Niculsescu, G.Mohring, R.M.Gueye, P.Abbott, D.Ahmidouch, A.Amatuni, Ts.A.Ambrozewicz, P.Angelescu, T.Armstrong, C.S.Assamagan, K.Avery, S.Bailey, K.Baker, O.K.Beard, K.Beedoe, S.Beise, E.Breuer, H.Carlini, R.Cha, J.Chang, C.C.Chant, N.Cisbani, E.Collins, G.Cummings, W.Danagoulian, S.DeLeo, R.Duncan, F.Dunne, J.Dutta, D.Eden, T.Ent, R.Eyraud, L.Ewell, L.Finn, M.Fortune, T.Frolov, V.Frullani, S.Furget, C.Garibaldi, F.Gaskell, D.Geesaman, D.F.Gustafsson, K.K.Hansen, J.-O.Harvey, M.Hinton, W.Hungerford, E.Iodice, M.Jackson, C.Keppel, C.Kim, W.Kino, K.Koltenuk, D.Kox, S.Kramer, L.Leone, T.Lolos, G.Lung, A.Mack, D.Madey, R.Maeda, M.Majewski, S.Markowitz, P.Martoff, C.J.Meekins, D.Mihul, A.Mitchell, J.Mkrtchyan, H.Mtingwa, S.Niculescu, I.Perrino, R.Potterveld, D.Price, J.W.Raue, B.A.Real, J.-S.Reinhold, J.Roos, P.Saito, T.Savage, G.Sawafta, R.Segel, R.Stepanyan, S.Stoler, P.Tadevosian, V.Tang, L.Teodorescu, L.Terasawa, T.Tsubota, H.Urciuoli, G.M.Volmer, J.Vulcan, W.Welch, P.Williams, R.Wood, S.Yan, C.Zeidman, B.The 1H(e,e′K+)Λ reaction was studied as a function of the squared four-momentum transfer, Q2, and the virtual photon polarization, ɛ. For each of four Q2 settings, 0.52, 0.75, 1.00, and 2.00 (GeV/c)2, the longitudinal and transverse virtual photon cross sections were extracted in measurements at three virtual photon polarizations. The Q2 dependence of the σL/σT ratio differs significantly from current theoretical predictions. This, combined with the precision of the measurement, implies a need for revision of existing calculations.en-UShydrogenelectromagnetic productionkaonsArticle