共查询到20条相似文献,搜索用时 15 毫秒
1.
For a class of analytical parametrizations of the freeze-out state of relativistic heavy ion collisions, we perform a simultaneous analysis of the single-particle m ⊥-spectra and two-particle Bose-Einstein correlations measured in central Pb+Pb collisions at the CERN SPS. The analysis includes a full model parameter scan with χ2 confidence levels. A comparison of different transverse density profiles for the particle emission region allows for a quantitative discussion of possible model dependencies of the results. Our fit results suggest a low thermal freeze-out temperature T≈95±15 MeV and a large average transverse flow velocity \(\bar v_ \bot \approx 0.55 \pm 0.07\). Moreover, the fit favours a box-shaped transverse density profile over a Gaussian one. We discuss the origins and the consequences of these results in detail. In order to reproduce the measured pion multiplicity our model requires a positive pion chemical potential. A study of the pion phase-space density indicates μπ≈60 MeV for T=100 MeV. 相似文献
2.
Using the hydrokinetic model of pionic emission in heavy ion collisions, we study the effects of continuous particle emission
for 3D azimuthal symmetric Bjorken-type expansion. We describe RHIC pion data in central A + A collisions and make predictions for LHC based on the hydrokinetic model and initial conditions taken from the color glass
condensate model.
The text was submitted by the authors in English. 相似文献
3.
4.
The transverse momentum distributions of W± and Z0 are predicted at RHIC and LHC. A resummation formalism with power corrections to the renormalization group equations is used. Shadowing effects are discussed and found to be unimportant at RHIC, but important for LHC. We study the enhancement of power corrections due to multiple scattering in nuclear collisions and numerically illustrate the weak effects of the dependence on the nuclear mass. 相似文献
5.
K. Olimov K. G. Gulamov V. V. Lugovoi S. L. Lutpullaev Kh. K. Olimov V. I. Petrov 《Physics of Atomic Nuclei》2007,70(11):1977-1979
6.
N. Oshimo 《The European Physical Journal C - Particles and Fields》2005,39(3):383-388
The measurability of generation mixing is studied on pair production of sneutrinos in e
+
e
- collisions and their subsequent decays into two different charged leptons e and μ with two lighter charginos. The analyses are made systematically in a general framework of the supersymmetric extension
of the standard model. The production and decay process depends on the parameters of the chargino sector as well as those
of the sneutrino sector. Although generation-changing interactions are severely constrained by radiative charged-lepton decays,
sizable regions in the parameter space could still be explored at e
+
e
- colliders in the near future.
Received: 6 October 2004, Revised: 14 November 2004, Published online: 14 January 2005
PACS:
11.30.Hv, 12.15.Ff, 12.60.Jv, 14.80.Ly 相似文献
7.
Peng-Ming Zhang Xi-Guo Lee Shao-Feng Wu 《International Journal of Theoretical Physics》2007,46(12):3234-3241
We investigate the solitons in the CP
N
model in terms of the decomposition of gauge potential. Based on the φ-mapping topological current theory, the charge and position of solitons is determined by the properties of the typical component.
Furthermore, the motion and the bifurcation of multi-soliton is discussed. And the knotted solitons in high dimension is explored
also. 相似文献
8.
R. Escribano 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):454-457
The scalar contributions to the radiative decay φ→K
0ˉ0
γ are studied within the framework of the Linear Sigma Model (LσM). Theoretical predictions for the associated subprocesses φ→f
0
γ and φ→a
0
γ as well as the ratio φ→f
0
γ/a
0
γ are also given. 相似文献
9.
N. N. Achasov 《Physics of Atomic Nuclei》2007,70(5):862-863
It is argued that the realization of gauge invariance condition as a consequent of cancellation between the ϕ → γf
0 → γπ
0
π
0 resonance contribution and the ϕ → γπ
0
π
0 background one, suggested by A.V. Anisovich et al., Yad. Fiz. 68, 1614 (2005), is misleading.
The text was submitted by the author in English. 相似文献
10.
The concept of ‘D-Differentiation’, which, in the context of smooth manifolds, generalises Lie and covariant differentiation, is extended to
R
∞ -supermanifolds under the name of ‘Super D-Differentiation’. This is done by defining new (non-linear) mappings, called ‘μ-mappings’ and by relating their non-linearity to the Leibniz rule that a derivation must satisfy when it acts on a tensor
product. The resulting axiomatics, which is basis-independent and coordinate-free, is then expressed in a general basis (not
necessarily holonomic). Super Lie and Super covariant differentiation are, amongst others, special cases of Super D-Differentiation. In particular, the transformation rules for the connection coefficients and the commutation coefficients
of non-holonomic bases are obtained. These special cases are found to be in agreement with the DeWitt Super covariant and
Super Lie derivatives.
相似文献
11.
12.
David Kerr 《Communications in Mathematical Physics》2003,232(3):501-534
We introduce notions of dimension and dynamical entropy for unital C
*
-algebras ``metrized' by means of , which are complex-scalar versions of the Lip-norms constitutive of Rieffel's compact quantum metric spaces. Our examples
involve the UHF algebras and noncommutative tori. In particular we show that the entropy of a noncommutative toral automorphism with respect to the
canonical coincides with the topological entropy of its commutative analogue.
Received: 13 February 2002 / Accepted: 20 August 2002 Published online: 22 November 2002 相似文献
13.
Doubly-charged scalars, predicted in many models having exotic Higgs rep-resentations, can in general have lepton-number violating
(LFV) couplings. We show that by using an associated monoenergetic final state photon seen at a future linear e
−
e
− collider, we can have a clear and distinct signature for a doubly-charged resonance. The strength of the ΔL = 2 coupling can also be probed quite effectively as a function of the recoil mass of the doubly-charged scalar.
相似文献
14.
E. A. Kuraev S. Bakmaev Yu. M. Bystritskiy O. P. Solovtsova T. V. Shishkina 《JETP Letters》2008,87(7):354-358
The Born cross section and the radiative corrections to its lowest order are considered in the framework of QED with structureless
nucleons including the emission of virtual and real photons. The result is generalized to take into account the radiative
corrections in higher orders of the perturbation theory in the leading and next-to-leading logarithmic approximation. The
crossing processes are considered in the leading approximation.
The text was submitted by the authors in English. 相似文献
15.
A. Gasparyan J. Haidenbauer C. Hanhart K. Miyagawa 《The European Physical Journal A - Hadrons and Nuclei》2007,32(1):61-67
The prospects of utilizing the strangeness production reaction γd→K
+
Λn for the determination of the Λn low-energy scattering parameters are investigated. The spin observables that need to be measured in order to isolate the
Λn singlet (1
S
0) and triplet (3
S
1) states are identified. Possible kinematical regions where the extraction of the Λn scattering lengths might be feasible are discussed. 相似文献
16.
17.
G. Pancheri O. Shekhovtsova G. Venanzoni 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):458-460
Effects due to the non-pointlike behaviour of pions in the process e
+
e
-→π
+
π
-
γ can arise for hard photons in the final state. By means of a Monte Carlo event generator, which also includes the contribution
of the direct decay φ→π
+
π
-
γ, we estimate these effects in the framework of the resonance perturbation theory. We consider angular cuts used in the KLOE
analysis of the pion form factor at threshold. A method to reveal the effects of the non-pointlike behaviour of pions in a
model-independent way is proposed. 相似文献
18.
O. V. Vikhrova Yu. A. Danilov Yu. N. Drozdov B. N. Zvonkov A. V. Kudrin V. V. Podol’skii M. V. Sapozhnikov 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(1):25-27
The magnetotransport properties of epitaxial ferromagnet/semiconductor heterostructures based on MnAs and GaMnAs ferromagnetic layers, separated by a nonmagnetic semiconductor layer (InAs or GaAs), have been investigated. Structures were obtained by combination of laser deposition and metal-organic chemical vapor deposition. A spin-valve effect was observed in magnetoresistance measurements. This fact suggests spin-polarized transport of carriers between ferromagnetic layers. 相似文献
19.
Toshiyuki Abe Chongying Dong Haisheng Li 《Communications in Mathematical Physics》2005,253(1):171-219
The fusion rules for the vertex operator algebras M(1)+ (of any rank) and V+L (for any positive definite even lattice L) are determined completely.Supported by JSPS Research Fellowships for Young ScientistsPartially supported by NSF grants and a research grant from the Committee on Research, UC Santa CruzPartially supported by a NSA grant and a grant from Rutgers University Research Council 相似文献
20.
Santosh Kumar Rai 《Pramana》2007,69(5):815-818
Loop-driven decay modes of the Higgs are sensitive to new physics contributions because of new particles in the loops. To
highlight this we look at the dilepton-dijet signal in the dominant Higgs production channel at a linear e
+
e
− collider. We show that by taking a simple ratio between cross-sections of two different final states such contributions can
be very easily identified.
相似文献