Udit Raha

Investigation of the

The possibility of an

nn\Lambda

nn\mathrm{\ensuremath{\Lambda}}

bound state in pionless effective theory

bound state is investigated in the framework of pionless effective field theory at leading order. A system of coupled integral equations are constructed in the spin-isospin basis, of which numerical solutions are investigated. In particular, we make use of the limit cycle behavior, i.e., cyclic singularities of coupled integral equations of the system, which would be associated with the formation of a three-body bound state, the so-called Efimov state, in the unitary limit. Furthermore, we find that, when the sharp momentum cutoff introduced in the integral equations is taken to be significantly larger than the hard scale of the effective theory, the coupling of a three-body contact interaction becomes cyclically singular indicating the onset of an Efimov-like bound state formation. However, the paucity of empirical information to determine the parameters of the theory precludes a definitive conclusion on the existence of such a bound state. As a simple test of the feasibility of the

Ordinary muon capture in hydrogen reexamined

nn\mathrm{\ensuremath{\Lambda}}

Radiative corrections to antineutrino-proton scattering at low energies

bound system in nature, we explore the cutoff dependence of the theory, and uncertainties of the present study are discussed as well.

Erratum: Radiative corrections to antineutrino-proton scattering at low energies [Phys. Rev. C85, 045502 (2012)]

The rate of muon capture in a muonic hydrogen atom is calculated in heavy-nucleon chiral perturbation theory up to next-to-next-to leading order. To this order, we present the systematic evaluation of all the corrections due to the QED and electroweak radiative corrections and the proton-size effect. Since the low-energy constants involved can be determined from other independent sources of information, the theory has predictive power. For the hyperfine-singlet

Low-Energy Lepton-Proton Bremsstrahlung via Effective Field Theory.

\mu p

Universal physics of the few-body system of two neutrons and one flavored meson

capture rate

Low-Energy Effective Field Theory of Lepton-Proton Bremsstrahlung

\Gamma_0

Universal physics of two neutrons with one flavored meson

, our calculation gives