# Average Luminosities at HESR

• The table shows the average luminosities for different HESR/RESR accelerator modes in units of [1/(nb·d)] for maximum target density nt = 4·1015/cm2.
• Modes are:
• HL = High Luminosity mode (accumulation in RESR; rate R=2·107/s; Nmax=1011 antiprotons)
• HR = High Resolution mode (accumulation in RESR; rate R=2·107/s; Nmax=1010 antiprotons)
• HESR = HESR mode (accumulation in HESR with beam dump after cycle; rate R=1·107/s; Nmax=1010 antiprotons)
• HESRr = HESR mode (accumulation in HESR recycling previous beam current; rate R=1·107/s; Nmax=1010 antiprotons)

• Recommended for first day phyiscs are HESR(r) modes.
• Target density roughly scales linearly for p>4 GeV/c: L(k·nt) ≈ k·L(nt).

• Compute expected number of reactions/day → Multiply by cross section σ [nb].
Example: Daily production of a resonance at Ecm = 3.87 GeV (p = 7GeV/c), cross section σ = 50nb in HESRr is dN/dt = 50 nb · 1170/(nb·d) = 58500/d
• Conversion factor to [1/(cm2·s)]: f = 1.157·1028 (nb·d)/(cm2s)
Example: Lavg = 1170/(nb·d) = 1170 × 1.157·1028/(cm2·s) = 1.35·1031/(cm2·s)
 L [1/(nb·d)] p [GeV/c] Ecm [GeV] HL HR HESR HESRr 1,5 2,25 6732 1073 627 788 2,0 2,43 8270 1128 689 862 2,5 2,60 9555 1170 737 917 3,0 2,77 10627 1204 776 961 3,5 2,93 11493 1230 809 997 4,0 3,08 12662 1304 871 1070 4,5 3,22 13123 1322 895 1095 5,0 3,36 13363 1336 916 1116 5,5 3,50 13475 1348 933 1133 6,0 3,63 13563 1356 948 1148 6,5 3,75 13631 1363 961 1160 7,0 3,87 13683 1368 972 1170 7,5 3,99 13722 1372 982 1179 8,0 4,11 13751 1375 990 1186 8,5 4,22 13771 1377 998 1192 9,0 4,33 13783 1378 1004 1197 9,5 4,44 13790 1379 1010 1202 10,0 4,54 13792 1379 1015 1205 10,5 4,64 13791 1379 1020 1208 11,0 4,74 13786 1379 1024 1211 11,5 4,84 13778 1378 1028 1213 12,0 4,93 13769 1377 1031 1215 12,5 5,03 13757 1376 1034 1216 13,0 5,12 13744 1374 1037 1217 13,5 5,21 13730 1373 1039 1218 14,0 5,30 13714 1371 1041 1219 14,5 5,39 13698 1370 1043 1219 15,0 5,47 13681 1368 1045 1220 15,5 5,56 13663 1366 1047 1220