Jefferson Lab Hall C: Precision Physics at the Luminosity Frontier

Over the last three decades, Hall C has been a key contributor to progress in the understanding of hadron structure and interactions. An outline of a potential future Hall C physics program focused on precision measurements of small cross sections is presented. A detailed overview of this unique facility, whose flexible configuration allows many opportunities for new experimental equipment that help address a wide range of questions in hadronic physics, is included as well

First Measurement of the EMC Effect in 10^{10}B and 11^{11}B

International audienceThe nuclear dependence of the inclusive inelastic electron scattering cross section (the EMC effect) has been measured for the first time in $^{10}$B and $^{11}$B. Previous measurements of the EMC effect in $A \leq 12$ nuclei showed an unexpected nuclear dependence; $^{10}$B and $^{11}$B were measured to explore the EMC effect in this region in more detail. Results are presented for $^9$Be, $^{10}$B, $^{11}$B, and $^{12}$C at an incident beam energy of 10.6~GeV. The EMC effect in the boron isotopes was found to be similar to that for $^9$Be and $^{12}$C, yielding almost no nuclear dependence in the EMC effect in the range $A=4-12$. This represents important, new data supporting the hypothesis that the EMC effect depends primarily on the local nuclear environment due to the cluster structure of these nuclei

Constraints on the onset of color transparency from quasi-elastic 12^{12}C(e,e′p)(e,e'p) up to Q2= 14.2 Q^2=\,14.2\,(GeV/c)2/c)^2

International audienceQuasi-elastic scattering on $^{12}$C$(e,e'p)$ was measured in Hall C at Jefferson Lab for space-like 4-momentum transfer squared $Q^2$ in the range of 8--14.2 (GeV/$c$)$^2$ with proton momenta up to 8.3 GeV/$c$. The experiment was carried out in the upgraded Hall C at Jefferson Lab. It used the existing high momentum spectrometer and the new super high momentum spectrometer to detect the scattered electrons and protons in coincidence. The nuclear transparency was extracted as the ratio of the measured yield to the yield calculated in the plane wave impulse approximation. Additionally, the transparency of the $1s_{1/2}$ and $1p_{3/2}$ shell protons in $^{12}$C was extracted, and the asymmetry of the missing momentum distribution was examined for hints of the quantum chromodynamics prediction of Color Transparency. All of these results were found to be consistent with traditional nuclear physics and inconsistent with the onset of Color Transparency

First Measurement of the EMC effect in <math><mmultiscripts><mi mathvariant="normal">B</mi><mprescripts/><none/><mn>10</mn></mmultiscripts></math> and <math><mmultiscripts><mi mathvariant="normal">B</mi><mprescripts/><none/><mn>11</mn></mmultiscripts></math>

International audienceThe nuclear dependence of the inclusive inelastic electron scattering cross section (the EMC effect) has been measured for the first time in B10 and B11. Previous measurements of the EMC effect in A≤12 nuclei showed an unexpected nuclear dependence; B10 and B11 were measured to explore the EMC effect in this region in more detail. Results are presented for Be9, B10, B11, and C12 at an incident beam energy of 10.6 GeV. The EMC effect in the boron isotopes was found to be similar to that for Be9 and C12, yielding almost no nuclear dependence in the EMC effect in the range A=4–12. This represents important new data supporting the hypothesis that the EMC effect depends primarily on the local nuclear environment due to the cluster structure of these nuclei