Quark condensate in the deuteron

We present a novel treatment for calculating the in-medium quark condensates. The advantage of this approach is that one does not need to make further assumptions on the derivatives of model parameters with respect to the quark current mass. The normally accepted model-independent result in nuclear matter is naturally reproduced. The change of the quark condensate induced by interactions depends on the incompressibility of nuclear matter. When it is greater than 260 MeV, the density at which the condensate vanishes is higher than that from the linear extrapolation. For the chiral condensate in quark matter, a similar model-independent linear behavior is found at lower densities, which means that the decreasing speed of the condensate in quark matter is merely half of that in nuclear matter if the pion-nucleon sigma commutator is six times the average current mass of u and d quarks. The modification due to QCD-like interactions is found to slow the decreasing speed of the condensate, compared with the linear extrapolation.

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“…On the other hand, we have already expressed ǫ in Eq. (10). So, replacing the ǫ here with the right hand side of Eq.…”

Section: The Chiral Condensate In Quark Mattermentioning

confidence: 99%

“…However, this value will be modified in a medium. The change produced by the deuteron has recently been investigated [10]. There are also considerable investigations on the modification due to nuclear and/or quark matter [11,12,13,14,15,16,17,18,19,20,21,22,23,24].…”

Section: Introductionmentioning

confidence: 99%

Chiral Condensates in Quark and Nuclear Matter

Peng

Chiang

Ning

et al. 2003

Int. J. Mod. Phys. A

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“…Since outside this region < N |qq(x)|N >→< 0|qq(x)|0 >, a constant, the integral diverges. To obtain a finite result one can follow several authors [20,21,22,23] to define…”

Section: The Role Of the Condensatementioning

confidence: 99%

The CONTRIBUTION OF THE LIGHT QUARK CONDENSATE TO THE ΠN SIGMA TERM

Gibbs

2003

Mod. Phys. Lett. A

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“…As discussed in the introduction of this paper, the existence of regular bands of γ -rays was always thought to imply the presence of well-deformed nuclear shapes. However, for the magnetic dipole bands lifetime measurements have shown that they have very small quadrupole deformations (|ε 2 | 0.1) [164][165][166][167][168][169][170]. In 1993 Frauendorf proposed that a new mechanism, the 'shears mechanism', was responsible for generating the regular structures in these weakly deformed nuclei.…”

Section: Interpretation Within the Tilted-axis Cranking Modelmentioning

confidence: 99%

“…The results confirmed the initial perpendicular coupling of the component proton and neutron spin vectors. Further proof was provided by accurate lifetime measurements of states within various bands in both the lead and tin/cadmium regions [164][165][166][167][168][169][170], where the predicted decline in the B(M1) transition strengths was observed. One should also remark that standard principal axis cranking calculations are not able to account for the observed rapid reduction of the B(M1) values.…”

Section: Interpretation Within the Tilted-axis Cranking Modelmentioning

confidence: 99%

The influence of microscopic structures on rotational motion in nuclei

Wadsworth

Nolan

2002

Rep. Prog. Phys.

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This paper will concentrate on a study of the role and influence of microscopic structures on the properties of rotational bands in nuclei. Collective rotational features are well known in nuclei. Much of the review will discuss examples taken from experimental investigations of highly/superdeformed structures and their theoretical interpretation, which provide some of best and clearest rotational phenomena observed in nuclei. These structures have welldefined rotational properties that can be described by a collective model. The link between the deformation of these structures and the valence particle configuration has been established in many nuclei and recent experimental data are presented. Detailed investigations with new, very sensitive, instrumentation have revealed some extremely interesting and unexpected phenomena, such as the observation of identical rotational bands in neighbouring nuclei and energy staggering between adjacent states within a single band. The experimental and theoretical aspects of these new features will be discussed. The spectroscopy of highly/superdeformed structures has been studied extensively and many bands observed in a given nucleus which arise from particle-hole excitations. Measurements are now available, through the strength of magnetic dipole transitions, of the properties of specific single-particle orbitals. In the medium mass (A ∼ 60) region highly deformed states have been observed to decay by both proton and alpha emission in addition to the normal γ -decay mode. The decay widths, which are retarded for these channels, are related to the microscopic structures of the states involved. Investigations of rotational motion in exotic triaxial and hyperdeformed nuclear shapes are also reviewed. Recent work on 'smooth band termination', in medium to medium-heavy nuclei, which results when a deformed collectively rotating nucleus gradually changes from a near-prolate to a non-collective oblate shape, has revealed detailed information on the configurations responsible and the effects on the bands as the spin contribution is exhausted. The concept of 'magnetic rotation', which gives rise to regular 'rotational-like' sequences of states in nuclei that are almost spherical, is discussed. This phenomenon is also found to primarily result from microscopic effects within the nucleus. A discussion of these two latter phenomena has been included in this paper, since they provide an important contribution to the topic under review.

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Quark condensate in the deuteron

Cited by 4 publications

References 42 publications

Chiral Condensates in Quark and Nuclear Matter

Chiral Condensates in Quark and Nuclear Matter

The CONTRIBUTION OF THE LIGHT QUARK CONDENSATE TO THE ΠN SIGMA TERM

The influence of microscopic structures on rotational motion in nuclei

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