Dec 08, 2012 supersymmetry is a beautiful theory that might explain dark matter now particle physicists at cern are putting it to the ultimate test, writes jeff forshaw. This relationship between matter particles and force carriers is called supersymmetry. No supersymmetric particle has yet been found, but experiments are underway at cern and fermilab to detect supersymmetric partner particles. It is the largest possible spacetime symmetry of nature and it relates space and time with a fundamental quantum property of. The super era of subatomic particle physics jay hauser abstract. The supersymmetry break can not be done permanently by the particles of the mssm as they. Every fermion would have a bosonic counterpart, and vice versa. Of the many wimp candidates, perhaps the best motivated and certainly the most theoretically developed is the neutralino, the lightest superpartner in many supersymmetric theories.
Supersymmetry is an extension of the standard model that aims to fill some of the gaps. Feb 16, 2015 supporters of supersymmetry, nicknamed susy, theorise that each of the elementary particles we know about has a superpartner, so an electron has a boson partner called a selectron and a gluon has. Apr 03, 2014 a sort of particlefree supersymmetry found in exotic materials behavior of electrons in topological superconductors emulates supersymmetry. We mainly look for supersymmetry by comparing our measured created particles to the current model standard model. Many families and subfamilies of elementary particles exist. If the lifetime is short enough for the decay to take place within the detector, ge is assumed to be undetected and to give rise to missing. Supersymmetric particles can acquire gauge invariant. Supersymmetry is one of the synergistic theories in current highenergy physics that predicts the existence of these shadow particles. Searches targeting the observation of di erent supersymmetric r parity conserving models are presented in this document. This document, and the material and data contained therein, was developed under sponsorship of the united states. For every particle, there is a superpartner whose spin differs by 12.
Documents, publications, lecture notes filessusy nd. So far, none of these predicted particles have been observed. The particle adventure unsolved mysteries supersymmetry. Supersymmetry is a theory where every elementary particle has a supersymmetric partner with identical properties other than mass and spin, doubling the number of elementary particles predicted to exist in the universe. In this dissertation we study supersymmetric particles in four spacetime dimensions and their relations to other physical observables. For example, for every type of quark there may be a type of particle called a squark. These new particles would solve a major problem with the. Supporters of supersymmetry, nicknamed susy, theorise that each of the elementary particles we know about has a superpartner, so an electron has a. Perturbative supersymmetry 8 lectures, the basics a. Within the sm, the mass of the higgs particle is extremely sensitive to any new physics at higher energies and its natural value is of order of the planck mass, if the. I will discuss the quantum numbers of new particles in the mssm and the connection of the mssm to the idea of grand uni.
Theoretically the high energy of some of the cosmic particles would suffice to create superpartners of sm particles if they exist and are in the energy range. Lectures on supersymmetry ii the collider detector at fermilab. Weak scale supersymmetry, cup 2006, by howard baer and xerxes. Aug 19, 2005 if it is true as suggested by selectron in the first post that supersymmetry particles always have 12 spin less than normal particles, then one hypothesis to explain this aspect of supersymmetry is that we have a unique relationship between deuteron nucleon clusters np, which are bosons with spin 1, and 3nucleon clusters e. Mssm is the minimal supersymmetrical model as it considers only the minimum number of new particle states and new interactions consistent with phenomenology. This is a list of names for supersymmetric particles sparticles. Pages in category hypothetical particles the following 19 pages are in this category, out of 19 total. The analyses use di erent sets of the data collected by the atlas experiment, and distinct strategies are exploited for the observation of susy particles. Martin department of physics, northern illinois university, dekalb il 60115 i provide a pedagogical introduction to supersymmetry. Desy heres a list of the particles we know exist, and their supersymmetric partners that we might find.
The fundamental particles are on the left and the supersymmetric particles are on the right. Explanation of absence of supersymmetric particles in ordinary experience highenergy physics colliders. New supersymmetry particles we might find business insider. If the world were exactly supersymmetric, every particle known would have superpartners with the same interactions and the same mass. Next we describe d4 theories with n2 and 4 extended supersymmetry, central charges and seibergwitten theory. Introduction to supersymmetry joseph conlon hilary term 2010 1 introduction and references these notes accompany the supersymmetry lecures given in hilary and trinity term 2009. Finally i focus on n 2 extended supersymmetric gauge theories followed by a rather detailed introduction to the determination of their lowenergy e. They are the fundamental objects of quantum field theory. A sort of particlefree supersymmetry found in exotic materials behavior of electrons in topological superconductors emulates supersymmetry. Susy particles at the lhc are described, and the status of susy in. A sort of particlefree supersymmetry found in exotic. When considering extensions of the standard model, the s prefix from sparticle is used to form names of.
Supersymmetry is a beautiful theory that might explain dark matter now particle physicists at cern are putting it to the ultimate test, writes jeff forshaw. Search for electroweak production of supersymmetric. Supersymmetric article about supersymmetric by the free. The standard paradigm for incorporating supersymmetry into a realistic theory is to have the underlying dynamics of the theory be supersymmetric, but the ground state of the theory does not respect the symmetry and supersymmetry is broken spontaneously. Supersymmetry particles from cosmic rays physics stack exchange. The supersymmetric nonlinear sigma model is discussed in some detail as it is relevant to the coupling of supergravity to matter multiplets. Pdf decays of supersymmetric particles the program. The standard model has worked beautifully to predict what experiments have shown so far about the basic building blocks of matter, but physicists recognize that it is incomplete. Such a supersymmetric origin also leads to events with large transverse missing energy and either 0, 1, 2 samesign, or 3 isolated leptons. A supersymmetric eld theory is a set of elds and a lagrangian which exhibit such a symmetry. Aug 14, 2006 repeated adjustments to the measured mass of the top quark has caused a dramatic narrowing of the window of reasonable expected masses of supersymmetric particles at available collider energies. Supersymmetry is an idea that history repeats itself to solve similar problems.
Decays of supersymmetric particles the program susyhit article pdf available in acta physica polonica series b 38 january 2007 with 104 reads how we measure reads. Pdf decays of supersymmetric particles the program susyhit. For a large class of fourdimensional n2 systems, the supersymmetric particles are described by the ground states of certain quiver quantum mechanics in the low energy limit. A supercollider is being built in europe which may produce dark matter and other particles predicted by the super. This means that people who do supersymmetric extensions of the standard model have to indulge in some unwelcome fine tuning to fit their models to. If supersymmetry were an exact symmetry of nature, then particles and their superpartners, which di. For the extension of this argument to nonidentical particles, particles with spin, inelastic collision, see coleman and mandulas paper. In particle physics, the lightest supersymmetric particle lsp is the generic name given to the lightest of the additional hypothetical particles found in supersymmetric models. The reason for this, according to current thinking, is that the supersymmetry is a broken one. There is nothing here that cannot be improved upon so here are some suggestions for further reading. Decoupling of supersymmetric particles internet archive. But fermions have boson superpartners, and vice versa. In a supersymmetry theory the additional parameters would include the masses of supersymmetric counterparts of the currently known particles, and parameters connected with the ways that supersymmetric particles which, if found, should all be unstable, probably with lifetimes that are very tiny fractions of a second would decay into currently. As ordinary eld theories, supersymmetric theories describe particles and interactions between them.
It predicts a partner particle for each particle in the standard model. Supersymmetry in particle physics an elementary introduction slac. The remaining sections of these lectures will map out the phenomenology of the new particles and interactions expected in models of supersymmetry. Soft supersymmetry breaking and the supersymmetric standard model. Georgi where we introduced the soft terms and the basic ingredients of the supersymmetric stan dard model, including the supersymmetric uni fication prediction. The level of discussion is aimed at readers who are familiar with the standard model and quantum.
Elementary particles are particles with no measurable internal structure. Supersymmetric particle searches particle data group. A multilepton signal for supersymmetric particles in tevatron. Susy manifests itself in the speci c particle spectrum a theory enjoys, and in the way particles interact between themselves. More exciting than higgs upgraded atomsmasher on the. Wilczek on the supersymmetric unification scale and the absence of proton decay in supersymmet ric theories. A sort of particlefree supersymmetry found in exotic materials. By doubling the number of particles again, there is similar cancellation between the process with ordinary particles only and another process with their superpartners. The minimal supersymmetric standard model mssm is an extension to the standard model that realizes supersymmetry. The formal proof of decoupling of supersymmetric particles from low energy physics is stated in terms of the effective action for the particles of the standard model that results by integrating out all the sparticles in the limit where their masses are larger than the electroweak scale. In models with rparity conservation, the lsp is stable. A multilepton signal for supersymmetric particles in.
1291 20 324 606 1037 1330 566 428 308 1552 77 1434 1649 1371 1114 257 281 1099 623 1080 1638 1573 422 894 459 939 1354 872 583 971 1371