Three-loop matching coefficients for hot QCD: Reduction and gauge independence

We perform an integral reduction for the 3-loop effective gauge coupling and screening mass of QCD at high temperatures, defined as matching coefficients appearing in the dimensionally reduced effective field theory (EQCD). Expressing both parameters in terms of a set master (sum-) integrals, we show explicit gauge parameter independence. The lack of suitable methods for solving the comparatively large number of master integrals forbids the complete evaluation at the moment. Taking one generic class of masters as an example, we highlight the calculational techniques involved. The full result would allow to improve on one of the classic probes for the convergence of the weak-coupling expansion at high temperatures, namely the comparison of full and effective theory determinations of the spatial string tension. Furthermore, the full result would also allow to determine one new contribution of order O(g**7) to the pressure of hot QCD.Comment: 19 pages, 2 figures. v2: new Section 6 discussing applications, to match journal versio

The distribution and density of water mice (Xeromys myoides) in the Maroochy River of Southeast Queensland, Australia

The water mouse is a small and vulnerable rodent present in coastal areas of south-west Papua New Guinea, and eastern Queensland and the Northern Territory of Australia. Current knowledge regarding the distribution of the water mouse is incomplete and the loss of one local population has been documented in southeast Queensland, a region where pressures from urban and industrial development are increasing. Water mouse populations have not been studied intensively enough to enable the primary factors responsible for the local decline to be identified. We surveyed the distribution and density of the water mouse along the Maroochy River of southeast Queensland, near the southern extent of the species’ range, to gather baseline data that may prove valuable for detecting any future decline in this population’s size or health. All areas of suitable habitat were surveyed on foot or by kayak or boat over a three-year period. We found 180 water mouse nests, of which ~94% were active. Permanent camera monitoring of one nest and limited supplementary live trapping suggested that up to three individual mice occupied active nests. Water mouse density was estimated to be 0.44 per hectare of suitable habitat along the Maroochy River. Should future monitoring reveal an adverse change in the water mouse population on the Maroochy River, a concerted effort should be made to identify contributing factors and address proximate reasons for the decline

Parity-Violating Hydrodynamics in 2+1 Dimensions

We study relativistic hydrodynamics of normal fluids in two spatial dimensions. When the microscopic theory breaks parity, extra transport coefficients appear in the hydrodynamic regime, including the Hall viscosity, and the anomalous Hall conductivity. In this work we classify all the transport coefficients in first order hydrodynamics. We then use properties of response functions and the positivity of entropy production to restrict the possible coefficients in the constitutive relations. All the parity-breaking transport coefficients are dissipationless, and some of them are related to the thermodynamic response to an external magnetic field and to vorticity. In addition, we give a holographic example of a strongly interacting relativistic fluid where the parity-violating transport coefficients are computable.Comment: 39+1 page

Neutrino Propagation in a Strongly Magnetized Medium

We derive general expressions at the one-loop level for the coefficients of the covariant structure of the neutrino self-energy in the presence of a constant magnetic field. The neutrino energy spectrum and index of refraction are obtained for neutral and charged media in the strong-field limit ($M_{W}\gg \sqrt{B}\gg m_{e},T,\mu ,| \mathbf{p}|$) using the lowest Landau level approximation. The results found within the lowest Landau level approximation are numerically validated, summing in all Landau levels, for strong $B\gg T^{2}$ and weakly-strong $B \gtrsim T^{2}$ fields. The neutrino energy in leading order of the Fermi coupling constant is expressed as the sum of three terms: a kinetic-energy term, a term of interaction between the magnetic field and an induced neutrino magnetic moment, and a rest-energy term. The leading radiative correction to the kinetic-energy term depends linearly on the magnetic field strength and is independent of the chemical potential. The other two terms are only present in a charged medium. For strong and weakly-strong fields, it is found that the field-dependent correction to the neutrino energy in a neutral medium is much larger than the thermal one. Possible applications to cosmology and astrophysics are considered.Comment: 23 pages, 4 figures. Corrected misprints in reference

Holographic Flow of Anomalous Transport Coefficients

We study the holographic flow of anomalous conductivities induced by gauge and gravitational Chern-Simons terms. We find that the contribution from the gauge Chern-Simons term gives rise to a flow that can be interpreted in terms of an effective, cutoff dependent chemical potential. In contrast the contribution of the gauge-gravitational Chern-Simons term is just the temperature squared and does not flow.Comment: 26 pages, no figure

Antibiotics prescribing practices in oral implantology among jordanian dentists. A cross sectional, observational study

<p>Abstract</p> <p>Background</p> <p>In oral implantology, there is no consensus on the most appropriate regimen for antibiotics prescribing, the decision to prescribe antibiotic is usually based on procedure, patient and clinician related factors. The aim of this study was to investigate the rationale of antibiotic prescribing among Jordanian clinicians who practice oral implantology.</p> <p>Findings</p> <p>The target sample for the study was the 250 Jordan Dental Implant Group members. A five page questionnaire contained 41 questions, both closed and open questions were used to collect data. Statistical analysis was performed using SPSS Windows 16.0 (SPSS Inc., Chicago, IL, USA). Descriptive statistics were generated.</p> <p>The response rate was (70.4%) 176/250. Mean age was 37.2 yrs, 49.4% always prescribe antibiotics mainly oral amoxicillin and amoxicillin with clavulinic acid. Antibiotics prescribing increased with flap raising, multiple implants and sinus or bone augmentation. Patient medical condition, periodontitis and oral hygiene were the most important clinical factors in antibiotic prescribing, non-clinical factors were; reading scientific materials, courses and lectures, knowledge gained during training, and the effectiveness and previous experience with the drug.</p> <p>Conclusions</p> <p>Wide variations in antibiotics types, routes, dose and duration of administration were found. Recommendations on antibiotic prescribing are needed to prevent antibiotic overprescribing and misuse.</p

Anomalous Transport from Kubo Formulae

Chiral anomalies have profound impact on the transport properties of relativistic fluids. In four dimensions there are different types of anomalies, pure gauge and mixed gauge-gravitational anomalies. They give rise to two new non-dissipative transport coefficients, the chiral magnetic conductivity and the chiral vortical conductivity. They can be calculated from the microscopic degrees of freedom with the help of Kubo formulae. We review the calculation of the anomalous transport coefficients via Kubo formulae with a particular emphasis on the contribution of the mixed gauge-gravitational anomaly.Comment: 36 pages, 4 figures, 1 table; to appear in Lect. Notes Phys. "Strongly interacting matter in magnetic fields" (Springer), edited by D. Kharzeev, K. Landsteiner, A. Schmitt, H.-U. Yee; v2 small changes in introduction, added references; v3 corrected eq. (21) and added eq. (77), added reference

Holographic Gravitational Anomaly and Chiral Vortical Effect

We analyze a holographic model with a pure gauge and a mixed gauge-gravitational Chern-Simons term in the action. These are the holographic implementations of the usual chiral and the mixed gauge-gravitational anomalies in four dimensional field theories with chiral fermions. We discuss the holographic renormalization and show that the gauge-gravitational Chern-Simons term does not induce new divergences. In order to cancel contributions from the extrinsic curvature at a boundary at finite distance a new type of counterterm has to be added however. This counterterm can also serve to make the Dirichlet problem well defined in case the gauge field strength vanishes on the boundary. A charged asymptotically AdS black hole is a solution to the theory and as an application we compute the chiral magnetic and chiral vortical conductivities via Kubo formulas. We find that the characteristic term proportional to T^2 is present also at strong coupling and that its numerical value is not renormalized compared to the weak coupling result.Comment: 27 pages, no figure

Holographic Hall conductivities from dyonic backgrounds

We develop a general framework for computing the holographic 2-point functions and the corresponding conductivities in asymptotically locally AdS backgrounds with an electric charge density, a constant magentic field, and possibly non-trivial scalar profiles, for a broad class of Einstein-Maxwell-Axion-Dilaton theories, including certain Chern-Simons terms. Holographic renormalization is carried out for any theory in this class and the computation of the renormalized AC conductivities at zero spatial momentum is reduced to solving a single decoupled first order Riccati equation. Moreover, we develop a first order fake supergravity formulalism for dyonic renormalization group flows in four dimensions, allowing us to construct analytically infinite families of such backgrounds by specifying a superpotential at will. These RG flows interpolate between AdS$_4$ in the UV and a hyperscaling violating Lifshitz geometry in the IR with exponents $1<z<3$ and $\theta=z+1$. For $1<z<2$ the spectrum of fluctuations is gapped and discrete. Our hope and intention is that this analysis can serve as a manual for computing the holographic 1- and 2-point functions and the corresponding transport coefficients in any dyonic background, both in the context of AdS/CMT and AdS/QCD

A Chiral Magnetic Effect from AdS/CFT with Flavor

For (3+1)-dimensional fermions, a net axial charge and external magnetic field can lead to a current parallel to the magnetic field. This is the chiral magnetic effect. We use gauge-gravity duality to study the chiral magnetic effect in large-Nc, strongly-coupled N=4 supersymmetric SU(Nc) Yang-Mills theory coupled to a number Nf << Nc of N=2 hypermultiplets in the Nc representation of SU(Nc), i.e. flavor fields. Specifically, we introduce an external magnetic field and a time-dependent phase for the mass of the flavor fields, which is equivalent to an axial chemical potential for the flavor fermions, and we compute holographically the resulting chiral magnetic current. For massless flavors we find that the current takes the value determined by the axial anomaly. For massive flavors the current appears only in the presence of a condensate of pseudo-scalar mesons, and has a smaller value than for massless flavors, dropping to zero for sufficiently large mass or magnetic field. The axial symmetry in our system is part of the R-symmetry, and the states we study involve a net flow of axial charge to the adjoint sector from an external source coupled to the flavors. We compute the time rate of change of axial charge and of energy both in field theory and from holography, with perfect agreement. In contrast to previous holographic models of the chiral magnetic effect, in our system the vector current is conserved and gauge-invariant without any special counterterms.Comment: 54 pages, 18 eps files in 6 figure