Showing papers on "Superpotential published in 2008"
TL;DR: In this paper, the authors studied the SU(4 R-symmetry of the ABJM theory and showed that it is dual to the U(1)_R x SU(3) invariant extremum of the N=8 superconformal gauge theory with a sextic superpotential.
Abstract: We discuss the N=2 superspace formulation of the N=8 superconformal Bagger-Lambert-Gustavsson theory, and of the N=6 superconformal Aharony-Bergman-Jafferis-Maldacena U(N)xU(N) Chern-Simons theory. In particular, we prove the full SU(4) R-symmetry of the ABJM theory. We then consider orbifold projections of this theory that give non-chiral and chiral (U(N)xU(N))^n superconformal quiver gauge theories. We argue that these theories are dual to certain AdS_4 x S^7/(Z_n x Z_k) backgrounds of M-theory. We also study a SU(3) invariant mass term in the superpotential that makes the N=8 theory flow to a N=2 superconformal gauge theory with a sextic superpotential. We conjecture that this gauge theory is dual to the U(1)_R x SU(3) invariant extremum of the N=8 gauged supergravity, which was discovered by N. Warner 25 years ago and whose uplifting to 11 dimensions was found more recently.
508 citations
TL;DR: In this article, the N = 2 superspace formulation of the Bagger-Lambert-Gustavsson theory was studied and the full SU(4)R-symmetry of the ABJM theory was proved.
Abstract: We discuss the N = 2 superspace formulation of the N = 8 superconformal Bagger-Lambert-Gustavsson theory, and of the N = 6 superconformal Aharony-Bergman-Jafferis-Maldacena U(N) x U(N) Chern-Simons theory. In particular, we prove the full SU(4)R-symmetry of the ABJM theory. We then consider orbifold projections of this theory that give non-chiral and chiral (U( N) x U(N))(n) superconformal quiver gauge theories. We argue that these theories are dual to certain AdS(4) x S-7/(Z(n) x Z (k$) over tilde) backgrounds of M-theory. We also study a SU(3) invariant mass term in the superpotential that makes the N = 8 theory flow to a N = 2 superconformal gauge theory with a sextic superpotential. We conjecture that this gauge theory is dual to the U(1)(R) x SU(3) invariant extremum of the N = 8 gauged supergravity, which was discovered by N. Warner 25 years ago and whose uplifting to 11 dimensions was found more recently.
494 citations
TL;DR: In this article, the authors studied the topological conditions for general Calabi-Yaus to get a non-supersymmetric AdS exponentially large volume minimum of the scalar potential in flux compactifications of IIB string theory.
Abstract: We study the topological conditions for general Calabi-Yaus to get a non-supersymmetric AdS exponentially large volume minimum of the scalar potential in flux compactifications of IIB string theory. We show that negative Euler number and the existence of at least one blow-up mode resolving point-like singularities are necessary and sufficient conditions for moduli stabilisation with exponentially large volumes. We also analyse the general effects of string loop corrections on this scenario. While the combination of α' and nonperturbative corrections are sufficient to stabilise blow-up modes and the overall volume, quantum corrections are needed to stabilise other directions transverse to the overall volume. This allows exponentially large volume minima to be realised for fibration Calabi-Yaus, with the various moduli of the fibration all being stabilised at exponentially large values. String loop corrections may also play a role in stabilising 4-cycles which support chiral matter and cannot enter directly into the non-perturbative superpotential. We illustrate these ideas by studying the scalar potential for various Calabi-Yau three-folds including K3 fibrations and briefly discuss the potential phenomenological and cosmological implications of our results.
250 citations
TL;DR: In this paper, a general analysis on the possibility of obtaining metastable vacua with spontaneously broken N = 1 supersymmetry and non-negative cosmological constant in the moduli sector of string models is presented.
Abstract: We perform a general analysis on the possibility of obtaining metastable vacua with spontaneously broken N = 1 supersymmetry and non-negative cosmological constant in the moduli sector of string models. More specifically, we study the condition under which the scalar partners of the Goldstino are non-tachyonic, which depends only on the Kahler potential. This condition is not only necessary but also sufficient, in the sense that all of the other scalar fields can be given arbitrarily large positive square masses if the superpotential is suitably tuned. We consider both heterotic and orientifold string compactifications in the large-volume limit and show that the no-scale property shared by these models severely restricts the allowed values for the 'sGoldstino' masses in the superpotential parameter space. We find that a positive mass term may be achieved only for certain types of compactifications and specific Goldstino directions. Additionally, we show how subleading corrections to the Kahler potential which break the no-scale property may allow to lift these masses.
223 citations
TL;DR: In this paper, the authors construct several (2+1) dimensional = 2 supersymmetric Chern-Simons theories, whose moduli space is given by non-compact toric Calabi-Yau four-folds.
Abstract: We construct several examples of (2+1) dimensional = 2 supersymmetric Chern-Simons theories, whose moduli space is given by non-compact toric Calabi-Yau four-folds, which are not derivable from any (3+1) dimensional CFT. One such example is the gauge theory associated with the cone over Q111. For several examples, we explicitly confirm the matter content, superpotential interactions and RG flows suggested by crystal models. Our results provide additional support to the idea that crystal models are relevant for describing the structure of these CFTs.
147 citations
TL;DR: In this article, the authors considered string theory compactifications of the form AdS4 x M6 with orientifold six-planes, where M6 is a six-dimensional compact space that is either a nilmanifold or a coset.
Abstract: We consider string theory compactifications of the form AdS4 x M6 with orientifold six-planes, where M6 is a six-dimensional compact space that is either a nilmanifold or a coset. For all known solutions of this type we obtain the four-dimensional N=1 low energy effective theory by computing the superpotential, the Kaehler potential and the mass spectrum for the light moduli. For the nilmanifold examples we perform a cross-check on the result for the mass spectrum by calculating it alternatively from a direct Kaluza-Klein reduction and find perfect agreement. We show that in all but one of the coset models all moduli are stabilized at the classical level. As an application we show that all but one of the coset models can potentially be used to bypass a recent no-go theorem against inflation in type IIA theory.
144 citations
TL;DR: In this paper, the authors consider the metastable N = 1 QCD model of Intriligator, Seiberg and Shih (ISS), deformed by adding a baryon term to the superpotential.
132 citations
Posted Content•
TL;DR: In this article, instantons correspond to Euclidean 3-branes which form a threshold bound state with spacetime filling 7branes and their contributions to the effective 4d superpotential can be determined in both perturbative string theory as well as directly via the topologically twisted theory on the 3brane world volume.
Abstract: We study instanton contributions to the superpotential of local F-theory compactifications which could potentially be used to engineer models of dynamical supersymmetry breaking. These instantons correspond to Euclidean 3-branes which form a threshold bound state with spacetime filling 7-branes. In certain cases, their contributions to the effective 4d superpotential can be determined in both perturbative string theory as well as directly via the topologically twisted theory on the 3-brane worldvolume, and in all cases we observe an exact match between these results. We further present an instanton generated Polonyi-like model, and characterize subleading corrections to the superpotential which arise from multi-instantons. We also study instanton contributions to 4d pure N=1 SU(N) gauge theory realized by a stack of 7-branes wrapping a rigid 4-cycle and find that there is a non-trivial contribution to the glueball superpotential from the single instanton sector. This correction is absent in the purely 4d theory and could conceivably be used either to stabilize moduli or to break supersymmetry.
121 citations
TL;DR: In this paper, the spectrum of short multiplets around the extremum of N=8 gauged supergravity potential was calculated using group theoretic methods, and it was shown that the monopole operators have a number of desired properties, such as supersymmetry and SU(3) global symmetry.
Abstract: We use group theoretic methods to calculate the spectrum of short multiplets around the extremum of N=8 gauged supergravity potential which possesses N=2 supersymmetry and SU(3) global symmetry. Upon uplifting to M-theory, it describes a warped product of AdS_4 and a certain squashed and stretched 7-sphere. We find quantum numbers in agreement with those of the gauge invariant operators in the N=2 superconformal Chern-Simons theory recently proposed to be the dual of this M-theory background. This theory is obtained from the U(N)xU(N) theory through deforming the superpotential by a term quadratic in one of the superfields. To construct this model explicitly, one needs to employ monopole operators whose complete understanding is still lacking. However, for the U(2)xU(2) gauge theory we make a proposal for the form of the monopole operators which has a number of desired properties. In particular, this proposal implies enhanced symmetry of the U(2)xU(2) ABJM theory for k=1,2; it makes its similarity to and subtle difference from the BLG theory quite explicit.
120 citations
TL;DR: In this paper, the physics of D-brane theories that exhibit dynamical SUSY breaking due to stringy instanton effects is well captured by geometric transitions, which recast the nonperturbative superpotential as a classical flux super-potential.
114 citations
TL;DR: In this paper, a unified view of the previous results in the literature and new exact solutions and new asymptotic solutions were presented, giving a resolution to an old puzzle related to the beta function and a sufficient criteria for screening.
Abstract: We study the string dual to $N=1$ supersymmetric QCD deformed by a quartic superpotential in the quark superfields. We present a unified view of the previous results in the literature and find new exact solutions and new asymptotic solutions. Then we study the physics encoded in these backgrounds, giving, among other things, a resolution to an old puzzle related to the beta function and a sufficient criteria for screening. We also extend our results to the $SO({N}_{c})$ case where we present a candidate for the Wilson loop in the spinorial representation. Various aspects of this line of research are critically analyzed.
TL;DR: In this article, Euclidean E3-branes are used to induce non-perturbative scalar couplings including exponentially suppressed scalar bilinears, which are consistent with the U(1) symmetries carried by the D3/D7 branes.
Abstract: We study different aspects of the non-perturbative superpotentials induced by Euclidean E3-branes on systems of D3/D7-branes located at Abelian orbifold singularities. We discuss in detail how the induced couplings are consistent with the U(1) symmetries carried by the D3/D7 branes. We construct different compact and non-compact examples, and show phenomenologically relevant couplings like μ-terms or certain Yukawa couplings generated by these E3 instantons. Some other novel effects are described. We show an example where E3 instantons combine with standard gauge instantons to yield new multi-instanton effects contributing to superpotential, along the lines of ref. [28]. In the case of non-SUSY ZN tachyon-free singularities it is shown how E3-instantons give rise to non perturbative scalar couplings including exponentially suppressed scalar bilinears.
Posted Content•
TL;DR: In this article, a systematic investigation of the space of 2+1 dimensional quiver gauge theories is initiated, with a succinct forward algorithm, and the authors show how these theories arise from M2-branes probing toric Calabi-Yau 4-folds by explicitly obtaining the toric data.
Abstract: We initiate a systematic investigation of the space of 2+1 dimensional quiver gauge theories, emphasising a succinct "forward algorithm". Few "order parametres" are introduced such as the number of terms in the superpotential and the number of gauge groups. Starting with two terms in the superpotential, we find a generating function, with interesting geometric interpretation, which counts the number of inequivalent theories for a given number of gauge groups and fields. We demonstratively list these theories for some low numbers thereof. Furthermore, we show how these theories arise from M2-branes probing toric Calabi-Yau 4-folds by explicitly obtaining the toric data of the vacuum moduli space. By observing equivalences of the vacua between markedly different theories, we see a new emergence of "toric duality".
TL;DR: In this article, it was shown that the Ext algebra of S as an A -module, enriched with its natural A -infinity structure, can be used to reconstruct the completion of A at the augmentation ideal.
TL;DR: In this paper, a supersymmetric extension of the Standard Model based on discrete A4 × Z3 × Z4 flavor symmetry is studied and the top quark Yukawa interaction is present at renormalizable level in the superpotential while all the other Yukawa interactions arise only at higher orders.
Abstract: We study a supersymmetric extension of the Standard Model based on discrete A4 × Z3 × Z4 flavor symmetry. We obtain quark mixing angles as well as a realistic fermion mass spectrum and we predict tribimaximal leptonic mixing by a spontaneous breaking of A4. The top quark Yukawa interaction is present at the renormalizable level in the superpotential while all the other Yukawa interactions arise only at higher orders. We study the Higgs potential and show that it can potentially solve the so called vacuum alignment problem. The leading order predictions are not spoiled by subleading corrections.
Posted Content•
TL;DR: In this paper, it was shown that any N-Koszul, twisted Calabi-Yau algebra must have a superpotential and construct its minimal resolution in terms of derivations of the (twisted) potential.
Abstract: We consider algebras defined from quivers with relations that are k-th order derivations of a superpotential, generalizing results of Dubois-Violette to the quiver case. We give a construction compatible with Morita equivalence, and show that many important algebras arise in this way, including McKay correspondence algebras for GL_n for all n, and four-dimensional Sklyanin algebras. More generally, we show that any N-Koszul, (twisted) Calabi-Yau algebra must have a (twisted) superpotential, and construct its minimal resolution in terms of derivations of the (twisted) superpotential. This yields an equivalence between N-Koszul twisted Calabi-Yau algebras A and algebras defined by a superpotential such that an associated complex is a bimodule resolution of A. Finally, we apply these results to give a description of the moduli space of four-dimensional Sklyanin algebras using the Weil representation of SL_2(Z/4).
TL;DR: The behavior of non-perturbative superpotentials in 4d N = 1 type II compactifications near lines of marginal stability has been studied in this article, where the spectrum of contributing BPS D-brane instantons changes discontinuously.
Abstract: We discuss the behaviour of non-perturbative superpotentials in 4d N = 1 type II compactifications (and orientifolds thereof) near lines of marginal stability, where the spectrum of contributing BPS D-brane instantons changes discontinuously. The super- potential is nevertheless continuous, in agreement with its holomorphic dependence on the closed string moduli. The microscopic mechanism ensuring this continuity involves novel contributions to the superpotential: As an instanton becomes unstable against decay to several instantons, the latter provide a multi-instanton contribution which reconstructs that of the single-instanton before decay. The process can be understood as a non-perturbative lifting of additional fermion zero modes of an instanton by interactions induced by other instantons. These effects provide mechanisms via which instantons with U(1) symmetry can contribute to the superpotential. We provide explicit examples of these effects for non-gauge D-brane instantons, and for D-brane gauge instantons (where the motions in moduli space can be interpreted as Higgsing, or Seiberg dualities).
TL;DR: In this paper, it was shown that it is possible to derive non-perturbative superpotential terms from a stringy instanton without introducing orientifold planes, where the instanton is realized by a Euclidean D brane wrapping a non-trivial cycle upon which we also wrap a single space-filling d brane.
Abstract: In this paper we show that it is possible to derive non-perturbative superpotential terms from a stringy instanton without introducing orientifold planes. The instanton is realized by a Euclidean D brane wrapping a non-trivial cycle upon which we also wrap a single space-filling D brane. The standard problem of unwanted neutral fermionic zero modes is evaded by the appearance of couplings to charged bosonic zero modes in the instanton moduli action. Since the Euclidean D brane wraps a cycle which is not associated to any low energy gauge dynamics, it can not be interpreted as an ordinary gauge instanton, but rather as a stringy one. By considering such a brane configuration at an orbifold singularity, we can explicitly evaluate the instanton moduli space integral and find a holomorphic superpotential term with the structure of a baryonic mass term.
TL;DR: This work constructs the first globally consistent semirealistic type I string vacua on an elliptically fibered manifold where the zero modes of the Euclidean D1-instanton sector allow for the generation of nonperturbative Majorana masses of an intermediate scale.
Abstract: We construct the first globally consistent semi-realistic Type I string vacua on an elliptically fibered manifold where the zero modes of the Euclidean D1-instanton sector allow for the generation of non-perturbative Majorana masses of an intermediate scale. In another class of global models, a D1-brane instanton can generate a Polonyi-type superpotential breaking supersymmetry at an exponentially suppressed scale.
TL;DR: This work deals with defect structures in models described by scalar fields with the kinetic term modified to allow for a diversity of possibilities, and develops a new framework which searches for first-order differential equations which solve the equations of motion.
TL;DR: In this article, it was shown that a 4D N = 1 supersymmetric theory with higher derivative operators in either the Kahler or the superpotential part of the Lagrangian and with an arbitrary super-potential, is equivalent to a second order theory of second order with additional superfields and renormalised interactions.
Abstract: Using a superfield language it is shown that a 4D N=1 supersymmetric theory with higher derivative operators in either the Kahler or the superpotential part of the Lagrangian and with an otherwise arbitrary superpotential, is equivalent to a 4D N=1 theory of second order (i.e. without higher derivatives) with additional superfields and renormalised interactions. If the theory has no other higher dimensional operators, under additional assumptions for the analytical continuation Minkowski-Euclidean space, the theory can be renormalisable. We provide examples where a free theory with trivial supersymmetry breaking provided by a linear superpotential becomes, in the presence of higher derivatives terms and in the second order version, a non-trivial interactive one with spontaneous supersymmetry breaking. The couplings of the equivalent theory acquire a threshold correction through their dependence on the scale of the higher dimensional operator(s). The scalar potential in the second order theory is not necessarily positive definite, and one can in principle have a vanishing potential with broken supersymmetry. We provide an application to MSSM and argue that at tree-level and for a mass scale associated to a higher derivative term in the TeV range, the Higgs mass can be lifted above the current experimental limits.
TL;DR: Ambjorn, R. Loll, Y. Watabiki, W. Westra, S. Zohren as mentioned in this paper showed that the Dyson-Schwinger equations of this string field theory are reproduced by a cubic matrix model.
TL;DR: Misra et al. as mentioned in this paper showed the possibility of slow roll axionic inflation in the large volume limit of Swiss cheese Calabi-Yau orientifold compactifications of type IIB string theory.
TL;DR: In this article, the authors considered non-Abelian Bogomol'nyi-Prasad-Sommerfield-saturated flux tubes (strings) in N = 2 supersymmetric QCD deformed by superpotential terms of a special type breaking N=2 supersymmetry down to N=1.
Abstract: We consider non-Abelian Bogomol'nyi-Prasad-Sommerfield-saturated flux tubes (strings) in N=2 supersymmetric QCD deformed by superpotential terms of a special type breaking N=2 supersymmetry down to N=1. Previously it was believed that world sheet supersymmetry is accidentally enhanced due to the facts that N=(1,1) supersymmetry is automatically elevated up to N=(2,2) on CP(N-1) and, at the same time, there are no N=(0,2) generalizations of the bosonic CP(N-1) model. Edalati and Tong noted that the target space is in fact CP(N-1)xC rather than CP(N-1). This allowed them to suggest a heterotic N=(0,2) sigma model, with the CP(N-1) target space for bosonic fields and an extra right-handed fermion which couples to the fermion fields of the N=(2,2) CP(N-1) model. We derive the heterotic N=(0,2) world sheet model directly from the bulk theory. The relation between the bulk and world sheet deformation parameters we obtain does not coincide with that suggested by Edalati and Tong at large values of the deformation parameter. For polynomial deformation superpotentials in the bulk we find nonpolynomial response in the world sheet model. We find a geometric representation for the heterotic model. Supersymmetry is proven to be spontaneously broken for small deformations (at the quantum level). This confirms Tong's conjecture.more » A proof valid for large deformations will be presented in the subsequent publication.« less
TL;DR: In this paper, the existence of poly-instanton corrections to holomorphic couplings in four-dimensional N = 1 supersymmetric string compactifications has been investigated and shown to have a power tower-like proliferation of instanton corrections.
Abstract: We provide arguments for the existence of novel hereinafter called poly-instanton corrections to holomorphic couplings in four-dimensional N = 1 supersymmetric string compactifications After refining quantitatively the D-brane instanton calculus for corrections to the gauge kinetic function, we explicitly apply it to the Type I toroidal orbifold defined in arXiv:07103080 and compare the results to the proposed heterotic S-dual model This leads us to the intriguing conclusion that N = 1 string vacua feature a power tower like proliferation of instanton corrections
TL;DR: In this article, the authors consider nonperturbative terms in the 4D effective action due to BPS Dbrane instantons, and study their continuity properties in moduli space as instantons cross lines of BPS stability, potentially becoming non-BPS.
Abstract: We consider non-perturbative terms in the 4d effective action due to BPS D-brane instantons, and study their continuity properties in moduli space as instantons cross lines of BPS stability, potentially becoming non-BPS. We argue that BPS instantons contributing to the superpotential cannot become non-BPS anywhere in moduli space, since they cannot account for the required four goldstino fermion zero modes. At most they can reach lines of threshold stability, where they split into mutually BPS multi-instantons, as already discussed in the literature. On the other hand, instantons with additional fermion zero modes, contributing to multi-fermion F-terms, can indeed cross genuine lines of marginal stability, beyond which they lead to non-BPS systems. The non-BPS instanton generates an operator which is a D-term locally in moduli space, but not globally. This is due to a cohomological obstruction localized on the BPS locus, where the D-term must be written as an F-term, thus ensuring the continuity of the 4d contribution to the effective action. We also point out an interesting relation between lifting of fermion zero modes on instantons and 4d supersymmetry breaking.
TL;DR: In this paper, rolling tachyon solutions of open and boundary string field theory (OSFT and BSFT, respectively), in the bosonic and supersymmetric (susy) case, were constructed.
Abstract: We construct rolling tachyon solutions of open and boundary string field theory (OSFT and BSFT, respectively), in the bosonic and supersymmetric (susy) case. The wildly oscillating solution of susy OSFT is recovered, together with a family of time-dependent BSFT solutions, for the bosonic and susy string. These are parametrized by an arbitrary constant r involved in solving the Green equation of the target fields. When r=0 we recover previous results in BSFT, whereas for r attaining the value predicted by OSFT it is shown that the bosonic OSFT solution is the derivative of the boundary one; in the supersymmetric case the relation between the two solutions is more complicated. This technical correspondence sheds some light on the nature of wild oscillations, which appear in both theories whenever r>0.
TL;DR: In this article, an extension of the minimal supersymmetric standard model (MSSM) by adding a hypercharge-neutral, $SU(2)$-triplet chiral superfield was considered.
Abstract: We revisit an extension of the minimal supersymmetric standard model (MSSM) by adding a hypercharge-neutral, $SU(2)$-triplet chiral superfield. Similar to the next-to-minimal supersymmetric standard model , the triplet gives an additional contribution to the quartic coupling in the Higgs potential, and the mass of the lightest $CP$-even Higgs boson can be greater than ${M}_{Z}$ at tree level. In addition to discussing the perturbativity, fine-tuning, and decoupling issues of this model, we compute the dominant 1-loop corrections to the mass of the lightest $CP$-even Higgs boson from the triplet sector. When the Higgs-Higgs-Triplet coupling in the superpotential is comparable to the top Yukawa coupling, we find that the Higgs mass can be as heavy as 140 GeV even without the traditional contributions from the top--s-top sector, and at the same time consistent with the precision electroweak constraints. At the expense of having Landau poles before the grand unified theory scale, this opens up a previously forbidden region in the MSSM parameter space where both s-tops are light. In addition to having relatively small fine-tuning (about one part in 30), this leads to a gluophilic Higgs boson whose production via gluon-gluon fusion at the CERN LHC can be twice as large as the standard model prediction.
TL;DR: In this article, the metastable vacua in supersymmetric QCD in the presence of single and multitrace deformations of the superpotential are explored, with the aim of obtaining an acceptable phenomenology.
Abstract: Metastable vacua in supersymmetric QCD in the presence of single and multitrace deformations of the superpotential are explored, with the aim of obtaining an acceptable phenomenology. The metastable vacua appear at one loop, have a broken R-symmetry, and a magnetic gauge group that is completely Higgsed. With only a single trace deformation, the adjoint fermions from the meson superfield are approximately massless at one loop, even though they are massive at tree level and R-symmetry is broken. Consequently, if charged under the standard model, they are unacceptably light. A multitrace quadratic deformation generates fermion masses proportional to the deformation parameter. Phenomenologically viable models of direct gauge mediation can then be obtained, and some of their features are discussed.
TL;DR: In this article, the effect of canonical normalization on the fermion mixing angles was investigated in the context of locally supersymmetric models of flavour, where the necessary procedure of redefining the fields in order to restore canonically normalised kinetic terms, i.e. canonical normalisation, can lead to significant corrections to the fermanion mixing angle.
Abstract: We re-analyse the effect of corrections from canonical normalisation of kinetic terms on the quark and lepton mixing angles. This type of corrections emerges, for example, from effective higher-dimensional Kahler potential operators in the context of locally supersymmetric models of flavour. In contrast to previous studies we find that the necessary procedure of redefining the fields in order to restore canonically normalised kinetic terms, i.e. canonical normalisation, can lead to significant corrections to the fermion mixing angles (as determined from the superpotential). Such potentially large effects are characteristic of flavour models based on non-Abelian family symmetries, where some of the possible Kahler potential (and superpotential) operators, in particular those associated with the third family, are only mildly suppressed. We investigate under which conditions the messenger sector of such flavour models generates such Kahler potential operators for which the canonical normalisation effects are sizeable, and under which conditions these operators may be absent and canonical normalisation effects are small. As explicit examples for potentially relevant CN effects, we will discuss the corrections to the CKM matrix element |Vcb| as well as corrections to tri-bimaximal neutrino mixing.