15 research outputs found
Meta-stable States in Quark-Gluon Plasma
We study the meta-stable states in high temperature phase of QCD
characterised by nonzero expectation values for the imaginary part of the
Polyakov loop. We consider dynamical staggered quarks, and carry
out simulations at various values of the coupling to observe these
states. In particular, we find the value of the coupling () above
which the meta-stable states appear. The resulting value of
corresponds to temperature MeV for .Comment: This version includes new simulations carried out on bigger lattices,
particularly on and $32^3 x 6
Strings with a confining core in a Quark-Gluon Plasma
We consider the intersection of N different interfaces interpolating between
different vacua of an SU(N) gauge theory using the Polyakov loop order
parameter. Topological arguments show that at such a string-like junction, the
order parameter should vanish, implying that the core of this string (i.e. the
junction region of all the interfaces) is in the confining phase. Using the
effective potential for the Polyakov loop proposed by Pisarski for QCD, we use
numerical minimization technique and estimate the energy per unit length of the
core of this string to be about 2.7 GeV/fm at a temperature about twice the
critical temperature. For the parameters used, the interface tension is
obtained to be about 7 GeV/fm. Lattice simulation of pure gauge theories
should be able to investigate properties of these strings. For QCD with quarks,
it has been discussed in the literature that this symmetry may still be
meaningful, with quark contributions leading to explicit breaking of this
symmetry. With this interpretation, such {\it QGP} strings may play important
role in the evolution of the quark-gluon plasma phase and in the dynamics of
quark-hadron transition.Comment: 18 pages, 6 figures, RevTe
Does Quarkonia Suppression serve as a probe for the deconfinement in small systems?
In high multiplicity proton-proton collisions, the formation of a
deconfined state of quarks and gluons akin to Heavy Ion Collisions (HIC) has
been a subject of significant interest. In proton-proton () collisions,
the transverse size of the system is comparable to the longitudinal (Lorentz
contracted) dimension, unlike the case in Nucleus-Nucleus () collision,
leading to a hitherto unexplored effect of rapid decrease of temperature of the
medium on quark-antiquark bound states. This allows us to probe a unique
possibility of hadronization occurring before quarkonia dissociation within the
medium. In small systems, a rapid change in temperature also introduces sudden
changes in the Hamiltonian. This scenario prompts consideration of
non-adiabatic evolution, challenging the traditional adiabatic framework. We
demonstrate that non-adiabatic evolution may extend the longevity of
quark-anti-quark bound states in collisions, even at higher
multiplicities, offering new insights into the dynamics of strongly interacting
matter produced in smaller collision systems.Comment: 7 pages, 4 figures, comments are welcom
Baryon Inhomogeneity Generation in the Quark-Gluon Plasma Phase
We discuss the possibility of generation of baryon inhomogeneities in a
quark-gluon plasma phase due to moving Z(3) interfaces. By modeling the
dependence of effective mass of the quarks on the Polyakov loop order
parameter, we study the reflection of quarks from collapsing Z(3) interfaces
and estimate resulting baryon inhomogeneities in the context of the early
universe. We argue that in the context of certain low energy scale inflationary
models, it is possible that large Z(3) walls arise at the end of the reheating
stage. Collapse of such walls could lead to baryon inhomogeneities which may be
separated by large distances near the QCD scale. Importantly, the generation of
these inhomogeneities is insensitive to the order, or even the existence, of
the quark-hadron phase transition. We also briefly discuss the possibility of
formation of quark nuggets in this model, as well as baryon inhomogeneity
generation in relativistic heavy-ion collisions.Comment: 11 pages, 2 figures, revtex4, more detailed discussion added about
formation and evolution of Z(3)domain walls in the univers
All New Faces of Diatoms: Potential Source of Nanomaterials and Beyond
Nature’s silicon marvel, the diatoms have lately astounded the scientific community with its intricate designs and lasting durability. Diatoms are a major group of phytoplanktons involved in the biogeochemical cycling of silica and are virtually inherent in every environment ranging from water to ice to soil. The usage of diatoms has proved prudently cost effective and its handling neither requires costly materials nor sophisticated instruments. Diatoms can easily be acquired from the environment, their culture requires ambient condition and does not involve any costly media or expensive instruments, besides, they can be transported in small quantities and proliferated to a desirable confluence from that scratch, thus are excellent cost effective industrial raw material. Naturally occurring diatom frustules are a source of nanomaterials. Their silica bio-shells have raised curiosity among nanotechnologists who hope that diatoms will facilitate tailoring minuscule structures which are beyond the capabilities of material scientists. Additionally, there is a colossal diversity in the dimensions of diatoms as the frustule shape differs from species to species; this provides a scope for the choice of a particular species of diatom to be tailored to an exacting requisite, thus paving the way to create desired three dimensional nanocomposites. The present article explores the use of diatoms in various arenas of science, may it be in nanotechnology, biotechnology, environmental science, biophysics or biochemistry and summarizes facets of diatom biology under one umbrella. Special emphasis has been given to biosilicification, biomineralization and use of diatoms as nanomaterials’, drug delivery vehicles, optical and immune-biosensors, filters, immunodiagnostics, aquaculture feeds, lab-on-a-chip, metabolites, and biofuels
Multi-Drug Resistant Coliform: Water Sanitary Standards and Health Hazards
Water constitutes and sustains life; however, its pollution afflicts its necessity, further worsening its scarcity. Coliform is one of the largest groups of bacteria evident in fecally polluted water, a major public health concern. Coliform thrive as commensals in the gut of warm-blooded animals, and are indefinitely passed through their feces into the environment. They are also called as model organisms as their presence is indicative of the prevalence of other potential pathogens, thus coliform are and unanimously employed as adept indicators of fecal pollution. As only a limited accessible source of fresh water is available on the planet, its contamination severely affects its usability. Coliform densities vary geographically and seasonally which leads to the lack of universally uniform regulatory guidelines regarding water potability often leads to ineffective detection of these model organisms and the misinterpretation of water quality status. Remedial measures such as disinfection, reducing the nutrient concentration or re-population doesn’t hold context in huge lotic ecosystems such as freshwater rivers. There is also an escalating concern regarding the prevalence of multi-drug resistance in coliforms which renders antibiotic therapy incompetent. Antimicrobials are increasingly used in household, clinical, veterinary, animal husbandry and agricultural settings. Sub-optimal concentrations of these antimicrobials are unintentionally but regularly dispensed into the environment through seepages, sewages or runoffs from clinical or agricultural settings substantially adding to the ever-increasing pool of antibiotic resistance genes. When present below their minimum inhibitory concentration (MIC), these antimicrobials trigger the transfer of antibiotic-resistant genes that the coliform readily assimilate and further propagate to pathogens, the severity of which is evidenced by the high Multiple Antibiotic Resistance (MAR) index shown by the bacterial isolates procured from the environmental. This review attempts to assiduously anthologize the use of coliforms as water quality standards, their existent methods of detection and the issue of arising multi-drug resistance in them