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1.
A general analysis of the Slavnov-Taylor identity connecting the triple gluon and ghost-ghost-gluon vertices and its consequences
for two momentum subtraction (symmetric and asymmetric) renormalization schemes are given. It is shown that in the asymmetric
scheme proposed in this paper the relation
follows directly from the identity for a simple and natural definition of the renormalization constants. Explicit one-loop
expressions for the renormalization constants
in an arbitrary covariant gauge, including quark masses are given in support of the general analysis. 相似文献
2.
The maximum number of non-vanishing and independent second order photoelastic coefficients required by the seven pentagonal
and the two icosahedral point groups 5(C5),
(S10),
(C5h
),
m2(D5h
), 52(D5), 5m(C5v
),
2m(D5d
); 235(I), 2/m
(I
h
)—that describe the quasicrystals symmetry groups in two and three dimensions—is obtained. The schemes of non-vanishing and
independent coefficients have been calculated and listed. Finally the results of this group-theoretical study are briefly
discussed. 相似文献
3.
We examine the effects of mixing induced non-diagonal light-heavy neutrino weak neutral currents on the amplitude for the
process
(with a=e, μ or τ). By imposing constraint that the amplitude should not exceed the perturbative unitarity limit at high energy
, we obtain bounds on light-heavy neutrino mixing parameter sin2
where
is the mixing angle. In the case of one heavy neutrino (mass mξ) or mass degenerate heavy neutrinos, for Λ=1 TeV, no bound is obtained for mξ<0.50 TeV. However, sin2
≤3.8 × 10−6 for mξ=5 TeV and sin
≤6.0 × 10−8 for mξ=10 TeV. For Λ=∞, no constraint is obtained for mξ<0.99 TeV and sin2
≤3.8 × 10−2 (for mξ=5 TeV) and sin2
≤9.6 × 10−3 (for mξ=10 TeV). 相似文献
4.
Mohammad Sami 《Pramana》1982,18(5):451-460
The associated production of Higgs particles andZ (W) bosons inpp and
collisions is studied. The total cross-section of the processpp
→HXl
+
l
− is estimated. 相似文献
5.
We report results on event-by-event fluctuations in mean transverse momentum in AuAu collisions at
GeV measured by the STAR experiment at RHIC. The dynamical fluctuations,
is found to be about 1.2 ±02% of the mean transverse momentum for particles in pseudo-rapidity range of −0.5 < η < 0.5 and
for the top 6% central collisions. 相似文献
6.
It is shown that the (8, 8) model and explicitηπ
0 mixing successfully explain theη→3π decay width whereas the decay width calculated from the mass difference
is about one order less than the experimental value. 相似文献
7.
An estimation of the mass difference of
system with heavy quark symmetry formalism is presented. The effective Hamiltonian describing the transition
(whereh=b forB
d
0
-system) is considered in a manifest left right symmetric (MLRS) model along with contribution from neutral Higgs boson. We
use the spin and flavor symmetry for heavy quarks to obtain the transition matrix element 〈B
d
0
|ℋeff(x)|
d
0
〉 in terms of Isgur-Wise function. Assuming thatB
d
0
and
states are at rest, we find that Isgur-Wise function turns out to be unity. However using the experimental values of ΔM
K and
as input, we find thatM
R=835 GeV andM
H⩾2·9 TeV. 相似文献
8.
The existence of a topological double-covering for the GL(n, R) and diffeomorphism groups is reviewed. These groups do not
have finite-dimensional faithful representations. An explicit construction and the classification of all
(n, R), n=3,4 unitary irreducible representations is presented. Infinite-component spinorial and tensorial
fields, “manifields”, are introduced. Particle content of the ladder manifields, as given by the
(3, R) “little” group, is determined. The manifields are lifted to the corresponding world spinorial and tensorial manifields
by making use of generalized infinite-component frame fields. World manifields transform w.r.t. corresponding
representations, which are constructed explicitly.
Supported in part by the Science Foundation (Belgrade). 相似文献
9.
KN sigma commutator has been calculated in the framework of the (6,
)+(
, 6) model. It is found that though this model could not be discarded in favour of the (3,
)+(
, 3) or (8, 8) model, a very large value forKN sigma term is required to get a positive value ofπN sigma term. 相似文献
10.
Isothermal remanent magnetization decay,M
r(t), and ‘in-field’ growth of zero-field-cooled magnetization,M
ZFC(t), with time have been measured over four decades in time at temperatures ranging from 0.25T
c to 1.25T
c (whereT
c is the Curie temperature, determined previously for the same sample from static critical phenomena measurements) for a nearly
ordered intermetallic compound Ni3Al, which is an experimental realization of a three-dimensional (d = 3) ferromagnet with weak quenched random-exchange disorder. None of the functional forms ofM
r(t) predicted by the existing phenomenological models of relaxation dynamics in spin systems with quenched randomness, but only
the expressions
and
closely reproduce such data in the present case. The most striking features of magnetic relaxation in the system in question
are as follows: Aging effects are absent in bothM
r
t andM
ZFC(t) at all temperatures in the temperature range covered in the present experiments. A cross-over in equilibrium dynamics from
the one, characteristic of a pured = 3 ferromagnet with complete atomic ordering and prevalent at temperatures away from Tc, to that, typical of ad = 3 random-exchange ferromagnet, occurs asT → Tc. The relaxation times τ1(T)(τ1
′(T)) and τ2(T)(τ2
′(T)) exhibit logarithmic divergence at critical temperatures
and
;
and
both increase with the external magnetic field strength,H, such that at any given field value,
. The exponent characterizing the logarithmic divergence in τ
1
′
(T) and τ
2
′
T possesses a field-independent value of ≃16 for both relaxation times. Of all the available theoretical models, the droplet
fluctuation model alone provides a qualitative explanation for some aspects of the present magnetic relaxation data 相似文献
11.
A Dega-Dałkowska 《Pramana》1990,35(4):355-360
The temperature dependence of shear viscosity of the system nitrobenzene-n-heptane has been studied near the critical concentration. The critical exponent of the shear viscosity Φ was calculated from
the empirical formula
and compared with the theoretical and experimental results obtained for other critical systems. The shear viscosity satisfies
scaling law relations similar to those previously established for equilibrium properties. 相似文献
12.
Finitely generated free modular ortholattices. II 总被引:2,自引:0,他引:2
M. Haviar P. Konôpka C. B. Wegener 《International Journal of Theoretical Physics》1997,36(12):2661-2679
13.
E. Nolte T. Faestermann A. Gillitzer G. Korschinek D. Müller V. M. Novikov A. A. Pomansky A. Ljubicic D. Miljanic 《Zeitschrift für Physik A Hadrons and Nuclei》1991,340(4):411-413
The Pauli exclusion principle was tested by searching with accelerator mass spectrometry for non-Paulian atoms with three electrons in theK-shell and for non-Paulian nuclei with three protons or three neutrons in the nuclear 1 s1/2 shell. For non-Paulian atoms of
and
the following limits have been obtained:
and
. For non-Paulian nuclei of
and
with three protons or three neutrons, respectively, in the nuclear 1 s1/2 shell the following limits have been measured:
for a range of proton separation energies of
between 0 and 50 MeV and
for neutron separation energies between 0 and 32 MeV. The result for5Li is used to deduce a limit for the probability 2/2 of finding two colliding protons in the symmetric state with respect to exchange to be 2/2<>–32.Dedicated to Prof. Dr. P. Kienle on the occasion of his 60th birthday. Supported by the BMFT 相似文献
14.
R N Mohapatra 《Pramana》2006,67(5):783-791
See-saw mechanism has been a dominant paradigm in the discussion of neutrino masses. We discuss how this idea can be tested
via a baryon number violating process such as N-
oscillation. Since the expected see-saw scale is high and the N-
amplitude goes like M
R
−5
, one might think that this process is not observable in realistic see-saw models for neutrino masses. In this talk I show
that in supersymmetric models, the above conclusion is circumvented leading to an enhanced and observable rate for N
oscillation. I also discuss a new mechanism for baryogenesis in generic models for neutron-anti-neutron oscillation. 相似文献
15.
C. Chris Wu 《Journal of statistical physics》1996,88(5-6):1399-1408
We consider an inhomogeneous contact process on a tree
of degreek, where the infection rate at any site isλ, the death rate at any site in
isδ (with 0 <δ ⩽ 1) and that at any site in
is 1. Denote by
the critical value for thehomogeneous model (i.e.,δ=1) on
and byϑ(δ, λ) the survival probability of the inhomogeneous model on
. We prove that whenk > 4, if
, a subtree embedded in
, with 1 ⩽σ ⩽ √k, then three existsδ
c
σ
strictly between (
) and 1 such that (
) whenδ >δ
c
σ
andϑ(δ, λ
c(
) > 0 whenδ <δ
c
σ
; ifS={o}, the origin of
, then
for anyδ ε (0, 1). 相似文献
16.
We present an analysis of nonannihilation channels in four-pronged
interactions at 5·68 GeV/c. The transverse momenta and azimuthal angles distributions of nucléons and -mesons are compared with phase space. No essential influence of
production on azimuthal correlation has been found. The seen difference of azimuthal angle distributions for like and unlike charged pions in annihilations appears to be more pronounced for small transverse momenta and for small transverse masses. For 10971 events of the reaction ¯pp¯pp–+ we present cross sections for
production and differential cross sections. The reaction is dominated by the strong quasi-two-body channel
with cross section (1·66 ±±0·10) mb. We study in detail the production mechanism of this channel in terms of the absorption model.Dedicated to Academician Václav Votruba on the occasion of his seventieth birthday.The authors are indebted to the CERN-Prague collaboration on ¯pp interactions at 5·7 GeV/c for experimental data used in this paper and to Dr. M. Novak for valuable comments. 相似文献
17.
R. Shimizu 《Applied Physics A: Materials Science & Processing》1979,18(4):425-426
The statistics of the sputtering process, which has been used to explain sputterbroadening effect due to surface roughness,
has been treated with conditional probabilities. This results in the relationship,
, instead of
derived by S. Hofmann [Appl. Phys.9, 59 (1976)], where δz,z, and
are the depth resolution, sputtered depth and sputtering yield, respectively. 相似文献
18.
The transport coefficients for the nine point groups
—which represent the symmetry groups of the quasicrystals in two and three dimensions—have been evaluated and tabulated in
this work, employing group-theoretical methods. 相似文献
19.
We show that the Ashtekar-Isham extension
of the configuration space of Yang-Mills theories
is (topologically and measure-theoretically) the projective limit of a family of finite dimensional spaces associated with arbitrary finite lattices.These results are then used to prove that
is contained in a zero measure subset of
with respect to the diffeomorphism invariant Ashtekar-Lewandowski measure on
. Much as in scalar field theory, this implies that states in the quantum theory associated with this measure can be realized as functions on the extended configuration space
. 相似文献
20.
The effect of the order-parameter-dependent mobility,
, on phase-ordering dynamics of self-assembled fluids is studied analytically within the large-N limit. The study is for quenching from an uncorrelated high temperature state into the Lifshitz line within the microemulsion
phase. In the later stage of the ordering process, the structure factor exhibits multiscaling behavior with characteristic
length scale
The order-parameter-dependent mobility is found to slow down the rate of coarsening. 相似文献