|   | 
Details
   web
Records
Author Bernabeu, J.; Segarra, A.
Title Stimulated transitions in resonant atom Majorana mixing Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 017 - 16pp
Keywords Neutrino Physics; Beyond Standard Model; Global Symmetries
Abstract Massive neutrinos demand to ask whether they are Dirac or Majorana particles. Majorana neutrinos are an irrefutable proof of physics beyond the Standard Model. Neutrinoless double electron capture is not a process but a virtual Delta L = 2 mixing between a parent (A)Z atom and a daughter (A)(Z – 2) excited atom with two electron holes. As a mixing between two neutral atoms and the observable signal in terms of emitted two-hole X-rays, the strategy, experimental signature and background are different from neutrinoless double beta decay. The mixing is resonantly enhanced for almost degeneracy and, under these conditions, there is no irreducible background from the standard two-neutrino channel. We reconstruct the natural time history of a nominally stable parent atom since its production either by nature or in the laboratory. After the time periods of atom oscillations and the decay of the short-lived daughter atom, at observable times the relevant 'stationary" states are the mixed metastable long-lived state and the non-orthogonal short-lived excited state, as well as the ground state of the daughter atom. We find that they have a natural population inversion which is most appropriate for exploiting the bosonic nature of the observed atomic transitions radiation. Among different observables of the atom Majorana mixing, we include the enhanced rate of stimulated X-ray emission from the long-lived metastable state by a high-intensity X-ray beam: a gain factor of 100 can be envisaged at current XFEL facilities. On the other hand, the historical population of the daughter atom ground state can be probed by exciting it with a current pulsed optical laser, showing the characteristic absorption lines: the whole population can be excited in a shorter time than typical pulse duration.
Address [Bernabeu, Jose] Univ Valencia, CSIC, Dept Fis Teor, Calle Dr Moliner 50, E-46100 Burjassot, Spain, Email: Jose.Bernabeu@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:000424101600008 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3475
Permanent link to this record
 

 
Author ATLAS Collaboration (Aaboud, M. et al); Alvarez Piqueras, D.; Barranco Navarro, L.; Cabrera Urban, S.; Castillo Gimenez, V.; Cerda Alberich, L.; Costa, M.J.; Escobar, C.; Estrada Pastor, O.; Fernandez Martinez, P.; 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.; 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.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M.
Title Measurement of the W-boson mass in pp collisions at root s=7 TeV with the ATLAS detector Type Journal Article
Year 2018 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 78 Issue 2 Pages 110 - 61pp
Keywords
Abstract A measurement of the mass of the W boson is presented based on proton-proton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector at the LHC, and corresponding to 4.6 fb(-1) of integrated luminosity. The selected data sample consists of 7.8 x 10(6) candidates in the W -> μnu channel and 5.9 x 10(6) candidates in the W -> e nu channel. The W-boson mass is obtained from template fits to the reconstructed distributions of the charged lepton transverse momentum and of the W boson transverse mass in the electron and muon decay channels, yielding m(W) = 80370 +/- 7 (stat.) +/- 11(exp. syst.) +/- 14 (mod. syst.) MeV = 80370 +/- 19 MeV, where the first uncertainty is statistical, the second corresponds to the experimental systematic uncertainty, and the third to the physics-modelling systematic uncertainty. A measurement of the mass difference between the W+ and W- bosons yields m(W+) – m(W-) = -29 +/- 28 MeV.
Address [Chelkov, G. A.; Jackson, P.; Lee, L.; Petridis, A.; 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:000424385500005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3482
Permanent link to this record
 

 
Author ATLAS Collaboration (Aaboud, M. et al); Alvarez Piqueras, D.; Barranco Navarro, L.; Cabrera Urban, S.; Castillo Gimenez, V.; Cerda Alberich, L.; Costa, M.J.; Escobar, C.; Estrada Pastor, O.; Fernandez Martinez, P.; 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.; 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.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M.
Title Search for new phenomena in high-mass final states with a photon and a jet from pp collisions at root s=13 TeV with the ATLAS detector Type Journal Article
Year 2018 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 78 Issue 2 Pages 102 - 25pp
Keywords
Abstract A search is performed for new phenomena in events having a photon with high transverse momentum and a jet collected in 36.7 fb(-1) of proton-proton collisions at a centre-of-mass energy of root s = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider. The invariant mass distribution of the leading photon and jet is examined to look for the resonant production of new particles or the presence of new high-mass states beyond the Standard Model. No significant deviation from the background-only hypothesis is observed and cross-section limits for generic Gaussian-shaped resonances are extracted. Excited quarks hypothesized in quark compositeness models and high-mass states predicted in quantum black hole models with extra dimensions are also examined in the analysis. The observed data exclude, at 95% confidence level, the mass range below 5.3 TeV for excited quarks and 7.1 TeV (4.4 TeV) for quantum black holes in the Arkani-Hamed-Dimopoulos-Dvali (Randall-Sundrum) model with six (one) extra dimensions.
Address [Aloisio, A.; Alonso, A.; Gonzalez, B. Alvarez; Amoroso, S.; Andreazza, A.; Armbruster, A. J.; Avolio, G.; Barisits, M-S; Beermann, T. A.; Bella, G.; Beltramello, O.; Bortfeldt, J.; Boyd, J.; Butti, P.; Camarda, S.; Campana, S.; Capeans Garrido, M. D. M.; Carli, T.; Carrillo-Montoya, G. D.; Catinaccio, A.; Cattai, A.; Chelstowska, M. A.; Chisholm, A. S.; Conti, G.; Cortes-Gonzalez, A.; Czodrowski, P.; Dell'Acqua, A.; Deviveiros, P. O.; Di Girolamo, A.; Di Girolamo, B.; Di Nardo, R.; Dittus, F.; Dobos, D.; Dudarev, A.; Duhrssen, M.; Eifert, T.; Ellis, N.; Elsing, M.; Faltova, J.; Farthouat, P.; Fassnacht, P.; Feng, E. J.; Francis, D.; Fressard-Batraneanu, S. M.; Froidevaux, D.; Gadatsch, S.; Goossens, L.; Gorini, B.; Guenther, J.; Guindon, S.; Gumpert, C.; Hawkings, R. J.; Helary, L.; Helsens, C.; Correia, A. M. Henriques; Hervas, L.; Hoecker, A.; Hrdinka, J.; Huhtinen, M.; Iengo, P.; Jenni, P.; Klioutchnikova, T.; Krasznahorkay, A.; Kuehn, S.; Langenberg, R. J.; Lassnig, M.; Lehmann Miotto, G.; Lenzi, B.; Malyukov, S.; Manousos, A.; Mapelli, L.; Marin Tobon, C. A.; Marzin, A.; Mcfayden, J. A.; Berlingen, J. Montejo; Llacer, M. Moreno; Morgenstern, S.; Morley, A. K.; Mornacchi, G.; Musheghyan, H.; Nairz, A. M.; Nessi, M.; Nordberg, M.; Palestini, S.; Pani, P.; Pauly, T.; Pernegger, H.; Petersen, B. A.; Polifka, R.; Pommes, K.; Poveda, J.; Astigarraga, M. E. Pozo; Raymond, M.; Rembser, C.; Ristic, B.; Ritsch, E.; Roe, S.; Ruthmann, N.; Salzburger, A.; Schlenker, S.; Schmieden, K.; Schovancova, J.; Sanchez, C. A. Solans; Spigo, G.; Staerz, S.; Stelzer, H. J.; Ten Kate, H.; Unal, G.; Vandelli, W.; Venturi, N.; Voss, R.; Vuillermet, R.; Wells, P. S.; Wengler, T.; Wenig, S.; Werner, P.; Wilkens, H. G.; Wotschack, J.; Young, C. J. S.; Zwalinski, L.] CERN, CH-1211 Geneva 23, Switzerland
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:000424102800003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3484
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Valls, P.; Ruiz Vidal, J.; Sanchez Mayordomo, C.
Title Search for excited B-c(+) states Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 138 - 18pp
Keywords B physics; Hadron-Hadron scattering (experiments); Spectroscopy
Abstract A search is performed in the invariant mass spectrum of the B-c(+)pi(+) pi(-) system for the excited B-c(+) states B-c (2(1)S(0)) + and B-c(2(3)S(1)) + using a data sample of p p collisions collected by the LHCb experiment at the centre- of- mass energy of root s = 8TeV, corresponding to an integrated luminosity of 2 fb(-1). No evidence is seen for either state. Upper limits on the ratios of the production cross- sections of the Bc (2(1)S(0)) + and B-c(2(3)S(1)) + states times the branching fractions of Bc (2(1)S(0))(+) -> B-c(+)pi(+) pi(-) and B-c (2(3) S-1)(+) -> B-c*(+)pi(+) pi(-) over the production cross- section of the B-c(+) state are given as a function of their masses. They are found to be between 0.02 and 0.14 at 95% con fi dence level for B-c (2(1)S(0)) + and B-c (2(3)S(1)) + in the mass ranges [6830; 6890] MeV/c(2) and [6795; 6890] MeV/c(2), respectively.
Address [Bediaga, I.; Cruz Torres, M.; De Miranda, J. M.; Gomes, A.; Massafferri, A.; Molina Rodriguez, J.; Dos Reis, A. C.; Lavra, L. Soares; Aoude, R. Tourinho Jadallah] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil
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:000424644300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3485
Permanent link to this record
 

 
Author Bossingham, T.; Mavromatos, N.E.; Sarkar, S.
Title Leptogenesis from heavy right-handed neutrinos in CPT violating backgrounds Type Journal Article
Year 2018 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 78 Issue 2 Pages 113 - 33pp
Keywords
Abstract We discuss leptogenesis in a model with heavy right-handed Majorana neutrinos propagating in a constant but otherwise generic CPT-violating axial time-like background (motivated by string theory). At temperatures much higher than the temperature of the electroweak phase transition, we solve approximately, but analytically (using Pade approximants), the corresponding Boltzmann equations, which describe the generation of lepton asymmetry from the tree-level decays of heavy neutrinos into Standard Model leptons. At such temperatures these leptons are effectively massless. The current work completes in a rigorous way a preliminary treatment of the same system, by some of the present authors. In this earlier work, lepton asymmetry was crudely estimated considering the decay of a righthanded neutrino at rest. Our present analysis includes thermal momentum modes for the heavy neutrino and this leads to a total lepton asymmetry which is bigger by a factor of two as compared to the previous estimate. Nevertheless, our current and preliminary results for the freezeout are found to be in agreement (within a similar to 12.5% uncertainty). Our analysis depends on a novel use of Pade approximants to solve the Boltzmann equations and may be more widely useful in cosmology.
Address [Bossingham, Thomas; Mavromatos, Nick E.; Sarkar, Sarben] Kings Coll London, Dept Phys, Theoret Particle Phys & Cosmol Grp, London WC2R 2LS, England, Email: Nikolaos.Mavromatos@cern.ch
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:000424657600002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3486
Permanent link to this record