Nuclear Commons^™

Beam Spin Asymmetry In Semi-Inclusive Electroproduction Of Hadron Pairs, M. J. Amaryan, M. Hattawy, S. E. Kuhn, Y. Prok, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration

Physics Faculty Publications

A first measurement of the longitudinal beam spin asymmetry A_LU in the semi-inclusive electroproduction of pairs of charged pions is reported. A_LU is a higher-twist observable and offers the cleanest access to the nucleon twist-3 parton distribution function e(x). Data have been collected in the Hall-B at Jefferson Lab by impinging a 5.498-GeV electron beam on a liquid-hydrogen target, and reconstructing the scattered electron and the pion pair with the CLAS detector. One-dimensional projections of the A^sin_LU^ϕR moments are extracted for the kinematic variables of interest in the valence quark region. The …

Ruling Out Color Transparency In Quasielastic ¹²C(E,E'P) Up To Q² Of 14.2 (Gev/C)², D. Bhetuwal, J. Matter, H. Szumila-Vance, F. Hauenstein, C. Yero, J. Zhang, Et Al., Hall C. Collaboration

Physics Faculty Publications

Quasielastic ¹²C(e,e'p) scattering was measured at spacelike 4-momentum transfer squared Q² = 8, 9.4, 11.4, and 14.2 (GeV/c)², the highest ever achieved to date. Nuclear transparency for this reaction was extracted by comparing the measured yield to that expected from a plane-wave impulse approximation calculation without any final state interactions. The measured transparency was consistent with no Q² dependence, up to proton momenta of 8.5 GeV/c, ruling out the quantum chromodynamics effect of color transparency at the measured Q² scales in exclusive (e, e'p) reactions. These results impose strict constraints on models of color …

Photoproduction Of The F₂(1270) Meson Using The Clas Detector, Krishna P. Adhikari, Moskov J. Amaryan, Dilini Bulumulla, Mohammad Hattawy, G. Gavalian, Charles E. Hyde, Yelena Prok, J. Zhang, Et Al., Clas Collaboration

Physics Faculty Publications

The quark structure of the f₂(1270) meson has, for many years, been assumed to be a pure quark-antiquark (qq⁻) resonance with quantum numbers J^PC = 2⁺⁺. Recently, it was proposed that the f₂(1270) is a molecular state made from the attractive interaction of two 𝜌 mesons. Such a state would be expected to decay strongly to final states with charged pions due to the dominant decay 𝜌 → π⁺π^-, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction 𝛾p …

Differential Cross Sections For Λ (1520) Using Photoproduction At Clas, K. P. Adhikari, M.J. Amaryan, G. Gavalian, M. Hattawy, Y. Prok, Et. Al., The Clas Collaboration

Physics Faculty Publications

The reaction 𝛾p → K+Λ (1520) using photoproduction data from the CLAS g12 experiment at Jefferson Lab is studied. The decay of Λ(1520) into two exclusive channels, Σπ⁺π^- and Σ^-π⁺, is studied from the detected K⁺, π⁺, and π^- particles. A good agreement is established for the Λ(1520) differential cross sections with the previous CLAS measurements. The differential cross sections as a function of center-of-mass angle are extended to higher photon energies. Newly added are the differential cross sections as a function of invariant four-momentum transfer t, …

Measurement Of The Ar(E, E' P) And Ti(E, E' P) Cross Sections In Jefferson Lab Hall A, L. Gu, D. Abrams, A.M. Ankowski, L. Jiang, B. Aljawrneh, S. Alsalmi, F. Hauenstein, C. Hyde, Et Al., The Jefferson Lab Hall A. Collaboration

Physics Faculty Publications

The E12-14-012 experiment, performed in Jefferson Lab Hall A, has collected exclusive electron-scattering data (e, e'p) in parallel kinematics using natural argon and natural titanium targets. Here we report the first results of the analysis of the data set corresponding to beam energy 2222 GeV, electron scattering angle 21.5 degrees, and proton emission angle -50°. The differential cross sections, measured with ≈ 4% uncertainty, have been studied as a function of missing energy and missing momentum, and compared to the results of Monte Carlo simulations, obtained from a model based on the distorted-wave impulse approximation.

Experimental Tests Of Qcd Scaling Laws At Large Momentum Transfer In Exclusive Light-Meson Photoproduction, Moskov J. Amaryan, William J. Briscoe, Michael G. Ryskin, Igor I. Strakovsky

Physics Faculty Publications

We evaluated CLAS Collaboration measurements for the 90^◦ meson photoproduction off the nucleon using a tagged photon beam spanning the energy interval s = 3–11 GeV². The results are compared with the “quark counting rules” predictions.

Accurate Determination Of The Neutron Skin Thickness Of 208Pb, D. Adhikari, H. Albataineh, D. Androic, F. Hauenstein, M.N.H. Rashad, W. Zhang, J. Zhang, X. Zheng

Physics Faculty Publications

We report a precision measurement of the parity-violating asymmetry A_pv in the elastic scattering of longitudinally polarized electrons from ²⁰⁸Pb. We measure A_pv = 550 ± 16(stat) ± 8(syst) parts per billion, leading to an extraction of the neutral weak form factor F_w (Q² = 0.00616 GeV²) = 0.368 ± 0.013. Combined with our previous measurement, the extracted neutron skin thickness is R_n - R_p = 0.283 ± 0.071 fm. The result also yields the first significant direct measurement of the interior weak density of ²⁰⁸Pb: ρ⁰_w = …

Consistency Checks For Two-Body Finite-Volume Matrix Elements: Conserved Currents And Bound States, Raúl A. Briceño, Christopher J. Monahan

Physics Faculty Publications

We present a model-independent framework to determine finite-volume corrections of matrix elements of spatially separated current-current operators. We define these matrix elements in terms of Compton-like amplitudes, i.e., amplitudes coupling single-particle states via two current insertions. We show that the infrared behavior of these matrix elements is dominated by the single-particle pole, which is approximated by the elastic form factors of the lowest-lying hadron. Therefore, given lattice data on the relevant elastic form factors, the finite-volume effects can be estimated nonperturbatively and without recourse to effective field theories. For illustration purposes, we investigate the implications of the proposed formalism for …

Two- And Three-Nucleon Contact Interactions And Ground-State Energies Of Light- And Medium-Mass Nuclei, R. Schiavilla, L. Girlanda, A. Gnech, A. Kievsky, A. Lovato, L. E. Marcucci, M. Piarulli, M. Viviani

Physics Faculty Publications

Classes of two-nucleon (2N) contact interactions are developed in configuration space at leading order (LO), next-to-leading order (NLO), and next-to-next-to-next-to-leading order (N3LO) by fitting the experimental singlet np scattering length and deuteron binding energy at LO, and np and pp scattering data in the laboratory-energy ranges 0–15 MeV at NLO and 0–25 MeV at N3LO. These interactions are regularized by including two Gaussian cutoffs, one for T=0 and the other for T=1 channels. The cutoffs are taken to vary in the ranges R₀=(1.5–2.3) fm and R₁=(1.5–3.0) fm. The 780 (1100) data points up to …

Observation Of Beam Spin Asymmetries In The Process Ep → E'Π⁺Π⁻ X With Clas 12, T. B. Hayward, C. Dilks, A. Vossen, Dilini Bulumulla, Mohammad Hattawy, Florian Hauenstein, Mariana Khachatryan, Sebastian E. Kuhn, Yelena Prok, B. Yale, N. Zachariou, J. Zhang, Et Al., Clas Collaboration

Physics Faculty Publications

The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function e(x), which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function …

Solving Relativistic Three-Body Integral Equations In The Presence Of Bound States, Andrew W. Jackura, Raúl A. Briceño, Sebastian M. Dawid, Md. Habib E. Islam, Connor Mccarty

Physics Faculty Publications

We present a simple scheme for solving relativistic integral equations for the partial-wave projected three-body amplitudes. Our techniques are used to solve a problem of three scalar particles with a formation of a S-wave two-body bound state. We rewrite the problem in a form suitable for numerical solution and then explore three solving strategies. In particular, we discuss different ways of incorporating the bound-state pole contribution in the integral equations. All of them lead to agreement with previous results obtained using finite-volume spectra of the same theory, providing further evidence of the validity of the existing finite- and infinite-volume formalism …

Measurement Of Deeply Virtual Compton Scattering Off 4He With The Cebaf Large Acceptance Spectrometer At Jefferson Lab, Clas Collaboration, R. Dupré, Mohammad Hattawy, N. A. Batzell, Stephen Bültmann, Bayram Torayev, Moskov Amaryan, Dilini L. Bulumulla, M. Mayer, David C. Payette, Yelena Prok, Jiwan Poudel, Lawrence B. Weinstein, B. Yale, N. Zachariou, J. Zhang, Et Al.

Physics Faculty Publications

We report on the measurement of the beam spin asymmetry in the deeply virtual Compton scattering off ⁴He using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab using a 6 GeV longitudinally polarized electron beam incident on a pressurized ⁴He gaseous target. We detail the method used to ensure the exclusivity of the measured reactions, in particular the upgrade of CLAS with a radial time projection chamber to detect the low-energy recoiling ⁴He nuclei and an inner calorimeter to extend the photon detection acceptance at forward angles. Our results confirm the theoretically predicted enhancement of the …

Constraining 1 + 𝒥 → 2 Coupled-Channel Amplitudes In A Finite Volume, Raúl A. Briceño, Jozef J. Dudek, Luka Leskovec

Physics Faculty Publications

Whether one is interested in accessing the excited spectrum of hadrons or testing the standard model of particle physics, electroweak transition processes involving multihadron channels in the final state play an important role in a variety of experiments. Presently the primary theoretical tool with which one can study such reactions is lattice QCD, which is defined in a finite spacetime volume. In this work, we investigate the feasibility of implementing existing finite-volume formalism in realistic lattice QCD calculation of reactions in which a stable hadron can transition to one of several two-hadron channels under the action of an external current. …

Towards High-Precision Parton Distributions From Lattice Qcd Via Distillation, Colin Egerer, Robert G. Edwards, Christos Kallidonis, Kostas Orginos, Anatoly V. Radyushkin, David G. Richards, Eloy Romero, Savvas Zafeiropoulos, On Behalf Of The Hadstruc Collaboration

Physics Faculty Publications

We apply the Distillation spatial smearing program to the extraction of the unpolarized isovector valence PDF of the nucleon. The improved volume sampling and control of excited-states afforded by distillation leads to a dramatically improved determination of the requisite Ioffe-time Pseudo-distribution (pITD). The impact of higher-twist effects is subsequently explored by extending the Wilson line length present in our non-local operators to one half the spatial extent of the lattice ensemble considered. The valence PDF is extracted by analyzing both the matched Ioffe-time Distribution (ITD), as well as a direct matching of the pITD to the PDF. Through development of …

Unpolarized Gluon Distribution In The Nucleon From Lattice Quantum Chromodynamics, Tanjib Khan, Raza Sabbir Sufian, Joseph Karpie, Christopher J. Monahan, Colin Egerer, Bálint Joó, Wayne Morris, Kostas Orginos, Anatoly Radyushkin, David G. Richards, Eloy Romero, Savvas Zafeiropoulos, On Behalf Of The Hadstruc Collaboration

Physics Faculty Publications

In this study, we present a determination of the unpolarized gluon Ioffe-time distribution in the nucleon from a first principles lattice quantum chromodynamics calculation. We carry out the lattice calculation on a 32³ × 64 ensemble with a pion mass of 358 MeV and lattice spacing of 0.094 fm. We construct the nucleon interpolating fields using the distillation technique, flow the gauge fields using the gradient flow, and solve the summed generalized eigenvalue problem to determine the gluonic matrix elements. Combining these techniques allows us to provide a statistically well-controlled Ioffe-time distribution and unpolarized gluon parton distribution function. We …

¹² C(E,E'Pn) Measurements Of Short Range Correlations In The Tensor-To-Scalar Interaction Transition Region, I. Korover, J. R. Pybus, A. Schmidt, F. Hauenstein, M. Duer, L. B. Weinstein, M. J. Amaryan, D. Bullumulla, M. Hattawy, X. Zheng, Et Al., The Clas Collaboration

Physics Faculty Publications

High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the ¹²C(e,'p) and ¹²C (e,e'pN) reactions (where N is either n or p), at high Q² and 𝒙_B > 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 …

First Measurement Of Timeline Compton Scattering, P. Chatagnon, S. Niccolai, S. Stepanyan, M. J. Amaryan, C. E. Hyde, S. E. Kuhn, P. Pandey, Jiwan Poudel, Y. Prok, N. Zachariou, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration

Physics Faculty Publications

We present the first measurement of the timelike Compton scattering process, 𝛾p →p′𝛾^∗(𝛾^∗→e⁺e⁻), obtained with the CLAS12 detector at Jefferson Lab. The photon beam polarization and the decay lepton angular asymmetries are reported in the range of timelike photon virtualities 2.25 < Q² < 9  GeV², squared momentum transferred 0.1 < −t < 0.8  GeV², and average total center-of-mass energy squared s = 14.5  GeV² . The photon beam polarization asymmetry, similar to the beam-spin asymmetry in deep virtual Compton scattering, is sensitive to the imaginary part of the Compton form factors and provides a …

Deeply Virtual Compton Scattering Off Helium Nuclei With Positron Beams, Sara Fucini, Mohammad Hattawy, Matteo Rinaldi, Segio Scopetta

Physics Faculty Publications

Positron initiated deeply virtual Compton scattering (DVCS) off ⁴He and ³He nuclei is described. The way the so-called d-term could be obtained from the real part of the relevant Compton form factor is summarized, and the importance and novelty of this measurement is discussed. The measurements addressed for ³He targets could be very useful even in a standard unpolarized target setup, measuring beam spin and beam charge asymmetries only. The unpolarized beam charge asymmetries for DVCS off ³He and ⁴He are also estimated, at JLab kinematics and, for ⁴He, also at a configuration typical …

P-Wave Nucleon-Pion Scattering Amplitude In The Δ(1232) Channel From Lattice Qcd, Giorgio Silvi, Srijit Paul, Constantia Alexandrou, Stefan Krieg, Luka Leskovec, Stefan Meinel, John Negele, Marcus Petschlies, Andrew Pochinsky, Gumaro Rendon, Sergey Syritsyn, Antonio Todaro

Physics Faculty Publications

We determine the Δ(1232) resonance parameters using lattice QCD and the Lüscher method. The resonance occurs in elastic pion-nucleon scattering with J^P = 3/2⁺ in the isospin I=3/2, P-wave channel. Our calculation is performed with N_f = 2+1 flavors of clover fermions on a lattice with L ≈ 2.8 fm. The pion and nucleon masses are m_π = 255.4 (1.6) MeV and mN = 1073(5) MeV, respectively, and the strong decay channel Δ → _πN is found to be above the threshold. To thoroughly map out the energy dependence of the nucleon-pion …

Improved Λp Elastic Scattering Cross Sections Between 0.9 And 2.0 Gev/C As A Main Ingredient Of The Neutron Star Equation Of State, J. Rowley, N. Compton, C. Djalali, Krishna P. Adhikari, Dilini L. Bulumulla, Mohammad Hattawy, Sebastian E. Kuhn, Pushpa Pandey, Yelena Prok, M. Yurov, J. Zhang, Z. W. Zhao, Et Al., Clas Collaboration

Physics Faculty Publications

Strange matter is believed to exist in the cores of neutron stars based on simple kinematics. If this is true, then hyperon-nucleon interactions will play a significant part in the neutron star equation of state. Yet, compared to other elastic scattering processes, there is very little data on Λ-N scattering. This experiment utilized the CEBAF Large Acceptance Spectrometer (CLAS) detector to study the Λp→Λp elastic scattering cross section in the incident Λ momentum range 0.9-2.0  GeV/c. These are the first data on this reaction since the 1970s. The new cross sections have significantly better accuracy and precision than the existing …

Parton Distribution Functions From Ioffe Time Pseudodistributions From Lattice Calculations: Approaching The Physical Point, Bálint Joó, Joseph Karpie, Kostas Orginos, Anatoly V. Radyushkin, David G. Richards, Savvas Zafeiropoulos

Physics Faculty Publications

We present results for the unpolarized parton distribution function of the nucleon computed in lattice QCD at the physical pion mass. This is the first study of its kind employing the method of Ioffe time pseudodistributions. Beyond the reconstruction of the Bjorken-x dependence, we also extract the lowest moments of the distribution function using the small Ioffe time expansion of the Ioffe time pseudodistribution. We compare our findings with the pertinent phenomenological determinations.

Heavy Quark Expansion For Heavy-Light Light-Cone Operators, Shuai Zhao

Physics Faculty Publications

We generalize the celebrated heavy quark expansion to nonlocal QCD operators. By taking nonlocal heavy-light current on the light-cone as an example, we confirm that the collinear singularities are common between QCD operator and the corresponding operator in heavy quark effective theory (HQET), at the leading power of 1/M expansion. Based on a perturbative calculation in operator form at one-loop level, a factorization formula linking QCD and HQET operators is investigated and the matching coefficient is determined. The matching between QCD and HQET light-cone distribution amplitudes (LCDAs) as well as other momentum distributions of hadron can be derived as …

Improving Inverse Compton Sources By Avoiding Non-Linearities, B. Terzić, G. A. Krafft, V. Petrillo, I. Drebot, M. Ruijter

Physics Faculty Publications

We present a new, more nuanced understanding of non-linear effects in inverse Compton sources. Deleterious non-linear effects can arise even at low laser intensities, a regime previously viewed as linear. After laying out a survey of non-linear phenomena which degrade the effectiveness of inverse Compton sources, we discuss two powerful techniques designed to avoid these non-linearities. Starting with the known technique of non-linear longitudinal chirping of the laser pulse in the high laser field regime, we show that the simple stretching of the laser pulse, while keeping the energy constant, can significantly increase the spectral density of the scattered radiation …

Origin Of Single Transverse-Spin Asymmetries In High-Energy Collisions, Justin Cammarota, Leonard Gamberg, Zhong-Bo Kang, Joshua A. Miller, Daniel Pitonyak, Alexei Prokudin, Ted C. Rogers, Nobuo Sato

Physics Faculty Publications

In this paper, we perform the first simultaneous QCD global analysis of data from semi-inclusive deep inelastic scattering, Drell-Yan, 𝑒⁺⁢𝑒⁻ annihilation into hadron pairs, and proton-proton collisions. Consequently, we are able to extract a universal set of nonperturbative functions that describes the observed asymmetries in these reactions. The outcome of our analysis indicates single transverse-spin asymmetries in high-energy collisions have a common origin. Furthermore, we achieve the first phenomenological agreement with lattice QCD on the up and down quark tensor charges.

Jeopardy Update On E12-06-106: Rg-D Experiment Study Of Color Transparency In Exclusive Vector Meson Electroproduction Off Nuclei, W. Armstrong, C. Ayerbe, W. Brooks, T. Chetry, R. Dupré, D. Dutta, A. El Alaoui, L. El Fassi, S. Joosten, J. Kim, K. Hafidi, M. Hattawy, M. Holtrop, J. Lopez, Z. -E. Meziani, T. Mineeva, B. Mustapha, C. Peng, L. Weinstein, J. Xie

Physics Faculty Publications

Experiment E12-06-106 (RG-D) aims to study the color transparency (CT) phenomenon in the exclusive diffractive p⁰ electro-production off nuclei, using the CLAS-12 spectrometer in Hall-B. This experiment was endorsed by PAC30 back in 2006 and was reviewed by PAC36 in 2010 [1], at which time it was approved for 60 PAC days and granted the B⁺ rating.

CT is one of the underlying properties of Quantum Chromo Dynamics (QCD) related to the presence of color degrees of freedom in the strongly interacting matter. It refers to the suppression of interactions of the colorless small size configuration in the nuclear …

Probing Few-Body Nuclear Dynamics Via ³H And ³He (E E'P) Pn Cross-Section Measurements, R. Cruz-Torres, F. Hauenstein, D. Bulumulla, C. Hyde, M. Khachatryan, M.N.H. Rashad, L.B. Weinstein, Et. Al., Jefferson Lab Hall A. Tritium Collaboration

Physics Faculty Publications

We report the first measurement of the (e, e'p) three-body breakup reaction cross sections in helium-3 (³He) and tritium (³H) at large momentum transfer [< Q²> ≈ 1.9 (GeV/c)²] and x_B> 1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40 ≤ p_miss ≤ 500 MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall …

Generalized Contact Formalism Analysis Of The ⁴He(E,E′Pn) Reaction, J.R. Pybus, I. Korover, R. Weiss, A. Schmidt, N. Barnea, D.W. Higinbotham, E. Piasetzky, M. Strikman, L. B. Weinstein, O. Hen

Physics Faculty Publications

Measurements of short-range correlations in exclusive ⁴He (e , e ′ p N) reactions are analyzed using the Generalized Contact Formalism (GCF). We consider both instant-form and light-cone formulations with both the AV18 and local N2LO(1.0) nucleon-nucleon (NN) potentials. We find that kinematic distributions, such as the reconstructed pair opening angle, recoil neutron momentum distribution, and pair center of mass motion, as well as the measured missing energy, missing mass distributions, are all well reproduced by GCF calculations. The missing momentum dependence of the measured ⁴He (e , e ′ p N) /⁴He (e , e …

Results On Total And Elastic Cross Sections In Proton–Proton Collisions At √S = 200 Gev, J. Adam, L. Adamczyk, J. R. Adams, S. Bueltmann, Z. Zhu, M. Zyzak, Et Al., Star Collaboration

Physics Faculty Publications

We report results on the total and elastic cross sections in proton-proton collisions at √s = 200 GeV obtained with the Roman Pot setup of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The elastic differential cross section was measured in the squared four-momentum transfer range 0.045 ≤ −t ≤ 0.135 GeV². The value of the exponential slope parameter B of the elastic differential cross section dσ/dt ∼ e^−Bt in the measured −t range was found to be B = 14.32 ± 0.09 (stat.)^+0.13_−0.28(syst.) GeV⁻². The total cross section σ_tot, obtained from …

Chiral Effective Field Theory Calculations Of Weak Transitions In Light Nuclei, G.B. King, L. Andreoli, S. Pastore, M. Piarulli, R. Schiavilla, R.B. Wiringa, J. Carlson, S. Gandolfi

Physics Faculty Publications

We report quantum Monte Carlo calculations of weak transitions in A 10 nuclei, based on the Norfolk two-and three-nucleon chiral interactions, and associated one-and two-body axial currents. We find that the contribution from two-body currents is at the 2-3% level, with the exception of matrix elements entering the rates of Li-8, B-8, and He-8 beta decay. These matrix elements are suppressed in impulse approximation based on the (leading order) Gamow Teller transition operator alone; two-body currents provide a 20-30% correction, which is, however, insufficient to bring theory in agreement with experimental data. For the other transitions, the agreement with the …

Novel Observation Of Isospin Structure Of Short-Range Correlations In Calcium Isotopes, D. Nguyen, Z. Ye, Lawrence Weinstein, X. Zheng, P. Zhu, R. Zielinski, Et Al., Jefferson Lab Hall A Collaboration

Physics Faculty Publications

Short-range correlations (SRCs) have been identified as being responsible for the high-momentum tail of the nucleon momentum distribution, n(k). Hard, short-range interactions of nucleon pairs generate the high-momentum tail and imprint a universal character on n(k) for all nuclei at large momentum. Triple coincidence experiments have shown a strong dominance of np pairs, but these measurements involve large final-state interactions. This paper presents the results from Jefferson Lab experiment E08014 which measured inclusive electron scattering cross section from Ca isotopes. By comparing the inclusive cross section from ⁴⁸Ca to ⁴⁰Ca in a kinematic region dominated by SRCs …