53704512
Lepton Number Violation via Intermediate Black Hole Processes
Black holes at the TeV scale are investigated in the extra large dimension scenario. We interpret the lightest black hole excitation as a singlet scalar field, and show how interaction terms can be appended to the standard model at the dimension five non-renormalizable level. Lepton family number violation is natural in this model. Muon magnetic moment, and neutrino masses are investigated. We also present a quantization scheme in n dimensions.
121960660
Neutral-current cross sections for double-pion production by neutrinos
We have derived expressions for the differential cross sections for two-pion production by the neutral current in a neutrino-induced hadron reaction. We assume a general V, A form of the neutral current with arbitrary admixture of isotopic scalar and vector parts and utilize the algebra of currents and the PCAC (partial conservation of the axial-vector current) hypothesis to obtain the amplitude for ..nu.. + N ..-->.. ..nu.. + N + ..pi.. + ..pi... Two different cases have been studied: (i) Both the outgoing pions are at threshold. (ii) They are produced via the formation of N*. The results are useful to examine the structure of the neutral current.
125314068
Supersymmetric effects in B(s) ---> l+ l- gamma decays
118238640
HIGH-ORDER LOW-ENERGY THEOREMS FOR NUCLEON COMPTON SCATTERING.
The well-known zero- and first-order (in photon energy) low-energy theorems for nucleon Compton scattering have recently been derived by Abarbanel and Goldberger using only the physical helicity amplitudes for the process and exploiting their kinematical singularities and zeros. We use this approach to study higher-order terms in photon energy and find the result, not entirely new, that four of the six independent helicity amplitudes are determined in second order by the mass, charge, and magnetic moment of the nucleon. Therefore, these parameters together with two structure-dependent constants, which can be interpreted approximately as electric and magnetic polarizabilities, completely determine the Compton scattering to second order in energy. Similar simplifications occurring in the structure of higher-order terms in energy are also discussed. The kinematical singularity structure of helicity amplitudes is a manifestation of Lorentz invariance. We claim to have fully exploited the requirements of Lorentz invariance and therefore to have derived the complete set of low-energy theorems for this process.
10367884
Comment on "New interaction for the enhancement of the Delta I=1/2 amplitude in weak decays"
122154027
Relativistic oscillator in a Bethe-Salpeter model: Nonexistence of discrete bound states
We investigate the solutions of the covariant Bethe-Salpeter equation for bound states of a scalar quark-antiquark system with an effective confining kernel which in coordinate four-space behaves as ${R}^{2}$. Using a suitable set of new variables we separate the equation into one-dimensional equations and study the eigenvalue problem. We find that the covariant bound-state Bethe-Salpeter equation with the above kernel possesses only a continuous spectrum.
119286198
A step toward exploring the features of Gravidilaton sector in Randall–Sundrum scenario via lightest Kaluza–Klein graviton mass
In this paper we study the role of the 5D Gauss–Bonnet corrections and two-loop higher genus contribution to the gravity action in type IIB string theory inspired low energy supergravity theory in the light of gravidilatonic interactions on the lightest Kaluza–Klein graviton mass spectrum. From the latest constraints on the lightest Kaluza–Klein graviton mass as obtained from the ATLAS dilepton search in 7 TeV proton–proton collision experiments, we have shown that due to the presence of Gauss–Bonnet and string loop corrections, the warping solution in an $$\mathbf{AdS_{5}}$$AdS5 bulk is quite distinct from the Randall–Sundrum scenario. We discuss the constraints on the model parameters to fit with the present ATLAS data.
119262207
Higgs inflation from new Kähler potential
Abstract We introduce a new class of models of Higgs inflation using the superconformal approach to supergravity by modifying the Kahler geometry. Using the above-mentioned mechanism, we construct a phenomenological functional form of a new Kahler potential followed by construction of various types of models which are characterized by a superconformal symmetry breaking parameter χ . Depending on the numerical values of χ we classify the proposed models into three categories. Models with minimal coupling are identified by χ = ± 2 3 branch which are made up of shift symmetry preserving flat directions. We also propose various other models by introducing a non-minimal coupling of the inflaton field to gravity described by χ ≠ 2 3 branch. We employ all these proposed models to study the inflationary paradigm by estimating the major cosmological observables and confront them with recent observational data from WMAP9 along with other complementary data sets, as well as independently with PLANCK. We also mention an allowed range of non-minimal couplings and the Yukawa type of couplings appearing in the proposed models used for cosmological parameter estimation.
73661546
Galileogenesis: A new cosmophenomenological zip code for reheating through R-parity violating coupling
In this paper we introduce an idea of leptogenesis scenario in higher derivative gravity induced DBI Galileon framework aka Galileog enesis in presence of one-loop R-parity violating couplings in the background of a low energy effective supergravity setup derived from higher dimensional string theory framework. We have studied extensively the detailed feature of reheating constraints and the cosmophenomenological consequences of thermal gravitino dark matter in light of PLANCK and PDG data. Finally, we have also established a direct cosmophenomenological connection among dark matter relic abundance, reheating temperature and tensor-to-scalar ratio in the context of DBI Galileon inflation.
118476324
Inflamagnetogenesis redux: Unzipping sub-Planckian inflation via various cosmoparticle probes
Abstract In this paper I introduce a precise constraint on primordial magnetogenesis, for a generic class of single-field inflationary model followed by small field excursion below the Planck scale. I also establish a connection between the magnetic field at the present epoch and primordial gravity waves (r) via non-vanishing CP asymmetry parameter ( ϵ CP ), which triggers the leptogenesis scenario. Finally, I explore various hidden cosmophenomenological features of theoretical CMB B-mode polarization spectra, which can be treated as a significant probe to put further stringent constraint on low and high scale small field inflationary models after releasing the Planck B-mode polarization data.
56054159
An accurate bound on tensor-to-scalar ratio and the scale of inflation
Abstract In this paper we provide an accurate bound on primordial gravitational waves, i.e. tensor-to-scalar ratio ( r ) for a general class of single-field models of inflation where inflation occurs always below the Planck scale, and the field displacement during inflation remains sub-Planckian. If inflation has to make connection with the real particle physics framework then it must be explained within an effective field theory description where it can be trustable below the UV cut-off of the scale of gravity. We provide an analytical estimation and estimate the largest possible r , i.e. r ⩽ 0.12 , for the field displacement less than the Planck cut-off.