UScholar Works
 
Filters: Format: "application/pdf" Collection: "ir_uspace" Subject: "Phase transitions"
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CreatorTitleDescriptionSubjectDate
1 Ailion, David Charles109Ag NMR investigation of atomic motions in the incommensurate and paraelectric phases of proustite (Ag3AsS3)109Ag NMR line shape, T1 , Hahn spin echo, and Carr-Purcell-Meiboom-Gill ~CPMG! spin-echo measurements were performed in proustite (Ag3AsS3) between 420 and 47 K in order to understand the role of atomic motions in phase transitions in a system containing an incommensurate phase. These measurements ...NMR; Atomic motion; Proustitie; Phase transitions; Line shape2000
2 DeTar, CarletonCritical behavior at the chiral phase transitionIt is generally expected that two-flavor QCD undergoes a high temperature chiral symmetry restoring phase transition at zero quark mass, with O(4) critical behavior[1]. Verifying this expectation is important for understanding the phenomenology of the transition and for facilitating an extrapolation...Phase transitions; Staggered fermions1998-04
3 DeTar, CarletonCritical behavior in Nt=4 staggered fermion thermodynamicsQuantum chromodynamics with two zero mass flavors is expected to exhibit a phase transition with O(4) critical behavior. Fixing the universality class is important for phenomenology and for facilitating the extrapolation of simulation data to physical quark mass values. Other groups have reported r...Staggered fermions; Phase transitions; Quark-gluon plasma; Chiral symmetry2000-01
4 DeTar, CarletonCritical behavior in Nt=4 staggered fermion thermodynamicsQuantum chromodynamics with two zero mass flavors is expected to exhibit a phase transition with O(4) critical behavior. Fixing the universality class is important for phenomenology and for facilitating the extrapolation of simulation data to physical quark mass values. Other groups have reported r...Staggered fermions; Phase transitions2000-01
5 DeTar, CarletonEquation of state and QCD transition at finite temperatureWe calculate the equation of state in 2 + 1 flavor QCD at finite temperature with physical strange quark mass and almost physical light quark masses using lattices with temporal extent Nr = 8. Calculations have been performed with two different improved staggered fermion actions, the asqtad and p4 a...Deconfinement; Chiral symmetry; Staggered fermions; Phase transitions; Polyakov loop2009-07
6 DeTar, CarletonEquation of state for two flavor QCD at Nt=6We calculate the two flavor equation of state for QCD on lattices with lattice spacing a=(6T)21 and find that cutoff effects are substantially reduced compared to an earlier study using a=(4T)21. However, it is likely that significant cutoff effects remain. We fit the lattice data to expected forms ...Phase transitions; Quark-gluon plasma; Chiral symmetry1997-06
7 DeTar, CarletonEquation of state for two flavor QCD at Nt=6We calculate the two flavor equation of state for QCD on lattices with lattice spacing a=(6T)21 and find that cutoff effects are substantially reduced compared to an earlier study using a=(4T)21. However, it is likely that significant cutoff effects remain. We fit the lattice data to expected forms ...Phase transitions; Quark-gluon plasma; Dynamical quarks1997-06
8 DeTar, CarletonFinite temperature QCD: progress and outstanding problemsI review recent progress in numerical simulations of finite temperature quantum chromodynamics and discuss the status of some outstanding problems. Included is (1) a discussion of recent results determining the temperature of the "phase transition" in full QCD, (2) a scaling analysis of the Polyakov...Phase transitions; Staggered fermions; Wilson fermions; Polyakov loop; Deconfinement; Instanton1995-04
9 Ailion, David CharlesGallium and thallium NMR study of phase transitions and incomemensurability in the layered semiconductor TlGaSe2We report on the first NMR study of phase transitions and incommensurability in the layered semiconductor TlGaSe2. 69,71Ga and 205Tl NMR data from a powder sample show phase transitions at 118, 108 and around 69 K. The 69Ga and 71Ga spin-lattice relaxation times T1 are short and nearly temperature i...NMR; Atomic motion; Phase transitions; Spin-lattice; Relaxation-time2004
10 DeTar, CarletonHadronic spectrum of the quark plasmaWe have carried out a numerical simulation in SU(3) lattice gauge theory with four flavors of low-mass staggered fermions at zero baryon-number density in the vicinity of the high-temperature phase transition on 6x 103 and 6x 102x20 lattices. Static screening masses (static susceptibilities) were m...Hadronic matter; Quark plasma; Chiral symmetry; Phase transitions1987-07
11 DeTar, CarletonMeasuring the hadronic spectrum of the quark plasmaIn an effort to characterize the large-scale structure and composition of the Q C D plasma at zero baryon-number density in the vicinity of the high-temperature phase transition, we have carried out a numerical simulation in SU(3) lattice gauge theory with four flavors of low-mass staggered fermions...Quark plasma; Gluon plasma; Hadronic matter; Deconfinement; Chiral symmetry; Phase transitions1987-11
12 DeTar, CarletonNature of the thermal phase transition with Wilson quarksWe describe a series of simulations of high temperature QCD with two flavors of Wilson quarks aimed at clarifying the nature of the high temperature phase found in current simulations. Most of our work is with four time slices, although we include some runs with six and eight time slices for compar...Wilson quarks; Landau gauge; Polyakov loop; Phase transitions1994-04
13 DeTar, CarletonPhenomenological lattice model of the high-temperature phase transition in quantum chromodynamicsWe propose a simple phenomenological lattice model for the high-temperature phase transition in a quark-gluon plasma, in which the elementary dynamical variables are Wilson lines and SU(iV) chiral spins. A mean-field analysis of the model shows a second-order chiral phase transition for N=2 and a fi...Quark plasma; Gluon plasma; Chiral symmetry; Phase transitions1987-06
14 DeTar, CarletonPotts flux tube model at nonzero chemical potentialWe model the deconfinement phase transition in quantum chromodynamics at nonzero baryon number density and large quark mass by extending the flux tube model ~three-state, three-dimensional Potts model! to nonzero chemical potential. In a direct numerical simulation we confirm mean-field-theory pre...Phase transitions; Quark-gluon plasma; Chemical potential; Potts model2000-03
15 DeTar, CarletonPseudodeconfinement and dynamical confinement in the quark plasmaWe elaborate upon phenomenological models of high-temperature hadronic matter at zero baryon density. We discuss the choice of a practical set of "fundamental" degrees of freedom, indicate their relationship to dynamically confined plasma modes, and suggest in what way they may account for the phase...Quark plasma; Gluon plasma; Hadronic matter; Deconfinement; Glueballs; Mesons; Phase transitions1988-04
16 DeTar, CarletonQCD thermodynamics with an improved lattice actionWe have investigated QCD with two flavors of degenerate fermions using the Symanzik-improvement program for both the gauge and fermion actions. Our study focuses on the deconfinement transition on an Nt=4 lattice. Having located the thermal transition, we performed zero temperature simulations nea...Wilson fermions; Polyakov loop; Chiral symmetry; Phase transitions1997-11
17 DeTar, CarletonQCD thermodynamics with three flavors of improved staggered quarksWe report on a study of QCD thermodynamics with three flavors of quarks, using a Symanzik improved gauge action and the Asqtad O(a2) improved staggered quark action. Simulations were carried out with lattice spacings 1/4T, 1/6T, and 1/8T both for three degenerate quarks with masses less than or equa...Quark-gluon plasma; Staggered quarks; Phase transitions; Polyakov loop2005-02
18 DeTar, CarletonQCD thermodynamics with two flavors at Nt=6The first results of numerical simulations of quantum chromodynamics on the Intel iPSC/860 parallel processor are presented. We performed calculations with two flavors of Kogut-Susskind quarks at Nt = 6 with masses of 0.15T and 0.075T (0.025 and 0.0125 in lattice units) in order to locate the crosso...Kogut-Susskind quarks; Crossover temperature; Chiral symmetry; Polyakov loop; Phase transitions1992-05
19 DeTar, CarletonQCD thermodynamics with two flavors of Wilson quarks at Nt=6We report on a study of hadron thermodynamics with two flavors of Wilson quarks on 123 X6 lattices. We have studied the crossover between the high- and low-temperature regimes for three values of the hopping parameter, K=0. 16, 0.17, and 0.18. At each of these values of K we have carried out spect...Wilson quarks; Staggered quarks; Chiral symmetry; Phase transitions1992-11
20 DeTar, CarletonQCD thermodynamics with Wilson quarks at large KWe extend our study of the high temperature transition with two flavors of Wilson quarks on 123 x 6 lattices to K = 0.19. We also perform spectrum calculations on 123 x 24 lattices at K = 0.19 to find the physical lattice spacing and quark mass. At this value of K the transition is remarkable in tha...Wilson quarks; Polyakov loop; Phase transitions1994-09
21 Vardeny, Zeev ValentineRaman-scattering study of pressure-induced phase transitions in CuIThe pressure-induced phase transitions: zinc-blende (ZB) --* rhombohedral -> tetragonal in Cul were studied by Raman scattering. The rhombohedral primitive cell is presented as a slightly distorted ZB unit cell that is twice as long as the primitive cell in the [111] direction. By folding back the Z...Raman-scattering; Pressure cell; Phase transitions1977-01
22 DeTar, CarletonRole of baryons in chiral-symmetry restoration at high temperatureTo help provide insight into the apparent remarkable rise in baryon susceptibility at the high-temperature phase transition in QCD, we study the three-dimensional lattice SU(2) chiral model at finite temperature. The purpose of this study is to determine the extent to which a rising susceptibility i...Chiral model; Chiral symmetry; Quark plasma; Skyrmions; Phase transitions1990-07
23 DeTar, CarletonSignals for hadronic modes in the quark plasmaWe give a new argument for the occurrence of hadronic modes in the high-temperature quark plasma, present a crude phenomenological model of the plasma, and discuss possible experimental signatures for the low-lying modes.Quark plasma; Hadronic matter; Phase transitions1988-01
24 DeTar, CarletonStatic screening lengths in the gluon plasmaWe report results of an extensive numerical simulation in lattice gauge theory to study various static screening lengths in a finite-temperature pure gluon plasma. Measurements are made for fixed triplet charges (Wilson lines) and a variety of local operators near and above the phase transition for ...Gluon plasma; Phase transitions; Deconfinement; Strange quarks1986-10
25 DeTar, CarletonSU(3) lattice gauge theory with adjoint action at nonzero temperatureWe study the thermal phase diagram of pure SU(3) gauge theory with fundamental and adjoint couplings. We improve previous estimates of the position of the bulk transition line and determine the thermal deconfinement transition lines for Nt = 2,4,6, and 8. For Nt > 4 the deconfinement transition li...Phase transitions; Deconfinement1995-04
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