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Author T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P.
Title Search for neutral-current induced single photon production at the ND280 near detector in T2K Type Journal Article
Year 2019 Publication Journal of Physics G Abbreviated Journal J. Phys. G
Volume 46 Issue 8 Pages 08LT01 - 16pp
Keywords T2K; neutrino; neutrino oscillation; neutrino interaction; Mini-BooNE; CP violation
Abstract Neutrino neutral-current (NC) induced single photon production is a sub-leading order process for accelerator-based neutrino beam experiments including T2K. It is, however, an important process to understand because it is a background for electron (anti)neutrino appearance oscillation experiments. Here, we performed the first search of this process below 1 GeV using the fine-grained detector at the T2K ND280 off-axis near detector. By reconstructing single photon kinematics from electron-positron pairs, we achieved 95% pure gamma ray sample from 5.738 x 10(20) protons-on-targets neutrino mode data. We do not find positive evidence of NC induced single photon production in this sample. We set the model-dependent upper limit on the cross-section for this process, at 0.114 x 10(-38) cm(2) (90% C.L.) per nucleon, using the J-PARC off-axis neutrino beam with an average energy of < E-v > similar to 0.6 GeV. This is the first limit on this process below 1 GeV which is important for current and future oscillation experiments looking for electron neutrino appearance oscillation signals.
Address [Berguno, D. Bravo; Ishii, T.; Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid, Spain
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 (up) 0954-3899 ISBN Medium
Area Expedition Conference
Notes WOS:000518888100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4318
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Author NEXT Collaboration (Henriques, C.A.O. et al); Alvarez, V.; Benlloch-Rodriguez, J.M.; Botas, A.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Kekic, M.; Laing, A.; Lopez-March, N.; Martinez, A.; Martinez-Lema, G.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Perez, J.; Querol, M.; Renner, J.; Rodriguez, J.; Romo-Luque, C.; Simon, A.; Sorel, M.; Yahlali, N.
Title Electroluminescence TPCs at the thermal diffusion limit Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 027 - 23pp
Keywords Dark Matter and Double Beta Decay (experiments); Photon production; Particle correlations and fluctuations; Rare decay
Abstract The NEXT experiment aims at searching for the hypothetical neutrinoless double-beta decay from the Xe-136 isotope using a high-purity xenon TPC. Efficient discrimination of the events through pattern recognition of the topology of primary ionisation tracks is a major requirement for the experiment. However, it is limited by the diffusion of electrons. It is known that the addition of a small fraction of a molecular gas to xenon reduces electron diffusion. On the other hand, the electroluminescence (EL) yield drops and the achievable energy resolution may be compromised. We have studied the effect of adding several molecular gases to xenon (CO2, CH4 and CF4) on the EL yield and energy resolution obtained in a small prototype of driftless gas proportional scintillation counter. We have compared our results on the scintillation characteristics (EL yield and energy resolution) with a microscopic simulation, obtaining the diffusion coefficients in those conditions as well. Accordingly, electron diffusion may be reduced from about 10 for pure xenon down to 2.5 using additive concentrations of about 0.05%, 0.2% and 0.02% for CO2, CH4 and CF4, respectively. Our results show that CF4 admixtures present the highest EL yield in those conditions, but very poor energy resolution as a result of huge fluctuations observed in the EL formation. CH4 presents the best energy resolution despite the EL yield being the lowest. The results obtained with xenon admixtures are extrapolated to the operational conditions of the NEXT-100 TPC. CO2 and CH4 show potential as molecular additives in a large xenon TPC. While CO2 has some operational constraints, making it difficult to be used in a large TPC, CH4 shows the best performance and stability as molecular additive to be used in the NEXT-100 TPC, with an extrapolated energy resolution of 0.4% at 2.45 MeV for concentrations below 0.4%, which is only slightly worse than the one obtained for pure xenon. We demonstrate the possibility to have an electroluminescence TPC operating very close to the thermal diffusion limit without jeopardizing the TPC performance, if CO2 or CH4 are chosen as additives.
Address [Henriques, C. A. O.; Monteiro, C. M. B.; Freitas, E. D. C.; Mano, R. D. P.; Jorge, M. R.; Fernandes, A. F. M.; Fernandes, L. M. P.; dos Santos, J. M. F.] Univ Coimbra, Phys Dept, LIBPhys, Rua Larga, P-3004516 Coimbra, Portugal, Email: pancho@gian.fis.uc.pt
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 (up) 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000455157300002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3873
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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 heavy Majorana or Dirac neutrinos and right-handed W gauge bosons in final states with two charged leptons and two jets at TeV with the ATLAS detector Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 016 - 45pp
Keywords Hadron-Hadron scattering (experiments)
Abstract A search for heavy right-handed Majorana or Dirac neutrinos N (R) and heavy right-handed gauge bosons W (R) is performed in events with a pair of energetic electrons or muons, with the same or opposite electric charge, and two energetic jets. The events are selected from pp collision data with an integrated luminosity of 36.1 fb(-1) collected by the ATLAS detector at TeV. No significant deviations from the Standard Model are observed. The results are interpreted within the theoretical framework of a left-right symmetric model and lower limits are set on masses in the heavy right-handed W boson and neutrino mass plane. The excluded region extends to TeV for both Majorana and Dirac N (R) neutrinos.
Address [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 Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000456888300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3895
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Author Carcamo Hernandez, A.E.; Kovalenko, S.; Valle, J.W.F.; Vaquera-Araujo, C.A.
Title Neutrino predictions from a left-right symmetric flavored extension of the standard model Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 065 - 24pp
Keywords Beyond Standard Model; Discrete Symmetries; Neutrino Physics; Quark Masses and SM Parameters
Abstract We propose a left-right symmetric electroweak extension of the Standard Model based on the Delta (27) family symmetry. The masses of all electrically charged Standard Model fermions lighter than the top quark are induced by a Universal Seesaw mechanism mediated by exotic fermions. The top quark is the only Standard Model fermion to get mass directly from a tree level renormalizable Yukawa interaction, while neutrinos are unique in that they get calculable radiative masses through a low-scale seesaw mechanism. The scheme has generalized μ- tau symmetry and leads to a restricted range of neutrino oscillations parameters, with a nonzero neutrinoless double beta decay amplitude lying at the upper ranges generically associated to normal and inverted neutrino mass ordering.
Address [Carcamo Hernandez, A. E.; Kovalenko, Sergey] Univ Tecn Federico Santa Maria, Casilla 110-5, Valparaiso, Chile, Email: antonio.carcamo@usm.cl;
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 (up) 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000459168900003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3917
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Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C.
Title Prompt Lambda+c production in pPb collisions at root s(NN)=5.02 TeV Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 102 - 26pp
Keywords Charm physics; Forward physics; Heavy Ion Experiments; Heavy quark production
Abstract The prompt production of +c baryons is studied in proton- lead collisions collected with the LHCb detector at the LHC. The data sample corresponds to an integrated luminosity of 1 : 58 nb recorded at a nucleon- nucleon centre- of- mass energy of p sNN = 5 : 02TeV. Measurements of the di ff erential cross- section and the forwardbackward production ratio are reported for +c baryons with transverse momenta in the range 2 < pT < 10 GeV =c and rapidities in the ranges 1 : 5 < y < 4 : 0 and 4 : 5 < y < 2 : 5 in the nucleon- nucleon centre- of- mass system. The ratio of cross- sections of +c baryons and D0 mesons is also reported. The results are compared with next- to- leading order calculations that use nuclear parton distribution functions.
Address [Bediaga, I.; Torres, M. Cruz; De Miranda, J. M.; Gomes, A.; Massafferri, A.; Rodriguez, J. Molina; dos Reis, A. C.; Lavra, L. Soares; Tourinho Jadallah Aoude, R.] CBPF, Rio De Janeiro, Brazil, Email: jiayin.sun@cern.ch
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 (up) 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000459198100004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3918
Permanent link to this record
 

 
Author Driencourt-Mangin, F.; Rodrigo, G.; Sborlini, G.F.R.; Torres Bobadilla, W.J.
Title Universal four-dimensional representation of H -> gamma gamma at two loops through the Loop-Tree Duality Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 143 - 39pp
Keywords Scattering Amplitudes; Higgs Physics; Perturbative QCD
Abstract We extend useful properties of the H unintegrated dual amplitudes from one- to two-loop level, using the Loop-Tree Duality formalism. In particular, we show that the universality of the functional form regardless of the nature of the internal particle still holds at this order. We also present an algorithmic way to renormalise two-loop amplitudes, by locally cancelling the ultraviolet singularities at integrand level, thus allowing a full four-dimensional numerical implementation of the method. Our results are compared with analytic expressions already available in the literature, finding a perfect numerical agreement. The success of this computation plays a crucial role for the development of a fully local four-dimensional framework to compute physical observables at Next-to-Next-to Leading order and beyond.
Address [Driencourt-Mangin, Felix; Rodrigo, German; Sborlini, German F. R.; Bobadilla, William J. Torres] Univ Valencia, CSIC, IFIC, Apt Correus 22085, E-46071 Valencia, Spain, Email: felix.dm@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 (up) 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000459485300005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3922
Permanent link to this record
 

 
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 CP violation through an amplitude analysis of D-0 K+K-+- decays Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 126 - 34pp
Keywords Charm physics; CP violation; Flavor physics; Hadron-Hadron scattering (experiments)
Abstract A search for CP violation in the Cabibbo-suppressed D-0 K+K-+- decay mode is performed using an amplitude analysis. The measurement uses a sample of pp collisions recorded by the LHCb experiment during 2011 and 2012, corresponding to an integrated luminosity of 3.0 fb(-1). The D-0 mesons are reconstructed from semileptonic b-hadron decays into D0-X final states. The selected sample contains more than 160 000 signal decays, allowing the most precise amplitude modelling of this D-0 decay to date. The obtained amplitude model is used to perform the search for CP violation. The result is compatible with CP symmetry, with a sensitivity ranging from 1% to 15% depending on the amplitude considered.
Address [Bediaga, I.; Cruz Torres, M.; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Soares Lavra, l.; Tourinho Jadallah Aoude, R.] CBPF, Rio De Janeiro, Brazil, Email: maxime.schubiger@cern.ch
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 (up) 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000459484700002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3927
Permanent link to this record
 

 
Author Chen, P.; Centelles Chulia, S.; Ding, G.J.; Srivastava, R.; Valle, J.W.F.
Title CP symmetries as guiding posts: revamping tri-bi-maximal mixing. Part I Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 036 - 27pp
Keywords CP violation; Discrete Symmetries; Neutrino Physics
Abstract We analyze the possible generalized CP symmetries admitted by the Tri-Bi-Maximal (TBM) neutrino mixing. Taking advantage of these symmetries we construct in a systematic way other variants of the standard TBM Ansatz. Depending on the type and number of generalized CP symmetries imposed, we get new mixing matrices, all of which related to the original TBM matrix. One of such revamped TBM variants is the recently discussed mixing matrix of arXiv:1806.03367. We also briefly discuss the phenomenological implications following from these mixing patterns.
Address [Chen, Peng] Ocean Univ China, Coll Informat Sci & Engn, 238 Songling Rd, Qingdao 266100, Shandong, Peoples R China, Email: pche@mail.ustc.edu.cn;
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 (up) 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000460751400004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3941
Permanent link to this record
 

 
Author Escudero, M.; Hooper, D.; Krnjaic, G.; Pierre, M.
Title Cosmology with a very light Lmu – Ltau gauge boson Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 071 - 29pp
Keywords Cosmology of Theories beyond the SM; Beyond Standard Model; Neutrino Physics
Abstract In this paper, we explore in detail the cosmological implications of an abelian L – L gauge extension of the Standard Model featuring a light and weakly coupled Z. Such a scenario is motivated by the longstanding approximate to 4 sigma discrepancy between the measured and predicted values of the muon's anomalous magnetic moment, (g – 2), as well as the tension between late and early time determinations of the Hubble constant. If sufficiently light, the Z population will decay to neutrinos, increasing the overall energy density of radiation and altering the expansion history of the early universe. We identify two distinct regions of parameter space in this model in which the Hubble tension can be significantly relaxed. The first of these is the previously identified region in which a approximate to 10 – 20 MeV Z reaches equilibrium in the early universe and then decays, heating the neutrino population and delaying the process of neutrino decoupling. For a coupling of g (-) similar or equal to (3 – 8) x 10(-4), such a particle can also explain the observed (g – 2) anomaly. In the second region, the Z is very light (mZ approximate to 1eV to MeV) and very weakly coupled (g (-) approximate to 10(-13) to 10(-9)). In this case, the Z population is produced through freeze-in, and decays to neutrinos after neutrino decoupling. Across large regions of parameter space, we predict a contribution to the energy density of radiation that can appreciably relax the reported Hubble tension, N-eff similar or equal to 0.2.
Address [Escudero, Miguel] Kings Coll London, Dept Phys, London WC2R 2LS, England, Email: miguel.escudero@kcl.ac.uk;
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 (up) 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000461295500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3945
Permanent link to this record
 

 
Author ATLAS Collaboration (Aaboud, M. et al); Alvarez Piqueras, D.; Bailey, A.J.; Barranco Navarro, L.; Cabrera Urban, S.; Castillo Gimenez, V.; Cerda Alberich, L.; Costa, M.J.; Escobar, C.; Estrada Pastor, O.; 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.; Lozano Bahilo, J.J.; Madaffari, D.; Mamuzic, J.; Marti-Garcia, S.; Melini, D.; Mitsou, V.A.; Pedraza Lopez, S.; Rodriguez Bosca, S.; Rodriguez Rodriguez, D.; Romero Adam, E.; Salt, J.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M.
Title Search for pair production of Higgs bosons in the b(b)over-barb(b)over-bar final state using proton-proton collisions 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 01 Issue 1 Pages 030 - 49pp
Keywords Hadron-Hadron scattering (experiments)
Abstract A search for Higgs boson pair production in the bbbb final state is carried out with up to 36.1 fb(-1) of LHC proton-proton collision data collected at s=13 TeV with the ATLAS detector in 2015 and 2016. Three benchmark signals are studied: a spin-2 graviton decaying into a Higgs boson pair, a scalar resonance decaying into a Higgs boson pair, and Standard Model non-resonant Higgs boson pair production. Two analyses are carried out, each implementing a particular technique for the event reconstruction that targets Higgs bosons reconstructed as pairs of jets or single boosted jets. The resonance mass range covered is 260-3000 GeV. The analyses are statistically combined and upper limits on the production cross section of Higgs boson pairs times branching ratio to bbbb are set in each model. No significant excess is observed; the largest deviation of data over prediction is found at a mass of 280 GeV, corresponding to 2.3 standard deviations globally. The observed 95% confidence level upper limit on the non-resonant production is 13 times the Standard Model prediction.
Address [Aloisio, A.; Alonso, A.; Betti, A.; Bingul, A.; Bruni, A.; Manjarres Ramos, J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia
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 (up) 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000455324200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3946
Permanent link to this record