# Black Hole War Part 3

Classical Mechanics Level pending

Following on from Part 2, you managed to figure out the energy required to move the Earth to investigate this new black hole. Weirdly, you find that the black hole is emitting 75GeV/c protons, $$\pi^+$$ and $$K^+$$. You decide to investigate if these behave as you'd expect, to see if there's something special about them that could be used to help turn the black hole back into the sun.

You make a detector, which has $$1.38*10^{6}$$ protons, $$0.36*10^{6} K^+$$ and $$4.2*10^{6} \pi^+$$ passing through it each second.

First, you make these particles into a beam and pam these particles through a large tank of gas with refractive index n=1.10000, with a spherical mirror of focal length f=5.00000m. You have two apertures on the focal plane of the mirror, above and below the beamline by 2.29100metres, with photomultipliers behind them. You notice a set of events that trigger both of these photomultipliers.

The beam is then sent into a 60metre vacuum fiducial region, along the edge of this region are photon detectors, which your set of events don't trigger.

Along the beamline is a drift tube spectrometer(STRAW), a liquid krypton calorimeter(LKr) and a RICH detector. Your set of events all trigger exactly one hit in the STRAW and LKr, and never more than one hit in the RICH.

You have a fast scintillator behind a 0.8 metre thick lead wall, that none of your set of events trigger, despite being geometrically linked with it.

All of your events have detected momentum <71GeV/c and >20GeV/c

You use the LKr in conjunction with the STRAW to ensure all of your events have an E/P > 0.9875c.

After all of this you leave your detector running until you get 4813 of these events, and you plot the missing four momentum of them, shown here

What decay have you measured that is peaked at 0 in the above graph? To answer please write your answer as a 3 digit number, the first digit being to indicate which particle has decayed (1 for proton, 2 for $$\pi^+$$, 3 for $$K^+$$) and then the next two digits to indicate which decay mode of this particle has been measured, ordered by the branching fraction (0 for no decay, 1 for the most likely decay, 2 for the 2nd most likely decay, 3 for 3rd, etc.)

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