Showing papers on "Gauge boson published in 2002"
TL;DR: In this article, a general relation between theories of infinite number of higher-spin massless gauge fields in AdS d + 1 and large N conformal theories in d dimensions containing N -component vector fields was proposed.
1,260 citations
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TL;DR: In this paper, an economical theory of natural electroweak symmetry breaking was proposed, which stabilizes the electroweak scale with a naturally light Higgs and weakly coupled new physics at TeV energies.
Abstract: We present an economical theory of natural electroweak symmetry breaking, generalizing an approach based on deconstruction. This theory is the smallest extension of the Standard Model to date that stabilizes the electroweak scale with a naturally light Higgs and weakly coupled new physics at TeV energies. The Higgs is one of a set of pseudo Goldstone bosons in an SU(5)/SO(5) nonlinear sigma model. The symmetry breaking scale f is around a TeV, with the cutoff Λ4πf ~ 10 TeV. A single electroweak doublet, the `little Higgs', is automatically much lighter than the other pseudo Goldstone bosons. The quartic self-coupling for the little Higgs is generated by the gauge and Yukawa interactions with a natural size (g2, λt2), while the top Yukawa coupling generates a negative mass squared triggering electroweak symmetry breaking. Beneath the TeV scale the effective theory is simply the minimal Standard Model. The new particle content at TeV energies consists of one set of spin one bosons with the same quantum numbers as the electroweak gauge bosons, an electroweak singlet quark with charge 2/3, and an electroweak triplet scalar. One loop quadratically divergent corrections to the Higgs mass are cancelled by interactions with these additional particles.
1,004 citations
TL;DR: In this article, the supergravity dual of the D7-D3 system was shown to be a type IIA configuration and the general type IIB solutions of this type were discussed.
Abstract: We consider configurations of D7-branes and whole and fractional D3-branes with $\mathcal{N}=2$ supersymmetry. On the supergravity side these have a warp factor, three-form flux and a nonconstant dilaton. We discuss general type IIB solutions of this type and then obtain the specific solutions for the D7-D3 system. On the gauge side the D7-branes add matter in the fundamental representation of the D3-brane gauge theory. We find that the gauge and supergravity metrics on moduli space agree. However, in many cases the supergravity curvature is large even when the gauge theory is strongly coupled. In these cases we argue that the useful supergravity dual must be a type IIA configuration.
375 citations
TL;DR: In this paper, the authors make explicit the statement that the minimal supersymmetric (SUSY) SU(5) model has been excluded by the SuperKamiokande search for the process.
Abstract: We make explicit the statement that the minimal supersymmetric (SUSY) SU(5) model has been excluded by the SuperKamiokande search for the process $\stackrel{\ensuremath{\rightarrow}}{p}{K}^{+}\overline{\ensuremath{
u}}.$ This exclusion is made by first placing limits on the colored Higgs triplet mass, by forcing the gauge couplings to unify. We also show that taking the superpartners of the first two generations to be very heavy in order to avoid flavor changing neutral currents, the so-called ``decoupling'' idea, is insufficient to resurrect the minimal SUSY SU(5). We comment on various mechanisms to further suppress proton decay in SUSY SU(5). Finally, we address the contributions to proton decay from gauge boson exchange in the minimal SUSY SU(5) and flipped SU(5) models.
342 citations
TL;DR: In this article, it was shown that the final-state interaction effects in the single target spin asymmetry discovered by Brodsky et al. can be reproduced by either a standard light-cone gauge definition of the parton distributions with a prescription for the lightcone singularities consistent with the light cone gauge link, or a modified lightcone gauge defined with a gauge link involving the gauge potential at the spatial infinity.
272 citations
TL;DR: In this paper, the Higgs potential is generated by the gauge and Yukawa interactions, and is distinctly different from that of the minimal supersymmetric standard model, and the new bosonic degrees of freedom are a single neutral complex scalar and a second copy of U(1)$ gauge bosons.
Abstract: We construct an $\mathrm{SU}(6)/Sp(6)$ non-linear sigma model in which the Higgs bosons arise as pseudo Goldstone bosons. There are two Higgs doublets whose masses have no one-loop quadratic sensitivity to the cutoff of the effective theory, which can be at around 10 TeV. The Higgs potential is generated by gauge and Yukawa interactions, and is distinctly different from that of the minimal supersymmetric standard model. At the TeV scale, the new bosonic degrees of freedom are a single neutral complex scalar and a second copy of $\mathrm{SU}(2)\ifmmode\times\else\texttimes\fi{}U(1)$ gauge bosons. Additional vector-like pairs of colored fermions are also present.
269 citations
Book•
26 May 2002
TL;DR: For example, the authors states that "you will unquestionably discover a extra experience and triumph by spending more cash". Yet when do you understand that you require to get those all needs similar to having significantly cash?
Abstract: Eventually, you will unquestionably discover a extra experience and triumph by spending more cash. yet when? do you understand that you require to get those all needs similar to having significantly cash? Why don't you try to acquire something basic in the beginning? That's something that will lead you to comprehend even more all but the globe, experience, some places, like history, amusement, and a lot more?
249 citations
TL;DR: In this paper, the elastic scattering cross sections between KK dark matter and nuclei both when the LKP is a KK mode of a weak gauge boson, and when it is a neutrino.
Abstract: Recently a new dark-matter candidate has been proposed as a consequence of universal compact extra dimensions. It was found that to account for cosmological observations, the masses of the first Kaluza-Klein (KK) modes (and thus the approximate size of the extra dimension) should be in the range 600-1200 GeV when the lightest Kaluza-Klein particle (LKP) corresponds to the hypercharge boson and in the range 1-1.8 TeV when it corresponds to a neutrino. In this paper, we compute the elastic scattering cross sections between KK dark matter and nuclei both when the LKP is a KK mode of a weak gauge boson, and when it is a neutrino. We include nuclear form factor effects which are important to take into account due to the large LKP masses favoured by estimates of the relic density. We present both differential and integrated rates for present and proposed germanium, NaI and xenon detectors. Observable rates at current detectors are typically less than one event per year, but the next generation of detectors can probe a significant fraction of the relevant parameter space.
190 citations
TL;DR: In this paper, the authors consider the gauging of L μ − L τ as an explanation of a possibly large muon anomalous magnetic moment and show how neutrino masses with bimaximal mixing may be obtained in this framework.
190 citations
TL;DR: In this article, the two-brane Randall-Sundrum (RS) model with bulk gauge fields was considered and a 4D low-energy effective Lagrangian was proposed.
Abstract: We consider the two-brane Randall-Sundrum (RS) model with bulk gauge fields. We carefully match the bulk theory to a 4D low-energy effective Lagrangian. In addition to the four-fermion operators induced by KK exchange we find that large negative S and T parameters are induced in the effective theory. This is a tree-level effect and is a consequence of the shapes of the W and Z wave functions in the bulk. Such effects are generic in extra dimensional theories where the standard model (SM) gauge bosons have non-uniform wave functions along the extra dimension. The corrections to precision electroweak observables in the RS model are mostly dominated by S. We fit the parameters of the RS model to the experimental data and find somewhat stronger bounds than previously obtained; however, the standard model bound on the Higgs mass from precision measurements can only be slightly relaxed in this theory.
175 citations
TL;DR: In this article, it was shown that a nontrivial Z2-parity assignment allows some of the extra-space component to have radiatively induced vev, which strongly modifies the mass spectrum and gauge symmetry, realized by orbifolding.
Abstract: We pursue the possibility of the scenario in which the Higgs field is identified with the extra-space component of a bulk gauge field. The space–time we take is M4 ⊗ S1/Z2. We show that a nontrivial Z2-parity assignment allows some of the extra-space component to have radiatively induced vev, which strongly modifies the mass spectrum and gauge symmetry of the theory, realized by orbifolding. In particular we investigate the dynamical mass generation of zero-mode fermion and spontaneous gauge symmetry breaking due to the vev. The gauge theories we adopt are a prototype model SU(2) and SU(3) model, of special interest as the realistic minimal scheme to incorporate the standard model SU(2) × U(1).
CERN1
TL;DR: In this article, the masses of anomalous U(1) gauge bosons in four-dimensional orientifold vacua were computed and their localization properties in the internal (compactified) space were studied.
Abstract: We perform a systematic string computation of the masses of anomalous U(1) gauge bosons in four-dimensional orientifold vacua, and we study their localization properties in the internal (compactified) space. We find that N=1 supersymmetric sectors yield four-dimensional contributions, localized in the whole six-dimensional internal space, while N=2 sectors give contributions localized in four internal dimensions. As a result, the U(1) gauge fields can be much lighter than the string scale, so that when the latter is at the TeV, they can mediate new non-universal repulsive forces at submillimeter distances much stronger than gravity. We also point out that even U(1)s which are free of four-dimensional anomalies may acquire non-zero masses as a consequence of six-dimensional anomalies.
TL;DR: In this paper, one-loop bulk and brane mass renormalization effects in a five-dimensional gauge theory compactified on the M 4 ×S 1 /Z 2 orbifold are computed.
TL;DR: In this article, the masses of anomalous U(1) gauge bosons in four-dimensional orientifold vacua were computed and their localization properties in the internal (compactified) space were studied.
TL;DR: In this paper, it was shown that the existence of extra U(1) gauge symmetries beyond hypercharge can be found in D-brane string models with a low string scale MS 1 -10 TeV, and that some fraction of the experimentally measured Z 0 mass would be due to mixing with these closed string fields.
Abstract: Generic D-brane string models of particle physics predict the existence of extra U(1) gauge symmetries beyond hypercharge. These symmetries are not of the E6 class but rather include the gauging of Baryon and Lepton numbers as well as certain Peccei-Quinn-like symmetries. Some of the U(1)'s have triangle anomalies, but they are cancelled by a Green-Schwarz mechanism. The corresponding gauge bosons typically acquire a mass of order the string scale MS by combining with two-index antisymmetric fields coming from the closed string sector of the theory. We argue that in string models with a low string scale MS1--10 TeV, the presence of these generic U(1)'s may be amenable to experimental test. Present constraints from electroweak precision data already set important bounds on the mass of these extra gauge bosons. In particular, for large classes of models, ?-parameter constraints imply MS ? 1.5 TeV. In the present scheme some fraction of the experimentally measured Z0 mass would be due not to the Higgs mechanism, but rather to the mixing with these closed string fields. We give explicit formulae for recently constructed classes of intersecting D6- and D5-brane models yielding the Standard Model (SM) fermion spectrum.
TL;DR: In this paper, the effects associated with the chiral anomaly for a cascading SU(N+M)×SU(N) gauge theory using gauge/gravity duality were studied.
Abstract: We study effects associated with the chiral anomaly for a cascading SU(N+ M)×SU(N) gauge theory using gauge/gravity duality. In the gravity dual the anomaly is a classical feature of the supergravity solution, and the breaking of the U(1) R-symmetry down to Z2M proceeds via the Higgs mechanism.
10 May 2002
TL;DR: In this paper, an extension of the AdS/CFT correspondence to gauge/gravity dualities with N = 1 supersymmetry is presented. But the authors only consider the conformai case and do not consider the gravity case.
Abstract: We review extensions of the AdS/CFT correspondence to gauge/ gravity dualities with N = 1 supersymmetry. In particular, we describe the gauge/gravity dualities that emerge from placing D3-branes at the apex of the conifold. We consider first the conformai case, with discussions of chiral primary operators and wrapped D-branes. Next, we break the conformai symmetry by adding a stack of partially wrapped D5-branes to the system, changing the gauge group and introducing a logarithmic renormalization group flow. In the gravity dual, the effect of these wrapped D5-branes is to turn on the flux of 3-form field strengths. The associated RR 2-form potential breaks the U(1) R-symmetry to ℤ2M and we study this phenomenon in detail. This extra flux also leads to deformation of the cone near the apex, which describes the chiral symmetry breaking and confinement in the dual gauge theory.
TL;DR: It is found that it should be possible at the LHC with design luminosity to establish that the standard model Higgs boson has a nonzero self-coupling and that lambda/lambda(SM) can be restricted to a range of 0-3.7 at 95% confidence level if its mass is between 150 and 200 GeV.
Abstract: Inclusive standard model Higgs boson pair production and subsequent decay to same-sign dileptons via weak gauge W+/- bosons at the CERN Large Hadron Collider (LHC) has the capability to determine the Higgs boson self-coupling, lambda. The large top quark mass limit is found not to be a good approximation for the signal if one wishes to utilize differential distributions in the analysis. We find that it should be possible at the LHC with design luminosity to establish that the standard model Higgs boson has a nonzero self-coupling and that lambda/lambda(SM) can be restricted to a range of 0-3.7 at 95% confidence level if its mass is between 150 and 200 GeV.
TL;DR: In this paper, the authors derive an expansion scheme in which the gravitational gauge fields are treated exactly and the gravitational curvatures and the higher spin gauge fields as weak perturbations, and give the details of an explicit iteration procedure for obtaining the field equations to arbitrary order in curvatures.
Abstract: The minimal bosonic higher spin gauge theory in four dimensions contains massless particles of spin s=0,2,4,.. that arise in the symmetric product of two spin 0 singletons. It is based on an infinite dimensional extension of the AdS_4 algebra a la Vasiliev. We derive an expansion scheme in which the gravitational gauge fields are treated exactly and the gravitational curvatures and the higher spin gauge fields as weak perturbations. We also give the details of an explicit iteration procedure for obtaining the field equations to arbitrary order in curvatures. In particular, we highlight the structure of all the quadratic terms in the field equations.
TL;DR: In this article, the NuTeV anomaly can be explained by QCD efiects such as new physics in propagators or couplings of the vector bosons (not really), loops of supersymmetric particles (no), dimension six operators (yes, for one speciflc SU(2)L-invariant operator), leptoquarks (not in a minimal way), extra U(1) gauge bosons(maybe: an unmixed Z 0 coupled to Bi3L" also increases the muon gi2 by about 10 i9 and
Abstract: We discuss whether the NuTeV anomaly can be explained, compatibly with all other data, by QCD efiects (maybe, if the strange sea is asymmetric, or there is a tiny violation of isospin), new physics in propagators or couplings of the vector bosons (not really), loops of supersymmetric particles (no), dimension six operators (yes, for one speciflc SU(2)L-invariant operator), leptoquarks (not in a minimal way), extra U(1) gauge bosons (maybe: an unmixed Z 0 coupled to Bi3L" also increases the muon gi2 by about 10 i9 and gives a 'burst' to cosmic rays above the GZK cutofi).
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TL;DR: In this article, an economical theory of natural electroweak symmetry breaking was proposed, which stabilizes the electroweak scale with a naturally light Higgs and weakly coupled new physics at TeV energies.
Abstract: We present an economical theory of natural electroweak symmetry breaking, generalizing an approach based on deconstruction. This theory is the smallest extension of the Standard Model to date that stabilizes the electroweak scale with a naturally light Higgs and weakly coupled new physics at TeV energies. The Higgs is one of a set of pseudo Goldstone bosons in an $SU(5)/SO(5)$ nonlinear sigma model. The symmetry breaking scale $f$ is around a TeV, with the cutoff $\Lambda \lsim 4\pi f \sim $ 10 TeV. A single electroweak doublet, the ``little Higgs'', is automatically much lighter than the other pseudo Goldstone bosons. The quartic self-coupling for the little Higgs is generated by the gauge and Yukawa interactions with a natural size $O(g^2,\lambda_t^2)$, while the top Yukawa coupling generates a negative mass squared triggering electroweak symmetry breaking. Beneath the TeV scale the effective theory is simply the minimal Standard Model. The new particle content at TeV energies consists of one set of spin one bosons with the same quantum numbers as the electroweak gauge bosons, an electroweak singlet quark with charge 2/3, and an electroweak triplet scalar. One loop quadratically divergent corrections to the Higgs mass are cancelled by interactions with these additional particles.
TL;DR: In this paper, one-loop bulk and brane mass renormalization effects in a five-dimensional gauge theory compactified on the M_4 \times S^1/Z_2 orbifold are computed.
Abstract: We have computed one-loop bulk and brane mass renormalization effects in a five-dimensional gauge theory compactified on the M_4 \times S^1/Z_2 orbifold, where an arbitrary gauge group G is broken by the orbifold action to its subgroup H. The space-time components of the gauge boson zero modes along the H generators span the gauge theory on the orbifold fixed point branes while the zero modes of the higher-dimensional components of the gauge bosons along the G/H generators play the role of Higgs fields with respect to the gauge group H. No quadratic divergences in the mass renormalization of the gauge and Higgs fields are found either in the bulk or on the branes. All brane effects for the Higgs field masses vanish (only wave function renormalization effects survive) while bulk effects are finite and can trigger, depending on the fermionic content of the theory, spontaneous Hosotani breaking of the brane gauge group H. For the gauge fields we do find logarithmic divergences corresponding to mass renormalization of their heavy Kaluza-Klein modes. Two-loop brane effects for Higgs field masses are expected from wave function renormalization brane effects inserted into finite bulk mass corrections.
TL;DR: In this article, the Standard Model strictly forbidden Z -> gamma gamma and Z -> gg decay modes coming from the gauge sector of the Noncommutative Standard Model as a place where noncommutativity could be experimentally discovered.
Abstract: On noncommutative spacetime, the Standard Model allows new, usually Standard Model forbidden, triple gauge boson interactions. In this letter we propose the Standard Model strictly forbidden Z -> gamma gamma and Z -> gg decay modes coming from the gauge sector of the Noncommutative Standard Model as a place where noncommutativity could be experimentally discovered.
TL;DR: In this article, the authors considered minimal 5-dimensional extensions of the standard model compactified on an ∆ ∆ 1/Z ∆ 2/2/Z 2/Z/2$ orbifold, in which the gauge fields and Higgs bosons may or may not all propagate in the fifth dimension while the observable matter is always assumed to be confined to a 4dimensional subspace.
Abstract: We consider minimal 5-dimensional extensions of the standard model compactified on an ${S}^{1}{/Z}_{2}$ orbifold, in which the $\mathrm{SU}{(2)}_{L}$ and $\mathrm{U}{(1)}_{Y}$ gauge fields and Higgs bosons may or may not all propagate in the fifth dimension while the observable matter is always assumed to be confined to a 4-dimensional subspace. We pay particular attention to consistently quantize the higher-dimensional models in the generalized ${R}_{\ensuremath{\xi}}$ gauge and derive analytic expressions for the mass spectrum of the resulting Kaluza-Klein states and their couplings to matter. Based on recent data from electroweak precision tests, we improve previous limits obtained in the 5-dimensional standard model with a common compactification radius and extend our analysis to other possible 5-dimensional standard-model constructions. We find that the usually derived lower bound of $\ensuremath{\sim}4 \mathrm{TeV}$ on a universal compactification scale may be considerably relaxed to $\ensuremath{\sim}3 \mathrm{TeV}$ in a minimal scenario, in which the $\mathrm{SU}{(2)}_{L}$ gauge boson is the only field that feels the presence of the fifth dimension.
TL;DR: In this article, the fermion contributions to the shift of the position of the poles of the massive gauge boson propagators at two-loop order in the Standard Model were calculated.
Abstract: We have calculated the fermion contributions to the shift of the position of the poles of the massive gauge boson propagators at two-loop order in the Standard Model. Together with the bosonic contributions calculated previously the full two-loop corrections are available. This allows us to investigate the full correction in the relationship between MS and pole masses of the vector bosons Z and W. Two-loop renormalization and the corresponding renormalization group equations are discussed. Analytical results for the master-integrals appearing in the massless fermion contributions are given. A new approach of summing multiple binomial sums has been developed.
TL;DR: In this article, the authors discuss the possible origin of scaling violations on the gauge theory side of SU(N) SYM theory and propose a solution for superstrings in $AdS_5\times S^5$ to predict the dimension of gauge theory operators.
Abstract: Semi-classical soliton solutions for superstrings in $AdS_5\times S^5$ are used to predict the dimension of gauge theory operators in $\N=4 $ SU(N) SYM theory. We discuss the possible origin of scaling violations on the gauge theory side.
TL;DR: In this article, the authors formulate gauge invariant interactions of totally symmetric tensor and tensor-spinor higher spin gauge fields in AdS(5) that properly account for higher-spin-gravitational interactions at the action level in the first nontrivial order.
Abstract: We formulate gauge invariant interactions of totally symmetric tensor and tensor-spinor higher spin gauge fields in AdS(5) that properly account for higher-spin-gravitational interactions at the action level in the first nontrivial order.
TL;DR: Gauge symmetry breaking by boundary conditions on a manifold is known to be equivalent to Wilson-line breaking through a background gauge field, and is therefore spontaneous as mentioned in this paper, however, there is no gauge where all the breaking can be attributed to a background field.
TL;DR: In this article, the anomalous magnetic moment of the muon is evaluated in the D-brane realization of the Standard Model and it is pointed out that the massive anomalous U(1) gauge bosons predicted, give extra contributions that are compatible with current experimental data.
Abstract: The anomalous magnetic moment of the muon is evaluated in the D-brane realization of the Standard Model. It is pointed out that the massive anomalous U(1) gauge bosons predicted, give extra contributions that are compatible with current experimental data.
TL;DR: In this paper, the relationship between MS and pole masses of the vector bosons Z and W is calculated at the two-loop level in the Standard Model using the method of asymptotic expansions.