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秀行, 橋本

doi:10.7143/jhep.32.88

Cited by 33 publications

(71 citation statements)

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“…So to find the π-meson masses it is enough to deal with the effective action S (2) mesons (24), which is a generating functional of the one-particle irreducible (1PI) Green functions of σ-and π-meson fields. In this case, instead of π i (x)-fields (10), we will use the new fields π…”

Section: Meson Massesmentioning

confidence: 99%

Mesons and diquarks in neutral color superconducting quark matter withβequilibrium

2007

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The spectrum of meson and diquark excitations in cold color-superconducting (2SC) quark matter is investigated under local color and electric neutrality constraints with β-equilibrium. A 2-flavored Nambu-Jona-Lasinio type model including a baryon µB, color µ8, and electric µQ chemical potentials is used. The contribution from free electrons to the free energy is added to take into account the β-equilibrium. The sensitivity of the model to the tuning of the interaction constants in the diquark (H) and quark-antiquark (G) channels is examined for two different parameterization schemes by choosing the ratio H/G to be 3/4 and 1, respectively. At H = 3G/4 the gapless-and at H = G the gapped neutral color superconductivity is realized. It is shown that color and electrical neutrality together with β-equilibrium lead to a strong mass splitting within the pion isotriplet in the 2SC phase (both gapped and gapless), in contrast with non-neutral matter. The π-and σ-meson masses are evaluated to be ∼ 300 MeV. It is also shown that the properties of the physical SU (2)c-singlet diquark excitation in the 2SC ground state varies for different parameterization schemes. Thus, for H = 3G/4 one finds a heavy resonance with mass ∼ 1100 MeV in the non-neutral (gapped) case, whereas, if neutrality is imposed, a stable diquark with mass ∼ |µQ| ∼ 200 MeV appears in the gapless 2SC environment. For a stronger attraction in the diquark channel (H = G), there is again a resonance (with the mass ∼ 300 MeV) in the neutral gapped 2SC phase. Hence, the existence of the stable massive SU(2)c-singlet diquark excitation is a new peculiarity of the gapless 2SC. In addition, the behaviour of the diquark mass in vacuum, i. e. , at µB = 0, as a function of H has been investigated.

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Section: Meson Massesmentioning

confidence: 99%

Mesons and diquarks in neutral color superconducting quark matter withβequilibrium

2007

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“…Results of lattice calculations for B K (2 GeV) have been summarized in [4,5]; a central value of B K (2 GeV) = 0.58(4) from quenched determinations was advocated in [4]. The uncertainty associated with this value does not include the systematic error induced by quenching, i.e.…”

Section: Introductionmentioning

confidence: 99%

One-loop matching ofΔS=2four-quark operators with improved staggered fermions

2005

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We compute O(αs) lattice-to-continuum perturbative matching coefficients for the ∆S = 2 flavor changing four-quark operators for the Asqtad improved staggered action. In conjunction with lattice simulations with three flavors of light, dynamical quarks, our results yield an unquenched determination of BK , the parameter that determines the amount of indirect CP violation in the neutral kaon system. Its value is an important input for the unitarity triangle analysis of weak decays.

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“…Further insight on the structure of the inhomogeneity cannot be gained without exploring the higher order terms of the nonlinear realization (25). A more direct approach to obtain the favorite structure of the ground state is to compare the free energy of various candidate states, which include the mixed phase, the single-plane wave FF state, striped LO state and multi-plane wave states.…”

Section: Nonzero Momentum Casementioning

confidence: 99%

“…However, we started to appreciate the importance of this unconventional superconducting state only after relating it to chromomagnetic instabilities of gapless CSC [21]. Recent studies have demonstrated that the single plane wave FF state is unavoidably induced by the instability of the local phase fluctuation of the superconducting order parameter, i.e., the Nambu-Goldstone boson fields [22,23,24,25,26].…”

Section: Introductionmentioning

confidence: 99%

Inhomogeneity driven by Higgs instability in a gapless superconductor

et al. 2007

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The fluctuations of the Higgs and pseudo Nambu-Goldstone fields in the 2SC phase with mismatched pairing are described in the nonlinear realization framework of the gauged Nambu-JonaLasinio model. In the gapless 2SC phase, not only Nambu-Goldstone currents can be spontaneously generated, but the Higgs field also exhibits instablity. The Nambu-Goldstone currents generation indicates the formation of the single plane wave LOFF state and breaks rotation symmetry, while the Higgs instability favors spatial inhomogeneity and breaks translation invariance. In this paper, we focus on the Higgs instability which has not drawn much attention yet. The Higgs instability cannot be removed without a long range force, thus it persists in the gapless superfluidity and induces phase separation. In the case of g2SC state, the Higgs instability can only be partially removed by the electric Coulomb energy. However, it is not excluded that the Higgs instability might be completely removed in the charge neutral gCFL phase by the color Coulomb energy.

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Cited by 33 publications

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Mesons and diquarks in neutral color superconducting quark matter withβequilibrium

Mesons and diquarks in neutral color superconducting quark matter withβequilibrium

One-loop matching ofΔS=2four-quark operators with improved staggered fermions

Inhomogeneity driven by Higgs instability in a gapless superconductor

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