North-Holland PHYSICS LETTERS B Constraints on anomalous WW, and WW,y couplings

We examine the potential of a future 500 GeV linear e+e collider (NLC) to probe the "minimal " set (x r, 2v) of anomalous WW7 and WW,Iy couplings via the (sub) processes "fy-~W+W-, e-f~W v and e+e-~W+W-, for comparison. Photon beams both from classical Bremsstrahlung and, notably, from backscanering laser light off e ± beams are considered. The differential cross ections da/d cos 0 of the three reactions are calculated analytically and used as observables in a Z 2 analysis under identical assumptions onmachine parameters. The constraints emerging from the use of laser photon beams appear very encouraging, are independent ofxz and 2z and impressively underline the importance ofrealizing laser photon beams at the NLC. Research and development on linear e+e colliders at SLAC, KEK, DESY, CERN and Novosibirsk has been progressing rapidly and the physics potential of such future machines i presently under intensive study. A very important task at a future 500 GeV linear e+e- collider (NLC) is to verify the non abelian gauge structure of the electroweak standard model by probing the three and four gauge boson couplings as directly and precisely as possible. Of particular interest is the "classical " set of anomalous WW~, and WWZ couplings XT.z and 27,z, with ~c 7, 27 related to the W magnetic dipole and electric quadrupole moments/tw and Qw, respectively, as e e ktW=2mw (1+/c7+27) ' Qw = rnw (/c7-273 ' (1,2)