Proposal to Search for a Dark Photon in Positron on Target Collisions at DA<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.0pt;width:17.025px;" id="M1" height="14.875" version="1.1" viewBox="0 0 17.025 14.875" width="17.025">
	
		
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z"></path></g>

		
	
</svg>NE Linac

<table>Gamma energy versus the opening angle for <svg height="18.549999" id="M246" style="vertical-align:-2.34499pt" version="1.1" viewbox="0 0 74.9375 18.549999" width="74.9375" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
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<g transform="matrix(.017,-0,0,-.017,14.713,14.05)"><path d="M391 364q0 -28 -20.5 -53.5t-50 -43.5t-70 -34t-73.5 -25t-68 -17v-29q0 -48 20 -81t65 -33q73 0 157 76l16 -23q-107 -113 -221 -113q-21 0 -40.5 6.5t-39 22t-31.5 47t-12 75.5q0 69 33.5 139.5t95.5 114.5q77 55 143 55q42 0 69 -24.5t27 -59.5zM313 350
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<g transform="matrix(.012,-0,0,-.012,21.75,5.887)"><path d="M535 230h-483v50h483v-50z" id="x2212"></path></g>
<g transform="matrix(.017,-0,0,-.017,36.912,14.05)"><path d="M901 255q-71 -62 -185 -187l-22 15l102 147h-727v50h727l-102 147l22 15q114 -125 185 -187z" id="x2192"></path></g><g transform="matrix(.017,-0,0,-.017,57.838,14.05)"><path d="M478 372q0 -39 -31 -97t-61 -98t-78 -98q-45 -55 -73 -102q-13 -79 -13 -197q-11 -11 -43.5 -25.5t-53.5 -15.5l-15 17q5 35 26 101.5t47 123.5q8 72 -1.5 174.5t-37.5 178.5q-14 37 -29 37q-20 0 -67 -65l-25 21q37 60 73 90.5t63 30.5q47 0 72 -112q13 -56 17.5 -141.5
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</svg> or <svg height="15.6125" id="M247" style="vertical-align:-2.34499pt" version="1.1" viewbox="0 0 45.387501 15.6125" width="45.387501" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,2.9,11.112)"><path d="M901 255q-71 -62 -185 -187l-22 15l102 147h-727v50h727l-102 147l22 15q114 -125 185 -187z" id="x2192"></path></g><g transform="matrix(.017,-0,0,-.017,23.825,11.112)"><path d="M751 650l-6 -28q-53 -1 -69 -12.5t-24 -38.5q-23 -85 -43 -192l-13 -69q-34 -181 -130 -262q-79 -65 -185 -65t-171 57q-87 77 -54 258l42 232q12 58 0.5 73t-75.5 19l8 28h263l-6 -28q-63 -5 -78 -18t-26 -74l-41 -226q-25 -135 22 -201t139 -66q99 0 161.5 68t91.5 217
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</svg> for different <svg height="11.4625" id="M248" style="vertical-align:-0.16302pt" version="1.1" viewbox="0 0 13.1 11.4625" width="13.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,11.112)"><path d="M751 650l-6 -28q-53 -1 -69 -12.5t-24 -38.5q-23 -85 -43 -192l-13 -69q-34 -181 -130 -262q-79 -65 -185 -65t-171 57q-87 77 -54 258l42 232q12 58 0.5 73t-75.5 19l8 28h263l-6 -28q-63 -5 -78 -18t-26 -74l-41 -226q-25 -135 22 -201t139 -66q99 0 161.5 68t91.5 217
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</svg> boson masses. Beam energy is 550 MeV.</table>

Advances in High Energy Physics

fig14

Figure 14

Figure 14: Proposal to Search for a Dark Photon in Positron on Target Collisions at DA<svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" style="vertical-align:-0.0pt;width:17.025px;" id="M1" height="14.875" version="1.1" viewBox="0 0 17.025 14.875" width="17.025">
	
		
			<g transform="matrix(.022,-0,0,-.022,.062,14.813)"><path id="x3A6" d="M488 658v-28q-47 -3 -58.5 -12t-11.5 -39q49 -2 97 -15t93.5 -39.5t73.5 -75t28 -112.5q0 -53 -19.5 -96.5t-50 -71t-70 -47t-77.5 -27.5t-75 -9q0 -36 11.5 -45.5t58.5 -12.5v-28h-223v28q47 3 58.5 12.5t11.5 45.5q-47 1 -94.5 14t-93 39.5t-74.5 76t-29 114.5
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z"></path></g>

		
	
</svg>NE Linac 

Advances in High Energy Physics

Proposal to Search for a Dark Photon in Positron on Target Collisions at DA NE Linac

Figure 14

Proposal to Search for a Dark Photon in Positron on Target Collisions at DANE Linac