119113929
VARIOUS FORMS OF BRST SYMMETRY IN ABELIAN 2-FORM GAUGE THEORY
We derive the various forms of BRST symmetry using Batalin–Fradkin–Vilkovisky approach in the case of Abelian 2-form gauge theory. We show that the so-called dual BRST symmetry is not an independent symmetry but the generalization of BRST symmetry obtained from the canonical transformation in the bosonic and ghost sector. We further obtain the new forms of both BRST and dual-BRST symmetry by making a general transformation in the Lagrange multipliers of the bosonic and ghost sector of the theory.
118400642
Finite Nilpotent BRST Transformations in Hamiltonian Formulation
We consider the finite field dependent BRST (FFBRST) transformations in the context of Hamiltonian formulation using Batalin-Fradkin-Vilkovisky method. The non-trivial Jacobian of such transformations is calculated in extended phase space. The contribution from Jacobian can be written as exponential of some local functional of fields which can be added to the effective Hamiltonian of the system. Thus, FFBRST in Hamiltonian formulation with extended phase space also connects different effective theories. We establish this result with the help of two explicit examples. We also show that the FFBRST transformations is similar to the canonical transformations in the sector of Lagrange multiplier and its corresponding momenta.
204937401
Off-shell nilpotent finite BRST/anti-BRST transformations
We develop the off-shell nilpotent finite field dependent BRST transformations and show that for different choices of the finite field dependent parameter these connect the generating functionals corresponding to different effective theories. We also construct both on-shell and off-shell finite field dependent anti-BRST tranformations for Yang Mills theories and show that these transformations play the similar role in connecting different generating functionals of different effective theories. Analogous to the finite field dependent BRST transformations, the non-trivial Jacobians of the path integral measure which arise due to the finite field dependent anti-BRST transformations are responsible for the new results. We consider several explicit examples in each case to demonstrate the results.
119269850
Relating the generating functionals in field/antifield formulation through finite field dependent BRST transformation
We study the field/antifield formulation of pure Yang Mills theory in the framework of the finite field dependent BRST transformation. We show that the generating functionals corresponding to different solutions of the quantum master equation are connected through the finite field dependent BRST transformations. We establish this result with the help of several explicit examples.
1542255
ABSOLUTE ANTICOMMUTATIVITY OF THE NILPOTENT SYMMETRIES IN THE HAMILTONIAN FORMALISM: FREE ABELIAN 2-FORM GAUGE THEORY
The celebrated Curci–Ferrari (CF) type of restrictions are invoked to obtain the off-shell nilpotent and absolutely anticommuting (anti-)BRST as well as (anti-)co-BRST symmetry transformations in the context of the Lagrangian description of the physical four (3+1)-dimensional (4D) free Abelian 2-form gauge theory. We show that the above CF-type conditions, which turn out to be the secondary constraints of the theory, remain invariant with respect to the time-evolution of the above 2-form gauge system in the Hamiltonian formulation. This time-evolution invariance (i) physically ensures the linear independence of the BRST versus anti-BRST as well as co-BRST versus anti-co-BRST symmetry transformations, and (ii) provides a logical reason behind the imposition of the above CF-type restrictions in the proof of the absolute anticommutativity of the off-shell nilpotent (anti-)BRST as well as (anti-)co-BRST symmetry transformations.
119230768
Noncommutative Dirac oscillator in an external magnetic field
Abstract We show that ( 2 + 1 ) -dimensional noncommutative Dirac oscillator in an external magnetic field is mapped onto the same but with reduced angular frequency in absence of magnetic field. We construct the relativistic Landau levels by solving corresponding Dirac equation in ( 2 + 1 ) -dimensional noncommutative phase space. All the Landau levels become independent of noncommutative parameter for a critical value of the magnetic field. Several other interesting features along with the relevance of such models in the study of atomic transitions in a radiation field have been discussed.
9570302
Tagging sneutrino resonances at a linear collider with associated photons
Sneutrino resonances at a high-energy linear ${e}^{+}{e}^{\ensuremath{-}}$ collider may be one of the clearest signals of supersymmetry without $R$ parity, especially when the $R$-parity-violating coupling is too small to produce observable excesses in four-fermion processes. However, there is no guarantee that the sneutrino pole will lie anywhere near the machine energy. We show that associated photon production induces the necessary energy spread, and that the resonance then leaves a clear imprint in the photon spectrum. It follows that tagging of a hard monoenergetic photon for a variety of possible final states provides a realistic method of separating sneutrino resonance signals from the standard model backgrounds.
118497844
Top SU(5) Models: Baryon and Lepton Number Violating Resonances at the LHC
We propose minimal and renormalizable nonsupersymmetric top SU(5) models where the SU(5)(C) X SU(3)'(C) X SU(2)'(L) X U(1)'(Y) gauge symmetry is broken down to the Standard Model gauge symmetry at the TeV scale. The first two families of the Standard Model fermions are charged under SU(3)'C X SU(2)'(L) X U(1)'(Y), while the third family is charged under SU(5). In the minimal top SU(5) model, we show that the quark Cabibbo-Kobayashi-Maskawa mixing matrix can be generated via dimension-five operators, and the proton decay problem can be solved by fine-tuning the coefficients of the higher-dimensional operators at the order of 10(-4). In the renormalizable top SU(5) model, we can explain the quark Cabibbo-Kobayashi-Maskawa mixing matrix by introducing vectorlike particles, and we do not have the proton decay problem. The models give rise to leptoquark and diquark gauge bosons which violate both lepton and baryon numbers involving the third-family quarks and leptons. The current experimental limits for these particles is well below the TeV scale. We also discuss the productions and decays of these new gauge bosons, and their ensuing signals, as well as their reach at the LHC.
118512651
Disentangling the Unparticles with polarized beams at e+e- colliders
A recently proposed idea of unparticles arising due to a scale invariant sector in the theory can give rise to effective operators with different Lorentz structures. We show that, by using the different polarization options at the future linear e + e - colliders, the nature of these effective operators can be easily understood. The unique feature of a complex phase in the propagator of the unparticle can also be understood distinctively for the different spins by exploiting the initial beam polarizations at the International Linear Collider.
14078543
Single photon signals for warped quantum gravity at a linear e+e− collider
We study the `single photon' process e+e−→γν with contributions due to exchange of massive gravitons in the Randall-Sundrum model of low-scale quantum gravity. It is shown that for significant regions in the parameter space, this process unambiguously highlights the resonance structure of the graviton sector. Even in the non-resonant part of the parameter space, we show that comparison with the benchmark process e+e−→μ+μ− can clearly distinguish signals for warped gravity from similar signals for large extra dimensions.
18791525
On distinguishing radions from Higgs bosons
Abstract Radion couplings are almost identical in form to Higgs boson couplings, making it very difficult to distinguish the two states when the masses and branching ratios to Standard Model particles are similar. The only real difference lies in the fact that the coupling of radions to off-shell fermions is proportional to the momentum rather than the mass of the fermion. This extra contribution gets cancelled in all tree-level processes and shows up only in loop-induced processes like Φ → γ γ and Φ → g g . We perform a careful calculation of these branching ratios and establish that they can prove crucial in clearly distinguishing a radion from a Higgs boson. This claim is made concrete by evaluating the exclusive cross-sections in a radiative process involving elementary scalars.