Average CsI neutron density distribution from COHERENT data

Abstract

Using the coherent elastic neutrino-nucleus scattering data of the COHERENT experiment, we determine for the first time the average neutron rms radius of 133 Cs and 127 I. We obtain the practically model-independent value Rn = 5.5 +0.9 −1.1 fm using the symmetrized Fermi and Helm form factors. We also point out that the COHERENT data show a 2.3σ evidence of the nuclear structure suppression of the full coherence.

Coherent elastic neutrino-nucleus scattering at the European Spallation Source

“…I, a precision measurement of CEνNS provides a direct probe to both SM and beyond the standard model (BSM) physics. Paradigmatic examples of the former are the determination of the weak mixing angle at very low momentum transfer [27][28][29], and the study of nuclear structure [17][18][19][20]. The program of BSM exploration with CEνNS is broad (see [6-15, 21-26, 30, 32-34, 126, 127] for an incomplete list) being most sensitive to a variety of scenarios leading to modified neutrino interactions with nuclei -in particular at low momentum transfer -but extending also to the production of new light neutral states, and sterile neutrino searches, among others.…”

Concept of Coherence in Neutrino and Antineutrino Scattering off Nuclei

“…, then, according to (80) and normalization condition for spin wave functions (76), the amplitude . If this amplitude is defined for the case of as , at any it can be written as follows: (81) The common kinematic factor in ( 79) can be rearranged with separating out the leading factor , where and are the masses of the nucleon and the nucleus, and introducing the correction with the value of about unity (82) Substituting ( 78), (80), and ( 82) into (79), we obtain a "final" formula of this section for the amplitude of the process in the leading order in the Fermi constant (83) where (84) is the scalar product of the leptonic and th nucleon weak neutral currents. In particular, for the neutrino one obtains Matrix element ( 83) is a sum of lepton-nucleon amplitudes proportional to the scalar product of the currents weighted with two factors, each being not very different from unity.…”

“…( ) 1 3 Based on the universally accepted Fermi (or Woods-Saxon) charge density distribution, the symmetrized Fermi (SF) form factor, according to [82], has the form (141) where the parameters expressed in fm (142) have the meaning of the half-density radius and the diffuseness. The nuclear surface thickness is parametrized in the form of the relation [84]. For the SF form factor, the first three moments in expansion (137) are, according to [54], (143) There is also the Klein-Nystrand (KN) form factor, which formally follows from the convolution of the…”

“…In particular, the root-mean-square neutron radius of a nucleus and the difference between and the root-meansquare proton radius (the so-called neutron shell) are the main components of the equation of state of nuclear matter (EOS). The latter plays a significant role in the understanding of some points, such as nuclear properties in laboratory experiments, features of heavy-ion collisions, properties of superheavy elements, and structure and evolution of compact astrophysical objects like neutron stars (see, for example, [84] and references therein).…”

The CENNS-10 liquid argon detector to measure CEvNS at the Spallation Neutron Source

“…For example, is the interaction rate and recoil distribution as predicted by the standard model? The answer will have large implications in understanding supernovae [4,5], non-standard interactions [6][7][8], and the nuclear physics of neutron distributions [9,10].…”