共查询到20条相似文献,搜索用时 31 毫秒
1.
Until now there has been no empirical evidence for the existence of the Higgs particle, although the Higgs mechanism of symmetry breaking is very successful. We propose a scalar-tensor theory of gravity with the Higgs field of theSU(3)×SU(2)×U(1) standard model of the elementary particles as scalar field, which results finally in Einstein's gravity and in theSU(3)×SU(2)×U(1) standard model without any influence of the excited Higgs field. 相似文献
2.
Nils Dalarsson 《International Journal of Theoretical Physics》1996,35(4):819-837
We suggest a quantum stabilization method for theSU(2) σ-model, based on the constant-cutoff limit of the cutoff quantization method developed by Balakrishnaet al., which avoids the difficulties with the usual soliton boundary conditions pointed out by Iwasaki and Ohyama. We investigate
the baryon numberB = 1 sector of the model and show that after the collective coordinate quantization it admits a stable soliton solution which
depends on a single dimensional arbitrary constant. We then study strong and electromagnetic properties of the Λ(1405) hyperon
in the bound-state approach to theSU(3)-soliton model for the hyperons, withSU(3)-symmetry breaking. We calculate the strong coupling constantg
Λ*NK;
, the magnetic moment of Λ*, the mean square radii, and the radiative decay amplitudes. Finally we compare the present results
with those obtained using other models and with the available empirical data. We show that there is a general qualitative
agreement between our results and the results of other models and available empirical data, except for the Λ*πΣ coupling,
which, as in the case of the complete Skyrme model, vanishes in the second-order approximation of the kaon fluctuations used
in this work. 相似文献
3.
Carlos Castro 《International Journal of Theoretical Physics》2012,51(10):3318-3329
A unification model of 4D gravity and SU(3)×SU(2)×U(1) Yang-Mills theory is presented. It is obtained from a Kaluza-Klein compactification of 8D quaternionic gravity on an internal CP 2=SU(3)/U(2) symmetric space. We proceed to explore the nonlinear connection formalism used in Finsler geometry to show how ordinary gravity in D=4+2 dimensions has enough degrees of freedom to encode a 4D gravitational and SU(5) Yang-Mills theory. This occurs when the internal two-dim space is a sphere S 2. This is an appealing result because SU(5) is one of the candidate GUT groups. We conclude by discussing how the nonlinear connection formalism of Finsler geometry provides an infinite hierarchical extension of the Standard Model within a six dimensional gravitational theory due to the embedding of SU(3)×SU(2)×U(1)⊂SU(5)⊂SU(∞). 相似文献
4.
J. Sładkowski 《International Journal of Theoretical Physics》1996,35(10):2075-2083
We investigate how exotic differential structures may reveal themselves in particle physics. The analysis is based on A. Connes'
construction of the standard model. It is shown that, if one of the copies of the spacetime manifold is equipped with an exotic
differential structure, a compact object of geometric origin may exist even if the spacetime is topologically trivial. Possible
implications are discussed. AnSU(3) ⊗SU(2) ⊗U(1) gauge model is constructed. This model may not be realistic, but it shows what kind of physical phenomena might be expected
due to the existence of exotic differential structures on the spacetime manifold. 相似文献
5.
Nils Dalarsson 《International Journal of Theoretical Physics》1997,36(7):1623-1639
We suggest a quantum stabilization method for theSU(2) σ-model, based on the constant-cutoff limit of the cutoff quantization method developed by Balakrishnaet al., which avoids the difficulties with the usual soliton boundary conditions pointed out by Iwasaki and Ohyama. We investigate
the baryon numberB=1 sector of the model and show that after the collective coordinate quantization it admits a stable soliton solution which
depends on a single dimensional arbitrary constant. We then apply this approach to the calculation of electric and magnetic
static polarizabilities of octet hyperons in the bound-stateSU(3)-soliton model for hyperons, withSU(3)-symmetry breaking. The results, with both seagull and dispersive contributions included, are compared with the predictions
obtained using the complete Skyrme model. 相似文献
6.
A. E. Bernardini 《International Journal of Theoretical Physics》2008,47(4):971-976
We propose a generalized way to formally obtain the gauge invariance of the kinetic part of a field Lagrangian over which
a gauge transformation ruled by an SU(n)
U
⊗
SU(m)
V
coupling symmetry is applied. As an illustrative example, we employ such a formal construction for reproducing the standard
model Lagrangian. This generalized formulation is supposed to contribute for initiating the study of gauge transformation
applied to generalized SU(n)
U
⊗
SU(m)
V
symmetries as well as for complementing an introductory study of the standard model of elementary particles. 相似文献
7.
8.
Nils Dalarsson 《International Journal of Theoretical Physics》1997,36(4):935-947
We suggest a quantum stabilization method for theSU(2) σ-model, based on the constant-cutoff limit of the cutoff quantization method developed by Balakrishnaet al., which avoids the difficulties with the usual soliton boundary conditions pointed out by Iwasaki and Ohyama. We investigate
the baryon numberB=1 sector of the model and show that after the collective coordinate quantization it admits a stable soliton solution which
depends on a single dimensional arbitrary constant. We then study the radiative decays ofJ
π=3/2+ baryons using the constant-cutoff approach to theSU(3) collective treatment of the Skyrme model for hyperons. Thus we evaluate the widths and E2/M1 ratios, showing that there
is a general qualitative agreement with the results obtained using the complete Skyrme model, as well as the nonrelativistic
quark model and quenched lattice model, for the total widths. 相似文献
9.
K. Tsubakihara H. Maekawa A. Ohnishi 《The European Physical Journal A - Hadrons and Nuclei》2007,33(3):295-298
We develop a chiral SU(3) RMF model for octet baryons, as an extension of the recently developed chiral SU(2) RMF model with logarithmic sigma potential. For Σ -meson coupling, strong repulsion (SR) and weak repulsion (WR) cases
are examined in existing atomic shift data of Σ- . In both of these cases, we need an attractive pocket of a few MeV depth around nuclear surface. 相似文献
10.
Electroweak unification is obtained in anSU(7) model at a mass scale 3×1010≦M≦3×1016 GeV's, with left-right symmetric subgroups and sin2
θ
w
(M)=3/8. BelowM, the model reduces toSU(3)
L
×SU(3)
R
, the flavor sector of the “trinification theory” of Glashow et al., or of theE
6 grand unified theory. This model predicts a natural massless neutrino, and fractionally charged leptons with masses in theM regime. 相似文献
11.
J. J. van der Bij 《General Relativity and Gravitation》2011,43(9):2499-2507
I present an argument, based on the topology of the universe, why there are three generations of fermions. The argument implies
a preferred unified gauge group of SU(5), but with SO(10) representations of the fermions. The breaking pattern SU(5) → SU(3) × SU(2) × U(1) is preferred over the pattern SU(5) → SU(4) × U(1). On the basis of the argument one expects an asymmetry in the early universe microwave data, which might have been detected
already. 相似文献
12.
A possible minimal model of the gauge–Higgs unification based on the higher dimensional spacetime M
4⊗(S
1/Z
2) and the bulk gauge symmetry SU(3)
C
⊗SU(3)
W
⊗U(1)
X
is constructed in some detail. We argue that the Weinberg angle and the electromagnetic current can be correctly identified
if one introduces the extra U(1)
X
above and a bulk scalar triplet. The VEV of this scalar as well as the orbifold boundary conditions will break the bulk gauge
symmetry down to that of the standard model. A new neutral zero-mode gauge boson Z′ exists that gains mass via this VEV. We propose a simple fermion content that is free from all the anomalies when the extra
brane-localized chiral fermions are taken into account as well. The issues on recovering a standard model chiral-fermion spectrum
with the masses and flavor mixing are also discussed, where we need to introduce the two other brane scalars which also contribute
to the Z′ mass in the similar way as the scalar triplet. The neutrinos can get small masses via a type I seesaw mechanism. In this
model, the mass of the Z′ boson and the compactification scale are very constrained being, respectively, given in the ranges: 2.7 TeV<m
Z′<13.6 TeV and 40 TeV<1/R<200 TeV. 相似文献
13.
In this paper we further develop the theory of α-induction for nets of subfactors, in particular in view of the system of
sectors obtained by mixing the two kinds of induction arising from the two choices of braiding. We construct a relative braiding
between the irreducible subsectors of the two “chiral” induced systems, providing a proper braiding on their intersection.
We also express the principal and dual principal graphs of the local subfactors in terms of the induced sector systems. This
extended theory is again applied to conformal or orbifold embeddings of SU(n WZW models. A simple formula for the corresponding modular invariant matrix is established in terms of the two inductions,
and we show that it holds if and only if the sets of irreducible subsectors of the two chiral induced systems intersect minimally
on the set of marked vertices, i.e. on the “physical spectrum” of the embedding theory,
or if and only if the canonical endomorphism sector of the conformal or orbifold inclusion subfactor is in the full induced
system. We can prove either condition for all simple current extensions of SU
(
n
) and many conformal inclusions, covering in particular all type I modular invariants of SU(2) and SU(3), and we conjecture that it holds also for any other conformal inclusion of SU
(
n
) as well. As a by-product of our calculations, the dual principal graph for the conformal inclusion SU(3)5⊂SU(6)1 is computed for the first time.
Received: 24 December 1998 / Accepted: 22 February 1999 相似文献
14.
The t’Hooft ansatz, which reduces the classical Yang-Mills theory to the λϕ4 one, is under consideration. It is shown that, in the framework of this ansatz, the real-time classical solutions for the
arbitrary SU(N) gauge group are obtained by embedding SU(2) × SU(2) into SU(N). It is argued that this group structure is the only possibility in the framework of the considered ansatz. New explicit solutions
for SU(3) and SU(5) gauge groups are shown.
The text was submitted by the authors in English. 相似文献
15.
H.D. Kim J.E. Kim H.M. Lee 《The European Physical Journal C - Particles and Fields》2002,24(1):159-164
Supersymmetric 5D SU(5) grand unification is considered. SU(5) is broken down to by the assignment of the bulk field(s). The matter fields are located at the fixed point(s). In the bulk, a Higgs multiplet (containing the bottom doublet ) and the SU(5) gauge multiplet are located. At one fixed point, (the top doublet) and the standard model matter multiplets are presented. Because of the difference of the locations of and , one can obtain a hierarchy between top and bottom Yukawa couplings. We also present a possible way to understand the s– mass puzzle in this framework of the split multiplet.
Received: 10 December 2001 / Revised version: 22 January 2002 / Published online: 5 April 2002 相似文献
16.
S.U. Chung E. Klempt J.G. Körner 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):539-542
An exotic meson, the π1(1400) with J
PC = 1- +, has been seen to decay into a p-wave ηπ system. If this decay conserves flavor SU(3), then it can be shown that this exotic meson must be a four-quark state ( qˉq + qˉq) belonging to a flavor ˉ10 representation of SU(3). In contrast, the π1(1600) with a substantial decay mode into π is likely to be a member of a flavor octet.
Received: 27 March 2002 / Accepted: 8 August 2002 / Published online: 10 December 2002
RID="b"
ID="b"e-mail: klempt@iskp.uni-bonn.de
Communicated by V. Vento 相似文献
17.
Sukanta Dutta Ashok Goyal Mamta 《The European Physical Journal C - Particles and Fields》2009,63(2):305-315
We study the one-loop new physics effects to the CP even triple neutral gauge boson vertices γ
⋆
γ
Z, γ
⋆
Z
Z, Z
⋆
Z
γ and Z
⋆
ZZ in the context of Little Higgs models. We compute the contribution of the additional fermions in Little Higgs models in the
framework of direct product groups where [SU(2)×U(1)]2 gauge symmetry is embedded in SU(5) global symmetry and also in the framework of the simple group where SU(N)×U(1) gauge symmetry breaks down to SU(2)
L
×U(1). We calculate the contribution of the fermions to these couplings when T parity is invoked. In addition, we re-examine the MSSM contribution at the chosen point of SPS1a′ and compare with the SM
and Little Higgs models. 相似文献
18.
Yun Chang Shin Bong Soo Han Myung Ki Cheoun K.S. Kim Il-Tong Cheon 《The European Physical Journal A - Hadrons and Nuclei》2000,9(2):269-276
A SU(2) effective Lagrangian is extended to a SU
L(3) ⊗SU
R(3) by including the vector and axial vector meson. With this effective Lagrangian, electromagnetic form factors of charged
pion and kaon are calculated in both time- and space-like regions. The pseudoscalar meson loops are taken into account. Good
agreement with experimental data is obtained for those form factors and charged pseudoscalar meson radii. Decay widths of
ρ→ππ and φ→K
+
K
- are also calculated and shown to agree with experimental data very well.
Received: 20 December 1999 / Accepted: 12 October 2000 相似文献
19.
Ctirad Klimčík 《International Journal of Theoretical Physics》2007,46(10):2443-2463
We show that D-branes in the Euclidean AdS
3 can be naturally associated to the maximally isotropic subgroups of the Lu–Weinstein double of SU(2). This picture makes very transparent the residual loop group symmetry of the D-brane configurations and gives also immediately the D-branes shapes and the σ-model boundary conditions in the de Sitter T-dual of the SL(2,C)/SU(2) WZW model. 相似文献
20.
We give an elementary treatment of the defining representation and Lie algebra of the three-dimensional unitary unimodular
groupSU(3). The geometrical properties of the Lie algebra, which is an eight dimensional real linear vector space, are developed
in anSU(3) covariant manner. Thef andd symbols ofSU(3) lead to two ways of ‘multiplying’ two vectors to produce a third, and several useful geometric and algebraic identities
are derived. The axis-angle parametrization ofSU(3) is developed as a generalization of that forSU(2), and the specifically new features are brought out. Application to the dynamics of three-level systems is outlined. 相似文献