scholarly journals The role of strangeness in chiral and $$U(1)_A$$ restoration

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
A. Gómez Nicola ◽  
J. Ruiz de Elvira ◽  
A. Vioque-Rodríguez ◽  
D. Álvarez-Herrero
Keyword(s):  
Strange Quark ◽  
Energy State ◽  
Quark Condensate ◽  
Lattice Data ◽  
Chiral Perturbation ◽  
Quark Masses ◽  
Peak Structure ◽  
Chiral Transition ◽  
Consistent Picture

AbstractWe use recently derived Ward identities and lattice data for the light- and strange-quark condensates to reconstruct the scalar and pseudoscalar susceptibilities ($$\chi _S^\kappa $$ χ S κ , $$\chi _P^K$$ χ P K ) in the isospin 1/2 channel. We show that $$\chi _S^\kappa $$ χ S κ develops a maximum above the QCD chiral transition, after which it degenerates with $$\chi _P^K$$ χ P K . We also obtain $$\chi _S^\kappa $$ χ S κ within Unitarized Chiral Perturbation Theory (UChPT) at finite temperature, when it is saturated with the $$K_0^*(700)$$ K 0 ∗ ( 700 ) (or $$\kappa $$ κ ) meson, the dominant lowest-energy state in the isospin 1/2 scalar channel of $$\pi K$$ π K scattering. Such UChPT result reproduces the expected peak structure, revealing the importance of thermal interactions, and makes it possible to examine the $$\chi _S^\kappa $$ χ S κ dependence on the light- and strange-quark masses. A consistent picture emerges controlled by the $$m_l/m_s$$ m l / m s ratio that allows one studying $$K-\kappa $$ K - κ degeneration in the chiral, two-flavor and SU(3) limits. These results provide an alternative sign for $$O(4)\times U(1)_A$$ O ( 4 ) × U ( 1 ) A restoration that can be explored in lattice simulations and highlight the role of strangeness, which regulated by the strange-quark condensate helps to reconcile the current tension among lattice results regarding $$U(1)_A$$ U ( 1 ) A restoration.

scholarly journals Quark, pion and axial condensates in three-flavor finite isospin chiral perturbation theory

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Prabal Adhikari ◽  
Jens O. Andersen ◽  
Martin A. Mojahed
Keyword(s):  
Perturbation Theory ◽  
Lattice Qcd ◽  
Chiral Perturbation Theory ◽  
Strange Quark ◽  
Chemical Potential ◽  
Light Quark ◽  
Quark Condensate ◽  
Lattice Data ◽  
Chiral Perturbation ◽  
Good Agreement

AbstractWe calculate the light-quark condensate, the strange-quark condensate, the pion condensate, and the axial condensate in three-flavor chiral perturbation theory ($$\chi $$ χ PT) in the presence of an isospin chemical potential at next-to-leading order at zero temperature. It is shown that the three-flavor $$\chi $$ χ PT effective potential and condensates can be mapped onto two-flavor $$\chi $$ χ PT ones by integrating out mesons with strange-quark content (kaons and eta), with renormalized couplings. We compare the results for the light-quark and pion condensates at finite pseudoscalar source with ($$2+1$$ 2 + 1 )-flavor lattice QCD, and we also compare the axial condensate at zero pseudoscalar and axial sources with lattice QCD data. We find that the light-quark, pion, and axial condensates are in very good agreement with lattice data. There is an overall improvement by including NLO effects.

scholarly journals Light- and strange-quark mass dependence of the ρ(770) meson revisited

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
R. Molina ◽  
J. Ruiz de Elvira
Keyword(s):  
Perturbation Theory ◽  
Chiral Perturbation Theory ◽  
Quark Mass ◽  
Strange Quark ◽  
Global Analysis ◽  
Mass Dependence ◽  
Chiral Perturbation ◽  
Quark Masses ◽  
Strange Quark Mass ◽  
Quark Mass Dependence

Abstract Recent lattice data on ππ-scattering phase shifts in the vector-isovector channel, pseudoscalar meson masses and decay constants for strange-quark masses smaller or equal to the physical value allow us to study the strangeness dependence of these observables for the first time. We perform a global analysis on two kind of lattice trajectories depending on whether the sum of quark masses or the strange-quark mass is kept fixed to the physical point. The quark mass dependence of these observables is extracted from unitarized coupled-channel one-loop Chiral Perturbation Theory. This analysis guides new predictions on the ρ(770) meson properties over trajectories where the strange-quark mass is lighter than the physical mass, as well as on the SU(3) symmetric line. As a result, the light- and strange-quark mass dependence of the ρ(770) meson parameters are discussed and precise values of the Low Energy Constants present in unitarized one-loop Chiral Perturbation Theory are given. Finally, the current discrepancy between two- and three-flavor lattice results for the ρ(770) meson is studied.

scholarly journals Regge trajectories of exotic hadrons in the flux tube model

2016 ◽  
Vol 31 (04n05) ◽  
pp. 1650007 ◽  
Author(s):  
Hemwati Nandan ◽  
Akhilesh Ranjan
Keyword(s):  
Flux Tube ◽  
Tube Model ◽  
Lattice Data ◽  
High Rotational Speed ◽  
Quark Masses ◽  
Regge Trajectories ◽  
Linear Behavior ◽  
Exotic Hadrons ◽  
Tube Structure ◽  
Current Quark

We have investigated the Regge trajectories of exotic hadrons by considering different possible pentaquark configurations with finite quark mass in the flux tube model. Significant deviation is observed in the linear behavior of the Regge trajectories for pentaquark systems in view of the universal value of the Regge slope parameter for hadrons. The modified Regge trajectories are also compared with the available experimental and lattice data. It is observed that the nonlinear Regge trajectories of such pentaquark systems can be well described by the relativistic corrections in view of the current quark masses and the high rotational speed of the quarks at the end of flux tube structure.

ROLE OF THE ELECTRON–PHONON INTERACTION ON THE SPECTRAL DENSITY AND PSEUDOGAP IN CUPRATES

2002 ◽  
Vol 16 (23) ◽  
pp. 3465-3471
Author(s):  
I. CHAUDHURI ◽  
S. K. GHATAK
Keyword(s):  
Critical Temperature ◽  
Spectral Density ◽  
Low Energy ◽  
Phonon Interaction ◽  
Energy Excitation ◽  
Electron Phonon Interaction ◽  
Peak Structure ◽  
Electronic Model ◽  
Jahn Teller

The pseudogap structure in low energy excitation in cuprates appears below a temperature and the spectral density exhibits strong wave-vector dependence. An electronic model that emphasized the coupling of carrier in Cu-O with phonon is examined for pseudogap. The electron–phonon interaction originates from the modulation of on-site and hopping energy and leads to spontaneous Jahn–Teller-like distortion and pseudogap below a critical temperature. At low temperature the spectral density has two-peak structure about the Fermi level for all k along Γ-M whereas such structure exists along Γ-X for small k only. The magnitude of pseudogap shows strong k-dependence — maximum along Γ-M and vanishes along Γ-X. These features emphasize the role of electron–phonon interaction in formation of pseudogap.

scholarly journals DETERMINATION OF LIGHT QUARK MASSES IN QCD

2010 ◽  
Vol 25 (29) ◽  
pp. 5223-5234 ◽  
Author(s):  
C. A. DOMINGUEZ
Keyword(s):  
Strange Quark ◽  
Sum Rules ◽  
Standard Procedure ◽  
Light Quark ◽  
Qcd Sum Rules ◽  
Quark Masses ◽  
Systematic Uncertainties ◽  
Better Than ◽  
The Ideal

The standard procedure to determine (analytically) the values of the quark masses is to relate QCD two-point functions to experimental data in the framework of QCD sum rules. In the case of the light quark sector, the ideal Green function is the pseudoscalar correlator which involves the quark masses as an overall multiplicative factor. For the past thirty years this method has been affected by systematic uncertainties originating in the hadronic resonance sector, thus limiting the accuracy of the results. Recently, a major breakthrough has been made allowing for a considerable reduction of these systematic uncertainties and leading to light quark masses accurate to better than 8%. This procedure will be described in this talk for the up-, down-, strange-quark masses, after a general introduction to the method of QCD sum rules.

scholarly journals A Note on Koide’s Doubly Special Parametrization of Quark Masses

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 427-429
Author(s):  
Piotr Żenczykowski
Keyword(s):  
Charged Lepton ◽  
Strange Quark ◽  
Scale Parameter ◽  
Low Energy ◽  
Quark Masses ◽  
Quark Sector ◽  
Energy Regime ◽  
Two Parameters

Abstract Three charged lepton masses may be expressed in terms of a Z3-symmetric parametrization relevant for the discussion of Koide’s formula. After disregarding the overall scale parameter, the observed pattern of lepton masses can be described extremely well if the remaining two parameters acquire the unexpectedly simple values of 1 and 2/9. We argue that an analogue of this doubly special feature of the parametrization can also be seen in the quark sector provided that the mass of the strange quark is taken to be around 160 MeV, as might be expected in the low-energy regime.

Energy state and vasomotor tone in hypoxic pig lungs

1991 ◽  
Vol 70 (4) ◽  
pp. 1874-1881 ◽  
Author(s):  
P. C. Buescher ◽  
D. B. Pearse ◽  
R. P. Pillai ◽  
M. C. Litt ◽  
M. C. Mitchell ◽  
...  
Keyword(s):  
Pulmonary Arterial Pressure ◽  
Energy State ◽  
Adenine Nucleotides ◽  
Pulmonary Vasculature ◽  
Resonance Spectroscopy ◽  
Vasomotor Tone ◽  
Hypoxic Vasoconstriction ◽  
Lung Compartment ◽  
Pulmonary Arterial

To evaluate the role of energy state in pulmonary vascular responses to hypoxia, we exposed isolated pig lungs to decreases in inspired PO2 or increases in perfusate NaCN concentration. Lung energy state was assessed by 31P nuclear magnetic resonance spectroscopy or measurement of adenine nucleotides by high-pressure liquid chromatography in freeze-clamped biopsies. In ventilated lungs, inspired PO2 of 200 (normoxia), 50 (hypoxia), and 0 Torr (anoxia) did not change adenine nucleotides but resulted in steady-state pulmonary arterial pressure (Ppa) values of 15.5 +/- 1.4, 30.3 +/- 1.8, and 17.2 +/- 1.9 mmHg, respectively, indicating vasoconstriction during hypoxia and reversal of vasoconstriction during anoxia. In degassed lungs, similar changes in Ppa were observed; however, energy state deteriorated during anoxia. An increase in perfusate NaCN concentration from 0 to 0.1 mM progressively increased Ppa and did not alter adenine nucleotides, whereas 1 mM reversed this vasoconstriction and caused deterioration of energy state. These results suggest that 1) pulmonary vasoconstrictor responses to hypoxia or cyanide occurred independently of whole lung energy state, 2) the inability of the pulmonary vasculature to sustain hypoxic vasoconstriction during anoxia might be associated with decreased energy state in some lung compartment, and 3) atelectasis was detrimental to whole lung energy state.

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