Related papers: $S$-factor and scattering parameters from ${}^3$He…
The astrophysical $S$-factor for the radiative capture $d(p,\gamma)^3$He in the energy-range of interest for Big Bang Nucleosynthesis (BBN) is calculated using an {\it ab-initio} approach. The nuclear Hamiltonian retains both two- and…
Elastic electron scattering off $^3$He and $^4$He has recently been studied at forward and backward scattering angles in Hall A at JLab. The results will provide accurate data on the elastic form factors, charge and magnetic for $^3$He and…
Measurements of the elastic scattering cross section of 3He and 4He are important in order to improve constraints on theoretical models of 4He(3He,g)7Be, a key reaction in Big Bang nucleosynthesis and solar neutrino production. The…
We extend previous halo effective field theory analyses of low-energy elastic scattering of $^{3}$He-$^{4}$He, including the $\frac{7}{2}^{-}$ $f$-wave resonance as an explicit degree of freedom. The presence of this resonance necessitates…
Cutoff regularized subleading order ${}^1S_0$ NN potential of effective field theory (EFT) is iterated using Lippmann-Schwinger equation. It is shown that the scattering amplitudes calculated in cutoff and subtractively renormalized EFT are…
We present a new calculation of the ${}^6{\rm Li}(p,\gamma){}^7{\rm Be}$ radiative capture astrophysical $S$-factor in a cluster model framework. We consider several intercluster potentials, adjusted to reproduce the ${}^7{\rm Be}$ bound…
We use an effective field theory for short-range forces (SREFT) to analyze systems of three identical bosons interacting via a two-body potential that generates a scattering length, $a$, which is large compared to the range of the…
Using halo effective field theory (EFT), an expansion in $R_{core}/R_{halo}$, where $R_{core}$ is the radius of the core and $R_{halo}$ the radius of the halo nucleus, we calculate the charge and neutron form factors of the two-neutron halo…
We study the nonresonant part of the $^7$Be($p,\gamma$)$^8$B reaction using a three-cluster resonating group model that is variationally converged and virtually complete in the $^4$He+$^3$He+$p$ model space. The importance of using adequate…
The astrophysical S-factor for the process p7Be --> 8Bgamma of radiative capture by the 8B ground state is described up to 5 MeV, within the modified potential cluster model. The signatures of the S-factor resonances at 0.632, 2.18 and 3.36…
I outline the effective field theory (EFT) calculation of nucleon-nucleon scattering which was recently carried out to next-to-next-to-leading order (NNLO) by Noam Shoresh and myself. In this calculation only potential pion contributions…
To study scattering amplitudes at high-energy, the T-product of two currents can be expanded in terms of coefficient functions (impact factors) and matrix elements of ``composite color dipoles'' made of Wilson line operators with rapidity…
A new analysis of the modern precise measured astrophysical $S$ factors for the direct capture $^3He(\alpha,\gamma)^7{\rm {Be}}$ reaction [B.S. Nara Singh {\it et al.}, Phys.Rev.Lett. {\bf 93}, 262503 (2004); D. Bemmerer {\it et al.},…
The astrophysical $S$-factor for the reaction $^7$Be(p,$\gamma$)$^8$B up to an energy of 2~MeV (c.m.) and the capture cross section of $^7$Li(n,$\gamma$)$^8$Li up to 1~MeV (c.m.) are calculated using the Direct Capture model (DC). Both…
The astrophysical factor for the proton weak capture on 3He is calculated with correlated-hyperspherical-harmonics bound and continuum wave functions corresponding to a realistic Hamiltonian consisting of the Argonne v18 two-nucleon and…
We find the complete set of conditions satisfied by the forward $2\to2$ scattering amplitude in unitarity and causal theories. These are based on an infinite set of energy dependent quantities -- the arcs -- which are dispersively expressed…
In nuclear astrophysics, the experimental scenario is still unclear for BBN relevant energies from 30-300 keV. Here, we report our measurements of cross section and astrophysical S(E) factor for pd capture reaction using proton beam…
We present precision measurements of the 3He + 4He --> 7Be reaction in the range ECM = 0.33 to 1.23 MeV using a small gas cell and detection of both prompt gamma rays and 7Be activity. Our prompt and activity measurements are in good…
Astrophysical $S$ factors and reaction rates of the direct radiative capture processes $^{3}{\rm He}(\alpha, \gamma)^{7}{\rm Be}$ and $^{3}{\rm H}(\alpha,\gamma)^{7}{\rm Li}$, as well as the primordial abundance of the $^{7}{\rm Li}$…
Halo nuclei are a promising new arena for studies based on effective field theory (EFT). We develop an EFT for shallow p-wave states and discuss the application to elastic n-alpha scattering. In contrast to the s-wave case, both the…