated software tools to collect, store and query this information. ATLAS records several billion particle interactions every year of operation, processes them for analysis and generates even larger simulated data samples; a global catalogue is needed to keep track of the location of each event record and be able to search and retrieve specific events for in-depth investigations. Each EventIndex record includes summary information on the event itself and the pointers to the files containing the full event. Most components of the EventIndex system are implemented using BigData free and open-source software. This paper describes the architectural choices and their evolution in time, as well as the past, current and foreseen future implementations of all EventIndex components.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6079
Permanent link to this record
 

 
Author Martinez-Mirave, P.; Tamborra, I.; Tortola, M.
Title The Sun and core-collapse supernovae are leading probes of the neutrino lifetime Type Journal Article
Year 2024 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 05 Issue 5 Pages (up) 002 - 39pp
Keywords neutrino properties; solar and atmospheric neutrinos; supernova neutrinos
Abstract The large distances travelled by neutrinos emitted from the Sun and core -collapse supernovae together with the characteristic energy of such neutrinos provide ideal conditions to probe their lifetime, when the decay products evade detection. We investigate the prospects of probing invisible neutrino decay capitalising on the detection of solar and supernova neutrinos as well as the diffuse supernova neutrino background (DSNB) in the next -generation neutrino observatories Hyper-Kamiokande, DUNE, JUNO, DARWIN, and RES-NOVA. We find that future solar neutrino data will be sensitive to values of the lifetime -to -mass ratio tau 1 /m 1 and tau 2 /m 2 of O(10 – 1 -10 – 2 ) s/eV. From a core -collapse supernova explosion at 10 kpc, lifetime -to -mass ratios of the three mass eigenstates of O(10 5 ) s/eV could be tested. After 20 years of data taking, the DSNB would extend the sensitivity reach of tau 1 /m 1 to 10 8 s/eV. These results promise an improvement of about 6-15 orders of magnitude on the values of the decay parameters with respect to existing limits.
Address [Martinez-Mirave, Pablo; Tamborra, Irene] Univ Copenhagen, Niels Bohr Inst, Niels Bohr Int Acad, Blegdamsvej 17, DK-2100 Copenhagen, Denmark, Email: pablo.mirave@nbi.ku.dk;
Corporate Author Thesis
Publisher IOP Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:001217801000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6144
Permanent link to this record
 

 
Author CLICdp Collaboration (Abramowicz, H. et al.); Boronat, M.; Fullana, E.; Fuster, J.; Garcia, I.; Gomis Lopez, P.; Perello, M.; Ros, E.; Vos, M.
Title Top-quark physics at the CLIC electron-positron linear collider Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue 11 Pages (up) 003 - 88pp
Keywords e plus -e- Experiments; Top physics
Abstract The Compact Linear Collider (CLIC) is a proposed future high-luminosity linear electron-positron collider operating at three energy stages, with nominal centre-of-mass energies root s = 380 GeV, 1.5 TeV, and 3 TeV. Its aim is to explore the energy frontier, providing sensitivity to physics beyond the Standard Model (BSM) and precision measurements of Standard Model processes with an emphasis on Higgs boson and top-quark physics. The opportunities for top-quark physics at CLIC are discussed in this paper. The initial stage of operation focuses on top-quark pair production measurements, as well as the search for rare flavour-changing neutral current (FCNC) top-quark decays. It also includes a top-quark pair production threshold scan around 350 GeV which provides a precise measurement of the top-quark mass in a well-defined theoretical framework. At the higher-energy stages, studies are made of top-quark pairs produced in association with other particles. A study of ttH production including the extraction of the top Yukawa coupling is presented as well as a study of vector boson fusion (VBF) production, which gives direct access to high-energy electroweak interactions. Operation above 1 TeV leads to more highly collimated jet environments where dedicated methods are used to analyse the jet constituents. These techniques enable studies of the top-quark pair production, and hence the sensitivity to BSM physics, to be extended to higher energies. This paper also includes phenomenological interpretations that may be performed using the results from the extensive top-quark physics programme at CLIC.
Address [Abramowicz, H.; Benhammou, Y.; Borysov, O.; Joffe, A.; Levy, A.; Levy, I.] Tel Aviv Univ, Raymond & Beverly Sackler Sch Phys & Astron, Tel Aviv, Israel
Corporate Author Thesis
Publisher 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:000497709600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4203
Permanent link to this record