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1.
We obtain exact results in α′ for open and closed A-model topological string amplitudes on a large class of toric Calabi-Yau threefolds by using their correspondence with five
dimensional gauge theories. The toric Calabi-Yaus that we analyze are obtained as minimal resolution of cones over Y
p,q
manifolds and give rise via M-theory compactification to SU(p) gauge theories on . As an application we present a detailed study of the local case and compute open and closed genus zero Gromov-Witten invariants of the orbifold. We also display the modular structure of the topological wave function and give predictions for higher genus amplitudes.
The mirror curve in this case is the spectral curve of the relativistic A
1 Toda chain. Our results also indicate the existence of a wider class of relativistic integrable systems associated to generic
Y
p,q
geometries. 相似文献
2.
We construct a family of self-adjoint operators D N , ${N\in{\mathbb Z}}We construct a family of self-adjoint operators D
N
,
N ? \mathbb Z{N\in{\mathbb Z}} , which have compact resolvent and bounded commutators with the coordinate algebra of the quantum projective space
\mathbb CPlq{{\mathbb C}{\rm P}^{\ell}_q} , for any ℓ ≥ 2 and 0 < q < 1. They provide 0+-dimensional equivariant even spectral triples. If ℓ is odd and
N=\frac12(l+1){N=\frac{1}{2}(\ell+1)} , the spectral triple is real with KO-dimension 2ℓ mod 8. 相似文献
3.
The spectral functor of an ergodic action of a compact quantum group G on a unital C
*-algebra is quasitensor, in the sense that the tensor product of two spectral subspaces is isometrically contained in the
spectral subspace of the tensor product representation, and the inclusion maps satisfy natural properties. We show that any
quasitensor *-functor from Rep(G) to the category of Hilbert spaces is the spectral functor of an ergodic action of G on a unital C
*-algebra.
As an application, we associate an ergodic G-action on a unital C
*-algebra to an inclusion of Rep(G) into an abstract tensor C
*-category .
If the inclusion arises from a quantum subgroup K of G, the associated G-system is just the quotient space K\G. If G is a group and has permutation symmetry, the associated G-system is commutative, and therefore isomorphic to the classical quotient space by a subgroup of G.
If a tensor C
*-category has a Hecke symmetry making an object ρ of dimension d and μ-determinant 1, then there is an ergodic action of S
μ
U(d) on a unital C
*-algebra having the as its spectral subspaces. The special case of is discussed. 相似文献
4.
U. Aglietti F. Di Lodovico G. Ferrera G. Ricciardi 《The European Physical Journal C - Particles and Fields》2009,59(4):831-840
By analyzing B→X
u
ℓ
ν
ℓ
spectra with a model based on soft-gluon resummation and an analytic time-like QCD coupling, we obtain
where the first and the second error refer to experimental and theoretical error, respectively. This model successfully describes
the accurate experimental data in beauty fragmentation, which has similar soft-gluon effects. The |V
ub
| value is obtained from the available measured semileptonic branching fractions in limited regions of the phase space. The
distributions in the lepton energy E
ℓ
, the hadron invariant mass m
X
, the light-cone momentum
, together with the double distributions in (m
X
,q
2) and (E
ℓ
,s
hmax ), are used to select the phase-space regions. q
2 is the dilepton squared momentum and s
hmax is the maximal m
X
2 at fixed q
2 and E
ℓ
. The |V
ub
| value obtained is in complete agreement with the value coming from exclusive B decays and from an over-all fit to the standard model parameters. We show that the slight disagreement (up to +2σ) with respect to previous inclusive measurements is not related to different choices for the b (and c) masses, but to a different modeling of the threshold (Sudakov) region. 相似文献
5.
A new evaluation of the hadronic vacuum polarization contribution to the muon magnetic moment is presented. We take into account the reanalysis of the low-energy e
+
e
-annihilation cross section into hadrons by the CMD-2 Collaboration. The agreement between e
+
e
-and
spectral functions in the
channel is found to be much improved. Nevertheless, significant discrepancies remain in the center-of-mass energy range between 0.85 and
, so that we refrain from averaging the two data sets. The values found for the lowest-order hadronic vacuum polarization contributions are
where the errors have been separated according to their sources: experimental, missing radiative corrections in e
+
e
-data, and isospin breaking. The corresponding Standard Model predictions for the muon magnetic anomaly read
where the errors account for the hadronic, light-by-light (LBL) scattering and electroweak contributions. The deviations from the measurement at BNL are found to be
(1.9
) and
(0.7
) for the e
+
e
-- and
-based estimates, respectively, where the second error is from the LBL contribution and the third one from the BNL measurement.Received: 7 September 2003, Published online: 30 October 2003 相似文献
6.
We constrain the possible time variation of the Higgs vacuum expectation value (v) by recent results on the primordial 4He abundance (Y
P
). For that, we use an analytic approach which enables us to take important issues into consideration, that have been ignored
by previous works, like the v-dependence of the relevant cross sections of deuterium production and photodisintegration, including the full Klein–Nishina
cross section. Furthermore, we take a non-equilibrium Ansatz for the freeze-out concentration of neutrons and protons and
incorporate the latest results on the neutron decay. Finally, we approximate the key-parameters of the primordial 4He production (the mean lifetime of the free neutron and the binding energy of the deuteron) by terms of
(where v
0 denotes the present theoretical estimate). Eventually, we derive the relation
and the most stringent limit on a possible time variation of v is given by:
. 相似文献
7.
G. Meierhofer P. Kudejova L. Canella P. Grabmayr J. Jochum J. Jolie 《The European Physical Journal A - Hadrons and Nuclei》2009,40(1):61-64
The thermal neutron capture cross-sections of the 76Ge(n,)77Ge and the 76Ge(n,)77m
Ge reactions have been measured by activating targets of isotopically enriched GeO2 through cold neutrons. The -decay spectra after the -decay of 77Ge and 77m
Ge were measured with HPGe detectors. From these spectra the cross-sections for the 76Ge(n,) reactions were derived relative to the cross-section of 197Au using the absolute emission probabilities of the observed -ray energies. The methods used in this work result in smaller systematic uncertainties than those obtained in previous experiments. 相似文献
8.
The nuclear spectroscopic quadrupole moments for the πh9/25/2-, 1/2-[541] and the πh11/29/2-, 9/2-[514] isomeric states in 169Ta have been measured employing the time differential perturbed angular-distribution technique following the nuclear reaction
159Tb(16O, 6nγ)169Ta at beam energy 104 MeV. The ratio of the intrinsic quadrupole moments
has been derived as 1.87(13) from the measured quadrupole precession frequencies of the corresponding states. The model-independent
analysis of the equilibrium deformation indicates strong prolate- and oblate-driving nature of the 1/2-[541] and 9/2-[514] orbitals in 169,171Ta isotopes, respectively. 相似文献
9.
John A. Toth 《Communications in Mathematical Physics》2009,288(1):379-401
We show that for a quantum completely integrable system in two dimensions, the L
2-normalized joint eigenfunctions of the commuting semiclassical pseudodifferential operators satisfy restriction bounds of
the form for generic curves γ on the surface. We also prove that the maximal restriction bounds of Burq-Gerard-Tzvetkov [BGT] are generically attained
for certain exceptional subsequences of eigenfunctions.
The author was supported by a William Dawson Fellowship and NSERC Grant OGP0170280. 相似文献
10.
Tadayoshi Adachi 《Letters in Mathematical Physics》2007,82(1):1-8
For an N-body Stark Hamiltonian , the resolvent estimate holds uniformly in with Re and Im , where , and is a compact interval. This estimate is well known as the limiting absorption principle. In this paper, we report that by
introducing the localization in the configuration space, a refined resolvent estimate holds uniformly in with Re and Im .
Dedicated to Professor Hideo Tamura on the occasion of his 60th birthday 相似文献
11.
The T = 1 admixture into the T = 0 member of a recently discovered
isospin-doublet in 54Co is obtained from the measured electromagnetic E2/M1 multipole mixing ratio,
of the
transition. Combining these data with shell model calculations for strong isovector M1 and isoscalar E2 electromagnetic matrix elements one obtains a value for the T = 1 admixture into the T = 0, 4 + state of
. The corresponding mixing matrix element in the 4 + doublet is
keV.Received: 31 October 2002, Published online: 9 March 2004PACS:
21.10.Hw Spin, parity, and isobaric spin - 21.60.Cs Shell model - 23.20.Gq Multipole mixing ratios 相似文献
12.
Final results from the DELPHI Collaboration on the lifetime of B + and B0 mesons and the mean b-hadron lifetime, are presented using the data collected at the Z0 peak in 1994 and 1995. Elaborate, inclusive, secondary vertexing methods have been employed to ensure a b-hadron reconstruction with good efficiency. To separate samples of B + and B0 mesons, high performance neural network techniques are used that achieve very high purity signals. The results obtained are:
and for the average b-hadron lifetime:
Received: 6 October 2003, Revised: 12 December 2003, Published online: 25 February 2004 相似文献
13.
T. Shizuma T. Ishii H. Makii T. Hayakawa M. Matsuda 《The European Physical Journal A - Hadrons and Nuclei》2009,39(3):263-266
Excited states in neutron-rich 183Ta have been studied using a two-neutron transfer reaction of 181Ta(18O,16O) . In-beam -rays were measured in coincidence with scattered ions detected by a high-resolution
E -E Si telescope for reaction channel selection. Previously known 1-quasiparticle bands are extended to higher spins, and several
levels including a T
1/2 = 0.9(3) μs 3-quasiparticle isomer are identified. 相似文献
14.
Upper limits on the cross-section of the pair-production process
, assuming 100
branching fraction to hadrons, are derived from a new search for the
hadrons final state, independently of the hadronic flavour of the decay products. This study, combined with previously published searches for the neutral Higgs bosons h0 and A0, is used to constrain the Type II Two Higgs Doublet Model (2HDM(II)) with no CP violation in the Higgs sector and no additional non-Standard Model particles besides the five Higgs bosons. The analysis combines LEP1 and LEP2 data collected with the OPAL detector up to the highest available centre-of-mass energies. The searches are sensitive to the
and
decay modes of the Higgs bosons. A benchmark scan of the 2HDM(II) parameter space is performed. Large regions of the 2HDM(II) parameter space explored are excluded at the 95% CL in the (
and
planes, using both direct neutral Higgs boson searches and indirect limits derived from Standard Model high precision measurements. The region
GeV and
GeV is excluded at 95 % CL, independently of
and for selected values of
which are representative of a complete
-scan.Received: 28 July 2004, Revised: 4 January 2005, Published online: 3 March 2005 相似文献
15.
K. Terasaki 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):676-678
Although assigning D
s0
+(2317) to the I
3 = 0 component
of iso-triplet four-quark mesons is favored by experiments, its neutral and doubly charged partners have not yet been observed.
It is discussed why they were not observed in inclusive e
+
e
-→cˉ experiment and that they can be observed in B decays. 相似文献
16.
For the Lie algebra
N we introduce a system of differential operators called the dynamical operators. We prove that the dynamical differential operators commute with the
N rational quantized Knizhnik–Zamolodchikov difference operators. We describe the transformations of the dynamical operators under the natural action of the
N Weyl group.Mathematics Subject Classifications (2000). 17B37, 17B80, 81R10. 相似文献
17.
We consider the Schrödinger operatorH = – +V(|x|) onR
3. Letn
denote the number of bound states with angular momentum (not counting the 2 + 1 degeneracy). We prove the following bounds onn
. LetV 0 and d/dr r
1-2p
(-V)1 –p
0 for somep [1/2, 1) then
相似文献
18.
Covariant differential calculi on the quantum space
for the quantum group SL
q
(2) are classified. Our main assumptions are thatq is not a root of unity and that the differentials de
j
of the generators of
form a free right module basis for the first-order forms. Our result says, in particular, that apart from the two casesc =c(3), there exists a unique differential calculus with the above properties on the space
which corresponds to Podles' quantum sphereS
qc
/2
. 相似文献
19.
Anton Gerasimov Dimitri Lebedev Sergey Oblezin 《Communications in Mathematical Physics》2010,294(1):97-119
We propose a new explicit form of q-deformed Whittaker functions solving q-deformed ${\mathfrak{gl}_{\ell+1}}
20.
The spectral action on the equivariant real spectral triple over is computed explicitly. Properties of the differential calculus arising from the Dirac operator are studied and the results
are compared to the commutative case of the sphere .
UMR 6207, – Unité Mixte de Recherche du CNRS et des Universités Aix-Marseille I, Aix-Marseille II et de l’Université du Sud
Toulon-Var, Laboratoire affilié à la FRUMAM – FR 2291.
Partially supported by Polish Government grants 189/6.PRUE/2007/7; 115/E-343/SPB/6.PR UE/DIE and N 201 1770 33. 相似文献
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