共查询到20条相似文献,搜索用时 109 毫秒
1.
N. V. Krasnikov 《Physics letters. [Part B]》1984,140(5-6):337-338
We propose an SU(3) SU(2) U(1) gauge model with an invisible axion and a single Higgs isodoublet. The main peculiarity of the model is the use of non-renormalizable effective interactions left over from whatever theory combines SU(3) SU(2) U(1) with gravity. We also discuss the SU(5) extensions of the proposed model. 相似文献
2.
I.I. Tkachev 《Physics letters. [Part B]》1984,146(5):328-332
The phase structure of the SU(5) Coleman-Weinberg theory in the one-loop approximation is obtained with account of temperature and space-time curvature. We show that the most essential contribution is that from the interaction between 5 and 24 scalar fields which reflects the existence of two strongly different mass scales in the model. A stability boundary of the SU(3) × SU(2) × U(1) phase is found. It is shown that the SU(4) × U(1) phase in the Coleman-Weinberg theory is unstable. 相似文献
3.
Saul Barshay 《Zeitschrift fur Physik C Particles and Fields》1980,4(1):63-66
The various symmetry breaking patterns that are possible with a 24-plet and a 5-plet of Higgs fields in SU(5) are classified. Spontaneous breakdown of SU(5) to SU(3)colour×U(1) em can be achieved (excluding the gauge hierarchy problem) without imposing unnatural constraints on the parameters of the Higgs potential. 相似文献
4.
Bruce Campbell
John Ellis
John Hagelin
D. V. Nanopoulos
Keith A. Olive
《Physics letters. [Part B]》1988,200(4):483-488We consider the possibilities for generating a baryon asymmetry in the early universe in a flipped SU(5) × U(1) model inspired by the superstring. Depending on the temperature of the radiation background after inflation we can distinguish between two scenarios for baryogenesis: (1) after reheating the original SU(5) × U(1) symmetry is restored, or there was no inflation at all; (2) reheating after inflation is rather weak and SU(5) × U(1) is broken. In either case the asymmetry is generated by the out-of-equilibrium decays of a massive SU(3) × SU(2) × U(1) singlet field φm. In the flipped SU(5) × U(1) model, gauge symmetry breaking is triggered by strong coupling phenomena, and is in general accompanied by the production of entropy. We examine constraints on the reheating temperature and the strong coupling scale in each of the scenarios. 相似文献
5.
将费米子动力学对称模型包含G费米子对能够构造出SP(10)或SO(12)动力学对称群.本文用GeneralizedDyson玻色子映射方法求出SP(10)对称群精确的玻色子映像,其子群SU(5)生成元的玻色子映像与sdg相互作用玻色子模型(IBM)SU(5)生成元相同,唯象sdgIBMSU(5)极限能谱公式可由费米子动力学对称模型的微观参数描述. 相似文献
6.
本文假设N=8扩充超引力能形成复合超多重态,并探讨了{3/2,8}N=8SU(8)和{2,28}N=8SU(8)两种复合超多重态容纳SU(5)超对称大统一理论的可能性。在较为苛刻的假设下,能由{3/2,8}N=8SU(8)方案得到三代轻子夸克和较满意的SU(5)超对称大统一粒子谱。在较为合理的假设下,能由{2,28}N=8SU(8)
关键词: 相似文献
7.
Supergravity in eleven dimensions is known to have classical solutions of the type (anti-de Sitter space-time) × (7-dimensional Einstein space). We give a list of all homogeneous 7-manifolds which admit an Einstein metric. Known solutions are reviewed, with some emphasis on the SU(3) × SU(2) × U(1) compactifications. Their topology is discussed in detail.The list includes three new solutions, with symmetry groups SU(3) × SU(2), SO(5) and SO(5) × U(1). The first solution has no supersymmetry, while the second and third yield respectively N = 1 and N = 2 supersymmetry in four dimensions. The last two solutions may be extended to solutions with nonzero internal photon curl, breaking all supersymmetry.The existence of a spin structure on homogeneous manifolds is discussed and related to topological properties of . As an illustration, we treat the coset spaces SU(m + 1) × SU(n + 1)/SU(m) × SU(n) × U(1), which include the spaces with SU(3) × SU(2) × U(1) symmetry. 相似文献
8.
It is shown that dimension five non-renormalizable interactions can produce light Dirac neutrinos in an extension of the minimal
SU(5) GUT containing additional SU(5) singlets and global U(1) symmetries. 相似文献
9.
The SU(5) → SU(3) × SU(2) × U(1) phase transition is examined in the case of zero Higgs bare mass. We find that, depending on assumptions made, two scenarios are most likely to occur. Either the transition is rapidly completed into the SU(3) × SU(2) × U(1) phase, or the Universe supercools down to temperatures where the theory gets strongly coupled. In the latter case non-perturbative effects come into play. 相似文献
10.
Using Monte Carlo techniques on a four-dimensional space-time lattice, we study SU(N)/ZN gauge theories for N = 3, 4, 5 and 6. We find first-order phase transitions at critical inverse temperatures of βc = 6.40, 12.0, 19.5 and 32.0 and SU(3)/Z3,SU(4)/Z4,SU(5)/Z5and SU (6)Z6, respectively. 相似文献
11.
We study the long-distance behaviour of pure unified SU(5) gauge theory in the limit when the electroweak subgroup is unbroken. We show that the symmetry breaking pattern SU(5)→SU(3)c×SU(2)×U(1)Y, with SU(3)c and SU(2) ×U(1)Y realized, respectively, in confining and coulombic phases, is a possible dynamical phase of the SU(5) theory. The proof relies on showing that the duality equation of 't Hooft, relating the electric and magnetic flux, is exactly satisfied for the above symmetry breaking pattern. The infrared structure of SU(5), broken down to SU(3)c×SU(2)×U(1)Y, is not self-dual. 相似文献
12.
We discuss ordinary as well as supersymmetric SU(5) ×?(1) models in the hope of accomodating acceptable τp and sin2θW. The ordinary SU(5) ×?(1) model does not have the monopole. The supersymmetric SU(5) ×?(1) model can be unified in SO(10). 相似文献
13.
The monopoles of the unified SU(5) gauge theory broken down to HE = SU(3)c ? U(1)EM [or to KE = SU(3)c ? SU(2) ? U(1)Y], are classified. They belong to representations of a magnetic group HM(KM), which is found to be isomorphic to HE(KE). For SU(5) broken down to HE, there exists a regular and stable monopole which is a colour magnetic triplet, and carries a non-zero abelian magnetic charge. It is suggested that composite operators made out of this monopole and its antiparticle fields develop a non-zero vacuum expectation value, and so lead to a squeezing of the colour electric flux. Finally, we comment on the cosmological production of SU(5) monopoles. 相似文献
14.
We study the topological structure of thesymmetry group of the standard model, GSM =U(1) × SU(2) × SU(3). Locally,GSM S1 ×(S3)2 × S5. For SU(3), whichis an S3-bundle over S5 (and therefore a local product of thesespheres) we give a canonical gauge i.e., a canonical setof local trivializations. These formulas give explicitlythe matrices of SU(3) without using the Lie algebra (Gell-Mann matrices). Globally, we prove thatthe characteristic function of SU(3) is the suspensionof the Hopf map
. We also study the case of SU(n) forarbitrary n, in particular the cases of SU(4), a flavor group, and of SU(5),a candidate group for grand unification. We show thatthe 2-sphere is also related to the fundamentalsymmetries of nature due to its relation to SO0(3, 1), the identity component of the Lorentz group, asubgroup of the symmetry group of several gauge theoriesof gravity. 相似文献
15.
《Physics letters. [Part B]》1988,207(4):451-456
We supplement a previous discussion of baryosynthesis in flipped SU(5)×U(1) GUTs by including (1) the large incoherent field energy density which is likely SU(5) is broken, and (2) the possibility of additional Higgs triplet fields suggested by four dimensional string model-building. We consider strong (weak) reheating scenarios in which the Universe is (is not) SU(5) symmetric after inflation. We find an adequate baryon asymmetry subsequent to strong reheating, whatever the number of Higgs triplets (although beware of possible difficulties with quasi-stable relic particles), whereas weak reheating requires at least two Higgs triplets. 相似文献
16.
We consider the most general renormalizable O(10) invariant potential for a representation of Higgs fields. We show that O(10) can be spontaneously broken down to SU(5), SU(4) × U(1) or SU(3) × SU(2) × U(1), this last case being, of course, the most appealing. 相似文献
17.
We investigate all spherically symmetric fundamental monopole solutions with fixed topological charge in the SU(5)-->[SU(3) x SU(2) x U(1)]/Z(3) x Z(2) symmetry breaking. We find that there are three solutions that are gauge equivalent but, as we argue, would correspond to physically distinct degrees of freedom in the dualized version of the model. The triplication of monopoles could help us understand the observed family structure of standard model particles. 相似文献
18.
J. L. Chkareuli 《Physics letters. [Part B]》1993,300(4):361-366
We argue that there is a natural inclusion of the standard model with the family-unified chiral local symmetry SU(3)H in a new SU(8) GUT inspired by Georgi's SU(11) model. The SU(8) symmetry breaking along the chain with the intermediate electro-weak-horizontal unification SU(8)→SU(5)EWH×SU(3)c×U(1) is proved d to be the distinguished pattern. The model predicts a long-lived proton (1033–1035yr) and practically the observed value of the Weinberg angle, in sharp contrast to the ordinary GUTs. The observation of the specific flavour-changing baryon decays (p→π,μ,Ke,…) could unambiguously single out the flavour unified GUTs as well as confirm the existence of the elementary horizontal forces at small distances. 相似文献
19.
We show that the proton can be made absolutely stable, without introducing superheavy bosons, by imposing a global U(1) color symmetry on the Higgs couplings of the theory. Vector-like SU(5) and SU(6) models are discussed in detail. 相似文献
20.
Because of the spin and Dirac-valley degrees of freedom, graphene allows the observation of one-, two- or four-component fractional quantum Hall effects in different parameter regions. We address the stability of various states in the SU(2) and SU(4) limits. In the SU(4) limit, we predict that new low-energy Goldstone modes determine the stability of the fractional quantum Hall states at 2/5, 3/7, etc; SU(4) skyrmions are not found to be relevant for the low-energy physics. These results are discussed in light of experiments. 相似文献