Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: What can the L3 $\gamma\gamma ll$ events be?   We consider the 4 $\gamma\gamma ll$ ($l=\mu,\ e$) events reported by the L3
collaboration, and go through the logical possibilities which could explain the
events. If they are not coincidental bremsstrahlung events, we find that the
physics which they could point to is extremely limited. One possibility would
be to have a new 60 GeV scalar (or pseudoscalar) particle $X^0$ with an
off-diagonal coupling to a $Z$ and $Z'$ which is non-perturbative ($\alpha >
1$), where the $Z'$ couplings to $\nu\bar\nu$ are suppressed. One could also
construct a model involving $X^0$, and a second scalar $X'^0$ with a large
$X'll$ coupling. We do not promote either of these models, but hope they would
prove to be useful guidelines, should the L3 events turn out to be new physics.

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The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
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The categories of this paper are: eess
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The categories of this paper are: econ
2
The categories of this paper are: math
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph