Understanding Dark Matter Properties Using Particle Colliders
Presenter Status
Graduate Student, Physics Department
Presentation Type
Oral Presentation
Session
D
Location
Chan Shun 108
Start Date
19-5-2017 3:30 PM
End Date
19-5-2017 3:50 PM
Presentation Abstract
Quite early in the 20th century we learned that matter, in its most fundamental form, is composed by heavy positively charged particles (protons) surrounded by lighter negatively charged ones (electrons). The elements we find in nature are organized in the periodic table according to the number of protons each element posses in its nucleus. In this picture, the existence of isotopes (heavier versions of the same element) could suggest that there were different types of protons. However, the truth is that isotopes posses, besides protons, neutral particles in their nucleus called neutrons. The neutron used to be a "dark particle" for us because we did not understand the nature of the forces it feels, this is, the nuclear forces. After understanding the nuclear forces and the particles that interact through these forces, history tells us how technological applications emerged a bit later (for the good and bad of humanity). Since almost 70 years ago, physicists have been collecting strong evidences of the existence of a new type of matter in the universe, matter that does not interact with light for which is called Dark Matter (DM). This matter cannot be directly seen by any type of telescope, but astronomers and cosmologists have evidences for how this dark matter effects luminous matter. The DM puzzle is getting exciting because, as we learned from the story of the neutron, there could be a new type of interaction (force), which existence is still a mystery for us, and understanding it might open a new world of technological applications and a better understanding of our universe.
As particle physicists we wonder if the particle(s) that compound Dark Matter can be detected at particle colliders. We also wonder if we can learn about DM properties and the properties of the "messenger" particles that connect the visible with the dark sectors of matter. In the most powerful particle collider ever made, the Large Hadron Collider (LHC) in Europe, we collide protons at very high energies and we measure the particles created from such highly energetic environment (remember Einstein's formula E = m c^2, which explains that energy can be transformed into matter or vice-versa). Protons are not fundamental particles for they are compound of quarks (three quarks make a proton). In my research we study a family of models in which DM interacts with both quarks and electrons through messenger particles. If DM interacts with quarks, it could be produced at the LHC. If DM also interacts with electrons, it would perturb electron signals at the LHC. We study how the properties of DM can reshape electron production distributions. We set bounds on DM mass as a function of the messengers' masses. For some values of DM mass here explored, the electron distributions place stronger bounds than the bounds from searches at the LHC for missing energy, or searches at experiments that look for DM scattering off from heavy elements (called direct detection experiments like the LUX collaboration in the USA).
Biographical Sketch
Bachelor in physics from the University of Atlantico, Colombia (2010), Master in physics from the Institute of theoretical Physics of the Paulista State University, Brazil (2013) and currently a PhD student in physics at the University of Notre Dame, USA.
Rodolfo has experience in Elementary Particles Physics and Field Theory. His PhD research focus on Higgs phenomenology, Supersymmetric extensions of the Standard Model of Particle Physics, and Dark Matter signals in particle colliders.
Rodolfo also enjoys teaching physics: Besides his experience teaching in different institutions, Rodolfo is currently running an outreach project to teach Quantum Physics concepts for high schoolers. His project was awarded with the Ganey Community Based Stipend of the Center for Social Concerns at the University of Notre Dame.
Understanding Dark Matter Properties Using Particle Colliders
Chan Shun 108
Quite early in the 20th century we learned that matter, in its most fundamental form, is composed by heavy positively charged particles (protons) surrounded by lighter negatively charged ones (electrons). The elements we find in nature are organized in the periodic table according to the number of protons each element posses in its nucleus. In this picture, the existence of isotopes (heavier versions of the same element) could suggest that there were different types of protons. However, the truth is that isotopes posses, besides protons, neutral particles in their nucleus called neutrons. The neutron used to be a "dark particle" for us because we did not understand the nature of the forces it feels, this is, the nuclear forces. After understanding the nuclear forces and the particles that interact through these forces, history tells us how technological applications emerged a bit later (for the good and bad of humanity). Since almost 70 years ago, physicists have been collecting strong evidences of the existence of a new type of matter in the universe, matter that does not interact with light for which is called Dark Matter (DM). This matter cannot be directly seen by any type of telescope, but astronomers and cosmologists have evidences for how this dark matter effects luminous matter. The DM puzzle is getting exciting because, as we learned from the story of the neutron, there could be a new type of interaction (force), which existence is still a mystery for us, and understanding it might open a new world of technological applications and a better understanding of our universe.
As particle physicists we wonder if the particle(s) that compound Dark Matter can be detected at particle colliders. We also wonder if we can learn about DM properties and the properties of the "messenger" particles that connect the visible with the dark sectors of matter. In the most powerful particle collider ever made, the Large Hadron Collider (LHC) in Europe, we collide protons at very high energies and we measure the particles created from such highly energetic environment (remember Einstein's formula E = m c^2, which explains that energy can be transformed into matter or vice-versa). Protons are not fundamental particles for they are compound of quarks (three quarks make a proton). In my research we study a family of models in which DM interacts with both quarks and electrons through messenger particles. If DM interacts with quarks, it could be produced at the LHC. If DM also interacts with electrons, it would perturb electron signals at the LHC. We study how the properties of DM can reshape electron production distributions. We set bounds on DM mass as a function of the messengers' masses. For some values of DM mass here explored, the electron distributions place stronger bounds than the bounds from searches at the LHC for missing energy, or searches at experiments that look for DM scattering off from heavy elements (called direct detection experiments like the LUX collaboration in the USA).
Acknowledgements
This presentation is based on ongoing work with professors Adam Martin and Antonio Delgado, as well as the post-doctoral fellow Nirmal Raj, at the University of Notre Dame.