118673440
Rigid rotor as a toy model for Hodge theory
We apply the superfield approach to the toy model of a rigid rotor and show the existence of the nilpotent and absolutely anticommuting Becchi–Rouet–Stora–Tyutin (BRST) and anti-BRST symmetry transformations, under which, the kinetic term and the action remain invariant. Furthermore, we also derive the off-shell nilpotent and absolutely anticommuting (anti-) co-BRST symmetry transformations, under which, the gauge-fixing term and the Lagrangian remain invariant. The anticommutator of the above nilpotent symmetry transformations leads to the derivation of a bosonic symmetry transformation, under which, the ghost terms and the action remain invariant. Together, the above transformations (and their corresponding generators) respect an algebra that turns out to be a physical realization of the algebra obeyed by the de Rham cohomological operators of differential geometry. Thus, our present model is a toy model for the Hodge theory.
121188687
Basic canonical brackets in the gauge field theoretic models for the Hodge theory
118643338
An Interacting Gauge Field Theoretic Model for the Hodge Theory: Basic Canonical Brackets
We derive the basic canonical brackets amongst the creation and annihilation operators for a two (1 + 1)-dimensional (2D) gauge field theoretic model of an interacting Hodge theory where a U(1) gauge field (A_\mu) is coupled with the fermionic Dirac fields (\psi and \bar \psi). In this derivation, we exploit the spin-statistics theorem, normal ordering and the strength of the underlying six infinitesimal continuous symmetries (and the concept of their generators) that are present in the theory. We do not use the definition of the canonical conjugate momenta (corresponding to the basic fields of the theory) anywhere in our whole discussion. Thus, we conjecture that our present approach provides an alternative to the canonical method of quantization for a class of gauge field theories that are physical examples of Hodge theory where the continuous symmetries (and corresponding generators) provide the physical realizations of the de Rham cohomological operators of differential geometry at the algebraic level.
118967100
PSEUDO-HERMITIAN INTERACTIONS IN DIRAC THEORY: EXAMPLES
We consider a couple of examples to study the pseudo-Hermitian interaction in relativistic quantum mechanics. Rasbha interaction, commonly used to study the spin Hall effect, is considered with imaginary coupling. The corresponding Dirac Hamiltonian is shown to be parity pseudo-Hermitian. In the other example we consider parity pseudo-Hermitian scalar interaction with arbitrary parameter in Dirac theory. In both cases we show that the energy spectrum is real and all the other features of nonrelativistic pseudo-Hermitian formulation are present. Using the spectral method, the positive definite metric operator (η) has been calculated explicitly for both the models to ensure positive definite norms for the state vectors.
118739941
Novel symmetries in vector Schwinger model
We derive nilpotent and absolutely anticommuting (anti-)co-BRST symmetry transformations for the bosonized version of (1+1)-dimensional (2D) vector Schwinger model. These symmetry transformations turn out to be the analog of co-exterior derivative of differential geometry as the total gauge-fixing term remains invariant under it. The exterior derivative is realized in terms of the (anti-)BRST symmetry transformations of the theory whereas the bosonic symmetries find their analog in the Laplacian operator. The algebra obeyed by these symmetry transformations turns out to be exactly same as the algebra obeyed by the de Rham cohomological operators of differential geometry.
118402302
Superfield approach to nilpotent symmetries in 3D Jackiw-Pi model of massive non-Abelian theory
In the available literature, only the Becchi-Rouet-Stora-Tyutin (BRST) symmetries are known for the Jackiw-Pi model of the three (2 + 1)-dimensional (3D) massive non-Abelian gauge theory. We derive the off-shell nilpotent (s_{(a)b}^2 = 0) and absolutely anticommuting (s_b \,s_{ab} + s_{ab}\, s_b = 0) (anti-)BRST transformations s_{(a)b} corresponding to the usual Yang-Mills gauge transformations of this model by exploiting the "augmented" superfield formalism where the horizontality condition and gauge invariant restrictions blend together in a meaningful manner. There is a non-Yang-Mills (NYM) symmetry in this theory, too. However, we do not touch the NYM symmetry in our present endeavor. This superfield formalism leads to the derivation of an (anti-)BRST invariant Curci-Ferrari restriction which plays a key role in the proof of absolute anticommutativity of s_{(a)b}. The derivation of the proper anti-BRST symmetry transformations is important from the point of view of geometrical objects called gerbes. A novel feature of our present investigation is the derivation of the (anti-)BRST transformations for the auxiliary field \rho from our superfield formalism which is neither generated by the (anti-)BRST charges nor obtained from the requirements of nilpotency and/or absolute anticommutativity of the (anti-)BRST symmetries for our present 3D non-Abelian 1-form gauge theory.
119201920
Probing Randall-Sundram Model using triphotons at the LHC
We investigate triphoton signals of the Randall-Sundram model at the Large Hadron Collider. Such a signal can be an important probe to the RS model as these are relatively cleaner from the hadronic activity and bear significant rate. The corresponding standard model background has also been studied in detail. We also show that a clear graviton reconstruction is possible in such signal.
119408212
Lattice QCD results on strangeness and quasi-quarks in heavy-ion collisions
Fluctuations of conserved quantities in heavy-ion collisions have been proposed as diagnostic tools for the nature of the produced phase. These can be related to the predictions of quark number susceptibilities (QNS) from lattice QCD. Using the diagonal QNS, we extracted the Wroblewski parameter in a dynamical QCD computation. Our results on the cross-correlations χBQ, χBY, χBS and χQY allow us to explore the charge and baryon number of objects that carry flavour. We present evidence that in the high-temperature phase of QCD the different flavour quantum numbers are excited in linkages which are exactly the same as one expects from quarks.
123179533
Fusion barriers for heavy-ion systems
Analytical expressions for the fusion barrier height and radius have been derived from a four-parameter empirical fusion cross section formula for heavy ions. The fusion barrier parameters calculated, using these expressions, are in good agreement with the literature values.
118484055
Symmetry energy from fragment observables in the canonical thermodynamic model
Different formulas relating measurable fragment isotopic observables to the symmetry energy of excited nuclei were proposed and applied to the analysis of heavy ion collision data in the recent literature. In this article, we examine the quality of the different expressions in the framework of the McGill canonical thermodynamic model (CTM). We show that even in the idealized situation of canonical equilibrium and in the absence of secondary decay, these formulas do not give a precise reconstruction of the symmetry energy of the fragmenting source. However, both isotopic widths and isoscaling appear very well correlated to the physical symmetry energy.
121860723
Possibility of structure in projectile fragmentation in high energy heavy ion reactions
Abstract We show that a quantum mechanical analogue of the Goldhaber model predicts a structure in the momentum distribution of α's fragmenting from the projectile 6 Li. This structure should be measurable.