The K L 0 -K S 0 mass difference in the quark model

1970 ◽  
Vol 3 (5) ◽  
pp. 139-142 ◽  
Author(s):  
D. Flamm ◽  
W. Majerotto
Keyword(s):  
1992 ◽  
Vol 07 (32) ◽  
pp. 3037-3043 ◽  
Author(s):  
T. GOLDMAN ◽  
J.A. HENDERSON ◽  
A.W. THOMAS

In generating a charge-symmetry breaking potential using ρ-ω mixing it is usually assumed that the mixing amplitude is constant (at the on-mass-shell value). Since the exchanged meson is actually far off-shell one must question the validity of this assumption. By constructing a simple quark model in which the mixing is generated by the u-d quark mass difference, we find that the assumption seems to be a very poor one.


1997 ◽  
Vol 06 (04) ◽  
pp. 693-709 ◽  
Author(s):  
H. J. Weber ◽  
K. Bodoor

The spin and flavor fractions of constituent quarks in the baryon octet are obtained from their lowest order chiral fluctuations involving Goldstone bosons. SU(3) breaking suggested by the mass difference between the strange and up, down quarks is included, as are relativistic effects by means of a light-cone quark model for the proton, and the gluon contribution from the axial anomaly in the singlet channel. Magnetic moments from the Karl-Sehgal formulas are analyzed in this framework as well.


2017 ◽  
Vol 32 (39) ◽  
pp. 1750218 ◽  
Author(s):  
Seung-il Nam

We investigate the pseudoscalar (PS) meson ([Formula: see text] and [Formula: see text]) quasi-distribution amplitude (QDA), which is supposed to be an asymptotic analog to the meson distribution amplitude (DA) [Formula: see text] in the limit of the large longitudinal PS-meson momentum, i.e. [Formula: see text], in the non-perturbative (NP) region. For this purpose, we employ the nonlocal chiral-quark model (NLChQM) in the light-front (LF) formalism with a minimal Fock-state for the mesons [Formula: see text][Formula: see text][Formula: see text] at the low-energy scale parameter of the model [Formula: see text][Formula: see text][Formula: see text][Formula: see text]1 GeV. As a trial, we extract the transverse-momentum distribution amplitude (TMDA) from the light-front wave function (LFWF) within the model, and convert it to QDA with help of the virtuality-distribution amplitude (VDA). By doing that, we derive an analytical expression for the NP QDA with the current-quark mass correction up to [Formula: see text]. Numerically, we confirm that the obtained TMDA reproduces the experimental data for the photon-pion transition form factor [Formula: see text] at the low-[Formula: see text] qualitatively well. We also observe that the obtained QDA approaches to DA as [Formula: see text] increases, showing the symmetric and asymmetric curves with respect to [Formula: see text] for the pion and kaon, respectively, due to the current-quark mass difference [Formula: see text]. Assigning [Formula: see text], the moments [Formula: see text] are computed, using the pion and kaon QDAs, and there appear only a few percent deviations in the moments for [Formula: see text] in comparison to the values calculated directly from DAs. It turns out that the higher moments are more sensitive to the change of [Formula: see text], whereas the lower ones depend less on it.


1967 ◽  
Vol 47 (3) ◽  
pp. 626-633 ◽  
Author(s):  
A. Frenkel ◽  
M. Posch ◽  
G. Surányi ◽  
P. Surányi

1989 ◽  
Vol 04 (15) ◽  
pp. 1403-1408 ◽  
Author(s):  
KIM MALTMAN

It is argued that the neglect of intrinsic quark motions within the nucleon implicit in traditional nuclear estimates of magnetic contributions to the A=3 binding energy difference produces an underestimate of the size of these contributions. A schematic non-relativistic quark model calculation demonstrates that the magnitude of the discrepancy is unlikely to be neglible, and that the sign of the effect is such as to require an increase in charge symmetry breaking from other sources.


Author(s):  
Steven E. Vigdor

Chapter 4 deals with the stability of the proton, hence of hydrogen, and how to reconcile that stability with the baryon number nonconservation (or baryon conservation) needed to establish a matter–antimatter imbalance in the infant universe. Sakharov’s three conditions for establishing a matter–antimatter imbalance are presented. Grand unified theories and experimental searches for proton decay are described. The concept of spontaneous symmetry breaking is introduced in describing the electroweak phase transition in the infant universe. That transition is treated as the potential site for introducing the imbalance between quarks and antiquarks, via either baryogenesis or leptogenesis models. The up–down quark mass difference is presented as essential for providing the stability of hydrogen and of the deuteron, which serves as a crucial stepping stone in stellar hydrogen-burning reactions that generate the energy and elements needed for life. Constraints on quark masses from lattice QCD calculations and violations of chiral symmetry are discussed.


1974 ◽  
Vol 9 (7) ◽  
pp. 2056-2063 ◽  
Author(s):  
Ramesh Chand
Keyword(s):  

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