15953435
Pion - nucleon phase shifts in heavy baryon chiral perturbation theory
We calculate the phase shifts in pion-nucleon scattering using the heavy baryon formalism. We consider phase shifts for the pion energy range of 140 to 200 MeV. We employ two different methods for calculating the phase shifts{emdash}the first using the full third order calculation of the pion-nucleon scattering amplitude and the second by including the resonances {Delta} and N{sup *} as explicit degrees of freedom in the Lagrangian. We compare the results of the two methods with phase shifts extracted from fits to the pion-nucleon scattering data. We find good to fair agreement between the calculations and the phase shifts from scattering data. {copyright} {ital 1997} {ital The American Physical Society}
15656176
Understanding the nature of Ds(2317) and Ds(2460) through nonleptonic B decays
We consider the nonleptonic B decays B→D(∗)Ds(2317) and B→D(∗)Ds(2460), involving the newly discovered Ds(2317) and the Ds(2460) states. We find that experiments indicate disagreement with model calculations of their properties and/or breakdown of the factorization assumption for these decays. We point out that decays involving Bs mesons where the Ds resonances can be produced via the weak decay of the b quark can provide further information about the nature of these newly discovered states. We also propose a model to calculate the two body nonleptonic decays B→D(∗)Ds(2317)(Ds(2460)), if the Ds(2317) and Ds(2460) are interpreted as DK and D∗K molecules.
199680997
The Charged Lepton Mass Matrix and Non-zero $\theta_{13}$ with TeV Scale New Physics
119063690
$B \to VV$ Decays - Polarization and Triple Products
We discuss how triple product asymmetries can be used to discover and constrain new physics in $B \to VV$ decays.
118496504
Model independent predictions for rare top decays with weak coupling
Measurements at B factories have provided important constraints on new physics in several rare processes involving the B meson. New physics, if present in the b quark sector may also affect the top sector. In an effective Lagrangian approach, we write down operators, where effects in the bottom and the top sector are related. Assuming the couplings of the operators to be of the same size as the weak coupling g of the standard model and taking into account constraints on new physics from the bottom sector as well as top branching ratios, we make predictions for the rare top decays t{yields}cV, where V={gamma}, Z. We find branching fractions for these decays within possible reach of the LHC. Predictions are also made for t{yields}sW.
118720377
Explaining the $B \to K^\ast \mu^+ \mu^-$ data with scalar interactions
Recent LHCb results on the decay $B \to K^\ast \mu^+ \mu^-$ show significant deviations from the SM estimates in some of the angular correlations. In this paper we study the possibility of explaining these deviations using new scalar interactions. We show that new dimension-6 four-quark operators of scalar and pseudo-scalar type can successfully account for the discrepancies even after being consistent with other experimental measurements. We also briefly discuss possible extensions of the Standard Model where these operators can be generated.
118715386
LHC limits on KK-parity non-conservation in the strong sector of universal extra-dimension models
Abstract In five-dimensional universal extra-dimensional models compactified on an S 1 / Z 2 orbifold four-dimensional kinetic terms are allowed at the two fixed points. If these terms are unequal then Kaluza–Klein (KK) parity is broken. Within such a framework we consider resonant production of the n = 1 KK-gluon at the LHC and its subsequent decay to t t ¯ , where both production and decay are KK-parity non-conserving. We use, for the first time, the exclusion data for a t t ¯ resonance obtained by the LHC experiments to limit the mass range of the lowest gluon excitation and, in a correlated fashion, of the n = 1 quark excitation of the KK-parity-violating model which are both found to be in the ballpark of 600–2000 GeV.
5434210
Radiative production of invisible charginos in photon photon collisions
If, in a supersymmetric model, the lightest chargino is nearly degenerate with the lightest neutralino, the former can decay into the latter alongwith a soft pion (or a lepton-neutrino pair). Near degeneracy of the chargino and neutralino masses can cause the other decay products (the pion or the lepton) to be almost invisible. Photon-photon colliders offer a possibility of clean detection of such an event through a hard photon tag.
14418894
Heavy quark production via supersymmetric interaction at a neutrino factory
Abstract We investigate b -quark production in both charged and neutral current channels through ν μ – N scattering at a neutrino factory, mediated by the lepton flavour violating interactions present in a supersymmetric theory with broken R -parity. Using values of the effective interaction strengths well below the current and projected experimental bounds, we are still able to predict markedly enhanced event rates, especially for the neutral current events which are not allowed at the lowest order in the standard model (SM). Data from neutrino factories can therefore be used to probe strengths of such interactions to considerably higher precision than what can be envisioned in other experiments.
125209638
What does the mu(nu) oscillate into
15627100
Phenomenology of spinless adjoints in two Universal Extra Dimensions
Abstract We discuss the phenomenology of ( 1 , 1 ) -mode adjoint scalars in the framework of two Universal Extra Dimensions. The Kaluza–Klein (KK) towers of these adjoint scalars arise in the 4-dimensional effective theory from the 6th component of the gauge fields after compactification. Adjoint scalars can have KK-number conserving as well as KK-number violating interactions. We calculate the KK-number violating operators involving these scalars and two Standard Model fields. Decay widths of these scalars into different channels have been estimated. We have also briefly discussed pair-production and single production of such scalars at the Large Hadron Collider.