TY - JOUR

T1 - The GSO projection, BRST cohomology and picture-changing in N = 2 string theory

AU - Bischoff, Jan

AU - Ketov, Sergei V.

AU - Lechtenfeld, Olaf

N1 - Funding Information: * Supported in part by the 'Deutsche Forschungsgemeinschaft'. 1 E-mail: bischoff@itp.uni-hannover.de 2 On leave of absence from High Current Electronics Institute of the Russian Academy of Sciences, Siberian Branch, Akademiehesky4 , Tomsk 634055, Russia. 3 E-mail: ketov@itp.uni-hannover.de 4 E-mail: lechtenf@itp.uni-hannover.de 5 See Refs. \[7,8\f]o r a review. Copyright: Copyright 2015 Elsevier B.V., All rights reserved.

PY - 1995/3/27

Y1 - 1995/3/27

N2 - We investigate in detail the critical N = 2 fermionic string with and without a global Z2 twist. An analysis of BRST cohomology shows that twisted sectors contain massless 'spacetime' fermions which are non-local with respect to the standard massless boson. However, two distinct GSO projections exist, one (untwisted) retaining merely the usual boson and its spectral-flow partner, the other (twisted) yielding two fermions and one boson, on the massless level. The corresponding chiral BRST-invariant vertex operators are constructed in certain pictures, and their fusion and picture-changing are investigated, including the construction of inverse picture-changing operators. The N = 2 'spacetime supersymmetry' generators are null operators, since the twisted massless states fail to interact. The untwisted three- and four-point functions are recalculated at tree-level.

AB - We investigate in detail the critical N = 2 fermionic string with and without a global Z2 twist. An analysis of BRST cohomology shows that twisted sectors contain massless 'spacetime' fermions which are non-local with respect to the standard massless boson. However, two distinct GSO projections exist, one (untwisted) retaining merely the usual boson and its spectral-flow partner, the other (twisted) yielding two fermions and one boson, on the massless level. The corresponding chiral BRST-invariant vertex operators are constructed in certain pictures, and their fusion and picture-changing are investigated, including the construction of inverse picture-changing operators. The N = 2 'spacetime supersymmetry' generators are null operators, since the twisted massless states fail to interact. The untwisted three- and four-point functions are recalculated at tree-level.

UR - http://www.scopus.com/inward/record.url?scp=0001470549&partnerID=8YFLogxK

U2 - 10.1016/0550-3213(94)00536-N

DO - 10.1016/0550-3213(94)00536-N

M3 - Article

AN - SCOPUS:0001470549

VL - 438

SP - 373

EP - 409

JO - Nuclear Physics, Section B

JF - Nuclear Physics, Section B

SN - 0550-3213

IS - 1-2

ER -