119211758
Hidden extra U(1) at the electroweak/TeV scale
We propose a simple extension of the standard model (SM) by adding an extra U(1) symmetry which is hidden from the SM sector. Such a hidden U(1) has not been considered before, and its existence at the TeV scale can be explored at the LHC. This hidden U(1) does not couple directly to the SM particles, and couples only to new SU(2){sub L} singlet exotic quarks and singlet Higgs bosons, and is broken at the TeV scale. The dominant signals at the high-energy hadron colliders are multilepton and multi-b-jet final states with or without missing energy. We calculate the signal rates as well as the corresponding standard model background for these final states. A very distinctive signal is 6 high p{sub T} b-jets in the final state with no missing energy. For a wide range of the exotic quarks masses the signals are observable above the background at the LHC.
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.
17144767
Associated Photons and New Physics Signals at Linear Colliders
We study signals for beyond standard model physics and consider the virtues of single photon signals or associated photons in the final states in identifying different scenarios of new physics models in a very efficient and novel way.
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.
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
118550604
Unity of elementary particles and forces for the third family
We propose a non-supersymmetric SU(5) model in which only the third family of fermions are unified. The model remedies the non-unification of the three Standard Model couplings in non-supersymmetric SU(5). It also provides a mechanism for baryon number violation which is needed for the baryon asymmetry of the Universe and is not present in the Standard Model. Current experimental constraints on the leptoquark gauge bosons, mediating such baryon and lepton violating interactions in our model, allow their masses to be at the TeV scale. These can be searched for as a (b tau) or (tt) resonance at the Large Hadron Collider as predicted in our model. (C) 2012 Elsevier B.V. All rights reserved.
119203482
NEW FORMS OF BRST SYMMETRY IN RIGID ROTOR
We derive the different forms of BRST symmetry by using the Batalin–Fradkin–Vilkovisky formalism in a rigid rotor. The so-called "dual-BRST" symmetry is obtained from the usual BRST symmetry by making a canonical transformation in the ghost sector. On the other hand, a canonical transformation in the sector involving Lagrange multiplier and its corresponding momentum leads to a new form of BRST as well as dual-BRST symmetry.
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.
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.