OPERA tau neutrino candidate event 11113019758

Name: OPERA tau neutrino candidate event 11113019758
Creator: OPERA collaboration
Published: 2018

OPERA tau neutrino candidate event 11113019758, OPERA collaboration

Cite as: OPERA collaboration (2018). OPERA tau neutrino candidate event 11113019758. CERN Open Data Portal. DOI:10.7483/OPENDATA.OPERA.ASER.L87Y

Data recorded in 2011 and published in 2018

Dataset Derived OPERA CERN-SPS

Description

This neutrino interaction occurred on April $23^{rd}$ 2011 in a brick lacated in the 4$^{th}$ wall of the first super-module. No muon was identified by the reconstruction of the data provided by electronic detectors.

It occurred in the lead plate between the 22$^{nd}$ and 23$^{rd}$ emulsion films, 6.1 radiation lengths far from the downstream edge of the brick. The primary vertex lies close to the downstream emulsion film, at a depth in lead of only 120~${\mu}$m, and consists of two tracks: the ${\tau}$ lepton candidate and another track, which was classified as an hadron by combining the information from its momentum and range and exploiting their correlation. A nuclear fragment going forward was also detected at a large angle and it was associated to the primary vertex, with an impact parameter of 15~${\mu}$m.

The ${\tau}$ lepton decay occurred in the plastic base, showing a trident topology after a flight length of ${(1466\pm 10)}$~${\mu}$m. The kink angle, evaluated as the mean kink angle for each daughter track, is $(87.4\pm 1.5)$~mrad. Having found the decay vertex in the plastic base allowed to exclude the emission of highly ionising nuclear fragments with an efficiency above 99.8${\%}$ at ${90\%}$~C.L.~up to ${\tan\theta=3}$. The absence of any fragment at the secondary vertex confirmed the hypothesis of a particle dacay.

One of the $\tau$ daughters shows an interaction 1.3~cm downstream, in the same brick containing the neutrino vertex. The final state of this hadronic interaction shows two charged tracks and four back-scattered nuclear fragments.

The total energy of this neutrino interaction was estimated to be $(12.7^{+1.7}_{-2.3})$~GeV/c.

This event was thus interpreted as a $\nu_{\tau}$ charged-current interaction with the $\tau$ lepton decaying into three hadrons. A detailed description of the event is reported in 10.1007/JHEP11(2013)036.

Related datasets

This event is part of OPERA Electronic Detector tau appearance dataset

Electronic detector data for tau neutrino appearance studies

This event is part of OPERA Emulsion Detector tau appearance dataset

Emulsion data for neutrino tau appearance studies

Dataset characteristics

1 event. 14 files. 17.2 KiB in total.

Dataset semantics

Variable	Type	Description
amplL	PMT amplitude measured from the "left" side of a scintillator strip (in photo-electrons)
amplR	PMT amplitude measured from the "right" side of a scintillator strip (in photo-electrons)
amplRec	PMT amplitude reconstructed from the "left" and "right" side amplitudes of a scintillator strip taking into account light attenuation in a WLS fiber (in photo-electrons)
clLength	cluster length (in cm)
driftDist	drift distance (in cm)
enHad	energy of a hadron jet (in GeV)
enNeu	energy of a neutrino (in GeV)
enVis	visible energy (in MeV)
evID	event Id (10- or 11-digit number)
globPosX	X position of a vertex in the OPERA detector system of reference (in cm)
globPosY	Y position of a vertex in the OPERA detector system of reference (in cm)
globPosZ	Z position of a vertex in the OPERA detector system of reference (in cm)
muMom	momentum of a muon (in GeV/c)
posX	For Electronic Detector events, X position of a drift tube, RPC, Target Tracker hit in the OPERA detector system of reference (in cm). For Emulsion Detector events, X position of a track/vertex in the OPERA brick system of reference (in micrometers).
posX1	X position of the beginning of a line in the OPERA brick system of reference (in micrometers)
posX2	X position of the end of a line in the OPERA brick system of reference (in micrometers)
posY	For Electronic Detector events, Y position of an RPC hit in the OPERA detector system of reference (in cm). For Emulsion Detector events, Y position of a track/vertex in the OPERA brick system of reference (in micrometers).
posY1	Y position of the beginning of a line in the OPERA brick system of reference (in micrometers)
posY2	Y position of the end of a line in the OPERA brick system of reference (in micrometers)
posZ	For Electronic Detector events, Z position of a drift tube, RPC, Target Tracker hit in the OPERA detector system of reference (in cm). For Emulsion Detector events, Z position of a track/vertex in the OPERA brick system of reference (in micrometers).
posZ1	Z position of the beginning of a line in the OPERA brick system of reference (in micrometers)
posZ2	Z position of the end of a line in the OPERA brick system of reference (in micrometers)
primary	flag of a vertex: 1 - primary vertex; 0 - not primary vertex
slopeXZ	tangent of a track angle in XZ view
slopeYZ	tangent of a track angle in YZ view
timestamp	event time in milliseconds since 01/01/1970
trType	type of a track: 1 - muon; 2 - hadron; 3 - electron/positron; 8 - tau lepton