Limits for Excited ${{\mathit e}}$ (${{\mathit e}^{*}}$) from Single Production

INSPIRE   PDGID:
S054EXS
These limits are from ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{*}}{{\mathit e}}$, ${{\mathit W}}$ $\rightarrow$ ${{\mathit e}^{*}}{{\mathit \nu}}$, or ${{\mathit e}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}^{*}}$ X and depend on transition magnetic coupling between ${{\mathit e}}$ and ${{\mathit e}^{*}}$. All limits assume ${{\mathit e}^{*}}$ $\rightarrow$ ${{\mathit e}}{{\mathit \gamma}}$ decay except as noted. Limits from LEP, UA2, and H1 are for chiral coupling, whereas all other limits are for nonchiral coupling, ${{\mathit \eta}_{{{L}}}}$ = ${{\mathit \eta}_{{{R}}}}$ = 1. In most papers, the limit is expressed in the form of an excluded region in the $\lambda −{\mathit m}_{{{\mathit e}^{*}}}$ plane. See the original papers.

For limits prior to 1987, see our 1992 edition (Physical Review D45 S1 (1992)).
VALUE (GeV) CL% DOCUMENT ID TECN  COMMENT
$\bf{> 5600}$ 95 1
SIRUNYAN
2020AJ
CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}}{{\mathit e}^{*}}{{\mathit X}}$
• • We do not use the following data for averages, fits, limits, etc. • •
$> 4800$ 95 2
AABOUD
2019AZ
ATLS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}}{{\mathit e}^{*}}{{\mathit X}}$
$> 3900$ 95 3
SIRUNYAN
2019Z
CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}}{{\mathit e}^{*}}{{\mathit X}}$
$> 2450$ 95 4
KHACHATRYAN
2016AQ
CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}}{{\mathit e}^{*}}{{\mathit X}}$
$> 3000$ 95 5
AAD
2015AP
ATLS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}^{(*)}}{{\mathit e}^{*}}{{\mathit X}}$
$> 2200$ 95 6
AAD
2013BB
ATLS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}}{{\mathit e}^{*}}{{\mathit X}}$
$> 1900$ 95 7
CHATRCHYAN
2013AE
CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}}{{\mathit e}^{*}}{{\mathit X}}$
$> 1870$ 95 8
AAD
2012AZ
ATLS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit e}^{(*)}}{{\mathit e}^{*}}{{\mathit X}}$
1  SIRUNYAN 2020AJ search for ${{\mathit e}^{*}}$ production in 2 ${{\mathit e}}$2 ${{\mathit j}}$ final states in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV. The quoted limit assumes ${{\mathit \Lambda}}$ = ${\mathit m}_{{{\mathit e}^{*}}}$, ${{\mathit f}}$ = ${{\mathit f}^{\,'}}$ = 1. The contact interaction is included. See their Fig.11 for exclusion limits in ${\mathit m}_{{{\mathit e}^{*}}}-{{\mathit \Lambda}}$ plane.
2  AABOUD 2019AZ search for single ${{\mathit e}^{*}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV. The limit quoted above is from ${{\mathit e}^{*}}$ $\rightarrow$ ${{\mathit e}}{{\mathit q}}{{\overline{\mathit q}}}$ and ${{\mathit e}^{*}}$ $\rightarrow$ ${{\mathit \nu}}{{\mathit W}}$ decays assuming ${{\mathit f}}$ = ${{\mathit f}^{\,'}}$ = 1 and ${\mathit m}_{{{\mathit e}^{*}}}$ = ${{\mathit \Lambda}}$. The contact interaction is included in ${{\mathit e}^{*}}$ production and decay amplitudes. See their Fig.6 for exclusion limits in ${\mathit m}_{{{\mathit e}^{*}}}−{{\mathit \Lambda}}$ plane.
3  SIRUNYAN 2019Z search for ${{\mathit e}^{*}}$ production in ${{\mathit \ell}}{{\mathit \ell}}{{\mathit \gamma}}$ final states in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV. The quoted limit assumes $\Lambda $ = ${\mathit m}_{{{\mathit e}^{*}}}$, ${{\mathit f}}$ = ${{\mathit f}^{\,'}}$ = 1. The contact interaction is included in the ${{\mathit e}^{*}}$ production and decay amplitudes.
4  KHACHATRYAN 2016AQ search for single ${{\mathit e}^{*}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV. The limit above is from the ${{\mathit e}^{*}}$ $\rightarrow$ ${{\mathit e}}{{\mathit \gamma}}$ search channel assuming ${{\mathit f}}$ = ${{\mathit f}^{\,'}}$ = 1, ${\mathit m}_{{{\mathit e}^{*}}}$ = $\Lambda $. See their Table 7 for limits in other search channels or with different assumptions.
5  AAD 2015AP search for ${{\mathit e}^{*}}$ production in evens with three or more charged leptons in ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV. The quoted limit assumes ${{\mathit \Lambda}}$ = ${\mathit m}_{{{\mathit e}^{*}}}$, ${{\mathit f}}$ = ${{\mathit f}^{\,'}}$ = 1. The contact interaction is included in the ${{\mathit e}^{*}}$ production and decay amplitudes.
6  AAD 2013BB search for single ${{\mathit e}^{*}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions with ${{\mathit e}^{*}}$ $\rightarrow$ ${{\mathit e}}{{\mathit \gamma}}$ decay. ${{\mathit f}}$ = ${{\mathit f}^{\,'}}$ = 1, and ${{\mathit e}^{*}}$ production via contact interaction with ${{\mathit \Lambda}}$ = ${\mathit m}_{{{\mathit e}^{*}}}$ are assumed.
7  CHATRCHYAN 2013AE search for single ${{\mathit e}^{*}}$ production in ${{\mathit p}}{{\mathit p}}$ collisions with ${{\mathit e}^{*}}$ $\rightarrow$ ${{\mathit e}}{{\mathit \gamma}}$ decay. ${{\mathit f}}$ = ${{\mathit f}^{\,'}}$ = 1, and ${{\mathit e}^{*}}$ production via contact interaction with ${{\mathit \Lambda}}$ = ${\mathit m}_{{{\mathit e}^{*}}}$ are assumed.
8  AAD 2012AZ search for ${{\mathit e}^{*}}$ production via four-fermion contact interaction in ${{\mathit p}}{{\mathit p}}$ collisions with ${{\mathit e}^{*}}$ $\rightarrow$ ${{\mathit e}}{{\mathit \gamma}}$ decay. The quoted limit assumes ${{\mathit \Lambda}}$ = ${\mathit m}_{{{\mathit e}^{*}}}$. See their Fig. 8 for the exclusion plot in the mass-coupling plane.
References