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1.
Dian-Yong Chen Xiang Liu Xue-Qian Li 《The European Physical Journal C - Particles and Fields》2011,71(11):1808
To solve the discrepancy between the experimental data on the partial widths and lineshapes of the dipion emission of ϒ(4S) and the theoretical predictions, we suggest that there is an additional contribution, which had not been taken into account
in previous calculations. Noticing that the mass of ϒ(4S) is above the production threshold of B[`(B)]B\bar{B}, the contribution of the sequential process
\varUpsilon(4S)? B[`(B)]? \varUpsilon(nS)+S?\varUpsilon(nS)+p+p-\varUpsilon(4S)\to B\bar{B}\to \varUpsilon(nS)+S\to\varUpsilon(nS)+\pi^{+}\pi^{-} (n=1,2) may be sizable, and its interference with that from the direct production would be important. The goal of this work
is to investigate if a sum of the two contributions with a relative phase indeed reproduces the data. Our numerical results
on the partial widths and the lineshapes
d\varGamma(\varUpsilon(4S)?\varUpsilon(2S,1S)p+p-)/d(mp+p-)d\varGamma(\varUpsilon(4S)\to\varUpsilon(2S,1S)\pi^{+}\pi^{-})/d(m_{\pi ^{+}\pi^{-}}) are satisfactorily consistent with the measurements; thus the role of this mechanism is confirmed. Moreover, with the parameters
obtained by fitting the data of the Belle and BaBar collaborations, we predict the distributions dΓ(ϒ(4S)→ϒ(2S,1S)π
+
π
−)/dcosθ, which have not been measured yet. 相似文献
2.
We obtain convergent multi-scale expansions for the one-and two-point correlation functions of the low temperature lattice classical N - vector spin model in d S 3 dimensions, N S 2. The Gibbs factor is taken as exp[-b(1/2 ||?f||2 +l/8 || |f|2 - 1 ||2 + v/2||f- h||2)], \exp [-\beta (1/2 ||\partial \phi||^2 +\lambda/8 ||\, |\phi|^2 - 1 ||^2 + v/2||\phi - h||^2)], where f(x), h ? RN\phi(x), h \in R^N, x ? Zdx \in Z^d, |h|=1, b < ¥|h|=1, \beta < \infty, l 3 ¥\lambda \geq \infty are large and 0 < v h 1. In the thermodynamic and v ˉ 0v \downarrow 0 limits, with h = e1, and j L ½ , the expansion gives áf1(x)? = 1+0(1/b1/2)\langle \phi_1(x)\rangle = 1+0(1/\beta^{1/2}) (spontaneous magnetization), áf1(x)fi(y)? = 0\langle \phi_1(x)\phi_i(y)\rangle=0, áfi (x)fi (y)? = c0 D-1(x,y)+R(x,y)\langle \phi_i (x)\phi_i (y)\rangle = c_0 \Delta^{-1}(x,y)+R(x,y) (Goldstone Bosons), i = 2, 3, ?, Ni= 2, 3,\,\ldots, N, and áf1(x)f1(y)?T=R¢(x,y)\langle \phi_1(x)\phi_1(y)\rangle^T=R'(x,y), where |R(x,y)||R(x,y)|, |R¢(x,y)| < 0(1)(1+|x-y|)d-2+r|R'(x,y)|< 0(1)(1+|x-y|)^{d-2+\rho} for some > 0, and c0 is aprecisely determined constant. 相似文献
3.
In this article, we study the mass spectrum of the baryon-antibaryon bound states p
[`(p)] \bar{{p}} , S \Sigma
[`(S)] \bar{{\Sigma}} , X \Xi
[`(X)] \bar{{\Xi}} , L \Lambda
[`(L)] \bar{{\Lambda}} , p
[`(N)] \bar{{N}}(1440) , S \Sigma
[`(S)] \bar{{\Sigma}}(1660) , X \Xi
[`(X)]¢ \bar{{\Xi}}^{{\prime}}_{} and L \Lambda
[`(L)] \bar{{\Lambda}}(1600) with the Bethe-Salpeter equation. The numerical results indicate that the p
[`(p)] \bar{{p}} , S \Sigma
[`(S)] \bar{{\Sigma}} , X \Xi
[`(X)] \bar{{\Xi}} , p
[`(N)] \bar{{N}}(1440) , S \Sigma
[`(S)] \bar{{\Sigma}}(1660) , X \Xi
[`(X)]¢ \bar{{\Xi}}^{{\prime}}_{} bound states maybe exist, and the new resonances X(1835) and X(2370) can be tentatively identified as the p
[`(p)] \bar{{p}} and p
[`(N)] \bar{{N}}(1440) (or N(1400)[`(p)] \bar{{p}} bound states, respectively, with some gluon constituents, and the new resonance X(2120) may be a pseudoscalar glueball. On the other hand, the Regge trajectory favors identifying the X(1835) , X(2120) and X(2370) as the excited h¢ \eta^{{\prime}}_{}(958) mesons with the radial quantum numbers n = 3 , 4 and 5, respectively. 相似文献
4.
潘峰 周丹 杨思雨 Grigor Sargsyan 赫英雯 Kristina D.Launey Jerry P.Draayer 《中国物理C(英文版)》2019,43(7):074106-074106-9
competition of isovector and isoscalar pairing in A=18 and 20 even-even N≈Z nuclei is analyzed in the framework of the mean-field plus the dynamic quadurpole-quadurpole, pairing and particle-hole interactions, whose Hamiltonian is diagonalized in the basis U(24) ?(U(6) ? S U(3) ? S O(3))■(U(4) ? S US(2)■ S UT(2)) in the L = 0 configuration subspace. Besides the pairing interaction, it is observed that the quadurpole-quadurpole and particlehole interactions also play a significant role in determining the relative positions of low-lying excited 0~+ and 1~+ levels and their energy gaps, which can result in the ground state first-order quantum phase transition from J = 0 to J = 1.The strengths of the isovector and isoscalar pairing interactions in these even-even nuclei are estimated with respect to the energy gap and the total contribution to the binding energy. Most importantly, it is shown that although the mechanism of the particle-hole contribution to the binding energy is different, it is indirectly related to the Wigner term in the binding energy. 相似文献
5.
M. Cleven F. -K. Guo C. Hanhart U. -G. Meißner 《The European Physical Journal A - Hadrons and Nuclei》2011,47(2):19
We calculate the masses of the resonances Ds0*(2317)\ensuremath D_{s0}^{\ast}(2317) and Ds1(2460)\ensuremath D_{s1}(2460) as well as their bottom partners as bound states of a kaon and a D(*)\ensuremath D^{(\ast)} - and B(*)\ensuremath B^{(\ast)} -meson, respectively, in unitarized chiral perturbation theory at next-to-leading order. After fixing the parameters in the
Ds0*(2317)\ensuremath D_{s0}^{\ast}(2317) channel, the calculated mass for the Ds1(2460)\ensuremath D_{s1}(2460) is found in excellent agreement with experiment. The masses for the analogous states with a bottom quark are predicted to
be MB*s0=(5696±40)\ensuremath M_{B^{\ast}_{s0}}=(5696\pm 40) MeV and MBs1=(5742±40)\ensuremath M_{B_{s1}}=(5742\pm 40) MeV in reasonable agreement with previous analyses. In particular, we predict MBs1-MBs0*=46±1\ensuremath M_{B_{s1}}{-}M_{B_{s0}^{\ast}}=46\pm 1 MeV. We also explore the dependence of the states on the pion and kaon masses. We argue that the kaon mass dependence of
a kaonic bound state should be almost linear with slope about unity. Such a dependence is specific to the assumed molecular nature of the states. We suggest to extract the kaon mass dependence
of these states from lattice QCD calculations. 相似文献
6.
P. Ortwein W. Woiwode S. Wagner M. Gisi V. Ebert 《Applied physics. B, Lasers and optics》2010,100(2):341-347
A high-resolution spectrometer based on a vertical-cavity surface-emitting laser (VCSEL) was developed and used to determine
the line strength S(T
0)=12.53(11)×10−21 cm−1/(molec cm−2) and the self-broadening coefficient
g0HCl=0.021787(61)\gamma^{0}_{\mathrm{HCl}}=0.021787(61)
cm−1/atm of the R(3) absorption line in the first rovibrational overtone (2←0) band of H35Cl. Furthermore, the first laser-based high-pressure study on the pressure broadening of HCl by He, N2 and
O2(g0N2=0.07292(5)\mathrm{O}_{2}(\gamma^{0}_{\mathrm{N}_{2}}=0.07292(5)
cm−1/atm,
g0He=0.02113(1)\gamma^{0}_{\mathrm{He}}=0.02113(1)
cm−1/atm,
g0O2=0.03978(6)\gamma^{0}_{\mathrm{O}_{2}}=0.03978(6)
cm−1/atm) is presented covering pressures of up to 1 MPa. The results are compared to previously available low-pressure data. 相似文献
7.
For systems of N charged fermions (e.g. electrons) interacting with longitudinal optical quantized lattice vibrations of a polar crystal we derive upper and lower bounds on the minimal energy within the model of H. Fröhlich. The only parameters of this model, after removing the ultraviolet cutoff, are the constants U > 0 and α > 0 measuring the electron-electron and the electron-phonon coupling strengths. They are constrained by the condition ${\sqrt{2}\alpha < U}For systems of N charged fermions (e.g. electrons) interacting with longitudinal optical quantized lattice vibrations of a polar crystal we
derive upper and lower bounds on the minimal energy within the model of H. Fr?hlich. The only parameters of this model, after
removing the ultraviolet cutoff, are the constants U > 0 and α > 0 measuring the electron-electron and the electron-phonon coupling strengths. They are constrained by the condition ?2a < U{\sqrt{2}\alpha < U}, which follows from the dependence of U and α on electrical properties of the crystal. We show that the large N asymptotic behavior of the minimal energy E
N
changes at ?2a = U{\sqrt{2}\alpha=U} and that ?2a £ U{\sqrt{2}\alpha\leq U} is necessary for thermodynamic stability: for ${\sqrt{2}\alpha > U}${\sqrt{2}\alpha > U} the phonon-mediated electron-electron attraction overcomes the Coulomb repulsion and E
N
behaves like −N
7/3. 相似文献
8.
The well-known Heun equation has the form
ll{Q(z)\frac d2dz2+P(z)\fracddz+V(z)}S(z)=0,\begin{array}{ll}\left\{Q(z)\frac {d^2}{dz^2}+P(z)\frac{d}{dz}+V(z)\right\}S(z)=0,\end{array} 相似文献
9.
C. S. Fischer T. Goecke R. Williams 《The European Physical Journal A - Hadrons and Nuclei》2011,47(2):28
Using the Dyson-Schwinger and Bethe-Salpeter equations, we calculate the hadronic light-by-light scattering contribution to
the anomalous magnetic moment of the muon am\ensuremath a_\mu , using a phenomenological model for the gluon and quark-gluon interaction. We find am=(84 ±13)×10-11\ensuremath a_\mu=(84 \pm 13)\times 10^{-11} for meson exchange, and am = (107 ±2 ±46)×10-11\ensuremath a_\mu = (107 \pm 2 \pm 46)\times 10^{-11} for the quark loop. The former is commensurate with past calculations; the latter much larger due to dressing effects. This
leads to a revised estimate of am=116 591 865.0(96.6)×10-11\ensuremath a_\mu=116 591 865.0(96.6)\times 10^{-11} , reducing the difference between theory and experiment to ≃ 1.9s \sigma . 相似文献
10.
Andrzej Trautman 《International Journal of Theoretical Physics》1977,16(8):561-565
It is shown that the magnetic pole of lowest strength and the pseudoparticle solution of the Yang-Mills equations correspond to natural connections defined on the principal bundlesU(2)/U(1)=S
3 S
2 andSp(2)/Sp(1)=S
7 S
4, respectively. This observation leads to a general methods of constructing new, topologically nontrivial solutions of the Maxwell and Yang-Mills equations. Among them is an electromagnetic instanton defined over the two-dimensional complex projective space endowed with the Fubini-Study metric.On leave from the Institute of Theoretical Physics, Warsaw University, Hoza 69, Warsaw, Poland. 相似文献
11.
H.?W.?Grie?hammer M.?R.?Schindler 《The European Physical Journal A - Hadrons and Nuclei》2010,46(1):73-83
We address the typical strengths of hadronic parity-violating three-nucleon interactions in “pion-less” Effective Field Theory
(EFT) in the nucleon-deuteron (iso-doublet) system. By analysing the superficial degree of divergence of loop diagrams, we
conclude that no such interactions are needed at leading order, O(eQ-1)\ensuremath {O}(\epsilon Q^{-1}) . The only two distinct parity-violating three-nucleon structures with one derivative mix
2S\frac12\ensuremath ^2S_{\frac{1}{2}} and
2P\frac12\ensuremath ^2P_{\frac{1}{2}} waves with iso-spin transitions D \Delta
I = 0 or 1. Due to their structure, they cannot absorb any divergence ostensibly appearing at next-to-leading order, O(eQ0)\ensuremath {O}(\epsilon Q^0) . This observation is based on the approximate realisation of Wigner’s combined SU(4) spin-isospin symmetry in the two-nucleon system, even when effective-range corrections are included. Parity-violating
three-nucleon interactions thus only appear beyond next-to-leading order. This guarantees renormalisability of the theory
to that order without introducing new, unknown coupling constants and allows the direct extraction of parity-violating two-nucleon
interactions from three-nucleon experiments. 相似文献
12.
We extend the formalism of integrable operators à la Its-Izergin-Korepin-Slavnov to matrix-valued convolution operators on
a semi–infinite interval and to matrix integral operators with a kernel of the form
\fracE1T(l) E2(m)l+m{\frac{E_1^T(\lambda) E_2(\mu)}{\lambda+\mu}}, thus proving that their resolvent operators can be expressed in terms of solutions of some specific Riemann-Hilbert problems.
We also describe some applications, mainly to a noncommutative version of Painlevé II (recently introduced by Retakh and Rubtsov)
and a related noncommutative equation of Painlevé type. We construct a particular family of solutions of the noncommutative
Painlevé II that are pole-free (for real values of the variables) and hence analogous to the Hastings-McLeod solution of (commutative)
Painlevé II. Such a solution plays the same role as its commutative counterpart relative to the Tracy–Widom theorem, but for
the computation of the Fredholm determinant of a matrix version of the Airy kernel. 相似文献
13.
Manuel del Pino Patricio L. Felmer Peter Sternberg 《Communications in Mathematical Physics》2000,210(2):413-446
We examine the asymptotic behavior of the eigenvalue w(h) and corresponding eigenfunction associated with the variational problem m(h) o infy ? H1(W;C ) \fracòW \abs(i?+hA)y2 dx dy òW\absy2 dx dy \mu(h)\equiv\inf_{\psi\in H^{1}(\Omega;{\bf C} )} \frac{\int_{\Omega } \abs{(i\nabla+h{\bf A})\psi}^{2}\,dx\,dy} {\int_{\Omega }\abs{\psi}^{2}\,dx\,dy} in the regime h>>1. Here A is any vector field with curl equal to 1. The problem arises within the Ginzburg-Landau model for superconductivity with the function w(h) yielding the relationship between the critical temperature vs. applied magnetic field strength in the transition from normal to superconducting state in a thin mesoscopic sample with cross-section W ì \R2\Omega\subset\R^{2}. We first carry out a rigorous analysis of the associated problem on a half-plane and then rigorously justify some of the formal arguments of [BS], obtaining an expansion for w while also proving that the first eigenfunction decays to zero somewhere along the sample boundary ?W\partial \Omega when z is not a disc. For interior decay, we demonstrate that the rate is exponential. 相似文献
14.
Olaf Lechtenfeld 《Czechoslovak Journal of Physics》2004,54(11):1351-1357
The sine-Gordon model may be obtained by dimensional and algebraic reduction from (2+2)-dimensional self-dual U(2) Yang-Mills through a (2+1)-dimensional integrable U(2) sigma model. It is argued that the noncommutative (Moyal) deformation of this procedure should relax the algebraic reduction from U(2) U(1) to U(2)U(1) × U(1). The result are novel noncommutative sine-Gordon equations for a pair of scalar fields. The dressing method is outlined for constructing its multi-soliton solutions. Finally, the tree-level amplitudes demonstrate that this model possesses a factorizable and causal S-matrix in spite of its time-space noncommutativity. 相似文献
15.
In this paper we compute some of the higher order terms in the asymptotic behavior of the two point function
\mathbbP(A2(0) £ s1,A2(t) £ s2)\mathbb{P}(\mathcal {A}_{2}(0)\leq s_{1},\mathcal{A}_{2}(t)\leq s_{2}), extending the previous work of Adler and van Moerbeke (; Ann. Probab. 33, 1326–1361, 2005) and Widom (J. Stat. Phys. 115, 1129–1134, 2004). We prove that it is possible to represent any order asymptotic approximation as a polynomial and integrals of the Painlevé
II function q and its derivative q′. Further, for up to tenth order we give this asymptotic approximation as a linear combination of the Tracy-Widom GUE density
function f
2 and its derivatives. As a corollary to this, the asymptotic covariance is expressed up to tenth order in terms of the moments
of the Tracy-Widom GUE distribution. 相似文献
16.
We investigate the concept of projectively equivariant quantization in the framework of super projective geometry. When the
projective superalgebra
\mathfrakpgl(p+1|q){\mathfrak{pgl}(p+1|q)} is simple, our result is similar to the classical one in the purely even case: we prove the existence and uniqueness of the
quantization except in some critical situations. When the projective superalgebra is not simple (i.e. in the case of
\mathfrakpgl(n|n)\not @ \mathfraksl(n|n){\mathfrak{pgl}(n|n)\not\cong \mathfrak{sl}(n|n)}), we show the existence of a one-parameter family of equivariant quantizations. We also provide explicit formulas in terms
of a generalized divergence operator acting on supersymmetric tensor fields. 相似文献
17.
Universality in the Two Matrix Model with a Monomial Quartic and a General Even Polynomial Potential
M. Y. Mo 《Communications in Mathematical Physics》2009,291(3):863-894
In this paper we studied the asymptotic eigenvalue statistics of the 2 matrix model with the probability measure
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