14703063
Signatures of doubly-charged Higgsinos at colliders
Several supersymmetric models with extended gauge structures predict light doubly‐charged Higgsinos. Their distinctive signature at the large hadron collider is highlighted by studying its production and decay characteristics.
17830332
Single production of doubly charged Higgsinos at linear e-e-colliders
Several extended supersymmetric models, motivated by either grand unification, or by neutrino mass generation, predict light doubly charged higgsinos. We study the production of a single doubly charged higgsino and its decay channels at the International Linear Collider (ILC) operating in the e − e − mode. We analyze the production cross section for e − e − → ˜ � −− χ 0 as a function of different kinematic variables, followed by the decay, through several channels, of the doubly charged higgsino into a final state of two leptons plus missing energy. We include the standard model background and discuss how kinematic cuts could be used effectively to limit this background. Single production of these exotics could provide a spectacular signal for a new underlying symmetry and for physics beyond the minimal supersymmetric standard model. PACS: 12.60.Jv, 12.60.Fr, 14.80.-j
2753711
Anomalous magnetic moment of the muon in a composite model
We make a fresh evaluation of contributions to (g-2) of the muon in the framework of a preonic model with coloured vectorlike leptons and heavy coloured Z bosons and discuss their implications in the light of the recent Brookhaven measurement. It is shown that the observed deviation can be explained within this framework with masses and couplings consistent with all constraints.
55202970
Signals of doubly-charged Higgsinos at the CERN Large Hadron Collider
Several supersymmetric models with extended gauge structures, motivated by either grand unification or by neutrino mass generation, predict light doubly-charged Higgsinos. In this work we study productions and decays of doubly-charged Higgsinos present in left-right supersymmetric models, and show that they invariably lead to novel collider signals not found in the minimal supersymmetric model or in any of its extensions motivated by the {mu} problem or even in extra dimensional theories. We investigate their distinctive signatures at the Large Hadron Collider in both pair- and single-production modes, and show that they are powerful tools in determining the underlying model via the measurements at the Large Hadron Collider experiments.
14702466
Right-Chiral Sneutrino LSP in mSUGRA: Event characteristics of NLSP at the LHC
We study a supersymmetric scenario where the lighter tau-sneutrino is the lightest supersymmetric particle, while the lighter stau-state is the next lightest. Such a scenario can be motivated within the framework of minimal supergravity, with just the addition of a right-chiral neutrino superfield. Such a spectrum leads to rather unusual signals of supersymmetry, showing stable tracks of the stau in the muon chambers. We study the event characteristics of the long-lived staus at the LHC and demonstrate that the stau tracks can be distinguished from the muonic ones through proper kinematic cuts which also enable one to remove all standard model backgrounds.
16071084
Universal extra dimensions, radiative returns and the inverse problem at a linear e + e − collider
In a five-dimensional model with one universal extra dimension, signals for a pair of n=1 Kaluza-Klein excitations could be easily observed at a future e{sup +}e{sup -} collider if the process in question is kinematically allowed. However, these signals would prove difficult to distinguish from those predicted in other models, such as those with an extended gauge symmetry or supersymmetry. A much better power of discrimination is provided by the fact that the same machine could also produce the n=2 gauge bosons {gamma}{sub 2} and Z{sub 2} as resonances in fermion pair production without any upgrade in the collision energy {radical}(s). Assuming a fixed {radical}(s)--as is expected at upcoming e{sup +}e{sup -} machines--we investigate the role of beam radiation in helping to excite such resonances through radiative returns. We then show how these resonances could yield unambiguous signals for a universal extra dimension, if taken in conjunction with the production of Z{sub 1} pairs, identified by their decays to leptons and missing transverse energy.
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.
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.
119264016
Finite nilpotent symmetry in Batalin-Vilkovisky formalism
We consider the Batalin-Vilkovisky formulation of both 1-form and 2-form gauge theories in the context of generalized BRST transformations with a finite field-dependent parameter. In the usual Faddeev-Popov (FP) formulation of gauge theories such finite field-dependent BRST (FFBRST) transformations do not leave the generating functionals invariant as the path integral measure changes in a non-trivial way for finite transformations. Here we show that FFBRST transformation, with the appropriate choice of a finite field-dependent parameter, is the symmetry of the generating functionals in the Batalin-Vilkovisky formalism. The finite parameter is chosen in such a way that the contribution from the Jacobian of the path integral measure is adjusted with gauge fixed fermions which do not change the generating functionals. Several examples for such finite parameters are constructed.
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.
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.