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Author Helo, J.C.; Hirsch, M.; Ota, T. url  doi
openurl 
  Title (up) Proton decay and light sterile neutrinos Type Journal Article
  Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 06 Issue 6 Pages 047 - 15pp  
  Keywords Beyond Standard Model; Neutrino Physics  
  Abstract Within the standard model, non-renormalizable operators at dimension six (d = 6) violate baryon and lepton number by one unit and thus lead to proton decay. Here, we point out that the proton decay mode with a charged pion and missing energy can be a characteristic signature of d = 6 operators containing a light sterile neutrino, if it is not accompanied by the standard pi(0)e(+) final state. We discuss this effect first at the level of effective operators and then provide a concrete model with new physics at the TeV scale, in which the lightness of the active neutrinos and the stability of the proton are related.  
  Address [Helo, Juan C.] Univ La Serena, Fac Ciencias, Dept Fis, Ave Cisternas 1200, La Serena, Chile, Email: jchelo@userena.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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000435023100004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3610  
Permanent link to this record
 

 
Author Kuehn, S. et al; Bernabeu, J.; Lacasta, C.; Marco-Hernandez, R.; Rodriguez Rodriguez, D.; Santoyo, D.; Solaz, C.; Soldevila Serrano, U. url  doi
openurl 
  Title (up) Prototyping of petalets for the Phase-II upgrade of the silicon strip tracking detector of the ATLAS experiment Type Journal Article
  Year 2018 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.  
  Volume 13 Issue Pages T03004 - 22pp  
  Keywords Particle tracking detectors (Solid-state detectors); Si microstrip and pad detectors; Solid state detectors; Performance of High Energy Physics Detectors  
  Abstract In the high luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. To cope with the resultant increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The ITk consists of a silicon pixel and a strip detector and exploits the concept of modularity. Prototyping and testing of various strip detector components has been carried out. This paper presents the developments and results obtained with reduced-size structures equivalent to those foreseen to be used in the forward region of the silicon strip detector. Referred to as petalets, these structures are built around a composite sandwich with embedded cooling pipes and electrical tapes for routing the signals and power. Detector modules built using electronic flex boards and silicon strip sensors are glued on both the front and back side surfaces of the carbon structure. Details are given on the assembly, testing and evaluation of several petalets. Measurement results of both mechanical and electrical quantities are shown. Moreover, an outlook is given for improved prototyping plans for large structures.  
  Address [Kuehn, S.] European Org Nucl Res, CERN, Geneva, Switzerland, Email: susanne.kuehn@cern.ch  
  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 1748-0221 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000428146400003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3530  
Permanent link to this record
 

 
Author Liang, W.H.; Oset, E. url  doi
openurl 
  Title (up) Pseudoscalar or vector meson production in non-leptonic decays of heavy hadrons Type Journal Article
  Year 2018 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C  
  Volume 78 Issue 6 Pages 528 - 26pp  
  Keywords  
  Abstract We have addressed the study of non-leptonic weak decays of heavy hadrons (Lambda b, Lambda c, B and D), with external and internal emission to give two final hadrons, taking into account the spin-angular momentum structure of the mesons and baryons produced. A detailed angular momentum formulation is developed which leads to easy final formulas. By means of them we have made predictions for a large amount of reactions, up to a global factor, common tomany of them, that we take from some particular data. Comparing the theoretical predictions with the experimental data, the agreement found is quite good in general and the discrepancies should give valuable information on intrinsic form factors, independent of the spin structure studied here. The formulas obtained are also useful in order to evaluate meson-meson or meson-baryon loops, for instance of B decays, in which one has PP, PV, VP or VV intermediate states, with P for pseudoscalar mesons and V for vector meson and lay the grounds for studies of decays into three final particles.  
  Address [Liang, Wei-Hong] Guangxi Normal Univ, Dept Phys, Guilin 541004, Peoples R China, Email: liangwh@gxnu.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 1434-6044 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000437225200001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3644  
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Author Delafosse, C. et al; Gadea, A.; Perez-Vidal, R.M.; Domingo-Pardo, C. doi  openurl
  Title (up) Pseudospin Symmetry and Microscopic Origin of Shape Coexistence in the Ni-78 Region: A Hint from Lifetime Measurements Type Journal Article
  Year 2018 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 121 Issue 19 Pages 192502 - 7pp  
  Keywords  
  Abstract Lifetime measurements of excited states of the light N = 52 isotones Kr-88, Se-86, and Ge-84 have been performed, using the recoil distance Doppler shift method and VAMOS and AGATA spectrometers for particle identification and gamma spectroscopy, respectively. The reduced electric quadrupole transition probabilities B(E2; 2(+)-> 0(+)) and B(E2; 4(+)-> 2(+)) were obtained for the first time for the hard-to-reach 84Ge. While the B(E2; 2(+)-> 0(+) ) values of Kr-88, Se-86 saturate the maximum quadrupole collectivity offered by the natural valence (3s, 2d, 1g(7/2), 1h(11/2)) space of an inert Ni-78 core, the value obtained for Ge-84 largely exceeds it, suggesting that shape coexistence phenomena, previously reported at N less than or similar to 49, extend beyond N = 50. The onset of collectivity at Z = 32 is understood as due to a pseudo-SU(3) organization of the proton single-particle sequence reflecting a clear manifestation of pseudospin symmetry. It is realized that the latter provides actually reliable guidance for understanding the observed proton and neutron single particle structure in the whole medium-mass region, from Ni to Sn, pointing towards the important role of the isovector-vector rho field in shell-structure evolution.  
  Address [Delafosse, C.; Verney, D.; Marevic, P.; Gottardo, A.; Babo, M.; Franchoo, S.; Ibrahim, F.; Matea, I; Olivier, L.; Portail, C.; Stefan, I] Univ Paris Saclay, Univ Paris Sud, CNRS IN2P3, Inst Phys Nucl, F-91406 Orsay, France, Email: verney@ipno.in2p3.fr  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000449791600008 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3800  
Permanent link to this record
 

 
Author Luo, X.L. et al; Agramunt, J.; Egea, F.J.; Gadea, A.; Huyuk, T. doi  openurl
  Title (up) Pulse pile-up identification and reconstruction for liquid scintillator based neutron detectors Type Journal Article
  Year 2018 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 897 Issue Pages 59-65  
  Keywords Pile-up; Digital; First-order derivative; Neutron-gamma discrimination; Liquid scintillator  
  Abstract The issue of pulse pile-up is frequently encountered in nuclear experiments involving high counting rates, which will distort the pulse shapes and the energy spectra. A digital method of off-line processing of pile-up pulses is presented. The pile-up pulses were firstly identified by detecting the downward-going zero-crossings in the first-order derivative of the original signal, and then the constituent pulses were reconstructed based on comparing the pile-up pulse with four models that are generated by combining pairs of neutron and.. standard pulses together with a controllable time interval. The accuracy of this method in resolving the pile-up events was investigated as a function of the time interval between two pulses constituting a pile-up event. The obtained results show that the method is capable of disentangling two pulses with a time interval among them down to 20 ns, as well as classifying them as neutrons or gamma rays. Furthermore, the error of reconstructing pile-up pulses could be kept below 6% when successive peaks were separated by more than 50 ns. By applying the method in a high counting rate of pile-up events measurement of the NEutron Detector Array (NEDA), it was empirically found that this method can reconstruct the pile-up pulses and perform neutron-gamma discrimination quite accurately. It can also significantly correct the distorted pulse height spectrum due to pile-up events.  
  Address [Luo, X. L.] Acad Mil Med Sci, Natl Innovat Inst Def Technol, Beijing 100010, Peoples R China, Email: delongtmac@163.com  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000433206800010 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3591  
Permanent link to this record
 

 
Author AGATA Collaboration (Hadynska-Klek, K. et al); Gadea, A. doi  openurl
  Title (up) Quadrupole collectivity in Ca-42 from low-energy Coulomb excitation with AGATA Type Journal Article
  Year 2018 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 97 Issue 2 Pages 024326 - 20pp  
  Keywords  
  Abstract ACoulomb-excitation experiment to study electromagnetic properties of Ca-42 was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. gamma rays from excited states in Ca-42 were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E2 matrix elements coupling six low-lying states in Ca-42, including the diagonal E2 matrix elements of 2(1)(+) and 2(2)(+) states, were determined using the least-squares code GOSIA. The obtained set of reduced E2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 0(1),(+)(2) and 2(1,2)(+) states, as well as triaxiality for 0(1,2)(+) states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca-42. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in Ca-42.  
  Address [Hadynska-Klek, K.; Napiorkowski, P. J.; Zielinska, M.; Srebrny, J.; Abraham, T.; Iwanicki, J.; Jaworski, G.; Kisielinski, M.; Komorowska, M.; Kowalczyk, M.; Ozmen, S. F.; Palacz, M.; Prochniak, L.; Rusek, K.; Wrzosek-Lipska, K.] Univ Warsaw, Heavy Ion Lab, Pasteura 5A, PL-02093 Warsaw, Poland, Email: katarzyna.hadynska@lnl.infn.it  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000425604200003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3506  
Permanent link to this record
 

 
Author Aguilar, A.C.; Cardona, J.C.; Ferreira, M.N.; Papavassiliou, J. url  doi
openurl 
  Title (up) Quark gap equation with non-Abelian Ball-Chiu vertex Type Journal Article
  Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 98 Issue 1 Pages 014002 - 15pp  
  Keywords  
  Abstract The full quark-gluon vertex is a crucial ingredient for the dynamical generation of a constituent quark mass from the standard quark gap equation, and its nontransverse part may be determined exactly from the nonlinear Slav nov-Taylor identity that it satisfies. The resulting expression involves not only the quark propagator, but also the ghost dressing function and the quark-ghost kernel, and constitutes the non-abelian extension of the so-called “Ball-Chiu vertex,” known from QED. In the present work we carry out a detailed study of the impact of this vertex on the gap equation and the quark masses generated from it, putting particular emphasis on the contributions directly related with the ghost sector of the theory, and especially the quark-ghost kernel. In particular, we set up and solve the coupled system of six equations that determine the four form factors of the latter kernel and the two typical Dirac structures composing the quark propagator. Due to the incomplete implementation of the multiplicative renormalizability at the level of the gap equation, the correct anomalous dimension of the quark mass is recovered through the inclusion of a certain function, whose ultraviolet behavior is fixed, but its infrared completion is unknown; three particular Ansatze for this function are considered, and their effect on the quark mass and the pion decay constant is explored. The main results of this study indicate that the numerical impact of the quark-ghost kernel is considerable; the transition from a tree-level kernel to the one computed hem leads to a 20% increase in the value of the quark mass at the origin. Particularly interesting is the contribution of the fourth Ball-Chiu form factor, which, contrary to the Abelian case, is nonvanishing, and accounts for 10% of the total constituent quark mass.  
  Address [Aguilar, A. C.; Cardona, J. C.; Ferreira, M. N.] Univ Campinas UNICAMP, Inst Phys Gleb Wataghin, BR-13083859 Campinas, SP, Brazil  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000436941600003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3642  
Permanent link to this record
 

 
Author Anamiati, G.; Fonseca, R.M.; Hirsch, M. url  doi
openurl 
  Title (up) Quasi-Dirac neutrino oscillations Type Journal Article
  Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 97 Issue 9 Pages 095008 - 16pp  
  Keywords  
  Abstract Dirac neutrino masses require two distinct neutral Weyl spinors per generation, with a special arrangement of masses and interactions with charged leptons. Once this arrangement is perturbed, lepton number is no longer conserved and neutrinos become Majorana particles. If these lepton number violating perturbations are small compared to the Dirac mass terms, neutrinos are quasi-Dirac particles. Alternatively, this scenario can be characterized by the existence of pairs of neutrinos with almost degenerate masses, and a lepton mixing matrix which has 12 angles and 12 phases. In this work we discuss the phenomenology of quasi-Dirac neutrino oscillations and derive limits on the relevant parameter space from various experiments. In one parameter perturbations of the Dirac limit, very stringent bounds can be derived on the mass splittings between the almost degenerate pairs of neutrinos. However, we also demonstrate that with suitable changes to the lepton mixing matrix, limits on such mass splittings are much weaker, or even completely absent. Finally, we consider the possibility that the mass splittings are too small to be measured and discuss bounds on the new, nonstandard lepton mixing angles from current experiments for this case.  
  Address [Anamiati, Gaetana; Fonseca, Renato M.; Hirsch, Martin] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Edificio Inst Paterna,Apartado 22085, E-46071 Valencia, Spain, Email: anamiati@ific.uv.es;  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000432970600004 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 3581  
Permanent link to this record
 

 
Author n_TOF Collaboration (Lerendegui-Marco, J. et al.); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A. doi  openurl
  Title (up) Radiative neutron capture on Pu-242 in the resonance region at the CERN n_TOF-EAR1 facility Type Journal Article
  Year 2018 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 97 Issue 2 Pages 024605 - 21pp  
  Keywords  
  Abstract The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with uranium to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. However, an extensive use of MOX fuels, in particular in fast reactors, requires more accurate capture and fission cross sections for some Pu isotopes. In the case of Pu-242 there are sizable discrepancies among the existing capture cross-section measurements included in the evaluations (all from the 1970s) resulting in an uncertainty as high as 35% in the fast energy region. Moreover, postirradiation experiments evaluated with JEFF-3.1 indicate an overestimation of 14% in the capture cross section in the fast neutron energy region. In this context, the Nuclear Energy Agency (NEA) requested an accuracy of 8% in this cross section in the energy region between 500 meV and 500 keV. This paper presents a new time-of-flight capture measurement on Pu-242 carried out at nTOF-EAR1 (CERN), focusing on the analysis and statistical properties of the resonance region, below 4 keV. The Pu-242(n, gamma) reaction on a sample containing 95(4) mg enriched to 99.959% was measured with an array of four C6D6 detectors and applying the total energy detection technique. The high neutron energy resolution of nTOF-EAR1 and the good statistics accumulated have allowed us to extend the resonance analysis up to 4 keV, obtaining new individual and average resonance parameters from a capture cross section featuring a systematic uncertainty of 5%, fulfilling the request of the NEA.  
  Address [Lerendegui-Marco, J.; Guerrero, C.; Quesada, J. M.; Cortes-Giraldo, M. A.; Praena, J.; Sabate-Gilarte, M.] Univ Seville, Dept Fis Atom Mol & Nucl, E-41012 Seville, Spain, Email: cguerrero4@us.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000424190700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3474  
Permanent link to this record
 

 
Author Chen, P.; Centelles Chulia, S.; Ding, G.J.; Srivastava, R.; Valle, J.W.F. url  doi
openurl 
  Title (up) Realistic tribimaximal neutrino mixing Type Journal Article
  Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 98 Issue 5 Pages 055019 - 6pp  
  Keywords  
  Abstract We propose a generalized version of the tribimaximal (TBM) ansatz for lepton mixing, leading to a nonzero reactor angle theta(13) and CP violation. The latter is characterized by two CP phases. The Dirac phase, affecting neutrino oscillations, is nearly maximal (delta(CP) similar to +/- pi/2), while the Majorana phase implies narrow allowed ranges for the neutrinoless double beta decay amplitude. The solar angle theta(12) lies nearly at its TBM value, while the atmospheric angle theta(23) has the TBM value for a maximal delta(CP). Neutrino oscillation predictions can be tested in present and upcoming experiments.  
  Address [Chen, Peng] Ocean Univ China, Coll Informat Sci & Engn, Qingdao 266100, Peoples R China, Email: pche@mail.ustc.edu.cn;  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000444729900004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3733  
Permanent link to this record
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