Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A look into the "hedgehog" events in pp collisions using a new event
  shape -- flatenicity   The UA1 and CDF collaborations have reported the presence of events with a
very extended structure of low momentum tracks filling in a uniform way the
$\eta-\varphi$ phase space. However, these events have not caused interest with
respect to the details of the interaction that originate them. We have
undertaken to study whether such events are predicted by present event
generators like PYTHIA 8. We report the existence of events without any
discernible jet structure in high-multiplicity pp collisions. In the
simulations those events originate from a moderate number of parton-parton
scatterings within the same pp collision. A new event shape, $\rho$
(flatenicity), is proposed to allow for easily triggering on such events.

22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph