Two-photon exchange contributions to elastic ep scattering in the non-local field formalism

We construct a non-local gauge-invariant Lagrangian to model the electromagnetic interaction of the proton. The Lagrangian includes all allowed operators with dimension up to five. We compute the two-photon exchange contribution to elastic electron–proton scattering using this effective non-local Lagrangian. The one-loop calculation in this model includes the standard box and cross box diagram with the standard on-shell form of the hadron electromagnetic vertices. Besides this we find an extra contribution, which depends on an unknown constant. We use experimentally extracted form factors for our calculation. We find that the correction to the reduced cross section is slightly non-linear as a function of the photon longitudinal polarization ε. The non-linearity seen is within the experimental error bars of the Rosenbluth data. The final result completely explains the difference between the form factor ratio G_E/G_M extracted by Rosenbluth separation technique at SLAC and polarization transfer technique at JLAB.     

Metal-free synthesis of secondary amines by the reaction of tosyl triazene and aryl boronic acid

A metal free noncatalytic amination process has been developed for the synthesis of N-substituted aniline using a new amine source. The amine source p-toluene sulfonyl triazene (PhN?NNHTs) has been prepared by treating aryldiazonium salt with p-tosylamide. Various unsymmetrical amines could be synthesized by treating this reagent and boronic acid in toluene at 110?°C in the presence of DBU and 4?Å molecular sieve. A large variety of N-substituted aniline could be synthesized with moderate yield.     

Bonding and Reactivity in RB-As R Systems(R=H,F,OH,CH_3,CMe_3,CF_3,SiF_3,BO): Substituent Effects

Density functional theory-based calculations have been carried out to study the bonding and reactivity in RB-As R(R=H,F,OH,CH3,CMe_3,CF_3,SiF_3,BO)systems.Our calculations demonstrated that all the studied systems adopted bent geometry(DR-B-As≈180°andDB-As-R≈90°or less).The reason for this bending was explained with the help of a valence-orbital model.The potential energy surfaces for three possible isomers of RB-As R systems were also generated,indicating that the RB-As R isomer was more stable than R_2B-As R when R=SiF_3,CMe_3,and H.The B-As bond character was analyzed using natural bond orbital(NBO)and Wiberg bond index(WBI)calculations.The WBI values for B-As bonds in F3Si B-As SiF_3 and HB-As H were 2.254 and 2.209,respectively,indicating that this bond has some triple-bond character in these systems.While the B centers prefer nucleophilic attack,the As centers prefer electrophilic attack.     

Covariant and consistent anomalies in two dimensions in path-integral formulation

We give a definition of a one-parameter family of regularized chiral currents in a chiral non-Abelian gauge theory in two dimensions in path-integral formulation. We show that covariant and consistent currents are obtained from this family by selecting two specific values of the free parameter, and thus our regularization interpolates between these two. Our procedure uses chiral bases constructed from eigenfunctions of thesame operator for defining _L and . Definition of integration measure and regularization is done in terms of thesame Hermitian operator . Covariant and consistent currents (and indeed the entire family) are classically conserved. Difference with previous works are explained, in particular, that anomaly in a general basis does differ from the Jacobian contribution.