scholarly journals Topological susceptibility with a single light quark flavour

2018 ◽  
Vol 175 ◽  
pp. 14017 ◽  
Author(s):  
Julien Frison ◽  
Ryuichiro Kitano ◽  
Norikazu Yamada
Keyword(s):  
Quark Mass ◽  
Continuum Limit ◽  
Light Quark ◽  
The Other ◽  
Theoretical Argument ◽  
Up Quark ◽  
Order Of Magnitude ◽  
Quark Flavour ◽  
Definition Of ◽  
The Continuum

One of the historical suggestions to tackle the strong CP problem is to take the up quark mass to zero while keeping md finite. The θ angle is then supposed to become irrelevant, i.e. the topological susceptibility vanishes. However, the definition of the quark mass is scheme-dependent and identifying the mu = 0 point is not trivial, in particular with Wilson-like fermions. More specifically, up to our knowledge there is no theoretical argument guaranteeing that the topological susceptibility exactly vanishes when the PCAC mass does. We will present our recent progresses on the empirical check of this property using Nf = 1 + 2 flavours of clover fermions, where the lightest fermion is tuned very close to [see formula in PDF] and the mass of the other two is kept of the order of magnitude of the physical ms. This choice is indeed expected to amplify any unknown non-perturbative effect caused by mu ≠ md. The simulation is repeated for several βs and those results, although preliminary, give a hint about what happens in the continuum limit.

CHIRALLY EXTENDED QUANTUM CHROMODYNAMICS

1995 ◽  
Vol 06 (05) ◽  
pp. 725-742 ◽  
Author(s):  
RICHARD C. BROWER ◽  
YUE SHEN ◽  
CHUNG-I TAN
Keyword(s):  
Quantum Chromodynamics ◽  
Quark Mass ◽  
Continuum Limit ◽  
Chiral Limit ◽  
Scalar Fields ◽  
Weak Coupling Limit ◽  
Slowing Down ◽  
Large N ◽  
Chiral Invariance ◽  
The Continuum

We propose an extended Quantum Chromodynamics (XQCD) Lagrangian in which the fermions are coupled to elementary scalar fields through a Yukawa coupling which preserves chiral invariance. Our principle motivation is to find a new lattice formulation for QCD which avoids the source of critical slowing down usually encountered as the bare quark mass is tuned to the chiral limit. The phase diagram and the weak coupling limit for XQCD are studied. They suggest a conjecture that the continuum limit of XQCD is the same as the continuum limit of conventional lattice formulation of QCD. As examples of such universality, we present the large N solutions of two prototype models for XQCD, in which the mass of the spurious pion and sigma resonance go to infinity with the cut-off. Even if the universality conjecture turns out to be false, we believe that XQCD will still be useful as a low energy effective action for QCD phenomenology on the lattice. Numerical simulations are recommended to further investigate the possible benefits of XQCD in extracting QCD predictions.

scholarly journals The continuum limit of the quark mass step scaling function in quenched lattice QCD

2004 ◽  
Vol 2004 (05) ◽  
pp. 001-001 ◽  
Author(s):  
M Guagnelli ◽  
J Heitger ◽  
F Palombi ◽  
C Pena ◽  
A Vladikas
Keyword(s):  
Lattice Qcd ◽  
Quark Mass ◽  
Continuum Limit ◽  
Scaling Function ◽  
The Continuum

THE CHIRAL U(1) SYMMETRY IN LATTICE QCD WITH WILSON FERMIONS

1995 ◽  
Vol 10 (15) ◽  
pp. 2269-2290 ◽  
Author(s):  
CARLO UNGARELLI
Keyword(s):  
Lattice Qcd ◽  
Chiral Symmetry ◽  
Continuum Limit ◽  
Axial Current ◽  
Numerical Results ◽  
Ward Identities ◽  
Definition Of ◽  
The Continuum ◽  
Wilson Fermions

The properties of singlet flavor chiral symmetry of lattice QCD with Wilson fermions are analyzed. We show that a suitable U(1) axial current can be defined, satisfying, in the continuum limit, the Adler-Bell-Jackiw anomaly. Moreover, the renormalization properties of composite operators which appear in U(1) chiral Ward identities are discussed. Finally, starting from the renormalized Ward identities for the axial U(1) current, we analyze a definition of topological susceptibility suitable for nonperturbative studies and discuss preliminary numerical results.

scholarly journals DISCRETIZED LAPLACIANS ON AN INTERVAL AND THEIR RENORMALIZATION GROUP

1994 ◽  
Vol 09 (25) ◽  
pp. 4485-4509 ◽  
Author(s):  
E. ERCOLESSI ◽  
P. TEOTONIO-SOBRINHO ◽  
G. BIMONTE
Keyword(s):  
Boundary Conditions ◽  
Laplace Operator ◽  
Continuum Limit ◽  
Wave Functions ◽  
The Other ◽  
Scale Invariant ◽  
Dimensional Parameter ◽  
Finite Dimensional ◽  
The Laplace Operator ◽  
The Continuum

The Laplace operator admits infinite self-adjoint extensions when considered on a segment of the real line. They have different domains of essential self-adjointness characterized by a suitable set of boundary conditions on the wave functions. In this paper we show how these extensions can be recovered by studying the continuum limit of certain discretized versions of the Laplace operator on a lattice. Associated to this limiting procedure, there is a renormalization flow in the finite-dimensional parameter space describing the discretized operators. This flow is shown to have infinite fixed points, corresponding to the self-adjoint extensions characterized by scale-invariant boundary conditions. The other extensions are recovered by looking at the other trajectories of the flow.

Adding police to a mathematical model of burglary

2010 ◽  
Vol 21 (4-5) ◽  
pp. 401-419 ◽  
Author(s):  
ASHLEY B. PITCHER
Keyword(s):  
Mathematical Model ◽  
Partial Differential Equations ◽  
Differential Equations ◽  
Continuum Limit ◽  
The Other ◽  
Residential Burglary ◽  
Partial Differential ◽  
Linear Partial Differential Equations ◽  
Non Linear ◽  
The Continuum

We review the Short model of urban residential burglary derived from taking the continuum limit of two difference equations – one of which models the attractiveness of individual houses to burglary, and the other of which models burglar movement. This leads to a system of non-linear partial differential equations. We propose a change to the Short model and also add deterrence caused by the presence of uniformed officers to the model. We solve the resulting system of non-linear partial differential equations numerically and present results both with and without deterrence.

scholarly journals New Affine Coherent States Based on Elements of Nonrenormalizable Scalar Field Models

2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
John R. Klauder
Keyword(s):  
Scalar Field ◽  
Ground State ◽  
Coherent States ◽  
Continuum Limit ◽  
Quantum Fields ◽  
Commutation Relations ◽  
Scalar Field Models ◽  
Scalar Quantum ◽  
Definition Of ◽  
The Continuum

Recent proposals for a nontrivial quantization of covariant, nonrenormalizable, self-interacting, scalar quantum fields have emphasized the importance of quantum fields that obey affine commutation relations rather than canonical commutation relations. When formulated on a spacetime lattice, such models have a lattice version of the associated ground state, and this vector is used as the fiducial vector for the definition of the associated affine coherent states, thus ensuring that in the continuum limit, the affine field operators are compatible with the system Hamiltonian. In this article, we define and analyze the associated affine coherent states as well as briefly review the author's approach to nontrivial formulations of such nonrenormalizable models.

scholarly journals Minimal texture of quark mass matrices and precision CKM measurements

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Shivali Kaundal ◽  
Aakriti Bagai ◽  
Gulsheen Ahuja ◽  
Manmohan Gupta
Keyword(s):  
Quark Mass ◽  
Light Quark ◽  
The Other ◽  
Quark Masses ◽  
Extensive Analysis ◽  
Quark Mixing ◽  
Mass Matrices ◽  
Good Number

Abstract We have carried out an extensive analysis of all possible minimal texture quark mass matrices implying 169 texture-6 zero combinations. One finds that all these combinations are ruled out: a good number of these analytically, the other possibilities being excluded by the present quark mixing data. Interestingly, even if there are future changes in the ranges of the light quark masses, these conclusions remain valid.

C. The Continuous Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney
Keyword(s):  
Continuous Spectrum ◽  
Variable Stars ◽  
Velocity Fields ◽  
The Other ◽  
Line Spectrum ◽  
Direct Information ◽  
Thermodynamic Structure ◽  
Diagnostic Interpretation ◽  
Pulsating Variable Stars ◽  
The Continuum

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Medicine and Empathy in Contemporary British Fiction

2017 ◽  
Author(s):  
Anne Whitehead
Keyword(s):  
Feminist Theory ◽  
Medical Humanities ◽  
Illness Experience ◽  
Contemporary Fiction ◽  
Theoretical Argument ◽  
Cultural Relations ◽  
Night Time ◽  
British Fiction ◽  
Definition Of ◽  
Relations Of Power

This book offers a critique of the dominant understanding and deployment of empathy in the mainstream medical humanities. Drawing on feminist theory, it positions empathy not as something that one has or lacks, and needs to accrue, but as something that one does and that is embedded within structural, institutional and cultural relations of power. It aims to provide a critically informed definition of empathy, drawing on phenomenology, in order to counter the vagueness of the term as it has often been used. It questions, too, the assumption that empathy is limited to the clinical relation, looking to a broader and more encompassing definition of the ‘medical’. Combining theoretical argument with literary case studies of Mark Haddon’s The Curious Incident of the Dog in the Night-Time, Pat Barker’s Life Class, Ian McEwan’s Saturday, Aminatta Forna’s The Memory of Love and Kazuo Ishiguro’s Never Let Me Go, this book contends that contemporary fiction is not a vehicle for accessing another’s illness experience, but itself engages critically with the question of empathy and its limits. The volume marks a key contribution to the rapidly evolving field of the critical medical humanities.

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