12C(e,e'pN) measurements of short range correlations in the tensor-to-scalar interaction transition region

I Korover,D Protopopescu,R Paremuzyan,O Pogorelko,J Rowley,G Niculescu,M Holtrop,R Cruz-Torres,H Voskanyan,Y Ilieva,A El Alaoui,S Adhikari,T Mineeva,S Mey-Tal Beck,J Zhang,R De Vita,B Mckinnon,D Heddle,H Egiyan,M Guidal,N Harrison,T Chetry,L El Fassi,A Movsisyan,M Osipenko,C Salgado,J Ritman,D Sokhan,M Khandaker,P Lenisa,X Wei,L Lanza,V Mascagna,L Barion,K Hicks,X Zheng,R Fersch,M Battaglieri,K Neupane,N Markov,T Wang,F Sabatié,G Gavalian,K Hafidi,A Denniston,E Pasyuk,N Sparveris,L Venturelli,C.W Kim,C Djalali,O Hen,A Rizzo,E Voutier,H Atac,D Bulumulla,M Hattawy,E Piasetzky,K Joo,L Elouadrhiri,F Hauenstein,A Filippi,B Mustapha,G Rosner,V Kubarovsky,L Clark,A Bianconi,L Marsicano,S Boiarinov,M Leali,I Bedlinskiy,M Contalbrigo,A Khanal,P Chatagnon,M Paolone,S Stepanyan,A Kim,Y Prok,W Phelps,M Ehrhart,M Defurne,D Marchand,M Khachatryan,A Deur,M Ripani,M Duer,P Eugenio,M Ungaro,M Mirazita,A Celentano,A Beck,K Livingston,N Zachariou,D Keller,S Strauch,J.R Pybus,E Golovatch,S Joosten,H Hakobyan,V Lucherini,D S Carman ,Stefan Diehl ,J W Price ,H S Jo ,Z W Zhao ,Larry Weinstein ,I J D Macgregor ,K P Adhikari ,T A Forest ,W J Briscoe ,T B Hayward ,Uttam Shrestha ,I I Strakovsky ,Axel Schmidt ,R A Schumacher ,A D’angelo ,E P Segarra ,A I Ostrovidov ,P L Cole ,R W Gothe ,K A Griffioen ,Y G Sharabian ,R Dupré ,N J C Tyler ,David Jenkins ,M J Amaryan ,M H Wood ,J A Tan ,E L Isupov ,P Nadel-Turoński ,F X Girod ,D P Watts ,F Benmokhtar ,D W Higinbotham ,B A Raue ,C Muñoz Camacho ,L L Pappalardo ,V Credé ,O Soto ,D G Ireland ,W K Brooks ,Volker Burkert ,G Angelini ,B A Clary ,A Biselli ,F J Klein

doi:10.1016/j.physletb.2021.136523

Abstract

High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the 12C(e,e′p) and 12C(e,e′pN) reactions (where N is either n or p), at high-Q2 and xB>1.1. The data span a missing-momentum range of 300–1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction. The data are well reproduced by theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological nucleon-nucleon (NN) interaction models. This agreement suggests that the measured high missing-momentum protons up to 1000 MeV/c predominantly belong to short-ranged correlated (SRC) pairs. The measured 12C(e,e′pN) / 12C(e,e′p) and 12C(e,e′pp) / 12C(e,e′pn) cross-section ratios are consistent with a decrease in the fraction of proton-neutron SRC pairs and increase in the fraction of proton-proton SRC pairs with increasing missing momentum. This confirms the transition from an isospin-dependent tensor NN interaction at ∼400 MeV/c to an isospin-independent scalar interaction at high-momentum around ∼800 MeV/c as predicted by theoretical calculation.

Highlights

High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the 12C(e, e p) and 12C(e, e pN) reactions, at high-Q 2 and xB > 1.1
The measured 12C(e, e pN) / 12C(e, e p) and 12C(e, e pp) / 12C(e, e pn) cross-section ratios are consistent with a decrease in the fraction of proton-neutron short-ranged correlated (SRC) pairs and increase in the fraction of proton-proton SRC pairs with increasing missing momentum
The existence and characteristics of SRC pairs are related to outstanding issues in particle, nuclear, and astrophysics, including the modification of the internal structure of nucleons bound in atomic nuclei [2,3,4,5,6], matrix elements used to interpret searches for neutrinoless double beta decay [7,8,9,10], scale separation and factorization of many-body nuclear wavefunctions [1,11,12,13,14], nuclear charge radii [15], and the nuclear symmetry energy governing neutron star properties [16,17,18]

Summary

Introduction

High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the 12C(e, e p) and 12C(e, e pN) reactions (where N is either n or p), at high-Q 2 and xB > 1.1. The data span a missing-momentum range of 300–1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction.

Results

Conclusion