Effects of quantum mechanical identity in particle scattering: experimental observations (and lack thereof)

Abstract

On the occasion of the 150th anniversary of Ernest Rutherford's birth I discuss how indistinguishabilty profoundly affects the collisions of identical particles. In the case of a Coulombic interaction this leads to a dramatic modification of Rutherford's famous scattering formula as predicted by Nevill Mott. An even more extreme example is provided by a low-energy scattering experiment of identical fermions interacting via a short range potential. Here indistinguishability will make or break the observation of scattered particles. This fascinating phenomenon has been observed using a laser-based collider for ultracold fermionic potassium atoms.

No cleverness – just greatness

“…In our opinion, Rutherford was a scientist to the bone who could carry his own weight. In particular, he brought forward his hypothesis on the atomic nucleus as a sole author (Rutherford 1911;Kjaergaard 2021;Barrette 2021). As Hans Geiger recalls:…”

Scattering by harmonically trapped 2D quantum gas near and around the critical regime

“…In all the instances provided above, the scatterer or scatterers are either stationary or exhibit classical motion. A comprehensive investigation into the temperature-dependent variations of the differential scattering cross-section (DSC) for particle scattering has not been studied while taking into account the quantized bound motion of the scatterer, except in a few cases [10][11][12][13][14]. Experimental investigations have explored the scattering of impurity atoms within a Bose-Einstein condensate (BEC) that is harmonically trapped [15].…”

“…When n approaches infinity for classical scatterers, the scattering amplitude becomes infinitely narrow. At higher temperature limits, DSC follows the Maxwell-Boltzmann distribution in equation (10) for ideal quantum gases and is explained by Boltzmann's kinetic theory. The intensity patterns of elastic scattering provide valuable information on coherence phenomena for investigating interference effects in momentum space [57].…”