119235421
Gauged B-x(i)L origin of R parity and its implications
Abstract Gauged B − L is a popular candidate for the origin of the conservation of R parity, i.e. R = ( − ) 3 B + L + 2 j , in supersymmetry, but it fails to forbid the effective dimension-five terms arising from the superfield combinations Q Q Q L , u c u c d c e c , and u c d c d c N c , which allow the proton to decay. Changing it to B − x i L , where x e + x μ + x τ = 3 (with x i ≠ 1 ) for the three families, would forbid these terms while still serving as a gauge origin of R parity. We show how this is achieved in two minimal models with realistic neutrino mass matrices, and discuss their phenomenological implications.
118567798
Long-range interaction effects on neutrino oscillation
Motivated by the recent anomaly in the muon neutrino and anti-muon neutrino disappearance experiments, we consider a long-range interaction with an extremely light gauge boson and extraordinarily weak coupling. A long-range interaction, consistent with current bounds, could have very pronounced effects on atmospheric neutrino disappearance that will be studied with the IceCube DeepCore array, currently in operation, and can have a significant effect on future high-precision long-baseline oscillation experiments. This invited talk was based on the paper with Hooman Davoudiasl and William Marciano [1].
119280824
Four-lepton resonance at the Large Hadron Collider
New physics models admit the interesting possibility of a Z{sup '} weak boson associated with an extra U(1) gauge symmetry and a Higgs boson that is heavy enough to decay into a pair of Z bosons. Then Z{sup '} production and decay via Z{sup '}->ZH->ZZZ has a distinctive LHC signal that is nearly background-free and reconstructs the H and Z{sup '} masses and widths. The Z{sup '} decay to 3 pairs of leptons is especially distinctive. The ZH decay mode exists even if the Z{sup '} is decoupled from leptons, which motivates an independent 6-lepton resonance search regardless of the dilepton search results.
118173341
Lightest U‐parity Particle (LUP): a hidden sector dark matter candidate
We introduce a new dark matter candidate, the lightest U‐parity particle (LUP). We suggest it as a good dark matter candidate especially in the R‐parity violating supersymmetric model.
118692473
“Dark” Z implications for parity violation, rare meson decays, and Higgs physics
General consequences of mass mixing between the ordinary Z boson and a relatively light Z_d boson, the "dark" Z, arising from a U(1)_d gauge symmetry, associated with a hidden sector such as dark matter, are examined. New effects beyond kinetic mixing are emphasized. Z-Z_d mixing introduces a new source of low energy parity violation well explored by possible future atomic parity violation and planned polarized electron scattering experiments. Rare K (B) meson decays into pi (K) l^+ l^- (l = e, mu) and pi (K) nu anti-nu are found to already place tight constraints on the size of Z-Z_d mixing. Those sensitivities can be further improved with future dedicated searches at K and B factories as well as binned studies of existing data. Z-Z_d mixing can also lead to the Higgs decay H -> Z Z_d, followed by Z -> l_1^+ l_1^- and Z_d -> l_2^+ l_2^- or "missing energy", providing a potential hidden sector discovery channel at the LHC. An illustrative realization of these effects in a 2 Higgs doublet model is presented.
118614634
Dark side of Higgs diphoton decays and muon g − 2
We propose that the LHC hints for a Higgs diphoton excess and the muon g-2 (g_mu-2) discrepancy between theory and experiment may be related by vector-like "leptons" charged under both U(1)_Y hypercharge and a "dark" U(1)_d. Quantum loops of such leptons can enhance the Higgs diphoton rate and also generically lead to U(1)_Y - U(1)_d kinetic mixing. The induced coupling of a light U(1)_d gauge boson Z_d to electric charge can naturally explain the measured g_mu-2. We update Z_d mass and coupling constraints based on comparison of the electron g-2 experiment and theory, and find that explaining g_mu-2 while satisfying other constraints requires Z_d to have a mass ~ 20-100 MeV. We predict new Higgs decay channels gamma Z_d and Z_d Z_d, with rates below the diphoton mode but potentially observable. The boosted Z_d -> e+e- in these decays would mimic a promptly converted photon and could provide a fraction of the apparent diphoton excess. More statistics or a closer inspection of extant data may reveal such events.
92983543
Dark matter, {mu} problem, and neutrino mass with gauged R symmetry
We show that the {mu} problem and the strong CP problem can be resolved in the context of the gauged U(1){sub R} symmetry, realizing an automatic Peccei-Quinn symmetry. In this scheme, right-handed neutrinos can be introduced to explain small Majorana or Dirac neutrino mass. The U(1){sub R} D-term mediated supersymmetry (SUSY) breaking, called the U(1){sub R} mediation, gives rise to a specific form of the flavor-conserving superpartner masses. For the given solution to the {mu} problem, electroweak symmetry breaking condition requires the superpartners of the standard model at low energy to be much heavier than the gravitino. Thus, the dark matter candidate can be either gravitino or right-handed sneutrino. In the Majorana neutrino case, only gravitino is a natural dark matter candidate. On the other hand, in the Dirac neutrino case, the right-handed sneutrino can be also a dark matter candidate as it gets mass only from SUSY breaking. We discuss the non-thermal production of our dark matter candidates from the late decay of stau and find that the constraints from the big bang nucleosynthesis can be evaded for a TeV-scale stau mass.
1498438
Gravitino in six-dimensional warped supergravity
Abstract We consider the gravitino spectrum for the general warped solution in a specific six-dimensional gauged supergravity. We find that although the brane tensions introduced at the conical singularities break the bulk supersymmetry explicitly, massless modes of the gravitino can exist with a nontrivial wave function profile, due to a nonzero U ( 1 ) R gauge flux. We also compute the wave function and the mass spectrum of Kaluza–Klein massive modes of the gravitino explicitly. We show that the introduction of a gravitino mass term on a regularized brane can give a suppressed effective gravitino mass compared to the compactification scale, due to the delocalization of the wave function of the zero-mode gravitino.
10538564
Anomalies on orbifolds with gauge symmetry breaking
We embed two 4D chiral multiplets of opposite representations in the 5D N = 2 SU(N+K) gauge theory compactified on an orbifold S1/(Z2 ? Z'2). There are two types of orbifold boundary conditions in the extra dimension to obtain the 4D N = 1 SU(N) ? SU(K) ? U(1) gauge theory from the bulk: in type-I, one has the bulk gauge group at y = 0 and the unbroken gauge group at y = ?R/2 while in type-II, one has the unbroken gauge group at both fixed points. In both types of orbifold boundary conditions, we consider the zero mode(s) as coming from a bulk (K+N)-plet and brane fields at the fixed point(s) with the unbroken gauge group. We check the consistency of this embedding of fields by the localized anomalies and the localized FI terms. We show that the localized anomalies in type-I are cancelled exactly by the introduction of a bulk Chern-Simons term. On the other hand, in some class of type-II, the Chern-Simons term is not enough to cancel all localized anomalies even if they are globally vanishing. We also find that for the consistent embedding of brane fields, there appear only the localized log FI terms at the fixed point(s) with a U(1) factor.
10943748
Higher derivatives and brane-localised kinetic terms in gauge theories on orbifolds
We perform a detailed analysis of one-loop corrections to the self-energy of the (off-shell) gauge bosons in six-dimensional = 1 supersymmetric gauge theories on orbifolds. After discussing the Abelian case in the standard Feynman diagram approach, we extend the analysis to the non-Abelian case by employing the method of an orbifold-compatible one-loop effective action for a classical background gauge field. We find that bulk higher derivative and brane-localised gauge kinetic terms are required to cancel one-loop divergences of the gauge boson self energy. After their renormalisation we study the momentum dependence of both the higher derivative coupling h(k2) and the effective gauge coupling geff(k2). For momenta smaller than the compactification scales, we obtain the 4D logarithmic running of geff(k2), with suppressed power-like corrections, while the higher derivative coupling is constant. We present in detail the threshold corrections to the low energy gauge coupling, due to the massive bulk modes. At momentum scales above the compactification scales, the higher derivative operator becomes important and leads to a power-like running of geff(k2) with respect to the momentum scale. The coefficient of this running is at all scales equal to the renormalised coupling of the higher derivative operator which ensures the quantum consistency of the model. We discuss the relation to the similar one-loop correction in the heterotic string, to show that the higher derivative operators are relevant in that case too, since the field theory limit of the one-loop string correction does not commute with the infrared regularisation of the (on-shell) string result.
16830627
U(1)R-mediated supersymmetry breaking from a six-dimensional flux compactification
We study the U(1)R-mediated supersymmetry breaking in a flux compactification of 6D chiral gauged supergravity with codimension-two branes. We consider a concrete model with manifest U(1)R invariance for moduli stabilization and visible sector in the context of 4D effective supergravity with gauged U(1)R and determine soft scalar masses in the visible sector mainly by a nonzero U(1)R D-term. We obtain a low energy superparticle spectrum and discuss on the implications of the obtained non-universal scalar soft masses on the SUSY phenomenology such as dark matter relic abundances.