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Author Hirsch, M.; Reichert, L.; Porod, W.; Staub, F.
Title Phenomenology of a supersymmetric U(1)(B-L) x U(1)(R) extension of the standard model with inverse seesaw mechanism Type Journal Article
Year (down) 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 86 Issue 9 Pages 093018 - 26pp
Keywords
Abstract We discuss the minimal supersymmetric U(1)(B-L) X U(1)(R) extension of the standard model. Gauge couplings unify as in the minimal supersymmetric standard model (MSSM), even if the scale of U(1)(B-L) X U(1)(R) breaking is as low as order TeV and the model can be embedded into a SO(10) grand unified theory. The phenomenology of the model differs in some important aspects from the MSSM, leading potentially to rich phenomenology at the LHC. It predicts more light Higgs states and the mostly left CP-even Higgs having a mass that easily reaches 125 GeV, with no constraints on the supersymmetry spectrum. Right sneutrinos can be the lightest supersymmetric particle, changing all dark matter constraints on supersymmetry parameter space. The model has seven neutralinos, and squark/gluino decay chains involve more complicated cascades than in the MSSM. We also briefly discuss low-energy and accelerator constraints on the model, where the most important limits come from recent Z' searches at the LHC and upper limits on lepton flavor violation.
Address [Hirsch, M.; Reichert, L.; Porod, W.] Univ Valencia, CSIC, Inst Fis Corpuscular, Astroparticles & High Energy Phys Grp, E-46071 Valencia, Spain, Email: mahirsch@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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000311142800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1221
Permanent link to this record
 
 
Author Esteves, J.N.; Romao, J.C.; Hirsch, M.; Staub, F.; Porod, W.
Title Supersymmetric type-III seesaw mechanism: Lepton flavor violating decays and dark matter Type Journal Article
Year (down) 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 83 Issue 1 Pages 013003 - 21pp
Keywords
Abstract We study a supersymmetric version of the seesaw mechanism type III. The model consists of the minimal supersymmetric extension of the standard model particle content plus three copies of 24 superfields. The fermionic part of the SU(2) triplet contained in the 24 is responsible for the type-III seesaw, which is used to explain the observed neutrino masses and mixings. Complete copies of 24 are introduced to maintain gauge coupling unification. These additional states change the beta functions of the gauge couplings above the seesaw scale. Using minimal Supergravity boundary conditions, we calculate the resulting supersymmetric mass spectra at the electroweak scale using full 2-loop renormalization group equations. We show that the resulting spectrum can be quite different compared to the usual minimal Supergravity spectrum. We discuss how this might be used to obtain information on the seesaw scale from mass measurements. Constraints on the model space due to limits on lepton flavour violating decays are discussed. The main constraints come from the bounds on μ-> e gamma but there are also regions where the decay tau -> μgamma gives stronger constraints. We also calculate the regions allowed by the dark matter constraint. For the sake of completeness, we compare our results with those for the supersymmetric seesaw type II and, to some extent, with type I.
Address [Esteves, J. N.; Romao, J. C.] Inst Super Tecn, Dept Fis, P-1049001 Lisbon, Portugal, Email: joaomest@cftp.ist.utl.pt
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 1550-7998 ISBN Medium
Area Expedition Conference
Notes ISI:000286765100002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 583
Permanent link to this record
 
 
Author Bartl, A.; Eberl, H.; Herrmann, B.; Hidaka, K.; Majerotto, W.; Porod, W.
Title Impact of squark generation mixing on the search for squarks decaying into fermions at LHC Type Journal Article
Year (down) 2011 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 698 Issue 5 Pages 380-388
Keywords Supersymmetry; Squark; Flavour violation; LHC
Abstract We study the effect of squark generation mixing on squark production and decays at LHC in the Minimal Supersymmetric Standard Model (MSSM). We show that the effect can be very large despite the very strong constraints on quark-flavour violation (QFV) from experimental data on B mesons. We find that the two lightest up-type squarks (u) over bar (1.2) can have large branching ratios for the decays into c (chi) over bar (0)(1) and t (chi) over bar (0)(1) at the same time due to squark generation mixing, leading to QFV signals 'pp -> c (t) over bar (t (c) over bar) + missing-E-T + X' with a significant rate. The observation of this remarkable signature would provide a powerful test of supersymmetric QFV at LHC. This could have a significant impact on the search for squarks and the determination of the underlying MSSM parameters.
Address [Hidaka, K.] Tokyo Gakugei Univ, Dept Phys, Tokyo 1848501, Japan, Email: hidaka@u-gakugei.ac.jp
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 0370-2693 ISBN Medium
Area Expedition Conference
Notes ISI:000290185500005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 630
Permanent link to this record
 
 
Author Hirsch, M.; Reichert, L.; Porod, W.
Title Supersymmetric mass spectra and the seesaw scale Type Journal Article
Year (down) 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages 086 - 32pp
Keywords Supersymmetry Phenomenology
Abstract Supersymmetric mass spectra within two variants of the seesaw mechanism, commonly known as type-II and type-III seesaw, are calculated using full 2-loop RGEs and minimal Supergravity boundary conditions. The type-II seesaw is realized using one pair of 15 and (15) over bar superfields, while the type-III is realized using three copies of 24(M) superfields. Using published, estimated errors on SUSY mass observables attainable at the LHC and in a combined LHC+ILC analysis, we calculate expected errors for the parameters of the models, most notably the seesaw scale. If SUSY particles are within the reach of the ILC, pure mSugra can be distinguished from mSugra plus type-II or type-III seesaw for nearly all relevant values of the seesaw scale. Even in the case when only the much less accurate LHC measurements are used, we find that indications for the seesaw can be found in favourable parts of the parameter space. Since our conclusions crucially depend on the reliability of the theoretically forecasted error bars, we discuss in some detail the accuracies which need to be achieved for the most important LHC and ILC observables before an analysis, such as the one presented here, can find any hints for type-II or type-III seesaw in SUSY spectra.
Address [Hirsch, M; Reichert, L] Univ Valencia, CSIC, AHEP Grp, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: mahirsch@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 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000291364500018 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 685
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Author Krauss, M.B.; Ota, T.; Porod, W.; Winter, W.
Title Neutrino mass from higher than d=5 effective operators in supersymmetry, and its test at the LHC Type Journal Article
Year (down) 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 84 Issue 11 Pages 115023 - 14pp
Keywords
Abstract We discuss neutrino masses from higher than d = 5 effective operators in a supersymmetric framework, where we explicitly demonstrate which operators could be the leading contribution to neutrino mass in the minimal supersymmetric standard model and next to minimal supersymmetric standard model. As an example, we focus on the d = 7 operator LLH(u)H(u)H(d)H(u), for which we systematically derive all tree-level decompositions. We argue that many of these lead to a linear or inverse seesaw scenario with two extra neutral fermions, where the lepton number violating term is naturally suppressed by a heavy mass scale when the extra mediators are integrated out. We choose one example, for which we discuss possible implementations of the neutrino flavor structure. In addition, we show that the heavy mediators, in this case SU(2) doublet fermions, may indeed be observable at the LHC, since they can be produced by Drell-Yan processes and lead to displaced vertices when they decay. However, the direct observation of lepton number violating processes is on the edge at LHC.
Address [Krauss, Martin B.; Porod, Werner; Winter, Walter] Univ Wurzburg, Inst Theoret Phys & Astrophys, D-97074 Wurzburg, Germany, Email: martin.krauss@physik.uni-wuerzburg.de
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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000298642900005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 856
Permanent link to this record