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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 Measurement of b hadron fractions in 13 TeV pp collisions Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 100 Issue 3 Pages 031102 - 11pp
Keywords
Abstract The production fractions of (B) over bar (0)(s) and Lambda(0)(b) hadrons, normalized to the sum of B- and (B) over bar (0) fractions, arc measured in 13 TeV pp collisions using data collected by the LHCb experiment, corresponding to an integrated luminosity of 1.67 fb(-1). These ratios, averaged over the b hadron transverse momenta from 4 to 25 GeV and pseudorapidity from 2 to 5, are 0.122 +/- 0.006 for (B) over bar (0)(s) and 0.259 +/- 0.018 for Lambda(0)(b) where the uncertainties arise from both statistical and systematic sources. The Lambda(0)(b) ratio depends strongly on transverse momentum, while the (B) over bar (0)(s) ratio shows a mild dependence. Neither ratio shows variations with pseudorapidity. The measurements are made using semileptonic decays to minimize theoretical uncertainties. In addition, the ratio of D+ to D-0 mesons produced in the sum of (B) over bar (0) and B- semileptonic decays is determined as 0.359 +/- 0.006 +/- 0.009, where the uncertainties are statistical and systematic.
Address [Bediaga, I.; Torres, M. Cruz; De Miranda, J. M.; Dos Reis, A. C.; Gomes, A.; Massafferri, A.; Lavra, L. Soares; Aoude, R. Tourinho Jadallah] CBPF, Rio De Janeiro, 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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000482854000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4125
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Author Arbelaez, C.; Helo, J.C.; Hirsch, M.
Title Long-lived heavy particles in neutrino mass models Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 100 Issue 5 Pages 055001 - 15pp
Keywords
Abstract All extensions of the standard model that generate Majorana neutrino masses at the electroweak scale introduce some heavy mediators, either fermions and/or scalars, weakly coupled to leptons. Here, by “heavy,” we mean implicitly the mass range between a few 100 GeV up to, say, roughly 2 TeV, such that these particles can be searched for at the LHC. We study decay widths of these mediators for several different tree-level neutrino mass models. The models we consider range from the simplest d = 5 seesaw up to d = 11 neutrino mass models. For each of the models, we identify the most interesting parts of the parameter space, where the heavy mediator fields are particularly long lived and can decay with experimentally measurable decay lengths. One has to distinguish two different scenarios, depending on whether fermions or scalars are the lighter of the heavy particles. For fermions, we find that the decay lengths correlate with the inverse of the overall neutrino mass scale. Thus, since no lower limit on the lightest neutrino mass exists, nearly arbitrarily long decay lengths can be obtained for the case in which fermions are the lighter of the heavy particles. For charged scalars, on the other hand, there exists a maximum value for the decay length in these models. This maximum value depends on the model and on the electric charge of the scalar under consideration but can at most be of the order of a few millimeters. Interestingly, independent of the model, this maximum occurs always in a region of parameter space, where leptonic and gauge boson final states have similar branching ratios, i.e., where the observation of lepton number-violating final states from scalar decays is possible.
Address [Arbelaez, Carolina] Univ Tecn Federico Santa Maria, Casilla 110-V, Valparaiso, Chile, Email: carolina.arbelaez@usm.cl;
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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000483583000006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4127
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Author Tang, C.; Gao, F.; Liu, Y.X.
Title Practical scheme from QCD to phenomena via Dyson-Schwinger equations Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 100 Issue 5 Pages 056001 - 16pp
Keywords
Abstract We deliver a scheme to compute the quark propagator and the quark-gluon interaction vertex through the coupled Dyson-Schwinger equations (DSEs) of QCD. We take the three-gluon vertex into account in our calculations, and implement the gluon propagator and the running coupling function fitted by the solutions of their respective DSEs. We obtain the momentum and current mass dependence of the quark propagator and the quark-gluon vertex, and the chiral quark condensate that agrees with previous results excellently. We also compute the quark-photon vertex within this scheme and give the anomalous chromo- and electromagnetic moment of the quark. The obtained results are excellently consistent with previous ones. These applications manifest that the scheme is realistic and then practical for explaining the QCD-related phenomena.
Address [Tang, Can; Liu, Yu-xin] Peking Univ, Dept Phys, Beijing 100871, Peoples R China, Email: yxliu@pku.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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000483583000008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4128
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Author Fileviez Perez, P.; Murgui, C.; Plascencia, A.D.
Title Neutrino-dark matter connections in gauge theories Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 100 Issue 3 Pages 035041 - 14pp
Keywords
Abstract We discuss the connection between the origin of neutrino masses and the properties of dark matter candidates in the context of gauge extensions of the Standard Model. We investigate minimal gauge theories for neutrino masses where the neutrinos arc predicted to be Dirac or Majorana fermions. We find that the upper bound on the effective number of relativistic species provides a strong constraint in the scenarios with Dirac neutrinos. In the context of theories where the lepton number is a local gauge symmetry spontaneously broken at the low scale, the existence of dark matter is predicted from the condition of anomaly cancellation. Applying the cosmological bound on the dark matter relic density, we find an upper bound on the symmetry breaking scale in the multi-TeV region. These results imply that we could test simple gauge theories for neutrino masses at current or future experiments.
Address [Perez, Pavel Fileviez; Plascencia, Alexis D.] Case Western Reserve Univ, Phys Dept, Rockefeller Bldg,2076 Adelbert Rd, Cleveland, OH 44106 USA, Email: pxf112@case.edu;
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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000483349300005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4129
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 tribimaximal mixing. II Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 100 Issue 5 Pages 053001 - 15pp
Keywords
Abstract In this follow up of arXiv:1812.04663 we analyze the generalized CP symmetries of the charged lepton mass matrix compatible with the complex version of the tribimaximal (TBM) lepton mixing pattern. These symmetries are used to “revamp” the simplest TBM Ansatz in a systematic way. Our generalized patterns share some of the attractive features of the original TBM matrix and are consistent with current oscillation experiments. We also discuss their phenomenological implications both for upcoming neutrino oscillation and neutrinoless double beta decay experiments.
Address [Chen, Peng] Ocean Univ China, Coll Informat Sci & Engn, Qingdao 266100, Shandong, 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 (down) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000483938300002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4134
Permanent link to this record