DA DARK RK M MATTER TTER Guillermo Martorell Hurtado What is - - PowerPoint PPT Presentation

DA DARK RK M MATTER TTER

Guillermo Martorell Hurtado

¿What is it?

• Necessary to explain the dynamics of the rotation of

celestial bodies

• (Obviously) Invisible: does not emit photons
• Not included in the Standard Model

¡WE DON'T KNOW WHAT IT IS! BUT THERE ARE CANDIDATES

Fritz Zwicky Vera Rubin

WIMPs

• Candidate of Dark Matter
• Weakly Interactive Massive Particles
• Very massive particles, purely experiment gravitational

effects, that's what makes detection extremely difficult

• They gather in massive celestial bodies: Sun, Earth,

Galactic Centres, Dwarf Spherical Galaxies...

• They collide and annihilate
• Move slowly

WIMP-WIMP Annihilation

?

SM

¡NEUTRINO! Leptons, quarks, bosons. (unstable)

To Detect Neutrinos...

ANTARES KM3NET

Data Analysis

• We start with two simulation data: one of

neutrino (isotropical) and other with atmospheric neutrinos

• Our aim is to start from the simulation to obtain

“filters” or “cuts” that will allow us to delete effectively the background (or noise) and apply thos methods to real data, with the objective of

• btaining concluding results (enough evidence

to be a “discovery”).

• PROBLEM: very small signal over a large

background

FIRST “ROUGH” FILTER

θ

In order to distinguish between neutrino and atmospheric muons, we need to “block” all that comes from “above the earth” (theta between 90 and 180 degrees).

NEXT STEP: Signal filters

• In order to distinguish between signal neutrino

(who come from a certain source) and background neutrino, we need to apply more filters to the remaining neutrino simulated data

• Energy spectrum->

Apply weights (depending

• n what

we want to see and the theoretical model)

In the end, all we try to do is see the way that our simulation (which we consider to reflect the reality) behaves, and if we observe something similar in our data, then we MAY see if we have detected a source. Okay, but one thing...

PARTICLE PHYSICS SKYMAP ASTRO- PHYSICS TEST STATISTICS

PPROBABILITY DISTRIBUTIONS:

• BACKGROUND
• SIGNAL

¿Where's the real data?

π

Opening the data

• Now it is time to open our data!
• Then is when we perform an analysis of the

data with all the parameters that we have set before, and run a “Test Statistics” on the data.

• If the result of all of that process seems to be

consistent with the signal distribution (there is no evidence to reject that we have found a source), then we can say we have succeded!

• The result, however, seems to be negative or

inconclusive most of the times

THE DATA IS DESTROYED

WHAT HAPPENS WITH THE DATA?