Indirect Limits for Excited ${{\mathit e}}$ (${{\mathit e}^{*}}$)

INSPIRE   PDGID:
S054EXI
These limits make use of loop effects involving ${{\mathit e}^{*}}$ and are therefore subject to theoretical uncertainty.
VALUE (GeV) DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
1
DORENBOSCH
1989
CHRM ${{\overline{\mathit \nu}}_{{{\mu}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{{\mu}}}}{{\mathit e}}$, ${{\mathit \nu}_{{{\mu}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit \nu}_{{{\mu}}}}{{\mathit e}}$
2
GRIFOLS
1986
THEO ${{\mathit \nu}_{{{\mu}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit \nu}_{{{\mu}}}}{{\mathit e}}$
3
RENARD
1982
THEO $\mathit g-2$ of electron
1  DORENBOSCH 1989 obtain the limit $\lambda {}^{2}_{\gamma }\Lambda {}^{2}_{{\mathrm {cut}}}/{{\mathit m}^{2}}_{{{\mathit e}^{*}}}$ $<$ $2.6$ (95$\%$ CL), where $\Lambda _{{\mathrm {cut}}}$ is the cutoff scale, based on the one-loop calculation by GRIFOLS 1986. If one assumes that $\Lambda _{{\mathrm {cut}}}$ = 1 TeV and ${{\mathit \lambda}_{{{\gamma}}}}$ = 1, one obtains ${\mathit m}_{{{\mathit e}^{*}}}$ $>$ 620 GeV. However, one generally expects ${{\mathit \lambda}_{{{\gamma}}}}{}\approx{}{\mathit m}_{{{\mathit e}^{*}}}/\Lambda _{{\mathrm {cut}}}$ in composite models.
2  GRIFOLS 1986 uses ${{\mathit \nu}_{{{\mu}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\mathit \nu}_{{{\mu}}}}{{\mathit e}}$ and ${{\overline{\mathit \nu}}_{{{\mu}}}}$ ${{\mathit e}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{{\mu}}}}{{\mathit e}}$ data from CHARM Collaboration to derive mass limits which depend on the scale of compositeness.
3  RENARD 1982 derived from $\mathit g-2$ data limits on mass and couplings of ${{\mathit e}^{*}}$ and ${{\mathit \mu}^{*}}$. See figures 2 and 3 of the paper.
References