8021098
Next-to-leading order QCD corrections to the Drell-Yan cross section in models of TeV-scale gravity
Abstract The first results on next-to-leading order QCD corrections to graviton-induced processes in hadron collisions in models of TeV-scale gravity are presented focusing on the case of dilepton pair production in p ¯ p and pp collisions. Distributions in the invariant mass Q , the longitudinal fraction x F , the rapidity Y and the forward–backward asymmetry of the lepton pair are studied. The quantitative impact of the QCD corrections for searches of extra dimensions at hadron colliders is investigated. It turns out that at the LHC ( S = 14  TeV ) the K -factor is rather large ( K = 1.6 ) for large invariant mass Q of the lepton pair, indicating the importance of accounting for these QCD corrections in the experimental search for TeV-scale gravity. At the Tevatron, the K -factor does not substantially deviate from the Standard Model value. However, its inclusion is necessitated to make the cross section stable with respect to scale variations.
119270253
NNLO QCD corrections to the resonant sneutrino/slepton production at hadron colliders
We present a complete next to next to leading order QCD corrections to the resonant sneutrino and charged slepton production cross sections at hadronic colliders such as the Tevatron and the Large Hadron Collider within the context of R-parity violating supersymmetric model. We have demonstrated the role of these corrections in reducing uncertainties resulting from renormalisation and factorisation scales and thereby making our predictions reliable. We have incorporated soft gluon effects at N 3 LO level in order to study the stability of our results under perturbation. The NNLO corrections are found to be large and significant. The results obtained in this article are also applicable to resonance production of any color-neutral scalar.
15386012
Searching for signals of minimal length in extra dimensional models using dilepton production at hadron colliders
Theories of quantum gravity suggest the existence of a minimal length scale. It is interesting to speculate what the consequences of the existence of such a length scale would be for models of large extra dimensions, in particular, the ADD model. When ADD model is conflated with the minimal length scale scenario, processes involving virtual exchange of gravitons cease to be ulraviolet divergent. We study the production of dileptons at hadron colliders as an example of a process mediated by virtual gravitons. We find that the bounds we derive on the effective string scale are significantly different (in fact, less stringent) from those derived in the conventional ADD model, both at the upgraded Tevatron and the large hadron collider.
9952561
Testing TeV scale quantum gravity using Dijet production at the Tevatron
Dijet production at the Tevatron including effects of virtual exchanges of spin-2 Kaluza-Klein modes in theories with large extra dimensions is considered. The experimental dijet mass and angular distribution are exploited to obtain stringent limits ( > 1.2 TeV) on the effective string scale MS.
121522381
GLUONIC CONTRIBUTIONS TO SPIN-DEPENDENT WEAK STRUCTURE FUNCTIONS: METHOD OF FACTORIZATION
We compute the gluonic contributions to the spin-dependent weak structure functions (i=1, 3, 4), using the factorization theorem in the minimal subtraction scheme, . We have considered the most general case where the quark flavor masses are distinguished and the gluons are off mass shell. The gluonic contribution to the first moment of is found to vanish and do not receive leading order gluonic contribution. These results are shown to be free of mass singularities.
121827797
Finite tension strings in SU(2) gauge theory
Abstract The second-order field equations of the SU(2) Higgs model are studied and a new class of string solutions is obtained. The tension is finite and scale-dependent and the strings are of minus one unit flux.
120364020
Causality and indefiniteness of charge in spin 3/2 field theories
The possibility of retaining causality of propagation of classical spin 3/2 fields in the presence of an external electromagnetic interaction is investigated. It is shown that in the case of the mixed spin 3/2-spin 1/2 theory of Bhabha and Gupta, causality in the interacting situation may be retained by giving up the positive definiteness of the free total charge and making an appropriate choice of the arbitrary parameters appearing in the Bhabha-Gupta Lagrangian. The authors demonstrate that the causal spin 3/2 equation proposed recently by Fisk and Tait (see abstr. A22979 of 1973) also shares the same feature, namely the indefiniteness of the free total charge.
119688870
Poincaré and TCP invariance in the determination of wave equations for particles of arbitrary spin
A brief outline is given of different types of approaches to the derivation of relativistic wave equations for free particles of arbitrary mass m and spin s. It is pointed out that all such equations can be subsumed in a standard form involving wavefunctions transforming according to the representation D (0,s) ⊕ D (s,0) of the Lorentz group. Generalizing earlier work employing this standard form, we determine all such equations (in a standard form) which are invariant under the Poincare group and the combined operation Θ ≡ TCP. It is shown that the resulting equations are automatically invariant under T, C, and P separately.
119922926
Massive Vector Field: Covariant Definition of Independent Components and Quantization
A new approach to the theory of the vector field is presented in which inelegant features like negative terms in the energy do not make an appearance at any stage. All components of the field are handled in a completely symmetric fashion and the explicitly covariant appearance of the theory is preserved in the process of quantization as well as in earlier stages. Though the special features which arise when the mass vanishes are pointed out, a detailed treatment of that case is not included here and will be given separately.
120399594
A simple accurate formula for the energy levels of oscillators with a quartic potential
Abstract In this note we present a simple analytical formula which reproduces the energy eigenvalues Ek(λ) of the pure quartic and quartic anharmonic oscillators with high accuracy for all values of the anharmonicity parameter λ and the level number k.
120740147
Relativistic wave equations: proper Lorentz invariance and invariance under discrete transformations
Considering the standard form i∂ψ/∂t=Hψ [with ψ transforming according to D(0,s)⊕D(s,0)] of wave equations for free particles of arbitrary spin, we determined in a recent paper the admissible forms of H consistent with invariance of the equation under the Poincare group and under T, C, and P. Here we show that even if T and C invariance is not imposed, the admissible Hamiltonians are the same (apart from one extra possibility H = E). Expressed differently, except for the trivial case H = E, invariance of free‐particle equations under the connected Poincare group and P implies T and C also.