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1.
We discuss the suppression of the decay of heavy lepton τ into πvτ,by assuming that τ and/or vτ carry spin 3/2. For the case of spin 3/2 T and spin 1/2 vτ, using the weak current ψμ(τ)(a+bγ5)Ψ(vτ)we find that the πvτ decay channel relative to the vτvll-channel is suppressed 12/5 times, while other decay channels are not changed appreciably. △R=σ(e+e-τ+τ-)/σ(e+e-μ+μ-) is also discussed.  相似文献   

2.
We continue the investigation of the equation and its solutions for the bound states of mesons discussed previously, emphasizing on large values of v, a parameter characterizing the shape of the potential. The results show that the dependence of the eigenvalues λ and some related physical quantities upon the potential parameters v and E is approximately the same as in our previous work. But the average radii of the bound mesons cease increasing as v increases. For each value of v, there exists a maximum average radius√<R2>max, and all these √<R2>max are approximately equal to 12.6 M-1 (M being the mass of the straton), which is much smaller than the experimental value of the radius of the π meson. However, if we assume, in addition to the attractive potential, there exists, for the straton-anti-straton superstrong interactions, also a repulsive potential, and, in particular, if we introduce a differencetype potential VDr) corresponding to the potential Vvr) in our previous work, the calculated radii of the bound mesons do approach the experimental value.  相似文献   

3.
Due to the possible production of neutral and charge heavy leptons by vμ, models consisting of four elements per "line", e.g. ve, e-, E0, E- vμ, μ-, M0, M- vτ, τ-, T0, T- ……are analysed. Non-diagonal neutral currents cannot be avoided. Nevertheless, a model is proposed within SU(2)×U(1) in which the process μ can still be suppressed by the Bjorken-Lane-Weinberg mechanism; various production cross-sections for heavy leptons are reasonable when compared with experiments. Models corresponding to SU(3)×U(1) and still higher symmetries are discussed.  相似文献   

4.
A method for finding potentials corresponding to polynomial-factor eigenfunc-tions is given for the Schr(?)dinger equation as an example.It is shown that theeigen-solutions for harmonic and Columb's potentials in quantum mechanics are the twoexamples which can be given by this method and some other examples are discovered.This method and some results of this paper may be useful for hadron structure mo-del theory.One of the examples is the equation in Ref.(4)which is derived fromBethe-Salpeter equation for the case that the straton is tightly bounded in certain po-tential well.When this method is applied to that equation for three dimensionalcentral symmetric potential V(r)=V0—2(N+(1/2))β-1(√V6r2)+(V6r6), some resultsare obtained as shown in Fig. 2 in which λ′ must be considered as a linear function of m2.The so called“quasic Regge trajectory”behavior is manifested.  相似文献   

5.
Enlarging the dimensionality of Minkowski space from 4 to 5,and relating the restmass of particle with x5 as m=—i&#8706;/(&#8706;x5)))we discuss the 5-dimensional non-linear con-formal group CM5)under which dx12+dx22+dx32-dx02+dx52=0 is invariant.The CM5)group is isomorphic to the linear group SO(5,2)from which we study thespace-time property of Fermion number,and the relations between half-integral(in-tegral)spin and odd(even)Fermion number are obtained.  相似文献   

6.
Let F be a SUN gauge field on the space-time manifold M4, bλx) (λ=0,1, 2, 3) the gauge potentials, the field strengths and Qx) a Higgs field. All quantities b, fλμ and Qx) are SUN'-valued, i.e. they are represented by N×N anti-hermitian traceless matrices.Let M4' be the set of x such that Qx)≠0 and define on M4', where The following results are obtained:Theorem 1. The 1st set of Maxwell equations Fλμ,v+Fμv+Fvλ,μ=0 are satisfied for arbitrary bλ if and only if with Here s is an integer, 1≤sN-1.Suppose the conditions in theorem 1 are satisfied.Theorem 2. If s is a space-like two-dimensional surface, the value of dual charges contained in s defined by is equal to lq', where l is an integer and Theorem 3. The value of dual charges contained in S is equal to the integral which is independent of the gauge potentials.Theorem 4. The least positive value q' of dual charge can be attained by some Higgs fields.Remarks(a) When N=2, the results obtained are consistent with those of t Hooft, Arafune and Hou etc.(b) For N=3, we give an answer to the question of quantized values of dual charges which was discussed by Marciano and Pagels.(c) The Higgs field ø(x) is a mapping from M'4 into the AⅢ type symmetric space SUN/S(Us X UN-s) and the integral is an extension of Kronecker index for N=2.  相似文献   

7.
A formalism for studying the interference between the direct reaction and the compound resonance processes is presented by the S-matrix theory; The mechanism of 12C(d, d) 12C, 12C(d, p113C* and 12C(d, p213C* reactions in the energy range Ed=1.63 MeV to 2.05 MeV is analysed.Te results show that: the interference between these two processes exists; and the quantitative relation between them is given. While the parameters of direct reactions and compound resonance processes, particularly for four resonance states with Ed=1.726, 1.767, 1.792 and 1.86 MeV are determined.  相似文献   

8.
The excitation functions of the 23Na(p,α020Neg·s.and the 23Na(p,α120Nelst reae-tion have been measured from Ep=1 to 2.5 MeV at θL=30°,150° and 30°,respectively.Around the resonance at 2.171 MeV,the excitation functions of the(p,α0)reactionhave been measured at 12 angles,then,some angular distributions have been obtained from these excitation functions.In addition,the angular distribution of the(p,α0)reaction for the resonance at 2.171 MeV has also been measured directly at energy ofthe resonance peak of the excitation function at 150°.For the resonance at 2.117MeV,the angular distribution have been measured at two energies,one at the energyof the resonance peak of the excitation function at 150°,another at the energy of thehalf maximum point of the resonance peak on the higher energy side.Around the re-sonance at 2.075 MeV,the excitation functions have been measured at 16 angles,andthe angular distribution has been obtained from three excitation functions.The an-gular distributions of the three resonances are not symmetric about 90°,and the posi-tions of the resonance peaks of these resonances varies with the angle of measurement.By means of the compound nucleus theory,discussions have been made for these non-solated resonances.  相似文献   

9.
In this paper we work out the relativistic covariant B-S wave function for the(π+ π-s atoms.Some properties of the“direct channel diagram”of the produc-tion the (π+ π-s atoms are discussed by calculating the cross-section of the process π+ +np+(π+ π-s with the help of the relativistic covariant wave function and assuming the lowest termin the perturbation expansion series of the quantized composite field theory——the“direct channel diagram”is dominant.Besides this calcuation perhaps presentsa rough estimate for the interesting process μ+ +n→(μ+ π-)+p.  相似文献   

10.
In this note we propose that the electromagnetic self energy of lepton may beconnected with quantum number n by( (δm)/m)=(1/(2π))n-b ,in which b is a constant.Wefnrther propose that the cut-off value of momentum M is connected with gravitationalconstant κ and fine structure constant α by M=(1/√καe-1-b.So we obtainthe mass formula of charged leptons M=(1/√κα exp{-3/4-b-(1/3α)n-b}.By using the masses of e- and μ- and the value of a as in put,we get the calculatedvalues of κ=(6.67231±0.00026)×10-8cm3g-1sec-2and mr=(1782.306±0.078)MeVwhich agree very well with experimental values κ=(6.6720±0.0041)×10-8cm3g-1sec-2 and mτ=(1782-4+3)MeV respectively.The mass of the fourth charged leptonpredicted by the formula should be m=(11725.47±0.51)MeV,which can be checkedby experiments in the near future.We also discuss briefly the proposed formula andthe obtained results.  相似文献   

11.
If the antiproton optical potential is inclusive of the spin orbit interaction term,the A(p,p)A* inelastic scattering not only can excited the normal parity states,but also can excited the abnormal parity states.There are also induced the polarization Pf(θ) at the inelastic scattering.In the framework of DWIA,we derived the inelastic scattering cross section (dσ/dΩ)f,i,and polarization Pf(θ),and calculated the (dσ/dΩ)f,i, and Pf(θ) for 12C(p,p)12C* with 2+,3 and 1+ states at antiproton energies of 46.8 and 179.7MeV.They fited experiment data quite well.Due to the abnormal partity states in the inelastic process have been measured,the spin orbit term can not be neglect.  相似文献   

12.
The cancellation properties of the nonhermitian single-particle (SP) potential uαβ=Mαβεβ) [or Mαβεα)] according to the principle of maximal cancellation of perturbation diagrams are investigated in detail. The mass operator Mαβω) is separated into two parts Mαβonω) and Mαβoffω) as usual, however, a new criterion for their definition will be proposed. It is shown that the exact mass operator insertion is equal to the sum of the following three types of terms:(1) terms contributed by the poles of Mαβoffω). They are truly non-factorizable and must be considered separately,(2) terms which can be cancelled to all orders by the nonhermitian choice uαβ=Mαβεβ) [or Mαβεα)]. Hence, they serve to define uαβ,(3) the remaining terms, which can be summed to all orders in a simple way and may be interpreted as amplitude renormalization of the SP Green function.In order to illustrate the usefulness of the above results, we have considered the renormalized random phase approximation (RRPA) for the particle-hole Green function as an example. Related formulae are derived. In RRPA, not only the SP propagator renormalization which includes all the effects except those contributed by the poles of Mαβoffω), but also the off energy shell property of the G matrix elements have been taken into account.  相似文献   

13.
It is proved that under the Gelfand-Biedenharn phase convention any SUn singletfactor (SF) belongs to the type of the derivable or underivable,designated as (SUnSF)d and (SUr SF) respectively,and (SUn SF)d=(SUr SF),n=r+1,r+2,….Therefore the calculation of any SUn Clebsch-Gordan coefficients is reduced to thecalculation of a few underivable singlet factor (SUr SF).  相似文献   

14.
In this paper,we suggest a two-nucleon model of the A(p,π-) B reaction.Areduced formulation of the reactoin amplitude and a relation between the reactionamplitude and the nuclear structure are given.The differential cross section of 13C(p,π-14Og.s,at EP=185 MeV is calculated in the plane wave approximation.The results+s can explain the experimental data qualilatively.  相似文献   

15.
We give an approximate sequence for Ut,t0)-operator.We prove the follow-ing theorems:Theorem 1.If the norm ||Ht)|| of Ht)in equation(2.1)is a Lebesgue in-tegrable function with respect to t,then there is an approximate sequence{Un},such that for any state vector |Φ〉,|Ψ〉,the sequence <Φ|U1|Ψ><Φ|U2|Ψ>,......,<Φ|Un|Ψ>,......is uniform convergent with respect to t.Theorem 2.If in finite time interval,the norm ||Ht)|| of Ht)in equation (2.1)is a Lebesgue integrable function,then equation(2.1)has unique solution.  相似文献   

16.
Recent studies of levels in even-even 68,70,72Ge,70,72,74Se,74,76,78,80Kr and 65Ga and 74Br have led to the discovery of a wide variety of different collective band structures.These include bands built on near spherical ground states and excited more well de-formed shapes that may include triaxial shapes,rotation-aligned bands built on thesame orbital (g(9/2)2 for both protons and neutrons,RAL negative parity bands witheven and odd spins,and ΔI=1 γ-type vibrational bands in even-even nuclei.As recent as 1974,a survey of the energy level in the even-even Ge and Se iso-topes[1] revealed little was known above a spin of 4+ (see for examples Figs.1 and 2 of Ref.1).With the exception of the unusally low-lying excited 0+ states in 70,72Ge,first discovered in 72Ge in 1948 at Vanderbilt[2],the theoretical treatment of thesenuclei was limited primarily to some variation of the vibrational model.However,very recently there has been a surge of information on nuclei in this region that hasrevealed fascinating new features and also provided new insight into the excited 0+’states.Particularly striking are the multiple,independent and highly collective bandstructures which we have discovered in our in-beam γ-ray spectroscopy studies fol-lowing heavy-ion induced reaction.Evidence for and the theoretical understandingof the richness of the collective band structures that are found in our studies of68,70,72Ge (Refs.3—6),70,72,74Se (Refs.7—13) and 74,76,78,80Kr (Refs.14—18),as illustratedby the at least seven different bands found in our studies of the levels of 68Ge 74Se,and 76Kr (Figs.1—3),are described in this paper.These multiple structures includethe following:a) coexistence of ground bands built on near-spherical shapes andexcited bands with larger deformation built on O+′ band heads;b) bands with 8+ band heads interpreted as rotation-aligned,RAL,bands built on both neutron and/orproton (g(9/2)2 quasiparticle configurations coexisting with the ground-state band;c)RAL neutron and proton odd-parity bands formed from coupling of a g(9/2 quasipar-ticle and a p(1/2),p(3/2) or f(5/2),quasiparticle with the core;d) ΔI=1 even-parity bands,which are best characterized as gamma-vibrational bands;and e) additional bandswhose nature are presently not known.  相似文献   

17.
In this paper, we analyse the commutation relations of the infintesimal opera-tors of the group SU3 and find that the eight infinitesimal operators of the groupSU3 can be written as a scalar operator A, three angular momentum operators (L1,Lo, L-1,)and two sets of the irreducible tensor operators of rank 1/2, (T±1/2,V±1/2)By means of the commutation relations of these operators, all irreducible represen-tations of the group SU3 can be easily obtained. In this pape, the matrices corresponding to these operators in the irreduciblerepresentation(λμ), are given; therefore the irreducible representation and its re-presentation space Rλμ are completely defined. Besides, a method for calculatingthe scalar factors of the reduction coefficients and the symmetric relations of thosefactors are also given. As examples, the scalar factors of the reduction coefficientsof (λμ)×(10), (λμ)×(01), (λμ)×(20) and (λμ)×(11) are calculated. In the last part of this paper, we define the irreducible tensor operators ofthe group SU3 and prove the corresponding Wigner-Eckart theory. The method used in the discussion of the group SU3 be extended to allof the compact simple Lie groups of rank 2 and we shall discuss them in two suc-ceeding papers.  相似文献   

18.
In this paper we disscuse disscuse the physicsical aspect of cross-section differences ΔAB=(ABcγX)-(ABcγX) and give the simple rules to select the elementary subprocesses which contribute to cross-section differences.
We bind a way to test the gluon distribution functions of hadrons through the measurement of cross-section difference or combination of cross-section differences in the large PT process with direct photon emission. Moreover we obtain simple relations between each combination of cross-sections and the corresponding gluon distribution functions of proton, neutron, pion and daon:
Gp8(x)/(Δpp-Δpp)=Gn8(x)/(Δpp)=Gπ8(x)/(Δπ+pπ-p=GK8(x)/(ΔK+pK-p)which are expected to be test in experiment.  相似文献   

19.
At an altitude of 3220 meters above sea level in Yunnan Province, we measured, by using a G-M counter-magnetic spectrometer, the vertical integratted momentum spectrum of the cosmic muon with momentum larger than 4 GeV/c. The spectrum obtained from this experiment is expressed by a power function in the form of I(>p)=Qp+4)-1.86±0.06(cm-2·sr-1·s-1), where p is in GeV/c and Q is a constant. We also measured the charge ratio of muon in the 4—23 GeV/c momentum range. The result is Nμ/Nμ-=1.26±0.11. The error in the momentum measurement with spectrometer has been discussed and calculated.  相似文献   

20.
In this paper the following results are proved:although the single-particle(sp)potential uαβ=Mαβεβ)defined in terms of the mass operator Mαβω) is nonhermi-tian,the discrete energy eigenvalues determined by the Schrödinger equation h|γ>=(t+u)|γ>=εγ|γ> are real;moreover,they satisfy exactly the following relation:(εγ=±[EnγN±1)—E0N)] where E0N)denotes the exact ground state energy of a closed-shell nucleus N,and EN±1)are excat energy eigenvalues of its neighbouring N±1 nucleus.Further,in order to determine whether the bound state energies obtained by anyother sp potential may or not satisfy the above relation,a simple method is sugges-ted.It is shown that the amplitude renormalization of the sp Green function canalso be calculated easily by means of this method.  相似文献   

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